diff.con commit diff.c: pass sign_index to emit_line_ws_markup (bc9feb0)
   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                                int sign_index, const char *line, int len,
1206                                unsigned ws_rule, int blank_at_eof)
1207{
1208        const char *ws = NULL;
1209        int sign = o->output_indicators[sign_index];
1210
1211        if (o->ws_error_highlight & ws_rule) {
1212                ws = diff_get_color_opt(o, DIFF_WHITESPACE);
1213                if (!*ws)
1214                        ws = NULL;
1215        }
1216
1217        if (!ws && !set_sign)
1218                emit_line_0(o, set, NULL, 0, reset, sign, line, len);
1219        else if (!ws) {
1220                emit_line_0(o, set_sign, set, !!set_sign, reset, sign, line, len);
1221        } else if (blank_at_eof)
1222                /* Blank line at EOF - paint '+' as well */
1223                emit_line_0(o, ws, NULL, 0, reset, sign, line, len);
1224        else {
1225                /* Emit just the prefix, then the rest. */
1226                emit_line_0(o, set_sign ? set_sign : set, NULL, !!set_sign, reset,
1227                            sign, "", 0);
1228                ws_check_emit(line, len, ws_rule,
1229                              o->file, set, reset, ws);
1230        }
1231}
1232
1233static void emit_diff_symbol_from_struct(struct diff_options *o,
1234                                         struct emitted_diff_symbol *eds)
1235{
1236        static const char *nneof = " No newline at end of file\n";
1237        const char *context, *reset, *set, *set_sign, *meta, *fraginfo;
1238        struct strbuf sb = STRBUF_INIT;
1239
1240        enum diff_symbol s = eds->s;
1241        const char *line = eds->line;
1242        int len = eds->len;
1243        unsigned flags = eds->flags;
1244
1245        switch (s) {
1246        case DIFF_SYMBOL_NO_LF_EOF:
1247                context = diff_get_color_opt(o, DIFF_CONTEXT);
1248                reset = diff_get_color_opt(o, DIFF_RESET);
1249                putc('\n', o->file);
1250                emit_line_0(o, context, NULL, 0, reset, '\\',
1251                            nneof, strlen(nneof));
1252                break;
1253        case DIFF_SYMBOL_SUBMODULE_HEADER:
1254        case DIFF_SYMBOL_SUBMODULE_ERROR:
1255        case DIFF_SYMBOL_SUBMODULE_PIPETHROUGH:
1256        case DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES:
1257        case DIFF_SYMBOL_SUMMARY:
1258        case DIFF_SYMBOL_STATS_LINE:
1259        case DIFF_SYMBOL_BINARY_DIFF_BODY:
1260        case DIFF_SYMBOL_CONTEXT_FRAGINFO:
1261                emit_line(o, "", "", line, len);
1262                break;
1263        case DIFF_SYMBOL_CONTEXT_INCOMPLETE:
1264        case DIFF_SYMBOL_CONTEXT_MARKER:
1265                context = diff_get_color_opt(o, DIFF_CONTEXT);
1266                reset = diff_get_color_opt(o, DIFF_RESET);
1267                emit_line(o, context, reset, line, len);
1268                break;
1269        case DIFF_SYMBOL_SEPARATOR:
1270                fprintf(o->file, "%s%c",
1271                        diff_line_prefix(o),
1272                        o->line_termination);
1273                break;
1274        case DIFF_SYMBOL_CONTEXT:
1275                set = diff_get_color_opt(o, DIFF_CONTEXT);
1276                reset = diff_get_color_opt(o, DIFF_RESET);
1277                set_sign = NULL;
1278                if (o->flags.dual_color_diffed_diffs) {
1279                        char c = !len ? 0 : line[0];
1280
1281                        if (c == '+')
1282                                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1283                        else if (c == '@')
1284                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1285                        else if (c == '-')
1286                                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1287                }
1288                emit_line_ws_markup(o, set_sign, set, reset,
1289                                    OUTPUT_INDICATOR_CONTEXT, 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                                    OUTPUT_INDICATOR_NEW, line, len,
1334                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK,
1335                                    flags & DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF);
1336                break;
1337        case DIFF_SYMBOL_MINUS:
1338                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1339                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1340                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1341                case DIFF_SYMBOL_MOVED_LINE |
1342                     DIFF_SYMBOL_MOVED_LINE_ALT |
1343                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1344                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT_DIM);
1345                        break;
1346                case DIFF_SYMBOL_MOVED_LINE |
1347                     DIFF_SYMBOL_MOVED_LINE_ALT:
1348                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT);
1349                        break;
1350                case DIFF_SYMBOL_MOVED_LINE |
1351                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1352                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_DIM);
1353                        break;
1354                case DIFF_SYMBOL_MOVED_LINE:
1355                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED);
1356                        break;
1357                default:
1358                        set = diff_get_color_opt(o, DIFF_FILE_OLD);
1359                }
1360                reset = diff_get_color_opt(o, DIFF_RESET);
1361                if (!o->flags.dual_color_diffed_diffs)
1362                        set_sign = NULL;
1363                else {
1364                        char c = !len ? 0 : line[0];
1365
1366                        set_sign = set;
1367                        if (c == '+')
1368                                set = diff_get_color_opt(o, DIFF_FILE_NEW_DIM);
1369                        else if (c == '@')
1370                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1371                        else if (c == '-')
1372                                set = diff_get_color_opt(o, DIFF_FILE_OLD_DIM);
1373                        else
1374                                set = diff_get_color_opt(o, DIFF_CONTEXT_DIM);
1375                }
1376                emit_line_ws_markup(o, set_sign, set, reset,
1377                                    OUTPUT_INDICATOR_OLD, line, len,
1378                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK, 0);
1379                break;
1380        case DIFF_SYMBOL_WORDS_PORCELAIN:
1381                context = diff_get_color_opt(o, DIFF_CONTEXT);
1382                reset = diff_get_color_opt(o, DIFF_RESET);
1383                emit_line(o, context, reset, line, len);
1384                fputs("~\n", o->file);
1385                break;
1386        case DIFF_SYMBOL_WORDS:
1387                context = diff_get_color_opt(o, DIFF_CONTEXT);
1388                reset = diff_get_color_opt(o, DIFF_RESET);
1389                /*
1390                 * Skip the prefix character, if any.  With
1391                 * diff_suppress_blank_empty, there may be
1392                 * none.
1393                 */
1394                if (line[0] != '\n') {
1395                        line++;
1396                        len--;
1397                }
1398                emit_line(o, context, reset, line, len);
1399                break;
1400        case DIFF_SYMBOL_FILEPAIR_PLUS:
1401                meta = diff_get_color_opt(o, DIFF_METAINFO);
1402                reset = diff_get_color_opt(o, DIFF_RESET);
1403                fprintf(o->file, "%s%s+++ %s%s%s\n", diff_line_prefix(o), meta,
1404                        line, reset,
1405                        strchr(line, ' ') ? "\t" : "");
1406                break;
1407        case DIFF_SYMBOL_FILEPAIR_MINUS:
1408                meta = diff_get_color_opt(o, DIFF_METAINFO);
1409                reset = diff_get_color_opt(o, DIFF_RESET);
1410                fprintf(o->file, "%s%s--- %s%s%s\n", diff_line_prefix(o), meta,
1411                        line, reset,
1412                        strchr(line, ' ') ? "\t" : "");
1413                break;
1414        case DIFF_SYMBOL_BINARY_FILES:
1415        case DIFF_SYMBOL_HEADER:
1416                fprintf(o->file, "%s", line);
1417                break;
1418        case DIFF_SYMBOL_BINARY_DIFF_HEADER:
1419                fprintf(o->file, "%sGIT binary patch\n", diff_line_prefix(o));
1420                break;
1421        case DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA:
1422                fprintf(o->file, "%sdelta %s\n", diff_line_prefix(o), line);
1423                break;
1424        case DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL:
1425                fprintf(o->file, "%sliteral %s\n", diff_line_prefix(o), line);
1426                break;
1427        case DIFF_SYMBOL_BINARY_DIFF_FOOTER:
1428                fputs(diff_line_prefix(o), o->file);
1429                fputc('\n', o->file);
1430                break;
1431        case DIFF_SYMBOL_REWRITE_DIFF:
1432                fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
1433                reset = diff_get_color_opt(o, DIFF_RESET);
1434                emit_line(o, fraginfo, reset, line, len);
1435                break;
1436        case DIFF_SYMBOL_SUBMODULE_ADD:
1437                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1438                reset = diff_get_color_opt(o, DIFF_RESET);
1439                emit_line(o, set, reset, line, len);
1440                break;
1441        case DIFF_SYMBOL_SUBMODULE_DEL:
1442                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1443                reset = diff_get_color_opt(o, DIFF_RESET);
1444                emit_line(o, set, reset, line, len);
1445                break;
1446        case DIFF_SYMBOL_SUBMODULE_UNTRACKED:
1447                fprintf(o->file, "%sSubmodule %s contains untracked content\n",
1448                        diff_line_prefix(o), line);
1449                break;
1450        case DIFF_SYMBOL_SUBMODULE_MODIFIED:
1451                fprintf(o->file, "%sSubmodule %s contains modified content\n",
1452                        diff_line_prefix(o), line);
1453                break;
1454        case DIFF_SYMBOL_STATS_SUMMARY_NO_FILES:
1455                emit_line(o, "", "", " 0 files changed\n",
1456                          strlen(" 0 files changed\n"));
1457                break;
1458        case DIFF_SYMBOL_STATS_SUMMARY_ABBREV:
1459                emit_line(o, "", "", " ...\n", strlen(" ...\n"));
1460                break;
1461        case DIFF_SYMBOL_WORD_DIFF:
1462                fprintf(o->file, "%.*s", len, line);
1463                break;
1464        case DIFF_SYMBOL_STAT_SEP:
1465                fputs(o->stat_sep, o->file);
1466                break;
1467        default:
1468                BUG("unknown diff symbol");
1469        }
1470        strbuf_release(&sb);
1471}
1472
1473static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
1474                             const char *line, int len, unsigned flags)
1475{
1476        struct emitted_diff_symbol e = {line, len, flags, s};
1477
1478        if (o->emitted_symbols)
1479                append_emitted_diff_symbol(o, &e);
1480        else
1481                emit_diff_symbol_from_struct(o, &e);
1482}
1483
1484void diff_emit_submodule_del(struct diff_options *o, const char *line)
1485{
1486        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_DEL, line, strlen(line), 0);
1487}
1488
1489void diff_emit_submodule_add(struct diff_options *o, const char *line)
1490{
1491        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ADD, line, strlen(line), 0);
1492}
1493
1494void diff_emit_submodule_untracked(struct diff_options *o, const char *path)
1495{
1496        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_UNTRACKED,
1497                         path, strlen(path), 0);
1498}
1499
1500void diff_emit_submodule_modified(struct diff_options *o, const char *path)
1501{
1502        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_MODIFIED,
1503                         path, strlen(path), 0);
1504}
1505
1506void diff_emit_submodule_header(struct diff_options *o, const char *header)
1507{
1508        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_HEADER,
1509                         header, strlen(header), 0);
1510}
1511
1512void diff_emit_submodule_error(struct diff_options *o, const char *err)
1513{
1514        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ERROR, err, strlen(err), 0);
1515}
1516
1517void diff_emit_submodule_pipethrough(struct diff_options *o,
1518                                     const char *line, int len)
1519{
1520        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_PIPETHROUGH, line, len, 0);
1521}
1522
1523static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
1524{
1525        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
1526              ecbdata->blank_at_eof_in_preimage &&
1527              ecbdata->blank_at_eof_in_postimage &&
1528              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
1529              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
1530                return 0;
1531        return ws_blank_line(line, len, ecbdata->ws_rule);
1532}
1533
1534static void emit_add_line(const char *reset,
1535                          struct emit_callback *ecbdata,
1536                          const char *line, int len)
1537{
1538        unsigned flags = WSEH_NEW | ecbdata->ws_rule;
1539        if (new_blank_line_at_eof(ecbdata, line, len))
1540                flags |= DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF;
1541
1542        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_PLUS, line, len, flags);
1543}
1544
1545static void emit_del_line(const char *reset,
1546                          struct emit_callback *ecbdata,
1547                          const char *line, int len)
1548{
1549        unsigned flags = WSEH_OLD | ecbdata->ws_rule;
1550        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_MINUS, line, len, flags);
1551}
1552
1553static void emit_context_line(const char *reset,
1554                              struct emit_callback *ecbdata,
1555                              const char *line, int len)
1556{
1557        unsigned flags = WSEH_CONTEXT | ecbdata->ws_rule;
1558        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_CONTEXT, line, len, flags);
1559}
1560
1561static void emit_hunk_header(struct emit_callback *ecbdata,
1562                             const char *line, int len)
1563{
1564        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
1565        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
1566        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
1567        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1568        const char *reverse = ecbdata->color_diff ? GIT_COLOR_REVERSE : "";
1569        static const char atat[2] = { '@', '@' };
1570        const char *cp, *ep;
1571        struct strbuf msgbuf = STRBUF_INIT;
1572        int org_len = len;
1573        int i = 1;
1574
1575        /*
1576         * As a hunk header must begin with "@@ -<old>, +<new> @@",
1577         * it always is at least 10 bytes long.
1578         */
1579        if (len < 10 ||
1580            memcmp(line, atat, 2) ||
1581            !(ep = memmem(line + 2, len - 2, atat, 2))) {
1582                emit_diff_symbol(ecbdata->opt,
1583                                 DIFF_SYMBOL_CONTEXT_MARKER, line, len, 0);
1584                return;
1585        }
1586        ep += 2; /* skip over @@ */
1587
1588        /* The hunk header in fraginfo color */
1589        if (ecbdata->opt->flags.dual_color_diffed_diffs)
1590                strbuf_addstr(&msgbuf, reverse);
1591        strbuf_addstr(&msgbuf, frag);
1592        strbuf_add(&msgbuf, line, ep - line);
1593        strbuf_addstr(&msgbuf, reset);
1594
1595        /*
1596         * trailing "\r\n"
1597         */
1598        for ( ; i < 3; i++)
1599                if (line[len - i] == '\r' || line[len - i] == '\n')
1600                        len--;
1601
1602        /* blank before the func header */
1603        for (cp = ep; ep - line < len; ep++)
1604                if (*ep != ' ' && *ep != '\t')
1605                        break;
1606        if (ep != cp) {
1607                strbuf_addstr(&msgbuf, context);
1608                strbuf_add(&msgbuf, cp, ep - cp);
1609                strbuf_addstr(&msgbuf, reset);
1610        }
1611
1612        if (ep < line + len) {
1613                strbuf_addstr(&msgbuf, func);
1614                strbuf_add(&msgbuf, ep, line + len - ep);
1615                strbuf_addstr(&msgbuf, reset);
1616        }
1617
1618        strbuf_add(&msgbuf, line + len, org_len - len);
1619        strbuf_complete_line(&msgbuf);
1620        emit_diff_symbol(ecbdata->opt,
1621                         DIFF_SYMBOL_CONTEXT_FRAGINFO, msgbuf.buf, msgbuf.len, 0);
1622        strbuf_release(&msgbuf);
1623}
1624
1625static struct diff_tempfile *claim_diff_tempfile(void) {
1626        int i;
1627        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
1628                if (!diff_temp[i].name)
1629                        return diff_temp + i;
1630        BUG("diff is failing to clean up its tempfiles");
1631}
1632
1633static void remove_tempfile(void)
1634{
1635        int i;
1636        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
1637                if (is_tempfile_active(diff_temp[i].tempfile))
1638                        delete_tempfile(&diff_temp[i].tempfile);
1639                diff_temp[i].name = NULL;
1640        }
1641}
1642
1643static void add_line_count(struct strbuf *out, int count)
1644{
1645        switch (count) {
1646        case 0:
1647                strbuf_addstr(out, "0,0");
1648                break;
1649        case 1:
1650                strbuf_addstr(out, "1");
1651                break;
1652        default:
1653                strbuf_addf(out, "1,%d", count);
1654                break;
1655        }
1656}
1657
1658static void emit_rewrite_lines(struct emit_callback *ecb,
1659                               int prefix, const char *data, int size)
1660{
1661        const char *endp = NULL;
1662        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
1663
1664        while (0 < size) {
1665                int len;
1666
1667                endp = memchr(data, '\n', size);
1668                len = endp ? (endp - data + 1) : size;
1669                if (prefix != '+') {
1670                        ecb->lno_in_preimage++;
1671                        emit_del_line(reset, ecb, data, len);
1672                } else {
1673                        ecb->lno_in_postimage++;
1674                        emit_add_line(reset, ecb, data, len);
1675                }
1676                size -= len;
1677                data += len;
1678        }
1679        if (!endp)
1680                emit_diff_symbol(ecb->opt, DIFF_SYMBOL_NO_LF_EOF, NULL, 0, 0);
1681}
1682
1683static void emit_rewrite_diff(const char *name_a,
1684                              const char *name_b,
1685                              struct diff_filespec *one,
1686                              struct diff_filespec *two,
1687                              struct userdiff_driver *textconv_one,
1688                              struct userdiff_driver *textconv_two,
1689                              struct diff_options *o)
1690{
1691        int lc_a, lc_b;
1692        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
1693        const char *a_prefix, *b_prefix;
1694        char *data_one, *data_two;
1695        size_t size_one, size_two;
1696        struct emit_callback ecbdata;
1697        struct strbuf out = STRBUF_INIT;
1698
1699        if (diff_mnemonic_prefix && o->flags.reverse_diff) {
1700                a_prefix = o->b_prefix;
1701                b_prefix = o->a_prefix;
1702        } else {
1703                a_prefix = o->a_prefix;
1704                b_prefix = o->b_prefix;
1705        }
1706
1707        name_a += (*name_a == '/');
1708        name_b += (*name_b == '/');
1709
1710        strbuf_reset(&a_name);
1711        strbuf_reset(&b_name);
1712        quote_two_c_style(&a_name, a_prefix, name_a, 0);
1713        quote_two_c_style(&b_name, b_prefix, name_b, 0);
1714
1715        size_one = fill_textconv(textconv_one, one, &data_one);
1716        size_two = fill_textconv(textconv_two, two, &data_two);
1717
1718        memset(&ecbdata, 0, sizeof(ecbdata));
1719        ecbdata.color_diff = want_color(o->use_color);
1720        ecbdata.ws_rule = whitespace_rule(name_b);
1721        ecbdata.opt = o;
1722        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
1723                mmfile_t mf1, mf2;
1724                mf1.ptr = (char *)data_one;
1725                mf2.ptr = (char *)data_two;
1726                mf1.size = size_one;
1727                mf2.size = size_two;
1728                check_blank_at_eof(&mf1, &mf2, &ecbdata);
1729        }
1730        ecbdata.lno_in_preimage = 1;
1731        ecbdata.lno_in_postimage = 1;
1732
1733        lc_a = count_lines(data_one, size_one);
1734        lc_b = count_lines(data_two, size_two);
1735
1736        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
1737                         a_name.buf, a_name.len, 0);
1738        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
1739                         b_name.buf, b_name.len, 0);
1740
1741        strbuf_addstr(&out, "@@ -");
1742        if (!o->irreversible_delete)
1743                add_line_count(&out, lc_a);
1744        else
1745                strbuf_addstr(&out, "?,?");
1746        strbuf_addstr(&out, " +");
1747        add_line_count(&out, lc_b);
1748        strbuf_addstr(&out, " @@\n");
1749        emit_diff_symbol(o, DIFF_SYMBOL_REWRITE_DIFF, out.buf, out.len, 0);
1750        strbuf_release(&out);
1751
1752        if (lc_a && !o->irreversible_delete)
1753                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
1754        if (lc_b)
1755                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
1756        if (textconv_one)
1757                free((char *)data_one);
1758        if (textconv_two)
1759                free((char *)data_two);
1760}
1761
1762struct diff_words_buffer {
1763        mmfile_t text;
1764        unsigned long alloc;
1765        struct diff_words_orig {
1766                const char *begin, *end;
1767        } *orig;
1768        int orig_nr, orig_alloc;
1769};
1770
1771static void diff_words_append(char *line, unsigned long len,
1772                struct diff_words_buffer *buffer)
1773{
1774        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
1775        line++;
1776        len--;
1777        memcpy(buffer->text.ptr + buffer->text.size, line, len);
1778        buffer->text.size += len;
1779        buffer->text.ptr[buffer->text.size] = '\0';
1780}
1781
1782struct diff_words_style_elem {
1783        const char *prefix;
1784        const char *suffix;
1785        const char *color; /* NULL; filled in by the setup code if
1786                            * color is enabled */
1787};
1788
1789struct diff_words_style {
1790        enum diff_words_type type;
1791        struct diff_words_style_elem new_word, old_word, ctx;
1792        const char *newline;
1793};
1794
1795static struct diff_words_style diff_words_styles[] = {
1796        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
1797        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
1798        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
1799};
1800
1801struct diff_words_data {
1802        struct diff_words_buffer minus, plus;
1803        const char *current_plus;
1804        int last_minus;
1805        struct diff_options *opt;
1806        regex_t *word_regex;
1807        enum diff_words_type type;
1808        struct diff_words_style *style;
1809};
1810
1811static int fn_out_diff_words_write_helper(struct diff_options *o,
1812                                          struct diff_words_style_elem *st_el,
1813                                          const char *newline,
1814                                          size_t count, const char *buf)
1815{
1816        int print = 0;
1817        struct strbuf sb = STRBUF_INIT;
1818
1819        while (count) {
1820                char *p = memchr(buf, '\n', count);
1821                if (print)
1822                        strbuf_addstr(&sb, diff_line_prefix(o));
1823
1824                if (p != buf) {
1825                        const char *reset = st_el->color && *st_el->color ?
1826                                            GIT_COLOR_RESET : NULL;
1827                        if (st_el->color && *st_el->color)
1828                                strbuf_addstr(&sb, st_el->color);
1829                        strbuf_addstr(&sb, st_el->prefix);
1830                        strbuf_add(&sb, buf, p ? p - buf : count);
1831                        strbuf_addstr(&sb, st_el->suffix);
1832                        if (reset)
1833                                strbuf_addstr(&sb, reset);
1834                }
1835                if (!p)
1836                        goto out;
1837
1838                strbuf_addstr(&sb, newline);
1839                count -= p + 1 - buf;
1840                buf = p + 1;
1841                print = 1;
1842                if (count) {
1843                        emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1844                                         sb.buf, sb.len, 0);
1845                        strbuf_reset(&sb);
1846                }
1847        }
1848
1849out:
1850        if (sb.len)
1851                emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1852                                 sb.buf, sb.len, 0);
1853        strbuf_release(&sb);
1854        return 0;
1855}
1856
1857/*
1858 * '--color-words' algorithm can be described as:
1859 *
1860 *   1. collect the minus/plus lines of a diff hunk, divided into
1861 *      minus-lines and plus-lines;
1862 *
1863 *   2. break both minus-lines and plus-lines into words and
1864 *      place them into two mmfile_t with one word for each line;
1865 *
1866 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
1867 *
1868 * And for the common parts of the both file, we output the plus side text.
1869 * diff_words->current_plus is used to trace the current position of the plus file
1870 * which printed. diff_words->last_minus is used to trace the last minus word
1871 * printed.
1872 *
1873 * For '--graph' to work with '--color-words', we need to output the graph prefix
1874 * on each line of color words output. Generally, there are two conditions on
1875 * which we should output the prefix.
1876 *
1877 *   1. diff_words->last_minus == 0 &&
1878 *      diff_words->current_plus == diff_words->plus.text.ptr
1879 *
1880 *      that is: the plus text must start as a new line, and if there is no minus
1881 *      word printed, a graph prefix must be printed.
1882 *
1883 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
1884 *      *(diff_words->current_plus - 1) == '\n'
1885 *
1886 *      that is: a graph prefix must be printed following a '\n'
1887 */
1888static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
1889{
1890        if ((diff_words->last_minus == 0 &&
1891                diff_words->current_plus == diff_words->plus.text.ptr) ||
1892                (diff_words->current_plus > diff_words->plus.text.ptr &&
1893                *(diff_words->current_plus - 1) == '\n')) {
1894                return 1;
1895        } else {
1896                return 0;
1897        }
1898}
1899
1900static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
1901{
1902        struct diff_words_data *diff_words = priv;
1903        struct diff_words_style *style = diff_words->style;
1904        int minus_first, minus_len, plus_first, plus_len;
1905        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
1906        struct diff_options *opt = diff_words->opt;
1907        const char *line_prefix;
1908
1909        if (line[0] != '@' || parse_hunk_header(line, len,
1910                        &minus_first, &minus_len, &plus_first, &plus_len))
1911                return;
1912
1913        assert(opt);
1914        line_prefix = diff_line_prefix(opt);
1915
1916        /* POSIX requires that first be decremented by one if len == 0... */
1917        if (minus_len) {
1918                minus_begin = diff_words->minus.orig[minus_first].begin;
1919                minus_end =
1920                        diff_words->minus.orig[minus_first + minus_len - 1].end;
1921        } else
1922                minus_begin = minus_end =
1923                        diff_words->minus.orig[minus_first].end;
1924
1925        if (plus_len) {
1926                plus_begin = diff_words->plus.orig[plus_first].begin;
1927                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
1928        } else
1929                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
1930
1931        if (color_words_output_graph_prefix(diff_words)) {
1932                fputs(line_prefix, diff_words->opt->file);
1933        }
1934        if (diff_words->current_plus != plus_begin) {
1935                fn_out_diff_words_write_helper(diff_words->opt,
1936                                &style->ctx, style->newline,
1937                                plus_begin - diff_words->current_plus,
1938                                diff_words->current_plus);
1939        }
1940        if (minus_begin != minus_end) {
1941                fn_out_diff_words_write_helper(diff_words->opt,
1942                                &style->old_word, style->newline,
1943                                minus_end - minus_begin, minus_begin);
1944        }
1945        if (plus_begin != plus_end) {
1946                fn_out_diff_words_write_helper(diff_words->opt,
1947                                &style->new_word, style->newline,
1948                                plus_end - plus_begin, plus_begin);
1949        }
1950
1951        diff_words->current_plus = plus_end;
1952        diff_words->last_minus = minus_first;
1953}
1954
1955/* This function starts looking at *begin, and returns 0 iff a word was found. */
1956static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
1957                int *begin, int *end)
1958{
1959        if (word_regex && *begin < buffer->size) {
1960                regmatch_t match[1];
1961                if (!regexec_buf(word_regex, buffer->ptr + *begin,
1962                                 buffer->size - *begin, 1, match, 0)) {
1963                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
1964                                        '\n', match[0].rm_eo - match[0].rm_so);
1965                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
1966                        *begin += match[0].rm_so;
1967                        return *begin >= *end;
1968                }
1969                return -1;
1970        }
1971
1972        /* find the next word */
1973        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
1974                (*begin)++;
1975        if (*begin >= buffer->size)
1976                return -1;
1977
1978        /* find the end of the word */
1979        *end = *begin + 1;
1980        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
1981                (*end)++;
1982
1983        return 0;
1984}
1985
1986/*
1987 * This function splits the words in buffer->text, stores the list with
1988 * newline separator into out, and saves the offsets of the original words
1989 * in buffer->orig.
1990 */
1991static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
1992                regex_t *word_regex)
1993{
1994        int i, j;
1995        long alloc = 0;
1996
1997        out->size = 0;
1998        out->ptr = NULL;
1999
2000        /* fake an empty "0th" word */
2001        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
2002        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
2003        buffer->orig_nr = 1;
2004
2005        for (i = 0; i < buffer->text.size; i++) {
2006                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
2007                        return;
2008
2009                /* store original boundaries */
2010                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
2011                                buffer->orig_alloc);
2012                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
2013                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
2014                buffer->orig_nr++;
2015
2016                /* store one word */
2017                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
2018                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
2019                out->ptr[out->size + j - i] = '\n';
2020                out->size += j - i + 1;
2021
2022                i = j - 1;
2023        }
2024}
2025
2026/* this executes the word diff on the accumulated buffers */
2027static void diff_words_show(struct diff_words_data *diff_words)
2028{
2029        xpparam_t xpp;
2030        xdemitconf_t xecfg;
2031        mmfile_t minus, plus;
2032        struct diff_words_style *style = diff_words->style;
2033
2034        struct diff_options *opt = diff_words->opt;
2035        const char *line_prefix;
2036
2037        assert(opt);
2038        line_prefix = diff_line_prefix(opt);
2039
2040        /* special case: only removal */
2041        if (!diff_words->plus.text.size) {
2042                emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
2043                                 line_prefix, strlen(line_prefix), 0);
2044                fn_out_diff_words_write_helper(diff_words->opt,
2045                        &style->old_word, style->newline,
2046                        diff_words->minus.text.size,
2047                        diff_words->minus.text.ptr);
2048                diff_words->minus.text.size = 0;
2049                return;
2050        }
2051
2052        diff_words->current_plus = diff_words->plus.text.ptr;
2053        diff_words->last_minus = 0;
2054
2055        memset(&xpp, 0, sizeof(xpp));
2056        memset(&xecfg, 0, sizeof(xecfg));
2057        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
2058        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
2059        xpp.flags = 0;
2060        /* as only the hunk header will be parsed, we need a 0-context */
2061        xecfg.ctxlen = 0;
2062        if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
2063                          &xpp, &xecfg))
2064                die("unable to generate word diff");
2065        free(minus.ptr);
2066        free(plus.ptr);
2067        if (diff_words->current_plus != diff_words->plus.text.ptr +
2068                        diff_words->plus.text.size) {
2069                if (color_words_output_graph_prefix(diff_words))
2070                        emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
2071                                         line_prefix, strlen(line_prefix), 0);
2072                fn_out_diff_words_write_helper(diff_words->opt,
2073                        &style->ctx, style->newline,
2074                        diff_words->plus.text.ptr + diff_words->plus.text.size
2075                        - diff_words->current_plus, diff_words->current_plus);
2076        }
2077        diff_words->minus.text.size = diff_words->plus.text.size = 0;
2078}
2079
2080/* In "color-words" mode, show word-diff of words accumulated in the buffer */
2081static void diff_words_flush(struct emit_callback *ecbdata)
2082{
2083        struct diff_options *wo = ecbdata->diff_words->opt;
2084
2085        if (ecbdata->diff_words->minus.text.size ||
2086            ecbdata->diff_words->plus.text.size)
2087                diff_words_show(ecbdata->diff_words);
2088
2089        if (wo->emitted_symbols) {
2090                struct diff_options *o = ecbdata->opt;
2091                struct emitted_diff_symbols *wol = wo->emitted_symbols;
2092                int i;
2093
2094                /*
2095                 * NEEDSWORK:
2096                 * Instead of appending each, concat all words to a line?
2097                 */
2098                for (i = 0; i < wol->nr; i++)
2099                        append_emitted_diff_symbol(o, &wol->buf[i]);
2100
2101                for (i = 0; i < wol->nr; i++)
2102                        free((void *)wol->buf[i].line);
2103
2104                wol->nr = 0;
2105        }
2106}
2107
2108static void diff_filespec_load_driver(struct diff_filespec *one)
2109{
2110        /* Use already-loaded driver */
2111        if (one->driver)
2112                return;
2113
2114        if (S_ISREG(one->mode))
2115                one->driver = userdiff_find_by_path(one->path);
2116
2117        /* Fallback to default settings */
2118        if (!one->driver)
2119                one->driver = userdiff_find_by_name("default");
2120}
2121
2122static const char *userdiff_word_regex(struct diff_filespec *one)
2123{
2124        diff_filespec_load_driver(one);
2125        return one->driver->word_regex;
2126}
2127
2128static void init_diff_words_data(struct emit_callback *ecbdata,
2129                                 struct diff_options *orig_opts,
2130                                 struct diff_filespec *one,
2131                                 struct diff_filespec *two)
2132{
2133        int i;
2134        struct diff_options *o = xmalloc(sizeof(struct diff_options));
2135        memcpy(o, orig_opts, sizeof(struct diff_options));
2136
2137        ecbdata->diff_words =
2138                xcalloc(1, sizeof(struct diff_words_data));
2139        ecbdata->diff_words->type = o->word_diff;
2140        ecbdata->diff_words->opt = o;
2141
2142        if (orig_opts->emitted_symbols)
2143                o->emitted_symbols =
2144                        xcalloc(1, sizeof(struct emitted_diff_symbols));
2145
2146        if (!o->word_regex)
2147                o->word_regex = userdiff_word_regex(one);
2148        if (!o->word_regex)
2149                o->word_regex = userdiff_word_regex(two);
2150        if (!o->word_regex)
2151                o->word_regex = diff_word_regex_cfg;
2152        if (o->word_regex) {
2153                ecbdata->diff_words->word_regex = (regex_t *)
2154                        xmalloc(sizeof(regex_t));
2155                if (regcomp(ecbdata->diff_words->word_regex,
2156                            o->word_regex,
2157                            REG_EXTENDED | REG_NEWLINE))
2158                        die("invalid regular expression: %s",
2159                            o->word_regex);
2160        }
2161        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2162                if (o->word_diff == diff_words_styles[i].type) {
2163                        ecbdata->diff_words->style =
2164                                &diff_words_styles[i];
2165                        break;
2166                }
2167        }
2168        if (want_color(o->use_color)) {
2169                struct diff_words_style *st = ecbdata->diff_words->style;
2170                st->old_word.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2171                st->new_word.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2172                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
2173        }
2174}
2175
2176static void free_diff_words_data(struct emit_callback *ecbdata)
2177{
2178        if (ecbdata->diff_words) {
2179                diff_words_flush(ecbdata);
2180                free (ecbdata->diff_words->opt->emitted_symbols);
2181                free (ecbdata->diff_words->opt);
2182                free (ecbdata->diff_words->minus.text.ptr);
2183                free (ecbdata->diff_words->minus.orig);
2184                free (ecbdata->diff_words->plus.text.ptr);
2185                free (ecbdata->diff_words->plus.orig);
2186                if (ecbdata->diff_words->word_regex) {
2187                        regfree(ecbdata->diff_words->word_regex);
2188                        free(ecbdata->diff_words->word_regex);
2189                }
2190                FREE_AND_NULL(ecbdata->diff_words);
2191        }
2192}
2193
2194const char *diff_get_color(int diff_use_color, enum color_diff ix)
2195{
2196        if (want_color(diff_use_color))
2197                return diff_colors[ix];
2198        return "";
2199}
2200
2201const char *diff_line_prefix(struct diff_options *opt)
2202{
2203        struct strbuf *msgbuf;
2204        if (!opt->output_prefix)
2205                return "";
2206
2207        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
2208        return msgbuf->buf;
2209}
2210
2211static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
2212{
2213        const char *cp;
2214        unsigned long allot;
2215        size_t l = len;
2216
2217        cp = line;
2218        allot = l;
2219        while (0 < l) {
2220                (void) utf8_width(&cp, &l);
2221                if (!cp)
2222                        break; /* truncated in the middle? */
2223        }
2224        return allot - l;
2225}
2226
2227static void find_lno(const char *line, struct emit_callback *ecbdata)
2228{
2229        const char *p;
2230        ecbdata->lno_in_preimage = 0;
2231        ecbdata->lno_in_postimage = 0;
2232        p = strchr(line, '-');
2233        if (!p)
2234                return; /* cannot happen */
2235        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
2236        p = strchr(p, '+');
2237        if (!p)
2238                return; /* cannot happen */
2239        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
2240}
2241
2242static void fn_out_consume(void *priv, char *line, unsigned long len)
2243{
2244        struct emit_callback *ecbdata = priv;
2245        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
2246        struct diff_options *o = ecbdata->opt;
2247
2248        o->found_changes = 1;
2249
2250        if (ecbdata->header) {
2251                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
2252                                 ecbdata->header->buf, ecbdata->header->len, 0);
2253                strbuf_reset(ecbdata->header);
2254                ecbdata->header = NULL;
2255        }
2256
2257        if (ecbdata->label_path[0]) {
2258                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
2259                                 ecbdata->label_path[0],
2260                                 strlen(ecbdata->label_path[0]), 0);
2261                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
2262                                 ecbdata->label_path[1],
2263                                 strlen(ecbdata->label_path[1]), 0);
2264                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
2265        }
2266
2267        if (diff_suppress_blank_empty
2268            && len == 2 && line[0] == ' ' && line[1] == '\n') {
2269                line[0] = '\n';
2270                len = 1;
2271        }
2272
2273        if (line[0] == '@') {
2274                if (ecbdata->diff_words)
2275                        diff_words_flush(ecbdata);
2276                len = sane_truncate_line(ecbdata, line, len);
2277                find_lno(line, ecbdata);
2278                emit_hunk_header(ecbdata, line, len);
2279                return;
2280        }
2281
2282        if (ecbdata->diff_words) {
2283                enum diff_symbol s =
2284                        ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN ?
2285                        DIFF_SYMBOL_WORDS_PORCELAIN : DIFF_SYMBOL_WORDS;
2286                if (line[0] == '-') {
2287                        diff_words_append(line, len,
2288                                          &ecbdata->diff_words->minus);
2289                        return;
2290                } else if (line[0] == '+') {
2291                        diff_words_append(line, len,
2292                                          &ecbdata->diff_words->plus);
2293                        return;
2294                } else if (starts_with(line, "\\ ")) {
2295                        /*
2296                         * Eat the "no newline at eof" marker as if we
2297                         * saw a "+" or "-" line with nothing on it,
2298                         * and return without diff_words_flush() to
2299                         * defer processing. If this is the end of
2300                         * preimage, more "+" lines may come after it.
2301                         */
2302                        return;
2303                }
2304                diff_words_flush(ecbdata);
2305                emit_diff_symbol(o, s, line, len, 0);
2306                return;
2307        }
2308
2309        switch (line[0]) {
2310        case '+':
2311                ecbdata->lno_in_postimage++;
2312                emit_add_line(reset, ecbdata, line + 1, len - 1);
2313                break;
2314        case '-':
2315                ecbdata->lno_in_preimage++;
2316                emit_del_line(reset, ecbdata, line + 1, len - 1);
2317                break;
2318        case ' ':
2319                ecbdata->lno_in_postimage++;
2320                ecbdata->lno_in_preimage++;
2321                emit_context_line(reset, ecbdata, line + 1, len - 1);
2322                break;
2323        default:
2324                /* incomplete line at the end */
2325                ecbdata->lno_in_preimage++;
2326                emit_diff_symbol(o, DIFF_SYMBOL_CONTEXT_INCOMPLETE,
2327                                 line, len, 0);
2328                break;
2329        }
2330}
2331
2332static void pprint_rename(struct strbuf *name, const char *a, const char *b)
2333{
2334        const char *old_name = a;
2335        const char *new_name = b;
2336        int pfx_length, sfx_length;
2337        int pfx_adjust_for_slash;
2338        int len_a = strlen(a);
2339        int len_b = strlen(b);
2340        int a_midlen, b_midlen;
2341        int qlen_a = quote_c_style(a, NULL, NULL, 0);
2342        int qlen_b = quote_c_style(b, NULL, NULL, 0);
2343
2344        if (qlen_a || qlen_b) {
2345                quote_c_style(a, name, NULL, 0);
2346                strbuf_addstr(name, " => ");
2347                quote_c_style(b, name, NULL, 0);
2348                return;
2349        }
2350
2351        /* Find common prefix */
2352        pfx_length = 0;
2353        while (*old_name && *new_name && *old_name == *new_name) {
2354                if (*old_name == '/')
2355                        pfx_length = old_name - a + 1;
2356                old_name++;
2357                new_name++;
2358        }
2359
2360        /* Find common suffix */
2361        old_name = a + len_a;
2362        new_name = b + len_b;
2363        sfx_length = 0;
2364        /*
2365         * If there is a common prefix, it must end in a slash.  In
2366         * that case we let this loop run 1 into the prefix to see the
2367         * same slash.
2368         *
2369         * If there is no common prefix, we cannot do this as it would
2370         * underrun the input strings.
2371         */
2372        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
2373        while (a + pfx_length - pfx_adjust_for_slash <= old_name &&
2374               b + pfx_length - pfx_adjust_for_slash <= new_name &&
2375               *old_name == *new_name) {
2376                if (*old_name == '/')
2377                        sfx_length = len_a - (old_name - a);
2378                old_name--;
2379                new_name--;
2380        }
2381
2382        /*
2383         * pfx{mid-a => mid-b}sfx
2384         * {pfx-a => pfx-b}sfx
2385         * pfx{sfx-a => sfx-b}
2386         * name-a => name-b
2387         */
2388        a_midlen = len_a - pfx_length - sfx_length;
2389        b_midlen = len_b - pfx_length - sfx_length;
2390        if (a_midlen < 0)
2391                a_midlen = 0;
2392        if (b_midlen < 0)
2393                b_midlen = 0;
2394
2395        strbuf_grow(name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
2396        if (pfx_length + sfx_length) {
2397                strbuf_add(name, a, pfx_length);
2398                strbuf_addch(name, '{');
2399        }
2400        strbuf_add(name, a + pfx_length, a_midlen);
2401        strbuf_addstr(name, " => ");
2402        strbuf_add(name, b + pfx_length, b_midlen);
2403        if (pfx_length + sfx_length) {
2404                strbuf_addch(name, '}');
2405                strbuf_add(name, a + len_a - sfx_length, sfx_length);
2406        }
2407}
2408
2409struct diffstat_t {
2410        int nr;
2411        int alloc;
2412        struct diffstat_file {
2413                char *from_name;
2414                char *name;
2415                char *print_name;
2416                const char *comments;
2417                unsigned is_unmerged:1;
2418                unsigned is_binary:1;
2419                unsigned is_renamed:1;
2420                unsigned is_interesting:1;
2421                uintmax_t added, deleted;
2422        } **files;
2423};
2424
2425static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
2426                                          const char *name_a,
2427                                          const char *name_b)
2428{
2429        struct diffstat_file *x;
2430        x = xcalloc(1, sizeof(*x));
2431        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
2432        diffstat->files[diffstat->nr++] = x;
2433        if (name_b) {
2434                x->from_name = xstrdup(name_a);
2435                x->name = xstrdup(name_b);
2436                x->is_renamed = 1;
2437        }
2438        else {
2439                x->from_name = NULL;
2440                x->name = xstrdup(name_a);
2441        }
2442        return x;
2443}
2444
2445static void diffstat_consume(void *priv, char *line, unsigned long len)
2446{
2447        struct diffstat_t *diffstat = priv;
2448        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
2449
2450        if (line[0] == '+')
2451                x->added++;
2452        else if (line[0] == '-')
2453                x->deleted++;
2454}
2455
2456const char mime_boundary_leader[] = "------------";
2457
2458static int scale_linear(int it, int width, int max_change)
2459{
2460        if (!it)
2461                return 0;
2462        /*
2463         * make sure that at least one '-' or '+' is printed if
2464         * there is any change to this path. The easiest way is to
2465         * scale linearly as if the alloted width is one column shorter
2466         * than it is, and then add 1 to the result.
2467         */
2468        return 1 + (it * (width - 1) / max_change);
2469}
2470
2471static void show_graph(struct strbuf *out, char ch, int cnt,
2472                       const char *set, const char *reset)
2473{
2474        if (cnt <= 0)
2475                return;
2476        strbuf_addstr(out, set);
2477        strbuf_addchars(out, ch, cnt);
2478        strbuf_addstr(out, reset);
2479}
2480
2481static void fill_print_name(struct diffstat_file *file)
2482{
2483        struct strbuf pname = STRBUF_INIT;
2484
2485        if (file->print_name)
2486                return;
2487
2488        if (file->is_renamed)
2489                pprint_rename(&pname, file->from_name, file->name);
2490        else
2491                quote_c_style(file->name, &pname, NULL, 0);
2492
2493        if (file->comments)
2494                strbuf_addf(&pname, " (%s)", file->comments);
2495
2496        file->print_name = strbuf_detach(&pname, NULL);
2497}
2498
2499static void print_stat_summary_inserts_deletes(struct diff_options *options,
2500                int files, int insertions, int deletions)
2501{
2502        struct strbuf sb = STRBUF_INIT;
2503
2504        if (!files) {
2505                assert(insertions == 0 && deletions == 0);
2506                emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
2507                                 NULL, 0, 0);
2508                return;
2509        }
2510
2511        strbuf_addf(&sb,
2512                    (files == 1) ? " %d file changed" : " %d files changed",
2513                    files);
2514
2515        /*
2516         * For binary diff, the caller may want to print "x files
2517         * changed" with insertions == 0 && deletions == 0.
2518         *
2519         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
2520         * is probably less confusing (i.e skip over "2 files changed
2521         * but nothing about added/removed lines? Is this a bug in Git?").
2522         */
2523        if (insertions || deletions == 0) {
2524                strbuf_addf(&sb,
2525                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
2526                            insertions);
2527        }
2528
2529        if (deletions || insertions == 0) {
2530                strbuf_addf(&sb,
2531                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
2532                            deletions);
2533        }
2534        strbuf_addch(&sb, '\n');
2535        emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
2536                         sb.buf, sb.len, 0);
2537        strbuf_release(&sb);
2538}
2539
2540void print_stat_summary(FILE *fp, int files,
2541                        int insertions, int deletions)
2542{
2543        struct diff_options o;
2544        memset(&o, 0, sizeof(o));
2545        o.file = fp;
2546
2547        print_stat_summary_inserts_deletes(&o, files, insertions, deletions);
2548}
2549
2550static void show_stats(struct diffstat_t *data, struct diff_options *options)
2551{
2552        int i, len, add, del, adds = 0, dels = 0;
2553        uintmax_t max_change = 0, max_len = 0;
2554        int total_files = data->nr, count;
2555        int width, name_width, graph_width, number_width = 0, bin_width = 0;
2556        const char *reset, *add_c, *del_c;
2557        int extra_shown = 0;
2558        const char *line_prefix = diff_line_prefix(options);
2559        struct strbuf out = STRBUF_INIT;
2560
2561        if (data->nr == 0)
2562                return;
2563
2564        count = options->stat_count ? options->stat_count : data->nr;
2565
2566        reset = diff_get_color_opt(options, DIFF_RESET);
2567        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
2568        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
2569
2570        /*
2571         * Find the longest filename and max number of changes
2572         */
2573        for (i = 0; (i < count) && (i < data->nr); i++) {
2574                struct diffstat_file *file = data->files[i];
2575                uintmax_t change = file->added + file->deleted;
2576
2577                if (!file->is_interesting && (change == 0)) {
2578                        count++; /* not shown == room for one more */
2579                        continue;
2580                }
2581                fill_print_name(file);
2582                len = strlen(file->print_name);
2583                if (max_len < len)
2584                        max_len = len;
2585
2586                if (file->is_unmerged) {
2587                        /* "Unmerged" is 8 characters */
2588                        bin_width = bin_width < 8 ? 8 : bin_width;
2589                        continue;
2590                }
2591                if (file->is_binary) {
2592                        /* "Bin XXX -> YYY bytes" */
2593                        int w = 14 + decimal_width(file->added)
2594                                + decimal_width(file->deleted);
2595                        bin_width = bin_width < w ? w : bin_width;
2596                        /* Display change counts aligned with "Bin" */
2597                        number_width = 3;
2598                        continue;
2599                }
2600
2601                if (max_change < change)
2602                        max_change = change;
2603        }
2604        count = i; /* where we can stop scanning in data->files[] */
2605
2606        /*
2607         * We have width = stat_width or term_columns() columns total.
2608         * We want a maximum of min(max_len, stat_name_width) for the name part.
2609         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
2610         * We also need 1 for " " and 4 + decimal_width(max_change)
2611         * for " | NNNN " and one the empty column at the end, altogether
2612         * 6 + decimal_width(max_change).
2613         *
2614         * If there's not enough space, we will use the smaller of
2615         * stat_name_width (if set) and 5/8*width for the filename,
2616         * and the rest for constant elements + graph part, but no more
2617         * than stat_graph_width for the graph part.
2618         * (5/8 gives 50 for filename and 30 for the constant parts + graph
2619         * for the standard terminal size).
2620         *
2621         * In other words: stat_width limits the maximum width, and
2622         * stat_name_width fixes the maximum width of the filename,
2623         * and is also used to divide available columns if there
2624         * aren't enough.
2625         *
2626         * Binary files are displayed with "Bin XXX -> YYY bytes"
2627         * instead of the change count and graph. This part is treated
2628         * similarly to the graph part, except that it is not
2629         * "scaled". If total width is too small to accommodate the
2630         * guaranteed minimum width of the filename part and the
2631         * separators and this message, this message will "overflow"
2632         * making the line longer than the maximum width.
2633         */
2634
2635        if (options->stat_width == -1)
2636                width = term_columns() - strlen(line_prefix);
2637        else
2638                width = options->stat_width ? options->stat_width : 80;
2639        number_width = decimal_width(max_change) > number_width ?
2640                decimal_width(max_change) : number_width;
2641
2642        if (options->stat_graph_width == -1)
2643                options->stat_graph_width = diff_stat_graph_width;
2644
2645        /*
2646         * Guarantee 3/8*16==6 for the graph part
2647         * and 5/8*16==10 for the filename part
2648         */
2649        if (width < 16 + 6 + number_width)
2650                width = 16 + 6 + number_width;
2651
2652        /*
2653         * First assign sizes that are wanted, ignoring available width.
2654         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
2655         * starting from "XXX" should fit in graph_width.
2656         */
2657        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
2658        if (options->stat_graph_width &&
2659            options->stat_graph_width < graph_width)
2660                graph_width = options->stat_graph_width;
2661
2662        name_width = (options->stat_name_width > 0 &&
2663                      options->stat_name_width < max_len) ?
2664                options->stat_name_width : max_len;
2665
2666        /*
2667         * Adjust adjustable widths not to exceed maximum width
2668         */
2669        if (name_width + number_width + 6 + graph_width > width) {
2670                if (graph_width > width * 3/8 - number_width - 6) {
2671                        graph_width = width * 3/8 - number_width - 6;
2672                        if (graph_width < 6)
2673                                graph_width = 6;
2674                }
2675
2676                if (options->stat_graph_width &&
2677                    graph_width > options->stat_graph_width)
2678                        graph_width = options->stat_graph_width;
2679                if (name_width > width - number_width - 6 - graph_width)
2680                        name_width = width - number_width - 6 - graph_width;
2681                else
2682                        graph_width = width - number_width - 6 - name_width;
2683        }
2684
2685        /*
2686         * From here name_width is the width of the name area,
2687         * and graph_width is the width of the graph area.
2688         * max_change is used to scale graph properly.
2689         */
2690        for (i = 0; i < count; i++) {
2691                const char *prefix = "";
2692                struct diffstat_file *file = data->files[i];
2693                char *name = file->print_name;
2694                uintmax_t added = file->added;
2695                uintmax_t deleted = file->deleted;
2696                int name_len;
2697
2698                if (!file->is_interesting && (added + deleted == 0))
2699                        continue;
2700
2701                /*
2702                 * "scale" the filename
2703                 */
2704                len = name_width;
2705                name_len = strlen(name);
2706                if (name_width < name_len) {
2707                        char *slash;
2708                        prefix = "...";
2709                        len -= 3;
2710                        name += name_len - len;
2711                        slash = strchr(name, '/');
2712                        if (slash)
2713                                name = slash;
2714                }
2715
2716                if (file->is_binary) {
2717                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2718                        strbuf_addf(&out, " %*s", number_width, "Bin");
2719                        if (!added && !deleted) {
2720                                strbuf_addch(&out, '\n');
2721                                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2722                                                 out.buf, out.len, 0);
2723                                strbuf_reset(&out);
2724                                continue;
2725                        }
2726                        strbuf_addf(&out, " %s%"PRIuMAX"%s",
2727                                del_c, deleted, reset);
2728                        strbuf_addstr(&out, " -> ");
2729                        strbuf_addf(&out, "%s%"PRIuMAX"%s",
2730                                add_c, added, reset);
2731                        strbuf_addstr(&out, " bytes\n");
2732                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2733                                         out.buf, out.len, 0);
2734                        strbuf_reset(&out);
2735                        continue;
2736                }
2737                else if (file->is_unmerged) {
2738                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2739                        strbuf_addstr(&out, " Unmerged\n");
2740                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2741                                         out.buf, out.len, 0);
2742                        strbuf_reset(&out);
2743                        continue;
2744                }
2745
2746                /*
2747                 * scale the add/delete
2748                 */
2749                add = added;
2750                del = deleted;
2751
2752                if (graph_width <= max_change) {
2753                        int total = scale_linear(add + del, graph_width, max_change);
2754                        if (total < 2 && add && del)
2755                                /* width >= 2 due to the sanity check */
2756                                total = 2;
2757                        if (add < del) {
2758                                add = scale_linear(add, graph_width, max_change);
2759                                del = total - add;
2760                        } else {
2761                                del = scale_linear(del, graph_width, max_change);
2762                                add = total - del;
2763                        }
2764                }
2765                strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2766                strbuf_addf(&out, " %*"PRIuMAX"%s",
2767                        number_width, added + deleted,
2768                        added + deleted ? " " : "");
2769                show_graph(&out, '+', add, add_c, reset);
2770                show_graph(&out, '-', del, del_c, reset);
2771                strbuf_addch(&out, '\n');
2772                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2773                                 out.buf, out.len, 0);
2774                strbuf_reset(&out);
2775        }
2776
2777        for (i = 0; i < data->nr; i++) {
2778                struct diffstat_file *file = data->files[i];
2779                uintmax_t added = file->added;
2780                uintmax_t deleted = file->deleted;
2781
2782                if (file->is_unmerged ||
2783                    (!file->is_interesting && (added + deleted == 0))) {
2784                        total_files--;
2785                        continue;
2786                }
2787
2788                if (!file->is_binary) {
2789                        adds += added;
2790                        dels += deleted;
2791                }
2792                if (i < count)
2793                        continue;
2794                if (!extra_shown)
2795                        emit_diff_symbol(options,
2796                                         DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
2797                                         NULL, 0, 0);
2798                extra_shown = 1;
2799        }
2800
2801        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2802        strbuf_release(&out);
2803}
2804
2805static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
2806{
2807        int i, adds = 0, dels = 0, total_files = data->nr;
2808
2809        if (data->nr == 0)
2810                return;
2811
2812        for (i = 0; i < data->nr; i++) {
2813                int added = data->files[i]->added;
2814                int deleted = data->files[i]->deleted;
2815
2816                if (data->files[i]->is_unmerged ||
2817                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
2818                        total_files--;
2819                } else if (!data->files[i]->is_binary) { /* don't count bytes */
2820                        adds += added;
2821                        dels += deleted;
2822                }
2823        }
2824        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2825}
2826
2827static void show_numstat(struct diffstat_t *data, struct diff_options *options)
2828{
2829        int i;
2830
2831        if (data->nr == 0)
2832                return;
2833
2834        for (i = 0; i < data->nr; i++) {
2835                struct diffstat_file *file = data->files[i];
2836
2837                fprintf(options->file, "%s", diff_line_prefix(options));
2838
2839                if (file->is_binary)
2840                        fprintf(options->file, "-\t-\t");
2841                else
2842                        fprintf(options->file,
2843                                "%"PRIuMAX"\t%"PRIuMAX"\t",
2844                                file->added, file->deleted);
2845                if (options->line_termination) {
2846                        fill_print_name(file);
2847                        if (!file->is_renamed)
2848                                write_name_quoted(file->name, options->file,
2849                                                  options->line_termination);
2850                        else {
2851                                fputs(file->print_name, options->file);
2852                                putc(options->line_termination, options->file);
2853                        }
2854                } else {
2855                        if (file->is_renamed) {
2856                                putc('\0', options->file);
2857                                write_name_quoted(file->from_name, options->file, '\0');
2858                        }
2859                        write_name_quoted(file->name, options->file, '\0');
2860                }
2861        }
2862}
2863
2864struct dirstat_file {
2865        const char *name;
2866        unsigned long changed;
2867};
2868
2869struct dirstat_dir {
2870        struct dirstat_file *files;
2871        int alloc, nr, permille, cumulative;
2872};
2873
2874static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
2875                unsigned long changed, const char *base, int baselen)
2876{
2877        unsigned long sum_changes = 0;
2878        unsigned int sources = 0;
2879        const char *line_prefix = diff_line_prefix(opt);
2880
2881        while (dir->nr) {
2882                struct dirstat_file *f = dir->files;
2883                int namelen = strlen(f->name);
2884                unsigned long changes;
2885                char *slash;
2886
2887                if (namelen < baselen)
2888                        break;
2889                if (memcmp(f->name, base, baselen))
2890                        break;
2891                slash = strchr(f->name + baselen, '/');
2892                if (slash) {
2893                        int newbaselen = slash + 1 - f->name;
2894                        changes = gather_dirstat(opt, dir, changed, f->name, newbaselen);
2895                        sources++;
2896                } else {
2897                        changes = f->changed;
2898                        dir->files++;
2899                        dir->nr--;
2900                        sources += 2;
2901                }
2902                sum_changes += changes;
2903        }
2904
2905        /*
2906         * We don't report dirstat's for
2907         *  - the top level
2908         *  - or cases where everything came from a single directory
2909         *    under this directory (sources == 1).
2910         */
2911        if (baselen && sources != 1) {
2912                if (sum_changes) {
2913                        int permille = sum_changes * 1000 / changed;
2914                        if (permille >= dir->permille) {
2915                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
2916                                        permille / 10, permille % 10, baselen, base);
2917                                if (!dir->cumulative)
2918                                        return 0;
2919                        }
2920                }
2921        }
2922        return sum_changes;
2923}
2924
2925static int dirstat_compare(const void *_a, const void *_b)
2926{
2927        const struct dirstat_file *a = _a;
2928        const struct dirstat_file *b = _b;
2929        return strcmp(a->name, b->name);
2930}
2931
2932static void show_dirstat(struct diff_options *options)
2933{
2934        int i;
2935        unsigned long changed;
2936        struct dirstat_dir dir;
2937        struct diff_queue_struct *q = &diff_queued_diff;
2938
2939        dir.files = NULL;
2940        dir.alloc = 0;
2941        dir.nr = 0;
2942        dir.permille = options->dirstat_permille;
2943        dir.cumulative = options->flags.dirstat_cumulative;
2944
2945        changed = 0;
2946        for (i = 0; i < q->nr; i++) {
2947                struct diff_filepair *p = q->queue[i];
2948                const char *name;
2949                unsigned long copied, added, damage;
2950
2951                name = p->two->path ? p->two->path : p->one->path;
2952
2953                if (p->one->oid_valid && p->two->oid_valid &&
2954                    oideq(&p->one->oid, &p->two->oid)) {
2955                        /*
2956                         * The SHA1 has not changed, so pre-/post-content is
2957                         * identical. We can therefore skip looking at the
2958                         * file contents altogether.
2959                         */
2960                        damage = 0;
2961                        goto found_damage;
2962                }
2963
2964                if (options->flags.dirstat_by_file) {
2965                        /*
2966                         * In --dirstat-by-file mode, we don't really need to
2967                         * look at the actual file contents at all.
2968                         * The fact that the SHA1 changed is enough for us to
2969                         * add this file to the list of results
2970                         * (with each file contributing equal damage).
2971                         */
2972                        damage = 1;
2973                        goto found_damage;
2974                }
2975
2976                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
2977                        diff_populate_filespec(p->one, 0);
2978                        diff_populate_filespec(p->two, 0);
2979                        diffcore_count_changes(p->one, p->two, NULL, NULL,
2980                                               &copied, &added);
2981                        diff_free_filespec_data(p->one);
2982                        diff_free_filespec_data(p->two);
2983                } else if (DIFF_FILE_VALID(p->one)) {
2984                        diff_populate_filespec(p->one, CHECK_SIZE_ONLY);
2985                        copied = added = 0;
2986                        diff_free_filespec_data(p->one);
2987                } else if (DIFF_FILE_VALID(p->two)) {
2988                        diff_populate_filespec(p->two, CHECK_SIZE_ONLY);
2989                        copied = 0;
2990                        added = p->two->size;
2991                        diff_free_filespec_data(p->two);
2992                } else
2993                        continue;
2994
2995                /*
2996                 * Original minus copied is the removed material,
2997                 * added is the new material.  They are both damages
2998                 * made to the preimage.
2999                 * If the resulting damage is zero, we know that
3000                 * diffcore_count_changes() considers the two entries to
3001                 * be identical, but since the oid changed, we
3002                 * know that there must have been _some_ kind of change,
3003                 * so we force all entries to have damage > 0.
3004                 */
3005                damage = (p->one->size - copied) + added;
3006                if (!damage)
3007                        damage = 1;
3008
3009found_damage:
3010                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
3011                dir.files[dir.nr].name = name;
3012                dir.files[dir.nr].changed = damage;
3013                changed += damage;
3014                dir.nr++;
3015        }
3016
3017        /* This can happen even with many files, if everything was renames */
3018        if (!changed)
3019                return;
3020
3021        /* Show all directories with more than x% of the changes */
3022        QSORT(dir.files, dir.nr, dirstat_compare);
3023        gather_dirstat(options, &dir, changed, "", 0);
3024}
3025
3026static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
3027{
3028        int i;
3029        unsigned long changed;
3030        struct dirstat_dir dir;
3031
3032        if (data->nr == 0)
3033                return;
3034
3035        dir.files = NULL;
3036        dir.alloc = 0;
3037        dir.nr = 0;
3038        dir.permille = options->dirstat_permille;
3039        dir.cumulative = options->flags.dirstat_cumulative;
3040
3041        changed = 0;
3042        for (i = 0; i < data->nr; i++) {
3043                struct diffstat_file *file = data->files[i];
3044                unsigned long damage = file->added + file->deleted;
3045                if (file->is_binary)
3046                        /*
3047                         * binary files counts bytes, not lines. Must find some
3048                         * way to normalize binary bytes vs. textual lines.
3049                         * The following heuristic assumes that there are 64
3050                         * bytes per "line".
3051                         * This is stupid and ugly, but very cheap...
3052                         */
3053                        damage = DIV_ROUND_UP(damage, 64);
3054                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
3055                dir.files[dir.nr].name = file->name;
3056                dir.files[dir.nr].changed = damage;
3057                changed += damage;
3058                dir.nr++;
3059        }
3060
3061        /* This can happen even with many files, if everything was renames */
3062        if (!changed)
3063                return;
3064
3065        /* Show all directories with more than x% of the changes */
3066        QSORT(dir.files, dir.nr, dirstat_compare);
3067        gather_dirstat(options, &dir, changed, "", 0);
3068}
3069
3070static void free_diffstat_info(struct diffstat_t *diffstat)
3071{
3072        int i;
3073        for (i = 0; i < diffstat->nr; i++) {
3074                struct diffstat_file *f = diffstat->files[i];
3075                free(f->print_name);
3076                free(f->name);
3077                free(f->from_name);
3078                free(f);
3079        }
3080        free(diffstat->files);
3081}
3082
3083struct checkdiff_t {
3084        const char *filename;
3085        int lineno;
3086        int conflict_marker_size;
3087        struct diff_options *o;
3088        unsigned ws_rule;
3089        unsigned status;
3090};
3091
3092static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
3093{
3094        char firstchar;
3095        int cnt;
3096
3097        if (len < marker_size + 1)
3098                return 0;
3099        firstchar = line[0];
3100        switch (firstchar) {
3101        case '=': case '>': case '<': case '|':
3102                break;
3103        default:
3104                return 0;
3105        }
3106        for (cnt = 1; cnt < marker_size; cnt++)
3107                if (line[cnt] != firstchar)
3108                        return 0;
3109        /* line[1] thru line[marker_size-1] are same as firstchar */
3110        if (len < marker_size + 1 || !isspace(line[marker_size]))
3111                return 0;
3112        return 1;
3113}
3114
3115static void checkdiff_consume(void *priv, char *line, unsigned long len)
3116{
3117        struct checkdiff_t *data = priv;
3118        int marker_size = data->conflict_marker_size;
3119        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
3120        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
3121        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
3122        char *err;
3123        const char *line_prefix;
3124
3125        assert(data->o);
3126        line_prefix = diff_line_prefix(data->o);
3127
3128        if (line[0] == '+') {
3129                unsigned bad;
3130                data->lineno++;
3131                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
3132                        data->status |= 1;
3133                        fprintf(data->o->file,
3134                                "%s%s:%d: leftover conflict marker\n",
3135                                line_prefix, data->filename, data->lineno);
3136                }
3137                bad = ws_check(line + 1, len - 1, data->ws_rule);
3138                if (!bad)
3139                        return;
3140                data->status |= bad;
3141                err = whitespace_error_string(bad);
3142                fprintf(data->o->file, "%s%s:%d: %s.\n",
3143                        line_prefix, data->filename, data->lineno, err);
3144                free(err);
3145                emit_line(data->o, set, reset, line, 1);
3146                ws_check_emit(line + 1, len - 1, data->ws_rule,
3147                              data->o->file, set, reset, ws);
3148        } else if (line[0] == ' ') {
3149                data->lineno++;
3150        } else if (line[0] == '@') {
3151                char *plus = strchr(line, '+');
3152                if (plus)
3153                        data->lineno = strtol(plus, NULL, 10) - 1;
3154                else
3155                        die("invalid diff");
3156        }
3157}
3158
3159static unsigned char *deflate_it(char *data,
3160                                 unsigned long size,
3161                                 unsigned long *result_size)
3162{
3163        int bound;
3164        unsigned char *deflated;
3165        git_zstream stream;
3166
3167        git_deflate_init(&stream, zlib_compression_level);
3168        bound = git_deflate_bound(&stream, size);
3169        deflated = xmalloc(bound);
3170        stream.next_out = deflated;
3171        stream.avail_out = bound;
3172
3173        stream.next_in = (unsigned char *)data;
3174        stream.avail_in = size;
3175        while (git_deflate(&stream, Z_FINISH) == Z_OK)
3176                ; /* nothing */
3177        git_deflate_end(&stream);
3178        *result_size = stream.total_out;
3179        return deflated;
3180}
3181
3182static void emit_binary_diff_body(struct diff_options *o,
3183                                  mmfile_t *one, mmfile_t *two)
3184{
3185        void *cp;
3186        void *delta;
3187        void *deflated;
3188        void *data;
3189        unsigned long orig_size;
3190        unsigned long delta_size;
3191        unsigned long deflate_size;
3192        unsigned long data_size;
3193
3194        /* We could do deflated delta, or we could do just deflated two,
3195         * whichever is smaller.
3196         */
3197        delta = NULL;
3198        deflated = deflate_it(two->ptr, two->size, &deflate_size);
3199        if (one->size && two->size) {
3200                delta = diff_delta(one->ptr, one->size,
3201                                   two->ptr, two->size,
3202                                   &delta_size, deflate_size);
3203                if (delta) {
3204                        void *to_free = delta;
3205                        orig_size = delta_size;
3206                        delta = deflate_it(delta, delta_size, &delta_size);
3207                        free(to_free);
3208                }
3209        }
3210
3211        if (delta && delta_size < deflate_size) {
3212                char *s = xstrfmt("%lu", orig_size);
3213                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
3214                                 s, strlen(s), 0);
3215                free(s);
3216                free(deflated);
3217                data = delta;
3218                data_size = delta_size;
3219        } else {
3220                char *s = xstrfmt("%lu", two->size);
3221                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
3222                                 s, strlen(s), 0);
3223                free(s);
3224                free(delta);
3225                data = deflated;
3226                data_size = deflate_size;
3227        }
3228
3229        /* emit data encoded in base85 */
3230        cp = data;
3231        while (data_size) {
3232                int len;
3233                int bytes = (52 < data_size) ? 52 : data_size;
3234                char line[71];
3235                data_size -= bytes;
3236                if (bytes <= 26)
3237                        line[0] = bytes + 'A' - 1;
3238                else
3239                        line[0] = bytes - 26 + 'a' - 1;
3240                encode_85(line + 1, cp, bytes);
3241                cp = (char *) cp + bytes;
3242
3243                len = strlen(line);
3244                line[len++] = '\n';
3245                line[len] = '\0';
3246
3247                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_BODY,
3248                                 line, len, 0);
3249        }
3250        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_FOOTER, NULL, 0, 0);
3251        free(data);
3252}
3253
3254static void emit_binary_diff(struct diff_options *o,
3255                             mmfile_t *one, mmfile_t *two)
3256{
3257        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER, NULL, 0, 0);
3258        emit_binary_diff_body(o, one, two);
3259        emit_binary_diff_body(o, two, one);
3260}
3261
3262int diff_filespec_is_binary(struct diff_filespec *one)
3263{
3264        if (one->is_binary == -1) {
3265                diff_filespec_load_driver(one);
3266                if (one->driver->binary != -1)
3267                        one->is_binary = one->driver->binary;
3268                else {
3269                        if (!one->data && DIFF_FILE_VALID(one))
3270                                diff_populate_filespec(one, CHECK_BINARY);
3271                        if (one->is_binary == -1 && one->data)
3272                                one->is_binary = buffer_is_binary(one->data,
3273                                                one->size);
3274                        if (one->is_binary == -1)
3275                                one->is_binary = 0;
3276                }
3277        }
3278        return one->is_binary;
3279}
3280
3281static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
3282{
3283        diff_filespec_load_driver(one);
3284        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
3285}
3286
3287void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
3288{
3289        if (!options->a_prefix)
3290                options->a_prefix = a;
3291        if (!options->b_prefix)
3292                options->b_prefix = b;
3293}
3294
3295struct userdiff_driver *get_textconv(struct diff_filespec *one)
3296{
3297        if (!DIFF_FILE_VALID(one))
3298                return NULL;
3299
3300        diff_filespec_load_driver(one);
3301        return userdiff_get_textconv(one->driver);
3302}
3303
3304static void builtin_diff(const char *name_a,
3305                         const char *name_b,
3306                         struct diff_filespec *one,
3307                         struct diff_filespec *two,
3308                         const char *xfrm_msg,
3309                         int must_show_header,
3310                         struct diff_options *o,
3311                         int complete_rewrite)
3312{
3313        mmfile_t mf1, mf2;
3314        const char *lbl[2];
3315        char *a_one, *b_two;
3316        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
3317        const char *reset = diff_get_color_opt(o, DIFF_RESET);
3318        const char *a_prefix, *b_prefix;
3319        struct userdiff_driver *textconv_one = NULL;
3320        struct userdiff_driver *textconv_two = NULL;
3321        struct strbuf header = STRBUF_INIT;
3322        const char *line_prefix = diff_line_prefix(o);
3323
3324        diff_set_mnemonic_prefix(o, "a/", "b/");
3325        if (o->flags.reverse_diff) {
3326                a_prefix = o->b_prefix;
3327                b_prefix = o->a_prefix;
3328        } else {
3329                a_prefix = o->a_prefix;
3330                b_prefix = o->b_prefix;
3331        }
3332
3333        if (o->submodule_format == DIFF_SUBMODULE_LOG &&
3334            (!one->mode || S_ISGITLINK(one->mode)) &&
3335            (!two->mode || S_ISGITLINK(two->mode))) {
3336                show_submodule_summary(o, one->path ? one->path : two->path,
3337                                &one->oid, &two->oid,
3338                                two->dirty_submodule);
3339                return;
3340        } else if (o->submodule_format == DIFF_SUBMODULE_INLINE_DIFF &&
3341                   (!one->mode || S_ISGITLINK(one->mode)) &&
3342                   (!two->mode || S_ISGITLINK(two->mode))) {
3343                show_submodule_inline_diff(o, one->path ? one->path : two->path,
3344                                &one->oid, &two->oid,
3345                                two->dirty_submodule);
3346                return;
3347        }
3348
3349        if (o->flags.allow_textconv) {
3350                textconv_one = get_textconv(one);
3351                textconv_two = get_textconv(two);
3352        }
3353
3354        /* Never use a non-valid filename anywhere if at all possible */
3355        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
3356        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
3357
3358        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
3359        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
3360        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
3361        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
3362        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
3363        if (lbl[0][0] == '/') {
3364                /* /dev/null */
3365                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
3366                if (xfrm_msg)
3367                        strbuf_addstr(&header, xfrm_msg);
3368                must_show_header = 1;
3369        }
3370        else if (lbl[1][0] == '/') {
3371                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
3372                if (xfrm_msg)
3373                        strbuf_addstr(&header, xfrm_msg);
3374                must_show_header = 1;
3375        }
3376        else {
3377                if (one->mode != two->mode) {
3378                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
3379                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
3380                        must_show_header = 1;
3381                }
3382                if (xfrm_msg)
3383                        strbuf_addstr(&header, xfrm_msg);
3384
3385                /*
3386                 * we do not run diff between different kind
3387                 * of objects.
3388                 */
3389                if ((one->mode ^ two->mode) & S_IFMT)
3390                        goto free_ab_and_return;
3391                if (complete_rewrite &&
3392                    (textconv_one || !diff_filespec_is_binary(one)) &&
3393                    (textconv_two || !diff_filespec_is_binary(two))) {
3394                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3395                                         header.buf, header.len, 0);
3396                        strbuf_reset(&header);
3397                        emit_rewrite_diff(name_a, name_b, one, two,
3398                                                textconv_one, textconv_two, o);
3399                        o->found_changes = 1;
3400                        goto free_ab_and_return;
3401                }
3402        }
3403
3404        if (o->irreversible_delete && lbl[1][0] == '/') {
3405                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf,
3406                                 header.len, 0);
3407                strbuf_reset(&header);
3408                goto free_ab_and_return;
3409        } else if (!o->flags.text &&
3410            ( (!textconv_one && diff_filespec_is_binary(one)) ||
3411              (!textconv_two && diff_filespec_is_binary(two)) )) {
3412                struct strbuf sb = STRBUF_INIT;
3413                if (!one->data && !two->data &&
3414                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
3415                    !o->flags.binary) {
3416                        if (oideq(&one->oid, &two->oid)) {
3417                                if (must_show_header)
3418                                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3419                                                         header.buf, header.len,
3420                                                         0);
3421                                goto free_ab_and_return;
3422                        }
3423                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3424                                         header.buf, header.len, 0);
3425                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3426                                    diff_line_prefix(o), lbl[0], lbl[1]);
3427                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3428                                         sb.buf, sb.len, 0);
3429                        strbuf_release(&sb);
3430                        goto free_ab_and_return;
3431                }
3432                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3433                        die("unable to read files to diff");
3434                /* Quite common confusing case */
3435                if (mf1.size == mf2.size &&
3436                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
3437                        if (must_show_header)
3438                                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3439                                                 header.buf, header.len, 0);
3440                        goto free_ab_and_return;
3441                }
3442                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf, header.len, 0);
3443                strbuf_reset(&header);
3444                if (o->flags.binary)
3445                        emit_binary_diff(o, &mf1, &mf2);
3446                else {
3447                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3448                                    diff_line_prefix(o), lbl[0], lbl[1]);
3449                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3450                                         sb.buf, sb.len, 0);
3451                        strbuf_release(&sb);
3452                }
3453                o->found_changes = 1;
3454        } else {
3455                /* Crazy xdl interfaces.. */
3456                const char *diffopts = getenv("GIT_DIFF_OPTS");
3457                const char *v;
3458                xpparam_t xpp;
3459                xdemitconf_t xecfg;
3460                struct emit_callback ecbdata;
3461                const struct userdiff_funcname *pe;
3462
3463                if (must_show_header) {
3464                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3465                                         header.buf, header.len, 0);
3466                        strbuf_reset(&header);
3467                }
3468
3469                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
3470                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
3471
3472                pe = diff_funcname_pattern(one);
3473                if (!pe)
3474                        pe = diff_funcname_pattern(two);
3475
3476                memset(&xpp, 0, sizeof(xpp));
3477                memset(&xecfg, 0, sizeof(xecfg));
3478                memset(&ecbdata, 0, sizeof(ecbdata));
3479                if (o->flags.suppress_diff_headers)
3480                        lbl[0] = NULL;
3481                ecbdata.label_path = lbl;
3482                ecbdata.color_diff = want_color(o->use_color);
3483                ecbdata.ws_rule = whitespace_rule(name_b);
3484                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
3485                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3486                ecbdata.opt = o;
3487                if (header.len && !o->flags.suppress_diff_headers)
3488                        ecbdata.header = &header;
3489                xpp.flags = o->xdl_opts;
3490                xpp.anchors = o->anchors;
3491                xpp.anchors_nr = o->anchors_nr;
3492                xecfg.ctxlen = o->context;
3493                xecfg.interhunkctxlen = o->interhunkcontext;
3494                xecfg.flags = XDL_EMIT_FUNCNAMES;
3495                if (o->flags.funccontext)
3496                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
3497                if (pe)
3498                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
3499                if (!diffopts)
3500                        ;
3501                else if (skip_prefix(diffopts, "--unified=", &v))
3502                        xecfg.ctxlen = strtoul(v, NULL, 10);
3503                else if (skip_prefix(diffopts, "-u", &v))
3504                        xecfg.ctxlen = strtoul(v, NULL, 10);
3505                if (o->word_diff)
3506                        init_diff_words_data(&ecbdata, o, one, two);
3507                if (xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
3508                                  &xpp, &xecfg))
3509                        die("unable to generate diff for %s", one->path);
3510                if (o->word_diff)
3511                        free_diff_words_data(&ecbdata);
3512                if (textconv_one)
3513                        free(mf1.ptr);
3514                if (textconv_two)
3515                        free(mf2.ptr);
3516                xdiff_clear_find_func(&xecfg);
3517        }
3518
3519 free_ab_and_return:
3520        strbuf_release(&header);
3521        diff_free_filespec_data(one);
3522        diff_free_filespec_data(two);
3523        free(a_one);
3524        free(b_two);
3525        return;
3526}
3527
3528static char *get_compact_summary(const struct diff_filepair *p, int is_renamed)
3529{
3530        if (!is_renamed) {
3531                if (p->status == DIFF_STATUS_ADDED) {
3532                        if (S_ISLNK(p->two->mode))
3533                                return "new +l";
3534                        else if ((p->two->mode & 0777) == 0755)
3535                                return "new +x";
3536                        else
3537                                return "new";
3538                } else if (p->status == DIFF_STATUS_DELETED)
3539                        return "gone";
3540        }
3541        if (S_ISLNK(p->one->mode) && !S_ISLNK(p->two->mode))
3542                return "mode -l";
3543        else if (!S_ISLNK(p->one->mode) && S_ISLNK(p->two->mode))
3544                return "mode +l";
3545        else if ((p->one->mode & 0777) == 0644 &&
3546                 (p->two->mode & 0777) == 0755)
3547                return "mode +x";
3548        else if ((p->one->mode & 0777) == 0755 &&
3549                 (p->two->mode & 0777) == 0644)
3550                return "mode -x";
3551        return NULL;
3552}
3553
3554static void builtin_diffstat(const char *name_a, const char *name_b,
3555                             struct diff_filespec *one,
3556                             struct diff_filespec *two,
3557                             struct diffstat_t *diffstat,
3558                             struct diff_options *o,
3559                             struct diff_filepair *p)
3560{
3561        mmfile_t mf1, mf2;
3562        struct diffstat_file *data;
3563        int same_contents;
3564        int complete_rewrite = 0;
3565
3566        if (!DIFF_PAIR_UNMERGED(p)) {
3567                if (p->status == DIFF_STATUS_MODIFIED && p->score)
3568                        complete_rewrite = 1;
3569        }
3570
3571        data = diffstat_add(diffstat, name_a, name_b);
3572        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
3573        if (o->flags.stat_with_summary)
3574                data->comments = get_compact_summary(p, data->is_renamed);
3575
3576        if (!one || !two) {
3577                data->is_unmerged = 1;
3578                return;
3579        }
3580
3581        same_contents = oideq(&one->oid, &two->oid);
3582
3583        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
3584                data->is_binary = 1;
3585                if (same_contents) {
3586                        data->added = 0;
3587                        data->deleted = 0;
3588                } else {
3589                        data->added = diff_filespec_size(two);
3590                        data->deleted = diff_filespec_size(one);
3591                }
3592        }
3593
3594        else if (complete_rewrite) {
3595                diff_populate_filespec(one, 0);
3596                diff_populate_filespec(two, 0);
3597                data->deleted = count_lines(one->data, one->size);
3598                data->added = count_lines(two->data, two->size);
3599        }
3600
3601        else if (!same_contents) {
3602                /* Crazy xdl interfaces.. */
3603                xpparam_t xpp;
3604                xdemitconf_t xecfg;
3605
3606                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3607                        die("unable to read files to diff");
3608
3609                memset(&xpp, 0, sizeof(xpp));
3610                memset(&xecfg, 0, sizeof(xecfg));
3611                xpp.flags = o->xdl_opts;
3612                xpp.anchors = o->anchors;
3613                xpp.anchors_nr = o->anchors_nr;
3614                xecfg.ctxlen = o->context;
3615                xecfg.interhunkctxlen = o->interhunkcontext;
3616                if (xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
3617                                  &xpp, &xecfg))
3618                        die("unable to generate diffstat for %s", one->path);
3619        }
3620
3621        diff_free_filespec_data(one);
3622        diff_free_filespec_data(two);
3623}
3624
3625static void builtin_checkdiff(const char *name_a, const char *name_b,
3626                              const char *attr_path,
3627                              struct diff_filespec *one,
3628                              struct diff_filespec *two,
3629                              struct diff_options *o)
3630{
3631        mmfile_t mf1, mf2;
3632        struct checkdiff_t data;
3633
3634        if (!two)
3635                return;
3636
3637        memset(&data, 0, sizeof(data));
3638        data.filename = name_b ? name_b : name_a;
3639        data.lineno = 0;
3640        data.o = o;
3641        data.ws_rule = whitespace_rule(attr_path);
3642        data.conflict_marker_size = ll_merge_marker_size(attr_path);
3643
3644        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3645                die("unable to read files to diff");
3646
3647        /*
3648         * All the other codepaths check both sides, but not checking
3649         * the "old" side here is deliberate.  We are checking the newly
3650         * introduced changes, and as long as the "new" side is text, we
3651         * can and should check what it introduces.
3652         */
3653        if (diff_filespec_is_binary(two))
3654                goto free_and_return;
3655        else {
3656                /* Crazy xdl interfaces.. */
3657                xpparam_t xpp;
3658                xdemitconf_t xecfg;
3659
3660                memset(&xpp, 0, sizeof(xpp));
3661                memset(&xecfg, 0, sizeof(xecfg));
3662                xecfg.ctxlen = 1; /* at least one context line */
3663                xpp.flags = 0;
3664                if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
3665                                  &xpp, &xecfg))
3666                        die("unable to generate checkdiff for %s", one->path);
3667
3668                if (data.ws_rule & WS_BLANK_AT_EOF) {
3669                        struct emit_callback ecbdata;
3670                        int blank_at_eof;
3671
3672                        ecbdata.ws_rule = data.ws_rule;
3673                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3674                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
3675
3676                        if (blank_at_eof) {
3677                                static char *err;
3678                                if (!err)
3679                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
3680                                fprintf(o->file, "%s:%d: %s.\n",
3681                                        data.filename, blank_at_eof, err);
3682                                data.status = 1; /* report errors */
3683                        }
3684                }
3685        }
3686 free_and_return:
3687        diff_free_filespec_data(one);
3688        diff_free_filespec_data(two);
3689        if (data.status)
3690                o->flags.check_failed = 1;
3691}
3692
3693struct diff_filespec *alloc_filespec(const char *path)
3694{
3695        struct diff_filespec *spec;
3696
3697        FLEXPTR_ALLOC_STR(spec, path, path);
3698        spec->count = 1;
3699        spec->is_binary = -1;
3700        return spec;
3701}
3702
3703void free_filespec(struct diff_filespec *spec)
3704{
3705        if (!--spec->count) {
3706                diff_free_filespec_data(spec);
3707                free(spec);
3708        }
3709}
3710
3711void fill_filespec(struct diff_filespec *spec, const struct object_id *oid,
3712                   int oid_valid, unsigned short mode)
3713{
3714        if (mode) {
3715                spec->mode = canon_mode(mode);
3716                oidcpy(&spec->oid, oid);
3717                spec->oid_valid = oid_valid;
3718        }
3719}
3720
3721/*
3722 * Given a name and sha1 pair, if the index tells us the file in
3723 * the work tree has that object contents, return true, so that
3724 * prepare_temp_file() does not have to inflate and extract.
3725 */
3726static int reuse_worktree_file(const char *name, const struct object_id *oid, int want_file)
3727{
3728        const struct cache_entry *ce;
3729        struct stat st;
3730        int pos, len;
3731
3732        /*
3733         * We do not read the cache ourselves here, because the
3734         * benchmark with my previous version that always reads cache
3735         * shows that it makes things worse for diff-tree comparing
3736         * two linux-2.6 kernel trees in an already checked out work
3737         * tree.  This is because most diff-tree comparisons deal with
3738         * only a small number of files, while reading the cache is
3739         * expensive for a large project, and its cost outweighs the
3740         * savings we get by not inflating the object to a temporary
3741         * file.  Practically, this code only helps when we are used
3742         * by diff-cache --cached, which does read the cache before
3743         * calling us.
3744         */
3745        if (!active_cache)
3746                return 0;
3747
3748        /* We want to avoid the working directory if our caller
3749         * doesn't need the data in a normal file, this system
3750         * is rather slow with its stat/open/mmap/close syscalls,
3751         * and the object is contained in a pack file.  The pack
3752         * is probably already open and will be faster to obtain
3753         * the data through than the working directory.  Loose
3754         * objects however would tend to be slower as they need
3755         * to be individually opened and inflated.
3756         */
3757        if (!FAST_WORKING_DIRECTORY && !want_file && has_object_pack(oid))
3758                return 0;
3759
3760        /*
3761         * Similarly, if we'd have to convert the file contents anyway, that
3762         * makes the optimization not worthwhile.
3763         */
3764        if (!want_file && would_convert_to_git(&the_index, name))
3765                return 0;
3766
3767        len = strlen(name);
3768        pos = cache_name_pos(name, len);
3769        if (pos < 0)
3770                return 0;
3771        ce = active_cache[pos];
3772
3773        /*
3774         * This is not the sha1 we are looking for, or
3775         * unreusable because it is not a regular file.
3776         */
3777        if (!oideq(oid, &ce->oid) || !S_ISREG(ce->ce_mode))
3778                return 0;
3779
3780        /*
3781         * If ce is marked as "assume unchanged", there is no
3782         * guarantee that work tree matches what we are looking for.
3783         */
3784        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
3785                return 0;
3786
3787        /*
3788         * If ce matches the file in the work tree, we can reuse it.
3789         */
3790        if (ce_uptodate(ce) ||
3791            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
3792                return 1;
3793
3794        return 0;
3795}
3796
3797static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
3798{
3799        struct strbuf buf = STRBUF_INIT;
3800        char *dirty = "";
3801
3802        /* Are we looking at the work tree? */
3803        if (s->dirty_submodule)
3804                dirty = "-dirty";
3805
3806        strbuf_addf(&buf, "Subproject commit %s%s\n",
3807                    oid_to_hex(&s->oid), dirty);
3808        s->size = buf.len;
3809        if (size_only) {
3810                s->data = NULL;
3811                strbuf_release(&buf);
3812        } else {
3813                s->data = strbuf_detach(&buf, NULL);
3814                s->should_free = 1;
3815        }
3816        return 0;
3817}
3818
3819/*
3820 * While doing rename detection and pickaxe operation, we may need to
3821 * grab the data for the blob (or file) for our own in-core comparison.
3822 * diff_filespec has data and size fields for this purpose.
3823 */
3824int diff_populate_filespec(struct diff_filespec *s, unsigned int flags)
3825{
3826        int size_only = flags & CHECK_SIZE_ONLY;
3827        int err = 0;
3828        int conv_flags = global_conv_flags_eol;
3829        /*
3830         * demote FAIL to WARN to allow inspecting the situation
3831         * instead of refusing.
3832         */
3833        if (conv_flags & CONV_EOL_RNDTRP_DIE)
3834                conv_flags = CONV_EOL_RNDTRP_WARN;
3835
3836        if (!DIFF_FILE_VALID(s))
3837                die("internal error: asking to populate invalid file.");
3838        if (S_ISDIR(s->mode))
3839                return -1;
3840
3841        if (s->data)
3842                return 0;
3843
3844        if (size_only && 0 < s->size)
3845                return 0;
3846
3847        if (S_ISGITLINK(s->mode))
3848                return diff_populate_gitlink(s, size_only);
3849
3850        if (!s->oid_valid ||
3851            reuse_worktree_file(s->path, &s->oid, 0)) {
3852                struct strbuf buf = STRBUF_INIT;
3853                struct stat st;
3854                int fd;
3855
3856                if (lstat(s->path, &st) < 0) {
3857                err_empty:
3858                        err = -1;
3859                empty:
3860                        s->data = (char *)"";
3861                        s->size = 0;
3862                        return err;
3863                }
3864                s->size = xsize_t(st.st_size);
3865                if (!s->size)
3866                        goto empty;
3867                if (S_ISLNK(st.st_mode)) {
3868                        struct strbuf sb = STRBUF_INIT;
3869
3870                        if (strbuf_readlink(&sb, s->path, s->size))
3871                                goto err_empty;
3872                        s->size = sb.len;
3873                        s->data = strbuf_detach(&sb, NULL);
3874                        s->should_free = 1;
3875                        return 0;
3876                }
3877
3878                /*
3879                 * Even if the caller would be happy with getting
3880                 * only the size, we cannot return early at this
3881                 * point if the path requires us to run the content
3882                 * conversion.
3883                 */
3884                if (size_only && !would_convert_to_git(&the_index, s->path))
3885                        return 0;
3886
3887                /*
3888                 * Note: this check uses xsize_t(st.st_size) that may
3889                 * not be the true size of the blob after it goes
3890                 * through convert_to_git().  This may not strictly be
3891                 * correct, but the whole point of big_file_threshold
3892                 * and is_binary check being that we want to avoid
3893                 * opening the file and inspecting the contents, this
3894                 * is probably fine.
3895                 */
3896                if ((flags & CHECK_BINARY) &&
3897                    s->size > big_file_threshold && s->is_binary == -1) {
3898                        s->is_binary = 1;
3899                        return 0;
3900                }
3901                fd = open(s->path, O_RDONLY);
3902                if (fd < 0)
3903                        goto err_empty;
3904                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
3905                close(fd);
3906                s->should_munmap = 1;
3907
3908                /*
3909                 * Convert from working tree format to canonical git format
3910                 */
3911                if (convert_to_git(&the_index, s->path, s->data, s->size, &buf, conv_flags)) {
3912                        size_t size = 0;
3913                        munmap(s->data, s->size);
3914                        s->should_munmap = 0;
3915                        s->data = strbuf_detach(&buf, &size);
3916                        s->size = size;
3917                        s->should_free = 1;
3918                }
3919        }
3920        else {
3921                enum object_type type;
3922                if (size_only || (flags & CHECK_BINARY)) {
3923                        type = oid_object_info(the_repository, &s->oid,
3924                                               &s->size);
3925                        if (type < 0)
3926                                die("unable to read %s",
3927                                    oid_to_hex(&s->oid));
3928                        if (size_only)
3929                                return 0;
3930                        if (s->size > big_file_threshold && s->is_binary == -1) {
3931                                s->is_binary = 1;
3932                                return 0;
3933                        }
3934                }
3935                s->data = read_object_file(&s->oid, &type, &s->size);
3936                if (!s->data)
3937                        die("unable to read %s", oid_to_hex(&s->oid));
3938                s->should_free = 1;
3939        }
3940        return 0;
3941}
3942
3943void diff_free_filespec_blob(struct diff_filespec *s)
3944{
3945        if (s->should_free)
3946                free(s->data);
3947        else if (s->should_munmap)
3948                munmap(s->data, s->size);
3949
3950        if (s->should_free || s->should_munmap) {
3951                s->should_free = s->should_munmap = 0;
3952                s->data = NULL;
3953        }
3954}
3955
3956void diff_free_filespec_data(struct diff_filespec *s)
3957{
3958        diff_free_filespec_blob(s);
3959        FREE_AND_NULL(s->cnt_data);
3960}
3961
3962static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
3963                           void *blob,
3964                           unsigned long size,
3965                           const struct object_id *oid,
3966                           int mode)
3967{
3968        struct strbuf buf = STRBUF_INIT;
3969        struct strbuf tempfile = STRBUF_INIT;
3970        char *path_dup = xstrdup(path);
3971        const char *base = basename(path_dup);
3972
3973        /* Generate "XXXXXX_basename.ext" */
3974        strbuf_addstr(&tempfile, "XXXXXX_");
3975        strbuf_addstr(&tempfile, base);
3976
3977        temp->tempfile = mks_tempfile_ts(tempfile.buf, strlen(base) + 1);
3978        if (!temp->tempfile)
3979                die_errno("unable to create temp-file");
3980        if (convert_to_working_tree(&the_index, path,
3981                        (const char *)blob, (size_t)size, &buf)) {
3982                blob = buf.buf;
3983                size = buf.len;
3984        }
3985        if (write_in_full(temp->tempfile->fd, blob, size) < 0 ||
3986            close_tempfile_gently(temp->tempfile))
3987                die_errno("unable to write temp-file");
3988        temp->name = get_tempfile_path(temp->tempfile);
3989        oid_to_hex_r(temp->hex, oid);
3990        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
3991        strbuf_release(&buf);
3992        strbuf_release(&tempfile);
3993        free(path_dup);
3994}
3995
3996static struct diff_tempfile *prepare_temp_file(const char *name,
3997                struct diff_filespec *one)
3998{
3999        struct diff_tempfile *temp = claim_diff_tempfile();
4000
4001        if (!DIFF_FILE_VALID(one)) {
4002        not_a_valid_file:
4003                /* A '-' entry produces this for file-2, and
4004                 * a '+' entry produces this for file-1.
4005                 */
4006                temp->name = "/dev/null";
4007                xsnprintf(temp->hex, sizeof(temp->hex), ".");
4008                xsnprintf(temp->mode, sizeof(temp->mode), ".");
4009                return temp;
4010        }
4011
4012        if (!S_ISGITLINK(one->mode) &&
4013            (!one->oid_valid ||
4014             reuse_worktree_file(name, &one->oid, 1))) {
4015                struct stat st;
4016                if (lstat(name, &st) < 0) {
4017                        if (errno == ENOENT)
4018                                goto not_a_valid_file;
4019                        die_errno("stat(%s)", name);
4020                }
4021                if (S_ISLNK(st.st_mode)) {
4022                        struct strbuf sb = STRBUF_INIT;
4023                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
4024                                die_errno("readlink(%s)", name);
4025                        prep_temp_blob(name, temp, sb.buf, sb.len,
4026                                       (one->oid_valid ?
4027                                        &one->oid : &null_oid),
4028                                       (one->oid_valid ?
4029                                        one->mode : S_IFLNK));
4030                        strbuf_release(&sb);
4031                }
4032                else {
4033                        /* we can borrow from the file in the work tree */
4034                        temp->name = name;
4035                        if (!one->oid_valid)
4036                                oid_to_hex_r(temp->hex, &null_oid);
4037                        else
4038                                oid_to_hex_r(temp->hex, &one->oid);
4039                        /* Even though we may sometimes borrow the
4040                         * contents from the work tree, we always want
4041                         * one->mode.  mode is trustworthy even when
4042                         * !(one->oid_valid), as long as
4043                         * DIFF_FILE_VALID(one).
4044                         */
4045                        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
4046                }
4047                return temp;
4048        }
4049        else {
4050                if (diff_populate_filespec(one, 0))
4051                        die("cannot read data blob for %s", one->path);
4052                prep_temp_blob(name, temp, one->data, one->size,
4053                               &one->oid, one->mode);
4054        }
4055        return temp;
4056}
4057
4058static void add_external_diff_name(struct argv_array *argv,
4059                                   const char *name,
4060                                   struct diff_filespec *df)
4061{
4062        struct diff_tempfile *temp = prepare_temp_file(name, df);
4063        argv_array_push(argv, temp->name);
4064        argv_array_push(argv, temp->hex);
4065        argv_array_push(argv, temp->mode);
4066}
4067
4068/* An external diff command takes:
4069 *
4070 * diff-cmd name infile1 infile1-sha1 infile1-mode \
4071 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
4072 *
4073 */
4074static void run_external_diff(const char *pgm,
4075                              const char *name,
4076                              const char *other,
4077                              struct diff_filespec *one,
4078                              struct diff_filespec *two,
4079                              const char *xfrm_msg,
4080                              int complete_rewrite,
4081                              struct diff_options *o)
4082{
4083        struct argv_array argv = ARGV_ARRAY_INIT;
4084        struct argv_array env = ARGV_ARRAY_INIT;
4085        struct diff_queue_struct *q = &diff_queued_diff;
4086
4087        argv_array_push(&argv, pgm);
4088        argv_array_push(&argv, name);
4089
4090        if (one && two) {
4091                add_external_diff_name(&argv, name, one);
4092                if (!other)
4093                        add_external_diff_name(&argv, name, two);
4094                else {
4095                        add_external_diff_name(&argv, other, two);
4096                        argv_array_push(&argv, other);
4097                        argv_array_push(&argv, xfrm_msg);
4098                }
4099        }
4100
4101        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
4102        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
4103
4104        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
4105                die(_("external diff died, stopping at %s"), name);
4106
4107        remove_tempfile();
4108        argv_array_clear(&argv);
4109        argv_array_clear(&env);
4110}
4111
4112static int similarity_index(struct diff_filepair *p)
4113{
4114        return p->score * 100 / MAX_SCORE;
4115}
4116
4117static const char *diff_abbrev_oid(const struct object_id *oid, int abbrev)
4118{
4119        if (startup_info->have_repository)
4120                return find_unique_abbrev(oid, abbrev);
4121        else {
4122                char *hex = oid_to_hex(oid);
4123                if (abbrev < 0)
4124                        abbrev = FALLBACK_DEFAULT_ABBREV;
4125                if (abbrev > the_hash_algo->hexsz)
4126                        BUG("oid abbreviation out of range: %d", abbrev);
4127                if (abbrev)
4128                        hex[abbrev] = '\0';
4129                return hex;
4130        }
4131}
4132
4133static void fill_metainfo(struct strbuf *msg,
4134                          const char *name,
4135                          const char *other,
4136                          struct diff_filespec *one,
4137                          struct diff_filespec *two,
4138                          struct diff_options *o,
4139                          struct diff_filepair *p,
4140                          int *must_show_header,
4141                          int use_color)
4142{
4143        const char *set = diff_get_color(use_color, DIFF_METAINFO);
4144        const char *reset = diff_get_color(use_color, DIFF_RESET);
4145        const char *line_prefix = diff_line_prefix(o);
4146
4147        *must_show_header = 1;
4148        strbuf_init(msg, PATH_MAX * 2 + 300);
4149        switch (p->status) {
4150        case DIFF_STATUS_COPIED:
4151                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4152                            line_prefix, set, similarity_index(p));
4153                strbuf_addf(msg, "%s\n%s%scopy from ",
4154                            reset,  line_prefix, set);
4155                quote_c_style(name, msg, NULL, 0);
4156                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
4157                quote_c_style(other, msg, NULL, 0);
4158                strbuf_addf(msg, "%s\n", reset);
4159                break;
4160        case DIFF_STATUS_RENAMED:
4161                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4162                            line_prefix, set, similarity_index(p));
4163                strbuf_addf(msg, "%s\n%s%srename from ",
4164                            reset, line_prefix, set);
4165                quote_c_style(name, msg, NULL, 0);
4166                strbuf_addf(msg, "%s\n%s%srename to ",
4167                            reset, line_prefix, set);
4168                quote_c_style(other, msg, NULL, 0);
4169                strbuf_addf(msg, "%s\n", reset);
4170                break;
4171        case DIFF_STATUS_MODIFIED:
4172                if (p->score) {
4173                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
4174                                    line_prefix,
4175                                    set, similarity_index(p), reset);
4176                        break;
4177                }
4178                /* fallthru */
4179        default:
4180                *must_show_header = 0;
4181        }
4182        if (one && two && !oideq(&one->oid, &two->oid)) {
4183                const unsigned hexsz = the_hash_algo->hexsz;
4184                int abbrev = o->flags.full_index ? hexsz : DEFAULT_ABBREV;
4185
4186                if (o->flags.binary) {
4187                        mmfile_t mf;
4188                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
4189                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
4190                                abbrev = hexsz;
4191                }
4192                strbuf_addf(msg, "%s%sindex %s..%s", line_prefix, set,
4193                            diff_abbrev_oid(&one->oid, abbrev),
4194                            diff_abbrev_oid(&two->oid, abbrev));
4195                if (one->mode == two->mode)
4196                        strbuf_addf(msg, " %06o", one->mode);
4197                strbuf_addf(msg, "%s\n", reset);
4198        }
4199}
4200
4201static void run_diff_cmd(const char *pgm,
4202                         const char *name,
4203                         const char *other,
4204                         const char *attr_path,
4205                         struct diff_filespec *one,
4206                         struct diff_filespec *two,
4207                         struct strbuf *msg,
4208                         struct diff_options *o,
4209                         struct diff_filepair *p)
4210{
4211        const char *xfrm_msg = NULL;
4212        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
4213        int must_show_header = 0;
4214
4215
4216        if (o->flags.allow_external) {
4217                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
4218                if (drv && drv->external)
4219                        pgm = drv->external;
4220        }
4221
4222        if (msg) {
4223                /*
4224                 * don't use colors when the header is intended for an
4225                 * external diff driver
4226                 */
4227                fill_metainfo(msg, name, other, one, two, o, p,
4228                              &must_show_header,
4229                              want_color(o->use_color) && !pgm);
4230                xfrm_msg = msg->len ? msg->buf : NULL;
4231        }
4232
4233        if (pgm) {
4234                run_external_diff(pgm, name, other, one, two, xfrm_msg,
4235                                  complete_rewrite, o);
4236                return;
4237        }
4238        if (one && two)
4239                builtin_diff(name, other ? other : name,
4240                             one, two, xfrm_msg, must_show_header,
4241                             o, complete_rewrite);
4242        else
4243                fprintf(o->file, "* Unmerged path %s\n", name);
4244}
4245
4246static void diff_fill_oid_info(struct diff_filespec *one)
4247{
4248        if (DIFF_FILE_VALID(one)) {
4249                if (!one->oid_valid) {
4250                        struct stat st;
4251                        if (one->is_stdin) {
4252                                oidclr(&one->oid);
4253                                return;
4254                        }
4255                        if (lstat(one->path, &st) < 0)
4256                                die_errno("stat '%s'", one->path);
4257                        if (index_path(&one->oid, one->path, &st, 0))
4258                                die("cannot hash %s", one->path);
4259                }
4260        }
4261        else
4262                oidclr(&one->oid);
4263}
4264
4265static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
4266{
4267        /* Strip the prefix but do not molest /dev/null and absolute paths */
4268        if (*namep && **namep != '/') {
4269                *namep += prefix_length;
4270                if (**namep == '/')
4271                        ++*namep;
4272        }
4273        if (*otherp && **otherp != '/') {
4274                *otherp += prefix_length;
4275                if (**otherp == '/')
4276                        ++*otherp;
4277        }
4278}
4279
4280static void run_diff(struct diff_filepair *p, struct diff_options *o)
4281{
4282        const char *pgm = external_diff();
4283        struct strbuf msg;
4284        struct diff_filespec *one = p->one;
4285        struct diff_filespec *two = p->two;
4286        const char *name;
4287        const char *other;
4288        const char *attr_path;
4289
4290        name  = one->path;
4291        other = (strcmp(name, two->path) ? two->path : NULL);
4292        attr_path = name;
4293        if (o->prefix_length)
4294                strip_prefix(o->prefix_length, &name, &other);
4295
4296        if (!o->flags.allow_external)
4297                pgm = NULL;
4298
4299        if (DIFF_PAIR_UNMERGED(p)) {
4300                run_diff_cmd(pgm, name, NULL, attr_path,
4301                             NULL, NULL, NULL, o, p);
4302                return;
4303        }
4304
4305        diff_fill_oid_info(one);
4306        diff_fill_oid_info(two);
4307
4308        if (!pgm &&
4309            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
4310            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
4311                /*
4312                 * a filepair that changes between file and symlink
4313                 * needs to be split into deletion and creation.
4314                 */
4315                struct diff_filespec *null = alloc_filespec(two->path);
4316                run_diff_cmd(NULL, name, other, attr_path,
4317                             one, null, &msg, o, p);
4318                free(null);
4319                strbuf_release(&msg);
4320
4321                null = alloc_filespec(one->path);
4322                run_diff_cmd(NULL, name, other, attr_path,
4323                             null, two, &msg, o, p);
4324                free(null);
4325        }
4326        else
4327                run_diff_cmd(pgm, name, other, attr_path,
4328                             one, two, &msg, o, p);
4329
4330        strbuf_release(&msg);
4331}
4332
4333static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
4334                         struct diffstat_t *diffstat)
4335{
4336        const char *name;
4337        const char *other;
4338
4339        if (DIFF_PAIR_UNMERGED(p)) {
4340                /* unmerged */
4341                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, p);
4342                return;
4343        }
4344
4345        name = p->one->path;
4346        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4347
4348        if (o->prefix_length)
4349                strip_prefix(o->prefix_length, &name, &other);
4350
4351        diff_fill_oid_info(p->one);
4352        diff_fill_oid_info(p->two);
4353
4354        builtin_diffstat(name, other, p->one, p->two, diffstat, o, p);
4355}
4356
4357static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
4358{
4359        const char *name;
4360        const char *other;
4361        const char *attr_path;
4362
4363        if (DIFF_PAIR_UNMERGED(p)) {
4364                /* unmerged */
4365                return;
4366        }
4367
4368        name = p->one->path;
4369        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4370        attr_path = other ? other : name;
4371
4372        if (o->prefix_length)
4373                strip_prefix(o->prefix_length, &name, &other);
4374
4375        diff_fill_oid_info(p->one);
4376        diff_fill_oid_info(p->two);
4377
4378        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
4379}
4380
4381void diff_setup(struct diff_options *options)
4382{
4383        memcpy(options, &default_diff_options, sizeof(*options));
4384
4385        options->file = stdout;
4386
4387        options->output_indicators[OUTPUT_INDICATOR_NEW] = '+';
4388        options->output_indicators[OUTPUT_INDICATOR_OLD] = '-';
4389        options->output_indicators[OUTPUT_INDICATOR_CONTEXT] = ' ';
4390        options->abbrev = DEFAULT_ABBREV;
4391        options->line_termination = '\n';
4392        options->break_opt = -1;
4393        options->rename_limit = -1;
4394        options->dirstat_permille = diff_dirstat_permille_default;
4395        options->context = diff_context_default;
4396        options->interhunkcontext = diff_interhunk_context_default;
4397        options->ws_error_highlight = ws_error_highlight_default;
4398        options->flags.rename_empty = 1;
4399        options->objfind = NULL;
4400
4401        /* pathchange left =NULL by default */
4402        options->change = diff_change;
4403        options->add_remove = diff_addremove;
4404        options->use_color = diff_use_color_default;
4405        options->detect_rename = diff_detect_rename_default;
4406        options->xdl_opts |= diff_algorithm;
4407        if (diff_indent_heuristic)
4408                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4409
4410        options->orderfile = diff_order_file_cfg;
4411
4412        if (diff_no_prefix) {
4413                options->a_prefix = options->b_prefix = "";
4414        } else if (!diff_mnemonic_prefix) {
4415                options->a_prefix = "a/";
4416                options->b_prefix = "b/";
4417        }
4418
4419        options->color_moved = diff_color_moved_default;
4420        options->color_moved_ws_handling = diff_color_moved_ws_default;
4421}
4422
4423void diff_setup_done(struct diff_options *options)
4424{
4425        unsigned check_mask = DIFF_FORMAT_NAME |
4426                              DIFF_FORMAT_NAME_STATUS |
4427                              DIFF_FORMAT_CHECKDIFF |
4428                              DIFF_FORMAT_NO_OUTPUT;
4429        /*
4430         * This must be signed because we're comparing against a potentially
4431         * negative value.
4432         */
4433        const int hexsz = the_hash_algo->hexsz;
4434
4435        if (options->set_default)
4436                options->set_default(options);
4437
4438        if (HAS_MULTI_BITS(options->output_format & check_mask))
4439                die(_("--name-only, --name-status, --check and -s are mutually exclusive"));
4440
4441        if (HAS_MULTI_BITS(options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK))
4442                die(_("-G, -S and --find-object are mutually exclusive"));
4443
4444        /*
4445         * Most of the time we can say "there are changes"
4446         * only by checking if there are changed paths, but
4447         * --ignore-whitespace* options force us to look
4448         * inside contents.
4449         */
4450
4451        if ((options->xdl_opts & XDF_WHITESPACE_FLAGS))
4452                options->flags.diff_from_contents = 1;
4453        else
4454                options->flags.diff_from_contents = 0;
4455
4456        if (options->flags.find_copies_harder)
4457                options->detect_rename = DIFF_DETECT_COPY;
4458
4459        if (!options->flags.relative_name)
4460                options->prefix = NULL;
4461        if (options->prefix)
4462                options->prefix_length = strlen(options->prefix);
4463        else
4464                options->prefix_length = 0;
4465
4466        if (options->output_format & (DIFF_FORMAT_NAME |
4467                                      DIFF_FORMAT_NAME_STATUS |
4468                                      DIFF_FORMAT_CHECKDIFF |
4469                                      DIFF_FORMAT_NO_OUTPUT))
4470                options->output_format &= ~(DIFF_FORMAT_RAW |
4471                                            DIFF_FORMAT_NUMSTAT |
4472                                            DIFF_FORMAT_DIFFSTAT |
4473                                            DIFF_FORMAT_SHORTSTAT |
4474                                            DIFF_FORMAT_DIRSTAT |
4475                                            DIFF_FORMAT_SUMMARY |
4476                                            DIFF_FORMAT_PATCH);
4477
4478        /*
4479         * These cases always need recursive; we do not drop caller-supplied
4480         * recursive bits for other formats here.
4481         */
4482        if (options->output_format & (DIFF_FORMAT_PATCH |
4483                                      DIFF_FORMAT_NUMSTAT |
4484                                      DIFF_FORMAT_DIFFSTAT |
4485                                      DIFF_FORMAT_SHORTSTAT |
4486                                      DIFF_FORMAT_DIRSTAT |
4487                                      DIFF_FORMAT_SUMMARY |
4488                                      DIFF_FORMAT_CHECKDIFF))
4489                options->flags.recursive = 1;
4490        /*
4491         * Also pickaxe would not work very well if you do not say recursive
4492         */
4493        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
4494                options->flags.recursive = 1;
4495        /*
4496         * When patches are generated, submodules diffed against the work tree
4497         * must be checked for dirtiness too so it can be shown in the output
4498         */
4499        if (options->output_format & DIFF_FORMAT_PATCH)
4500                options->flags.dirty_submodules = 1;
4501
4502        if (options->detect_rename && options->rename_limit < 0)
4503                options->rename_limit = diff_rename_limit_default;
4504        if (hexsz < options->abbrev)
4505                options->abbrev = hexsz; /* full */
4506
4507        /*
4508         * It does not make sense to show the first hit we happened
4509         * to have found.  It does not make sense not to return with
4510         * exit code in such a case either.
4511         */
4512        if (options->flags.quick) {
4513                options->output_format = DIFF_FORMAT_NO_OUTPUT;
4514                options->flags.exit_with_status = 1;
4515        }
4516
4517        options->diff_path_counter = 0;
4518
4519        if (options->flags.follow_renames && options->pathspec.nr != 1)
4520                die(_("--follow requires exactly one pathspec"));
4521
4522        if (!options->use_color || external_diff())
4523                options->color_moved = 0;
4524}
4525
4526static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
4527{
4528        char c, *eq;
4529        int len;
4530
4531        if (*arg != '-')
4532                return 0;
4533        c = *++arg;
4534        if (!c)
4535                return 0;
4536        if (c == arg_short) {
4537                c = *++arg;
4538                if (!c)
4539                        return 1;
4540                if (val && isdigit(c)) {
4541                        char *end;
4542                        int n = strtoul(arg, &end, 10);
4543                        if (*end)
4544                                return 0;
4545                        *val = n;
4546                        return 1;
4547                }
4548                return 0;
4549        }
4550        if (c != '-')
4551                return 0;
4552        arg++;
4553        eq = strchrnul(arg, '=');
4554        len = eq - arg;
4555        if (!len || strncmp(arg, arg_long, len))
4556                return 0;
4557        if (*eq) {
4558                int n;
4559                char *end;
4560                if (!isdigit(*++eq))
4561                        return 0;
4562                n = strtoul(eq, &end, 10);
4563                if (*end)
4564                        return 0;
4565                *val = n;
4566        }
4567        return 1;
4568}
4569
4570static int diff_scoreopt_parse(const char *opt);
4571
4572static inline int short_opt(char opt, const char **argv,
4573                            const char **optarg)
4574{
4575        const char *arg = argv[0];
4576        if (arg[0] != '-' || arg[1] != opt)
4577                return 0;
4578        if (arg[2] != '\0') {
4579                *optarg = arg + 2;
4580                return 1;
4581        }
4582        if (!argv[1])
4583                die("Option '%c' requires a value", opt);
4584        *optarg = argv[1];
4585        return 2;
4586}
4587
4588int parse_long_opt(const char *opt, const char **argv,
4589                   const char **optarg)
4590{
4591        const char *arg = argv[0];
4592        if (!skip_prefix(arg, "--", &arg))
4593                return 0;
4594        if (!skip_prefix(arg, opt, &arg))
4595                return 0;
4596        if (*arg == '=') { /* stuck form: --option=value */
4597                *optarg = arg + 1;
4598                return 1;
4599        }
4600        if (*arg != '\0')
4601                return 0;
4602        /* separate form: --option value */
4603        if (!argv[1])
4604                die("Option '--%s' requires a value", opt);
4605        *optarg = argv[1];
4606        return 2;
4607}
4608
4609static int stat_opt(struct diff_options *options, const char **av)
4610{
4611        const char *arg = av[0];
4612        char *end;
4613        int width = options->stat_width;
4614        int name_width = options->stat_name_width;
4615        int graph_width = options->stat_graph_width;
4616        int count = options->stat_count;
4617        int argcount = 1;
4618
4619        if (!skip_prefix(arg, "--stat", &arg))
4620                BUG("stat option does not begin with --stat: %s", arg);
4621        end = (char *)arg;
4622
4623        switch (*arg) {
4624        case '-':
4625                if (skip_prefix(arg, "-width", &arg)) {
4626                        if (*arg == '=')
4627                                width = strtoul(arg + 1, &end, 10);
4628                        else if (!*arg && !av[1])
4629                                die_want_option("--stat-width");
4630                        else if (!*arg) {
4631                                width = strtoul(av[1], &end, 10);
4632                                argcount = 2;
4633                        }
4634                } else if (skip_prefix(arg, "-name-width", &arg)) {
4635                        if (*arg == '=')
4636                                name_width = strtoul(arg + 1, &end, 10);
4637                        else if (!*arg && !av[1])
4638                                die_want_option("--stat-name-width");
4639                        else if (!*arg) {
4640                                name_width = strtoul(av[1], &end, 10);
4641                                argcount = 2;
4642                        }
4643                } else if (skip_prefix(arg, "-graph-width", &arg)) {
4644                        if (*arg == '=')
4645                                graph_width = strtoul(arg + 1, &end, 10);
4646                        else if (!*arg && !av[1])
4647                                die_want_option("--stat-graph-width");
4648                        else if (!*arg) {
4649                                graph_width = strtoul(av[1], &end, 10);
4650                                argcount = 2;
4651                        }
4652                } else if (skip_prefix(arg, "-count", &arg)) {
4653                        if (*arg == '=')
4654                                count = strtoul(arg + 1, &end, 10);
4655                        else if (!*arg && !av[1])
4656                                die_want_option("--stat-count");
4657                        else if (!*arg) {
4658                                count = strtoul(av[1], &end, 10);
4659                                argcount = 2;
4660                        }
4661                }
4662                break;
4663        case '=':
4664                width = strtoul(arg+1, &end, 10);
4665                if (*end == ',')
4666                        name_width = strtoul(end+1, &end, 10);
4667                if (*end == ',')
4668                        count = strtoul(end+1, &end, 10);
4669        }
4670
4671        /* Important! This checks all the error cases! */
4672        if (*end)
4673                return 0;
4674        options->output_format |= DIFF_FORMAT_DIFFSTAT;
4675        options->stat_name_width = name_width;
4676        options->stat_graph_width = graph_width;
4677        options->stat_width = width;
4678        options->stat_count = count;
4679        return argcount;
4680}
4681
4682static int parse_dirstat_opt(struct diff_options *options, const char *params)
4683{
4684        struct strbuf errmsg = STRBUF_INIT;
4685        if (parse_dirstat_params(options, params, &errmsg))
4686                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
4687                    errmsg.buf);
4688        strbuf_release(&errmsg);
4689        /*
4690         * The caller knows a dirstat-related option is given from the command
4691         * line; allow it to say "return this_function();"
4692         */
4693        options->output_format |= DIFF_FORMAT_DIRSTAT;
4694        return 1;
4695}
4696
4697static int parse_submodule_opt(struct diff_options *options, const char *value)
4698{
4699        if (parse_submodule_params(options, value))
4700                die(_("Failed to parse --submodule option parameter: '%s'"),
4701                        value);
4702        return 1;
4703}
4704
4705static const char diff_status_letters[] = {
4706        DIFF_STATUS_ADDED,
4707        DIFF_STATUS_COPIED,
4708        DIFF_STATUS_DELETED,
4709        DIFF_STATUS_MODIFIED,
4710        DIFF_STATUS_RENAMED,
4711        DIFF_STATUS_TYPE_CHANGED,
4712        DIFF_STATUS_UNKNOWN,
4713        DIFF_STATUS_UNMERGED,
4714        DIFF_STATUS_FILTER_AON,
4715        DIFF_STATUS_FILTER_BROKEN,
4716        '\0',
4717};
4718
4719static unsigned int filter_bit['Z' + 1];
4720
4721static void prepare_filter_bits(void)
4722{
4723        int i;
4724
4725        if (!filter_bit[DIFF_STATUS_ADDED]) {
4726                for (i = 0; diff_status_letters[i]; i++)
4727                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
4728        }
4729}
4730
4731static unsigned filter_bit_tst(char status, const struct diff_options *opt)
4732{
4733        return opt->filter & filter_bit[(int) status];
4734}
4735
4736static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
4737{
4738        int i, optch;
4739
4740        prepare_filter_bits();
4741
4742        /*
4743         * If there is a negation e.g. 'd' in the input, and we haven't
4744         * initialized the filter field with another --diff-filter, start
4745         * from full set of bits, except for AON.
4746         */
4747        if (!opt->filter) {
4748                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4749                        if (optch < 'a' || 'z' < optch)
4750                                continue;
4751                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
4752                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
4753                        break;
4754                }
4755        }
4756
4757        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4758                unsigned int bit;
4759                int negate;
4760
4761                if ('a' <= optch && optch <= 'z') {
4762                        negate = 1;
4763                        optch = toupper(optch);
4764                } else {
4765                        negate = 0;
4766                }
4767
4768                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
4769                if (!bit)
4770                        return optarg[i];
4771                if (negate)
4772                        opt->filter &= ~bit;
4773                else
4774                        opt->filter |= bit;
4775        }
4776        return 0;
4777}
4778
4779static void enable_patch_output(int *fmt) {
4780        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
4781        *fmt |= DIFF_FORMAT_PATCH;
4782}
4783
4784static int parse_ws_error_highlight_opt(struct diff_options *opt, const char *arg)
4785{
4786        int val = parse_ws_error_highlight(arg);
4787
4788        if (val < 0) {
4789                error("unknown value after ws-error-highlight=%.*s",
4790                      -1 - val, arg);
4791                return 0;
4792        }
4793        opt->ws_error_highlight = val;
4794        return 1;
4795}
4796
4797static int parse_objfind_opt(struct diff_options *opt, const char *arg)
4798{
4799        struct object_id oid;
4800
4801        if (get_oid(arg, &oid))
4802                return error("unable to resolve '%s'", arg);
4803
4804        if (!opt->objfind)
4805                opt->objfind = xcalloc(1, sizeof(*opt->objfind));
4806
4807        opt->pickaxe_opts |= DIFF_PICKAXE_KIND_OBJFIND;
4808        opt->flags.recursive = 1;
4809        opt->flags.tree_in_recursive = 1;
4810        oidset_insert(opt->objfind, &oid);
4811        return 1;
4812}
4813
4814int diff_opt_parse(struct diff_options *options,
4815                   const char **av, int ac, const char *prefix)
4816{
4817        const char *arg = av[0];
4818        const char *optarg;
4819        int argcount;
4820
4821        if (!prefix)
4822                prefix = "";
4823
4824        /* Output format options */
4825        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
4826            || opt_arg(arg, 'U', "unified", &options->context))
4827                enable_patch_output(&options->output_format);
4828        else if (!strcmp(arg, "--raw"))
4829                options->output_format |= DIFF_FORMAT_RAW;
4830        else if (!strcmp(arg, "--patch-with-raw")) {
4831                enable_patch_output(&options->output_format);
4832                options->output_format |= DIFF_FORMAT_RAW;
4833        } else if (!strcmp(arg, "--numstat"))
4834                options->output_format |= DIFF_FORMAT_NUMSTAT;
4835        else if (!strcmp(arg, "--shortstat"))
4836                options->output_format |= DIFF_FORMAT_SHORTSTAT;
4837        else if (skip_prefix(arg, "-X", &arg) ||
4838                 skip_to_optional_arg(arg, "--dirstat", &arg))
4839                return parse_dirstat_opt(options, arg);
4840        else if (!strcmp(arg, "--cumulative"))
4841                return parse_dirstat_opt(options, "cumulative");
4842        else if (skip_to_optional_arg(arg, "--dirstat-by-file", &arg)) {
4843                parse_dirstat_opt(options, "files");
4844                return parse_dirstat_opt(options, arg);
4845        }
4846        else if (!strcmp(arg, "--check"))
4847                options->output_format |= DIFF_FORMAT_CHECKDIFF;
4848        else if (!strcmp(arg, "--summary"))
4849                options->output_format |= DIFF_FORMAT_SUMMARY;
4850        else if (!strcmp(arg, "--patch-with-stat")) {
4851                enable_patch_output(&options->output_format);
4852                options->output_format |= DIFF_FORMAT_DIFFSTAT;
4853        } else if (!strcmp(arg, "--name-only"))
4854                options->output_format |= DIFF_FORMAT_NAME;
4855        else if (!strcmp(arg, "--name-status"))
4856                options->output_format |= DIFF_FORMAT_NAME_STATUS;
4857        else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
4858                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
4859        else if (starts_with(arg, "--stat"))
4860                /* --stat, --stat-width, --stat-name-width, or --stat-count */
4861                return stat_opt(options, av);
4862        else if (!strcmp(arg, "--compact-summary")) {
4863                 options->flags.stat_with_summary = 1;
4864                 options->output_format |= DIFF_FORMAT_DIFFSTAT;
4865        } else if (!strcmp(arg, "--no-compact-summary"))
4866                 options->flags.stat_with_summary = 0;
4867        else if (skip_prefix(arg, "--output-indicator-new=", &arg))
4868                options->output_indicators[OUTPUT_INDICATOR_NEW] = arg[0];
4869        else if (skip_prefix(arg, "--output-indicator-old=", &arg))
4870                options->output_indicators[OUTPUT_INDICATOR_OLD] = arg[0];
4871        else if (skip_prefix(arg, "--output-indicator-context=", &arg))
4872                options->output_indicators[OUTPUT_INDICATOR_CONTEXT] = arg[0];
4873
4874        /* renames options */
4875        else if (starts_with(arg, "-B") ||
4876                 skip_to_optional_arg(arg, "--break-rewrites", NULL)) {
4877                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
4878                        return error("invalid argument to -B: %s", arg+2);
4879        }
4880        else if (starts_with(arg, "-M") ||
4881                 skip_to_optional_arg(arg, "--find-renames", NULL)) {
4882                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4883                        return error("invalid argument to -M: %s", arg+2);
4884                options->detect_rename = DIFF_DETECT_RENAME;
4885        }
4886        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
4887                options->irreversible_delete = 1;
4888        }
4889        else if (starts_with(arg, "-C") ||
4890                 skip_to_optional_arg(arg, "--find-copies", NULL)) {
4891                if (options->detect_rename == DIFF_DETECT_COPY)
4892                        options->flags.find_copies_harder = 1;
4893                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4894                        return error("invalid argument to -C: %s", arg+2);
4895                options->detect_rename = DIFF_DETECT_COPY;
4896        }
4897        else if (!strcmp(arg, "--no-renames"))
4898                options->detect_rename = 0;
4899        else if (!strcmp(arg, "--rename-empty"))
4900                options->flags.rename_empty = 1;
4901        else if (!strcmp(arg, "--no-rename-empty"))
4902                options->flags.rename_empty = 0;
4903        else if (skip_to_optional_arg_default(arg, "--relative", &arg, NULL)) {
4904                options->flags.relative_name = 1;
4905                if (arg)
4906                        options->prefix = arg;
4907        }
4908
4909        /* xdiff options */
4910        else if (!strcmp(arg, "--minimal"))
4911                DIFF_XDL_SET(options, NEED_MINIMAL);
4912        else if (!strcmp(arg, "--no-minimal"))
4913                DIFF_XDL_CLR(options, NEED_MINIMAL);
4914        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
4915                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
4916        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
4917                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
4918        else if (!strcmp(arg, "--ignore-space-at-eol"))
4919                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
4920        else if (!strcmp(arg, "--ignore-cr-at-eol"))
4921                DIFF_XDL_SET(options, IGNORE_CR_AT_EOL);
4922        else if (!strcmp(arg, "--ignore-blank-lines"))
4923                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
4924        else if (!strcmp(arg, "--indent-heuristic"))
4925                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4926        else if (!strcmp(arg, "--no-indent-heuristic"))
4927                DIFF_XDL_CLR(options, INDENT_HEURISTIC);
4928        else if (!strcmp(arg, "--patience")) {
4929                int i;
4930                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4931                /*
4932                 * Both --patience and --anchored use PATIENCE_DIFF
4933                 * internally, so remove any anchors previously
4934                 * specified.
4935                 */
4936                for (i = 0; i < options->anchors_nr; i++)
4937                        free(options->anchors[i]);
4938                options->anchors_nr = 0;
4939        } else if (!strcmp(arg, "--histogram"))
4940                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
4941        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
4942                long value = parse_algorithm_value(optarg);
4943                if (value < 0)
4944                        return error("option diff-algorithm accepts \"myers\", "
4945                                     "\"minimal\", \"patience\" and \"histogram\"");
4946                /* clear out previous settings */
4947                DIFF_XDL_CLR(options, NEED_MINIMAL);
4948                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
4949                options->xdl_opts |= value;
4950                return argcount;
4951        } else if (skip_prefix(arg, "--anchored=", &arg)) {
4952                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4953                ALLOC_GROW(options->anchors, options->anchors_nr + 1,
4954                           options->anchors_alloc);
4955                options->anchors[options->anchors_nr++] = xstrdup(arg);
4956        }
4957
4958        /* flags options */
4959        else if (!strcmp(arg, "--binary")) {
4960                enable_patch_output(&options->output_format);
4961                options->flags.binary = 1;
4962        }
4963        else if (!strcmp(arg, "--full-index"))
4964                options->flags.full_index = 1;
4965        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
4966                options->flags.text = 1;
4967        else if (!strcmp(arg, "-R"))
4968                options->flags.reverse_diff = 1;
4969        else if (!strcmp(arg, "--find-copies-harder"))
4970                options->flags.find_copies_harder = 1;
4971        else if (!strcmp(arg, "--follow"))
4972                options->flags.follow_renames = 1;
4973        else if (!strcmp(arg, "--no-follow")) {
4974                options->flags.follow_renames = 0;
4975                options->flags.default_follow_renames = 0;
4976        } else if (skip_to_optional_arg_default(arg, "--color", &arg, "always")) {
4977                int value = git_config_colorbool(NULL, arg);
4978                if (value < 0)
4979                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
4980                options->use_color = value;
4981        }
4982        else if (!strcmp(arg, "--no-color"))
4983                options->use_color = 0;
4984        else if (!strcmp(arg, "--color-moved")) {
4985                if (diff_color_moved_default)
4986                        options->color_moved = diff_color_moved_default;
4987                if (options->color_moved == COLOR_MOVED_NO)
4988                        options->color_moved = COLOR_MOVED_DEFAULT;
4989        } else if (!strcmp(arg, "--no-color-moved"))
4990                options->color_moved = COLOR_MOVED_NO;
4991        else if (skip_prefix(arg, "--color-moved=", &arg)) {
4992                int cm = parse_color_moved(arg);
4993                if (cm < 0)
4994                        die("bad --color-moved argument: %s", arg);
4995                options->color_moved = cm;
4996        } else if (skip_prefix(arg, "--color-moved-ws=", &arg)) {
4997                options->color_moved_ws_handling = parse_color_moved_ws(arg);
4998        } else if (skip_to_optional_arg_default(arg, "--color-words", &options->word_regex, NULL)) {
4999                options->use_color = 1;
5000                options->word_diff = DIFF_WORDS_COLOR;
5001        }
5002        else if (!strcmp(arg, "--word-diff")) {
5003                if (options->word_diff == DIFF_WORDS_NONE)
5004                        options->word_diff = DIFF_WORDS_PLAIN;
5005        }
5006        else if (skip_prefix(arg, "--word-diff=", &arg)) {
5007                if (!strcmp(arg, "plain"))
5008                        options->word_diff = DIFF_WORDS_PLAIN;
5009                else if (!strcmp(arg, "color")) {
5010                        options->use_color = 1;
5011                        options->word_diff = DIFF_WORDS_COLOR;
5012                }
5013                else if (!strcmp(arg, "porcelain"))
5014                        options->word_diff = DIFF_WORDS_PORCELAIN;
5015                else if (!strcmp(arg, "none"))
5016                        options->word_diff = DIFF_WORDS_NONE;
5017                else
5018                        die("bad --word-diff argument: %s", arg);
5019        }
5020        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
5021                if (options->word_diff == DIFF_WORDS_NONE)
5022                        options->word_diff = DIFF_WORDS_PLAIN;
5023                options->word_regex = optarg;
5024                return argcount;
5025        }
5026        else if (!strcmp(arg, "--exit-code"))
5027                options->flags.exit_with_status = 1;
5028        else if (!strcmp(arg, "--quiet"))
5029                options->flags.quick = 1;
5030        else if (!strcmp(arg, "--ext-diff"))
5031                options->flags.allow_external = 1;
5032        else if (!strcmp(arg, "--no-ext-diff"))
5033                options->flags.allow_external = 0;
5034        else if (!strcmp(arg, "--textconv")) {
5035                options->flags.allow_textconv = 1;
5036                options->flags.textconv_set_via_cmdline = 1;
5037        } else if (!strcmp(arg, "--no-textconv"))
5038                options->flags.allow_textconv = 0;
5039        else if (skip_to_optional_arg_default(arg, "--ignore-submodules", &arg, "all")) {
5040                options->flags.override_submodule_config = 1;
5041                handle_ignore_submodules_arg(options, arg);
5042        } else if (skip_to_optional_arg_default(arg, "--submodule", &arg, "log"))
5043                return parse_submodule_opt(options, arg);
5044        else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
5045                return parse_ws_error_highlight_opt(options, arg);
5046        else if (!strcmp(arg, "--ita-invisible-in-index"))
5047                options->ita_invisible_in_index = 1;
5048        else if (!strcmp(arg, "--ita-visible-in-index"))
5049                options->ita_invisible_in_index = 0;
5050
5051        /* misc options */
5052        else if (!strcmp(arg, "-z"))
5053                options->line_termination = 0;
5054        else if ((argcount = short_opt('l', av, &optarg))) {
5055                options->rename_limit = strtoul(optarg, NULL, 10);
5056                return argcount;
5057        }
5058        else if ((argcount = short_opt('S', av, &optarg))) {
5059                options->pickaxe = optarg;
5060                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
5061                return argcount;
5062        } else if ((argcount = short_opt('G', av, &optarg))) {
5063                options->pickaxe = optarg;
5064                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
5065                return argcount;
5066        }
5067        else if (!strcmp(arg, "--pickaxe-all"))
5068                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
5069        else if (!strcmp(arg, "--pickaxe-regex"))
5070                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
5071        else if ((argcount = short_opt('O', av, &optarg))) {
5072                options->orderfile = prefix_filename(prefix, optarg);
5073                return argcount;
5074        } else if (skip_prefix(arg, "--find-object=", &arg))
5075                return parse_objfind_opt(options, arg);
5076        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
5077                int offending = parse_diff_filter_opt(optarg, options);
5078                if (offending)
5079                        die("unknown change class '%c' in --diff-filter=%s",
5080                            offending, optarg);
5081                return argcount;
5082        }
5083        else if (!strcmp(arg, "--no-abbrev"))
5084                options->abbrev = 0;
5085        else if (!strcmp(arg, "--abbrev"))
5086                options->abbrev = DEFAULT_ABBREV;
5087        else if (skip_prefix(arg, "--abbrev=", &arg)) {
5088                options->abbrev = strtoul(arg, NULL, 10);
5089                if (options->abbrev < MINIMUM_ABBREV)
5090                        options->abbrev = MINIMUM_ABBREV;
5091                else if (the_hash_algo->hexsz < options->abbrev)
5092                        options->abbrev = the_hash_algo->hexsz;
5093        }
5094        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
5095                options->a_prefix = optarg;
5096                return argcount;
5097        }
5098        else if ((argcount = parse_long_opt("line-prefix", av, &optarg))) {
5099                options->line_prefix = optarg;
5100                options->line_prefix_length = strlen(options->line_prefix);
5101                graph_setup_line_prefix(options);
5102                return argcount;
5103        }
5104        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
5105                options->b_prefix = optarg;
5106                return argcount;
5107        }
5108        else if (!strcmp(arg, "--no-prefix"))
5109                options->a_prefix = options->b_prefix = "";
5110        else if (opt_arg(arg, '\0', "inter-hunk-context",
5111                         &options->interhunkcontext))
5112                ;
5113        else if (!strcmp(arg, "-W"))
5114                options->flags.funccontext = 1;
5115        else if (!strcmp(arg, "--function-context"))
5116                options->flags.funccontext = 1;
5117        else if (!strcmp(arg, "--no-function-context"))
5118                options->flags.funccontext = 0;
5119        else if ((argcount = parse_long_opt("output", av, &optarg))) {
5120                char *path = prefix_filename(prefix, optarg);
5121                options->file = xfopen(path, "w");
5122                options->close_file = 1;
5123                if (options->use_color != GIT_COLOR_ALWAYS)
5124                        options->use_color = GIT_COLOR_NEVER;
5125                free(path);
5126                return argcount;
5127        } else
5128                return 0;
5129        return 1;
5130}
5131
5132int parse_rename_score(const char **cp_p)
5133{
5134        unsigned long num, scale;
5135        int ch, dot;
5136        const char *cp = *cp_p;
5137
5138        num = 0;
5139        scale = 1;
5140        dot = 0;
5141        for (;;) {
5142                ch = *cp;
5143                if ( !dot && ch == '.' ) {
5144                        scale = 1;
5145                        dot = 1;
5146                } else if ( ch == '%' ) {
5147                        scale = dot ? scale*100 : 100;
5148                        cp++;   /* % is always at the end */
5149                        break;
5150                } else if ( ch >= '0' && ch <= '9' ) {
5151                        if ( scale < 100000 ) {
5152                                scale *= 10;
5153                                num = (num*10) + (ch-'0');
5154                        }
5155                } else {
5156                        break;
5157                }
5158                cp++;
5159        }
5160        *cp_p = cp;
5161
5162        /* user says num divided by scale and we say internally that
5163         * is MAX_SCORE * num / scale.
5164         */
5165        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
5166}
5167
5168static int diff_scoreopt_parse(const char *opt)
5169{
5170        int opt1, opt2, cmd;
5171
5172        if (*opt++ != '-')
5173                return -1;
5174        cmd = *opt++;
5175        if (cmd == '-') {
5176                /* convert the long-form arguments into short-form versions */
5177                if (skip_prefix(opt, "break-rewrites", &opt)) {
5178                        if (*opt == 0 || *opt++ == '=')
5179                                cmd = 'B';
5180                } else if (skip_prefix(opt, "find-copies", &opt)) {
5181                        if (*opt == 0 || *opt++ == '=')
5182                                cmd = 'C';
5183                } else if (skip_prefix(opt, "find-renames", &opt)) {
5184                        if (*opt == 0 || *opt++ == '=')
5185                                cmd = 'M';
5186                }
5187        }
5188        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
5189                return -1; /* that is not a -M, -C, or -B option */
5190
5191        opt1 = parse_rename_score(&opt);
5192        if (cmd != 'B')
5193                opt2 = 0;
5194        else {
5195                if (*opt == 0)
5196                        opt2 = 0;
5197                else if (*opt != '/')
5198                        return -1; /* we expect -B80/99 or -B80 */
5199                else {
5200                        opt++;
5201                        opt2 = parse_rename_score(&opt);
5202                }
5203        }
5204        if (*opt != 0)
5205                return -1;
5206        return opt1 | (opt2 << 16);
5207}
5208
5209struct diff_queue_struct diff_queued_diff;
5210
5211void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
5212{
5213        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
5214        queue->queue[queue->nr++] = dp;
5215}
5216
5217struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
5218                                 struct diff_filespec *one,
5219                                 struct diff_filespec *two)
5220{
5221        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
5222        dp->one = one;
5223        dp->two = two;
5224        if (queue)
5225                diff_q(queue, dp);
5226        return dp;
5227}
5228
5229void diff_free_filepair(struct diff_filepair *p)
5230{
5231        free_filespec(p->one);
5232        free_filespec(p->two);
5233        free(p);
5234}
5235
5236const char *diff_aligned_abbrev(const struct object_id *oid, int len)
5237{
5238        int abblen;
5239        const char *abbrev;
5240
5241        /* Do we want all 40 hex characters? */
5242        if (len == the_hash_algo->hexsz)
5243                return oid_to_hex(oid);
5244
5245        /* An abbreviated value is fine, possibly followed by an ellipsis. */
5246        abbrev = diff_abbrev_oid(oid, len);
5247
5248        if (!print_sha1_ellipsis())
5249                return abbrev;
5250
5251        abblen = strlen(abbrev);
5252
5253        /*
5254         * In well-behaved cases, where the abbreviated result is the
5255         * same as the requested length, append three dots after the
5256         * abbreviation (hence the whole logic is limited to the case
5257         * where abblen < 37); when the actual abbreviated result is a
5258         * bit longer than the requested length, we reduce the number
5259         * of dots so that they match the well-behaved ones.  However,
5260         * if the actual abbreviation is longer than the requested
5261         * length by more than three, we give up on aligning, and add
5262         * three dots anyway, to indicate that the output is not the
5263         * full object name.  Yes, this may be suboptimal, but this
5264         * appears only in "diff --raw --abbrev" output and it is not
5265         * worth the effort to change it now.  Note that this would
5266         * likely to work fine when the automatic sizing of default
5267         * abbreviation length is used--we would be fed -1 in "len" in
5268         * that case, and will end up always appending three-dots, but
5269         * the automatic sizing is supposed to give abblen that ensures
5270         * uniqueness across all objects (statistically speaking).
5271         */
5272        if (abblen < the_hash_algo->hexsz - 3) {
5273                static char hex[GIT_MAX_HEXSZ + 1];
5274                if (len < abblen && abblen <= len + 2)
5275                        xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
5276                else
5277                        xsnprintf(hex, sizeof(hex), "%s...", abbrev);
5278                return hex;
5279        }
5280
5281        return oid_to_hex(oid);
5282}
5283
5284static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
5285{
5286        int line_termination = opt->line_termination;
5287        int inter_name_termination = line_termination ? '\t' : '\0';
5288
5289        fprintf(opt->file, "%s", diff_line_prefix(opt));
5290        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
5291                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
5292                        diff_aligned_abbrev(&p->one->oid, opt->abbrev));
5293                fprintf(opt->file, "%s ",
5294                        diff_aligned_abbrev(&p->two->oid, opt->abbrev));
5295        }
5296        if (p->score) {
5297                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
5298                        inter_name_termination);
5299        } else {
5300                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
5301        }
5302
5303        if (p->status == DIFF_STATUS_COPIED ||
5304            p->status == DIFF_STATUS_RENAMED) {
5305                const char *name_a, *name_b;
5306                name_a = p->one->path;
5307                name_b = p->two->path;
5308                strip_prefix(opt->prefix_length, &name_a, &name_b);
5309                write_name_quoted(name_a, opt->file, inter_name_termination);
5310                write_name_quoted(name_b, opt->file, line_termination);
5311        } else {
5312                const char *name_a, *name_b;
5313                name_a = p->one->mode ? p->one->path : p->two->path;
5314                name_b = NULL;
5315                strip_prefix(opt->prefix_length, &name_a, &name_b);
5316                write_name_quoted(name_a, opt->file, line_termination);
5317        }
5318}
5319
5320int diff_unmodified_pair(struct diff_filepair *p)
5321{
5322        /* This function is written stricter than necessary to support
5323         * the currently implemented transformers, but the idea is to
5324         * let transformers to produce diff_filepairs any way they want,
5325         * and filter and clean them up here before producing the output.
5326         */
5327        struct diff_filespec *one = p->one, *two = p->two;
5328
5329        if (DIFF_PAIR_UNMERGED(p))
5330                return 0; /* unmerged is interesting */
5331
5332        /* deletion, addition, mode or type change
5333         * and rename are all interesting.
5334         */
5335        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
5336            DIFF_PAIR_MODE_CHANGED(p) ||
5337            strcmp(one->path, two->path))
5338                return 0;
5339
5340        /* both are valid and point at the same path.  that is, we are
5341         * dealing with a change.
5342         */
5343        if (one->oid_valid && two->oid_valid &&
5344            oideq(&one->oid, &two->oid) &&
5345            !one->dirty_submodule && !two->dirty_submodule)
5346                return 1; /* no change */
5347        if (!one->oid_valid && !two->oid_valid)
5348                return 1; /* both look at the same file on the filesystem. */
5349        return 0;
5350}
5351
5352static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
5353{
5354        if (diff_unmodified_pair(p))
5355                return;
5356
5357        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5358            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5359                return; /* no tree diffs in patch format */
5360
5361        run_diff(p, o);
5362}
5363
5364static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
5365                            struct diffstat_t *diffstat)
5366{
5367        if (diff_unmodified_pair(p))
5368                return;
5369
5370        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5371            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5372                return; /* no useful stat for tree diffs */
5373
5374        run_diffstat(p, o, diffstat);
5375}
5376
5377static void diff_flush_checkdiff(struct diff_filepair *p,
5378                struct diff_options *o)
5379{
5380        if (diff_unmodified_pair(p))
5381                return;
5382
5383        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5384            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5385                return; /* nothing to check in tree diffs */
5386
5387        run_checkdiff(p, o);
5388}
5389
5390int diff_queue_is_empty(void)
5391{
5392        struct diff_queue_struct *q = &diff_queued_diff;
5393        int i;
5394        for (i = 0; i < q->nr; i++)
5395                if (!diff_unmodified_pair(q->queue[i]))
5396                        return 0;
5397        return 1;
5398}
5399
5400#if DIFF_DEBUG
5401void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
5402{
5403        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
5404                x, one ? one : "",
5405                s->path,
5406                DIFF_FILE_VALID(s) ? "valid" : "invalid",
5407                s->mode,
5408                s->oid_valid ? oid_to_hex(&s->oid) : "");
5409        fprintf(stderr, "queue[%d] %s size %lu\n",
5410                x, one ? one : "",
5411                s->size);
5412}
5413
5414void diff_debug_filepair(const struct diff_filepair *p, int i)
5415{
5416        diff_debug_filespec(p->one, i, "one");
5417        diff_debug_filespec(p->two, i, "two");
5418        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
5419                p->score, p->status ? p->status : '?',
5420                p->one->rename_used, p->broken_pair);
5421}
5422
5423void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
5424{
5425        int i;
5426        if (msg)
5427                fprintf(stderr, "%s\n", msg);
5428        fprintf(stderr, "q->nr = %d\n", q->nr);
5429        for (i = 0; i < q->nr; i++) {
5430                struct diff_filepair *p = q->queue[i];
5431                diff_debug_filepair(p, i);
5432        }
5433}
5434#endif
5435
5436static void diff_resolve_rename_copy(void)
5437{
5438        int i;
5439        struct diff_filepair *p;
5440        struct diff_queue_struct *q = &diff_queued_diff;
5441
5442        diff_debug_queue("resolve-rename-copy", q);
5443
5444        for (i = 0; i < q->nr; i++) {
5445                p = q->queue[i];
5446                p->status = 0; /* undecided */
5447                if (DIFF_PAIR_UNMERGED(p))
5448                        p->status = DIFF_STATUS_UNMERGED;
5449                else if (!DIFF_FILE_VALID(p->one))
5450                        p->status = DIFF_STATUS_ADDED;
5451                else if (!DIFF_FILE_VALID(p->two))
5452                        p->status = DIFF_STATUS_DELETED;
5453                else if (DIFF_PAIR_TYPE_CHANGED(p))
5454                        p->status = DIFF_STATUS_TYPE_CHANGED;
5455
5456                /* from this point on, we are dealing with a pair
5457                 * whose both sides are valid and of the same type, i.e.
5458                 * either in-place edit or rename/copy edit.
5459                 */
5460                else if (DIFF_PAIR_RENAME(p)) {
5461                        /*
5462                         * A rename might have re-connected a broken
5463                         * pair up, causing the pathnames to be the
5464                         * same again. If so, that's not a rename at
5465                         * all, just a modification..
5466                         *
5467                         * Otherwise, see if this source was used for
5468                         * multiple renames, in which case we decrement
5469                         * the count, and call it a copy.
5470                         */
5471                        if (!strcmp(p->one->path, p->two->path))
5472                                p->status = DIFF_STATUS_MODIFIED;
5473                        else if (--p->one->rename_used > 0)
5474                                p->status = DIFF_STATUS_COPIED;
5475                        else
5476                                p->status = DIFF_STATUS_RENAMED;
5477                }
5478                else if (!oideq(&p->one->oid, &p->two->oid) ||
5479                         p->one->mode != p->two->mode ||
5480                         p->one->dirty_submodule ||
5481                         p->two->dirty_submodule ||
5482                         is_null_oid(&p->one->oid))
5483                        p->status = DIFF_STATUS_MODIFIED;
5484                else {
5485                        /* This is a "no-change" entry and should not
5486                         * happen anymore, but prepare for broken callers.
5487                         */
5488                        error("feeding unmodified %s to diffcore",
5489                              p->one->path);
5490                        p->status = DIFF_STATUS_UNKNOWN;
5491                }
5492        }
5493        diff_debug_queue("resolve-rename-copy done", q);
5494}
5495
5496static int check_pair_status(struct diff_filepair *p)
5497{
5498        switch (p->status) {
5499        case DIFF_STATUS_UNKNOWN:
5500                return 0;
5501        case 0:
5502                die("internal error in diff-resolve-rename-copy");
5503        default:
5504                return 1;
5505        }
5506}
5507
5508static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
5509{
5510        int fmt = opt->output_format;
5511
5512        if (fmt & DIFF_FORMAT_CHECKDIFF)
5513                diff_flush_checkdiff(p, opt);
5514        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
5515                diff_flush_raw(p, opt);
5516        else if (fmt & DIFF_FORMAT_NAME) {
5517                const char *name_a, *name_b;
5518                name_a = p->two->path;
5519                name_b = NULL;
5520                strip_prefix(opt->prefix_length, &name_a, &name_b);
5521                fprintf(opt->file, "%s", diff_line_prefix(opt));
5522                write_name_quoted(name_a, opt->file, opt->line_termination);
5523        }
5524}
5525
5526static void show_file_mode_name(struct diff_options *opt, const char *newdelete, struct diff_filespec *fs)
5527{
5528        struct strbuf sb = STRBUF_INIT;
5529        if (fs->mode)
5530                strbuf_addf(&sb, " %s mode %06o ", newdelete, fs->mode);
5531        else
5532                strbuf_addf(&sb, " %s ", newdelete);
5533
5534        quote_c_style(fs->path, &sb, NULL, 0);
5535        strbuf_addch(&sb, '\n');
5536        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5537                         sb.buf, sb.len, 0);
5538        strbuf_release(&sb);
5539}
5540
5541static void show_mode_change(struct diff_options *opt, struct diff_filepair *p,
5542                int show_name)
5543{
5544        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
5545                struct strbuf sb = STRBUF_INIT;
5546                strbuf_addf(&sb, " mode change %06o => %06o",
5547                            p->one->mode, p->two->mode);
5548                if (show_name) {
5549                        strbuf_addch(&sb, ' ');
5550                        quote_c_style(p->two->path, &sb, NULL, 0);
5551                }
5552                strbuf_addch(&sb, '\n');
5553                emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5554                                 sb.buf, sb.len, 0);
5555                strbuf_release(&sb);
5556        }
5557}
5558
5559static void show_rename_copy(struct diff_options *opt, const char *renamecopy,
5560                struct diff_filepair *p)
5561{
5562        struct strbuf sb = STRBUF_INIT;
5563        struct strbuf names = STRBUF_INIT;
5564
5565        pprint_rename(&names, p->one->path, p->two->path);
5566        strbuf_addf(&sb, " %s %s (%d%%)\n",
5567                    renamecopy, names.buf, similarity_index(p));
5568        strbuf_release(&names);
5569        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5570                                 sb.buf, sb.len, 0);
5571        show_mode_change(opt, p, 0);
5572        strbuf_release(&sb);
5573}
5574
5575static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
5576{
5577        switch(p->status) {
5578        case DIFF_STATUS_DELETED:
5579                show_file_mode_name(opt, "delete", p->one);
5580                break;
5581        case DIFF_STATUS_ADDED:
5582                show_file_mode_name(opt, "create", p->two);
5583                break;
5584        case DIFF_STATUS_COPIED:
5585                show_rename_copy(opt, "copy", p);
5586                break;
5587        case DIFF_STATUS_RENAMED:
5588                show_rename_copy(opt, "rename", p);
5589                break;
5590        default:
5591                if (p->score) {
5592                        struct strbuf sb = STRBUF_INIT;
5593                        strbuf_addstr(&sb, " rewrite ");
5594                        quote_c_style(p->two->path, &sb, NULL, 0);
5595                        strbuf_addf(&sb, " (%d%%)\n", similarity_index(p));
5596                        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5597                                         sb.buf, sb.len, 0);
5598                        strbuf_release(&sb);
5599                }
5600                show_mode_change(opt, p, !p->score);
5601                break;
5602        }
5603}
5604
5605struct patch_id_t {
5606        git_SHA_CTX *ctx;
5607        int patchlen;
5608};
5609
5610static int remove_space(char *line, int len)
5611{
5612        int i;
5613        char *dst = line;
5614        unsigned char c;
5615
5616        for (i = 0; i < len; i++)
5617                if (!isspace((c = line[i])))
5618                        *dst++ = c;
5619
5620        return dst - line;
5621}
5622
5623static void patch_id_consume(void *priv, char *line, unsigned long len)
5624{
5625        struct patch_id_t *data = priv;
5626        int new_len;
5627
5628        /* Ignore line numbers when computing the SHA1 of the patch */
5629        if (starts_with(line, "@@ -"))
5630                return;
5631
5632        new_len = remove_space(line, len);
5633
5634        git_SHA1_Update(data->ctx, line, new_len);
5635        data->patchlen += new_len;
5636}
5637
5638static void patch_id_add_string(git_SHA_CTX *ctx, const char *str)
5639{
5640        git_SHA1_Update(ctx, str, strlen(str));
5641}
5642
5643static void patch_id_add_mode(git_SHA_CTX *ctx, unsigned mode)
5644{
5645        /* large enough for 2^32 in octal */
5646        char buf[12];
5647        int len = xsnprintf(buf, sizeof(buf), "%06o", mode);
5648        git_SHA1_Update(ctx, buf, len);
5649}
5650
5651/* returns 0 upon success, and writes result into sha1 */
5652static int diff_get_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5653{
5654        struct diff_queue_struct *q = &diff_queued_diff;
5655        int i;
5656        git_SHA_CTX ctx;
5657        struct patch_id_t data;
5658
5659        git_SHA1_Init(&ctx);
5660        memset(&data, 0, sizeof(struct patch_id_t));
5661        data.ctx = &ctx;
5662
5663        for (i = 0; i < q->nr; i++) {
5664                xpparam_t xpp;
5665                xdemitconf_t xecfg;
5666                mmfile_t mf1, mf2;
5667                struct diff_filepair *p = q->queue[i];
5668                int len1, len2;
5669
5670                memset(&xpp, 0, sizeof(xpp));
5671                memset(&xecfg, 0, sizeof(xecfg));
5672                if (p->status == 0)
5673                        return error("internal diff status error");
5674                if (p->status == DIFF_STATUS_UNKNOWN)
5675                        continue;
5676                if (diff_unmodified_pair(p))
5677                        continue;
5678                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5679                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5680                        continue;
5681                if (DIFF_PAIR_UNMERGED(p))
5682                        continue;
5683
5684                diff_fill_oid_info(p->one);
5685                diff_fill_oid_info(p->two);
5686
5687                len1 = remove_space(p->one->path, strlen(p->one->path));
5688                len2 = remove_space(p->two->path, strlen(p->two->path));
5689                patch_id_add_string(&ctx, "diff--git");
5690                patch_id_add_string(&ctx, "a/");
5691                git_SHA1_Update(&ctx, p->one->path, len1);
5692                patch_id_add_string(&ctx, "b/");
5693                git_SHA1_Update(&ctx, p->two->path, len2);
5694
5695                if (p->one->mode == 0) {
5696                        patch_id_add_string(&ctx, "newfilemode");
5697                        patch_id_add_mode(&ctx, p->two->mode);
5698                        patch_id_add_string(&ctx, "---/dev/null");
5699                        patch_id_add_string(&ctx, "+++b/");
5700                        git_SHA1_Update(&ctx, p->two->path, len2);
5701                } else if (p->two->mode == 0) {
5702                        patch_id_add_string(&ctx, "deletedfilemode");
5703                        patch_id_add_mode(&ctx, p->one->mode);
5704                        patch_id_add_string(&ctx, "---a/");
5705                        git_SHA1_Update(&ctx, p->one->path, len1);
5706                        patch_id_add_string(&ctx, "+++/dev/null");
5707                } else {
5708                        patch_id_add_string(&ctx, "---a/");
5709                        git_SHA1_Update(&ctx, p->one->path, len1);
5710                        patch_id_add_string(&ctx, "+++b/");
5711                        git_SHA1_Update(&ctx, p->two->path, len2);
5712                }
5713
5714                if (diff_header_only)
5715                        continue;
5716
5717                if (fill_mmfile(&mf1, p->one) < 0 ||
5718                    fill_mmfile(&mf2, p->two) < 0)
5719                        return error("unable to read files to diff");
5720
5721                if (diff_filespec_is_binary(p->one) ||
5722                    diff_filespec_is_binary(p->two)) {
5723                        git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
5724                                        GIT_SHA1_HEXSZ);
5725                        git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
5726                                        GIT_SHA1_HEXSZ);
5727                        continue;
5728                }
5729
5730                xpp.flags = 0;
5731                xecfg.ctxlen = 3;
5732                xecfg.flags = 0;
5733                if (xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
5734                                  &xpp, &xecfg))
5735                        return error("unable to generate patch-id diff for %s",
5736                                     p->one->path);
5737        }
5738
5739        git_SHA1_Final(oid->hash, &ctx);
5740        return 0;
5741}
5742
5743int diff_flush_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5744{
5745        struct diff_queue_struct *q = &diff_queued_diff;
5746        int i;
5747        int result = diff_get_patch_id(options, oid, diff_header_only);
5748
5749        for (i = 0; i < q->nr; i++)
5750                diff_free_filepair(q->queue[i]);
5751
5752        free(q->queue);
5753        DIFF_QUEUE_CLEAR(q);
5754
5755        return result;
5756}
5757
5758static int is_summary_empty(const struct diff_queue_struct *q)
5759{
5760        int i;
5761
5762        for (i = 0; i < q->nr; i++) {
5763                const struct diff_filepair *p = q->queue[i];
5764
5765                switch (p->status) {
5766                case DIFF_STATUS_DELETED:
5767                case DIFF_STATUS_ADDED:
5768                case DIFF_STATUS_COPIED:
5769                case DIFF_STATUS_RENAMED:
5770                        return 0;
5771                default:
5772                        if (p->score)
5773                                return 0;
5774                        if (p->one->mode && p->two->mode &&
5775                            p->one->mode != p->two->mode)
5776                                return 0;
5777                        break;
5778                }
5779        }
5780        return 1;
5781}
5782
5783static const char rename_limit_warning[] =
5784N_("inexact rename detection was skipped due to too many files.");
5785
5786static const char degrade_cc_to_c_warning[] =
5787N_("only found copies from modified paths due to too many files.");
5788
5789static const char rename_limit_advice[] =
5790N_("you may want to set your %s variable to at least "
5791   "%d and retry the command.");
5792
5793void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
5794{
5795        fflush(stdout);
5796        if (degraded_cc)
5797                warning(_(degrade_cc_to_c_warning));
5798        else if (needed)
5799                warning(_(rename_limit_warning));
5800        else
5801                return;
5802        if (0 < needed)
5803                warning(_(rename_limit_advice), varname, needed);
5804}
5805
5806static void diff_flush_patch_all_file_pairs(struct diff_options *o)
5807{
5808        int i;
5809        static struct emitted_diff_symbols esm = EMITTED_DIFF_SYMBOLS_INIT;
5810        struct diff_queue_struct *q = &diff_queued_diff;
5811
5812        if (WSEH_NEW & WS_RULE_MASK)
5813                BUG("WS rules bit mask overlaps with diff symbol flags");
5814
5815        if (o->color_moved)
5816                o->emitted_symbols = &esm;
5817
5818        for (i = 0; i < q->nr; i++) {
5819                struct diff_filepair *p = q->queue[i];
5820                if (check_pair_status(p))
5821                        diff_flush_patch(p, o);
5822        }
5823
5824        if (o->emitted_symbols) {
5825                if (o->color_moved) {
5826                        struct hashmap add_lines, del_lines;
5827
5828                        if (o->color_moved_ws_handling &
5829                            COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
5830                                o->color_moved_ws_handling |= XDF_IGNORE_WHITESPACE;
5831
5832                        hashmap_init(&del_lines, moved_entry_cmp, o, 0);
5833                        hashmap_init(&add_lines, moved_entry_cmp, o, 0);
5834
5835                        add_lines_to_move_detection(o, &add_lines, &del_lines);
5836                        mark_color_as_moved(o, &add_lines, &del_lines);
5837                        if (o->color_moved == COLOR_MOVED_ZEBRA_DIM)
5838                                dim_moved_lines(o);
5839
5840                        hashmap_free(&add_lines, 0);
5841                        hashmap_free(&del_lines, 0);
5842                }
5843
5844                for (i = 0; i < esm.nr; i++)
5845                        emit_diff_symbol_from_struct(o, &esm.buf[i]);
5846
5847                for (i = 0; i < esm.nr; i++)
5848                        free((void *)esm.buf[i].line);
5849        }
5850        esm.nr = 0;
5851}
5852
5853void diff_flush(struct diff_options *options)
5854{
5855        struct diff_queue_struct *q = &diff_queued_diff;
5856        int i, output_format = options->output_format;
5857        int separator = 0;
5858        int dirstat_by_line = 0;
5859
5860        /*
5861         * Order: raw, stat, summary, patch
5862         * or:    name/name-status/checkdiff (other bits clear)
5863         */
5864        if (!q->nr)
5865                goto free_queue;
5866
5867        if (output_format & (DIFF_FORMAT_RAW |
5868                             DIFF_FORMAT_NAME |
5869                             DIFF_FORMAT_NAME_STATUS |
5870                             DIFF_FORMAT_CHECKDIFF)) {
5871                for (i = 0; i < q->nr; i++) {
5872                        struct diff_filepair *p = q->queue[i];
5873                        if (check_pair_status(p))
5874                                flush_one_pair(p, options);
5875                }
5876                separator++;
5877        }
5878
5879        if (output_format & DIFF_FORMAT_DIRSTAT && options->flags.dirstat_by_line)
5880                dirstat_by_line = 1;
5881
5882        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
5883            dirstat_by_line) {
5884                struct diffstat_t diffstat;
5885
5886                memset(&diffstat, 0, sizeof(struct diffstat_t));
5887                for (i = 0; i < q->nr; i++) {
5888                        struct diff_filepair *p = q->queue[i];
5889                        if (check_pair_status(p))
5890                                diff_flush_stat(p, options, &diffstat);
5891                }
5892                if (output_format & DIFF_FORMAT_NUMSTAT)
5893                        show_numstat(&diffstat, options);
5894                if (output_format & DIFF_FORMAT_DIFFSTAT)
5895                        show_stats(&diffstat, options);
5896                if (output_format & DIFF_FORMAT_SHORTSTAT)
5897                        show_shortstats(&diffstat, options);
5898                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
5899                        show_dirstat_by_line(&diffstat, options);
5900                free_diffstat_info(&diffstat);
5901                separator++;
5902        }
5903        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
5904                show_dirstat(options);
5905
5906        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
5907                for (i = 0; i < q->nr; i++) {
5908                        diff_summary(options, q->queue[i]);
5909                }
5910                separator++;
5911        }
5912
5913        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
5914            options->flags.exit_with_status &&
5915            options->flags.diff_from_contents) {
5916                /*
5917                 * run diff_flush_patch for the exit status. setting
5918                 * options->file to /dev/null should be safe, because we
5919                 * aren't supposed to produce any output anyway.
5920                 */
5921                if (options->close_file)
5922                        fclose(options->file);
5923                options->file = xfopen("/dev/null", "w");
5924                options->close_file = 1;
5925                options->color_moved = 0;
5926                for (i = 0; i < q->nr; i++) {
5927                        struct diff_filepair *p = q->queue[i];
5928                        if (check_pair_status(p))
5929                                diff_flush_patch(p, options);
5930                        if (options->found_changes)
5931                                break;
5932                }
5933        }
5934
5935        if (output_format & DIFF_FORMAT_PATCH) {
5936                if (separator) {
5937                        emit_diff_symbol(options, DIFF_SYMBOL_SEPARATOR, NULL, 0, 0);
5938                        if (options->stat_sep)
5939                                /* attach patch instead of inline */
5940                                emit_diff_symbol(options, DIFF_SYMBOL_STAT_SEP,
5941                                                 NULL, 0, 0);
5942                }
5943
5944                diff_flush_patch_all_file_pairs(options);
5945        }
5946
5947        if (output_format & DIFF_FORMAT_CALLBACK)
5948                options->format_callback(q, options, options->format_callback_data);
5949
5950        for (i = 0; i < q->nr; i++)
5951                diff_free_filepair(q->queue[i]);
5952free_queue:
5953        free(q->queue);
5954        DIFF_QUEUE_CLEAR(q);
5955        if (options->close_file)
5956                fclose(options->file);
5957
5958        /*
5959         * Report the content-level differences with HAS_CHANGES;
5960         * diff_addremove/diff_change does not set the bit when
5961         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
5962         */
5963        if (options->flags.diff_from_contents) {
5964                if (options->found_changes)
5965                        options->flags.has_changes = 1;
5966                else
5967                        options->flags.has_changes = 0;
5968        }
5969}
5970
5971static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
5972{
5973        return (((p->status == DIFF_STATUS_MODIFIED) &&
5974                 ((p->score &&
5975                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
5976                  (!p->score &&
5977                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
5978                ((p->status != DIFF_STATUS_MODIFIED) &&
5979                 filter_bit_tst(p->status, options)));
5980}
5981
5982static void diffcore_apply_filter(struct diff_options *options)
5983{
5984        int i;
5985        struct diff_queue_struct *q = &diff_queued_diff;
5986        struct diff_queue_struct outq;
5987
5988        DIFF_QUEUE_CLEAR(&outq);
5989
5990        if (!options->filter)
5991                return;
5992
5993        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
5994                int found;
5995                for (i = found = 0; !found && i < q->nr; i++) {
5996                        if (match_filter(options, q->queue[i]))
5997                                found++;
5998                }
5999                if (found)
6000                        return;
6001
6002                /* otherwise we will clear the whole queue
6003                 * by copying the empty outq at the end of this
6004                 * function, but first clear the current entries
6005                 * in the queue.
6006                 */
6007                for (i = 0; i < q->nr; i++)
6008                        diff_free_filepair(q->queue[i]);
6009        }
6010        else {
6011                /* Only the matching ones */
6012                for (i = 0; i < q->nr; i++) {
6013                        struct diff_filepair *p = q->queue[i];
6014                        if (match_filter(options, p))
6015                                diff_q(&outq, p);
6016                        else
6017                                diff_free_filepair(p);
6018                }
6019        }
6020        free(q->queue);
6021        *q = outq;
6022}
6023
6024/* Check whether two filespecs with the same mode and size are identical */
6025static int diff_filespec_is_identical(struct diff_filespec *one,
6026                                      struct diff_filespec *two)
6027{
6028        if (S_ISGITLINK(one->mode))
6029                return 0;
6030        if (diff_populate_filespec(one, 0))
6031                return 0;
6032        if (diff_populate_filespec(two, 0))
6033                return 0;
6034        return !memcmp(one->data, two->data, one->size);
6035}
6036
6037static int diff_filespec_check_stat_unmatch(struct diff_filepair *p)
6038{
6039        if (p->done_skip_stat_unmatch)
6040                return p->skip_stat_unmatch_result;
6041
6042        p->done_skip_stat_unmatch = 1;
6043        p->skip_stat_unmatch_result = 0;
6044        /*
6045         * 1. Entries that come from stat info dirtiness
6046         *    always have both sides (iow, not create/delete),
6047         *    one side of the object name is unknown, with
6048         *    the same mode and size.  Keep the ones that
6049         *    do not match these criteria.  They have real
6050         *    differences.
6051         *
6052         * 2. At this point, the file is known to be modified,
6053         *    with the same mode and size, and the object
6054         *    name of one side is unknown.  Need to inspect
6055         *    the identical contents.
6056         */
6057        if (!DIFF_FILE_VALID(p->one) || /* (1) */
6058            !DIFF_FILE_VALID(p->two) ||
6059            (p->one->oid_valid && p->two->oid_valid) ||
6060            (p->one->mode != p->two->mode) ||
6061            diff_populate_filespec(p->one, CHECK_SIZE_ONLY) ||
6062            diff_populate_filespec(p->two, CHECK_SIZE_ONLY) ||
6063            (p->one->size != p->two->size) ||
6064            !diff_filespec_is_identical(p->one, p->two)) /* (2) */
6065                p->skip_stat_unmatch_result = 1;
6066        return p->skip_stat_unmatch_result;
6067}
6068
6069static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
6070{
6071        int i;
6072        struct diff_queue_struct *q = &diff_queued_diff;
6073        struct diff_queue_struct outq;
6074        DIFF_QUEUE_CLEAR(&outq);
6075
6076        for (i = 0; i < q->nr; i++) {
6077                struct diff_filepair *p = q->queue[i];
6078
6079                if (diff_filespec_check_stat_unmatch(p))
6080                        diff_q(&outq, p);
6081                else {
6082                        /*
6083                         * The caller can subtract 1 from skip_stat_unmatch
6084                         * to determine how many paths were dirty only
6085                         * due to stat info mismatch.
6086                         */
6087                        if (!diffopt->flags.no_index)
6088                                diffopt->skip_stat_unmatch++;
6089                        diff_free_filepair(p);
6090                }
6091        }
6092        free(q->queue);
6093        *q = outq;
6094}
6095
6096static int diffnamecmp(const void *a_, const void *b_)
6097{
6098        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
6099        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
6100        const char *name_a, *name_b;
6101
6102        name_a = a->one ? a->one->path : a->two->path;
6103        name_b = b->one ? b->one->path : b->two->path;
6104        return strcmp(name_a, name_b);
6105}
6106
6107void diffcore_fix_diff_index(struct diff_options *options)
6108{
6109        struct diff_queue_struct *q = &diff_queued_diff;
6110        QSORT(q->queue, q->nr, diffnamecmp);
6111}
6112
6113void diffcore_std(struct diff_options *options)
6114{
6115        /* NOTE please keep the following in sync with diff_tree_combined() */
6116        if (options->skip_stat_unmatch)
6117                diffcore_skip_stat_unmatch(options);
6118        if (!options->found_follow) {
6119                /* See try_to_follow_renames() in tree-diff.c */
6120                if (options->break_opt != -1)
6121                        diffcore_break(options->break_opt);
6122                if (options->detect_rename)
6123                        diffcore_rename(options);
6124                if (options->break_opt != -1)
6125                        diffcore_merge_broken();
6126        }
6127        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
6128                diffcore_pickaxe(options);
6129        if (options->orderfile)
6130                diffcore_order(options->orderfile);
6131        if (!options->found_follow)
6132                /* See try_to_follow_renames() in tree-diff.c */
6133                diff_resolve_rename_copy();
6134        diffcore_apply_filter(options);
6135
6136        if (diff_queued_diff.nr && !options->flags.diff_from_contents)
6137                options->flags.has_changes = 1;
6138        else
6139                options->flags.has_changes = 0;
6140
6141        options->found_follow = 0;
6142}
6143
6144int diff_result_code(struct diff_options *opt, int status)
6145{
6146        int result = 0;
6147
6148        diff_warn_rename_limit("diff.renameLimit",
6149                               opt->needed_rename_limit,
6150                               opt->degraded_cc_to_c);
6151        if (!opt->flags.exit_with_status &&
6152            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
6153                return status;
6154        if (opt->flags.exit_with_status &&
6155            opt->flags.has_changes)
6156                result |= 01;
6157        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
6158            opt->flags.check_failed)
6159                result |= 02;
6160        return result;
6161}
6162
6163int diff_can_quit_early(struct diff_options *opt)
6164{
6165        return (opt->flags.quick &&
6166                !opt->filter &&
6167                opt->flags.has_changes);
6168}
6169
6170/*
6171 * Shall changes to this submodule be ignored?
6172 *
6173 * Submodule changes can be configured to be ignored separately for each path,
6174 * but that configuration can be overridden from the command line.
6175 */
6176static int is_submodule_ignored(const char *path, struct diff_options *options)
6177{
6178        int ignored = 0;
6179        struct diff_flags orig_flags = options->flags;
6180        if (!options->flags.override_submodule_config)
6181                set_diffopt_flags_from_submodule_config(options, path);
6182        if (options->flags.ignore_submodules)
6183                ignored = 1;
6184        options->flags = orig_flags;
6185        return ignored;
6186}
6187
6188void diff_addremove(struct diff_options *options,
6189                    int addremove, unsigned mode,
6190                    const struct object_id *oid,
6191                    int oid_valid,
6192                    const char *concatpath, unsigned dirty_submodule)
6193{
6194        struct diff_filespec *one, *two;
6195
6196        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
6197                return;
6198
6199        /* This may look odd, but it is a preparation for
6200         * feeding "there are unchanged files which should
6201         * not produce diffs, but when you are doing copy
6202         * detection you would need them, so here they are"
6203         * entries to the diff-core.  They will be prefixed
6204         * with something like '=' or '*' (I haven't decided
6205         * which but should not make any difference).
6206         * Feeding the same new and old to diff_change()
6207         * also has the same effect.
6208         * Before the final output happens, they are pruned after
6209         * merged into rename/copy pairs as appropriate.
6210         */
6211        if (options->flags.reverse_diff)
6212                addremove = (addremove == '+' ? '-' :
6213                             addremove == '-' ? '+' : addremove);
6214
6215        if (options->prefix &&
6216            strncmp(concatpath, options->prefix, options->prefix_length))
6217                return;
6218
6219        one = alloc_filespec(concatpath);
6220        two = alloc_filespec(concatpath);
6221
6222        if (addremove != '+')
6223                fill_filespec(one, oid, oid_valid, mode);
6224        if (addremove != '-') {
6225                fill_filespec(two, oid, oid_valid, mode);
6226                two->dirty_submodule = dirty_submodule;
6227        }
6228
6229        diff_queue(&diff_queued_diff, one, two);
6230        if (!options->flags.diff_from_contents)
6231                options->flags.has_changes = 1;
6232}
6233
6234void diff_change(struct diff_options *options,
6235                 unsigned old_mode, unsigned new_mode,
6236                 const struct object_id *old_oid,
6237                 const struct object_id *new_oid,
6238                 int old_oid_valid, int new_oid_valid,
6239                 const char *concatpath,
6240                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
6241{
6242        struct diff_filespec *one, *two;
6243        struct diff_filepair *p;
6244
6245        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
6246            is_submodule_ignored(concatpath, options))
6247                return;
6248
6249        if (options->flags.reverse_diff) {
6250                SWAP(old_mode, new_mode);
6251                SWAP(old_oid, new_oid);
6252                SWAP(old_oid_valid, new_oid_valid);
6253                SWAP(old_dirty_submodule, new_dirty_submodule);
6254        }
6255
6256        if (options->prefix &&
6257            strncmp(concatpath, options->prefix, options->prefix_length))
6258                return;
6259
6260        one = alloc_filespec(concatpath);
6261        two = alloc_filespec(concatpath);
6262        fill_filespec(one, old_oid, old_oid_valid, old_mode);
6263        fill_filespec(two, new_oid, new_oid_valid, new_mode);
6264        one->dirty_submodule = old_dirty_submodule;
6265        two->dirty_submodule = new_dirty_submodule;
6266        p = diff_queue(&diff_queued_diff, one, two);
6267
6268        if (options->flags.diff_from_contents)
6269                return;
6270
6271        if (options->flags.quick && options->skip_stat_unmatch &&
6272            !diff_filespec_check_stat_unmatch(p))
6273                return;
6274
6275        options->flags.has_changes = 1;
6276}
6277
6278struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
6279{
6280        struct diff_filepair *pair;
6281        struct diff_filespec *one, *two;
6282
6283        if (options->prefix &&
6284            strncmp(path, options->prefix, options->prefix_length))
6285                return NULL;
6286
6287        one = alloc_filespec(path);
6288        two = alloc_filespec(path);
6289        pair = diff_queue(&diff_queued_diff, one, two);
6290        pair->is_unmerged = 1;
6291        return pair;
6292}
6293
6294static char *run_textconv(const char *pgm, struct diff_filespec *spec,
6295                size_t *outsize)
6296{
6297        struct diff_tempfile *temp;
6298        const char *argv[3];
6299        const char **arg = argv;
6300        struct child_process child = CHILD_PROCESS_INIT;
6301        struct strbuf buf = STRBUF_INIT;
6302        int err = 0;
6303
6304        temp = prepare_temp_file(spec->path, spec);
6305        *arg++ = pgm;
6306        *arg++ = temp->name;
6307        *arg = NULL;
6308
6309        child.use_shell = 1;
6310        child.argv = argv;
6311        child.out = -1;
6312        if (start_command(&child)) {
6313                remove_tempfile();
6314                return NULL;
6315        }
6316
6317        if (strbuf_read(&buf, child.out, 0) < 0)
6318                err = error("error reading from textconv command '%s'", pgm);
6319        close(child.out);
6320
6321        if (finish_command(&child) || err) {
6322                strbuf_release(&buf);
6323                remove_tempfile();
6324                return NULL;
6325        }
6326        remove_tempfile();
6327
6328        return strbuf_detach(&buf, outsize);
6329}
6330
6331size_t fill_textconv(struct userdiff_driver *driver,
6332                     struct diff_filespec *df,
6333                     char **outbuf)
6334{
6335        size_t size;
6336
6337        if (!driver) {
6338                if (!DIFF_FILE_VALID(df)) {
6339                        *outbuf = "";
6340                        return 0;
6341                }
6342                if (diff_populate_filespec(df, 0))
6343                        die("unable to read files to diff");
6344                *outbuf = df->data;
6345                return df->size;
6346        }
6347
6348        if (!driver->textconv)
6349                BUG("fill_textconv called with non-textconv driver");
6350
6351        if (driver->textconv_cache && df->oid_valid) {
6352                *outbuf = notes_cache_get(driver->textconv_cache,
6353                                          &df->oid,
6354                                          &size);
6355                if (*outbuf)
6356                        return size;
6357        }
6358
6359        *outbuf = run_textconv(driver->textconv, df, &size);
6360        if (!*outbuf)
6361                die("unable to read files to diff");
6362
6363        if (driver->textconv_cache && df->oid_valid) {
6364                /* ignore errors, as we might be in a readonly repository */
6365                notes_cache_put(driver->textconv_cache, &df->oid, *outbuf,
6366                                size);
6367                /*
6368                 * we could save up changes and flush them all at the end,
6369                 * but we would need an extra call after all diffing is done.
6370                 * Since generating a cache entry is the slow path anyway,
6371                 * this extra overhead probably isn't a big deal.
6372                 */
6373                notes_cache_write(driver->textconv_cache);
6374        }
6375
6376        return size;
6377}
6378
6379int textconv_object(const char *path,
6380                    unsigned mode,
6381                    const struct object_id *oid,
6382                    int oid_valid,
6383                    char **buf,
6384                    unsigned long *buf_size)
6385{
6386        struct diff_filespec *df;
6387        struct userdiff_driver *textconv;
6388
6389        df = alloc_filespec(path);
6390        fill_filespec(df, oid, oid_valid, mode);
6391        textconv = get_textconv(df);
6392        if (!textconv) {
6393                free_filespec(df);
6394                return 0;
6395        }
6396
6397        *buf_size = fill_textconv(textconv, df, buf);
6398        free_filespec(df);
6399        return 1;
6400}
6401
6402void setup_diff_pager(struct diff_options *opt)
6403{
6404        /*
6405         * If the user asked for our exit code, then either they want --quiet
6406         * or --exit-code. We should definitely not bother with a pager in the
6407         * former case, as we will generate no output. Since we still properly
6408         * report our exit code even when a pager is run, we _could_ run a
6409         * pager with --exit-code. But since we have not done so historically,
6410         * and because it is easy to find people oneline advising "git diff
6411         * --exit-code" in hooks and other scripts, we do not do so.
6412         */
6413        if (!opt->flags.exit_with_status &&
6414            check_pager_config("diff") != 0)
6415                setup_pager();
6416}