diff.con commit Merge branch 'tg/rerere-doc-updates' (d88949d)
   1/*
   2 * Copyright (C) 2005 Junio C Hamano
   3 */
   4#include "cache.h"
   5#include "config.h"
   6#include "tempfile.h"
   7#include "quote.h"
   8#include "diff.h"
   9#include "diffcore.h"
  10#include "delta.h"
  11#include "xdiff-interface.h"
  12#include "color.h"
  13#include "attr.h"
  14#include "run-command.h"
  15#include "utf8.h"
  16#include "object-store.h"
  17#include "userdiff.h"
  18#include "submodule-config.h"
  19#include "submodule.h"
  20#include "hashmap.h"
  21#include "ll-merge.h"
  22#include "string-list.h"
  23#include "argv-array.h"
  24#include "graph.h"
  25#include "packfile.h"
  26#include "help.h"
  27
  28#ifdef NO_FAST_WORKING_DIRECTORY
  29#define FAST_WORKING_DIRECTORY 0
  30#else
  31#define FAST_WORKING_DIRECTORY 1
  32#endif
  33
  34static int diff_detect_rename_default;
  35static int diff_indent_heuristic = 1;
  36static int diff_rename_limit_default = 400;
  37static int diff_suppress_blank_empty;
  38static int diff_use_color_default = -1;
  39static int diff_color_moved_default;
  40static int diff_color_moved_ws_default;
  41static int diff_context_default = 3;
  42static int diff_interhunk_context_default;
  43static const char *diff_word_regex_cfg;
  44static const char *external_diff_cmd_cfg;
  45static const char *diff_order_file_cfg;
  46int diff_auto_refresh_index = 1;
  47static int diff_mnemonic_prefix;
  48static int diff_no_prefix;
  49static int diff_stat_graph_width;
  50static int diff_dirstat_permille_default = 30;
  51static struct diff_options default_diff_options;
  52static long diff_algorithm;
  53static unsigned ws_error_highlight_default = WSEH_NEW;
  54
  55static char diff_colors[][COLOR_MAXLEN] = {
  56        GIT_COLOR_RESET,
  57        GIT_COLOR_NORMAL,       /* CONTEXT */
  58        GIT_COLOR_BOLD,         /* METAINFO */
  59        GIT_COLOR_CYAN,         /* FRAGINFO */
  60        GIT_COLOR_RED,          /* OLD */
  61        GIT_COLOR_GREEN,        /* NEW */
  62        GIT_COLOR_YELLOW,       /* COMMIT */
  63        GIT_COLOR_BG_RED,       /* WHITESPACE */
  64        GIT_COLOR_NORMAL,       /* FUNCINFO */
  65        GIT_COLOR_BOLD_MAGENTA, /* OLD_MOVED */
  66        GIT_COLOR_BOLD_BLUE,    /* OLD_MOVED ALTERNATIVE */
  67        GIT_COLOR_FAINT,        /* OLD_MOVED_DIM */
  68        GIT_COLOR_FAINT_ITALIC, /* OLD_MOVED_ALTERNATIVE_DIM */
  69        GIT_COLOR_BOLD_CYAN,    /* NEW_MOVED */
  70        GIT_COLOR_BOLD_YELLOW,  /* NEW_MOVED ALTERNATIVE */
  71        GIT_COLOR_FAINT,        /* NEW_MOVED_DIM */
  72        GIT_COLOR_FAINT_ITALIC, /* NEW_MOVED_ALTERNATIVE_DIM */
  73        GIT_COLOR_FAINT,        /* CONTEXT_DIM */
  74        GIT_COLOR_FAINT_RED,    /* OLD_DIM */
  75        GIT_COLOR_FAINT_GREEN,  /* NEW_DIM */
  76        GIT_COLOR_BOLD,         /* CONTEXT_BOLD */
  77        GIT_COLOR_BOLD_RED,     /* OLD_BOLD */
  78        GIT_COLOR_BOLD_GREEN,   /* NEW_BOLD */
  79};
  80
  81static const char *color_diff_slots[] = {
  82        [DIFF_CONTEXT]                = "context",
  83        [DIFF_METAINFO]               = "meta",
  84        [DIFF_FRAGINFO]               = "frag",
  85        [DIFF_FILE_OLD]               = "old",
  86        [DIFF_FILE_NEW]               = "new",
  87        [DIFF_COMMIT]                 = "commit",
  88        [DIFF_WHITESPACE]             = "whitespace",
  89        [DIFF_FUNCINFO]               = "func",
  90        [DIFF_FILE_OLD_MOVED]         = "oldMoved",
  91        [DIFF_FILE_OLD_MOVED_ALT]     = "oldMovedAlternative",
  92        [DIFF_FILE_OLD_MOVED_DIM]     = "oldMovedDimmed",
  93        [DIFF_FILE_OLD_MOVED_ALT_DIM] = "oldMovedAlternativeDimmed",
  94        [DIFF_FILE_NEW_MOVED]         = "newMoved",
  95        [DIFF_FILE_NEW_MOVED_ALT]     = "newMovedAlternative",
  96        [DIFF_FILE_NEW_MOVED_DIM]     = "newMovedDimmed",
  97        [DIFF_FILE_NEW_MOVED_ALT_DIM] = "newMovedAlternativeDimmed",
  98        [DIFF_CONTEXT_DIM]            = "contextDimmed",
  99        [DIFF_FILE_OLD_DIM]           = "oldDimmed",
 100        [DIFF_FILE_NEW_DIM]           = "newDimmed",
 101        [DIFF_CONTEXT_BOLD]           = "contextBold",
 102        [DIFF_FILE_OLD_BOLD]          = "oldBold",
 103        [DIFF_FILE_NEW_BOLD]          = "newBold",
 104};
 105
 106static NORETURN void die_want_option(const char *option_name)
 107{
 108        die(_("option '%s' requires a value"), option_name);
 109}
 110
 111define_list_config_array_extra(color_diff_slots, {"plain"});
 112
 113static int parse_diff_color_slot(const char *var)
 114{
 115        if (!strcasecmp(var, "plain"))
 116                return DIFF_CONTEXT;
 117        return LOOKUP_CONFIG(color_diff_slots, var);
 118}
 119
 120static int parse_dirstat_params(struct diff_options *options, const char *params_string,
 121                                struct strbuf *errmsg)
 122{
 123        char *params_copy = xstrdup(params_string);
 124        struct string_list params = STRING_LIST_INIT_NODUP;
 125        int ret = 0;
 126        int i;
 127
 128        if (*params_copy)
 129                string_list_split_in_place(&params, params_copy, ',', -1);
 130        for (i = 0; i < params.nr; i++) {
 131                const char *p = params.items[i].string;
 132                if (!strcmp(p, "changes")) {
 133                        options->flags.dirstat_by_line = 0;
 134                        options->flags.dirstat_by_file = 0;
 135                } else if (!strcmp(p, "lines")) {
 136                        options->flags.dirstat_by_line = 1;
 137                        options->flags.dirstat_by_file = 0;
 138                } else if (!strcmp(p, "files")) {
 139                        options->flags.dirstat_by_line = 0;
 140                        options->flags.dirstat_by_file = 1;
 141                } else if (!strcmp(p, "noncumulative")) {
 142                        options->flags.dirstat_cumulative = 0;
 143                } else if (!strcmp(p, "cumulative")) {
 144                        options->flags.dirstat_cumulative = 1;
 145                } else if (isdigit(*p)) {
 146                        char *end;
 147                        int permille = strtoul(p, &end, 10) * 10;
 148                        if (*end == '.' && isdigit(*++end)) {
 149                                /* only use first digit */
 150                                permille += *end - '0';
 151                                /* .. and ignore any further digits */
 152                                while (isdigit(*++end))
 153                                        ; /* nothing */
 154                        }
 155                        if (!*end)
 156                                options->dirstat_permille = permille;
 157                        else {
 158                                strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%s'\n"),
 159                                            p);
 160                                ret++;
 161                        }
 162                } else {
 163                        strbuf_addf(errmsg, _("  Unknown dirstat parameter '%s'\n"), p);
 164                        ret++;
 165                }
 166
 167        }
 168        string_list_clear(&params, 0);
 169        free(params_copy);
 170        return ret;
 171}
 172
 173static int parse_submodule_params(struct diff_options *options, const char *value)
 174{
 175        if (!strcmp(value, "log"))
 176                options->submodule_format = DIFF_SUBMODULE_LOG;
 177        else if (!strcmp(value, "short"))
 178                options->submodule_format = DIFF_SUBMODULE_SHORT;
 179        else if (!strcmp(value, "diff"))
 180                options->submodule_format = DIFF_SUBMODULE_INLINE_DIFF;
 181        else
 182                return -1;
 183        return 0;
 184}
 185
 186int git_config_rename(const char *var, const char *value)
 187{
 188        if (!value)
 189                return DIFF_DETECT_RENAME;
 190        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 191                return  DIFF_DETECT_COPY;
 192        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 193}
 194
 195long parse_algorithm_value(const char *value)
 196{
 197        if (!value)
 198                return -1;
 199        else if (!strcasecmp(value, "myers") || !strcasecmp(value, "default"))
 200                return 0;
 201        else if (!strcasecmp(value, "minimal"))
 202                return XDF_NEED_MINIMAL;
 203        else if (!strcasecmp(value, "patience"))
 204                return XDF_PATIENCE_DIFF;
 205        else if (!strcasecmp(value, "histogram"))
 206                return XDF_HISTOGRAM_DIFF;
 207        return -1;
 208}
 209
 210static int parse_one_token(const char **arg, const char *token)
 211{
 212        const char *rest;
 213        if (skip_prefix(*arg, token, &rest) && (!*rest || *rest == ',')) {
 214                *arg = rest;
 215                return 1;
 216        }
 217        return 0;
 218}
 219
 220static int parse_ws_error_highlight(const char *arg)
 221{
 222        const char *orig_arg = arg;
 223        unsigned val = 0;
 224
 225        while (*arg) {
 226                if (parse_one_token(&arg, "none"))
 227                        val = 0;
 228                else if (parse_one_token(&arg, "default"))
 229                        val = WSEH_NEW;
 230                else if (parse_one_token(&arg, "all"))
 231                        val = WSEH_NEW | WSEH_OLD | WSEH_CONTEXT;
 232                else if (parse_one_token(&arg, "new"))
 233                        val |= WSEH_NEW;
 234                else if (parse_one_token(&arg, "old"))
 235                        val |= WSEH_OLD;
 236                else if (parse_one_token(&arg, "context"))
 237                        val |= WSEH_CONTEXT;
 238                else {
 239                        return -1 - (int)(arg - orig_arg);
 240                }
 241                if (*arg)
 242                        arg++;
 243        }
 244        return val;
 245}
 246
 247/*
 248 * These are to give UI layer defaults.
 249 * The core-level commands such as git-diff-files should
 250 * never be affected by the setting of diff.renames
 251 * the user happens to have in the configuration file.
 252 */
 253void init_diff_ui_defaults(void)
 254{
 255        diff_detect_rename_default = DIFF_DETECT_RENAME;
 256}
 257
 258int git_diff_heuristic_config(const char *var, const char *value, void *cb)
 259{
 260        if (!strcmp(var, "diff.indentheuristic"))
 261                diff_indent_heuristic = git_config_bool(var, value);
 262        return 0;
 263}
 264
 265static int parse_color_moved(const char *arg)
 266{
 267        switch (git_parse_maybe_bool(arg)) {
 268        case 0:
 269                return COLOR_MOVED_NO;
 270        case 1:
 271                return COLOR_MOVED_DEFAULT;
 272        default:
 273                break;
 274        }
 275
 276        if (!strcmp(arg, "no"))
 277                return COLOR_MOVED_NO;
 278        else if (!strcmp(arg, "plain"))
 279                return COLOR_MOVED_PLAIN;
 280        else if (!strcmp(arg, "blocks"))
 281                return COLOR_MOVED_BLOCKS;
 282        else if (!strcmp(arg, "zebra"))
 283                return COLOR_MOVED_ZEBRA;
 284        else if (!strcmp(arg, "default"))
 285                return COLOR_MOVED_DEFAULT;
 286        else if (!strcmp(arg, "dimmed-zebra"))
 287                return COLOR_MOVED_ZEBRA_DIM;
 288        else if (!strcmp(arg, "dimmed_zebra"))
 289                return COLOR_MOVED_ZEBRA_DIM;
 290        else
 291                return error(_("color moved setting must be one of 'no', 'default', 'blocks', 'zebra', 'dimmed-zebra', 'plain'"));
 292}
 293
 294static int parse_color_moved_ws(const char *arg)
 295{
 296        int ret = 0;
 297        struct string_list l = STRING_LIST_INIT_DUP;
 298        struct string_list_item *i;
 299
 300        string_list_split(&l, arg, ',', -1);
 301
 302        for_each_string_list_item(i, &l) {
 303                struct strbuf sb = STRBUF_INIT;
 304                strbuf_addstr(&sb, i->string);
 305                strbuf_trim(&sb);
 306
 307                if (!strcmp(sb.buf, "ignore-space-change"))
 308                        ret |= XDF_IGNORE_WHITESPACE_CHANGE;
 309                else if (!strcmp(sb.buf, "ignore-space-at-eol"))
 310                        ret |= XDF_IGNORE_WHITESPACE_AT_EOL;
 311                else if (!strcmp(sb.buf, "ignore-all-space"))
 312                        ret |= XDF_IGNORE_WHITESPACE;
 313                else if (!strcmp(sb.buf, "allow-indentation-change"))
 314                        ret |= COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE;
 315                else
 316                        error(_("ignoring unknown color-moved-ws mode '%s'"), sb.buf);
 317
 318                strbuf_release(&sb);
 319        }
 320
 321        if ((ret & COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) &&
 322            (ret & XDF_WHITESPACE_FLAGS))
 323                die(_("color-moved-ws: allow-indentation-change cannot be combined with other white space modes"));
 324
 325        string_list_clear(&l, 0);
 326
 327        return ret;
 328}
 329
 330int git_diff_ui_config(const char *var, const char *value, void *cb)
 331{
 332        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 333                diff_use_color_default = git_config_colorbool(var, value);
 334                return 0;
 335        }
 336        if (!strcmp(var, "diff.colormoved")) {
 337                int cm = parse_color_moved(value);
 338                if (cm < 0)
 339                        return -1;
 340                diff_color_moved_default = cm;
 341                return 0;
 342        }
 343        if (!strcmp(var, "diff.colormovedws")) {
 344                int cm = parse_color_moved_ws(value);
 345                if (cm < 0)
 346                        return -1;
 347                diff_color_moved_ws_default = cm;
 348                return 0;
 349        }
 350        if (!strcmp(var, "diff.context")) {
 351                diff_context_default = git_config_int(var, value);
 352                if (diff_context_default < 0)
 353                        return -1;
 354                return 0;
 355        }
 356        if (!strcmp(var, "diff.interhunkcontext")) {
 357                diff_interhunk_context_default = git_config_int(var, value);
 358                if (diff_interhunk_context_default < 0)
 359                        return -1;
 360                return 0;
 361        }
 362        if (!strcmp(var, "diff.renames")) {
 363                diff_detect_rename_default = git_config_rename(var, value);
 364                return 0;
 365        }
 366        if (!strcmp(var, "diff.autorefreshindex")) {
 367                diff_auto_refresh_index = git_config_bool(var, value);
 368                return 0;
 369        }
 370        if (!strcmp(var, "diff.mnemonicprefix")) {
 371                diff_mnemonic_prefix = git_config_bool(var, value);
 372                return 0;
 373        }
 374        if (!strcmp(var, "diff.noprefix")) {
 375                diff_no_prefix = git_config_bool(var, value);
 376                return 0;
 377        }
 378        if (!strcmp(var, "diff.statgraphwidth")) {
 379                diff_stat_graph_width = git_config_int(var, value);
 380                return 0;
 381        }
 382        if (!strcmp(var, "diff.external"))
 383                return git_config_string(&external_diff_cmd_cfg, var, value);
 384        if (!strcmp(var, "diff.wordregex"))
 385                return git_config_string(&diff_word_regex_cfg, var, value);
 386        if (!strcmp(var, "diff.orderfile"))
 387                return git_config_pathname(&diff_order_file_cfg, var, value);
 388
 389        if (!strcmp(var, "diff.ignoresubmodules"))
 390                handle_ignore_submodules_arg(&default_diff_options, value);
 391
 392        if (!strcmp(var, "diff.submodule")) {
 393                if (parse_submodule_params(&default_diff_options, value))
 394                        warning(_("Unknown value for 'diff.submodule' config variable: '%s'"),
 395                                value);
 396                return 0;
 397        }
 398
 399        if (!strcmp(var, "diff.algorithm")) {
 400                diff_algorithm = parse_algorithm_value(value);
 401                if (diff_algorithm < 0)
 402                        return -1;
 403                return 0;
 404        }
 405
 406        if (!strcmp(var, "diff.wserrorhighlight")) {
 407                int val = parse_ws_error_highlight(value);
 408                if (val < 0)
 409                        return -1;
 410                ws_error_highlight_default = val;
 411                return 0;
 412        }
 413
 414        if (git_color_config(var, value, cb) < 0)
 415                return -1;
 416
 417        return git_diff_basic_config(var, value, cb);
 418}
 419
 420int git_diff_basic_config(const char *var, const char *value, void *cb)
 421{
 422        const char *name;
 423
 424        if (!strcmp(var, "diff.renamelimit")) {
 425                diff_rename_limit_default = git_config_int(var, value);
 426                return 0;
 427        }
 428
 429        if (userdiff_config(var, value) < 0)
 430                return -1;
 431
 432        if (skip_prefix(var, "diff.color.", &name) ||
 433            skip_prefix(var, "color.diff.", &name)) {
 434                int slot = parse_diff_color_slot(name);
 435                if (slot < 0)
 436                        return 0;
 437                if (!value)
 438                        return config_error_nonbool(var);
 439                return color_parse(value, diff_colors[slot]);
 440        }
 441
 442        /* like GNU diff's --suppress-blank-empty option  */
 443        if (!strcmp(var, "diff.suppressblankempty") ||
 444                        /* for backwards compatibility */
 445                        !strcmp(var, "diff.suppress-blank-empty")) {
 446                diff_suppress_blank_empty = git_config_bool(var, value);
 447                return 0;
 448        }
 449
 450        if (!strcmp(var, "diff.dirstat")) {
 451                struct strbuf errmsg = STRBUF_INIT;
 452                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 453                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 454                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 455                                errmsg.buf);
 456                strbuf_release(&errmsg);
 457                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 458                return 0;
 459        }
 460
 461        if (git_diff_heuristic_config(var, value, cb) < 0)
 462                return -1;
 463
 464        return git_default_config(var, value, cb);
 465}
 466
 467static char *quote_two(const char *one, const char *two)
 468{
 469        int need_one = quote_c_style(one, NULL, NULL, 1);
 470        int need_two = quote_c_style(two, NULL, NULL, 1);
 471        struct strbuf res = STRBUF_INIT;
 472
 473        if (need_one + need_two) {
 474                strbuf_addch(&res, '"');
 475                quote_c_style(one, &res, NULL, 1);
 476                quote_c_style(two, &res, NULL, 1);
 477                strbuf_addch(&res, '"');
 478        } else {
 479                strbuf_addstr(&res, one);
 480                strbuf_addstr(&res, two);
 481        }
 482        return strbuf_detach(&res, NULL);
 483}
 484
 485static const char *external_diff(void)
 486{
 487        static const char *external_diff_cmd = NULL;
 488        static int done_preparing = 0;
 489
 490        if (done_preparing)
 491                return external_diff_cmd;
 492        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 493        if (!external_diff_cmd)
 494                external_diff_cmd = external_diff_cmd_cfg;
 495        done_preparing = 1;
 496        return external_diff_cmd;
 497}
 498
 499/*
 500 * Keep track of files used for diffing. Sometimes such an entry
 501 * refers to a temporary file, sometimes to an existing file, and
 502 * sometimes to "/dev/null".
 503 */
 504static struct diff_tempfile {
 505        /*
 506         * filename external diff should read from, or NULL if this
 507         * entry is currently not in use:
 508         */
 509        const char *name;
 510
 511        char hex[GIT_MAX_HEXSZ + 1];
 512        char mode[10];
 513
 514        /*
 515         * If this diff_tempfile instance refers to a temporary file,
 516         * this tempfile object is used to manage its lifetime.
 517         */
 518        struct tempfile *tempfile;
 519} diff_temp[2];
 520
 521struct emit_callback {
 522        int color_diff;
 523        unsigned ws_rule;
 524        int blank_at_eof_in_preimage;
 525        int blank_at_eof_in_postimage;
 526        int lno_in_preimage;
 527        int lno_in_postimage;
 528        const char **label_path;
 529        struct diff_words_data *diff_words;
 530        struct diff_options *opt;
 531        struct strbuf *header;
 532};
 533
 534static int count_lines(const char *data, int size)
 535{
 536        int count, ch, completely_empty = 1, nl_just_seen = 0;
 537        count = 0;
 538        while (0 < size--) {
 539                ch = *data++;
 540                if (ch == '\n') {
 541                        count++;
 542                        nl_just_seen = 1;
 543                        completely_empty = 0;
 544                }
 545                else {
 546                        nl_just_seen = 0;
 547                        completely_empty = 0;
 548                }
 549        }
 550        if (completely_empty)
 551                return 0;
 552        if (!nl_just_seen)
 553                count++; /* no trailing newline */
 554        return count;
 555}
 556
 557static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 558{
 559        if (!DIFF_FILE_VALID(one)) {
 560                mf->ptr = (char *)""; /* does not matter */
 561                mf->size = 0;
 562                return 0;
 563        }
 564        else if (diff_populate_filespec(one, 0))
 565                return -1;
 566
 567        mf->ptr = one->data;
 568        mf->size = one->size;
 569        return 0;
 570}
 571
 572/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 573static unsigned long diff_filespec_size(struct diff_filespec *one)
 574{
 575        if (!DIFF_FILE_VALID(one))
 576                return 0;
 577        diff_populate_filespec(one, CHECK_SIZE_ONLY);
 578        return one->size;
 579}
 580
 581static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 582{
 583        char *ptr = mf->ptr;
 584        long size = mf->size;
 585        int cnt = 0;
 586
 587        if (!size)
 588                return cnt;
 589        ptr += size - 1; /* pointing at the very end */
 590        if (*ptr != '\n')
 591                ; /* incomplete line */
 592        else
 593                ptr--; /* skip the last LF */
 594        while (mf->ptr < ptr) {
 595                char *prev_eol;
 596                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 597                        if (*prev_eol == '\n')
 598                                break;
 599                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 600                        break;
 601                cnt++;
 602                ptr = prev_eol - 1;
 603        }
 604        return cnt;
 605}
 606
 607static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 608                               struct emit_callback *ecbdata)
 609{
 610        int l1, l2, at;
 611        unsigned ws_rule = ecbdata->ws_rule;
 612        l1 = count_trailing_blank(mf1, ws_rule);
 613        l2 = count_trailing_blank(mf2, ws_rule);
 614        if (l2 <= l1) {
 615                ecbdata->blank_at_eof_in_preimage = 0;
 616                ecbdata->blank_at_eof_in_postimage = 0;
 617                return;
 618        }
 619        at = count_lines(mf1->ptr, mf1->size);
 620        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 621
 622        at = count_lines(mf2->ptr, mf2->size);
 623        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 624}
 625
 626static void emit_line_0(struct diff_options *o,
 627                        const char *set_sign, const char *set, unsigned reverse, const char *reset,
 628                        int first, const char *line, int len)
 629{
 630        int has_trailing_newline, has_trailing_carriage_return;
 631        int needs_reset = 0; /* at the end of the line */
 632        FILE *file = o->file;
 633
 634        fputs(diff_line_prefix(o), file);
 635
 636        has_trailing_newline = (len > 0 && line[len-1] == '\n');
 637        if (has_trailing_newline)
 638                len--;
 639
 640        has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 641        if (has_trailing_carriage_return)
 642                len--;
 643
 644        if (!len && !first)
 645                goto end_of_line;
 646
 647        if (reverse && want_color(o->use_color)) {
 648                fputs(GIT_COLOR_REVERSE, file);
 649                needs_reset = 1;
 650        }
 651
 652        if (set_sign) {
 653                fputs(set_sign, file);
 654                needs_reset = 1;
 655        }
 656
 657        if (first)
 658                fputc(first, file);
 659
 660        if (!len)
 661                goto end_of_line;
 662
 663        if (set) {
 664                if (set_sign && set != set_sign)
 665                        fputs(reset, file);
 666                fputs(set, file);
 667                needs_reset = 1;
 668        }
 669        fwrite(line, len, 1, file);
 670        needs_reset = 1; /* 'line' may contain color codes. */
 671
 672end_of_line:
 673        if (needs_reset)
 674                fputs(reset, file);
 675        if (has_trailing_carriage_return)
 676                fputc('\r', file);
 677        if (has_trailing_newline)
 678                fputc('\n', file);
 679}
 680
 681static void emit_line(struct diff_options *o, const char *set, const char *reset,
 682                      const char *line, int len)
 683{
 684        emit_line_0(o, set, NULL, 0, reset, 0, line, len);
 685}
 686
 687enum diff_symbol {
 688        DIFF_SYMBOL_BINARY_DIFF_HEADER,
 689        DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
 690        DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
 691        DIFF_SYMBOL_BINARY_DIFF_BODY,
 692        DIFF_SYMBOL_BINARY_DIFF_FOOTER,
 693        DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
 694        DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
 695        DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
 696        DIFF_SYMBOL_STATS_LINE,
 697        DIFF_SYMBOL_WORD_DIFF,
 698        DIFF_SYMBOL_STAT_SEP,
 699        DIFF_SYMBOL_SUMMARY,
 700        DIFF_SYMBOL_SUBMODULE_ADD,
 701        DIFF_SYMBOL_SUBMODULE_DEL,
 702        DIFF_SYMBOL_SUBMODULE_UNTRACKED,
 703        DIFF_SYMBOL_SUBMODULE_MODIFIED,
 704        DIFF_SYMBOL_SUBMODULE_HEADER,
 705        DIFF_SYMBOL_SUBMODULE_ERROR,
 706        DIFF_SYMBOL_SUBMODULE_PIPETHROUGH,
 707        DIFF_SYMBOL_REWRITE_DIFF,
 708        DIFF_SYMBOL_BINARY_FILES,
 709        DIFF_SYMBOL_HEADER,
 710        DIFF_SYMBOL_FILEPAIR_PLUS,
 711        DIFF_SYMBOL_FILEPAIR_MINUS,
 712        DIFF_SYMBOL_WORDS_PORCELAIN,
 713        DIFF_SYMBOL_WORDS,
 714        DIFF_SYMBOL_CONTEXT,
 715        DIFF_SYMBOL_CONTEXT_INCOMPLETE,
 716        DIFF_SYMBOL_PLUS,
 717        DIFF_SYMBOL_MINUS,
 718        DIFF_SYMBOL_NO_LF_EOF,
 719        DIFF_SYMBOL_CONTEXT_FRAGINFO,
 720        DIFF_SYMBOL_CONTEXT_MARKER,
 721        DIFF_SYMBOL_SEPARATOR
 722};
 723/*
 724 * Flags for content lines:
 725 * 0..12 are whitespace rules
 726 * 13-15 are WSEH_NEW | WSEH_OLD | WSEH_CONTEXT
 727 * 16 is marking if the line is blank at EOF
 728 */
 729#define DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF      (1<<16)
 730#define DIFF_SYMBOL_MOVED_LINE                  (1<<17)
 731#define DIFF_SYMBOL_MOVED_LINE_ALT              (1<<18)
 732#define DIFF_SYMBOL_MOVED_LINE_UNINTERESTING    (1<<19)
 733#define DIFF_SYMBOL_CONTENT_WS_MASK (WSEH_NEW | WSEH_OLD | WSEH_CONTEXT | WS_RULE_MASK)
 734
 735/*
 736 * This struct is used when we need to buffer the output of the diff output.
 737 *
 738 * NEEDSWORK: Instead of storing a copy of the line, add an offset pointer
 739 * into the pre/post image file. This pointer could be a union with the
 740 * line pointer. By storing an offset into the file instead of the literal line,
 741 * we can decrease the memory footprint for the buffered output. At first we
 742 * may want to only have indirection for the content lines, but we could also
 743 * enhance the state for emitting prefabricated lines, e.g. the similarity
 744 * score line or hunk/file headers would only need to store a number or path
 745 * and then the output can be constructed later on depending on state.
 746 */
 747struct emitted_diff_symbol {
 748        const char *line;
 749        int len;
 750        int flags;
 751        enum diff_symbol s;
 752};
 753#define EMITTED_DIFF_SYMBOL_INIT {NULL}
 754
 755struct emitted_diff_symbols {
 756        struct emitted_diff_symbol *buf;
 757        int nr, alloc;
 758};
 759#define EMITTED_DIFF_SYMBOLS_INIT {NULL, 0, 0}
 760
 761static void append_emitted_diff_symbol(struct diff_options *o,
 762                                       struct emitted_diff_symbol *e)
 763{
 764        struct emitted_diff_symbol *f;
 765
 766        ALLOC_GROW(o->emitted_symbols->buf,
 767                   o->emitted_symbols->nr + 1,
 768                   o->emitted_symbols->alloc);
 769        f = &o->emitted_symbols->buf[o->emitted_symbols->nr++];
 770
 771        memcpy(f, e, sizeof(struct emitted_diff_symbol));
 772        f->line = e->line ? xmemdupz(e->line, e->len) : NULL;
 773}
 774
 775struct moved_entry {
 776        struct hashmap_entry ent;
 777        const struct emitted_diff_symbol *es;
 778        struct moved_entry *next_line;
 779        struct ws_delta *wsd;
 780};
 781
 782/**
 783 * The struct ws_delta holds white space differences between moved lines, i.e.
 784 * between '+' and '-' lines that have been detected to be a move.
 785 * The string contains the difference in leading white spaces, before the
 786 * rest of the line is compared using the white space config for move
 787 * coloring. The current_longer indicates if the first string in the
 788 * comparision is longer than the second.
 789 */
 790struct ws_delta {
 791        char *string;
 792        unsigned int current_longer : 1;
 793};
 794#define WS_DELTA_INIT { NULL, 0 }
 795
 796static int compute_ws_delta(const struct emitted_diff_symbol *a,
 797                             const struct emitted_diff_symbol *b,
 798                             struct ws_delta *out)
 799{
 800        const struct emitted_diff_symbol *longer =  a->len > b->len ? a : b;
 801        const struct emitted_diff_symbol *shorter = a->len > b->len ? b : a;
 802        int d = longer->len - shorter->len;
 803
 804        out->string = xmemdupz(longer->line, d);
 805        out->current_longer = (a == longer);
 806
 807        return !strncmp(longer->line + d, shorter->line, shorter->len);
 808}
 809
 810static int cmp_in_block_with_wsd(const struct diff_options *o,
 811                                 const struct moved_entry *cur,
 812                                 const struct moved_entry *match,
 813                                 struct moved_entry *pmb,
 814                                 int n)
 815{
 816        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
 817        int al = cur->es->len, cl = l->len;
 818        const char *a = cur->es->line,
 819                   *b = match->es->line,
 820                   *c = l->line;
 821
 822        int wslen;
 823
 824        /*
 825         * We need to check if 'cur' is equal to 'match'.
 826         * As those are from the same (+/-) side, we do not need to adjust for
 827         * indent changes. However these were found using fuzzy matching
 828         * so we do have to check if they are equal.
 829         */
 830        if (strcmp(a, b))
 831                return 1;
 832
 833        if (!pmb->wsd)
 834                /*
 835                 * No white space delta was carried forward? This can happen
 836                 * when we exit early in this function and do not carry
 837                 * forward ws.
 838                 */
 839                return 1;
 840
 841        /*
 842         * The indent changes of the block are known and carried forward in
 843         * pmb->wsd; however we need to check if the indent changes of the
 844         * current line are still the same as before.
 845         *
 846         * To do so we need to compare 'l' to 'cur', adjusting the
 847         * one of them for the white spaces, depending which was longer.
 848         */
 849
 850        wslen = strlen(pmb->wsd->string);
 851        if (pmb->wsd->current_longer) {
 852                c += wslen;
 853                cl -= wslen;
 854        } else {
 855                a += wslen;
 856                al -= wslen;
 857        }
 858
 859        if (strcmp(a, c))
 860                return 1;
 861
 862        return 0;
 863}
 864
 865static int moved_entry_cmp(const void *hashmap_cmp_fn_data,
 866                           const void *entry,
 867                           const void *entry_or_key,
 868                           const void *keydata)
 869{
 870        const struct diff_options *diffopt = hashmap_cmp_fn_data;
 871        const struct moved_entry *a = entry;
 872        const struct moved_entry *b = entry_or_key;
 873        unsigned flags = diffopt->color_moved_ws_handling
 874                         & XDF_WHITESPACE_FLAGS;
 875
 876        if (diffopt->color_moved_ws_handling &
 877            COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
 878                /*
 879                 * As there is not specific white space config given,
 880                 * we'd need to check for a new block, so ignore all
 881                 * white space. The setup of the white space
 882                 * configuration for the next block is done else where
 883                 */
 884                flags |= XDF_IGNORE_WHITESPACE;
 885
 886        return !xdiff_compare_lines(a->es->line, a->es->len,
 887                                    b->es->line, b->es->len,
 888                                    flags);
 889}
 890
 891static struct moved_entry *prepare_entry(struct diff_options *o,
 892                                         int line_no)
 893{
 894        struct moved_entry *ret = xmalloc(sizeof(*ret));
 895        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[line_no];
 896        unsigned flags = o->color_moved_ws_handling & XDF_WHITESPACE_FLAGS;
 897
 898        ret->ent.hash = xdiff_hash_string(l->line, l->len, flags);
 899        ret->es = l;
 900        ret->next_line = NULL;
 901        ret->wsd = NULL;
 902
 903        return ret;
 904}
 905
 906static void add_lines_to_move_detection(struct diff_options *o,
 907                                        struct hashmap *add_lines,
 908                                        struct hashmap *del_lines)
 909{
 910        struct moved_entry *prev_line = NULL;
 911
 912        int n;
 913        for (n = 0; n < o->emitted_symbols->nr; n++) {
 914                struct hashmap *hm;
 915                struct moved_entry *key;
 916
 917                switch (o->emitted_symbols->buf[n].s) {
 918                case DIFF_SYMBOL_PLUS:
 919                        hm = add_lines;
 920                        break;
 921                case DIFF_SYMBOL_MINUS:
 922                        hm = del_lines;
 923                        break;
 924                default:
 925                        prev_line = NULL;
 926                        continue;
 927                }
 928
 929                key = prepare_entry(o, n);
 930                if (prev_line && prev_line->es->s == o->emitted_symbols->buf[n].s)
 931                        prev_line->next_line = key;
 932
 933                hashmap_add(hm, key);
 934                prev_line = key;
 935        }
 936}
 937
 938static void pmb_advance_or_null(struct diff_options *o,
 939                                struct moved_entry *match,
 940                                struct hashmap *hm,
 941                                struct moved_entry **pmb,
 942                                int pmb_nr)
 943{
 944        int i;
 945        for (i = 0; i < pmb_nr; i++) {
 946                struct moved_entry *prev = pmb[i];
 947                struct moved_entry *cur = (prev && prev->next_line) ?
 948                                prev->next_line : NULL;
 949                if (cur && !hm->cmpfn(o, cur, match, NULL)) {
 950                        pmb[i] = cur;
 951                } else {
 952                        pmb[i] = NULL;
 953                }
 954        }
 955}
 956
 957static void pmb_advance_or_null_multi_match(struct diff_options *o,
 958                                            struct moved_entry *match,
 959                                            struct hashmap *hm,
 960                                            struct moved_entry **pmb,
 961                                            int pmb_nr, int n)
 962{
 963        int i;
 964        char *got_match = xcalloc(1, pmb_nr);
 965
 966        for (; match; match = hashmap_get_next(hm, match)) {
 967                for (i = 0; i < pmb_nr; i++) {
 968                        struct moved_entry *prev = pmb[i];
 969                        struct moved_entry *cur = (prev && prev->next_line) ?
 970                                        prev->next_line : NULL;
 971                        if (!cur)
 972                                continue;
 973                        if (!cmp_in_block_with_wsd(o, cur, match, pmb[i], n))
 974                                got_match[i] |= 1;
 975                }
 976        }
 977
 978        for (i = 0; i < pmb_nr; i++) {
 979                if (got_match[i]) {
 980                        /* Carry the white space delta forward */
 981                        pmb[i]->next_line->wsd = pmb[i]->wsd;
 982                        pmb[i] = pmb[i]->next_line;
 983                } else
 984                        pmb[i] = NULL;
 985        }
 986}
 987
 988static int shrink_potential_moved_blocks(struct moved_entry **pmb,
 989                                         int pmb_nr)
 990{
 991        int lp, rp;
 992
 993        /* Shrink the set of potential block to the remaining running */
 994        for (lp = 0, rp = pmb_nr - 1; lp <= rp;) {
 995                while (lp < pmb_nr && pmb[lp])
 996                        lp++;
 997                /* lp points at the first NULL now */
 998
 999                while (rp > -1 && !pmb[rp])
1000                        rp--;
1001                /* rp points at the last non-NULL */
1002
1003                if (lp < pmb_nr && rp > -1 && lp < rp) {
1004                        pmb[lp] = pmb[rp];
1005                        if (pmb[rp]->wsd) {
1006                                free(pmb[rp]->wsd->string);
1007                                FREE_AND_NULL(pmb[rp]->wsd);
1008                        }
1009                        pmb[rp] = NULL;
1010                        rp--;
1011                        lp++;
1012                }
1013        }
1014
1015        /* Remember the number of running sets */
1016        return rp + 1;
1017}
1018
1019/*
1020 * If o->color_moved is COLOR_MOVED_PLAIN, this function does nothing.
1021 *
1022 * Otherwise, if the last block has fewer alphanumeric characters than
1023 * COLOR_MOVED_MIN_ALNUM_COUNT, unset DIFF_SYMBOL_MOVED_LINE on all lines in
1024 * that block.
1025 *
1026 * The last block consists of the (n - block_length)'th line up to but not
1027 * including the nth line.
1028 *
1029 * NEEDSWORK: This uses the same heuristic as blame_entry_score() in blame.c.
1030 * Think of a way to unify them.
1031 */
1032static void adjust_last_block(struct diff_options *o, int n, int block_length)
1033{
1034        int i, alnum_count = 0;
1035        if (o->color_moved == COLOR_MOVED_PLAIN)
1036                return;
1037        for (i = 1; i < block_length + 1; i++) {
1038                const char *c = o->emitted_symbols->buf[n - i].line;
1039                for (; *c; c++) {
1040                        if (!isalnum(*c))
1041                                continue;
1042                        alnum_count++;
1043                        if (alnum_count >= COLOR_MOVED_MIN_ALNUM_COUNT)
1044                                return;
1045                }
1046        }
1047        for (i = 1; i < block_length + 1; i++)
1048                o->emitted_symbols->buf[n - i].flags &= ~DIFF_SYMBOL_MOVED_LINE;
1049}
1050
1051/* Find blocks of moved code, delegate actual coloring decision to helper */
1052static void mark_color_as_moved(struct diff_options *o,
1053                                struct hashmap *add_lines,
1054                                struct hashmap *del_lines)
1055{
1056        struct moved_entry **pmb = NULL; /* potentially moved blocks */
1057        int pmb_nr = 0, pmb_alloc = 0;
1058        int n, flipped_block = 1, block_length = 0;
1059
1060
1061        for (n = 0; n < o->emitted_symbols->nr; n++) {
1062                struct hashmap *hm = NULL;
1063                struct moved_entry *key;
1064                struct moved_entry *match = NULL;
1065                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
1066
1067                switch (l->s) {
1068                case DIFF_SYMBOL_PLUS:
1069                        hm = del_lines;
1070                        key = prepare_entry(o, n);
1071                        match = hashmap_get(hm, key, NULL);
1072                        free(key);
1073                        break;
1074                case DIFF_SYMBOL_MINUS:
1075                        hm = add_lines;
1076                        key = prepare_entry(o, n);
1077                        match = hashmap_get(hm, key, NULL);
1078                        free(key);
1079                        break;
1080                default:
1081                        flipped_block = 1;
1082                }
1083
1084                if (!match) {
1085                        adjust_last_block(o, n, block_length);
1086                        pmb_nr = 0;
1087                        block_length = 0;
1088                        continue;
1089                }
1090
1091                l->flags |= DIFF_SYMBOL_MOVED_LINE;
1092
1093                if (o->color_moved == COLOR_MOVED_PLAIN)
1094                        continue;
1095
1096                if (o->color_moved_ws_handling &
1097                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
1098                        pmb_advance_or_null_multi_match(o, match, hm, pmb, pmb_nr, n);
1099                else
1100                        pmb_advance_or_null(o, match, hm, pmb, pmb_nr);
1101
1102                pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
1103
1104                if (pmb_nr == 0) {
1105                        /*
1106                         * The current line is the start of a new block.
1107                         * Setup the set of potential blocks.
1108                         */
1109                        for (; match; match = hashmap_get_next(hm, match)) {
1110                                ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
1111                                if (o->color_moved_ws_handling &
1112                                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) {
1113                                        struct ws_delta *wsd = xmalloc(sizeof(*match->wsd));
1114                                        if (compute_ws_delta(l, match->es, wsd)) {
1115                                                match->wsd = wsd;
1116                                                pmb[pmb_nr++] = match;
1117                                        } else
1118                                                free(wsd);
1119                                } else {
1120                                        pmb[pmb_nr++] = match;
1121                                }
1122                        }
1123
1124                        flipped_block = (flipped_block + 1) % 2;
1125
1126                        adjust_last_block(o, n, block_length);
1127                        block_length = 0;
1128                }
1129
1130                block_length++;
1131
1132                if (flipped_block && o->color_moved != COLOR_MOVED_BLOCKS)
1133                        l->flags |= DIFF_SYMBOL_MOVED_LINE_ALT;
1134        }
1135        adjust_last_block(o, n, block_length);
1136
1137        free(pmb);
1138}
1139
1140#define DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK \
1141  (DIFF_SYMBOL_MOVED_LINE | DIFF_SYMBOL_MOVED_LINE_ALT)
1142static void dim_moved_lines(struct diff_options *o)
1143{
1144        int n;
1145        for (n = 0; n < o->emitted_symbols->nr; n++) {
1146                struct emitted_diff_symbol *prev = (n != 0) ?
1147                                &o->emitted_symbols->buf[n - 1] : NULL;
1148                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
1149                struct emitted_diff_symbol *next =
1150                                (n < o->emitted_symbols->nr - 1) ?
1151                                &o->emitted_symbols->buf[n + 1] : NULL;
1152
1153                /* Not a plus or minus line? */
1154                if (l->s != DIFF_SYMBOL_PLUS && l->s != DIFF_SYMBOL_MINUS)
1155                        continue;
1156
1157                /* Not a moved line? */
1158                if (!(l->flags & DIFF_SYMBOL_MOVED_LINE))
1159                        continue;
1160
1161                /*
1162                 * If prev or next are not a plus or minus line,
1163                 * pretend they don't exist
1164                 */
1165                if (prev && prev->s != DIFF_SYMBOL_PLUS &&
1166                            prev->s != DIFF_SYMBOL_MINUS)
1167                        prev = NULL;
1168                if (next && next->s != DIFF_SYMBOL_PLUS &&
1169                            next->s != DIFF_SYMBOL_MINUS)
1170                        next = NULL;
1171
1172                /* Inside a block? */
1173                if ((prev &&
1174                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
1175                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK)) &&
1176                    (next &&
1177                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
1178                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK))) {
1179                        l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1180                        continue;
1181                }
1182
1183                /* Check if we are at an interesting bound: */
1184                if (prev && (prev->flags & DIFF_SYMBOL_MOVED_LINE) &&
1185                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1186                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1187                        continue;
1188                if (next && (next->flags & DIFF_SYMBOL_MOVED_LINE) &&
1189                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1190                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1191                        continue;
1192
1193                /*
1194                 * The boundary to prev and next are not interesting,
1195                 * so this line is not interesting as a whole
1196                 */
1197                l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1198        }
1199}
1200
1201static void emit_line_ws_markup(struct diff_options *o,
1202                                const char *set_sign, const char *set,
1203                                const char *reset,
1204                                char sign, const char *line, int len,
1205                                unsigned ws_rule, int blank_at_eof)
1206{
1207        const char *ws = NULL;
1208
1209        if (o->ws_error_highlight & ws_rule) {
1210                ws = diff_get_color_opt(o, DIFF_WHITESPACE);
1211                if (!*ws)
1212                        ws = NULL;
1213        }
1214
1215        if (!ws && !set_sign)
1216                emit_line_0(o, set, NULL, 0, reset, sign, line, len);
1217        else if (!ws) {
1218                emit_line_0(o, set_sign, set, !!set_sign, reset, sign, line, len);
1219        } else if (blank_at_eof)
1220                /* Blank line at EOF - paint '+' as well */
1221                emit_line_0(o, ws, NULL, 0, reset, sign, line, len);
1222        else {
1223                /* Emit just the prefix, then the rest. */
1224                emit_line_0(o, set_sign ? set_sign : set, NULL, !!set_sign, reset,
1225                            sign, "", 0);
1226                ws_check_emit(line, len, ws_rule,
1227                              o->file, set, reset, ws);
1228        }
1229}
1230
1231static void emit_diff_symbol_from_struct(struct diff_options *o,
1232                                         struct emitted_diff_symbol *eds)
1233{
1234        static const char *nneof = " No newline at end of file\n";
1235        const char *context, *reset, *set, *set_sign, *meta, *fraginfo;
1236        struct strbuf sb = STRBUF_INIT;
1237
1238        enum diff_symbol s = eds->s;
1239        const char *line = eds->line;
1240        int len = eds->len;
1241        unsigned flags = eds->flags;
1242
1243        switch (s) {
1244        case DIFF_SYMBOL_NO_LF_EOF:
1245                context = diff_get_color_opt(o, DIFF_CONTEXT);
1246                reset = diff_get_color_opt(o, DIFF_RESET);
1247                putc('\n', o->file);
1248                emit_line_0(o, context, NULL, 0, reset, '\\',
1249                            nneof, strlen(nneof));
1250                break;
1251        case DIFF_SYMBOL_SUBMODULE_HEADER:
1252        case DIFF_SYMBOL_SUBMODULE_ERROR:
1253        case DIFF_SYMBOL_SUBMODULE_PIPETHROUGH:
1254        case DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES:
1255        case DIFF_SYMBOL_SUMMARY:
1256        case DIFF_SYMBOL_STATS_LINE:
1257        case DIFF_SYMBOL_BINARY_DIFF_BODY:
1258        case DIFF_SYMBOL_CONTEXT_FRAGINFO:
1259                emit_line(o, "", "", line, len);
1260                break;
1261        case DIFF_SYMBOL_CONTEXT_INCOMPLETE:
1262        case DIFF_SYMBOL_CONTEXT_MARKER:
1263                context = diff_get_color_opt(o, DIFF_CONTEXT);
1264                reset = diff_get_color_opt(o, DIFF_RESET);
1265                emit_line(o, context, reset, line, len);
1266                break;
1267        case DIFF_SYMBOL_SEPARATOR:
1268                fprintf(o->file, "%s%c",
1269                        diff_line_prefix(o),
1270                        o->line_termination);
1271                break;
1272        case DIFF_SYMBOL_CONTEXT:
1273                set = diff_get_color_opt(o, DIFF_CONTEXT);
1274                reset = diff_get_color_opt(o, DIFF_RESET);
1275                set_sign = NULL;
1276                if (o->flags.dual_color_diffed_diffs) {
1277                        char c = !len ? 0 : line[0];
1278
1279                        if (c == '+')
1280                                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1281                        else if (c == '@')
1282                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1283                        else if (c == '-')
1284                                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1285                }
1286                emit_line_ws_markup(o, set_sign, set, reset,
1287                                    o->output_indicators[OUTPUT_INDICATOR_CONTEXT],
1288                                    line, len,
1289                                    flags & (DIFF_SYMBOL_CONTENT_WS_MASK), 0);
1290                break;
1291        case DIFF_SYMBOL_PLUS:
1292                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1293                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1294                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1295                case DIFF_SYMBOL_MOVED_LINE |
1296                     DIFF_SYMBOL_MOVED_LINE_ALT |
1297                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1298                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT_DIM);
1299                        break;
1300                case DIFF_SYMBOL_MOVED_LINE |
1301                     DIFF_SYMBOL_MOVED_LINE_ALT:
1302                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT);
1303                        break;
1304                case DIFF_SYMBOL_MOVED_LINE |
1305                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1306                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_DIM);
1307                        break;
1308                case DIFF_SYMBOL_MOVED_LINE:
1309                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED);
1310                        break;
1311                default:
1312                        set = diff_get_color_opt(o, DIFF_FILE_NEW);
1313                }
1314                reset = diff_get_color_opt(o, DIFF_RESET);
1315                if (!o->flags.dual_color_diffed_diffs)
1316                        set_sign = NULL;
1317                else {
1318                        char c = !len ? 0 : line[0];
1319
1320                        set_sign = set;
1321                        if (c == '-')
1322                                set = diff_get_color_opt(o, DIFF_FILE_OLD_BOLD);
1323                        else if (c == '@')
1324                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1325                        else if (c == '+')
1326                                set = diff_get_color_opt(o, DIFF_FILE_NEW_BOLD);
1327                        else
1328                                set = diff_get_color_opt(o, DIFF_CONTEXT_BOLD);
1329                        flags &= ~DIFF_SYMBOL_CONTENT_WS_MASK;
1330                }
1331                emit_line_ws_markup(o, set_sign, set, reset,
1332                                    o->output_indicators[OUTPUT_INDICATOR_NEW],
1333                                    line, len,
1334                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK,
1335                                    flags & DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF);
1336                break;
1337        case DIFF_SYMBOL_MINUS:
1338                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1339                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1340                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1341                case DIFF_SYMBOL_MOVED_LINE |
1342                     DIFF_SYMBOL_MOVED_LINE_ALT |
1343                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1344                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT_DIM);
1345                        break;
1346                case DIFF_SYMBOL_MOVED_LINE |
1347                     DIFF_SYMBOL_MOVED_LINE_ALT:
1348                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT);
1349                        break;
1350                case DIFF_SYMBOL_MOVED_LINE |
1351                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1352                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_DIM);
1353                        break;
1354                case DIFF_SYMBOL_MOVED_LINE:
1355                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED);
1356                        break;
1357                default:
1358                        set = diff_get_color_opt(o, DIFF_FILE_OLD);
1359                }
1360                reset = diff_get_color_opt(o, DIFF_RESET);
1361                if (!o->flags.dual_color_diffed_diffs)
1362                        set_sign = NULL;
1363                else {
1364                        char c = !len ? 0 : line[0];
1365
1366                        set_sign = set;
1367                        if (c == '+')
1368                                set = diff_get_color_opt(o, DIFF_FILE_NEW_DIM);
1369                        else if (c == '@')
1370                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1371                        else if (c == '-')
1372                                set = diff_get_color_opt(o, DIFF_FILE_OLD_DIM);
1373                        else
1374                                set = diff_get_color_opt(o, DIFF_CONTEXT_DIM);
1375                }
1376                emit_line_ws_markup(o, set_sign, set, reset,
1377                                    o->output_indicators[OUTPUT_INDICATOR_OLD],
1378                                    line, len,
1379                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK, 0);
1380                break;
1381        case DIFF_SYMBOL_WORDS_PORCELAIN:
1382                context = diff_get_color_opt(o, DIFF_CONTEXT);
1383                reset = diff_get_color_opt(o, DIFF_RESET);
1384                emit_line(o, context, reset, line, len);
1385                fputs("~\n", o->file);
1386                break;
1387        case DIFF_SYMBOL_WORDS:
1388                context = diff_get_color_opt(o, DIFF_CONTEXT);
1389                reset = diff_get_color_opt(o, DIFF_RESET);
1390                /*
1391                 * Skip the prefix character, if any.  With
1392                 * diff_suppress_blank_empty, there may be
1393                 * none.
1394                 */
1395                if (line[0] != '\n') {
1396                        line++;
1397                        len--;
1398                }
1399                emit_line(o, context, reset, line, len);
1400                break;
1401        case DIFF_SYMBOL_FILEPAIR_PLUS:
1402                meta = diff_get_color_opt(o, DIFF_METAINFO);
1403                reset = diff_get_color_opt(o, DIFF_RESET);
1404                fprintf(o->file, "%s%s+++ %s%s%s\n", diff_line_prefix(o), meta,
1405                        line, reset,
1406                        strchr(line, ' ') ? "\t" : "");
1407                break;
1408        case DIFF_SYMBOL_FILEPAIR_MINUS:
1409                meta = diff_get_color_opt(o, DIFF_METAINFO);
1410                reset = diff_get_color_opt(o, DIFF_RESET);
1411                fprintf(o->file, "%s%s--- %s%s%s\n", diff_line_prefix(o), meta,
1412                        line, reset,
1413                        strchr(line, ' ') ? "\t" : "");
1414                break;
1415        case DIFF_SYMBOL_BINARY_FILES:
1416        case DIFF_SYMBOL_HEADER:
1417                fprintf(o->file, "%s", line);
1418                break;
1419        case DIFF_SYMBOL_BINARY_DIFF_HEADER:
1420                fprintf(o->file, "%sGIT binary patch\n", diff_line_prefix(o));
1421                break;
1422        case DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA:
1423                fprintf(o->file, "%sdelta %s\n", diff_line_prefix(o), line);
1424                break;
1425        case DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL:
1426                fprintf(o->file, "%sliteral %s\n", diff_line_prefix(o), line);
1427                break;
1428        case DIFF_SYMBOL_BINARY_DIFF_FOOTER:
1429                fputs(diff_line_prefix(o), o->file);
1430                fputc('\n', o->file);
1431                break;
1432        case DIFF_SYMBOL_REWRITE_DIFF:
1433                fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
1434                reset = diff_get_color_opt(o, DIFF_RESET);
1435                emit_line(o, fraginfo, reset, line, len);
1436                break;
1437        case DIFF_SYMBOL_SUBMODULE_ADD:
1438                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1439                reset = diff_get_color_opt(o, DIFF_RESET);
1440                emit_line(o, set, reset, line, len);
1441                break;
1442        case DIFF_SYMBOL_SUBMODULE_DEL:
1443                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1444                reset = diff_get_color_opt(o, DIFF_RESET);
1445                emit_line(o, set, reset, line, len);
1446                break;
1447        case DIFF_SYMBOL_SUBMODULE_UNTRACKED:
1448                fprintf(o->file, "%sSubmodule %s contains untracked content\n",
1449                        diff_line_prefix(o), line);
1450                break;
1451        case DIFF_SYMBOL_SUBMODULE_MODIFIED:
1452                fprintf(o->file, "%sSubmodule %s contains modified content\n",
1453                        diff_line_prefix(o), line);
1454                break;
1455        case DIFF_SYMBOL_STATS_SUMMARY_NO_FILES:
1456                emit_line(o, "", "", " 0 files changed\n",
1457                          strlen(" 0 files changed\n"));
1458                break;
1459        case DIFF_SYMBOL_STATS_SUMMARY_ABBREV:
1460                emit_line(o, "", "", " ...\n", strlen(" ...\n"));
1461                break;
1462        case DIFF_SYMBOL_WORD_DIFF:
1463                fprintf(o->file, "%.*s", len, line);
1464                break;
1465        case DIFF_SYMBOL_STAT_SEP:
1466                fputs(o->stat_sep, o->file);
1467                break;
1468        default:
1469                BUG("unknown diff symbol");
1470        }
1471        strbuf_release(&sb);
1472}
1473
1474static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
1475                             const char *line, int len, unsigned flags)
1476{
1477        struct emitted_diff_symbol e = {line, len, flags, s};
1478
1479        if (o->emitted_symbols)
1480                append_emitted_diff_symbol(o, &e);
1481        else
1482                emit_diff_symbol_from_struct(o, &e);
1483}
1484
1485void diff_emit_submodule_del(struct diff_options *o, const char *line)
1486{
1487        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_DEL, line, strlen(line), 0);
1488}
1489
1490void diff_emit_submodule_add(struct diff_options *o, const char *line)
1491{
1492        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ADD, line, strlen(line), 0);
1493}
1494
1495void diff_emit_submodule_untracked(struct diff_options *o, const char *path)
1496{
1497        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_UNTRACKED,
1498                         path, strlen(path), 0);
1499}
1500
1501void diff_emit_submodule_modified(struct diff_options *o, const char *path)
1502{
1503        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_MODIFIED,
1504                         path, strlen(path), 0);
1505}
1506
1507void diff_emit_submodule_header(struct diff_options *o, const char *header)
1508{
1509        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_HEADER,
1510                         header, strlen(header), 0);
1511}
1512
1513void diff_emit_submodule_error(struct diff_options *o, const char *err)
1514{
1515        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ERROR, err, strlen(err), 0);
1516}
1517
1518void diff_emit_submodule_pipethrough(struct diff_options *o,
1519                                     const char *line, int len)
1520{
1521        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_PIPETHROUGH, line, len, 0);
1522}
1523
1524static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
1525{
1526        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
1527              ecbdata->blank_at_eof_in_preimage &&
1528              ecbdata->blank_at_eof_in_postimage &&
1529              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
1530              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
1531                return 0;
1532        return ws_blank_line(line, len, ecbdata->ws_rule);
1533}
1534
1535static void emit_add_line(const char *reset,
1536                          struct emit_callback *ecbdata,
1537                          const char *line, int len)
1538{
1539        unsigned flags = WSEH_NEW | ecbdata->ws_rule;
1540        if (new_blank_line_at_eof(ecbdata, line, len))
1541                flags |= DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF;
1542
1543        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_PLUS, line, len, flags);
1544}
1545
1546static void emit_del_line(const char *reset,
1547                          struct emit_callback *ecbdata,
1548                          const char *line, int len)
1549{
1550        unsigned flags = WSEH_OLD | ecbdata->ws_rule;
1551        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_MINUS, line, len, flags);
1552}
1553
1554static void emit_context_line(const char *reset,
1555                              struct emit_callback *ecbdata,
1556                              const char *line, int len)
1557{
1558        unsigned flags = WSEH_CONTEXT | ecbdata->ws_rule;
1559        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_CONTEXT, line, len, flags);
1560}
1561
1562static void emit_hunk_header(struct emit_callback *ecbdata,
1563                             const char *line, int len)
1564{
1565        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
1566        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
1567        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
1568        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1569        const char *reverse = ecbdata->color_diff ? GIT_COLOR_REVERSE : "";
1570        static const char atat[2] = { '@', '@' };
1571        const char *cp, *ep;
1572        struct strbuf msgbuf = STRBUF_INIT;
1573        int org_len = len;
1574        int i = 1;
1575
1576        /*
1577         * As a hunk header must begin with "@@ -<old>, +<new> @@",
1578         * it always is at least 10 bytes long.
1579         */
1580        if (len < 10 ||
1581            memcmp(line, atat, 2) ||
1582            !(ep = memmem(line + 2, len - 2, atat, 2))) {
1583                emit_diff_symbol(ecbdata->opt,
1584                                 DIFF_SYMBOL_CONTEXT_MARKER, line, len, 0);
1585                return;
1586        }
1587        ep += 2; /* skip over @@ */
1588
1589        /* The hunk header in fraginfo color */
1590        if (ecbdata->opt->flags.dual_color_diffed_diffs)
1591                strbuf_addstr(&msgbuf, reverse);
1592        strbuf_addstr(&msgbuf, frag);
1593        strbuf_add(&msgbuf, line, ep - line);
1594        strbuf_addstr(&msgbuf, reset);
1595
1596        /*
1597         * trailing "\r\n"
1598         */
1599        for ( ; i < 3; i++)
1600                if (line[len - i] == '\r' || line[len - i] == '\n')
1601                        len--;
1602
1603        /* blank before the func header */
1604        for (cp = ep; ep - line < len; ep++)
1605                if (*ep != ' ' && *ep != '\t')
1606                        break;
1607        if (ep != cp) {
1608                strbuf_addstr(&msgbuf, context);
1609                strbuf_add(&msgbuf, cp, ep - cp);
1610                strbuf_addstr(&msgbuf, reset);
1611        }
1612
1613        if (ep < line + len) {
1614                strbuf_addstr(&msgbuf, func);
1615                strbuf_add(&msgbuf, ep, line + len - ep);
1616                strbuf_addstr(&msgbuf, reset);
1617        }
1618
1619        strbuf_add(&msgbuf, line + len, org_len - len);
1620        strbuf_complete_line(&msgbuf);
1621        emit_diff_symbol(ecbdata->opt,
1622                         DIFF_SYMBOL_CONTEXT_FRAGINFO, msgbuf.buf, msgbuf.len, 0);
1623        strbuf_release(&msgbuf);
1624}
1625
1626static struct diff_tempfile *claim_diff_tempfile(void) {
1627        int i;
1628        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
1629                if (!diff_temp[i].name)
1630                        return diff_temp + i;
1631        BUG("diff is failing to clean up its tempfiles");
1632}
1633
1634static void remove_tempfile(void)
1635{
1636        int i;
1637        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
1638                if (is_tempfile_active(diff_temp[i].tempfile))
1639                        delete_tempfile(&diff_temp[i].tempfile);
1640                diff_temp[i].name = NULL;
1641        }
1642}
1643
1644static void add_line_count(struct strbuf *out, int count)
1645{
1646        switch (count) {
1647        case 0:
1648                strbuf_addstr(out, "0,0");
1649                break;
1650        case 1:
1651                strbuf_addstr(out, "1");
1652                break;
1653        default:
1654                strbuf_addf(out, "1,%d", count);
1655                break;
1656        }
1657}
1658
1659static void emit_rewrite_lines(struct emit_callback *ecb,
1660                               int prefix, const char *data, int size)
1661{
1662        const char *endp = NULL;
1663        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
1664
1665        while (0 < size) {
1666                int len;
1667
1668                endp = memchr(data, '\n', size);
1669                len = endp ? (endp - data + 1) : size;
1670                if (prefix != '+') {
1671                        ecb->lno_in_preimage++;
1672                        emit_del_line(reset, ecb, data, len);
1673                } else {
1674                        ecb->lno_in_postimage++;
1675                        emit_add_line(reset, ecb, data, len);
1676                }
1677                size -= len;
1678                data += len;
1679        }
1680        if (!endp)
1681                emit_diff_symbol(ecb->opt, DIFF_SYMBOL_NO_LF_EOF, NULL, 0, 0);
1682}
1683
1684static void emit_rewrite_diff(const char *name_a,
1685                              const char *name_b,
1686                              struct diff_filespec *one,
1687                              struct diff_filespec *two,
1688                              struct userdiff_driver *textconv_one,
1689                              struct userdiff_driver *textconv_two,
1690                              struct diff_options *o)
1691{
1692        int lc_a, lc_b;
1693        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
1694        const char *a_prefix, *b_prefix;
1695        char *data_one, *data_two;
1696        size_t size_one, size_two;
1697        struct emit_callback ecbdata;
1698        struct strbuf out = STRBUF_INIT;
1699
1700        if (diff_mnemonic_prefix && o->flags.reverse_diff) {
1701                a_prefix = o->b_prefix;
1702                b_prefix = o->a_prefix;
1703        } else {
1704                a_prefix = o->a_prefix;
1705                b_prefix = o->b_prefix;
1706        }
1707
1708        name_a += (*name_a == '/');
1709        name_b += (*name_b == '/');
1710
1711        strbuf_reset(&a_name);
1712        strbuf_reset(&b_name);
1713        quote_two_c_style(&a_name, a_prefix, name_a, 0);
1714        quote_two_c_style(&b_name, b_prefix, name_b, 0);
1715
1716        size_one = fill_textconv(textconv_one, one, &data_one);
1717        size_two = fill_textconv(textconv_two, two, &data_two);
1718
1719        memset(&ecbdata, 0, sizeof(ecbdata));
1720        ecbdata.color_diff = want_color(o->use_color);
1721        ecbdata.ws_rule = whitespace_rule(name_b);
1722        ecbdata.opt = o;
1723        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
1724                mmfile_t mf1, mf2;
1725                mf1.ptr = (char *)data_one;
1726                mf2.ptr = (char *)data_two;
1727                mf1.size = size_one;
1728                mf2.size = size_two;
1729                check_blank_at_eof(&mf1, &mf2, &ecbdata);
1730        }
1731        ecbdata.lno_in_preimage = 1;
1732        ecbdata.lno_in_postimage = 1;
1733
1734        lc_a = count_lines(data_one, size_one);
1735        lc_b = count_lines(data_two, size_two);
1736
1737        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
1738                         a_name.buf, a_name.len, 0);
1739        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
1740                         b_name.buf, b_name.len, 0);
1741
1742        strbuf_addstr(&out, "@@ -");
1743        if (!o->irreversible_delete)
1744                add_line_count(&out, lc_a);
1745        else
1746                strbuf_addstr(&out, "?,?");
1747        strbuf_addstr(&out, " +");
1748        add_line_count(&out, lc_b);
1749        strbuf_addstr(&out, " @@\n");
1750        emit_diff_symbol(o, DIFF_SYMBOL_REWRITE_DIFF, out.buf, out.len, 0);
1751        strbuf_release(&out);
1752
1753        if (lc_a && !o->irreversible_delete)
1754                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
1755        if (lc_b)
1756                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
1757        if (textconv_one)
1758                free((char *)data_one);
1759        if (textconv_two)
1760                free((char *)data_two);
1761}
1762
1763struct diff_words_buffer {
1764        mmfile_t text;
1765        unsigned long alloc;
1766        struct diff_words_orig {
1767                const char *begin, *end;
1768        } *orig;
1769        int orig_nr, orig_alloc;
1770};
1771
1772static void diff_words_append(char *line, unsigned long len,
1773                struct diff_words_buffer *buffer)
1774{
1775        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
1776        line++;
1777        len--;
1778        memcpy(buffer->text.ptr + buffer->text.size, line, len);
1779        buffer->text.size += len;
1780        buffer->text.ptr[buffer->text.size] = '\0';
1781}
1782
1783struct diff_words_style_elem {
1784        const char *prefix;
1785        const char *suffix;
1786        const char *color; /* NULL; filled in by the setup code if
1787                            * color is enabled */
1788};
1789
1790struct diff_words_style {
1791        enum diff_words_type type;
1792        struct diff_words_style_elem new_word, old_word, ctx;
1793        const char *newline;
1794};
1795
1796static struct diff_words_style diff_words_styles[] = {
1797        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
1798        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
1799        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
1800};
1801
1802struct diff_words_data {
1803        struct diff_words_buffer minus, plus;
1804        const char *current_plus;
1805        int last_minus;
1806        struct diff_options *opt;
1807        regex_t *word_regex;
1808        enum diff_words_type type;
1809        struct diff_words_style *style;
1810};
1811
1812static int fn_out_diff_words_write_helper(struct diff_options *o,
1813                                          struct diff_words_style_elem *st_el,
1814                                          const char *newline,
1815                                          size_t count, const char *buf)
1816{
1817        int print = 0;
1818        struct strbuf sb = STRBUF_INIT;
1819
1820        while (count) {
1821                char *p = memchr(buf, '\n', count);
1822                if (print)
1823                        strbuf_addstr(&sb, diff_line_prefix(o));
1824
1825                if (p != buf) {
1826                        const char *reset = st_el->color && *st_el->color ?
1827                                            GIT_COLOR_RESET : NULL;
1828                        if (st_el->color && *st_el->color)
1829                                strbuf_addstr(&sb, st_el->color);
1830                        strbuf_addstr(&sb, st_el->prefix);
1831                        strbuf_add(&sb, buf, p ? p - buf : count);
1832                        strbuf_addstr(&sb, st_el->suffix);
1833                        if (reset)
1834                                strbuf_addstr(&sb, reset);
1835                }
1836                if (!p)
1837                        goto out;
1838
1839                strbuf_addstr(&sb, newline);
1840                count -= p + 1 - buf;
1841                buf = p + 1;
1842                print = 1;
1843                if (count) {
1844                        emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1845                                         sb.buf, sb.len, 0);
1846                        strbuf_reset(&sb);
1847                }
1848        }
1849
1850out:
1851        if (sb.len)
1852                emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1853                                 sb.buf, sb.len, 0);
1854        strbuf_release(&sb);
1855        return 0;
1856}
1857
1858/*
1859 * '--color-words' algorithm can be described as:
1860 *
1861 *   1. collect the minus/plus lines of a diff hunk, divided into
1862 *      minus-lines and plus-lines;
1863 *
1864 *   2. break both minus-lines and plus-lines into words and
1865 *      place them into two mmfile_t with one word for each line;
1866 *
1867 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
1868 *
1869 * And for the common parts of the both file, we output the plus side text.
1870 * diff_words->current_plus is used to trace the current position of the plus file
1871 * which printed. diff_words->last_minus is used to trace the last minus word
1872 * printed.
1873 *
1874 * For '--graph' to work with '--color-words', we need to output the graph prefix
1875 * on each line of color words output. Generally, there are two conditions on
1876 * which we should output the prefix.
1877 *
1878 *   1. diff_words->last_minus == 0 &&
1879 *      diff_words->current_plus == diff_words->plus.text.ptr
1880 *
1881 *      that is: the plus text must start as a new line, and if there is no minus
1882 *      word printed, a graph prefix must be printed.
1883 *
1884 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
1885 *      *(diff_words->current_plus - 1) == '\n'
1886 *
1887 *      that is: a graph prefix must be printed following a '\n'
1888 */
1889static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
1890{
1891        if ((diff_words->last_minus == 0 &&
1892                diff_words->current_plus == diff_words->plus.text.ptr) ||
1893                (diff_words->current_plus > diff_words->plus.text.ptr &&
1894                *(diff_words->current_plus - 1) == '\n')) {
1895                return 1;
1896        } else {
1897                return 0;
1898        }
1899}
1900
1901static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
1902{
1903        struct diff_words_data *diff_words = priv;
1904        struct diff_words_style *style = diff_words->style;
1905        int minus_first, minus_len, plus_first, plus_len;
1906        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
1907        struct diff_options *opt = diff_words->opt;
1908        const char *line_prefix;
1909
1910        if (line[0] != '@' || parse_hunk_header(line, len,
1911                        &minus_first, &minus_len, &plus_first, &plus_len))
1912                return;
1913
1914        assert(opt);
1915        line_prefix = diff_line_prefix(opt);
1916
1917        /* POSIX requires that first be decremented by one if len == 0... */
1918        if (minus_len) {
1919                minus_begin = diff_words->minus.orig[minus_first].begin;
1920                minus_end =
1921                        diff_words->minus.orig[minus_first + minus_len - 1].end;
1922        } else
1923                minus_begin = minus_end =
1924                        diff_words->minus.orig[minus_first].end;
1925
1926        if (plus_len) {
1927                plus_begin = diff_words->plus.orig[plus_first].begin;
1928                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
1929        } else
1930                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
1931
1932        if (color_words_output_graph_prefix(diff_words)) {
1933                fputs(line_prefix, diff_words->opt->file);
1934        }
1935        if (diff_words->current_plus != plus_begin) {
1936                fn_out_diff_words_write_helper(diff_words->opt,
1937                                &style->ctx, style->newline,
1938                                plus_begin - diff_words->current_plus,
1939                                diff_words->current_plus);
1940        }
1941        if (minus_begin != minus_end) {
1942                fn_out_diff_words_write_helper(diff_words->opt,
1943                                &style->old_word, style->newline,
1944                                minus_end - minus_begin, minus_begin);
1945        }
1946        if (plus_begin != plus_end) {
1947                fn_out_diff_words_write_helper(diff_words->opt,
1948                                &style->new_word, style->newline,
1949                                plus_end - plus_begin, plus_begin);
1950        }
1951
1952        diff_words->current_plus = plus_end;
1953        diff_words->last_minus = minus_first;
1954}
1955
1956/* This function starts looking at *begin, and returns 0 iff a word was found. */
1957static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
1958                int *begin, int *end)
1959{
1960        if (word_regex && *begin < buffer->size) {
1961                regmatch_t match[1];
1962                if (!regexec_buf(word_regex, buffer->ptr + *begin,
1963                                 buffer->size - *begin, 1, match, 0)) {
1964                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
1965                                        '\n', match[0].rm_eo - match[0].rm_so);
1966                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
1967                        *begin += match[0].rm_so;
1968                        return *begin >= *end;
1969                }
1970                return -1;
1971        }
1972
1973        /* find the next word */
1974        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
1975                (*begin)++;
1976        if (*begin >= buffer->size)
1977                return -1;
1978
1979        /* find the end of the word */
1980        *end = *begin + 1;
1981        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
1982                (*end)++;
1983
1984        return 0;
1985}
1986
1987/*
1988 * This function splits the words in buffer->text, stores the list with
1989 * newline separator into out, and saves the offsets of the original words
1990 * in buffer->orig.
1991 */
1992static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
1993                regex_t *word_regex)
1994{
1995        int i, j;
1996        long alloc = 0;
1997
1998        out->size = 0;
1999        out->ptr = NULL;
2000
2001        /* fake an empty "0th" word */
2002        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
2003        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
2004        buffer->orig_nr = 1;
2005
2006        for (i = 0; i < buffer->text.size; i++) {
2007                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
2008                        return;
2009
2010                /* store original boundaries */
2011                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
2012                                buffer->orig_alloc);
2013                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
2014                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
2015                buffer->orig_nr++;
2016
2017                /* store one word */
2018                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
2019                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
2020                out->ptr[out->size + j - i] = '\n';
2021                out->size += j - i + 1;
2022
2023                i = j - 1;
2024        }
2025}
2026
2027/* this executes the word diff on the accumulated buffers */
2028static void diff_words_show(struct diff_words_data *diff_words)
2029{
2030        xpparam_t xpp;
2031        xdemitconf_t xecfg;
2032        mmfile_t minus, plus;
2033        struct diff_words_style *style = diff_words->style;
2034
2035        struct diff_options *opt = diff_words->opt;
2036        const char *line_prefix;
2037
2038        assert(opt);
2039        line_prefix = diff_line_prefix(opt);
2040
2041        /* special case: only removal */
2042        if (!diff_words->plus.text.size) {
2043                emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
2044                                 line_prefix, strlen(line_prefix), 0);
2045                fn_out_diff_words_write_helper(diff_words->opt,
2046                        &style->old_word, style->newline,
2047                        diff_words->minus.text.size,
2048                        diff_words->minus.text.ptr);
2049                diff_words->minus.text.size = 0;
2050                return;
2051        }
2052
2053        diff_words->current_plus = diff_words->plus.text.ptr;
2054        diff_words->last_minus = 0;
2055
2056        memset(&xpp, 0, sizeof(xpp));
2057        memset(&xecfg, 0, sizeof(xecfg));
2058        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
2059        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
2060        xpp.flags = 0;
2061        /* as only the hunk header will be parsed, we need a 0-context */
2062        xecfg.ctxlen = 0;
2063        if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
2064                          &xpp, &xecfg))
2065                die("unable to generate word diff");
2066        free(minus.ptr);
2067        free(plus.ptr);
2068        if (diff_words->current_plus != diff_words->plus.text.ptr +
2069                        diff_words->plus.text.size) {
2070                if (color_words_output_graph_prefix(diff_words))
2071                        emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
2072                                         line_prefix, strlen(line_prefix), 0);
2073                fn_out_diff_words_write_helper(diff_words->opt,
2074                        &style->ctx, style->newline,
2075                        diff_words->plus.text.ptr + diff_words->plus.text.size
2076                        - diff_words->current_plus, diff_words->current_plus);
2077        }
2078        diff_words->minus.text.size = diff_words->plus.text.size = 0;
2079}
2080
2081/* In "color-words" mode, show word-diff of words accumulated in the buffer */
2082static void diff_words_flush(struct emit_callback *ecbdata)
2083{
2084        struct diff_options *wo = ecbdata->diff_words->opt;
2085
2086        if (ecbdata->diff_words->minus.text.size ||
2087            ecbdata->diff_words->plus.text.size)
2088                diff_words_show(ecbdata->diff_words);
2089
2090        if (wo->emitted_symbols) {
2091                struct diff_options *o = ecbdata->opt;
2092                struct emitted_diff_symbols *wol = wo->emitted_symbols;
2093                int i;
2094
2095                /*
2096                 * NEEDSWORK:
2097                 * Instead of appending each, concat all words to a line?
2098                 */
2099                for (i = 0; i < wol->nr; i++)
2100                        append_emitted_diff_symbol(o, &wol->buf[i]);
2101
2102                for (i = 0; i < wol->nr; i++)
2103                        free((void *)wol->buf[i].line);
2104
2105                wol->nr = 0;
2106        }
2107}
2108
2109static void diff_filespec_load_driver(struct diff_filespec *one)
2110{
2111        /* Use already-loaded driver */
2112        if (one->driver)
2113                return;
2114
2115        if (S_ISREG(one->mode))
2116                one->driver = userdiff_find_by_path(one->path);
2117
2118        /* Fallback to default settings */
2119        if (!one->driver)
2120                one->driver = userdiff_find_by_name("default");
2121}
2122
2123static const char *userdiff_word_regex(struct diff_filespec *one)
2124{
2125        diff_filespec_load_driver(one);
2126        return one->driver->word_regex;
2127}
2128
2129static void init_diff_words_data(struct emit_callback *ecbdata,
2130                                 struct diff_options *orig_opts,
2131                                 struct diff_filespec *one,
2132                                 struct diff_filespec *two)
2133{
2134        int i;
2135        struct diff_options *o = xmalloc(sizeof(struct diff_options));
2136        memcpy(o, orig_opts, sizeof(struct diff_options));
2137
2138        ecbdata->diff_words =
2139                xcalloc(1, sizeof(struct diff_words_data));
2140        ecbdata->diff_words->type = o->word_diff;
2141        ecbdata->diff_words->opt = o;
2142
2143        if (orig_opts->emitted_symbols)
2144                o->emitted_symbols =
2145                        xcalloc(1, sizeof(struct emitted_diff_symbols));
2146
2147        if (!o->word_regex)
2148                o->word_regex = userdiff_word_regex(one);
2149        if (!o->word_regex)
2150                o->word_regex = userdiff_word_regex(two);
2151        if (!o->word_regex)
2152                o->word_regex = diff_word_regex_cfg;
2153        if (o->word_regex) {
2154                ecbdata->diff_words->word_regex = (regex_t *)
2155                        xmalloc(sizeof(regex_t));
2156                if (regcomp(ecbdata->diff_words->word_regex,
2157                            o->word_regex,
2158                            REG_EXTENDED | REG_NEWLINE))
2159                        die("invalid regular expression: %s",
2160                            o->word_regex);
2161        }
2162        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2163                if (o->word_diff == diff_words_styles[i].type) {
2164                        ecbdata->diff_words->style =
2165                                &diff_words_styles[i];
2166                        break;
2167                }
2168        }
2169        if (want_color(o->use_color)) {
2170                struct diff_words_style *st = ecbdata->diff_words->style;
2171                st->old_word.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2172                st->new_word.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2173                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
2174        }
2175}
2176
2177static void free_diff_words_data(struct emit_callback *ecbdata)
2178{
2179        if (ecbdata->diff_words) {
2180                diff_words_flush(ecbdata);
2181                free (ecbdata->diff_words->opt->emitted_symbols);
2182                free (ecbdata->diff_words->opt);
2183                free (ecbdata->diff_words->minus.text.ptr);
2184                free (ecbdata->diff_words->minus.orig);
2185                free (ecbdata->diff_words->plus.text.ptr);
2186                free (ecbdata->diff_words->plus.orig);
2187                if (ecbdata->diff_words->word_regex) {
2188                        regfree(ecbdata->diff_words->word_regex);
2189                        free(ecbdata->diff_words->word_regex);
2190                }
2191                FREE_AND_NULL(ecbdata->diff_words);
2192        }
2193}
2194
2195const char *diff_get_color(int diff_use_color, enum color_diff ix)
2196{
2197        if (want_color(diff_use_color))
2198                return diff_colors[ix];
2199        return "";
2200}
2201
2202const char *diff_line_prefix(struct diff_options *opt)
2203{
2204        struct strbuf *msgbuf;
2205        if (!opt->output_prefix)
2206                return "";
2207
2208        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
2209        return msgbuf->buf;
2210}
2211
2212static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
2213{
2214        const char *cp;
2215        unsigned long allot;
2216        size_t l = len;
2217
2218        cp = line;
2219        allot = l;
2220        while (0 < l) {
2221                (void) utf8_width(&cp, &l);
2222                if (!cp)
2223                        break; /* truncated in the middle? */
2224        }
2225        return allot - l;
2226}
2227
2228static void find_lno(const char *line, struct emit_callback *ecbdata)
2229{
2230        const char *p;
2231        ecbdata->lno_in_preimage = 0;
2232        ecbdata->lno_in_postimage = 0;
2233        p = strchr(line, '-');
2234        if (!p)
2235                return; /* cannot happen */
2236        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
2237        p = strchr(p, '+');
2238        if (!p)
2239                return; /* cannot happen */
2240        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
2241}
2242
2243static void fn_out_consume(void *priv, char *line, unsigned long len)
2244{
2245        struct emit_callback *ecbdata = priv;
2246        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
2247        struct diff_options *o = ecbdata->opt;
2248
2249        o->found_changes = 1;
2250
2251        if (ecbdata->header) {
2252                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
2253                                 ecbdata->header->buf, ecbdata->header->len, 0);
2254                strbuf_reset(ecbdata->header);
2255                ecbdata->header = NULL;
2256        }
2257
2258        if (ecbdata->label_path[0]) {
2259                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
2260                                 ecbdata->label_path[0],
2261                                 strlen(ecbdata->label_path[0]), 0);
2262                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
2263                                 ecbdata->label_path[1],
2264                                 strlen(ecbdata->label_path[1]), 0);
2265                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
2266        }
2267
2268        if (diff_suppress_blank_empty
2269            && len == 2 && line[0] == ' ' && line[1] == '\n') {
2270                line[0] = '\n';
2271                len = 1;
2272        }
2273
2274        if (line[0] == '@') {
2275                if (ecbdata->diff_words)
2276                        diff_words_flush(ecbdata);
2277                len = sane_truncate_line(ecbdata, line, len);
2278                find_lno(line, ecbdata);
2279                emit_hunk_header(ecbdata, line, len);
2280                return;
2281        }
2282
2283        if (ecbdata->diff_words) {
2284                enum diff_symbol s =
2285                        ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN ?
2286                        DIFF_SYMBOL_WORDS_PORCELAIN : DIFF_SYMBOL_WORDS;
2287                if (line[0] == '-') {
2288                        diff_words_append(line, len,
2289                                          &ecbdata->diff_words->minus);
2290                        return;
2291                } else if (line[0] == '+') {
2292                        diff_words_append(line, len,
2293                                          &ecbdata->diff_words->plus);
2294                        return;
2295                } else if (starts_with(line, "\\ ")) {
2296                        /*
2297                         * Eat the "no newline at eof" marker as if we
2298                         * saw a "+" or "-" line with nothing on it,
2299                         * and return without diff_words_flush() to
2300                         * defer processing. If this is the end of
2301                         * preimage, more "+" lines may come after it.
2302                         */
2303                        return;
2304                }
2305                diff_words_flush(ecbdata);
2306                emit_diff_symbol(o, s, line, len, 0);
2307                return;
2308        }
2309
2310        switch (line[0]) {
2311        case '+':
2312                ecbdata->lno_in_postimage++;
2313                emit_add_line(reset, ecbdata, line + 1, len - 1);
2314                break;
2315        case '-':
2316                ecbdata->lno_in_preimage++;
2317                emit_del_line(reset, ecbdata, line + 1, len - 1);
2318                break;
2319        case ' ':
2320                ecbdata->lno_in_postimage++;
2321                ecbdata->lno_in_preimage++;
2322                emit_context_line(reset, ecbdata, line + 1, len - 1);
2323                break;
2324        default:
2325                /* incomplete line at the end */
2326                ecbdata->lno_in_preimage++;
2327                emit_diff_symbol(o, DIFF_SYMBOL_CONTEXT_INCOMPLETE,
2328                                 line, len, 0);
2329                break;
2330        }
2331}
2332
2333static void pprint_rename(struct strbuf *name, const char *a, const char *b)
2334{
2335        const char *old_name = a;
2336        const char *new_name = b;
2337        int pfx_length, sfx_length;
2338        int pfx_adjust_for_slash;
2339        int len_a = strlen(a);
2340        int len_b = strlen(b);
2341        int a_midlen, b_midlen;
2342        int qlen_a = quote_c_style(a, NULL, NULL, 0);
2343        int qlen_b = quote_c_style(b, NULL, NULL, 0);
2344
2345        if (qlen_a || qlen_b) {
2346                quote_c_style(a, name, NULL, 0);
2347                strbuf_addstr(name, " => ");
2348                quote_c_style(b, name, NULL, 0);
2349                return;
2350        }
2351
2352        /* Find common prefix */
2353        pfx_length = 0;
2354        while (*old_name && *new_name && *old_name == *new_name) {
2355                if (*old_name == '/')
2356                        pfx_length = old_name - a + 1;
2357                old_name++;
2358                new_name++;
2359        }
2360
2361        /* Find common suffix */
2362        old_name = a + len_a;
2363        new_name = b + len_b;
2364        sfx_length = 0;
2365        /*
2366         * If there is a common prefix, it must end in a slash.  In
2367         * that case we let this loop run 1 into the prefix to see the
2368         * same slash.
2369         *
2370         * If there is no common prefix, we cannot do this as it would
2371         * underrun the input strings.
2372         */
2373        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
2374        while (a + pfx_length - pfx_adjust_for_slash <= old_name &&
2375               b + pfx_length - pfx_adjust_for_slash <= new_name &&
2376               *old_name == *new_name) {
2377                if (*old_name == '/')
2378                        sfx_length = len_a - (old_name - a);
2379                old_name--;
2380                new_name--;
2381        }
2382
2383        /*
2384         * pfx{mid-a => mid-b}sfx
2385         * {pfx-a => pfx-b}sfx
2386         * pfx{sfx-a => sfx-b}
2387         * name-a => name-b
2388         */
2389        a_midlen = len_a - pfx_length - sfx_length;
2390        b_midlen = len_b - pfx_length - sfx_length;
2391        if (a_midlen < 0)
2392                a_midlen = 0;
2393        if (b_midlen < 0)
2394                b_midlen = 0;
2395
2396        strbuf_grow(name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
2397        if (pfx_length + sfx_length) {
2398                strbuf_add(name, a, pfx_length);
2399                strbuf_addch(name, '{');
2400        }
2401        strbuf_add(name, a + pfx_length, a_midlen);
2402        strbuf_addstr(name, " => ");
2403        strbuf_add(name, b + pfx_length, b_midlen);
2404        if (pfx_length + sfx_length) {
2405                strbuf_addch(name, '}');
2406                strbuf_add(name, a + len_a - sfx_length, sfx_length);
2407        }
2408}
2409
2410struct diffstat_t {
2411        int nr;
2412        int alloc;
2413        struct diffstat_file {
2414                char *from_name;
2415                char *name;
2416                char *print_name;
2417                const char *comments;
2418                unsigned is_unmerged:1;
2419                unsigned is_binary:1;
2420                unsigned is_renamed:1;
2421                unsigned is_interesting:1;
2422                uintmax_t added, deleted;
2423        } **files;
2424};
2425
2426static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
2427                                          const char *name_a,
2428                                          const char *name_b)
2429{
2430        struct diffstat_file *x;
2431        x = xcalloc(1, sizeof(*x));
2432        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
2433        diffstat->files[diffstat->nr++] = x;
2434        if (name_b) {
2435                x->from_name = xstrdup(name_a);
2436                x->name = xstrdup(name_b);
2437                x->is_renamed = 1;
2438        }
2439        else {
2440                x->from_name = NULL;
2441                x->name = xstrdup(name_a);
2442        }
2443        return x;
2444}
2445
2446static void diffstat_consume(void *priv, char *line, unsigned long len)
2447{
2448        struct diffstat_t *diffstat = priv;
2449        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
2450
2451        if (line[0] == '+')
2452                x->added++;
2453        else if (line[0] == '-')
2454                x->deleted++;
2455}
2456
2457const char mime_boundary_leader[] = "------------";
2458
2459static int scale_linear(int it, int width, int max_change)
2460{
2461        if (!it)
2462                return 0;
2463        /*
2464         * make sure that at least one '-' or '+' is printed if
2465         * there is any change to this path. The easiest way is to
2466         * scale linearly as if the alloted width is one column shorter
2467         * than it is, and then add 1 to the result.
2468         */
2469        return 1 + (it * (width - 1) / max_change);
2470}
2471
2472static void show_graph(struct strbuf *out, char ch, int cnt,
2473                       const char *set, const char *reset)
2474{
2475        if (cnt <= 0)
2476                return;
2477        strbuf_addstr(out, set);
2478        strbuf_addchars(out, ch, cnt);
2479        strbuf_addstr(out, reset);
2480}
2481
2482static void fill_print_name(struct diffstat_file *file)
2483{
2484        struct strbuf pname = STRBUF_INIT;
2485
2486        if (file->print_name)
2487                return;
2488
2489        if (file->is_renamed)
2490                pprint_rename(&pname, file->from_name, file->name);
2491        else
2492                quote_c_style(file->name, &pname, NULL, 0);
2493
2494        if (file->comments)
2495                strbuf_addf(&pname, " (%s)", file->comments);
2496
2497        file->print_name = strbuf_detach(&pname, NULL);
2498}
2499
2500static void print_stat_summary_inserts_deletes(struct diff_options *options,
2501                int files, int insertions, int deletions)
2502{
2503        struct strbuf sb = STRBUF_INIT;
2504
2505        if (!files) {
2506                assert(insertions == 0 && deletions == 0);
2507                emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
2508                                 NULL, 0, 0);
2509                return;
2510        }
2511
2512        strbuf_addf(&sb,
2513                    (files == 1) ? " %d file changed" : " %d files changed",
2514                    files);
2515
2516        /*
2517         * For binary diff, the caller may want to print "x files
2518         * changed" with insertions == 0 && deletions == 0.
2519         *
2520         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
2521         * is probably less confusing (i.e skip over "2 files changed
2522         * but nothing about added/removed lines? Is this a bug in Git?").
2523         */
2524        if (insertions || deletions == 0) {
2525                strbuf_addf(&sb,
2526                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
2527                            insertions);
2528        }
2529
2530        if (deletions || insertions == 0) {
2531                strbuf_addf(&sb,
2532                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
2533                            deletions);
2534        }
2535        strbuf_addch(&sb, '\n');
2536        emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
2537                         sb.buf, sb.len, 0);
2538        strbuf_release(&sb);
2539}
2540
2541void print_stat_summary(FILE *fp, int files,
2542                        int insertions, int deletions)
2543{
2544        struct diff_options o;
2545        memset(&o, 0, sizeof(o));
2546        o.file = fp;
2547
2548        print_stat_summary_inserts_deletes(&o, files, insertions, deletions);
2549}
2550
2551static void show_stats(struct diffstat_t *data, struct diff_options *options)
2552{
2553        int i, len, add, del, adds = 0, dels = 0;
2554        uintmax_t max_change = 0, max_len = 0;
2555        int total_files = data->nr, count;
2556        int width, name_width, graph_width, number_width = 0, bin_width = 0;
2557        const char *reset, *add_c, *del_c;
2558        int extra_shown = 0;
2559        const char *line_prefix = diff_line_prefix(options);
2560        struct strbuf out = STRBUF_INIT;
2561
2562        if (data->nr == 0)
2563                return;
2564
2565        count = options->stat_count ? options->stat_count : data->nr;
2566
2567        reset = diff_get_color_opt(options, DIFF_RESET);
2568        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
2569        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
2570
2571        /*
2572         * Find the longest filename and max number of changes
2573         */
2574        for (i = 0; (i < count) && (i < data->nr); i++) {
2575                struct diffstat_file *file = data->files[i];
2576                uintmax_t change = file->added + file->deleted;
2577
2578                if (!file->is_interesting && (change == 0)) {
2579                        count++; /* not shown == room for one more */
2580                        continue;
2581                }
2582                fill_print_name(file);
2583                len = strlen(file->print_name);
2584                if (max_len < len)
2585                        max_len = len;
2586
2587                if (file->is_unmerged) {
2588                        /* "Unmerged" is 8 characters */
2589                        bin_width = bin_width < 8 ? 8 : bin_width;
2590                        continue;
2591                }
2592                if (file->is_binary) {
2593                        /* "Bin XXX -> YYY bytes" */
2594                        int w = 14 + decimal_width(file->added)
2595                                + decimal_width(file->deleted);
2596                        bin_width = bin_width < w ? w : bin_width;
2597                        /* Display change counts aligned with "Bin" */
2598                        number_width = 3;
2599                        continue;
2600                }
2601
2602                if (max_change < change)
2603                        max_change = change;
2604        }
2605        count = i; /* where we can stop scanning in data->files[] */
2606
2607        /*
2608         * We have width = stat_width or term_columns() columns total.
2609         * We want a maximum of min(max_len, stat_name_width) for the name part.
2610         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
2611         * We also need 1 for " " and 4 + decimal_width(max_change)
2612         * for " | NNNN " and one the empty column at the end, altogether
2613         * 6 + decimal_width(max_change).
2614         *
2615         * If there's not enough space, we will use the smaller of
2616         * stat_name_width (if set) and 5/8*width for the filename,
2617         * and the rest for constant elements + graph part, but no more
2618         * than stat_graph_width for the graph part.
2619         * (5/8 gives 50 for filename and 30 for the constant parts + graph
2620         * for the standard terminal size).
2621         *
2622         * In other words: stat_width limits the maximum width, and
2623         * stat_name_width fixes the maximum width of the filename,
2624         * and is also used to divide available columns if there
2625         * aren't enough.
2626         *
2627         * Binary files are displayed with "Bin XXX -> YYY bytes"
2628         * instead of the change count and graph. This part is treated
2629         * similarly to the graph part, except that it is not
2630         * "scaled". If total width is too small to accommodate the
2631         * guaranteed minimum width of the filename part and the
2632         * separators and this message, this message will "overflow"
2633         * making the line longer than the maximum width.
2634         */
2635
2636        if (options->stat_width == -1)
2637                width = term_columns() - strlen(line_prefix);
2638        else
2639                width = options->stat_width ? options->stat_width : 80;
2640        number_width = decimal_width(max_change) > number_width ?
2641                decimal_width(max_change) : number_width;
2642
2643        if (options->stat_graph_width == -1)
2644                options->stat_graph_width = diff_stat_graph_width;
2645
2646        /*
2647         * Guarantee 3/8*16==6 for the graph part
2648         * and 5/8*16==10 for the filename part
2649         */
2650        if (width < 16 + 6 + number_width)
2651                width = 16 + 6 + number_width;
2652
2653        /*
2654         * First assign sizes that are wanted, ignoring available width.
2655         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
2656         * starting from "XXX" should fit in graph_width.
2657         */
2658        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
2659        if (options->stat_graph_width &&
2660            options->stat_graph_width < graph_width)
2661                graph_width = options->stat_graph_width;
2662
2663        name_width = (options->stat_name_width > 0 &&
2664                      options->stat_name_width < max_len) ?
2665                options->stat_name_width : max_len;
2666
2667        /*
2668         * Adjust adjustable widths not to exceed maximum width
2669         */
2670        if (name_width + number_width + 6 + graph_width > width) {
2671                if (graph_width > width * 3/8 - number_width - 6) {
2672                        graph_width = width * 3/8 - number_width - 6;
2673                        if (graph_width < 6)
2674                                graph_width = 6;
2675                }
2676
2677                if (options->stat_graph_width &&
2678                    graph_width > options->stat_graph_width)
2679                        graph_width = options->stat_graph_width;
2680                if (name_width > width - number_width - 6 - graph_width)
2681                        name_width = width - number_width - 6 - graph_width;
2682                else
2683                        graph_width = width - number_width - 6 - name_width;
2684        }
2685
2686        /*
2687         * From here name_width is the width of the name area,
2688         * and graph_width is the width of the graph area.
2689         * max_change is used to scale graph properly.
2690         */
2691        for (i = 0; i < count; i++) {
2692                const char *prefix = "";
2693                struct diffstat_file *file = data->files[i];
2694                char *name = file->print_name;
2695                uintmax_t added = file->added;
2696                uintmax_t deleted = file->deleted;
2697                int name_len;
2698
2699                if (!file->is_interesting && (added + deleted == 0))
2700                        continue;
2701
2702                /*
2703                 * "scale" the filename
2704                 */
2705                len = name_width;
2706                name_len = strlen(name);
2707                if (name_width < name_len) {
2708                        char *slash;
2709                        prefix = "...";
2710                        len -= 3;
2711                        name += name_len - len;
2712                        slash = strchr(name, '/');
2713                        if (slash)
2714                                name = slash;
2715                }
2716
2717                if (file->is_binary) {
2718                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2719                        strbuf_addf(&out, " %*s", number_width, "Bin");
2720                        if (!added && !deleted) {
2721                                strbuf_addch(&out, '\n');
2722                                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2723                                                 out.buf, out.len, 0);
2724                                strbuf_reset(&out);
2725                                continue;
2726                        }
2727                        strbuf_addf(&out, " %s%"PRIuMAX"%s",
2728                                del_c, deleted, reset);
2729                        strbuf_addstr(&out, " -> ");
2730                        strbuf_addf(&out, "%s%"PRIuMAX"%s",
2731                                add_c, added, reset);
2732                        strbuf_addstr(&out, " bytes\n");
2733                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2734                                         out.buf, out.len, 0);
2735                        strbuf_reset(&out);
2736                        continue;
2737                }
2738                else if (file->is_unmerged) {
2739                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2740                        strbuf_addstr(&out, " Unmerged\n");
2741                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2742                                         out.buf, out.len, 0);
2743                        strbuf_reset(&out);
2744                        continue;
2745                }
2746
2747                /*
2748                 * scale the add/delete
2749                 */
2750                add = added;
2751                del = deleted;
2752
2753                if (graph_width <= max_change) {
2754                        int total = scale_linear(add + del, graph_width, max_change);
2755                        if (total < 2 && add && del)
2756                                /* width >= 2 due to the sanity check */
2757                                total = 2;
2758                        if (add < del) {
2759                                add = scale_linear(add, graph_width, max_change);
2760                                del = total - add;
2761                        } else {
2762                                del = scale_linear(del, graph_width, max_change);
2763                                add = total - del;
2764                        }
2765                }
2766                strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2767                strbuf_addf(&out, " %*"PRIuMAX"%s",
2768                        number_width, added + deleted,
2769                        added + deleted ? " " : "");
2770                show_graph(&out, '+', add, add_c, reset);
2771                show_graph(&out, '-', del, del_c, reset);
2772                strbuf_addch(&out, '\n');
2773                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2774                                 out.buf, out.len, 0);
2775                strbuf_reset(&out);
2776        }
2777
2778        for (i = 0; i < data->nr; i++) {
2779                struct diffstat_file *file = data->files[i];
2780                uintmax_t added = file->added;
2781                uintmax_t deleted = file->deleted;
2782
2783                if (file->is_unmerged ||
2784                    (!file->is_interesting && (added + deleted == 0))) {
2785                        total_files--;
2786                        continue;
2787                }
2788
2789                if (!file->is_binary) {
2790                        adds += added;
2791                        dels += deleted;
2792                }
2793                if (i < count)
2794                        continue;
2795                if (!extra_shown)
2796                        emit_diff_symbol(options,
2797                                         DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
2798                                         NULL, 0, 0);
2799                extra_shown = 1;
2800        }
2801
2802        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2803        strbuf_release(&out);
2804}
2805
2806static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
2807{
2808        int i, adds = 0, dels = 0, total_files = data->nr;
2809
2810        if (data->nr == 0)
2811                return;
2812
2813        for (i = 0; i < data->nr; i++) {
2814                int added = data->files[i]->added;
2815                int deleted = data->files[i]->deleted;
2816
2817                if (data->files[i]->is_unmerged ||
2818                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
2819                        total_files--;
2820                } else if (!data->files[i]->is_binary) { /* don't count bytes */
2821                        adds += added;
2822                        dels += deleted;
2823                }
2824        }
2825        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2826}
2827
2828static void show_numstat(struct diffstat_t *data, struct diff_options *options)
2829{
2830        int i;
2831
2832        if (data->nr == 0)
2833                return;
2834
2835        for (i = 0; i < data->nr; i++) {
2836                struct diffstat_file *file = data->files[i];
2837
2838                fprintf(options->file, "%s", diff_line_prefix(options));
2839
2840                if (file->is_binary)
2841                        fprintf(options->file, "-\t-\t");
2842                else
2843                        fprintf(options->file,
2844                                "%"PRIuMAX"\t%"PRIuMAX"\t",
2845                                file->added, file->deleted);
2846                if (options->line_termination) {
2847                        fill_print_name(file);
2848                        if (!file->is_renamed)
2849                                write_name_quoted(file->name, options->file,
2850                                                  options->line_termination);
2851                        else {
2852                                fputs(file->print_name, options->file);
2853                                putc(options->line_termination, options->file);
2854                        }
2855                } else {
2856                        if (file->is_renamed) {
2857                                putc('\0', options->file);
2858                                write_name_quoted(file->from_name, options->file, '\0');
2859                        }
2860                        write_name_quoted(file->name, options->file, '\0');
2861                }
2862        }
2863}
2864
2865struct dirstat_file {
2866        const char *name;
2867        unsigned long changed;
2868};
2869
2870struct dirstat_dir {
2871        struct dirstat_file *files;
2872        int alloc, nr, permille, cumulative;
2873};
2874
2875static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
2876                unsigned long changed, const char *base, int baselen)
2877{
2878        unsigned long sum_changes = 0;
2879        unsigned int sources = 0;
2880        const char *line_prefix = diff_line_prefix(opt);
2881
2882        while (dir->nr) {
2883                struct dirstat_file *f = dir->files;
2884                int namelen = strlen(f->name);
2885                unsigned long changes;
2886                char *slash;
2887
2888                if (namelen < baselen)
2889                        break;
2890                if (memcmp(f->name, base, baselen))
2891                        break;
2892                slash = strchr(f->name + baselen, '/');
2893                if (slash) {
2894                        int newbaselen = slash + 1 - f->name;
2895                        changes = gather_dirstat(opt, dir, changed, f->name, newbaselen);
2896                        sources++;
2897                } else {
2898                        changes = f->changed;
2899                        dir->files++;
2900                        dir->nr--;
2901                        sources += 2;
2902                }
2903                sum_changes += changes;
2904        }
2905
2906        /*
2907         * We don't report dirstat's for
2908         *  - the top level
2909         *  - or cases where everything came from a single directory
2910         *    under this directory (sources == 1).
2911         */
2912        if (baselen && sources != 1) {
2913                if (sum_changes) {
2914                        int permille = sum_changes * 1000 / changed;
2915                        if (permille >= dir->permille) {
2916                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
2917                                        permille / 10, permille % 10, baselen, base);
2918                                if (!dir->cumulative)
2919                                        return 0;
2920                        }
2921                }
2922        }
2923        return sum_changes;
2924}
2925
2926static int dirstat_compare(const void *_a, const void *_b)
2927{
2928        const struct dirstat_file *a = _a;
2929        const struct dirstat_file *b = _b;
2930        return strcmp(a->name, b->name);
2931}
2932
2933static void show_dirstat(struct diff_options *options)
2934{
2935        int i;
2936        unsigned long changed;
2937        struct dirstat_dir dir;
2938        struct diff_queue_struct *q = &diff_queued_diff;
2939
2940        dir.files = NULL;
2941        dir.alloc = 0;
2942        dir.nr = 0;
2943        dir.permille = options->dirstat_permille;
2944        dir.cumulative = options->flags.dirstat_cumulative;
2945
2946        changed = 0;
2947        for (i = 0; i < q->nr; i++) {
2948                struct diff_filepair *p = q->queue[i];
2949                const char *name;
2950                unsigned long copied, added, damage;
2951                int content_changed;
2952
2953                name = p->two->path ? p->two->path : p->one->path;
2954
2955                if (p->one->oid_valid && p->two->oid_valid)
2956                        content_changed = oidcmp(&p->one->oid, &p->two->oid);
2957                else
2958                        content_changed = 1;
2959
2960                if (!content_changed) {
2961                        /*
2962                         * The SHA1 has not changed, so pre-/post-content is
2963                         * identical. We can therefore skip looking at the
2964                         * file contents altogether.
2965                         */
2966                        damage = 0;
2967                        goto found_damage;
2968                }
2969
2970                if (options->flags.dirstat_by_file) {
2971                        /*
2972                         * In --dirstat-by-file mode, we don't really need to
2973                         * look at the actual file contents at all.
2974                         * The fact that the SHA1 changed is enough for us to
2975                         * add this file to the list of results
2976                         * (with each file contributing equal damage).
2977                         */
2978                        damage = 1;
2979                        goto found_damage;
2980                }
2981
2982                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
2983                        diff_populate_filespec(p->one, 0);
2984                        diff_populate_filespec(p->two, 0);
2985                        diffcore_count_changes(p->one, p->two, NULL, NULL,
2986                                               &copied, &added);
2987                        diff_free_filespec_data(p->one);
2988                        diff_free_filespec_data(p->two);
2989                } else if (DIFF_FILE_VALID(p->one)) {
2990                        diff_populate_filespec(p->one, CHECK_SIZE_ONLY);
2991                        copied = added = 0;
2992                        diff_free_filespec_data(p->one);
2993                } else if (DIFF_FILE_VALID(p->two)) {
2994                        diff_populate_filespec(p->two, CHECK_SIZE_ONLY);
2995                        copied = 0;
2996                        added = p->two->size;
2997                        diff_free_filespec_data(p->two);
2998                } else
2999                        continue;
3000
3001                /*
3002                 * Original minus copied is the removed material,
3003                 * added is the new material.  They are both damages
3004                 * made to the preimage.
3005                 * If the resulting damage is zero, we know that
3006                 * diffcore_count_changes() considers the two entries to
3007                 * be identical, but since content_changed is true, we
3008                 * know that there must have been _some_ kind of change,
3009                 * so we force all entries to have damage > 0.
3010                 */
3011                damage = (p->one->size - copied) + added;
3012                if (!damage)
3013                        damage = 1;
3014
3015found_damage:
3016                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
3017                dir.files[dir.nr].name = name;
3018                dir.files[dir.nr].changed = damage;
3019                changed += damage;
3020                dir.nr++;
3021        }
3022
3023        /* This can happen even with many files, if everything was renames */
3024        if (!changed)
3025                return;
3026
3027        /* Show all directories with more than x% of the changes */
3028        QSORT(dir.files, dir.nr, dirstat_compare);
3029        gather_dirstat(options, &dir, changed, "", 0);
3030}
3031
3032static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
3033{
3034        int i;
3035        unsigned long changed;
3036        struct dirstat_dir dir;
3037
3038        if (data->nr == 0)
3039                return;
3040
3041        dir.files = NULL;
3042        dir.alloc = 0;
3043        dir.nr = 0;
3044        dir.permille = options->dirstat_permille;
3045        dir.cumulative = options->flags.dirstat_cumulative;
3046
3047        changed = 0;
3048        for (i = 0; i < data->nr; i++) {
3049                struct diffstat_file *file = data->files[i];
3050                unsigned long damage = file->added + file->deleted;
3051                if (file->is_binary)
3052                        /*
3053                         * binary files counts bytes, not lines. Must find some
3054                         * way to normalize binary bytes vs. textual lines.
3055                         * The following heuristic assumes that there are 64
3056                         * bytes per "line".
3057                         * This is stupid and ugly, but very cheap...
3058                         */
3059                        damage = DIV_ROUND_UP(damage, 64);
3060                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
3061                dir.files[dir.nr].name = file->name;
3062                dir.files[dir.nr].changed = damage;
3063                changed += damage;
3064                dir.nr++;
3065        }
3066
3067        /* This can happen even with many files, if everything was renames */
3068        if (!changed)
3069                return;
3070
3071        /* Show all directories with more than x% of the changes */
3072        QSORT(dir.files, dir.nr, dirstat_compare);
3073        gather_dirstat(options, &dir, changed, "", 0);
3074}
3075
3076static void free_diffstat_info(struct diffstat_t *diffstat)
3077{
3078        int i;
3079        for (i = 0; i < diffstat->nr; i++) {
3080                struct diffstat_file *f = diffstat->files[i];
3081                free(f->print_name);
3082                free(f->name);
3083                free(f->from_name);
3084                free(f);
3085        }
3086        free(diffstat->files);
3087}
3088
3089struct checkdiff_t {
3090        const char *filename;
3091        int lineno;
3092        int conflict_marker_size;
3093        struct diff_options *o;
3094        unsigned ws_rule;
3095        unsigned status;
3096};
3097
3098static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
3099{
3100        char firstchar;
3101        int cnt;
3102
3103        if (len < marker_size + 1)
3104                return 0;
3105        firstchar = line[0];
3106        switch (firstchar) {
3107        case '=': case '>': case '<': case '|':
3108                break;
3109        default:
3110                return 0;
3111        }
3112        for (cnt = 1; cnt < marker_size; cnt++)
3113                if (line[cnt] != firstchar)
3114                        return 0;
3115        /* line[1] thru line[marker_size-1] are same as firstchar */
3116        if (len < marker_size + 1 || !isspace(line[marker_size]))
3117                return 0;
3118        return 1;
3119}
3120
3121static void checkdiff_consume(void *priv, char *line, unsigned long len)
3122{
3123        struct checkdiff_t *data = priv;
3124        int marker_size = data->conflict_marker_size;
3125        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
3126        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
3127        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
3128        char *err;
3129        const char *line_prefix;
3130
3131        assert(data->o);
3132        line_prefix = diff_line_prefix(data->o);
3133
3134        if (line[0] == '+') {
3135                unsigned bad;
3136                data->lineno++;
3137                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
3138                        data->status |= 1;
3139                        fprintf(data->o->file,
3140                                "%s%s:%d: leftover conflict marker\n",
3141                                line_prefix, data->filename, data->lineno);
3142                }
3143                bad = ws_check(line + 1, len - 1, data->ws_rule);
3144                if (!bad)
3145                        return;
3146                data->status |= bad;
3147                err = whitespace_error_string(bad);
3148                fprintf(data->o->file, "%s%s:%d: %s.\n",
3149                        line_prefix, data->filename, data->lineno, err);
3150                free(err);
3151                emit_line(data->o, set, reset, line, 1);
3152                ws_check_emit(line + 1, len - 1, data->ws_rule,
3153                              data->o->file, set, reset, ws);
3154        } else if (line[0] == ' ') {
3155                data->lineno++;
3156        } else if (line[0] == '@') {
3157                char *plus = strchr(line, '+');
3158                if (plus)
3159                        data->lineno = strtol(plus, NULL, 10) - 1;
3160                else
3161                        die("invalid diff");
3162        }
3163}
3164
3165static unsigned char *deflate_it(char *data,
3166                                 unsigned long size,
3167                                 unsigned long *result_size)
3168{
3169        int bound;
3170        unsigned char *deflated;
3171        git_zstream stream;
3172
3173        git_deflate_init(&stream, zlib_compression_level);
3174        bound = git_deflate_bound(&stream, size);
3175        deflated = xmalloc(bound);
3176        stream.next_out = deflated;
3177        stream.avail_out = bound;
3178
3179        stream.next_in = (unsigned char *)data;
3180        stream.avail_in = size;
3181        while (git_deflate(&stream, Z_FINISH) == Z_OK)
3182                ; /* nothing */
3183        git_deflate_end(&stream);
3184        *result_size = stream.total_out;
3185        return deflated;
3186}
3187
3188static void emit_binary_diff_body(struct diff_options *o,
3189                                  mmfile_t *one, mmfile_t *two)
3190{
3191        void *cp;
3192        void *delta;
3193        void *deflated;
3194        void *data;
3195        unsigned long orig_size;
3196        unsigned long delta_size;
3197        unsigned long deflate_size;
3198        unsigned long data_size;
3199
3200        /* We could do deflated delta, or we could do just deflated two,
3201         * whichever is smaller.
3202         */
3203        delta = NULL;
3204        deflated = deflate_it(two->ptr, two->size, &deflate_size);
3205        if (one->size && two->size) {
3206                delta = diff_delta(one->ptr, one->size,
3207                                   two->ptr, two->size,
3208                                   &delta_size, deflate_size);
3209                if (delta) {
3210                        void *to_free = delta;
3211                        orig_size = delta_size;
3212                        delta = deflate_it(delta, delta_size, &delta_size);
3213                        free(to_free);
3214                }
3215        }
3216
3217        if (delta && delta_size < deflate_size) {
3218                char *s = xstrfmt("%lu", orig_size);
3219                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
3220                                 s, strlen(s), 0);
3221                free(s);
3222                free(deflated);
3223                data = delta;
3224                data_size = delta_size;
3225        } else {
3226                char *s = xstrfmt("%lu", two->size);
3227                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
3228                                 s, strlen(s), 0);
3229                free(s);
3230                free(delta);
3231                data = deflated;
3232                data_size = deflate_size;
3233        }
3234
3235        /* emit data encoded in base85 */
3236        cp = data;
3237        while (data_size) {
3238                int len;
3239                int bytes = (52 < data_size) ? 52 : data_size;
3240                char line[71];
3241                data_size -= bytes;
3242                if (bytes <= 26)
3243                        line[0] = bytes + 'A' - 1;
3244                else
3245                        line[0] = bytes - 26 + 'a' - 1;
3246                encode_85(line + 1, cp, bytes);
3247                cp = (char *) cp + bytes;
3248
3249                len = strlen(line);
3250                line[len++] = '\n';
3251                line[len] = '\0';
3252
3253                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_BODY,
3254                                 line, len, 0);
3255        }
3256        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_FOOTER, NULL, 0, 0);
3257        free(data);
3258}
3259
3260static void emit_binary_diff(struct diff_options *o,
3261                             mmfile_t *one, mmfile_t *two)
3262{
3263        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER, NULL, 0, 0);
3264        emit_binary_diff_body(o, one, two);
3265        emit_binary_diff_body(o, two, one);
3266}
3267
3268int diff_filespec_is_binary(struct diff_filespec *one)
3269{
3270        if (one->is_binary == -1) {
3271                diff_filespec_load_driver(one);
3272                if (one->driver->binary != -1)
3273                        one->is_binary = one->driver->binary;
3274                else {
3275                        if (!one->data && DIFF_FILE_VALID(one))
3276                                diff_populate_filespec(one, CHECK_BINARY);
3277                        if (one->is_binary == -1 && one->data)
3278                                one->is_binary = buffer_is_binary(one->data,
3279                                                one->size);
3280                        if (one->is_binary == -1)
3281                                one->is_binary = 0;
3282                }
3283        }
3284        return one->is_binary;
3285}
3286
3287static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
3288{
3289        diff_filespec_load_driver(one);
3290        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
3291}
3292
3293void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
3294{
3295        if (!options->a_prefix)
3296                options->a_prefix = a;
3297        if (!options->b_prefix)
3298                options->b_prefix = b;
3299}
3300
3301struct userdiff_driver *get_textconv(struct diff_filespec *one)
3302{
3303        if (!DIFF_FILE_VALID(one))
3304                return NULL;
3305
3306        diff_filespec_load_driver(one);
3307        return userdiff_get_textconv(one->driver);
3308}
3309
3310static void builtin_diff(const char *name_a,
3311                         const char *name_b,
3312                         struct diff_filespec *one,
3313                         struct diff_filespec *two,
3314                         const char *xfrm_msg,
3315                         int must_show_header,
3316                         struct diff_options *o,
3317                         int complete_rewrite)
3318{
3319        mmfile_t mf1, mf2;
3320        const char *lbl[2];
3321        char *a_one, *b_two;
3322        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
3323        const char *reset = diff_get_color_opt(o, DIFF_RESET);
3324        const char *a_prefix, *b_prefix;
3325        struct userdiff_driver *textconv_one = NULL;
3326        struct userdiff_driver *textconv_two = NULL;
3327        struct strbuf header = STRBUF_INIT;
3328        const char *line_prefix = diff_line_prefix(o);
3329
3330        diff_set_mnemonic_prefix(o, "a/", "b/");
3331        if (o->flags.reverse_diff) {
3332                a_prefix = o->b_prefix;
3333                b_prefix = o->a_prefix;
3334        } else {
3335                a_prefix = o->a_prefix;
3336                b_prefix = o->b_prefix;
3337        }
3338
3339        if (o->submodule_format == DIFF_SUBMODULE_LOG &&
3340            (!one->mode || S_ISGITLINK(one->mode)) &&
3341            (!two->mode || S_ISGITLINK(two->mode))) {
3342                show_submodule_summary(o, one->path ? one->path : two->path,
3343                                &one->oid, &two->oid,
3344                                two->dirty_submodule);
3345                return;
3346        } else if (o->submodule_format == DIFF_SUBMODULE_INLINE_DIFF &&
3347                   (!one->mode || S_ISGITLINK(one->mode)) &&
3348                   (!two->mode || S_ISGITLINK(two->mode))) {
3349                show_submodule_inline_diff(o, one->path ? one->path : two->path,
3350                                &one->oid, &two->oid,
3351                                two->dirty_submodule);
3352                return;
3353        }
3354
3355        if (o->flags.allow_textconv) {
3356                textconv_one = get_textconv(one);
3357                textconv_two = get_textconv(two);
3358        }
3359
3360        /* Never use a non-valid filename anywhere if at all possible */
3361        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
3362        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
3363
3364        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
3365        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
3366        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
3367        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
3368        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
3369        if (lbl[0][0] == '/') {
3370                /* /dev/null */
3371                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
3372                if (xfrm_msg)
3373                        strbuf_addstr(&header, xfrm_msg);
3374                must_show_header = 1;
3375        }
3376        else if (lbl[1][0] == '/') {
3377                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
3378                if (xfrm_msg)
3379                        strbuf_addstr(&header, xfrm_msg);
3380                must_show_header = 1;
3381        }
3382        else {
3383                if (one->mode != two->mode) {
3384                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
3385                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
3386                        must_show_header = 1;
3387                }
3388                if (xfrm_msg)
3389                        strbuf_addstr(&header, xfrm_msg);
3390
3391                /*
3392                 * we do not run diff between different kind
3393                 * of objects.
3394                 */
3395                if ((one->mode ^ two->mode) & S_IFMT)
3396                        goto free_ab_and_return;
3397                if (complete_rewrite &&
3398                    (textconv_one || !diff_filespec_is_binary(one)) &&
3399                    (textconv_two || !diff_filespec_is_binary(two))) {
3400                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3401                                         header.buf, header.len, 0);
3402                        strbuf_reset(&header);
3403                        emit_rewrite_diff(name_a, name_b, one, two,
3404                                                textconv_one, textconv_two, o);
3405                        o->found_changes = 1;
3406                        goto free_ab_and_return;
3407                }
3408        }
3409
3410        if (o->irreversible_delete && lbl[1][0] == '/') {
3411                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf,
3412                                 header.len, 0);
3413                strbuf_reset(&header);
3414                goto free_ab_and_return;
3415        } else if (!o->flags.text &&
3416            ( (!textconv_one && diff_filespec_is_binary(one)) ||
3417              (!textconv_two && diff_filespec_is_binary(two)) )) {
3418                struct strbuf sb = STRBUF_INIT;
3419                if (!one->data && !two->data &&
3420                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
3421                    !o->flags.binary) {
3422                        if (!oidcmp(&one->oid, &two->oid)) {
3423                                if (must_show_header)
3424                                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3425                                                         header.buf, header.len,
3426                                                         0);
3427                                goto free_ab_and_return;
3428                        }
3429                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3430                                         header.buf, header.len, 0);
3431                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3432                                    diff_line_prefix(o), lbl[0], lbl[1]);
3433                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3434                                         sb.buf, sb.len, 0);
3435                        strbuf_release(&sb);
3436                        goto free_ab_and_return;
3437                }
3438                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3439                        die("unable to read files to diff");
3440                /* Quite common confusing case */
3441                if (mf1.size == mf2.size &&
3442                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
3443                        if (must_show_header)
3444                                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3445                                                 header.buf, header.len, 0);
3446                        goto free_ab_and_return;
3447                }
3448                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf, header.len, 0);
3449                strbuf_reset(&header);
3450                if (o->flags.binary)
3451                        emit_binary_diff(o, &mf1, &mf2);
3452                else {
3453                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3454                                    diff_line_prefix(o), lbl[0], lbl[1]);
3455                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3456                                         sb.buf, sb.len, 0);
3457                        strbuf_release(&sb);
3458                }
3459                o->found_changes = 1;
3460        } else {
3461                /* Crazy xdl interfaces.. */
3462                const char *diffopts = getenv("GIT_DIFF_OPTS");
3463                const char *v;
3464                xpparam_t xpp;
3465                xdemitconf_t xecfg;
3466                struct emit_callback ecbdata;
3467                const struct userdiff_funcname *pe;
3468
3469                if (must_show_header) {
3470                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3471                                         header.buf, header.len, 0);
3472                        strbuf_reset(&header);
3473                }
3474
3475                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
3476                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
3477
3478                pe = diff_funcname_pattern(one);
3479                if (!pe)
3480                        pe = diff_funcname_pattern(two);
3481
3482                memset(&xpp, 0, sizeof(xpp));
3483                memset(&xecfg, 0, sizeof(xecfg));
3484                memset(&ecbdata, 0, sizeof(ecbdata));
3485                if (o->flags.suppress_diff_headers)
3486                        lbl[0] = NULL;
3487                ecbdata.label_path = lbl;
3488                ecbdata.color_diff = want_color(o->use_color);
3489                ecbdata.ws_rule = whitespace_rule(name_b);
3490                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
3491                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3492                ecbdata.opt = o;
3493                if (header.len && !o->flags.suppress_diff_headers)
3494                        ecbdata.header = &header;
3495                xpp.flags = o->xdl_opts;
3496                xpp.anchors = o->anchors;
3497                xpp.anchors_nr = o->anchors_nr;
3498                xecfg.ctxlen = o->context;
3499                xecfg.interhunkctxlen = o->interhunkcontext;
3500                xecfg.flags = XDL_EMIT_FUNCNAMES;
3501                if (o->flags.funccontext)
3502                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
3503                if (pe)
3504                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
3505                if (!diffopts)
3506                        ;
3507                else if (skip_prefix(diffopts, "--unified=", &v))
3508                        xecfg.ctxlen = strtoul(v, NULL, 10);
3509                else if (skip_prefix(diffopts, "-u", &v))
3510                        xecfg.ctxlen = strtoul(v, NULL, 10);
3511                if (o->word_diff)
3512                        init_diff_words_data(&ecbdata, o, one, two);
3513                if (xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
3514                                  &xpp, &xecfg))
3515                        die("unable to generate diff for %s", one->path);
3516                if (o->word_diff)
3517                        free_diff_words_data(&ecbdata);
3518                if (textconv_one)
3519                        free(mf1.ptr);
3520                if (textconv_two)
3521                        free(mf2.ptr);
3522                xdiff_clear_find_func(&xecfg);
3523        }
3524
3525 free_ab_and_return:
3526        strbuf_release(&header);
3527        diff_free_filespec_data(one);
3528        diff_free_filespec_data(two);
3529        free(a_one);
3530        free(b_two);
3531        return;
3532}
3533
3534static char *get_compact_summary(const struct diff_filepair *p, int is_renamed)
3535{
3536        if (!is_renamed) {
3537                if (p->status == DIFF_STATUS_ADDED) {
3538                        if (S_ISLNK(p->two->mode))
3539                                return "new +l";
3540                        else if ((p->two->mode & 0777) == 0755)
3541                                return "new +x";
3542                        else
3543                                return "new";
3544                } else if (p->status == DIFF_STATUS_DELETED)
3545                        return "gone";
3546        }
3547        if (S_ISLNK(p->one->mode) && !S_ISLNK(p->two->mode))
3548                return "mode -l";
3549        else if (!S_ISLNK(p->one->mode) && S_ISLNK(p->two->mode))
3550                return "mode +l";
3551        else if ((p->one->mode & 0777) == 0644 &&
3552                 (p->two->mode & 0777) == 0755)
3553                return "mode +x";
3554        else if ((p->one->mode & 0777) == 0755 &&
3555                 (p->two->mode & 0777) == 0644)
3556                return "mode -x";
3557        return NULL;
3558}
3559
3560static void builtin_diffstat(const char *name_a, const char *name_b,
3561                             struct diff_filespec *one,
3562                             struct diff_filespec *two,
3563                             struct diffstat_t *diffstat,
3564                             struct diff_options *o,
3565                             struct diff_filepair *p)
3566{
3567        mmfile_t mf1, mf2;
3568        struct diffstat_file *data;
3569        int same_contents;
3570        int complete_rewrite = 0;
3571
3572        if (!DIFF_PAIR_UNMERGED(p)) {
3573                if (p->status == DIFF_STATUS_MODIFIED && p->score)
3574                        complete_rewrite = 1;
3575        }
3576
3577        data = diffstat_add(diffstat, name_a, name_b);
3578        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
3579        if (o->flags.stat_with_summary)
3580                data->comments = get_compact_summary(p, data->is_renamed);
3581
3582        if (!one || !two) {
3583                data->is_unmerged = 1;
3584                return;
3585        }
3586
3587        same_contents = !oidcmp(&one->oid, &two->oid);
3588
3589        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
3590                data->is_binary = 1;
3591                if (same_contents) {
3592                        data->added = 0;
3593                        data->deleted = 0;
3594                } else {
3595                        data->added = diff_filespec_size(two);
3596                        data->deleted = diff_filespec_size(one);
3597                }
3598        }
3599
3600        else if (complete_rewrite) {
3601                diff_populate_filespec(one, 0);
3602                diff_populate_filespec(two, 0);
3603                data->deleted = count_lines(one->data, one->size);
3604                data->added = count_lines(two->data, two->size);
3605        }
3606
3607        else if (!same_contents) {
3608                /* Crazy xdl interfaces.. */
3609                xpparam_t xpp;
3610                xdemitconf_t xecfg;
3611
3612                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3613                        die("unable to read files to diff");
3614
3615                memset(&xpp, 0, sizeof(xpp));
3616                memset(&xecfg, 0, sizeof(xecfg));
3617                xpp.flags = o->xdl_opts;
3618                xpp.anchors = o->anchors;
3619                xpp.anchors_nr = o->anchors_nr;
3620                xecfg.ctxlen = o->context;
3621                xecfg.interhunkctxlen = o->interhunkcontext;
3622                if (xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
3623                                  &xpp, &xecfg))
3624                        die("unable to generate diffstat for %s", one->path);
3625        }
3626
3627        diff_free_filespec_data(one);
3628        diff_free_filespec_data(two);
3629}
3630
3631static void builtin_checkdiff(const char *name_a, const char *name_b,
3632                              const char *attr_path,
3633                              struct diff_filespec *one,
3634                              struct diff_filespec *two,
3635                              struct diff_options *o)
3636{
3637        mmfile_t mf1, mf2;
3638        struct checkdiff_t data;
3639
3640        if (!two)
3641                return;
3642
3643        memset(&data, 0, sizeof(data));
3644        data.filename = name_b ? name_b : name_a;
3645        data.lineno = 0;
3646        data.o = o;
3647        data.ws_rule = whitespace_rule(attr_path);
3648        data.conflict_marker_size = ll_merge_marker_size(attr_path);
3649
3650        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3651                die("unable to read files to diff");
3652
3653        /*
3654         * All the other codepaths check both sides, but not checking
3655         * the "old" side here is deliberate.  We are checking the newly
3656         * introduced changes, and as long as the "new" side is text, we
3657         * can and should check what it introduces.
3658         */
3659        if (diff_filespec_is_binary(two))
3660                goto free_and_return;
3661        else {
3662                /* Crazy xdl interfaces.. */
3663                xpparam_t xpp;
3664                xdemitconf_t xecfg;
3665
3666                memset(&xpp, 0, sizeof(xpp));
3667                memset(&xecfg, 0, sizeof(xecfg));
3668                xecfg.ctxlen = 1; /* at least one context line */
3669                xpp.flags = 0;
3670                if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
3671                                  &xpp, &xecfg))
3672                        die("unable to generate checkdiff for %s", one->path);
3673
3674                if (data.ws_rule & WS_BLANK_AT_EOF) {
3675                        struct emit_callback ecbdata;
3676                        int blank_at_eof;
3677
3678                        ecbdata.ws_rule = data.ws_rule;
3679                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3680                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
3681
3682                        if (blank_at_eof) {
3683                                static char *err;
3684                                if (!err)
3685                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
3686                                fprintf(o->file, "%s:%d: %s.\n",
3687                                        data.filename, blank_at_eof, err);
3688                                data.status = 1; /* report errors */
3689                        }
3690                }
3691        }
3692 free_and_return:
3693        diff_free_filespec_data(one);
3694        diff_free_filespec_data(two);
3695        if (data.status)
3696                o->flags.check_failed = 1;
3697}
3698
3699struct diff_filespec *alloc_filespec(const char *path)
3700{
3701        struct diff_filespec *spec;
3702
3703        FLEXPTR_ALLOC_STR(spec, path, path);
3704        spec->count = 1;
3705        spec->is_binary = -1;
3706        return spec;
3707}
3708
3709void free_filespec(struct diff_filespec *spec)
3710{
3711        if (!--spec->count) {
3712                diff_free_filespec_data(spec);
3713                free(spec);
3714        }
3715}
3716
3717void fill_filespec(struct diff_filespec *spec, const struct object_id *oid,
3718                   int oid_valid, unsigned short mode)
3719{
3720        if (mode) {
3721                spec->mode = canon_mode(mode);
3722                oidcpy(&spec->oid, oid);
3723                spec->oid_valid = oid_valid;
3724        }
3725}
3726
3727/*
3728 * Given a name and sha1 pair, if the index tells us the file in
3729 * the work tree has that object contents, return true, so that
3730 * prepare_temp_file() does not have to inflate and extract.
3731 */
3732static int reuse_worktree_file(const char *name, const struct object_id *oid, int want_file)
3733{
3734        const struct cache_entry *ce;
3735        struct stat st;
3736        int pos, len;
3737
3738        /*
3739         * We do not read the cache ourselves here, because the
3740         * benchmark with my previous version that always reads cache
3741         * shows that it makes things worse for diff-tree comparing
3742         * two linux-2.6 kernel trees in an already checked out work
3743         * tree.  This is because most diff-tree comparisons deal with
3744         * only a small number of files, while reading the cache is
3745         * expensive for a large project, and its cost outweighs the
3746         * savings we get by not inflating the object to a temporary
3747         * file.  Practically, this code only helps when we are used
3748         * by diff-cache --cached, which does read the cache before
3749         * calling us.
3750         */
3751        if (!active_cache)
3752                return 0;
3753
3754        /* We want to avoid the working directory if our caller
3755         * doesn't need the data in a normal file, this system
3756         * is rather slow with its stat/open/mmap/close syscalls,
3757         * and the object is contained in a pack file.  The pack
3758         * is probably already open and will be faster to obtain
3759         * the data through than the working directory.  Loose
3760         * objects however would tend to be slower as they need
3761         * to be individually opened and inflated.
3762         */
3763        if (!FAST_WORKING_DIRECTORY && !want_file && has_object_pack(oid))
3764                return 0;
3765
3766        /*
3767         * Similarly, if we'd have to convert the file contents anyway, that
3768         * makes the optimization not worthwhile.
3769         */
3770        if (!want_file && would_convert_to_git(&the_index, name))
3771                return 0;
3772
3773        len = strlen(name);
3774        pos = cache_name_pos(name, len);
3775        if (pos < 0)
3776                return 0;
3777        ce = active_cache[pos];
3778
3779        /*
3780         * This is not the sha1 we are looking for, or
3781         * unreusable because it is not a regular file.
3782         */
3783        if (oidcmp(oid, &ce->oid) || !S_ISREG(ce->ce_mode))
3784                return 0;
3785
3786        /*
3787         * If ce is marked as "assume unchanged", there is no
3788         * guarantee that work tree matches what we are looking for.
3789         */
3790        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
3791                return 0;
3792
3793        /*
3794         * If ce matches the file in the work tree, we can reuse it.
3795         */
3796        if (ce_uptodate(ce) ||
3797            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
3798                return 1;
3799
3800        return 0;
3801}
3802
3803static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
3804{
3805        struct strbuf buf = STRBUF_INIT;
3806        char *dirty = "";
3807
3808        /* Are we looking at the work tree? */
3809        if (s->dirty_submodule)
3810                dirty = "-dirty";
3811
3812        strbuf_addf(&buf, "Subproject commit %s%s\n",
3813                    oid_to_hex(&s->oid), dirty);
3814        s->size = buf.len;
3815        if (size_only) {
3816                s->data = NULL;
3817                strbuf_release(&buf);
3818        } else {
3819                s->data = strbuf_detach(&buf, NULL);
3820                s->should_free = 1;
3821        }
3822        return 0;
3823}
3824
3825/*
3826 * While doing rename detection and pickaxe operation, we may need to
3827 * grab the data for the blob (or file) for our own in-core comparison.
3828 * diff_filespec has data and size fields for this purpose.
3829 */
3830int diff_populate_filespec(struct diff_filespec *s, unsigned int flags)
3831{
3832        int size_only = flags & CHECK_SIZE_ONLY;
3833        int err = 0;
3834        int conv_flags = global_conv_flags_eol;
3835        /*
3836         * demote FAIL to WARN to allow inspecting the situation
3837         * instead of refusing.
3838         */
3839        if (conv_flags & CONV_EOL_RNDTRP_DIE)
3840                conv_flags = CONV_EOL_RNDTRP_WARN;
3841
3842        if (!DIFF_FILE_VALID(s))
3843                die("internal error: asking to populate invalid file.");
3844        if (S_ISDIR(s->mode))
3845                return -1;
3846
3847        if (s->data)
3848                return 0;
3849
3850        if (size_only && 0 < s->size)
3851                return 0;
3852
3853        if (S_ISGITLINK(s->mode))
3854                return diff_populate_gitlink(s, size_only);
3855
3856        if (!s->oid_valid ||
3857            reuse_worktree_file(s->path, &s->oid, 0)) {
3858                struct strbuf buf = STRBUF_INIT;
3859                struct stat st;
3860                int fd;
3861
3862                if (lstat(s->path, &st) < 0) {
3863                err_empty:
3864                        err = -1;
3865                empty:
3866                        s->data = (char *)"";
3867                        s->size = 0;
3868                        return err;
3869                }
3870                s->size = xsize_t(st.st_size);
3871                if (!s->size)
3872                        goto empty;
3873                if (S_ISLNK(st.st_mode)) {
3874                        struct strbuf sb = STRBUF_INIT;
3875
3876                        if (strbuf_readlink(&sb, s->path, s->size))
3877                                goto err_empty;
3878                        s->size = sb.len;
3879                        s->data = strbuf_detach(&sb, NULL);
3880                        s->should_free = 1;
3881                        return 0;
3882                }
3883
3884                /*
3885                 * Even if the caller would be happy with getting
3886                 * only the size, we cannot return early at this
3887                 * point if the path requires us to run the content
3888                 * conversion.
3889                 */
3890                if (size_only && !would_convert_to_git(&the_index, s->path))
3891                        return 0;
3892
3893                /*
3894                 * Note: this check uses xsize_t(st.st_size) that may
3895                 * not be the true size of the blob after it goes
3896                 * through convert_to_git().  This may not strictly be
3897                 * correct, but the whole point of big_file_threshold
3898                 * and is_binary check being that we want to avoid
3899                 * opening the file and inspecting the contents, this
3900                 * is probably fine.
3901                 */
3902                if ((flags & CHECK_BINARY) &&
3903                    s->size > big_file_threshold && s->is_binary == -1) {
3904                        s->is_binary = 1;
3905                        return 0;
3906                }
3907                fd = open(s->path, O_RDONLY);
3908                if (fd < 0)
3909                        goto err_empty;
3910                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
3911                close(fd);
3912                s->should_munmap = 1;
3913
3914                /*
3915                 * Convert from working tree format to canonical git format
3916                 */
3917                if (convert_to_git(&the_index, s->path, s->data, s->size, &buf, conv_flags)) {
3918                        size_t size = 0;
3919                        munmap(s->data, s->size);
3920                        s->should_munmap = 0;
3921                        s->data = strbuf_detach(&buf, &size);
3922                        s->size = size;
3923                        s->should_free = 1;
3924                }
3925        }
3926        else {
3927                enum object_type type;
3928                if (size_only || (flags & CHECK_BINARY)) {
3929                        type = oid_object_info(the_repository, &s->oid,
3930                                               &s->size);
3931                        if (type < 0)
3932                                die("unable to read %s",
3933                                    oid_to_hex(&s->oid));
3934                        if (size_only)
3935                                return 0;
3936                        if (s->size > big_file_threshold && s->is_binary == -1) {
3937                                s->is_binary = 1;
3938                                return 0;
3939                        }
3940                }
3941                s->data = read_object_file(&s->oid, &type, &s->size);
3942                if (!s->data)
3943                        die("unable to read %s", oid_to_hex(&s->oid));
3944                s->should_free = 1;
3945        }
3946        return 0;
3947}
3948
3949void diff_free_filespec_blob(struct diff_filespec *s)
3950{
3951        if (s->should_free)
3952                free(s->data);
3953        else if (s->should_munmap)
3954                munmap(s->data, s->size);
3955
3956        if (s->should_free || s->should_munmap) {
3957                s->should_free = s->should_munmap = 0;
3958                s->data = NULL;
3959        }
3960}
3961
3962void diff_free_filespec_data(struct diff_filespec *s)
3963{
3964        diff_free_filespec_blob(s);
3965        FREE_AND_NULL(s->cnt_data);
3966}
3967
3968static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
3969                           void *blob,
3970                           unsigned long size,
3971                           const struct object_id *oid,
3972                           int mode)
3973{
3974        struct strbuf buf = STRBUF_INIT;
3975        struct strbuf tempfile = STRBUF_INIT;
3976        char *path_dup = xstrdup(path);
3977        const char *base = basename(path_dup);
3978
3979        /* Generate "XXXXXX_basename.ext" */
3980        strbuf_addstr(&tempfile, "XXXXXX_");
3981        strbuf_addstr(&tempfile, base);
3982
3983        temp->tempfile = mks_tempfile_ts(tempfile.buf, strlen(base) + 1);
3984        if (!temp->tempfile)
3985                die_errno("unable to create temp-file");
3986        if (convert_to_working_tree(&the_index, path,
3987                        (const char *)blob, (size_t)size, &buf)) {
3988                blob = buf.buf;
3989                size = buf.len;
3990        }
3991        if (write_in_full(temp->tempfile->fd, blob, size) < 0 ||
3992            close_tempfile_gently(temp->tempfile))
3993                die_errno("unable to write temp-file");
3994        temp->name = get_tempfile_path(temp->tempfile);
3995        oid_to_hex_r(temp->hex, oid);
3996        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
3997        strbuf_release(&buf);
3998        strbuf_release(&tempfile);
3999        free(path_dup);
4000}
4001
4002static struct diff_tempfile *prepare_temp_file(const char *name,
4003                struct diff_filespec *one)
4004{
4005        struct diff_tempfile *temp = claim_diff_tempfile();
4006
4007        if (!DIFF_FILE_VALID(one)) {
4008        not_a_valid_file:
4009                /* A '-' entry produces this for file-2, and
4010                 * a '+' entry produces this for file-1.
4011                 */
4012                temp->name = "/dev/null";
4013                xsnprintf(temp->hex, sizeof(temp->hex), ".");
4014                xsnprintf(temp->mode, sizeof(temp->mode), ".");
4015                return temp;
4016        }
4017
4018        if (!S_ISGITLINK(one->mode) &&
4019            (!one->oid_valid ||
4020             reuse_worktree_file(name, &one->oid, 1))) {
4021                struct stat st;
4022                if (lstat(name, &st) < 0) {
4023                        if (errno == ENOENT)
4024                                goto not_a_valid_file;
4025                        die_errno("stat(%s)", name);
4026                }
4027                if (S_ISLNK(st.st_mode)) {
4028                        struct strbuf sb = STRBUF_INIT;
4029                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
4030                                die_errno("readlink(%s)", name);
4031                        prep_temp_blob(name, temp, sb.buf, sb.len,
4032                                       (one->oid_valid ?
4033                                        &one->oid : &null_oid),
4034                                       (one->oid_valid ?
4035                                        one->mode : S_IFLNK));
4036                        strbuf_release(&sb);
4037                }
4038                else {
4039                        /* we can borrow from the file in the work tree */
4040                        temp->name = name;
4041                        if (!one->oid_valid)
4042                                oid_to_hex_r(temp->hex, &null_oid);
4043                        else
4044                                oid_to_hex_r(temp->hex, &one->oid);
4045                        /* Even though we may sometimes borrow the
4046                         * contents from the work tree, we always want
4047                         * one->mode.  mode is trustworthy even when
4048                         * !(one->oid_valid), as long as
4049                         * DIFF_FILE_VALID(one).
4050                         */
4051                        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
4052                }
4053                return temp;
4054        }
4055        else {
4056                if (diff_populate_filespec(one, 0))
4057                        die("cannot read data blob for %s", one->path);
4058                prep_temp_blob(name, temp, one->data, one->size,
4059                               &one->oid, one->mode);
4060        }
4061        return temp;
4062}
4063
4064static void add_external_diff_name(struct argv_array *argv,
4065                                   const char *name,
4066                                   struct diff_filespec *df)
4067{
4068        struct diff_tempfile *temp = prepare_temp_file(name, df);
4069        argv_array_push(argv, temp->name);
4070        argv_array_push(argv, temp->hex);
4071        argv_array_push(argv, temp->mode);
4072}
4073
4074/* An external diff command takes:
4075 *
4076 * diff-cmd name infile1 infile1-sha1 infile1-mode \
4077 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
4078 *
4079 */
4080static void run_external_diff(const char *pgm,
4081                              const char *name,
4082                              const char *other,
4083                              struct diff_filespec *one,
4084                              struct diff_filespec *two,
4085                              const char *xfrm_msg,
4086                              int complete_rewrite,
4087                              struct diff_options *o)
4088{
4089        struct argv_array argv = ARGV_ARRAY_INIT;
4090        struct argv_array env = ARGV_ARRAY_INIT;
4091        struct diff_queue_struct *q = &diff_queued_diff;
4092
4093        argv_array_push(&argv, pgm);
4094        argv_array_push(&argv, name);
4095
4096        if (one && two) {
4097                add_external_diff_name(&argv, name, one);
4098                if (!other)
4099                        add_external_diff_name(&argv, name, two);
4100                else {
4101                        add_external_diff_name(&argv, other, two);
4102                        argv_array_push(&argv, other);
4103                        argv_array_push(&argv, xfrm_msg);
4104                }
4105        }
4106
4107        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
4108        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
4109
4110        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
4111                die(_("external diff died, stopping at %s"), name);
4112
4113        remove_tempfile();
4114        argv_array_clear(&argv);
4115        argv_array_clear(&env);
4116}
4117
4118static int similarity_index(struct diff_filepair *p)
4119{
4120        return p->score * 100 / MAX_SCORE;
4121}
4122
4123static const char *diff_abbrev_oid(const struct object_id *oid, int abbrev)
4124{
4125        if (startup_info->have_repository)
4126                return find_unique_abbrev(oid, abbrev);
4127        else {
4128                char *hex = oid_to_hex(oid);
4129                if (abbrev < 0)
4130                        abbrev = FALLBACK_DEFAULT_ABBREV;
4131                if (abbrev > the_hash_algo->hexsz)
4132                        BUG("oid abbreviation out of range: %d", abbrev);
4133                if (abbrev)
4134                        hex[abbrev] = '\0';
4135                return hex;
4136        }
4137}
4138
4139static void fill_metainfo(struct strbuf *msg,
4140                          const char *name,
4141                          const char *other,
4142                          struct diff_filespec *one,
4143                          struct diff_filespec *two,
4144                          struct diff_options *o,
4145                          struct diff_filepair *p,
4146                          int *must_show_header,
4147                          int use_color)
4148{
4149        const char *set = diff_get_color(use_color, DIFF_METAINFO);
4150        const char *reset = diff_get_color(use_color, DIFF_RESET);
4151        const char *line_prefix = diff_line_prefix(o);
4152
4153        *must_show_header = 1;
4154        strbuf_init(msg, PATH_MAX * 2 + 300);
4155        switch (p->status) {
4156        case DIFF_STATUS_COPIED:
4157                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4158                            line_prefix, set, similarity_index(p));
4159                strbuf_addf(msg, "%s\n%s%scopy from ",
4160                            reset,  line_prefix, set);
4161                quote_c_style(name, msg, NULL, 0);
4162                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
4163                quote_c_style(other, msg, NULL, 0);
4164                strbuf_addf(msg, "%s\n", reset);
4165                break;
4166        case DIFF_STATUS_RENAMED:
4167                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4168                            line_prefix, set, similarity_index(p));
4169                strbuf_addf(msg, "%s\n%s%srename from ",
4170                            reset, line_prefix, set);
4171                quote_c_style(name, msg, NULL, 0);
4172                strbuf_addf(msg, "%s\n%s%srename to ",
4173                            reset, line_prefix, set);
4174                quote_c_style(other, msg, NULL, 0);
4175                strbuf_addf(msg, "%s\n", reset);
4176                break;
4177        case DIFF_STATUS_MODIFIED:
4178                if (p->score) {
4179                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
4180                                    line_prefix,
4181                                    set, similarity_index(p), reset);
4182                        break;
4183                }
4184                /* fallthru */
4185        default:
4186                *must_show_header = 0;
4187        }
4188        if (one && two && oidcmp(&one->oid, &two->oid)) {
4189                const unsigned hexsz = the_hash_algo->hexsz;
4190                int abbrev = o->flags.full_index ? hexsz : DEFAULT_ABBREV;
4191
4192                if (o->flags.binary) {
4193                        mmfile_t mf;
4194                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
4195                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
4196                                abbrev = hexsz;
4197                }
4198                strbuf_addf(msg, "%s%sindex %s..%s", line_prefix, set,
4199                            diff_abbrev_oid(&one->oid, abbrev),
4200                            diff_abbrev_oid(&two->oid, abbrev));
4201                if (one->mode == two->mode)
4202                        strbuf_addf(msg, " %06o", one->mode);
4203                strbuf_addf(msg, "%s\n", reset);
4204        }
4205}
4206
4207static void run_diff_cmd(const char *pgm,
4208                         const char *name,
4209                         const char *other,
4210                         const char *attr_path,
4211                         struct diff_filespec *one,
4212                         struct diff_filespec *two,
4213                         struct strbuf *msg,
4214                         struct diff_options *o,
4215                         struct diff_filepair *p)
4216{
4217        const char *xfrm_msg = NULL;
4218        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
4219        int must_show_header = 0;
4220
4221
4222        if (o->flags.allow_external) {
4223                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
4224                if (drv && drv->external)
4225                        pgm = drv->external;
4226        }
4227
4228        if (msg) {
4229                /*
4230                 * don't use colors when the header is intended for an
4231                 * external diff driver
4232                 */
4233                fill_metainfo(msg, name, other, one, two, o, p,
4234                              &must_show_header,
4235                              want_color(o->use_color) && !pgm);
4236                xfrm_msg = msg->len ? msg->buf : NULL;
4237        }
4238
4239        if (pgm) {
4240                run_external_diff(pgm, name, other, one, two, xfrm_msg,
4241                                  complete_rewrite, o);
4242                return;
4243        }
4244        if (one && two)
4245                builtin_diff(name, other ? other : name,
4246                             one, two, xfrm_msg, must_show_header,
4247                             o, complete_rewrite);
4248        else
4249                fprintf(o->file, "* Unmerged path %s\n", name);
4250}
4251
4252static void diff_fill_oid_info(struct diff_filespec *one)
4253{
4254        if (DIFF_FILE_VALID(one)) {
4255                if (!one->oid_valid) {
4256                        struct stat st;
4257                        if (one->is_stdin) {
4258                                oidclr(&one->oid);
4259                                return;
4260                        }
4261                        if (lstat(one->path, &st) < 0)
4262                                die_errno("stat '%s'", one->path);
4263                        if (index_path(&one->oid, one->path, &st, 0))
4264                                die("cannot hash %s", one->path);
4265                }
4266        }
4267        else
4268                oidclr(&one->oid);
4269}
4270
4271static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
4272{
4273        /* Strip the prefix but do not molest /dev/null and absolute paths */
4274        if (*namep && **namep != '/') {
4275                *namep += prefix_length;
4276                if (**namep == '/')
4277                        ++*namep;
4278        }
4279        if (*otherp && **otherp != '/') {
4280                *otherp += prefix_length;
4281                if (**otherp == '/')
4282                        ++*otherp;
4283        }
4284}
4285
4286static void run_diff(struct diff_filepair *p, struct diff_options *o)
4287{
4288        const char *pgm = external_diff();
4289        struct strbuf msg;
4290        struct diff_filespec *one = p->one;
4291        struct diff_filespec *two = p->two;
4292        const char *name;
4293        const char *other;
4294        const char *attr_path;
4295
4296        name  = one->path;
4297        other = (strcmp(name, two->path) ? two->path : NULL);
4298        attr_path = name;
4299        if (o->prefix_length)
4300                strip_prefix(o->prefix_length, &name, &other);
4301
4302        if (!o->flags.allow_external)
4303                pgm = NULL;
4304
4305        if (DIFF_PAIR_UNMERGED(p)) {
4306                run_diff_cmd(pgm, name, NULL, attr_path,
4307                             NULL, NULL, NULL, o, p);
4308                return;
4309        }
4310
4311        diff_fill_oid_info(one);
4312        diff_fill_oid_info(two);
4313
4314        if (!pgm &&
4315            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
4316            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
4317                /*
4318                 * a filepair that changes between file and symlink
4319                 * needs to be split into deletion and creation.
4320                 */
4321                struct diff_filespec *null = alloc_filespec(two->path);
4322                run_diff_cmd(NULL, name, other, attr_path,
4323                             one, null, &msg, o, p);
4324                free(null);
4325                strbuf_release(&msg);
4326
4327                null = alloc_filespec(one->path);
4328                run_diff_cmd(NULL, name, other, attr_path,
4329                             null, two, &msg, o, p);
4330                free(null);
4331        }
4332        else
4333                run_diff_cmd(pgm, name, other, attr_path,
4334                             one, two, &msg, o, p);
4335
4336        strbuf_release(&msg);
4337}
4338
4339static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
4340                         struct diffstat_t *diffstat)
4341{
4342        const char *name;
4343        const char *other;
4344
4345        if (DIFF_PAIR_UNMERGED(p)) {
4346                /* unmerged */
4347                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, p);
4348                return;
4349        }
4350
4351        name = p->one->path;
4352        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4353
4354        if (o->prefix_length)
4355                strip_prefix(o->prefix_length, &name, &other);
4356
4357        diff_fill_oid_info(p->one);
4358        diff_fill_oid_info(p->two);
4359
4360        builtin_diffstat(name, other, p->one, p->two, diffstat, o, p);
4361}
4362
4363static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
4364{
4365        const char *name;
4366        const char *other;
4367        const char *attr_path;
4368
4369        if (DIFF_PAIR_UNMERGED(p)) {
4370                /* unmerged */
4371                return;
4372        }
4373
4374        name = p->one->path;
4375        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4376        attr_path = other ? other : name;
4377
4378        if (o->prefix_length)
4379                strip_prefix(o->prefix_length, &name, &other);
4380
4381        diff_fill_oid_info(p->one);
4382        diff_fill_oid_info(p->two);
4383
4384        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
4385}
4386
4387void diff_setup(struct diff_options *options)
4388{
4389        memcpy(options, &default_diff_options, sizeof(*options));
4390
4391        options->file = stdout;
4392
4393        options->output_indicators[OUTPUT_INDICATOR_NEW] = '+';
4394        options->output_indicators[OUTPUT_INDICATOR_OLD] = '-';
4395        options->output_indicators[OUTPUT_INDICATOR_CONTEXT] = ' ';
4396        options->abbrev = DEFAULT_ABBREV;
4397        options->line_termination = '\n';
4398        options->break_opt = -1;
4399        options->rename_limit = -1;
4400        options->dirstat_permille = diff_dirstat_permille_default;
4401        options->context = diff_context_default;
4402        options->interhunkcontext = diff_interhunk_context_default;
4403        options->ws_error_highlight = ws_error_highlight_default;
4404        options->flags.rename_empty = 1;
4405        options->objfind = NULL;
4406
4407        /* pathchange left =NULL by default */
4408        options->change = diff_change;
4409        options->add_remove = diff_addremove;
4410        options->use_color = diff_use_color_default;
4411        options->detect_rename = diff_detect_rename_default;
4412        options->xdl_opts |= diff_algorithm;
4413        if (diff_indent_heuristic)
4414                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4415
4416        options->orderfile = diff_order_file_cfg;
4417
4418        if (diff_no_prefix) {
4419                options->a_prefix = options->b_prefix = "";
4420        } else if (!diff_mnemonic_prefix) {
4421                options->a_prefix = "a/";
4422                options->b_prefix = "b/";
4423        }
4424
4425        options->color_moved = diff_color_moved_default;
4426        options->color_moved_ws_handling = diff_color_moved_ws_default;
4427}
4428
4429void diff_setup_done(struct diff_options *options)
4430{
4431        unsigned check_mask = DIFF_FORMAT_NAME |
4432                              DIFF_FORMAT_NAME_STATUS |
4433                              DIFF_FORMAT_CHECKDIFF |
4434                              DIFF_FORMAT_NO_OUTPUT;
4435        /*
4436         * This must be signed because we're comparing against a potentially
4437         * negative value.
4438         */
4439        const int hexsz = the_hash_algo->hexsz;
4440
4441        if (options->set_default)
4442                options->set_default(options);
4443
4444        if (HAS_MULTI_BITS(options->output_format & check_mask))
4445                die(_("--name-only, --name-status, --check and -s are mutually exclusive"));
4446
4447        if (HAS_MULTI_BITS(options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK))
4448                die(_("-G, -S and --find-object are mutually exclusive"));
4449
4450        /*
4451         * Most of the time we can say "there are changes"
4452         * only by checking if there are changed paths, but
4453         * --ignore-whitespace* options force us to look
4454         * inside contents.
4455         */
4456
4457        if ((options->xdl_opts & XDF_WHITESPACE_FLAGS))
4458                options->flags.diff_from_contents = 1;
4459        else
4460                options->flags.diff_from_contents = 0;
4461
4462        if (options->flags.find_copies_harder)
4463                options->detect_rename = DIFF_DETECT_COPY;
4464
4465        if (!options->flags.relative_name)
4466                options->prefix = NULL;
4467        if (options->prefix)
4468                options->prefix_length = strlen(options->prefix);
4469        else
4470                options->prefix_length = 0;
4471
4472        if (options->output_format & (DIFF_FORMAT_NAME |
4473                                      DIFF_FORMAT_NAME_STATUS |
4474                                      DIFF_FORMAT_CHECKDIFF |
4475                                      DIFF_FORMAT_NO_OUTPUT))
4476                options->output_format &= ~(DIFF_FORMAT_RAW |
4477                                            DIFF_FORMAT_NUMSTAT |
4478                                            DIFF_FORMAT_DIFFSTAT |
4479                                            DIFF_FORMAT_SHORTSTAT |
4480                                            DIFF_FORMAT_DIRSTAT |
4481                                            DIFF_FORMAT_SUMMARY |
4482                                            DIFF_FORMAT_PATCH);
4483
4484        /*
4485         * These cases always need recursive; we do not drop caller-supplied
4486         * recursive bits for other formats here.
4487         */
4488        if (options->output_format & (DIFF_FORMAT_PATCH |
4489                                      DIFF_FORMAT_NUMSTAT |
4490                                      DIFF_FORMAT_DIFFSTAT |
4491                                      DIFF_FORMAT_SHORTSTAT |
4492                                      DIFF_FORMAT_DIRSTAT |
4493                                      DIFF_FORMAT_SUMMARY |
4494                                      DIFF_FORMAT_CHECKDIFF))
4495                options->flags.recursive = 1;
4496        /*
4497         * Also pickaxe would not work very well if you do not say recursive
4498         */
4499        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
4500                options->flags.recursive = 1;
4501        /*
4502         * When patches are generated, submodules diffed against the work tree
4503         * must be checked for dirtiness too so it can be shown in the output
4504         */
4505        if (options->output_format & DIFF_FORMAT_PATCH)
4506                options->flags.dirty_submodules = 1;
4507
4508        if (options->detect_rename && options->rename_limit < 0)
4509                options->rename_limit = diff_rename_limit_default;
4510        if (hexsz < options->abbrev)
4511                options->abbrev = hexsz; /* full */
4512
4513        /*
4514         * It does not make sense to show the first hit we happened
4515         * to have found.  It does not make sense not to return with
4516         * exit code in such a case either.
4517         */
4518        if (options->flags.quick) {
4519                options->output_format = DIFF_FORMAT_NO_OUTPUT;
4520                options->flags.exit_with_status = 1;
4521        }
4522
4523        options->diff_path_counter = 0;
4524
4525        if (options->flags.follow_renames && options->pathspec.nr != 1)
4526                die(_("--follow requires exactly one pathspec"));
4527
4528        if (!options->use_color || external_diff())
4529                options->color_moved = 0;
4530}
4531
4532static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
4533{
4534        char c, *eq;
4535        int len;
4536
4537        if (*arg != '-')
4538                return 0;
4539        c = *++arg;
4540        if (!c)
4541                return 0;
4542        if (c == arg_short) {
4543                c = *++arg;
4544                if (!c)
4545                        return 1;
4546                if (val && isdigit(c)) {
4547                        char *end;
4548                        int n = strtoul(arg, &end, 10);
4549                        if (*end)
4550                                return 0;
4551                        *val = n;
4552                        return 1;
4553                }
4554                return 0;
4555        }
4556        if (c != '-')
4557                return 0;
4558        arg++;
4559        eq = strchrnul(arg, '=');
4560        len = eq - arg;
4561        if (!len || strncmp(arg, arg_long, len))
4562                return 0;
4563        if (*eq) {
4564                int n;
4565                char *end;
4566                if (!isdigit(*++eq))
4567                        return 0;
4568                n = strtoul(eq, &end, 10);
4569                if (*end)
4570                        return 0;
4571                *val = n;
4572        }
4573        return 1;
4574}
4575
4576static int diff_scoreopt_parse(const char *opt);
4577
4578static inline int short_opt(char opt, const char **argv,
4579                            const char **optarg)
4580{
4581        const char *arg = argv[0];
4582        if (arg[0] != '-' || arg[1] != opt)
4583                return 0;
4584        if (arg[2] != '\0') {
4585                *optarg = arg + 2;
4586                return 1;
4587        }
4588        if (!argv[1])
4589                die("Option '%c' requires a value", opt);
4590        *optarg = argv[1];
4591        return 2;
4592}
4593
4594int parse_long_opt(const char *opt, const char **argv,
4595                   const char **optarg)
4596{
4597        const char *arg = argv[0];
4598        if (!skip_prefix(arg, "--", &arg))
4599                return 0;
4600        if (!skip_prefix(arg, opt, &arg))
4601                return 0;
4602        if (*arg == '=') { /* stuck form: --option=value */
4603                *optarg = arg + 1;
4604                return 1;
4605        }
4606        if (*arg != '\0')
4607                return 0;
4608        /* separate form: --option value */
4609        if (!argv[1])
4610                die("Option '--%s' requires a value", opt);
4611        *optarg = argv[1];
4612        return 2;
4613}
4614
4615static int stat_opt(struct diff_options *options, const char **av)
4616{
4617        const char *arg = av[0];
4618        char *end;
4619        int width = options->stat_width;
4620        int name_width = options->stat_name_width;
4621        int graph_width = options->stat_graph_width;
4622        int count = options->stat_count;
4623        int argcount = 1;
4624
4625        if (!skip_prefix(arg, "--stat", &arg))
4626                BUG("stat option does not begin with --stat: %s", arg);
4627        end = (char *)arg;
4628
4629        switch (*arg) {
4630        case '-':
4631                if (skip_prefix(arg, "-width", &arg)) {
4632                        if (*arg == '=')
4633                                width = strtoul(arg + 1, &end, 10);
4634                        else if (!*arg && !av[1])
4635                                die_want_option("--stat-width");
4636                        else if (!*arg) {
4637                                width = strtoul(av[1], &end, 10);
4638                                argcount = 2;
4639                        }
4640                } else if (skip_prefix(arg, "-name-width", &arg)) {
4641                        if (*arg == '=')
4642                                name_width = strtoul(arg + 1, &end, 10);
4643                        else if (!*arg && !av[1])
4644                                die_want_option("--stat-name-width");
4645                        else if (!*arg) {
4646                                name_width = strtoul(av[1], &end, 10);
4647                                argcount = 2;
4648                        }
4649                } else if (skip_prefix(arg, "-graph-width", &arg)) {
4650                        if (*arg == '=')
4651                                graph_width = strtoul(arg + 1, &end, 10);
4652                        else if (!*arg && !av[1])
4653                                die_want_option("--stat-graph-width");
4654                        else if (!*arg) {
4655                                graph_width = strtoul(av[1], &end, 10);
4656                                argcount = 2;
4657                        }
4658                } else if (skip_prefix(arg, "-count", &arg)) {
4659                        if (*arg == '=')
4660                                count = strtoul(arg + 1, &end, 10);
4661                        else if (!*arg && !av[1])
4662                                die_want_option("--stat-count");
4663                        else if (!*arg) {
4664                                count = strtoul(av[1], &end, 10);
4665                                argcount = 2;
4666                        }
4667                }
4668                break;
4669        case '=':
4670                width = strtoul(arg+1, &end, 10);
4671                if (*end == ',')
4672                        name_width = strtoul(end+1, &end, 10);
4673                if (*end == ',')
4674                        count = strtoul(end+1, &end, 10);
4675        }
4676
4677        /* Important! This checks all the error cases! */
4678        if (*end)
4679                return 0;
4680        options->output_format |= DIFF_FORMAT_DIFFSTAT;
4681        options->stat_name_width = name_width;
4682        options->stat_graph_width = graph_width;
4683        options->stat_width = width;
4684        options->stat_count = count;
4685        return argcount;
4686}
4687
4688static int parse_dirstat_opt(struct diff_options *options, const char *params)
4689{
4690        struct strbuf errmsg = STRBUF_INIT;
4691        if (parse_dirstat_params(options, params, &errmsg))
4692                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
4693                    errmsg.buf);
4694        strbuf_release(&errmsg);
4695        /*
4696         * The caller knows a dirstat-related option is given from the command
4697         * line; allow it to say "return this_function();"
4698         */
4699        options->output_format |= DIFF_FORMAT_DIRSTAT;
4700        return 1;
4701}
4702
4703static int parse_submodule_opt(struct diff_options *options, const char *value)
4704{
4705        if (parse_submodule_params(options, value))
4706                die(_("Failed to parse --submodule option parameter: '%s'"),
4707                        value);
4708        return 1;
4709}
4710
4711static const char diff_status_letters[] = {
4712        DIFF_STATUS_ADDED,
4713        DIFF_STATUS_COPIED,
4714        DIFF_STATUS_DELETED,
4715        DIFF_STATUS_MODIFIED,
4716        DIFF_STATUS_RENAMED,
4717        DIFF_STATUS_TYPE_CHANGED,
4718        DIFF_STATUS_UNKNOWN,
4719        DIFF_STATUS_UNMERGED,
4720        DIFF_STATUS_FILTER_AON,
4721        DIFF_STATUS_FILTER_BROKEN,
4722        '\0',
4723};
4724
4725static unsigned int filter_bit['Z' + 1];
4726
4727static void prepare_filter_bits(void)
4728{
4729        int i;
4730
4731        if (!filter_bit[DIFF_STATUS_ADDED]) {
4732                for (i = 0; diff_status_letters[i]; i++)
4733                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
4734        }
4735}
4736
4737static unsigned filter_bit_tst(char status, const struct diff_options *opt)
4738{
4739        return opt->filter & filter_bit[(int) status];
4740}
4741
4742static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
4743{
4744        int i, optch;
4745
4746        prepare_filter_bits();
4747
4748        /*
4749         * If there is a negation e.g. 'd' in the input, and we haven't
4750         * initialized the filter field with another --diff-filter, start
4751         * from full set of bits, except for AON.
4752         */
4753        if (!opt->filter) {
4754                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4755                        if (optch < 'a' || 'z' < optch)
4756                                continue;
4757                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
4758                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
4759                        break;
4760                }
4761        }
4762
4763        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4764                unsigned int bit;
4765                int negate;
4766
4767                if ('a' <= optch && optch <= 'z') {
4768                        negate = 1;
4769                        optch = toupper(optch);
4770                } else {
4771                        negate = 0;
4772                }
4773
4774                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
4775                if (!bit)
4776                        return optarg[i];
4777                if (negate)
4778                        opt->filter &= ~bit;
4779                else
4780                        opt->filter |= bit;
4781        }
4782        return 0;
4783}
4784
4785static void enable_patch_output(int *fmt) {
4786        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
4787        *fmt |= DIFF_FORMAT_PATCH;
4788}
4789
4790static int parse_ws_error_highlight_opt(struct diff_options *opt, const char *arg)
4791{
4792        int val = parse_ws_error_highlight(arg);
4793
4794        if (val < 0) {
4795                error("unknown value after ws-error-highlight=%.*s",
4796                      -1 - val, arg);
4797                return 0;
4798        }
4799        opt->ws_error_highlight = val;
4800        return 1;
4801}
4802
4803static int parse_objfind_opt(struct diff_options *opt, const char *arg)
4804{
4805        struct object_id oid;
4806
4807        if (get_oid(arg, &oid))
4808                return error("unable to resolve '%s'", arg);
4809
4810        if (!opt->objfind)
4811                opt->objfind = xcalloc(1, sizeof(*opt->objfind));
4812
4813        opt->pickaxe_opts |= DIFF_PICKAXE_KIND_OBJFIND;
4814        opt->flags.recursive = 1;
4815        opt->flags.tree_in_recursive = 1;
4816        oidset_insert(opt->objfind, &oid);
4817        return 1;
4818}
4819
4820int diff_opt_parse(struct diff_options *options,
4821                   const char **av, int ac, const char *prefix)
4822{
4823        const char *arg = av[0];
4824        const char *optarg;
4825        int argcount;
4826
4827        if (!prefix)
4828                prefix = "";
4829
4830        /* Output format options */
4831        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
4832            || opt_arg(arg, 'U', "unified", &options->context))
4833                enable_patch_output(&options->output_format);
4834        else if (!strcmp(arg, "--raw"))
4835                options->output_format |= DIFF_FORMAT_RAW;
4836        else if (!strcmp(arg, "--patch-with-raw")) {
4837                enable_patch_output(&options->output_format);
4838                options->output_format |= DIFF_FORMAT_RAW;
4839        } else if (!strcmp(arg, "--numstat"))
4840                options->output_format |= DIFF_FORMAT_NUMSTAT;
4841        else if (!strcmp(arg, "--shortstat"))
4842                options->output_format |= DIFF_FORMAT_SHORTSTAT;
4843        else if (skip_prefix(arg, "-X", &arg) ||
4844                 skip_to_optional_arg(arg, "--dirstat", &arg))
4845                return parse_dirstat_opt(options, arg);
4846        else if (!strcmp(arg, "--cumulative"))
4847                return parse_dirstat_opt(options, "cumulative");
4848        else if (skip_to_optional_arg(arg, "--dirstat-by-file", &arg)) {
4849                parse_dirstat_opt(options, "files");
4850                return parse_dirstat_opt(options, arg);
4851        }
4852        else if (!strcmp(arg, "--check"))
4853                options->output_format |= DIFF_FORMAT_CHECKDIFF;
4854        else if (!strcmp(arg, "--summary"))
4855                options->output_format |= DIFF_FORMAT_SUMMARY;
4856        else if (!strcmp(arg, "--patch-with-stat")) {
4857                enable_patch_output(&options->output_format);
4858                options->output_format |= DIFF_FORMAT_DIFFSTAT;
4859        } else if (!strcmp(arg, "--name-only"))
4860                options->output_format |= DIFF_FORMAT_NAME;
4861        else if (!strcmp(arg, "--name-status"))
4862                options->output_format |= DIFF_FORMAT_NAME_STATUS;
4863        else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
4864                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
4865        else if (starts_with(arg, "--stat"))
4866                /* --stat, --stat-width, --stat-name-width, or --stat-count */
4867                return stat_opt(options, av);
4868        else if (!strcmp(arg, "--compact-summary")) {
4869                 options->flags.stat_with_summary = 1;
4870                 options->output_format |= DIFF_FORMAT_DIFFSTAT;
4871        } else if (!strcmp(arg, "--no-compact-summary"))
4872                 options->flags.stat_with_summary = 0;
4873        else if (skip_prefix(arg, "--output-indicator-new=", &arg))
4874                options->output_indicators[OUTPUT_INDICATOR_NEW] = arg[0];
4875        else if (skip_prefix(arg, "--output-indicator-old=", &arg))
4876                options->output_indicators[OUTPUT_INDICATOR_OLD] = arg[0];
4877        else if (skip_prefix(arg, "--output-indicator-context=", &arg))
4878                options->output_indicators[OUTPUT_INDICATOR_CONTEXT] = arg[0];
4879
4880        /* renames options */
4881        else if (starts_with(arg, "-B") ||
4882                 skip_to_optional_arg(arg, "--break-rewrites", NULL)) {
4883                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
4884                        return error("invalid argument to -B: %s", arg+2);
4885        }
4886        else if (starts_with(arg, "-M") ||
4887                 skip_to_optional_arg(arg, "--find-renames", NULL)) {
4888                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4889                        return error("invalid argument to -M: %s", arg+2);
4890                options->detect_rename = DIFF_DETECT_RENAME;
4891        }
4892        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
4893                options->irreversible_delete = 1;
4894        }
4895        else if (starts_with(arg, "-C") ||
4896                 skip_to_optional_arg(arg, "--find-copies", NULL)) {
4897                if (options->detect_rename == DIFF_DETECT_COPY)
4898                        options->flags.find_copies_harder = 1;
4899                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4900                        return error("invalid argument to -C: %s", arg+2);
4901                options->detect_rename = DIFF_DETECT_COPY;
4902        }
4903        else if (!strcmp(arg, "--no-renames"))
4904                options->detect_rename = 0;
4905        else if (!strcmp(arg, "--rename-empty"))
4906                options->flags.rename_empty = 1;
4907        else if (!strcmp(arg, "--no-rename-empty"))
4908                options->flags.rename_empty = 0;
4909        else if (skip_to_optional_arg_default(arg, "--relative", &arg, NULL)) {
4910                options->flags.relative_name = 1;
4911                if (arg)
4912                        options->prefix = arg;
4913        }
4914
4915        /* xdiff options */
4916        else if (!strcmp(arg, "--minimal"))
4917                DIFF_XDL_SET(options, NEED_MINIMAL);
4918        else if (!strcmp(arg, "--no-minimal"))
4919                DIFF_XDL_CLR(options, NEED_MINIMAL);
4920        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
4921                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
4922        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
4923                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
4924        else if (!strcmp(arg, "--ignore-space-at-eol"))
4925                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
4926        else if (!strcmp(arg, "--ignore-cr-at-eol"))
4927                DIFF_XDL_SET(options, IGNORE_CR_AT_EOL);
4928        else if (!strcmp(arg, "--ignore-blank-lines"))
4929                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
4930        else if (!strcmp(arg, "--indent-heuristic"))
4931                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4932        else if (!strcmp(arg, "--no-indent-heuristic"))
4933                DIFF_XDL_CLR(options, INDENT_HEURISTIC);
4934        else if (!strcmp(arg, "--patience")) {
4935                int i;
4936                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4937                /*
4938                 * Both --patience and --anchored use PATIENCE_DIFF
4939                 * internally, so remove any anchors previously
4940                 * specified.
4941                 */
4942                for (i = 0; i < options->anchors_nr; i++)
4943                        free(options->anchors[i]);
4944                options->anchors_nr = 0;
4945        } else if (!strcmp(arg, "--histogram"))
4946                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
4947        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
4948                long value = parse_algorithm_value(optarg);
4949                if (value < 0)
4950                        return error("option diff-algorithm accepts \"myers\", "
4951                                     "\"minimal\", \"patience\" and \"histogram\"");
4952                /* clear out previous settings */
4953                DIFF_XDL_CLR(options, NEED_MINIMAL);
4954                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
4955                options->xdl_opts |= value;
4956                return argcount;
4957        } else if (skip_prefix(arg, "--anchored=", &arg)) {
4958                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4959                ALLOC_GROW(options->anchors, options->anchors_nr + 1,
4960                           options->anchors_alloc);
4961                options->anchors[options->anchors_nr++] = xstrdup(arg);
4962        }
4963
4964        /* flags options */
4965        else if (!strcmp(arg, "--binary")) {
4966                enable_patch_output(&options->output_format);
4967                options->flags.binary = 1;
4968        }
4969        else if (!strcmp(arg, "--full-index"))
4970                options->flags.full_index = 1;
4971        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
4972                options->flags.text = 1;
4973        else if (!strcmp(arg, "-R"))
4974                options->flags.reverse_diff = 1;
4975        else if (!strcmp(arg, "--find-copies-harder"))
4976                options->flags.find_copies_harder = 1;
4977        else if (!strcmp(arg, "--follow"))
4978                options->flags.follow_renames = 1;
4979        else if (!strcmp(arg, "--no-follow")) {
4980                options->flags.follow_renames = 0;
4981                options->flags.default_follow_renames = 0;
4982        } else if (skip_to_optional_arg_default(arg, "--color", &arg, "always")) {
4983                int value = git_config_colorbool(NULL, arg);
4984                if (value < 0)
4985                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
4986                options->use_color = value;
4987        }
4988        else if (!strcmp(arg, "--no-color"))
4989                options->use_color = 0;
4990        else if (!strcmp(arg, "--color-moved")) {
4991                if (diff_color_moved_default)
4992                        options->color_moved = diff_color_moved_default;
4993                if (options->color_moved == COLOR_MOVED_NO)
4994                        options->color_moved = COLOR_MOVED_DEFAULT;
4995        } else if (!strcmp(arg, "--no-color-moved"))
4996                options->color_moved = COLOR_MOVED_NO;
4997        else if (skip_prefix(arg, "--color-moved=", &arg)) {
4998                int cm = parse_color_moved(arg);
4999                if (cm < 0)
5000                        die("bad --color-moved argument: %s", arg);
5001                options->color_moved = cm;
5002        } else if (skip_prefix(arg, "--color-moved-ws=", &arg)) {
5003                options->color_moved_ws_handling = parse_color_moved_ws(arg);
5004        } else if (skip_to_optional_arg_default(arg, "--color-words", &options->word_regex, NULL)) {
5005                options->use_color = 1;
5006                options->word_diff = DIFF_WORDS_COLOR;
5007        }
5008        else if (!strcmp(arg, "--word-diff")) {
5009                if (options->word_diff == DIFF_WORDS_NONE)
5010                        options->word_diff = DIFF_WORDS_PLAIN;
5011        }
5012        else if (skip_prefix(arg, "--word-diff=", &arg)) {
5013                if (!strcmp(arg, "plain"))
5014                        options->word_diff = DIFF_WORDS_PLAIN;
5015                else if (!strcmp(arg, "color")) {
5016                        options->use_color = 1;
5017                        options->word_diff = DIFF_WORDS_COLOR;
5018                }
5019                else if (!strcmp(arg, "porcelain"))
5020                        options->word_diff = DIFF_WORDS_PORCELAIN;
5021                else if (!strcmp(arg, "none"))
5022                        options->word_diff = DIFF_WORDS_NONE;
5023                else
5024                        die("bad --word-diff argument: %s", arg);
5025        }
5026        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
5027                if (options->word_diff == DIFF_WORDS_NONE)
5028                        options->word_diff = DIFF_WORDS_PLAIN;
5029                options->word_regex = optarg;
5030                return argcount;
5031        }
5032        else if (!strcmp(arg, "--exit-code"))
5033                options->flags.exit_with_status = 1;
5034        else if (!strcmp(arg, "--quiet"))
5035                options->flags.quick = 1;
5036        else if (!strcmp(arg, "--ext-diff"))
5037                options->flags.allow_external = 1;
5038        else if (!strcmp(arg, "--no-ext-diff"))
5039                options->flags.allow_external = 0;
5040        else if (!strcmp(arg, "--textconv")) {
5041                options->flags.allow_textconv = 1;
5042                options->flags.textconv_set_via_cmdline = 1;
5043        } else if (!strcmp(arg, "--no-textconv"))
5044                options->flags.allow_textconv = 0;
5045        else if (skip_to_optional_arg_default(arg, "--ignore-submodules", &arg, "all")) {
5046                options->flags.override_submodule_config = 1;
5047                handle_ignore_submodules_arg(options, arg);
5048        } else if (skip_to_optional_arg_default(arg, "--submodule", &arg, "log"))
5049                return parse_submodule_opt(options, arg);
5050        else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
5051                return parse_ws_error_highlight_opt(options, arg);
5052        else if (!strcmp(arg, "--ita-invisible-in-index"))
5053                options->ita_invisible_in_index = 1;
5054        else if (!strcmp(arg, "--ita-visible-in-index"))
5055                options->ita_invisible_in_index = 0;
5056
5057        /* misc options */
5058        else if (!strcmp(arg, "-z"))
5059                options->line_termination = 0;
5060        else if ((argcount = short_opt('l', av, &optarg))) {
5061                options->rename_limit = strtoul(optarg, NULL, 10);
5062                return argcount;
5063        }
5064        else if ((argcount = short_opt('S', av, &optarg))) {
5065                options->pickaxe = optarg;
5066                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
5067                return argcount;
5068        } else if ((argcount = short_opt('G', av, &optarg))) {
5069                options->pickaxe = optarg;
5070                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
5071                return argcount;
5072        }
5073        else if (!strcmp(arg, "--pickaxe-all"))
5074                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
5075        else if (!strcmp(arg, "--pickaxe-regex"))
5076                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
5077        else if ((argcount = short_opt('O', av, &optarg))) {
5078                options->orderfile = prefix_filename(prefix, optarg);
5079                return argcount;
5080        } else if (skip_prefix(arg, "--find-object=", &arg))
5081                return parse_objfind_opt(options, arg);
5082        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
5083                int offending = parse_diff_filter_opt(optarg, options);
5084                if (offending)
5085                        die("unknown change class '%c' in --diff-filter=%s",
5086                            offending, optarg);
5087                return argcount;
5088        }
5089        else if (!strcmp(arg, "--no-abbrev"))
5090                options->abbrev = 0;
5091        else if (!strcmp(arg, "--abbrev"))
5092                options->abbrev = DEFAULT_ABBREV;
5093        else if (skip_prefix(arg, "--abbrev=", &arg)) {
5094                options->abbrev = strtoul(arg, NULL, 10);
5095                if (options->abbrev < MINIMUM_ABBREV)
5096                        options->abbrev = MINIMUM_ABBREV;
5097                else if (the_hash_algo->hexsz < options->abbrev)
5098                        options->abbrev = the_hash_algo->hexsz;
5099        }
5100        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
5101                options->a_prefix = optarg;
5102                return argcount;
5103        }
5104        else if ((argcount = parse_long_opt("line-prefix", av, &optarg))) {
5105                options->line_prefix = optarg;
5106                options->line_prefix_length = strlen(options->line_prefix);
5107                graph_setup_line_prefix(options);
5108                return argcount;
5109        }
5110        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
5111                options->b_prefix = optarg;
5112                return argcount;
5113        }
5114        else if (!strcmp(arg, "--no-prefix"))
5115                options->a_prefix = options->b_prefix = "";
5116        else if (opt_arg(arg, '\0', "inter-hunk-context",
5117                         &options->interhunkcontext))
5118                ;
5119        else if (!strcmp(arg, "-W"))
5120                options->flags.funccontext = 1;
5121        else if (!strcmp(arg, "--function-context"))
5122                options->flags.funccontext = 1;
5123        else if (!strcmp(arg, "--no-function-context"))
5124                options->flags.funccontext = 0;
5125        else if ((argcount = parse_long_opt("output", av, &optarg))) {
5126                char *path = prefix_filename(prefix, optarg);
5127                options->file = xfopen(path, "w");
5128                options->close_file = 1;
5129                if (options->use_color != GIT_COLOR_ALWAYS)
5130                        options->use_color = GIT_COLOR_NEVER;
5131                free(path);
5132                return argcount;
5133        } else
5134                return 0;
5135        return 1;
5136}
5137
5138int parse_rename_score(const char **cp_p)
5139{
5140        unsigned long num, scale;
5141        int ch, dot;
5142        const char *cp = *cp_p;
5143
5144        num = 0;
5145        scale = 1;
5146        dot = 0;
5147        for (;;) {
5148                ch = *cp;
5149                if ( !dot && ch == '.' ) {
5150                        scale = 1;
5151                        dot = 1;
5152                } else if ( ch == '%' ) {
5153                        scale = dot ? scale*100 : 100;
5154                        cp++;   /* % is always at the end */
5155                        break;
5156                } else if ( ch >= '0' && ch <= '9' ) {
5157                        if ( scale < 100000 ) {
5158                                scale *= 10;
5159                                num = (num*10) + (ch-'0');
5160                        }
5161                } else {
5162                        break;
5163                }
5164                cp++;
5165        }
5166        *cp_p = cp;
5167
5168        /* user says num divided by scale and we say internally that
5169         * is MAX_SCORE * num / scale.
5170         */
5171        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
5172}
5173
5174static int diff_scoreopt_parse(const char *opt)
5175{
5176        int opt1, opt2, cmd;
5177
5178        if (*opt++ != '-')
5179                return -1;
5180        cmd = *opt++;
5181        if (cmd == '-') {
5182                /* convert the long-form arguments into short-form versions */
5183                if (skip_prefix(opt, "break-rewrites", &opt)) {
5184                        if (*opt == 0 || *opt++ == '=')
5185                                cmd = 'B';
5186                } else if (skip_prefix(opt, "find-copies", &opt)) {
5187                        if (*opt == 0 || *opt++ == '=')
5188                                cmd = 'C';
5189                } else if (skip_prefix(opt, "find-renames", &opt)) {
5190                        if (*opt == 0 || *opt++ == '=')
5191                                cmd = 'M';
5192                }
5193        }
5194        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
5195                return -1; /* that is not a -M, -C, or -B option */
5196
5197        opt1 = parse_rename_score(&opt);
5198        if (cmd != 'B')
5199                opt2 = 0;
5200        else {
5201                if (*opt == 0)
5202                        opt2 = 0;
5203                else if (*opt != '/')
5204                        return -1; /* we expect -B80/99 or -B80 */
5205                else {
5206                        opt++;
5207                        opt2 = parse_rename_score(&opt);
5208                }
5209        }
5210        if (*opt != 0)
5211                return -1;
5212        return opt1 | (opt2 << 16);
5213}
5214
5215struct diff_queue_struct diff_queued_diff;
5216
5217void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
5218{
5219        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
5220        queue->queue[queue->nr++] = dp;
5221}
5222
5223struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
5224                                 struct diff_filespec *one,
5225                                 struct diff_filespec *two)
5226{
5227        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
5228        dp->one = one;
5229        dp->two = two;
5230        if (queue)
5231                diff_q(queue, dp);
5232        return dp;
5233}
5234
5235void diff_free_filepair(struct diff_filepair *p)
5236{
5237        free_filespec(p->one);
5238        free_filespec(p->two);
5239        free(p);
5240}
5241
5242const char *diff_aligned_abbrev(const struct object_id *oid, int len)
5243{
5244        int abblen;
5245        const char *abbrev;
5246
5247        /* Do we want all 40 hex characters? */
5248        if (len == the_hash_algo->hexsz)
5249                return oid_to_hex(oid);
5250
5251        /* An abbreviated value is fine, possibly followed by an ellipsis. */
5252        abbrev = diff_abbrev_oid(oid, len);
5253
5254        if (!print_sha1_ellipsis())
5255                return abbrev;
5256
5257        abblen = strlen(abbrev);
5258
5259        /*
5260         * In well-behaved cases, where the abbreviated result is the
5261         * same as the requested length, append three dots after the
5262         * abbreviation (hence the whole logic is limited to the case
5263         * where abblen < 37); when the actual abbreviated result is a
5264         * bit longer than the requested length, we reduce the number
5265         * of dots so that they match the well-behaved ones.  However,
5266         * if the actual abbreviation is longer than the requested
5267         * length by more than three, we give up on aligning, and add
5268         * three dots anyway, to indicate that the output is not the
5269         * full object name.  Yes, this may be suboptimal, but this
5270         * appears only in "diff --raw --abbrev" output and it is not
5271         * worth the effort to change it now.  Note that this would
5272         * likely to work fine when the automatic sizing of default
5273         * abbreviation length is used--we would be fed -1 in "len" in
5274         * that case, and will end up always appending three-dots, but
5275         * the automatic sizing is supposed to give abblen that ensures
5276         * uniqueness across all objects (statistically speaking).
5277         */
5278        if (abblen < the_hash_algo->hexsz - 3) {
5279                static char hex[GIT_MAX_HEXSZ + 1];
5280                if (len < abblen && abblen <= len + 2)
5281                        xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
5282                else
5283                        xsnprintf(hex, sizeof(hex), "%s...", abbrev);
5284                return hex;
5285        }
5286
5287        return oid_to_hex(oid);
5288}
5289
5290static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
5291{
5292        int line_termination = opt->line_termination;
5293        int inter_name_termination = line_termination ? '\t' : '\0';
5294
5295        fprintf(opt->file, "%s", diff_line_prefix(opt));
5296        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
5297                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
5298                        diff_aligned_abbrev(&p->one->oid, opt->abbrev));
5299                fprintf(opt->file, "%s ",
5300                        diff_aligned_abbrev(&p->two->oid, opt->abbrev));
5301        }
5302        if (p->score) {
5303                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
5304                        inter_name_termination);
5305        } else {
5306                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
5307        }
5308
5309        if (p->status == DIFF_STATUS_COPIED ||
5310            p->status == DIFF_STATUS_RENAMED) {
5311                const char *name_a, *name_b;
5312                name_a = p->one->path;
5313                name_b = p->two->path;
5314                strip_prefix(opt->prefix_length, &name_a, &name_b);
5315                write_name_quoted(name_a, opt->file, inter_name_termination);
5316                write_name_quoted(name_b, opt->file, line_termination);
5317        } else {
5318                const char *name_a, *name_b;
5319                name_a = p->one->mode ? p->one->path : p->two->path;
5320                name_b = NULL;
5321                strip_prefix(opt->prefix_length, &name_a, &name_b);
5322                write_name_quoted(name_a, opt->file, line_termination);
5323        }
5324}
5325
5326int diff_unmodified_pair(struct diff_filepair *p)
5327{
5328        /* This function is written stricter than necessary to support
5329         * the currently implemented transformers, but the idea is to
5330         * let transformers to produce diff_filepairs any way they want,
5331         * and filter and clean them up here before producing the output.
5332         */
5333        struct diff_filespec *one = p->one, *two = p->two;
5334
5335        if (DIFF_PAIR_UNMERGED(p))
5336                return 0; /* unmerged is interesting */
5337
5338        /* deletion, addition, mode or type change
5339         * and rename are all interesting.
5340         */
5341        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
5342            DIFF_PAIR_MODE_CHANGED(p) ||
5343            strcmp(one->path, two->path))
5344                return 0;
5345
5346        /* both are valid and point at the same path.  that is, we are
5347         * dealing with a change.
5348         */
5349        if (one->oid_valid && two->oid_valid &&
5350            !oidcmp(&one->oid, &two->oid) &&
5351            !one->dirty_submodule && !two->dirty_submodule)
5352                return 1; /* no change */
5353        if (!one->oid_valid && !two->oid_valid)
5354                return 1; /* both look at the same file on the filesystem. */
5355        return 0;
5356}
5357
5358static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
5359{
5360        if (diff_unmodified_pair(p))
5361                return;
5362
5363        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5364            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5365                return; /* no tree diffs in patch format */
5366
5367        run_diff(p, o);
5368}
5369
5370static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
5371                            struct diffstat_t *diffstat)
5372{
5373        if (diff_unmodified_pair(p))
5374                return;
5375
5376        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5377            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5378                return; /* no useful stat for tree diffs */
5379
5380        run_diffstat(p, o, diffstat);
5381}
5382
5383static void diff_flush_checkdiff(struct diff_filepair *p,
5384                struct diff_options *o)
5385{
5386        if (diff_unmodified_pair(p))
5387                return;
5388
5389        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5390            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5391                return; /* nothing to check in tree diffs */
5392
5393        run_checkdiff(p, o);
5394}
5395
5396int diff_queue_is_empty(void)
5397{
5398        struct diff_queue_struct *q = &diff_queued_diff;
5399        int i;
5400        for (i = 0; i < q->nr; i++)
5401                if (!diff_unmodified_pair(q->queue[i]))
5402                        return 0;
5403        return 1;
5404}
5405
5406#if DIFF_DEBUG
5407void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
5408{
5409        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
5410                x, one ? one : "",
5411                s->path,
5412                DIFF_FILE_VALID(s) ? "valid" : "invalid",
5413                s->mode,
5414                s->oid_valid ? oid_to_hex(&s->oid) : "");
5415        fprintf(stderr, "queue[%d] %s size %lu\n",
5416                x, one ? one : "",
5417                s->size);
5418}
5419
5420void diff_debug_filepair(const struct diff_filepair *p, int i)
5421{
5422        diff_debug_filespec(p->one, i, "one");
5423        diff_debug_filespec(p->two, i, "two");
5424        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
5425                p->score, p->status ? p->status : '?',
5426                p->one->rename_used, p->broken_pair);
5427}
5428
5429void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
5430{
5431        int i;
5432        if (msg)
5433                fprintf(stderr, "%s\n", msg);
5434        fprintf(stderr, "q->nr = %d\n", q->nr);
5435        for (i = 0; i < q->nr; i++) {
5436                struct diff_filepair *p = q->queue[i];
5437                diff_debug_filepair(p, i);
5438        }
5439}
5440#endif
5441
5442static void diff_resolve_rename_copy(void)
5443{
5444        int i;
5445        struct diff_filepair *p;
5446        struct diff_queue_struct *q = &diff_queued_diff;
5447
5448        diff_debug_queue("resolve-rename-copy", q);
5449
5450        for (i = 0; i < q->nr; i++) {
5451                p = q->queue[i];
5452                p->status = 0; /* undecided */
5453                if (DIFF_PAIR_UNMERGED(p))
5454                        p->status = DIFF_STATUS_UNMERGED;
5455                else if (!DIFF_FILE_VALID(p->one))
5456                        p->status = DIFF_STATUS_ADDED;
5457                else if (!DIFF_FILE_VALID(p->two))
5458                        p->status = DIFF_STATUS_DELETED;
5459                else if (DIFF_PAIR_TYPE_CHANGED(p))
5460                        p->status = DIFF_STATUS_TYPE_CHANGED;
5461
5462                /* from this point on, we are dealing with a pair
5463                 * whose both sides are valid and of the same type, i.e.
5464                 * either in-place edit or rename/copy edit.
5465                 */
5466                else if (DIFF_PAIR_RENAME(p)) {
5467                        /*
5468                         * A rename might have re-connected a broken
5469                         * pair up, causing the pathnames to be the
5470                         * same again. If so, that's not a rename at
5471                         * all, just a modification..
5472                         *
5473                         * Otherwise, see if this source was used for
5474                         * multiple renames, in which case we decrement
5475                         * the count, and call it a copy.
5476                         */
5477                        if (!strcmp(p->one->path, p->two->path))
5478                                p->status = DIFF_STATUS_MODIFIED;
5479                        else if (--p->one->rename_used > 0)
5480                                p->status = DIFF_STATUS_COPIED;
5481                        else
5482                                p->status = DIFF_STATUS_RENAMED;
5483                }
5484                else if (oidcmp(&p->one->oid, &p->two->oid) ||
5485                         p->one->mode != p->two->mode ||
5486                         p->one->dirty_submodule ||
5487                         p->two->dirty_submodule ||
5488                         is_null_oid(&p->one->oid))
5489                        p->status = DIFF_STATUS_MODIFIED;
5490                else {
5491                        /* This is a "no-change" entry and should not
5492                         * happen anymore, but prepare for broken callers.
5493                         */
5494                        error("feeding unmodified %s to diffcore",
5495                              p->one->path);
5496                        p->status = DIFF_STATUS_UNKNOWN;
5497                }
5498        }
5499        diff_debug_queue("resolve-rename-copy done", q);
5500}
5501
5502static int check_pair_status(struct diff_filepair *p)
5503{
5504        switch (p->status) {
5505        case DIFF_STATUS_UNKNOWN:
5506                return 0;
5507        case 0:
5508                die("internal error in diff-resolve-rename-copy");
5509        default:
5510                return 1;
5511        }
5512}
5513
5514static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
5515{
5516        int fmt = opt->output_format;
5517
5518        if (fmt & DIFF_FORMAT_CHECKDIFF)
5519                diff_flush_checkdiff(p, opt);
5520        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
5521                diff_flush_raw(p, opt);
5522        else if (fmt & DIFF_FORMAT_NAME) {
5523                const char *name_a, *name_b;
5524                name_a = p->two->path;
5525                name_b = NULL;
5526                strip_prefix(opt->prefix_length, &name_a, &name_b);
5527                fprintf(opt->file, "%s", diff_line_prefix(opt));
5528                write_name_quoted(name_a, opt->file, opt->line_termination);
5529        }
5530}
5531
5532static void show_file_mode_name(struct diff_options *opt, const char *newdelete, struct diff_filespec *fs)
5533{
5534        struct strbuf sb = STRBUF_INIT;
5535        if (fs->mode)
5536                strbuf_addf(&sb, " %s mode %06o ", newdelete, fs->mode);
5537        else
5538                strbuf_addf(&sb, " %s ", newdelete);
5539
5540        quote_c_style(fs->path, &sb, NULL, 0);
5541        strbuf_addch(&sb, '\n');
5542        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5543                         sb.buf, sb.len, 0);
5544        strbuf_release(&sb);
5545}
5546
5547static void show_mode_change(struct diff_options *opt, struct diff_filepair *p,
5548                int show_name)
5549{
5550        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
5551                struct strbuf sb = STRBUF_INIT;
5552                strbuf_addf(&sb, " mode change %06o => %06o",
5553                            p->one->mode, p->two->mode);
5554                if (show_name) {
5555                        strbuf_addch(&sb, ' ');
5556                        quote_c_style(p->two->path, &sb, NULL, 0);
5557                }
5558                strbuf_addch(&sb, '\n');
5559                emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5560                                 sb.buf, sb.len, 0);
5561                strbuf_release(&sb);
5562        }
5563}
5564
5565static void show_rename_copy(struct diff_options *opt, const char *renamecopy,
5566                struct diff_filepair *p)
5567{
5568        struct strbuf sb = STRBUF_INIT;
5569        struct strbuf names = STRBUF_INIT;
5570
5571        pprint_rename(&names, p->one->path, p->two->path);
5572        strbuf_addf(&sb, " %s %s (%d%%)\n",
5573                    renamecopy, names.buf, similarity_index(p));
5574        strbuf_release(&names);
5575        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5576                                 sb.buf, sb.len, 0);
5577        show_mode_change(opt, p, 0);
5578        strbuf_release(&sb);
5579}
5580
5581static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
5582{
5583        switch(p->status) {
5584        case DIFF_STATUS_DELETED:
5585                show_file_mode_name(opt, "delete", p->one);
5586                break;
5587        case DIFF_STATUS_ADDED:
5588                show_file_mode_name(opt, "create", p->two);
5589                break;
5590        case DIFF_STATUS_COPIED:
5591                show_rename_copy(opt, "copy", p);
5592                break;
5593        case DIFF_STATUS_RENAMED:
5594                show_rename_copy(opt, "rename", p);
5595                break;
5596        default:
5597                if (p->score) {
5598                        struct strbuf sb = STRBUF_INIT;
5599                        strbuf_addstr(&sb, " rewrite ");
5600                        quote_c_style(p->two->path, &sb, NULL, 0);
5601                        strbuf_addf(&sb, " (%d%%)\n", similarity_index(p));
5602                        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5603                                         sb.buf, sb.len, 0);
5604                        strbuf_release(&sb);
5605                }
5606                show_mode_change(opt, p, !p->score);
5607                break;
5608        }
5609}
5610
5611struct patch_id_t {
5612        git_SHA_CTX *ctx;
5613        int patchlen;
5614};
5615
5616static int remove_space(char *line, int len)
5617{
5618        int i;
5619        char *dst = line;
5620        unsigned char c;
5621
5622        for (i = 0; i < len; i++)
5623                if (!isspace((c = line[i])))
5624                        *dst++ = c;
5625
5626        return dst - line;
5627}
5628
5629static void patch_id_consume(void *priv, char *line, unsigned long len)
5630{
5631        struct patch_id_t *data = priv;
5632        int new_len;
5633
5634        /* Ignore line numbers when computing the SHA1 of the patch */
5635        if (starts_with(line, "@@ -"))
5636                return;
5637
5638        new_len = remove_space(line, len);
5639
5640        git_SHA1_Update(data->ctx, line, new_len);
5641        data->patchlen += new_len;
5642}
5643
5644static void patch_id_add_string(git_SHA_CTX *ctx, const char *str)
5645{
5646        git_SHA1_Update(ctx, str, strlen(str));
5647}
5648
5649static void patch_id_add_mode(git_SHA_CTX *ctx, unsigned mode)
5650{
5651        /* large enough for 2^32 in octal */
5652        char buf[12];
5653        int len = xsnprintf(buf, sizeof(buf), "%06o", mode);
5654        git_SHA1_Update(ctx, buf, len);
5655}
5656
5657/* returns 0 upon success, and writes result into sha1 */
5658static int diff_get_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5659{
5660        struct diff_queue_struct *q = &diff_queued_diff;
5661        int i;
5662        git_SHA_CTX ctx;
5663        struct patch_id_t data;
5664
5665        git_SHA1_Init(&ctx);
5666        memset(&data, 0, sizeof(struct patch_id_t));
5667        data.ctx = &ctx;
5668
5669        for (i = 0; i < q->nr; i++) {
5670                xpparam_t xpp;
5671                xdemitconf_t xecfg;
5672                mmfile_t mf1, mf2;
5673                struct diff_filepair *p = q->queue[i];
5674                int len1, len2;
5675
5676                memset(&xpp, 0, sizeof(xpp));
5677                memset(&xecfg, 0, sizeof(xecfg));
5678                if (p->status == 0)
5679                        return error("internal diff status error");
5680                if (p->status == DIFF_STATUS_UNKNOWN)
5681                        continue;
5682                if (diff_unmodified_pair(p))
5683                        continue;
5684                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5685                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5686                        continue;
5687                if (DIFF_PAIR_UNMERGED(p))
5688                        continue;
5689
5690                diff_fill_oid_info(p->one);
5691                diff_fill_oid_info(p->two);
5692
5693                len1 = remove_space(p->one->path, strlen(p->one->path));
5694                len2 = remove_space(p->two->path, strlen(p->two->path));
5695                patch_id_add_string(&ctx, "diff--git");
5696                patch_id_add_string(&ctx, "a/");
5697                git_SHA1_Update(&ctx, p->one->path, len1);
5698                patch_id_add_string(&ctx, "b/");
5699                git_SHA1_Update(&ctx, p->two->path, len2);
5700
5701                if (p->one->mode == 0) {
5702                        patch_id_add_string(&ctx, "newfilemode");
5703                        patch_id_add_mode(&ctx, p->two->mode);
5704                        patch_id_add_string(&ctx, "---/dev/null");
5705                        patch_id_add_string(&ctx, "+++b/");
5706                        git_SHA1_Update(&ctx, p->two->path, len2);
5707                } else if (p->two->mode == 0) {
5708                        patch_id_add_string(&ctx, "deletedfilemode");
5709                        patch_id_add_mode(&ctx, p->one->mode);
5710                        patch_id_add_string(&ctx, "---a/");
5711                        git_SHA1_Update(&ctx, p->one->path, len1);
5712                        patch_id_add_string(&ctx, "+++/dev/null");
5713                } else {
5714                        patch_id_add_string(&ctx, "---a/");
5715                        git_SHA1_Update(&ctx, p->one->path, len1);
5716                        patch_id_add_string(&ctx, "+++b/");
5717                        git_SHA1_Update(&ctx, p->two->path, len2);
5718                }
5719
5720                if (diff_header_only)
5721                        continue;
5722
5723                if (fill_mmfile(&mf1, p->one) < 0 ||
5724                    fill_mmfile(&mf2, p->two) < 0)
5725                        return error("unable to read files to diff");
5726
5727                if (diff_filespec_is_binary(p->one) ||
5728                    diff_filespec_is_binary(p->two)) {
5729                        git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
5730                                        GIT_SHA1_HEXSZ);
5731                        git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
5732                                        GIT_SHA1_HEXSZ);
5733                        continue;
5734                }
5735
5736                xpp.flags = 0;
5737                xecfg.ctxlen = 3;
5738                xecfg.flags = 0;
5739                if (xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
5740                                  &xpp, &xecfg))
5741                        return error("unable to generate patch-id diff for %s",
5742                                     p->one->path);
5743        }
5744
5745        git_SHA1_Final(oid->hash, &ctx);
5746        return 0;
5747}
5748
5749int diff_flush_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5750{
5751        struct diff_queue_struct *q = &diff_queued_diff;
5752        int i;
5753        int result = diff_get_patch_id(options, oid, diff_header_only);
5754
5755        for (i = 0; i < q->nr; i++)
5756                diff_free_filepair(q->queue[i]);
5757
5758        free(q->queue);
5759        DIFF_QUEUE_CLEAR(q);
5760
5761        return result;
5762}
5763
5764static int is_summary_empty(const struct diff_queue_struct *q)
5765{
5766        int i;
5767
5768        for (i = 0; i < q->nr; i++) {
5769                const struct diff_filepair *p = q->queue[i];
5770
5771                switch (p->status) {
5772                case DIFF_STATUS_DELETED:
5773                case DIFF_STATUS_ADDED:
5774                case DIFF_STATUS_COPIED:
5775                case DIFF_STATUS_RENAMED:
5776                        return 0;
5777                default:
5778                        if (p->score)
5779                                return 0;
5780                        if (p->one->mode && p->two->mode &&
5781                            p->one->mode != p->two->mode)
5782                                return 0;
5783                        break;
5784                }
5785        }
5786        return 1;
5787}
5788
5789static const char rename_limit_warning[] =
5790N_("inexact rename detection was skipped due to too many files.");
5791
5792static const char degrade_cc_to_c_warning[] =
5793N_("only found copies from modified paths due to too many files.");
5794
5795static const char rename_limit_advice[] =
5796N_("you may want to set your %s variable to at least "
5797   "%d and retry the command.");
5798
5799void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
5800{
5801        fflush(stdout);
5802        if (degraded_cc)
5803                warning(_(degrade_cc_to_c_warning));
5804        else if (needed)
5805                warning(_(rename_limit_warning));
5806        else
5807                return;
5808        if (0 < needed)
5809                warning(_(rename_limit_advice), varname, needed);
5810}
5811
5812static void diff_flush_patch_all_file_pairs(struct diff_options *o)
5813{
5814        int i;
5815        static struct emitted_diff_symbols esm = EMITTED_DIFF_SYMBOLS_INIT;
5816        struct diff_queue_struct *q = &diff_queued_diff;
5817
5818        if (WSEH_NEW & WS_RULE_MASK)
5819                BUG("WS rules bit mask overlaps with diff symbol flags");
5820
5821        if (o->color_moved)
5822                o->emitted_symbols = &esm;
5823
5824        for (i = 0; i < q->nr; i++) {
5825                struct diff_filepair *p = q->queue[i];
5826                if (check_pair_status(p))
5827                        diff_flush_patch(p, o);
5828        }
5829
5830        if (o->emitted_symbols) {
5831                if (o->color_moved) {
5832                        struct hashmap add_lines, del_lines;
5833
5834                        if (o->color_moved_ws_handling &
5835                            COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
5836                                o->color_moved_ws_handling |= XDF_IGNORE_WHITESPACE;
5837
5838                        hashmap_init(&del_lines, moved_entry_cmp, o, 0);
5839                        hashmap_init(&add_lines, moved_entry_cmp, o, 0);
5840
5841                        add_lines_to_move_detection(o, &add_lines, &del_lines);
5842                        mark_color_as_moved(o, &add_lines, &del_lines);
5843                        if (o->color_moved == COLOR_MOVED_ZEBRA_DIM)
5844                                dim_moved_lines(o);
5845
5846                        hashmap_free(&add_lines, 0);
5847                        hashmap_free(&del_lines, 0);
5848                }
5849
5850                for (i = 0; i < esm.nr; i++)
5851                        emit_diff_symbol_from_struct(o, &esm.buf[i]);
5852
5853                for (i = 0; i < esm.nr; i++)
5854                        free((void *)esm.buf[i].line);
5855        }
5856        esm.nr = 0;
5857}
5858
5859void diff_flush(struct diff_options *options)
5860{
5861        struct diff_queue_struct *q = &diff_queued_diff;
5862        int i, output_format = options->output_format;
5863        int separator = 0;
5864        int dirstat_by_line = 0;
5865
5866        /*
5867         * Order: raw, stat, summary, patch
5868         * or:    name/name-status/checkdiff (other bits clear)
5869         */
5870        if (!q->nr)
5871                goto free_queue;
5872
5873        if (output_format & (DIFF_FORMAT_RAW |
5874                             DIFF_FORMAT_NAME |
5875                             DIFF_FORMAT_NAME_STATUS |
5876                             DIFF_FORMAT_CHECKDIFF)) {
5877                for (i = 0; i < q->nr; i++) {
5878                        struct diff_filepair *p = q->queue[i];
5879                        if (check_pair_status(p))
5880                                flush_one_pair(p, options);
5881                }
5882                separator++;
5883        }
5884
5885        if (output_format & DIFF_FORMAT_DIRSTAT && options->flags.dirstat_by_line)
5886                dirstat_by_line = 1;
5887
5888        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
5889            dirstat_by_line) {
5890                struct diffstat_t diffstat;
5891
5892                memset(&diffstat, 0, sizeof(struct diffstat_t));
5893                for (i = 0; i < q->nr; i++) {
5894                        struct diff_filepair *p = q->queue[i];
5895                        if (check_pair_status(p))
5896                                diff_flush_stat(p, options, &diffstat);
5897                }
5898                if (output_format & DIFF_FORMAT_NUMSTAT)
5899                        show_numstat(&diffstat, options);
5900                if (output_format & DIFF_FORMAT_DIFFSTAT)
5901                        show_stats(&diffstat, options);
5902                if (output_format & DIFF_FORMAT_SHORTSTAT)
5903                        show_shortstats(&diffstat, options);
5904                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
5905                        show_dirstat_by_line(&diffstat, options);
5906                free_diffstat_info(&diffstat);
5907                separator++;
5908        }
5909        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
5910                show_dirstat(options);
5911
5912        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
5913                for (i = 0; i < q->nr; i++) {
5914                        diff_summary(options, q->queue[i]);
5915                }
5916                separator++;
5917        }
5918
5919        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
5920            options->flags.exit_with_status &&
5921            options->flags.diff_from_contents) {
5922                /*
5923                 * run diff_flush_patch for the exit status. setting
5924                 * options->file to /dev/null should be safe, because we
5925                 * aren't supposed to produce any output anyway.
5926                 */
5927                if (options->close_file)
5928                        fclose(options->file);
5929                options->file = xfopen("/dev/null", "w");
5930                options->close_file = 1;
5931                options->color_moved = 0;
5932                for (i = 0; i < q->nr; i++) {
5933                        struct diff_filepair *p = q->queue[i];
5934                        if (check_pair_status(p))
5935                                diff_flush_patch(p, options);
5936                        if (options->found_changes)
5937                                break;
5938                }
5939        }
5940
5941        if (output_format & DIFF_FORMAT_PATCH) {
5942                if (separator) {
5943                        emit_diff_symbol(options, DIFF_SYMBOL_SEPARATOR, NULL, 0, 0);
5944                        if (options->stat_sep)
5945                                /* attach patch instead of inline */
5946                                emit_diff_symbol(options, DIFF_SYMBOL_STAT_SEP,
5947                                                 NULL, 0, 0);
5948                }
5949
5950                diff_flush_patch_all_file_pairs(options);
5951        }
5952
5953        if (output_format & DIFF_FORMAT_CALLBACK)
5954                options->format_callback(q, options, options->format_callback_data);
5955
5956        for (i = 0; i < q->nr; i++)
5957                diff_free_filepair(q->queue[i]);
5958free_queue:
5959        free(q->queue);
5960        DIFF_QUEUE_CLEAR(q);
5961        if (options->close_file)
5962                fclose(options->file);
5963
5964        /*
5965         * Report the content-level differences with HAS_CHANGES;
5966         * diff_addremove/diff_change does not set the bit when
5967         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
5968         */
5969        if (options->flags.diff_from_contents) {
5970                if (options->found_changes)
5971                        options->flags.has_changes = 1;
5972                else
5973                        options->flags.has_changes = 0;
5974        }
5975}
5976
5977static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
5978{
5979        return (((p->status == DIFF_STATUS_MODIFIED) &&
5980                 ((p->score &&
5981                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
5982                  (!p->score &&
5983                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
5984                ((p->status != DIFF_STATUS_MODIFIED) &&
5985                 filter_bit_tst(p->status, options)));
5986}
5987
5988static void diffcore_apply_filter(struct diff_options *options)
5989{
5990        int i;
5991        struct diff_queue_struct *q = &diff_queued_diff;
5992        struct diff_queue_struct outq;
5993
5994        DIFF_QUEUE_CLEAR(&outq);
5995
5996        if (!options->filter)
5997                return;
5998
5999        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
6000                int found;
6001                for (i = found = 0; !found && i < q->nr; i++) {
6002                        if (match_filter(options, q->queue[i]))
6003                                found++;
6004                }
6005                if (found)
6006                        return;
6007
6008                /* otherwise we will clear the whole queue
6009                 * by copying the empty outq at the end of this
6010                 * function, but first clear the current entries
6011                 * in the queue.
6012                 */
6013                for (i = 0; i < q->nr; i++)
6014                        diff_free_filepair(q->queue[i]);
6015        }
6016        else {
6017                /* Only the matching ones */
6018                for (i = 0; i < q->nr; i++) {
6019                        struct diff_filepair *p = q->queue[i];
6020                        if (match_filter(options, p))
6021                                diff_q(&outq, p);
6022                        else
6023                                diff_free_filepair(p);
6024                }
6025        }
6026        free(q->queue);
6027        *q = outq;
6028}
6029
6030/* Check whether two filespecs with the same mode and size are identical */
6031static int diff_filespec_is_identical(struct diff_filespec *one,
6032                                      struct diff_filespec *two)
6033{
6034        if (S_ISGITLINK(one->mode))
6035                return 0;
6036        if (diff_populate_filespec(one, 0))
6037                return 0;
6038        if (diff_populate_filespec(two, 0))
6039                return 0;
6040        return !memcmp(one->data, two->data, one->size);
6041}
6042
6043static int diff_filespec_check_stat_unmatch(struct diff_filepair *p)
6044{
6045        if (p->done_skip_stat_unmatch)
6046                return p->skip_stat_unmatch_result;
6047
6048        p->done_skip_stat_unmatch = 1;
6049        p->skip_stat_unmatch_result = 0;
6050        /*
6051         * 1. Entries that come from stat info dirtiness
6052         *    always have both sides (iow, not create/delete),
6053         *    one side of the object name is unknown, with
6054         *    the same mode and size.  Keep the ones that
6055         *    do not match these criteria.  They have real
6056         *    differences.
6057         *
6058         * 2. At this point, the file is known to be modified,
6059         *    with the same mode and size, and the object
6060         *    name of one side is unknown.  Need to inspect
6061         *    the identical contents.
6062         */
6063        if (!DIFF_FILE_VALID(p->one) || /* (1) */
6064            !DIFF_FILE_VALID(p->two) ||
6065            (p->one->oid_valid && p->two->oid_valid) ||
6066            (p->one->mode != p->two->mode) ||
6067            diff_populate_filespec(p->one, CHECK_SIZE_ONLY) ||
6068            diff_populate_filespec(p->two, CHECK_SIZE_ONLY) ||
6069            (p->one->size != p->two->size) ||
6070            !diff_filespec_is_identical(p->one, p->two)) /* (2) */
6071                p->skip_stat_unmatch_result = 1;
6072        return p->skip_stat_unmatch_result;
6073}
6074
6075static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
6076{
6077        int i;
6078        struct diff_queue_struct *q = &diff_queued_diff;
6079        struct diff_queue_struct outq;
6080        DIFF_QUEUE_CLEAR(&outq);
6081
6082        for (i = 0; i < q->nr; i++) {
6083                struct diff_filepair *p = q->queue[i];
6084
6085                if (diff_filespec_check_stat_unmatch(p))
6086                        diff_q(&outq, p);
6087                else {
6088                        /*
6089                         * The caller can subtract 1 from skip_stat_unmatch
6090                         * to determine how many paths were dirty only
6091                         * due to stat info mismatch.
6092                         */
6093                        if (!diffopt->flags.no_index)
6094                                diffopt->skip_stat_unmatch++;
6095                        diff_free_filepair(p);
6096                }
6097        }
6098        free(q->queue);
6099        *q = outq;
6100}
6101
6102static int diffnamecmp(const void *a_, const void *b_)
6103{
6104        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
6105        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
6106        const char *name_a, *name_b;
6107
6108        name_a = a->one ? a->one->path : a->two->path;
6109        name_b = b->one ? b->one->path : b->two->path;
6110        return strcmp(name_a, name_b);
6111}
6112
6113void diffcore_fix_diff_index(struct diff_options *options)
6114{
6115        struct diff_queue_struct *q = &diff_queued_diff;
6116        QSORT(q->queue, q->nr, diffnamecmp);
6117}
6118
6119void diffcore_std(struct diff_options *options)
6120{
6121        /* NOTE please keep the following in sync with diff_tree_combined() */
6122        if (options->skip_stat_unmatch)
6123                diffcore_skip_stat_unmatch(options);
6124        if (!options->found_follow) {
6125                /* See try_to_follow_renames() in tree-diff.c */
6126                if (options->break_opt != -1)
6127                        diffcore_break(options->break_opt);
6128                if (options->detect_rename)
6129                        diffcore_rename(options);
6130                if (options->break_opt != -1)
6131                        diffcore_merge_broken();
6132        }
6133        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
6134                diffcore_pickaxe(options);
6135        if (options->orderfile)
6136                diffcore_order(options->orderfile);
6137        if (!options->found_follow)
6138                /* See try_to_follow_renames() in tree-diff.c */
6139                diff_resolve_rename_copy();
6140        diffcore_apply_filter(options);
6141
6142        if (diff_queued_diff.nr && !options->flags.diff_from_contents)
6143                options->flags.has_changes = 1;
6144        else
6145                options->flags.has_changes = 0;
6146
6147        options->found_follow = 0;
6148}
6149
6150int diff_result_code(struct diff_options *opt, int status)
6151{
6152        int result = 0;
6153
6154        diff_warn_rename_limit("diff.renameLimit",
6155                               opt->needed_rename_limit,
6156                               opt->degraded_cc_to_c);
6157        if (!opt->flags.exit_with_status &&
6158            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
6159                return status;
6160        if (opt->flags.exit_with_status &&
6161            opt->flags.has_changes)
6162                result |= 01;
6163        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
6164            opt->flags.check_failed)
6165                result |= 02;
6166        return result;
6167}
6168
6169int diff_can_quit_early(struct diff_options *opt)
6170{
6171        return (opt->flags.quick &&
6172                !opt->filter &&
6173                opt->flags.has_changes);
6174}
6175
6176/*
6177 * Shall changes to this submodule be ignored?
6178 *
6179 * Submodule changes can be configured to be ignored separately for each path,
6180 * but that configuration can be overridden from the command line.
6181 */
6182static int is_submodule_ignored(const char *path, struct diff_options *options)
6183{
6184        int ignored = 0;
6185        struct diff_flags orig_flags = options->flags;
6186        if (!options->flags.override_submodule_config)
6187                set_diffopt_flags_from_submodule_config(options, path);
6188        if (options->flags.ignore_submodules)
6189                ignored = 1;
6190        options->flags = orig_flags;
6191        return ignored;
6192}
6193
6194void diff_addremove(struct diff_options *options,
6195                    int addremove, unsigned mode,
6196                    const struct object_id *oid,
6197                    int oid_valid,
6198                    const char *concatpath, unsigned dirty_submodule)
6199{
6200        struct diff_filespec *one, *two;
6201
6202        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
6203                return;
6204
6205        /* This may look odd, but it is a preparation for
6206         * feeding "there are unchanged files which should
6207         * not produce diffs, but when you are doing copy
6208         * detection you would need them, so here they are"
6209         * entries to the diff-core.  They will be prefixed
6210         * with something like '=' or '*' (I haven't decided
6211         * which but should not make any difference).
6212         * Feeding the same new and old to diff_change()
6213         * also has the same effect.
6214         * Before the final output happens, they are pruned after
6215         * merged into rename/copy pairs as appropriate.
6216         */
6217        if (options->flags.reverse_diff)
6218                addremove = (addremove == '+' ? '-' :
6219                             addremove == '-' ? '+' : addremove);
6220
6221        if (options->prefix &&
6222            strncmp(concatpath, options->prefix, options->prefix_length))
6223                return;
6224
6225        one = alloc_filespec(concatpath);
6226        two = alloc_filespec(concatpath);
6227
6228        if (addremove != '+')
6229                fill_filespec(one, oid, oid_valid, mode);
6230        if (addremove != '-') {
6231                fill_filespec(two, oid, oid_valid, mode);
6232                two->dirty_submodule = dirty_submodule;
6233        }
6234
6235        diff_queue(&diff_queued_diff, one, two);
6236        if (!options->flags.diff_from_contents)
6237                options->flags.has_changes = 1;
6238}
6239
6240void diff_change(struct diff_options *options,
6241                 unsigned old_mode, unsigned new_mode,
6242                 const struct object_id *old_oid,
6243                 const struct object_id *new_oid,
6244                 int old_oid_valid, int new_oid_valid,
6245                 const char *concatpath,
6246                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
6247{
6248        struct diff_filespec *one, *two;
6249        struct diff_filepair *p;
6250
6251        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
6252            is_submodule_ignored(concatpath, options))
6253                return;
6254
6255        if (options->flags.reverse_diff) {
6256                SWAP(old_mode, new_mode);
6257                SWAP(old_oid, new_oid);
6258                SWAP(old_oid_valid, new_oid_valid);
6259                SWAP(old_dirty_submodule, new_dirty_submodule);
6260        }
6261
6262        if (options->prefix &&
6263            strncmp(concatpath, options->prefix, options->prefix_length))
6264                return;
6265
6266        one = alloc_filespec(concatpath);
6267        two = alloc_filespec(concatpath);
6268        fill_filespec(one, old_oid, old_oid_valid, old_mode);
6269        fill_filespec(two, new_oid, new_oid_valid, new_mode);
6270        one->dirty_submodule = old_dirty_submodule;
6271        two->dirty_submodule = new_dirty_submodule;
6272        p = diff_queue(&diff_queued_diff, one, two);
6273
6274        if (options->flags.diff_from_contents)
6275                return;
6276
6277        if (options->flags.quick && options->skip_stat_unmatch &&
6278            !diff_filespec_check_stat_unmatch(p))
6279                return;
6280
6281        options->flags.has_changes = 1;
6282}
6283
6284struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
6285{
6286        struct diff_filepair *pair;
6287        struct diff_filespec *one, *two;
6288
6289        if (options->prefix &&
6290            strncmp(path, options->prefix, options->prefix_length))
6291                return NULL;
6292
6293        one = alloc_filespec(path);
6294        two = alloc_filespec(path);
6295        pair = diff_queue(&diff_queued_diff, one, two);
6296        pair->is_unmerged = 1;
6297        return pair;
6298}
6299
6300static char *run_textconv(const char *pgm, struct diff_filespec *spec,
6301                size_t *outsize)
6302{
6303        struct diff_tempfile *temp;
6304        const char *argv[3];
6305        const char **arg = argv;
6306        struct child_process child = CHILD_PROCESS_INIT;
6307        struct strbuf buf = STRBUF_INIT;
6308        int err = 0;
6309
6310        temp = prepare_temp_file(spec->path, spec);
6311        *arg++ = pgm;
6312        *arg++ = temp->name;
6313        *arg = NULL;
6314
6315        child.use_shell = 1;
6316        child.argv = argv;
6317        child.out = -1;
6318        if (start_command(&child)) {
6319                remove_tempfile();
6320                return NULL;
6321        }
6322
6323        if (strbuf_read(&buf, child.out, 0) < 0)
6324                err = error("error reading from textconv command '%s'", pgm);
6325        close(child.out);
6326
6327        if (finish_command(&child) || err) {
6328                strbuf_release(&buf);
6329                remove_tempfile();
6330                return NULL;
6331        }
6332        remove_tempfile();
6333
6334        return strbuf_detach(&buf, outsize);
6335}
6336
6337size_t fill_textconv(struct userdiff_driver *driver,
6338                     struct diff_filespec *df,
6339                     char **outbuf)
6340{
6341        size_t size;
6342
6343        if (!driver) {
6344                if (!DIFF_FILE_VALID(df)) {
6345                        *outbuf = "";
6346                        return 0;
6347                }
6348                if (diff_populate_filespec(df, 0))
6349                        die("unable to read files to diff");
6350                *outbuf = df->data;
6351                return df->size;
6352        }
6353
6354        if (!driver->textconv)
6355                BUG("fill_textconv called with non-textconv driver");
6356
6357        if (driver->textconv_cache && df->oid_valid) {
6358                *outbuf = notes_cache_get(driver->textconv_cache,
6359                                          &df->oid,
6360                                          &size);
6361                if (*outbuf)
6362                        return size;
6363        }
6364
6365        *outbuf = run_textconv(driver->textconv, df, &size);
6366        if (!*outbuf)
6367                die("unable to read files to diff");
6368
6369        if (driver->textconv_cache && df->oid_valid) {
6370                /* ignore errors, as we might be in a readonly repository */
6371                notes_cache_put(driver->textconv_cache, &df->oid, *outbuf,
6372                                size);
6373                /*
6374                 * we could save up changes and flush them all at the end,
6375                 * but we would need an extra call after all diffing is done.
6376                 * Since generating a cache entry is the slow path anyway,
6377                 * this extra overhead probably isn't a big deal.
6378                 */
6379                notes_cache_write(driver->textconv_cache);
6380        }
6381
6382        return size;
6383}
6384
6385int textconv_object(const char *path,
6386                    unsigned mode,
6387                    const struct object_id *oid,
6388                    int oid_valid,
6389                    char **buf,
6390                    unsigned long *buf_size)
6391{
6392        struct diff_filespec *df;
6393        struct userdiff_driver *textconv;
6394
6395        df = alloc_filespec(path);
6396        fill_filespec(df, oid, oid_valid, mode);
6397        textconv = get_textconv(df);
6398        if (!textconv) {
6399                free_filespec(df);
6400                return 0;
6401        }
6402
6403        *buf_size = fill_textconv(textconv, df, buf);
6404        free_filespec(df);
6405        return 1;
6406}
6407
6408void setup_diff_pager(struct diff_options *opt)
6409{
6410        /*
6411         * If the user asked for our exit code, then either they want --quiet
6412         * or --exit-code. We should definitely not bother with a pager in the
6413         * former case, as we will generate no output. Since we still properly
6414         * report our exit code even when a pager is run, we _could_ run a
6415         * pager with --exit-code. But since we have not done so historically,
6416         * and because it is easy to find people oneline advising "git diff
6417         * --exit-code" in hooks and other scripts, we do not do so.
6418         */
6419        if (!opt->flags.exit_with_status &&
6420            check_pager_config("diff") != 0)
6421                setup_pager();
6422}