diff.con commit xdiff-interface: provide a separate consume callback for hunks (9346d6d)
   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, 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 nofirst;
 632        FILE *file = o->file;
 633
 634        if (first)
 635                fputs(diff_line_prefix(o), file);
 636        else if (!len)
 637                return;
 638
 639        if (len == 0) {
 640                has_trailing_newline = (first == '\n');
 641                has_trailing_carriage_return = (!has_trailing_newline &&
 642                                                (first == '\r'));
 643                nofirst = has_trailing_newline || has_trailing_carriage_return;
 644        } else {
 645                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 646                if (has_trailing_newline)
 647                        len--;
 648                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 649                if (has_trailing_carriage_return)
 650                        len--;
 651                nofirst = 0;
 652        }
 653
 654        if (len || !nofirst) {
 655                if (reverse && want_color(o->use_color))
 656                        fputs(GIT_COLOR_REVERSE, file);
 657                fputs(set, file);
 658                if (first && !nofirst)
 659                        fputc(first, file);
 660                fwrite(line, len, 1, file);
 661                fputs(reset, file);
 662        }
 663        if (has_trailing_carriage_return)
 664                fputc('\r', file);
 665        if (has_trailing_newline)
 666                fputc('\n', file);
 667}
 668
 669static void emit_line(struct diff_options *o, const char *set, const char *reset,
 670                      const char *line, int len)
 671{
 672        emit_line_0(o, set, 0, reset, line[0], line+1, len-1);
 673}
 674
 675enum diff_symbol {
 676        DIFF_SYMBOL_BINARY_DIFF_HEADER,
 677        DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
 678        DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
 679        DIFF_SYMBOL_BINARY_DIFF_BODY,
 680        DIFF_SYMBOL_BINARY_DIFF_FOOTER,
 681        DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
 682        DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
 683        DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
 684        DIFF_SYMBOL_STATS_LINE,
 685        DIFF_SYMBOL_WORD_DIFF,
 686        DIFF_SYMBOL_STAT_SEP,
 687        DIFF_SYMBOL_SUMMARY,
 688        DIFF_SYMBOL_SUBMODULE_ADD,
 689        DIFF_SYMBOL_SUBMODULE_DEL,
 690        DIFF_SYMBOL_SUBMODULE_UNTRACKED,
 691        DIFF_SYMBOL_SUBMODULE_MODIFIED,
 692        DIFF_SYMBOL_SUBMODULE_HEADER,
 693        DIFF_SYMBOL_SUBMODULE_ERROR,
 694        DIFF_SYMBOL_SUBMODULE_PIPETHROUGH,
 695        DIFF_SYMBOL_REWRITE_DIFF,
 696        DIFF_SYMBOL_BINARY_FILES,
 697        DIFF_SYMBOL_HEADER,
 698        DIFF_SYMBOL_FILEPAIR_PLUS,
 699        DIFF_SYMBOL_FILEPAIR_MINUS,
 700        DIFF_SYMBOL_WORDS_PORCELAIN,
 701        DIFF_SYMBOL_WORDS,
 702        DIFF_SYMBOL_CONTEXT,
 703        DIFF_SYMBOL_CONTEXT_INCOMPLETE,
 704        DIFF_SYMBOL_PLUS,
 705        DIFF_SYMBOL_MINUS,
 706        DIFF_SYMBOL_NO_LF_EOF,
 707        DIFF_SYMBOL_CONTEXT_FRAGINFO,
 708        DIFF_SYMBOL_CONTEXT_MARKER,
 709        DIFF_SYMBOL_SEPARATOR
 710};
 711/*
 712 * Flags for content lines:
 713 * 0..12 are whitespace rules
 714 * 13-15 are WSEH_NEW | WSEH_OLD | WSEH_CONTEXT
 715 * 16 is marking if the line is blank at EOF
 716 */
 717#define DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF      (1<<16)
 718#define DIFF_SYMBOL_MOVED_LINE                  (1<<17)
 719#define DIFF_SYMBOL_MOVED_LINE_ALT              (1<<18)
 720#define DIFF_SYMBOL_MOVED_LINE_UNINTERESTING    (1<<19)
 721#define DIFF_SYMBOL_CONTENT_WS_MASK (WSEH_NEW | WSEH_OLD | WSEH_CONTEXT | WS_RULE_MASK)
 722
 723/*
 724 * This struct is used when we need to buffer the output of the diff output.
 725 *
 726 * NEEDSWORK: Instead of storing a copy of the line, add an offset pointer
 727 * into the pre/post image file. This pointer could be a union with the
 728 * line pointer. By storing an offset into the file instead of the literal line,
 729 * we can decrease the memory footprint for the buffered output. At first we
 730 * may want to only have indirection for the content lines, but we could also
 731 * enhance the state for emitting prefabricated lines, e.g. the similarity
 732 * score line or hunk/file headers would only need to store a number or path
 733 * and then the output can be constructed later on depending on state.
 734 */
 735struct emitted_diff_symbol {
 736        const char *line;
 737        int len;
 738        int flags;
 739        enum diff_symbol s;
 740};
 741#define EMITTED_DIFF_SYMBOL_INIT {NULL}
 742
 743struct emitted_diff_symbols {
 744        struct emitted_diff_symbol *buf;
 745        int nr, alloc;
 746};
 747#define EMITTED_DIFF_SYMBOLS_INIT {NULL, 0, 0}
 748
 749static void append_emitted_diff_symbol(struct diff_options *o,
 750                                       struct emitted_diff_symbol *e)
 751{
 752        struct emitted_diff_symbol *f;
 753
 754        ALLOC_GROW(o->emitted_symbols->buf,
 755                   o->emitted_symbols->nr + 1,
 756                   o->emitted_symbols->alloc);
 757        f = &o->emitted_symbols->buf[o->emitted_symbols->nr++];
 758
 759        memcpy(f, e, sizeof(struct emitted_diff_symbol));
 760        f->line = e->line ? xmemdupz(e->line, e->len) : NULL;
 761}
 762
 763struct moved_entry {
 764        struct hashmap_entry ent;
 765        const struct emitted_diff_symbol *es;
 766        struct moved_entry *next_line;
 767        struct ws_delta *wsd;
 768};
 769
 770/**
 771 * The struct ws_delta holds white space differences between moved lines, i.e.
 772 * between '+' and '-' lines that have been detected to be a move.
 773 * The string contains the difference in leading white spaces, before the
 774 * rest of the line is compared using the white space config for move
 775 * coloring. The current_longer indicates if the first string in the
 776 * comparision is longer than the second.
 777 */
 778struct ws_delta {
 779        char *string;
 780        unsigned int current_longer : 1;
 781};
 782#define WS_DELTA_INIT { NULL, 0 }
 783
 784static int compute_ws_delta(const struct emitted_diff_symbol *a,
 785                             const struct emitted_diff_symbol *b,
 786                             struct ws_delta *out)
 787{
 788        const struct emitted_diff_symbol *longer =  a->len > b->len ? a : b;
 789        const struct emitted_diff_symbol *shorter = a->len > b->len ? b : a;
 790        int d = longer->len - shorter->len;
 791
 792        out->string = xmemdupz(longer->line, d);
 793        out->current_longer = (a == longer);
 794
 795        return !strncmp(longer->line + d, shorter->line, shorter->len);
 796}
 797
 798static int cmp_in_block_with_wsd(const struct diff_options *o,
 799                                 const struct moved_entry *cur,
 800                                 const struct moved_entry *match,
 801                                 struct moved_entry *pmb,
 802                                 int n)
 803{
 804        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
 805        int al = cur->es->len, cl = l->len;
 806        const char *a = cur->es->line,
 807                   *b = match->es->line,
 808                   *c = l->line;
 809
 810        int wslen;
 811
 812        /*
 813         * We need to check if 'cur' is equal to 'match'.
 814         * As those are from the same (+/-) side, we do not need to adjust for
 815         * indent changes. However these were found using fuzzy matching
 816         * so we do have to check if they are equal.
 817         */
 818        if (strcmp(a, b))
 819                return 1;
 820
 821        if (!pmb->wsd)
 822                /*
 823                 * No white space delta was carried forward? This can happen
 824                 * when we exit early in this function and do not carry
 825                 * forward ws.
 826                 */
 827                return 1;
 828
 829        /*
 830         * The indent changes of the block are known and carried forward in
 831         * pmb->wsd; however we need to check if the indent changes of the
 832         * current line are still the same as before.
 833         *
 834         * To do so we need to compare 'l' to 'cur', adjusting the
 835         * one of them for the white spaces, depending which was longer.
 836         */
 837
 838        wslen = strlen(pmb->wsd->string);
 839        if (pmb->wsd->current_longer) {
 840                c += wslen;
 841                cl -= wslen;
 842        } else {
 843                a += wslen;
 844                al -= wslen;
 845        }
 846
 847        if (strcmp(a, c))
 848                return 1;
 849
 850        return 0;
 851}
 852
 853static int moved_entry_cmp(const void *hashmap_cmp_fn_data,
 854                           const void *entry,
 855                           const void *entry_or_key,
 856                           const void *keydata)
 857{
 858        const struct diff_options *diffopt = hashmap_cmp_fn_data;
 859        const struct moved_entry *a = entry;
 860        const struct moved_entry *b = entry_or_key;
 861        unsigned flags = diffopt->color_moved_ws_handling
 862                         & XDF_WHITESPACE_FLAGS;
 863
 864        if (diffopt->color_moved_ws_handling &
 865            COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
 866                /*
 867                 * As there is not specific white space config given,
 868                 * we'd need to check for a new block, so ignore all
 869                 * white space. The setup of the white space
 870                 * configuration for the next block is done else where
 871                 */
 872                flags |= XDF_IGNORE_WHITESPACE;
 873
 874        return !xdiff_compare_lines(a->es->line, a->es->len,
 875                                    b->es->line, b->es->len,
 876                                    flags);
 877}
 878
 879static struct moved_entry *prepare_entry(struct diff_options *o,
 880                                         int line_no)
 881{
 882        struct moved_entry *ret = xmalloc(sizeof(*ret));
 883        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[line_no];
 884        unsigned flags = o->color_moved_ws_handling & XDF_WHITESPACE_FLAGS;
 885
 886        ret->ent.hash = xdiff_hash_string(l->line, l->len, flags);
 887        ret->es = l;
 888        ret->next_line = NULL;
 889        ret->wsd = NULL;
 890
 891        return ret;
 892}
 893
 894static void add_lines_to_move_detection(struct diff_options *o,
 895                                        struct hashmap *add_lines,
 896                                        struct hashmap *del_lines)
 897{
 898        struct moved_entry *prev_line = NULL;
 899
 900        int n;
 901        for (n = 0; n < o->emitted_symbols->nr; n++) {
 902                struct hashmap *hm;
 903                struct moved_entry *key;
 904
 905                switch (o->emitted_symbols->buf[n].s) {
 906                case DIFF_SYMBOL_PLUS:
 907                        hm = add_lines;
 908                        break;
 909                case DIFF_SYMBOL_MINUS:
 910                        hm = del_lines;
 911                        break;
 912                default:
 913                        prev_line = NULL;
 914                        continue;
 915                }
 916
 917                key = prepare_entry(o, n);
 918                if (prev_line && prev_line->es->s == o->emitted_symbols->buf[n].s)
 919                        prev_line->next_line = key;
 920
 921                hashmap_add(hm, key);
 922                prev_line = key;
 923        }
 924}
 925
 926static void pmb_advance_or_null(struct diff_options *o,
 927                                struct moved_entry *match,
 928                                struct hashmap *hm,
 929                                struct moved_entry **pmb,
 930                                int pmb_nr)
 931{
 932        int i;
 933        for (i = 0; i < pmb_nr; i++) {
 934                struct moved_entry *prev = pmb[i];
 935                struct moved_entry *cur = (prev && prev->next_line) ?
 936                                prev->next_line : NULL;
 937                if (cur && !hm->cmpfn(o, cur, match, NULL)) {
 938                        pmb[i] = cur;
 939                } else {
 940                        pmb[i] = NULL;
 941                }
 942        }
 943}
 944
 945static void pmb_advance_or_null_multi_match(struct diff_options *o,
 946                                            struct moved_entry *match,
 947                                            struct hashmap *hm,
 948                                            struct moved_entry **pmb,
 949                                            int pmb_nr, int n)
 950{
 951        int i;
 952        char *got_match = xcalloc(1, pmb_nr);
 953
 954        for (; match; match = hashmap_get_next(hm, match)) {
 955                for (i = 0; i < pmb_nr; i++) {
 956                        struct moved_entry *prev = pmb[i];
 957                        struct moved_entry *cur = (prev && prev->next_line) ?
 958                                        prev->next_line : NULL;
 959                        if (!cur)
 960                                continue;
 961                        if (!cmp_in_block_with_wsd(o, cur, match, pmb[i], n))
 962                                got_match[i] |= 1;
 963                }
 964        }
 965
 966        for (i = 0; i < pmb_nr; i++) {
 967                if (got_match[i]) {
 968                        /* Carry the white space delta forward */
 969                        pmb[i]->next_line->wsd = pmb[i]->wsd;
 970                        pmb[i] = pmb[i]->next_line;
 971                } else
 972                        pmb[i] = NULL;
 973        }
 974}
 975
 976static int shrink_potential_moved_blocks(struct moved_entry **pmb,
 977                                         int pmb_nr)
 978{
 979        int lp, rp;
 980
 981        /* Shrink the set of potential block to the remaining running */
 982        for (lp = 0, rp = pmb_nr - 1; lp <= rp;) {
 983                while (lp < pmb_nr && pmb[lp])
 984                        lp++;
 985                /* lp points at the first NULL now */
 986
 987                while (rp > -1 && !pmb[rp])
 988                        rp--;
 989                /* rp points at the last non-NULL */
 990
 991                if (lp < pmb_nr && rp > -1 && lp < rp) {
 992                        pmb[lp] = pmb[rp];
 993                        if (pmb[rp]->wsd) {
 994                                free(pmb[rp]->wsd->string);
 995                                FREE_AND_NULL(pmb[rp]->wsd);
 996                        }
 997                        pmb[rp] = NULL;
 998                        rp--;
 999                        lp++;
1000                }
1001        }
1002
1003        /* Remember the number of running sets */
1004        return rp + 1;
1005}
1006
1007/*
1008 * If o->color_moved is COLOR_MOVED_PLAIN, this function does nothing.
1009 *
1010 * Otherwise, if the last block has fewer alphanumeric characters than
1011 * COLOR_MOVED_MIN_ALNUM_COUNT, unset DIFF_SYMBOL_MOVED_LINE on all lines in
1012 * that block.
1013 *
1014 * The last block consists of the (n - block_length)'th line up to but not
1015 * including the nth line.
1016 *
1017 * NEEDSWORK: This uses the same heuristic as blame_entry_score() in blame.c.
1018 * Think of a way to unify them.
1019 */
1020static void adjust_last_block(struct diff_options *o, int n, int block_length)
1021{
1022        int i, alnum_count = 0;
1023        if (o->color_moved == COLOR_MOVED_PLAIN)
1024                return;
1025        for (i = 1; i < block_length + 1; i++) {
1026                const char *c = o->emitted_symbols->buf[n - i].line;
1027                for (; *c; c++) {
1028                        if (!isalnum(*c))
1029                                continue;
1030                        alnum_count++;
1031                        if (alnum_count >= COLOR_MOVED_MIN_ALNUM_COUNT)
1032                                return;
1033                }
1034        }
1035        for (i = 1; i < block_length + 1; i++)
1036                o->emitted_symbols->buf[n - i].flags &= ~DIFF_SYMBOL_MOVED_LINE;
1037}
1038
1039/* Find blocks of moved code, delegate actual coloring decision to helper */
1040static void mark_color_as_moved(struct diff_options *o,
1041                                struct hashmap *add_lines,
1042                                struct hashmap *del_lines)
1043{
1044        struct moved_entry **pmb = NULL; /* potentially moved blocks */
1045        int pmb_nr = 0, pmb_alloc = 0;
1046        int n, flipped_block = 1, block_length = 0;
1047
1048
1049        for (n = 0; n < o->emitted_symbols->nr; n++) {
1050                struct hashmap *hm = NULL;
1051                struct moved_entry *key;
1052                struct moved_entry *match = NULL;
1053                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
1054
1055                switch (l->s) {
1056                case DIFF_SYMBOL_PLUS:
1057                        hm = del_lines;
1058                        key = prepare_entry(o, n);
1059                        match = hashmap_get(hm, key, NULL);
1060                        free(key);
1061                        break;
1062                case DIFF_SYMBOL_MINUS:
1063                        hm = add_lines;
1064                        key = prepare_entry(o, n);
1065                        match = hashmap_get(hm, key, NULL);
1066                        free(key);
1067                        break;
1068                default:
1069                        flipped_block = 1;
1070                }
1071
1072                if (!match) {
1073                        adjust_last_block(o, n, block_length);
1074                        pmb_nr = 0;
1075                        block_length = 0;
1076                        continue;
1077                }
1078
1079                l->flags |= DIFF_SYMBOL_MOVED_LINE;
1080
1081                if (o->color_moved == COLOR_MOVED_PLAIN)
1082                        continue;
1083
1084                if (o->color_moved_ws_handling &
1085                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
1086                        pmb_advance_or_null_multi_match(o, match, hm, pmb, pmb_nr, n);
1087                else
1088                        pmb_advance_or_null(o, match, hm, pmb, pmb_nr);
1089
1090                pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
1091
1092                if (pmb_nr == 0) {
1093                        /*
1094                         * The current line is the start of a new block.
1095                         * Setup the set of potential blocks.
1096                         */
1097                        for (; match; match = hashmap_get_next(hm, match)) {
1098                                ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
1099                                if (o->color_moved_ws_handling &
1100                                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) {
1101                                        struct ws_delta *wsd = xmalloc(sizeof(*match->wsd));
1102                                        if (compute_ws_delta(l, match->es, wsd)) {
1103                                                match->wsd = wsd;
1104                                                pmb[pmb_nr++] = match;
1105                                        } else
1106                                                free(wsd);
1107                                } else {
1108                                        pmb[pmb_nr++] = match;
1109                                }
1110                        }
1111
1112                        flipped_block = (flipped_block + 1) % 2;
1113
1114                        adjust_last_block(o, n, block_length);
1115                        block_length = 0;
1116                }
1117
1118                block_length++;
1119
1120                if (flipped_block && o->color_moved != COLOR_MOVED_BLOCKS)
1121                        l->flags |= DIFF_SYMBOL_MOVED_LINE_ALT;
1122        }
1123        adjust_last_block(o, n, block_length);
1124
1125        free(pmb);
1126}
1127
1128#define DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK \
1129  (DIFF_SYMBOL_MOVED_LINE | DIFF_SYMBOL_MOVED_LINE_ALT)
1130static void dim_moved_lines(struct diff_options *o)
1131{
1132        int n;
1133        for (n = 0; n < o->emitted_symbols->nr; n++) {
1134                struct emitted_diff_symbol *prev = (n != 0) ?
1135                                &o->emitted_symbols->buf[n - 1] : NULL;
1136                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
1137                struct emitted_diff_symbol *next =
1138                                (n < o->emitted_symbols->nr - 1) ?
1139                                &o->emitted_symbols->buf[n + 1] : NULL;
1140
1141                /* Not a plus or minus line? */
1142                if (l->s != DIFF_SYMBOL_PLUS && l->s != DIFF_SYMBOL_MINUS)
1143                        continue;
1144
1145                /* Not a moved line? */
1146                if (!(l->flags & DIFF_SYMBOL_MOVED_LINE))
1147                        continue;
1148
1149                /*
1150                 * If prev or next are not a plus or minus line,
1151                 * pretend they don't exist
1152                 */
1153                if (prev && prev->s != DIFF_SYMBOL_PLUS &&
1154                            prev->s != DIFF_SYMBOL_MINUS)
1155                        prev = NULL;
1156                if (next && next->s != DIFF_SYMBOL_PLUS &&
1157                            next->s != DIFF_SYMBOL_MINUS)
1158                        next = NULL;
1159
1160                /* Inside a block? */
1161                if ((prev &&
1162                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
1163                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK)) &&
1164                    (next &&
1165                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
1166                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK))) {
1167                        l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1168                        continue;
1169                }
1170
1171                /* Check if we are at an interesting bound: */
1172                if (prev && (prev->flags & DIFF_SYMBOL_MOVED_LINE) &&
1173                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1174                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1175                        continue;
1176                if (next && (next->flags & DIFF_SYMBOL_MOVED_LINE) &&
1177                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1178                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1179                        continue;
1180
1181                /*
1182                 * The boundary to prev and next are not interesting,
1183                 * so this line is not interesting as a whole
1184                 */
1185                l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1186        }
1187}
1188
1189static void emit_line_ws_markup(struct diff_options *o,
1190                                const char *set, const char *reset,
1191                                const char *line, int len,
1192                                const char *set_sign, char sign,
1193                                unsigned ws_rule, int blank_at_eof)
1194{
1195        const char *ws = NULL;
1196
1197        if (o->ws_error_highlight & ws_rule) {
1198                ws = diff_get_color_opt(o, DIFF_WHITESPACE);
1199                if (!*ws)
1200                        ws = NULL;
1201        }
1202
1203        if (!ws && !set_sign)
1204                emit_line_0(o, set, 0, reset, sign, line, len);
1205        else if (!ws) {
1206                /* Emit just the prefix, then the rest. */
1207                emit_line_0(o, set_sign ? set_sign : set, !!set_sign, reset,
1208                            sign, "", 0);
1209                emit_line_0(o, set, 0, reset, 0, line, len);
1210        } else if (blank_at_eof)
1211                /* Blank line at EOF - paint '+' as well */
1212                emit_line_0(o, ws, 0, reset, sign, line, len);
1213        else {
1214                /* Emit just the prefix, then the rest. */
1215                emit_line_0(o, set_sign ? set_sign : set, !!set_sign, reset,
1216                            sign, "", 0);
1217                ws_check_emit(line, len, ws_rule,
1218                              o->file, set, reset, ws);
1219        }
1220}
1221
1222static void emit_diff_symbol_from_struct(struct diff_options *o,
1223                                         struct emitted_diff_symbol *eds)
1224{
1225        static const char *nneof = " No newline at end of file\n";
1226        const char *context, *reset, *set, *set_sign, *meta, *fraginfo;
1227        struct strbuf sb = STRBUF_INIT;
1228
1229        enum diff_symbol s = eds->s;
1230        const char *line = eds->line;
1231        int len = eds->len;
1232        unsigned flags = eds->flags;
1233
1234        switch (s) {
1235        case DIFF_SYMBOL_NO_LF_EOF:
1236                context = diff_get_color_opt(o, DIFF_CONTEXT);
1237                reset = diff_get_color_opt(o, DIFF_RESET);
1238                putc('\n', o->file);
1239                emit_line_0(o, context, 0, reset, '\\',
1240                            nneof, strlen(nneof));
1241                break;
1242        case DIFF_SYMBOL_SUBMODULE_HEADER:
1243        case DIFF_SYMBOL_SUBMODULE_ERROR:
1244        case DIFF_SYMBOL_SUBMODULE_PIPETHROUGH:
1245        case DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES:
1246        case DIFF_SYMBOL_SUMMARY:
1247        case DIFF_SYMBOL_STATS_LINE:
1248        case DIFF_SYMBOL_BINARY_DIFF_BODY:
1249        case DIFF_SYMBOL_CONTEXT_FRAGINFO:
1250                emit_line(o, "", "", line, len);
1251                break;
1252        case DIFF_SYMBOL_CONTEXT_INCOMPLETE:
1253        case DIFF_SYMBOL_CONTEXT_MARKER:
1254                context = diff_get_color_opt(o, DIFF_CONTEXT);
1255                reset = diff_get_color_opt(o, DIFF_RESET);
1256                emit_line(o, context, reset, line, len);
1257                break;
1258        case DIFF_SYMBOL_SEPARATOR:
1259                fprintf(o->file, "%s%c",
1260                        diff_line_prefix(o),
1261                        o->line_termination);
1262                break;
1263        case DIFF_SYMBOL_CONTEXT:
1264                set = diff_get_color_opt(o, DIFF_CONTEXT);
1265                reset = diff_get_color_opt(o, DIFF_RESET);
1266                set_sign = NULL;
1267                if (o->flags.dual_color_diffed_diffs) {
1268                        char c = !len ? 0 : line[0];
1269
1270                        if (c == '+')
1271                                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1272                        else if (c == '@')
1273                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1274                        else if (c == '-')
1275                                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1276                }
1277                emit_line_ws_markup(o, set, reset, line, len, set_sign, ' ',
1278                                    flags & (DIFF_SYMBOL_CONTENT_WS_MASK), 0);
1279                break;
1280        case DIFF_SYMBOL_PLUS:
1281                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1282                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1283                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1284                case DIFF_SYMBOL_MOVED_LINE |
1285                     DIFF_SYMBOL_MOVED_LINE_ALT |
1286                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1287                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT_DIM);
1288                        break;
1289                case DIFF_SYMBOL_MOVED_LINE |
1290                     DIFF_SYMBOL_MOVED_LINE_ALT:
1291                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT);
1292                        break;
1293                case DIFF_SYMBOL_MOVED_LINE |
1294                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1295                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_DIM);
1296                        break;
1297                case DIFF_SYMBOL_MOVED_LINE:
1298                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED);
1299                        break;
1300                default:
1301                        set = diff_get_color_opt(o, DIFF_FILE_NEW);
1302                }
1303                reset = diff_get_color_opt(o, DIFF_RESET);
1304                if (!o->flags.dual_color_diffed_diffs)
1305                        set_sign = NULL;
1306                else {
1307                        char c = !len ? 0 : line[0];
1308
1309                        set_sign = set;
1310                        if (c == '-')
1311                                set = diff_get_color_opt(o, DIFF_FILE_OLD_BOLD);
1312                        else if (c == '@')
1313                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1314                        else if (c == '+')
1315                                set = diff_get_color_opt(o, DIFF_FILE_NEW_BOLD);
1316                        else
1317                                set = diff_get_color_opt(o, DIFF_CONTEXT_BOLD);
1318                        flags &= ~DIFF_SYMBOL_CONTENT_WS_MASK;
1319                }
1320                emit_line_ws_markup(o, set, reset, line, len, set_sign, '+',
1321                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK,
1322                                    flags & DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF);
1323                break;
1324        case DIFF_SYMBOL_MINUS:
1325                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1326                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1327                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1328                case DIFF_SYMBOL_MOVED_LINE |
1329                     DIFF_SYMBOL_MOVED_LINE_ALT |
1330                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1331                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT_DIM);
1332                        break;
1333                case DIFF_SYMBOL_MOVED_LINE |
1334                     DIFF_SYMBOL_MOVED_LINE_ALT:
1335                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT);
1336                        break;
1337                case DIFF_SYMBOL_MOVED_LINE |
1338                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1339                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_DIM);
1340                        break;
1341                case DIFF_SYMBOL_MOVED_LINE:
1342                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED);
1343                        break;
1344                default:
1345                        set = diff_get_color_opt(o, DIFF_FILE_OLD);
1346                }
1347                reset = diff_get_color_opt(o, DIFF_RESET);
1348                if (!o->flags.dual_color_diffed_diffs)
1349                        set_sign = NULL;
1350                else {
1351                        char c = !len ? 0 : line[0];
1352
1353                        set_sign = set;
1354                        if (c == '+')
1355                                set = diff_get_color_opt(o, DIFF_FILE_NEW_DIM);
1356                        else if (c == '@')
1357                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1358                        else if (c == '-')
1359                                set = diff_get_color_opt(o, DIFF_FILE_OLD_DIM);
1360                        else
1361                                set = diff_get_color_opt(o, DIFF_CONTEXT_DIM);
1362                }
1363                emit_line_ws_markup(o, set, reset, line, len, set_sign, '-',
1364                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK, 0);
1365                break;
1366        case DIFF_SYMBOL_WORDS_PORCELAIN:
1367                context = diff_get_color_opt(o, DIFF_CONTEXT);
1368                reset = diff_get_color_opt(o, DIFF_RESET);
1369                emit_line(o, context, reset, line, len);
1370                fputs("~\n", o->file);
1371                break;
1372        case DIFF_SYMBOL_WORDS:
1373                context = diff_get_color_opt(o, DIFF_CONTEXT);
1374                reset = diff_get_color_opt(o, DIFF_RESET);
1375                /*
1376                 * Skip the prefix character, if any.  With
1377                 * diff_suppress_blank_empty, there may be
1378                 * none.
1379                 */
1380                if (line[0] != '\n') {
1381                        line++;
1382                        len--;
1383                }
1384                emit_line(o, context, reset, line, len);
1385                break;
1386        case DIFF_SYMBOL_FILEPAIR_PLUS:
1387                meta = diff_get_color_opt(o, DIFF_METAINFO);
1388                reset = diff_get_color_opt(o, DIFF_RESET);
1389                fprintf(o->file, "%s%s+++ %s%s%s\n", diff_line_prefix(o), meta,
1390                        line, reset,
1391                        strchr(line, ' ') ? "\t" : "");
1392                break;
1393        case DIFF_SYMBOL_FILEPAIR_MINUS:
1394                meta = diff_get_color_opt(o, DIFF_METAINFO);
1395                reset = diff_get_color_opt(o, DIFF_RESET);
1396                fprintf(o->file, "%s%s--- %s%s%s\n", diff_line_prefix(o), meta,
1397                        line, reset,
1398                        strchr(line, ' ') ? "\t" : "");
1399                break;
1400        case DIFF_SYMBOL_BINARY_FILES:
1401        case DIFF_SYMBOL_HEADER:
1402                fprintf(o->file, "%s", line);
1403                break;
1404        case DIFF_SYMBOL_BINARY_DIFF_HEADER:
1405                fprintf(o->file, "%sGIT binary patch\n", diff_line_prefix(o));
1406                break;
1407        case DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA:
1408                fprintf(o->file, "%sdelta %s\n", diff_line_prefix(o), line);
1409                break;
1410        case DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL:
1411                fprintf(o->file, "%sliteral %s\n", diff_line_prefix(o), line);
1412                break;
1413        case DIFF_SYMBOL_BINARY_DIFF_FOOTER:
1414                fputs(diff_line_prefix(o), o->file);
1415                fputc('\n', o->file);
1416                break;
1417        case DIFF_SYMBOL_REWRITE_DIFF:
1418                fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
1419                reset = diff_get_color_opt(o, DIFF_RESET);
1420                emit_line(o, fraginfo, reset, line, len);
1421                break;
1422        case DIFF_SYMBOL_SUBMODULE_ADD:
1423                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1424                reset = diff_get_color_opt(o, DIFF_RESET);
1425                emit_line(o, set, reset, line, len);
1426                break;
1427        case DIFF_SYMBOL_SUBMODULE_DEL:
1428                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1429                reset = diff_get_color_opt(o, DIFF_RESET);
1430                emit_line(o, set, reset, line, len);
1431                break;
1432        case DIFF_SYMBOL_SUBMODULE_UNTRACKED:
1433                fprintf(o->file, "%sSubmodule %s contains untracked content\n",
1434                        diff_line_prefix(o), line);
1435                break;
1436        case DIFF_SYMBOL_SUBMODULE_MODIFIED:
1437                fprintf(o->file, "%sSubmodule %s contains modified content\n",
1438                        diff_line_prefix(o), line);
1439                break;
1440        case DIFF_SYMBOL_STATS_SUMMARY_NO_FILES:
1441                emit_line(o, "", "", " 0 files changed\n",
1442                          strlen(" 0 files changed\n"));
1443                break;
1444        case DIFF_SYMBOL_STATS_SUMMARY_ABBREV:
1445                emit_line(o, "", "", " ...\n", strlen(" ...\n"));
1446                break;
1447        case DIFF_SYMBOL_WORD_DIFF:
1448                fprintf(o->file, "%.*s", len, line);
1449                break;
1450        case DIFF_SYMBOL_STAT_SEP:
1451                fputs(o->stat_sep, o->file);
1452                break;
1453        default:
1454                BUG("unknown diff symbol");
1455        }
1456        strbuf_release(&sb);
1457}
1458
1459static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
1460                             const char *line, int len, unsigned flags)
1461{
1462        struct emitted_diff_symbol e = {line, len, flags, s};
1463
1464        if (o->emitted_symbols)
1465                append_emitted_diff_symbol(o, &e);
1466        else
1467                emit_diff_symbol_from_struct(o, &e);
1468}
1469
1470void diff_emit_submodule_del(struct diff_options *o, const char *line)
1471{
1472        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_DEL, line, strlen(line), 0);
1473}
1474
1475void diff_emit_submodule_add(struct diff_options *o, const char *line)
1476{
1477        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ADD, line, strlen(line), 0);
1478}
1479
1480void diff_emit_submodule_untracked(struct diff_options *o, const char *path)
1481{
1482        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_UNTRACKED,
1483                         path, strlen(path), 0);
1484}
1485
1486void diff_emit_submodule_modified(struct diff_options *o, const char *path)
1487{
1488        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_MODIFIED,
1489                         path, strlen(path), 0);
1490}
1491
1492void diff_emit_submodule_header(struct diff_options *o, const char *header)
1493{
1494        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_HEADER,
1495                         header, strlen(header), 0);
1496}
1497
1498void diff_emit_submodule_error(struct diff_options *o, const char *err)
1499{
1500        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ERROR, err, strlen(err), 0);
1501}
1502
1503void diff_emit_submodule_pipethrough(struct diff_options *o,
1504                                     const char *line, int len)
1505{
1506        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_PIPETHROUGH, line, len, 0);
1507}
1508
1509static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
1510{
1511        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
1512              ecbdata->blank_at_eof_in_preimage &&
1513              ecbdata->blank_at_eof_in_postimage &&
1514              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
1515              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
1516                return 0;
1517        return ws_blank_line(line, len, ecbdata->ws_rule);
1518}
1519
1520static void emit_add_line(const char *reset,
1521                          struct emit_callback *ecbdata,
1522                          const char *line, int len)
1523{
1524        unsigned flags = WSEH_NEW | ecbdata->ws_rule;
1525        if (new_blank_line_at_eof(ecbdata, line, len))
1526                flags |= DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF;
1527
1528        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_PLUS, line, len, flags);
1529}
1530
1531static void emit_del_line(const char *reset,
1532                          struct emit_callback *ecbdata,
1533                          const char *line, int len)
1534{
1535        unsigned flags = WSEH_OLD | ecbdata->ws_rule;
1536        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_MINUS, line, len, flags);
1537}
1538
1539static void emit_context_line(const char *reset,
1540                              struct emit_callback *ecbdata,
1541                              const char *line, int len)
1542{
1543        unsigned flags = WSEH_CONTEXT | ecbdata->ws_rule;
1544        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_CONTEXT, line, len, flags);
1545}
1546
1547static void emit_hunk_header(struct emit_callback *ecbdata,
1548                             const char *line, int len)
1549{
1550        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
1551        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
1552        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
1553        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1554        const char *reverse = ecbdata->color_diff ? GIT_COLOR_REVERSE : "";
1555        static const char atat[2] = { '@', '@' };
1556        const char *cp, *ep;
1557        struct strbuf msgbuf = STRBUF_INIT;
1558        int org_len = len;
1559        int i = 1;
1560
1561        /*
1562         * As a hunk header must begin with "@@ -<old>, +<new> @@",
1563         * it always is at least 10 bytes long.
1564         */
1565        if (len < 10 ||
1566            memcmp(line, atat, 2) ||
1567            !(ep = memmem(line + 2, len - 2, atat, 2))) {
1568                emit_diff_symbol(ecbdata->opt,
1569                                 DIFF_SYMBOL_CONTEXT_MARKER, line, len, 0);
1570                return;
1571        }
1572        ep += 2; /* skip over @@ */
1573
1574        /* The hunk header in fraginfo color */
1575        if (ecbdata->opt->flags.dual_color_diffed_diffs)
1576                strbuf_addstr(&msgbuf, reverse);
1577        strbuf_addstr(&msgbuf, frag);
1578        strbuf_add(&msgbuf, line, ep - line);
1579        strbuf_addstr(&msgbuf, reset);
1580
1581        /*
1582         * trailing "\r\n"
1583         */
1584        for ( ; i < 3; i++)
1585                if (line[len - i] == '\r' || line[len - i] == '\n')
1586                        len--;
1587
1588        /* blank before the func header */
1589        for (cp = ep; ep - line < len; ep++)
1590                if (*ep != ' ' && *ep != '\t')
1591                        break;
1592        if (ep != cp) {
1593                strbuf_addstr(&msgbuf, context);
1594                strbuf_add(&msgbuf, cp, ep - cp);
1595                strbuf_addstr(&msgbuf, reset);
1596        }
1597
1598        if (ep < line + len) {
1599                strbuf_addstr(&msgbuf, func);
1600                strbuf_add(&msgbuf, ep, line + len - ep);
1601                strbuf_addstr(&msgbuf, reset);
1602        }
1603
1604        strbuf_add(&msgbuf, line + len, org_len - len);
1605        strbuf_complete_line(&msgbuf);
1606        emit_diff_symbol(ecbdata->opt,
1607                         DIFF_SYMBOL_CONTEXT_FRAGINFO, msgbuf.buf, msgbuf.len, 0);
1608        strbuf_release(&msgbuf);
1609}
1610
1611static struct diff_tempfile *claim_diff_tempfile(void) {
1612        int i;
1613        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
1614                if (!diff_temp[i].name)
1615                        return diff_temp + i;
1616        BUG("diff is failing to clean up its tempfiles");
1617}
1618
1619static void remove_tempfile(void)
1620{
1621        int i;
1622        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
1623                if (is_tempfile_active(diff_temp[i].tempfile))
1624                        delete_tempfile(&diff_temp[i].tempfile);
1625                diff_temp[i].name = NULL;
1626        }
1627}
1628
1629static void add_line_count(struct strbuf *out, int count)
1630{
1631        switch (count) {
1632        case 0:
1633                strbuf_addstr(out, "0,0");
1634                break;
1635        case 1:
1636                strbuf_addstr(out, "1");
1637                break;
1638        default:
1639                strbuf_addf(out, "1,%d", count);
1640                break;
1641        }
1642}
1643
1644static void emit_rewrite_lines(struct emit_callback *ecb,
1645                               int prefix, const char *data, int size)
1646{
1647        const char *endp = NULL;
1648        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
1649
1650        while (0 < size) {
1651                int len;
1652
1653                endp = memchr(data, '\n', size);
1654                len = endp ? (endp - data + 1) : size;
1655                if (prefix != '+') {
1656                        ecb->lno_in_preimage++;
1657                        emit_del_line(reset, ecb, data, len);
1658                } else {
1659                        ecb->lno_in_postimage++;
1660                        emit_add_line(reset, ecb, data, len);
1661                }
1662                size -= len;
1663                data += len;
1664        }
1665        if (!endp)
1666                emit_diff_symbol(ecb->opt, DIFF_SYMBOL_NO_LF_EOF, NULL, 0, 0);
1667}
1668
1669static void emit_rewrite_diff(const char *name_a,
1670                              const char *name_b,
1671                              struct diff_filespec *one,
1672                              struct diff_filespec *two,
1673                              struct userdiff_driver *textconv_one,
1674                              struct userdiff_driver *textconv_two,
1675                              struct diff_options *o)
1676{
1677        int lc_a, lc_b;
1678        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
1679        const char *a_prefix, *b_prefix;
1680        char *data_one, *data_two;
1681        size_t size_one, size_two;
1682        struct emit_callback ecbdata;
1683        struct strbuf out = STRBUF_INIT;
1684
1685        if (diff_mnemonic_prefix && o->flags.reverse_diff) {
1686                a_prefix = o->b_prefix;
1687                b_prefix = o->a_prefix;
1688        } else {
1689                a_prefix = o->a_prefix;
1690                b_prefix = o->b_prefix;
1691        }
1692
1693        name_a += (*name_a == '/');
1694        name_b += (*name_b == '/');
1695
1696        strbuf_reset(&a_name);
1697        strbuf_reset(&b_name);
1698        quote_two_c_style(&a_name, a_prefix, name_a, 0);
1699        quote_two_c_style(&b_name, b_prefix, name_b, 0);
1700
1701        size_one = fill_textconv(textconv_one, one, &data_one);
1702        size_two = fill_textconv(textconv_two, two, &data_two);
1703
1704        memset(&ecbdata, 0, sizeof(ecbdata));
1705        ecbdata.color_diff = want_color(o->use_color);
1706        ecbdata.ws_rule = whitespace_rule(name_b);
1707        ecbdata.opt = o;
1708        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
1709                mmfile_t mf1, mf2;
1710                mf1.ptr = (char *)data_one;
1711                mf2.ptr = (char *)data_two;
1712                mf1.size = size_one;
1713                mf2.size = size_two;
1714                check_blank_at_eof(&mf1, &mf2, &ecbdata);
1715        }
1716        ecbdata.lno_in_preimage = 1;
1717        ecbdata.lno_in_postimage = 1;
1718
1719        lc_a = count_lines(data_one, size_one);
1720        lc_b = count_lines(data_two, size_two);
1721
1722        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
1723                         a_name.buf, a_name.len, 0);
1724        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
1725                         b_name.buf, b_name.len, 0);
1726
1727        strbuf_addstr(&out, "@@ -");
1728        if (!o->irreversible_delete)
1729                add_line_count(&out, lc_a);
1730        else
1731                strbuf_addstr(&out, "?,?");
1732        strbuf_addstr(&out, " +");
1733        add_line_count(&out, lc_b);
1734        strbuf_addstr(&out, " @@\n");
1735        emit_diff_symbol(o, DIFF_SYMBOL_REWRITE_DIFF, out.buf, out.len, 0);
1736        strbuf_release(&out);
1737
1738        if (lc_a && !o->irreversible_delete)
1739                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
1740        if (lc_b)
1741                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
1742        if (textconv_one)
1743                free((char *)data_one);
1744        if (textconv_two)
1745                free((char *)data_two);
1746}
1747
1748struct diff_words_buffer {
1749        mmfile_t text;
1750        unsigned long alloc;
1751        struct diff_words_orig {
1752                const char *begin, *end;
1753        } *orig;
1754        int orig_nr, orig_alloc;
1755};
1756
1757static void diff_words_append(char *line, unsigned long len,
1758                struct diff_words_buffer *buffer)
1759{
1760        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
1761        line++;
1762        len--;
1763        memcpy(buffer->text.ptr + buffer->text.size, line, len);
1764        buffer->text.size += len;
1765        buffer->text.ptr[buffer->text.size] = '\0';
1766}
1767
1768struct diff_words_style_elem {
1769        const char *prefix;
1770        const char *suffix;
1771        const char *color; /* NULL; filled in by the setup code if
1772                            * color is enabled */
1773};
1774
1775struct diff_words_style {
1776        enum diff_words_type type;
1777        struct diff_words_style_elem new_word, old_word, ctx;
1778        const char *newline;
1779};
1780
1781static struct diff_words_style diff_words_styles[] = {
1782        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
1783        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
1784        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
1785};
1786
1787struct diff_words_data {
1788        struct diff_words_buffer minus, plus;
1789        const char *current_plus;
1790        int last_minus;
1791        struct diff_options *opt;
1792        regex_t *word_regex;
1793        enum diff_words_type type;
1794        struct diff_words_style *style;
1795};
1796
1797static int fn_out_diff_words_write_helper(struct diff_options *o,
1798                                          struct diff_words_style_elem *st_el,
1799                                          const char *newline,
1800                                          size_t count, const char *buf)
1801{
1802        int print = 0;
1803        struct strbuf sb = STRBUF_INIT;
1804
1805        while (count) {
1806                char *p = memchr(buf, '\n', count);
1807                if (print)
1808                        strbuf_addstr(&sb, diff_line_prefix(o));
1809
1810                if (p != buf) {
1811                        const char *reset = st_el->color && *st_el->color ?
1812                                            GIT_COLOR_RESET : NULL;
1813                        if (st_el->color && *st_el->color)
1814                                strbuf_addstr(&sb, st_el->color);
1815                        strbuf_addstr(&sb, st_el->prefix);
1816                        strbuf_add(&sb, buf, p ? p - buf : count);
1817                        strbuf_addstr(&sb, st_el->suffix);
1818                        if (reset)
1819                                strbuf_addstr(&sb, reset);
1820                }
1821                if (!p)
1822                        goto out;
1823
1824                strbuf_addstr(&sb, newline);
1825                count -= p + 1 - buf;
1826                buf = p + 1;
1827                print = 1;
1828                if (count) {
1829                        emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1830                                         sb.buf, sb.len, 0);
1831                        strbuf_reset(&sb);
1832                }
1833        }
1834
1835out:
1836        if (sb.len)
1837                emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1838                                 sb.buf, sb.len, 0);
1839        strbuf_release(&sb);
1840        return 0;
1841}
1842
1843/*
1844 * '--color-words' algorithm can be described as:
1845 *
1846 *   1. collect the minus/plus lines of a diff hunk, divided into
1847 *      minus-lines and plus-lines;
1848 *
1849 *   2. break both minus-lines and plus-lines into words and
1850 *      place them into two mmfile_t with one word for each line;
1851 *
1852 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
1853 *
1854 * And for the common parts of the both file, we output the plus side text.
1855 * diff_words->current_plus is used to trace the current position of the plus file
1856 * which printed. diff_words->last_minus is used to trace the last minus word
1857 * printed.
1858 *
1859 * For '--graph' to work with '--color-words', we need to output the graph prefix
1860 * on each line of color words output. Generally, there are two conditions on
1861 * which we should output the prefix.
1862 *
1863 *   1. diff_words->last_minus == 0 &&
1864 *      diff_words->current_plus == diff_words->plus.text.ptr
1865 *
1866 *      that is: the plus text must start as a new line, and if there is no minus
1867 *      word printed, a graph prefix must be printed.
1868 *
1869 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
1870 *      *(diff_words->current_plus - 1) == '\n'
1871 *
1872 *      that is: a graph prefix must be printed following a '\n'
1873 */
1874static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
1875{
1876        if ((diff_words->last_minus == 0 &&
1877                diff_words->current_plus == diff_words->plus.text.ptr) ||
1878                (diff_words->current_plus > diff_words->plus.text.ptr &&
1879                *(diff_words->current_plus - 1) == '\n')) {
1880                return 1;
1881        } else {
1882                return 0;
1883        }
1884}
1885
1886static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
1887{
1888        struct diff_words_data *diff_words = priv;
1889        struct diff_words_style *style = diff_words->style;
1890        int minus_first, minus_len, plus_first, plus_len;
1891        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
1892        struct diff_options *opt = diff_words->opt;
1893        const char *line_prefix;
1894
1895        if (line[0] != '@' || parse_hunk_header(line, len,
1896                        &minus_first, &minus_len, &plus_first, &plus_len))
1897                return;
1898
1899        assert(opt);
1900        line_prefix = diff_line_prefix(opt);
1901
1902        /* POSIX requires that first be decremented by one if len == 0... */
1903        if (minus_len) {
1904                minus_begin = diff_words->minus.orig[minus_first].begin;
1905                minus_end =
1906                        diff_words->minus.orig[minus_first + minus_len - 1].end;
1907        } else
1908                minus_begin = minus_end =
1909                        diff_words->minus.orig[minus_first].end;
1910
1911        if (plus_len) {
1912                plus_begin = diff_words->plus.orig[plus_first].begin;
1913                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
1914        } else
1915                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
1916
1917        if (color_words_output_graph_prefix(diff_words)) {
1918                fputs(line_prefix, diff_words->opt->file);
1919        }
1920        if (diff_words->current_plus != plus_begin) {
1921                fn_out_diff_words_write_helper(diff_words->opt,
1922                                &style->ctx, style->newline,
1923                                plus_begin - diff_words->current_plus,
1924                                diff_words->current_plus);
1925        }
1926        if (minus_begin != minus_end) {
1927                fn_out_diff_words_write_helper(diff_words->opt,
1928                                &style->old_word, style->newline,
1929                                minus_end - minus_begin, minus_begin);
1930        }
1931        if (plus_begin != plus_end) {
1932                fn_out_diff_words_write_helper(diff_words->opt,
1933                                &style->new_word, style->newline,
1934                                plus_end - plus_begin, plus_begin);
1935        }
1936
1937        diff_words->current_plus = plus_end;
1938        diff_words->last_minus = minus_first;
1939}
1940
1941/* This function starts looking at *begin, and returns 0 iff a word was found. */
1942static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
1943                int *begin, int *end)
1944{
1945        if (word_regex && *begin < buffer->size) {
1946                regmatch_t match[1];
1947                if (!regexec_buf(word_regex, buffer->ptr + *begin,
1948                                 buffer->size - *begin, 1, match, 0)) {
1949                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
1950                                        '\n', match[0].rm_eo - match[0].rm_so);
1951                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
1952                        *begin += match[0].rm_so;
1953                        return *begin >= *end;
1954                }
1955                return -1;
1956        }
1957
1958        /* find the next word */
1959        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
1960                (*begin)++;
1961        if (*begin >= buffer->size)
1962                return -1;
1963
1964        /* find the end of the word */
1965        *end = *begin + 1;
1966        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
1967                (*end)++;
1968
1969        return 0;
1970}
1971
1972/*
1973 * This function splits the words in buffer->text, stores the list with
1974 * newline separator into out, and saves the offsets of the original words
1975 * in buffer->orig.
1976 */
1977static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
1978                regex_t *word_regex)
1979{
1980        int i, j;
1981        long alloc = 0;
1982
1983        out->size = 0;
1984        out->ptr = NULL;
1985
1986        /* fake an empty "0th" word */
1987        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
1988        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
1989        buffer->orig_nr = 1;
1990
1991        for (i = 0; i < buffer->text.size; i++) {
1992                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
1993                        return;
1994
1995                /* store original boundaries */
1996                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
1997                                buffer->orig_alloc);
1998                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
1999                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
2000                buffer->orig_nr++;
2001
2002                /* store one word */
2003                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
2004                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
2005                out->ptr[out->size + j - i] = '\n';
2006                out->size += j - i + 1;
2007
2008                i = j - 1;
2009        }
2010}
2011
2012/* this executes the word diff on the accumulated buffers */
2013static void diff_words_show(struct diff_words_data *diff_words)
2014{
2015        xpparam_t xpp;
2016        xdemitconf_t xecfg;
2017        mmfile_t minus, plus;
2018        struct diff_words_style *style = diff_words->style;
2019
2020        struct diff_options *opt = diff_words->opt;
2021        const char *line_prefix;
2022
2023        assert(opt);
2024        line_prefix = diff_line_prefix(opt);
2025
2026        /* special case: only removal */
2027        if (!diff_words->plus.text.size) {
2028                emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
2029                                 line_prefix, strlen(line_prefix), 0);
2030                fn_out_diff_words_write_helper(diff_words->opt,
2031                        &style->old_word, style->newline,
2032                        diff_words->minus.text.size,
2033                        diff_words->minus.text.ptr);
2034                diff_words->minus.text.size = 0;
2035                return;
2036        }
2037
2038        diff_words->current_plus = diff_words->plus.text.ptr;
2039        diff_words->last_minus = 0;
2040
2041        memset(&xpp, 0, sizeof(xpp));
2042        memset(&xecfg, 0, sizeof(xecfg));
2043        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
2044        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
2045        xpp.flags = 0;
2046        /* as only the hunk header will be parsed, we need a 0-context */
2047        xecfg.ctxlen = 0;
2048        if (xdi_diff_outf(&minus, &plus, NULL, fn_out_diff_words_aux,
2049                          diff_words, &xpp, &xecfg))
2050                die("unable to generate word diff");
2051        free(minus.ptr);
2052        free(plus.ptr);
2053        if (diff_words->current_plus != diff_words->plus.text.ptr +
2054                        diff_words->plus.text.size) {
2055                if (color_words_output_graph_prefix(diff_words))
2056                        emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
2057                                         line_prefix, strlen(line_prefix), 0);
2058                fn_out_diff_words_write_helper(diff_words->opt,
2059                        &style->ctx, style->newline,
2060                        diff_words->plus.text.ptr + diff_words->plus.text.size
2061                        - diff_words->current_plus, diff_words->current_plus);
2062        }
2063        diff_words->minus.text.size = diff_words->plus.text.size = 0;
2064}
2065
2066/* In "color-words" mode, show word-diff of words accumulated in the buffer */
2067static void diff_words_flush(struct emit_callback *ecbdata)
2068{
2069        struct diff_options *wo = ecbdata->diff_words->opt;
2070
2071        if (ecbdata->diff_words->minus.text.size ||
2072            ecbdata->diff_words->plus.text.size)
2073                diff_words_show(ecbdata->diff_words);
2074
2075        if (wo->emitted_symbols) {
2076                struct diff_options *o = ecbdata->opt;
2077                struct emitted_diff_symbols *wol = wo->emitted_symbols;
2078                int i;
2079
2080                /*
2081                 * NEEDSWORK:
2082                 * Instead of appending each, concat all words to a line?
2083                 */
2084                for (i = 0; i < wol->nr; i++)
2085                        append_emitted_diff_symbol(o, &wol->buf[i]);
2086
2087                for (i = 0; i < wol->nr; i++)
2088                        free((void *)wol->buf[i].line);
2089
2090                wol->nr = 0;
2091        }
2092}
2093
2094static void diff_filespec_load_driver(struct diff_filespec *one)
2095{
2096        /* Use already-loaded driver */
2097        if (one->driver)
2098                return;
2099
2100        if (S_ISREG(one->mode))
2101                one->driver = userdiff_find_by_path(one->path);
2102
2103        /* Fallback to default settings */
2104        if (!one->driver)
2105                one->driver = userdiff_find_by_name("default");
2106}
2107
2108static const char *userdiff_word_regex(struct diff_filespec *one)
2109{
2110        diff_filespec_load_driver(one);
2111        return one->driver->word_regex;
2112}
2113
2114static void init_diff_words_data(struct emit_callback *ecbdata,
2115                                 struct diff_options *orig_opts,
2116                                 struct diff_filespec *one,
2117                                 struct diff_filespec *two)
2118{
2119        int i;
2120        struct diff_options *o = xmalloc(sizeof(struct diff_options));
2121        memcpy(o, orig_opts, sizeof(struct diff_options));
2122
2123        ecbdata->diff_words =
2124                xcalloc(1, sizeof(struct diff_words_data));
2125        ecbdata->diff_words->type = o->word_diff;
2126        ecbdata->diff_words->opt = o;
2127
2128        if (orig_opts->emitted_symbols)
2129                o->emitted_symbols =
2130                        xcalloc(1, sizeof(struct emitted_diff_symbols));
2131
2132        if (!o->word_regex)
2133                o->word_regex = userdiff_word_regex(one);
2134        if (!o->word_regex)
2135                o->word_regex = userdiff_word_regex(two);
2136        if (!o->word_regex)
2137                o->word_regex = diff_word_regex_cfg;
2138        if (o->word_regex) {
2139                ecbdata->diff_words->word_regex = (regex_t *)
2140                        xmalloc(sizeof(regex_t));
2141                if (regcomp(ecbdata->diff_words->word_regex,
2142                            o->word_regex,
2143                            REG_EXTENDED | REG_NEWLINE))
2144                        die("invalid regular expression: %s",
2145                            o->word_regex);
2146        }
2147        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2148                if (o->word_diff == diff_words_styles[i].type) {
2149                        ecbdata->diff_words->style =
2150                                &diff_words_styles[i];
2151                        break;
2152                }
2153        }
2154        if (want_color(o->use_color)) {
2155                struct diff_words_style *st = ecbdata->diff_words->style;
2156                st->old_word.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2157                st->new_word.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2158                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
2159        }
2160}
2161
2162static void free_diff_words_data(struct emit_callback *ecbdata)
2163{
2164        if (ecbdata->diff_words) {
2165                diff_words_flush(ecbdata);
2166                free (ecbdata->diff_words->opt->emitted_symbols);
2167                free (ecbdata->diff_words->opt);
2168                free (ecbdata->diff_words->minus.text.ptr);
2169                free (ecbdata->diff_words->minus.orig);
2170                free (ecbdata->diff_words->plus.text.ptr);
2171                free (ecbdata->diff_words->plus.orig);
2172                if (ecbdata->diff_words->word_regex) {
2173                        regfree(ecbdata->diff_words->word_regex);
2174                        free(ecbdata->diff_words->word_regex);
2175                }
2176                FREE_AND_NULL(ecbdata->diff_words);
2177        }
2178}
2179
2180const char *diff_get_color(int diff_use_color, enum color_diff ix)
2181{
2182        if (want_color(diff_use_color))
2183                return diff_colors[ix];
2184        return "";
2185}
2186
2187const char *diff_line_prefix(struct diff_options *opt)
2188{
2189        struct strbuf *msgbuf;
2190        if (!opt->output_prefix)
2191                return "";
2192
2193        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
2194        return msgbuf->buf;
2195}
2196
2197static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
2198{
2199        const char *cp;
2200        unsigned long allot;
2201        size_t l = len;
2202
2203        cp = line;
2204        allot = l;
2205        while (0 < l) {
2206                (void) utf8_width(&cp, &l);
2207                if (!cp)
2208                        break; /* truncated in the middle? */
2209        }
2210        return allot - l;
2211}
2212
2213static void find_lno(const char *line, struct emit_callback *ecbdata)
2214{
2215        const char *p;
2216        ecbdata->lno_in_preimage = 0;
2217        ecbdata->lno_in_postimage = 0;
2218        p = strchr(line, '-');
2219        if (!p)
2220                return; /* cannot happen */
2221        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
2222        p = strchr(p, '+');
2223        if (!p)
2224                return; /* cannot happen */
2225        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
2226}
2227
2228static void fn_out_consume(void *priv, char *line, unsigned long len)
2229{
2230        struct emit_callback *ecbdata = priv;
2231        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
2232        struct diff_options *o = ecbdata->opt;
2233
2234        o->found_changes = 1;
2235
2236        if (ecbdata->header) {
2237                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
2238                                 ecbdata->header->buf, ecbdata->header->len, 0);
2239                strbuf_reset(ecbdata->header);
2240                ecbdata->header = NULL;
2241        }
2242
2243        if (ecbdata->label_path[0]) {
2244                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
2245                                 ecbdata->label_path[0],
2246                                 strlen(ecbdata->label_path[0]), 0);
2247                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
2248                                 ecbdata->label_path[1],
2249                                 strlen(ecbdata->label_path[1]), 0);
2250                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
2251        }
2252
2253        if (diff_suppress_blank_empty
2254            && len == 2 && line[0] == ' ' && line[1] == '\n') {
2255                line[0] = '\n';
2256                len = 1;
2257        }
2258
2259        if (line[0] == '@') {
2260                if (ecbdata->diff_words)
2261                        diff_words_flush(ecbdata);
2262                len = sane_truncate_line(ecbdata, line, len);
2263                find_lno(line, ecbdata);
2264                emit_hunk_header(ecbdata, line, len);
2265                return;
2266        }
2267
2268        if (ecbdata->diff_words) {
2269                enum diff_symbol s =
2270                        ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN ?
2271                        DIFF_SYMBOL_WORDS_PORCELAIN : DIFF_SYMBOL_WORDS;
2272                if (line[0] == '-') {
2273                        diff_words_append(line, len,
2274                                          &ecbdata->diff_words->minus);
2275                        return;
2276                } else if (line[0] == '+') {
2277                        diff_words_append(line, len,
2278                                          &ecbdata->diff_words->plus);
2279                        return;
2280                } else if (starts_with(line, "\\ ")) {
2281                        /*
2282                         * Eat the "no newline at eof" marker as if we
2283                         * saw a "+" or "-" line with nothing on it,
2284                         * and return without diff_words_flush() to
2285                         * defer processing. If this is the end of
2286                         * preimage, more "+" lines may come after it.
2287                         */
2288                        return;
2289                }
2290                diff_words_flush(ecbdata);
2291                emit_diff_symbol(o, s, line, len, 0);
2292                return;
2293        }
2294
2295        switch (line[0]) {
2296        case '+':
2297                ecbdata->lno_in_postimage++;
2298                emit_add_line(reset, ecbdata, line + 1, len - 1);
2299                break;
2300        case '-':
2301                ecbdata->lno_in_preimage++;
2302                emit_del_line(reset, ecbdata, line + 1, len - 1);
2303                break;
2304        case ' ':
2305                ecbdata->lno_in_postimage++;
2306                ecbdata->lno_in_preimage++;
2307                emit_context_line(reset, ecbdata, line + 1, len - 1);
2308                break;
2309        default:
2310                /* incomplete line at the end */
2311                ecbdata->lno_in_preimage++;
2312                emit_diff_symbol(o, DIFF_SYMBOL_CONTEXT_INCOMPLETE,
2313                                 line, len, 0);
2314                break;
2315        }
2316}
2317
2318static void pprint_rename(struct strbuf *name, const char *a, const char *b)
2319{
2320        const char *old_name = a;
2321        const char *new_name = b;
2322        int pfx_length, sfx_length;
2323        int pfx_adjust_for_slash;
2324        int len_a = strlen(a);
2325        int len_b = strlen(b);
2326        int a_midlen, b_midlen;
2327        int qlen_a = quote_c_style(a, NULL, NULL, 0);
2328        int qlen_b = quote_c_style(b, NULL, NULL, 0);
2329
2330        if (qlen_a || qlen_b) {
2331                quote_c_style(a, name, NULL, 0);
2332                strbuf_addstr(name, " => ");
2333                quote_c_style(b, name, NULL, 0);
2334                return;
2335        }
2336
2337        /* Find common prefix */
2338        pfx_length = 0;
2339        while (*old_name && *new_name && *old_name == *new_name) {
2340                if (*old_name == '/')
2341                        pfx_length = old_name - a + 1;
2342                old_name++;
2343                new_name++;
2344        }
2345
2346        /* Find common suffix */
2347        old_name = a + len_a;
2348        new_name = b + len_b;
2349        sfx_length = 0;
2350        /*
2351         * If there is a common prefix, it must end in a slash.  In
2352         * that case we let this loop run 1 into the prefix to see the
2353         * same slash.
2354         *
2355         * If there is no common prefix, we cannot do this as it would
2356         * underrun the input strings.
2357         */
2358        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
2359        while (a + pfx_length - pfx_adjust_for_slash <= old_name &&
2360               b + pfx_length - pfx_adjust_for_slash <= new_name &&
2361               *old_name == *new_name) {
2362                if (*old_name == '/')
2363                        sfx_length = len_a - (old_name - a);
2364                old_name--;
2365                new_name--;
2366        }
2367
2368        /*
2369         * pfx{mid-a => mid-b}sfx
2370         * {pfx-a => pfx-b}sfx
2371         * pfx{sfx-a => sfx-b}
2372         * name-a => name-b
2373         */
2374        a_midlen = len_a - pfx_length - sfx_length;
2375        b_midlen = len_b - pfx_length - sfx_length;
2376        if (a_midlen < 0)
2377                a_midlen = 0;
2378        if (b_midlen < 0)
2379                b_midlen = 0;
2380
2381        strbuf_grow(name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
2382        if (pfx_length + sfx_length) {
2383                strbuf_add(name, a, pfx_length);
2384                strbuf_addch(name, '{');
2385        }
2386        strbuf_add(name, a + pfx_length, a_midlen);
2387        strbuf_addstr(name, " => ");
2388        strbuf_add(name, b + pfx_length, b_midlen);
2389        if (pfx_length + sfx_length) {
2390                strbuf_addch(name, '}');
2391                strbuf_add(name, a + len_a - sfx_length, sfx_length);
2392        }
2393}
2394
2395struct diffstat_t {
2396        int nr;
2397        int alloc;
2398        struct diffstat_file {
2399                char *from_name;
2400                char *name;
2401                char *print_name;
2402                const char *comments;
2403                unsigned is_unmerged:1;
2404                unsigned is_binary:1;
2405                unsigned is_renamed:1;
2406                unsigned is_interesting:1;
2407                uintmax_t added, deleted;
2408        } **files;
2409};
2410
2411static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
2412                                          const char *name_a,
2413                                          const char *name_b)
2414{
2415        struct diffstat_file *x;
2416        x = xcalloc(1, sizeof(*x));
2417        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
2418        diffstat->files[diffstat->nr++] = x;
2419        if (name_b) {
2420                x->from_name = xstrdup(name_a);
2421                x->name = xstrdup(name_b);
2422                x->is_renamed = 1;
2423        }
2424        else {
2425                x->from_name = NULL;
2426                x->name = xstrdup(name_a);
2427        }
2428        return x;
2429}
2430
2431static void diffstat_consume(void *priv, char *line, unsigned long len)
2432{
2433        struct diffstat_t *diffstat = priv;
2434        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
2435
2436        if (line[0] == '+')
2437                x->added++;
2438        else if (line[0] == '-')
2439                x->deleted++;
2440}
2441
2442const char mime_boundary_leader[] = "------------";
2443
2444static int scale_linear(int it, int width, int max_change)
2445{
2446        if (!it)
2447                return 0;
2448        /*
2449         * make sure that at least one '-' or '+' is printed if
2450         * there is any change to this path. The easiest way is to
2451         * scale linearly as if the alloted width is one column shorter
2452         * than it is, and then add 1 to the result.
2453         */
2454        return 1 + (it * (width - 1) / max_change);
2455}
2456
2457static void show_graph(struct strbuf *out, char ch, int cnt,
2458                       const char *set, const char *reset)
2459{
2460        if (cnt <= 0)
2461                return;
2462        strbuf_addstr(out, set);
2463        strbuf_addchars(out, ch, cnt);
2464        strbuf_addstr(out, reset);
2465}
2466
2467static void fill_print_name(struct diffstat_file *file)
2468{
2469        struct strbuf pname = STRBUF_INIT;
2470
2471        if (file->print_name)
2472                return;
2473
2474        if (file->is_renamed)
2475                pprint_rename(&pname, file->from_name, file->name);
2476        else
2477                quote_c_style(file->name, &pname, NULL, 0);
2478
2479        if (file->comments)
2480                strbuf_addf(&pname, " (%s)", file->comments);
2481
2482        file->print_name = strbuf_detach(&pname, NULL);
2483}
2484
2485static void print_stat_summary_inserts_deletes(struct diff_options *options,
2486                int files, int insertions, int deletions)
2487{
2488        struct strbuf sb = STRBUF_INIT;
2489
2490        if (!files) {
2491                assert(insertions == 0 && deletions == 0);
2492                emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
2493                                 NULL, 0, 0);
2494                return;
2495        }
2496
2497        strbuf_addf(&sb,
2498                    (files == 1) ? " %d file changed" : " %d files changed",
2499                    files);
2500
2501        /*
2502         * For binary diff, the caller may want to print "x files
2503         * changed" with insertions == 0 && deletions == 0.
2504         *
2505         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
2506         * is probably less confusing (i.e skip over "2 files changed
2507         * but nothing about added/removed lines? Is this a bug in Git?").
2508         */
2509        if (insertions || deletions == 0) {
2510                strbuf_addf(&sb,
2511                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
2512                            insertions);
2513        }
2514
2515        if (deletions || insertions == 0) {
2516                strbuf_addf(&sb,
2517                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
2518                            deletions);
2519        }
2520        strbuf_addch(&sb, '\n');
2521        emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
2522                         sb.buf, sb.len, 0);
2523        strbuf_release(&sb);
2524}
2525
2526void print_stat_summary(FILE *fp, int files,
2527                        int insertions, int deletions)
2528{
2529        struct diff_options o;
2530        memset(&o, 0, sizeof(o));
2531        o.file = fp;
2532
2533        print_stat_summary_inserts_deletes(&o, files, insertions, deletions);
2534}
2535
2536static void show_stats(struct diffstat_t *data, struct diff_options *options)
2537{
2538        int i, len, add, del, adds = 0, dels = 0;
2539        uintmax_t max_change = 0, max_len = 0;
2540        int total_files = data->nr, count;
2541        int width, name_width, graph_width, number_width = 0, bin_width = 0;
2542        const char *reset, *add_c, *del_c;
2543        int extra_shown = 0;
2544        const char *line_prefix = diff_line_prefix(options);
2545        struct strbuf out = STRBUF_INIT;
2546
2547        if (data->nr == 0)
2548                return;
2549
2550        count = options->stat_count ? options->stat_count : data->nr;
2551
2552        reset = diff_get_color_opt(options, DIFF_RESET);
2553        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
2554        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
2555
2556        /*
2557         * Find the longest filename and max number of changes
2558         */
2559        for (i = 0; (i < count) && (i < data->nr); i++) {
2560                struct diffstat_file *file = data->files[i];
2561                uintmax_t change = file->added + file->deleted;
2562
2563                if (!file->is_interesting && (change == 0)) {
2564                        count++; /* not shown == room for one more */
2565                        continue;
2566                }
2567                fill_print_name(file);
2568                len = strlen(file->print_name);
2569                if (max_len < len)
2570                        max_len = len;
2571
2572                if (file->is_unmerged) {
2573                        /* "Unmerged" is 8 characters */
2574                        bin_width = bin_width < 8 ? 8 : bin_width;
2575                        continue;
2576                }
2577                if (file->is_binary) {
2578                        /* "Bin XXX -> YYY bytes" */
2579                        int w = 14 + decimal_width(file->added)
2580                                + decimal_width(file->deleted);
2581                        bin_width = bin_width < w ? w : bin_width;
2582                        /* Display change counts aligned with "Bin" */
2583                        number_width = 3;
2584                        continue;
2585                }
2586
2587                if (max_change < change)
2588                        max_change = change;
2589        }
2590        count = i; /* where we can stop scanning in data->files[] */
2591
2592        /*
2593         * We have width = stat_width or term_columns() columns total.
2594         * We want a maximum of min(max_len, stat_name_width) for the name part.
2595         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
2596         * We also need 1 for " " and 4 + decimal_width(max_change)
2597         * for " | NNNN " and one the empty column at the end, altogether
2598         * 6 + decimal_width(max_change).
2599         *
2600         * If there's not enough space, we will use the smaller of
2601         * stat_name_width (if set) and 5/8*width for the filename,
2602         * and the rest for constant elements + graph part, but no more
2603         * than stat_graph_width for the graph part.
2604         * (5/8 gives 50 for filename and 30 for the constant parts + graph
2605         * for the standard terminal size).
2606         *
2607         * In other words: stat_width limits the maximum width, and
2608         * stat_name_width fixes the maximum width of the filename,
2609         * and is also used to divide available columns if there
2610         * aren't enough.
2611         *
2612         * Binary files are displayed with "Bin XXX -> YYY bytes"
2613         * instead of the change count and graph. This part is treated
2614         * similarly to the graph part, except that it is not
2615         * "scaled". If total width is too small to accommodate the
2616         * guaranteed minimum width of the filename part and the
2617         * separators and this message, this message will "overflow"
2618         * making the line longer than the maximum width.
2619         */
2620
2621        if (options->stat_width == -1)
2622                width = term_columns() - strlen(line_prefix);
2623        else
2624                width = options->stat_width ? options->stat_width : 80;
2625        number_width = decimal_width(max_change) > number_width ?
2626                decimal_width(max_change) : number_width;
2627
2628        if (options->stat_graph_width == -1)
2629                options->stat_graph_width = diff_stat_graph_width;
2630
2631        /*
2632         * Guarantee 3/8*16==6 for the graph part
2633         * and 5/8*16==10 for the filename part
2634         */
2635        if (width < 16 + 6 + number_width)
2636                width = 16 + 6 + number_width;
2637
2638        /*
2639         * First assign sizes that are wanted, ignoring available width.
2640         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
2641         * starting from "XXX" should fit in graph_width.
2642         */
2643        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
2644        if (options->stat_graph_width &&
2645            options->stat_graph_width < graph_width)
2646                graph_width = options->stat_graph_width;
2647
2648        name_width = (options->stat_name_width > 0 &&
2649                      options->stat_name_width < max_len) ?
2650                options->stat_name_width : max_len;
2651
2652        /*
2653         * Adjust adjustable widths not to exceed maximum width
2654         */
2655        if (name_width + number_width + 6 + graph_width > width) {
2656                if (graph_width > width * 3/8 - number_width - 6) {
2657                        graph_width = width * 3/8 - number_width - 6;
2658                        if (graph_width < 6)
2659                                graph_width = 6;
2660                }
2661
2662                if (options->stat_graph_width &&
2663                    graph_width > options->stat_graph_width)
2664                        graph_width = options->stat_graph_width;
2665                if (name_width > width - number_width - 6 - graph_width)
2666                        name_width = width - number_width - 6 - graph_width;
2667                else
2668                        graph_width = width - number_width - 6 - name_width;
2669        }
2670
2671        /*
2672         * From here name_width is the width of the name area,
2673         * and graph_width is the width of the graph area.
2674         * max_change is used to scale graph properly.
2675         */
2676        for (i = 0; i < count; i++) {
2677                const char *prefix = "";
2678                struct diffstat_file *file = data->files[i];
2679                char *name = file->print_name;
2680                uintmax_t added = file->added;
2681                uintmax_t deleted = file->deleted;
2682                int name_len;
2683
2684                if (!file->is_interesting && (added + deleted == 0))
2685                        continue;
2686
2687                /*
2688                 * "scale" the filename
2689                 */
2690                len = name_width;
2691                name_len = strlen(name);
2692                if (name_width < name_len) {
2693                        char *slash;
2694                        prefix = "...";
2695                        len -= 3;
2696                        name += name_len - len;
2697                        slash = strchr(name, '/');
2698                        if (slash)
2699                                name = slash;
2700                }
2701
2702                if (file->is_binary) {
2703                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2704                        strbuf_addf(&out, " %*s", number_width, "Bin");
2705                        if (!added && !deleted) {
2706                                strbuf_addch(&out, '\n');
2707                                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2708                                                 out.buf, out.len, 0);
2709                                strbuf_reset(&out);
2710                                continue;
2711                        }
2712                        strbuf_addf(&out, " %s%"PRIuMAX"%s",
2713                                del_c, deleted, reset);
2714                        strbuf_addstr(&out, " -> ");
2715                        strbuf_addf(&out, "%s%"PRIuMAX"%s",
2716                                add_c, added, reset);
2717                        strbuf_addstr(&out, " bytes\n");
2718                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2719                                         out.buf, out.len, 0);
2720                        strbuf_reset(&out);
2721                        continue;
2722                }
2723                else if (file->is_unmerged) {
2724                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2725                        strbuf_addstr(&out, " Unmerged\n");
2726                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2727                                         out.buf, out.len, 0);
2728                        strbuf_reset(&out);
2729                        continue;
2730                }
2731
2732                /*
2733                 * scale the add/delete
2734                 */
2735                add = added;
2736                del = deleted;
2737
2738                if (graph_width <= max_change) {
2739                        int total = scale_linear(add + del, graph_width, max_change);
2740                        if (total < 2 && add && del)
2741                                /* width >= 2 due to the sanity check */
2742                                total = 2;
2743                        if (add < del) {
2744                                add = scale_linear(add, graph_width, max_change);
2745                                del = total - add;
2746                        } else {
2747                                del = scale_linear(del, graph_width, max_change);
2748                                add = total - del;
2749                        }
2750                }
2751                strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2752                strbuf_addf(&out, " %*"PRIuMAX"%s",
2753                        number_width, added + deleted,
2754                        added + deleted ? " " : "");
2755                show_graph(&out, '+', add, add_c, reset);
2756                show_graph(&out, '-', del, del_c, reset);
2757                strbuf_addch(&out, '\n');
2758                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2759                                 out.buf, out.len, 0);
2760                strbuf_reset(&out);
2761        }
2762
2763        for (i = 0; i < data->nr; i++) {
2764                struct diffstat_file *file = data->files[i];
2765                uintmax_t added = file->added;
2766                uintmax_t deleted = file->deleted;
2767
2768                if (file->is_unmerged ||
2769                    (!file->is_interesting && (added + deleted == 0))) {
2770                        total_files--;
2771                        continue;
2772                }
2773
2774                if (!file->is_binary) {
2775                        adds += added;
2776                        dels += deleted;
2777                }
2778                if (i < count)
2779                        continue;
2780                if (!extra_shown)
2781                        emit_diff_symbol(options,
2782                                         DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
2783                                         NULL, 0, 0);
2784                extra_shown = 1;
2785        }
2786
2787        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2788        strbuf_release(&out);
2789}
2790
2791static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
2792{
2793        int i, adds = 0, dels = 0, total_files = data->nr;
2794
2795        if (data->nr == 0)
2796                return;
2797
2798        for (i = 0; i < data->nr; i++) {
2799                int added = data->files[i]->added;
2800                int deleted = data->files[i]->deleted;
2801
2802                if (data->files[i]->is_unmerged ||
2803                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
2804                        total_files--;
2805                } else if (!data->files[i]->is_binary) { /* don't count bytes */
2806                        adds += added;
2807                        dels += deleted;
2808                }
2809        }
2810        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2811}
2812
2813static void show_numstat(struct diffstat_t *data, struct diff_options *options)
2814{
2815        int i;
2816
2817        if (data->nr == 0)
2818                return;
2819
2820        for (i = 0; i < data->nr; i++) {
2821                struct diffstat_file *file = data->files[i];
2822
2823                fprintf(options->file, "%s", diff_line_prefix(options));
2824
2825                if (file->is_binary)
2826                        fprintf(options->file, "-\t-\t");
2827                else
2828                        fprintf(options->file,
2829                                "%"PRIuMAX"\t%"PRIuMAX"\t",
2830                                file->added, file->deleted);
2831                if (options->line_termination) {
2832                        fill_print_name(file);
2833                        if (!file->is_renamed)
2834                                write_name_quoted(file->name, options->file,
2835                                                  options->line_termination);
2836                        else {
2837                                fputs(file->print_name, options->file);
2838                                putc(options->line_termination, options->file);
2839                        }
2840                } else {
2841                        if (file->is_renamed) {
2842                                putc('\0', options->file);
2843                                write_name_quoted(file->from_name, options->file, '\0');
2844                        }
2845                        write_name_quoted(file->name, options->file, '\0');
2846                }
2847        }
2848}
2849
2850struct dirstat_file {
2851        const char *name;
2852        unsigned long changed;
2853};
2854
2855struct dirstat_dir {
2856        struct dirstat_file *files;
2857        int alloc, nr, permille, cumulative;
2858};
2859
2860static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
2861                unsigned long changed, const char *base, int baselen)
2862{
2863        unsigned long sum_changes = 0;
2864        unsigned int sources = 0;
2865        const char *line_prefix = diff_line_prefix(opt);
2866
2867        while (dir->nr) {
2868                struct dirstat_file *f = dir->files;
2869                int namelen = strlen(f->name);
2870                unsigned long changes;
2871                char *slash;
2872
2873                if (namelen < baselen)
2874                        break;
2875                if (memcmp(f->name, base, baselen))
2876                        break;
2877                slash = strchr(f->name + baselen, '/');
2878                if (slash) {
2879                        int newbaselen = slash + 1 - f->name;
2880                        changes = gather_dirstat(opt, dir, changed, f->name, newbaselen);
2881                        sources++;
2882                } else {
2883                        changes = f->changed;
2884                        dir->files++;
2885                        dir->nr--;
2886                        sources += 2;
2887                }
2888                sum_changes += changes;
2889        }
2890
2891        /*
2892         * We don't report dirstat's for
2893         *  - the top level
2894         *  - or cases where everything came from a single directory
2895         *    under this directory (sources == 1).
2896         */
2897        if (baselen && sources != 1) {
2898                if (sum_changes) {
2899                        int permille = sum_changes * 1000 / changed;
2900                        if (permille >= dir->permille) {
2901                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
2902                                        permille / 10, permille % 10, baselen, base);
2903                                if (!dir->cumulative)
2904                                        return 0;
2905                        }
2906                }
2907        }
2908        return sum_changes;
2909}
2910
2911static int dirstat_compare(const void *_a, const void *_b)
2912{
2913        const struct dirstat_file *a = _a;
2914        const struct dirstat_file *b = _b;
2915        return strcmp(a->name, b->name);
2916}
2917
2918static void show_dirstat(struct diff_options *options)
2919{
2920        int i;
2921        unsigned long changed;
2922        struct dirstat_dir dir;
2923        struct diff_queue_struct *q = &diff_queued_diff;
2924
2925        dir.files = NULL;
2926        dir.alloc = 0;
2927        dir.nr = 0;
2928        dir.permille = options->dirstat_permille;
2929        dir.cumulative = options->flags.dirstat_cumulative;
2930
2931        changed = 0;
2932        for (i = 0; i < q->nr; i++) {
2933                struct diff_filepair *p = q->queue[i];
2934                const char *name;
2935                unsigned long copied, added, damage;
2936                int content_changed;
2937
2938                name = p->two->path ? p->two->path : p->one->path;
2939
2940                if (p->one->oid_valid && p->two->oid_valid)
2941                        content_changed = oidcmp(&p->one->oid, &p->two->oid);
2942                else
2943                        content_changed = 1;
2944
2945                if (!content_changed) {
2946                        /*
2947                         * The SHA1 has not changed, so pre-/post-content is
2948                         * identical. We can therefore skip looking at the
2949                         * file contents altogether.
2950                         */
2951                        damage = 0;
2952                        goto found_damage;
2953                }
2954
2955                if (options->flags.dirstat_by_file) {
2956                        /*
2957                         * In --dirstat-by-file mode, we don't really need to
2958                         * look at the actual file contents at all.
2959                         * The fact that the SHA1 changed is enough for us to
2960                         * add this file to the list of results
2961                         * (with each file contributing equal damage).
2962                         */
2963                        damage = 1;
2964                        goto found_damage;
2965                }
2966
2967                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
2968                        diff_populate_filespec(p->one, 0);
2969                        diff_populate_filespec(p->two, 0);
2970                        diffcore_count_changes(p->one, p->two, NULL, NULL,
2971                                               &copied, &added);
2972                        diff_free_filespec_data(p->one);
2973                        diff_free_filespec_data(p->two);
2974                } else if (DIFF_FILE_VALID(p->one)) {
2975                        diff_populate_filespec(p->one, CHECK_SIZE_ONLY);
2976                        copied = added = 0;
2977                        diff_free_filespec_data(p->one);
2978                } else if (DIFF_FILE_VALID(p->two)) {
2979                        diff_populate_filespec(p->two, CHECK_SIZE_ONLY);
2980                        copied = 0;
2981                        added = p->two->size;
2982                        diff_free_filespec_data(p->two);
2983                } else
2984                        continue;
2985
2986                /*
2987                 * Original minus copied is the removed material,
2988                 * added is the new material.  They are both damages
2989                 * made to the preimage.
2990                 * If the resulting damage is zero, we know that
2991                 * diffcore_count_changes() considers the two entries to
2992                 * be identical, but since content_changed is true, we
2993                 * know that there must have been _some_ kind of change,
2994                 * so we force all entries to have damage > 0.
2995                 */
2996                damage = (p->one->size - copied) + added;
2997                if (!damage)
2998                        damage = 1;
2999
3000found_damage:
3001                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
3002                dir.files[dir.nr].name = name;
3003                dir.files[dir.nr].changed = damage;
3004                changed += damage;
3005                dir.nr++;
3006        }
3007
3008        /* This can happen even with many files, if everything was renames */
3009        if (!changed)
3010                return;
3011
3012        /* Show all directories with more than x% of the changes */
3013        QSORT(dir.files, dir.nr, dirstat_compare);
3014        gather_dirstat(options, &dir, changed, "", 0);
3015}
3016
3017static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
3018{
3019        int i;
3020        unsigned long changed;
3021        struct dirstat_dir dir;
3022
3023        if (data->nr == 0)
3024                return;
3025
3026        dir.files = NULL;
3027        dir.alloc = 0;
3028        dir.nr = 0;
3029        dir.permille = options->dirstat_permille;
3030        dir.cumulative = options->flags.dirstat_cumulative;
3031
3032        changed = 0;
3033        for (i = 0; i < data->nr; i++) {
3034                struct diffstat_file *file = data->files[i];
3035                unsigned long damage = file->added + file->deleted;
3036                if (file->is_binary)
3037                        /*
3038                         * binary files counts bytes, not lines. Must find some
3039                         * way to normalize binary bytes vs. textual lines.
3040                         * The following heuristic assumes that there are 64
3041                         * bytes per "line".
3042                         * This is stupid and ugly, but very cheap...
3043                         */
3044                        damage = DIV_ROUND_UP(damage, 64);
3045                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
3046                dir.files[dir.nr].name = file->name;
3047                dir.files[dir.nr].changed = damage;
3048                changed += damage;
3049                dir.nr++;
3050        }
3051
3052        /* This can happen even with many files, if everything was renames */
3053        if (!changed)
3054                return;
3055
3056        /* Show all directories with more than x% of the changes */
3057        QSORT(dir.files, dir.nr, dirstat_compare);
3058        gather_dirstat(options, &dir, changed, "", 0);
3059}
3060
3061static void free_diffstat_info(struct diffstat_t *diffstat)
3062{
3063        int i;
3064        for (i = 0; i < diffstat->nr; i++) {
3065                struct diffstat_file *f = diffstat->files[i];
3066                free(f->print_name);
3067                free(f->name);
3068                free(f->from_name);
3069                free(f);
3070        }
3071        free(diffstat->files);
3072}
3073
3074struct checkdiff_t {
3075        const char *filename;
3076        int lineno;
3077        int conflict_marker_size;
3078        struct diff_options *o;
3079        unsigned ws_rule;
3080        unsigned status;
3081};
3082
3083static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
3084{
3085        char firstchar;
3086        int cnt;
3087
3088        if (len < marker_size + 1)
3089                return 0;
3090        firstchar = line[0];
3091        switch (firstchar) {
3092        case '=': case '>': case '<': case '|':
3093                break;
3094        default:
3095                return 0;
3096        }
3097        for (cnt = 1; cnt < marker_size; cnt++)
3098                if (line[cnt] != firstchar)
3099                        return 0;
3100        /* line[1] thru line[marker_size-1] are same as firstchar */
3101        if (len < marker_size + 1 || !isspace(line[marker_size]))
3102                return 0;
3103        return 1;
3104}
3105
3106static void checkdiff_consume(void *priv, char *line, unsigned long len)
3107{
3108        struct checkdiff_t *data = priv;
3109        int marker_size = data->conflict_marker_size;
3110        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
3111        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
3112        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
3113        char *err;
3114        const char *line_prefix;
3115
3116        assert(data->o);
3117        line_prefix = diff_line_prefix(data->o);
3118
3119        if (line[0] == '+') {
3120                unsigned bad;
3121                data->lineno++;
3122                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
3123                        data->status |= 1;
3124                        fprintf(data->o->file,
3125                                "%s%s:%d: leftover conflict marker\n",
3126                                line_prefix, data->filename, data->lineno);
3127                }
3128                bad = ws_check(line + 1, len - 1, data->ws_rule);
3129                if (!bad)
3130                        return;
3131                data->status |= bad;
3132                err = whitespace_error_string(bad);
3133                fprintf(data->o->file, "%s%s:%d: %s.\n",
3134                        line_prefix, data->filename, data->lineno, err);
3135                free(err);
3136                emit_line(data->o, set, reset, line, 1);
3137                ws_check_emit(line + 1, len - 1, data->ws_rule,
3138                              data->o->file, set, reset, ws);
3139        } else if (line[0] == ' ') {
3140                data->lineno++;
3141        } else if (line[0] == '@') {
3142                char *plus = strchr(line, '+');
3143                if (plus)
3144                        data->lineno = strtol(plus, NULL, 10) - 1;
3145                else
3146                        die("invalid diff");
3147        }
3148}
3149
3150static unsigned char *deflate_it(char *data,
3151                                 unsigned long size,
3152                                 unsigned long *result_size)
3153{
3154        int bound;
3155        unsigned char *deflated;
3156        git_zstream stream;
3157
3158        git_deflate_init(&stream, zlib_compression_level);
3159        bound = git_deflate_bound(&stream, size);
3160        deflated = xmalloc(bound);
3161        stream.next_out = deflated;
3162        stream.avail_out = bound;
3163
3164        stream.next_in = (unsigned char *)data;
3165        stream.avail_in = size;
3166        while (git_deflate(&stream, Z_FINISH) == Z_OK)
3167                ; /* nothing */
3168        git_deflate_end(&stream);
3169        *result_size = stream.total_out;
3170        return deflated;
3171}
3172
3173static void emit_binary_diff_body(struct diff_options *o,
3174                                  mmfile_t *one, mmfile_t *two)
3175{
3176        void *cp;
3177        void *delta;
3178        void *deflated;
3179        void *data;
3180        unsigned long orig_size;
3181        unsigned long delta_size;
3182        unsigned long deflate_size;
3183        unsigned long data_size;
3184
3185        /* We could do deflated delta, or we could do just deflated two,
3186         * whichever is smaller.
3187         */
3188        delta = NULL;
3189        deflated = deflate_it(two->ptr, two->size, &deflate_size);
3190        if (one->size && two->size) {
3191                delta = diff_delta(one->ptr, one->size,
3192                                   two->ptr, two->size,
3193                                   &delta_size, deflate_size);
3194                if (delta) {
3195                        void *to_free = delta;
3196                        orig_size = delta_size;
3197                        delta = deflate_it(delta, delta_size, &delta_size);
3198                        free(to_free);
3199                }
3200        }
3201
3202        if (delta && delta_size < deflate_size) {
3203                char *s = xstrfmt("%lu", orig_size);
3204                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
3205                                 s, strlen(s), 0);
3206                free(s);
3207                free(deflated);
3208                data = delta;
3209                data_size = delta_size;
3210        } else {
3211                char *s = xstrfmt("%lu", two->size);
3212                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
3213                                 s, strlen(s), 0);
3214                free(s);
3215                free(delta);
3216                data = deflated;
3217                data_size = deflate_size;
3218        }
3219
3220        /* emit data encoded in base85 */
3221        cp = data;
3222        while (data_size) {
3223                int len;
3224                int bytes = (52 < data_size) ? 52 : data_size;
3225                char line[71];
3226                data_size -= bytes;
3227                if (bytes <= 26)
3228                        line[0] = bytes + 'A' - 1;
3229                else
3230                        line[0] = bytes - 26 + 'a' - 1;
3231                encode_85(line + 1, cp, bytes);
3232                cp = (char *) cp + bytes;
3233
3234                len = strlen(line);
3235                line[len++] = '\n';
3236                line[len] = '\0';
3237
3238                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_BODY,
3239                                 line, len, 0);
3240        }
3241        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_FOOTER, NULL, 0, 0);
3242        free(data);
3243}
3244
3245static void emit_binary_diff(struct diff_options *o,
3246                             mmfile_t *one, mmfile_t *two)
3247{
3248        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER, NULL, 0, 0);
3249        emit_binary_diff_body(o, one, two);
3250        emit_binary_diff_body(o, two, one);
3251}
3252
3253int diff_filespec_is_binary(struct diff_filespec *one)
3254{
3255        if (one->is_binary == -1) {
3256                diff_filespec_load_driver(one);
3257                if (one->driver->binary != -1)
3258                        one->is_binary = one->driver->binary;
3259                else {
3260                        if (!one->data && DIFF_FILE_VALID(one))
3261                                diff_populate_filespec(one, CHECK_BINARY);
3262                        if (one->is_binary == -1 && one->data)
3263                                one->is_binary = buffer_is_binary(one->data,
3264                                                one->size);
3265                        if (one->is_binary == -1)
3266                                one->is_binary = 0;
3267                }
3268        }
3269        return one->is_binary;
3270}
3271
3272static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
3273{
3274        diff_filespec_load_driver(one);
3275        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
3276}
3277
3278void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
3279{
3280        if (!options->a_prefix)
3281                options->a_prefix = a;
3282        if (!options->b_prefix)
3283                options->b_prefix = b;
3284}
3285
3286struct userdiff_driver *get_textconv(struct diff_filespec *one)
3287{
3288        if (!DIFF_FILE_VALID(one))
3289                return NULL;
3290
3291        diff_filespec_load_driver(one);
3292        return userdiff_get_textconv(one->driver);
3293}
3294
3295static void builtin_diff(const char *name_a,
3296                         const char *name_b,
3297                         struct diff_filespec *one,
3298                         struct diff_filespec *two,
3299                         const char *xfrm_msg,
3300                         int must_show_header,
3301                         struct diff_options *o,
3302                         int complete_rewrite)
3303{
3304        mmfile_t mf1, mf2;
3305        const char *lbl[2];
3306        char *a_one, *b_two;
3307        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
3308        const char *reset = diff_get_color_opt(o, DIFF_RESET);
3309        const char *a_prefix, *b_prefix;
3310        struct userdiff_driver *textconv_one = NULL;
3311        struct userdiff_driver *textconv_two = NULL;
3312        struct strbuf header = STRBUF_INIT;
3313        const char *line_prefix = diff_line_prefix(o);
3314
3315        diff_set_mnemonic_prefix(o, "a/", "b/");
3316        if (o->flags.reverse_diff) {
3317                a_prefix = o->b_prefix;
3318                b_prefix = o->a_prefix;
3319        } else {
3320                a_prefix = o->a_prefix;
3321                b_prefix = o->b_prefix;
3322        }
3323
3324        if (o->submodule_format == DIFF_SUBMODULE_LOG &&
3325            (!one->mode || S_ISGITLINK(one->mode)) &&
3326            (!two->mode || S_ISGITLINK(two->mode))) {
3327                show_submodule_summary(o, one->path ? one->path : two->path,
3328                                &one->oid, &two->oid,
3329                                two->dirty_submodule);
3330                return;
3331        } else if (o->submodule_format == DIFF_SUBMODULE_INLINE_DIFF &&
3332                   (!one->mode || S_ISGITLINK(one->mode)) &&
3333                   (!two->mode || S_ISGITLINK(two->mode))) {
3334                show_submodule_inline_diff(o, one->path ? one->path : two->path,
3335                                &one->oid, &two->oid,
3336                                two->dirty_submodule);
3337                return;
3338        }
3339
3340        if (o->flags.allow_textconv) {
3341                textconv_one = get_textconv(one);
3342                textconv_two = get_textconv(two);
3343        }
3344
3345        /* Never use a non-valid filename anywhere if at all possible */
3346        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
3347        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
3348
3349        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
3350        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
3351        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
3352        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
3353        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
3354        if (lbl[0][0] == '/') {
3355                /* /dev/null */
3356                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
3357                if (xfrm_msg)
3358                        strbuf_addstr(&header, xfrm_msg);
3359                must_show_header = 1;
3360        }
3361        else if (lbl[1][0] == '/') {
3362                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
3363                if (xfrm_msg)
3364                        strbuf_addstr(&header, xfrm_msg);
3365                must_show_header = 1;
3366        }
3367        else {
3368                if (one->mode != two->mode) {
3369                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
3370                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
3371                        must_show_header = 1;
3372                }
3373                if (xfrm_msg)
3374                        strbuf_addstr(&header, xfrm_msg);
3375
3376                /*
3377                 * we do not run diff between different kind
3378                 * of objects.
3379                 */
3380                if ((one->mode ^ two->mode) & S_IFMT)
3381                        goto free_ab_and_return;
3382                if (complete_rewrite &&
3383                    (textconv_one || !diff_filespec_is_binary(one)) &&
3384                    (textconv_two || !diff_filespec_is_binary(two))) {
3385                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3386                                         header.buf, header.len, 0);
3387                        strbuf_reset(&header);
3388                        emit_rewrite_diff(name_a, name_b, one, two,
3389                                                textconv_one, textconv_two, o);
3390                        o->found_changes = 1;
3391                        goto free_ab_and_return;
3392                }
3393        }
3394
3395        if (o->irreversible_delete && lbl[1][0] == '/') {
3396                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf,
3397                                 header.len, 0);
3398                strbuf_reset(&header);
3399                goto free_ab_and_return;
3400        } else if (!o->flags.text &&
3401            ( (!textconv_one && diff_filespec_is_binary(one)) ||
3402              (!textconv_two && diff_filespec_is_binary(two)) )) {
3403                struct strbuf sb = STRBUF_INIT;
3404                if (!one->data && !two->data &&
3405                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
3406                    !o->flags.binary) {
3407                        if (!oidcmp(&one->oid, &two->oid)) {
3408                                if (must_show_header)
3409                                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3410                                                         header.buf, header.len,
3411                                                         0);
3412                                goto free_ab_and_return;
3413                        }
3414                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3415                                         header.buf, header.len, 0);
3416                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3417                                    diff_line_prefix(o), lbl[0], lbl[1]);
3418                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3419                                         sb.buf, sb.len, 0);
3420                        strbuf_release(&sb);
3421                        goto free_ab_and_return;
3422                }
3423                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3424                        die("unable to read files to diff");
3425                /* Quite common confusing case */
3426                if (mf1.size == mf2.size &&
3427                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
3428                        if (must_show_header)
3429                                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3430                                                 header.buf, header.len, 0);
3431                        goto free_ab_and_return;
3432                }
3433                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf, header.len, 0);
3434                strbuf_reset(&header);
3435                if (o->flags.binary)
3436                        emit_binary_diff(o, &mf1, &mf2);
3437                else {
3438                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3439                                    diff_line_prefix(o), lbl[0], lbl[1]);
3440                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3441                                         sb.buf, sb.len, 0);
3442                        strbuf_release(&sb);
3443                }
3444                o->found_changes = 1;
3445        } else {
3446                /* Crazy xdl interfaces.. */
3447                const char *diffopts = getenv("GIT_DIFF_OPTS");
3448                const char *v;
3449                xpparam_t xpp;
3450                xdemitconf_t xecfg;
3451                struct emit_callback ecbdata;
3452                const struct userdiff_funcname *pe;
3453
3454                if (must_show_header) {
3455                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3456                                         header.buf, header.len, 0);
3457                        strbuf_reset(&header);
3458                }
3459
3460                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
3461                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
3462
3463                pe = diff_funcname_pattern(one);
3464                if (!pe)
3465                        pe = diff_funcname_pattern(two);
3466
3467                memset(&xpp, 0, sizeof(xpp));
3468                memset(&xecfg, 0, sizeof(xecfg));
3469                memset(&ecbdata, 0, sizeof(ecbdata));
3470                if (o->flags.suppress_diff_headers)
3471                        lbl[0] = NULL;
3472                ecbdata.label_path = lbl;
3473                ecbdata.color_diff = want_color(o->use_color);
3474                ecbdata.ws_rule = whitespace_rule(name_b);
3475                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
3476                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3477                ecbdata.opt = o;
3478                if (header.len && !o->flags.suppress_diff_headers)
3479                        ecbdata.header = &header;
3480                xpp.flags = o->xdl_opts;
3481                xpp.anchors = o->anchors;
3482                xpp.anchors_nr = o->anchors_nr;
3483                xecfg.ctxlen = o->context;
3484                xecfg.interhunkctxlen = o->interhunkcontext;
3485                xecfg.flags = XDL_EMIT_FUNCNAMES;
3486                if (o->flags.funccontext)
3487                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
3488                if (pe)
3489                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
3490                if (!diffopts)
3491                        ;
3492                else if (skip_prefix(diffopts, "--unified=", &v))
3493                        xecfg.ctxlen = strtoul(v, NULL, 10);
3494                else if (skip_prefix(diffopts, "-u", &v))
3495                        xecfg.ctxlen = strtoul(v, NULL, 10);
3496                if (o->word_diff)
3497                        init_diff_words_data(&ecbdata, o, one, two);
3498                if (xdi_diff_outf(&mf1, &mf2, NULL, fn_out_consume,
3499                                  &ecbdata, &xpp, &xecfg))
3500                        die("unable to generate diff for %s", one->path);
3501                if (o->word_diff)
3502                        free_diff_words_data(&ecbdata);
3503                if (textconv_one)
3504                        free(mf1.ptr);
3505                if (textconv_two)
3506                        free(mf2.ptr);
3507                xdiff_clear_find_func(&xecfg);
3508        }
3509
3510 free_ab_and_return:
3511        strbuf_release(&header);
3512        diff_free_filespec_data(one);
3513        diff_free_filespec_data(two);
3514        free(a_one);
3515        free(b_two);
3516        return;
3517}
3518
3519static char *get_compact_summary(const struct diff_filepair *p, int is_renamed)
3520{
3521        if (!is_renamed) {
3522                if (p->status == DIFF_STATUS_ADDED) {
3523                        if (S_ISLNK(p->two->mode))
3524                                return "new +l";
3525                        else if ((p->two->mode & 0777) == 0755)
3526                                return "new +x";
3527                        else
3528                                return "new";
3529                } else if (p->status == DIFF_STATUS_DELETED)
3530                        return "gone";
3531        }
3532        if (S_ISLNK(p->one->mode) && !S_ISLNK(p->two->mode))
3533                return "mode -l";
3534        else if (!S_ISLNK(p->one->mode) && S_ISLNK(p->two->mode))
3535                return "mode +l";
3536        else if ((p->one->mode & 0777) == 0644 &&
3537                 (p->two->mode & 0777) == 0755)
3538                return "mode +x";
3539        else if ((p->one->mode & 0777) == 0755 &&
3540                 (p->two->mode & 0777) == 0644)
3541                return "mode -x";
3542        return NULL;
3543}
3544
3545static void builtin_diffstat(const char *name_a, const char *name_b,
3546                             struct diff_filespec *one,
3547                             struct diff_filespec *two,
3548                             struct diffstat_t *diffstat,
3549                             struct diff_options *o,
3550                             struct diff_filepair *p)
3551{
3552        mmfile_t mf1, mf2;
3553        struct diffstat_file *data;
3554        int same_contents;
3555        int complete_rewrite = 0;
3556
3557        if (!DIFF_PAIR_UNMERGED(p)) {
3558                if (p->status == DIFF_STATUS_MODIFIED && p->score)
3559                        complete_rewrite = 1;
3560        }
3561
3562        data = diffstat_add(diffstat, name_a, name_b);
3563        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
3564        if (o->flags.stat_with_summary)
3565                data->comments = get_compact_summary(p, data->is_renamed);
3566
3567        if (!one || !two) {
3568                data->is_unmerged = 1;
3569                return;
3570        }
3571
3572        same_contents = !oidcmp(&one->oid, &two->oid);
3573
3574        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
3575                data->is_binary = 1;
3576                if (same_contents) {
3577                        data->added = 0;
3578                        data->deleted = 0;
3579                } else {
3580                        data->added = diff_filespec_size(two);
3581                        data->deleted = diff_filespec_size(one);
3582                }
3583        }
3584
3585        else if (complete_rewrite) {
3586                diff_populate_filespec(one, 0);
3587                diff_populate_filespec(two, 0);
3588                data->deleted = count_lines(one->data, one->size);
3589                data->added = count_lines(two->data, two->size);
3590        }
3591
3592        else if (!same_contents) {
3593                /* Crazy xdl interfaces.. */
3594                xpparam_t xpp;
3595                xdemitconf_t xecfg;
3596
3597                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3598                        die("unable to read files to diff");
3599
3600                memset(&xpp, 0, sizeof(xpp));
3601                memset(&xecfg, 0, sizeof(xecfg));
3602                xpp.flags = o->xdl_opts;
3603                xpp.anchors = o->anchors;
3604                xpp.anchors_nr = o->anchors_nr;
3605                xecfg.ctxlen = o->context;
3606                xecfg.interhunkctxlen = o->interhunkcontext;
3607                if (xdi_diff_outf(&mf1, &mf2, NULL, diffstat_consume,
3608                                  diffstat, &xpp, &xecfg))
3609                        die("unable to generate diffstat for %s", one->path);
3610        }
3611
3612        diff_free_filespec_data(one);
3613        diff_free_filespec_data(two);
3614}
3615
3616static void builtin_checkdiff(const char *name_a, const char *name_b,
3617                              const char *attr_path,
3618                              struct diff_filespec *one,
3619                              struct diff_filespec *two,
3620                              struct diff_options *o)
3621{
3622        mmfile_t mf1, mf2;
3623        struct checkdiff_t data;
3624
3625        if (!two)
3626                return;
3627
3628        memset(&data, 0, sizeof(data));
3629        data.filename = name_b ? name_b : name_a;
3630        data.lineno = 0;
3631        data.o = o;
3632        data.ws_rule = whitespace_rule(attr_path);
3633        data.conflict_marker_size = ll_merge_marker_size(attr_path);
3634
3635        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3636                die("unable to read files to diff");
3637
3638        /*
3639         * All the other codepaths check both sides, but not checking
3640         * the "old" side here is deliberate.  We are checking the newly
3641         * introduced changes, and as long as the "new" side is text, we
3642         * can and should check what it introduces.
3643         */
3644        if (diff_filespec_is_binary(two))
3645                goto free_and_return;
3646        else {
3647                /* Crazy xdl interfaces.. */
3648                xpparam_t xpp;
3649                xdemitconf_t xecfg;
3650
3651                memset(&xpp, 0, sizeof(xpp));
3652                memset(&xecfg, 0, sizeof(xecfg));
3653                xecfg.ctxlen = 1; /* at least one context line */
3654                xpp.flags = 0;
3655                if (xdi_diff_outf(&mf1, &mf2, NULL, checkdiff_consume,
3656                                  &data, &xpp, &xecfg))
3657                        die("unable to generate checkdiff for %s", one->path);
3658
3659                if (data.ws_rule & WS_BLANK_AT_EOF) {
3660                        struct emit_callback ecbdata;
3661                        int blank_at_eof;
3662
3663                        ecbdata.ws_rule = data.ws_rule;
3664                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3665                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
3666
3667                        if (blank_at_eof) {
3668                                static char *err;
3669                                if (!err)
3670                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
3671                                fprintf(o->file, "%s:%d: %s.\n",
3672                                        data.filename, blank_at_eof, err);
3673                                data.status = 1; /* report errors */
3674                        }
3675                }
3676        }
3677 free_and_return:
3678        diff_free_filespec_data(one);
3679        diff_free_filespec_data(two);
3680        if (data.status)
3681                o->flags.check_failed = 1;
3682}
3683
3684struct diff_filespec *alloc_filespec(const char *path)
3685{
3686        struct diff_filespec *spec;
3687
3688        FLEXPTR_ALLOC_STR(spec, path, path);
3689        spec->count = 1;
3690        spec->is_binary = -1;
3691        return spec;
3692}
3693
3694void free_filespec(struct diff_filespec *spec)
3695{
3696        if (!--spec->count) {
3697                diff_free_filespec_data(spec);
3698                free(spec);
3699        }
3700}
3701
3702void fill_filespec(struct diff_filespec *spec, const struct object_id *oid,
3703                   int oid_valid, unsigned short mode)
3704{
3705        if (mode) {
3706                spec->mode = canon_mode(mode);
3707                oidcpy(&spec->oid, oid);
3708                spec->oid_valid = oid_valid;
3709        }
3710}
3711
3712/*
3713 * Given a name and sha1 pair, if the index tells us the file in
3714 * the work tree has that object contents, return true, so that
3715 * prepare_temp_file() does not have to inflate and extract.
3716 */
3717static int reuse_worktree_file(const char *name, const struct object_id *oid, int want_file)
3718{
3719        const struct cache_entry *ce;
3720        struct stat st;
3721        int pos, len;
3722
3723        /*
3724         * We do not read the cache ourselves here, because the
3725         * benchmark with my previous version that always reads cache
3726         * shows that it makes things worse for diff-tree comparing
3727         * two linux-2.6 kernel trees in an already checked out work
3728         * tree.  This is because most diff-tree comparisons deal with
3729         * only a small number of files, while reading the cache is
3730         * expensive for a large project, and its cost outweighs the
3731         * savings we get by not inflating the object to a temporary
3732         * file.  Practically, this code only helps when we are used
3733         * by diff-cache --cached, which does read the cache before
3734         * calling us.
3735         */
3736        if (!active_cache)
3737                return 0;
3738
3739        /* We want to avoid the working directory if our caller
3740         * doesn't need the data in a normal file, this system
3741         * is rather slow with its stat/open/mmap/close syscalls,
3742         * and the object is contained in a pack file.  The pack
3743         * is probably already open and will be faster to obtain
3744         * the data through than the working directory.  Loose
3745         * objects however would tend to be slower as they need
3746         * to be individually opened and inflated.
3747         */
3748        if (!FAST_WORKING_DIRECTORY && !want_file && has_object_pack(oid))
3749                return 0;
3750
3751        /*
3752         * Similarly, if we'd have to convert the file contents anyway, that
3753         * makes the optimization not worthwhile.
3754         */
3755        if (!want_file && would_convert_to_git(&the_index, name))
3756                return 0;
3757
3758        len = strlen(name);
3759        pos = cache_name_pos(name, len);
3760        if (pos < 0)
3761                return 0;
3762        ce = active_cache[pos];
3763
3764        /*
3765         * This is not the sha1 we are looking for, or
3766         * unreusable because it is not a regular file.
3767         */
3768        if (oidcmp(oid, &ce->oid) || !S_ISREG(ce->ce_mode))
3769                return 0;
3770
3771        /*
3772         * If ce is marked as "assume unchanged", there is no
3773         * guarantee that work tree matches what we are looking for.
3774         */
3775        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
3776                return 0;
3777
3778        /*
3779         * If ce matches the file in the work tree, we can reuse it.
3780         */
3781        if (ce_uptodate(ce) ||
3782            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
3783                return 1;
3784
3785        return 0;
3786}
3787
3788static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
3789{
3790        struct strbuf buf = STRBUF_INIT;
3791        char *dirty = "";
3792
3793        /* Are we looking at the work tree? */
3794        if (s->dirty_submodule)
3795                dirty = "-dirty";
3796
3797        strbuf_addf(&buf, "Subproject commit %s%s\n",
3798                    oid_to_hex(&s->oid), dirty);
3799        s->size = buf.len;
3800        if (size_only) {
3801                s->data = NULL;
3802                strbuf_release(&buf);
3803        } else {
3804                s->data = strbuf_detach(&buf, NULL);
3805                s->should_free = 1;
3806        }
3807        return 0;
3808}
3809
3810/*
3811 * While doing rename detection and pickaxe operation, we may need to
3812 * grab the data for the blob (or file) for our own in-core comparison.
3813 * diff_filespec has data and size fields for this purpose.
3814 */
3815int diff_populate_filespec(struct diff_filespec *s, unsigned int flags)
3816{
3817        int size_only = flags & CHECK_SIZE_ONLY;
3818        int err = 0;
3819        int conv_flags = global_conv_flags_eol;
3820        /*
3821         * demote FAIL to WARN to allow inspecting the situation
3822         * instead of refusing.
3823         */
3824        if (conv_flags & CONV_EOL_RNDTRP_DIE)
3825                conv_flags = CONV_EOL_RNDTRP_WARN;
3826
3827        if (!DIFF_FILE_VALID(s))
3828                die("internal error: asking to populate invalid file.");
3829        if (S_ISDIR(s->mode))
3830                return -1;
3831
3832        if (s->data)
3833                return 0;
3834
3835        if (size_only && 0 < s->size)
3836                return 0;
3837
3838        if (S_ISGITLINK(s->mode))
3839                return diff_populate_gitlink(s, size_only);
3840
3841        if (!s->oid_valid ||
3842            reuse_worktree_file(s->path, &s->oid, 0)) {
3843                struct strbuf buf = STRBUF_INIT;
3844                struct stat st;
3845                int fd;
3846
3847                if (lstat(s->path, &st) < 0) {
3848                err_empty:
3849                        err = -1;
3850                empty:
3851                        s->data = (char *)"";
3852                        s->size = 0;
3853                        return err;
3854                }
3855                s->size = xsize_t(st.st_size);
3856                if (!s->size)
3857                        goto empty;
3858                if (S_ISLNK(st.st_mode)) {
3859                        struct strbuf sb = STRBUF_INIT;
3860
3861                        if (strbuf_readlink(&sb, s->path, s->size))
3862                                goto err_empty;
3863                        s->size = sb.len;
3864                        s->data = strbuf_detach(&sb, NULL);
3865                        s->should_free = 1;
3866                        return 0;
3867                }
3868
3869                /*
3870                 * Even if the caller would be happy with getting
3871                 * only the size, we cannot return early at this
3872                 * point if the path requires us to run the content
3873                 * conversion.
3874                 */
3875                if (size_only && !would_convert_to_git(&the_index, s->path))
3876                        return 0;
3877
3878                /*
3879                 * Note: this check uses xsize_t(st.st_size) that may
3880                 * not be the true size of the blob after it goes
3881                 * through convert_to_git().  This may not strictly be
3882                 * correct, but the whole point of big_file_threshold
3883                 * and is_binary check being that we want to avoid
3884                 * opening the file and inspecting the contents, this
3885                 * is probably fine.
3886                 */
3887                if ((flags & CHECK_BINARY) &&
3888                    s->size > big_file_threshold && s->is_binary == -1) {
3889                        s->is_binary = 1;
3890                        return 0;
3891                }
3892                fd = open(s->path, O_RDONLY);
3893                if (fd < 0)
3894                        goto err_empty;
3895                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
3896                close(fd);
3897                s->should_munmap = 1;
3898
3899                /*
3900                 * Convert from working tree format to canonical git format
3901                 */
3902                if (convert_to_git(&the_index, s->path, s->data, s->size, &buf, conv_flags)) {
3903                        size_t size = 0;
3904                        munmap(s->data, s->size);
3905                        s->should_munmap = 0;
3906                        s->data = strbuf_detach(&buf, &size);
3907                        s->size = size;
3908                        s->should_free = 1;
3909                }
3910        }
3911        else {
3912                enum object_type type;
3913                if (size_only || (flags & CHECK_BINARY)) {
3914                        type = oid_object_info(the_repository, &s->oid,
3915                                               &s->size);
3916                        if (type < 0)
3917                                die("unable to read %s",
3918                                    oid_to_hex(&s->oid));
3919                        if (size_only)
3920                                return 0;
3921                        if (s->size > big_file_threshold && s->is_binary == -1) {
3922                                s->is_binary = 1;
3923                                return 0;
3924                        }
3925                }
3926                s->data = read_object_file(&s->oid, &type, &s->size);
3927                if (!s->data)
3928                        die("unable to read %s", oid_to_hex(&s->oid));
3929                s->should_free = 1;
3930        }
3931        return 0;
3932}
3933
3934void diff_free_filespec_blob(struct diff_filespec *s)
3935{
3936        if (s->should_free)
3937                free(s->data);
3938        else if (s->should_munmap)
3939                munmap(s->data, s->size);
3940
3941        if (s->should_free || s->should_munmap) {
3942                s->should_free = s->should_munmap = 0;
3943                s->data = NULL;
3944        }
3945}
3946
3947void diff_free_filespec_data(struct diff_filespec *s)
3948{
3949        diff_free_filespec_blob(s);
3950        FREE_AND_NULL(s->cnt_data);
3951}
3952
3953static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
3954                           void *blob,
3955                           unsigned long size,
3956                           const struct object_id *oid,
3957                           int mode)
3958{
3959        struct strbuf buf = STRBUF_INIT;
3960        struct strbuf tempfile = STRBUF_INIT;
3961        char *path_dup = xstrdup(path);
3962        const char *base = basename(path_dup);
3963
3964        /* Generate "XXXXXX_basename.ext" */
3965        strbuf_addstr(&tempfile, "XXXXXX_");
3966        strbuf_addstr(&tempfile, base);
3967
3968        temp->tempfile = mks_tempfile_ts(tempfile.buf, strlen(base) + 1);
3969        if (!temp->tempfile)
3970                die_errno("unable to create temp-file");
3971        if (convert_to_working_tree(&the_index, path,
3972                        (const char *)blob, (size_t)size, &buf)) {
3973                blob = buf.buf;
3974                size = buf.len;
3975        }
3976        if (write_in_full(temp->tempfile->fd, blob, size) < 0 ||
3977            close_tempfile_gently(temp->tempfile))
3978                die_errno("unable to write temp-file");
3979        temp->name = get_tempfile_path(temp->tempfile);
3980        oid_to_hex_r(temp->hex, oid);
3981        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
3982        strbuf_release(&buf);
3983        strbuf_release(&tempfile);
3984        free(path_dup);
3985}
3986
3987static struct diff_tempfile *prepare_temp_file(const char *name,
3988                struct diff_filespec *one)
3989{
3990        struct diff_tempfile *temp = claim_diff_tempfile();
3991
3992        if (!DIFF_FILE_VALID(one)) {
3993        not_a_valid_file:
3994                /* A '-' entry produces this for file-2, and
3995                 * a '+' entry produces this for file-1.
3996                 */
3997                temp->name = "/dev/null";
3998                xsnprintf(temp->hex, sizeof(temp->hex), ".");
3999                xsnprintf(temp->mode, sizeof(temp->mode), ".");
4000                return temp;
4001        }
4002
4003        if (!S_ISGITLINK(one->mode) &&
4004            (!one->oid_valid ||
4005             reuse_worktree_file(name, &one->oid, 1))) {
4006                struct stat st;
4007                if (lstat(name, &st) < 0) {
4008                        if (errno == ENOENT)
4009                                goto not_a_valid_file;
4010                        die_errno("stat(%s)", name);
4011                }
4012                if (S_ISLNK(st.st_mode)) {
4013                        struct strbuf sb = STRBUF_INIT;
4014                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
4015                                die_errno("readlink(%s)", name);
4016                        prep_temp_blob(name, temp, sb.buf, sb.len,
4017                                       (one->oid_valid ?
4018                                        &one->oid : &null_oid),
4019                                       (one->oid_valid ?
4020                                        one->mode : S_IFLNK));
4021                        strbuf_release(&sb);
4022                }
4023                else {
4024                        /* we can borrow from the file in the work tree */
4025                        temp->name = name;
4026                        if (!one->oid_valid)
4027                                oid_to_hex_r(temp->hex, &null_oid);
4028                        else
4029                                oid_to_hex_r(temp->hex, &one->oid);
4030                        /* Even though we may sometimes borrow the
4031                         * contents from the work tree, we always want
4032                         * one->mode.  mode is trustworthy even when
4033                         * !(one->oid_valid), as long as
4034                         * DIFF_FILE_VALID(one).
4035                         */
4036                        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
4037                }
4038                return temp;
4039        }
4040        else {
4041                if (diff_populate_filespec(one, 0))
4042                        die("cannot read data blob for %s", one->path);
4043                prep_temp_blob(name, temp, one->data, one->size,
4044                               &one->oid, one->mode);
4045        }
4046        return temp;
4047}
4048
4049static void add_external_diff_name(struct argv_array *argv,
4050                                   const char *name,
4051                                   struct diff_filespec *df)
4052{
4053        struct diff_tempfile *temp = prepare_temp_file(name, df);
4054        argv_array_push(argv, temp->name);
4055        argv_array_push(argv, temp->hex);
4056        argv_array_push(argv, temp->mode);
4057}
4058
4059/* An external diff command takes:
4060 *
4061 * diff-cmd name infile1 infile1-sha1 infile1-mode \
4062 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
4063 *
4064 */
4065static void run_external_diff(const char *pgm,
4066                              const char *name,
4067                              const char *other,
4068                              struct diff_filespec *one,
4069                              struct diff_filespec *two,
4070                              const char *xfrm_msg,
4071                              int complete_rewrite,
4072                              struct diff_options *o)
4073{
4074        struct argv_array argv = ARGV_ARRAY_INIT;
4075        struct argv_array env = ARGV_ARRAY_INIT;
4076        struct diff_queue_struct *q = &diff_queued_diff;
4077
4078        argv_array_push(&argv, pgm);
4079        argv_array_push(&argv, name);
4080
4081        if (one && two) {
4082                add_external_diff_name(&argv, name, one);
4083                if (!other)
4084                        add_external_diff_name(&argv, name, two);
4085                else {
4086                        add_external_diff_name(&argv, other, two);
4087                        argv_array_push(&argv, other);
4088                        argv_array_push(&argv, xfrm_msg);
4089                }
4090        }
4091
4092        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
4093        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
4094
4095        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
4096                die(_("external diff died, stopping at %s"), name);
4097
4098        remove_tempfile();
4099        argv_array_clear(&argv);
4100        argv_array_clear(&env);
4101}
4102
4103static int similarity_index(struct diff_filepair *p)
4104{
4105        return p->score * 100 / MAX_SCORE;
4106}
4107
4108static const char *diff_abbrev_oid(const struct object_id *oid, int abbrev)
4109{
4110        if (startup_info->have_repository)
4111                return find_unique_abbrev(oid, abbrev);
4112        else {
4113                char *hex = oid_to_hex(oid);
4114                if (abbrev < 0)
4115                        abbrev = FALLBACK_DEFAULT_ABBREV;
4116                if (abbrev > the_hash_algo->hexsz)
4117                        BUG("oid abbreviation out of range: %d", abbrev);
4118                if (abbrev)
4119                        hex[abbrev] = '\0';
4120                return hex;
4121        }
4122}
4123
4124static void fill_metainfo(struct strbuf *msg,
4125                          const char *name,
4126                          const char *other,
4127                          struct diff_filespec *one,
4128                          struct diff_filespec *two,
4129                          struct diff_options *o,
4130                          struct diff_filepair *p,
4131                          int *must_show_header,
4132                          int use_color)
4133{
4134        const char *set = diff_get_color(use_color, DIFF_METAINFO);
4135        const char *reset = diff_get_color(use_color, DIFF_RESET);
4136        const char *line_prefix = diff_line_prefix(o);
4137
4138        *must_show_header = 1;
4139        strbuf_init(msg, PATH_MAX * 2 + 300);
4140        switch (p->status) {
4141        case DIFF_STATUS_COPIED:
4142                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4143                            line_prefix, set, similarity_index(p));
4144                strbuf_addf(msg, "%s\n%s%scopy from ",
4145                            reset,  line_prefix, set);
4146                quote_c_style(name, msg, NULL, 0);
4147                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
4148                quote_c_style(other, msg, NULL, 0);
4149                strbuf_addf(msg, "%s\n", reset);
4150                break;
4151        case DIFF_STATUS_RENAMED:
4152                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4153                            line_prefix, set, similarity_index(p));
4154                strbuf_addf(msg, "%s\n%s%srename from ",
4155                            reset, line_prefix, set);
4156                quote_c_style(name, msg, NULL, 0);
4157                strbuf_addf(msg, "%s\n%s%srename to ",
4158                            reset, line_prefix, set);
4159                quote_c_style(other, msg, NULL, 0);
4160                strbuf_addf(msg, "%s\n", reset);
4161                break;
4162        case DIFF_STATUS_MODIFIED:
4163                if (p->score) {
4164                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
4165                                    line_prefix,
4166                                    set, similarity_index(p), reset);
4167                        break;
4168                }
4169                /* fallthru */
4170        default:
4171                *must_show_header = 0;
4172        }
4173        if (one && two && oidcmp(&one->oid, &two->oid)) {
4174                const unsigned hexsz = the_hash_algo->hexsz;
4175                int abbrev = o->flags.full_index ? hexsz : DEFAULT_ABBREV;
4176
4177                if (o->flags.binary) {
4178                        mmfile_t mf;
4179                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
4180                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
4181                                abbrev = hexsz;
4182                }
4183                strbuf_addf(msg, "%s%sindex %s..%s", line_prefix, set,
4184                            diff_abbrev_oid(&one->oid, abbrev),
4185                            diff_abbrev_oid(&two->oid, abbrev));
4186                if (one->mode == two->mode)
4187                        strbuf_addf(msg, " %06o", one->mode);
4188                strbuf_addf(msg, "%s\n", reset);
4189        }
4190}
4191
4192static void run_diff_cmd(const char *pgm,
4193                         const char *name,
4194                         const char *other,
4195                         const char *attr_path,
4196                         struct diff_filespec *one,
4197                         struct diff_filespec *two,
4198                         struct strbuf *msg,
4199                         struct diff_options *o,
4200                         struct diff_filepair *p)
4201{
4202        const char *xfrm_msg = NULL;
4203        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
4204        int must_show_header = 0;
4205
4206
4207        if (o->flags.allow_external) {
4208                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
4209                if (drv && drv->external)
4210                        pgm = drv->external;
4211        }
4212
4213        if (msg) {
4214                /*
4215                 * don't use colors when the header is intended for an
4216                 * external diff driver
4217                 */
4218                fill_metainfo(msg, name, other, one, two, o, p,
4219                              &must_show_header,
4220                              want_color(o->use_color) && !pgm);
4221                xfrm_msg = msg->len ? msg->buf : NULL;
4222        }
4223
4224        if (pgm) {
4225                run_external_diff(pgm, name, other, one, two, xfrm_msg,
4226                                  complete_rewrite, o);
4227                return;
4228        }
4229        if (one && two)
4230                builtin_diff(name, other ? other : name,
4231                             one, two, xfrm_msg, must_show_header,
4232                             o, complete_rewrite);
4233        else
4234                fprintf(o->file, "* Unmerged path %s\n", name);
4235}
4236
4237static void diff_fill_oid_info(struct diff_filespec *one)
4238{
4239        if (DIFF_FILE_VALID(one)) {
4240                if (!one->oid_valid) {
4241                        struct stat st;
4242                        if (one->is_stdin) {
4243                                oidclr(&one->oid);
4244                                return;
4245                        }
4246                        if (lstat(one->path, &st) < 0)
4247                                die_errno("stat '%s'", one->path);
4248                        if (index_path(&one->oid, one->path, &st, 0))
4249                                die("cannot hash %s", one->path);
4250                }
4251        }
4252        else
4253                oidclr(&one->oid);
4254}
4255
4256static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
4257{
4258        /* Strip the prefix but do not molest /dev/null and absolute paths */
4259        if (*namep && **namep != '/') {
4260                *namep += prefix_length;
4261                if (**namep == '/')
4262                        ++*namep;
4263        }
4264        if (*otherp && **otherp != '/') {
4265                *otherp += prefix_length;
4266                if (**otherp == '/')
4267                        ++*otherp;
4268        }
4269}
4270
4271static void run_diff(struct diff_filepair *p, struct diff_options *o)
4272{
4273        const char *pgm = external_diff();
4274        struct strbuf msg;
4275        struct diff_filespec *one = p->one;
4276        struct diff_filespec *two = p->two;
4277        const char *name;
4278        const char *other;
4279        const char *attr_path;
4280
4281        name  = one->path;
4282        other = (strcmp(name, two->path) ? two->path : NULL);
4283        attr_path = name;
4284        if (o->prefix_length)
4285                strip_prefix(o->prefix_length, &name, &other);
4286
4287        if (!o->flags.allow_external)
4288                pgm = NULL;
4289
4290        if (DIFF_PAIR_UNMERGED(p)) {
4291                run_diff_cmd(pgm, name, NULL, attr_path,
4292                             NULL, NULL, NULL, o, p);
4293                return;
4294        }
4295
4296        diff_fill_oid_info(one);
4297        diff_fill_oid_info(two);
4298
4299        if (!pgm &&
4300            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
4301            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
4302                /*
4303                 * a filepair that changes between file and symlink
4304                 * needs to be split into deletion and creation.
4305                 */
4306                struct diff_filespec *null = alloc_filespec(two->path);
4307                run_diff_cmd(NULL, name, other, attr_path,
4308                             one, null, &msg, o, p);
4309                free(null);
4310                strbuf_release(&msg);
4311
4312                null = alloc_filespec(one->path);
4313                run_diff_cmd(NULL, name, other, attr_path,
4314                             null, two, &msg, o, p);
4315                free(null);
4316        }
4317        else
4318                run_diff_cmd(pgm, name, other, attr_path,
4319                             one, two, &msg, o, p);
4320
4321        strbuf_release(&msg);
4322}
4323
4324static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
4325                         struct diffstat_t *diffstat)
4326{
4327        const char *name;
4328        const char *other;
4329
4330        if (DIFF_PAIR_UNMERGED(p)) {
4331                /* unmerged */
4332                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, p);
4333                return;
4334        }
4335
4336        name = p->one->path;
4337        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4338
4339        if (o->prefix_length)
4340                strip_prefix(o->prefix_length, &name, &other);
4341
4342        diff_fill_oid_info(p->one);
4343        diff_fill_oid_info(p->two);
4344
4345        builtin_diffstat(name, other, p->one, p->two, diffstat, o, p);
4346}
4347
4348static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
4349{
4350        const char *name;
4351        const char *other;
4352        const char *attr_path;
4353
4354        if (DIFF_PAIR_UNMERGED(p)) {
4355                /* unmerged */
4356                return;
4357        }
4358
4359        name = p->one->path;
4360        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4361        attr_path = other ? other : name;
4362
4363        if (o->prefix_length)
4364                strip_prefix(o->prefix_length, &name, &other);
4365
4366        diff_fill_oid_info(p->one);
4367        diff_fill_oid_info(p->two);
4368
4369        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
4370}
4371
4372void diff_setup(struct diff_options *options)
4373{
4374        memcpy(options, &default_diff_options, sizeof(*options));
4375
4376        options->file = stdout;
4377
4378        options->abbrev = DEFAULT_ABBREV;
4379        options->line_termination = '\n';
4380        options->break_opt = -1;
4381        options->rename_limit = -1;
4382        options->dirstat_permille = diff_dirstat_permille_default;
4383        options->context = diff_context_default;
4384        options->interhunkcontext = diff_interhunk_context_default;
4385        options->ws_error_highlight = ws_error_highlight_default;
4386        options->flags.rename_empty = 1;
4387        options->objfind = NULL;
4388
4389        /* pathchange left =NULL by default */
4390        options->change = diff_change;
4391        options->add_remove = diff_addremove;
4392        options->use_color = diff_use_color_default;
4393        options->detect_rename = diff_detect_rename_default;
4394        options->xdl_opts |= diff_algorithm;
4395        if (diff_indent_heuristic)
4396                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4397
4398        options->orderfile = diff_order_file_cfg;
4399
4400        if (diff_no_prefix) {
4401                options->a_prefix = options->b_prefix = "";
4402        } else if (!diff_mnemonic_prefix) {
4403                options->a_prefix = "a/";
4404                options->b_prefix = "b/";
4405        }
4406
4407        options->color_moved = diff_color_moved_default;
4408        options->color_moved_ws_handling = diff_color_moved_ws_default;
4409}
4410
4411void diff_setup_done(struct diff_options *options)
4412{
4413        unsigned check_mask = DIFF_FORMAT_NAME |
4414                              DIFF_FORMAT_NAME_STATUS |
4415                              DIFF_FORMAT_CHECKDIFF |
4416                              DIFF_FORMAT_NO_OUTPUT;
4417        /*
4418         * This must be signed because we're comparing against a potentially
4419         * negative value.
4420         */
4421        const int hexsz = the_hash_algo->hexsz;
4422
4423        if (options->set_default)
4424                options->set_default(options);
4425
4426        if (HAS_MULTI_BITS(options->output_format & check_mask))
4427                die(_("--name-only, --name-status, --check and -s are mutually exclusive"));
4428
4429        if (HAS_MULTI_BITS(options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK))
4430                die(_("-G, -S and --find-object are mutually exclusive"));
4431
4432        /*
4433         * Most of the time we can say "there are changes"
4434         * only by checking if there are changed paths, but
4435         * --ignore-whitespace* options force us to look
4436         * inside contents.
4437         */
4438
4439        if ((options->xdl_opts & XDF_WHITESPACE_FLAGS))
4440                options->flags.diff_from_contents = 1;
4441        else
4442                options->flags.diff_from_contents = 0;
4443
4444        if (options->flags.find_copies_harder)
4445                options->detect_rename = DIFF_DETECT_COPY;
4446
4447        if (!options->flags.relative_name)
4448                options->prefix = NULL;
4449        if (options->prefix)
4450                options->prefix_length = strlen(options->prefix);
4451        else
4452                options->prefix_length = 0;
4453
4454        if (options->output_format & (DIFF_FORMAT_NAME |
4455                                      DIFF_FORMAT_NAME_STATUS |
4456                                      DIFF_FORMAT_CHECKDIFF |
4457                                      DIFF_FORMAT_NO_OUTPUT))
4458                options->output_format &= ~(DIFF_FORMAT_RAW |
4459                                            DIFF_FORMAT_NUMSTAT |
4460                                            DIFF_FORMAT_DIFFSTAT |
4461                                            DIFF_FORMAT_SHORTSTAT |
4462                                            DIFF_FORMAT_DIRSTAT |
4463                                            DIFF_FORMAT_SUMMARY |
4464                                            DIFF_FORMAT_PATCH);
4465
4466        /*
4467         * These cases always need recursive; we do not drop caller-supplied
4468         * recursive bits for other formats here.
4469         */
4470        if (options->output_format & (DIFF_FORMAT_PATCH |
4471                                      DIFF_FORMAT_NUMSTAT |
4472                                      DIFF_FORMAT_DIFFSTAT |
4473                                      DIFF_FORMAT_SHORTSTAT |
4474                                      DIFF_FORMAT_DIRSTAT |
4475                                      DIFF_FORMAT_SUMMARY |
4476                                      DIFF_FORMAT_CHECKDIFF))
4477                options->flags.recursive = 1;
4478        /*
4479         * Also pickaxe would not work very well if you do not say recursive
4480         */
4481        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
4482                options->flags.recursive = 1;
4483        /*
4484         * When patches are generated, submodules diffed against the work tree
4485         * must be checked for dirtiness too so it can be shown in the output
4486         */
4487        if (options->output_format & DIFF_FORMAT_PATCH)
4488                options->flags.dirty_submodules = 1;
4489
4490        if (options->detect_rename && options->rename_limit < 0)
4491                options->rename_limit = diff_rename_limit_default;
4492        if (hexsz < options->abbrev)
4493                options->abbrev = hexsz; /* full */
4494
4495        /*
4496         * It does not make sense to show the first hit we happened
4497         * to have found.  It does not make sense not to return with
4498         * exit code in such a case either.
4499         */
4500        if (options->flags.quick) {
4501                options->output_format = DIFF_FORMAT_NO_OUTPUT;
4502                options->flags.exit_with_status = 1;
4503        }
4504
4505        options->diff_path_counter = 0;
4506
4507        if (options->flags.follow_renames && options->pathspec.nr != 1)
4508                die(_("--follow requires exactly one pathspec"));
4509
4510        if (!options->use_color || external_diff())
4511                options->color_moved = 0;
4512}
4513
4514static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
4515{
4516        char c, *eq;
4517        int len;
4518
4519        if (*arg != '-')
4520                return 0;
4521        c = *++arg;
4522        if (!c)
4523                return 0;
4524        if (c == arg_short) {
4525                c = *++arg;
4526                if (!c)
4527                        return 1;
4528                if (val && isdigit(c)) {
4529                        char *end;
4530                        int n = strtoul(arg, &end, 10);
4531                        if (*end)
4532                                return 0;
4533                        *val = n;
4534                        return 1;
4535                }
4536                return 0;
4537        }
4538        if (c != '-')
4539                return 0;
4540        arg++;
4541        eq = strchrnul(arg, '=');
4542        len = eq - arg;
4543        if (!len || strncmp(arg, arg_long, len))
4544                return 0;
4545        if (*eq) {
4546                int n;
4547                char *end;
4548                if (!isdigit(*++eq))
4549                        return 0;
4550                n = strtoul(eq, &end, 10);
4551                if (*end)
4552                        return 0;
4553                *val = n;
4554        }
4555        return 1;
4556}
4557
4558static int diff_scoreopt_parse(const char *opt);
4559
4560static inline int short_opt(char opt, const char **argv,
4561                            const char **optarg)
4562{
4563        const char *arg = argv[0];
4564        if (arg[0] != '-' || arg[1] != opt)
4565                return 0;
4566        if (arg[2] != '\0') {
4567                *optarg = arg + 2;
4568                return 1;
4569        }
4570        if (!argv[1])
4571                die("Option '%c' requires a value", opt);
4572        *optarg = argv[1];
4573        return 2;
4574}
4575
4576int parse_long_opt(const char *opt, const char **argv,
4577                   const char **optarg)
4578{
4579        const char *arg = argv[0];
4580        if (!skip_prefix(arg, "--", &arg))
4581                return 0;
4582        if (!skip_prefix(arg, opt, &arg))
4583                return 0;
4584        if (*arg == '=') { /* stuck form: --option=value */
4585                *optarg = arg + 1;
4586                return 1;
4587        }
4588        if (*arg != '\0')
4589                return 0;
4590        /* separate form: --option value */
4591        if (!argv[1])
4592                die("Option '--%s' requires a value", opt);
4593        *optarg = argv[1];
4594        return 2;
4595}
4596
4597static int stat_opt(struct diff_options *options, const char **av)
4598{
4599        const char *arg = av[0];
4600        char *end;
4601        int width = options->stat_width;
4602        int name_width = options->stat_name_width;
4603        int graph_width = options->stat_graph_width;
4604        int count = options->stat_count;
4605        int argcount = 1;
4606
4607        if (!skip_prefix(arg, "--stat", &arg))
4608                BUG("stat option does not begin with --stat: %s", arg);
4609        end = (char *)arg;
4610
4611        switch (*arg) {
4612        case '-':
4613                if (skip_prefix(arg, "-width", &arg)) {
4614                        if (*arg == '=')
4615                                width = strtoul(arg + 1, &end, 10);
4616                        else if (!*arg && !av[1])
4617                                die_want_option("--stat-width");
4618                        else if (!*arg) {
4619                                width = strtoul(av[1], &end, 10);
4620                                argcount = 2;
4621                        }
4622                } else if (skip_prefix(arg, "-name-width", &arg)) {
4623                        if (*arg == '=')
4624                                name_width = strtoul(arg + 1, &end, 10);
4625                        else if (!*arg && !av[1])
4626                                die_want_option("--stat-name-width");
4627                        else if (!*arg) {
4628                                name_width = strtoul(av[1], &end, 10);
4629                                argcount = 2;
4630                        }
4631                } else if (skip_prefix(arg, "-graph-width", &arg)) {
4632                        if (*arg == '=')
4633                                graph_width = strtoul(arg + 1, &end, 10);
4634                        else if (!*arg && !av[1])
4635                                die_want_option("--stat-graph-width");
4636                        else if (!*arg) {
4637                                graph_width = strtoul(av[1], &end, 10);
4638                                argcount = 2;
4639                        }
4640                } else if (skip_prefix(arg, "-count", &arg)) {
4641                        if (*arg == '=')
4642                                count = strtoul(arg + 1, &end, 10);
4643                        else if (!*arg && !av[1])
4644                                die_want_option("--stat-count");
4645                        else if (!*arg) {
4646                                count = strtoul(av[1], &end, 10);
4647                                argcount = 2;
4648                        }
4649                }
4650                break;
4651        case '=':
4652                width = strtoul(arg+1, &end, 10);
4653                if (*end == ',')
4654                        name_width = strtoul(end+1, &end, 10);
4655                if (*end == ',')
4656                        count = strtoul(end+1, &end, 10);
4657        }
4658
4659        /* Important! This checks all the error cases! */
4660        if (*end)
4661                return 0;
4662        options->output_format |= DIFF_FORMAT_DIFFSTAT;
4663        options->stat_name_width = name_width;
4664        options->stat_graph_width = graph_width;
4665        options->stat_width = width;
4666        options->stat_count = count;
4667        return argcount;
4668}
4669
4670static int parse_dirstat_opt(struct diff_options *options, const char *params)
4671{
4672        struct strbuf errmsg = STRBUF_INIT;
4673        if (parse_dirstat_params(options, params, &errmsg))
4674                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
4675                    errmsg.buf);
4676        strbuf_release(&errmsg);
4677        /*
4678         * The caller knows a dirstat-related option is given from the command
4679         * line; allow it to say "return this_function();"
4680         */
4681        options->output_format |= DIFF_FORMAT_DIRSTAT;
4682        return 1;
4683}
4684
4685static int parse_submodule_opt(struct diff_options *options, const char *value)
4686{
4687        if (parse_submodule_params(options, value))
4688                die(_("Failed to parse --submodule option parameter: '%s'"),
4689                        value);
4690        return 1;
4691}
4692
4693static const char diff_status_letters[] = {
4694        DIFF_STATUS_ADDED,
4695        DIFF_STATUS_COPIED,
4696        DIFF_STATUS_DELETED,
4697        DIFF_STATUS_MODIFIED,
4698        DIFF_STATUS_RENAMED,
4699        DIFF_STATUS_TYPE_CHANGED,
4700        DIFF_STATUS_UNKNOWN,
4701        DIFF_STATUS_UNMERGED,
4702        DIFF_STATUS_FILTER_AON,
4703        DIFF_STATUS_FILTER_BROKEN,
4704        '\0',
4705};
4706
4707static unsigned int filter_bit['Z' + 1];
4708
4709static void prepare_filter_bits(void)
4710{
4711        int i;
4712
4713        if (!filter_bit[DIFF_STATUS_ADDED]) {
4714                for (i = 0; diff_status_letters[i]; i++)
4715                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
4716        }
4717}
4718
4719static unsigned filter_bit_tst(char status, const struct diff_options *opt)
4720{
4721        return opt->filter & filter_bit[(int) status];
4722}
4723
4724static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
4725{
4726        int i, optch;
4727
4728        prepare_filter_bits();
4729
4730        /*
4731         * If there is a negation e.g. 'd' in the input, and we haven't
4732         * initialized the filter field with another --diff-filter, start
4733         * from full set of bits, except for AON.
4734         */
4735        if (!opt->filter) {
4736                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4737                        if (optch < 'a' || 'z' < optch)
4738                                continue;
4739                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
4740                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
4741                        break;
4742                }
4743        }
4744
4745        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4746                unsigned int bit;
4747                int negate;
4748
4749                if ('a' <= optch && optch <= 'z') {
4750                        negate = 1;
4751                        optch = toupper(optch);
4752                } else {
4753                        negate = 0;
4754                }
4755
4756                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
4757                if (!bit)
4758                        return optarg[i];
4759                if (negate)
4760                        opt->filter &= ~bit;
4761                else
4762                        opt->filter |= bit;
4763        }
4764        return 0;
4765}
4766
4767static void enable_patch_output(int *fmt) {
4768        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
4769        *fmt |= DIFF_FORMAT_PATCH;
4770}
4771
4772static int parse_ws_error_highlight_opt(struct diff_options *opt, const char *arg)
4773{
4774        int val = parse_ws_error_highlight(arg);
4775
4776        if (val < 0) {
4777                error("unknown value after ws-error-highlight=%.*s",
4778                      -1 - val, arg);
4779                return 0;
4780        }
4781        opt->ws_error_highlight = val;
4782        return 1;
4783}
4784
4785static int parse_objfind_opt(struct diff_options *opt, const char *arg)
4786{
4787        struct object_id oid;
4788
4789        if (get_oid(arg, &oid))
4790                return error("unable to resolve '%s'", arg);
4791
4792        if (!opt->objfind)
4793                opt->objfind = xcalloc(1, sizeof(*opt->objfind));
4794
4795        opt->pickaxe_opts |= DIFF_PICKAXE_KIND_OBJFIND;
4796        opt->flags.recursive = 1;
4797        opt->flags.tree_in_recursive = 1;
4798        oidset_insert(opt->objfind, &oid);
4799        return 1;
4800}
4801
4802int diff_opt_parse(struct diff_options *options,
4803                   const char **av, int ac, const char *prefix)
4804{
4805        const char *arg = av[0];
4806        const char *optarg;
4807        int argcount;
4808
4809        if (!prefix)
4810                prefix = "";
4811
4812        /* Output format options */
4813        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
4814            || opt_arg(arg, 'U', "unified", &options->context))
4815                enable_patch_output(&options->output_format);
4816        else if (!strcmp(arg, "--raw"))
4817                options->output_format |= DIFF_FORMAT_RAW;
4818        else if (!strcmp(arg, "--patch-with-raw")) {
4819                enable_patch_output(&options->output_format);
4820                options->output_format |= DIFF_FORMAT_RAW;
4821        } else if (!strcmp(arg, "--numstat"))
4822                options->output_format |= DIFF_FORMAT_NUMSTAT;
4823        else if (!strcmp(arg, "--shortstat"))
4824                options->output_format |= DIFF_FORMAT_SHORTSTAT;
4825        else if (skip_prefix(arg, "-X", &arg) ||
4826                 skip_to_optional_arg(arg, "--dirstat", &arg))
4827                return parse_dirstat_opt(options, arg);
4828        else if (!strcmp(arg, "--cumulative"))
4829                return parse_dirstat_opt(options, "cumulative");
4830        else if (skip_to_optional_arg(arg, "--dirstat-by-file", &arg)) {
4831                parse_dirstat_opt(options, "files");
4832                return parse_dirstat_opt(options, arg);
4833        }
4834        else if (!strcmp(arg, "--check"))
4835                options->output_format |= DIFF_FORMAT_CHECKDIFF;
4836        else if (!strcmp(arg, "--summary"))
4837                options->output_format |= DIFF_FORMAT_SUMMARY;
4838        else if (!strcmp(arg, "--patch-with-stat")) {
4839                enable_patch_output(&options->output_format);
4840                options->output_format |= DIFF_FORMAT_DIFFSTAT;
4841        } else if (!strcmp(arg, "--name-only"))
4842                options->output_format |= DIFF_FORMAT_NAME;
4843        else if (!strcmp(arg, "--name-status"))
4844                options->output_format |= DIFF_FORMAT_NAME_STATUS;
4845        else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
4846                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
4847        else if (starts_with(arg, "--stat"))
4848                /* --stat, --stat-width, --stat-name-width, or --stat-count */
4849                return stat_opt(options, av);
4850        else if (!strcmp(arg, "--compact-summary")) {
4851                 options->flags.stat_with_summary = 1;
4852                 options->output_format |= DIFF_FORMAT_DIFFSTAT;
4853        } else if (!strcmp(arg, "--no-compact-summary"))
4854                 options->flags.stat_with_summary = 0;
4855
4856        /* renames options */
4857        else if (starts_with(arg, "-B") ||
4858                 skip_to_optional_arg(arg, "--break-rewrites", NULL)) {
4859                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
4860                        return error("invalid argument to -B: %s", arg+2);
4861        }
4862        else if (starts_with(arg, "-M") ||
4863                 skip_to_optional_arg(arg, "--find-renames", NULL)) {
4864                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4865                        return error("invalid argument to -M: %s", arg+2);
4866                options->detect_rename = DIFF_DETECT_RENAME;
4867        }
4868        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
4869                options->irreversible_delete = 1;
4870        }
4871        else if (starts_with(arg, "-C") ||
4872                 skip_to_optional_arg(arg, "--find-copies", NULL)) {
4873                if (options->detect_rename == DIFF_DETECT_COPY)
4874                        options->flags.find_copies_harder = 1;
4875                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4876                        return error("invalid argument to -C: %s", arg+2);
4877                options->detect_rename = DIFF_DETECT_COPY;
4878        }
4879        else if (!strcmp(arg, "--no-renames"))
4880                options->detect_rename = 0;
4881        else if (!strcmp(arg, "--rename-empty"))
4882                options->flags.rename_empty = 1;
4883        else if (!strcmp(arg, "--no-rename-empty"))
4884                options->flags.rename_empty = 0;
4885        else if (skip_to_optional_arg_default(arg, "--relative", &arg, NULL)) {
4886                options->flags.relative_name = 1;
4887                if (arg)
4888                        options->prefix = arg;
4889        }
4890
4891        /* xdiff options */
4892        else if (!strcmp(arg, "--minimal"))
4893                DIFF_XDL_SET(options, NEED_MINIMAL);
4894        else if (!strcmp(arg, "--no-minimal"))
4895                DIFF_XDL_CLR(options, NEED_MINIMAL);
4896        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
4897                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
4898        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
4899                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
4900        else if (!strcmp(arg, "--ignore-space-at-eol"))
4901                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
4902        else if (!strcmp(arg, "--ignore-cr-at-eol"))
4903                DIFF_XDL_SET(options, IGNORE_CR_AT_EOL);
4904        else if (!strcmp(arg, "--ignore-blank-lines"))
4905                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
4906        else if (!strcmp(arg, "--indent-heuristic"))
4907                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4908        else if (!strcmp(arg, "--no-indent-heuristic"))
4909                DIFF_XDL_CLR(options, INDENT_HEURISTIC);
4910        else if (!strcmp(arg, "--patience")) {
4911                int i;
4912                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4913                /*
4914                 * Both --patience and --anchored use PATIENCE_DIFF
4915                 * internally, so remove any anchors previously
4916                 * specified.
4917                 */
4918                for (i = 0; i < options->anchors_nr; i++)
4919                        free(options->anchors[i]);
4920                options->anchors_nr = 0;
4921        } else if (!strcmp(arg, "--histogram"))
4922                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
4923        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
4924                long value = parse_algorithm_value(optarg);
4925                if (value < 0)
4926                        return error("option diff-algorithm accepts \"myers\", "
4927                                     "\"minimal\", \"patience\" and \"histogram\"");
4928                /* clear out previous settings */
4929                DIFF_XDL_CLR(options, NEED_MINIMAL);
4930                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
4931                options->xdl_opts |= value;
4932                return argcount;
4933        } else if (skip_prefix(arg, "--anchored=", &arg)) {
4934                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4935                ALLOC_GROW(options->anchors, options->anchors_nr + 1,
4936                           options->anchors_alloc);
4937                options->anchors[options->anchors_nr++] = xstrdup(arg);
4938        }
4939
4940        /* flags options */
4941        else if (!strcmp(arg, "--binary")) {
4942                enable_patch_output(&options->output_format);
4943                options->flags.binary = 1;
4944        }
4945        else if (!strcmp(arg, "--full-index"))
4946                options->flags.full_index = 1;
4947        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
4948                options->flags.text = 1;
4949        else if (!strcmp(arg, "-R"))
4950                options->flags.reverse_diff = 1;
4951        else if (!strcmp(arg, "--find-copies-harder"))
4952                options->flags.find_copies_harder = 1;
4953        else if (!strcmp(arg, "--follow"))
4954                options->flags.follow_renames = 1;
4955        else if (!strcmp(arg, "--no-follow")) {
4956                options->flags.follow_renames = 0;
4957                options->flags.default_follow_renames = 0;
4958        } else if (skip_to_optional_arg_default(arg, "--color", &arg, "always")) {
4959                int value = git_config_colorbool(NULL, arg);
4960                if (value < 0)
4961                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
4962                options->use_color = value;
4963        }
4964        else if (!strcmp(arg, "--no-color"))
4965                options->use_color = 0;
4966        else if (!strcmp(arg, "--color-moved")) {
4967                if (diff_color_moved_default)
4968                        options->color_moved = diff_color_moved_default;
4969                if (options->color_moved == COLOR_MOVED_NO)
4970                        options->color_moved = COLOR_MOVED_DEFAULT;
4971        } else if (!strcmp(arg, "--no-color-moved"))
4972                options->color_moved = COLOR_MOVED_NO;
4973        else if (skip_prefix(arg, "--color-moved=", &arg)) {
4974                int cm = parse_color_moved(arg);
4975                if (cm < 0)
4976                        die("bad --color-moved argument: %s", arg);
4977                options->color_moved = cm;
4978        } else if (skip_prefix(arg, "--color-moved-ws=", &arg)) {
4979                options->color_moved_ws_handling = parse_color_moved_ws(arg);
4980        } else if (skip_to_optional_arg_default(arg, "--color-words", &options->word_regex, NULL)) {
4981                options->use_color = 1;
4982                options->word_diff = DIFF_WORDS_COLOR;
4983        }
4984        else if (!strcmp(arg, "--word-diff")) {
4985                if (options->word_diff == DIFF_WORDS_NONE)
4986                        options->word_diff = DIFF_WORDS_PLAIN;
4987        }
4988        else if (skip_prefix(arg, "--word-diff=", &arg)) {
4989                if (!strcmp(arg, "plain"))
4990                        options->word_diff = DIFF_WORDS_PLAIN;
4991                else if (!strcmp(arg, "color")) {
4992                        options->use_color = 1;
4993                        options->word_diff = DIFF_WORDS_COLOR;
4994                }
4995                else if (!strcmp(arg, "porcelain"))
4996                        options->word_diff = DIFF_WORDS_PORCELAIN;
4997                else if (!strcmp(arg, "none"))
4998                        options->word_diff = DIFF_WORDS_NONE;
4999                else
5000                        die("bad --word-diff argument: %s", arg);
5001        }
5002        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
5003                if (options->word_diff == DIFF_WORDS_NONE)
5004                        options->word_diff = DIFF_WORDS_PLAIN;
5005                options->word_regex = optarg;
5006                return argcount;
5007        }
5008        else if (!strcmp(arg, "--exit-code"))
5009                options->flags.exit_with_status = 1;
5010        else if (!strcmp(arg, "--quiet"))
5011                options->flags.quick = 1;
5012        else if (!strcmp(arg, "--ext-diff"))
5013                options->flags.allow_external = 1;
5014        else if (!strcmp(arg, "--no-ext-diff"))
5015                options->flags.allow_external = 0;
5016        else if (!strcmp(arg, "--textconv")) {
5017                options->flags.allow_textconv = 1;
5018                options->flags.textconv_set_via_cmdline = 1;
5019        } else if (!strcmp(arg, "--no-textconv"))
5020                options->flags.allow_textconv = 0;
5021        else if (skip_to_optional_arg_default(arg, "--ignore-submodules", &arg, "all")) {
5022                options->flags.override_submodule_config = 1;
5023                handle_ignore_submodules_arg(options, arg);
5024        } else if (skip_to_optional_arg_default(arg, "--submodule", &arg, "log"))
5025                return parse_submodule_opt(options, arg);
5026        else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
5027                return parse_ws_error_highlight_opt(options, arg);
5028        else if (!strcmp(arg, "--ita-invisible-in-index"))
5029                options->ita_invisible_in_index = 1;
5030        else if (!strcmp(arg, "--ita-visible-in-index"))
5031                options->ita_invisible_in_index = 0;
5032
5033        /* misc options */
5034        else if (!strcmp(arg, "-z"))
5035                options->line_termination = 0;
5036        else if ((argcount = short_opt('l', av, &optarg))) {
5037                options->rename_limit = strtoul(optarg, NULL, 10);
5038                return argcount;
5039        }
5040        else if ((argcount = short_opt('S', av, &optarg))) {
5041                options->pickaxe = optarg;
5042                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
5043                return argcount;
5044        } else if ((argcount = short_opt('G', av, &optarg))) {
5045                options->pickaxe = optarg;
5046                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
5047                return argcount;
5048        }
5049        else if (!strcmp(arg, "--pickaxe-all"))
5050                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
5051        else if (!strcmp(arg, "--pickaxe-regex"))
5052                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
5053        else if ((argcount = short_opt('O', av, &optarg))) {
5054                options->orderfile = prefix_filename(prefix, optarg);
5055                return argcount;
5056        } else if (skip_prefix(arg, "--find-object=", &arg))
5057                return parse_objfind_opt(options, arg);
5058        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
5059                int offending = parse_diff_filter_opt(optarg, options);
5060                if (offending)
5061                        die("unknown change class '%c' in --diff-filter=%s",
5062                            offending, optarg);
5063                return argcount;
5064        }
5065        else if (!strcmp(arg, "--no-abbrev"))
5066                options->abbrev = 0;
5067        else if (!strcmp(arg, "--abbrev"))
5068                options->abbrev = DEFAULT_ABBREV;
5069        else if (skip_prefix(arg, "--abbrev=", &arg)) {
5070                options->abbrev = strtoul(arg, NULL, 10);
5071                if (options->abbrev < MINIMUM_ABBREV)
5072                        options->abbrev = MINIMUM_ABBREV;
5073                else if (the_hash_algo->hexsz < options->abbrev)
5074                        options->abbrev = the_hash_algo->hexsz;
5075        }
5076        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
5077                options->a_prefix = optarg;
5078                return argcount;
5079        }
5080        else if ((argcount = parse_long_opt("line-prefix", av, &optarg))) {
5081                options->line_prefix = optarg;
5082                options->line_prefix_length = strlen(options->line_prefix);
5083                graph_setup_line_prefix(options);
5084                return argcount;
5085        }
5086        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
5087                options->b_prefix = optarg;
5088                return argcount;
5089        }
5090        else if (!strcmp(arg, "--no-prefix"))
5091                options->a_prefix = options->b_prefix = "";
5092        else if (opt_arg(arg, '\0', "inter-hunk-context",
5093                         &options->interhunkcontext))
5094                ;
5095        else if (!strcmp(arg, "-W"))
5096                options->flags.funccontext = 1;
5097        else if (!strcmp(arg, "--function-context"))
5098                options->flags.funccontext = 1;
5099        else if (!strcmp(arg, "--no-function-context"))
5100                options->flags.funccontext = 0;
5101        else if ((argcount = parse_long_opt("output", av, &optarg))) {
5102                char *path = prefix_filename(prefix, optarg);
5103                options->file = xfopen(path, "w");
5104                options->close_file = 1;
5105                if (options->use_color != GIT_COLOR_ALWAYS)
5106                        options->use_color = GIT_COLOR_NEVER;
5107                free(path);
5108                return argcount;
5109        } else
5110                return 0;
5111        return 1;
5112}
5113
5114int parse_rename_score(const char **cp_p)
5115{
5116        unsigned long num, scale;
5117        int ch, dot;
5118        const char *cp = *cp_p;
5119
5120        num = 0;
5121        scale = 1;
5122        dot = 0;
5123        for (;;) {
5124                ch = *cp;
5125                if ( !dot && ch == '.' ) {
5126                        scale = 1;
5127                        dot = 1;
5128                } else if ( ch == '%' ) {
5129                        scale = dot ? scale*100 : 100;
5130                        cp++;   /* % is always at the end */
5131                        break;
5132                } else if ( ch >= '0' && ch <= '9' ) {
5133                        if ( scale < 100000 ) {
5134                                scale *= 10;
5135                                num = (num*10) + (ch-'0');
5136                        }
5137                } else {
5138                        break;
5139                }
5140                cp++;
5141        }
5142        *cp_p = cp;
5143
5144        /* user says num divided by scale and we say internally that
5145         * is MAX_SCORE * num / scale.
5146         */
5147        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
5148}
5149
5150static int diff_scoreopt_parse(const char *opt)
5151{
5152        int opt1, opt2, cmd;
5153
5154        if (*opt++ != '-')
5155                return -1;
5156        cmd = *opt++;
5157        if (cmd == '-') {
5158                /* convert the long-form arguments into short-form versions */
5159                if (skip_prefix(opt, "break-rewrites", &opt)) {
5160                        if (*opt == 0 || *opt++ == '=')
5161                                cmd = 'B';
5162                } else if (skip_prefix(opt, "find-copies", &opt)) {
5163                        if (*opt == 0 || *opt++ == '=')
5164                                cmd = 'C';
5165                } else if (skip_prefix(opt, "find-renames", &opt)) {
5166                        if (*opt == 0 || *opt++ == '=')
5167                                cmd = 'M';
5168                }
5169        }
5170        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
5171                return -1; /* that is not a -M, -C, or -B option */
5172
5173        opt1 = parse_rename_score(&opt);
5174        if (cmd != 'B')
5175                opt2 = 0;
5176        else {
5177                if (*opt == 0)
5178                        opt2 = 0;
5179                else if (*opt != '/')
5180                        return -1; /* we expect -B80/99 or -B80 */
5181                else {
5182                        opt++;
5183                        opt2 = parse_rename_score(&opt);
5184                }
5185        }
5186        if (*opt != 0)
5187                return -1;
5188        return opt1 | (opt2 << 16);
5189}
5190
5191struct diff_queue_struct diff_queued_diff;
5192
5193void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
5194{
5195        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
5196        queue->queue[queue->nr++] = dp;
5197}
5198
5199struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
5200                                 struct diff_filespec *one,
5201                                 struct diff_filespec *two)
5202{
5203        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
5204        dp->one = one;
5205        dp->two = two;
5206        if (queue)
5207                diff_q(queue, dp);
5208        return dp;
5209}
5210
5211void diff_free_filepair(struct diff_filepair *p)
5212{
5213        free_filespec(p->one);
5214        free_filespec(p->two);
5215        free(p);
5216}
5217
5218const char *diff_aligned_abbrev(const struct object_id *oid, int len)
5219{
5220        int abblen;
5221        const char *abbrev;
5222
5223        /* Do we want all 40 hex characters? */
5224        if (len == the_hash_algo->hexsz)
5225                return oid_to_hex(oid);
5226
5227        /* An abbreviated value is fine, possibly followed by an ellipsis. */
5228        abbrev = diff_abbrev_oid(oid, len);
5229
5230        if (!print_sha1_ellipsis())
5231                return abbrev;
5232
5233        abblen = strlen(abbrev);
5234
5235        /*
5236         * In well-behaved cases, where the abbreviated result is the
5237         * same as the requested length, append three dots after the
5238         * abbreviation (hence the whole logic is limited to the case
5239         * where abblen < 37); when the actual abbreviated result is a
5240         * bit longer than the requested length, we reduce the number
5241         * of dots so that they match the well-behaved ones.  However,
5242         * if the actual abbreviation is longer than the requested
5243         * length by more than three, we give up on aligning, and add
5244         * three dots anyway, to indicate that the output is not the
5245         * full object name.  Yes, this may be suboptimal, but this
5246         * appears only in "diff --raw --abbrev" output and it is not
5247         * worth the effort to change it now.  Note that this would
5248         * likely to work fine when the automatic sizing of default
5249         * abbreviation length is used--we would be fed -1 in "len" in
5250         * that case, and will end up always appending three-dots, but
5251         * the automatic sizing is supposed to give abblen that ensures
5252         * uniqueness across all objects (statistically speaking).
5253         */
5254        if (abblen < the_hash_algo->hexsz - 3) {
5255                static char hex[GIT_MAX_HEXSZ + 1];
5256                if (len < abblen && abblen <= len + 2)
5257                        xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
5258                else
5259                        xsnprintf(hex, sizeof(hex), "%s...", abbrev);
5260                return hex;
5261        }
5262
5263        return oid_to_hex(oid);
5264}
5265
5266static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
5267{
5268        int line_termination = opt->line_termination;
5269        int inter_name_termination = line_termination ? '\t' : '\0';
5270
5271        fprintf(opt->file, "%s", diff_line_prefix(opt));
5272        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
5273                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
5274                        diff_aligned_abbrev(&p->one->oid, opt->abbrev));
5275                fprintf(opt->file, "%s ",
5276                        diff_aligned_abbrev(&p->two->oid, opt->abbrev));
5277        }
5278        if (p->score) {
5279                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
5280                        inter_name_termination);
5281        } else {
5282                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
5283        }
5284
5285        if (p->status == DIFF_STATUS_COPIED ||
5286            p->status == DIFF_STATUS_RENAMED) {
5287                const char *name_a, *name_b;
5288                name_a = p->one->path;
5289                name_b = p->two->path;
5290                strip_prefix(opt->prefix_length, &name_a, &name_b);
5291                write_name_quoted(name_a, opt->file, inter_name_termination);
5292                write_name_quoted(name_b, opt->file, line_termination);
5293        } else {
5294                const char *name_a, *name_b;
5295                name_a = p->one->mode ? p->one->path : p->two->path;
5296                name_b = NULL;
5297                strip_prefix(opt->prefix_length, &name_a, &name_b);
5298                write_name_quoted(name_a, opt->file, line_termination);
5299        }
5300}
5301
5302int diff_unmodified_pair(struct diff_filepair *p)
5303{
5304        /* This function is written stricter than necessary to support
5305         * the currently implemented transformers, but the idea is to
5306         * let transformers to produce diff_filepairs any way they want,
5307         * and filter and clean them up here before producing the output.
5308         */
5309        struct diff_filespec *one = p->one, *two = p->two;
5310
5311        if (DIFF_PAIR_UNMERGED(p))
5312                return 0; /* unmerged is interesting */
5313
5314        /* deletion, addition, mode or type change
5315         * and rename are all interesting.
5316         */
5317        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
5318            DIFF_PAIR_MODE_CHANGED(p) ||
5319            strcmp(one->path, two->path))
5320                return 0;
5321
5322        /* both are valid and point at the same path.  that is, we are
5323         * dealing with a change.
5324         */
5325        if (one->oid_valid && two->oid_valid &&
5326            !oidcmp(&one->oid, &two->oid) &&
5327            !one->dirty_submodule && !two->dirty_submodule)
5328                return 1; /* no change */
5329        if (!one->oid_valid && !two->oid_valid)
5330                return 1; /* both look at the same file on the filesystem. */
5331        return 0;
5332}
5333
5334static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
5335{
5336        if (diff_unmodified_pair(p))
5337                return;
5338
5339        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5340            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5341                return; /* no tree diffs in patch format */
5342
5343        run_diff(p, o);
5344}
5345
5346static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
5347                            struct diffstat_t *diffstat)
5348{
5349        if (diff_unmodified_pair(p))
5350                return;
5351
5352        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5353            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5354                return; /* no useful stat for tree diffs */
5355
5356        run_diffstat(p, o, diffstat);
5357}
5358
5359static void diff_flush_checkdiff(struct diff_filepair *p,
5360                struct diff_options *o)
5361{
5362        if (diff_unmodified_pair(p))
5363                return;
5364
5365        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5366            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5367                return; /* nothing to check in tree diffs */
5368
5369        run_checkdiff(p, o);
5370}
5371
5372int diff_queue_is_empty(void)
5373{
5374        struct diff_queue_struct *q = &diff_queued_diff;
5375        int i;
5376        for (i = 0; i < q->nr; i++)
5377                if (!diff_unmodified_pair(q->queue[i]))
5378                        return 0;
5379        return 1;
5380}
5381
5382#if DIFF_DEBUG
5383void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
5384{
5385        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
5386                x, one ? one : "",
5387                s->path,
5388                DIFF_FILE_VALID(s) ? "valid" : "invalid",
5389                s->mode,
5390                s->oid_valid ? oid_to_hex(&s->oid) : "");
5391        fprintf(stderr, "queue[%d] %s size %lu\n",
5392                x, one ? one : "",
5393                s->size);
5394}
5395
5396void diff_debug_filepair(const struct diff_filepair *p, int i)
5397{
5398        diff_debug_filespec(p->one, i, "one");
5399        diff_debug_filespec(p->two, i, "two");
5400        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
5401                p->score, p->status ? p->status : '?',
5402                p->one->rename_used, p->broken_pair);
5403}
5404
5405void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
5406{
5407        int i;
5408        if (msg)
5409                fprintf(stderr, "%s\n", msg);
5410        fprintf(stderr, "q->nr = %d\n", q->nr);
5411        for (i = 0; i < q->nr; i++) {
5412                struct diff_filepair *p = q->queue[i];
5413                diff_debug_filepair(p, i);
5414        }
5415}
5416#endif
5417
5418static void diff_resolve_rename_copy(void)
5419{
5420        int i;
5421        struct diff_filepair *p;
5422        struct diff_queue_struct *q = &diff_queued_diff;
5423
5424        diff_debug_queue("resolve-rename-copy", q);
5425
5426        for (i = 0; i < q->nr; i++) {
5427                p = q->queue[i];
5428                p->status = 0; /* undecided */
5429                if (DIFF_PAIR_UNMERGED(p))
5430                        p->status = DIFF_STATUS_UNMERGED;
5431                else if (!DIFF_FILE_VALID(p->one))
5432                        p->status = DIFF_STATUS_ADDED;
5433                else if (!DIFF_FILE_VALID(p->two))
5434                        p->status = DIFF_STATUS_DELETED;
5435                else if (DIFF_PAIR_TYPE_CHANGED(p))
5436                        p->status = DIFF_STATUS_TYPE_CHANGED;
5437
5438                /* from this point on, we are dealing with a pair
5439                 * whose both sides are valid and of the same type, i.e.
5440                 * either in-place edit or rename/copy edit.
5441                 */
5442                else if (DIFF_PAIR_RENAME(p)) {
5443                        /*
5444                         * A rename might have re-connected a broken
5445                         * pair up, causing the pathnames to be the
5446                         * same again. If so, that's not a rename at
5447                         * all, just a modification..
5448                         *
5449                         * Otherwise, see if this source was used for
5450                         * multiple renames, in which case we decrement
5451                         * the count, and call it a copy.
5452                         */
5453                        if (!strcmp(p->one->path, p->two->path))
5454                                p->status = DIFF_STATUS_MODIFIED;
5455                        else if (--p->one->rename_used > 0)
5456                                p->status = DIFF_STATUS_COPIED;
5457                        else
5458                                p->status = DIFF_STATUS_RENAMED;
5459                }
5460                else if (oidcmp(&p->one->oid, &p->two->oid) ||
5461                         p->one->mode != p->two->mode ||
5462                         p->one->dirty_submodule ||
5463                         p->two->dirty_submodule ||
5464                         is_null_oid(&p->one->oid))
5465                        p->status = DIFF_STATUS_MODIFIED;
5466                else {
5467                        /* This is a "no-change" entry and should not
5468                         * happen anymore, but prepare for broken callers.
5469                         */
5470                        error("feeding unmodified %s to diffcore",
5471                              p->one->path);
5472                        p->status = DIFF_STATUS_UNKNOWN;
5473                }
5474        }
5475        diff_debug_queue("resolve-rename-copy done", q);
5476}
5477
5478static int check_pair_status(struct diff_filepair *p)
5479{
5480        switch (p->status) {
5481        case DIFF_STATUS_UNKNOWN:
5482                return 0;
5483        case 0:
5484                die("internal error in diff-resolve-rename-copy");
5485        default:
5486                return 1;
5487        }
5488}
5489
5490static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
5491{
5492        int fmt = opt->output_format;
5493
5494        if (fmt & DIFF_FORMAT_CHECKDIFF)
5495                diff_flush_checkdiff(p, opt);
5496        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
5497                diff_flush_raw(p, opt);
5498        else if (fmt & DIFF_FORMAT_NAME) {
5499                const char *name_a, *name_b;
5500                name_a = p->two->path;
5501                name_b = NULL;
5502                strip_prefix(opt->prefix_length, &name_a, &name_b);
5503                fprintf(opt->file, "%s", diff_line_prefix(opt));
5504                write_name_quoted(name_a, opt->file, opt->line_termination);
5505        }
5506}
5507
5508static void show_file_mode_name(struct diff_options *opt, const char *newdelete, struct diff_filespec *fs)
5509{
5510        struct strbuf sb = STRBUF_INIT;
5511        if (fs->mode)
5512                strbuf_addf(&sb, " %s mode %06o ", newdelete, fs->mode);
5513        else
5514                strbuf_addf(&sb, " %s ", newdelete);
5515
5516        quote_c_style(fs->path, &sb, NULL, 0);
5517        strbuf_addch(&sb, '\n');
5518        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5519                         sb.buf, sb.len, 0);
5520        strbuf_release(&sb);
5521}
5522
5523static void show_mode_change(struct diff_options *opt, struct diff_filepair *p,
5524                int show_name)
5525{
5526        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
5527                struct strbuf sb = STRBUF_INIT;
5528                strbuf_addf(&sb, " mode change %06o => %06o",
5529                            p->one->mode, p->two->mode);
5530                if (show_name) {
5531                        strbuf_addch(&sb, ' ');
5532                        quote_c_style(p->two->path, &sb, NULL, 0);
5533                }
5534                strbuf_addch(&sb, '\n');
5535                emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5536                                 sb.buf, sb.len, 0);
5537                strbuf_release(&sb);
5538        }
5539}
5540
5541static void show_rename_copy(struct diff_options *opt, const char *renamecopy,
5542                struct diff_filepair *p)
5543{
5544        struct strbuf sb = STRBUF_INIT;
5545        struct strbuf names = STRBUF_INIT;
5546
5547        pprint_rename(&names, p->one->path, p->two->path);
5548        strbuf_addf(&sb, " %s %s (%d%%)\n",
5549                    renamecopy, names.buf, similarity_index(p));
5550        strbuf_release(&names);
5551        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5552                                 sb.buf, sb.len, 0);
5553        show_mode_change(opt, p, 0);
5554        strbuf_release(&sb);
5555}
5556
5557static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
5558{
5559        switch(p->status) {
5560        case DIFF_STATUS_DELETED:
5561                show_file_mode_name(opt, "delete", p->one);
5562                break;
5563        case DIFF_STATUS_ADDED:
5564                show_file_mode_name(opt, "create", p->two);
5565                break;
5566        case DIFF_STATUS_COPIED:
5567                show_rename_copy(opt, "copy", p);
5568                break;
5569        case DIFF_STATUS_RENAMED:
5570                show_rename_copy(opt, "rename", p);
5571                break;
5572        default:
5573                if (p->score) {
5574                        struct strbuf sb = STRBUF_INIT;
5575                        strbuf_addstr(&sb, " rewrite ");
5576                        quote_c_style(p->two->path, &sb, NULL, 0);
5577                        strbuf_addf(&sb, " (%d%%)\n", similarity_index(p));
5578                        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5579                                         sb.buf, sb.len, 0);
5580                        strbuf_release(&sb);
5581                }
5582                show_mode_change(opt, p, !p->score);
5583                break;
5584        }
5585}
5586
5587struct patch_id_t {
5588        git_SHA_CTX *ctx;
5589        int patchlen;
5590};
5591
5592static int remove_space(char *line, int len)
5593{
5594        int i;
5595        char *dst = line;
5596        unsigned char c;
5597
5598        for (i = 0; i < len; i++)
5599                if (!isspace((c = line[i])))
5600                        *dst++ = c;
5601
5602        return dst - line;
5603}
5604
5605static void patch_id_consume(void *priv, char *line, unsigned long len)
5606{
5607        struct patch_id_t *data = priv;
5608        int new_len;
5609
5610        /* Ignore line numbers when computing the SHA1 of the patch */
5611        if (starts_with(line, "@@ -"))
5612                return;
5613
5614        new_len = remove_space(line, len);
5615
5616        git_SHA1_Update(data->ctx, line, new_len);
5617        data->patchlen += new_len;
5618}
5619
5620static void patch_id_add_string(git_SHA_CTX *ctx, const char *str)
5621{
5622        git_SHA1_Update(ctx, str, strlen(str));
5623}
5624
5625static void patch_id_add_mode(git_SHA_CTX *ctx, unsigned mode)
5626{
5627        /* large enough for 2^32 in octal */
5628        char buf[12];
5629        int len = xsnprintf(buf, sizeof(buf), "%06o", mode);
5630        git_SHA1_Update(ctx, buf, len);
5631}
5632
5633/* returns 0 upon success, and writes result into sha1 */
5634static int diff_get_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5635{
5636        struct diff_queue_struct *q = &diff_queued_diff;
5637        int i;
5638        git_SHA_CTX ctx;
5639        struct patch_id_t data;
5640
5641        git_SHA1_Init(&ctx);
5642        memset(&data, 0, sizeof(struct patch_id_t));
5643        data.ctx = &ctx;
5644
5645        for (i = 0; i < q->nr; i++) {
5646                xpparam_t xpp;
5647                xdemitconf_t xecfg;
5648                mmfile_t mf1, mf2;
5649                struct diff_filepair *p = q->queue[i];
5650                int len1, len2;
5651
5652                memset(&xpp, 0, sizeof(xpp));
5653                memset(&xecfg, 0, sizeof(xecfg));
5654                if (p->status == 0)
5655                        return error("internal diff status error");
5656                if (p->status == DIFF_STATUS_UNKNOWN)
5657                        continue;
5658                if (diff_unmodified_pair(p))
5659                        continue;
5660                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5661                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5662                        continue;
5663                if (DIFF_PAIR_UNMERGED(p))
5664                        continue;
5665
5666                diff_fill_oid_info(p->one);
5667                diff_fill_oid_info(p->two);
5668
5669                len1 = remove_space(p->one->path, strlen(p->one->path));
5670                len2 = remove_space(p->two->path, strlen(p->two->path));
5671                patch_id_add_string(&ctx, "diff--git");
5672                patch_id_add_string(&ctx, "a/");
5673                git_SHA1_Update(&ctx, p->one->path, len1);
5674                patch_id_add_string(&ctx, "b/");
5675                git_SHA1_Update(&ctx, p->two->path, len2);
5676
5677                if (p->one->mode == 0) {
5678                        patch_id_add_string(&ctx, "newfilemode");
5679                        patch_id_add_mode(&ctx, p->two->mode);
5680                        patch_id_add_string(&ctx, "---/dev/null");
5681                        patch_id_add_string(&ctx, "+++b/");
5682                        git_SHA1_Update(&ctx, p->two->path, len2);
5683                } else if (p->two->mode == 0) {
5684                        patch_id_add_string(&ctx, "deletedfilemode");
5685                        patch_id_add_mode(&ctx, p->one->mode);
5686                        patch_id_add_string(&ctx, "---a/");
5687                        git_SHA1_Update(&ctx, p->one->path, len1);
5688                        patch_id_add_string(&ctx, "+++/dev/null");
5689                } else {
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
5696                if (diff_header_only)
5697                        continue;
5698
5699                if (fill_mmfile(&mf1, p->one) < 0 ||
5700                    fill_mmfile(&mf2, p->two) < 0)
5701                        return error("unable to read files to diff");
5702
5703                if (diff_filespec_is_binary(p->one) ||
5704                    diff_filespec_is_binary(p->two)) {
5705                        git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
5706                                        GIT_SHA1_HEXSZ);
5707                        git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
5708                                        GIT_SHA1_HEXSZ);
5709                        continue;
5710                }
5711
5712                xpp.flags = 0;
5713                xecfg.ctxlen = 3;
5714                xecfg.flags = 0;
5715                if (xdi_diff_outf(&mf1, &mf2, NULL, patch_id_consume,
5716                                  &data, &xpp, &xecfg))
5717                        return error("unable to generate patch-id diff for %s",
5718                                     p->one->path);
5719        }
5720
5721        git_SHA1_Final(oid->hash, &ctx);
5722        return 0;
5723}
5724
5725int diff_flush_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5726{
5727        struct diff_queue_struct *q = &diff_queued_diff;
5728        int i;
5729        int result = diff_get_patch_id(options, oid, diff_header_only);
5730
5731        for (i = 0; i < q->nr; i++)
5732                diff_free_filepair(q->queue[i]);
5733
5734        free(q->queue);
5735        DIFF_QUEUE_CLEAR(q);
5736
5737        return result;
5738}
5739
5740static int is_summary_empty(const struct diff_queue_struct *q)
5741{
5742        int i;
5743
5744        for (i = 0; i < q->nr; i++) {
5745                const struct diff_filepair *p = q->queue[i];
5746
5747                switch (p->status) {
5748                case DIFF_STATUS_DELETED:
5749                case DIFF_STATUS_ADDED:
5750                case DIFF_STATUS_COPIED:
5751                case DIFF_STATUS_RENAMED:
5752                        return 0;
5753                default:
5754                        if (p->score)
5755                                return 0;
5756                        if (p->one->mode && p->two->mode &&
5757                            p->one->mode != p->two->mode)
5758                                return 0;
5759                        break;
5760                }
5761        }
5762        return 1;
5763}
5764
5765static const char rename_limit_warning[] =
5766N_("inexact rename detection was skipped due to too many files.");
5767
5768static const char degrade_cc_to_c_warning[] =
5769N_("only found copies from modified paths due to too many files.");
5770
5771static const char rename_limit_advice[] =
5772N_("you may want to set your %s variable to at least "
5773   "%d and retry the command.");
5774
5775void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
5776{
5777        fflush(stdout);
5778        if (degraded_cc)
5779                warning(_(degrade_cc_to_c_warning));
5780        else if (needed)
5781                warning(_(rename_limit_warning));
5782        else
5783                return;
5784        if (0 < needed)
5785                warning(_(rename_limit_advice), varname, needed);
5786}
5787
5788static void diff_flush_patch_all_file_pairs(struct diff_options *o)
5789{
5790        int i;
5791        static struct emitted_diff_symbols esm = EMITTED_DIFF_SYMBOLS_INIT;
5792        struct diff_queue_struct *q = &diff_queued_diff;
5793
5794        if (WSEH_NEW & WS_RULE_MASK)
5795                BUG("WS rules bit mask overlaps with diff symbol flags");
5796
5797        if (o->color_moved)
5798                o->emitted_symbols = &esm;
5799
5800        for (i = 0; i < q->nr; i++) {
5801                struct diff_filepair *p = q->queue[i];
5802                if (check_pair_status(p))
5803                        diff_flush_patch(p, o);
5804        }
5805
5806        if (o->emitted_symbols) {
5807                if (o->color_moved) {
5808                        struct hashmap add_lines, del_lines;
5809
5810                        if (o->color_moved_ws_handling &
5811                            COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
5812                                o->color_moved_ws_handling |= XDF_IGNORE_WHITESPACE;
5813
5814                        hashmap_init(&del_lines, moved_entry_cmp, o, 0);
5815                        hashmap_init(&add_lines, moved_entry_cmp, o, 0);
5816
5817                        add_lines_to_move_detection(o, &add_lines, &del_lines);
5818                        mark_color_as_moved(o, &add_lines, &del_lines);
5819                        if (o->color_moved == COLOR_MOVED_ZEBRA_DIM)
5820                                dim_moved_lines(o);
5821
5822                        hashmap_free(&add_lines, 0);
5823                        hashmap_free(&del_lines, 0);
5824                }
5825
5826                for (i = 0; i < esm.nr; i++)
5827                        emit_diff_symbol_from_struct(o, &esm.buf[i]);
5828
5829                for (i = 0; i < esm.nr; i++)
5830                        free((void *)esm.buf[i].line);
5831        }
5832        esm.nr = 0;
5833}
5834
5835void diff_flush(struct diff_options *options)
5836{
5837        struct diff_queue_struct *q = &diff_queued_diff;
5838        int i, output_format = options->output_format;
5839        int separator = 0;
5840        int dirstat_by_line = 0;
5841
5842        /*
5843         * Order: raw, stat, summary, patch
5844         * or:    name/name-status/checkdiff (other bits clear)
5845         */
5846        if (!q->nr)
5847                goto free_queue;
5848
5849        if (output_format & (DIFF_FORMAT_RAW |
5850                             DIFF_FORMAT_NAME |
5851                             DIFF_FORMAT_NAME_STATUS |
5852                             DIFF_FORMAT_CHECKDIFF)) {
5853                for (i = 0; i < q->nr; i++) {
5854                        struct diff_filepair *p = q->queue[i];
5855                        if (check_pair_status(p))
5856                                flush_one_pair(p, options);
5857                }
5858                separator++;
5859        }
5860
5861        if (output_format & DIFF_FORMAT_DIRSTAT && options->flags.dirstat_by_line)
5862                dirstat_by_line = 1;
5863
5864        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
5865            dirstat_by_line) {
5866                struct diffstat_t diffstat;
5867
5868                memset(&diffstat, 0, sizeof(struct diffstat_t));
5869                for (i = 0; i < q->nr; i++) {
5870                        struct diff_filepair *p = q->queue[i];
5871                        if (check_pair_status(p))
5872                                diff_flush_stat(p, options, &diffstat);
5873                }
5874                if (output_format & DIFF_FORMAT_NUMSTAT)
5875                        show_numstat(&diffstat, options);
5876                if (output_format & DIFF_FORMAT_DIFFSTAT)
5877                        show_stats(&diffstat, options);
5878                if (output_format & DIFF_FORMAT_SHORTSTAT)
5879                        show_shortstats(&diffstat, options);
5880                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
5881                        show_dirstat_by_line(&diffstat, options);
5882                free_diffstat_info(&diffstat);
5883                separator++;
5884        }
5885        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
5886                show_dirstat(options);
5887
5888        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
5889                for (i = 0; i < q->nr; i++) {
5890                        diff_summary(options, q->queue[i]);
5891                }
5892                separator++;
5893        }
5894
5895        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
5896            options->flags.exit_with_status &&
5897            options->flags.diff_from_contents) {
5898                /*
5899                 * run diff_flush_patch for the exit status. setting
5900                 * options->file to /dev/null should be safe, because we
5901                 * aren't supposed to produce any output anyway.
5902                 */
5903                if (options->close_file)
5904                        fclose(options->file);
5905                options->file = xfopen("/dev/null", "w");
5906                options->close_file = 1;
5907                options->color_moved = 0;
5908                for (i = 0; i < q->nr; i++) {
5909                        struct diff_filepair *p = q->queue[i];
5910                        if (check_pair_status(p))
5911                                diff_flush_patch(p, options);
5912                        if (options->found_changes)
5913                                break;
5914                }
5915        }
5916
5917        if (output_format & DIFF_FORMAT_PATCH) {
5918                if (separator) {
5919                        emit_diff_symbol(options, DIFF_SYMBOL_SEPARATOR, NULL, 0, 0);
5920                        if (options->stat_sep)
5921                                /* attach patch instead of inline */
5922                                emit_diff_symbol(options, DIFF_SYMBOL_STAT_SEP,
5923                                                 NULL, 0, 0);
5924                }
5925
5926                diff_flush_patch_all_file_pairs(options);
5927        }
5928
5929        if (output_format & DIFF_FORMAT_CALLBACK)
5930                options->format_callback(q, options, options->format_callback_data);
5931
5932        for (i = 0; i < q->nr; i++)
5933                diff_free_filepair(q->queue[i]);
5934free_queue:
5935        free(q->queue);
5936        DIFF_QUEUE_CLEAR(q);
5937        if (options->close_file)
5938                fclose(options->file);
5939
5940        /*
5941         * Report the content-level differences with HAS_CHANGES;
5942         * diff_addremove/diff_change does not set the bit when
5943         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
5944         */
5945        if (options->flags.diff_from_contents) {
5946                if (options->found_changes)
5947                        options->flags.has_changes = 1;
5948                else
5949                        options->flags.has_changes = 0;
5950        }
5951}
5952
5953static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
5954{
5955        return (((p->status == DIFF_STATUS_MODIFIED) &&
5956                 ((p->score &&
5957                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
5958                  (!p->score &&
5959                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
5960                ((p->status != DIFF_STATUS_MODIFIED) &&
5961                 filter_bit_tst(p->status, options)));
5962}
5963
5964static void diffcore_apply_filter(struct diff_options *options)
5965{
5966        int i;
5967        struct diff_queue_struct *q = &diff_queued_diff;
5968        struct diff_queue_struct outq;
5969
5970        DIFF_QUEUE_CLEAR(&outq);
5971
5972        if (!options->filter)
5973                return;
5974
5975        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
5976                int found;
5977                for (i = found = 0; !found && i < q->nr; i++) {
5978                        if (match_filter(options, q->queue[i]))
5979                                found++;
5980                }
5981                if (found)
5982                        return;
5983
5984                /* otherwise we will clear the whole queue
5985                 * by copying the empty outq at the end of this
5986                 * function, but first clear the current entries
5987                 * in the queue.
5988                 */
5989                for (i = 0; i < q->nr; i++)
5990                        diff_free_filepair(q->queue[i]);
5991        }
5992        else {
5993                /* Only the matching ones */
5994                for (i = 0; i < q->nr; i++) {
5995                        struct diff_filepair *p = q->queue[i];
5996                        if (match_filter(options, p))
5997                                diff_q(&outq, p);
5998                        else
5999                                diff_free_filepair(p);
6000                }
6001        }
6002        free(q->queue);
6003        *q = outq;
6004}
6005
6006/* Check whether two filespecs with the same mode and size are identical */
6007static int diff_filespec_is_identical(struct diff_filespec *one,
6008                                      struct diff_filespec *two)
6009{
6010        if (S_ISGITLINK(one->mode))
6011                return 0;
6012        if (diff_populate_filespec(one, 0))
6013                return 0;
6014        if (diff_populate_filespec(two, 0))
6015                return 0;
6016        return !memcmp(one->data, two->data, one->size);
6017}
6018
6019static int diff_filespec_check_stat_unmatch(struct diff_filepair *p)
6020{
6021        if (p->done_skip_stat_unmatch)
6022                return p->skip_stat_unmatch_result;
6023
6024        p->done_skip_stat_unmatch = 1;
6025        p->skip_stat_unmatch_result = 0;
6026        /*
6027         * 1. Entries that come from stat info dirtiness
6028         *    always have both sides (iow, not create/delete),
6029         *    one side of the object name is unknown, with
6030         *    the same mode and size.  Keep the ones that
6031         *    do not match these criteria.  They have real
6032         *    differences.
6033         *
6034         * 2. At this point, the file is known to be modified,
6035         *    with the same mode and size, and the object
6036         *    name of one side is unknown.  Need to inspect
6037         *    the identical contents.
6038         */
6039        if (!DIFF_FILE_VALID(p->one) || /* (1) */
6040            !DIFF_FILE_VALID(p->two) ||
6041            (p->one->oid_valid && p->two->oid_valid) ||
6042            (p->one->mode != p->two->mode) ||
6043            diff_populate_filespec(p->one, CHECK_SIZE_ONLY) ||
6044            diff_populate_filespec(p->two, CHECK_SIZE_ONLY) ||
6045            (p->one->size != p->two->size) ||
6046            !diff_filespec_is_identical(p->one, p->two)) /* (2) */
6047                p->skip_stat_unmatch_result = 1;
6048        return p->skip_stat_unmatch_result;
6049}
6050
6051static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
6052{
6053        int i;
6054        struct diff_queue_struct *q = &diff_queued_diff;
6055        struct diff_queue_struct outq;
6056        DIFF_QUEUE_CLEAR(&outq);
6057
6058        for (i = 0; i < q->nr; i++) {
6059                struct diff_filepair *p = q->queue[i];
6060
6061                if (diff_filespec_check_stat_unmatch(p))
6062                        diff_q(&outq, p);
6063                else {
6064                        /*
6065                         * The caller can subtract 1 from skip_stat_unmatch
6066                         * to determine how many paths were dirty only
6067                         * due to stat info mismatch.
6068                         */
6069                        if (!diffopt->flags.no_index)
6070                                diffopt->skip_stat_unmatch++;
6071                        diff_free_filepair(p);
6072                }
6073        }
6074        free(q->queue);
6075        *q = outq;
6076}
6077
6078static int diffnamecmp(const void *a_, const void *b_)
6079{
6080        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
6081        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
6082        const char *name_a, *name_b;
6083
6084        name_a = a->one ? a->one->path : a->two->path;
6085        name_b = b->one ? b->one->path : b->two->path;
6086        return strcmp(name_a, name_b);
6087}
6088
6089void diffcore_fix_diff_index(struct diff_options *options)
6090{
6091        struct diff_queue_struct *q = &diff_queued_diff;
6092        QSORT(q->queue, q->nr, diffnamecmp);
6093}
6094
6095void diffcore_std(struct diff_options *options)
6096{
6097        /* NOTE please keep the following in sync with diff_tree_combined() */
6098        if (options->skip_stat_unmatch)
6099                diffcore_skip_stat_unmatch(options);
6100        if (!options->found_follow) {
6101                /* See try_to_follow_renames() in tree-diff.c */
6102                if (options->break_opt != -1)
6103                        diffcore_break(options->break_opt);
6104                if (options->detect_rename)
6105                        diffcore_rename(options);
6106                if (options->break_opt != -1)
6107                        diffcore_merge_broken();
6108        }
6109        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
6110                diffcore_pickaxe(options);
6111        if (options->orderfile)
6112                diffcore_order(options->orderfile);
6113        if (!options->found_follow)
6114                /* See try_to_follow_renames() in tree-diff.c */
6115                diff_resolve_rename_copy();
6116        diffcore_apply_filter(options);
6117
6118        if (diff_queued_diff.nr && !options->flags.diff_from_contents)
6119                options->flags.has_changes = 1;
6120        else
6121                options->flags.has_changes = 0;
6122
6123        options->found_follow = 0;
6124}
6125
6126int diff_result_code(struct diff_options *opt, int status)
6127{
6128        int result = 0;
6129
6130        diff_warn_rename_limit("diff.renameLimit",
6131                               opt->needed_rename_limit,
6132                               opt->degraded_cc_to_c);
6133        if (!opt->flags.exit_with_status &&
6134            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
6135                return status;
6136        if (opt->flags.exit_with_status &&
6137            opt->flags.has_changes)
6138                result |= 01;
6139        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
6140            opt->flags.check_failed)
6141                result |= 02;
6142        return result;
6143}
6144
6145int diff_can_quit_early(struct diff_options *opt)
6146{
6147        return (opt->flags.quick &&
6148                !opt->filter &&
6149                opt->flags.has_changes);
6150}
6151
6152/*
6153 * Shall changes to this submodule be ignored?
6154 *
6155 * Submodule changes can be configured to be ignored separately for each path,
6156 * but that configuration can be overridden from the command line.
6157 */
6158static int is_submodule_ignored(const char *path, struct diff_options *options)
6159{
6160        int ignored = 0;
6161        struct diff_flags orig_flags = options->flags;
6162        if (!options->flags.override_submodule_config)
6163                set_diffopt_flags_from_submodule_config(options, path);
6164        if (options->flags.ignore_submodules)
6165                ignored = 1;
6166        options->flags = orig_flags;
6167        return ignored;
6168}
6169
6170void diff_addremove(struct diff_options *options,
6171                    int addremove, unsigned mode,
6172                    const struct object_id *oid,
6173                    int oid_valid,
6174                    const char *concatpath, unsigned dirty_submodule)
6175{
6176        struct diff_filespec *one, *two;
6177
6178        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
6179                return;
6180
6181        /* This may look odd, but it is a preparation for
6182         * feeding "there are unchanged files which should
6183         * not produce diffs, but when you are doing copy
6184         * detection you would need them, so here they are"
6185         * entries to the diff-core.  They will be prefixed
6186         * with something like '=' or '*' (I haven't decided
6187         * which but should not make any difference).
6188         * Feeding the same new and old to diff_change()
6189         * also has the same effect.
6190         * Before the final output happens, they are pruned after
6191         * merged into rename/copy pairs as appropriate.
6192         */
6193        if (options->flags.reverse_diff)
6194                addremove = (addremove == '+' ? '-' :
6195                             addremove == '-' ? '+' : addremove);
6196
6197        if (options->prefix &&
6198            strncmp(concatpath, options->prefix, options->prefix_length))
6199                return;
6200
6201        one = alloc_filespec(concatpath);
6202        two = alloc_filespec(concatpath);
6203
6204        if (addremove != '+')
6205                fill_filespec(one, oid, oid_valid, mode);
6206        if (addremove != '-') {
6207                fill_filespec(two, oid, oid_valid, mode);
6208                two->dirty_submodule = dirty_submodule;
6209        }
6210
6211        diff_queue(&diff_queued_diff, one, two);
6212        if (!options->flags.diff_from_contents)
6213                options->flags.has_changes = 1;
6214}
6215
6216void diff_change(struct diff_options *options,
6217                 unsigned old_mode, unsigned new_mode,
6218                 const struct object_id *old_oid,
6219                 const struct object_id *new_oid,
6220                 int old_oid_valid, int new_oid_valid,
6221                 const char *concatpath,
6222                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
6223{
6224        struct diff_filespec *one, *two;
6225        struct diff_filepair *p;
6226
6227        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
6228            is_submodule_ignored(concatpath, options))
6229                return;
6230
6231        if (options->flags.reverse_diff) {
6232                SWAP(old_mode, new_mode);
6233                SWAP(old_oid, new_oid);
6234                SWAP(old_oid_valid, new_oid_valid);
6235                SWAP(old_dirty_submodule, new_dirty_submodule);
6236        }
6237
6238        if (options->prefix &&
6239            strncmp(concatpath, options->prefix, options->prefix_length))
6240                return;
6241
6242        one = alloc_filespec(concatpath);
6243        two = alloc_filespec(concatpath);
6244        fill_filespec(one, old_oid, old_oid_valid, old_mode);
6245        fill_filespec(two, new_oid, new_oid_valid, new_mode);
6246        one->dirty_submodule = old_dirty_submodule;
6247        two->dirty_submodule = new_dirty_submodule;
6248        p = diff_queue(&diff_queued_diff, one, two);
6249
6250        if (options->flags.diff_from_contents)
6251                return;
6252
6253        if (options->flags.quick && options->skip_stat_unmatch &&
6254            !diff_filespec_check_stat_unmatch(p))
6255                return;
6256
6257        options->flags.has_changes = 1;
6258}
6259
6260struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
6261{
6262        struct diff_filepair *pair;
6263        struct diff_filespec *one, *two;
6264
6265        if (options->prefix &&
6266            strncmp(path, options->prefix, options->prefix_length))
6267                return NULL;
6268
6269        one = alloc_filespec(path);
6270        two = alloc_filespec(path);
6271        pair = diff_queue(&diff_queued_diff, one, two);
6272        pair->is_unmerged = 1;
6273        return pair;
6274}
6275
6276static char *run_textconv(const char *pgm, struct diff_filespec *spec,
6277                size_t *outsize)
6278{
6279        struct diff_tempfile *temp;
6280        const char *argv[3];
6281        const char **arg = argv;
6282        struct child_process child = CHILD_PROCESS_INIT;
6283        struct strbuf buf = STRBUF_INIT;
6284        int err = 0;
6285
6286        temp = prepare_temp_file(spec->path, spec);
6287        *arg++ = pgm;
6288        *arg++ = temp->name;
6289        *arg = NULL;
6290
6291        child.use_shell = 1;
6292        child.argv = argv;
6293        child.out = -1;
6294        if (start_command(&child)) {
6295                remove_tempfile();
6296                return NULL;
6297        }
6298
6299        if (strbuf_read(&buf, child.out, 0) < 0)
6300                err = error("error reading from textconv command '%s'", pgm);
6301        close(child.out);
6302
6303        if (finish_command(&child) || err) {
6304                strbuf_release(&buf);
6305                remove_tempfile();
6306                return NULL;
6307        }
6308        remove_tempfile();
6309
6310        return strbuf_detach(&buf, outsize);
6311}
6312
6313size_t fill_textconv(struct userdiff_driver *driver,
6314                     struct diff_filespec *df,
6315                     char **outbuf)
6316{
6317        size_t size;
6318
6319        if (!driver) {
6320                if (!DIFF_FILE_VALID(df)) {
6321                        *outbuf = "";
6322                        return 0;
6323                }
6324                if (diff_populate_filespec(df, 0))
6325                        die("unable to read files to diff");
6326                *outbuf = df->data;
6327                return df->size;
6328        }
6329
6330        if (!driver->textconv)
6331                BUG("fill_textconv called with non-textconv driver");
6332
6333        if (driver->textconv_cache && df->oid_valid) {
6334                *outbuf = notes_cache_get(driver->textconv_cache,
6335                                          &df->oid,
6336                                          &size);
6337                if (*outbuf)
6338                        return size;
6339        }
6340
6341        *outbuf = run_textconv(driver->textconv, df, &size);
6342        if (!*outbuf)
6343                die("unable to read files to diff");
6344
6345        if (driver->textconv_cache && df->oid_valid) {
6346                /* ignore errors, as we might be in a readonly repository */
6347                notes_cache_put(driver->textconv_cache, &df->oid, *outbuf,
6348                                size);
6349                /*
6350                 * we could save up changes and flush them all at the end,
6351                 * but we would need an extra call after all diffing is done.
6352                 * Since generating a cache entry is the slow path anyway,
6353                 * this extra overhead probably isn't a big deal.
6354                 */
6355                notes_cache_write(driver->textconv_cache);
6356        }
6357
6358        return size;
6359}
6360
6361int textconv_object(const char *path,
6362                    unsigned mode,
6363                    const struct object_id *oid,
6364                    int oid_valid,
6365                    char **buf,
6366                    unsigned long *buf_size)
6367{
6368        struct diff_filespec *df;
6369        struct userdiff_driver *textconv;
6370
6371        df = alloc_filespec(path);
6372        fill_filespec(df, oid, oid_valid, mode);
6373        textconv = get_textconv(df);
6374        if (!textconv) {
6375                free_filespec(df);
6376                return 0;
6377        }
6378
6379        *buf_size = fill_textconv(textconv, df, buf);
6380        free_filespec(df);
6381        return 1;
6382}
6383
6384void setup_diff_pager(struct diff_options *opt)
6385{
6386        /*
6387         * If the user asked for our exit code, then either they want --quiet
6388         * or --exit-code. We should definitely not bother with a pager in the
6389         * former case, as we will generate no output. Since we still properly
6390         * report our exit code even when a pager is run, we _could_ run a
6391         * pager with --exit-code. But since we have not done so historically,
6392         * and because it is easy to find people oneline advising "git diff
6393         * --exit-code" in hooks and other scripts, we do not do so.
6394         */
6395        if (!opt->flags.exit_with_status &&
6396            check_pager_config("diff") != 0)
6397                setup_pager();
6398}