diff.con commit Merge branch 'jk/dev-build-format-security' (2bdbe4a)
   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                        if (pmb[i]->wsd) {
 985                                free(pmb[i]->wsd->string);
 986                                FREE_AND_NULL(pmb[i]->wsd);
 987                        }
 988                        pmb[i] = NULL;
 989                }
 990        }
 991}
 992
 993static int shrink_potential_moved_blocks(struct moved_entry **pmb,
 994                                         int pmb_nr)
 995{
 996        int lp, rp;
 997
 998        /* Shrink the set of potential block to the remaining running */
 999        for (lp = 0, rp = pmb_nr - 1; lp <= rp;) {
1000                while (lp < pmb_nr && pmb[lp])
1001                        lp++;
1002                /* lp points at the first NULL now */
1003
1004                while (rp > -1 && !pmb[rp])
1005                        rp--;
1006                /* rp points at the last non-NULL */
1007
1008                if (lp < pmb_nr && rp > -1 && lp < rp) {
1009                        pmb[lp] = pmb[rp];
1010                        pmb[rp] = NULL;
1011                        rp--;
1012                        lp++;
1013                }
1014        }
1015
1016        /* Remember the number of running sets */
1017        return rp + 1;
1018}
1019
1020/*
1021 * If o->color_moved is COLOR_MOVED_PLAIN, this function does nothing.
1022 *
1023 * Otherwise, if the last block has fewer alphanumeric characters than
1024 * COLOR_MOVED_MIN_ALNUM_COUNT, unset DIFF_SYMBOL_MOVED_LINE on all lines in
1025 * that block.
1026 *
1027 * The last block consists of the (n - block_length)'th line up to but not
1028 * including the nth line.
1029 *
1030 * NEEDSWORK: This uses the same heuristic as blame_entry_score() in blame.c.
1031 * Think of a way to unify them.
1032 */
1033static void adjust_last_block(struct diff_options *o, int n, int block_length)
1034{
1035        int i, alnum_count = 0;
1036        if (o->color_moved == COLOR_MOVED_PLAIN)
1037                return;
1038        for (i = 1; i < block_length + 1; i++) {
1039                const char *c = o->emitted_symbols->buf[n - i].line;
1040                for (; *c; c++) {
1041                        if (!isalnum(*c))
1042                                continue;
1043                        alnum_count++;
1044                        if (alnum_count >= COLOR_MOVED_MIN_ALNUM_COUNT)
1045                                return;
1046                }
1047        }
1048        for (i = 1; i < block_length + 1; i++)
1049                o->emitted_symbols->buf[n - i].flags &= ~DIFF_SYMBOL_MOVED_LINE;
1050}
1051
1052/* Find blocks of moved code, delegate actual coloring decision to helper */
1053static void mark_color_as_moved(struct diff_options *o,
1054                                struct hashmap *add_lines,
1055                                struct hashmap *del_lines)
1056{
1057        struct moved_entry **pmb = NULL; /* potentially moved blocks */
1058        int pmb_nr = 0, pmb_alloc = 0;
1059        int n, flipped_block = 1, block_length = 0;
1060
1061
1062        for (n = 0; n < o->emitted_symbols->nr; n++) {
1063                struct hashmap *hm = NULL;
1064                struct moved_entry *key;
1065                struct moved_entry *match = NULL;
1066                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
1067
1068                switch (l->s) {
1069                case DIFF_SYMBOL_PLUS:
1070                        hm = del_lines;
1071                        key = prepare_entry(o, n);
1072                        match = hashmap_get(hm, key, NULL);
1073                        free(key);
1074                        break;
1075                case DIFF_SYMBOL_MINUS:
1076                        hm = add_lines;
1077                        key = prepare_entry(o, n);
1078                        match = hashmap_get(hm, key, NULL);
1079                        free(key);
1080                        break;
1081                default:
1082                        flipped_block = 1;
1083                }
1084
1085                if (!match) {
1086                        adjust_last_block(o, n, block_length);
1087                        pmb_nr = 0;
1088                        block_length = 0;
1089                        continue;
1090                }
1091
1092                l->flags |= DIFF_SYMBOL_MOVED_LINE;
1093
1094                if (o->color_moved == COLOR_MOVED_PLAIN)
1095                        continue;
1096
1097                if (o->color_moved_ws_handling &
1098                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
1099                        pmb_advance_or_null_multi_match(o, match, hm, pmb, pmb_nr, n);
1100                else
1101                        pmb_advance_or_null(o, match, hm, pmb, pmb_nr);
1102
1103                pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
1104
1105                if (pmb_nr == 0) {
1106                        /*
1107                         * The current line is the start of a new block.
1108                         * Setup the set of potential blocks.
1109                         */
1110                        for (; match; match = hashmap_get_next(hm, match)) {
1111                                ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
1112                                if (o->color_moved_ws_handling &
1113                                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) {
1114                                        struct ws_delta *wsd = xmalloc(sizeof(*match->wsd));
1115                                        if (compute_ws_delta(l, match->es, wsd)) {
1116                                                match->wsd = wsd;
1117                                                pmb[pmb_nr++] = match;
1118                                        } else
1119                                                free(wsd);
1120                                } else {
1121                                        pmb[pmb_nr++] = match;
1122                                }
1123                        }
1124
1125                        flipped_block = (flipped_block + 1) % 2;
1126
1127                        adjust_last_block(o, n, block_length);
1128                        block_length = 0;
1129                }
1130
1131                block_length++;
1132
1133                if (flipped_block && o->color_moved != COLOR_MOVED_BLOCKS)
1134                        l->flags |= DIFF_SYMBOL_MOVED_LINE_ALT;
1135        }
1136        adjust_last_block(o, n, block_length);
1137
1138        free(pmb);
1139}
1140
1141#define DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK \
1142  (DIFF_SYMBOL_MOVED_LINE | DIFF_SYMBOL_MOVED_LINE_ALT)
1143static void dim_moved_lines(struct diff_options *o)
1144{
1145        int n;
1146        for (n = 0; n < o->emitted_symbols->nr; n++) {
1147                struct emitted_diff_symbol *prev = (n != 0) ?
1148                                &o->emitted_symbols->buf[n - 1] : NULL;
1149                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
1150                struct emitted_diff_symbol *next =
1151                                (n < o->emitted_symbols->nr - 1) ?
1152                                &o->emitted_symbols->buf[n + 1] : NULL;
1153
1154                /* Not a plus or minus line? */
1155                if (l->s != DIFF_SYMBOL_PLUS && l->s != DIFF_SYMBOL_MINUS)
1156                        continue;
1157
1158                /* Not a moved line? */
1159                if (!(l->flags & DIFF_SYMBOL_MOVED_LINE))
1160                        continue;
1161
1162                /*
1163                 * If prev or next are not a plus or minus line,
1164                 * pretend they don't exist
1165                 */
1166                if (prev && prev->s != DIFF_SYMBOL_PLUS &&
1167                            prev->s != DIFF_SYMBOL_MINUS)
1168                        prev = NULL;
1169                if (next && next->s != DIFF_SYMBOL_PLUS &&
1170                            next->s != DIFF_SYMBOL_MINUS)
1171                        next = NULL;
1172
1173                /* Inside a block? */
1174                if ((prev &&
1175                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
1176                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK)) &&
1177                    (next &&
1178                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
1179                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK))) {
1180                        l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1181                        continue;
1182                }
1183
1184                /* Check if we are at an interesting bound: */
1185                if (prev && (prev->flags & DIFF_SYMBOL_MOVED_LINE) &&
1186                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1187                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1188                        continue;
1189                if (next && (next->flags & DIFF_SYMBOL_MOVED_LINE) &&
1190                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1191                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1192                        continue;
1193
1194                /*
1195                 * The boundary to prev and next are not interesting,
1196                 * so this line is not interesting as a whole
1197                 */
1198                l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1199        }
1200}
1201
1202static void emit_line_ws_markup(struct diff_options *o,
1203                                const char *set_sign, const char *set,
1204                                const char *reset,
1205                                char sign, const char *line, int len,
1206                                unsigned ws_rule, int blank_at_eof)
1207{
1208        const char *ws = NULL;
1209
1210        if (o->ws_error_highlight & ws_rule) {
1211                ws = diff_get_color_opt(o, DIFF_WHITESPACE);
1212                if (!*ws)
1213                        ws = NULL;
1214        }
1215
1216        if (!ws && !set_sign)
1217                emit_line_0(o, set, NULL, 0, reset, sign, line, len);
1218        else if (!ws) {
1219                emit_line_0(o, set_sign, set, !!set_sign, reset, sign, line, len);
1220        } else if (blank_at_eof)
1221                /* Blank line at EOF - paint '+' as well */
1222                emit_line_0(o, ws, NULL, 0, reset, sign, line, len);
1223        else {
1224                /* Emit just the prefix, then the rest. */
1225                emit_line_0(o, set_sign ? set_sign : set, NULL, !!set_sign, reset,
1226                            sign, "", 0);
1227                ws_check_emit(line, len, ws_rule,
1228                              o->file, set, reset, ws);
1229        }
1230}
1231
1232static void emit_diff_symbol_from_struct(struct diff_options *o,
1233                                         struct emitted_diff_symbol *eds)
1234{
1235        static const char *nneof = " No newline at end of file\n";
1236        const char *context, *reset, *set, *set_sign, *meta, *fraginfo;
1237        struct strbuf sb = STRBUF_INIT;
1238
1239        enum diff_symbol s = eds->s;
1240        const char *line = eds->line;
1241        int len = eds->len;
1242        unsigned flags = eds->flags;
1243
1244        switch (s) {
1245        case DIFF_SYMBOL_NO_LF_EOF:
1246                context = diff_get_color_opt(o, DIFF_CONTEXT);
1247                reset = diff_get_color_opt(o, DIFF_RESET);
1248                putc('\n', o->file);
1249                emit_line_0(o, context, NULL, 0, reset, '\\',
1250                            nneof, strlen(nneof));
1251                break;
1252        case DIFF_SYMBOL_SUBMODULE_HEADER:
1253        case DIFF_SYMBOL_SUBMODULE_ERROR:
1254        case DIFF_SYMBOL_SUBMODULE_PIPETHROUGH:
1255        case DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES:
1256        case DIFF_SYMBOL_SUMMARY:
1257        case DIFF_SYMBOL_STATS_LINE:
1258        case DIFF_SYMBOL_BINARY_DIFF_BODY:
1259        case DIFF_SYMBOL_CONTEXT_FRAGINFO:
1260                emit_line(o, "", "", line, len);
1261                break;
1262        case DIFF_SYMBOL_CONTEXT_INCOMPLETE:
1263        case DIFF_SYMBOL_CONTEXT_MARKER:
1264                context = diff_get_color_opt(o, DIFF_CONTEXT);
1265                reset = diff_get_color_opt(o, DIFF_RESET);
1266                emit_line(o, context, reset, line, len);
1267                break;
1268        case DIFF_SYMBOL_SEPARATOR:
1269                fprintf(o->file, "%s%c",
1270                        diff_line_prefix(o),
1271                        o->line_termination);
1272                break;
1273        case DIFF_SYMBOL_CONTEXT:
1274                set = diff_get_color_opt(o, DIFF_CONTEXT);
1275                reset = diff_get_color_opt(o, DIFF_RESET);
1276                set_sign = NULL;
1277                if (o->flags.dual_color_diffed_diffs) {
1278                        char c = !len ? 0 : line[0];
1279
1280                        if (c == '+')
1281                                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1282                        else if (c == '@')
1283                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1284                        else if (c == '-')
1285                                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1286                }
1287                emit_line_ws_markup(o, set_sign, set, reset,
1288                                    o->output_indicators[OUTPUT_INDICATOR_CONTEXT],
1289                                    line, len,
1290                                    flags & (DIFF_SYMBOL_CONTENT_WS_MASK), 0);
1291                break;
1292        case DIFF_SYMBOL_PLUS:
1293                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1294                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1295                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1296                case DIFF_SYMBOL_MOVED_LINE |
1297                     DIFF_SYMBOL_MOVED_LINE_ALT |
1298                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1299                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT_DIM);
1300                        break;
1301                case DIFF_SYMBOL_MOVED_LINE |
1302                     DIFF_SYMBOL_MOVED_LINE_ALT:
1303                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT);
1304                        break;
1305                case DIFF_SYMBOL_MOVED_LINE |
1306                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1307                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_DIM);
1308                        break;
1309                case DIFF_SYMBOL_MOVED_LINE:
1310                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED);
1311                        break;
1312                default:
1313                        set = diff_get_color_opt(o, DIFF_FILE_NEW);
1314                }
1315                reset = diff_get_color_opt(o, DIFF_RESET);
1316                if (!o->flags.dual_color_diffed_diffs)
1317                        set_sign = NULL;
1318                else {
1319                        char c = !len ? 0 : line[0];
1320
1321                        set_sign = set;
1322                        if (c == '-')
1323                                set = diff_get_color_opt(o, DIFF_FILE_OLD_BOLD);
1324                        else if (c == '@')
1325                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1326                        else if (c == '+')
1327                                set = diff_get_color_opt(o, DIFF_FILE_NEW_BOLD);
1328                        else
1329                                set = diff_get_color_opt(o, DIFF_CONTEXT_BOLD);
1330                        flags &= ~DIFF_SYMBOL_CONTENT_WS_MASK;
1331                }
1332                emit_line_ws_markup(o, set_sign, set, reset,
1333                                    o->output_indicators[OUTPUT_INDICATOR_NEW],
1334                                    line, len,
1335                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK,
1336                                    flags & DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF);
1337                break;
1338        case DIFF_SYMBOL_MINUS:
1339                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1340                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1341                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1342                case DIFF_SYMBOL_MOVED_LINE |
1343                     DIFF_SYMBOL_MOVED_LINE_ALT |
1344                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1345                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT_DIM);
1346                        break;
1347                case DIFF_SYMBOL_MOVED_LINE |
1348                     DIFF_SYMBOL_MOVED_LINE_ALT:
1349                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT);
1350                        break;
1351                case DIFF_SYMBOL_MOVED_LINE |
1352                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1353                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_DIM);
1354                        break;
1355                case DIFF_SYMBOL_MOVED_LINE:
1356                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED);
1357                        break;
1358                default:
1359                        set = diff_get_color_opt(o, DIFF_FILE_OLD);
1360                }
1361                reset = diff_get_color_opt(o, DIFF_RESET);
1362                if (!o->flags.dual_color_diffed_diffs)
1363                        set_sign = NULL;
1364                else {
1365                        char c = !len ? 0 : line[0];
1366
1367                        set_sign = set;
1368                        if (c == '+')
1369                                set = diff_get_color_opt(o, DIFF_FILE_NEW_DIM);
1370                        else if (c == '@')
1371                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1372                        else if (c == '-')
1373                                set = diff_get_color_opt(o, DIFF_FILE_OLD_DIM);
1374                        else
1375                                set = diff_get_color_opt(o, DIFF_CONTEXT_DIM);
1376                }
1377                emit_line_ws_markup(o, set_sign, set, reset,
1378                                    o->output_indicators[OUTPUT_INDICATOR_OLD],
1379                                    line, len,
1380                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK, 0);
1381                break;
1382        case DIFF_SYMBOL_WORDS_PORCELAIN:
1383                context = diff_get_color_opt(o, DIFF_CONTEXT);
1384                reset = diff_get_color_opt(o, DIFF_RESET);
1385                emit_line(o, context, reset, line, len);
1386                fputs("~\n", o->file);
1387                break;
1388        case DIFF_SYMBOL_WORDS:
1389                context = diff_get_color_opt(o, DIFF_CONTEXT);
1390                reset = diff_get_color_opt(o, DIFF_RESET);
1391                /*
1392                 * Skip the prefix character, if any.  With
1393                 * diff_suppress_blank_empty, there may be
1394                 * none.
1395                 */
1396                if (line[0] != '\n') {
1397                        line++;
1398                        len--;
1399                }
1400                emit_line(o, context, reset, line, len);
1401                break;
1402        case DIFF_SYMBOL_FILEPAIR_PLUS:
1403                meta = diff_get_color_opt(o, DIFF_METAINFO);
1404                reset = diff_get_color_opt(o, DIFF_RESET);
1405                fprintf(o->file, "%s%s+++ %s%s%s\n", diff_line_prefix(o), meta,
1406                        line, reset,
1407                        strchr(line, ' ') ? "\t" : "");
1408                break;
1409        case DIFF_SYMBOL_FILEPAIR_MINUS:
1410                meta = diff_get_color_opt(o, DIFF_METAINFO);
1411                reset = diff_get_color_opt(o, DIFF_RESET);
1412                fprintf(o->file, "%s%s--- %s%s%s\n", diff_line_prefix(o), meta,
1413                        line, reset,
1414                        strchr(line, ' ') ? "\t" : "");
1415                break;
1416        case DIFF_SYMBOL_BINARY_FILES:
1417        case DIFF_SYMBOL_HEADER:
1418                fprintf(o->file, "%s", line);
1419                break;
1420        case DIFF_SYMBOL_BINARY_DIFF_HEADER:
1421                fprintf(o->file, "%sGIT binary patch\n", diff_line_prefix(o));
1422                break;
1423        case DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA:
1424                fprintf(o->file, "%sdelta %s\n", diff_line_prefix(o), line);
1425                break;
1426        case DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL:
1427                fprintf(o->file, "%sliteral %s\n", diff_line_prefix(o), line);
1428                break;
1429        case DIFF_SYMBOL_BINARY_DIFF_FOOTER:
1430                fputs(diff_line_prefix(o), o->file);
1431                fputc('\n', o->file);
1432                break;
1433        case DIFF_SYMBOL_REWRITE_DIFF:
1434                fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
1435                reset = diff_get_color_opt(o, DIFF_RESET);
1436                emit_line(o, fraginfo, reset, line, len);
1437                break;
1438        case DIFF_SYMBOL_SUBMODULE_ADD:
1439                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1440                reset = diff_get_color_opt(o, DIFF_RESET);
1441                emit_line(o, set, reset, line, len);
1442                break;
1443        case DIFF_SYMBOL_SUBMODULE_DEL:
1444                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1445                reset = diff_get_color_opt(o, DIFF_RESET);
1446                emit_line(o, set, reset, line, len);
1447                break;
1448        case DIFF_SYMBOL_SUBMODULE_UNTRACKED:
1449                fprintf(o->file, "%sSubmodule %s contains untracked content\n",
1450                        diff_line_prefix(o), line);
1451                break;
1452        case DIFF_SYMBOL_SUBMODULE_MODIFIED:
1453                fprintf(o->file, "%sSubmodule %s contains modified content\n",
1454                        diff_line_prefix(o), line);
1455                break;
1456        case DIFF_SYMBOL_STATS_SUMMARY_NO_FILES:
1457                emit_line(o, "", "", " 0 files changed\n",
1458                          strlen(" 0 files changed\n"));
1459                break;
1460        case DIFF_SYMBOL_STATS_SUMMARY_ABBREV:
1461                emit_line(o, "", "", " ...\n", strlen(" ...\n"));
1462                break;
1463        case DIFF_SYMBOL_WORD_DIFF:
1464                fprintf(o->file, "%.*s", len, line);
1465                break;
1466        case DIFF_SYMBOL_STAT_SEP:
1467                fputs(o->stat_sep, o->file);
1468                break;
1469        default:
1470                BUG("unknown diff symbol");
1471        }
1472        strbuf_release(&sb);
1473}
1474
1475static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
1476                             const char *line, int len, unsigned flags)
1477{
1478        struct emitted_diff_symbol e = {line, len, flags, s};
1479
1480        if (o->emitted_symbols)
1481                append_emitted_diff_symbol(o, &e);
1482        else
1483                emit_diff_symbol_from_struct(o, &e);
1484}
1485
1486void diff_emit_submodule_del(struct diff_options *o, const char *line)
1487{
1488        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_DEL, line, strlen(line), 0);
1489}
1490
1491void diff_emit_submodule_add(struct diff_options *o, const char *line)
1492{
1493        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ADD, line, strlen(line), 0);
1494}
1495
1496void diff_emit_submodule_untracked(struct diff_options *o, const char *path)
1497{
1498        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_UNTRACKED,
1499                         path, strlen(path), 0);
1500}
1501
1502void diff_emit_submodule_modified(struct diff_options *o, const char *path)
1503{
1504        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_MODIFIED,
1505                         path, strlen(path), 0);
1506}
1507
1508void diff_emit_submodule_header(struct diff_options *o, const char *header)
1509{
1510        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_HEADER,
1511                         header, strlen(header), 0);
1512}
1513
1514void diff_emit_submodule_error(struct diff_options *o, const char *err)
1515{
1516        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ERROR, err, strlen(err), 0);
1517}
1518
1519void diff_emit_submodule_pipethrough(struct diff_options *o,
1520                                     const char *line, int len)
1521{
1522        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_PIPETHROUGH, line, len, 0);
1523}
1524
1525static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
1526{
1527        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
1528              ecbdata->blank_at_eof_in_preimage &&
1529              ecbdata->blank_at_eof_in_postimage &&
1530              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
1531              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
1532                return 0;
1533        return ws_blank_line(line, len, ecbdata->ws_rule);
1534}
1535
1536static void emit_add_line(const char *reset,
1537                          struct emit_callback *ecbdata,
1538                          const char *line, int len)
1539{
1540        unsigned flags = WSEH_NEW | ecbdata->ws_rule;
1541        if (new_blank_line_at_eof(ecbdata, line, len))
1542                flags |= DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF;
1543
1544        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_PLUS, line, len, flags);
1545}
1546
1547static void emit_del_line(const char *reset,
1548                          struct emit_callback *ecbdata,
1549                          const char *line, int len)
1550{
1551        unsigned flags = WSEH_OLD | ecbdata->ws_rule;
1552        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_MINUS, line, len, flags);
1553}
1554
1555static void emit_context_line(const char *reset,
1556                              struct emit_callback *ecbdata,
1557                              const char *line, int len)
1558{
1559        unsigned flags = WSEH_CONTEXT | ecbdata->ws_rule;
1560        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_CONTEXT, line, len, flags);
1561}
1562
1563static void emit_hunk_header(struct emit_callback *ecbdata,
1564                             const char *line, int len)
1565{
1566        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
1567        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
1568        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
1569        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1570        const char *reverse = ecbdata->color_diff ? GIT_COLOR_REVERSE : "";
1571        static const char atat[2] = { '@', '@' };
1572        const char *cp, *ep;
1573        struct strbuf msgbuf = STRBUF_INIT;
1574        int org_len = len;
1575        int i = 1;
1576
1577        /*
1578         * As a hunk header must begin with "@@ -<old>, +<new> @@",
1579         * it always is at least 10 bytes long.
1580         */
1581        if (len < 10 ||
1582            memcmp(line, atat, 2) ||
1583            !(ep = memmem(line + 2, len - 2, atat, 2))) {
1584                emit_diff_symbol(ecbdata->opt,
1585                                 DIFF_SYMBOL_CONTEXT_MARKER, line, len, 0);
1586                return;
1587        }
1588        ep += 2; /* skip over @@ */
1589
1590        /* The hunk header in fraginfo color */
1591        if (ecbdata->opt->flags.dual_color_diffed_diffs)
1592                strbuf_addstr(&msgbuf, reverse);
1593        strbuf_addstr(&msgbuf, frag);
1594        strbuf_add(&msgbuf, line, ep - line);
1595        strbuf_addstr(&msgbuf, reset);
1596
1597        /*
1598         * trailing "\r\n"
1599         */
1600        for ( ; i < 3; i++)
1601                if (line[len - i] == '\r' || line[len - i] == '\n')
1602                        len--;
1603
1604        /* blank before the func header */
1605        for (cp = ep; ep - line < len; ep++)
1606                if (*ep != ' ' && *ep != '\t')
1607                        break;
1608        if (ep != cp) {
1609                strbuf_addstr(&msgbuf, context);
1610                strbuf_add(&msgbuf, cp, ep - cp);
1611                strbuf_addstr(&msgbuf, reset);
1612        }
1613
1614        if (ep < line + len) {
1615                strbuf_addstr(&msgbuf, func);
1616                strbuf_add(&msgbuf, ep, line + len - ep);
1617                strbuf_addstr(&msgbuf, reset);
1618        }
1619
1620        strbuf_add(&msgbuf, line + len, org_len - len);
1621        strbuf_complete_line(&msgbuf);
1622        emit_diff_symbol(ecbdata->opt,
1623                         DIFF_SYMBOL_CONTEXT_FRAGINFO, msgbuf.buf, msgbuf.len, 0);
1624        strbuf_release(&msgbuf);
1625}
1626
1627static struct diff_tempfile *claim_diff_tempfile(void) {
1628        int i;
1629        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
1630                if (!diff_temp[i].name)
1631                        return diff_temp + i;
1632        BUG("diff is failing to clean up its tempfiles");
1633}
1634
1635static void remove_tempfile(void)
1636{
1637        int i;
1638        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
1639                if (is_tempfile_active(diff_temp[i].tempfile))
1640                        delete_tempfile(&diff_temp[i].tempfile);
1641                diff_temp[i].name = NULL;
1642        }
1643}
1644
1645static void add_line_count(struct strbuf *out, int count)
1646{
1647        switch (count) {
1648        case 0:
1649                strbuf_addstr(out, "0,0");
1650                break;
1651        case 1:
1652                strbuf_addstr(out, "1");
1653                break;
1654        default:
1655                strbuf_addf(out, "1,%d", count);
1656                break;
1657        }
1658}
1659
1660static void emit_rewrite_lines(struct emit_callback *ecb,
1661                               int prefix, const char *data, int size)
1662{
1663        const char *endp = NULL;
1664        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
1665
1666        while (0 < size) {
1667                int len;
1668
1669                endp = memchr(data, '\n', size);
1670                len = endp ? (endp - data + 1) : size;
1671                if (prefix != '+') {
1672                        ecb->lno_in_preimage++;
1673                        emit_del_line(reset, ecb, data, len);
1674                } else {
1675                        ecb->lno_in_postimage++;
1676                        emit_add_line(reset, ecb, data, len);
1677                }
1678                size -= len;
1679                data += len;
1680        }
1681        if (!endp)
1682                emit_diff_symbol(ecb->opt, DIFF_SYMBOL_NO_LF_EOF, NULL, 0, 0);
1683}
1684
1685static void emit_rewrite_diff(const char *name_a,
1686                              const char *name_b,
1687                              struct diff_filespec *one,
1688                              struct diff_filespec *two,
1689                              struct userdiff_driver *textconv_one,
1690                              struct userdiff_driver *textconv_two,
1691                              struct diff_options *o)
1692{
1693        int lc_a, lc_b;
1694        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
1695        const char *a_prefix, *b_prefix;
1696        char *data_one, *data_two;
1697        size_t size_one, size_two;
1698        struct emit_callback ecbdata;
1699        struct strbuf out = STRBUF_INIT;
1700
1701        if (diff_mnemonic_prefix && o->flags.reverse_diff) {
1702                a_prefix = o->b_prefix;
1703                b_prefix = o->a_prefix;
1704        } else {
1705                a_prefix = o->a_prefix;
1706                b_prefix = o->b_prefix;
1707        }
1708
1709        name_a += (*name_a == '/');
1710        name_b += (*name_b == '/');
1711
1712        strbuf_reset(&a_name);
1713        strbuf_reset(&b_name);
1714        quote_two_c_style(&a_name, a_prefix, name_a, 0);
1715        quote_two_c_style(&b_name, b_prefix, name_b, 0);
1716
1717        size_one = fill_textconv(textconv_one, one, &data_one);
1718        size_two = fill_textconv(textconv_two, two, &data_two);
1719
1720        memset(&ecbdata, 0, sizeof(ecbdata));
1721        ecbdata.color_diff = want_color(o->use_color);
1722        ecbdata.ws_rule = whitespace_rule(name_b);
1723        ecbdata.opt = o;
1724        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
1725                mmfile_t mf1, mf2;
1726                mf1.ptr = (char *)data_one;
1727                mf2.ptr = (char *)data_two;
1728                mf1.size = size_one;
1729                mf2.size = size_two;
1730                check_blank_at_eof(&mf1, &mf2, &ecbdata);
1731        }
1732        ecbdata.lno_in_preimage = 1;
1733        ecbdata.lno_in_postimage = 1;
1734
1735        lc_a = count_lines(data_one, size_one);
1736        lc_b = count_lines(data_two, size_two);
1737
1738        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
1739                         a_name.buf, a_name.len, 0);
1740        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
1741                         b_name.buf, b_name.len, 0);
1742
1743        strbuf_addstr(&out, "@@ -");
1744        if (!o->irreversible_delete)
1745                add_line_count(&out, lc_a);
1746        else
1747                strbuf_addstr(&out, "?,?");
1748        strbuf_addstr(&out, " +");
1749        add_line_count(&out, lc_b);
1750        strbuf_addstr(&out, " @@\n");
1751        emit_diff_symbol(o, DIFF_SYMBOL_REWRITE_DIFF, out.buf, out.len, 0);
1752        strbuf_release(&out);
1753
1754        if (lc_a && !o->irreversible_delete)
1755                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
1756        if (lc_b)
1757                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
1758        if (textconv_one)
1759                free((char *)data_one);
1760        if (textconv_two)
1761                free((char *)data_two);
1762}
1763
1764struct diff_words_buffer {
1765        mmfile_t text;
1766        unsigned long alloc;
1767        struct diff_words_orig {
1768                const char *begin, *end;
1769        } *orig;
1770        int orig_nr, orig_alloc;
1771};
1772
1773static void diff_words_append(char *line, unsigned long len,
1774                struct diff_words_buffer *buffer)
1775{
1776        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
1777        line++;
1778        len--;
1779        memcpy(buffer->text.ptr + buffer->text.size, line, len);
1780        buffer->text.size += len;
1781        buffer->text.ptr[buffer->text.size] = '\0';
1782}
1783
1784struct diff_words_style_elem {
1785        const char *prefix;
1786        const char *suffix;
1787        const char *color; /* NULL; filled in by the setup code if
1788                            * color is enabled */
1789};
1790
1791struct diff_words_style {
1792        enum diff_words_type type;
1793        struct diff_words_style_elem new_word, old_word, ctx;
1794        const char *newline;
1795};
1796
1797static struct diff_words_style diff_words_styles[] = {
1798        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
1799        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
1800        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
1801};
1802
1803struct diff_words_data {
1804        struct diff_words_buffer minus, plus;
1805        const char *current_plus;
1806        int last_minus;
1807        struct diff_options *opt;
1808        regex_t *word_regex;
1809        enum diff_words_type type;
1810        struct diff_words_style *style;
1811};
1812
1813static int fn_out_diff_words_write_helper(struct diff_options *o,
1814                                          struct diff_words_style_elem *st_el,
1815                                          const char *newline,
1816                                          size_t count, const char *buf)
1817{
1818        int print = 0;
1819        struct strbuf sb = STRBUF_INIT;
1820
1821        while (count) {
1822                char *p = memchr(buf, '\n', count);
1823                if (print)
1824                        strbuf_addstr(&sb, diff_line_prefix(o));
1825
1826                if (p != buf) {
1827                        const char *reset = st_el->color && *st_el->color ?
1828                                            GIT_COLOR_RESET : NULL;
1829                        if (st_el->color && *st_el->color)
1830                                strbuf_addstr(&sb, st_el->color);
1831                        strbuf_addstr(&sb, st_el->prefix);
1832                        strbuf_add(&sb, buf, p ? p - buf : count);
1833                        strbuf_addstr(&sb, st_el->suffix);
1834                        if (reset)
1835                                strbuf_addstr(&sb, reset);
1836                }
1837                if (!p)
1838                        goto out;
1839
1840                strbuf_addstr(&sb, newline);
1841                count -= p + 1 - buf;
1842                buf = p + 1;
1843                print = 1;
1844                if (count) {
1845                        emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1846                                         sb.buf, sb.len, 0);
1847                        strbuf_reset(&sb);
1848                }
1849        }
1850
1851out:
1852        if (sb.len)
1853                emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1854                                 sb.buf, sb.len, 0);
1855        strbuf_release(&sb);
1856        return 0;
1857}
1858
1859/*
1860 * '--color-words' algorithm can be described as:
1861 *
1862 *   1. collect the minus/plus lines of a diff hunk, divided into
1863 *      minus-lines and plus-lines;
1864 *
1865 *   2. break both minus-lines and plus-lines into words and
1866 *      place them into two mmfile_t with one word for each line;
1867 *
1868 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
1869 *
1870 * And for the common parts of the both file, we output the plus side text.
1871 * diff_words->current_plus is used to trace the current position of the plus file
1872 * which printed. diff_words->last_minus is used to trace the last minus word
1873 * printed.
1874 *
1875 * For '--graph' to work with '--color-words', we need to output the graph prefix
1876 * on each line of color words output. Generally, there are two conditions on
1877 * which we should output the prefix.
1878 *
1879 *   1. diff_words->last_minus == 0 &&
1880 *      diff_words->current_plus == diff_words->plus.text.ptr
1881 *
1882 *      that is: the plus text must start as a new line, and if there is no minus
1883 *      word printed, a graph prefix must be printed.
1884 *
1885 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
1886 *      *(diff_words->current_plus - 1) == '\n'
1887 *
1888 *      that is: a graph prefix must be printed following a '\n'
1889 */
1890static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
1891{
1892        if ((diff_words->last_minus == 0 &&
1893                diff_words->current_plus == diff_words->plus.text.ptr) ||
1894                (diff_words->current_plus > diff_words->plus.text.ptr &&
1895                *(diff_words->current_plus - 1) == '\n')) {
1896                return 1;
1897        } else {
1898                return 0;
1899        }
1900}
1901
1902static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
1903{
1904        struct diff_words_data *diff_words = priv;
1905        struct diff_words_style *style = diff_words->style;
1906        int minus_first, minus_len, plus_first, plus_len;
1907        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
1908        struct diff_options *opt = diff_words->opt;
1909        const char *line_prefix;
1910
1911        if (line[0] != '@' || parse_hunk_header(line, len,
1912                        &minus_first, &minus_len, &plus_first, &plus_len))
1913                return;
1914
1915        assert(opt);
1916        line_prefix = diff_line_prefix(opt);
1917
1918        /* POSIX requires that first be decremented by one if len == 0... */
1919        if (minus_len) {
1920                minus_begin = diff_words->minus.orig[minus_first].begin;
1921                minus_end =
1922                        diff_words->minus.orig[minus_first + minus_len - 1].end;
1923        } else
1924                minus_begin = minus_end =
1925                        diff_words->minus.orig[minus_first].end;
1926
1927        if (plus_len) {
1928                plus_begin = diff_words->plus.orig[plus_first].begin;
1929                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
1930        } else
1931                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
1932
1933        if (color_words_output_graph_prefix(diff_words)) {
1934                fputs(line_prefix, diff_words->opt->file);
1935        }
1936        if (diff_words->current_plus != plus_begin) {
1937                fn_out_diff_words_write_helper(diff_words->opt,
1938                                &style->ctx, style->newline,
1939                                plus_begin - diff_words->current_plus,
1940                                diff_words->current_plus);
1941        }
1942        if (minus_begin != minus_end) {
1943                fn_out_diff_words_write_helper(diff_words->opt,
1944                                &style->old_word, style->newline,
1945                                minus_end - minus_begin, minus_begin);
1946        }
1947        if (plus_begin != plus_end) {
1948                fn_out_diff_words_write_helper(diff_words->opt,
1949                                &style->new_word, style->newline,
1950                                plus_end - plus_begin, plus_begin);
1951        }
1952
1953        diff_words->current_plus = plus_end;
1954        diff_words->last_minus = minus_first;
1955}
1956
1957/* This function starts looking at *begin, and returns 0 iff a word was found. */
1958static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
1959                int *begin, int *end)
1960{
1961        if (word_regex && *begin < buffer->size) {
1962                regmatch_t match[1];
1963                if (!regexec_buf(word_regex, buffer->ptr + *begin,
1964                                 buffer->size - *begin, 1, match, 0)) {
1965                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
1966                                        '\n', match[0].rm_eo - match[0].rm_so);
1967                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
1968                        *begin += match[0].rm_so;
1969                        return *begin >= *end;
1970                }
1971                return -1;
1972        }
1973
1974        /* find the next word */
1975        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
1976                (*begin)++;
1977        if (*begin >= buffer->size)
1978                return -1;
1979
1980        /* find the end of the word */
1981        *end = *begin + 1;
1982        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
1983                (*end)++;
1984
1985        return 0;
1986}
1987
1988/*
1989 * This function splits the words in buffer->text, stores the list with
1990 * newline separator into out, and saves the offsets of the original words
1991 * in buffer->orig.
1992 */
1993static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
1994                regex_t *word_regex)
1995{
1996        int i, j;
1997        long alloc = 0;
1998
1999        out->size = 0;
2000        out->ptr = NULL;
2001
2002        /* fake an empty "0th" word */
2003        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
2004        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
2005        buffer->orig_nr = 1;
2006
2007        for (i = 0; i < buffer->text.size; i++) {
2008                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
2009                        return;
2010
2011                /* store original boundaries */
2012                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
2013                                buffer->orig_alloc);
2014                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
2015                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
2016                buffer->orig_nr++;
2017
2018                /* store one word */
2019                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
2020                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
2021                out->ptr[out->size + j - i] = '\n';
2022                out->size += j - i + 1;
2023
2024                i = j - 1;
2025        }
2026}
2027
2028/* this executes the word diff on the accumulated buffers */
2029static void diff_words_show(struct diff_words_data *diff_words)
2030{
2031        xpparam_t xpp;
2032        xdemitconf_t xecfg;
2033        mmfile_t minus, plus;
2034        struct diff_words_style *style = diff_words->style;
2035
2036        struct diff_options *opt = diff_words->opt;
2037        const char *line_prefix;
2038
2039        assert(opt);
2040        line_prefix = diff_line_prefix(opt);
2041
2042        /* special case: only removal */
2043        if (!diff_words->plus.text.size) {
2044                emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
2045                                 line_prefix, strlen(line_prefix), 0);
2046                fn_out_diff_words_write_helper(diff_words->opt,
2047                        &style->old_word, style->newline,
2048                        diff_words->minus.text.size,
2049                        diff_words->minus.text.ptr);
2050                diff_words->minus.text.size = 0;
2051                return;
2052        }
2053
2054        diff_words->current_plus = diff_words->plus.text.ptr;
2055        diff_words->last_minus = 0;
2056
2057        memset(&xpp, 0, sizeof(xpp));
2058        memset(&xecfg, 0, sizeof(xecfg));
2059        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
2060        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
2061        xpp.flags = 0;
2062        /* as only the hunk header will be parsed, we need a 0-context */
2063        xecfg.ctxlen = 0;
2064        if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
2065                          &xpp, &xecfg))
2066                die("unable to generate word diff");
2067        free(minus.ptr);
2068        free(plus.ptr);
2069        if (diff_words->current_plus != diff_words->plus.text.ptr +
2070                        diff_words->plus.text.size) {
2071                if (color_words_output_graph_prefix(diff_words))
2072                        emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
2073                                         line_prefix, strlen(line_prefix), 0);
2074                fn_out_diff_words_write_helper(diff_words->opt,
2075                        &style->ctx, style->newline,
2076                        diff_words->plus.text.ptr + diff_words->plus.text.size
2077                        - diff_words->current_plus, diff_words->current_plus);
2078        }
2079        diff_words->minus.text.size = diff_words->plus.text.size = 0;
2080}
2081
2082/* In "color-words" mode, show word-diff of words accumulated in the buffer */
2083static void diff_words_flush(struct emit_callback *ecbdata)
2084{
2085        struct diff_options *wo = ecbdata->diff_words->opt;
2086
2087        if (ecbdata->diff_words->minus.text.size ||
2088            ecbdata->diff_words->plus.text.size)
2089                diff_words_show(ecbdata->diff_words);
2090
2091        if (wo->emitted_symbols) {
2092                struct diff_options *o = ecbdata->opt;
2093                struct emitted_diff_symbols *wol = wo->emitted_symbols;
2094                int i;
2095
2096                /*
2097                 * NEEDSWORK:
2098                 * Instead of appending each, concat all words to a line?
2099                 */
2100                for (i = 0; i < wol->nr; i++)
2101                        append_emitted_diff_symbol(o, &wol->buf[i]);
2102
2103                for (i = 0; i < wol->nr; i++)
2104                        free((void *)wol->buf[i].line);
2105
2106                wol->nr = 0;
2107        }
2108}
2109
2110static void diff_filespec_load_driver(struct diff_filespec *one)
2111{
2112        /* Use already-loaded driver */
2113        if (one->driver)
2114                return;
2115
2116        if (S_ISREG(one->mode))
2117                one->driver = userdiff_find_by_path(one->path);
2118
2119        /* Fallback to default settings */
2120        if (!one->driver)
2121                one->driver = userdiff_find_by_name("default");
2122}
2123
2124static const char *userdiff_word_regex(struct diff_filespec *one)
2125{
2126        diff_filespec_load_driver(one);
2127        return one->driver->word_regex;
2128}
2129
2130static void init_diff_words_data(struct emit_callback *ecbdata,
2131                                 struct diff_options *orig_opts,
2132                                 struct diff_filespec *one,
2133                                 struct diff_filespec *two)
2134{
2135        int i;
2136        struct diff_options *o = xmalloc(sizeof(struct diff_options));
2137        memcpy(o, orig_opts, sizeof(struct diff_options));
2138
2139        ecbdata->diff_words =
2140                xcalloc(1, sizeof(struct diff_words_data));
2141        ecbdata->diff_words->type = o->word_diff;
2142        ecbdata->diff_words->opt = o;
2143
2144        if (orig_opts->emitted_symbols)
2145                o->emitted_symbols =
2146                        xcalloc(1, sizeof(struct emitted_diff_symbols));
2147
2148        if (!o->word_regex)
2149                o->word_regex = userdiff_word_regex(one);
2150        if (!o->word_regex)
2151                o->word_regex = userdiff_word_regex(two);
2152        if (!o->word_regex)
2153                o->word_regex = diff_word_regex_cfg;
2154        if (o->word_regex) {
2155                ecbdata->diff_words->word_regex = (regex_t *)
2156                        xmalloc(sizeof(regex_t));
2157                if (regcomp(ecbdata->diff_words->word_regex,
2158                            o->word_regex,
2159                            REG_EXTENDED | REG_NEWLINE))
2160                        die("invalid regular expression: %s",
2161                            o->word_regex);
2162        }
2163        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2164                if (o->word_diff == diff_words_styles[i].type) {
2165                        ecbdata->diff_words->style =
2166                                &diff_words_styles[i];
2167                        break;
2168                }
2169        }
2170        if (want_color(o->use_color)) {
2171                struct diff_words_style *st = ecbdata->diff_words->style;
2172                st->old_word.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2173                st->new_word.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2174                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
2175        }
2176}
2177
2178static void free_diff_words_data(struct emit_callback *ecbdata)
2179{
2180        if (ecbdata->diff_words) {
2181                diff_words_flush(ecbdata);
2182                free (ecbdata->diff_words->opt->emitted_symbols);
2183                free (ecbdata->diff_words->opt);
2184                free (ecbdata->diff_words->minus.text.ptr);
2185                free (ecbdata->diff_words->minus.orig);
2186                free (ecbdata->diff_words->plus.text.ptr);
2187                free (ecbdata->diff_words->plus.orig);
2188                if (ecbdata->diff_words->word_regex) {
2189                        regfree(ecbdata->diff_words->word_regex);
2190                        free(ecbdata->diff_words->word_regex);
2191                }
2192                FREE_AND_NULL(ecbdata->diff_words);
2193        }
2194}
2195
2196const char *diff_get_color(int diff_use_color, enum color_diff ix)
2197{
2198        if (want_color(diff_use_color))
2199                return diff_colors[ix];
2200        return "";
2201}
2202
2203const char *diff_line_prefix(struct diff_options *opt)
2204{
2205        struct strbuf *msgbuf;
2206        if (!opt->output_prefix)
2207                return "";
2208
2209        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
2210        return msgbuf->buf;
2211}
2212
2213static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
2214{
2215        const char *cp;
2216        unsigned long allot;
2217        size_t l = len;
2218
2219        cp = line;
2220        allot = l;
2221        while (0 < l) {
2222                (void) utf8_width(&cp, &l);
2223                if (!cp)
2224                        break; /* truncated in the middle? */
2225        }
2226        return allot - l;
2227}
2228
2229static void find_lno(const char *line, struct emit_callback *ecbdata)
2230{
2231        const char *p;
2232        ecbdata->lno_in_preimage = 0;
2233        ecbdata->lno_in_postimage = 0;
2234        p = strchr(line, '-');
2235        if (!p)
2236                return; /* cannot happen */
2237        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
2238        p = strchr(p, '+');
2239        if (!p)
2240                return; /* cannot happen */
2241        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
2242}
2243
2244static void fn_out_consume(void *priv, char *line, unsigned long len)
2245{
2246        struct emit_callback *ecbdata = priv;
2247        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
2248        struct diff_options *o = ecbdata->opt;
2249
2250        o->found_changes = 1;
2251
2252        if (ecbdata->header) {
2253                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
2254                                 ecbdata->header->buf, ecbdata->header->len, 0);
2255                strbuf_reset(ecbdata->header);
2256                ecbdata->header = NULL;
2257        }
2258
2259        if (ecbdata->label_path[0]) {
2260                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
2261                                 ecbdata->label_path[0],
2262                                 strlen(ecbdata->label_path[0]), 0);
2263                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
2264                                 ecbdata->label_path[1],
2265                                 strlen(ecbdata->label_path[1]), 0);
2266                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
2267        }
2268
2269        if (diff_suppress_blank_empty
2270            && len == 2 && line[0] == ' ' && line[1] == '\n') {
2271                line[0] = '\n';
2272                len = 1;
2273        }
2274
2275        if (line[0] == '@') {
2276                if (ecbdata->diff_words)
2277                        diff_words_flush(ecbdata);
2278                len = sane_truncate_line(ecbdata, line, len);
2279                find_lno(line, ecbdata);
2280                emit_hunk_header(ecbdata, line, len);
2281                return;
2282        }
2283
2284        if (ecbdata->diff_words) {
2285                enum diff_symbol s =
2286                        ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN ?
2287                        DIFF_SYMBOL_WORDS_PORCELAIN : DIFF_SYMBOL_WORDS;
2288                if (line[0] == '-') {
2289                        diff_words_append(line, len,
2290                                          &ecbdata->diff_words->minus);
2291                        return;
2292                } else if (line[0] == '+') {
2293                        diff_words_append(line, len,
2294                                          &ecbdata->diff_words->plus);
2295                        return;
2296                } else if (starts_with(line, "\\ ")) {
2297                        /*
2298                         * Eat the "no newline at eof" marker as if we
2299                         * saw a "+" or "-" line with nothing on it,
2300                         * and return without diff_words_flush() to
2301                         * defer processing. If this is the end of
2302                         * preimage, more "+" lines may come after it.
2303                         */
2304                        return;
2305                }
2306                diff_words_flush(ecbdata);
2307                emit_diff_symbol(o, s, line, len, 0);
2308                return;
2309        }
2310
2311        switch (line[0]) {
2312        case '+':
2313                ecbdata->lno_in_postimage++;
2314                emit_add_line(reset, ecbdata, line + 1, len - 1);
2315                break;
2316        case '-':
2317                ecbdata->lno_in_preimage++;
2318                emit_del_line(reset, ecbdata, line + 1, len - 1);
2319                break;
2320        case ' ':
2321                ecbdata->lno_in_postimage++;
2322                ecbdata->lno_in_preimage++;
2323                emit_context_line(reset, ecbdata, line + 1, len - 1);
2324                break;
2325        default:
2326                /* incomplete line at the end */
2327                ecbdata->lno_in_preimage++;
2328                emit_diff_symbol(o, DIFF_SYMBOL_CONTEXT_INCOMPLETE,
2329                                 line, len, 0);
2330                break;
2331        }
2332}
2333
2334static void pprint_rename(struct strbuf *name, const char *a, const char *b)
2335{
2336        const char *old_name = a;
2337        const char *new_name = b;
2338        int pfx_length, sfx_length;
2339        int pfx_adjust_for_slash;
2340        int len_a = strlen(a);
2341        int len_b = strlen(b);
2342        int a_midlen, b_midlen;
2343        int qlen_a = quote_c_style(a, NULL, NULL, 0);
2344        int qlen_b = quote_c_style(b, NULL, NULL, 0);
2345
2346        if (qlen_a || qlen_b) {
2347                quote_c_style(a, name, NULL, 0);
2348                strbuf_addstr(name, " => ");
2349                quote_c_style(b, name, NULL, 0);
2350                return;
2351        }
2352
2353        /* Find common prefix */
2354        pfx_length = 0;
2355        while (*old_name && *new_name && *old_name == *new_name) {
2356                if (*old_name == '/')
2357                        pfx_length = old_name - a + 1;
2358                old_name++;
2359                new_name++;
2360        }
2361
2362        /* Find common suffix */
2363        old_name = a + len_a;
2364        new_name = b + len_b;
2365        sfx_length = 0;
2366        /*
2367         * If there is a common prefix, it must end in a slash.  In
2368         * that case we let this loop run 1 into the prefix to see the
2369         * same slash.
2370         *
2371         * If there is no common prefix, we cannot do this as it would
2372         * underrun the input strings.
2373         */
2374        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
2375        while (a + pfx_length - pfx_adjust_for_slash <= old_name &&
2376               b + pfx_length - pfx_adjust_for_slash <= new_name &&
2377               *old_name == *new_name) {
2378                if (*old_name == '/')
2379                        sfx_length = len_a - (old_name - a);
2380                old_name--;
2381                new_name--;
2382        }
2383
2384        /*
2385         * pfx{mid-a => mid-b}sfx
2386         * {pfx-a => pfx-b}sfx
2387         * pfx{sfx-a => sfx-b}
2388         * name-a => name-b
2389         */
2390        a_midlen = len_a - pfx_length - sfx_length;
2391        b_midlen = len_b - pfx_length - sfx_length;
2392        if (a_midlen < 0)
2393                a_midlen = 0;
2394        if (b_midlen < 0)
2395                b_midlen = 0;
2396
2397        strbuf_grow(name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
2398        if (pfx_length + sfx_length) {
2399                strbuf_add(name, a, pfx_length);
2400                strbuf_addch(name, '{');
2401        }
2402        strbuf_add(name, a + pfx_length, a_midlen);
2403        strbuf_addstr(name, " => ");
2404        strbuf_add(name, b + pfx_length, b_midlen);
2405        if (pfx_length + sfx_length) {
2406                strbuf_addch(name, '}');
2407                strbuf_add(name, a + len_a - sfx_length, sfx_length);
2408        }
2409}
2410
2411struct diffstat_t {
2412        int nr;
2413        int alloc;
2414        struct diffstat_file {
2415                char *from_name;
2416                char *name;
2417                char *print_name;
2418                const char *comments;
2419                unsigned is_unmerged:1;
2420                unsigned is_binary:1;
2421                unsigned is_renamed:1;
2422                unsigned is_interesting:1;
2423                uintmax_t added, deleted;
2424        } **files;
2425};
2426
2427static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
2428                                          const char *name_a,
2429                                          const char *name_b)
2430{
2431        struct diffstat_file *x;
2432        x = xcalloc(1, sizeof(*x));
2433        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
2434        diffstat->files[diffstat->nr++] = x;
2435        if (name_b) {
2436                x->from_name = xstrdup(name_a);
2437                x->name = xstrdup(name_b);
2438                x->is_renamed = 1;
2439        }
2440        else {
2441                x->from_name = NULL;
2442                x->name = xstrdup(name_a);
2443        }
2444        return x;
2445}
2446
2447static void diffstat_consume(void *priv, char *line, unsigned long len)
2448{
2449        struct diffstat_t *diffstat = priv;
2450        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
2451
2452        if (line[0] == '+')
2453                x->added++;
2454        else if (line[0] == '-')
2455                x->deleted++;
2456}
2457
2458const char mime_boundary_leader[] = "------------";
2459
2460static int scale_linear(int it, int width, int max_change)
2461{
2462        if (!it)
2463                return 0;
2464        /*
2465         * make sure that at least one '-' or '+' is printed if
2466         * there is any change to this path. The easiest way is to
2467         * scale linearly as if the alloted width is one column shorter
2468         * than it is, and then add 1 to the result.
2469         */
2470        return 1 + (it * (width - 1) / max_change);
2471}
2472
2473static void show_graph(struct strbuf *out, char ch, int cnt,
2474                       const char *set, const char *reset)
2475{
2476        if (cnt <= 0)
2477                return;
2478        strbuf_addstr(out, set);
2479        strbuf_addchars(out, ch, cnt);
2480        strbuf_addstr(out, reset);
2481}
2482
2483static void fill_print_name(struct diffstat_file *file)
2484{
2485        struct strbuf pname = STRBUF_INIT;
2486
2487        if (file->print_name)
2488                return;
2489
2490        if (file->is_renamed)
2491                pprint_rename(&pname, file->from_name, file->name);
2492        else
2493                quote_c_style(file->name, &pname, NULL, 0);
2494
2495        if (file->comments)
2496                strbuf_addf(&pname, " (%s)", file->comments);
2497
2498        file->print_name = strbuf_detach(&pname, NULL);
2499}
2500
2501static void print_stat_summary_inserts_deletes(struct diff_options *options,
2502                int files, int insertions, int deletions)
2503{
2504        struct strbuf sb = STRBUF_INIT;
2505
2506        if (!files) {
2507                assert(insertions == 0 && deletions == 0);
2508                emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
2509                                 NULL, 0, 0);
2510                return;
2511        }
2512
2513        strbuf_addf(&sb,
2514                    (files == 1) ? " %d file changed" : " %d files changed",
2515                    files);
2516
2517        /*
2518         * For binary diff, the caller may want to print "x files
2519         * changed" with insertions == 0 && deletions == 0.
2520         *
2521         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
2522         * is probably less confusing (i.e skip over "2 files changed
2523         * but nothing about added/removed lines? Is this a bug in Git?").
2524         */
2525        if (insertions || deletions == 0) {
2526                strbuf_addf(&sb,
2527                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
2528                            insertions);
2529        }
2530
2531        if (deletions || insertions == 0) {
2532                strbuf_addf(&sb,
2533                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
2534                            deletions);
2535        }
2536        strbuf_addch(&sb, '\n');
2537        emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
2538                         sb.buf, sb.len, 0);
2539        strbuf_release(&sb);
2540}
2541
2542void print_stat_summary(FILE *fp, int files,
2543                        int insertions, int deletions)
2544{
2545        struct diff_options o;
2546        memset(&o, 0, sizeof(o));
2547        o.file = fp;
2548
2549        print_stat_summary_inserts_deletes(&o, files, insertions, deletions);
2550}
2551
2552static void show_stats(struct diffstat_t *data, struct diff_options *options)
2553{
2554        int i, len, add, del, adds = 0, dels = 0;
2555        uintmax_t max_change = 0, max_len = 0;
2556        int total_files = data->nr, count;
2557        int width, name_width, graph_width, number_width = 0, bin_width = 0;
2558        const char *reset, *add_c, *del_c;
2559        int extra_shown = 0;
2560        const char *line_prefix = diff_line_prefix(options);
2561        struct strbuf out = STRBUF_INIT;
2562
2563        if (data->nr == 0)
2564                return;
2565
2566        count = options->stat_count ? options->stat_count : data->nr;
2567
2568        reset = diff_get_color_opt(options, DIFF_RESET);
2569        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
2570        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
2571
2572        /*
2573         * Find the longest filename and max number of changes
2574         */
2575        for (i = 0; (i < count) && (i < data->nr); i++) {
2576                struct diffstat_file *file = data->files[i];
2577                uintmax_t change = file->added + file->deleted;
2578
2579                if (!file->is_interesting && (change == 0)) {
2580                        count++; /* not shown == room for one more */
2581                        continue;
2582                }
2583                fill_print_name(file);
2584                len = strlen(file->print_name);
2585                if (max_len < len)
2586                        max_len = len;
2587
2588                if (file->is_unmerged) {
2589                        /* "Unmerged" is 8 characters */
2590                        bin_width = bin_width < 8 ? 8 : bin_width;
2591                        continue;
2592                }
2593                if (file->is_binary) {
2594                        /* "Bin XXX -> YYY bytes" */
2595                        int w = 14 + decimal_width(file->added)
2596                                + decimal_width(file->deleted);
2597                        bin_width = bin_width < w ? w : bin_width;
2598                        /* Display change counts aligned with "Bin" */
2599                        number_width = 3;
2600                        continue;
2601                }
2602
2603                if (max_change < change)
2604                        max_change = change;
2605        }
2606        count = i; /* where we can stop scanning in data->files[] */
2607
2608        /*
2609         * We have width = stat_width or term_columns() columns total.
2610         * We want a maximum of min(max_len, stat_name_width) for the name part.
2611         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
2612         * We also need 1 for " " and 4 + decimal_width(max_change)
2613         * for " | NNNN " and one the empty column at the end, altogether
2614         * 6 + decimal_width(max_change).
2615         *
2616         * If there's not enough space, we will use the smaller of
2617         * stat_name_width (if set) and 5/8*width for the filename,
2618         * and the rest for constant elements + graph part, but no more
2619         * than stat_graph_width for the graph part.
2620         * (5/8 gives 50 for filename and 30 for the constant parts + graph
2621         * for the standard terminal size).
2622         *
2623         * In other words: stat_width limits the maximum width, and
2624         * stat_name_width fixes the maximum width of the filename,
2625         * and is also used to divide available columns if there
2626         * aren't enough.
2627         *
2628         * Binary files are displayed with "Bin XXX -> YYY bytes"
2629         * instead of the change count and graph. This part is treated
2630         * similarly to the graph part, except that it is not
2631         * "scaled". If total width is too small to accommodate the
2632         * guaranteed minimum width of the filename part and the
2633         * separators and this message, this message will "overflow"
2634         * making the line longer than the maximum width.
2635         */
2636
2637        if (options->stat_width == -1)
2638                width = term_columns() - strlen(line_prefix);
2639        else
2640                width = options->stat_width ? options->stat_width : 80;
2641        number_width = decimal_width(max_change) > number_width ?
2642                decimal_width(max_change) : number_width;
2643
2644        if (options->stat_graph_width == -1)
2645                options->stat_graph_width = diff_stat_graph_width;
2646
2647        /*
2648         * Guarantee 3/8*16==6 for the graph part
2649         * and 5/8*16==10 for the filename part
2650         */
2651        if (width < 16 + 6 + number_width)
2652                width = 16 + 6 + number_width;
2653
2654        /*
2655         * First assign sizes that are wanted, ignoring available width.
2656         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
2657         * starting from "XXX" should fit in graph_width.
2658         */
2659        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
2660        if (options->stat_graph_width &&
2661            options->stat_graph_width < graph_width)
2662                graph_width = options->stat_graph_width;
2663
2664        name_width = (options->stat_name_width > 0 &&
2665                      options->stat_name_width < max_len) ?
2666                options->stat_name_width : max_len;
2667
2668        /*
2669         * Adjust adjustable widths not to exceed maximum width
2670         */
2671        if (name_width + number_width + 6 + graph_width > width) {
2672                if (graph_width > width * 3/8 - number_width - 6) {
2673                        graph_width = width * 3/8 - number_width - 6;
2674                        if (graph_width < 6)
2675                                graph_width = 6;
2676                }
2677
2678                if (options->stat_graph_width &&
2679                    graph_width > options->stat_graph_width)
2680                        graph_width = options->stat_graph_width;
2681                if (name_width > width - number_width - 6 - graph_width)
2682                        name_width = width - number_width - 6 - graph_width;
2683                else
2684                        graph_width = width - number_width - 6 - name_width;
2685        }
2686
2687        /*
2688         * From here name_width is the width of the name area,
2689         * and graph_width is the width of the graph area.
2690         * max_change is used to scale graph properly.
2691         */
2692        for (i = 0; i < count; i++) {
2693                const char *prefix = "";
2694                struct diffstat_file *file = data->files[i];
2695                char *name = file->print_name;
2696                uintmax_t added = file->added;
2697                uintmax_t deleted = file->deleted;
2698                int name_len;
2699
2700                if (!file->is_interesting && (added + deleted == 0))
2701                        continue;
2702
2703                /*
2704                 * "scale" the filename
2705                 */
2706                len = name_width;
2707                name_len = strlen(name);
2708                if (name_width < name_len) {
2709                        char *slash;
2710                        prefix = "...";
2711                        len -= 3;
2712                        name += name_len - len;
2713                        slash = strchr(name, '/');
2714                        if (slash)
2715                                name = slash;
2716                }
2717
2718                if (file->is_binary) {
2719                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2720                        strbuf_addf(&out, " %*s", number_width, "Bin");
2721                        if (!added && !deleted) {
2722                                strbuf_addch(&out, '\n');
2723                                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2724                                                 out.buf, out.len, 0);
2725                                strbuf_reset(&out);
2726                                continue;
2727                        }
2728                        strbuf_addf(&out, " %s%"PRIuMAX"%s",
2729                                del_c, deleted, reset);
2730                        strbuf_addstr(&out, " -> ");
2731                        strbuf_addf(&out, "%s%"PRIuMAX"%s",
2732                                add_c, added, reset);
2733                        strbuf_addstr(&out, " bytes\n");
2734                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2735                                         out.buf, out.len, 0);
2736                        strbuf_reset(&out);
2737                        continue;
2738                }
2739                else if (file->is_unmerged) {
2740                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2741                        strbuf_addstr(&out, " Unmerged\n");
2742                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2743                                         out.buf, out.len, 0);
2744                        strbuf_reset(&out);
2745                        continue;
2746                }
2747
2748                /*
2749                 * scale the add/delete
2750                 */
2751                add = added;
2752                del = deleted;
2753
2754                if (graph_width <= max_change) {
2755                        int total = scale_linear(add + del, graph_width, max_change);
2756                        if (total < 2 && add && del)
2757                                /* width >= 2 due to the sanity check */
2758                                total = 2;
2759                        if (add < del) {
2760                                add = scale_linear(add, graph_width, max_change);
2761                                del = total - add;
2762                        } else {
2763                                del = scale_linear(del, graph_width, max_change);
2764                                add = total - del;
2765                        }
2766                }
2767                strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2768                strbuf_addf(&out, " %*"PRIuMAX"%s",
2769                        number_width, added + deleted,
2770                        added + deleted ? " " : "");
2771                show_graph(&out, '+', add, add_c, reset);
2772                show_graph(&out, '-', del, del_c, reset);
2773                strbuf_addch(&out, '\n');
2774                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2775                                 out.buf, out.len, 0);
2776                strbuf_reset(&out);
2777        }
2778
2779        for (i = 0; i < data->nr; i++) {
2780                struct diffstat_file *file = data->files[i];
2781                uintmax_t added = file->added;
2782                uintmax_t deleted = file->deleted;
2783
2784                if (file->is_unmerged ||
2785                    (!file->is_interesting && (added + deleted == 0))) {
2786                        total_files--;
2787                        continue;
2788                }
2789
2790                if (!file->is_binary) {
2791                        adds += added;
2792                        dels += deleted;
2793                }
2794                if (i < count)
2795                        continue;
2796                if (!extra_shown)
2797                        emit_diff_symbol(options,
2798                                         DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
2799                                         NULL, 0, 0);
2800                extra_shown = 1;
2801        }
2802
2803        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2804        strbuf_release(&out);
2805}
2806
2807static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
2808{
2809        int i, adds = 0, dels = 0, total_files = data->nr;
2810
2811        if (data->nr == 0)
2812                return;
2813
2814        for (i = 0; i < data->nr; i++) {
2815                int added = data->files[i]->added;
2816                int deleted = data->files[i]->deleted;
2817
2818                if (data->files[i]->is_unmerged ||
2819                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
2820                        total_files--;
2821                } else if (!data->files[i]->is_binary) { /* don't count bytes */
2822                        adds += added;
2823                        dels += deleted;
2824                }
2825        }
2826        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2827}
2828
2829static void show_numstat(struct diffstat_t *data, struct diff_options *options)
2830{
2831        int i;
2832
2833        if (data->nr == 0)
2834                return;
2835
2836        for (i = 0; i < data->nr; i++) {
2837                struct diffstat_file *file = data->files[i];
2838
2839                fprintf(options->file, "%s", diff_line_prefix(options));
2840
2841                if (file->is_binary)
2842                        fprintf(options->file, "-\t-\t");
2843                else
2844                        fprintf(options->file,
2845                                "%"PRIuMAX"\t%"PRIuMAX"\t",
2846                                file->added, file->deleted);
2847                if (options->line_termination) {
2848                        fill_print_name(file);
2849                        if (!file->is_renamed)
2850                                write_name_quoted(file->name, options->file,
2851                                                  options->line_termination);
2852                        else {
2853                                fputs(file->print_name, options->file);
2854                                putc(options->line_termination, options->file);
2855                        }
2856                } else {
2857                        if (file->is_renamed) {
2858                                putc('\0', options->file);
2859                                write_name_quoted(file->from_name, options->file, '\0');
2860                        }
2861                        write_name_quoted(file->name, options->file, '\0');
2862                }
2863        }
2864}
2865
2866struct dirstat_file {
2867        const char *name;
2868        unsigned long changed;
2869};
2870
2871struct dirstat_dir {
2872        struct dirstat_file *files;
2873        int alloc, nr, permille, cumulative;
2874};
2875
2876static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
2877                unsigned long changed, const char *base, int baselen)
2878{
2879        unsigned long sum_changes = 0;
2880        unsigned int sources = 0;
2881        const char *line_prefix = diff_line_prefix(opt);
2882
2883        while (dir->nr) {
2884                struct dirstat_file *f = dir->files;
2885                int namelen = strlen(f->name);
2886                unsigned long changes;
2887                char *slash;
2888
2889                if (namelen < baselen)
2890                        break;
2891                if (memcmp(f->name, base, baselen))
2892                        break;
2893                slash = strchr(f->name + baselen, '/');
2894                if (slash) {
2895                        int newbaselen = slash + 1 - f->name;
2896                        changes = gather_dirstat(opt, dir, changed, f->name, newbaselen);
2897                        sources++;
2898                } else {
2899                        changes = f->changed;
2900                        dir->files++;
2901                        dir->nr--;
2902                        sources += 2;
2903                }
2904                sum_changes += changes;
2905        }
2906
2907        /*
2908         * We don't report dirstat's for
2909         *  - the top level
2910         *  - or cases where everything came from a single directory
2911         *    under this directory (sources == 1).
2912         */
2913        if (baselen && sources != 1) {
2914                if (sum_changes) {
2915                        int permille = sum_changes * 1000 / changed;
2916                        if (permille >= dir->permille) {
2917                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
2918                                        permille / 10, permille % 10, baselen, base);
2919                                if (!dir->cumulative)
2920                                        return 0;
2921                        }
2922                }
2923        }
2924        return sum_changes;
2925}
2926
2927static int dirstat_compare(const void *_a, const void *_b)
2928{
2929        const struct dirstat_file *a = _a;
2930        const struct dirstat_file *b = _b;
2931        return strcmp(a->name, b->name);
2932}
2933
2934static void show_dirstat(struct diff_options *options)
2935{
2936        int i;
2937        unsigned long changed;
2938        struct dirstat_dir dir;
2939        struct diff_queue_struct *q = &diff_queued_diff;
2940
2941        dir.files = NULL;
2942        dir.alloc = 0;
2943        dir.nr = 0;
2944        dir.permille = options->dirstat_permille;
2945        dir.cumulative = options->flags.dirstat_cumulative;
2946
2947        changed = 0;
2948        for (i = 0; i < q->nr; i++) {
2949                struct diff_filepair *p = q->queue[i];
2950                const char *name;
2951                unsigned long copied, added, damage;
2952
2953                name = p->two->path ? p->two->path : p->one->path;
2954
2955                if (p->one->oid_valid && p->two->oid_valid &&
2956                    oideq(&p->one->oid, &p->two->oid)) {
2957                        /*
2958                         * The SHA1 has not changed, so pre-/post-content is
2959                         * identical. We can therefore skip looking at the
2960                         * file contents altogether.
2961                         */
2962                        damage = 0;
2963                        goto found_damage;
2964                }
2965
2966                if (options->flags.dirstat_by_file) {
2967                        /*
2968                         * In --dirstat-by-file mode, we don't really need to
2969                         * look at the actual file contents at all.
2970                         * The fact that the SHA1 changed is enough for us to
2971                         * add this file to the list of results
2972                         * (with each file contributing equal damage).
2973                         */
2974                        damage = 1;
2975                        goto found_damage;
2976                }
2977
2978                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
2979                        diff_populate_filespec(p->one, 0);
2980                        diff_populate_filespec(p->two, 0);
2981                        diffcore_count_changes(p->one, p->two, NULL, NULL,
2982                                               &copied, &added);
2983                        diff_free_filespec_data(p->one);
2984                        diff_free_filespec_data(p->two);
2985                } else if (DIFF_FILE_VALID(p->one)) {
2986                        diff_populate_filespec(p->one, CHECK_SIZE_ONLY);
2987                        copied = added = 0;
2988                        diff_free_filespec_data(p->one);
2989                } else if (DIFF_FILE_VALID(p->two)) {
2990                        diff_populate_filespec(p->two, CHECK_SIZE_ONLY);
2991                        copied = 0;
2992                        added = p->two->size;
2993                        diff_free_filespec_data(p->two);
2994                } else
2995                        continue;
2996
2997                /*
2998                 * Original minus copied is the removed material,
2999                 * added is the new material.  They are both damages
3000                 * made to the preimage.
3001                 * If the resulting damage is zero, we know that
3002                 * diffcore_count_changes() considers the two entries to
3003                 * be identical, but since the oid changed, we
3004                 * know that there must have been _some_ kind of change,
3005                 * so we force all entries to have damage > 0.
3006                 */
3007                damage = (p->one->size - copied) + added;
3008                if (!damage)
3009                        damage = 1;
3010
3011found_damage:
3012                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
3013                dir.files[dir.nr].name = name;
3014                dir.files[dir.nr].changed = damage;
3015                changed += damage;
3016                dir.nr++;
3017        }
3018
3019        /* This can happen even with many files, if everything was renames */
3020        if (!changed)
3021                return;
3022
3023        /* Show all directories with more than x% of the changes */
3024        QSORT(dir.files, dir.nr, dirstat_compare);
3025        gather_dirstat(options, &dir, changed, "", 0);
3026}
3027
3028static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
3029{
3030        int i;
3031        unsigned long changed;
3032        struct dirstat_dir dir;
3033
3034        if (data->nr == 0)
3035                return;
3036
3037        dir.files = NULL;
3038        dir.alloc = 0;
3039        dir.nr = 0;
3040        dir.permille = options->dirstat_permille;
3041        dir.cumulative = options->flags.dirstat_cumulative;
3042
3043        changed = 0;
3044        for (i = 0; i < data->nr; i++) {
3045                struct diffstat_file *file = data->files[i];
3046                unsigned long damage = file->added + file->deleted;
3047                if (file->is_binary)
3048                        /*
3049                         * binary files counts bytes, not lines. Must find some
3050                         * way to normalize binary bytes vs. textual lines.
3051                         * The following heuristic assumes that there are 64
3052                         * bytes per "line".
3053                         * This is stupid and ugly, but very cheap...
3054                         */
3055                        damage = DIV_ROUND_UP(damage, 64);
3056                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
3057                dir.files[dir.nr].name = file->name;
3058                dir.files[dir.nr].changed = damage;
3059                changed += damage;
3060                dir.nr++;
3061        }
3062
3063        /* This can happen even with many files, if everything was renames */
3064        if (!changed)
3065                return;
3066
3067        /* Show all directories with more than x% of the changes */
3068        QSORT(dir.files, dir.nr, dirstat_compare);
3069        gather_dirstat(options, &dir, changed, "", 0);
3070}
3071
3072static void free_diffstat_info(struct diffstat_t *diffstat)
3073{
3074        int i;
3075        for (i = 0; i < diffstat->nr; i++) {
3076                struct diffstat_file *f = diffstat->files[i];
3077                free(f->print_name);
3078                free(f->name);
3079                free(f->from_name);
3080                free(f);
3081        }
3082        free(diffstat->files);
3083}
3084
3085struct checkdiff_t {
3086        const char *filename;
3087        int lineno;
3088        int conflict_marker_size;
3089        struct diff_options *o;
3090        unsigned ws_rule;
3091        unsigned status;
3092};
3093
3094static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
3095{
3096        char firstchar;
3097        int cnt;
3098
3099        if (len < marker_size + 1)
3100                return 0;
3101        firstchar = line[0];
3102        switch (firstchar) {
3103        case '=': case '>': case '<': case '|':
3104                break;
3105        default:
3106                return 0;
3107        }
3108        for (cnt = 1; cnt < marker_size; cnt++)
3109                if (line[cnt] != firstchar)
3110                        return 0;
3111        /* line[1] thru line[marker_size-1] are same as firstchar */
3112        if (len < marker_size + 1 || !isspace(line[marker_size]))
3113                return 0;
3114        return 1;
3115}
3116
3117static void checkdiff_consume(void *priv, char *line, unsigned long len)
3118{
3119        struct checkdiff_t *data = priv;
3120        int marker_size = data->conflict_marker_size;
3121        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
3122        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
3123        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
3124        char *err;
3125        const char *line_prefix;
3126
3127        assert(data->o);
3128        line_prefix = diff_line_prefix(data->o);
3129
3130        if (line[0] == '+') {
3131                unsigned bad;
3132                data->lineno++;
3133                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
3134                        data->status |= 1;
3135                        fprintf(data->o->file,
3136                                "%s%s:%d: leftover conflict marker\n",
3137                                line_prefix, data->filename, data->lineno);
3138                }
3139                bad = ws_check(line + 1, len - 1, data->ws_rule);
3140                if (!bad)
3141                        return;
3142                data->status |= bad;
3143                err = whitespace_error_string(bad);
3144                fprintf(data->o->file, "%s%s:%d: %s.\n",
3145                        line_prefix, data->filename, data->lineno, err);
3146                free(err);
3147                emit_line(data->o, set, reset, line, 1);
3148                ws_check_emit(line + 1, len - 1, data->ws_rule,
3149                              data->o->file, set, reset, ws);
3150        } else if (line[0] == ' ') {
3151                data->lineno++;
3152        } else if (line[0] == '@') {
3153                char *plus = strchr(line, '+');
3154                if (plus)
3155                        data->lineno = strtol(plus, NULL, 10) - 1;
3156                else
3157                        die("invalid diff");
3158        }
3159}
3160
3161static unsigned char *deflate_it(char *data,
3162                                 unsigned long size,
3163                                 unsigned long *result_size)
3164{
3165        int bound;
3166        unsigned char *deflated;
3167        git_zstream stream;
3168
3169        git_deflate_init(&stream, zlib_compression_level);
3170        bound = git_deflate_bound(&stream, size);
3171        deflated = xmalloc(bound);
3172        stream.next_out = deflated;
3173        stream.avail_out = bound;
3174
3175        stream.next_in = (unsigned char *)data;
3176        stream.avail_in = size;
3177        while (git_deflate(&stream, Z_FINISH) == Z_OK)
3178                ; /* nothing */
3179        git_deflate_end(&stream);
3180        *result_size = stream.total_out;
3181        return deflated;
3182}
3183
3184static void emit_binary_diff_body(struct diff_options *o,
3185                                  mmfile_t *one, mmfile_t *two)
3186{
3187        void *cp;
3188        void *delta;
3189        void *deflated;
3190        void *data;
3191        unsigned long orig_size;
3192        unsigned long delta_size;
3193        unsigned long deflate_size;
3194        unsigned long data_size;
3195
3196        /* We could do deflated delta, or we could do just deflated two,
3197         * whichever is smaller.
3198         */
3199        delta = NULL;
3200        deflated = deflate_it(two->ptr, two->size, &deflate_size);
3201        if (one->size && two->size) {
3202                delta = diff_delta(one->ptr, one->size,
3203                                   two->ptr, two->size,
3204                                   &delta_size, deflate_size);
3205                if (delta) {
3206                        void *to_free = delta;
3207                        orig_size = delta_size;
3208                        delta = deflate_it(delta, delta_size, &delta_size);
3209                        free(to_free);
3210                }
3211        }
3212
3213        if (delta && delta_size < deflate_size) {
3214                char *s = xstrfmt("%lu", orig_size);
3215                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
3216                                 s, strlen(s), 0);
3217                free(s);
3218                free(deflated);
3219                data = delta;
3220                data_size = delta_size;
3221        } else {
3222                char *s = xstrfmt("%lu", two->size);
3223                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
3224                                 s, strlen(s), 0);
3225                free(s);
3226                free(delta);
3227                data = deflated;
3228                data_size = deflate_size;
3229        }
3230
3231        /* emit data encoded in base85 */
3232        cp = data;
3233        while (data_size) {
3234                int len;
3235                int bytes = (52 < data_size) ? 52 : data_size;
3236                char line[71];
3237                data_size -= bytes;
3238                if (bytes <= 26)
3239                        line[0] = bytes + 'A' - 1;
3240                else
3241                        line[0] = bytes - 26 + 'a' - 1;
3242                encode_85(line + 1, cp, bytes);
3243                cp = (char *) cp + bytes;
3244
3245                len = strlen(line);
3246                line[len++] = '\n';
3247                line[len] = '\0';
3248
3249                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_BODY,
3250                                 line, len, 0);
3251        }
3252        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_FOOTER, NULL, 0, 0);
3253        free(data);
3254}
3255
3256static void emit_binary_diff(struct diff_options *o,
3257                             mmfile_t *one, mmfile_t *two)
3258{
3259        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER, NULL, 0, 0);
3260        emit_binary_diff_body(o, one, two);
3261        emit_binary_diff_body(o, two, one);
3262}
3263
3264int diff_filespec_is_binary(struct diff_filespec *one)
3265{
3266        if (one->is_binary == -1) {
3267                diff_filespec_load_driver(one);
3268                if (one->driver->binary != -1)
3269                        one->is_binary = one->driver->binary;
3270                else {
3271                        if (!one->data && DIFF_FILE_VALID(one))
3272                                diff_populate_filespec(one, CHECK_BINARY);
3273                        if (one->is_binary == -1 && one->data)
3274                                one->is_binary = buffer_is_binary(one->data,
3275                                                one->size);
3276                        if (one->is_binary == -1)
3277                                one->is_binary = 0;
3278                }
3279        }
3280        return one->is_binary;
3281}
3282
3283static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
3284{
3285        diff_filespec_load_driver(one);
3286        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
3287}
3288
3289void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
3290{
3291        if (!options->a_prefix)
3292                options->a_prefix = a;
3293        if (!options->b_prefix)
3294                options->b_prefix = b;
3295}
3296
3297struct userdiff_driver *get_textconv(struct diff_filespec *one)
3298{
3299        if (!DIFF_FILE_VALID(one))
3300                return NULL;
3301
3302        diff_filespec_load_driver(one);
3303        return userdiff_get_textconv(one->driver);
3304}
3305
3306static void builtin_diff(const char *name_a,
3307                         const char *name_b,
3308                         struct diff_filespec *one,
3309                         struct diff_filespec *two,
3310                         const char *xfrm_msg,
3311                         int must_show_header,
3312                         struct diff_options *o,
3313                         int complete_rewrite)
3314{
3315        mmfile_t mf1, mf2;
3316        const char *lbl[2];
3317        char *a_one, *b_two;
3318        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
3319        const char *reset = diff_get_color_opt(o, DIFF_RESET);
3320        const char *a_prefix, *b_prefix;
3321        struct userdiff_driver *textconv_one = NULL;
3322        struct userdiff_driver *textconv_two = NULL;
3323        struct strbuf header = STRBUF_INIT;
3324        const char *line_prefix = diff_line_prefix(o);
3325
3326        diff_set_mnemonic_prefix(o, "a/", "b/");
3327        if (o->flags.reverse_diff) {
3328                a_prefix = o->b_prefix;
3329                b_prefix = o->a_prefix;
3330        } else {
3331                a_prefix = o->a_prefix;
3332                b_prefix = o->b_prefix;
3333        }
3334
3335        if (o->submodule_format == DIFF_SUBMODULE_LOG &&
3336            (!one->mode || S_ISGITLINK(one->mode)) &&
3337            (!two->mode || S_ISGITLINK(two->mode))) {
3338                show_submodule_summary(o, one->path ? one->path : two->path,
3339                                &one->oid, &two->oid,
3340                                two->dirty_submodule);
3341                return;
3342        } else if (o->submodule_format == DIFF_SUBMODULE_INLINE_DIFF &&
3343                   (!one->mode || S_ISGITLINK(one->mode)) &&
3344                   (!two->mode || S_ISGITLINK(two->mode))) {
3345                show_submodule_inline_diff(o, one->path ? one->path : two->path,
3346                                &one->oid, &two->oid,
3347                                two->dirty_submodule);
3348                return;
3349        }
3350
3351        if (o->flags.allow_textconv) {
3352                textconv_one = get_textconv(one);
3353                textconv_two = get_textconv(two);
3354        }
3355
3356        /* Never use a non-valid filename anywhere if at all possible */
3357        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
3358        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
3359
3360        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
3361        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
3362        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
3363        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
3364        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
3365        if (lbl[0][0] == '/') {
3366                /* /dev/null */
3367                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
3368                if (xfrm_msg)
3369                        strbuf_addstr(&header, xfrm_msg);
3370                must_show_header = 1;
3371        }
3372        else if (lbl[1][0] == '/') {
3373                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
3374                if (xfrm_msg)
3375                        strbuf_addstr(&header, xfrm_msg);
3376                must_show_header = 1;
3377        }
3378        else {
3379                if (one->mode != two->mode) {
3380                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
3381                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
3382                        must_show_header = 1;
3383                }
3384                if (xfrm_msg)
3385                        strbuf_addstr(&header, xfrm_msg);
3386
3387                /*
3388                 * we do not run diff between different kind
3389                 * of objects.
3390                 */
3391                if ((one->mode ^ two->mode) & S_IFMT)
3392                        goto free_ab_and_return;
3393                if (complete_rewrite &&
3394                    (textconv_one || !diff_filespec_is_binary(one)) &&
3395                    (textconv_two || !diff_filespec_is_binary(two))) {
3396                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3397                                         header.buf, header.len, 0);
3398                        strbuf_reset(&header);
3399                        emit_rewrite_diff(name_a, name_b, one, two,
3400                                                textconv_one, textconv_two, o);
3401                        o->found_changes = 1;
3402                        goto free_ab_and_return;
3403                }
3404        }
3405
3406        if (o->irreversible_delete && lbl[1][0] == '/') {
3407                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf,
3408                                 header.len, 0);
3409                strbuf_reset(&header);
3410                goto free_ab_and_return;
3411        } else if (!o->flags.text &&
3412            ( (!textconv_one && diff_filespec_is_binary(one)) ||
3413              (!textconv_two && diff_filespec_is_binary(two)) )) {
3414                struct strbuf sb = STRBUF_INIT;
3415                if (!one->data && !two->data &&
3416                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
3417                    !o->flags.binary) {
3418                        if (oideq(&one->oid, &two->oid)) {
3419                                if (must_show_header)
3420                                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3421                                                         header.buf, header.len,
3422                                                         0);
3423                                goto free_ab_and_return;
3424                        }
3425                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3426                                         header.buf, header.len, 0);
3427                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3428                                    diff_line_prefix(o), lbl[0], lbl[1]);
3429                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3430                                         sb.buf, sb.len, 0);
3431                        strbuf_release(&sb);
3432                        goto free_ab_and_return;
3433                }
3434                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3435                        die("unable to read files to diff");
3436                /* Quite common confusing case */
3437                if (mf1.size == mf2.size &&
3438                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
3439                        if (must_show_header)
3440                                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3441                                                 header.buf, header.len, 0);
3442                        goto free_ab_and_return;
3443                }
3444                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf, header.len, 0);
3445                strbuf_reset(&header);
3446                if (o->flags.binary)
3447                        emit_binary_diff(o, &mf1, &mf2);
3448                else {
3449                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3450                                    diff_line_prefix(o), lbl[0], lbl[1]);
3451                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3452                                         sb.buf, sb.len, 0);
3453                        strbuf_release(&sb);
3454                }
3455                o->found_changes = 1;
3456        } else {
3457                /* Crazy xdl interfaces.. */
3458                const char *diffopts = getenv("GIT_DIFF_OPTS");
3459                const char *v;
3460                xpparam_t xpp;
3461                xdemitconf_t xecfg;
3462                struct emit_callback ecbdata;
3463                const struct userdiff_funcname *pe;
3464
3465                if (must_show_header) {
3466                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3467                                         header.buf, header.len, 0);
3468                        strbuf_reset(&header);
3469                }
3470
3471                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
3472                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
3473
3474                pe = diff_funcname_pattern(one);
3475                if (!pe)
3476                        pe = diff_funcname_pattern(two);
3477
3478                memset(&xpp, 0, sizeof(xpp));
3479                memset(&xecfg, 0, sizeof(xecfg));
3480                memset(&ecbdata, 0, sizeof(ecbdata));
3481                if (o->flags.suppress_diff_headers)
3482                        lbl[0] = NULL;
3483                ecbdata.label_path = lbl;
3484                ecbdata.color_diff = want_color(o->use_color);
3485                ecbdata.ws_rule = whitespace_rule(name_b);
3486                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
3487                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3488                ecbdata.opt = o;
3489                if (header.len && !o->flags.suppress_diff_headers)
3490                        ecbdata.header = &header;
3491                xpp.flags = o->xdl_opts;
3492                xpp.anchors = o->anchors;
3493                xpp.anchors_nr = o->anchors_nr;
3494                xecfg.ctxlen = o->context;
3495                xecfg.interhunkctxlen = o->interhunkcontext;
3496                xecfg.flags = XDL_EMIT_FUNCNAMES;
3497                if (o->flags.funccontext)
3498                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
3499                if (pe)
3500                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
3501                if (!diffopts)
3502                        ;
3503                else if (skip_prefix(diffopts, "--unified=", &v))
3504                        xecfg.ctxlen = strtoul(v, NULL, 10);
3505                else if (skip_prefix(diffopts, "-u", &v))
3506                        xecfg.ctxlen = strtoul(v, NULL, 10);
3507                if (o->word_diff)
3508                        init_diff_words_data(&ecbdata, o, one, two);
3509                if (xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
3510                                  &xpp, &xecfg))
3511                        die("unable to generate diff for %s", one->path);
3512                if (o->word_diff)
3513                        free_diff_words_data(&ecbdata);
3514                if (textconv_one)
3515                        free(mf1.ptr);
3516                if (textconv_two)
3517                        free(mf2.ptr);
3518                xdiff_clear_find_func(&xecfg);
3519        }
3520
3521 free_ab_and_return:
3522        strbuf_release(&header);
3523        diff_free_filespec_data(one);
3524        diff_free_filespec_data(two);
3525        free(a_one);
3526        free(b_two);
3527        return;
3528}
3529
3530static char *get_compact_summary(const struct diff_filepair *p, int is_renamed)
3531{
3532        if (!is_renamed) {
3533                if (p->status == DIFF_STATUS_ADDED) {
3534                        if (S_ISLNK(p->two->mode))
3535                                return "new +l";
3536                        else if ((p->two->mode & 0777) == 0755)
3537                                return "new +x";
3538                        else
3539                                return "new";
3540                } else if (p->status == DIFF_STATUS_DELETED)
3541                        return "gone";
3542        }
3543        if (S_ISLNK(p->one->mode) && !S_ISLNK(p->two->mode))
3544                return "mode -l";
3545        else if (!S_ISLNK(p->one->mode) && S_ISLNK(p->two->mode))
3546                return "mode +l";
3547        else if ((p->one->mode & 0777) == 0644 &&
3548                 (p->two->mode & 0777) == 0755)
3549                return "mode +x";
3550        else if ((p->one->mode & 0777) == 0755 &&
3551                 (p->two->mode & 0777) == 0644)
3552                return "mode -x";
3553        return NULL;
3554}
3555
3556static void builtin_diffstat(const char *name_a, const char *name_b,
3557                             struct diff_filespec *one,
3558                             struct diff_filespec *two,
3559                             struct diffstat_t *diffstat,
3560                             struct diff_options *o,
3561                             struct diff_filepair *p)
3562{
3563        mmfile_t mf1, mf2;
3564        struct diffstat_file *data;
3565        int same_contents;
3566        int complete_rewrite = 0;
3567
3568        if (!DIFF_PAIR_UNMERGED(p)) {
3569                if (p->status == DIFF_STATUS_MODIFIED && p->score)
3570                        complete_rewrite = 1;
3571        }
3572
3573        data = diffstat_add(diffstat, name_a, name_b);
3574        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
3575        if (o->flags.stat_with_summary)
3576                data->comments = get_compact_summary(p, data->is_renamed);
3577
3578        if (!one || !two) {
3579                data->is_unmerged = 1;
3580                return;
3581        }
3582
3583        same_contents = oideq(&one->oid, &two->oid);
3584
3585        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
3586                data->is_binary = 1;
3587                if (same_contents) {
3588                        data->added = 0;
3589                        data->deleted = 0;
3590                } else {
3591                        data->added = diff_filespec_size(two);
3592                        data->deleted = diff_filespec_size(one);
3593                }
3594        }
3595
3596        else if (complete_rewrite) {
3597                diff_populate_filespec(one, 0);
3598                diff_populate_filespec(two, 0);
3599                data->deleted = count_lines(one->data, one->size);
3600                data->added = count_lines(two->data, two->size);
3601        }
3602
3603        else if (!same_contents) {
3604                /* Crazy xdl interfaces.. */
3605                xpparam_t xpp;
3606                xdemitconf_t xecfg;
3607
3608                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3609                        die("unable to read files to diff");
3610
3611                memset(&xpp, 0, sizeof(xpp));
3612                memset(&xecfg, 0, sizeof(xecfg));
3613                xpp.flags = o->xdl_opts;
3614                xpp.anchors = o->anchors;
3615                xpp.anchors_nr = o->anchors_nr;
3616                xecfg.ctxlen = o->context;
3617                xecfg.interhunkctxlen = o->interhunkcontext;
3618                if (xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
3619                                  &xpp, &xecfg))
3620                        die("unable to generate diffstat for %s", one->path);
3621        }
3622
3623        diff_free_filespec_data(one);
3624        diff_free_filespec_data(two);
3625}
3626
3627static void builtin_checkdiff(const char *name_a, const char *name_b,
3628                              const char *attr_path,
3629                              struct diff_filespec *one,
3630                              struct diff_filespec *two,
3631                              struct diff_options *o)
3632{
3633        mmfile_t mf1, mf2;
3634        struct checkdiff_t data;
3635
3636        if (!two)
3637                return;
3638
3639        memset(&data, 0, sizeof(data));
3640        data.filename = name_b ? name_b : name_a;
3641        data.lineno = 0;
3642        data.o = o;
3643        data.ws_rule = whitespace_rule(attr_path);
3644        data.conflict_marker_size = ll_merge_marker_size(attr_path);
3645
3646        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3647                die("unable to read files to diff");
3648
3649        /*
3650         * All the other codepaths check both sides, but not checking
3651         * the "old" side here is deliberate.  We are checking the newly
3652         * introduced changes, and as long as the "new" side is text, we
3653         * can and should check what it introduces.
3654         */
3655        if (diff_filespec_is_binary(two))
3656                goto free_and_return;
3657        else {
3658                /* Crazy xdl interfaces.. */
3659                xpparam_t xpp;
3660                xdemitconf_t xecfg;
3661
3662                memset(&xpp, 0, sizeof(xpp));
3663                memset(&xecfg, 0, sizeof(xecfg));
3664                xecfg.ctxlen = 1; /* at least one context line */
3665                xpp.flags = 0;
3666                if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
3667                                  &xpp, &xecfg))
3668                        die("unable to generate checkdiff for %s", one->path);
3669
3670                if (data.ws_rule & WS_BLANK_AT_EOF) {
3671                        struct emit_callback ecbdata;
3672                        int blank_at_eof;
3673
3674                        ecbdata.ws_rule = data.ws_rule;
3675                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3676                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
3677
3678                        if (blank_at_eof) {
3679                                static char *err;
3680                                if (!err)
3681                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
3682                                fprintf(o->file, "%s:%d: %s.\n",
3683                                        data.filename, blank_at_eof, err);
3684                                data.status = 1; /* report errors */
3685                        }
3686                }
3687        }
3688 free_and_return:
3689        diff_free_filespec_data(one);
3690        diff_free_filespec_data(two);
3691        if (data.status)
3692                o->flags.check_failed = 1;
3693}
3694
3695struct diff_filespec *alloc_filespec(const char *path)
3696{
3697        struct diff_filespec *spec;
3698
3699        FLEXPTR_ALLOC_STR(spec, path, path);
3700        spec->count = 1;
3701        spec->is_binary = -1;
3702        return spec;
3703}
3704
3705void free_filespec(struct diff_filespec *spec)
3706{
3707        if (!--spec->count) {
3708                diff_free_filespec_data(spec);
3709                free(spec);
3710        }
3711}
3712
3713void fill_filespec(struct diff_filespec *spec, const struct object_id *oid,
3714                   int oid_valid, unsigned short mode)
3715{
3716        if (mode) {
3717                spec->mode = canon_mode(mode);
3718                oidcpy(&spec->oid, oid);
3719                spec->oid_valid = oid_valid;
3720        }
3721}
3722
3723/*
3724 * Given a name and sha1 pair, if the index tells us the file in
3725 * the work tree has that object contents, return true, so that
3726 * prepare_temp_file() does not have to inflate and extract.
3727 */
3728static int reuse_worktree_file(const char *name, const struct object_id *oid, int want_file)
3729{
3730        const struct cache_entry *ce;
3731        struct stat st;
3732        int pos, len;
3733
3734        /*
3735         * We do not read the cache ourselves here, because the
3736         * benchmark with my previous version that always reads cache
3737         * shows that it makes things worse for diff-tree comparing
3738         * two linux-2.6 kernel trees in an already checked out work
3739         * tree.  This is because most diff-tree comparisons deal with
3740         * only a small number of files, while reading the cache is
3741         * expensive for a large project, and its cost outweighs the
3742         * savings we get by not inflating the object to a temporary
3743         * file.  Practically, this code only helps when we are used
3744         * by diff-cache --cached, which does read the cache before
3745         * calling us.
3746         */
3747        if (!active_cache)
3748                return 0;
3749
3750        /* We want to avoid the working directory if our caller
3751         * doesn't need the data in a normal file, this system
3752         * is rather slow with its stat/open/mmap/close syscalls,
3753         * and the object is contained in a pack file.  The pack
3754         * is probably already open and will be faster to obtain
3755         * the data through than the working directory.  Loose
3756         * objects however would tend to be slower as they need
3757         * to be individually opened and inflated.
3758         */
3759        if (!FAST_WORKING_DIRECTORY && !want_file && has_object_pack(oid))
3760                return 0;
3761
3762        /*
3763         * Similarly, if we'd have to convert the file contents anyway, that
3764         * makes the optimization not worthwhile.
3765         */
3766        if (!want_file && would_convert_to_git(&the_index, name))
3767                return 0;
3768
3769        len = strlen(name);
3770        pos = cache_name_pos(name, len);
3771        if (pos < 0)
3772                return 0;
3773        ce = active_cache[pos];
3774
3775        /*
3776         * This is not the sha1 we are looking for, or
3777         * unreusable because it is not a regular file.
3778         */
3779        if (!oideq(oid, &ce->oid) || !S_ISREG(ce->ce_mode))
3780                return 0;
3781
3782        /*
3783         * If ce is marked as "assume unchanged", there is no
3784         * guarantee that work tree matches what we are looking for.
3785         */
3786        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
3787                return 0;
3788
3789        /*
3790         * If ce matches the file in the work tree, we can reuse it.
3791         */
3792        if (ce_uptodate(ce) ||
3793            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
3794                return 1;
3795
3796        return 0;
3797}
3798
3799static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
3800{
3801        struct strbuf buf = STRBUF_INIT;
3802        char *dirty = "";
3803
3804        /* Are we looking at the work tree? */
3805        if (s->dirty_submodule)
3806                dirty = "-dirty";
3807
3808        strbuf_addf(&buf, "Subproject commit %s%s\n",
3809                    oid_to_hex(&s->oid), dirty);
3810        s->size = buf.len;
3811        if (size_only) {
3812                s->data = NULL;
3813                strbuf_release(&buf);
3814        } else {
3815                s->data = strbuf_detach(&buf, NULL);
3816                s->should_free = 1;
3817        }
3818        return 0;
3819}
3820
3821/*
3822 * While doing rename detection and pickaxe operation, we may need to
3823 * grab the data for the blob (or file) for our own in-core comparison.
3824 * diff_filespec has data and size fields for this purpose.
3825 */
3826int diff_populate_filespec(struct diff_filespec *s, unsigned int flags)
3827{
3828        int size_only = flags & CHECK_SIZE_ONLY;
3829        int err = 0;
3830        int conv_flags = global_conv_flags_eol;
3831        /*
3832         * demote FAIL to WARN to allow inspecting the situation
3833         * instead of refusing.
3834         */
3835        if (conv_flags & CONV_EOL_RNDTRP_DIE)
3836                conv_flags = CONV_EOL_RNDTRP_WARN;
3837
3838        if (!DIFF_FILE_VALID(s))
3839                die("internal error: asking to populate invalid file.");
3840        if (S_ISDIR(s->mode))
3841                return -1;
3842
3843        if (s->data)
3844                return 0;
3845
3846        if (size_only && 0 < s->size)
3847                return 0;
3848
3849        if (S_ISGITLINK(s->mode))
3850                return diff_populate_gitlink(s, size_only);
3851
3852        if (!s->oid_valid ||
3853            reuse_worktree_file(s->path, &s->oid, 0)) {
3854                struct strbuf buf = STRBUF_INIT;
3855                struct stat st;
3856                int fd;
3857
3858                if (lstat(s->path, &st) < 0) {
3859                err_empty:
3860                        err = -1;
3861                empty:
3862                        s->data = (char *)"";
3863                        s->size = 0;
3864                        return err;
3865                }
3866                s->size = xsize_t(st.st_size);
3867                if (!s->size)
3868                        goto empty;
3869                if (S_ISLNK(st.st_mode)) {
3870                        struct strbuf sb = STRBUF_INIT;
3871
3872                        if (strbuf_readlink(&sb, s->path, s->size))
3873                                goto err_empty;
3874                        s->size = sb.len;
3875                        s->data = strbuf_detach(&sb, NULL);
3876                        s->should_free = 1;
3877                        return 0;
3878                }
3879
3880                /*
3881                 * Even if the caller would be happy with getting
3882                 * only the size, we cannot return early at this
3883                 * point if the path requires us to run the content
3884                 * conversion.
3885                 */
3886                if (size_only && !would_convert_to_git(&the_index, s->path))
3887                        return 0;
3888
3889                /*
3890                 * Note: this check uses xsize_t(st.st_size) that may
3891                 * not be the true size of the blob after it goes
3892                 * through convert_to_git().  This may not strictly be
3893                 * correct, but the whole point of big_file_threshold
3894                 * and is_binary check being that we want to avoid
3895                 * opening the file and inspecting the contents, this
3896                 * is probably fine.
3897                 */
3898                if ((flags & CHECK_BINARY) &&
3899                    s->size > big_file_threshold && s->is_binary == -1) {
3900                        s->is_binary = 1;
3901                        return 0;
3902                }
3903                fd = open(s->path, O_RDONLY);
3904                if (fd < 0)
3905                        goto err_empty;
3906                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
3907                close(fd);
3908                s->should_munmap = 1;
3909
3910                /*
3911                 * Convert from working tree format to canonical git format
3912                 */
3913                if (convert_to_git(&the_index, s->path, s->data, s->size, &buf, conv_flags)) {
3914                        size_t size = 0;
3915                        munmap(s->data, s->size);
3916                        s->should_munmap = 0;
3917                        s->data = strbuf_detach(&buf, &size);
3918                        s->size = size;
3919                        s->should_free = 1;
3920                }
3921        }
3922        else {
3923                enum object_type type;
3924                if (size_only || (flags & CHECK_BINARY)) {
3925                        type = oid_object_info(the_repository, &s->oid,
3926                                               &s->size);
3927                        if (type < 0)
3928                                die("unable to read %s",
3929                                    oid_to_hex(&s->oid));
3930                        if (size_only)
3931                                return 0;
3932                        if (s->size > big_file_threshold && s->is_binary == -1) {
3933                                s->is_binary = 1;
3934                                return 0;
3935                        }
3936                }
3937                s->data = read_object_file(&s->oid, &type, &s->size);
3938                if (!s->data)
3939                        die("unable to read %s", oid_to_hex(&s->oid));
3940                s->should_free = 1;
3941        }
3942        return 0;
3943}
3944
3945void diff_free_filespec_blob(struct diff_filespec *s)
3946{
3947        if (s->should_free)
3948                free(s->data);
3949        else if (s->should_munmap)
3950                munmap(s->data, s->size);
3951
3952        if (s->should_free || s->should_munmap) {
3953                s->should_free = s->should_munmap = 0;
3954                s->data = NULL;
3955        }
3956}
3957
3958void diff_free_filespec_data(struct diff_filespec *s)
3959{
3960        diff_free_filespec_blob(s);
3961        FREE_AND_NULL(s->cnt_data);
3962}
3963
3964static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
3965                           void *blob,
3966                           unsigned long size,
3967                           const struct object_id *oid,
3968                           int mode)
3969{
3970        struct strbuf buf = STRBUF_INIT;
3971        struct strbuf tempfile = STRBUF_INIT;
3972        char *path_dup = xstrdup(path);
3973        const char *base = basename(path_dup);
3974
3975        /* Generate "XXXXXX_basename.ext" */
3976        strbuf_addstr(&tempfile, "XXXXXX_");
3977        strbuf_addstr(&tempfile, base);
3978
3979        temp->tempfile = mks_tempfile_ts(tempfile.buf, strlen(base) + 1);
3980        if (!temp->tempfile)
3981                die_errno("unable to create temp-file");
3982        if (convert_to_working_tree(&the_index, path,
3983                        (const char *)blob, (size_t)size, &buf)) {
3984                blob = buf.buf;
3985                size = buf.len;
3986        }
3987        if (write_in_full(temp->tempfile->fd, blob, size) < 0 ||
3988            close_tempfile_gently(temp->tempfile))
3989                die_errno("unable to write temp-file");
3990        temp->name = get_tempfile_path(temp->tempfile);
3991        oid_to_hex_r(temp->hex, oid);
3992        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
3993        strbuf_release(&buf);
3994        strbuf_release(&tempfile);
3995        free(path_dup);
3996}
3997
3998static struct diff_tempfile *prepare_temp_file(const char *name,
3999                struct diff_filespec *one)
4000{
4001        struct diff_tempfile *temp = claim_diff_tempfile();
4002
4003        if (!DIFF_FILE_VALID(one)) {
4004        not_a_valid_file:
4005                /* A '-' entry produces this for file-2, and
4006                 * a '+' entry produces this for file-1.
4007                 */
4008                temp->name = "/dev/null";
4009                xsnprintf(temp->hex, sizeof(temp->hex), ".");
4010                xsnprintf(temp->mode, sizeof(temp->mode), ".");
4011                return temp;
4012        }
4013
4014        if (!S_ISGITLINK(one->mode) &&
4015            (!one->oid_valid ||
4016             reuse_worktree_file(name, &one->oid, 1))) {
4017                struct stat st;
4018                if (lstat(name, &st) < 0) {
4019                        if (errno == ENOENT)
4020                                goto not_a_valid_file;
4021                        die_errno("stat(%s)", name);
4022                }
4023                if (S_ISLNK(st.st_mode)) {
4024                        struct strbuf sb = STRBUF_INIT;
4025                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
4026                                die_errno("readlink(%s)", name);
4027                        prep_temp_blob(name, temp, sb.buf, sb.len,
4028                                       (one->oid_valid ?
4029                                        &one->oid : &null_oid),
4030                                       (one->oid_valid ?
4031                                        one->mode : S_IFLNK));
4032                        strbuf_release(&sb);
4033                }
4034                else {
4035                        /* we can borrow from the file in the work tree */
4036                        temp->name = name;
4037                        if (!one->oid_valid)
4038                                oid_to_hex_r(temp->hex, &null_oid);
4039                        else
4040                                oid_to_hex_r(temp->hex, &one->oid);
4041                        /* Even though we may sometimes borrow the
4042                         * contents from the work tree, we always want
4043                         * one->mode.  mode is trustworthy even when
4044                         * !(one->oid_valid), as long as
4045                         * DIFF_FILE_VALID(one).
4046                         */
4047                        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
4048                }
4049                return temp;
4050        }
4051        else {
4052                if (diff_populate_filespec(one, 0))
4053                        die("cannot read data blob for %s", one->path);
4054                prep_temp_blob(name, temp, one->data, one->size,
4055                               &one->oid, one->mode);
4056        }
4057        return temp;
4058}
4059
4060static void add_external_diff_name(struct argv_array *argv,
4061                                   const char *name,
4062                                   struct diff_filespec *df)
4063{
4064        struct diff_tempfile *temp = prepare_temp_file(name, df);
4065        argv_array_push(argv, temp->name);
4066        argv_array_push(argv, temp->hex);
4067        argv_array_push(argv, temp->mode);
4068}
4069
4070/* An external diff command takes:
4071 *
4072 * diff-cmd name infile1 infile1-sha1 infile1-mode \
4073 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
4074 *
4075 */
4076static void run_external_diff(const char *pgm,
4077                              const char *name,
4078                              const char *other,
4079                              struct diff_filespec *one,
4080                              struct diff_filespec *two,
4081                              const char *xfrm_msg,
4082                              int complete_rewrite,
4083                              struct diff_options *o)
4084{
4085        struct argv_array argv = ARGV_ARRAY_INIT;
4086        struct argv_array env = ARGV_ARRAY_INIT;
4087        struct diff_queue_struct *q = &diff_queued_diff;
4088
4089        argv_array_push(&argv, pgm);
4090        argv_array_push(&argv, name);
4091
4092        if (one && two) {
4093                add_external_diff_name(&argv, name, one);
4094                if (!other)
4095                        add_external_diff_name(&argv, name, two);
4096                else {
4097                        add_external_diff_name(&argv, other, two);
4098                        argv_array_push(&argv, other);
4099                        argv_array_push(&argv, xfrm_msg);
4100                }
4101        }
4102
4103        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
4104        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
4105
4106        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
4107                die(_("external diff died, stopping at %s"), name);
4108
4109        remove_tempfile();
4110        argv_array_clear(&argv);
4111        argv_array_clear(&env);
4112}
4113
4114static int similarity_index(struct diff_filepair *p)
4115{
4116        return p->score * 100 / MAX_SCORE;
4117}
4118
4119static const char *diff_abbrev_oid(const struct object_id *oid, int abbrev)
4120{
4121        if (startup_info->have_repository)
4122                return find_unique_abbrev(oid, abbrev);
4123        else {
4124                char *hex = oid_to_hex(oid);
4125                if (abbrev < 0)
4126                        abbrev = FALLBACK_DEFAULT_ABBREV;
4127                if (abbrev > the_hash_algo->hexsz)
4128                        BUG("oid abbreviation out of range: %d", abbrev);
4129                if (abbrev)
4130                        hex[abbrev] = '\0';
4131                return hex;
4132        }
4133}
4134
4135static void fill_metainfo(struct strbuf *msg,
4136                          const char *name,
4137                          const char *other,
4138                          struct diff_filespec *one,
4139                          struct diff_filespec *two,
4140                          struct diff_options *o,
4141                          struct diff_filepair *p,
4142                          int *must_show_header,
4143                          int use_color)
4144{
4145        const char *set = diff_get_color(use_color, DIFF_METAINFO);
4146        const char *reset = diff_get_color(use_color, DIFF_RESET);
4147        const char *line_prefix = diff_line_prefix(o);
4148
4149        *must_show_header = 1;
4150        strbuf_init(msg, PATH_MAX * 2 + 300);
4151        switch (p->status) {
4152        case DIFF_STATUS_COPIED:
4153                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4154                            line_prefix, set, similarity_index(p));
4155                strbuf_addf(msg, "%s\n%s%scopy from ",
4156                            reset,  line_prefix, set);
4157                quote_c_style(name, msg, NULL, 0);
4158                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
4159                quote_c_style(other, msg, NULL, 0);
4160                strbuf_addf(msg, "%s\n", reset);
4161                break;
4162        case DIFF_STATUS_RENAMED:
4163                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4164                            line_prefix, set, similarity_index(p));
4165                strbuf_addf(msg, "%s\n%s%srename from ",
4166                            reset, line_prefix, set);
4167                quote_c_style(name, msg, NULL, 0);
4168                strbuf_addf(msg, "%s\n%s%srename to ",
4169                            reset, line_prefix, set);
4170                quote_c_style(other, msg, NULL, 0);
4171                strbuf_addf(msg, "%s\n", reset);
4172                break;
4173        case DIFF_STATUS_MODIFIED:
4174                if (p->score) {
4175                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
4176                                    line_prefix,
4177                                    set, similarity_index(p), reset);
4178                        break;
4179                }
4180                /* fallthru */
4181        default:
4182                *must_show_header = 0;
4183        }
4184        if (one && two && !oideq(&one->oid, &two->oid)) {
4185                const unsigned hexsz = the_hash_algo->hexsz;
4186                int abbrev = o->flags.full_index ? hexsz : DEFAULT_ABBREV;
4187
4188                if (o->flags.binary) {
4189                        mmfile_t mf;
4190                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
4191                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
4192                                abbrev = hexsz;
4193                }
4194                strbuf_addf(msg, "%s%sindex %s..%s", line_prefix, set,
4195                            diff_abbrev_oid(&one->oid, abbrev),
4196                            diff_abbrev_oid(&two->oid, abbrev));
4197                if (one->mode == two->mode)
4198                        strbuf_addf(msg, " %06o", one->mode);
4199                strbuf_addf(msg, "%s\n", reset);
4200        }
4201}
4202
4203static void run_diff_cmd(const char *pgm,
4204                         const char *name,
4205                         const char *other,
4206                         const char *attr_path,
4207                         struct diff_filespec *one,
4208                         struct diff_filespec *two,
4209                         struct strbuf *msg,
4210                         struct diff_options *o,
4211                         struct diff_filepair *p)
4212{
4213        const char *xfrm_msg = NULL;
4214        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
4215        int must_show_header = 0;
4216
4217
4218        if (o->flags.allow_external) {
4219                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
4220                if (drv && drv->external)
4221                        pgm = drv->external;
4222        }
4223
4224        if (msg) {
4225                /*
4226                 * don't use colors when the header is intended for an
4227                 * external diff driver
4228                 */
4229                fill_metainfo(msg, name, other, one, two, o, p,
4230                              &must_show_header,
4231                              want_color(o->use_color) && !pgm);
4232                xfrm_msg = msg->len ? msg->buf : NULL;
4233        }
4234
4235        if (pgm) {
4236                run_external_diff(pgm, name, other, one, two, xfrm_msg,
4237                                  complete_rewrite, o);
4238                return;
4239        }
4240        if (one && two)
4241                builtin_diff(name, other ? other : name,
4242                             one, two, xfrm_msg, must_show_header,
4243                             o, complete_rewrite);
4244        else
4245                fprintf(o->file, "* Unmerged path %s\n", name);
4246}
4247
4248static void diff_fill_oid_info(struct diff_filespec *one)
4249{
4250        if (DIFF_FILE_VALID(one)) {
4251                if (!one->oid_valid) {
4252                        struct stat st;
4253                        if (one->is_stdin) {
4254                                oidclr(&one->oid);
4255                                return;
4256                        }
4257                        if (lstat(one->path, &st) < 0)
4258                                die_errno("stat '%s'", one->path);
4259                        if (index_path(&one->oid, one->path, &st, 0))
4260                                die("cannot hash %s", one->path);
4261                }
4262        }
4263        else
4264                oidclr(&one->oid);
4265}
4266
4267static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
4268{
4269        /* Strip the prefix but do not molest /dev/null and absolute paths */
4270        if (*namep && **namep != '/') {
4271                *namep += prefix_length;
4272                if (**namep == '/')
4273                        ++*namep;
4274        }
4275        if (*otherp && **otherp != '/') {
4276                *otherp += prefix_length;
4277                if (**otherp == '/')
4278                        ++*otherp;
4279        }
4280}
4281
4282static void run_diff(struct diff_filepair *p, struct diff_options *o)
4283{
4284        const char *pgm = external_diff();
4285        struct strbuf msg;
4286        struct diff_filespec *one = p->one;
4287        struct diff_filespec *two = p->two;
4288        const char *name;
4289        const char *other;
4290        const char *attr_path;
4291
4292        name  = one->path;
4293        other = (strcmp(name, two->path) ? two->path : NULL);
4294        attr_path = name;
4295        if (o->prefix_length)
4296                strip_prefix(o->prefix_length, &name, &other);
4297
4298        if (!o->flags.allow_external)
4299                pgm = NULL;
4300
4301        if (DIFF_PAIR_UNMERGED(p)) {
4302                run_diff_cmd(pgm, name, NULL, attr_path,
4303                             NULL, NULL, NULL, o, p);
4304                return;
4305        }
4306
4307        diff_fill_oid_info(one);
4308        diff_fill_oid_info(two);
4309
4310        if (!pgm &&
4311            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
4312            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
4313                /*
4314                 * a filepair that changes between file and symlink
4315                 * needs to be split into deletion and creation.
4316                 */
4317                struct diff_filespec *null = alloc_filespec(two->path);
4318                run_diff_cmd(NULL, name, other, attr_path,
4319                             one, null, &msg, o, p);
4320                free(null);
4321                strbuf_release(&msg);
4322
4323                null = alloc_filespec(one->path);
4324                run_diff_cmd(NULL, name, other, attr_path,
4325                             null, two, &msg, o, p);
4326                free(null);
4327        }
4328        else
4329                run_diff_cmd(pgm, name, other, attr_path,
4330                             one, two, &msg, o, p);
4331
4332        strbuf_release(&msg);
4333}
4334
4335static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
4336                         struct diffstat_t *diffstat)
4337{
4338        const char *name;
4339        const char *other;
4340
4341        if (DIFF_PAIR_UNMERGED(p)) {
4342                /* unmerged */
4343                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, p);
4344                return;
4345        }
4346
4347        name = p->one->path;
4348        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4349
4350        if (o->prefix_length)
4351                strip_prefix(o->prefix_length, &name, &other);
4352
4353        diff_fill_oid_info(p->one);
4354        diff_fill_oid_info(p->two);
4355
4356        builtin_diffstat(name, other, p->one, p->two, diffstat, o, p);
4357}
4358
4359static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
4360{
4361        const char *name;
4362        const char *other;
4363        const char *attr_path;
4364
4365        if (DIFF_PAIR_UNMERGED(p)) {
4366                /* unmerged */
4367                return;
4368        }
4369
4370        name = p->one->path;
4371        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4372        attr_path = other ? other : name;
4373
4374        if (o->prefix_length)
4375                strip_prefix(o->prefix_length, &name, &other);
4376
4377        diff_fill_oid_info(p->one);
4378        diff_fill_oid_info(p->two);
4379
4380        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
4381}
4382
4383void diff_setup(struct diff_options *options)
4384{
4385        memcpy(options, &default_diff_options, sizeof(*options));
4386
4387        options->file = stdout;
4388
4389        options->output_indicators[OUTPUT_INDICATOR_NEW] = '+';
4390        options->output_indicators[OUTPUT_INDICATOR_OLD] = '-';
4391        options->output_indicators[OUTPUT_INDICATOR_CONTEXT] = ' ';
4392        options->abbrev = DEFAULT_ABBREV;
4393        options->line_termination = '\n';
4394        options->break_opt = -1;
4395        options->rename_limit = -1;
4396        options->dirstat_permille = diff_dirstat_permille_default;
4397        options->context = diff_context_default;
4398        options->interhunkcontext = diff_interhunk_context_default;
4399        options->ws_error_highlight = ws_error_highlight_default;
4400        options->flags.rename_empty = 1;
4401        options->objfind = NULL;
4402
4403        /* pathchange left =NULL by default */
4404        options->change = diff_change;
4405        options->add_remove = diff_addremove;
4406        options->use_color = diff_use_color_default;
4407        options->detect_rename = diff_detect_rename_default;
4408        options->xdl_opts |= diff_algorithm;
4409        if (diff_indent_heuristic)
4410                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4411
4412        options->orderfile = diff_order_file_cfg;
4413
4414        if (diff_no_prefix) {
4415                options->a_prefix = options->b_prefix = "";
4416        } else if (!diff_mnemonic_prefix) {
4417                options->a_prefix = "a/";
4418                options->b_prefix = "b/";
4419        }
4420
4421        options->color_moved = diff_color_moved_default;
4422        options->color_moved_ws_handling = diff_color_moved_ws_default;
4423}
4424
4425void diff_setup_done(struct diff_options *options)
4426{
4427        unsigned check_mask = DIFF_FORMAT_NAME |
4428                              DIFF_FORMAT_NAME_STATUS |
4429                              DIFF_FORMAT_CHECKDIFF |
4430                              DIFF_FORMAT_NO_OUTPUT;
4431        /*
4432         * This must be signed because we're comparing against a potentially
4433         * negative value.
4434         */
4435        const int hexsz = the_hash_algo->hexsz;
4436
4437        if (options->set_default)
4438                options->set_default(options);
4439
4440        if (HAS_MULTI_BITS(options->output_format & check_mask))
4441                die(_("--name-only, --name-status, --check and -s are mutually exclusive"));
4442
4443        if (HAS_MULTI_BITS(options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK))
4444                die(_("-G, -S and --find-object are mutually exclusive"));
4445
4446        /*
4447         * Most of the time we can say "there are changes"
4448         * only by checking if there are changed paths, but
4449         * --ignore-whitespace* options force us to look
4450         * inside contents.
4451         */
4452
4453        if ((options->xdl_opts & XDF_WHITESPACE_FLAGS))
4454                options->flags.diff_from_contents = 1;
4455        else
4456                options->flags.diff_from_contents = 0;
4457
4458        if (options->flags.find_copies_harder)
4459                options->detect_rename = DIFF_DETECT_COPY;
4460
4461        if (!options->flags.relative_name)
4462                options->prefix = NULL;
4463        if (options->prefix)
4464                options->prefix_length = strlen(options->prefix);
4465        else
4466                options->prefix_length = 0;
4467
4468        if (options->output_format & (DIFF_FORMAT_NAME |
4469                                      DIFF_FORMAT_NAME_STATUS |
4470                                      DIFF_FORMAT_CHECKDIFF |
4471                                      DIFF_FORMAT_NO_OUTPUT))
4472                options->output_format &= ~(DIFF_FORMAT_RAW |
4473                                            DIFF_FORMAT_NUMSTAT |
4474                                            DIFF_FORMAT_DIFFSTAT |
4475                                            DIFF_FORMAT_SHORTSTAT |
4476                                            DIFF_FORMAT_DIRSTAT |
4477                                            DIFF_FORMAT_SUMMARY |
4478                                            DIFF_FORMAT_PATCH);
4479
4480        /*
4481         * These cases always need recursive; we do not drop caller-supplied
4482         * recursive bits for other formats here.
4483         */
4484        if (options->output_format & (DIFF_FORMAT_PATCH |
4485                                      DIFF_FORMAT_NUMSTAT |
4486                                      DIFF_FORMAT_DIFFSTAT |
4487                                      DIFF_FORMAT_SHORTSTAT |
4488                                      DIFF_FORMAT_DIRSTAT |
4489                                      DIFF_FORMAT_SUMMARY |
4490                                      DIFF_FORMAT_CHECKDIFF))
4491                options->flags.recursive = 1;
4492        /*
4493         * Also pickaxe would not work very well if you do not say recursive
4494         */
4495        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
4496                options->flags.recursive = 1;
4497        /*
4498         * When patches are generated, submodules diffed against the work tree
4499         * must be checked for dirtiness too so it can be shown in the output
4500         */
4501        if (options->output_format & DIFF_FORMAT_PATCH)
4502                options->flags.dirty_submodules = 1;
4503
4504        if (options->detect_rename && options->rename_limit < 0)
4505                options->rename_limit = diff_rename_limit_default;
4506        if (hexsz < options->abbrev)
4507                options->abbrev = hexsz; /* full */
4508
4509        /*
4510         * It does not make sense to show the first hit we happened
4511         * to have found.  It does not make sense not to return with
4512         * exit code in such a case either.
4513         */
4514        if (options->flags.quick) {
4515                options->output_format = DIFF_FORMAT_NO_OUTPUT;
4516                options->flags.exit_with_status = 1;
4517        }
4518
4519        options->diff_path_counter = 0;
4520
4521        if (options->flags.follow_renames && options->pathspec.nr != 1)
4522                die(_("--follow requires exactly one pathspec"));
4523
4524        if (!options->use_color || external_diff())
4525                options->color_moved = 0;
4526}
4527
4528static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
4529{
4530        char c, *eq;
4531        int len;
4532
4533        if (*arg != '-')
4534                return 0;
4535        c = *++arg;
4536        if (!c)
4537                return 0;
4538        if (c == arg_short) {
4539                c = *++arg;
4540                if (!c)
4541                        return 1;
4542                if (val && isdigit(c)) {
4543                        char *end;
4544                        int n = strtoul(arg, &end, 10);
4545                        if (*end)
4546                                return 0;
4547                        *val = n;
4548                        return 1;
4549                }
4550                return 0;
4551        }
4552        if (c != '-')
4553                return 0;
4554        arg++;
4555        eq = strchrnul(arg, '=');
4556        len = eq - arg;
4557        if (!len || strncmp(arg, arg_long, len))
4558                return 0;
4559        if (*eq) {
4560                int n;
4561                char *end;
4562                if (!isdigit(*++eq))
4563                        return 0;
4564                n = strtoul(eq, &end, 10);
4565                if (*end)
4566                        return 0;
4567                *val = n;
4568        }
4569        return 1;
4570}
4571
4572static int diff_scoreopt_parse(const char *opt);
4573
4574static inline int short_opt(char opt, const char **argv,
4575                            const char **optarg)
4576{
4577        const char *arg = argv[0];
4578        if (arg[0] != '-' || arg[1] != opt)
4579                return 0;
4580        if (arg[2] != '\0') {
4581                *optarg = arg + 2;
4582                return 1;
4583        }
4584        if (!argv[1])
4585                die("Option '%c' requires a value", opt);
4586        *optarg = argv[1];
4587        return 2;
4588}
4589
4590int parse_long_opt(const char *opt, const char **argv,
4591                   const char **optarg)
4592{
4593        const char *arg = argv[0];
4594        if (!skip_prefix(arg, "--", &arg))
4595                return 0;
4596        if (!skip_prefix(arg, opt, &arg))
4597                return 0;
4598        if (*arg == '=') { /* stuck form: --option=value */
4599                *optarg = arg + 1;
4600                return 1;
4601        }
4602        if (*arg != '\0')
4603                return 0;
4604        /* separate form: --option value */
4605        if (!argv[1])
4606                die("Option '--%s' requires a value", opt);
4607        *optarg = argv[1];
4608        return 2;
4609}
4610
4611static int stat_opt(struct diff_options *options, const char **av)
4612{
4613        const char *arg = av[0];
4614        char *end;
4615        int width = options->stat_width;
4616        int name_width = options->stat_name_width;
4617        int graph_width = options->stat_graph_width;
4618        int count = options->stat_count;
4619        int argcount = 1;
4620
4621        if (!skip_prefix(arg, "--stat", &arg))
4622                BUG("stat option does not begin with --stat: %s", arg);
4623        end = (char *)arg;
4624
4625        switch (*arg) {
4626        case '-':
4627                if (skip_prefix(arg, "-width", &arg)) {
4628                        if (*arg == '=')
4629                                width = strtoul(arg + 1, &end, 10);
4630                        else if (!*arg && !av[1])
4631                                die_want_option("--stat-width");
4632                        else if (!*arg) {
4633                                width = strtoul(av[1], &end, 10);
4634                                argcount = 2;
4635                        }
4636                } else if (skip_prefix(arg, "-name-width", &arg)) {
4637                        if (*arg == '=')
4638                                name_width = strtoul(arg + 1, &end, 10);
4639                        else if (!*arg && !av[1])
4640                                die_want_option("--stat-name-width");
4641                        else if (!*arg) {
4642                                name_width = strtoul(av[1], &end, 10);
4643                                argcount = 2;
4644                        }
4645                } else if (skip_prefix(arg, "-graph-width", &arg)) {
4646                        if (*arg == '=')
4647                                graph_width = strtoul(arg + 1, &end, 10);
4648                        else if (!*arg && !av[1])
4649                                die_want_option("--stat-graph-width");
4650                        else if (!*arg) {
4651                                graph_width = strtoul(av[1], &end, 10);
4652                                argcount = 2;
4653                        }
4654                } else if (skip_prefix(arg, "-count", &arg)) {
4655                        if (*arg == '=')
4656                                count = strtoul(arg + 1, &end, 10);
4657                        else if (!*arg && !av[1])
4658                                die_want_option("--stat-count");
4659                        else if (!*arg) {
4660                                count = strtoul(av[1], &end, 10);
4661                                argcount = 2;
4662                        }
4663                }
4664                break;
4665        case '=':
4666                width = strtoul(arg+1, &end, 10);
4667                if (*end == ',')
4668                        name_width = strtoul(end+1, &end, 10);
4669                if (*end == ',')
4670                        count = strtoul(end+1, &end, 10);
4671        }
4672
4673        /* Important! This checks all the error cases! */
4674        if (*end)
4675                return 0;
4676        options->output_format |= DIFF_FORMAT_DIFFSTAT;
4677        options->stat_name_width = name_width;
4678        options->stat_graph_width = graph_width;
4679        options->stat_width = width;
4680        options->stat_count = count;
4681        return argcount;
4682}
4683
4684static int parse_dirstat_opt(struct diff_options *options, const char *params)
4685{
4686        struct strbuf errmsg = STRBUF_INIT;
4687        if (parse_dirstat_params(options, params, &errmsg))
4688                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
4689                    errmsg.buf);
4690        strbuf_release(&errmsg);
4691        /*
4692         * The caller knows a dirstat-related option is given from the command
4693         * line; allow it to say "return this_function();"
4694         */
4695        options->output_format |= DIFF_FORMAT_DIRSTAT;
4696        return 1;
4697}
4698
4699static int parse_submodule_opt(struct diff_options *options, const char *value)
4700{
4701        if (parse_submodule_params(options, value))
4702                die(_("Failed to parse --submodule option parameter: '%s'"),
4703                        value);
4704        return 1;
4705}
4706
4707static const char diff_status_letters[] = {
4708        DIFF_STATUS_ADDED,
4709        DIFF_STATUS_COPIED,
4710        DIFF_STATUS_DELETED,
4711        DIFF_STATUS_MODIFIED,
4712        DIFF_STATUS_RENAMED,
4713        DIFF_STATUS_TYPE_CHANGED,
4714        DIFF_STATUS_UNKNOWN,
4715        DIFF_STATUS_UNMERGED,
4716        DIFF_STATUS_FILTER_AON,
4717        DIFF_STATUS_FILTER_BROKEN,
4718        '\0',
4719};
4720
4721static unsigned int filter_bit['Z' + 1];
4722
4723static void prepare_filter_bits(void)
4724{
4725        int i;
4726
4727        if (!filter_bit[DIFF_STATUS_ADDED]) {
4728                for (i = 0; diff_status_letters[i]; i++)
4729                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
4730        }
4731}
4732
4733static unsigned filter_bit_tst(char status, const struct diff_options *opt)
4734{
4735        return opt->filter & filter_bit[(int) status];
4736}
4737
4738static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
4739{
4740        int i, optch;
4741
4742        prepare_filter_bits();
4743
4744        /*
4745         * If there is a negation e.g. 'd' in the input, and we haven't
4746         * initialized the filter field with another --diff-filter, start
4747         * from full set of bits, except for AON.
4748         */
4749        if (!opt->filter) {
4750                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4751                        if (optch < 'a' || 'z' < optch)
4752                                continue;
4753                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
4754                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
4755                        break;
4756                }
4757        }
4758
4759        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4760                unsigned int bit;
4761                int negate;
4762
4763                if ('a' <= optch && optch <= 'z') {
4764                        negate = 1;
4765                        optch = toupper(optch);
4766                } else {
4767                        negate = 0;
4768                }
4769
4770                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
4771                if (!bit)
4772                        return optarg[i];
4773                if (negate)
4774                        opt->filter &= ~bit;
4775                else
4776                        opt->filter |= bit;
4777        }
4778        return 0;
4779}
4780
4781static void enable_patch_output(int *fmt) {
4782        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
4783        *fmt |= DIFF_FORMAT_PATCH;
4784}
4785
4786static int parse_ws_error_highlight_opt(struct diff_options *opt, const char *arg)
4787{
4788        int val = parse_ws_error_highlight(arg);
4789
4790        if (val < 0) {
4791                error("unknown value after ws-error-highlight=%.*s",
4792                      -1 - val, arg);
4793                return 0;
4794        }
4795        opt->ws_error_highlight = val;
4796        return 1;
4797}
4798
4799static int parse_objfind_opt(struct diff_options *opt, const char *arg)
4800{
4801        struct object_id oid;
4802
4803        if (get_oid(arg, &oid))
4804                return error("unable to resolve '%s'", arg);
4805
4806        if (!opt->objfind)
4807                opt->objfind = xcalloc(1, sizeof(*opt->objfind));
4808
4809        opt->pickaxe_opts |= DIFF_PICKAXE_KIND_OBJFIND;
4810        opt->flags.recursive = 1;
4811        opt->flags.tree_in_recursive = 1;
4812        oidset_insert(opt->objfind, &oid);
4813        return 1;
4814}
4815
4816int diff_opt_parse(struct diff_options *options,
4817                   const char **av, int ac, const char *prefix)
4818{
4819        const char *arg = av[0];
4820        const char *optarg;
4821        int argcount;
4822
4823        if (!prefix)
4824                prefix = "";
4825
4826        /* Output format options */
4827        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
4828            || opt_arg(arg, 'U', "unified", &options->context))
4829                enable_patch_output(&options->output_format);
4830        else if (!strcmp(arg, "--raw"))
4831                options->output_format |= DIFF_FORMAT_RAW;
4832        else if (!strcmp(arg, "--patch-with-raw")) {
4833                enable_patch_output(&options->output_format);
4834                options->output_format |= DIFF_FORMAT_RAW;
4835        } else if (!strcmp(arg, "--numstat"))
4836                options->output_format |= DIFF_FORMAT_NUMSTAT;
4837        else if (!strcmp(arg, "--shortstat"))
4838                options->output_format |= DIFF_FORMAT_SHORTSTAT;
4839        else if (skip_prefix(arg, "-X", &arg) ||
4840                 skip_to_optional_arg(arg, "--dirstat", &arg))
4841                return parse_dirstat_opt(options, arg);
4842        else if (!strcmp(arg, "--cumulative"))
4843                return parse_dirstat_opt(options, "cumulative");
4844        else if (skip_to_optional_arg(arg, "--dirstat-by-file", &arg)) {
4845                parse_dirstat_opt(options, "files");
4846                return parse_dirstat_opt(options, arg);
4847        }
4848        else if (!strcmp(arg, "--check"))
4849                options->output_format |= DIFF_FORMAT_CHECKDIFF;
4850        else if (!strcmp(arg, "--summary"))
4851                options->output_format |= DIFF_FORMAT_SUMMARY;
4852        else if (!strcmp(arg, "--patch-with-stat")) {
4853                enable_patch_output(&options->output_format);
4854                options->output_format |= DIFF_FORMAT_DIFFSTAT;
4855        } else if (!strcmp(arg, "--name-only"))
4856                options->output_format |= DIFF_FORMAT_NAME;
4857        else if (!strcmp(arg, "--name-status"))
4858                options->output_format |= DIFF_FORMAT_NAME_STATUS;
4859        else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
4860                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
4861        else if (starts_with(arg, "--stat"))
4862                /* --stat, --stat-width, --stat-name-width, or --stat-count */
4863                return stat_opt(options, av);
4864        else if (!strcmp(arg, "--compact-summary")) {
4865                 options->flags.stat_with_summary = 1;
4866                 options->output_format |= DIFF_FORMAT_DIFFSTAT;
4867        } else if (!strcmp(arg, "--no-compact-summary"))
4868                 options->flags.stat_with_summary = 0;
4869        else if (skip_prefix(arg, "--output-indicator-new=", &arg))
4870                options->output_indicators[OUTPUT_INDICATOR_NEW] = arg[0];
4871        else if (skip_prefix(arg, "--output-indicator-old=", &arg))
4872                options->output_indicators[OUTPUT_INDICATOR_OLD] = arg[0];
4873        else if (skip_prefix(arg, "--output-indicator-context=", &arg))
4874                options->output_indicators[OUTPUT_INDICATOR_CONTEXT] = arg[0];
4875
4876        /* renames options */
4877        else if (starts_with(arg, "-B") ||
4878                 skip_to_optional_arg(arg, "--break-rewrites", NULL)) {
4879                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
4880                        return error("invalid argument to -B: %s", arg+2);
4881        }
4882        else if (starts_with(arg, "-M") ||
4883                 skip_to_optional_arg(arg, "--find-renames", NULL)) {
4884                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4885                        return error("invalid argument to -M: %s", arg+2);
4886                options->detect_rename = DIFF_DETECT_RENAME;
4887        }
4888        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
4889                options->irreversible_delete = 1;
4890        }
4891        else if (starts_with(arg, "-C") ||
4892                 skip_to_optional_arg(arg, "--find-copies", NULL)) {
4893                if (options->detect_rename == DIFF_DETECT_COPY)
4894                        options->flags.find_copies_harder = 1;
4895                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4896                        return error("invalid argument to -C: %s", arg+2);
4897                options->detect_rename = DIFF_DETECT_COPY;
4898        }
4899        else if (!strcmp(arg, "--no-renames"))
4900                options->detect_rename = 0;
4901        else if (!strcmp(arg, "--rename-empty"))
4902                options->flags.rename_empty = 1;
4903        else if (!strcmp(arg, "--no-rename-empty"))
4904                options->flags.rename_empty = 0;
4905        else if (skip_to_optional_arg_default(arg, "--relative", &arg, NULL)) {
4906                options->flags.relative_name = 1;
4907                if (arg)
4908                        options->prefix = arg;
4909        }
4910
4911        /* xdiff options */
4912        else if (!strcmp(arg, "--minimal"))
4913                DIFF_XDL_SET(options, NEED_MINIMAL);
4914        else if (!strcmp(arg, "--no-minimal"))
4915                DIFF_XDL_CLR(options, NEED_MINIMAL);
4916        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
4917                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
4918        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
4919                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
4920        else if (!strcmp(arg, "--ignore-space-at-eol"))
4921                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
4922        else if (!strcmp(arg, "--ignore-cr-at-eol"))
4923                DIFF_XDL_SET(options, IGNORE_CR_AT_EOL);
4924        else if (!strcmp(arg, "--ignore-blank-lines"))
4925                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
4926        else if (!strcmp(arg, "--indent-heuristic"))
4927                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4928        else if (!strcmp(arg, "--no-indent-heuristic"))
4929                DIFF_XDL_CLR(options, INDENT_HEURISTIC);
4930        else if (!strcmp(arg, "--patience")) {
4931                int i;
4932                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4933                /*
4934                 * Both --patience and --anchored use PATIENCE_DIFF
4935                 * internally, so remove any anchors previously
4936                 * specified.
4937                 */
4938                for (i = 0; i < options->anchors_nr; i++)
4939                        free(options->anchors[i]);
4940                options->anchors_nr = 0;
4941        } else if (!strcmp(arg, "--histogram"))
4942                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
4943        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
4944                long value = parse_algorithm_value(optarg);
4945                if (value < 0)
4946                        return error("option diff-algorithm accepts \"myers\", "
4947                                     "\"minimal\", \"patience\" and \"histogram\"");
4948                /* clear out previous settings */
4949                DIFF_XDL_CLR(options, NEED_MINIMAL);
4950                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
4951                options->xdl_opts |= value;
4952                return argcount;
4953        } else if (skip_prefix(arg, "--anchored=", &arg)) {
4954                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4955                ALLOC_GROW(options->anchors, options->anchors_nr + 1,
4956                           options->anchors_alloc);
4957                options->anchors[options->anchors_nr++] = xstrdup(arg);
4958        }
4959
4960        /* flags options */
4961        else if (!strcmp(arg, "--binary")) {
4962                enable_patch_output(&options->output_format);
4963                options->flags.binary = 1;
4964        }
4965        else if (!strcmp(arg, "--full-index"))
4966                options->flags.full_index = 1;
4967        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
4968                options->flags.text = 1;
4969        else if (!strcmp(arg, "-R"))
4970                options->flags.reverse_diff = 1;
4971        else if (!strcmp(arg, "--find-copies-harder"))
4972                options->flags.find_copies_harder = 1;
4973        else if (!strcmp(arg, "--follow"))
4974                options->flags.follow_renames = 1;
4975        else if (!strcmp(arg, "--no-follow")) {
4976                options->flags.follow_renames = 0;
4977                options->flags.default_follow_renames = 0;
4978        } else if (skip_to_optional_arg_default(arg, "--color", &arg, "always")) {
4979                int value = git_config_colorbool(NULL, arg);
4980                if (value < 0)
4981                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
4982                options->use_color = value;
4983        }
4984        else if (!strcmp(arg, "--no-color"))
4985                options->use_color = 0;
4986        else if (!strcmp(arg, "--color-moved")) {
4987                if (diff_color_moved_default)
4988                        options->color_moved = diff_color_moved_default;
4989                if (options->color_moved == COLOR_MOVED_NO)
4990                        options->color_moved = COLOR_MOVED_DEFAULT;
4991        } else if (!strcmp(arg, "--no-color-moved"))
4992                options->color_moved = COLOR_MOVED_NO;
4993        else if (skip_prefix(arg, "--color-moved=", &arg)) {
4994                int cm = parse_color_moved(arg);
4995                if (cm < 0)
4996                        die("bad --color-moved argument: %s", arg);
4997                options->color_moved = cm;
4998        } else if (skip_prefix(arg, "--color-moved-ws=", &arg)) {
4999                options->color_moved_ws_handling = parse_color_moved_ws(arg);
5000        } else if (skip_to_optional_arg_default(arg, "--color-words", &options->word_regex, NULL)) {
5001                options->use_color = 1;
5002                options->word_diff = DIFF_WORDS_COLOR;
5003        }
5004        else if (!strcmp(arg, "--word-diff")) {
5005                if (options->word_diff == DIFF_WORDS_NONE)
5006                        options->word_diff = DIFF_WORDS_PLAIN;
5007        }
5008        else if (skip_prefix(arg, "--word-diff=", &arg)) {
5009                if (!strcmp(arg, "plain"))
5010                        options->word_diff = DIFF_WORDS_PLAIN;
5011                else if (!strcmp(arg, "color")) {
5012                        options->use_color = 1;
5013                        options->word_diff = DIFF_WORDS_COLOR;
5014                }
5015                else if (!strcmp(arg, "porcelain"))
5016                        options->word_diff = DIFF_WORDS_PORCELAIN;
5017                else if (!strcmp(arg, "none"))
5018                        options->word_diff = DIFF_WORDS_NONE;
5019                else
5020                        die("bad --word-diff argument: %s", arg);
5021        }
5022        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
5023                if (options->word_diff == DIFF_WORDS_NONE)
5024                        options->word_diff = DIFF_WORDS_PLAIN;
5025                options->word_regex = optarg;
5026                return argcount;
5027        }
5028        else if (!strcmp(arg, "--exit-code"))
5029                options->flags.exit_with_status = 1;
5030        else if (!strcmp(arg, "--quiet"))
5031                options->flags.quick = 1;
5032        else if (!strcmp(arg, "--ext-diff"))
5033                options->flags.allow_external = 1;
5034        else if (!strcmp(arg, "--no-ext-diff"))
5035                options->flags.allow_external = 0;
5036        else if (!strcmp(arg, "--textconv")) {
5037                options->flags.allow_textconv = 1;
5038                options->flags.textconv_set_via_cmdline = 1;
5039        } else if (!strcmp(arg, "--no-textconv"))
5040                options->flags.allow_textconv = 0;
5041        else if (skip_to_optional_arg_default(arg, "--ignore-submodules", &arg, "all")) {
5042                options->flags.override_submodule_config = 1;
5043                handle_ignore_submodules_arg(options, arg);
5044        } else if (skip_to_optional_arg_default(arg, "--submodule", &arg, "log"))
5045                return parse_submodule_opt(options, arg);
5046        else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
5047                return parse_ws_error_highlight_opt(options, arg);
5048        else if (!strcmp(arg, "--ita-invisible-in-index"))
5049                options->ita_invisible_in_index = 1;
5050        else if (!strcmp(arg, "--ita-visible-in-index"))
5051                options->ita_invisible_in_index = 0;
5052
5053        /* misc options */
5054        else if (!strcmp(arg, "-z"))
5055                options->line_termination = 0;
5056        else if ((argcount = short_opt('l', av, &optarg))) {
5057                options->rename_limit = strtoul(optarg, NULL, 10);
5058                return argcount;
5059        }
5060        else if ((argcount = short_opt('S', av, &optarg))) {
5061                options->pickaxe = optarg;
5062                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
5063                return argcount;
5064        } else if ((argcount = short_opt('G', av, &optarg))) {
5065                options->pickaxe = optarg;
5066                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
5067                return argcount;
5068        }
5069        else if (!strcmp(arg, "--pickaxe-all"))
5070                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
5071        else if (!strcmp(arg, "--pickaxe-regex"))
5072                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
5073        else if ((argcount = short_opt('O', av, &optarg))) {
5074                options->orderfile = prefix_filename(prefix, optarg);
5075                return argcount;
5076        } else if (skip_prefix(arg, "--find-object=", &arg))
5077                return parse_objfind_opt(options, arg);
5078        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
5079                int offending = parse_diff_filter_opt(optarg, options);
5080                if (offending)
5081                        die("unknown change class '%c' in --diff-filter=%s",
5082                            offending, optarg);
5083                return argcount;
5084        }
5085        else if (!strcmp(arg, "--no-abbrev"))
5086                options->abbrev = 0;
5087        else if (!strcmp(arg, "--abbrev"))
5088                options->abbrev = DEFAULT_ABBREV;
5089        else if (skip_prefix(arg, "--abbrev=", &arg)) {
5090                options->abbrev = strtoul(arg, NULL, 10);
5091                if (options->abbrev < MINIMUM_ABBREV)
5092                        options->abbrev = MINIMUM_ABBREV;
5093                else if (the_hash_algo->hexsz < options->abbrev)
5094                        options->abbrev = the_hash_algo->hexsz;
5095        }
5096        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
5097                options->a_prefix = optarg;
5098                return argcount;
5099        }
5100        else if ((argcount = parse_long_opt("line-prefix", av, &optarg))) {
5101                options->line_prefix = optarg;
5102                options->line_prefix_length = strlen(options->line_prefix);
5103                graph_setup_line_prefix(options);
5104                return argcount;
5105        }
5106        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
5107                options->b_prefix = optarg;
5108                return argcount;
5109        }
5110        else if (!strcmp(arg, "--no-prefix"))
5111                options->a_prefix = options->b_prefix = "";
5112        else if (opt_arg(arg, '\0', "inter-hunk-context",
5113                         &options->interhunkcontext))
5114                ;
5115        else if (!strcmp(arg, "-W"))
5116                options->flags.funccontext = 1;
5117        else if (!strcmp(arg, "--function-context"))
5118                options->flags.funccontext = 1;
5119        else if (!strcmp(arg, "--no-function-context"))
5120                options->flags.funccontext = 0;
5121        else if ((argcount = parse_long_opt("output", av, &optarg))) {
5122                char *path = prefix_filename(prefix, optarg);
5123                options->file = xfopen(path, "w");
5124                options->close_file = 1;
5125                if (options->use_color != GIT_COLOR_ALWAYS)
5126                        options->use_color = GIT_COLOR_NEVER;
5127                free(path);
5128                return argcount;
5129        } else
5130                return 0;
5131        return 1;
5132}
5133
5134int parse_rename_score(const char **cp_p)
5135{
5136        unsigned long num, scale;
5137        int ch, dot;
5138        const char *cp = *cp_p;
5139
5140        num = 0;
5141        scale = 1;
5142        dot = 0;
5143        for (;;) {
5144                ch = *cp;
5145                if ( !dot && ch == '.' ) {
5146                        scale = 1;
5147                        dot = 1;
5148                } else if ( ch == '%' ) {
5149                        scale = dot ? scale*100 : 100;
5150                        cp++;   /* % is always at the end */
5151                        break;
5152                } else if ( ch >= '0' && ch <= '9' ) {
5153                        if ( scale < 100000 ) {
5154                                scale *= 10;
5155                                num = (num*10) + (ch-'0');
5156                        }
5157                } else {
5158                        break;
5159                }
5160                cp++;
5161        }
5162        *cp_p = cp;
5163
5164        /* user says num divided by scale and we say internally that
5165         * is MAX_SCORE * num / scale.
5166         */
5167        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
5168}
5169
5170static int diff_scoreopt_parse(const char *opt)
5171{
5172        int opt1, opt2, cmd;
5173
5174        if (*opt++ != '-')
5175                return -1;
5176        cmd = *opt++;
5177        if (cmd == '-') {
5178                /* convert the long-form arguments into short-form versions */
5179                if (skip_prefix(opt, "break-rewrites", &opt)) {
5180                        if (*opt == 0 || *opt++ == '=')
5181                                cmd = 'B';
5182                } else if (skip_prefix(opt, "find-copies", &opt)) {
5183                        if (*opt == 0 || *opt++ == '=')
5184                                cmd = 'C';
5185                } else if (skip_prefix(opt, "find-renames", &opt)) {
5186                        if (*opt == 0 || *opt++ == '=')
5187                                cmd = 'M';
5188                }
5189        }
5190        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
5191                return -1; /* that is not a -M, -C, or -B option */
5192
5193        opt1 = parse_rename_score(&opt);
5194        if (cmd != 'B')
5195                opt2 = 0;
5196        else {
5197                if (*opt == 0)
5198                        opt2 = 0;
5199                else if (*opt != '/')
5200                        return -1; /* we expect -B80/99 or -B80 */
5201                else {
5202                        opt++;
5203                        opt2 = parse_rename_score(&opt);
5204                }
5205        }
5206        if (*opt != 0)
5207                return -1;
5208        return opt1 | (opt2 << 16);
5209}
5210
5211struct diff_queue_struct diff_queued_diff;
5212
5213void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
5214{
5215        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
5216        queue->queue[queue->nr++] = dp;
5217}
5218
5219struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
5220                                 struct diff_filespec *one,
5221                                 struct diff_filespec *two)
5222{
5223        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
5224        dp->one = one;
5225        dp->two = two;
5226        if (queue)
5227                diff_q(queue, dp);
5228        return dp;
5229}
5230
5231void diff_free_filepair(struct diff_filepair *p)
5232{
5233        free_filespec(p->one);
5234        free_filespec(p->two);
5235        free(p);
5236}
5237
5238const char *diff_aligned_abbrev(const struct object_id *oid, int len)
5239{
5240        int abblen;
5241        const char *abbrev;
5242
5243        /* Do we want all 40 hex characters? */
5244        if (len == the_hash_algo->hexsz)
5245                return oid_to_hex(oid);
5246
5247        /* An abbreviated value is fine, possibly followed by an ellipsis. */
5248        abbrev = diff_abbrev_oid(oid, len);
5249
5250        if (!print_sha1_ellipsis())
5251                return abbrev;
5252
5253        abblen = strlen(abbrev);
5254
5255        /*
5256         * In well-behaved cases, where the abbreviated result is the
5257         * same as the requested length, append three dots after the
5258         * abbreviation (hence the whole logic is limited to the case
5259         * where abblen < 37); when the actual abbreviated result is a
5260         * bit longer than the requested length, we reduce the number
5261         * of dots so that they match the well-behaved ones.  However,
5262         * if the actual abbreviation is longer than the requested
5263         * length by more than three, we give up on aligning, and add
5264         * three dots anyway, to indicate that the output is not the
5265         * full object name.  Yes, this may be suboptimal, but this
5266         * appears only in "diff --raw --abbrev" output and it is not
5267         * worth the effort to change it now.  Note that this would
5268         * likely to work fine when the automatic sizing of default
5269         * abbreviation length is used--we would be fed -1 in "len" in
5270         * that case, and will end up always appending three-dots, but
5271         * the automatic sizing is supposed to give abblen that ensures
5272         * uniqueness across all objects (statistically speaking).
5273         */
5274        if (abblen < the_hash_algo->hexsz - 3) {
5275                static char hex[GIT_MAX_HEXSZ + 1];
5276                if (len < abblen && abblen <= len + 2)
5277                        xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
5278                else
5279                        xsnprintf(hex, sizeof(hex), "%s...", abbrev);
5280                return hex;
5281        }
5282
5283        return oid_to_hex(oid);
5284}
5285
5286static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
5287{
5288        int line_termination = opt->line_termination;
5289        int inter_name_termination = line_termination ? '\t' : '\0';
5290
5291        fprintf(opt->file, "%s", diff_line_prefix(opt));
5292        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
5293                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
5294                        diff_aligned_abbrev(&p->one->oid, opt->abbrev));
5295                fprintf(opt->file, "%s ",
5296                        diff_aligned_abbrev(&p->two->oid, opt->abbrev));
5297        }
5298        if (p->score) {
5299                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
5300                        inter_name_termination);
5301        } else {
5302                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
5303        }
5304
5305        if (p->status == DIFF_STATUS_COPIED ||
5306            p->status == DIFF_STATUS_RENAMED) {
5307                const char *name_a, *name_b;
5308                name_a = p->one->path;
5309                name_b = p->two->path;
5310                strip_prefix(opt->prefix_length, &name_a, &name_b);
5311                write_name_quoted(name_a, opt->file, inter_name_termination);
5312                write_name_quoted(name_b, opt->file, line_termination);
5313        } else {
5314                const char *name_a, *name_b;
5315                name_a = p->one->mode ? p->one->path : p->two->path;
5316                name_b = NULL;
5317                strip_prefix(opt->prefix_length, &name_a, &name_b);
5318                write_name_quoted(name_a, opt->file, line_termination);
5319        }
5320}
5321
5322int diff_unmodified_pair(struct diff_filepair *p)
5323{
5324        /* This function is written stricter than necessary to support
5325         * the currently implemented transformers, but the idea is to
5326         * let transformers to produce diff_filepairs any way they want,
5327         * and filter and clean them up here before producing the output.
5328         */
5329        struct diff_filespec *one = p->one, *two = p->two;
5330
5331        if (DIFF_PAIR_UNMERGED(p))
5332                return 0; /* unmerged is interesting */
5333
5334        /* deletion, addition, mode or type change
5335         * and rename are all interesting.
5336         */
5337        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
5338            DIFF_PAIR_MODE_CHANGED(p) ||
5339            strcmp(one->path, two->path))
5340                return 0;
5341
5342        /* both are valid and point at the same path.  that is, we are
5343         * dealing with a change.
5344         */
5345        if (one->oid_valid && two->oid_valid &&
5346            oideq(&one->oid, &two->oid) &&
5347            !one->dirty_submodule && !two->dirty_submodule)
5348                return 1; /* no change */
5349        if (!one->oid_valid && !two->oid_valid)
5350                return 1; /* both look at the same file on the filesystem. */
5351        return 0;
5352}
5353
5354static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
5355{
5356        if (diff_unmodified_pair(p))
5357                return;
5358
5359        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5360            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5361                return; /* no tree diffs in patch format */
5362
5363        run_diff(p, o);
5364}
5365
5366static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
5367                            struct diffstat_t *diffstat)
5368{
5369        if (diff_unmodified_pair(p))
5370                return;
5371
5372        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5373            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5374                return; /* no useful stat for tree diffs */
5375
5376        run_diffstat(p, o, diffstat);
5377}
5378
5379static void diff_flush_checkdiff(struct diff_filepair *p,
5380                struct diff_options *o)
5381{
5382        if (diff_unmodified_pair(p))
5383                return;
5384
5385        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5386            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5387                return; /* nothing to check in tree diffs */
5388
5389        run_checkdiff(p, o);
5390}
5391
5392int diff_queue_is_empty(void)
5393{
5394        struct diff_queue_struct *q = &diff_queued_diff;
5395        int i;
5396        for (i = 0; i < q->nr; i++)
5397                if (!diff_unmodified_pair(q->queue[i]))
5398                        return 0;
5399        return 1;
5400}
5401
5402#if DIFF_DEBUG
5403void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
5404{
5405        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
5406                x, one ? one : "",
5407                s->path,
5408                DIFF_FILE_VALID(s) ? "valid" : "invalid",
5409                s->mode,
5410                s->oid_valid ? oid_to_hex(&s->oid) : "");
5411        fprintf(stderr, "queue[%d] %s size %lu\n",
5412                x, one ? one : "",
5413                s->size);
5414}
5415
5416void diff_debug_filepair(const struct diff_filepair *p, int i)
5417{
5418        diff_debug_filespec(p->one, i, "one");
5419        diff_debug_filespec(p->two, i, "two");
5420        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
5421                p->score, p->status ? p->status : '?',
5422                p->one->rename_used, p->broken_pair);
5423}
5424
5425void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
5426{
5427        int i;
5428        if (msg)
5429                fprintf(stderr, "%s\n", msg);
5430        fprintf(stderr, "q->nr = %d\n", q->nr);
5431        for (i = 0; i < q->nr; i++) {
5432                struct diff_filepair *p = q->queue[i];
5433                diff_debug_filepair(p, i);
5434        }
5435}
5436#endif
5437
5438static void diff_resolve_rename_copy(void)
5439{
5440        int i;
5441        struct diff_filepair *p;
5442        struct diff_queue_struct *q = &diff_queued_diff;
5443
5444        diff_debug_queue("resolve-rename-copy", q);
5445
5446        for (i = 0; i < q->nr; i++) {
5447                p = q->queue[i];
5448                p->status = 0; /* undecided */
5449                if (DIFF_PAIR_UNMERGED(p))
5450                        p->status = DIFF_STATUS_UNMERGED;
5451                else if (!DIFF_FILE_VALID(p->one))
5452                        p->status = DIFF_STATUS_ADDED;
5453                else if (!DIFF_FILE_VALID(p->two))
5454                        p->status = DIFF_STATUS_DELETED;
5455                else if (DIFF_PAIR_TYPE_CHANGED(p))
5456                        p->status = DIFF_STATUS_TYPE_CHANGED;
5457
5458                /* from this point on, we are dealing with a pair
5459                 * whose both sides are valid and of the same type, i.e.
5460                 * either in-place edit or rename/copy edit.
5461                 */
5462                else if (DIFF_PAIR_RENAME(p)) {
5463                        /*
5464                         * A rename might have re-connected a broken
5465                         * pair up, causing the pathnames to be the
5466                         * same again. If so, that's not a rename at
5467                         * all, just a modification..
5468                         *
5469                         * Otherwise, see if this source was used for
5470                         * multiple renames, in which case we decrement
5471                         * the count, and call it a copy.
5472                         */
5473                        if (!strcmp(p->one->path, p->two->path))
5474                                p->status = DIFF_STATUS_MODIFIED;
5475                        else if (--p->one->rename_used > 0)
5476                                p->status = DIFF_STATUS_COPIED;
5477                        else
5478                                p->status = DIFF_STATUS_RENAMED;
5479                }
5480                else if (!oideq(&p->one->oid, &p->two->oid) ||
5481                         p->one->mode != p->two->mode ||
5482                         p->one->dirty_submodule ||
5483                         p->two->dirty_submodule ||
5484                         is_null_oid(&p->one->oid))
5485                        p->status = DIFF_STATUS_MODIFIED;
5486                else {
5487                        /* This is a "no-change" entry and should not
5488                         * happen anymore, but prepare for broken callers.
5489                         */
5490                        error("feeding unmodified %s to diffcore",
5491                              p->one->path);
5492                        p->status = DIFF_STATUS_UNKNOWN;
5493                }
5494        }
5495        diff_debug_queue("resolve-rename-copy done", q);
5496}
5497
5498static int check_pair_status(struct diff_filepair *p)
5499{
5500        switch (p->status) {
5501        case DIFF_STATUS_UNKNOWN:
5502                return 0;
5503        case 0:
5504                die("internal error in diff-resolve-rename-copy");
5505        default:
5506                return 1;
5507        }
5508}
5509
5510static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
5511{
5512        int fmt = opt->output_format;
5513
5514        if (fmt & DIFF_FORMAT_CHECKDIFF)
5515                diff_flush_checkdiff(p, opt);
5516        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
5517                diff_flush_raw(p, opt);
5518        else if (fmt & DIFF_FORMAT_NAME) {
5519                const char *name_a, *name_b;
5520                name_a = p->two->path;
5521                name_b = NULL;
5522                strip_prefix(opt->prefix_length, &name_a, &name_b);
5523                fprintf(opt->file, "%s", diff_line_prefix(opt));
5524                write_name_quoted(name_a, opt->file, opt->line_termination);
5525        }
5526}
5527
5528static void show_file_mode_name(struct diff_options *opt, const char *newdelete, struct diff_filespec *fs)
5529{
5530        struct strbuf sb = STRBUF_INIT;
5531        if (fs->mode)
5532                strbuf_addf(&sb, " %s mode %06o ", newdelete, fs->mode);
5533        else
5534                strbuf_addf(&sb, " %s ", newdelete);
5535
5536        quote_c_style(fs->path, &sb, NULL, 0);
5537        strbuf_addch(&sb, '\n');
5538        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5539                         sb.buf, sb.len, 0);
5540        strbuf_release(&sb);
5541}
5542
5543static void show_mode_change(struct diff_options *opt, struct diff_filepair *p,
5544                int show_name)
5545{
5546        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
5547                struct strbuf sb = STRBUF_INIT;
5548                strbuf_addf(&sb, " mode change %06o => %06o",
5549                            p->one->mode, p->two->mode);
5550                if (show_name) {
5551                        strbuf_addch(&sb, ' ');
5552                        quote_c_style(p->two->path, &sb, NULL, 0);
5553                }
5554                strbuf_addch(&sb, '\n');
5555                emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5556                                 sb.buf, sb.len, 0);
5557                strbuf_release(&sb);
5558        }
5559}
5560
5561static void show_rename_copy(struct diff_options *opt, const char *renamecopy,
5562                struct diff_filepair *p)
5563{
5564        struct strbuf sb = STRBUF_INIT;
5565        struct strbuf names = STRBUF_INIT;
5566
5567        pprint_rename(&names, p->one->path, p->two->path);
5568        strbuf_addf(&sb, " %s %s (%d%%)\n",
5569                    renamecopy, names.buf, similarity_index(p));
5570        strbuf_release(&names);
5571        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5572                                 sb.buf, sb.len, 0);
5573        show_mode_change(opt, p, 0);
5574        strbuf_release(&sb);
5575}
5576
5577static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
5578{
5579        switch(p->status) {
5580        case DIFF_STATUS_DELETED:
5581                show_file_mode_name(opt, "delete", p->one);
5582                break;
5583        case DIFF_STATUS_ADDED:
5584                show_file_mode_name(opt, "create", p->two);
5585                break;
5586        case DIFF_STATUS_COPIED:
5587                show_rename_copy(opt, "copy", p);
5588                break;
5589        case DIFF_STATUS_RENAMED:
5590                show_rename_copy(opt, "rename", p);
5591                break;
5592        default:
5593                if (p->score) {
5594                        struct strbuf sb = STRBUF_INIT;
5595                        strbuf_addstr(&sb, " rewrite ");
5596                        quote_c_style(p->two->path, &sb, NULL, 0);
5597                        strbuf_addf(&sb, " (%d%%)\n", similarity_index(p));
5598                        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5599                                         sb.buf, sb.len, 0);
5600                        strbuf_release(&sb);
5601                }
5602                show_mode_change(opt, p, !p->score);
5603                break;
5604        }
5605}
5606
5607struct patch_id_t {
5608        git_SHA_CTX *ctx;
5609        int patchlen;
5610};
5611
5612static int remove_space(char *line, int len)
5613{
5614        int i;
5615        char *dst = line;
5616        unsigned char c;
5617
5618        for (i = 0; i < len; i++)
5619                if (!isspace((c = line[i])))
5620                        *dst++ = c;
5621
5622        return dst - line;
5623}
5624
5625static void patch_id_consume(void *priv, char *line, unsigned long len)
5626{
5627        struct patch_id_t *data = priv;
5628        int new_len;
5629
5630        /* Ignore line numbers when computing the SHA1 of the patch */
5631        if (starts_with(line, "@@ -"))
5632                return;
5633
5634        new_len = remove_space(line, len);
5635
5636        git_SHA1_Update(data->ctx, line, new_len);
5637        data->patchlen += new_len;
5638}
5639
5640static void patch_id_add_string(git_SHA_CTX *ctx, const char *str)
5641{
5642        git_SHA1_Update(ctx, str, strlen(str));
5643}
5644
5645static void patch_id_add_mode(git_SHA_CTX *ctx, unsigned mode)
5646{
5647        /* large enough for 2^32 in octal */
5648        char buf[12];
5649        int len = xsnprintf(buf, sizeof(buf), "%06o", mode);
5650        git_SHA1_Update(ctx, buf, len);
5651}
5652
5653/* returns 0 upon success, and writes result into sha1 */
5654static int diff_get_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5655{
5656        struct diff_queue_struct *q = &diff_queued_diff;
5657        int i;
5658        git_SHA_CTX ctx;
5659        struct patch_id_t data;
5660
5661        git_SHA1_Init(&ctx);
5662        memset(&data, 0, sizeof(struct patch_id_t));
5663        data.ctx = &ctx;
5664
5665        for (i = 0; i < q->nr; i++) {
5666                xpparam_t xpp;
5667                xdemitconf_t xecfg;
5668                mmfile_t mf1, mf2;
5669                struct diff_filepair *p = q->queue[i];
5670                int len1, len2;
5671
5672                memset(&xpp, 0, sizeof(xpp));
5673                memset(&xecfg, 0, sizeof(xecfg));
5674                if (p->status == 0)
5675                        return error("internal diff status error");
5676                if (p->status == DIFF_STATUS_UNKNOWN)
5677                        continue;
5678                if (diff_unmodified_pair(p))
5679                        continue;
5680                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5681                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5682                        continue;
5683                if (DIFF_PAIR_UNMERGED(p))
5684                        continue;
5685
5686                diff_fill_oid_info(p->one);
5687                diff_fill_oid_info(p->two);
5688
5689                len1 = remove_space(p->one->path, strlen(p->one->path));
5690                len2 = remove_space(p->two->path, strlen(p->two->path));
5691                patch_id_add_string(&ctx, "diff--git");
5692                patch_id_add_string(&ctx, "a/");
5693                git_SHA1_Update(&ctx, p->one->path, len1);
5694                patch_id_add_string(&ctx, "b/");
5695                git_SHA1_Update(&ctx, p->two->path, len2);
5696
5697                if (p->one->mode == 0) {
5698                        patch_id_add_string(&ctx, "newfilemode");
5699                        patch_id_add_mode(&ctx, p->two->mode);
5700                        patch_id_add_string(&ctx, "---/dev/null");
5701                        patch_id_add_string(&ctx, "+++b/");
5702                        git_SHA1_Update(&ctx, p->two->path, len2);
5703                } else if (p->two->mode == 0) {
5704                        patch_id_add_string(&ctx, "deletedfilemode");
5705                        patch_id_add_mode(&ctx, p->one->mode);
5706                        patch_id_add_string(&ctx, "---a/");
5707                        git_SHA1_Update(&ctx, p->one->path, len1);
5708                        patch_id_add_string(&ctx, "+++/dev/null");
5709                } else {
5710                        patch_id_add_string(&ctx, "---a/");
5711                        git_SHA1_Update(&ctx, p->one->path, len1);
5712                        patch_id_add_string(&ctx, "+++b/");
5713                        git_SHA1_Update(&ctx, p->two->path, len2);
5714                }
5715
5716                if (diff_header_only)
5717                        continue;
5718
5719                if (fill_mmfile(&mf1, p->one) < 0 ||
5720                    fill_mmfile(&mf2, p->two) < 0)
5721                        return error("unable to read files to diff");
5722
5723                if (diff_filespec_is_binary(p->one) ||
5724                    diff_filespec_is_binary(p->two)) {
5725                        git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
5726                                        GIT_SHA1_HEXSZ);
5727                        git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
5728                                        GIT_SHA1_HEXSZ);
5729                        continue;
5730                }
5731
5732                xpp.flags = 0;
5733                xecfg.ctxlen = 3;
5734                xecfg.flags = 0;
5735                if (xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
5736                                  &xpp, &xecfg))
5737                        return error("unable to generate patch-id diff for %s",
5738                                     p->one->path);
5739        }
5740
5741        git_SHA1_Final(oid->hash, &ctx);
5742        return 0;
5743}
5744
5745int diff_flush_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5746{
5747        struct diff_queue_struct *q = &diff_queued_diff;
5748        int i;
5749        int result = diff_get_patch_id(options, oid, diff_header_only);
5750
5751        for (i = 0; i < q->nr; i++)
5752                diff_free_filepair(q->queue[i]);
5753
5754        free(q->queue);
5755        DIFF_QUEUE_CLEAR(q);
5756
5757        return result;
5758}
5759
5760static int is_summary_empty(const struct diff_queue_struct *q)
5761{
5762        int i;
5763
5764        for (i = 0; i < q->nr; i++) {
5765                const struct diff_filepair *p = q->queue[i];
5766
5767                switch (p->status) {
5768                case DIFF_STATUS_DELETED:
5769                case DIFF_STATUS_ADDED:
5770                case DIFF_STATUS_COPIED:
5771                case DIFF_STATUS_RENAMED:
5772                        return 0;
5773                default:
5774                        if (p->score)
5775                                return 0;
5776                        if (p->one->mode && p->two->mode &&
5777                            p->one->mode != p->two->mode)
5778                                return 0;
5779                        break;
5780                }
5781        }
5782        return 1;
5783}
5784
5785static const char rename_limit_warning[] =
5786N_("inexact rename detection was skipped due to too many files.");
5787
5788static const char degrade_cc_to_c_warning[] =
5789N_("only found copies from modified paths due to too many files.");
5790
5791static const char rename_limit_advice[] =
5792N_("you may want to set your %s variable to at least "
5793   "%d and retry the command.");
5794
5795void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
5796{
5797        fflush(stdout);
5798        if (degraded_cc)
5799                warning(_(degrade_cc_to_c_warning));
5800        else if (needed)
5801                warning(_(rename_limit_warning));
5802        else
5803                return;
5804        if (0 < needed)
5805                warning(_(rename_limit_advice), varname, needed);
5806}
5807
5808static void diff_flush_patch_all_file_pairs(struct diff_options *o)
5809{
5810        int i;
5811        static struct emitted_diff_symbols esm = EMITTED_DIFF_SYMBOLS_INIT;
5812        struct diff_queue_struct *q = &diff_queued_diff;
5813
5814        if (WSEH_NEW & WS_RULE_MASK)
5815                BUG("WS rules bit mask overlaps with diff symbol flags");
5816
5817        if (o->color_moved)
5818                o->emitted_symbols = &esm;
5819
5820        for (i = 0; i < q->nr; i++) {
5821                struct diff_filepair *p = q->queue[i];
5822                if (check_pair_status(p))
5823                        diff_flush_patch(p, o);
5824        }
5825
5826        if (o->emitted_symbols) {
5827                if (o->color_moved) {
5828                        struct hashmap add_lines, del_lines;
5829
5830                        if (o->color_moved_ws_handling &
5831                            COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
5832                                o->color_moved_ws_handling |= XDF_IGNORE_WHITESPACE;
5833
5834                        hashmap_init(&del_lines, moved_entry_cmp, o, 0);
5835                        hashmap_init(&add_lines, moved_entry_cmp, o, 0);
5836
5837                        add_lines_to_move_detection(o, &add_lines, &del_lines);
5838                        mark_color_as_moved(o, &add_lines, &del_lines);
5839                        if (o->color_moved == COLOR_MOVED_ZEBRA_DIM)
5840                                dim_moved_lines(o);
5841
5842                        hashmap_free(&add_lines, 0);
5843                        hashmap_free(&del_lines, 0);
5844                }
5845
5846                for (i = 0; i < esm.nr; i++)
5847                        emit_diff_symbol_from_struct(o, &esm.buf[i]);
5848
5849                for (i = 0; i < esm.nr; i++)
5850                        free((void *)esm.buf[i].line);
5851        }
5852        esm.nr = 0;
5853}
5854
5855void diff_flush(struct diff_options *options)
5856{
5857        struct diff_queue_struct *q = &diff_queued_diff;
5858        int i, output_format = options->output_format;
5859        int separator = 0;
5860        int dirstat_by_line = 0;
5861
5862        /*
5863         * Order: raw, stat, summary, patch
5864         * or:    name/name-status/checkdiff (other bits clear)
5865         */
5866        if (!q->nr)
5867                goto free_queue;
5868
5869        if (output_format & (DIFF_FORMAT_RAW |
5870                             DIFF_FORMAT_NAME |
5871                             DIFF_FORMAT_NAME_STATUS |
5872                             DIFF_FORMAT_CHECKDIFF)) {
5873                for (i = 0; i < q->nr; i++) {
5874                        struct diff_filepair *p = q->queue[i];
5875                        if (check_pair_status(p))
5876                                flush_one_pair(p, options);
5877                }
5878                separator++;
5879        }
5880
5881        if (output_format & DIFF_FORMAT_DIRSTAT && options->flags.dirstat_by_line)
5882                dirstat_by_line = 1;
5883
5884        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
5885            dirstat_by_line) {
5886                struct diffstat_t diffstat;
5887
5888                memset(&diffstat, 0, sizeof(struct diffstat_t));
5889                for (i = 0; i < q->nr; i++) {
5890                        struct diff_filepair *p = q->queue[i];
5891                        if (check_pair_status(p))
5892                                diff_flush_stat(p, options, &diffstat);
5893                }
5894                if (output_format & DIFF_FORMAT_NUMSTAT)
5895                        show_numstat(&diffstat, options);
5896                if (output_format & DIFF_FORMAT_DIFFSTAT)
5897                        show_stats(&diffstat, options);
5898                if (output_format & DIFF_FORMAT_SHORTSTAT)
5899                        show_shortstats(&diffstat, options);
5900                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
5901                        show_dirstat_by_line(&diffstat, options);
5902                free_diffstat_info(&diffstat);
5903                separator++;
5904        }
5905        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
5906                show_dirstat(options);
5907
5908        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
5909                for (i = 0; i < q->nr; i++) {
5910                        diff_summary(options, q->queue[i]);
5911                }
5912                separator++;
5913        }
5914
5915        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
5916            options->flags.exit_with_status &&
5917            options->flags.diff_from_contents) {
5918                /*
5919                 * run diff_flush_patch for the exit status. setting
5920                 * options->file to /dev/null should be safe, because we
5921                 * aren't supposed to produce any output anyway.
5922                 */
5923                if (options->close_file)
5924                        fclose(options->file);
5925                options->file = xfopen("/dev/null", "w");
5926                options->close_file = 1;
5927                options->color_moved = 0;
5928                for (i = 0; i < q->nr; i++) {
5929                        struct diff_filepair *p = q->queue[i];
5930                        if (check_pair_status(p))
5931                                diff_flush_patch(p, options);
5932                        if (options->found_changes)
5933                                break;
5934                }
5935        }
5936
5937        if (output_format & DIFF_FORMAT_PATCH) {
5938                if (separator) {
5939                        emit_diff_symbol(options, DIFF_SYMBOL_SEPARATOR, NULL, 0, 0);
5940                        if (options->stat_sep)
5941                                /* attach patch instead of inline */
5942                                emit_diff_symbol(options, DIFF_SYMBOL_STAT_SEP,
5943                                                 NULL, 0, 0);
5944                }
5945
5946                diff_flush_patch_all_file_pairs(options);
5947        }
5948
5949        if (output_format & DIFF_FORMAT_CALLBACK)
5950                options->format_callback(q, options, options->format_callback_data);
5951
5952        for (i = 0; i < q->nr; i++)
5953                diff_free_filepair(q->queue[i]);
5954free_queue:
5955        free(q->queue);
5956        DIFF_QUEUE_CLEAR(q);
5957        if (options->close_file)
5958                fclose(options->file);
5959
5960        /*
5961         * Report the content-level differences with HAS_CHANGES;
5962         * diff_addremove/diff_change does not set the bit when
5963         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
5964         */
5965        if (options->flags.diff_from_contents) {
5966                if (options->found_changes)
5967                        options->flags.has_changes = 1;
5968                else
5969                        options->flags.has_changes = 0;
5970        }
5971}
5972
5973static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
5974{
5975        return (((p->status == DIFF_STATUS_MODIFIED) &&
5976                 ((p->score &&
5977                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
5978                  (!p->score &&
5979                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
5980                ((p->status != DIFF_STATUS_MODIFIED) &&
5981                 filter_bit_tst(p->status, options)));
5982}
5983
5984static void diffcore_apply_filter(struct diff_options *options)
5985{
5986        int i;
5987        struct diff_queue_struct *q = &diff_queued_diff;
5988        struct diff_queue_struct outq;
5989
5990        DIFF_QUEUE_CLEAR(&outq);
5991
5992        if (!options->filter)
5993                return;
5994
5995        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
5996                int found;
5997                for (i = found = 0; !found && i < q->nr; i++) {
5998                        if (match_filter(options, q->queue[i]))
5999                                found++;
6000                }
6001                if (found)
6002                        return;
6003
6004                /* otherwise we will clear the whole queue
6005                 * by copying the empty outq at the end of this
6006                 * function, but first clear the current entries
6007                 * in the queue.
6008                 */
6009                for (i = 0; i < q->nr; i++)
6010                        diff_free_filepair(q->queue[i]);
6011        }
6012        else {
6013                /* Only the matching ones */
6014                for (i = 0; i < q->nr; i++) {
6015                        struct diff_filepair *p = q->queue[i];
6016                        if (match_filter(options, p))
6017                                diff_q(&outq, p);
6018                        else
6019                                diff_free_filepair(p);
6020                }
6021        }
6022        free(q->queue);
6023        *q = outq;
6024}
6025
6026/* Check whether two filespecs with the same mode and size are identical */
6027static int diff_filespec_is_identical(struct diff_filespec *one,
6028                                      struct diff_filespec *two)
6029{
6030        if (S_ISGITLINK(one->mode))
6031                return 0;
6032        if (diff_populate_filespec(one, 0))
6033                return 0;
6034        if (diff_populate_filespec(two, 0))
6035                return 0;
6036        return !memcmp(one->data, two->data, one->size);
6037}
6038
6039static int diff_filespec_check_stat_unmatch(struct diff_filepair *p)
6040{
6041        if (p->done_skip_stat_unmatch)
6042                return p->skip_stat_unmatch_result;
6043
6044        p->done_skip_stat_unmatch = 1;
6045        p->skip_stat_unmatch_result = 0;
6046        /*
6047         * 1. Entries that come from stat info dirtiness
6048         *    always have both sides (iow, not create/delete),
6049         *    one side of the object name is unknown, with
6050         *    the same mode and size.  Keep the ones that
6051         *    do not match these criteria.  They have real
6052         *    differences.
6053         *
6054         * 2. At this point, the file is known to be modified,
6055         *    with the same mode and size, and the object
6056         *    name of one side is unknown.  Need to inspect
6057         *    the identical contents.
6058         */
6059        if (!DIFF_FILE_VALID(p->one) || /* (1) */
6060            !DIFF_FILE_VALID(p->two) ||
6061            (p->one->oid_valid && p->two->oid_valid) ||
6062            (p->one->mode != p->two->mode) ||
6063            diff_populate_filespec(p->one, CHECK_SIZE_ONLY) ||
6064            diff_populate_filespec(p->two, CHECK_SIZE_ONLY) ||
6065            (p->one->size != p->two->size) ||
6066            !diff_filespec_is_identical(p->one, p->two)) /* (2) */
6067                p->skip_stat_unmatch_result = 1;
6068        return p->skip_stat_unmatch_result;
6069}
6070
6071static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
6072{
6073        int i;
6074        struct diff_queue_struct *q = &diff_queued_diff;
6075        struct diff_queue_struct outq;
6076        DIFF_QUEUE_CLEAR(&outq);
6077
6078        for (i = 0; i < q->nr; i++) {
6079                struct diff_filepair *p = q->queue[i];
6080
6081                if (diff_filespec_check_stat_unmatch(p))
6082                        diff_q(&outq, p);
6083                else {
6084                        /*
6085                         * The caller can subtract 1 from skip_stat_unmatch
6086                         * to determine how many paths were dirty only
6087                         * due to stat info mismatch.
6088                         */
6089                        if (!diffopt->flags.no_index)
6090                                diffopt->skip_stat_unmatch++;
6091                        diff_free_filepair(p);
6092                }
6093        }
6094        free(q->queue);
6095        *q = outq;
6096}
6097
6098static int diffnamecmp(const void *a_, const void *b_)
6099{
6100        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
6101        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
6102        const char *name_a, *name_b;
6103
6104        name_a = a->one ? a->one->path : a->two->path;
6105        name_b = b->one ? b->one->path : b->two->path;
6106        return strcmp(name_a, name_b);
6107}
6108
6109void diffcore_fix_diff_index(struct diff_options *options)
6110{
6111        struct diff_queue_struct *q = &diff_queued_diff;
6112        QSORT(q->queue, q->nr, diffnamecmp);
6113}
6114
6115void diffcore_std(struct diff_options *options)
6116{
6117        /* NOTE please keep the following in sync with diff_tree_combined() */
6118        if (options->skip_stat_unmatch)
6119                diffcore_skip_stat_unmatch(options);
6120        if (!options->found_follow) {
6121                /* See try_to_follow_renames() in tree-diff.c */
6122                if (options->break_opt != -1)
6123                        diffcore_break(options->break_opt);
6124                if (options->detect_rename)
6125                        diffcore_rename(options);
6126                if (options->break_opt != -1)
6127                        diffcore_merge_broken();
6128        }
6129        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
6130                diffcore_pickaxe(options);
6131        if (options->orderfile)
6132                diffcore_order(options->orderfile);
6133        if (!options->found_follow)
6134                /* See try_to_follow_renames() in tree-diff.c */
6135                diff_resolve_rename_copy();
6136        diffcore_apply_filter(options);
6137
6138        if (diff_queued_diff.nr && !options->flags.diff_from_contents)
6139                options->flags.has_changes = 1;
6140        else
6141                options->flags.has_changes = 0;
6142
6143        options->found_follow = 0;
6144}
6145
6146int diff_result_code(struct diff_options *opt, int status)
6147{
6148        int result = 0;
6149
6150        diff_warn_rename_limit("diff.renameLimit",
6151                               opt->needed_rename_limit,
6152                               opt->degraded_cc_to_c);
6153        if (!opt->flags.exit_with_status &&
6154            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
6155                return status;
6156        if (opt->flags.exit_with_status &&
6157            opt->flags.has_changes)
6158                result |= 01;
6159        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
6160            opt->flags.check_failed)
6161                result |= 02;
6162        return result;
6163}
6164
6165int diff_can_quit_early(struct diff_options *opt)
6166{
6167        return (opt->flags.quick &&
6168                !opt->filter &&
6169                opt->flags.has_changes);
6170}
6171
6172/*
6173 * Shall changes to this submodule be ignored?
6174 *
6175 * Submodule changes can be configured to be ignored separately for each path,
6176 * but that configuration can be overridden from the command line.
6177 */
6178static int is_submodule_ignored(const char *path, struct diff_options *options)
6179{
6180        int ignored = 0;
6181        struct diff_flags orig_flags = options->flags;
6182        if (!options->flags.override_submodule_config)
6183                set_diffopt_flags_from_submodule_config(options, path);
6184        if (options->flags.ignore_submodules)
6185                ignored = 1;
6186        options->flags = orig_flags;
6187        return ignored;
6188}
6189
6190void diff_addremove(struct diff_options *options,
6191                    int addremove, unsigned mode,
6192                    const struct object_id *oid,
6193                    int oid_valid,
6194                    const char *concatpath, unsigned dirty_submodule)
6195{
6196        struct diff_filespec *one, *two;
6197
6198        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
6199                return;
6200
6201        /* This may look odd, but it is a preparation for
6202         * feeding "there are unchanged files which should
6203         * not produce diffs, but when you are doing copy
6204         * detection you would need them, so here they are"
6205         * entries to the diff-core.  They will be prefixed
6206         * with something like '=' or '*' (I haven't decided
6207         * which but should not make any difference).
6208         * Feeding the same new and old to diff_change()
6209         * also has the same effect.
6210         * Before the final output happens, they are pruned after
6211         * merged into rename/copy pairs as appropriate.
6212         */
6213        if (options->flags.reverse_diff)
6214                addremove = (addremove == '+' ? '-' :
6215                             addremove == '-' ? '+' : addremove);
6216
6217        if (options->prefix &&
6218            strncmp(concatpath, options->prefix, options->prefix_length))
6219                return;
6220
6221        one = alloc_filespec(concatpath);
6222        two = alloc_filespec(concatpath);
6223
6224        if (addremove != '+')
6225                fill_filespec(one, oid, oid_valid, mode);
6226        if (addremove != '-') {
6227                fill_filespec(two, oid, oid_valid, mode);
6228                two->dirty_submodule = dirty_submodule;
6229        }
6230
6231        diff_queue(&diff_queued_diff, one, two);
6232        if (!options->flags.diff_from_contents)
6233                options->flags.has_changes = 1;
6234}
6235
6236void diff_change(struct diff_options *options,
6237                 unsigned old_mode, unsigned new_mode,
6238                 const struct object_id *old_oid,
6239                 const struct object_id *new_oid,
6240                 int old_oid_valid, int new_oid_valid,
6241                 const char *concatpath,
6242                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
6243{
6244        struct diff_filespec *one, *two;
6245        struct diff_filepair *p;
6246
6247        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
6248            is_submodule_ignored(concatpath, options))
6249                return;
6250
6251        if (options->flags.reverse_diff) {
6252                SWAP(old_mode, new_mode);
6253                SWAP(old_oid, new_oid);
6254                SWAP(old_oid_valid, new_oid_valid);
6255                SWAP(old_dirty_submodule, new_dirty_submodule);
6256        }
6257
6258        if (options->prefix &&
6259            strncmp(concatpath, options->prefix, options->prefix_length))
6260                return;
6261
6262        one = alloc_filespec(concatpath);
6263        two = alloc_filespec(concatpath);
6264        fill_filespec(one, old_oid, old_oid_valid, old_mode);
6265        fill_filespec(two, new_oid, new_oid_valid, new_mode);
6266        one->dirty_submodule = old_dirty_submodule;
6267        two->dirty_submodule = new_dirty_submodule;
6268        p = diff_queue(&diff_queued_diff, one, two);
6269
6270        if (options->flags.diff_from_contents)
6271                return;
6272
6273        if (options->flags.quick && options->skip_stat_unmatch &&
6274            !diff_filespec_check_stat_unmatch(p))
6275                return;
6276
6277        options->flags.has_changes = 1;
6278}
6279
6280struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
6281{
6282        struct diff_filepair *pair;
6283        struct diff_filespec *one, *two;
6284
6285        if (options->prefix &&
6286            strncmp(path, options->prefix, options->prefix_length))
6287                return NULL;
6288
6289        one = alloc_filespec(path);
6290        two = alloc_filespec(path);
6291        pair = diff_queue(&diff_queued_diff, one, two);
6292        pair->is_unmerged = 1;
6293        return pair;
6294}
6295
6296static char *run_textconv(const char *pgm, struct diff_filespec *spec,
6297                size_t *outsize)
6298{
6299        struct diff_tempfile *temp;
6300        const char *argv[3];
6301        const char **arg = argv;
6302        struct child_process child = CHILD_PROCESS_INIT;
6303        struct strbuf buf = STRBUF_INIT;
6304        int err = 0;
6305
6306        temp = prepare_temp_file(spec->path, spec);
6307        *arg++ = pgm;
6308        *arg++ = temp->name;
6309        *arg = NULL;
6310
6311        child.use_shell = 1;
6312        child.argv = argv;
6313        child.out = -1;
6314        if (start_command(&child)) {
6315                remove_tempfile();
6316                return NULL;
6317        }
6318
6319        if (strbuf_read(&buf, child.out, 0) < 0)
6320                err = error("error reading from textconv command '%s'", pgm);
6321        close(child.out);
6322
6323        if (finish_command(&child) || err) {
6324                strbuf_release(&buf);
6325                remove_tempfile();
6326                return NULL;
6327        }
6328        remove_tempfile();
6329
6330        return strbuf_detach(&buf, outsize);
6331}
6332
6333size_t fill_textconv(struct userdiff_driver *driver,
6334                     struct diff_filespec *df,
6335                     char **outbuf)
6336{
6337        size_t size;
6338
6339        if (!driver) {
6340                if (!DIFF_FILE_VALID(df)) {
6341                        *outbuf = "";
6342                        return 0;
6343                }
6344                if (diff_populate_filespec(df, 0))
6345                        die("unable to read files to diff");
6346                *outbuf = df->data;
6347                return df->size;
6348        }
6349
6350        if (!driver->textconv)
6351                BUG("fill_textconv called with non-textconv driver");
6352
6353        if (driver->textconv_cache && df->oid_valid) {
6354                *outbuf = notes_cache_get(driver->textconv_cache,
6355                                          &df->oid,
6356                                          &size);
6357                if (*outbuf)
6358                        return size;
6359        }
6360
6361        *outbuf = run_textconv(driver->textconv, df, &size);
6362        if (!*outbuf)
6363                die("unable to read files to diff");
6364
6365        if (driver->textconv_cache && df->oid_valid) {
6366                /* ignore errors, as we might be in a readonly repository */
6367                notes_cache_put(driver->textconv_cache, &df->oid, *outbuf,
6368                                size);
6369                /*
6370                 * we could save up changes and flush them all at the end,
6371                 * but we would need an extra call after all diffing is done.
6372                 * Since generating a cache entry is the slow path anyway,
6373                 * this extra overhead probably isn't a big deal.
6374                 */
6375                notes_cache_write(driver->textconv_cache);
6376        }
6377
6378        return size;
6379}
6380
6381int textconv_object(const char *path,
6382                    unsigned mode,
6383                    const struct object_id *oid,
6384                    int oid_valid,
6385                    char **buf,
6386                    unsigned long *buf_size)
6387{
6388        struct diff_filespec *df;
6389        struct userdiff_driver *textconv;
6390
6391        df = alloc_filespec(path);
6392        fill_filespec(df, oid, oid_valid, mode);
6393        textconv = get_textconv(df);
6394        if (!textconv) {
6395                free_filespec(df);
6396                return 0;
6397        }
6398
6399        *buf_size = fill_textconv(textconv, df, buf);
6400        free_filespec(df);
6401        return 1;
6402}
6403
6404void setup_diff_pager(struct diff_options *opt)
6405{
6406        /*
6407         * If the user asked for our exit code, then either they want --quiet
6408         * or --exit-code. We should definitely not bother with a pager in the
6409         * former case, as we will generate no output. Since we still properly
6410         * report our exit code even when a pager is run, we _could_ run a
6411         * pager with --exit-code. But since we have not done so historically,
6412         * and because it is easy to find people oneline advising "git diff
6413         * --exit-code" in hooks and other scripts, we do not do so.
6414         */
6415        if (!opt->flags.exit_with_status &&
6416            check_pager_config("diff") != 0)
6417                setup_pager();
6418}