diff.con commit refs/ref-cache.h: add missing declarations (hdr-check) (440984b)
   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        struct ws_delta *wsd;
 780};
 781
 782/**
 783 * The struct ws_delta holds white space differences between moved lines, i.e.
 784 * between '+' and '-' lines that have been detected to be a move.
 785 * The string contains the difference in leading white spaces, before the
 786 * rest of the line is compared using the white space config for move
 787 * coloring. The current_longer indicates if the first string in the
 788 * comparision is longer than the second.
 789 */
 790struct ws_delta {
 791        char *string;
 792        unsigned int current_longer : 1;
 793};
 794#define WS_DELTA_INIT { NULL, 0 }
 795
 796static int compute_ws_delta(const struct emitted_diff_symbol *a,
 797                             const struct emitted_diff_symbol *b,
 798                             struct ws_delta *out)
 799{
 800        const struct emitted_diff_symbol *longer =  a->len > b->len ? a : b;
 801        const struct emitted_diff_symbol *shorter = a->len > b->len ? b : a;
 802        int d = longer->len - shorter->len;
 803
 804        out->string = xmemdupz(longer->line, d);
 805        out->current_longer = (a == longer);
 806
 807        return !strncmp(longer->line + d, shorter->line, shorter->len);
 808}
 809
 810static int cmp_in_block_with_wsd(const struct diff_options *o,
 811                                 const struct moved_entry *cur,
 812                                 const struct moved_entry *match,
 813                                 struct moved_entry *pmb,
 814                                 int n)
 815{
 816        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
 817        int al = cur->es->len, cl = l->len;
 818        const char *a = cur->es->line,
 819                   *b = match->es->line,
 820                   *c = l->line;
 821
 822        int wslen;
 823
 824        /*
 825         * We need to check if 'cur' is equal to 'match'.
 826         * As those are from the same (+/-) side, we do not need to adjust for
 827         * indent changes. However these were found using fuzzy matching
 828         * so we do have to check if they are equal.
 829         */
 830        if (strcmp(a, b))
 831                return 1;
 832
 833        if (!pmb->wsd)
 834                /*
 835                 * No white space delta was carried forward? This can happen
 836                 * when we exit early in this function and do not carry
 837                 * forward ws.
 838                 */
 839                return 1;
 840
 841        /*
 842         * The indent changes of the block are known and carried forward in
 843         * pmb->wsd; however we need to check if the indent changes of the
 844         * current line are still the same as before.
 845         *
 846         * To do so we need to compare 'l' to 'cur', adjusting the
 847         * one of them for the white spaces, depending which was longer.
 848         */
 849
 850        wslen = strlen(pmb->wsd->string);
 851        if (pmb->wsd->current_longer) {
 852                c += wslen;
 853                cl -= wslen;
 854        } else {
 855                a += wslen;
 856                al -= wslen;
 857        }
 858
 859        if (strcmp(a, c))
 860                return 1;
 861
 862        return 0;
 863}
 864
 865static int moved_entry_cmp(const void *hashmap_cmp_fn_data,
 866                           const void *entry,
 867                           const void *entry_or_key,
 868                           const void *keydata)
 869{
 870        const struct diff_options *diffopt = hashmap_cmp_fn_data;
 871        const struct moved_entry *a = entry;
 872        const struct moved_entry *b = entry_or_key;
 873        unsigned flags = diffopt->color_moved_ws_handling
 874                         & XDF_WHITESPACE_FLAGS;
 875
 876        if (diffopt->color_moved_ws_handling &
 877            COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
 878                /*
 879                 * As there is not specific white space config given,
 880                 * we'd need to check for a new block, so ignore all
 881                 * white space. The setup of the white space
 882                 * configuration for the next block is done else where
 883                 */
 884                flags |= XDF_IGNORE_WHITESPACE;
 885
 886        return !xdiff_compare_lines(a->es->line, a->es->len,
 887                                    b->es->line, b->es->len,
 888                                    flags);
 889}
 890
 891static struct moved_entry *prepare_entry(struct diff_options *o,
 892                                         int line_no)
 893{
 894        struct moved_entry *ret = xmalloc(sizeof(*ret));
 895        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[line_no];
 896        unsigned flags = o->color_moved_ws_handling & XDF_WHITESPACE_FLAGS;
 897
 898        ret->ent.hash = xdiff_hash_string(l->line, l->len, flags);
 899        ret->es = l;
 900        ret->next_line = NULL;
 901        ret->wsd = NULL;
 902
 903        return ret;
 904}
 905
 906static void add_lines_to_move_detection(struct diff_options *o,
 907                                        struct hashmap *add_lines,
 908                                        struct hashmap *del_lines)
 909{
 910        struct moved_entry *prev_line = NULL;
 911
 912        int n;
 913        for (n = 0; n < o->emitted_symbols->nr; n++) {
 914                struct hashmap *hm;
 915                struct moved_entry *key;
 916
 917                switch (o->emitted_symbols->buf[n].s) {
 918                case DIFF_SYMBOL_PLUS:
 919                        hm = add_lines;
 920                        break;
 921                case DIFF_SYMBOL_MINUS:
 922                        hm = del_lines;
 923                        break;
 924                default:
 925                        prev_line = NULL;
 926                        continue;
 927                }
 928
 929                key = prepare_entry(o, n);
 930                if (prev_line && prev_line->es->s == o->emitted_symbols->buf[n].s)
 931                        prev_line->next_line = key;
 932
 933                hashmap_add(hm, key);
 934                prev_line = key;
 935        }
 936}
 937
 938static void pmb_advance_or_null(struct diff_options *o,
 939                                struct moved_entry *match,
 940                                struct hashmap *hm,
 941                                struct moved_entry **pmb,
 942                                int pmb_nr)
 943{
 944        int i;
 945        for (i = 0; i < pmb_nr; i++) {
 946                struct moved_entry *prev = pmb[i];
 947                struct moved_entry *cur = (prev && prev->next_line) ?
 948                                prev->next_line : NULL;
 949                if (cur && !hm->cmpfn(o, cur, match, NULL)) {
 950                        pmb[i] = cur;
 951                } else {
 952                        pmb[i] = NULL;
 953                }
 954        }
 955}
 956
 957static void pmb_advance_or_null_multi_match(struct diff_options *o,
 958                                            struct moved_entry *match,
 959                                            struct hashmap *hm,
 960                                            struct moved_entry **pmb,
 961                                            int pmb_nr, int n)
 962{
 963        int i;
 964        char *got_match = xcalloc(1, pmb_nr);
 965
 966        for (; match; match = hashmap_get_next(hm, match)) {
 967                for (i = 0; i < pmb_nr; i++) {
 968                        struct moved_entry *prev = pmb[i];
 969                        struct moved_entry *cur = (prev && prev->next_line) ?
 970                                        prev->next_line : NULL;
 971                        if (!cur)
 972                                continue;
 973                        if (!cmp_in_block_with_wsd(o, cur, match, pmb[i], n))
 974                                got_match[i] |= 1;
 975                }
 976        }
 977
 978        for (i = 0; i < pmb_nr; i++) {
 979                if (got_match[i]) {
 980                        /* Carry the white space delta forward */
 981                        pmb[i]->next_line->wsd = pmb[i]->wsd;
 982                        pmb[i] = pmb[i]->next_line;
 983                } else
 984                        pmb[i] = NULL;
 985        }
 986}
 987
 988static int shrink_potential_moved_blocks(struct moved_entry **pmb,
 989                                         int pmb_nr)
 990{
 991        int lp, rp;
 992
 993        /* Shrink the set of potential block to the remaining running */
 994        for (lp = 0, rp = pmb_nr - 1; lp <= rp;) {
 995                while (lp < pmb_nr && pmb[lp])
 996                        lp++;
 997                /* lp points at the first NULL now */
 998
 999                while (rp > -1 && !pmb[rp])
1000                        rp--;
1001                /* rp points at the last non-NULL */
1002
1003                if (lp < pmb_nr && rp > -1 && lp < rp) {
1004                        pmb[lp] = pmb[rp];
1005                        if (pmb[rp]->wsd) {
1006                                free(pmb[rp]->wsd->string);
1007                                FREE_AND_NULL(pmb[rp]->wsd);
1008                        }
1009                        pmb[rp] = NULL;
1010                        rp--;
1011                        lp++;
1012                }
1013        }
1014
1015        /* Remember the number of running sets */
1016        return rp + 1;
1017}
1018
1019/*
1020 * If o->color_moved is COLOR_MOVED_PLAIN, this function does nothing.
1021 *
1022 * Otherwise, if the last block has fewer alphanumeric characters than
1023 * COLOR_MOVED_MIN_ALNUM_COUNT, unset DIFF_SYMBOL_MOVED_LINE on all lines in
1024 * that block.
1025 *
1026 * The last block consists of the (n - block_length)'th line up to but not
1027 * including the nth line.
1028 *
1029 * NEEDSWORK: This uses the same heuristic as blame_entry_score() in blame.c.
1030 * Think of a way to unify them.
1031 */
1032static void adjust_last_block(struct diff_options *o, int n, int block_length)
1033{
1034        int i, alnum_count = 0;
1035        if (o->color_moved == COLOR_MOVED_PLAIN)
1036                return;
1037        for (i = 1; i < block_length + 1; i++) {
1038                const char *c = o->emitted_symbols->buf[n - i].line;
1039                for (; *c; c++) {
1040                        if (!isalnum(*c))
1041                                continue;
1042                        alnum_count++;
1043                        if (alnum_count >= COLOR_MOVED_MIN_ALNUM_COUNT)
1044                                return;
1045                }
1046        }
1047        for (i = 1; i < block_length + 1; i++)
1048                o->emitted_symbols->buf[n - i].flags &= ~DIFF_SYMBOL_MOVED_LINE;
1049}
1050
1051/* Find blocks of moved code, delegate actual coloring decision to helper */
1052static void mark_color_as_moved(struct diff_options *o,
1053                                struct hashmap *add_lines,
1054                                struct hashmap *del_lines)
1055{
1056        struct moved_entry **pmb = NULL; /* potentially moved blocks */
1057        int pmb_nr = 0, pmb_alloc = 0;
1058        int n, flipped_block = 1, block_length = 0;
1059
1060
1061        for (n = 0; n < o->emitted_symbols->nr; n++) {
1062                struct hashmap *hm = NULL;
1063                struct moved_entry *key;
1064                struct moved_entry *match = NULL;
1065                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
1066
1067                switch (l->s) {
1068                case DIFF_SYMBOL_PLUS:
1069                        hm = del_lines;
1070                        key = prepare_entry(o, n);
1071                        match = hashmap_get(hm, key, NULL);
1072                        free(key);
1073                        break;
1074                case DIFF_SYMBOL_MINUS:
1075                        hm = add_lines;
1076                        key = prepare_entry(o, n);
1077                        match = hashmap_get(hm, key, NULL);
1078                        free(key);
1079                        break;
1080                default:
1081                        flipped_block = 1;
1082                }
1083
1084                if (!match) {
1085                        adjust_last_block(o, n, block_length);
1086                        pmb_nr = 0;
1087                        block_length = 0;
1088                        continue;
1089                }
1090
1091                l->flags |= DIFF_SYMBOL_MOVED_LINE;
1092
1093                if (o->color_moved == COLOR_MOVED_PLAIN)
1094                        continue;
1095
1096                if (o->color_moved_ws_handling &
1097                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
1098                        pmb_advance_or_null_multi_match(o, match, hm, pmb, pmb_nr, n);
1099                else
1100                        pmb_advance_or_null(o, match, hm, pmb, pmb_nr);
1101
1102                pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
1103
1104                if (pmb_nr == 0) {
1105                        /*
1106                         * The current line is the start of a new block.
1107                         * Setup the set of potential blocks.
1108                         */
1109                        for (; match; match = hashmap_get_next(hm, match)) {
1110                                ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
1111                                if (o->color_moved_ws_handling &
1112                                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) {
1113                                        struct ws_delta *wsd = xmalloc(sizeof(*match->wsd));
1114                                        if (compute_ws_delta(l, match->es, wsd)) {
1115                                                match->wsd = wsd;
1116                                                pmb[pmb_nr++] = match;
1117                                        } else
1118                                                free(wsd);
1119                                } else {
1120                                        pmb[pmb_nr++] = match;
1121                                }
1122                        }
1123
1124                        flipped_block = (flipped_block + 1) % 2;
1125
1126                        adjust_last_block(o, n, block_length);
1127                        block_length = 0;
1128                }
1129
1130                block_length++;
1131
1132                if (flipped_block && o->color_moved != COLOR_MOVED_BLOCKS)
1133                        l->flags |= DIFF_SYMBOL_MOVED_LINE_ALT;
1134        }
1135        adjust_last_block(o, n, block_length);
1136
1137        free(pmb);
1138}
1139
1140#define DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK \
1141  (DIFF_SYMBOL_MOVED_LINE | DIFF_SYMBOL_MOVED_LINE_ALT)
1142static void dim_moved_lines(struct diff_options *o)
1143{
1144        int n;
1145        for (n = 0; n < o->emitted_symbols->nr; n++) {
1146                struct emitted_diff_symbol *prev = (n != 0) ?
1147                                &o->emitted_symbols->buf[n - 1] : NULL;
1148                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
1149                struct emitted_diff_symbol *next =
1150                                (n < o->emitted_symbols->nr - 1) ?
1151                                &o->emitted_symbols->buf[n + 1] : NULL;
1152
1153                /* Not a plus or minus line? */
1154                if (l->s != DIFF_SYMBOL_PLUS && l->s != DIFF_SYMBOL_MINUS)
1155                        continue;
1156
1157                /* Not a moved line? */
1158                if (!(l->flags & DIFF_SYMBOL_MOVED_LINE))
1159                        continue;
1160
1161                /*
1162                 * If prev or next are not a plus or minus line,
1163                 * pretend they don't exist
1164                 */
1165                if (prev && prev->s != DIFF_SYMBOL_PLUS &&
1166                            prev->s != DIFF_SYMBOL_MINUS)
1167                        prev = NULL;
1168                if (next && next->s != DIFF_SYMBOL_PLUS &&
1169                            next->s != DIFF_SYMBOL_MINUS)
1170                        next = NULL;
1171
1172                /* Inside a block? */
1173                if ((prev &&
1174                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
1175                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK)) &&
1176                    (next &&
1177                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
1178                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK))) {
1179                        l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1180                        continue;
1181                }
1182
1183                /* Check if we are at an interesting bound: */
1184                if (prev && (prev->flags & DIFF_SYMBOL_MOVED_LINE) &&
1185                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1186                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1187                        continue;
1188                if (next && (next->flags & DIFF_SYMBOL_MOVED_LINE) &&
1189                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1190                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1191                        continue;
1192
1193                /*
1194                 * The boundary to prev and next are not interesting,
1195                 * so this line is not interesting as a whole
1196                 */
1197                l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1198        }
1199}
1200
1201static void emit_line_ws_markup(struct diff_options *o,
1202                                const char *set_sign, const char *set,
1203                                const char *reset,
1204                                char sign, const char *line, int len,
1205                                unsigned ws_rule, int blank_at_eof)
1206{
1207        const char *ws = NULL;
1208
1209        if (o->ws_error_highlight & ws_rule) {
1210                ws = diff_get_color_opt(o, DIFF_WHITESPACE);
1211                if (!*ws)
1212                        ws = NULL;
1213        }
1214
1215        if (!ws && !set_sign)
1216                emit_line_0(o, set, NULL, 0, reset, sign, line, len);
1217        else if (!ws) {
1218                emit_line_0(o, set_sign, set, !!set_sign, reset, sign, line, len);
1219        } else if (blank_at_eof)
1220                /* Blank line at EOF - paint '+' as well */
1221                emit_line_0(o, ws, NULL, 0, reset, sign, line, len);
1222        else {
1223                /* Emit just the prefix, then the rest. */
1224                emit_line_0(o, set_sign ? set_sign : set, NULL, !!set_sign, reset,
1225                            sign, "", 0);
1226                ws_check_emit(line, len, ws_rule,
1227                              o->file, set, reset, ws);
1228        }
1229}
1230
1231static void emit_diff_symbol_from_struct(struct diff_options *o,
1232                                         struct emitted_diff_symbol *eds)
1233{
1234        static const char *nneof = " No newline at end of file\n";
1235        const char *context, *reset, *set, *set_sign, *meta, *fraginfo;
1236        struct strbuf sb = STRBUF_INIT;
1237
1238        enum diff_symbol s = eds->s;
1239        const char *line = eds->line;
1240        int len = eds->len;
1241        unsigned flags = eds->flags;
1242
1243        switch (s) {
1244        case DIFF_SYMBOL_NO_LF_EOF:
1245                context = diff_get_color_opt(o, DIFF_CONTEXT);
1246                reset = diff_get_color_opt(o, DIFF_RESET);
1247                putc('\n', o->file);
1248                emit_line_0(o, context, NULL, 0, reset, '\\',
1249                            nneof, strlen(nneof));
1250                break;
1251        case DIFF_SYMBOL_SUBMODULE_HEADER:
1252        case DIFF_SYMBOL_SUBMODULE_ERROR:
1253        case DIFF_SYMBOL_SUBMODULE_PIPETHROUGH:
1254        case DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES:
1255        case DIFF_SYMBOL_SUMMARY:
1256        case DIFF_SYMBOL_STATS_LINE:
1257        case DIFF_SYMBOL_BINARY_DIFF_BODY:
1258        case DIFF_SYMBOL_CONTEXT_FRAGINFO:
1259                emit_line(o, "", "", line, len);
1260                break;
1261        case DIFF_SYMBOL_CONTEXT_INCOMPLETE:
1262        case DIFF_SYMBOL_CONTEXT_MARKER:
1263                context = diff_get_color_opt(o, DIFF_CONTEXT);
1264                reset = diff_get_color_opt(o, DIFF_RESET);
1265                emit_line(o, context, reset, line, len);
1266                break;
1267        case DIFF_SYMBOL_SEPARATOR:
1268                fprintf(o->file, "%s%c",
1269                        diff_line_prefix(o),
1270                        o->line_termination);
1271                break;
1272        case DIFF_SYMBOL_CONTEXT:
1273                set = diff_get_color_opt(o, DIFF_CONTEXT);
1274                reset = diff_get_color_opt(o, DIFF_RESET);
1275                set_sign = NULL;
1276                if (o->flags.dual_color_diffed_diffs) {
1277                        char c = !len ? 0 : line[0];
1278
1279                        if (c == '+')
1280                                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1281                        else if (c == '@')
1282                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1283                        else if (c == '-')
1284                                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1285                }
1286                emit_line_ws_markup(o, set_sign, set, reset,
1287                                    o->output_indicators[OUTPUT_INDICATOR_CONTEXT],
1288                                    line, len,
1289                                    flags & (DIFF_SYMBOL_CONTENT_WS_MASK), 0);
1290                break;
1291        case DIFF_SYMBOL_PLUS:
1292                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1293                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1294                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1295                case DIFF_SYMBOL_MOVED_LINE |
1296                     DIFF_SYMBOL_MOVED_LINE_ALT |
1297                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1298                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT_DIM);
1299                        break;
1300                case DIFF_SYMBOL_MOVED_LINE |
1301                     DIFF_SYMBOL_MOVED_LINE_ALT:
1302                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT);
1303                        break;
1304                case DIFF_SYMBOL_MOVED_LINE |
1305                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1306                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_DIM);
1307                        break;
1308                case DIFF_SYMBOL_MOVED_LINE:
1309                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED);
1310                        break;
1311                default:
1312                        set = diff_get_color_opt(o, DIFF_FILE_NEW);
1313                }
1314                reset = diff_get_color_opt(o, DIFF_RESET);
1315                if (!o->flags.dual_color_diffed_diffs)
1316                        set_sign = NULL;
1317                else {
1318                        char c = !len ? 0 : line[0];
1319
1320                        set_sign = set;
1321                        if (c == '-')
1322                                set = diff_get_color_opt(o, DIFF_FILE_OLD_BOLD);
1323                        else if (c == '@')
1324                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1325                        else if (c == '+')
1326                                set = diff_get_color_opt(o, DIFF_FILE_NEW_BOLD);
1327                        else
1328                                set = diff_get_color_opt(o, DIFF_CONTEXT_BOLD);
1329                        flags &= ~DIFF_SYMBOL_CONTENT_WS_MASK;
1330                }
1331                emit_line_ws_markup(o, set_sign, set, reset,
1332                                    o->output_indicators[OUTPUT_INDICATOR_NEW],
1333                                    line, len,
1334                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK,
1335                                    flags & DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF);
1336                break;
1337        case DIFF_SYMBOL_MINUS:
1338                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1339                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1340                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1341                case DIFF_SYMBOL_MOVED_LINE |
1342                     DIFF_SYMBOL_MOVED_LINE_ALT |
1343                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1344                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT_DIM);
1345                        break;
1346                case DIFF_SYMBOL_MOVED_LINE |
1347                     DIFF_SYMBOL_MOVED_LINE_ALT:
1348                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT);
1349                        break;
1350                case DIFF_SYMBOL_MOVED_LINE |
1351                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1352                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_DIM);
1353                        break;
1354                case DIFF_SYMBOL_MOVED_LINE:
1355                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED);
1356                        break;
1357                default:
1358                        set = diff_get_color_opt(o, DIFF_FILE_OLD);
1359                }
1360                reset = diff_get_color_opt(o, DIFF_RESET);
1361                if (!o->flags.dual_color_diffed_diffs)
1362                        set_sign = NULL;
1363                else {
1364                        char c = !len ? 0 : line[0];
1365
1366                        set_sign = set;
1367                        if (c == '+')
1368                                set = diff_get_color_opt(o, DIFF_FILE_NEW_DIM);
1369                        else if (c == '@')
1370                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1371                        else if (c == '-')
1372                                set = diff_get_color_opt(o, DIFF_FILE_OLD_DIM);
1373                        else
1374                                set = diff_get_color_opt(o, DIFF_CONTEXT_DIM);
1375                }
1376                emit_line_ws_markup(o, set_sign, set, reset,
1377                                    o->output_indicators[OUTPUT_INDICATOR_OLD],
1378                                    line, len,
1379                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK, 0);
1380                break;
1381        case DIFF_SYMBOL_WORDS_PORCELAIN:
1382                context = diff_get_color_opt(o, DIFF_CONTEXT);
1383                reset = diff_get_color_opt(o, DIFF_RESET);
1384                emit_line(o, context, reset, line, len);
1385                fputs("~\n", o->file);
1386                break;
1387        case DIFF_SYMBOL_WORDS:
1388                context = diff_get_color_opt(o, DIFF_CONTEXT);
1389                reset = diff_get_color_opt(o, DIFF_RESET);
1390                /*
1391                 * Skip the prefix character, if any.  With
1392                 * diff_suppress_blank_empty, there may be
1393                 * none.
1394                 */
1395                if (line[0] != '\n') {
1396                        line++;
1397                        len--;
1398                }
1399                emit_line(o, context, reset, line, len);
1400                break;
1401        case DIFF_SYMBOL_FILEPAIR_PLUS:
1402                meta = diff_get_color_opt(o, DIFF_METAINFO);
1403                reset = diff_get_color_opt(o, DIFF_RESET);
1404                fprintf(o->file, "%s%s+++ %s%s%s\n", diff_line_prefix(o), meta,
1405                        line, reset,
1406                        strchr(line, ' ') ? "\t" : "");
1407                break;
1408        case DIFF_SYMBOL_FILEPAIR_MINUS:
1409                meta = diff_get_color_opt(o, DIFF_METAINFO);
1410                reset = diff_get_color_opt(o, DIFF_RESET);
1411                fprintf(o->file, "%s%s--- %s%s%s\n", diff_line_prefix(o), meta,
1412                        line, reset,
1413                        strchr(line, ' ') ? "\t" : "");
1414                break;
1415        case DIFF_SYMBOL_BINARY_FILES:
1416        case DIFF_SYMBOL_HEADER:
1417                fprintf(o->file, "%s", line);
1418                break;
1419        case DIFF_SYMBOL_BINARY_DIFF_HEADER:
1420                fprintf(o->file, "%sGIT binary patch\n", diff_line_prefix(o));
1421                break;
1422        case DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA:
1423                fprintf(o->file, "%sdelta %s\n", diff_line_prefix(o), line);
1424                break;
1425        case DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL:
1426                fprintf(o->file, "%sliteral %s\n", diff_line_prefix(o), line);
1427                break;
1428        case DIFF_SYMBOL_BINARY_DIFF_FOOTER:
1429                fputs(diff_line_prefix(o), o->file);
1430                fputc('\n', o->file);
1431                break;
1432        case DIFF_SYMBOL_REWRITE_DIFF:
1433                fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
1434                reset = diff_get_color_opt(o, DIFF_RESET);
1435                emit_line(o, fraginfo, reset, line, len);
1436                break;
1437        case DIFF_SYMBOL_SUBMODULE_ADD:
1438                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1439                reset = diff_get_color_opt(o, DIFF_RESET);
1440                emit_line(o, set, reset, line, len);
1441                break;
1442        case DIFF_SYMBOL_SUBMODULE_DEL:
1443                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1444                reset = diff_get_color_opt(o, DIFF_RESET);
1445                emit_line(o, set, reset, line, len);
1446                break;
1447        case DIFF_SYMBOL_SUBMODULE_UNTRACKED:
1448                fprintf(o->file, "%sSubmodule %s contains untracked content\n",
1449                        diff_line_prefix(o), line);
1450                break;
1451        case DIFF_SYMBOL_SUBMODULE_MODIFIED:
1452                fprintf(o->file, "%sSubmodule %s contains modified content\n",
1453                        diff_line_prefix(o), line);
1454                break;
1455        case DIFF_SYMBOL_STATS_SUMMARY_NO_FILES:
1456                emit_line(o, "", "", " 0 files changed\n",
1457                          strlen(" 0 files changed\n"));
1458                break;
1459        case DIFF_SYMBOL_STATS_SUMMARY_ABBREV:
1460                emit_line(o, "", "", " ...\n", strlen(" ...\n"));
1461                break;
1462        case DIFF_SYMBOL_WORD_DIFF:
1463                fprintf(o->file, "%.*s", len, line);
1464                break;
1465        case DIFF_SYMBOL_STAT_SEP:
1466                fputs(o->stat_sep, o->file);
1467                break;
1468        default:
1469                BUG("unknown diff symbol");
1470        }
1471        strbuf_release(&sb);
1472}
1473
1474static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
1475                             const char *line, int len, unsigned flags)
1476{
1477        struct emitted_diff_symbol e = {line, len, flags, s};
1478
1479        if (o->emitted_symbols)
1480                append_emitted_diff_symbol(o, &e);
1481        else
1482                emit_diff_symbol_from_struct(o, &e);
1483}
1484
1485void diff_emit_submodule_del(struct diff_options *o, const char *line)
1486{
1487        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_DEL, line, strlen(line), 0);
1488}
1489
1490void diff_emit_submodule_add(struct diff_options *o, const char *line)
1491{
1492        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ADD, line, strlen(line), 0);
1493}
1494
1495void diff_emit_submodule_untracked(struct diff_options *o, const char *path)
1496{
1497        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_UNTRACKED,
1498                         path, strlen(path), 0);
1499}
1500
1501void diff_emit_submodule_modified(struct diff_options *o, const char *path)
1502{
1503        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_MODIFIED,
1504                         path, strlen(path), 0);
1505}
1506
1507void diff_emit_submodule_header(struct diff_options *o, const char *header)
1508{
1509        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_HEADER,
1510                         header, strlen(header), 0);
1511}
1512
1513void diff_emit_submodule_error(struct diff_options *o, const char *err)
1514{
1515        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ERROR, err, strlen(err), 0);
1516}
1517
1518void diff_emit_submodule_pipethrough(struct diff_options *o,
1519                                     const char *line, int len)
1520{
1521        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_PIPETHROUGH, line, len, 0);
1522}
1523
1524static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
1525{
1526        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
1527              ecbdata->blank_at_eof_in_preimage &&
1528              ecbdata->blank_at_eof_in_postimage &&
1529              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
1530              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
1531                return 0;
1532        return ws_blank_line(line, len, ecbdata->ws_rule);
1533}
1534
1535static void emit_add_line(const char *reset,
1536                          struct emit_callback *ecbdata,
1537                          const char *line, int len)
1538{
1539        unsigned flags = WSEH_NEW | ecbdata->ws_rule;
1540        if (new_blank_line_at_eof(ecbdata, line, len))
1541                flags |= DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF;
1542
1543        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_PLUS, line, len, flags);
1544}
1545
1546static void emit_del_line(const char *reset,
1547                          struct emit_callback *ecbdata,
1548                          const char *line, int len)
1549{
1550        unsigned flags = WSEH_OLD | ecbdata->ws_rule;
1551        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_MINUS, line, len, flags);
1552}
1553
1554static void emit_context_line(const char *reset,
1555                              struct emit_callback *ecbdata,
1556                              const char *line, int len)
1557{
1558        unsigned flags = WSEH_CONTEXT | ecbdata->ws_rule;
1559        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_CONTEXT, line, len, flags);
1560}
1561
1562static void emit_hunk_header(struct emit_callback *ecbdata,
1563                             const char *line, int len)
1564{
1565        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
1566        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
1567        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
1568        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1569        const char *reverse = ecbdata->color_diff ? GIT_COLOR_REVERSE : "";
1570        static const char atat[2] = { '@', '@' };
1571        const char *cp, *ep;
1572        struct strbuf msgbuf = STRBUF_INIT;
1573        int org_len = len;
1574        int i = 1;
1575
1576        /*
1577         * As a hunk header must begin with "@@ -<old>, +<new> @@",
1578         * it always is at least 10 bytes long.
1579         */
1580        if (len < 10 ||
1581            memcmp(line, atat, 2) ||
1582            !(ep = memmem(line + 2, len - 2, atat, 2))) {
1583                emit_diff_symbol(ecbdata->opt,
1584                                 DIFF_SYMBOL_CONTEXT_MARKER, line, len, 0);
1585                return;
1586        }
1587        ep += 2; /* skip over @@ */
1588
1589        /* The hunk header in fraginfo color */
1590        if (ecbdata->opt->flags.dual_color_diffed_diffs)
1591                strbuf_addstr(&msgbuf, reverse);
1592        strbuf_addstr(&msgbuf, frag);
1593        strbuf_add(&msgbuf, line, ep - line);
1594        strbuf_addstr(&msgbuf, reset);
1595
1596        /*
1597         * trailing "\r\n"
1598         */
1599        for ( ; i < 3; i++)
1600                if (line[len - i] == '\r' || line[len - i] == '\n')
1601                        len--;
1602
1603        /* blank before the func header */
1604        for (cp = ep; ep - line < len; ep++)
1605                if (*ep != ' ' && *ep != '\t')
1606                        break;
1607        if (ep != cp) {
1608                strbuf_addstr(&msgbuf, context);
1609                strbuf_add(&msgbuf, cp, ep - cp);
1610                strbuf_addstr(&msgbuf, reset);
1611        }
1612
1613        if (ep < line + len) {
1614                strbuf_addstr(&msgbuf, func);
1615                strbuf_add(&msgbuf, ep, line + len - ep);
1616                strbuf_addstr(&msgbuf, reset);
1617        }
1618
1619        strbuf_add(&msgbuf, line + len, org_len - len);
1620        strbuf_complete_line(&msgbuf);
1621        emit_diff_symbol(ecbdata->opt,
1622                         DIFF_SYMBOL_CONTEXT_FRAGINFO, msgbuf.buf, msgbuf.len, 0);
1623        strbuf_release(&msgbuf);
1624}
1625
1626static struct diff_tempfile *claim_diff_tempfile(void) {
1627        int i;
1628        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
1629                if (!diff_temp[i].name)
1630                        return diff_temp + i;
1631        BUG("diff is failing to clean up its tempfiles");
1632}
1633
1634static void remove_tempfile(void)
1635{
1636        int i;
1637        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
1638                if (is_tempfile_active(diff_temp[i].tempfile))
1639                        delete_tempfile(&diff_temp[i].tempfile);
1640                diff_temp[i].name = NULL;
1641        }
1642}
1643
1644static void add_line_count(struct strbuf *out, int count)
1645{
1646        switch (count) {
1647        case 0:
1648                strbuf_addstr(out, "0,0");
1649                break;
1650        case 1:
1651                strbuf_addstr(out, "1");
1652                break;
1653        default:
1654                strbuf_addf(out, "1,%d", count);
1655                break;
1656        }
1657}
1658
1659static void emit_rewrite_lines(struct emit_callback *ecb,
1660                               int prefix, const char *data, int size)
1661{
1662        const char *endp = NULL;
1663        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
1664
1665        while (0 < size) {
1666                int len;
1667
1668                endp = memchr(data, '\n', size);
1669                len = endp ? (endp - data + 1) : size;
1670                if (prefix != '+') {
1671                        ecb->lno_in_preimage++;
1672                        emit_del_line(reset, ecb, data, len);
1673                } else {
1674                        ecb->lno_in_postimage++;
1675                        emit_add_line(reset, ecb, data, len);
1676                }
1677                size -= len;
1678                data += len;
1679        }
1680        if (!endp)
1681                emit_diff_symbol(ecb->opt, DIFF_SYMBOL_NO_LF_EOF, NULL, 0, 0);
1682}
1683
1684static void emit_rewrite_diff(const char *name_a,
1685                              const char *name_b,
1686                              struct diff_filespec *one,
1687                              struct diff_filespec *two,
1688                              struct userdiff_driver *textconv_one,
1689                              struct userdiff_driver *textconv_two,
1690                              struct diff_options *o)
1691{
1692        int lc_a, lc_b;
1693        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
1694        const char *a_prefix, *b_prefix;
1695        char *data_one, *data_two;
1696        size_t size_one, size_two;
1697        struct emit_callback ecbdata;
1698        struct strbuf out = STRBUF_INIT;
1699
1700        if (diff_mnemonic_prefix && o->flags.reverse_diff) {
1701                a_prefix = o->b_prefix;
1702                b_prefix = o->a_prefix;
1703        } else {
1704                a_prefix = o->a_prefix;
1705                b_prefix = o->b_prefix;
1706        }
1707
1708        name_a += (*name_a == '/');
1709        name_b += (*name_b == '/');
1710
1711        strbuf_reset(&a_name);
1712        strbuf_reset(&b_name);
1713        quote_two_c_style(&a_name, a_prefix, name_a, 0);
1714        quote_two_c_style(&b_name, b_prefix, name_b, 0);
1715
1716        size_one = fill_textconv(textconv_one, one, &data_one);
1717        size_two = fill_textconv(textconv_two, two, &data_two);
1718
1719        memset(&ecbdata, 0, sizeof(ecbdata));
1720        ecbdata.color_diff = want_color(o->use_color);
1721        ecbdata.ws_rule = whitespace_rule(name_b);
1722        ecbdata.opt = o;
1723        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
1724                mmfile_t mf1, mf2;
1725                mf1.ptr = (char *)data_one;
1726                mf2.ptr = (char *)data_two;
1727                mf1.size = size_one;
1728                mf2.size = size_two;
1729                check_blank_at_eof(&mf1, &mf2, &ecbdata);
1730        }
1731        ecbdata.lno_in_preimage = 1;
1732        ecbdata.lno_in_postimage = 1;
1733
1734        lc_a = count_lines(data_one, size_one);
1735        lc_b = count_lines(data_two, size_two);
1736
1737        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
1738                         a_name.buf, a_name.len, 0);
1739        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
1740                         b_name.buf, b_name.len, 0);
1741
1742        strbuf_addstr(&out, "@@ -");
1743        if (!o->irreversible_delete)
1744                add_line_count(&out, lc_a);
1745        else
1746                strbuf_addstr(&out, "?,?");
1747        strbuf_addstr(&out, " +");
1748        add_line_count(&out, lc_b);
1749        strbuf_addstr(&out, " @@\n");
1750        emit_diff_symbol(o, DIFF_SYMBOL_REWRITE_DIFF, out.buf, out.len, 0);
1751        strbuf_release(&out);
1752
1753        if (lc_a && !o->irreversible_delete)
1754                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
1755        if (lc_b)
1756                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
1757        if (textconv_one)
1758                free((char *)data_one);
1759        if (textconv_two)
1760                free((char *)data_two);
1761}
1762
1763struct diff_words_buffer {
1764        mmfile_t text;
1765        unsigned long alloc;
1766        struct diff_words_orig {
1767                const char *begin, *end;
1768        } *orig;
1769        int orig_nr, orig_alloc;
1770};
1771
1772static void diff_words_append(char *line, unsigned long len,
1773                struct diff_words_buffer *buffer)
1774{
1775        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
1776        line++;
1777        len--;
1778        memcpy(buffer->text.ptr + buffer->text.size, line, len);
1779        buffer->text.size += len;
1780        buffer->text.ptr[buffer->text.size] = '\0';
1781}
1782
1783struct diff_words_style_elem {
1784        const char *prefix;
1785        const char *suffix;
1786        const char *color; /* NULL; filled in by the setup code if
1787                            * color is enabled */
1788};
1789
1790struct diff_words_style {
1791        enum diff_words_type type;
1792        struct diff_words_style_elem new_word, old_word, ctx;
1793        const char *newline;
1794};
1795
1796static struct diff_words_style diff_words_styles[] = {
1797        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
1798        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
1799        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
1800};
1801
1802struct diff_words_data {
1803        struct diff_words_buffer minus, plus;
1804        const char *current_plus;
1805        int last_minus;
1806        struct diff_options *opt;
1807        regex_t *word_regex;
1808        enum diff_words_type type;
1809        struct diff_words_style *style;
1810};
1811
1812static int fn_out_diff_words_write_helper(struct diff_options *o,
1813                                          struct diff_words_style_elem *st_el,
1814                                          const char *newline,
1815                                          size_t count, const char *buf)
1816{
1817        int print = 0;
1818        struct strbuf sb = STRBUF_INIT;
1819
1820        while (count) {
1821                char *p = memchr(buf, '\n', count);
1822                if (print)
1823                        strbuf_addstr(&sb, diff_line_prefix(o));
1824
1825                if (p != buf) {
1826                        const char *reset = st_el->color && *st_el->color ?
1827                                            GIT_COLOR_RESET : NULL;
1828                        if (st_el->color && *st_el->color)
1829                                strbuf_addstr(&sb, st_el->color);
1830                        strbuf_addstr(&sb, st_el->prefix);
1831                        strbuf_add(&sb, buf, p ? p - buf : count);
1832                        strbuf_addstr(&sb, st_el->suffix);
1833                        if (reset)
1834                                strbuf_addstr(&sb, reset);
1835                }
1836                if (!p)
1837                        goto out;
1838
1839                strbuf_addstr(&sb, newline);
1840                count -= p + 1 - buf;
1841                buf = p + 1;
1842                print = 1;
1843                if (count) {
1844                        emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1845                                         sb.buf, sb.len, 0);
1846                        strbuf_reset(&sb);
1847                }
1848        }
1849
1850out:
1851        if (sb.len)
1852                emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1853                                 sb.buf, sb.len, 0);
1854        strbuf_release(&sb);
1855        return 0;
1856}
1857
1858/*
1859 * '--color-words' algorithm can be described as:
1860 *
1861 *   1. collect the minus/plus lines of a diff hunk, divided into
1862 *      minus-lines and plus-lines;
1863 *
1864 *   2. break both minus-lines and plus-lines into words and
1865 *      place them into two mmfile_t with one word for each line;
1866 *
1867 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
1868 *
1869 * And for the common parts of the both file, we output the plus side text.
1870 * diff_words->current_plus is used to trace the current position of the plus file
1871 * which printed. diff_words->last_minus is used to trace the last minus word
1872 * printed.
1873 *
1874 * For '--graph' to work with '--color-words', we need to output the graph prefix
1875 * on each line of color words output. Generally, there are two conditions on
1876 * which we should output the prefix.
1877 *
1878 *   1. diff_words->last_minus == 0 &&
1879 *      diff_words->current_plus == diff_words->plus.text.ptr
1880 *
1881 *      that is: the plus text must start as a new line, and if there is no minus
1882 *      word printed, a graph prefix must be printed.
1883 *
1884 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
1885 *      *(diff_words->current_plus - 1) == '\n'
1886 *
1887 *      that is: a graph prefix must be printed following a '\n'
1888 */
1889static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
1890{
1891        if ((diff_words->last_minus == 0 &&
1892                diff_words->current_plus == diff_words->plus.text.ptr) ||
1893                (diff_words->current_plus > diff_words->plus.text.ptr &&
1894                *(diff_words->current_plus - 1) == '\n')) {
1895                return 1;
1896        } else {
1897                return 0;
1898        }
1899}
1900
1901static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
1902{
1903        struct diff_words_data *diff_words = priv;
1904        struct diff_words_style *style = diff_words->style;
1905        int minus_first, minus_len, plus_first, plus_len;
1906        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
1907        struct diff_options *opt = diff_words->opt;
1908        const char *line_prefix;
1909
1910        if (line[0] != '@' || parse_hunk_header(line, len,
1911                        &minus_first, &minus_len, &plus_first, &plus_len))
1912                return;
1913
1914        assert(opt);
1915        line_prefix = diff_line_prefix(opt);
1916
1917        /* POSIX requires that first be decremented by one if len == 0... */
1918        if (minus_len) {
1919                minus_begin = diff_words->minus.orig[minus_first].begin;
1920                minus_end =
1921                        diff_words->minus.orig[minus_first + minus_len - 1].end;
1922        } else
1923                minus_begin = minus_end =
1924                        diff_words->minus.orig[minus_first].end;
1925
1926        if (plus_len) {
1927                plus_begin = diff_words->plus.orig[plus_first].begin;
1928                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
1929        } else
1930                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
1931
1932        if (color_words_output_graph_prefix(diff_words)) {
1933                fputs(line_prefix, diff_words->opt->file);
1934        }
1935        if (diff_words->current_plus != plus_begin) {
1936                fn_out_diff_words_write_helper(diff_words->opt,
1937                                &style->ctx, style->newline,
1938                                plus_begin - diff_words->current_plus,
1939                                diff_words->current_plus);
1940        }
1941        if (minus_begin != minus_end) {
1942                fn_out_diff_words_write_helper(diff_words->opt,
1943                                &style->old_word, style->newline,
1944                                minus_end - minus_begin, minus_begin);
1945        }
1946        if (plus_begin != plus_end) {
1947                fn_out_diff_words_write_helper(diff_words->opt,
1948                                &style->new_word, style->newline,
1949                                plus_end - plus_begin, plus_begin);
1950        }
1951
1952        diff_words->current_plus = plus_end;
1953        diff_words->last_minus = minus_first;
1954}
1955
1956/* This function starts looking at *begin, and returns 0 iff a word was found. */
1957static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
1958                int *begin, int *end)
1959{
1960        if (word_regex && *begin < buffer->size) {
1961                regmatch_t match[1];
1962                if (!regexec_buf(word_regex, buffer->ptr + *begin,
1963                                 buffer->size - *begin, 1, match, 0)) {
1964                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
1965                                        '\n', match[0].rm_eo - match[0].rm_so);
1966                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
1967                        *begin += match[0].rm_so;
1968                        return *begin >= *end;
1969                }
1970                return -1;
1971        }
1972
1973        /* find the next word */
1974        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
1975                (*begin)++;
1976        if (*begin >= buffer->size)
1977                return -1;
1978
1979        /* find the end of the word */
1980        *end = *begin + 1;
1981        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
1982                (*end)++;
1983
1984        return 0;
1985}
1986
1987/*
1988 * This function splits the words in buffer->text, stores the list with
1989 * newline separator into out, and saves the offsets of the original words
1990 * in buffer->orig.
1991 */
1992static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
1993                regex_t *word_regex)
1994{
1995        int i, j;
1996        long alloc = 0;
1997
1998        out->size = 0;
1999        out->ptr = NULL;
2000
2001        /* fake an empty "0th" word */
2002        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
2003        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
2004        buffer->orig_nr = 1;
2005
2006        for (i = 0; i < buffer->text.size; i++) {
2007                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
2008                        return;
2009
2010                /* store original boundaries */
2011                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
2012                                buffer->orig_alloc);
2013                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
2014                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
2015                buffer->orig_nr++;
2016
2017                /* store one word */
2018                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
2019                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
2020                out->ptr[out->size + j - i] = '\n';
2021                out->size += j - i + 1;
2022
2023                i = j - 1;
2024        }
2025}
2026
2027/* this executes the word diff on the accumulated buffers */
2028static void diff_words_show(struct diff_words_data *diff_words)
2029{
2030        xpparam_t xpp;
2031        xdemitconf_t xecfg;
2032        mmfile_t minus, plus;
2033        struct diff_words_style *style = diff_words->style;
2034
2035        struct diff_options *opt = diff_words->opt;
2036        const char *line_prefix;
2037
2038        assert(opt);
2039        line_prefix = diff_line_prefix(opt);
2040
2041        /* special case: only removal */
2042        if (!diff_words->plus.text.size) {
2043                emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
2044                                 line_prefix, strlen(line_prefix), 0);
2045                fn_out_diff_words_write_helper(diff_words->opt,
2046                        &style->old_word, style->newline,
2047                        diff_words->minus.text.size,
2048                        diff_words->minus.text.ptr);
2049                diff_words->minus.text.size = 0;
2050                return;
2051        }
2052
2053        diff_words->current_plus = diff_words->plus.text.ptr;
2054        diff_words->last_minus = 0;
2055
2056        memset(&xpp, 0, sizeof(xpp));
2057        memset(&xecfg, 0, sizeof(xecfg));
2058        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
2059        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
2060        xpp.flags = 0;
2061        /* as only the hunk header will be parsed, we need a 0-context */
2062        xecfg.ctxlen = 0;
2063        if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
2064                          &xpp, &xecfg))
2065                die("unable to generate word diff");
2066        free(minus.ptr);
2067        free(plus.ptr);
2068        if (diff_words->current_plus != diff_words->plus.text.ptr +
2069                        diff_words->plus.text.size) {
2070                if (color_words_output_graph_prefix(diff_words))
2071                        emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
2072                                         line_prefix, strlen(line_prefix), 0);
2073                fn_out_diff_words_write_helper(diff_words->opt,
2074                        &style->ctx, style->newline,
2075                        diff_words->plus.text.ptr + diff_words->plus.text.size
2076                        - diff_words->current_plus, diff_words->current_plus);
2077        }
2078        diff_words->minus.text.size = diff_words->plus.text.size = 0;
2079}
2080
2081/* In "color-words" mode, show word-diff of words accumulated in the buffer */
2082static void diff_words_flush(struct emit_callback *ecbdata)
2083{
2084        struct diff_options *wo = ecbdata->diff_words->opt;
2085
2086        if (ecbdata->diff_words->minus.text.size ||
2087            ecbdata->diff_words->plus.text.size)
2088                diff_words_show(ecbdata->diff_words);
2089
2090        if (wo->emitted_symbols) {
2091                struct diff_options *o = ecbdata->opt;
2092                struct emitted_diff_symbols *wol = wo->emitted_symbols;
2093                int i;
2094
2095                /*
2096                 * NEEDSWORK:
2097                 * Instead of appending each, concat all words to a line?
2098                 */
2099                for (i = 0; i < wol->nr; i++)
2100                        append_emitted_diff_symbol(o, &wol->buf[i]);
2101
2102                for (i = 0; i < wol->nr; i++)
2103                        free((void *)wol->buf[i].line);
2104
2105                wol->nr = 0;
2106        }
2107}
2108
2109static void diff_filespec_load_driver(struct diff_filespec *one)
2110{
2111        /* Use already-loaded driver */
2112        if (one->driver)
2113                return;
2114
2115        if (S_ISREG(one->mode))
2116                one->driver = userdiff_find_by_path(one->path);
2117
2118        /* Fallback to default settings */
2119        if (!one->driver)
2120                one->driver = userdiff_find_by_name("default");
2121}
2122
2123static const char *userdiff_word_regex(struct diff_filespec *one)
2124{
2125        diff_filespec_load_driver(one);
2126        return one->driver->word_regex;
2127}
2128
2129static void init_diff_words_data(struct emit_callback *ecbdata,
2130                                 struct diff_options *orig_opts,
2131                                 struct diff_filespec *one,
2132                                 struct diff_filespec *two)
2133{
2134        int i;
2135        struct diff_options *o = xmalloc(sizeof(struct diff_options));
2136        memcpy(o, orig_opts, sizeof(struct diff_options));
2137
2138        ecbdata->diff_words =
2139                xcalloc(1, sizeof(struct diff_words_data));
2140        ecbdata->diff_words->type = o->word_diff;
2141        ecbdata->diff_words->opt = o;
2142
2143        if (orig_opts->emitted_symbols)
2144                o->emitted_symbols =
2145                        xcalloc(1, sizeof(struct emitted_diff_symbols));
2146
2147        if (!o->word_regex)
2148                o->word_regex = userdiff_word_regex(one);
2149        if (!o->word_regex)
2150                o->word_regex = userdiff_word_regex(two);
2151        if (!o->word_regex)
2152                o->word_regex = diff_word_regex_cfg;
2153        if (o->word_regex) {
2154                ecbdata->diff_words->word_regex = (regex_t *)
2155                        xmalloc(sizeof(regex_t));
2156                if (regcomp(ecbdata->diff_words->word_regex,
2157                            o->word_regex,
2158                            REG_EXTENDED | REG_NEWLINE))
2159                        die("invalid regular expression: %s",
2160                            o->word_regex);
2161        }
2162        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2163                if (o->word_diff == diff_words_styles[i].type) {
2164                        ecbdata->diff_words->style =
2165                                &diff_words_styles[i];
2166                        break;
2167                }
2168        }
2169        if (want_color(o->use_color)) {
2170                struct diff_words_style *st = ecbdata->diff_words->style;
2171                st->old_word.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2172                st->new_word.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2173                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
2174        }
2175}
2176
2177static void free_diff_words_data(struct emit_callback *ecbdata)
2178{
2179        if (ecbdata->diff_words) {
2180                diff_words_flush(ecbdata);
2181                free (ecbdata->diff_words->opt->emitted_symbols);
2182                free (ecbdata->diff_words->opt);
2183                free (ecbdata->diff_words->minus.text.ptr);
2184                free (ecbdata->diff_words->minus.orig);
2185                free (ecbdata->diff_words->plus.text.ptr);
2186                free (ecbdata->diff_words->plus.orig);
2187                if (ecbdata->diff_words->word_regex) {
2188                        regfree(ecbdata->diff_words->word_regex);
2189                        free(ecbdata->diff_words->word_regex);
2190                }
2191                FREE_AND_NULL(ecbdata->diff_words);
2192        }
2193}
2194
2195const char *diff_get_color(int diff_use_color, enum color_diff ix)
2196{
2197        if (want_color(diff_use_color))
2198                return diff_colors[ix];
2199        return "";
2200}
2201
2202const char *diff_line_prefix(struct diff_options *opt)
2203{
2204        struct strbuf *msgbuf;
2205        if (!opt->output_prefix)
2206                return "";
2207
2208        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
2209        return msgbuf->buf;
2210}
2211
2212static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
2213{
2214        const char *cp;
2215        unsigned long allot;
2216        size_t l = len;
2217
2218        cp = line;
2219        allot = l;
2220        while (0 < l) {
2221                (void) utf8_width(&cp, &l);
2222                if (!cp)
2223                        break; /* truncated in the middle? */
2224        }
2225        return allot - l;
2226}
2227
2228static void find_lno(const char *line, struct emit_callback *ecbdata)
2229{
2230        const char *p;
2231        ecbdata->lno_in_preimage = 0;
2232        ecbdata->lno_in_postimage = 0;
2233        p = strchr(line, '-');
2234        if (!p)
2235                return; /* cannot happen */
2236        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
2237        p = strchr(p, '+');
2238        if (!p)
2239                return; /* cannot happen */
2240        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
2241}
2242
2243static void fn_out_consume(void *priv, char *line, unsigned long len)
2244{
2245        struct emit_callback *ecbdata = priv;
2246        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
2247        struct diff_options *o = ecbdata->opt;
2248
2249        o->found_changes = 1;
2250
2251        if (ecbdata->header) {
2252                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
2253                                 ecbdata->header->buf, ecbdata->header->len, 0);
2254                strbuf_reset(ecbdata->header);
2255                ecbdata->header = NULL;
2256        }
2257
2258        if (ecbdata->label_path[0]) {
2259                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
2260                                 ecbdata->label_path[0],
2261                                 strlen(ecbdata->label_path[0]), 0);
2262                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
2263                                 ecbdata->label_path[1],
2264                                 strlen(ecbdata->label_path[1]), 0);
2265                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
2266        }
2267
2268        if (diff_suppress_blank_empty
2269            && len == 2 && line[0] == ' ' && line[1] == '\n') {
2270                line[0] = '\n';
2271                len = 1;
2272        }
2273
2274        if (line[0] == '@') {
2275                if (ecbdata->diff_words)
2276                        diff_words_flush(ecbdata);
2277                len = sane_truncate_line(ecbdata, line, len);
2278                find_lno(line, ecbdata);
2279                emit_hunk_header(ecbdata, line, len);
2280                return;
2281        }
2282
2283        if (ecbdata->diff_words) {
2284                enum diff_symbol s =
2285                        ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN ?
2286                        DIFF_SYMBOL_WORDS_PORCELAIN : DIFF_SYMBOL_WORDS;
2287                if (line[0] == '-') {
2288                        diff_words_append(line, len,
2289                                          &ecbdata->diff_words->minus);
2290                        return;
2291                } else if (line[0] == '+') {
2292                        diff_words_append(line, len,
2293                                          &ecbdata->diff_words->plus);
2294                        return;
2295                } else if (starts_with(line, "\\ ")) {
2296                        /*
2297                         * Eat the "no newline at eof" marker as if we
2298                         * saw a "+" or "-" line with nothing on it,
2299                         * and return without diff_words_flush() to
2300                         * defer processing. If this is the end of
2301                         * preimage, more "+" lines may come after it.
2302                         */
2303                        return;
2304                }
2305                diff_words_flush(ecbdata);
2306                emit_diff_symbol(o, s, line, len, 0);
2307                return;
2308        }
2309
2310        switch (line[0]) {
2311        case '+':
2312                ecbdata->lno_in_postimage++;
2313                emit_add_line(reset, ecbdata, line + 1, len - 1);
2314                break;
2315        case '-':
2316                ecbdata->lno_in_preimage++;
2317                emit_del_line(reset, ecbdata, line + 1, len - 1);
2318                break;
2319        case ' ':
2320                ecbdata->lno_in_postimage++;
2321                ecbdata->lno_in_preimage++;
2322                emit_context_line(reset, ecbdata, line + 1, len - 1);
2323                break;
2324        default:
2325                /* incomplete line at the end */
2326                ecbdata->lno_in_preimage++;
2327                emit_diff_symbol(o, DIFF_SYMBOL_CONTEXT_INCOMPLETE,
2328                                 line, len, 0);
2329                break;
2330        }
2331}
2332
2333static void pprint_rename(struct strbuf *name, const char *a, const char *b)
2334{
2335        const char *old_name = a;
2336        const char *new_name = b;
2337        int pfx_length, sfx_length;
2338        int pfx_adjust_for_slash;
2339        int len_a = strlen(a);
2340        int len_b = strlen(b);
2341        int a_midlen, b_midlen;
2342        int qlen_a = quote_c_style(a, NULL, NULL, 0);
2343        int qlen_b = quote_c_style(b, NULL, NULL, 0);
2344
2345        if (qlen_a || qlen_b) {
2346                quote_c_style(a, name, NULL, 0);
2347                strbuf_addstr(name, " => ");
2348                quote_c_style(b, name, NULL, 0);
2349                return;
2350        }
2351
2352        /* Find common prefix */
2353        pfx_length = 0;
2354        while (*old_name && *new_name && *old_name == *new_name) {
2355                if (*old_name == '/')
2356                        pfx_length = old_name - a + 1;
2357                old_name++;
2358                new_name++;
2359        }
2360
2361        /* Find common suffix */
2362        old_name = a + len_a;
2363        new_name = b + len_b;
2364        sfx_length = 0;
2365        /*
2366         * If there is a common prefix, it must end in a slash.  In
2367         * that case we let this loop run 1 into the prefix to see the
2368         * same slash.
2369         *
2370         * If there is no common prefix, we cannot do this as it would
2371         * underrun the input strings.
2372         */
2373        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
2374        while (a + pfx_length - pfx_adjust_for_slash <= old_name &&
2375               b + pfx_length - pfx_adjust_for_slash <= new_name &&
2376               *old_name == *new_name) {
2377                if (*old_name == '/')
2378                        sfx_length = len_a - (old_name - a);
2379                old_name--;
2380                new_name--;
2381        }
2382
2383        /*
2384         * pfx{mid-a => mid-b}sfx
2385         * {pfx-a => pfx-b}sfx
2386         * pfx{sfx-a => sfx-b}
2387         * name-a => name-b
2388         */
2389        a_midlen = len_a - pfx_length - sfx_length;
2390        b_midlen = len_b - pfx_length - sfx_length;
2391        if (a_midlen < 0)
2392                a_midlen = 0;
2393        if (b_midlen < 0)
2394                b_midlen = 0;
2395
2396        strbuf_grow(name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
2397        if (pfx_length + sfx_length) {
2398                strbuf_add(name, a, pfx_length);
2399                strbuf_addch(name, '{');
2400        }
2401        strbuf_add(name, a + pfx_length, a_midlen);
2402        strbuf_addstr(name, " => ");
2403        strbuf_add(name, b + pfx_length, b_midlen);
2404        if (pfx_length + sfx_length) {
2405                strbuf_addch(name, '}');
2406                strbuf_add(name, a + len_a - sfx_length, sfx_length);
2407        }
2408}
2409
2410struct diffstat_t {
2411        int nr;
2412        int alloc;
2413        struct diffstat_file {
2414                char *from_name;
2415                char *name;
2416                char *print_name;
2417                const char *comments;
2418                unsigned is_unmerged:1;
2419                unsigned is_binary:1;
2420                unsigned is_renamed:1;
2421                unsigned is_interesting:1;
2422                uintmax_t added, deleted;
2423        } **files;
2424};
2425
2426static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
2427                                          const char *name_a,
2428                                          const char *name_b)
2429{
2430        struct diffstat_file *x;
2431        x = xcalloc(1, sizeof(*x));
2432        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
2433        diffstat->files[diffstat->nr++] = x;
2434        if (name_b) {
2435                x->from_name = xstrdup(name_a);
2436                x->name = xstrdup(name_b);
2437                x->is_renamed = 1;
2438        }
2439        else {
2440                x->from_name = NULL;
2441                x->name = xstrdup(name_a);
2442        }
2443        return x;
2444}
2445
2446static void diffstat_consume(void *priv, char *line, unsigned long len)
2447{
2448        struct diffstat_t *diffstat = priv;
2449        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
2450
2451        if (line[0] == '+')
2452                x->added++;
2453        else if (line[0] == '-')
2454                x->deleted++;
2455}
2456
2457const char mime_boundary_leader[] = "------------";
2458
2459static int scale_linear(int it, int width, int max_change)
2460{
2461        if (!it)
2462                return 0;
2463        /*
2464         * make sure that at least one '-' or '+' is printed if
2465         * there is any change to this path. The easiest way is to
2466         * scale linearly as if the alloted width is one column shorter
2467         * than it is, and then add 1 to the result.
2468         */
2469        return 1 + (it * (width - 1) / max_change);
2470}
2471
2472static void show_graph(struct strbuf *out, char ch, int cnt,
2473                       const char *set, const char *reset)
2474{
2475        if (cnt <= 0)
2476                return;
2477        strbuf_addstr(out, set);
2478        strbuf_addchars(out, ch, cnt);
2479        strbuf_addstr(out, reset);
2480}
2481
2482static void fill_print_name(struct diffstat_file *file)
2483{
2484        struct strbuf pname = STRBUF_INIT;
2485
2486        if (file->print_name)
2487                return;
2488
2489        if (file->is_renamed)
2490                pprint_rename(&pname, file->from_name, file->name);
2491        else
2492                quote_c_style(file->name, &pname, NULL, 0);
2493
2494        if (file->comments)
2495                strbuf_addf(&pname, " (%s)", file->comments);
2496
2497        file->print_name = strbuf_detach(&pname, NULL);
2498}
2499
2500static void print_stat_summary_inserts_deletes(struct diff_options *options,
2501                int files, int insertions, int deletions)
2502{
2503        struct strbuf sb = STRBUF_INIT;
2504
2505        if (!files) {
2506                assert(insertions == 0 && deletions == 0);
2507                emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
2508                                 NULL, 0, 0);
2509                return;
2510        }
2511
2512        strbuf_addf(&sb,
2513                    (files == 1) ? " %d file changed" : " %d files changed",
2514                    files);
2515
2516        /*
2517         * For binary diff, the caller may want to print "x files
2518         * changed" with insertions == 0 && deletions == 0.
2519         *
2520         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
2521         * is probably less confusing (i.e skip over "2 files changed
2522         * but nothing about added/removed lines? Is this a bug in Git?").
2523         */
2524        if (insertions || deletions == 0) {
2525                strbuf_addf(&sb,
2526                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
2527                            insertions);
2528        }
2529
2530        if (deletions || insertions == 0) {
2531                strbuf_addf(&sb,
2532                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
2533                            deletions);
2534        }
2535        strbuf_addch(&sb, '\n');
2536        emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
2537                         sb.buf, sb.len, 0);
2538        strbuf_release(&sb);
2539}
2540
2541void print_stat_summary(FILE *fp, int files,
2542                        int insertions, int deletions)
2543{
2544        struct diff_options o;
2545        memset(&o, 0, sizeof(o));
2546        o.file = fp;
2547
2548        print_stat_summary_inserts_deletes(&o, files, insertions, deletions);
2549}
2550
2551static void show_stats(struct diffstat_t *data, struct diff_options *options)
2552{
2553        int i, len, add, del, adds = 0, dels = 0;
2554        uintmax_t max_change = 0, max_len = 0;
2555        int total_files = data->nr, count;
2556        int width, name_width, graph_width, number_width = 0, bin_width = 0;
2557        const char *reset, *add_c, *del_c;
2558        int extra_shown = 0;
2559        const char *line_prefix = diff_line_prefix(options);
2560        struct strbuf out = STRBUF_INIT;
2561
2562        if (data->nr == 0)
2563                return;
2564
2565        count = options->stat_count ? options->stat_count : data->nr;
2566
2567        reset = diff_get_color_opt(options, DIFF_RESET);
2568        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
2569        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
2570
2571        /*
2572         * Find the longest filename and max number of changes
2573         */
2574        for (i = 0; (i < count) && (i < data->nr); i++) {
2575                struct diffstat_file *file = data->files[i];
2576                uintmax_t change = file->added + file->deleted;
2577
2578                if (!file->is_interesting && (change == 0)) {
2579                        count++; /* not shown == room for one more */
2580                        continue;
2581                }
2582                fill_print_name(file);
2583                len = strlen(file->print_name);
2584                if (max_len < len)
2585                        max_len = len;
2586
2587                if (file->is_unmerged) {
2588                        /* "Unmerged" is 8 characters */
2589                        bin_width = bin_width < 8 ? 8 : bin_width;
2590                        continue;
2591                }
2592                if (file->is_binary) {
2593                        /* "Bin XXX -> YYY bytes" */
2594                        int w = 14 + decimal_width(file->added)
2595                                + decimal_width(file->deleted);
2596                        bin_width = bin_width < w ? w : bin_width;
2597                        /* Display change counts aligned with "Bin" */
2598                        number_width = 3;
2599                        continue;
2600                }
2601
2602                if (max_change < change)
2603                        max_change = change;
2604        }
2605        count = i; /* where we can stop scanning in data->files[] */
2606
2607        /*
2608         * We have width = stat_width or term_columns() columns total.
2609         * We want a maximum of min(max_len, stat_name_width) for the name part.
2610         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
2611         * We also need 1 for " " and 4 + decimal_width(max_change)
2612         * for " | NNNN " and one the empty column at the end, altogether
2613         * 6 + decimal_width(max_change).
2614         *
2615         * If there's not enough space, we will use the smaller of
2616         * stat_name_width (if set) and 5/8*width for the filename,
2617         * and the rest for constant elements + graph part, but no more
2618         * than stat_graph_width for the graph part.
2619         * (5/8 gives 50 for filename and 30 for the constant parts + graph
2620         * for the standard terminal size).
2621         *
2622         * In other words: stat_width limits the maximum width, and
2623         * stat_name_width fixes the maximum width of the filename,
2624         * and is also used to divide available columns if there
2625         * aren't enough.
2626         *
2627         * Binary files are displayed with "Bin XXX -> YYY bytes"
2628         * instead of the change count and graph. This part is treated
2629         * similarly to the graph part, except that it is not
2630         * "scaled". If total width is too small to accommodate the
2631         * guaranteed minimum width of the filename part and the
2632         * separators and this message, this message will "overflow"
2633         * making the line longer than the maximum width.
2634         */
2635
2636        if (options->stat_width == -1)
2637                width = term_columns() - strlen(line_prefix);
2638        else
2639                width = options->stat_width ? options->stat_width : 80;
2640        number_width = decimal_width(max_change) > number_width ?
2641                decimal_width(max_change) : number_width;
2642
2643        if (options->stat_graph_width == -1)
2644                options->stat_graph_width = diff_stat_graph_width;
2645
2646        /*
2647         * Guarantee 3/8*16==6 for the graph part
2648         * and 5/8*16==10 for the filename part
2649         */
2650        if (width < 16 + 6 + number_width)
2651                width = 16 + 6 + number_width;
2652
2653        /*
2654         * First assign sizes that are wanted, ignoring available width.
2655         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
2656         * starting from "XXX" should fit in graph_width.
2657         */
2658        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
2659        if (options->stat_graph_width &&
2660            options->stat_graph_width < graph_width)
2661                graph_width = options->stat_graph_width;
2662
2663        name_width = (options->stat_name_width > 0 &&
2664                      options->stat_name_width < max_len) ?
2665                options->stat_name_width : max_len;
2666
2667        /*
2668         * Adjust adjustable widths not to exceed maximum width
2669         */
2670        if (name_width + number_width + 6 + graph_width > width) {
2671                if (graph_width > width * 3/8 - number_width - 6) {
2672                        graph_width = width * 3/8 - number_width - 6;
2673                        if (graph_width < 6)
2674                                graph_width = 6;
2675                }
2676
2677                if (options->stat_graph_width &&
2678                    graph_width > options->stat_graph_width)
2679                        graph_width = options->stat_graph_width;
2680                if (name_width > width - number_width - 6 - graph_width)
2681                        name_width = width - number_width - 6 - graph_width;
2682                else
2683                        graph_width = width - number_width - 6 - name_width;
2684        }
2685
2686        /*
2687         * From here name_width is the width of the name area,
2688         * and graph_width is the width of the graph area.
2689         * max_change is used to scale graph properly.
2690         */
2691        for (i = 0; i < count; i++) {
2692                const char *prefix = "";
2693                struct diffstat_file *file = data->files[i];
2694                char *name = file->print_name;
2695                uintmax_t added = file->added;
2696                uintmax_t deleted = file->deleted;
2697                int name_len;
2698
2699                if (!file->is_interesting && (added + deleted == 0))
2700                        continue;
2701
2702                /*
2703                 * "scale" the filename
2704                 */
2705                len = name_width;
2706                name_len = strlen(name);
2707                if (name_width < name_len) {
2708                        char *slash;
2709                        prefix = "...";
2710                        len -= 3;
2711                        name += name_len - len;
2712                        slash = strchr(name, '/');
2713                        if (slash)
2714                                name = slash;
2715                }
2716
2717                if (file->is_binary) {
2718                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2719                        strbuf_addf(&out, " %*s", number_width, "Bin");
2720                        if (!added && !deleted) {
2721                                strbuf_addch(&out, '\n');
2722                                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2723                                                 out.buf, out.len, 0);
2724                                strbuf_reset(&out);
2725                                continue;
2726                        }
2727                        strbuf_addf(&out, " %s%"PRIuMAX"%s",
2728                                del_c, deleted, reset);
2729                        strbuf_addstr(&out, " -> ");
2730                        strbuf_addf(&out, "%s%"PRIuMAX"%s",
2731                                add_c, added, reset);
2732                        strbuf_addstr(&out, " bytes\n");
2733                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2734                                         out.buf, out.len, 0);
2735                        strbuf_reset(&out);
2736                        continue;
2737                }
2738                else if (file->is_unmerged) {
2739                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2740                        strbuf_addstr(&out, " Unmerged\n");
2741                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2742                                         out.buf, out.len, 0);
2743                        strbuf_reset(&out);
2744                        continue;
2745                }
2746
2747                /*
2748                 * scale the add/delete
2749                 */
2750                add = added;
2751                del = deleted;
2752
2753                if (graph_width <= max_change) {
2754                        int total = scale_linear(add + del, graph_width, max_change);
2755                        if (total < 2 && add && del)
2756                                /* width >= 2 due to the sanity check */
2757                                total = 2;
2758                        if (add < del) {
2759                                add = scale_linear(add, graph_width, max_change);
2760                                del = total - add;
2761                        } else {
2762                                del = scale_linear(del, graph_width, max_change);
2763                                add = total - del;
2764                        }
2765                }
2766                strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2767                strbuf_addf(&out, " %*"PRIuMAX"%s",
2768                        number_width, added + deleted,
2769                        added + deleted ? " " : "");
2770                show_graph(&out, '+', add, add_c, reset);
2771                show_graph(&out, '-', del, del_c, reset);
2772                strbuf_addch(&out, '\n');
2773                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2774                                 out.buf, out.len, 0);
2775                strbuf_reset(&out);
2776        }
2777
2778        for (i = 0; i < data->nr; i++) {
2779                struct diffstat_file *file = data->files[i];
2780                uintmax_t added = file->added;
2781                uintmax_t deleted = file->deleted;
2782
2783                if (file->is_unmerged ||
2784                    (!file->is_interesting && (added + deleted == 0))) {
2785                        total_files--;
2786                        continue;
2787                }
2788
2789                if (!file->is_binary) {
2790                        adds += added;
2791                        dels += deleted;
2792                }
2793                if (i < count)
2794                        continue;
2795                if (!extra_shown)
2796                        emit_diff_symbol(options,
2797                                         DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
2798                                         NULL, 0, 0);
2799                extra_shown = 1;
2800        }
2801
2802        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2803        strbuf_release(&out);
2804}
2805
2806static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
2807{
2808        int i, adds = 0, dels = 0, total_files = data->nr;
2809
2810        if (data->nr == 0)
2811                return;
2812
2813        for (i = 0; i < data->nr; i++) {
2814                int added = data->files[i]->added;
2815                int deleted = data->files[i]->deleted;
2816
2817                if (data->files[i]->is_unmerged ||
2818                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
2819                        total_files--;
2820                } else if (!data->files[i]->is_binary) { /* don't count bytes */
2821                        adds += added;
2822                        dels += deleted;
2823                }
2824        }
2825        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2826}
2827
2828static void show_numstat(struct diffstat_t *data, struct diff_options *options)
2829{
2830        int i;
2831
2832        if (data->nr == 0)
2833                return;
2834
2835        for (i = 0; i < data->nr; i++) {
2836                struct diffstat_file *file = data->files[i];
2837
2838                fprintf(options->file, "%s", diff_line_prefix(options));
2839
2840                if (file->is_binary)
2841                        fprintf(options->file, "-\t-\t");
2842                else
2843                        fprintf(options->file,
2844                                "%"PRIuMAX"\t%"PRIuMAX"\t",
2845                                file->added, file->deleted);
2846                if (options->line_termination) {
2847                        fill_print_name(file);
2848                        if (!file->is_renamed)
2849                                write_name_quoted(file->name, options->file,
2850                                                  options->line_termination);
2851                        else {
2852                                fputs(file->print_name, options->file);
2853                                putc(options->line_termination, options->file);
2854                        }
2855                } else {
2856                        if (file->is_renamed) {
2857                                putc('\0', options->file);
2858                                write_name_quoted(file->from_name, options->file, '\0');
2859                        }
2860                        write_name_quoted(file->name, options->file, '\0');
2861                }
2862        }
2863}
2864
2865struct dirstat_file {
2866        const char *name;
2867        unsigned long changed;
2868};
2869
2870struct dirstat_dir {
2871        struct dirstat_file *files;
2872        int alloc, nr, permille, cumulative;
2873};
2874
2875static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
2876                unsigned long changed, const char *base, int baselen)
2877{
2878        unsigned long sum_changes = 0;
2879        unsigned int sources = 0;
2880        const char *line_prefix = diff_line_prefix(opt);
2881
2882        while (dir->nr) {
2883                struct dirstat_file *f = dir->files;
2884                int namelen = strlen(f->name);
2885                unsigned long changes;
2886                char *slash;
2887
2888                if (namelen < baselen)
2889                        break;
2890                if (memcmp(f->name, base, baselen))
2891                        break;
2892                slash = strchr(f->name + baselen, '/');
2893                if (slash) {
2894                        int newbaselen = slash + 1 - f->name;
2895                        changes = gather_dirstat(opt, dir, changed, f->name, newbaselen);
2896                        sources++;
2897                } else {
2898                        changes = f->changed;
2899                        dir->files++;
2900                        dir->nr--;
2901                        sources += 2;
2902                }
2903                sum_changes += changes;
2904        }
2905
2906        /*
2907         * We don't report dirstat's for
2908         *  - the top level
2909         *  - or cases where everything came from a single directory
2910         *    under this directory (sources == 1).
2911         */
2912        if (baselen && sources != 1) {
2913                if (sum_changes) {
2914                        int permille = sum_changes * 1000 / changed;
2915                        if (permille >= dir->permille) {
2916                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
2917                                        permille / 10, permille % 10, baselen, base);
2918                                if (!dir->cumulative)
2919                                        return 0;
2920                        }
2921                }
2922        }
2923        return sum_changes;
2924}
2925
2926static int dirstat_compare(const void *_a, const void *_b)
2927{
2928        const struct dirstat_file *a = _a;
2929        const struct dirstat_file *b = _b;
2930        return strcmp(a->name, b->name);
2931}
2932
2933static void show_dirstat(struct diff_options *options)
2934{
2935        int i;
2936        unsigned long changed;
2937        struct dirstat_dir dir;
2938        struct diff_queue_struct *q = &diff_queued_diff;
2939
2940        dir.files = NULL;
2941        dir.alloc = 0;
2942        dir.nr = 0;
2943        dir.permille = options->dirstat_permille;
2944        dir.cumulative = options->flags.dirstat_cumulative;
2945
2946        changed = 0;
2947        for (i = 0; i < q->nr; i++) {
2948                struct diff_filepair *p = q->queue[i];
2949                const char *name;
2950                unsigned long copied, added, damage;
2951
2952                name = p->two->path ? p->two->path : p->one->path;
2953
2954                if (p->one->oid_valid && p->two->oid_valid &&
2955                    oideq(&p->one->oid, &p->two->oid)) {
2956                        /*
2957                         * The SHA1 has not changed, so pre-/post-content is
2958                         * identical. We can therefore skip looking at the
2959                         * file contents altogether.
2960                         */
2961                        damage = 0;
2962                        goto found_damage;
2963                }
2964
2965                if (options->flags.dirstat_by_file) {
2966                        /*
2967                         * In --dirstat-by-file mode, we don't really need to
2968                         * look at the actual file contents at all.
2969                         * The fact that the SHA1 changed is enough for us to
2970                         * add this file to the list of results
2971                         * (with each file contributing equal damage).
2972                         */
2973                        damage = 1;
2974                        goto found_damage;
2975                }
2976
2977                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
2978                        diff_populate_filespec(p->one, 0);
2979                        diff_populate_filespec(p->two, 0);
2980                        diffcore_count_changes(p->one, p->two, NULL, NULL,
2981                                               &copied, &added);
2982                        diff_free_filespec_data(p->one);
2983                        diff_free_filespec_data(p->two);
2984                } else if (DIFF_FILE_VALID(p->one)) {
2985                        diff_populate_filespec(p->one, CHECK_SIZE_ONLY);
2986                        copied = added = 0;
2987                        diff_free_filespec_data(p->one);
2988                } else if (DIFF_FILE_VALID(p->two)) {
2989                        diff_populate_filespec(p->two, CHECK_SIZE_ONLY);
2990                        copied = 0;
2991                        added = p->two->size;
2992                        diff_free_filespec_data(p->two);
2993                } else
2994                        continue;
2995
2996                /*
2997                 * Original minus copied is the removed material,
2998                 * added is the new material.  They are both damages
2999                 * made to the preimage.
3000                 * If the resulting damage is zero, we know that
3001                 * diffcore_count_changes() considers the two entries to
3002                 * be identical, but since the oid changed, we
3003                 * know that there must have been _some_ kind of change,
3004                 * so we force all entries to have damage > 0.
3005                 */
3006                damage = (p->one->size - copied) + added;
3007                if (!damage)
3008                        damage = 1;
3009
3010found_damage:
3011                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
3012                dir.files[dir.nr].name = name;
3013                dir.files[dir.nr].changed = damage;
3014                changed += damage;
3015                dir.nr++;
3016        }
3017
3018        /* This can happen even with many files, if everything was renames */
3019        if (!changed)
3020                return;
3021
3022        /* Show all directories with more than x% of the changes */
3023        QSORT(dir.files, dir.nr, dirstat_compare);
3024        gather_dirstat(options, &dir, changed, "", 0);
3025}
3026
3027static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
3028{
3029        int i;
3030        unsigned long changed;
3031        struct dirstat_dir dir;
3032
3033        if (data->nr == 0)
3034                return;
3035
3036        dir.files = NULL;
3037        dir.alloc = 0;
3038        dir.nr = 0;
3039        dir.permille = options->dirstat_permille;
3040        dir.cumulative = options->flags.dirstat_cumulative;
3041
3042        changed = 0;
3043        for (i = 0; i < data->nr; i++) {
3044                struct diffstat_file *file = data->files[i];
3045                unsigned long damage = file->added + file->deleted;
3046                if (file->is_binary)
3047                        /*
3048                         * binary files counts bytes, not lines. Must find some
3049                         * way to normalize binary bytes vs. textual lines.
3050                         * The following heuristic assumes that there are 64
3051                         * bytes per "line".
3052                         * This is stupid and ugly, but very cheap...
3053                         */
3054                        damage = DIV_ROUND_UP(damage, 64);
3055                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
3056                dir.files[dir.nr].name = file->name;
3057                dir.files[dir.nr].changed = damage;
3058                changed += damage;
3059                dir.nr++;
3060        }
3061
3062        /* This can happen even with many files, if everything was renames */
3063        if (!changed)
3064                return;
3065
3066        /* Show all directories with more than x% of the changes */
3067        QSORT(dir.files, dir.nr, dirstat_compare);
3068        gather_dirstat(options, &dir, changed, "", 0);
3069}
3070
3071static void free_diffstat_info(struct diffstat_t *diffstat)
3072{
3073        int i;
3074        for (i = 0; i < diffstat->nr; i++) {
3075                struct diffstat_file *f = diffstat->files[i];
3076                free(f->print_name);
3077                free(f->name);
3078                free(f->from_name);
3079                free(f);
3080        }
3081        free(diffstat->files);
3082}
3083
3084struct checkdiff_t {
3085        const char *filename;
3086        int lineno;
3087        int conflict_marker_size;
3088        struct diff_options *o;
3089        unsigned ws_rule;
3090        unsigned status;
3091};
3092
3093static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
3094{
3095        char firstchar;
3096        int cnt;
3097
3098        if (len < marker_size + 1)
3099                return 0;
3100        firstchar = line[0];
3101        switch (firstchar) {
3102        case '=': case '>': case '<': case '|':
3103                break;
3104        default:
3105                return 0;
3106        }
3107        for (cnt = 1; cnt < marker_size; cnt++)
3108                if (line[cnt] != firstchar)
3109                        return 0;
3110        /* line[1] thru line[marker_size-1] are same as firstchar */
3111        if (len < marker_size + 1 || !isspace(line[marker_size]))
3112                return 0;
3113        return 1;
3114}
3115
3116static void checkdiff_consume(void *priv, char *line, unsigned long len)
3117{
3118        struct checkdiff_t *data = priv;
3119        int marker_size = data->conflict_marker_size;
3120        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
3121        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
3122        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
3123        char *err;
3124        const char *line_prefix;
3125
3126        assert(data->o);
3127        line_prefix = diff_line_prefix(data->o);
3128
3129        if (line[0] == '+') {
3130                unsigned bad;
3131                data->lineno++;
3132                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
3133                        data->status |= 1;
3134                        fprintf(data->o->file,
3135                                "%s%s:%d: leftover conflict marker\n",
3136                                line_prefix, data->filename, data->lineno);
3137                }
3138                bad = ws_check(line + 1, len - 1, data->ws_rule);
3139                if (!bad)
3140                        return;
3141                data->status |= bad;
3142                err = whitespace_error_string(bad);
3143                fprintf(data->o->file, "%s%s:%d: %s.\n",
3144                        line_prefix, data->filename, data->lineno, err);
3145                free(err);
3146                emit_line(data->o, set, reset, line, 1);
3147                ws_check_emit(line + 1, len - 1, data->ws_rule,
3148                              data->o->file, set, reset, ws);
3149        } else if (line[0] == ' ') {
3150                data->lineno++;
3151        } else if (line[0] == '@') {
3152                char *plus = strchr(line, '+');
3153                if (plus)
3154                        data->lineno = strtol(plus, NULL, 10) - 1;
3155                else
3156                        die("invalid diff");
3157        }
3158}
3159
3160static unsigned char *deflate_it(char *data,
3161                                 unsigned long size,
3162                                 unsigned long *result_size)
3163{
3164        int bound;
3165        unsigned char *deflated;
3166        git_zstream stream;
3167
3168        git_deflate_init(&stream, zlib_compression_level);
3169        bound = git_deflate_bound(&stream, size);
3170        deflated = xmalloc(bound);
3171        stream.next_out = deflated;
3172        stream.avail_out = bound;
3173
3174        stream.next_in = (unsigned char *)data;
3175        stream.avail_in = size;
3176        while (git_deflate(&stream, Z_FINISH) == Z_OK)
3177                ; /* nothing */
3178        git_deflate_end(&stream);
3179        *result_size = stream.total_out;
3180        return deflated;
3181}
3182
3183static void emit_binary_diff_body(struct diff_options *o,
3184                                  mmfile_t *one, mmfile_t *two)
3185{
3186        void *cp;
3187        void *delta;
3188        void *deflated;
3189        void *data;
3190        unsigned long orig_size;
3191        unsigned long delta_size;
3192        unsigned long deflate_size;
3193        unsigned long data_size;
3194
3195        /* We could do deflated delta, or we could do just deflated two,
3196         * whichever is smaller.
3197         */
3198        delta = NULL;
3199        deflated = deflate_it(two->ptr, two->size, &deflate_size);
3200        if (one->size && two->size) {
3201                delta = diff_delta(one->ptr, one->size,
3202                                   two->ptr, two->size,
3203                                   &delta_size, deflate_size);
3204                if (delta) {
3205                        void *to_free = delta;
3206                        orig_size = delta_size;
3207                        delta = deflate_it(delta, delta_size, &delta_size);
3208                        free(to_free);
3209                }
3210        }
3211
3212        if (delta && delta_size < deflate_size) {
3213                char *s = xstrfmt("%lu", orig_size);
3214                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
3215                                 s, strlen(s), 0);
3216                free(s);
3217                free(deflated);
3218                data = delta;
3219                data_size = delta_size;
3220        } else {
3221                char *s = xstrfmt("%lu", two->size);
3222                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
3223                                 s, strlen(s), 0);
3224                free(s);
3225                free(delta);
3226                data = deflated;
3227                data_size = deflate_size;
3228        }
3229
3230        /* emit data encoded in base85 */
3231        cp = data;
3232        while (data_size) {
3233                int len;
3234                int bytes = (52 < data_size) ? 52 : data_size;
3235                char line[71];
3236                data_size -= bytes;
3237                if (bytes <= 26)
3238                        line[0] = bytes + 'A' - 1;
3239                else
3240                        line[0] = bytes - 26 + 'a' - 1;
3241                encode_85(line + 1, cp, bytes);
3242                cp = (char *) cp + bytes;
3243
3244                len = strlen(line);
3245                line[len++] = '\n';
3246                line[len] = '\0';
3247
3248                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_BODY,
3249                                 line, len, 0);
3250        }
3251        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_FOOTER, NULL, 0, 0);
3252        free(data);
3253}
3254
3255static void emit_binary_diff(struct diff_options *o,
3256                             mmfile_t *one, mmfile_t *two)
3257{
3258        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER, NULL, 0, 0);
3259        emit_binary_diff_body(o, one, two);
3260        emit_binary_diff_body(o, two, one);
3261}
3262
3263int diff_filespec_is_binary(struct diff_filespec *one)
3264{
3265        if (one->is_binary == -1) {
3266                diff_filespec_load_driver(one);
3267                if (one->driver->binary != -1)
3268                        one->is_binary = one->driver->binary;
3269                else {
3270                        if (!one->data && DIFF_FILE_VALID(one))
3271                                diff_populate_filespec(one, CHECK_BINARY);
3272                        if (one->is_binary == -1 && one->data)
3273                                one->is_binary = buffer_is_binary(one->data,
3274                                                one->size);
3275                        if (one->is_binary == -1)
3276                                one->is_binary = 0;
3277                }
3278        }
3279        return one->is_binary;
3280}
3281
3282static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
3283{
3284        diff_filespec_load_driver(one);
3285        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
3286}
3287
3288void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
3289{
3290        if (!options->a_prefix)
3291                options->a_prefix = a;
3292        if (!options->b_prefix)
3293                options->b_prefix = b;
3294}
3295
3296struct userdiff_driver *get_textconv(struct diff_filespec *one)
3297{
3298        if (!DIFF_FILE_VALID(one))
3299                return NULL;
3300
3301        diff_filespec_load_driver(one);
3302        return userdiff_get_textconv(one->driver);
3303}
3304
3305static void builtin_diff(const char *name_a,
3306                         const char *name_b,
3307                         struct diff_filespec *one,
3308                         struct diff_filespec *two,
3309                         const char *xfrm_msg,
3310                         int must_show_header,
3311                         struct diff_options *o,
3312                         int complete_rewrite)
3313{
3314        mmfile_t mf1, mf2;
3315        const char *lbl[2];
3316        char *a_one, *b_two;
3317        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
3318        const char *reset = diff_get_color_opt(o, DIFF_RESET);
3319        const char *a_prefix, *b_prefix;
3320        struct userdiff_driver *textconv_one = NULL;
3321        struct userdiff_driver *textconv_two = NULL;
3322        struct strbuf header = STRBUF_INIT;
3323        const char *line_prefix = diff_line_prefix(o);
3324
3325        diff_set_mnemonic_prefix(o, "a/", "b/");
3326        if (o->flags.reverse_diff) {
3327                a_prefix = o->b_prefix;
3328                b_prefix = o->a_prefix;
3329        } else {
3330                a_prefix = o->a_prefix;
3331                b_prefix = o->b_prefix;
3332        }
3333
3334        if (o->submodule_format == DIFF_SUBMODULE_LOG &&
3335            (!one->mode || S_ISGITLINK(one->mode)) &&
3336            (!two->mode || S_ISGITLINK(two->mode))) {
3337                show_submodule_summary(o, one->path ? one->path : two->path,
3338                                &one->oid, &two->oid,
3339                                two->dirty_submodule);
3340                return;
3341        } else if (o->submodule_format == DIFF_SUBMODULE_INLINE_DIFF &&
3342                   (!one->mode || S_ISGITLINK(one->mode)) &&
3343                   (!two->mode || S_ISGITLINK(two->mode))) {
3344                show_submodule_inline_diff(o, one->path ? one->path : two->path,
3345                                &one->oid, &two->oid,
3346                                two->dirty_submodule);
3347                return;
3348        }
3349
3350        if (o->flags.allow_textconv) {
3351                textconv_one = get_textconv(one);
3352                textconv_two = get_textconv(two);
3353        }
3354
3355        /* Never use a non-valid filename anywhere if at all possible */
3356        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
3357        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
3358
3359        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
3360        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
3361        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
3362        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
3363        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
3364        if (lbl[0][0] == '/') {
3365                /* /dev/null */
3366                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
3367                if (xfrm_msg)
3368                        strbuf_addstr(&header, xfrm_msg);
3369                must_show_header = 1;
3370        }
3371        else if (lbl[1][0] == '/') {
3372                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
3373                if (xfrm_msg)
3374                        strbuf_addstr(&header, xfrm_msg);
3375                must_show_header = 1;
3376        }
3377        else {
3378                if (one->mode != two->mode) {
3379                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
3380                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
3381                        must_show_header = 1;
3382                }
3383                if (xfrm_msg)
3384                        strbuf_addstr(&header, xfrm_msg);
3385
3386                /*
3387                 * we do not run diff between different kind
3388                 * of objects.
3389                 */
3390                if ((one->mode ^ two->mode) & S_IFMT)
3391                        goto free_ab_and_return;
3392                if (complete_rewrite &&
3393                    (textconv_one || !diff_filespec_is_binary(one)) &&
3394                    (textconv_two || !diff_filespec_is_binary(two))) {
3395                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3396                                         header.buf, header.len, 0);
3397                        strbuf_reset(&header);
3398                        emit_rewrite_diff(name_a, name_b, one, two,
3399                                                textconv_one, textconv_two, o);
3400                        o->found_changes = 1;
3401                        goto free_ab_and_return;
3402                }
3403        }
3404
3405        if (o->irreversible_delete && lbl[1][0] == '/') {
3406                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf,
3407                                 header.len, 0);
3408                strbuf_reset(&header);
3409                goto free_ab_and_return;
3410        } else if (!o->flags.text &&
3411            ( (!textconv_one && diff_filespec_is_binary(one)) ||
3412              (!textconv_two && diff_filespec_is_binary(two)) )) {
3413                struct strbuf sb = STRBUF_INIT;
3414                if (!one->data && !two->data &&
3415                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
3416                    !o->flags.binary) {
3417                        if (oideq(&one->oid, &two->oid)) {
3418                                if (must_show_header)
3419                                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3420                                                         header.buf, header.len,
3421                                                         0);
3422                                goto free_ab_and_return;
3423                        }
3424                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3425                                         header.buf, header.len, 0);
3426                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3427                                    diff_line_prefix(o), lbl[0], lbl[1]);
3428                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3429                                         sb.buf, sb.len, 0);
3430                        strbuf_release(&sb);
3431                        goto free_ab_and_return;
3432                }
3433                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3434                        die("unable to read files to diff");
3435                /* Quite common confusing case */
3436                if (mf1.size == mf2.size &&
3437                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
3438                        if (must_show_header)
3439                                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3440                                                 header.buf, header.len, 0);
3441                        goto free_ab_and_return;
3442                }
3443                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf, header.len, 0);
3444                strbuf_reset(&header);
3445                if (o->flags.binary)
3446                        emit_binary_diff(o, &mf1, &mf2);
3447                else {
3448                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3449                                    diff_line_prefix(o), lbl[0], lbl[1]);
3450                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3451                                         sb.buf, sb.len, 0);
3452                        strbuf_release(&sb);
3453                }
3454                o->found_changes = 1;
3455        } else {
3456                /* Crazy xdl interfaces.. */
3457                const char *diffopts = getenv("GIT_DIFF_OPTS");
3458                const char *v;
3459                xpparam_t xpp;
3460                xdemitconf_t xecfg;
3461                struct emit_callback ecbdata;
3462                const struct userdiff_funcname *pe;
3463
3464                if (must_show_header) {
3465                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3466                                         header.buf, header.len, 0);
3467                        strbuf_reset(&header);
3468                }
3469
3470                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
3471                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
3472
3473                pe = diff_funcname_pattern(one);
3474                if (!pe)
3475                        pe = diff_funcname_pattern(two);
3476
3477                memset(&xpp, 0, sizeof(xpp));
3478                memset(&xecfg, 0, sizeof(xecfg));
3479                memset(&ecbdata, 0, sizeof(ecbdata));
3480                if (o->flags.suppress_diff_headers)
3481                        lbl[0] = NULL;
3482                ecbdata.label_path = lbl;
3483                ecbdata.color_diff = want_color(o->use_color);
3484                ecbdata.ws_rule = whitespace_rule(name_b);
3485                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
3486                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3487                ecbdata.opt = o;
3488                if (header.len && !o->flags.suppress_diff_headers)
3489                        ecbdata.header = &header;
3490                xpp.flags = o->xdl_opts;
3491                xpp.anchors = o->anchors;
3492                xpp.anchors_nr = o->anchors_nr;
3493                xecfg.ctxlen = o->context;
3494                xecfg.interhunkctxlen = o->interhunkcontext;
3495                xecfg.flags = XDL_EMIT_FUNCNAMES;
3496                if (o->flags.funccontext)
3497                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
3498                if (pe)
3499                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
3500                if (!diffopts)
3501                        ;
3502                else if (skip_prefix(diffopts, "--unified=", &v))
3503                        xecfg.ctxlen = strtoul(v, NULL, 10);
3504                else if (skip_prefix(diffopts, "-u", &v))
3505                        xecfg.ctxlen = strtoul(v, NULL, 10);
3506                if (o->word_diff)
3507                        init_diff_words_data(&ecbdata, o, one, two);
3508                if (xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
3509                                  &xpp, &xecfg))
3510                        die("unable to generate diff for %s", one->path);
3511                if (o->word_diff)
3512                        free_diff_words_data(&ecbdata);
3513                if (textconv_one)
3514                        free(mf1.ptr);
3515                if (textconv_two)
3516                        free(mf2.ptr);
3517                xdiff_clear_find_func(&xecfg);
3518        }
3519
3520 free_ab_and_return:
3521        strbuf_release(&header);
3522        diff_free_filespec_data(one);
3523        diff_free_filespec_data(two);
3524        free(a_one);
3525        free(b_two);
3526        return;
3527}
3528
3529static char *get_compact_summary(const struct diff_filepair *p, int is_renamed)
3530{
3531        if (!is_renamed) {
3532                if (p->status == DIFF_STATUS_ADDED) {
3533                        if (S_ISLNK(p->two->mode))
3534                                return "new +l";
3535                        else if ((p->two->mode & 0777) == 0755)
3536                                return "new +x";
3537                        else
3538                                return "new";
3539                } else if (p->status == DIFF_STATUS_DELETED)
3540                        return "gone";
3541        }
3542        if (S_ISLNK(p->one->mode) && !S_ISLNK(p->two->mode))
3543                return "mode -l";
3544        else if (!S_ISLNK(p->one->mode) && S_ISLNK(p->two->mode))
3545                return "mode +l";
3546        else if ((p->one->mode & 0777) == 0644 &&
3547                 (p->two->mode & 0777) == 0755)
3548                return "mode +x";
3549        else if ((p->one->mode & 0777) == 0755 &&
3550                 (p->two->mode & 0777) == 0644)
3551                return "mode -x";
3552        return NULL;
3553}
3554
3555static void builtin_diffstat(const char *name_a, const char *name_b,
3556                             struct diff_filespec *one,
3557                             struct diff_filespec *two,
3558                             struct diffstat_t *diffstat,
3559                             struct diff_options *o,
3560                             struct diff_filepair *p)
3561{
3562        mmfile_t mf1, mf2;
3563        struct diffstat_file *data;
3564        int same_contents;
3565        int complete_rewrite = 0;
3566
3567        if (!DIFF_PAIR_UNMERGED(p)) {
3568                if (p->status == DIFF_STATUS_MODIFIED && p->score)
3569                        complete_rewrite = 1;
3570        }
3571
3572        data = diffstat_add(diffstat, name_a, name_b);
3573        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
3574        if (o->flags.stat_with_summary)
3575                data->comments = get_compact_summary(p, data->is_renamed);
3576
3577        if (!one || !two) {
3578                data->is_unmerged = 1;
3579                return;
3580        }
3581
3582        same_contents = oideq(&one->oid, &two->oid);
3583
3584        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
3585                data->is_binary = 1;
3586                if (same_contents) {
3587                        data->added = 0;
3588                        data->deleted = 0;
3589                } else {
3590                        data->added = diff_filespec_size(two);
3591                        data->deleted = diff_filespec_size(one);
3592                }
3593        }
3594
3595        else if (complete_rewrite) {
3596                diff_populate_filespec(one, 0);
3597                diff_populate_filespec(two, 0);
3598                data->deleted = count_lines(one->data, one->size);
3599                data->added = count_lines(two->data, two->size);
3600        }
3601
3602        else if (!same_contents) {
3603                /* Crazy xdl interfaces.. */
3604                xpparam_t xpp;
3605                xdemitconf_t xecfg;
3606
3607                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3608                        die("unable to read files to diff");
3609
3610                memset(&xpp, 0, sizeof(xpp));
3611                memset(&xecfg, 0, sizeof(xecfg));
3612                xpp.flags = o->xdl_opts;
3613                xpp.anchors = o->anchors;
3614                xpp.anchors_nr = o->anchors_nr;
3615                xecfg.ctxlen = o->context;
3616                xecfg.interhunkctxlen = o->interhunkcontext;
3617                if (xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
3618                                  &xpp, &xecfg))
3619                        die("unable to generate diffstat for %s", one->path);
3620        }
3621
3622        diff_free_filespec_data(one);
3623        diff_free_filespec_data(two);
3624}
3625
3626static void builtin_checkdiff(const char *name_a, const char *name_b,
3627                              const char *attr_path,
3628                              struct diff_filespec *one,
3629                              struct diff_filespec *two,
3630                              struct diff_options *o)
3631{
3632        mmfile_t mf1, mf2;
3633        struct checkdiff_t data;
3634
3635        if (!two)
3636                return;
3637
3638        memset(&data, 0, sizeof(data));
3639        data.filename = name_b ? name_b : name_a;
3640        data.lineno = 0;
3641        data.o = o;
3642        data.ws_rule = whitespace_rule(attr_path);
3643        data.conflict_marker_size = ll_merge_marker_size(attr_path);
3644
3645        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3646                die("unable to read files to diff");
3647
3648        /*
3649         * All the other codepaths check both sides, but not checking
3650         * the "old" side here is deliberate.  We are checking the newly
3651         * introduced changes, and as long as the "new" side is text, we
3652         * can and should check what it introduces.
3653         */
3654        if (diff_filespec_is_binary(two))
3655                goto free_and_return;
3656        else {
3657                /* Crazy xdl interfaces.. */
3658                xpparam_t xpp;
3659                xdemitconf_t xecfg;
3660
3661                memset(&xpp, 0, sizeof(xpp));
3662                memset(&xecfg, 0, sizeof(xecfg));
3663                xecfg.ctxlen = 1; /* at least one context line */
3664                xpp.flags = 0;
3665                if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
3666                                  &xpp, &xecfg))
3667                        die("unable to generate checkdiff for %s", one->path);
3668
3669                if (data.ws_rule & WS_BLANK_AT_EOF) {
3670                        struct emit_callback ecbdata;
3671                        int blank_at_eof;
3672
3673                        ecbdata.ws_rule = data.ws_rule;
3674                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3675                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
3676
3677                        if (blank_at_eof) {
3678                                static char *err;
3679                                if (!err)
3680                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
3681                                fprintf(o->file, "%s:%d: %s.\n",
3682                                        data.filename, blank_at_eof, err);
3683                                data.status = 1; /* report errors */
3684                        }
3685                }
3686        }
3687 free_and_return:
3688        diff_free_filespec_data(one);
3689        diff_free_filespec_data(two);
3690        if (data.status)
3691                o->flags.check_failed = 1;
3692}
3693
3694struct diff_filespec *alloc_filespec(const char *path)
3695{
3696        struct diff_filespec *spec;
3697
3698        FLEXPTR_ALLOC_STR(spec, path, path);
3699        spec->count = 1;
3700        spec->is_binary = -1;
3701        return spec;
3702}
3703
3704void free_filespec(struct diff_filespec *spec)
3705{
3706        if (!--spec->count) {
3707                diff_free_filespec_data(spec);
3708                free(spec);
3709        }
3710}
3711
3712void fill_filespec(struct diff_filespec *spec, const struct object_id *oid,
3713                   int oid_valid, unsigned short mode)
3714{
3715        if (mode) {
3716                spec->mode = canon_mode(mode);
3717                oidcpy(&spec->oid, oid);
3718                spec->oid_valid = oid_valid;
3719        }
3720}
3721
3722/*
3723 * Given a name and sha1 pair, if the index tells us the file in
3724 * the work tree has that object contents, return true, so that
3725 * prepare_temp_file() does not have to inflate and extract.
3726 */
3727static int reuse_worktree_file(const char *name, const struct object_id *oid, int want_file)
3728{
3729        const struct cache_entry *ce;
3730        struct stat st;
3731        int pos, len;
3732
3733        /*
3734         * We do not read the cache ourselves here, because the
3735         * benchmark with my previous version that always reads cache
3736         * shows that it makes things worse for diff-tree comparing
3737         * two linux-2.6 kernel trees in an already checked out work
3738         * tree.  This is because most diff-tree comparisons deal with
3739         * only a small number of files, while reading the cache is
3740         * expensive for a large project, and its cost outweighs the
3741         * savings we get by not inflating the object to a temporary
3742         * file.  Practically, this code only helps when we are used
3743         * by diff-cache --cached, which does read the cache before
3744         * calling us.
3745         */
3746        if (!active_cache)
3747                return 0;
3748
3749        /* We want to avoid the working directory if our caller
3750         * doesn't need the data in a normal file, this system
3751         * is rather slow with its stat/open/mmap/close syscalls,
3752         * and the object is contained in a pack file.  The pack
3753         * is probably already open and will be faster to obtain
3754         * the data through than the working directory.  Loose
3755         * objects however would tend to be slower as they need
3756         * to be individually opened and inflated.
3757         */
3758        if (!FAST_WORKING_DIRECTORY && !want_file && has_object_pack(oid))
3759                return 0;
3760
3761        /*
3762         * Similarly, if we'd have to convert the file contents anyway, that
3763         * makes the optimization not worthwhile.
3764         */
3765        if (!want_file && would_convert_to_git(&the_index, name))
3766                return 0;
3767
3768        len = strlen(name);
3769        pos = cache_name_pos(name, len);
3770        if (pos < 0)
3771                return 0;
3772        ce = active_cache[pos];
3773
3774        /*
3775         * This is not the sha1 we are looking for, or
3776         * unreusable because it is not a regular file.
3777         */
3778        if (!oideq(oid, &ce->oid) || !S_ISREG(ce->ce_mode))
3779                return 0;
3780
3781        /*
3782         * If ce is marked as "assume unchanged", there is no
3783         * guarantee that work tree matches what we are looking for.
3784         */
3785        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
3786                return 0;
3787
3788        /*
3789         * If ce matches the file in the work tree, we can reuse it.
3790         */
3791        if (ce_uptodate(ce) ||
3792            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
3793                return 1;
3794
3795        return 0;
3796}
3797
3798static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
3799{
3800        struct strbuf buf = STRBUF_INIT;
3801        char *dirty = "";
3802
3803        /* Are we looking at the work tree? */
3804        if (s->dirty_submodule)
3805                dirty = "-dirty";
3806
3807        strbuf_addf(&buf, "Subproject commit %s%s\n",
3808                    oid_to_hex(&s->oid), dirty);
3809        s->size = buf.len;
3810        if (size_only) {
3811                s->data = NULL;
3812                strbuf_release(&buf);
3813        } else {
3814                s->data = strbuf_detach(&buf, NULL);
3815                s->should_free = 1;
3816        }
3817        return 0;
3818}
3819
3820/*
3821 * While doing rename detection and pickaxe operation, we may need to
3822 * grab the data for the blob (or file) for our own in-core comparison.
3823 * diff_filespec has data and size fields for this purpose.
3824 */
3825int diff_populate_filespec(struct diff_filespec *s, unsigned int flags)
3826{
3827        int size_only = flags & CHECK_SIZE_ONLY;
3828        int err = 0;
3829        int conv_flags = global_conv_flags_eol;
3830        /*
3831         * demote FAIL to WARN to allow inspecting the situation
3832         * instead of refusing.
3833         */
3834        if (conv_flags & CONV_EOL_RNDTRP_DIE)
3835                conv_flags = CONV_EOL_RNDTRP_WARN;
3836
3837        if (!DIFF_FILE_VALID(s))
3838                die("internal error: asking to populate invalid file.");
3839        if (S_ISDIR(s->mode))
3840                return -1;
3841
3842        if (s->data)
3843                return 0;
3844
3845        if (size_only && 0 < s->size)
3846                return 0;
3847
3848        if (S_ISGITLINK(s->mode))
3849                return diff_populate_gitlink(s, size_only);
3850
3851        if (!s->oid_valid ||
3852            reuse_worktree_file(s->path, &s->oid, 0)) {
3853                struct strbuf buf = STRBUF_INIT;
3854                struct stat st;
3855                int fd;
3856
3857                if (lstat(s->path, &st) < 0) {
3858                err_empty:
3859                        err = -1;
3860                empty:
3861                        s->data = (char *)"";
3862                        s->size = 0;
3863                        return err;
3864                }
3865                s->size = xsize_t(st.st_size);
3866                if (!s->size)
3867                        goto empty;
3868                if (S_ISLNK(st.st_mode)) {
3869                        struct strbuf sb = STRBUF_INIT;
3870
3871                        if (strbuf_readlink(&sb, s->path, s->size))
3872                                goto err_empty;
3873                        s->size = sb.len;
3874                        s->data = strbuf_detach(&sb, NULL);
3875                        s->should_free = 1;
3876                        return 0;
3877                }
3878
3879                /*
3880                 * Even if the caller would be happy with getting
3881                 * only the size, we cannot return early at this
3882                 * point if the path requires us to run the content
3883                 * conversion.
3884                 */
3885                if (size_only && !would_convert_to_git(&the_index, s->path))
3886                        return 0;
3887
3888                /*
3889                 * Note: this check uses xsize_t(st.st_size) that may
3890                 * not be the true size of the blob after it goes
3891                 * through convert_to_git().  This may not strictly be
3892                 * correct, but the whole point of big_file_threshold
3893                 * and is_binary check being that we want to avoid
3894                 * opening the file and inspecting the contents, this
3895                 * is probably fine.
3896                 */
3897                if ((flags & CHECK_BINARY) &&
3898                    s->size > big_file_threshold && s->is_binary == -1) {
3899                        s->is_binary = 1;
3900                        return 0;
3901                }
3902                fd = open(s->path, O_RDONLY);
3903                if (fd < 0)
3904                        goto err_empty;
3905                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
3906                close(fd);
3907                s->should_munmap = 1;
3908
3909                /*
3910                 * Convert from working tree format to canonical git format
3911                 */
3912                if (convert_to_git(&the_index, s->path, s->data, s->size, &buf, conv_flags)) {
3913                        size_t size = 0;
3914                        munmap(s->data, s->size);
3915                        s->should_munmap = 0;
3916                        s->data = strbuf_detach(&buf, &size);
3917                        s->size = size;
3918                        s->should_free = 1;
3919                }
3920        }
3921        else {
3922                enum object_type type;
3923                if (size_only || (flags & CHECK_BINARY)) {
3924                        type = oid_object_info(the_repository, &s->oid,
3925                                               &s->size);
3926                        if (type < 0)
3927                                die("unable to read %s",
3928                                    oid_to_hex(&s->oid));
3929                        if (size_only)
3930                                return 0;
3931                        if (s->size > big_file_threshold && s->is_binary == -1) {
3932                                s->is_binary = 1;
3933                                return 0;
3934                        }
3935                }
3936                s->data = read_object_file(&s->oid, &type, &s->size);
3937                if (!s->data)
3938                        die("unable to read %s", oid_to_hex(&s->oid));
3939                s->should_free = 1;
3940        }
3941        return 0;
3942}
3943
3944void diff_free_filespec_blob(struct diff_filespec *s)
3945{
3946        if (s->should_free)
3947                free(s->data);
3948        else if (s->should_munmap)
3949                munmap(s->data, s->size);
3950
3951        if (s->should_free || s->should_munmap) {
3952                s->should_free = s->should_munmap = 0;
3953                s->data = NULL;
3954        }
3955}
3956
3957void diff_free_filespec_data(struct diff_filespec *s)
3958{
3959        diff_free_filespec_blob(s);
3960        FREE_AND_NULL(s->cnt_data);
3961}
3962
3963static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
3964                           void *blob,
3965                           unsigned long size,
3966                           const struct object_id *oid,
3967                           int mode)
3968{
3969        struct strbuf buf = STRBUF_INIT;
3970        struct strbuf tempfile = STRBUF_INIT;
3971        char *path_dup = xstrdup(path);
3972        const char *base = basename(path_dup);
3973
3974        /* Generate "XXXXXX_basename.ext" */
3975        strbuf_addstr(&tempfile, "XXXXXX_");
3976        strbuf_addstr(&tempfile, base);
3977
3978        temp->tempfile = mks_tempfile_ts(tempfile.buf, strlen(base) + 1);
3979        if (!temp->tempfile)
3980                die_errno("unable to create temp-file");
3981        if (convert_to_working_tree(&the_index, path,
3982                        (const char *)blob, (size_t)size, &buf)) {
3983                blob = buf.buf;
3984                size = buf.len;
3985        }
3986        if (write_in_full(temp->tempfile->fd, blob, size) < 0 ||
3987            close_tempfile_gently(temp->tempfile))
3988                die_errno("unable to write temp-file");
3989        temp->name = get_tempfile_path(temp->tempfile);
3990        oid_to_hex_r(temp->hex, oid);
3991        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
3992        strbuf_release(&buf);
3993        strbuf_release(&tempfile);
3994        free(path_dup);
3995}
3996
3997static struct diff_tempfile *prepare_temp_file(const char *name,
3998                struct diff_filespec *one)
3999{
4000        struct diff_tempfile *temp = claim_diff_tempfile();
4001
4002        if (!DIFF_FILE_VALID(one)) {
4003        not_a_valid_file:
4004                /* A '-' entry produces this for file-2, and
4005                 * a '+' entry produces this for file-1.
4006                 */
4007                temp->name = "/dev/null";
4008                xsnprintf(temp->hex, sizeof(temp->hex), ".");
4009                xsnprintf(temp->mode, sizeof(temp->mode), ".");
4010                return temp;
4011        }
4012
4013        if (!S_ISGITLINK(one->mode) &&
4014            (!one->oid_valid ||
4015             reuse_worktree_file(name, &one->oid, 1))) {
4016                struct stat st;
4017                if (lstat(name, &st) < 0) {
4018                        if (errno == ENOENT)
4019                                goto not_a_valid_file;
4020                        die_errno("stat(%s)", name);
4021                }
4022                if (S_ISLNK(st.st_mode)) {
4023                        struct strbuf sb = STRBUF_INIT;
4024                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
4025                                die_errno("readlink(%s)", name);
4026                        prep_temp_blob(name, temp, sb.buf, sb.len,
4027                                       (one->oid_valid ?
4028                                        &one->oid : &null_oid),
4029                                       (one->oid_valid ?
4030                                        one->mode : S_IFLNK));
4031                        strbuf_release(&sb);
4032                }
4033                else {
4034                        /* we can borrow from the file in the work tree */
4035                        temp->name = name;
4036                        if (!one->oid_valid)
4037                                oid_to_hex_r(temp->hex, &null_oid);
4038                        else
4039                                oid_to_hex_r(temp->hex, &one->oid);
4040                        /* Even though we may sometimes borrow the
4041                         * contents from the work tree, we always want
4042                         * one->mode.  mode is trustworthy even when
4043                         * !(one->oid_valid), as long as
4044                         * DIFF_FILE_VALID(one).
4045                         */
4046                        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
4047                }
4048                return temp;
4049        }
4050        else {
4051                if (diff_populate_filespec(one, 0))
4052                        die("cannot read data blob for %s", one->path);
4053                prep_temp_blob(name, temp, one->data, one->size,
4054                               &one->oid, one->mode);
4055        }
4056        return temp;
4057}
4058
4059static void add_external_diff_name(struct argv_array *argv,
4060                                   const char *name,
4061                                   struct diff_filespec *df)
4062{
4063        struct diff_tempfile *temp = prepare_temp_file(name, df);
4064        argv_array_push(argv, temp->name);
4065        argv_array_push(argv, temp->hex);
4066        argv_array_push(argv, temp->mode);
4067}
4068
4069/* An external diff command takes:
4070 *
4071 * diff-cmd name infile1 infile1-sha1 infile1-mode \
4072 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
4073 *
4074 */
4075static void run_external_diff(const char *pgm,
4076                              const char *name,
4077                              const char *other,
4078                              struct diff_filespec *one,
4079                              struct diff_filespec *two,
4080                              const char *xfrm_msg,
4081                              int complete_rewrite,
4082                              struct diff_options *o)
4083{
4084        struct argv_array argv = ARGV_ARRAY_INIT;
4085        struct argv_array env = ARGV_ARRAY_INIT;
4086        struct diff_queue_struct *q = &diff_queued_diff;
4087
4088        argv_array_push(&argv, pgm);
4089        argv_array_push(&argv, name);
4090
4091        if (one && two) {
4092                add_external_diff_name(&argv, name, one);
4093                if (!other)
4094                        add_external_diff_name(&argv, name, two);
4095                else {
4096                        add_external_diff_name(&argv, other, two);
4097                        argv_array_push(&argv, other);
4098                        argv_array_push(&argv, xfrm_msg);
4099                }
4100        }
4101
4102        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
4103        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
4104
4105        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
4106                die(_("external diff died, stopping at %s"), name);
4107
4108        remove_tempfile();
4109        argv_array_clear(&argv);
4110        argv_array_clear(&env);
4111}
4112
4113static int similarity_index(struct diff_filepair *p)
4114{
4115        return p->score * 100 / MAX_SCORE;
4116}
4117
4118static const char *diff_abbrev_oid(const struct object_id *oid, int abbrev)
4119{
4120        if (startup_info->have_repository)
4121                return find_unique_abbrev(oid, abbrev);
4122        else {
4123                char *hex = oid_to_hex(oid);
4124                if (abbrev < 0)
4125                        abbrev = FALLBACK_DEFAULT_ABBREV;
4126                if (abbrev > the_hash_algo->hexsz)
4127                        BUG("oid abbreviation out of range: %d", abbrev);
4128                if (abbrev)
4129                        hex[abbrev] = '\0';
4130                return hex;
4131        }
4132}
4133
4134static void fill_metainfo(struct strbuf *msg,
4135                          const char *name,
4136                          const char *other,
4137                          struct diff_filespec *one,
4138                          struct diff_filespec *two,
4139                          struct diff_options *o,
4140                          struct diff_filepair *p,
4141                          int *must_show_header,
4142                          int use_color)
4143{
4144        const char *set = diff_get_color(use_color, DIFF_METAINFO);
4145        const char *reset = diff_get_color(use_color, DIFF_RESET);
4146        const char *line_prefix = diff_line_prefix(o);
4147
4148        *must_show_header = 1;
4149        strbuf_init(msg, PATH_MAX * 2 + 300);
4150        switch (p->status) {
4151        case DIFF_STATUS_COPIED:
4152                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4153                            line_prefix, set, similarity_index(p));
4154                strbuf_addf(msg, "%s\n%s%scopy from ",
4155                            reset,  line_prefix, set);
4156                quote_c_style(name, msg, NULL, 0);
4157                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
4158                quote_c_style(other, msg, NULL, 0);
4159                strbuf_addf(msg, "%s\n", reset);
4160                break;
4161        case DIFF_STATUS_RENAMED:
4162                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4163                            line_prefix, set, similarity_index(p));
4164                strbuf_addf(msg, "%s\n%s%srename from ",
4165                            reset, line_prefix, set);
4166                quote_c_style(name, msg, NULL, 0);
4167                strbuf_addf(msg, "%s\n%s%srename to ",
4168                            reset, line_prefix, set);
4169                quote_c_style(other, msg, NULL, 0);
4170                strbuf_addf(msg, "%s\n", reset);
4171                break;
4172        case DIFF_STATUS_MODIFIED:
4173                if (p->score) {
4174                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
4175                                    line_prefix,
4176                                    set, similarity_index(p), reset);
4177                        break;
4178                }
4179                /* fallthru */
4180        default:
4181                *must_show_header = 0;
4182        }
4183        if (one && two && !oideq(&one->oid, &two->oid)) {
4184                const unsigned hexsz = the_hash_algo->hexsz;
4185                int abbrev = o->flags.full_index ? hexsz : DEFAULT_ABBREV;
4186
4187                if (o->flags.binary) {
4188                        mmfile_t mf;
4189                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
4190                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
4191                                abbrev = hexsz;
4192                }
4193                strbuf_addf(msg, "%s%sindex %s..%s", line_prefix, set,
4194                            diff_abbrev_oid(&one->oid, abbrev),
4195                            diff_abbrev_oid(&two->oid, abbrev));
4196                if (one->mode == two->mode)
4197                        strbuf_addf(msg, " %06o", one->mode);
4198                strbuf_addf(msg, "%s\n", reset);
4199        }
4200}
4201
4202static void run_diff_cmd(const char *pgm,
4203                         const char *name,
4204                         const char *other,
4205                         const char *attr_path,
4206                         struct diff_filespec *one,
4207                         struct diff_filespec *two,
4208                         struct strbuf *msg,
4209                         struct diff_options *o,
4210                         struct diff_filepair *p)
4211{
4212        const char *xfrm_msg = NULL;
4213        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
4214        int must_show_header = 0;
4215
4216
4217        if (o->flags.allow_external) {
4218                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
4219                if (drv && drv->external)
4220                        pgm = drv->external;
4221        }
4222
4223        if (msg) {
4224                /*
4225                 * don't use colors when the header is intended for an
4226                 * external diff driver
4227                 */
4228                fill_metainfo(msg, name, other, one, two, o, p,
4229                              &must_show_header,
4230                              want_color(o->use_color) && !pgm);
4231                xfrm_msg = msg->len ? msg->buf : NULL;
4232        }
4233
4234        if (pgm) {
4235                run_external_diff(pgm, name, other, one, two, xfrm_msg,
4236                                  complete_rewrite, o);
4237                return;
4238        }
4239        if (one && two)
4240                builtin_diff(name, other ? other : name,
4241                             one, two, xfrm_msg, must_show_header,
4242                             o, complete_rewrite);
4243        else
4244                fprintf(o->file, "* Unmerged path %s\n", name);
4245}
4246
4247static void diff_fill_oid_info(struct diff_filespec *one)
4248{
4249        if (DIFF_FILE_VALID(one)) {
4250                if (!one->oid_valid) {
4251                        struct stat st;
4252                        if (one->is_stdin) {
4253                                oidclr(&one->oid);
4254                                return;
4255                        }
4256                        if (lstat(one->path, &st) < 0)
4257                                die_errno("stat '%s'", one->path);
4258                        if (index_path(&one->oid, one->path, &st, 0))
4259                                die("cannot hash %s", one->path);
4260                }
4261        }
4262        else
4263                oidclr(&one->oid);
4264}
4265
4266static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
4267{
4268        /* Strip the prefix but do not molest /dev/null and absolute paths */
4269        if (*namep && **namep != '/') {
4270                *namep += prefix_length;
4271                if (**namep == '/')
4272                        ++*namep;
4273        }
4274        if (*otherp && **otherp != '/') {
4275                *otherp += prefix_length;
4276                if (**otherp == '/')
4277                        ++*otherp;
4278        }
4279}
4280
4281static void run_diff(struct diff_filepair *p, struct diff_options *o)
4282{
4283        const char *pgm = external_diff();
4284        struct strbuf msg;
4285        struct diff_filespec *one = p->one;
4286        struct diff_filespec *two = p->two;
4287        const char *name;
4288        const char *other;
4289        const char *attr_path;
4290
4291        name  = one->path;
4292        other = (strcmp(name, two->path) ? two->path : NULL);
4293        attr_path = name;
4294        if (o->prefix_length)
4295                strip_prefix(o->prefix_length, &name, &other);
4296
4297        if (!o->flags.allow_external)
4298                pgm = NULL;
4299
4300        if (DIFF_PAIR_UNMERGED(p)) {
4301                run_diff_cmd(pgm, name, NULL, attr_path,
4302                             NULL, NULL, NULL, o, p);
4303                return;
4304        }
4305
4306        diff_fill_oid_info(one);
4307        diff_fill_oid_info(two);
4308
4309        if (!pgm &&
4310            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
4311            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
4312                /*
4313                 * a filepair that changes between file and symlink
4314                 * needs to be split into deletion and creation.
4315                 */
4316                struct diff_filespec *null = alloc_filespec(two->path);
4317                run_diff_cmd(NULL, name, other, attr_path,
4318                             one, null, &msg, o, p);
4319                free(null);
4320                strbuf_release(&msg);
4321
4322                null = alloc_filespec(one->path);
4323                run_diff_cmd(NULL, name, other, attr_path,
4324                             null, two, &msg, o, p);
4325                free(null);
4326        }
4327        else
4328                run_diff_cmd(pgm, name, other, attr_path,
4329                             one, two, &msg, o, p);
4330
4331        strbuf_release(&msg);
4332}
4333
4334static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
4335                         struct diffstat_t *diffstat)
4336{
4337        const char *name;
4338        const char *other;
4339
4340        if (DIFF_PAIR_UNMERGED(p)) {
4341                /* unmerged */
4342                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, p);
4343                return;
4344        }
4345
4346        name = p->one->path;
4347        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4348
4349        if (o->prefix_length)
4350                strip_prefix(o->prefix_length, &name, &other);
4351
4352        diff_fill_oid_info(p->one);
4353        diff_fill_oid_info(p->two);
4354
4355        builtin_diffstat(name, other, p->one, p->two, diffstat, o, p);
4356}
4357
4358static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
4359{
4360        const char *name;
4361        const char *other;
4362        const char *attr_path;
4363
4364        if (DIFF_PAIR_UNMERGED(p)) {
4365                /* unmerged */
4366                return;
4367        }
4368
4369        name = p->one->path;
4370        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4371        attr_path = other ? other : name;
4372
4373        if (o->prefix_length)
4374                strip_prefix(o->prefix_length, &name, &other);
4375
4376        diff_fill_oid_info(p->one);
4377        diff_fill_oid_info(p->two);
4378
4379        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
4380}
4381
4382void diff_setup(struct diff_options *options)
4383{
4384        memcpy(options, &default_diff_options, sizeof(*options));
4385
4386        options->file = stdout;
4387
4388        options->output_indicators[OUTPUT_INDICATOR_NEW] = '+';
4389        options->output_indicators[OUTPUT_INDICATOR_OLD] = '-';
4390        options->output_indicators[OUTPUT_INDICATOR_CONTEXT] = ' ';
4391        options->abbrev = DEFAULT_ABBREV;
4392        options->line_termination = '\n';
4393        options->break_opt = -1;
4394        options->rename_limit = -1;
4395        options->dirstat_permille = diff_dirstat_permille_default;
4396        options->context = diff_context_default;
4397        options->interhunkcontext = diff_interhunk_context_default;
4398        options->ws_error_highlight = ws_error_highlight_default;
4399        options->flags.rename_empty = 1;
4400        options->objfind = NULL;
4401
4402        /* pathchange left =NULL by default */
4403        options->change = diff_change;
4404        options->add_remove = diff_addremove;
4405        options->use_color = diff_use_color_default;
4406        options->detect_rename = diff_detect_rename_default;
4407        options->xdl_opts |= diff_algorithm;
4408        if (diff_indent_heuristic)
4409                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4410
4411        options->orderfile = diff_order_file_cfg;
4412
4413        if (diff_no_prefix) {
4414                options->a_prefix = options->b_prefix = "";
4415        } else if (!diff_mnemonic_prefix) {
4416                options->a_prefix = "a/";
4417                options->b_prefix = "b/";
4418        }
4419
4420        options->color_moved = diff_color_moved_default;
4421        options->color_moved_ws_handling = diff_color_moved_ws_default;
4422}
4423
4424void diff_setup_done(struct diff_options *options)
4425{
4426        unsigned check_mask = DIFF_FORMAT_NAME |
4427                              DIFF_FORMAT_NAME_STATUS |
4428                              DIFF_FORMAT_CHECKDIFF |
4429                              DIFF_FORMAT_NO_OUTPUT;
4430        /*
4431         * This must be signed because we're comparing against a potentially
4432         * negative value.
4433         */
4434        const int hexsz = the_hash_algo->hexsz;
4435
4436        if (options->set_default)
4437                options->set_default(options);
4438
4439        if (HAS_MULTI_BITS(options->output_format & check_mask))
4440                die(_("--name-only, --name-status, --check and -s are mutually exclusive"));
4441
4442        if (HAS_MULTI_BITS(options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK))
4443                die(_("-G, -S and --find-object are mutually exclusive"));
4444
4445        /*
4446         * Most of the time we can say "there are changes"
4447         * only by checking if there are changed paths, but
4448         * --ignore-whitespace* options force us to look
4449         * inside contents.
4450         */
4451
4452        if ((options->xdl_opts & XDF_WHITESPACE_FLAGS))
4453                options->flags.diff_from_contents = 1;
4454        else
4455                options->flags.diff_from_contents = 0;
4456
4457        if (options->flags.find_copies_harder)
4458                options->detect_rename = DIFF_DETECT_COPY;
4459
4460        if (!options->flags.relative_name)
4461                options->prefix = NULL;
4462        if (options->prefix)
4463                options->prefix_length = strlen(options->prefix);
4464        else
4465                options->prefix_length = 0;
4466
4467        if (options->output_format & (DIFF_FORMAT_NAME |
4468                                      DIFF_FORMAT_NAME_STATUS |
4469                                      DIFF_FORMAT_CHECKDIFF |
4470                                      DIFF_FORMAT_NO_OUTPUT))
4471                options->output_format &= ~(DIFF_FORMAT_RAW |
4472                                            DIFF_FORMAT_NUMSTAT |
4473                                            DIFF_FORMAT_DIFFSTAT |
4474                                            DIFF_FORMAT_SHORTSTAT |
4475                                            DIFF_FORMAT_DIRSTAT |
4476                                            DIFF_FORMAT_SUMMARY |
4477                                            DIFF_FORMAT_PATCH);
4478
4479        /*
4480         * These cases always need recursive; we do not drop caller-supplied
4481         * recursive bits for other formats here.
4482         */
4483        if (options->output_format & (DIFF_FORMAT_PATCH |
4484                                      DIFF_FORMAT_NUMSTAT |
4485                                      DIFF_FORMAT_DIFFSTAT |
4486                                      DIFF_FORMAT_SHORTSTAT |
4487                                      DIFF_FORMAT_DIRSTAT |
4488                                      DIFF_FORMAT_SUMMARY |
4489                                      DIFF_FORMAT_CHECKDIFF))
4490                options->flags.recursive = 1;
4491        /*
4492         * Also pickaxe would not work very well if you do not say recursive
4493         */
4494        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
4495                options->flags.recursive = 1;
4496        /*
4497         * When patches are generated, submodules diffed against the work tree
4498         * must be checked for dirtiness too so it can be shown in the output
4499         */
4500        if (options->output_format & DIFF_FORMAT_PATCH)
4501                options->flags.dirty_submodules = 1;
4502
4503        if (options->detect_rename && options->rename_limit < 0)
4504                options->rename_limit = diff_rename_limit_default;
4505        if (hexsz < options->abbrev)
4506                options->abbrev = hexsz; /* full */
4507
4508        /*
4509         * It does not make sense to show the first hit we happened
4510         * to have found.  It does not make sense not to return with
4511         * exit code in such a case either.
4512         */
4513        if (options->flags.quick) {
4514                options->output_format = DIFF_FORMAT_NO_OUTPUT;
4515                options->flags.exit_with_status = 1;
4516        }
4517
4518        options->diff_path_counter = 0;
4519
4520        if (options->flags.follow_renames && options->pathspec.nr != 1)
4521                die(_("--follow requires exactly one pathspec"));
4522
4523        if (!options->use_color || external_diff())
4524                options->color_moved = 0;
4525}
4526
4527static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
4528{
4529        char c, *eq;
4530        int len;
4531
4532        if (*arg != '-')
4533                return 0;
4534        c = *++arg;
4535        if (!c)
4536                return 0;
4537        if (c == arg_short) {
4538                c = *++arg;
4539                if (!c)
4540                        return 1;
4541                if (val && isdigit(c)) {
4542                        char *end;
4543                        int n = strtoul(arg, &end, 10);
4544                        if (*end)
4545                                return 0;
4546                        *val = n;
4547                        return 1;
4548                }
4549                return 0;
4550        }
4551        if (c != '-')
4552                return 0;
4553        arg++;
4554        eq = strchrnul(arg, '=');
4555        len = eq - arg;
4556        if (!len || strncmp(arg, arg_long, len))
4557                return 0;
4558        if (*eq) {
4559                int n;
4560                char *end;
4561                if (!isdigit(*++eq))
4562                        return 0;
4563                n = strtoul(eq, &end, 10);
4564                if (*end)
4565                        return 0;
4566                *val = n;
4567        }
4568        return 1;
4569}
4570
4571static int diff_scoreopt_parse(const char *opt);
4572
4573static inline int short_opt(char opt, const char **argv,
4574                            const char **optarg)
4575{
4576        const char *arg = argv[0];
4577        if (arg[0] != '-' || arg[1] != opt)
4578                return 0;
4579        if (arg[2] != '\0') {
4580                *optarg = arg + 2;
4581                return 1;
4582        }
4583        if (!argv[1])
4584                die("Option '%c' requires a value", opt);
4585        *optarg = argv[1];
4586        return 2;
4587}
4588
4589int parse_long_opt(const char *opt, const char **argv,
4590                   const char **optarg)
4591{
4592        const char *arg = argv[0];
4593        if (!skip_prefix(arg, "--", &arg))
4594                return 0;
4595        if (!skip_prefix(arg, opt, &arg))
4596                return 0;
4597        if (*arg == '=') { /* stuck form: --option=value */
4598                *optarg = arg + 1;
4599                return 1;
4600        }
4601        if (*arg != '\0')
4602                return 0;
4603        /* separate form: --option value */
4604        if (!argv[1])
4605                die("Option '--%s' requires a value", opt);
4606        *optarg = argv[1];
4607        return 2;
4608}
4609
4610static int stat_opt(struct diff_options *options, const char **av)
4611{
4612        const char *arg = av[0];
4613        char *end;
4614        int width = options->stat_width;
4615        int name_width = options->stat_name_width;
4616        int graph_width = options->stat_graph_width;
4617        int count = options->stat_count;
4618        int argcount = 1;
4619
4620        if (!skip_prefix(arg, "--stat", &arg))
4621                BUG("stat option does not begin with --stat: %s", arg);
4622        end = (char *)arg;
4623
4624        switch (*arg) {
4625        case '-':
4626                if (skip_prefix(arg, "-width", &arg)) {
4627                        if (*arg == '=')
4628                                width = strtoul(arg + 1, &end, 10);
4629                        else if (!*arg && !av[1])
4630                                die_want_option("--stat-width");
4631                        else if (!*arg) {
4632                                width = strtoul(av[1], &end, 10);
4633                                argcount = 2;
4634                        }
4635                } else if (skip_prefix(arg, "-name-width", &arg)) {
4636                        if (*arg == '=')
4637                                name_width = strtoul(arg + 1, &end, 10);
4638                        else if (!*arg && !av[1])
4639                                die_want_option("--stat-name-width");
4640                        else if (!*arg) {
4641                                name_width = strtoul(av[1], &end, 10);
4642                                argcount = 2;
4643                        }
4644                } else if (skip_prefix(arg, "-graph-width", &arg)) {
4645                        if (*arg == '=')
4646                                graph_width = strtoul(arg + 1, &end, 10);
4647                        else if (!*arg && !av[1])
4648                                die_want_option("--stat-graph-width");
4649                        else if (!*arg) {
4650                                graph_width = strtoul(av[1], &end, 10);
4651                                argcount = 2;
4652                        }
4653                } else if (skip_prefix(arg, "-count", &arg)) {
4654                        if (*arg == '=')
4655                                count = strtoul(arg + 1, &end, 10);
4656                        else if (!*arg && !av[1])
4657                                die_want_option("--stat-count");
4658                        else if (!*arg) {
4659                                count = strtoul(av[1], &end, 10);
4660                                argcount = 2;
4661                        }
4662                }
4663                break;
4664        case '=':
4665                width = strtoul(arg+1, &end, 10);
4666                if (*end == ',')
4667                        name_width = strtoul(end+1, &end, 10);
4668                if (*end == ',')
4669                        count = strtoul(end+1, &end, 10);
4670        }
4671
4672        /* Important! This checks all the error cases! */
4673        if (*end)
4674                return 0;
4675        options->output_format |= DIFF_FORMAT_DIFFSTAT;
4676        options->stat_name_width = name_width;
4677        options->stat_graph_width = graph_width;
4678        options->stat_width = width;
4679        options->stat_count = count;
4680        return argcount;
4681}
4682
4683static int parse_dirstat_opt(struct diff_options *options, const char *params)
4684{
4685        struct strbuf errmsg = STRBUF_INIT;
4686        if (parse_dirstat_params(options, params, &errmsg))
4687                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
4688                    errmsg.buf);
4689        strbuf_release(&errmsg);
4690        /*
4691         * The caller knows a dirstat-related option is given from the command
4692         * line; allow it to say "return this_function();"
4693         */
4694        options->output_format |= DIFF_FORMAT_DIRSTAT;
4695        return 1;
4696}
4697
4698static int parse_submodule_opt(struct diff_options *options, const char *value)
4699{
4700        if (parse_submodule_params(options, value))
4701                die(_("Failed to parse --submodule option parameter: '%s'"),
4702                        value);
4703        return 1;
4704}
4705
4706static const char diff_status_letters[] = {
4707        DIFF_STATUS_ADDED,
4708        DIFF_STATUS_COPIED,
4709        DIFF_STATUS_DELETED,
4710        DIFF_STATUS_MODIFIED,
4711        DIFF_STATUS_RENAMED,
4712        DIFF_STATUS_TYPE_CHANGED,
4713        DIFF_STATUS_UNKNOWN,
4714        DIFF_STATUS_UNMERGED,
4715        DIFF_STATUS_FILTER_AON,
4716        DIFF_STATUS_FILTER_BROKEN,
4717        '\0',
4718};
4719
4720static unsigned int filter_bit['Z' + 1];
4721
4722static void prepare_filter_bits(void)
4723{
4724        int i;
4725
4726        if (!filter_bit[DIFF_STATUS_ADDED]) {
4727                for (i = 0; diff_status_letters[i]; i++)
4728                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
4729        }
4730}
4731
4732static unsigned filter_bit_tst(char status, const struct diff_options *opt)
4733{
4734        return opt->filter & filter_bit[(int) status];
4735}
4736
4737static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
4738{
4739        int i, optch;
4740
4741        prepare_filter_bits();
4742
4743        /*
4744         * If there is a negation e.g. 'd' in the input, and we haven't
4745         * initialized the filter field with another --diff-filter, start
4746         * from full set of bits, except for AON.
4747         */
4748        if (!opt->filter) {
4749                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4750                        if (optch < 'a' || 'z' < optch)
4751                                continue;
4752                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
4753                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
4754                        break;
4755                }
4756        }
4757
4758        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4759                unsigned int bit;
4760                int negate;
4761
4762                if ('a' <= optch && optch <= 'z') {
4763                        negate = 1;
4764                        optch = toupper(optch);
4765                } else {
4766                        negate = 0;
4767                }
4768
4769                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
4770                if (!bit)
4771                        return optarg[i];
4772                if (negate)
4773                        opt->filter &= ~bit;
4774                else
4775                        opt->filter |= bit;
4776        }
4777        return 0;
4778}
4779
4780static void enable_patch_output(int *fmt) {
4781        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
4782        *fmt |= DIFF_FORMAT_PATCH;
4783}
4784
4785static int parse_ws_error_highlight_opt(struct diff_options *opt, const char *arg)
4786{
4787        int val = parse_ws_error_highlight(arg);
4788
4789        if (val < 0) {
4790                error("unknown value after ws-error-highlight=%.*s",
4791                      -1 - val, arg);
4792                return 0;
4793        }
4794        opt->ws_error_highlight = val;
4795        return 1;
4796}
4797
4798static int parse_objfind_opt(struct diff_options *opt, const char *arg)
4799{
4800        struct object_id oid;
4801
4802        if (get_oid(arg, &oid))
4803                return error("unable to resolve '%s'", arg);
4804
4805        if (!opt->objfind)
4806                opt->objfind = xcalloc(1, sizeof(*opt->objfind));
4807
4808        opt->pickaxe_opts |= DIFF_PICKAXE_KIND_OBJFIND;
4809        opt->flags.recursive = 1;
4810        opt->flags.tree_in_recursive = 1;
4811        oidset_insert(opt->objfind, &oid);
4812        return 1;
4813}
4814
4815int diff_opt_parse(struct diff_options *options,
4816                   const char **av, int ac, const char *prefix)
4817{
4818        const char *arg = av[0];
4819        const char *optarg;
4820        int argcount;
4821
4822        if (!prefix)
4823                prefix = "";
4824
4825        /* Output format options */
4826        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
4827            || opt_arg(arg, 'U', "unified", &options->context))
4828                enable_patch_output(&options->output_format);
4829        else if (!strcmp(arg, "--raw"))
4830                options->output_format |= DIFF_FORMAT_RAW;
4831        else if (!strcmp(arg, "--patch-with-raw")) {
4832                enable_patch_output(&options->output_format);
4833                options->output_format |= DIFF_FORMAT_RAW;
4834        } else if (!strcmp(arg, "--numstat"))
4835                options->output_format |= DIFF_FORMAT_NUMSTAT;
4836        else if (!strcmp(arg, "--shortstat"))
4837                options->output_format |= DIFF_FORMAT_SHORTSTAT;
4838        else if (skip_prefix(arg, "-X", &arg) ||
4839                 skip_to_optional_arg(arg, "--dirstat", &arg))
4840                return parse_dirstat_opt(options, arg);
4841        else if (!strcmp(arg, "--cumulative"))
4842                return parse_dirstat_opt(options, "cumulative");
4843        else if (skip_to_optional_arg(arg, "--dirstat-by-file", &arg)) {
4844                parse_dirstat_opt(options, "files");
4845                return parse_dirstat_opt(options, arg);
4846        }
4847        else if (!strcmp(arg, "--check"))
4848                options->output_format |= DIFF_FORMAT_CHECKDIFF;
4849        else if (!strcmp(arg, "--summary"))
4850                options->output_format |= DIFF_FORMAT_SUMMARY;
4851        else if (!strcmp(arg, "--patch-with-stat")) {
4852                enable_patch_output(&options->output_format);
4853                options->output_format |= DIFF_FORMAT_DIFFSTAT;
4854        } else if (!strcmp(arg, "--name-only"))
4855                options->output_format |= DIFF_FORMAT_NAME;
4856        else if (!strcmp(arg, "--name-status"))
4857                options->output_format |= DIFF_FORMAT_NAME_STATUS;
4858        else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
4859                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
4860        else if (starts_with(arg, "--stat"))
4861                /* --stat, --stat-width, --stat-name-width, or --stat-count */
4862                return stat_opt(options, av);
4863        else if (!strcmp(arg, "--compact-summary")) {
4864                 options->flags.stat_with_summary = 1;
4865                 options->output_format |= DIFF_FORMAT_DIFFSTAT;
4866        } else if (!strcmp(arg, "--no-compact-summary"))
4867                 options->flags.stat_with_summary = 0;
4868        else if (skip_prefix(arg, "--output-indicator-new=", &arg))
4869                options->output_indicators[OUTPUT_INDICATOR_NEW] = arg[0];
4870        else if (skip_prefix(arg, "--output-indicator-old=", &arg))
4871                options->output_indicators[OUTPUT_INDICATOR_OLD] = arg[0];
4872        else if (skip_prefix(arg, "--output-indicator-context=", &arg))
4873                options->output_indicators[OUTPUT_INDICATOR_CONTEXT] = arg[0];
4874
4875        /* renames options */
4876        else if (starts_with(arg, "-B") ||
4877                 skip_to_optional_arg(arg, "--break-rewrites", NULL)) {
4878                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
4879                        return error("invalid argument to -B: %s", arg+2);
4880        }
4881        else if (starts_with(arg, "-M") ||
4882                 skip_to_optional_arg(arg, "--find-renames", NULL)) {
4883                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4884                        return error("invalid argument to -M: %s", arg+2);
4885                options->detect_rename = DIFF_DETECT_RENAME;
4886        }
4887        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
4888                options->irreversible_delete = 1;
4889        }
4890        else if (starts_with(arg, "-C") ||
4891                 skip_to_optional_arg(arg, "--find-copies", NULL)) {
4892                if (options->detect_rename == DIFF_DETECT_COPY)
4893                        options->flags.find_copies_harder = 1;
4894                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4895                        return error("invalid argument to -C: %s", arg+2);
4896                options->detect_rename = DIFF_DETECT_COPY;
4897        }
4898        else if (!strcmp(arg, "--no-renames"))
4899                options->detect_rename = 0;
4900        else if (!strcmp(arg, "--rename-empty"))
4901                options->flags.rename_empty = 1;
4902        else if (!strcmp(arg, "--no-rename-empty"))
4903                options->flags.rename_empty = 0;
4904        else if (skip_to_optional_arg_default(arg, "--relative", &arg, NULL)) {
4905                options->flags.relative_name = 1;
4906                if (arg)
4907                        options->prefix = arg;
4908        }
4909
4910        /* xdiff options */
4911        else if (!strcmp(arg, "--minimal"))
4912                DIFF_XDL_SET(options, NEED_MINIMAL);
4913        else if (!strcmp(arg, "--no-minimal"))
4914                DIFF_XDL_CLR(options, NEED_MINIMAL);
4915        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
4916                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
4917        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
4918                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
4919        else if (!strcmp(arg, "--ignore-space-at-eol"))
4920                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
4921        else if (!strcmp(arg, "--ignore-cr-at-eol"))
4922                DIFF_XDL_SET(options, IGNORE_CR_AT_EOL);
4923        else if (!strcmp(arg, "--ignore-blank-lines"))
4924                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
4925        else if (!strcmp(arg, "--indent-heuristic"))
4926                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4927        else if (!strcmp(arg, "--no-indent-heuristic"))
4928                DIFF_XDL_CLR(options, INDENT_HEURISTIC);
4929        else if (!strcmp(arg, "--patience")) {
4930                int i;
4931                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4932                /*
4933                 * Both --patience and --anchored use PATIENCE_DIFF
4934                 * internally, so remove any anchors previously
4935                 * specified.
4936                 */
4937                for (i = 0; i < options->anchors_nr; i++)
4938                        free(options->anchors[i]);
4939                options->anchors_nr = 0;
4940        } else if (!strcmp(arg, "--histogram"))
4941                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
4942        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
4943                long value = parse_algorithm_value(optarg);
4944                if (value < 0)
4945                        return error("option diff-algorithm accepts \"myers\", "
4946                                     "\"minimal\", \"patience\" and \"histogram\"");
4947                /* clear out previous settings */
4948                DIFF_XDL_CLR(options, NEED_MINIMAL);
4949                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
4950                options->xdl_opts |= value;
4951                return argcount;
4952        } else if (skip_prefix(arg, "--anchored=", &arg)) {
4953                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4954                ALLOC_GROW(options->anchors, options->anchors_nr + 1,
4955                           options->anchors_alloc);
4956                options->anchors[options->anchors_nr++] = xstrdup(arg);
4957        }
4958
4959        /* flags options */
4960        else if (!strcmp(arg, "--binary")) {
4961                enable_patch_output(&options->output_format);
4962                options->flags.binary = 1;
4963        }
4964        else if (!strcmp(arg, "--full-index"))
4965                options->flags.full_index = 1;
4966        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
4967                options->flags.text = 1;
4968        else if (!strcmp(arg, "-R"))
4969                options->flags.reverse_diff = 1;
4970        else if (!strcmp(arg, "--find-copies-harder"))
4971                options->flags.find_copies_harder = 1;
4972        else if (!strcmp(arg, "--follow"))
4973                options->flags.follow_renames = 1;
4974        else if (!strcmp(arg, "--no-follow")) {
4975                options->flags.follow_renames = 0;
4976                options->flags.default_follow_renames = 0;
4977        } else if (skip_to_optional_arg_default(arg, "--color", &arg, "always")) {
4978                int value = git_config_colorbool(NULL, arg);
4979                if (value < 0)
4980                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
4981                options->use_color = value;
4982        }
4983        else if (!strcmp(arg, "--no-color"))
4984                options->use_color = 0;
4985        else if (!strcmp(arg, "--color-moved")) {
4986                if (diff_color_moved_default)
4987                        options->color_moved = diff_color_moved_default;
4988                if (options->color_moved == COLOR_MOVED_NO)
4989                        options->color_moved = COLOR_MOVED_DEFAULT;
4990        } else if (!strcmp(arg, "--no-color-moved"))
4991                options->color_moved = COLOR_MOVED_NO;
4992        else if (skip_prefix(arg, "--color-moved=", &arg)) {
4993                int cm = parse_color_moved(arg);
4994                if (cm < 0)
4995                        die("bad --color-moved argument: %s", arg);
4996                options->color_moved = cm;
4997        } else if (skip_prefix(arg, "--color-moved-ws=", &arg)) {
4998                options->color_moved_ws_handling = parse_color_moved_ws(arg);
4999        } else if (skip_to_optional_arg_default(arg, "--color-words", &options->word_regex, NULL)) {
5000                options->use_color = 1;
5001                options->word_diff = DIFF_WORDS_COLOR;
5002        }
5003        else if (!strcmp(arg, "--word-diff")) {
5004                if (options->word_diff == DIFF_WORDS_NONE)
5005                        options->word_diff = DIFF_WORDS_PLAIN;
5006        }
5007        else if (skip_prefix(arg, "--word-diff=", &arg)) {
5008                if (!strcmp(arg, "plain"))
5009                        options->word_diff = DIFF_WORDS_PLAIN;
5010                else if (!strcmp(arg, "color")) {
5011                        options->use_color = 1;
5012                        options->word_diff = DIFF_WORDS_COLOR;
5013                }
5014                else if (!strcmp(arg, "porcelain"))
5015                        options->word_diff = DIFF_WORDS_PORCELAIN;
5016                else if (!strcmp(arg, "none"))
5017                        options->word_diff = DIFF_WORDS_NONE;
5018                else
5019                        die("bad --word-diff argument: %s", arg);
5020        }
5021        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
5022                if (options->word_diff == DIFF_WORDS_NONE)
5023                        options->word_diff = DIFF_WORDS_PLAIN;
5024                options->word_regex = optarg;
5025                return argcount;
5026        }
5027        else if (!strcmp(arg, "--exit-code"))
5028                options->flags.exit_with_status = 1;
5029        else if (!strcmp(arg, "--quiet"))
5030                options->flags.quick = 1;
5031        else if (!strcmp(arg, "--ext-diff"))
5032                options->flags.allow_external = 1;
5033        else if (!strcmp(arg, "--no-ext-diff"))
5034                options->flags.allow_external = 0;
5035        else if (!strcmp(arg, "--textconv")) {
5036                options->flags.allow_textconv = 1;
5037                options->flags.textconv_set_via_cmdline = 1;
5038        } else if (!strcmp(arg, "--no-textconv"))
5039                options->flags.allow_textconv = 0;
5040        else if (skip_to_optional_arg_default(arg, "--ignore-submodules", &arg, "all")) {
5041                options->flags.override_submodule_config = 1;
5042                handle_ignore_submodules_arg(options, arg);
5043        } else if (skip_to_optional_arg_default(arg, "--submodule", &arg, "log"))
5044                return parse_submodule_opt(options, arg);
5045        else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
5046                return parse_ws_error_highlight_opt(options, arg);
5047        else if (!strcmp(arg, "--ita-invisible-in-index"))
5048                options->ita_invisible_in_index = 1;
5049        else if (!strcmp(arg, "--ita-visible-in-index"))
5050                options->ita_invisible_in_index = 0;
5051
5052        /* misc options */
5053        else if (!strcmp(arg, "-z"))
5054                options->line_termination = 0;
5055        else if ((argcount = short_opt('l', av, &optarg))) {
5056                options->rename_limit = strtoul(optarg, NULL, 10);
5057                return argcount;
5058        }
5059        else if ((argcount = short_opt('S', av, &optarg))) {
5060                options->pickaxe = optarg;
5061                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
5062                return argcount;
5063        } else if ((argcount = short_opt('G', av, &optarg))) {
5064                options->pickaxe = optarg;
5065                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
5066                return argcount;
5067        }
5068        else if (!strcmp(arg, "--pickaxe-all"))
5069                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
5070        else if (!strcmp(arg, "--pickaxe-regex"))
5071                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
5072        else if ((argcount = short_opt('O', av, &optarg))) {
5073                options->orderfile = prefix_filename(prefix, optarg);
5074                return argcount;
5075        } else if (skip_prefix(arg, "--find-object=", &arg))
5076                return parse_objfind_opt(options, arg);
5077        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
5078                int offending = parse_diff_filter_opt(optarg, options);
5079                if (offending)
5080                        die("unknown change class '%c' in --diff-filter=%s",
5081                            offending, optarg);
5082                return argcount;
5083        }
5084        else if (!strcmp(arg, "--no-abbrev"))
5085                options->abbrev = 0;
5086        else if (!strcmp(arg, "--abbrev"))
5087                options->abbrev = DEFAULT_ABBREV;
5088        else if (skip_prefix(arg, "--abbrev=", &arg)) {
5089                options->abbrev = strtoul(arg, NULL, 10);
5090                if (options->abbrev < MINIMUM_ABBREV)
5091                        options->abbrev = MINIMUM_ABBREV;
5092                else if (the_hash_algo->hexsz < options->abbrev)
5093                        options->abbrev = the_hash_algo->hexsz;
5094        }
5095        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
5096                options->a_prefix = optarg;
5097                return argcount;
5098        }
5099        else if ((argcount = parse_long_opt("line-prefix", av, &optarg))) {
5100                options->line_prefix = optarg;
5101                options->line_prefix_length = strlen(options->line_prefix);
5102                graph_setup_line_prefix(options);
5103                return argcount;
5104        }
5105        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
5106                options->b_prefix = optarg;
5107                return argcount;
5108        }
5109        else if (!strcmp(arg, "--no-prefix"))
5110                options->a_prefix = options->b_prefix = "";
5111        else if (opt_arg(arg, '\0', "inter-hunk-context",
5112                         &options->interhunkcontext))
5113                ;
5114        else if (!strcmp(arg, "-W"))
5115                options->flags.funccontext = 1;
5116        else if (!strcmp(arg, "--function-context"))
5117                options->flags.funccontext = 1;
5118        else if (!strcmp(arg, "--no-function-context"))
5119                options->flags.funccontext = 0;
5120        else if ((argcount = parse_long_opt("output", av, &optarg))) {
5121                char *path = prefix_filename(prefix, optarg);
5122                options->file = xfopen(path, "w");
5123                options->close_file = 1;
5124                if (options->use_color != GIT_COLOR_ALWAYS)
5125                        options->use_color = GIT_COLOR_NEVER;
5126                free(path);
5127                return argcount;
5128        } else
5129                return 0;
5130        return 1;
5131}
5132
5133int parse_rename_score(const char **cp_p)
5134{
5135        unsigned long num, scale;
5136        int ch, dot;
5137        const char *cp = *cp_p;
5138
5139        num = 0;
5140        scale = 1;
5141        dot = 0;
5142        for (;;) {
5143                ch = *cp;
5144                if ( !dot && ch == '.' ) {
5145                        scale = 1;
5146                        dot = 1;
5147                } else if ( ch == '%' ) {
5148                        scale = dot ? scale*100 : 100;
5149                        cp++;   /* % is always at the end */
5150                        break;
5151                } else if ( ch >= '0' && ch <= '9' ) {
5152                        if ( scale < 100000 ) {
5153                                scale *= 10;
5154                                num = (num*10) + (ch-'0');
5155                        }
5156                } else {
5157                        break;
5158                }
5159                cp++;
5160        }
5161        *cp_p = cp;
5162
5163        /* user says num divided by scale and we say internally that
5164         * is MAX_SCORE * num / scale.
5165         */
5166        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
5167}
5168
5169static int diff_scoreopt_parse(const char *opt)
5170{
5171        int opt1, opt2, cmd;
5172
5173        if (*opt++ != '-')
5174                return -1;
5175        cmd = *opt++;
5176        if (cmd == '-') {
5177                /* convert the long-form arguments into short-form versions */
5178                if (skip_prefix(opt, "break-rewrites", &opt)) {
5179                        if (*opt == 0 || *opt++ == '=')
5180                                cmd = 'B';
5181                } else if (skip_prefix(opt, "find-copies", &opt)) {
5182                        if (*opt == 0 || *opt++ == '=')
5183                                cmd = 'C';
5184                } else if (skip_prefix(opt, "find-renames", &opt)) {
5185                        if (*opt == 0 || *opt++ == '=')
5186                                cmd = 'M';
5187                }
5188        }
5189        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
5190                return -1; /* that is not a -M, -C, or -B option */
5191
5192        opt1 = parse_rename_score(&opt);
5193        if (cmd != 'B')
5194                opt2 = 0;
5195        else {
5196                if (*opt == 0)
5197                        opt2 = 0;
5198                else if (*opt != '/')
5199                        return -1; /* we expect -B80/99 or -B80 */
5200                else {
5201                        opt++;
5202                        opt2 = parse_rename_score(&opt);
5203                }
5204        }
5205        if (*opt != 0)
5206                return -1;
5207        return opt1 | (opt2 << 16);
5208}
5209
5210struct diff_queue_struct diff_queued_diff;
5211
5212void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
5213{
5214        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
5215        queue->queue[queue->nr++] = dp;
5216}
5217
5218struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
5219                                 struct diff_filespec *one,
5220                                 struct diff_filespec *two)
5221{
5222        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
5223        dp->one = one;
5224        dp->two = two;
5225        if (queue)
5226                diff_q(queue, dp);
5227        return dp;
5228}
5229
5230void diff_free_filepair(struct diff_filepair *p)
5231{
5232        free_filespec(p->one);
5233        free_filespec(p->two);
5234        free(p);
5235}
5236
5237const char *diff_aligned_abbrev(const struct object_id *oid, int len)
5238{
5239        int abblen;
5240        const char *abbrev;
5241
5242        /* Do we want all 40 hex characters? */
5243        if (len == the_hash_algo->hexsz)
5244                return oid_to_hex(oid);
5245
5246        /* An abbreviated value is fine, possibly followed by an ellipsis. */
5247        abbrev = diff_abbrev_oid(oid, len);
5248
5249        if (!print_sha1_ellipsis())
5250                return abbrev;
5251
5252        abblen = strlen(abbrev);
5253
5254        /*
5255         * In well-behaved cases, where the abbreviated result is the
5256         * same as the requested length, append three dots after the
5257         * abbreviation (hence the whole logic is limited to the case
5258         * where abblen < 37); when the actual abbreviated result is a
5259         * bit longer than the requested length, we reduce the number
5260         * of dots so that they match the well-behaved ones.  However,
5261         * if the actual abbreviation is longer than the requested
5262         * length by more than three, we give up on aligning, and add
5263         * three dots anyway, to indicate that the output is not the
5264         * full object name.  Yes, this may be suboptimal, but this
5265         * appears only in "diff --raw --abbrev" output and it is not
5266         * worth the effort to change it now.  Note that this would
5267         * likely to work fine when the automatic sizing of default
5268         * abbreviation length is used--we would be fed -1 in "len" in
5269         * that case, and will end up always appending three-dots, but
5270         * the automatic sizing is supposed to give abblen that ensures
5271         * uniqueness across all objects (statistically speaking).
5272         */
5273        if (abblen < the_hash_algo->hexsz - 3) {
5274                static char hex[GIT_MAX_HEXSZ + 1];
5275                if (len < abblen && abblen <= len + 2)
5276                        xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
5277                else
5278                        xsnprintf(hex, sizeof(hex), "%s...", abbrev);
5279                return hex;
5280        }
5281
5282        return oid_to_hex(oid);
5283}
5284
5285static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
5286{
5287        int line_termination = opt->line_termination;
5288        int inter_name_termination = line_termination ? '\t' : '\0';
5289
5290        fprintf(opt->file, "%s", diff_line_prefix(opt));
5291        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
5292                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
5293                        diff_aligned_abbrev(&p->one->oid, opt->abbrev));
5294                fprintf(opt->file, "%s ",
5295                        diff_aligned_abbrev(&p->two->oid, opt->abbrev));
5296        }
5297        if (p->score) {
5298                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
5299                        inter_name_termination);
5300        } else {
5301                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
5302        }
5303
5304        if (p->status == DIFF_STATUS_COPIED ||
5305            p->status == DIFF_STATUS_RENAMED) {
5306                const char *name_a, *name_b;
5307                name_a = p->one->path;
5308                name_b = p->two->path;
5309                strip_prefix(opt->prefix_length, &name_a, &name_b);
5310                write_name_quoted(name_a, opt->file, inter_name_termination);
5311                write_name_quoted(name_b, opt->file, line_termination);
5312        } else {
5313                const char *name_a, *name_b;
5314                name_a = p->one->mode ? p->one->path : p->two->path;
5315                name_b = NULL;
5316                strip_prefix(opt->prefix_length, &name_a, &name_b);
5317                write_name_quoted(name_a, opt->file, line_termination);
5318        }
5319}
5320
5321int diff_unmodified_pair(struct diff_filepair *p)
5322{
5323        /* This function is written stricter than necessary to support
5324         * the currently implemented transformers, but the idea is to
5325         * let transformers to produce diff_filepairs any way they want,
5326         * and filter and clean them up here before producing the output.
5327         */
5328        struct diff_filespec *one = p->one, *two = p->two;
5329
5330        if (DIFF_PAIR_UNMERGED(p))
5331                return 0; /* unmerged is interesting */
5332
5333        /* deletion, addition, mode or type change
5334         * and rename are all interesting.
5335         */
5336        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
5337            DIFF_PAIR_MODE_CHANGED(p) ||
5338            strcmp(one->path, two->path))
5339                return 0;
5340
5341        /* both are valid and point at the same path.  that is, we are
5342         * dealing with a change.
5343         */
5344        if (one->oid_valid && two->oid_valid &&
5345            oideq(&one->oid, &two->oid) &&
5346            !one->dirty_submodule && !two->dirty_submodule)
5347                return 1; /* no change */
5348        if (!one->oid_valid && !two->oid_valid)
5349                return 1; /* both look at the same file on the filesystem. */
5350        return 0;
5351}
5352
5353static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
5354{
5355        if (diff_unmodified_pair(p))
5356                return;
5357
5358        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5359            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5360                return; /* no tree diffs in patch format */
5361
5362        run_diff(p, o);
5363}
5364
5365static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
5366                            struct diffstat_t *diffstat)
5367{
5368        if (diff_unmodified_pair(p))
5369                return;
5370
5371        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5372            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5373                return; /* no useful stat for tree diffs */
5374
5375        run_diffstat(p, o, diffstat);
5376}
5377
5378static void diff_flush_checkdiff(struct diff_filepair *p,
5379                struct diff_options *o)
5380{
5381        if (diff_unmodified_pair(p))
5382                return;
5383
5384        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5385            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5386                return; /* nothing to check in tree diffs */
5387
5388        run_checkdiff(p, o);
5389}
5390
5391int diff_queue_is_empty(void)
5392{
5393        struct diff_queue_struct *q = &diff_queued_diff;
5394        int i;
5395        for (i = 0; i < q->nr; i++)
5396                if (!diff_unmodified_pair(q->queue[i]))
5397                        return 0;
5398        return 1;
5399}
5400
5401#if DIFF_DEBUG
5402void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
5403{
5404        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
5405                x, one ? one : "",
5406                s->path,
5407                DIFF_FILE_VALID(s) ? "valid" : "invalid",
5408                s->mode,
5409                s->oid_valid ? oid_to_hex(&s->oid) : "");
5410        fprintf(stderr, "queue[%d] %s size %lu\n",
5411                x, one ? one : "",
5412                s->size);
5413}
5414
5415void diff_debug_filepair(const struct diff_filepair *p, int i)
5416{
5417        diff_debug_filespec(p->one, i, "one");
5418        diff_debug_filespec(p->two, i, "two");
5419        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
5420                p->score, p->status ? p->status : '?',
5421                p->one->rename_used, p->broken_pair);
5422}
5423
5424void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
5425{
5426        int i;
5427        if (msg)
5428                fprintf(stderr, "%s\n", msg);
5429        fprintf(stderr, "q->nr = %d\n", q->nr);
5430        for (i = 0; i < q->nr; i++) {
5431                struct diff_filepair *p = q->queue[i];
5432                diff_debug_filepair(p, i);
5433        }
5434}
5435#endif
5436
5437static void diff_resolve_rename_copy(void)
5438{
5439        int i;
5440        struct diff_filepair *p;
5441        struct diff_queue_struct *q = &diff_queued_diff;
5442
5443        diff_debug_queue("resolve-rename-copy", q);
5444
5445        for (i = 0; i < q->nr; i++) {
5446                p = q->queue[i];
5447                p->status = 0; /* undecided */
5448                if (DIFF_PAIR_UNMERGED(p))
5449                        p->status = DIFF_STATUS_UNMERGED;
5450                else if (!DIFF_FILE_VALID(p->one))
5451                        p->status = DIFF_STATUS_ADDED;
5452                else if (!DIFF_FILE_VALID(p->two))
5453                        p->status = DIFF_STATUS_DELETED;
5454                else if (DIFF_PAIR_TYPE_CHANGED(p))
5455                        p->status = DIFF_STATUS_TYPE_CHANGED;
5456
5457                /* from this point on, we are dealing with a pair
5458                 * whose both sides are valid and of the same type, i.e.
5459                 * either in-place edit or rename/copy edit.
5460                 */
5461                else if (DIFF_PAIR_RENAME(p)) {
5462                        /*
5463                         * A rename might have re-connected a broken
5464                         * pair up, causing the pathnames to be the
5465                         * same again. If so, that's not a rename at
5466                         * all, just a modification..
5467                         *
5468                         * Otherwise, see if this source was used for
5469                         * multiple renames, in which case we decrement
5470                         * the count, and call it a copy.
5471                         */
5472                        if (!strcmp(p->one->path, p->two->path))
5473                                p->status = DIFF_STATUS_MODIFIED;
5474                        else if (--p->one->rename_used > 0)
5475                                p->status = DIFF_STATUS_COPIED;
5476                        else
5477                                p->status = DIFF_STATUS_RENAMED;
5478                }
5479                else if (!oideq(&p->one->oid, &p->two->oid) ||
5480                         p->one->mode != p->two->mode ||
5481                         p->one->dirty_submodule ||
5482                         p->two->dirty_submodule ||
5483                         is_null_oid(&p->one->oid))
5484                        p->status = DIFF_STATUS_MODIFIED;
5485                else {
5486                        /* This is a "no-change" entry and should not
5487                         * happen anymore, but prepare for broken callers.
5488                         */
5489                        error("feeding unmodified %s to diffcore",
5490                              p->one->path);
5491                        p->status = DIFF_STATUS_UNKNOWN;
5492                }
5493        }
5494        diff_debug_queue("resolve-rename-copy done", q);
5495}
5496
5497static int check_pair_status(struct diff_filepair *p)
5498{
5499        switch (p->status) {
5500        case DIFF_STATUS_UNKNOWN:
5501                return 0;
5502        case 0:
5503                die("internal error in diff-resolve-rename-copy");
5504        default:
5505                return 1;
5506        }
5507}
5508
5509static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
5510{
5511        int fmt = opt->output_format;
5512
5513        if (fmt & DIFF_FORMAT_CHECKDIFF)
5514                diff_flush_checkdiff(p, opt);
5515        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
5516                diff_flush_raw(p, opt);
5517        else if (fmt & DIFF_FORMAT_NAME) {
5518                const char *name_a, *name_b;
5519                name_a = p->two->path;
5520                name_b = NULL;
5521                strip_prefix(opt->prefix_length, &name_a, &name_b);
5522                fprintf(opt->file, "%s", diff_line_prefix(opt));
5523                write_name_quoted(name_a, opt->file, opt->line_termination);
5524        }
5525}
5526
5527static void show_file_mode_name(struct diff_options *opt, const char *newdelete, struct diff_filespec *fs)
5528{
5529        struct strbuf sb = STRBUF_INIT;
5530        if (fs->mode)
5531                strbuf_addf(&sb, " %s mode %06o ", newdelete, fs->mode);
5532        else
5533                strbuf_addf(&sb, " %s ", newdelete);
5534
5535        quote_c_style(fs->path, &sb, NULL, 0);
5536        strbuf_addch(&sb, '\n');
5537        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5538                         sb.buf, sb.len, 0);
5539        strbuf_release(&sb);
5540}
5541
5542static void show_mode_change(struct diff_options *opt, struct diff_filepair *p,
5543                int show_name)
5544{
5545        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
5546                struct strbuf sb = STRBUF_INIT;
5547                strbuf_addf(&sb, " mode change %06o => %06o",
5548                            p->one->mode, p->two->mode);
5549                if (show_name) {
5550                        strbuf_addch(&sb, ' ');
5551                        quote_c_style(p->two->path, &sb, NULL, 0);
5552                }
5553                strbuf_addch(&sb, '\n');
5554                emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5555                                 sb.buf, sb.len, 0);
5556                strbuf_release(&sb);
5557        }
5558}
5559
5560static void show_rename_copy(struct diff_options *opt, const char *renamecopy,
5561                struct diff_filepair *p)
5562{
5563        struct strbuf sb = STRBUF_INIT;
5564        struct strbuf names = STRBUF_INIT;
5565
5566        pprint_rename(&names, p->one->path, p->two->path);
5567        strbuf_addf(&sb, " %s %s (%d%%)\n",
5568                    renamecopy, names.buf, similarity_index(p));
5569        strbuf_release(&names);
5570        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5571                                 sb.buf, sb.len, 0);
5572        show_mode_change(opt, p, 0);
5573        strbuf_release(&sb);
5574}
5575
5576static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
5577{
5578        switch(p->status) {
5579        case DIFF_STATUS_DELETED:
5580                show_file_mode_name(opt, "delete", p->one);
5581                break;
5582        case DIFF_STATUS_ADDED:
5583                show_file_mode_name(opt, "create", p->two);
5584                break;
5585        case DIFF_STATUS_COPIED:
5586                show_rename_copy(opt, "copy", p);
5587                break;
5588        case DIFF_STATUS_RENAMED:
5589                show_rename_copy(opt, "rename", p);
5590                break;
5591        default:
5592                if (p->score) {
5593                        struct strbuf sb = STRBUF_INIT;
5594                        strbuf_addstr(&sb, " rewrite ");
5595                        quote_c_style(p->two->path, &sb, NULL, 0);
5596                        strbuf_addf(&sb, " (%d%%)\n", similarity_index(p));
5597                        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5598                                         sb.buf, sb.len, 0);
5599                        strbuf_release(&sb);
5600                }
5601                show_mode_change(opt, p, !p->score);
5602                break;
5603        }
5604}
5605
5606struct patch_id_t {
5607        git_SHA_CTX *ctx;
5608        int patchlen;
5609};
5610
5611static int remove_space(char *line, int len)
5612{
5613        int i;
5614        char *dst = line;
5615        unsigned char c;
5616
5617        for (i = 0; i < len; i++)
5618                if (!isspace((c = line[i])))
5619                        *dst++ = c;
5620
5621        return dst - line;
5622}
5623
5624static void patch_id_consume(void *priv, char *line, unsigned long len)
5625{
5626        struct patch_id_t *data = priv;
5627        int new_len;
5628
5629        /* Ignore line numbers when computing the SHA1 of the patch */
5630        if (starts_with(line, "@@ -"))
5631                return;
5632
5633        new_len = remove_space(line, len);
5634
5635        git_SHA1_Update(data->ctx, line, new_len);
5636        data->patchlen += new_len;
5637}
5638
5639static void patch_id_add_string(git_SHA_CTX *ctx, const char *str)
5640{
5641        git_SHA1_Update(ctx, str, strlen(str));
5642}
5643
5644static void patch_id_add_mode(git_SHA_CTX *ctx, unsigned mode)
5645{
5646        /* large enough for 2^32 in octal */
5647        char buf[12];
5648        int len = xsnprintf(buf, sizeof(buf), "%06o", mode);
5649        git_SHA1_Update(ctx, buf, len);
5650}
5651
5652/* returns 0 upon success, and writes result into sha1 */
5653static int diff_get_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5654{
5655        struct diff_queue_struct *q = &diff_queued_diff;
5656        int i;
5657        git_SHA_CTX ctx;
5658        struct patch_id_t data;
5659
5660        git_SHA1_Init(&ctx);
5661        memset(&data, 0, sizeof(struct patch_id_t));
5662        data.ctx = &ctx;
5663
5664        for (i = 0; i < q->nr; i++) {
5665                xpparam_t xpp;
5666                xdemitconf_t xecfg;
5667                mmfile_t mf1, mf2;
5668                struct diff_filepair *p = q->queue[i];
5669                int len1, len2;
5670
5671                memset(&xpp, 0, sizeof(xpp));
5672                memset(&xecfg, 0, sizeof(xecfg));
5673                if (p->status == 0)
5674                        return error("internal diff status error");
5675                if (p->status == DIFF_STATUS_UNKNOWN)
5676                        continue;
5677                if (diff_unmodified_pair(p))
5678                        continue;
5679                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5680                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5681                        continue;
5682                if (DIFF_PAIR_UNMERGED(p))
5683                        continue;
5684
5685                diff_fill_oid_info(p->one);
5686                diff_fill_oid_info(p->two);
5687
5688                len1 = remove_space(p->one->path, strlen(p->one->path));
5689                len2 = remove_space(p->two->path, strlen(p->two->path));
5690                patch_id_add_string(&ctx, "diff--git");
5691                patch_id_add_string(&ctx, "a/");
5692                git_SHA1_Update(&ctx, p->one->path, len1);
5693                patch_id_add_string(&ctx, "b/");
5694                git_SHA1_Update(&ctx, p->two->path, len2);
5695
5696                if (p->one->mode == 0) {
5697                        patch_id_add_string(&ctx, "newfilemode");
5698                        patch_id_add_mode(&ctx, p->two->mode);
5699                        patch_id_add_string(&ctx, "---/dev/null");
5700                        patch_id_add_string(&ctx, "+++b/");
5701                        git_SHA1_Update(&ctx, p->two->path, len2);
5702                } else if (p->two->mode == 0) {
5703                        patch_id_add_string(&ctx, "deletedfilemode");
5704                        patch_id_add_mode(&ctx, p->one->mode);
5705                        patch_id_add_string(&ctx, "---a/");
5706                        git_SHA1_Update(&ctx, p->one->path, len1);
5707                        patch_id_add_string(&ctx, "+++/dev/null");
5708                } else {
5709                        patch_id_add_string(&ctx, "---a/");
5710                        git_SHA1_Update(&ctx, p->one->path, len1);
5711                        patch_id_add_string(&ctx, "+++b/");
5712                        git_SHA1_Update(&ctx, p->two->path, len2);
5713                }
5714
5715                if (diff_header_only)
5716                        continue;
5717
5718                if (fill_mmfile(&mf1, p->one) < 0 ||
5719                    fill_mmfile(&mf2, p->two) < 0)
5720                        return error("unable to read files to diff");
5721
5722                if (diff_filespec_is_binary(p->one) ||
5723                    diff_filespec_is_binary(p->two)) {
5724                        git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
5725                                        GIT_SHA1_HEXSZ);
5726                        git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
5727                                        GIT_SHA1_HEXSZ);
5728                        continue;
5729                }
5730
5731                xpp.flags = 0;
5732                xecfg.ctxlen = 3;
5733                xecfg.flags = 0;
5734                if (xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
5735                                  &xpp, &xecfg))
5736                        return error("unable to generate patch-id diff for %s",
5737                                     p->one->path);
5738        }
5739
5740        git_SHA1_Final(oid->hash, &ctx);
5741        return 0;
5742}
5743
5744int diff_flush_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5745{
5746        struct diff_queue_struct *q = &diff_queued_diff;
5747        int i;
5748        int result = diff_get_patch_id(options, oid, diff_header_only);
5749
5750        for (i = 0; i < q->nr; i++)
5751                diff_free_filepair(q->queue[i]);
5752
5753        free(q->queue);
5754        DIFF_QUEUE_CLEAR(q);
5755
5756        return result;
5757}
5758
5759static int is_summary_empty(const struct diff_queue_struct *q)
5760{
5761        int i;
5762
5763        for (i = 0; i < q->nr; i++) {
5764                const struct diff_filepair *p = q->queue[i];
5765
5766                switch (p->status) {
5767                case DIFF_STATUS_DELETED:
5768                case DIFF_STATUS_ADDED:
5769                case DIFF_STATUS_COPIED:
5770                case DIFF_STATUS_RENAMED:
5771                        return 0;
5772                default:
5773                        if (p->score)
5774                                return 0;
5775                        if (p->one->mode && p->two->mode &&
5776                            p->one->mode != p->two->mode)
5777                                return 0;
5778                        break;
5779                }
5780        }
5781        return 1;
5782}
5783
5784static const char rename_limit_warning[] =
5785N_("inexact rename detection was skipped due to too many files.");
5786
5787static const char degrade_cc_to_c_warning[] =
5788N_("only found copies from modified paths due to too many files.");
5789
5790static const char rename_limit_advice[] =
5791N_("you may want to set your %s variable to at least "
5792   "%d and retry the command.");
5793
5794void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
5795{
5796        fflush(stdout);
5797        if (degraded_cc)
5798                warning(_(degrade_cc_to_c_warning));
5799        else if (needed)
5800                warning(_(rename_limit_warning));
5801        else
5802                return;
5803        if (0 < needed)
5804                warning(_(rename_limit_advice), varname, needed);
5805}
5806
5807static void diff_flush_patch_all_file_pairs(struct diff_options *o)
5808{
5809        int i;
5810        static struct emitted_diff_symbols esm = EMITTED_DIFF_SYMBOLS_INIT;
5811        struct diff_queue_struct *q = &diff_queued_diff;
5812
5813        if (WSEH_NEW & WS_RULE_MASK)
5814                BUG("WS rules bit mask overlaps with diff symbol flags");
5815
5816        if (o->color_moved)
5817                o->emitted_symbols = &esm;
5818
5819        for (i = 0; i < q->nr; i++) {
5820                struct diff_filepair *p = q->queue[i];
5821                if (check_pair_status(p))
5822                        diff_flush_patch(p, o);
5823        }
5824
5825        if (o->emitted_symbols) {
5826                if (o->color_moved) {
5827                        struct hashmap add_lines, del_lines;
5828
5829                        if (o->color_moved_ws_handling &
5830                            COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
5831                                o->color_moved_ws_handling |= XDF_IGNORE_WHITESPACE;
5832
5833                        hashmap_init(&del_lines, moved_entry_cmp, o, 0);
5834                        hashmap_init(&add_lines, moved_entry_cmp, o, 0);
5835
5836                        add_lines_to_move_detection(o, &add_lines, &del_lines);
5837                        mark_color_as_moved(o, &add_lines, &del_lines);
5838                        if (o->color_moved == COLOR_MOVED_ZEBRA_DIM)
5839                                dim_moved_lines(o);
5840
5841                        hashmap_free(&add_lines, 0);
5842                        hashmap_free(&del_lines, 0);
5843                }
5844
5845                for (i = 0; i < esm.nr; i++)
5846                        emit_diff_symbol_from_struct(o, &esm.buf[i]);
5847
5848                for (i = 0; i < esm.nr; i++)
5849                        free((void *)esm.buf[i].line);
5850        }
5851        esm.nr = 0;
5852}
5853
5854void diff_flush(struct diff_options *options)
5855{
5856        struct diff_queue_struct *q = &diff_queued_diff;
5857        int i, output_format = options->output_format;
5858        int separator = 0;
5859        int dirstat_by_line = 0;
5860
5861        /*
5862         * Order: raw, stat, summary, patch
5863         * or:    name/name-status/checkdiff (other bits clear)
5864         */
5865        if (!q->nr)
5866                goto free_queue;
5867
5868        if (output_format & (DIFF_FORMAT_RAW |
5869                             DIFF_FORMAT_NAME |
5870                             DIFF_FORMAT_NAME_STATUS |
5871                             DIFF_FORMAT_CHECKDIFF)) {
5872                for (i = 0; i < q->nr; i++) {
5873                        struct diff_filepair *p = q->queue[i];
5874                        if (check_pair_status(p))
5875                                flush_one_pair(p, options);
5876                }
5877                separator++;
5878        }
5879
5880        if (output_format & DIFF_FORMAT_DIRSTAT && options->flags.dirstat_by_line)
5881                dirstat_by_line = 1;
5882
5883        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
5884            dirstat_by_line) {
5885                struct diffstat_t diffstat;
5886
5887                memset(&diffstat, 0, sizeof(struct diffstat_t));
5888                for (i = 0; i < q->nr; i++) {
5889                        struct diff_filepair *p = q->queue[i];
5890                        if (check_pair_status(p))
5891                                diff_flush_stat(p, options, &diffstat);
5892                }
5893                if (output_format & DIFF_FORMAT_NUMSTAT)
5894                        show_numstat(&diffstat, options);
5895                if (output_format & DIFF_FORMAT_DIFFSTAT)
5896                        show_stats(&diffstat, options);
5897                if (output_format & DIFF_FORMAT_SHORTSTAT)
5898                        show_shortstats(&diffstat, options);
5899                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
5900                        show_dirstat_by_line(&diffstat, options);
5901                free_diffstat_info(&diffstat);
5902                separator++;
5903        }
5904        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
5905                show_dirstat(options);
5906
5907        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
5908                for (i = 0; i < q->nr; i++) {
5909                        diff_summary(options, q->queue[i]);
5910                }
5911                separator++;
5912        }
5913
5914        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
5915            options->flags.exit_with_status &&
5916            options->flags.diff_from_contents) {
5917                /*
5918                 * run diff_flush_patch for the exit status. setting
5919                 * options->file to /dev/null should be safe, because we
5920                 * aren't supposed to produce any output anyway.
5921                 */
5922                if (options->close_file)
5923                        fclose(options->file);
5924                options->file = xfopen("/dev/null", "w");
5925                options->close_file = 1;
5926                options->color_moved = 0;
5927                for (i = 0; i < q->nr; i++) {
5928                        struct diff_filepair *p = q->queue[i];
5929                        if (check_pair_status(p))
5930                                diff_flush_patch(p, options);
5931                        if (options->found_changes)
5932                                break;
5933                }
5934        }
5935
5936        if (output_format & DIFF_FORMAT_PATCH) {
5937                if (separator) {
5938                        emit_diff_symbol(options, DIFF_SYMBOL_SEPARATOR, NULL, 0, 0);
5939                        if (options->stat_sep)
5940                                /* attach patch instead of inline */
5941                                emit_diff_symbol(options, DIFF_SYMBOL_STAT_SEP,
5942                                                 NULL, 0, 0);
5943                }
5944
5945                diff_flush_patch_all_file_pairs(options);
5946        }
5947
5948        if (output_format & DIFF_FORMAT_CALLBACK)
5949                options->format_callback(q, options, options->format_callback_data);
5950
5951        for (i = 0; i < q->nr; i++)
5952                diff_free_filepair(q->queue[i]);
5953free_queue:
5954        free(q->queue);
5955        DIFF_QUEUE_CLEAR(q);
5956        if (options->close_file)
5957                fclose(options->file);
5958
5959        /*
5960         * Report the content-level differences with HAS_CHANGES;
5961         * diff_addremove/diff_change does not set the bit when
5962         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
5963         */
5964        if (options->flags.diff_from_contents) {
5965                if (options->found_changes)
5966                        options->flags.has_changes = 1;
5967                else
5968                        options->flags.has_changes = 0;
5969        }
5970}
5971
5972static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
5973{
5974        return (((p->status == DIFF_STATUS_MODIFIED) &&
5975                 ((p->score &&
5976                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
5977                  (!p->score &&
5978                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
5979                ((p->status != DIFF_STATUS_MODIFIED) &&
5980                 filter_bit_tst(p->status, options)));
5981}
5982
5983static void diffcore_apply_filter(struct diff_options *options)
5984{
5985        int i;
5986        struct diff_queue_struct *q = &diff_queued_diff;
5987        struct diff_queue_struct outq;
5988
5989        DIFF_QUEUE_CLEAR(&outq);
5990
5991        if (!options->filter)
5992                return;
5993
5994        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
5995                int found;
5996                for (i = found = 0; !found && i < q->nr; i++) {
5997                        if (match_filter(options, q->queue[i]))
5998                                found++;
5999                }
6000                if (found)
6001                        return;
6002
6003                /* otherwise we will clear the whole queue
6004                 * by copying the empty outq at the end of this
6005                 * function, but first clear the current entries
6006                 * in the queue.
6007                 */
6008                for (i = 0; i < q->nr; i++)
6009                        diff_free_filepair(q->queue[i]);
6010        }
6011        else {
6012                /* Only the matching ones */
6013                for (i = 0; i < q->nr; i++) {
6014                        struct diff_filepair *p = q->queue[i];
6015                        if (match_filter(options, p))
6016                                diff_q(&outq, p);
6017                        else
6018                                diff_free_filepair(p);
6019                }
6020        }
6021        free(q->queue);
6022        *q = outq;
6023}
6024
6025/* Check whether two filespecs with the same mode and size are identical */
6026static int diff_filespec_is_identical(struct diff_filespec *one,
6027                                      struct diff_filespec *two)
6028{
6029        if (S_ISGITLINK(one->mode))
6030                return 0;
6031        if (diff_populate_filespec(one, 0))
6032                return 0;
6033        if (diff_populate_filespec(two, 0))
6034                return 0;
6035        return !memcmp(one->data, two->data, one->size);
6036}
6037
6038static int diff_filespec_check_stat_unmatch(struct diff_filepair *p)
6039{
6040        if (p->done_skip_stat_unmatch)
6041                return p->skip_stat_unmatch_result;
6042
6043        p->done_skip_stat_unmatch = 1;
6044        p->skip_stat_unmatch_result = 0;
6045        /*
6046         * 1. Entries that come from stat info dirtiness
6047         *    always have both sides (iow, not create/delete),
6048         *    one side of the object name is unknown, with
6049         *    the same mode and size.  Keep the ones that
6050         *    do not match these criteria.  They have real
6051         *    differences.
6052         *
6053         * 2. At this point, the file is known to be modified,
6054         *    with the same mode and size, and the object
6055         *    name of one side is unknown.  Need to inspect
6056         *    the identical contents.
6057         */
6058        if (!DIFF_FILE_VALID(p->one) || /* (1) */
6059            !DIFF_FILE_VALID(p->two) ||
6060            (p->one->oid_valid && p->two->oid_valid) ||
6061            (p->one->mode != p->two->mode) ||
6062            diff_populate_filespec(p->one, CHECK_SIZE_ONLY) ||
6063            diff_populate_filespec(p->two, CHECK_SIZE_ONLY) ||
6064            (p->one->size != p->two->size) ||
6065            !diff_filespec_is_identical(p->one, p->two)) /* (2) */
6066                p->skip_stat_unmatch_result = 1;
6067        return p->skip_stat_unmatch_result;
6068}
6069
6070static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
6071{
6072        int i;
6073        struct diff_queue_struct *q = &diff_queued_diff;
6074        struct diff_queue_struct outq;
6075        DIFF_QUEUE_CLEAR(&outq);
6076
6077        for (i = 0; i < q->nr; i++) {
6078                struct diff_filepair *p = q->queue[i];
6079
6080                if (diff_filespec_check_stat_unmatch(p))
6081                        diff_q(&outq, p);
6082                else {
6083                        /*
6084                         * The caller can subtract 1 from skip_stat_unmatch
6085                         * to determine how many paths were dirty only
6086                         * due to stat info mismatch.
6087                         */
6088                        if (!diffopt->flags.no_index)
6089                                diffopt->skip_stat_unmatch++;
6090                        diff_free_filepair(p);
6091                }
6092        }
6093        free(q->queue);
6094        *q = outq;
6095}
6096
6097static int diffnamecmp(const void *a_, const void *b_)
6098{
6099        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
6100        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
6101        const char *name_a, *name_b;
6102
6103        name_a = a->one ? a->one->path : a->two->path;
6104        name_b = b->one ? b->one->path : b->two->path;
6105        return strcmp(name_a, name_b);
6106}
6107
6108void diffcore_fix_diff_index(struct diff_options *options)
6109{
6110        struct diff_queue_struct *q = &diff_queued_diff;
6111        QSORT(q->queue, q->nr, diffnamecmp);
6112}
6113
6114void diffcore_std(struct diff_options *options)
6115{
6116        /* NOTE please keep the following in sync with diff_tree_combined() */
6117        if (options->skip_stat_unmatch)
6118                diffcore_skip_stat_unmatch(options);
6119        if (!options->found_follow) {
6120                /* See try_to_follow_renames() in tree-diff.c */
6121                if (options->break_opt != -1)
6122                        diffcore_break(options->break_opt);
6123                if (options->detect_rename)
6124                        diffcore_rename(options);
6125                if (options->break_opt != -1)
6126                        diffcore_merge_broken();
6127        }
6128        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
6129                diffcore_pickaxe(options);
6130        if (options->orderfile)
6131                diffcore_order(options->orderfile);
6132        if (!options->found_follow)
6133                /* See try_to_follow_renames() in tree-diff.c */
6134                diff_resolve_rename_copy();
6135        diffcore_apply_filter(options);
6136
6137        if (diff_queued_diff.nr && !options->flags.diff_from_contents)
6138                options->flags.has_changes = 1;
6139        else
6140                options->flags.has_changes = 0;
6141
6142        options->found_follow = 0;
6143}
6144
6145int diff_result_code(struct diff_options *opt, int status)
6146{
6147        int result = 0;
6148
6149        diff_warn_rename_limit("diff.renameLimit",
6150                               opt->needed_rename_limit,
6151                               opt->degraded_cc_to_c);
6152        if (!opt->flags.exit_with_status &&
6153            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
6154                return status;
6155        if (opt->flags.exit_with_status &&
6156            opt->flags.has_changes)
6157                result |= 01;
6158        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
6159            opt->flags.check_failed)
6160                result |= 02;
6161        return result;
6162}
6163
6164int diff_can_quit_early(struct diff_options *opt)
6165{
6166        return (opt->flags.quick &&
6167                !opt->filter &&
6168                opt->flags.has_changes);
6169}
6170
6171/*
6172 * Shall changes to this submodule be ignored?
6173 *
6174 * Submodule changes can be configured to be ignored separately for each path,
6175 * but that configuration can be overridden from the command line.
6176 */
6177static int is_submodule_ignored(const char *path, struct diff_options *options)
6178{
6179        int ignored = 0;
6180        struct diff_flags orig_flags = options->flags;
6181        if (!options->flags.override_submodule_config)
6182                set_diffopt_flags_from_submodule_config(options, path);
6183        if (options->flags.ignore_submodules)
6184                ignored = 1;
6185        options->flags = orig_flags;
6186        return ignored;
6187}
6188
6189void diff_addremove(struct diff_options *options,
6190                    int addremove, unsigned mode,
6191                    const struct object_id *oid,
6192                    int oid_valid,
6193                    const char *concatpath, unsigned dirty_submodule)
6194{
6195        struct diff_filespec *one, *two;
6196
6197        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
6198                return;
6199
6200        /* This may look odd, but it is a preparation for
6201         * feeding "there are unchanged files which should
6202         * not produce diffs, but when you are doing copy
6203         * detection you would need them, so here they are"
6204         * entries to the diff-core.  They will be prefixed
6205         * with something like '=' or '*' (I haven't decided
6206         * which but should not make any difference).
6207         * Feeding the same new and old to diff_change()
6208         * also has the same effect.
6209         * Before the final output happens, they are pruned after
6210         * merged into rename/copy pairs as appropriate.
6211         */
6212        if (options->flags.reverse_diff)
6213                addremove = (addremove == '+' ? '-' :
6214                             addremove == '-' ? '+' : addremove);
6215
6216        if (options->prefix &&
6217            strncmp(concatpath, options->prefix, options->prefix_length))
6218                return;
6219
6220        one = alloc_filespec(concatpath);
6221        two = alloc_filespec(concatpath);
6222
6223        if (addremove != '+')
6224                fill_filespec(one, oid, oid_valid, mode);
6225        if (addremove != '-') {
6226                fill_filespec(two, oid, oid_valid, mode);
6227                two->dirty_submodule = dirty_submodule;
6228        }
6229
6230        diff_queue(&diff_queued_diff, one, two);
6231        if (!options->flags.diff_from_contents)
6232                options->flags.has_changes = 1;
6233}
6234
6235void diff_change(struct diff_options *options,
6236                 unsigned old_mode, unsigned new_mode,
6237                 const struct object_id *old_oid,
6238                 const struct object_id *new_oid,
6239                 int old_oid_valid, int new_oid_valid,
6240                 const char *concatpath,
6241                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
6242{
6243        struct diff_filespec *one, *two;
6244        struct diff_filepair *p;
6245
6246        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
6247            is_submodule_ignored(concatpath, options))
6248                return;
6249
6250        if (options->flags.reverse_diff) {
6251                SWAP(old_mode, new_mode);
6252                SWAP(old_oid, new_oid);
6253                SWAP(old_oid_valid, new_oid_valid);
6254                SWAP(old_dirty_submodule, new_dirty_submodule);
6255        }
6256
6257        if (options->prefix &&
6258            strncmp(concatpath, options->prefix, options->prefix_length))
6259                return;
6260
6261        one = alloc_filespec(concatpath);
6262        two = alloc_filespec(concatpath);
6263        fill_filespec(one, old_oid, old_oid_valid, old_mode);
6264        fill_filespec(two, new_oid, new_oid_valid, new_mode);
6265        one->dirty_submodule = old_dirty_submodule;
6266        two->dirty_submodule = new_dirty_submodule;
6267        p = diff_queue(&diff_queued_diff, one, two);
6268
6269        if (options->flags.diff_from_contents)
6270                return;
6271
6272        if (options->flags.quick && options->skip_stat_unmatch &&
6273            !diff_filespec_check_stat_unmatch(p))
6274                return;
6275
6276        options->flags.has_changes = 1;
6277}
6278
6279struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
6280{
6281        struct diff_filepair *pair;
6282        struct diff_filespec *one, *two;
6283
6284        if (options->prefix &&
6285            strncmp(path, options->prefix, options->prefix_length))
6286                return NULL;
6287
6288        one = alloc_filespec(path);
6289        two = alloc_filespec(path);
6290        pair = diff_queue(&diff_queued_diff, one, two);
6291        pair->is_unmerged = 1;
6292        return pair;
6293}
6294
6295static char *run_textconv(const char *pgm, struct diff_filespec *spec,
6296                size_t *outsize)
6297{
6298        struct diff_tempfile *temp;
6299        const char *argv[3];
6300        const char **arg = argv;
6301        struct child_process child = CHILD_PROCESS_INIT;
6302        struct strbuf buf = STRBUF_INIT;
6303        int err = 0;
6304
6305        temp = prepare_temp_file(spec->path, spec);
6306        *arg++ = pgm;
6307        *arg++ = temp->name;
6308        *arg = NULL;
6309
6310        child.use_shell = 1;
6311        child.argv = argv;
6312        child.out = -1;
6313        if (start_command(&child)) {
6314                remove_tempfile();
6315                return NULL;
6316        }
6317
6318        if (strbuf_read(&buf, child.out, 0) < 0)
6319                err = error("error reading from textconv command '%s'", pgm);
6320        close(child.out);
6321
6322        if (finish_command(&child) || err) {
6323                strbuf_release(&buf);
6324                remove_tempfile();
6325                return NULL;
6326        }
6327        remove_tempfile();
6328
6329        return strbuf_detach(&buf, outsize);
6330}
6331
6332size_t fill_textconv(struct userdiff_driver *driver,
6333                     struct diff_filespec *df,
6334                     char **outbuf)
6335{
6336        size_t size;
6337
6338        if (!driver) {
6339                if (!DIFF_FILE_VALID(df)) {
6340                        *outbuf = "";
6341                        return 0;
6342                }
6343                if (diff_populate_filespec(df, 0))
6344                        die("unable to read files to diff");
6345                *outbuf = df->data;
6346                return df->size;
6347        }
6348
6349        if (!driver->textconv)
6350                BUG("fill_textconv called with non-textconv driver");
6351
6352        if (driver->textconv_cache && df->oid_valid) {
6353                *outbuf = notes_cache_get(driver->textconv_cache,
6354                                          &df->oid,
6355                                          &size);
6356                if (*outbuf)
6357                        return size;
6358        }
6359
6360        *outbuf = run_textconv(driver->textconv, df, &size);
6361        if (!*outbuf)
6362                die("unable to read files to diff");
6363
6364        if (driver->textconv_cache && df->oid_valid) {
6365                /* ignore errors, as we might be in a readonly repository */
6366                notes_cache_put(driver->textconv_cache, &df->oid, *outbuf,
6367                                size);
6368                /*
6369                 * we could save up changes and flush them all at the end,
6370                 * but we would need an extra call after all diffing is done.
6371                 * Since generating a cache entry is the slow path anyway,
6372                 * this extra overhead probably isn't a big deal.
6373                 */
6374                notes_cache_write(driver->textconv_cache);
6375        }
6376
6377        return size;
6378}
6379
6380int textconv_object(const char *path,
6381                    unsigned mode,
6382                    const struct object_id *oid,
6383                    int oid_valid,
6384                    char **buf,
6385                    unsigned long *buf_size)
6386{
6387        struct diff_filespec *df;
6388        struct userdiff_driver *textconv;
6389
6390        df = alloc_filespec(path);
6391        fill_filespec(df, oid, oid_valid, mode);
6392        textconv = get_textconv(df);
6393        if (!textconv) {
6394                free_filespec(df);
6395                return 0;
6396        }
6397
6398        *buf_size = fill_textconv(textconv, df, buf);
6399        free_filespec(df);
6400        return 1;
6401}
6402
6403void setup_diff_pager(struct diff_options *opt)
6404{
6405        /*
6406         * If the user asked for our exit code, then either they want --quiet
6407         * or --exit-code. We should definitely not bother with a pager in the
6408         * former case, as we will generate no output. Since we still properly
6409         * report our exit code even when a pager is run, we _could_ run a
6410         * pager with --exit-code. But since we have not done so historically,
6411         * and because it is easy to find people oneline advising "git diff
6412         * --exit-code" in hooks and other scripts, we do not do so.
6413         */
6414        if (!opt->flags.exit_with_status &&
6415            check_pager_config("diff") != 0)
6416                setup_pager();
6417}