diff.con commit range-diff: offer to dual-color the diffs (31cf61a)
   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};
  74
  75static const char *color_diff_slots[] = {
  76        [DIFF_CONTEXT]                = "context",
  77        [DIFF_METAINFO]               = "meta",
  78        [DIFF_FRAGINFO]               = "frag",
  79        [DIFF_FILE_OLD]               = "old",
  80        [DIFF_FILE_NEW]               = "new",
  81        [DIFF_COMMIT]                 = "commit",
  82        [DIFF_WHITESPACE]             = "whitespace",
  83        [DIFF_FUNCINFO]               = "func",
  84        [DIFF_FILE_OLD_MOVED]         = "oldMoved",
  85        [DIFF_FILE_OLD_MOVED_ALT]     = "oldMovedAlternative",
  86        [DIFF_FILE_OLD_MOVED_DIM]     = "oldMovedDimmed",
  87        [DIFF_FILE_OLD_MOVED_ALT_DIM] = "oldMovedAlternativeDimmed",
  88        [DIFF_FILE_NEW_MOVED]         = "newMoved",
  89        [DIFF_FILE_NEW_MOVED_ALT]     = "newMovedAlternative",
  90        [DIFF_FILE_NEW_MOVED_DIM]     = "newMovedDimmed",
  91        [DIFF_FILE_NEW_MOVED_ALT_DIM] = "newMovedAlternativeDimmed",
  92};
  93
  94static NORETURN void die_want_option(const char *option_name)
  95{
  96        die(_("option '%s' requires a value"), option_name);
  97}
  98
  99define_list_config_array_extra(color_diff_slots, {"plain"});
 100
 101static int parse_diff_color_slot(const char *var)
 102{
 103        if (!strcasecmp(var, "plain"))
 104                return DIFF_CONTEXT;
 105        return LOOKUP_CONFIG(color_diff_slots, var);
 106}
 107
 108static int parse_dirstat_params(struct diff_options *options, const char *params_string,
 109                                struct strbuf *errmsg)
 110{
 111        char *params_copy = xstrdup(params_string);
 112        struct string_list params = STRING_LIST_INIT_NODUP;
 113        int ret = 0;
 114        int i;
 115
 116        if (*params_copy)
 117                string_list_split_in_place(&params, params_copy, ',', -1);
 118        for (i = 0; i < params.nr; i++) {
 119                const char *p = params.items[i].string;
 120                if (!strcmp(p, "changes")) {
 121                        options->flags.dirstat_by_line = 0;
 122                        options->flags.dirstat_by_file = 0;
 123                } else if (!strcmp(p, "lines")) {
 124                        options->flags.dirstat_by_line = 1;
 125                        options->flags.dirstat_by_file = 0;
 126                } else if (!strcmp(p, "files")) {
 127                        options->flags.dirstat_by_line = 0;
 128                        options->flags.dirstat_by_file = 1;
 129                } else if (!strcmp(p, "noncumulative")) {
 130                        options->flags.dirstat_cumulative = 0;
 131                } else if (!strcmp(p, "cumulative")) {
 132                        options->flags.dirstat_cumulative = 1;
 133                } else if (isdigit(*p)) {
 134                        char *end;
 135                        int permille = strtoul(p, &end, 10) * 10;
 136                        if (*end == '.' && isdigit(*++end)) {
 137                                /* only use first digit */
 138                                permille += *end - '0';
 139                                /* .. and ignore any further digits */
 140                                while (isdigit(*++end))
 141                                        ; /* nothing */
 142                        }
 143                        if (!*end)
 144                                options->dirstat_permille = permille;
 145                        else {
 146                                strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%s'\n"),
 147                                            p);
 148                                ret++;
 149                        }
 150                } else {
 151                        strbuf_addf(errmsg, _("  Unknown dirstat parameter '%s'\n"), p);
 152                        ret++;
 153                }
 154
 155        }
 156        string_list_clear(&params, 0);
 157        free(params_copy);
 158        return ret;
 159}
 160
 161static int parse_submodule_params(struct diff_options *options, const char *value)
 162{
 163        if (!strcmp(value, "log"))
 164                options->submodule_format = DIFF_SUBMODULE_LOG;
 165        else if (!strcmp(value, "short"))
 166                options->submodule_format = DIFF_SUBMODULE_SHORT;
 167        else if (!strcmp(value, "diff"))
 168                options->submodule_format = DIFF_SUBMODULE_INLINE_DIFF;
 169        else
 170                return -1;
 171        return 0;
 172}
 173
 174int git_config_rename(const char *var, const char *value)
 175{
 176        if (!value)
 177                return DIFF_DETECT_RENAME;
 178        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 179                return  DIFF_DETECT_COPY;
 180        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 181}
 182
 183long parse_algorithm_value(const char *value)
 184{
 185        if (!value)
 186                return -1;
 187        else if (!strcasecmp(value, "myers") || !strcasecmp(value, "default"))
 188                return 0;
 189        else if (!strcasecmp(value, "minimal"))
 190                return XDF_NEED_MINIMAL;
 191        else if (!strcasecmp(value, "patience"))
 192                return XDF_PATIENCE_DIFF;
 193        else if (!strcasecmp(value, "histogram"))
 194                return XDF_HISTOGRAM_DIFF;
 195        return -1;
 196}
 197
 198static int parse_one_token(const char **arg, const char *token)
 199{
 200        const char *rest;
 201        if (skip_prefix(*arg, token, &rest) && (!*rest || *rest == ',')) {
 202                *arg = rest;
 203                return 1;
 204        }
 205        return 0;
 206}
 207
 208static int parse_ws_error_highlight(const char *arg)
 209{
 210        const char *orig_arg = arg;
 211        unsigned val = 0;
 212
 213        while (*arg) {
 214                if (parse_one_token(&arg, "none"))
 215                        val = 0;
 216                else if (parse_one_token(&arg, "default"))
 217                        val = WSEH_NEW;
 218                else if (parse_one_token(&arg, "all"))
 219                        val = WSEH_NEW | WSEH_OLD | WSEH_CONTEXT;
 220                else if (parse_one_token(&arg, "new"))
 221                        val |= WSEH_NEW;
 222                else if (parse_one_token(&arg, "old"))
 223                        val |= WSEH_OLD;
 224                else if (parse_one_token(&arg, "context"))
 225                        val |= WSEH_CONTEXT;
 226                else {
 227                        return -1 - (int)(arg - orig_arg);
 228                }
 229                if (*arg)
 230                        arg++;
 231        }
 232        return val;
 233}
 234
 235/*
 236 * These are to give UI layer defaults.
 237 * The core-level commands such as git-diff-files should
 238 * never be affected by the setting of diff.renames
 239 * the user happens to have in the configuration file.
 240 */
 241void init_diff_ui_defaults(void)
 242{
 243        diff_detect_rename_default = DIFF_DETECT_RENAME;
 244}
 245
 246int git_diff_heuristic_config(const char *var, const char *value, void *cb)
 247{
 248        if (!strcmp(var, "diff.indentheuristic"))
 249                diff_indent_heuristic = git_config_bool(var, value);
 250        return 0;
 251}
 252
 253static int parse_color_moved(const char *arg)
 254{
 255        switch (git_parse_maybe_bool(arg)) {
 256        case 0:
 257                return COLOR_MOVED_NO;
 258        case 1:
 259                return COLOR_MOVED_DEFAULT;
 260        default:
 261                break;
 262        }
 263
 264        if (!strcmp(arg, "no"))
 265                return COLOR_MOVED_NO;
 266        else if (!strcmp(arg, "plain"))
 267                return COLOR_MOVED_PLAIN;
 268        else if (!strcmp(arg, "blocks"))
 269                return COLOR_MOVED_BLOCKS;
 270        else if (!strcmp(arg, "zebra"))
 271                return COLOR_MOVED_ZEBRA;
 272        else if (!strcmp(arg, "default"))
 273                return COLOR_MOVED_DEFAULT;
 274        else if (!strcmp(arg, "dimmed_zebra"))
 275                return COLOR_MOVED_ZEBRA_DIM;
 276        else
 277                return error(_("color moved setting must be one of 'no', 'default', 'blocks', 'zebra', 'dimmed_zebra', 'plain'"));
 278}
 279
 280static int parse_color_moved_ws(const char *arg)
 281{
 282        int ret = 0;
 283        struct string_list l = STRING_LIST_INIT_DUP;
 284        struct string_list_item *i;
 285
 286        string_list_split(&l, arg, ',', -1);
 287
 288        for_each_string_list_item(i, &l) {
 289                struct strbuf sb = STRBUF_INIT;
 290                strbuf_addstr(&sb, i->string);
 291                strbuf_trim(&sb);
 292
 293                if (!strcmp(sb.buf, "ignore-space-change"))
 294                        ret |= XDF_IGNORE_WHITESPACE_CHANGE;
 295                else if (!strcmp(sb.buf, "ignore-space-at-eol"))
 296                        ret |= XDF_IGNORE_WHITESPACE_AT_EOL;
 297                else if (!strcmp(sb.buf, "ignore-all-space"))
 298                        ret |= XDF_IGNORE_WHITESPACE;
 299                else if (!strcmp(sb.buf, "allow-indentation-change"))
 300                        ret |= COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE;
 301                else
 302                        error(_("ignoring unknown color-moved-ws mode '%s'"), sb.buf);
 303
 304                strbuf_release(&sb);
 305        }
 306
 307        if ((ret & COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) &&
 308            (ret & XDF_WHITESPACE_FLAGS))
 309                die(_("color-moved-ws: allow-indentation-change cannot be combined with other white space modes"));
 310
 311        string_list_clear(&l, 0);
 312
 313        return ret;
 314}
 315
 316int git_diff_ui_config(const char *var, const char *value, void *cb)
 317{
 318        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 319                diff_use_color_default = git_config_colorbool(var, value);
 320                return 0;
 321        }
 322        if (!strcmp(var, "diff.colormoved")) {
 323                int cm = parse_color_moved(value);
 324                if (cm < 0)
 325                        return -1;
 326                diff_color_moved_default = cm;
 327                return 0;
 328        }
 329        if (!strcmp(var, "diff.colormovedws")) {
 330                int cm = parse_color_moved_ws(value);
 331                if (cm < 0)
 332                        return -1;
 333                diff_color_moved_ws_default = cm;
 334                return 0;
 335        }
 336        if (!strcmp(var, "diff.context")) {
 337                diff_context_default = git_config_int(var, value);
 338                if (diff_context_default < 0)
 339                        return -1;
 340                return 0;
 341        }
 342        if (!strcmp(var, "diff.interhunkcontext")) {
 343                diff_interhunk_context_default = git_config_int(var, value);
 344                if (diff_interhunk_context_default < 0)
 345                        return -1;
 346                return 0;
 347        }
 348        if (!strcmp(var, "diff.renames")) {
 349                diff_detect_rename_default = git_config_rename(var, value);
 350                return 0;
 351        }
 352        if (!strcmp(var, "diff.autorefreshindex")) {
 353                diff_auto_refresh_index = git_config_bool(var, value);
 354                return 0;
 355        }
 356        if (!strcmp(var, "diff.mnemonicprefix")) {
 357                diff_mnemonic_prefix = git_config_bool(var, value);
 358                return 0;
 359        }
 360        if (!strcmp(var, "diff.noprefix")) {
 361                diff_no_prefix = git_config_bool(var, value);
 362                return 0;
 363        }
 364        if (!strcmp(var, "diff.statgraphwidth")) {
 365                diff_stat_graph_width = git_config_int(var, value);
 366                return 0;
 367        }
 368        if (!strcmp(var, "diff.external"))
 369                return git_config_string(&external_diff_cmd_cfg, var, value);
 370        if (!strcmp(var, "diff.wordregex"))
 371                return git_config_string(&diff_word_regex_cfg, var, value);
 372        if (!strcmp(var, "diff.orderfile"))
 373                return git_config_pathname(&diff_order_file_cfg, var, value);
 374
 375        if (!strcmp(var, "diff.ignoresubmodules"))
 376                handle_ignore_submodules_arg(&default_diff_options, value);
 377
 378        if (!strcmp(var, "diff.submodule")) {
 379                if (parse_submodule_params(&default_diff_options, value))
 380                        warning(_("Unknown value for 'diff.submodule' config variable: '%s'"),
 381                                value);
 382                return 0;
 383        }
 384
 385        if (!strcmp(var, "diff.algorithm")) {
 386                diff_algorithm = parse_algorithm_value(value);
 387                if (diff_algorithm < 0)
 388                        return -1;
 389                return 0;
 390        }
 391
 392        if (!strcmp(var, "diff.wserrorhighlight")) {
 393                int val = parse_ws_error_highlight(value);
 394                if (val < 0)
 395                        return -1;
 396                ws_error_highlight_default = val;
 397                return 0;
 398        }
 399
 400        if (git_color_config(var, value, cb) < 0)
 401                return -1;
 402
 403        return git_diff_basic_config(var, value, cb);
 404}
 405
 406int git_diff_basic_config(const char *var, const char *value, void *cb)
 407{
 408        const char *name;
 409
 410        if (!strcmp(var, "diff.renamelimit")) {
 411                diff_rename_limit_default = git_config_int(var, value);
 412                return 0;
 413        }
 414
 415        if (userdiff_config(var, value) < 0)
 416                return -1;
 417
 418        if (skip_prefix(var, "diff.color.", &name) ||
 419            skip_prefix(var, "color.diff.", &name)) {
 420                int slot = parse_diff_color_slot(name);
 421                if (slot < 0)
 422                        return 0;
 423                if (!value)
 424                        return config_error_nonbool(var);
 425                return color_parse(value, diff_colors[slot]);
 426        }
 427
 428        /* like GNU diff's --suppress-blank-empty option  */
 429        if (!strcmp(var, "diff.suppressblankempty") ||
 430                        /* for backwards compatibility */
 431                        !strcmp(var, "diff.suppress-blank-empty")) {
 432                diff_suppress_blank_empty = git_config_bool(var, value);
 433                return 0;
 434        }
 435
 436        if (!strcmp(var, "diff.dirstat")) {
 437                struct strbuf errmsg = STRBUF_INIT;
 438                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 439                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 440                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 441                                errmsg.buf);
 442                strbuf_release(&errmsg);
 443                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 444                return 0;
 445        }
 446
 447        if (git_diff_heuristic_config(var, value, cb) < 0)
 448                return -1;
 449
 450        return git_default_config(var, value, cb);
 451}
 452
 453static char *quote_two(const char *one, const char *two)
 454{
 455        int need_one = quote_c_style(one, NULL, NULL, 1);
 456        int need_two = quote_c_style(two, NULL, NULL, 1);
 457        struct strbuf res = STRBUF_INIT;
 458
 459        if (need_one + need_two) {
 460                strbuf_addch(&res, '"');
 461                quote_c_style(one, &res, NULL, 1);
 462                quote_c_style(two, &res, NULL, 1);
 463                strbuf_addch(&res, '"');
 464        } else {
 465                strbuf_addstr(&res, one);
 466                strbuf_addstr(&res, two);
 467        }
 468        return strbuf_detach(&res, NULL);
 469}
 470
 471static const char *external_diff(void)
 472{
 473        static const char *external_diff_cmd = NULL;
 474        static int done_preparing = 0;
 475
 476        if (done_preparing)
 477                return external_diff_cmd;
 478        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 479        if (!external_diff_cmd)
 480                external_diff_cmd = external_diff_cmd_cfg;
 481        done_preparing = 1;
 482        return external_diff_cmd;
 483}
 484
 485/*
 486 * Keep track of files used for diffing. Sometimes such an entry
 487 * refers to a temporary file, sometimes to an existing file, and
 488 * sometimes to "/dev/null".
 489 */
 490static struct diff_tempfile {
 491        /*
 492         * filename external diff should read from, or NULL if this
 493         * entry is currently not in use:
 494         */
 495        const char *name;
 496
 497        char hex[GIT_MAX_HEXSZ + 1];
 498        char mode[10];
 499
 500        /*
 501         * If this diff_tempfile instance refers to a temporary file,
 502         * this tempfile object is used to manage its lifetime.
 503         */
 504        struct tempfile *tempfile;
 505} diff_temp[2];
 506
 507struct emit_callback {
 508        int color_diff;
 509        unsigned ws_rule;
 510        int blank_at_eof_in_preimage;
 511        int blank_at_eof_in_postimage;
 512        int lno_in_preimage;
 513        int lno_in_postimage;
 514        const char **label_path;
 515        struct diff_words_data *diff_words;
 516        struct diff_options *opt;
 517        struct strbuf *header;
 518};
 519
 520static int count_lines(const char *data, int size)
 521{
 522        int count, ch, completely_empty = 1, nl_just_seen = 0;
 523        count = 0;
 524        while (0 < size--) {
 525                ch = *data++;
 526                if (ch == '\n') {
 527                        count++;
 528                        nl_just_seen = 1;
 529                        completely_empty = 0;
 530                }
 531                else {
 532                        nl_just_seen = 0;
 533                        completely_empty = 0;
 534                }
 535        }
 536        if (completely_empty)
 537                return 0;
 538        if (!nl_just_seen)
 539                count++; /* no trailing newline */
 540        return count;
 541}
 542
 543static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 544{
 545        if (!DIFF_FILE_VALID(one)) {
 546                mf->ptr = (char *)""; /* does not matter */
 547                mf->size = 0;
 548                return 0;
 549        }
 550        else if (diff_populate_filespec(one, 0))
 551                return -1;
 552
 553        mf->ptr = one->data;
 554        mf->size = one->size;
 555        return 0;
 556}
 557
 558/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 559static unsigned long diff_filespec_size(struct diff_filespec *one)
 560{
 561        if (!DIFF_FILE_VALID(one))
 562                return 0;
 563        diff_populate_filespec(one, CHECK_SIZE_ONLY);
 564        return one->size;
 565}
 566
 567static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 568{
 569        char *ptr = mf->ptr;
 570        long size = mf->size;
 571        int cnt = 0;
 572
 573        if (!size)
 574                return cnt;
 575        ptr += size - 1; /* pointing at the very end */
 576        if (*ptr != '\n')
 577                ; /* incomplete line */
 578        else
 579                ptr--; /* skip the last LF */
 580        while (mf->ptr < ptr) {
 581                char *prev_eol;
 582                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 583                        if (*prev_eol == '\n')
 584                                break;
 585                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 586                        break;
 587                cnt++;
 588                ptr = prev_eol - 1;
 589        }
 590        return cnt;
 591}
 592
 593static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 594                               struct emit_callback *ecbdata)
 595{
 596        int l1, l2, at;
 597        unsigned ws_rule = ecbdata->ws_rule;
 598        l1 = count_trailing_blank(mf1, ws_rule);
 599        l2 = count_trailing_blank(mf2, ws_rule);
 600        if (l2 <= l1) {
 601                ecbdata->blank_at_eof_in_preimage = 0;
 602                ecbdata->blank_at_eof_in_postimage = 0;
 603                return;
 604        }
 605        at = count_lines(mf1->ptr, mf1->size);
 606        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 607
 608        at = count_lines(mf2->ptr, mf2->size);
 609        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 610}
 611
 612static void emit_line_0(struct diff_options *o,
 613                        const char *set, unsigned reverse, const char *reset,
 614                        int first, const char *line, int len)
 615{
 616        int has_trailing_newline, has_trailing_carriage_return;
 617        int nofirst;
 618        FILE *file = o->file;
 619
 620        if (first)
 621                fputs(diff_line_prefix(o), file);
 622        else if (!len)
 623                return;
 624
 625        if (len == 0) {
 626                has_trailing_newline = (first == '\n');
 627                has_trailing_carriage_return = (!has_trailing_newline &&
 628                                                (first == '\r'));
 629                nofirst = has_trailing_newline || has_trailing_carriage_return;
 630        } else {
 631                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 632                if (has_trailing_newline)
 633                        len--;
 634                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 635                if (has_trailing_carriage_return)
 636                        len--;
 637                nofirst = 0;
 638        }
 639
 640        if (len || !nofirst) {
 641                if (reverse && want_color(o->use_color))
 642                        fputs(GIT_COLOR_REVERSE, file);
 643                fputs(set, file);
 644                if (first && !nofirst)
 645                        fputc(first, file);
 646                fwrite(line, len, 1, file);
 647                fputs(reset, file);
 648        }
 649        if (has_trailing_carriage_return)
 650                fputc('\r', file);
 651        if (has_trailing_newline)
 652                fputc('\n', file);
 653}
 654
 655static void emit_line(struct diff_options *o, const char *set, const char *reset,
 656                      const char *line, int len)
 657{
 658        emit_line_0(o, set, 0, reset, line[0], line+1, len-1);
 659}
 660
 661enum diff_symbol {
 662        DIFF_SYMBOL_BINARY_DIFF_HEADER,
 663        DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
 664        DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
 665        DIFF_SYMBOL_BINARY_DIFF_BODY,
 666        DIFF_SYMBOL_BINARY_DIFF_FOOTER,
 667        DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
 668        DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
 669        DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
 670        DIFF_SYMBOL_STATS_LINE,
 671        DIFF_SYMBOL_WORD_DIFF,
 672        DIFF_SYMBOL_STAT_SEP,
 673        DIFF_SYMBOL_SUMMARY,
 674        DIFF_SYMBOL_SUBMODULE_ADD,
 675        DIFF_SYMBOL_SUBMODULE_DEL,
 676        DIFF_SYMBOL_SUBMODULE_UNTRACKED,
 677        DIFF_SYMBOL_SUBMODULE_MODIFIED,
 678        DIFF_SYMBOL_SUBMODULE_HEADER,
 679        DIFF_SYMBOL_SUBMODULE_ERROR,
 680        DIFF_SYMBOL_SUBMODULE_PIPETHROUGH,
 681        DIFF_SYMBOL_REWRITE_DIFF,
 682        DIFF_SYMBOL_BINARY_FILES,
 683        DIFF_SYMBOL_HEADER,
 684        DIFF_SYMBOL_FILEPAIR_PLUS,
 685        DIFF_SYMBOL_FILEPAIR_MINUS,
 686        DIFF_SYMBOL_WORDS_PORCELAIN,
 687        DIFF_SYMBOL_WORDS,
 688        DIFF_SYMBOL_CONTEXT,
 689        DIFF_SYMBOL_CONTEXT_INCOMPLETE,
 690        DIFF_SYMBOL_PLUS,
 691        DIFF_SYMBOL_MINUS,
 692        DIFF_SYMBOL_NO_LF_EOF,
 693        DIFF_SYMBOL_CONTEXT_FRAGINFO,
 694        DIFF_SYMBOL_CONTEXT_MARKER,
 695        DIFF_SYMBOL_SEPARATOR
 696};
 697/*
 698 * Flags for content lines:
 699 * 0..12 are whitespace rules
 700 * 13-15 are WSEH_NEW | WSEH_OLD | WSEH_CONTEXT
 701 * 16 is marking if the line is blank at EOF
 702 */
 703#define DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF      (1<<16)
 704#define DIFF_SYMBOL_MOVED_LINE                  (1<<17)
 705#define DIFF_SYMBOL_MOVED_LINE_ALT              (1<<18)
 706#define DIFF_SYMBOL_MOVED_LINE_UNINTERESTING    (1<<19)
 707#define DIFF_SYMBOL_CONTENT_WS_MASK (WSEH_NEW | WSEH_OLD | WSEH_CONTEXT | WS_RULE_MASK)
 708
 709/*
 710 * This struct is used when we need to buffer the output of the diff output.
 711 *
 712 * NEEDSWORK: Instead of storing a copy of the line, add an offset pointer
 713 * into the pre/post image file. This pointer could be a union with the
 714 * line pointer. By storing an offset into the file instead of the literal line,
 715 * we can decrease the memory footprint for the buffered output. At first we
 716 * may want to only have indirection for the content lines, but we could also
 717 * enhance the state for emitting prefabricated lines, e.g. the similarity
 718 * score line or hunk/file headers would only need to store a number or path
 719 * and then the output can be constructed later on depending on state.
 720 */
 721struct emitted_diff_symbol {
 722        const char *line;
 723        int len;
 724        int flags;
 725        enum diff_symbol s;
 726};
 727#define EMITTED_DIFF_SYMBOL_INIT {NULL}
 728
 729struct emitted_diff_symbols {
 730        struct emitted_diff_symbol *buf;
 731        int nr, alloc;
 732};
 733#define EMITTED_DIFF_SYMBOLS_INIT {NULL, 0, 0}
 734
 735static void append_emitted_diff_symbol(struct diff_options *o,
 736                                       struct emitted_diff_symbol *e)
 737{
 738        struct emitted_diff_symbol *f;
 739
 740        ALLOC_GROW(o->emitted_symbols->buf,
 741                   o->emitted_symbols->nr + 1,
 742                   o->emitted_symbols->alloc);
 743        f = &o->emitted_symbols->buf[o->emitted_symbols->nr++];
 744
 745        memcpy(f, e, sizeof(struct emitted_diff_symbol));
 746        f->line = e->line ? xmemdupz(e->line, e->len) : NULL;
 747}
 748
 749struct moved_entry {
 750        struct hashmap_entry ent;
 751        const struct emitted_diff_symbol *es;
 752        struct moved_entry *next_line;
 753        struct ws_delta *wsd;
 754};
 755
 756/**
 757 * The struct ws_delta holds white space differences between moved lines, i.e.
 758 * between '+' and '-' lines that have been detected to be a move.
 759 * The string contains the difference in leading white spaces, before the
 760 * rest of the line is compared using the white space config for move
 761 * coloring. The current_longer indicates if the first string in the
 762 * comparision is longer than the second.
 763 */
 764struct ws_delta {
 765        char *string;
 766        unsigned int current_longer : 1;
 767};
 768#define WS_DELTA_INIT { NULL, 0 }
 769
 770static int compute_ws_delta(const struct emitted_diff_symbol *a,
 771                             const struct emitted_diff_symbol *b,
 772                             struct ws_delta *out)
 773{
 774        const struct emitted_diff_symbol *longer =  a->len > b->len ? a : b;
 775        const struct emitted_diff_symbol *shorter = a->len > b->len ? b : a;
 776        int d = longer->len - shorter->len;
 777
 778        out->string = xmemdupz(longer->line, d);
 779        out->current_longer = (a == longer);
 780
 781        return !strncmp(longer->line + d, shorter->line, shorter->len);
 782}
 783
 784static int cmp_in_block_with_wsd(const struct diff_options *o,
 785                                 const struct moved_entry *cur,
 786                                 const struct moved_entry *match,
 787                                 struct moved_entry *pmb,
 788                                 int n)
 789{
 790        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
 791        int al = cur->es->len, cl = l->len;
 792        const char *a = cur->es->line,
 793                   *b = match->es->line,
 794                   *c = l->line;
 795
 796        int wslen;
 797
 798        /*
 799         * We need to check if 'cur' is equal to 'match'.
 800         * As those are from the same (+/-) side, we do not need to adjust for
 801         * indent changes. However these were found using fuzzy matching
 802         * so we do have to check if they are equal.
 803         */
 804        if (strcmp(a, b))
 805                return 1;
 806
 807        if (!pmb->wsd)
 808                /*
 809                 * No white space delta was carried forward? This can happen
 810                 * when we exit early in this function and do not carry
 811                 * forward ws.
 812                 */
 813                return 1;
 814
 815        /*
 816         * The indent changes of the block are known and carried forward in
 817         * pmb->wsd; however we need to check if the indent changes of the
 818         * current line are still the same as before.
 819         *
 820         * To do so we need to compare 'l' to 'cur', adjusting the
 821         * one of them for the white spaces, depending which was longer.
 822         */
 823
 824        wslen = strlen(pmb->wsd->string);
 825        if (pmb->wsd->current_longer) {
 826                c += wslen;
 827                cl -= wslen;
 828        } else {
 829                a += wslen;
 830                al -= wslen;
 831        }
 832
 833        if (strcmp(a, c))
 834                return 1;
 835
 836        return 0;
 837}
 838
 839static int moved_entry_cmp(const void *hashmap_cmp_fn_data,
 840                           const void *entry,
 841                           const void *entry_or_key,
 842                           const void *keydata)
 843{
 844        const struct diff_options *diffopt = hashmap_cmp_fn_data;
 845        const struct moved_entry *a = entry;
 846        const struct moved_entry *b = entry_or_key;
 847        unsigned flags = diffopt->color_moved_ws_handling
 848                         & XDF_WHITESPACE_FLAGS;
 849
 850        if (diffopt->color_moved_ws_handling &
 851            COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
 852                /*
 853                 * As there is not specific white space config given,
 854                 * we'd need to check for a new block, so ignore all
 855                 * white space. The setup of the white space
 856                 * configuration for the next block is done else where
 857                 */
 858                flags |= XDF_IGNORE_WHITESPACE;
 859
 860        return !xdiff_compare_lines(a->es->line, a->es->len,
 861                                    b->es->line, b->es->len,
 862                                    flags);
 863}
 864
 865static struct moved_entry *prepare_entry(struct diff_options *o,
 866                                         int line_no)
 867{
 868        struct moved_entry *ret = xmalloc(sizeof(*ret));
 869        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[line_no];
 870        unsigned flags = o->color_moved_ws_handling & XDF_WHITESPACE_FLAGS;
 871
 872        ret->ent.hash = xdiff_hash_string(l->line, l->len, flags);
 873        ret->es = l;
 874        ret->next_line = NULL;
 875        ret->wsd = NULL;
 876
 877        return ret;
 878}
 879
 880static void add_lines_to_move_detection(struct diff_options *o,
 881                                        struct hashmap *add_lines,
 882                                        struct hashmap *del_lines)
 883{
 884        struct moved_entry *prev_line = NULL;
 885
 886        int n;
 887        for (n = 0; n < o->emitted_symbols->nr; n++) {
 888                struct hashmap *hm;
 889                struct moved_entry *key;
 890
 891                switch (o->emitted_symbols->buf[n].s) {
 892                case DIFF_SYMBOL_PLUS:
 893                        hm = add_lines;
 894                        break;
 895                case DIFF_SYMBOL_MINUS:
 896                        hm = del_lines;
 897                        break;
 898                default:
 899                        prev_line = NULL;
 900                        continue;
 901                }
 902
 903                key = prepare_entry(o, n);
 904                if (prev_line && prev_line->es->s == o->emitted_symbols->buf[n].s)
 905                        prev_line->next_line = key;
 906
 907                hashmap_add(hm, key);
 908                prev_line = key;
 909        }
 910}
 911
 912static void pmb_advance_or_null(struct diff_options *o,
 913                                struct moved_entry *match,
 914                                struct hashmap *hm,
 915                                struct moved_entry **pmb,
 916                                int pmb_nr)
 917{
 918        int i;
 919        for (i = 0; i < pmb_nr; i++) {
 920                struct moved_entry *prev = pmb[i];
 921                struct moved_entry *cur = (prev && prev->next_line) ?
 922                                prev->next_line : NULL;
 923                if (cur && !hm->cmpfn(o, cur, match, NULL)) {
 924                        pmb[i] = cur;
 925                } else {
 926                        pmb[i] = NULL;
 927                }
 928        }
 929}
 930
 931static void pmb_advance_or_null_multi_match(struct diff_options *o,
 932                                            struct moved_entry *match,
 933                                            struct hashmap *hm,
 934                                            struct moved_entry **pmb,
 935                                            int pmb_nr, int n)
 936{
 937        int i;
 938        char *got_match = xcalloc(1, pmb_nr);
 939
 940        for (; match; match = hashmap_get_next(hm, match)) {
 941                for (i = 0; i < pmb_nr; i++) {
 942                        struct moved_entry *prev = pmb[i];
 943                        struct moved_entry *cur = (prev && prev->next_line) ?
 944                                        prev->next_line : NULL;
 945                        if (!cur)
 946                                continue;
 947                        if (!cmp_in_block_with_wsd(o, cur, match, pmb[i], n))
 948                                got_match[i] |= 1;
 949                }
 950        }
 951
 952        for (i = 0; i < pmb_nr; i++) {
 953                if (got_match[i]) {
 954                        /* Carry the white space delta forward */
 955                        pmb[i]->next_line->wsd = pmb[i]->wsd;
 956                        pmb[i] = pmb[i]->next_line;
 957                } else
 958                        pmb[i] = NULL;
 959        }
 960}
 961
 962static int shrink_potential_moved_blocks(struct moved_entry **pmb,
 963                                         int pmb_nr)
 964{
 965        int lp, rp;
 966
 967        /* Shrink the set of potential block to the remaining running */
 968        for (lp = 0, rp = pmb_nr - 1; lp <= rp;) {
 969                while (lp < pmb_nr && pmb[lp])
 970                        lp++;
 971                /* lp points at the first NULL now */
 972
 973                while (rp > -1 && !pmb[rp])
 974                        rp--;
 975                /* rp points at the last non-NULL */
 976
 977                if (lp < pmb_nr && rp > -1 && lp < rp) {
 978                        pmb[lp] = pmb[rp];
 979                        if (pmb[rp]->wsd) {
 980                                free(pmb[rp]->wsd->string);
 981                                FREE_AND_NULL(pmb[rp]->wsd);
 982                        }
 983                        pmb[rp] = NULL;
 984                        rp--;
 985                        lp++;
 986                }
 987        }
 988
 989        /* Remember the number of running sets */
 990        return rp + 1;
 991}
 992
 993/*
 994 * If o->color_moved is COLOR_MOVED_PLAIN, this function does nothing.
 995 *
 996 * Otherwise, if the last block has fewer alphanumeric characters than
 997 * COLOR_MOVED_MIN_ALNUM_COUNT, unset DIFF_SYMBOL_MOVED_LINE on all lines in
 998 * that block.
 999 *
1000 * The last block consists of the (n - block_length)'th line up to but not
1001 * including the nth line.
1002 *
1003 * NEEDSWORK: This uses the same heuristic as blame_entry_score() in blame.c.
1004 * Think of a way to unify them.
1005 */
1006static void adjust_last_block(struct diff_options *o, int n, int block_length)
1007{
1008        int i, alnum_count = 0;
1009        if (o->color_moved == COLOR_MOVED_PLAIN)
1010                return;
1011        for (i = 1; i < block_length + 1; i++) {
1012                const char *c = o->emitted_symbols->buf[n - i].line;
1013                for (; *c; c++) {
1014                        if (!isalnum(*c))
1015                                continue;
1016                        alnum_count++;
1017                        if (alnum_count >= COLOR_MOVED_MIN_ALNUM_COUNT)
1018                                return;
1019                }
1020        }
1021        for (i = 1; i < block_length + 1; i++)
1022                o->emitted_symbols->buf[n - i].flags &= ~DIFF_SYMBOL_MOVED_LINE;
1023}
1024
1025/* Find blocks of moved code, delegate actual coloring decision to helper */
1026static void mark_color_as_moved(struct diff_options *o,
1027                                struct hashmap *add_lines,
1028                                struct hashmap *del_lines)
1029{
1030        struct moved_entry **pmb = NULL; /* potentially moved blocks */
1031        int pmb_nr = 0, pmb_alloc = 0;
1032        int n, flipped_block = 1, block_length = 0;
1033
1034
1035        for (n = 0; n < o->emitted_symbols->nr; n++) {
1036                struct hashmap *hm = NULL;
1037                struct moved_entry *key;
1038                struct moved_entry *match = NULL;
1039                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
1040
1041                switch (l->s) {
1042                case DIFF_SYMBOL_PLUS:
1043                        hm = del_lines;
1044                        key = prepare_entry(o, n);
1045                        match = hashmap_get(hm, key, NULL);
1046                        free(key);
1047                        break;
1048                case DIFF_SYMBOL_MINUS:
1049                        hm = add_lines;
1050                        key = prepare_entry(o, n);
1051                        match = hashmap_get(hm, key, NULL);
1052                        free(key);
1053                        break;
1054                default:
1055                        flipped_block = 1;
1056                }
1057
1058                if (!match) {
1059                        adjust_last_block(o, n, block_length);
1060                        pmb_nr = 0;
1061                        block_length = 0;
1062                        continue;
1063                }
1064
1065                l->flags |= DIFF_SYMBOL_MOVED_LINE;
1066
1067                if (o->color_moved == COLOR_MOVED_PLAIN)
1068                        continue;
1069
1070                if (o->color_moved_ws_handling &
1071                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
1072                        pmb_advance_or_null_multi_match(o, match, hm, pmb, pmb_nr, n);
1073                else
1074                        pmb_advance_or_null(o, match, hm, pmb, pmb_nr);
1075
1076                pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
1077
1078                if (pmb_nr == 0) {
1079                        /*
1080                         * The current line is the start of a new block.
1081                         * Setup the set of potential blocks.
1082                         */
1083                        for (; match; match = hashmap_get_next(hm, match)) {
1084                                ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
1085                                if (o->color_moved_ws_handling &
1086                                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) {
1087                                        struct ws_delta *wsd = xmalloc(sizeof(*match->wsd));
1088                                        if (compute_ws_delta(l, match->es, wsd)) {
1089                                                match->wsd = wsd;
1090                                                pmb[pmb_nr++] = match;
1091                                        } else
1092                                                free(wsd);
1093                                } else {
1094                                        pmb[pmb_nr++] = match;
1095                                }
1096                        }
1097
1098                        flipped_block = (flipped_block + 1) % 2;
1099
1100                        adjust_last_block(o, n, block_length);
1101                        block_length = 0;
1102                }
1103
1104                block_length++;
1105
1106                if (flipped_block && o->color_moved != COLOR_MOVED_BLOCKS)
1107                        l->flags |= DIFF_SYMBOL_MOVED_LINE_ALT;
1108        }
1109        adjust_last_block(o, n, block_length);
1110
1111        free(pmb);
1112}
1113
1114#define DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK \
1115  (DIFF_SYMBOL_MOVED_LINE | DIFF_SYMBOL_MOVED_LINE_ALT)
1116static void dim_moved_lines(struct diff_options *o)
1117{
1118        int n;
1119        for (n = 0; n < o->emitted_symbols->nr; n++) {
1120                struct emitted_diff_symbol *prev = (n != 0) ?
1121                                &o->emitted_symbols->buf[n - 1] : NULL;
1122                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
1123                struct emitted_diff_symbol *next =
1124                                (n < o->emitted_symbols->nr - 1) ?
1125                                &o->emitted_symbols->buf[n + 1] : NULL;
1126
1127                /* Not a plus or minus line? */
1128                if (l->s != DIFF_SYMBOL_PLUS && l->s != DIFF_SYMBOL_MINUS)
1129                        continue;
1130
1131                /* Not a moved line? */
1132                if (!(l->flags & DIFF_SYMBOL_MOVED_LINE))
1133                        continue;
1134
1135                /*
1136                 * If prev or next are not a plus or minus line,
1137                 * pretend they don't exist
1138                 */
1139                if (prev && prev->s != DIFF_SYMBOL_PLUS &&
1140                            prev->s != DIFF_SYMBOL_MINUS)
1141                        prev = NULL;
1142                if (next && next->s != DIFF_SYMBOL_PLUS &&
1143                            next->s != DIFF_SYMBOL_MINUS)
1144                        next = NULL;
1145
1146                /* Inside a block? */
1147                if ((prev &&
1148                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
1149                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK)) &&
1150                    (next &&
1151                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
1152                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK))) {
1153                        l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1154                        continue;
1155                }
1156
1157                /* Check if we are at an interesting bound: */
1158                if (prev && (prev->flags & DIFF_SYMBOL_MOVED_LINE) &&
1159                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1160                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1161                        continue;
1162                if (next && (next->flags & DIFF_SYMBOL_MOVED_LINE) &&
1163                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1164                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1165                        continue;
1166
1167                /*
1168                 * The boundary to prev and next are not interesting,
1169                 * so this line is not interesting as a whole
1170                 */
1171                l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1172        }
1173}
1174
1175static void emit_line_ws_markup(struct diff_options *o,
1176                                const char *set, const char *reset,
1177                                const char *line, int len,
1178                                const char *set_sign, char sign,
1179                                unsigned ws_rule, int blank_at_eof)
1180{
1181        const char *ws = NULL;
1182
1183        if (o->ws_error_highlight & ws_rule) {
1184                ws = diff_get_color_opt(o, DIFF_WHITESPACE);
1185                if (!*ws)
1186                        ws = NULL;
1187        }
1188
1189        if (!ws && !set_sign)
1190                emit_line_0(o, set, 0, reset, sign, line, len);
1191        else if (!ws) {
1192                /* Emit just the prefix, then the rest. */
1193                emit_line_0(o, set_sign ? set_sign : set, !!set_sign, reset,
1194                            sign, "", 0);
1195                emit_line_0(o, set, 0, reset, 0, line, len);
1196        } else if (blank_at_eof)
1197                /* Blank line at EOF - paint '+' as well */
1198                emit_line_0(o, ws, 0, reset, sign, line, len);
1199        else {
1200                /* Emit just the prefix, then the rest. */
1201                emit_line_0(o, set_sign ? set_sign : set, !!set_sign, reset,
1202                            sign, "", 0);
1203                ws_check_emit(line, len, ws_rule,
1204                              o->file, set, reset, ws);
1205        }
1206}
1207
1208static void emit_diff_symbol_from_struct(struct diff_options *o,
1209                                         struct emitted_diff_symbol *eds)
1210{
1211        static const char *nneof = " No newline at end of file\n";
1212        const char *context, *reset, *set, *set_sign, *meta, *fraginfo;
1213        struct strbuf sb = STRBUF_INIT;
1214
1215        enum diff_symbol s = eds->s;
1216        const char *line = eds->line;
1217        int len = eds->len;
1218        unsigned flags = eds->flags;
1219
1220        switch (s) {
1221        case DIFF_SYMBOL_NO_LF_EOF:
1222                context = diff_get_color_opt(o, DIFF_CONTEXT);
1223                reset = diff_get_color_opt(o, DIFF_RESET);
1224                putc('\n', o->file);
1225                emit_line_0(o, context, 0, reset, '\\',
1226                            nneof, strlen(nneof));
1227                break;
1228        case DIFF_SYMBOL_SUBMODULE_HEADER:
1229        case DIFF_SYMBOL_SUBMODULE_ERROR:
1230        case DIFF_SYMBOL_SUBMODULE_PIPETHROUGH:
1231        case DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES:
1232        case DIFF_SYMBOL_SUMMARY:
1233        case DIFF_SYMBOL_STATS_LINE:
1234        case DIFF_SYMBOL_BINARY_DIFF_BODY:
1235        case DIFF_SYMBOL_CONTEXT_FRAGINFO:
1236                emit_line(o, "", "", line, len);
1237                break;
1238        case DIFF_SYMBOL_CONTEXT_INCOMPLETE:
1239        case DIFF_SYMBOL_CONTEXT_MARKER:
1240                context = diff_get_color_opt(o, DIFF_CONTEXT);
1241                reset = diff_get_color_opt(o, DIFF_RESET);
1242                emit_line(o, context, reset, line, len);
1243                break;
1244        case DIFF_SYMBOL_SEPARATOR:
1245                fprintf(o->file, "%s%c",
1246                        diff_line_prefix(o),
1247                        o->line_termination);
1248                break;
1249        case DIFF_SYMBOL_CONTEXT:
1250                set = diff_get_color_opt(o, DIFF_CONTEXT);
1251                reset = diff_get_color_opt(o, DIFF_RESET);
1252                set_sign = NULL;
1253                if (o->flags.dual_color_diffed_diffs) {
1254                        char c = !len ? 0 : line[0];
1255
1256                        if (c == '+')
1257                                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1258                        else if (c == '@')
1259                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1260                        else if (c == '-')
1261                                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1262                }
1263                emit_line_ws_markup(o, set, reset, line, len, set_sign, ' ',
1264                                    flags & (DIFF_SYMBOL_CONTENT_WS_MASK), 0);
1265                break;
1266        case DIFF_SYMBOL_PLUS:
1267                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1268                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1269                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1270                case DIFF_SYMBOL_MOVED_LINE |
1271                     DIFF_SYMBOL_MOVED_LINE_ALT |
1272                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1273                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT_DIM);
1274                        break;
1275                case DIFF_SYMBOL_MOVED_LINE |
1276                     DIFF_SYMBOL_MOVED_LINE_ALT:
1277                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT);
1278                        break;
1279                case DIFF_SYMBOL_MOVED_LINE |
1280                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1281                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_DIM);
1282                        break;
1283                case DIFF_SYMBOL_MOVED_LINE:
1284                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED);
1285                        break;
1286                default:
1287                        set = diff_get_color_opt(o, DIFF_FILE_NEW);
1288                }
1289                reset = diff_get_color_opt(o, DIFF_RESET);
1290                if (!o->flags.dual_color_diffed_diffs)
1291                        set_sign = NULL;
1292                else {
1293                        char c = !len ? 0 : line[0];
1294
1295                        set_sign = set;
1296                        if (c == '-')
1297                                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1298                        else if (c == '@')
1299                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1300                        else if (c != '+')
1301                                set = diff_get_color_opt(o, DIFF_CONTEXT);
1302                }
1303                emit_line_ws_markup(o, set, reset, line, len, set_sign, '+',
1304                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK,
1305                                    flags & DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF);
1306                break;
1307        case DIFF_SYMBOL_MINUS:
1308                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1309                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1310                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1311                case DIFF_SYMBOL_MOVED_LINE |
1312                     DIFF_SYMBOL_MOVED_LINE_ALT |
1313                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1314                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT_DIM);
1315                        break;
1316                case DIFF_SYMBOL_MOVED_LINE |
1317                     DIFF_SYMBOL_MOVED_LINE_ALT:
1318                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT);
1319                        break;
1320                case DIFF_SYMBOL_MOVED_LINE |
1321                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1322                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_DIM);
1323                        break;
1324                case DIFF_SYMBOL_MOVED_LINE:
1325                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED);
1326                        break;
1327                default:
1328                        set = diff_get_color_opt(o, DIFF_FILE_OLD);
1329                }
1330                reset = diff_get_color_opt(o, DIFF_RESET);
1331                if (!o->flags.dual_color_diffed_diffs)
1332                        set_sign = NULL;
1333                else {
1334                        char c = !len ? 0 : line[0];
1335
1336                        set_sign = set;
1337                        if (c == '+')
1338                                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1339                        else if (c == '@')
1340                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1341                        else if (c != '-')
1342                                set = diff_get_color_opt(o, DIFF_CONTEXT);
1343                }
1344                emit_line_ws_markup(o, set, reset, line, len, set_sign, '-',
1345                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK, 0);
1346                break;
1347        case DIFF_SYMBOL_WORDS_PORCELAIN:
1348                context = diff_get_color_opt(o, DIFF_CONTEXT);
1349                reset = diff_get_color_opt(o, DIFF_RESET);
1350                emit_line(o, context, reset, line, len);
1351                fputs("~\n", o->file);
1352                break;
1353        case DIFF_SYMBOL_WORDS:
1354                context = diff_get_color_opt(o, DIFF_CONTEXT);
1355                reset = diff_get_color_opt(o, DIFF_RESET);
1356                /*
1357                 * Skip the prefix character, if any.  With
1358                 * diff_suppress_blank_empty, there may be
1359                 * none.
1360                 */
1361                if (line[0] != '\n') {
1362                        line++;
1363                        len--;
1364                }
1365                emit_line(o, context, reset, line, len);
1366                break;
1367        case DIFF_SYMBOL_FILEPAIR_PLUS:
1368                meta = diff_get_color_opt(o, DIFF_METAINFO);
1369                reset = diff_get_color_opt(o, DIFF_RESET);
1370                fprintf(o->file, "%s%s+++ %s%s%s\n", diff_line_prefix(o), meta,
1371                        line, reset,
1372                        strchr(line, ' ') ? "\t" : "");
1373                break;
1374        case DIFF_SYMBOL_FILEPAIR_MINUS:
1375                meta = diff_get_color_opt(o, DIFF_METAINFO);
1376                reset = diff_get_color_opt(o, DIFF_RESET);
1377                fprintf(o->file, "%s%s--- %s%s%s\n", diff_line_prefix(o), meta,
1378                        line, reset,
1379                        strchr(line, ' ') ? "\t" : "");
1380                break;
1381        case DIFF_SYMBOL_BINARY_FILES:
1382        case DIFF_SYMBOL_HEADER:
1383                fprintf(o->file, "%s", line);
1384                break;
1385        case DIFF_SYMBOL_BINARY_DIFF_HEADER:
1386                fprintf(o->file, "%sGIT binary patch\n", diff_line_prefix(o));
1387                break;
1388        case DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA:
1389                fprintf(o->file, "%sdelta %s\n", diff_line_prefix(o), line);
1390                break;
1391        case DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL:
1392                fprintf(o->file, "%sliteral %s\n", diff_line_prefix(o), line);
1393                break;
1394        case DIFF_SYMBOL_BINARY_DIFF_FOOTER:
1395                fputs(diff_line_prefix(o), o->file);
1396                fputc('\n', o->file);
1397                break;
1398        case DIFF_SYMBOL_REWRITE_DIFF:
1399                fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
1400                reset = diff_get_color_opt(o, DIFF_RESET);
1401                emit_line(o, fraginfo, reset, line, len);
1402                break;
1403        case DIFF_SYMBOL_SUBMODULE_ADD:
1404                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1405                reset = diff_get_color_opt(o, DIFF_RESET);
1406                emit_line(o, set, reset, line, len);
1407                break;
1408        case DIFF_SYMBOL_SUBMODULE_DEL:
1409                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1410                reset = diff_get_color_opt(o, DIFF_RESET);
1411                emit_line(o, set, reset, line, len);
1412                break;
1413        case DIFF_SYMBOL_SUBMODULE_UNTRACKED:
1414                fprintf(o->file, "%sSubmodule %s contains untracked content\n",
1415                        diff_line_prefix(o), line);
1416                break;
1417        case DIFF_SYMBOL_SUBMODULE_MODIFIED:
1418                fprintf(o->file, "%sSubmodule %s contains modified content\n",
1419                        diff_line_prefix(o), line);
1420                break;
1421        case DIFF_SYMBOL_STATS_SUMMARY_NO_FILES:
1422                emit_line(o, "", "", " 0 files changed\n",
1423                          strlen(" 0 files changed\n"));
1424                break;
1425        case DIFF_SYMBOL_STATS_SUMMARY_ABBREV:
1426                emit_line(o, "", "", " ...\n", strlen(" ...\n"));
1427                break;
1428        case DIFF_SYMBOL_WORD_DIFF:
1429                fprintf(o->file, "%.*s", len, line);
1430                break;
1431        case DIFF_SYMBOL_STAT_SEP:
1432                fputs(o->stat_sep, o->file);
1433                break;
1434        default:
1435                BUG("unknown diff symbol");
1436        }
1437        strbuf_release(&sb);
1438}
1439
1440static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
1441                             const char *line, int len, unsigned flags)
1442{
1443        struct emitted_diff_symbol e = {line, len, flags, s};
1444
1445        if (o->emitted_symbols)
1446                append_emitted_diff_symbol(o, &e);
1447        else
1448                emit_diff_symbol_from_struct(o, &e);
1449}
1450
1451void diff_emit_submodule_del(struct diff_options *o, const char *line)
1452{
1453        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_DEL, line, strlen(line), 0);
1454}
1455
1456void diff_emit_submodule_add(struct diff_options *o, const char *line)
1457{
1458        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ADD, line, strlen(line), 0);
1459}
1460
1461void diff_emit_submodule_untracked(struct diff_options *o, const char *path)
1462{
1463        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_UNTRACKED,
1464                         path, strlen(path), 0);
1465}
1466
1467void diff_emit_submodule_modified(struct diff_options *o, const char *path)
1468{
1469        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_MODIFIED,
1470                         path, strlen(path), 0);
1471}
1472
1473void diff_emit_submodule_header(struct diff_options *o, const char *header)
1474{
1475        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_HEADER,
1476                         header, strlen(header), 0);
1477}
1478
1479void diff_emit_submodule_error(struct diff_options *o, const char *err)
1480{
1481        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ERROR, err, strlen(err), 0);
1482}
1483
1484void diff_emit_submodule_pipethrough(struct diff_options *o,
1485                                     const char *line, int len)
1486{
1487        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_PIPETHROUGH, line, len, 0);
1488}
1489
1490static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
1491{
1492        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
1493              ecbdata->blank_at_eof_in_preimage &&
1494              ecbdata->blank_at_eof_in_postimage &&
1495              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
1496              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
1497                return 0;
1498        return ws_blank_line(line, len, ecbdata->ws_rule);
1499}
1500
1501static void emit_add_line(const char *reset,
1502                          struct emit_callback *ecbdata,
1503                          const char *line, int len)
1504{
1505        unsigned flags = WSEH_NEW | ecbdata->ws_rule;
1506        if (new_blank_line_at_eof(ecbdata, line, len))
1507                flags |= DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF;
1508
1509        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_PLUS, line, len, flags);
1510}
1511
1512static void emit_del_line(const char *reset,
1513                          struct emit_callback *ecbdata,
1514                          const char *line, int len)
1515{
1516        unsigned flags = WSEH_OLD | ecbdata->ws_rule;
1517        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_MINUS, line, len, flags);
1518}
1519
1520static void emit_context_line(const char *reset,
1521                              struct emit_callback *ecbdata,
1522                              const char *line, int len)
1523{
1524        unsigned flags = WSEH_CONTEXT | ecbdata->ws_rule;
1525        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_CONTEXT, line, len, flags);
1526}
1527
1528static void emit_hunk_header(struct emit_callback *ecbdata,
1529                             const char *line, int len)
1530{
1531        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
1532        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
1533        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
1534        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1535        const char *reverse = ecbdata->color_diff ? GIT_COLOR_REVERSE : "";
1536        static const char atat[2] = { '@', '@' };
1537        const char *cp, *ep;
1538        struct strbuf msgbuf = STRBUF_INIT;
1539        int org_len = len;
1540        int i = 1;
1541
1542        /*
1543         * As a hunk header must begin with "@@ -<old>, +<new> @@",
1544         * it always is at least 10 bytes long.
1545         */
1546        if (len < 10 ||
1547            memcmp(line, atat, 2) ||
1548            !(ep = memmem(line + 2, len - 2, atat, 2))) {
1549                emit_diff_symbol(ecbdata->opt,
1550                                 DIFF_SYMBOL_CONTEXT_MARKER, line, len, 0);
1551                return;
1552        }
1553        ep += 2; /* skip over @@ */
1554
1555        /* The hunk header in fraginfo color */
1556        if (ecbdata->opt->flags.dual_color_diffed_diffs)
1557                strbuf_addstr(&msgbuf, reverse);
1558        strbuf_addstr(&msgbuf, frag);
1559        strbuf_add(&msgbuf, line, ep - line);
1560        strbuf_addstr(&msgbuf, reset);
1561
1562        /*
1563         * trailing "\r\n"
1564         */
1565        for ( ; i < 3; i++)
1566                if (line[len - i] == '\r' || line[len - i] == '\n')
1567                        len--;
1568
1569        /* blank before the func header */
1570        for (cp = ep; ep - line < len; ep++)
1571                if (*ep != ' ' && *ep != '\t')
1572                        break;
1573        if (ep != cp) {
1574                strbuf_addstr(&msgbuf, context);
1575                strbuf_add(&msgbuf, cp, ep - cp);
1576                strbuf_addstr(&msgbuf, reset);
1577        }
1578
1579        if (ep < line + len) {
1580                strbuf_addstr(&msgbuf, func);
1581                strbuf_add(&msgbuf, ep, line + len - ep);
1582                strbuf_addstr(&msgbuf, reset);
1583        }
1584
1585        strbuf_add(&msgbuf, line + len, org_len - len);
1586        strbuf_complete_line(&msgbuf);
1587        emit_diff_symbol(ecbdata->opt,
1588                         DIFF_SYMBOL_CONTEXT_FRAGINFO, msgbuf.buf, msgbuf.len, 0);
1589        strbuf_release(&msgbuf);
1590}
1591
1592static struct diff_tempfile *claim_diff_tempfile(void) {
1593        int i;
1594        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
1595                if (!diff_temp[i].name)
1596                        return diff_temp + i;
1597        BUG("diff is failing to clean up its tempfiles");
1598}
1599
1600static void remove_tempfile(void)
1601{
1602        int i;
1603        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
1604                if (is_tempfile_active(diff_temp[i].tempfile))
1605                        delete_tempfile(&diff_temp[i].tempfile);
1606                diff_temp[i].name = NULL;
1607        }
1608}
1609
1610static void add_line_count(struct strbuf *out, int count)
1611{
1612        switch (count) {
1613        case 0:
1614                strbuf_addstr(out, "0,0");
1615                break;
1616        case 1:
1617                strbuf_addstr(out, "1");
1618                break;
1619        default:
1620                strbuf_addf(out, "1,%d", count);
1621                break;
1622        }
1623}
1624
1625static void emit_rewrite_lines(struct emit_callback *ecb,
1626                               int prefix, const char *data, int size)
1627{
1628        const char *endp = NULL;
1629        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
1630
1631        while (0 < size) {
1632                int len;
1633
1634                endp = memchr(data, '\n', size);
1635                len = endp ? (endp - data + 1) : size;
1636                if (prefix != '+') {
1637                        ecb->lno_in_preimage++;
1638                        emit_del_line(reset, ecb, data, len);
1639                } else {
1640                        ecb->lno_in_postimage++;
1641                        emit_add_line(reset, ecb, data, len);
1642                }
1643                size -= len;
1644                data += len;
1645        }
1646        if (!endp)
1647                emit_diff_symbol(ecb->opt, DIFF_SYMBOL_NO_LF_EOF, NULL, 0, 0);
1648}
1649
1650static void emit_rewrite_diff(const char *name_a,
1651                              const char *name_b,
1652                              struct diff_filespec *one,
1653                              struct diff_filespec *two,
1654                              struct userdiff_driver *textconv_one,
1655                              struct userdiff_driver *textconv_two,
1656                              struct diff_options *o)
1657{
1658        int lc_a, lc_b;
1659        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
1660        const char *a_prefix, *b_prefix;
1661        char *data_one, *data_two;
1662        size_t size_one, size_two;
1663        struct emit_callback ecbdata;
1664        struct strbuf out = STRBUF_INIT;
1665
1666        if (diff_mnemonic_prefix && o->flags.reverse_diff) {
1667                a_prefix = o->b_prefix;
1668                b_prefix = o->a_prefix;
1669        } else {
1670                a_prefix = o->a_prefix;
1671                b_prefix = o->b_prefix;
1672        }
1673
1674        name_a += (*name_a == '/');
1675        name_b += (*name_b == '/');
1676
1677        strbuf_reset(&a_name);
1678        strbuf_reset(&b_name);
1679        quote_two_c_style(&a_name, a_prefix, name_a, 0);
1680        quote_two_c_style(&b_name, b_prefix, name_b, 0);
1681
1682        size_one = fill_textconv(textconv_one, one, &data_one);
1683        size_two = fill_textconv(textconv_two, two, &data_two);
1684
1685        memset(&ecbdata, 0, sizeof(ecbdata));
1686        ecbdata.color_diff = want_color(o->use_color);
1687        ecbdata.ws_rule = whitespace_rule(name_b);
1688        ecbdata.opt = o;
1689        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
1690                mmfile_t mf1, mf2;
1691                mf1.ptr = (char *)data_one;
1692                mf2.ptr = (char *)data_two;
1693                mf1.size = size_one;
1694                mf2.size = size_two;
1695                check_blank_at_eof(&mf1, &mf2, &ecbdata);
1696        }
1697        ecbdata.lno_in_preimage = 1;
1698        ecbdata.lno_in_postimage = 1;
1699
1700        lc_a = count_lines(data_one, size_one);
1701        lc_b = count_lines(data_two, size_two);
1702
1703        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
1704                         a_name.buf, a_name.len, 0);
1705        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
1706                         b_name.buf, b_name.len, 0);
1707
1708        strbuf_addstr(&out, "@@ -");
1709        if (!o->irreversible_delete)
1710                add_line_count(&out, lc_a);
1711        else
1712                strbuf_addstr(&out, "?,?");
1713        strbuf_addstr(&out, " +");
1714        add_line_count(&out, lc_b);
1715        strbuf_addstr(&out, " @@\n");
1716        emit_diff_symbol(o, DIFF_SYMBOL_REWRITE_DIFF, out.buf, out.len, 0);
1717        strbuf_release(&out);
1718
1719        if (lc_a && !o->irreversible_delete)
1720                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
1721        if (lc_b)
1722                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
1723        if (textconv_one)
1724                free((char *)data_one);
1725        if (textconv_two)
1726                free((char *)data_two);
1727}
1728
1729struct diff_words_buffer {
1730        mmfile_t text;
1731        unsigned long alloc;
1732        struct diff_words_orig {
1733                const char *begin, *end;
1734        } *orig;
1735        int orig_nr, orig_alloc;
1736};
1737
1738static void diff_words_append(char *line, unsigned long len,
1739                struct diff_words_buffer *buffer)
1740{
1741        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
1742        line++;
1743        len--;
1744        memcpy(buffer->text.ptr + buffer->text.size, line, len);
1745        buffer->text.size += len;
1746        buffer->text.ptr[buffer->text.size] = '\0';
1747}
1748
1749struct diff_words_style_elem {
1750        const char *prefix;
1751        const char *suffix;
1752        const char *color; /* NULL; filled in by the setup code if
1753                            * color is enabled */
1754};
1755
1756struct diff_words_style {
1757        enum diff_words_type type;
1758        struct diff_words_style_elem new_word, old_word, ctx;
1759        const char *newline;
1760};
1761
1762static struct diff_words_style diff_words_styles[] = {
1763        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
1764        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
1765        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
1766};
1767
1768struct diff_words_data {
1769        struct diff_words_buffer minus, plus;
1770        const char *current_plus;
1771        int last_minus;
1772        struct diff_options *opt;
1773        regex_t *word_regex;
1774        enum diff_words_type type;
1775        struct diff_words_style *style;
1776};
1777
1778static int fn_out_diff_words_write_helper(struct diff_options *o,
1779                                          struct diff_words_style_elem *st_el,
1780                                          const char *newline,
1781                                          size_t count, const char *buf)
1782{
1783        int print = 0;
1784        struct strbuf sb = STRBUF_INIT;
1785
1786        while (count) {
1787                char *p = memchr(buf, '\n', count);
1788                if (print)
1789                        strbuf_addstr(&sb, diff_line_prefix(o));
1790
1791                if (p != buf) {
1792                        const char *reset = st_el->color && *st_el->color ?
1793                                            GIT_COLOR_RESET : NULL;
1794                        if (st_el->color && *st_el->color)
1795                                strbuf_addstr(&sb, st_el->color);
1796                        strbuf_addstr(&sb, st_el->prefix);
1797                        strbuf_add(&sb, buf, p ? p - buf : count);
1798                        strbuf_addstr(&sb, st_el->suffix);
1799                        if (reset)
1800                                strbuf_addstr(&sb, reset);
1801                }
1802                if (!p)
1803                        goto out;
1804
1805                strbuf_addstr(&sb, newline);
1806                count -= p + 1 - buf;
1807                buf = p + 1;
1808                print = 1;
1809                if (count) {
1810                        emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1811                                         sb.buf, sb.len, 0);
1812                        strbuf_reset(&sb);
1813                }
1814        }
1815
1816out:
1817        if (sb.len)
1818                emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1819                                 sb.buf, sb.len, 0);
1820        strbuf_release(&sb);
1821        return 0;
1822}
1823
1824/*
1825 * '--color-words' algorithm can be described as:
1826 *
1827 *   1. collect the minus/plus lines of a diff hunk, divided into
1828 *      minus-lines and plus-lines;
1829 *
1830 *   2. break both minus-lines and plus-lines into words and
1831 *      place them into two mmfile_t with one word for each line;
1832 *
1833 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
1834 *
1835 * And for the common parts of the both file, we output the plus side text.
1836 * diff_words->current_plus is used to trace the current position of the plus file
1837 * which printed. diff_words->last_minus is used to trace the last minus word
1838 * printed.
1839 *
1840 * For '--graph' to work with '--color-words', we need to output the graph prefix
1841 * on each line of color words output. Generally, there are two conditions on
1842 * which we should output the prefix.
1843 *
1844 *   1. diff_words->last_minus == 0 &&
1845 *      diff_words->current_plus == diff_words->plus.text.ptr
1846 *
1847 *      that is: the plus text must start as a new line, and if there is no minus
1848 *      word printed, a graph prefix must be printed.
1849 *
1850 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
1851 *      *(diff_words->current_plus - 1) == '\n'
1852 *
1853 *      that is: a graph prefix must be printed following a '\n'
1854 */
1855static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
1856{
1857        if ((diff_words->last_minus == 0 &&
1858                diff_words->current_plus == diff_words->plus.text.ptr) ||
1859                (diff_words->current_plus > diff_words->plus.text.ptr &&
1860                *(diff_words->current_plus - 1) == '\n')) {
1861                return 1;
1862        } else {
1863                return 0;
1864        }
1865}
1866
1867static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
1868{
1869        struct diff_words_data *diff_words = priv;
1870        struct diff_words_style *style = diff_words->style;
1871        int minus_first, minus_len, plus_first, plus_len;
1872        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
1873        struct diff_options *opt = diff_words->opt;
1874        const char *line_prefix;
1875
1876        if (line[0] != '@' || parse_hunk_header(line, len,
1877                        &minus_first, &minus_len, &plus_first, &plus_len))
1878                return;
1879
1880        assert(opt);
1881        line_prefix = diff_line_prefix(opt);
1882
1883        /* POSIX requires that first be decremented by one if len == 0... */
1884        if (minus_len) {
1885                minus_begin = diff_words->minus.orig[minus_first].begin;
1886                minus_end =
1887                        diff_words->minus.orig[minus_first + minus_len - 1].end;
1888        } else
1889                minus_begin = minus_end =
1890                        diff_words->minus.orig[minus_first].end;
1891
1892        if (plus_len) {
1893                plus_begin = diff_words->plus.orig[plus_first].begin;
1894                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
1895        } else
1896                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
1897
1898        if (color_words_output_graph_prefix(diff_words)) {
1899                fputs(line_prefix, diff_words->opt->file);
1900        }
1901        if (diff_words->current_plus != plus_begin) {
1902                fn_out_diff_words_write_helper(diff_words->opt,
1903                                &style->ctx, style->newline,
1904                                plus_begin - diff_words->current_plus,
1905                                diff_words->current_plus);
1906        }
1907        if (minus_begin != minus_end) {
1908                fn_out_diff_words_write_helper(diff_words->opt,
1909                                &style->old_word, style->newline,
1910                                minus_end - minus_begin, minus_begin);
1911        }
1912        if (plus_begin != plus_end) {
1913                fn_out_diff_words_write_helper(diff_words->opt,
1914                                &style->new_word, style->newline,
1915                                plus_end - plus_begin, plus_begin);
1916        }
1917
1918        diff_words->current_plus = plus_end;
1919        diff_words->last_minus = minus_first;
1920}
1921
1922/* This function starts looking at *begin, and returns 0 iff a word was found. */
1923static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
1924                int *begin, int *end)
1925{
1926        if (word_regex && *begin < buffer->size) {
1927                regmatch_t match[1];
1928                if (!regexec_buf(word_regex, buffer->ptr + *begin,
1929                                 buffer->size - *begin, 1, match, 0)) {
1930                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
1931                                        '\n', match[0].rm_eo - match[0].rm_so);
1932                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
1933                        *begin += match[0].rm_so;
1934                        return *begin >= *end;
1935                }
1936                return -1;
1937        }
1938
1939        /* find the next word */
1940        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
1941                (*begin)++;
1942        if (*begin >= buffer->size)
1943                return -1;
1944
1945        /* find the end of the word */
1946        *end = *begin + 1;
1947        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
1948                (*end)++;
1949
1950        return 0;
1951}
1952
1953/*
1954 * This function splits the words in buffer->text, stores the list with
1955 * newline separator into out, and saves the offsets of the original words
1956 * in buffer->orig.
1957 */
1958static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
1959                regex_t *word_regex)
1960{
1961        int i, j;
1962        long alloc = 0;
1963
1964        out->size = 0;
1965        out->ptr = NULL;
1966
1967        /* fake an empty "0th" word */
1968        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
1969        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
1970        buffer->orig_nr = 1;
1971
1972        for (i = 0; i < buffer->text.size; i++) {
1973                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
1974                        return;
1975
1976                /* store original boundaries */
1977                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
1978                                buffer->orig_alloc);
1979                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
1980                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
1981                buffer->orig_nr++;
1982
1983                /* store one word */
1984                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
1985                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
1986                out->ptr[out->size + j - i] = '\n';
1987                out->size += j - i + 1;
1988
1989                i = j - 1;
1990        }
1991}
1992
1993/* this executes the word diff on the accumulated buffers */
1994static void diff_words_show(struct diff_words_data *diff_words)
1995{
1996        xpparam_t xpp;
1997        xdemitconf_t xecfg;
1998        mmfile_t minus, plus;
1999        struct diff_words_style *style = diff_words->style;
2000
2001        struct diff_options *opt = diff_words->opt;
2002        const char *line_prefix;
2003
2004        assert(opt);
2005        line_prefix = diff_line_prefix(opt);
2006
2007        /* special case: only removal */
2008        if (!diff_words->plus.text.size) {
2009                emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
2010                                 line_prefix, strlen(line_prefix), 0);
2011                fn_out_diff_words_write_helper(diff_words->opt,
2012                        &style->old_word, style->newline,
2013                        diff_words->minus.text.size,
2014                        diff_words->minus.text.ptr);
2015                diff_words->minus.text.size = 0;
2016                return;
2017        }
2018
2019        diff_words->current_plus = diff_words->plus.text.ptr;
2020        diff_words->last_minus = 0;
2021
2022        memset(&xpp, 0, sizeof(xpp));
2023        memset(&xecfg, 0, sizeof(xecfg));
2024        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
2025        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
2026        xpp.flags = 0;
2027        /* as only the hunk header will be parsed, we need a 0-context */
2028        xecfg.ctxlen = 0;
2029        if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
2030                          &xpp, &xecfg))
2031                die("unable to generate word diff");
2032        free(minus.ptr);
2033        free(plus.ptr);
2034        if (diff_words->current_plus != diff_words->plus.text.ptr +
2035                        diff_words->plus.text.size) {
2036                if (color_words_output_graph_prefix(diff_words))
2037                        emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
2038                                         line_prefix, strlen(line_prefix), 0);
2039                fn_out_diff_words_write_helper(diff_words->opt,
2040                        &style->ctx, style->newline,
2041                        diff_words->plus.text.ptr + diff_words->plus.text.size
2042                        - diff_words->current_plus, diff_words->current_plus);
2043        }
2044        diff_words->minus.text.size = diff_words->plus.text.size = 0;
2045}
2046
2047/* In "color-words" mode, show word-diff of words accumulated in the buffer */
2048static void diff_words_flush(struct emit_callback *ecbdata)
2049{
2050        struct diff_options *wo = ecbdata->diff_words->opt;
2051
2052        if (ecbdata->diff_words->minus.text.size ||
2053            ecbdata->diff_words->plus.text.size)
2054                diff_words_show(ecbdata->diff_words);
2055
2056        if (wo->emitted_symbols) {
2057                struct diff_options *o = ecbdata->opt;
2058                struct emitted_diff_symbols *wol = wo->emitted_symbols;
2059                int i;
2060
2061                /*
2062                 * NEEDSWORK:
2063                 * Instead of appending each, concat all words to a line?
2064                 */
2065                for (i = 0; i < wol->nr; i++)
2066                        append_emitted_diff_symbol(o, &wol->buf[i]);
2067
2068                for (i = 0; i < wol->nr; i++)
2069                        free((void *)wol->buf[i].line);
2070
2071                wol->nr = 0;
2072        }
2073}
2074
2075static void diff_filespec_load_driver(struct diff_filespec *one)
2076{
2077        /* Use already-loaded driver */
2078        if (one->driver)
2079                return;
2080
2081        if (S_ISREG(one->mode))
2082                one->driver = userdiff_find_by_path(one->path);
2083
2084        /* Fallback to default settings */
2085        if (!one->driver)
2086                one->driver = userdiff_find_by_name("default");
2087}
2088
2089static const char *userdiff_word_regex(struct diff_filespec *one)
2090{
2091        diff_filespec_load_driver(one);
2092        return one->driver->word_regex;
2093}
2094
2095static void init_diff_words_data(struct emit_callback *ecbdata,
2096                                 struct diff_options *orig_opts,
2097                                 struct diff_filespec *one,
2098                                 struct diff_filespec *two)
2099{
2100        int i;
2101        struct diff_options *o = xmalloc(sizeof(struct diff_options));
2102        memcpy(o, orig_opts, sizeof(struct diff_options));
2103
2104        ecbdata->diff_words =
2105                xcalloc(1, sizeof(struct diff_words_data));
2106        ecbdata->diff_words->type = o->word_diff;
2107        ecbdata->diff_words->opt = o;
2108
2109        if (orig_opts->emitted_symbols)
2110                o->emitted_symbols =
2111                        xcalloc(1, sizeof(struct emitted_diff_symbols));
2112
2113        if (!o->word_regex)
2114                o->word_regex = userdiff_word_regex(one);
2115        if (!o->word_regex)
2116                o->word_regex = userdiff_word_regex(two);
2117        if (!o->word_regex)
2118                o->word_regex = diff_word_regex_cfg;
2119        if (o->word_regex) {
2120                ecbdata->diff_words->word_regex = (regex_t *)
2121                        xmalloc(sizeof(regex_t));
2122                if (regcomp(ecbdata->diff_words->word_regex,
2123                            o->word_regex,
2124                            REG_EXTENDED | REG_NEWLINE))
2125                        die ("Invalid regular expression: %s",
2126                             o->word_regex);
2127        }
2128        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2129                if (o->word_diff == diff_words_styles[i].type) {
2130                        ecbdata->diff_words->style =
2131                                &diff_words_styles[i];
2132                        break;
2133                }
2134        }
2135        if (want_color(o->use_color)) {
2136                struct diff_words_style *st = ecbdata->diff_words->style;
2137                st->old_word.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2138                st->new_word.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2139                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
2140        }
2141}
2142
2143static void free_diff_words_data(struct emit_callback *ecbdata)
2144{
2145        if (ecbdata->diff_words) {
2146                diff_words_flush(ecbdata);
2147                free (ecbdata->diff_words->opt->emitted_symbols);
2148                free (ecbdata->diff_words->opt);
2149                free (ecbdata->diff_words->minus.text.ptr);
2150                free (ecbdata->diff_words->minus.orig);
2151                free (ecbdata->diff_words->plus.text.ptr);
2152                free (ecbdata->diff_words->plus.orig);
2153                if (ecbdata->diff_words->word_regex) {
2154                        regfree(ecbdata->diff_words->word_regex);
2155                        free(ecbdata->diff_words->word_regex);
2156                }
2157                FREE_AND_NULL(ecbdata->diff_words);
2158        }
2159}
2160
2161const char *diff_get_color(int diff_use_color, enum color_diff ix)
2162{
2163        if (want_color(diff_use_color))
2164                return diff_colors[ix];
2165        return "";
2166}
2167
2168const char *diff_line_prefix(struct diff_options *opt)
2169{
2170        struct strbuf *msgbuf;
2171        if (!opt->output_prefix)
2172                return "";
2173
2174        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
2175        return msgbuf->buf;
2176}
2177
2178static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
2179{
2180        const char *cp;
2181        unsigned long allot;
2182        size_t l = len;
2183
2184        cp = line;
2185        allot = l;
2186        while (0 < l) {
2187                (void) utf8_width(&cp, &l);
2188                if (!cp)
2189                        break; /* truncated in the middle? */
2190        }
2191        return allot - l;
2192}
2193
2194static void find_lno(const char *line, struct emit_callback *ecbdata)
2195{
2196        const char *p;
2197        ecbdata->lno_in_preimage = 0;
2198        ecbdata->lno_in_postimage = 0;
2199        p = strchr(line, '-');
2200        if (!p)
2201                return; /* cannot happen */
2202        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
2203        p = strchr(p, '+');
2204        if (!p)
2205                return; /* cannot happen */
2206        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
2207}
2208
2209static void fn_out_consume(void *priv, char *line, unsigned long len)
2210{
2211        struct emit_callback *ecbdata = priv;
2212        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
2213        struct diff_options *o = ecbdata->opt;
2214
2215        o->found_changes = 1;
2216
2217        if (ecbdata->header) {
2218                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
2219                                 ecbdata->header->buf, ecbdata->header->len, 0);
2220                strbuf_reset(ecbdata->header);
2221                ecbdata->header = NULL;
2222        }
2223
2224        if (ecbdata->label_path[0]) {
2225                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
2226                                 ecbdata->label_path[0],
2227                                 strlen(ecbdata->label_path[0]), 0);
2228                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
2229                                 ecbdata->label_path[1],
2230                                 strlen(ecbdata->label_path[1]), 0);
2231                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
2232        }
2233
2234        if (diff_suppress_blank_empty
2235            && len == 2 && line[0] == ' ' && line[1] == '\n') {
2236                line[0] = '\n';
2237                len = 1;
2238        }
2239
2240        if (line[0] == '@') {
2241                if (ecbdata->diff_words)
2242                        diff_words_flush(ecbdata);
2243                len = sane_truncate_line(ecbdata, line, len);
2244                find_lno(line, ecbdata);
2245                emit_hunk_header(ecbdata, line, len);
2246                return;
2247        }
2248
2249        if (ecbdata->diff_words) {
2250                enum diff_symbol s =
2251                        ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN ?
2252                        DIFF_SYMBOL_WORDS_PORCELAIN : DIFF_SYMBOL_WORDS;
2253                if (line[0] == '-') {
2254                        diff_words_append(line, len,
2255                                          &ecbdata->diff_words->minus);
2256                        return;
2257                } else if (line[0] == '+') {
2258                        diff_words_append(line, len,
2259                                          &ecbdata->diff_words->plus);
2260                        return;
2261                } else if (starts_with(line, "\\ ")) {
2262                        /*
2263                         * Eat the "no newline at eof" marker as if we
2264                         * saw a "+" or "-" line with nothing on it,
2265                         * and return without diff_words_flush() to
2266                         * defer processing. If this is the end of
2267                         * preimage, more "+" lines may come after it.
2268                         */
2269                        return;
2270                }
2271                diff_words_flush(ecbdata);
2272                emit_diff_symbol(o, s, line, len, 0);
2273                return;
2274        }
2275
2276        switch (line[0]) {
2277        case '+':
2278                ecbdata->lno_in_postimage++;
2279                emit_add_line(reset, ecbdata, line + 1, len - 1);
2280                break;
2281        case '-':
2282                ecbdata->lno_in_preimage++;
2283                emit_del_line(reset, ecbdata, line + 1, len - 1);
2284                break;
2285        case ' ':
2286                ecbdata->lno_in_postimage++;
2287                ecbdata->lno_in_preimage++;
2288                emit_context_line(reset, ecbdata, line + 1, len - 1);
2289                break;
2290        default:
2291                /* incomplete line at the end */
2292                ecbdata->lno_in_preimage++;
2293                emit_diff_symbol(o, DIFF_SYMBOL_CONTEXT_INCOMPLETE,
2294                                 line, len, 0);
2295                break;
2296        }
2297}
2298
2299static void pprint_rename(struct strbuf *name, const char *a, const char *b)
2300{
2301        const char *old_name = a;
2302        const char *new_name = b;
2303        int pfx_length, sfx_length;
2304        int pfx_adjust_for_slash;
2305        int len_a = strlen(a);
2306        int len_b = strlen(b);
2307        int a_midlen, b_midlen;
2308        int qlen_a = quote_c_style(a, NULL, NULL, 0);
2309        int qlen_b = quote_c_style(b, NULL, NULL, 0);
2310
2311        if (qlen_a || qlen_b) {
2312                quote_c_style(a, name, NULL, 0);
2313                strbuf_addstr(name, " => ");
2314                quote_c_style(b, name, NULL, 0);
2315                return;
2316        }
2317
2318        /* Find common prefix */
2319        pfx_length = 0;
2320        while (*old_name && *new_name && *old_name == *new_name) {
2321                if (*old_name == '/')
2322                        pfx_length = old_name - a + 1;
2323                old_name++;
2324                new_name++;
2325        }
2326
2327        /* Find common suffix */
2328        old_name = a + len_a;
2329        new_name = b + len_b;
2330        sfx_length = 0;
2331        /*
2332         * If there is a common prefix, it must end in a slash.  In
2333         * that case we let this loop run 1 into the prefix to see the
2334         * same slash.
2335         *
2336         * If there is no common prefix, we cannot do this as it would
2337         * underrun the input strings.
2338         */
2339        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
2340        while (a + pfx_length - pfx_adjust_for_slash <= old_name &&
2341               b + pfx_length - pfx_adjust_for_slash <= new_name &&
2342               *old_name == *new_name) {
2343                if (*old_name == '/')
2344                        sfx_length = len_a - (old_name - a);
2345                old_name--;
2346                new_name--;
2347        }
2348
2349        /*
2350         * pfx{mid-a => mid-b}sfx
2351         * {pfx-a => pfx-b}sfx
2352         * pfx{sfx-a => sfx-b}
2353         * name-a => name-b
2354         */
2355        a_midlen = len_a - pfx_length - sfx_length;
2356        b_midlen = len_b - pfx_length - sfx_length;
2357        if (a_midlen < 0)
2358                a_midlen = 0;
2359        if (b_midlen < 0)
2360                b_midlen = 0;
2361
2362        strbuf_grow(name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
2363        if (pfx_length + sfx_length) {
2364                strbuf_add(name, a, pfx_length);
2365                strbuf_addch(name, '{');
2366        }
2367        strbuf_add(name, a + pfx_length, a_midlen);
2368        strbuf_addstr(name, " => ");
2369        strbuf_add(name, b + pfx_length, b_midlen);
2370        if (pfx_length + sfx_length) {
2371                strbuf_addch(name, '}');
2372                strbuf_add(name, a + len_a - sfx_length, sfx_length);
2373        }
2374}
2375
2376struct diffstat_t {
2377        int nr;
2378        int alloc;
2379        struct diffstat_file {
2380                char *from_name;
2381                char *name;
2382                char *print_name;
2383                const char *comments;
2384                unsigned is_unmerged:1;
2385                unsigned is_binary:1;
2386                unsigned is_renamed:1;
2387                unsigned is_interesting:1;
2388                uintmax_t added, deleted;
2389        } **files;
2390};
2391
2392static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
2393                                          const char *name_a,
2394                                          const char *name_b)
2395{
2396        struct diffstat_file *x;
2397        x = xcalloc(1, sizeof(*x));
2398        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
2399        diffstat->files[diffstat->nr++] = x;
2400        if (name_b) {
2401                x->from_name = xstrdup(name_a);
2402                x->name = xstrdup(name_b);
2403                x->is_renamed = 1;
2404        }
2405        else {
2406                x->from_name = NULL;
2407                x->name = xstrdup(name_a);
2408        }
2409        return x;
2410}
2411
2412static void diffstat_consume(void *priv, char *line, unsigned long len)
2413{
2414        struct diffstat_t *diffstat = priv;
2415        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
2416
2417        if (line[0] == '+')
2418                x->added++;
2419        else if (line[0] == '-')
2420                x->deleted++;
2421}
2422
2423const char mime_boundary_leader[] = "------------";
2424
2425static int scale_linear(int it, int width, int max_change)
2426{
2427        if (!it)
2428                return 0;
2429        /*
2430         * make sure that at least one '-' or '+' is printed if
2431         * there is any change to this path. The easiest way is to
2432         * scale linearly as if the alloted width is one column shorter
2433         * than it is, and then add 1 to the result.
2434         */
2435        return 1 + (it * (width - 1) / max_change);
2436}
2437
2438static void show_graph(struct strbuf *out, char ch, int cnt,
2439                       const char *set, const char *reset)
2440{
2441        if (cnt <= 0)
2442                return;
2443        strbuf_addstr(out, set);
2444        strbuf_addchars(out, ch, cnt);
2445        strbuf_addstr(out, reset);
2446}
2447
2448static void fill_print_name(struct diffstat_file *file)
2449{
2450        struct strbuf pname = STRBUF_INIT;
2451
2452        if (file->print_name)
2453                return;
2454
2455        if (file->is_renamed)
2456                pprint_rename(&pname, file->from_name, file->name);
2457        else
2458                quote_c_style(file->name, &pname, NULL, 0);
2459
2460        if (file->comments)
2461                strbuf_addf(&pname, " (%s)", file->comments);
2462
2463        file->print_name = strbuf_detach(&pname, NULL);
2464}
2465
2466static void print_stat_summary_inserts_deletes(struct diff_options *options,
2467                int files, int insertions, int deletions)
2468{
2469        struct strbuf sb = STRBUF_INIT;
2470
2471        if (!files) {
2472                assert(insertions == 0 && deletions == 0);
2473                emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
2474                                 NULL, 0, 0);
2475                return;
2476        }
2477
2478        strbuf_addf(&sb,
2479                    (files == 1) ? " %d file changed" : " %d files changed",
2480                    files);
2481
2482        /*
2483         * For binary diff, the caller may want to print "x files
2484         * changed" with insertions == 0 && deletions == 0.
2485         *
2486         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
2487         * is probably less confusing (i.e skip over "2 files changed
2488         * but nothing about added/removed lines? Is this a bug in Git?").
2489         */
2490        if (insertions || deletions == 0) {
2491                strbuf_addf(&sb,
2492                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
2493                            insertions);
2494        }
2495
2496        if (deletions || insertions == 0) {
2497                strbuf_addf(&sb,
2498                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
2499                            deletions);
2500        }
2501        strbuf_addch(&sb, '\n');
2502        emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
2503                         sb.buf, sb.len, 0);
2504        strbuf_release(&sb);
2505}
2506
2507void print_stat_summary(FILE *fp, int files,
2508                        int insertions, int deletions)
2509{
2510        struct diff_options o;
2511        memset(&o, 0, sizeof(o));
2512        o.file = fp;
2513
2514        print_stat_summary_inserts_deletes(&o, files, insertions, deletions);
2515}
2516
2517static void show_stats(struct diffstat_t *data, struct diff_options *options)
2518{
2519        int i, len, add, del, adds = 0, dels = 0;
2520        uintmax_t max_change = 0, max_len = 0;
2521        int total_files = data->nr, count;
2522        int width, name_width, graph_width, number_width = 0, bin_width = 0;
2523        const char *reset, *add_c, *del_c;
2524        int extra_shown = 0;
2525        const char *line_prefix = diff_line_prefix(options);
2526        struct strbuf out = STRBUF_INIT;
2527
2528        if (data->nr == 0)
2529                return;
2530
2531        count = options->stat_count ? options->stat_count : data->nr;
2532
2533        reset = diff_get_color_opt(options, DIFF_RESET);
2534        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
2535        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
2536
2537        /*
2538         * Find the longest filename and max number of changes
2539         */
2540        for (i = 0; (i < count) && (i < data->nr); i++) {
2541                struct diffstat_file *file = data->files[i];
2542                uintmax_t change = file->added + file->deleted;
2543
2544                if (!file->is_interesting && (change == 0)) {
2545                        count++; /* not shown == room for one more */
2546                        continue;
2547                }
2548                fill_print_name(file);
2549                len = strlen(file->print_name);
2550                if (max_len < len)
2551                        max_len = len;
2552
2553                if (file->is_unmerged) {
2554                        /* "Unmerged" is 8 characters */
2555                        bin_width = bin_width < 8 ? 8 : bin_width;
2556                        continue;
2557                }
2558                if (file->is_binary) {
2559                        /* "Bin XXX -> YYY bytes" */
2560                        int w = 14 + decimal_width(file->added)
2561                                + decimal_width(file->deleted);
2562                        bin_width = bin_width < w ? w : bin_width;
2563                        /* Display change counts aligned with "Bin" */
2564                        number_width = 3;
2565                        continue;
2566                }
2567
2568                if (max_change < change)
2569                        max_change = change;
2570        }
2571        count = i; /* where we can stop scanning in data->files[] */
2572
2573        /*
2574         * We have width = stat_width or term_columns() columns total.
2575         * We want a maximum of min(max_len, stat_name_width) for the name part.
2576         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
2577         * We also need 1 for " " and 4 + decimal_width(max_change)
2578         * for " | NNNN " and one the empty column at the end, altogether
2579         * 6 + decimal_width(max_change).
2580         *
2581         * If there's not enough space, we will use the smaller of
2582         * stat_name_width (if set) and 5/8*width for the filename,
2583         * and the rest for constant elements + graph part, but no more
2584         * than stat_graph_width for the graph part.
2585         * (5/8 gives 50 for filename and 30 for the constant parts + graph
2586         * for the standard terminal size).
2587         *
2588         * In other words: stat_width limits the maximum width, and
2589         * stat_name_width fixes the maximum width of the filename,
2590         * and is also used to divide available columns if there
2591         * aren't enough.
2592         *
2593         * Binary files are displayed with "Bin XXX -> YYY bytes"
2594         * instead of the change count and graph. This part is treated
2595         * similarly to the graph part, except that it is not
2596         * "scaled". If total width is too small to accommodate the
2597         * guaranteed minimum width of the filename part and the
2598         * separators and this message, this message will "overflow"
2599         * making the line longer than the maximum width.
2600         */
2601
2602        if (options->stat_width == -1)
2603                width = term_columns() - strlen(line_prefix);
2604        else
2605                width = options->stat_width ? options->stat_width : 80;
2606        number_width = decimal_width(max_change) > number_width ?
2607                decimal_width(max_change) : number_width;
2608
2609        if (options->stat_graph_width == -1)
2610                options->stat_graph_width = diff_stat_graph_width;
2611
2612        /*
2613         * Guarantee 3/8*16==6 for the graph part
2614         * and 5/8*16==10 for the filename part
2615         */
2616        if (width < 16 + 6 + number_width)
2617                width = 16 + 6 + number_width;
2618
2619        /*
2620         * First assign sizes that are wanted, ignoring available width.
2621         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
2622         * starting from "XXX" should fit in graph_width.
2623         */
2624        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
2625        if (options->stat_graph_width &&
2626            options->stat_graph_width < graph_width)
2627                graph_width = options->stat_graph_width;
2628
2629        name_width = (options->stat_name_width > 0 &&
2630                      options->stat_name_width < max_len) ?
2631                options->stat_name_width : max_len;
2632
2633        /*
2634         * Adjust adjustable widths not to exceed maximum width
2635         */
2636        if (name_width + number_width + 6 + graph_width > width) {
2637                if (graph_width > width * 3/8 - number_width - 6) {
2638                        graph_width = width * 3/8 - number_width - 6;
2639                        if (graph_width < 6)
2640                                graph_width = 6;
2641                }
2642
2643                if (options->stat_graph_width &&
2644                    graph_width > options->stat_graph_width)
2645                        graph_width = options->stat_graph_width;
2646                if (name_width > width - number_width - 6 - graph_width)
2647                        name_width = width - number_width - 6 - graph_width;
2648                else
2649                        graph_width = width - number_width - 6 - name_width;
2650        }
2651
2652        /*
2653         * From here name_width is the width of the name area,
2654         * and graph_width is the width of the graph area.
2655         * max_change is used to scale graph properly.
2656         */
2657        for (i = 0; i < count; i++) {
2658                const char *prefix = "";
2659                struct diffstat_file *file = data->files[i];
2660                char *name = file->print_name;
2661                uintmax_t added = file->added;
2662                uintmax_t deleted = file->deleted;
2663                int name_len;
2664
2665                if (!file->is_interesting && (added + deleted == 0))
2666                        continue;
2667
2668                /*
2669                 * "scale" the filename
2670                 */
2671                len = name_width;
2672                name_len = strlen(name);
2673                if (name_width < name_len) {
2674                        char *slash;
2675                        prefix = "...";
2676                        len -= 3;
2677                        name += name_len - len;
2678                        slash = strchr(name, '/');
2679                        if (slash)
2680                                name = slash;
2681                }
2682
2683                if (file->is_binary) {
2684                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2685                        strbuf_addf(&out, " %*s", number_width, "Bin");
2686                        if (!added && !deleted) {
2687                                strbuf_addch(&out, '\n');
2688                                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2689                                                 out.buf, out.len, 0);
2690                                strbuf_reset(&out);
2691                                continue;
2692                        }
2693                        strbuf_addf(&out, " %s%"PRIuMAX"%s",
2694                                del_c, deleted, reset);
2695                        strbuf_addstr(&out, " -> ");
2696                        strbuf_addf(&out, "%s%"PRIuMAX"%s",
2697                                add_c, added, reset);
2698                        strbuf_addstr(&out, " bytes\n");
2699                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2700                                         out.buf, out.len, 0);
2701                        strbuf_reset(&out);
2702                        continue;
2703                }
2704                else if (file->is_unmerged) {
2705                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2706                        strbuf_addstr(&out, " Unmerged\n");
2707                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2708                                         out.buf, out.len, 0);
2709                        strbuf_reset(&out);
2710                        continue;
2711                }
2712
2713                /*
2714                 * scale the add/delete
2715                 */
2716                add = added;
2717                del = deleted;
2718
2719                if (graph_width <= max_change) {
2720                        int total = scale_linear(add + del, graph_width, max_change);
2721                        if (total < 2 && add && del)
2722                                /* width >= 2 due to the sanity check */
2723                                total = 2;
2724                        if (add < del) {
2725                                add = scale_linear(add, graph_width, max_change);
2726                                del = total - add;
2727                        } else {
2728                                del = scale_linear(del, graph_width, max_change);
2729                                add = total - del;
2730                        }
2731                }
2732                strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2733                strbuf_addf(&out, " %*"PRIuMAX"%s",
2734                        number_width, added + deleted,
2735                        added + deleted ? " " : "");
2736                show_graph(&out, '+', add, add_c, reset);
2737                show_graph(&out, '-', del, del_c, reset);
2738                strbuf_addch(&out, '\n');
2739                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2740                                 out.buf, out.len, 0);
2741                strbuf_reset(&out);
2742        }
2743
2744        for (i = 0; i < data->nr; i++) {
2745                struct diffstat_file *file = data->files[i];
2746                uintmax_t added = file->added;
2747                uintmax_t deleted = file->deleted;
2748
2749                if (file->is_unmerged ||
2750                    (!file->is_interesting && (added + deleted == 0))) {
2751                        total_files--;
2752                        continue;
2753                }
2754
2755                if (!file->is_binary) {
2756                        adds += added;
2757                        dels += deleted;
2758                }
2759                if (i < count)
2760                        continue;
2761                if (!extra_shown)
2762                        emit_diff_symbol(options,
2763                                         DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
2764                                         NULL, 0, 0);
2765                extra_shown = 1;
2766        }
2767
2768        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2769        strbuf_release(&out);
2770}
2771
2772static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
2773{
2774        int i, adds = 0, dels = 0, total_files = data->nr;
2775
2776        if (data->nr == 0)
2777                return;
2778
2779        for (i = 0; i < data->nr; i++) {
2780                int added = data->files[i]->added;
2781                int deleted = data->files[i]->deleted;
2782
2783                if (data->files[i]->is_unmerged ||
2784                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
2785                        total_files--;
2786                } else if (!data->files[i]->is_binary) { /* don't count bytes */
2787                        adds += added;
2788                        dels += deleted;
2789                }
2790        }
2791        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2792}
2793
2794static void show_numstat(struct diffstat_t *data, struct diff_options *options)
2795{
2796        int i;
2797
2798        if (data->nr == 0)
2799                return;
2800
2801        for (i = 0; i < data->nr; i++) {
2802                struct diffstat_file *file = data->files[i];
2803
2804                fprintf(options->file, "%s", diff_line_prefix(options));
2805
2806                if (file->is_binary)
2807                        fprintf(options->file, "-\t-\t");
2808                else
2809                        fprintf(options->file,
2810                                "%"PRIuMAX"\t%"PRIuMAX"\t",
2811                                file->added, file->deleted);
2812                if (options->line_termination) {
2813                        fill_print_name(file);
2814                        if (!file->is_renamed)
2815                                write_name_quoted(file->name, options->file,
2816                                                  options->line_termination);
2817                        else {
2818                                fputs(file->print_name, options->file);
2819                                putc(options->line_termination, options->file);
2820                        }
2821                } else {
2822                        if (file->is_renamed) {
2823                                putc('\0', options->file);
2824                                write_name_quoted(file->from_name, options->file, '\0');
2825                        }
2826                        write_name_quoted(file->name, options->file, '\0');
2827                }
2828        }
2829}
2830
2831struct dirstat_file {
2832        const char *name;
2833        unsigned long changed;
2834};
2835
2836struct dirstat_dir {
2837        struct dirstat_file *files;
2838        int alloc, nr, permille, cumulative;
2839};
2840
2841static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
2842                unsigned long changed, const char *base, int baselen)
2843{
2844        unsigned long sum_changes = 0;
2845        unsigned int sources = 0;
2846        const char *line_prefix = diff_line_prefix(opt);
2847
2848        while (dir->nr) {
2849                struct dirstat_file *f = dir->files;
2850                int namelen = strlen(f->name);
2851                unsigned long changes;
2852                char *slash;
2853
2854                if (namelen < baselen)
2855                        break;
2856                if (memcmp(f->name, base, baselen))
2857                        break;
2858                slash = strchr(f->name + baselen, '/');
2859                if (slash) {
2860                        int newbaselen = slash + 1 - f->name;
2861                        changes = gather_dirstat(opt, dir, changed, f->name, newbaselen);
2862                        sources++;
2863                } else {
2864                        changes = f->changed;
2865                        dir->files++;
2866                        dir->nr--;
2867                        sources += 2;
2868                }
2869                sum_changes += changes;
2870        }
2871
2872        /*
2873         * We don't report dirstat's for
2874         *  - the top level
2875         *  - or cases where everything came from a single directory
2876         *    under this directory (sources == 1).
2877         */
2878        if (baselen && sources != 1) {
2879                if (sum_changes) {
2880                        int permille = sum_changes * 1000 / changed;
2881                        if (permille >= dir->permille) {
2882                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
2883                                        permille / 10, permille % 10, baselen, base);
2884                                if (!dir->cumulative)
2885                                        return 0;
2886                        }
2887                }
2888        }
2889        return sum_changes;
2890}
2891
2892static int dirstat_compare(const void *_a, const void *_b)
2893{
2894        const struct dirstat_file *a = _a;
2895        const struct dirstat_file *b = _b;
2896        return strcmp(a->name, b->name);
2897}
2898
2899static void show_dirstat(struct diff_options *options)
2900{
2901        int i;
2902        unsigned long changed;
2903        struct dirstat_dir dir;
2904        struct diff_queue_struct *q = &diff_queued_diff;
2905
2906        dir.files = NULL;
2907        dir.alloc = 0;
2908        dir.nr = 0;
2909        dir.permille = options->dirstat_permille;
2910        dir.cumulative = options->flags.dirstat_cumulative;
2911
2912        changed = 0;
2913        for (i = 0; i < q->nr; i++) {
2914                struct diff_filepair *p = q->queue[i];
2915                const char *name;
2916                unsigned long copied, added, damage;
2917                int content_changed;
2918
2919                name = p->two->path ? p->two->path : p->one->path;
2920
2921                if (p->one->oid_valid && p->two->oid_valid)
2922                        content_changed = oidcmp(&p->one->oid, &p->two->oid);
2923                else
2924                        content_changed = 1;
2925
2926                if (!content_changed) {
2927                        /*
2928                         * The SHA1 has not changed, so pre-/post-content is
2929                         * identical. We can therefore skip looking at the
2930                         * file contents altogether.
2931                         */
2932                        damage = 0;
2933                        goto found_damage;
2934                }
2935
2936                if (options->flags.dirstat_by_file) {
2937                        /*
2938                         * In --dirstat-by-file mode, we don't really need to
2939                         * look at the actual file contents at all.
2940                         * The fact that the SHA1 changed is enough for us to
2941                         * add this file to the list of results
2942                         * (with each file contributing equal damage).
2943                         */
2944                        damage = 1;
2945                        goto found_damage;
2946                }
2947
2948                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
2949                        diff_populate_filespec(p->one, 0);
2950                        diff_populate_filespec(p->two, 0);
2951                        diffcore_count_changes(p->one, p->two, NULL, NULL,
2952                                               &copied, &added);
2953                        diff_free_filespec_data(p->one);
2954                        diff_free_filespec_data(p->two);
2955                } else if (DIFF_FILE_VALID(p->one)) {
2956                        diff_populate_filespec(p->one, CHECK_SIZE_ONLY);
2957                        copied = added = 0;
2958                        diff_free_filespec_data(p->one);
2959                } else if (DIFF_FILE_VALID(p->two)) {
2960                        diff_populate_filespec(p->two, CHECK_SIZE_ONLY);
2961                        copied = 0;
2962                        added = p->two->size;
2963                        diff_free_filespec_data(p->two);
2964                } else
2965                        continue;
2966
2967                /*
2968                 * Original minus copied is the removed material,
2969                 * added is the new material.  They are both damages
2970                 * made to the preimage.
2971                 * If the resulting damage is zero, we know that
2972                 * diffcore_count_changes() considers the two entries to
2973                 * be identical, but since content_changed is true, we
2974                 * know that there must have been _some_ kind of change,
2975                 * so we force all entries to have damage > 0.
2976                 */
2977                damage = (p->one->size - copied) + added;
2978                if (!damage)
2979                        damage = 1;
2980
2981found_damage:
2982                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
2983                dir.files[dir.nr].name = name;
2984                dir.files[dir.nr].changed = damage;
2985                changed += damage;
2986                dir.nr++;
2987        }
2988
2989        /* This can happen even with many files, if everything was renames */
2990        if (!changed)
2991                return;
2992
2993        /* Show all directories with more than x% of the changes */
2994        QSORT(dir.files, dir.nr, dirstat_compare);
2995        gather_dirstat(options, &dir, changed, "", 0);
2996}
2997
2998static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
2999{
3000        int i;
3001        unsigned long changed;
3002        struct dirstat_dir dir;
3003
3004        if (data->nr == 0)
3005                return;
3006
3007        dir.files = NULL;
3008        dir.alloc = 0;
3009        dir.nr = 0;
3010        dir.permille = options->dirstat_permille;
3011        dir.cumulative = options->flags.dirstat_cumulative;
3012
3013        changed = 0;
3014        for (i = 0; i < data->nr; i++) {
3015                struct diffstat_file *file = data->files[i];
3016                unsigned long damage = file->added + file->deleted;
3017                if (file->is_binary)
3018                        /*
3019                         * binary files counts bytes, not lines. Must find some
3020                         * way to normalize binary bytes vs. textual lines.
3021                         * The following heuristic assumes that there are 64
3022                         * bytes per "line".
3023                         * This is stupid and ugly, but very cheap...
3024                         */
3025                        damage = DIV_ROUND_UP(damage, 64);
3026                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
3027                dir.files[dir.nr].name = file->name;
3028                dir.files[dir.nr].changed = damage;
3029                changed += damage;
3030                dir.nr++;
3031        }
3032
3033        /* This can happen even with many files, if everything was renames */
3034        if (!changed)
3035                return;
3036
3037        /* Show all directories with more than x% of the changes */
3038        QSORT(dir.files, dir.nr, dirstat_compare);
3039        gather_dirstat(options, &dir, changed, "", 0);
3040}
3041
3042static void free_diffstat_info(struct diffstat_t *diffstat)
3043{
3044        int i;
3045        for (i = 0; i < diffstat->nr; i++) {
3046                struct diffstat_file *f = diffstat->files[i];
3047                free(f->print_name);
3048                free(f->name);
3049                free(f->from_name);
3050                free(f);
3051        }
3052        free(diffstat->files);
3053}
3054
3055struct checkdiff_t {
3056        const char *filename;
3057        int lineno;
3058        int conflict_marker_size;
3059        struct diff_options *o;
3060        unsigned ws_rule;
3061        unsigned status;
3062};
3063
3064static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
3065{
3066        char firstchar;
3067        int cnt;
3068
3069        if (len < marker_size + 1)
3070                return 0;
3071        firstchar = line[0];
3072        switch (firstchar) {
3073        case '=': case '>': case '<': case '|':
3074                break;
3075        default:
3076                return 0;
3077        }
3078        for (cnt = 1; cnt < marker_size; cnt++)
3079                if (line[cnt] != firstchar)
3080                        return 0;
3081        /* line[1] thru line[marker_size-1] are same as firstchar */
3082        if (len < marker_size + 1 || !isspace(line[marker_size]))
3083                return 0;
3084        return 1;
3085}
3086
3087static void checkdiff_consume(void *priv, char *line, unsigned long len)
3088{
3089        struct checkdiff_t *data = priv;
3090        int marker_size = data->conflict_marker_size;
3091        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
3092        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
3093        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
3094        char *err;
3095        const char *line_prefix;
3096
3097        assert(data->o);
3098        line_prefix = diff_line_prefix(data->o);
3099
3100        if (line[0] == '+') {
3101                unsigned bad;
3102                data->lineno++;
3103                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
3104                        data->status |= 1;
3105                        fprintf(data->o->file,
3106                                "%s%s:%d: leftover conflict marker\n",
3107                                line_prefix, data->filename, data->lineno);
3108                }
3109                bad = ws_check(line + 1, len - 1, data->ws_rule);
3110                if (!bad)
3111                        return;
3112                data->status |= bad;
3113                err = whitespace_error_string(bad);
3114                fprintf(data->o->file, "%s%s:%d: %s.\n",
3115                        line_prefix, data->filename, data->lineno, err);
3116                free(err);
3117                emit_line(data->o, set, reset, line, 1);
3118                ws_check_emit(line + 1, len - 1, data->ws_rule,
3119                              data->o->file, set, reset, ws);
3120        } else if (line[0] == ' ') {
3121                data->lineno++;
3122        } else if (line[0] == '@') {
3123                char *plus = strchr(line, '+');
3124                if (plus)
3125                        data->lineno = strtol(plus, NULL, 10) - 1;
3126                else
3127                        die("invalid diff");
3128        }
3129}
3130
3131static unsigned char *deflate_it(char *data,
3132                                 unsigned long size,
3133                                 unsigned long *result_size)
3134{
3135        int bound;
3136        unsigned char *deflated;
3137        git_zstream stream;
3138
3139        git_deflate_init(&stream, zlib_compression_level);
3140        bound = git_deflate_bound(&stream, size);
3141        deflated = xmalloc(bound);
3142        stream.next_out = deflated;
3143        stream.avail_out = bound;
3144
3145        stream.next_in = (unsigned char *)data;
3146        stream.avail_in = size;
3147        while (git_deflate(&stream, Z_FINISH) == Z_OK)
3148                ; /* nothing */
3149        git_deflate_end(&stream);
3150        *result_size = stream.total_out;
3151        return deflated;
3152}
3153
3154static void emit_binary_diff_body(struct diff_options *o,
3155                                  mmfile_t *one, mmfile_t *two)
3156{
3157        void *cp;
3158        void *delta;
3159        void *deflated;
3160        void *data;
3161        unsigned long orig_size;
3162        unsigned long delta_size;
3163        unsigned long deflate_size;
3164        unsigned long data_size;
3165
3166        /* We could do deflated delta, or we could do just deflated two,
3167         * whichever is smaller.
3168         */
3169        delta = NULL;
3170        deflated = deflate_it(two->ptr, two->size, &deflate_size);
3171        if (one->size && two->size) {
3172                delta = diff_delta(one->ptr, one->size,
3173                                   two->ptr, two->size,
3174                                   &delta_size, deflate_size);
3175                if (delta) {
3176                        void *to_free = delta;
3177                        orig_size = delta_size;
3178                        delta = deflate_it(delta, delta_size, &delta_size);
3179                        free(to_free);
3180                }
3181        }
3182
3183        if (delta && delta_size < deflate_size) {
3184                char *s = xstrfmt("%lu", orig_size);
3185                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
3186                                 s, strlen(s), 0);
3187                free(s);
3188                free(deflated);
3189                data = delta;
3190                data_size = delta_size;
3191        } else {
3192                char *s = xstrfmt("%lu", two->size);
3193                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
3194                                 s, strlen(s), 0);
3195                free(s);
3196                free(delta);
3197                data = deflated;
3198                data_size = deflate_size;
3199        }
3200
3201        /* emit data encoded in base85 */
3202        cp = data;
3203        while (data_size) {
3204                int len;
3205                int bytes = (52 < data_size) ? 52 : data_size;
3206                char line[71];
3207                data_size -= bytes;
3208                if (bytes <= 26)
3209                        line[0] = bytes + 'A' - 1;
3210                else
3211                        line[0] = bytes - 26 + 'a' - 1;
3212                encode_85(line + 1, cp, bytes);
3213                cp = (char *) cp + bytes;
3214
3215                len = strlen(line);
3216                line[len++] = '\n';
3217                line[len] = '\0';
3218
3219                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_BODY,
3220                                 line, len, 0);
3221        }
3222        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_FOOTER, NULL, 0, 0);
3223        free(data);
3224}
3225
3226static void emit_binary_diff(struct diff_options *o,
3227                             mmfile_t *one, mmfile_t *two)
3228{
3229        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER, NULL, 0, 0);
3230        emit_binary_diff_body(o, one, two);
3231        emit_binary_diff_body(o, two, one);
3232}
3233
3234int diff_filespec_is_binary(struct diff_filespec *one)
3235{
3236        if (one->is_binary == -1) {
3237                diff_filespec_load_driver(one);
3238                if (one->driver->binary != -1)
3239                        one->is_binary = one->driver->binary;
3240                else {
3241                        if (!one->data && DIFF_FILE_VALID(one))
3242                                diff_populate_filespec(one, CHECK_BINARY);
3243                        if (one->is_binary == -1 && one->data)
3244                                one->is_binary = buffer_is_binary(one->data,
3245                                                one->size);
3246                        if (one->is_binary == -1)
3247                                one->is_binary = 0;
3248                }
3249        }
3250        return one->is_binary;
3251}
3252
3253static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
3254{
3255        diff_filespec_load_driver(one);
3256        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
3257}
3258
3259void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
3260{
3261        if (!options->a_prefix)
3262                options->a_prefix = a;
3263        if (!options->b_prefix)
3264                options->b_prefix = b;
3265}
3266
3267struct userdiff_driver *get_textconv(struct diff_filespec *one)
3268{
3269        if (!DIFF_FILE_VALID(one))
3270                return NULL;
3271
3272        diff_filespec_load_driver(one);
3273        return userdiff_get_textconv(one->driver);
3274}
3275
3276static void builtin_diff(const char *name_a,
3277                         const char *name_b,
3278                         struct diff_filespec *one,
3279                         struct diff_filespec *two,
3280                         const char *xfrm_msg,
3281                         int must_show_header,
3282                         struct diff_options *o,
3283                         int complete_rewrite)
3284{
3285        mmfile_t mf1, mf2;
3286        const char *lbl[2];
3287        char *a_one, *b_two;
3288        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
3289        const char *reset = diff_get_color_opt(o, DIFF_RESET);
3290        const char *a_prefix, *b_prefix;
3291        struct userdiff_driver *textconv_one = NULL;
3292        struct userdiff_driver *textconv_two = NULL;
3293        struct strbuf header = STRBUF_INIT;
3294        const char *line_prefix = diff_line_prefix(o);
3295
3296        diff_set_mnemonic_prefix(o, "a/", "b/");
3297        if (o->flags.reverse_diff) {
3298                a_prefix = o->b_prefix;
3299                b_prefix = o->a_prefix;
3300        } else {
3301                a_prefix = o->a_prefix;
3302                b_prefix = o->b_prefix;
3303        }
3304
3305        if (o->submodule_format == DIFF_SUBMODULE_LOG &&
3306            (!one->mode || S_ISGITLINK(one->mode)) &&
3307            (!two->mode || S_ISGITLINK(two->mode))) {
3308                show_submodule_summary(o, one->path ? one->path : two->path,
3309                                &one->oid, &two->oid,
3310                                two->dirty_submodule);
3311                return;
3312        } else if (o->submodule_format == DIFF_SUBMODULE_INLINE_DIFF &&
3313                   (!one->mode || S_ISGITLINK(one->mode)) &&
3314                   (!two->mode || S_ISGITLINK(two->mode))) {
3315                show_submodule_inline_diff(o, one->path ? one->path : two->path,
3316                                &one->oid, &two->oid,
3317                                two->dirty_submodule);
3318                return;
3319        }
3320
3321        if (o->flags.allow_textconv) {
3322                textconv_one = get_textconv(one);
3323                textconv_two = get_textconv(two);
3324        }
3325
3326        /* Never use a non-valid filename anywhere if at all possible */
3327        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
3328        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
3329
3330        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
3331        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
3332        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
3333        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
3334        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
3335        if (lbl[0][0] == '/') {
3336                /* /dev/null */
3337                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
3338                if (xfrm_msg)
3339                        strbuf_addstr(&header, xfrm_msg);
3340                must_show_header = 1;
3341        }
3342        else if (lbl[1][0] == '/') {
3343                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
3344                if (xfrm_msg)
3345                        strbuf_addstr(&header, xfrm_msg);
3346                must_show_header = 1;
3347        }
3348        else {
3349                if (one->mode != two->mode) {
3350                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
3351                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
3352                        must_show_header = 1;
3353                }
3354                if (xfrm_msg)
3355                        strbuf_addstr(&header, xfrm_msg);
3356
3357                /*
3358                 * we do not run diff between different kind
3359                 * of objects.
3360                 */
3361                if ((one->mode ^ two->mode) & S_IFMT)
3362                        goto free_ab_and_return;
3363                if (complete_rewrite &&
3364                    (textconv_one || !diff_filespec_is_binary(one)) &&
3365                    (textconv_two || !diff_filespec_is_binary(two))) {
3366                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3367                                         header.buf, header.len, 0);
3368                        strbuf_reset(&header);
3369                        emit_rewrite_diff(name_a, name_b, one, two,
3370                                                textconv_one, textconv_two, o);
3371                        o->found_changes = 1;
3372                        goto free_ab_and_return;
3373                }
3374        }
3375
3376        if (o->irreversible_delete && lbl[1][0] == '/') {
3377                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf,
3378                                 header.len, 0);
3379                strbuf_reset(&header);
3380                goto free_ab_and_return;
3381        } else if (!o->flags.text &&
3382            ( (!textconv_one && diff_filespec_is_binary(one)) ||
3383              (!textconv_two && diff_filespec_is_binary(two)) )) {
3384                struct strbuf sb = STRBUF_INIT;
3385                if (!one->data && !two->data &&
3386                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
3387                    !o->flags.binary) {
3388                        if (!oidcmp(&one->oid, &two->oid)) {
3389                                if (must_show_header)
3390                                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3391                                                         header.buf, header.len,
3392                                                         0);
3393                                goto free_ab_and_return;
3394                        }
3395                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3396                                         header.buf, header.len, 0);
3397                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3398                                    diff_line_prefix(o), lbl[0], lbl[1]);
3399                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3400                                         sb.buf, sb.len, 0);
3401                        strbuf_release(&sb);
3402                        goto free_ab_and_return;
3403                }
3404                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3405                        die("unable to read files to diff");
3406                /* Quite common confusing case */
3407                if (mf1.size == mf2.size &&
3408                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
3409                        if (must_show_header)
3410                                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3411                                                 header.buf, header.len, 0);
3412                        goto free_ab_and_return;
3413                }
3414                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf, header.len, 0);
3415                strbuf_reset(&header);
3416                if (o->flags.binary)
3417                        emit_binary_diff(o, &mf1, &mf2);
3418                else {
3419                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3420                                    diff_line_prefix(o), lbl[0], lbl[1]);
3421                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3422                                         sb.buf, sb.len, 0);
3423                        strbuf_release(&sb);
3424                }
3425                o->found_changes = 1;
3426        } else {
3427                /* Crazy xdl interfaces.. */
3428                const char *diffopts = getenv("GIT_DIFF_OPTS");
3429                const char *v;
3430                xpparam_t xpp;
3431                xdemitconf_t xecfg;
3432                struct emit_callback ecbdata;
3433                const struct userdiff_funcname *pe;
3434
3435                if (must_show_header) {
3436                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3437                                         header.buf, header.len, 0);
3438                        strbuf_reset(&header);
3439                }
3440
3441                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
3442                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
3443
3444                pe = diff_funcname_pattern(one);
3445                if (!pe)
3446                        pe = diff_funcname_pattern(two);
3447
3448                memset(&xpp, 0, sizeof(xpp));
3449                memset(&xecfg, 0, sizeof(xecfg));
3450                memset(&ecbdata, 0, sizeof(ecbdata));
3451                if (o->flags.suppress_diff_headers)
3452                        lbl[0] = NULL;
3453                ecbdata.label_path = lbl;
3454                ecbdata.color_diff = want_color(o->use_color);
3455                ecbdata.ws_rule = whitespace_rule(name_b);
3456                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
3457                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3458                ecbdata.opt = o;
3459                if (header.len && !o->flags.suppress_diff_headers)
3460                        ecbdata.header = &header;
3461                xpp.flags = o->xdl_opts;
3462                xpp.anchors = o->anchors;
3463                xpp.anchors_nr = o->anchors_nr;
3464                xecfg.ctxlen = o->context;
3465                xecfg.interhunkctxlen = o->interhunkcontext;
3466                xecfg.flags = XDL_EMIT_FUNCNAMES;
3467                if (o->flags.funccontext)
3468                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
3469                if (pe)
3470                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
3471                if (!diffopts)
3472                        ;
3473                else if (skip_prefix(diffopts, "--unified=", &v))
3474                        xecfg.ctxlen = strtoul(v, NULL, 10);
3475                else if (skip_prefix(diffopts, "-u", &v))
3476                        xecfg.ctxlen = strtoul(v, NULL, 10);
3477                if (o->word_diff)
3478                        init_diff_words_data(&ecbdata, o, one, two);
3479                if (xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
3480                                  &xpp, &xecfg))
3481                        die("unable to generate diff for %s", one->path);
3482                if (o->word_diff)
3483                        free_diff_words_data(&ecbdata);
3484                if (textconv_one)
3485                        free(mf1.ptr);
3486                if (textconv_two)
3487                        free(mf2.ptr);
3488                xdiff_clear_find_func(&xecfg);
3489        }
3490
3491 free_ab_and_return:
3492        strbuf_release(&header);
3493        diff_free_filespec_data(one);
3494        diff_free_filespec_data(two);
3495        free(a_one);
3496        free(b_two);
3497        return;
3498}
3499
3500static char *get_compact_summary(const struct diff_filepair *p, int is_renamed)
3501{
3502        if (!is_renamed) {
3503                if (p->status == DIFF_STATUS_ADDED) {
3504                        if (S_ISLNK(p->two->mode))
3505                                return "new +l";
3506                        else if ((p->two->mode & 0777) == 0755)
3507                                return "new +x";
3508                        else
3509                                return "new";
3510                } else if (p->status == DIFF_STATUS_DELETED)
3511                        return "gone";
3512        }
3513        if (S_ISLNK(p->one->mode) && !S_ISLNK(p->two->mode))
3514                return "mode -l";
3515        else if (!S_ISLNK(p->one->mode) && S_ISLNK(p->two->mode))
3516                return "mode +l";
3517        else if ((p->one->mode & 0777) == 0644 &&
3518                 (p->two->mode & 0777) == 0755)
3519                return "mode +x";
3520        else if ((p->one->mode & 0777) == 0755 &&
3521                 (p->two->mode & 0777) == 0644)
3522                return "mode -x";
3523        return NULL;
3524}
3525
3526static void builtin_diffstat(const char *name_a, const char *name_b,
3527                             struct diff_filespec *one,
3528                             struct diff_filespec *two,
3529                             struct diffstat_t *diffstat,
3530                             struct diff_options *o,
3531                             struct diff_filepair *p)
3532{
3533        mmfile_t mf1, mf2;
3534        struct diffstat_file *data;
3535        int same_contents;
3536        int complete_rewrite = 0;
3537
3538        if (!DIFF_PAIR_UNMERGED(p)) {
3539                if (p->status == DIFF_STATUS_MODIFIED && p->score)
3540                        complete_rewrite = 1;
3541        }
3542
3543        data = diffstat_add(diffstat, name_a, name_b);
3544        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
3545        if (o->flags.stat_with_summary)
3546                data->comments = get_compact_summary(p, data->is_renamed);
3547
3548        if (!one || !two) {
3549                data->is_unmerged = 1;
3550                return;
3551        }
3552
3553        same_contents = !oidcmp(&one->oid, &two->oid);
3554
3555        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
3556                data->is_binary = 1;
3557                if (same_contents) {
3558                        data->added = 0;
3559                        data->deleted = 0;
3560                } else {
3561                        data->added = diff_filespec_size(two);
3562                        data->deleted = diff_filespec_size(one);
3563                }
3564        }
3565
3566        else if (complete_rewrite) {
3567                diff_populate_filespec(one, 0);
3568                diff_populate_filespec(two, 0);
3569                data->deleted = count_lines(one->data, one->size);
3570                data->added = count_lines(two->data, two->size);
3571        }
3572
3573        else if (!same_contents) {
3574                /* Crazy xdl interfaces.. */
3575                xpparam_t xpp;
3576                xdemitconf_t xecfg;
3577
3578                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3579                        die("unable to read files to diff");
3580
3581                memset(&xpp, 0, sizeof(xpp));
3582                memset(&xecfg, 0, sizeof(xecfg));
3583                xpp.flags = o->xdl_opts;
3584                xpp.anchors = o->anchors;
3585                xpp.anchors_nr = o->anchors_nr;
3586                xecfg.ctxlen = o->context;
3587                xecfg.interhunkctxlen = o->interhunkcontext;
3588                if (xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
3589                                  &xpp, &xecfg))
3590                        die("unable to generate diffstat for %s", one->path);
3591        }
3592
3593        diff_free_filespec_data(one);
3594        diff_free_filespec_data(two);
3595}
3596
3597static void builtin_checkdiff(const char *name_a, const char *name_b,
3598                              const char *attr_path,
3599                              struct diff_filespec *one,
3600                              struct diff_filespec *two,
3601                              struct diff_options *o)
3602{
3603        mmfile_t mf1, mf2;
3604        struct checkdiff_t data;
3605
3606        if (!two)
3607                return;
3608
3609        memset(&data, 0, sizeof(data));
3610        data.filename = name_b ? name_b : name_a;
3611        data.lineno = 0;
3612        data.o = o;
3613        data.ws_rule = whitespace_rule(attr_path);
3614        data.conflict_marker_size = ll_merge_marker_size(attr_path);
3615
3616        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3617                die("unable to read files to diff");
3618
3619        /*
3620         * All the other codepaths check both sides, but not checking
3621         * the "old" side here is deliberate.  We are checking the newly
3622         * introduced changes, and as long as the "new" side is text, we
3623         * can and should check what it introduces.
3624         */
3625        if (diff_filespec_is_binary(two))
3626                goto free_and_return;
3627        else {
3628                /* Crazy xdl interfaces.. */
3629                xpparam_t xpp;
3630                xdemitconf_t xecfg;
3631
3632                memset(&xpp, 0, sizeof(xpp));
3633                memset(&xecfg, 0, sizeof(xecfg));
3634                xecfg.ctxlen = 1; /* at least one context line */
3635                xpp.flags = 0;
3636                if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
3637                                  &xpp, &xecfg))
3638                        die("unable to generate checkdiff for %s", one->path);
3639
3640                if (data.ws_rule & WS_BLANK_AT_EOF) {
3641                        struct emit_callback ecbdata;
3642                        int blank_at_eof;
3643
3644                        ecbdata.ws_rule = data.ws_rule;
3645                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3646                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
3647
3648                        if (blank_at_eof) {
3649                                static char *err;
3650                                if (!err)
3651                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
3652                                fprintf(o->file, "%s:%d: %s.\n",
3653                                        data.filename, blank_at_eof, err);
3654                                data.status = 1; /* report errors */
3655                        }
3656                }
3657        }
3658 free_and_return:
3659        diff_free_filespec_data(one);
3660        diff_free_filespec_data(two);
3661        if (data.status)
3662                o->flags.check_failed = 1;
3663}
3664
3665struct diff_filespec *alloc_filespec(const char *path)
3666{
3667        struct diff_filespec *spec;
3668
3669        FLEXPTR_ALLOC_STR(spec, path, path);
3670        spec->count = 1;
3671        spec->is_binary = -1;
3672        return spec;
3673}
3674
3675void free_filespec(struct diff_filespec *spec)
3676{
3677        if (!--spec->count) {
3678                diff_free_filespec_data(spec);
3679                free(spec);
3680        }
3681}
3682
3683void fill_filespec(struct diff_filespec *spec, const struct object_id *oid,
3684                   int oid_valid, unsigned short mode)
3685{
3686        if (mode) {
3687                spec->mode = canon_mode(mode);
3688                oidcpy(&spec->oid, oid);
3689                spec->oid_valid = oid_valid;
3690        }
3691}
3692
3693/*
3694 * Given a name and sha1 pair, if the index tells us the file in
3695 * the work tree has that object contents, return true, so that
3696 * prepare_temp_file() does not have to inflate and extract.
3697 */
3698static int reuse_worktree_file(const char *name, const struct object_id *oid, int want_file)
3699{
3700        const struct cache_entry *ce;
3701        struct stat st;
3702        int pos, len;
3703
3704        /*
3705         * We do not read the cache ourselves here, because the
3706         * benchmark with my previous version that always reads cache
3707         * shows that it makes things worse for diff-tree comparing
3708         * two linux-2.6 kernel trees in an already checked out work
3709         * tree.  This is because most diff-tree comparisons deal with
3710         * only a small number of files, while reading the cache is
3711         * expensive for a large project, and its cost outweighs the
3712         * savings we get by not inflating the object to a temporary
3713         * file.  Practically, this code only helps when we are used
3714         * by diff-cache --cached, which does read the cache before
3715         * calling us.
3716         */
3717        if (!active_cache)
3718                return 0;
3719
3720        /* We want to avoid the working directory if our caller
3721         * doesn't need the data in a normal file, this system
3722         * is rather slow with its stat/open/mmap/close syscalls,
3723         * and the object is contained in a pack file.  The pack
3724         * is probably already open and will be faster to obtain
3725         * the data through than the working directory.  Loose
3726         * objects however would tend to be slower as they need
3727         * to be individually opened and inflated.
3728         */
3729        if (!FAST_WORKING_DIRECTORY && !want_file && has_object_pack(oid))
3730                return 0;
3731
3732        /*
3733         * Similarly, if we'd have to convert the file contents anyway, that
3734         * makes the optimization not worthwhile.
3735         */
3736        if (!want_file && would_convert_to_git(&the_index, name))
3737                return 0;
3738
3739        len = strlen(name);
3740        pos = cache_name_pos(name, len);
3741        if (pos < 0)
3742                return 0;
3743        ce = active_cache[pos];
3744
3745        /*
3746         * This is not the sha1 we are looking for, or
3747         * unreusable because it is not a regular file.
3748         */
3749        if (oidcmp(oid, &ce->oid) || !S_ISREG(ce->ce_mode))
3750                return 0;
3751
3752        /*
3753         * If ce is marked as "assume unchanged", there is no
3754         * guarantee that work tree matches what we are looking for.
3755         */
3756        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
3757                return 0;
3758
3759        /*
3760         * If ce matches the file in the work tree, we can reuse it.
3761         */
3762        if (ce_uptodate(ce) ||
3763            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
3764                return 1;
3765
3766        return 0;
3767}
3768
3769static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
3770{
3771        struct strbuf buf = STRBUF_INIT;
3772        char *dirty = "";
3773
3774        /* Are we looking at the work tree? */
3775        if (s->dirty_submodule)
3776                dirty = "-dirty";
3777
3778        strbuf_addf(&buf, "Subproject commit %s%s\n",
3779                    oid_to_hex(&s->oid), dirty);
3780        s->size = buf.len;
3781        if (size_only) {
3782                s->data = NULL;
3783                strbuf_release(&buf);
3784        } else {
3785                s->data = strbuf_detach(&buf, NULL);
3786                s->should_free = 1;
3787        }
3788        return 0;
3789}
3790
3791/*
3792 * While doing rename detection and pickaxe operation, we may need to
3793 * grab the data for the blob (or file) for our own in-core comparison.
3794 * diff_filespec has data and size fields for this purpose.
3795 */
3796int diff_populate_filespec(struct diff_filespec *s, unsigned int flags)
3797{
3798        int size_only = flags & CHECK_SIZE_ONLY;
3799        int err = 0;
3800        int conv_flags = global_conv_flags_eol;
3801        /*
3802         * demote FAIL to WARN to allow inspecting the situation
3803         * instead of refusing.
3804         */
3805        if (conv_flags & CONV_EOL_RNDTRP_DIE)
3806                conv_flags = CONV_EOL_RNDTRP_WARN;
3807
3808        if (!DIFF_FILE_VALID(s))
3809                die("internal error: asking to populate invalid file.");
3810        if (S_ISDIR(s->mode))
3811                return -1;
3812
3813        if (s->data)
3814                return 0;
3815
3816        if (size_only && 0 < s->size)
3817                return 0;
3818
3819        if (S_ISGITLINK(s->mode))
3820                return diff_populate_gitlink(s, size_only);
3821
3822        if (!s->oid_valid ||
3823            reuse_worktree_file(s->path, &s->oid, 0)) {
3824                struct strbuf buf = STRBUF_INIT;
3825                struct stat st;
3826                int fd;
3827
3828                if (lstat(s->path, &st) < 0) {
3829                err_empty:
3830                        err = -1;
3831                empty:
3832                        s->data = (char *)"";
3833                        s->size = 0;
3834                        return err;
3835                }
3836                s->size = xsize_t(st.st_size);
3837                if (!s->size)
3838                        goto empty;
3839                if (S_ISLNK(st.st_mode)) {
3840                        struct strbuf sb = STRBUF_INIT;
3841
3842                        if (strbuf_readlink(&sb, s->path, s->size))
3843                                goto err_empty;
3844                        s->size = sb.len;
3845                        s->data = strbuf_detach(&sb, NULL);
3846                        s->should_free = 1;
3847                        return 0;
3848                }
3849
3850                /*
3851                 * Even if the caller would be happy with getting
3852                 * only the size, we cannot return early at this
3853                 * point if the path requires us to run the content
3854                 * conversion.
3855                 */
3856                if (size_only && !would_convert_to_git(&the_index, s->path))
3857                        return 0;
3858
3859                /*
3860                 * Note: this check uses xsize_t(st.st_size) that may
3861                 * not be the true size of the blob after it goes
3862                 * through convert_to_git().  This may not strictly be
3863                 * correct, but the whole point of big_file_threshold
3864                 * and is_binary check being that we want to avoid
3865                 * opening the file and inspecting the contents, this
3866                 * is probably fine.
3867                 */
3868                if ((flags & CHECK_BINARY) &&
3869                    s->size > big_file_threshold && s->is_binary == -1) {
3870                        s->is_binary = 1;
3871                        return 0;
3872                }
3873                fd = open(s->path, O_RDONLY);
3874                if (fd < 0)
3875                        goto err_empty;
3876                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
3877                close(fd);
3878                s->should_munmap = 1;
3879
3880                /*
3881                 * Convert from working tree format to canonical git format
3882                 */
3883                if (convert_to_git(&the_index, s->path, s->data, s->size, &buf, conv_flags)) {
3884                        size_t size = 0;
3885                        munmap(s->data, s->size);
3886                        s->should_munmap = 0;
3887                        s->data = strbuf_detach(&buf, &size);
3888                        s->size = size;
3889                        s->should_free = 1;
3890                }
3891        }
3892        else {
3893                enum object_type type;
3894                if (size_only || (flags & CHECK_BINARY)) {
3895                        type = oid_object_info(the_repository, &s->oid,
3896                                               &s->size);
3897                        if (type < 0)
3898                                die("unable to read %s",
3899                                    oid_to_hex(&s->oid));
3900                        if (size_only)
3901                                return 0;
3902                        if (s->size > big_file_threshold && s->is_binary == -1) {
3903                                s->is_binary = 1;
3904                                return 0;
3905                        }
3906                }
3907                s->data = read_object_file(&s->oid, &type, &s->size);
3908                if (!s->data)
3909                        die("unable to read %s", oid_to_hex(&s->oid));
3910                s->should_free = 1;
3911        }
3912        return 0;
3913}
3914
3915void diff_free_filespec_blob(struct diff_filespec *s)
3916{
3917        if (s->should_free)
3918                free(s->data);
3919        else if (s->should_munmap)
3920                munmap(s->data, s->size);
3921
3922        if (s->should_free || s->should_munmap) {
3923                s->should_free = s->should_munmap = 0;
3924                s->data = NULL;
3925        }
3926}
3927
3928void diff_free_filespec_data(struct diff_filespec *s)
3929{
3930        diff_free_filespec_blob(s);
3931        FREE_AND_NULL(s->cnt_data);
3932}
3933
3934static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
3935                           void *blob,
3936                           unsigned long size,
3937                           const struct object_id *oid,
3938                           int mode)
3939{
3940        struct strbuf buf = STRBUF_INIT;
3941        struct strbuf tempfile = STRBUF_INIT;
3942        char *path_dup = xstrdup(path);
3943        const char *base = basename(path_dup);
3944
3945        /* Generate "XXXXXX_basename.ext" */
3946        strbuf_addstr(&tempfile, "XXXXXX_");
3947        strbuf_addstr(&tempfile, base);
3948
3949        temp->tempfile = mks_tempfile_ts(tempfile.buf, strlen(base) + 1);
3950        if (!temp->tempfile)
3951                die_errno("unable to create temp-file");
3952        if (convert_to_working_tree(path,
3953                        (const char *)blob, (size_t)size, &buf)) {
3954                blob = buf.buf;
3955                size = buf.len;
3956        }
3957        if (write_in_full(temp->tempfile->fd, blob, size) < 0 ||
3958            close_tempfile_gently(temp->tempfile))
3959                die_errno("unable to write temp-file");
3960        temp->name = get_tempfile_path(temp->tempfile);
3961        oid_to_hex_r(temp->hex, oid);
3962        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
3963        strbuf_release(&buf);
3964        strbuf_release(&tempfile);
3965        free(path_dup);
3966}
3967
3968static struct diff_tempfile *prepare_temp_file(const char *name,
3969                struct diff_filespec *one)
3970{
3971        struct diff_tempfile *temp = claim_diff_tempfile();
3972
3973        if (!DIFF_FILE_VALID(one)) {
3974        not_a_valid_file:
3975                /* A '-' entry produces this for file-2, and
3976                 * a '+' entry produces this for file-1.
3977                 */
3978                temp->name = "/dev/null";
3979                xsnprintf(temp->hex, sizeof(temp->hex), ".");
3980                xsnprintf(temp->mode, sizeof(temp->mode), ".");
3981                return temp;
3982        }
3983
3984        if (!S_ISGITLINK(one->mode) &&
3985            (!one->oid_valid ||
3986             reuse_worktree_file(name, &one->oid, 1))) {
3987                struct stat st;
3988                if (lstat(name, &st) < 0) {
3989                        if (errno == ENOENT)
3990                                goto not_a_valid_file;
3991                        die_errno("stat(%s)", name);
3992                }
3993                if (S_ISLNK(st.st_mode)) {
3994                        struct strbuf sb = STRBUF_INIT;
3995                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
3996                                die_errno("readlink(%s)", name);
3997                        prep_temp_blob(name, temp, sb.buf, sb.len,
3998                                       (one->oid_valid ?
3999                                        &one->oid : &null_oid),
4000                                       (one->oid_valid ?
4001                                        one->mode : S_IFLNK));
4002                        strbuf_release(&sb);
4003                }
4004                else {
4005                        /* we can borrow from the file in the work tree */
4006                        temp->name = name;
4007                        if (!one->oid_valid)
4008                                oid_to_hex_r(temp->hex, &null_oid);
4009                        else
4010                                oid_to_hex_r(temp->hex, &one->oid);
4011                        /* Even though we may sometimes borrow the
4012                         * contents from the work tree, we always want
4013                         * one->mode.  mode is trustworthy even when
4014                         * !(one->oid_valid), as long as
4015                         * DIFF_FILE_VALID(one).
4016                         */
4017                        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
4018                }
4019                return temp;
4020        }
4021        else {
4022                if (diff_populate_filespec(one, 0))
4023                        die("cannot read data blob for %s", one->path);
4024                prep_temp_blob(name, temp, one->data, one->size,
4025                               &one->oid, one->mode);
4026        }
4027        return temp;
4028}
4029
4030static void add_external_diff_name(struct argv_array *argv,
4031                                   const char *name,
4032                                   struct diff_filespec *df)
4033{
4034        struct diff_tempfile *temp = prepare_temp_file(name, df);
4035        argv_array_push(argv, temp->name);
4036        argv_array_push(argv, temp->hex);
4037        argv_array_push(argv, temp->mode);
4038}
4039
4040/* An external diff command takes:
4041 *
4042 * diff-cmd name infile1 infile1-sha1 infile1-mode \
4043 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
4044 *
4045 */
4046static void run_external_diff(const char *pgm,
4047                              const char *name,
4048                              const char *other,
4049                              struct diff_filespec *one,
4050                              struct diff_filespec *two,
4051                              const char *xfrm_msg,
4052                              int complete_rewrite,
4053                              struct diff_options *o)
4054{
4055        struct argv_array argv = ARGV_ARRAY_INIT;
4056        struct argv_array env = ARGV_ARRAY_INIT;
4057        struct diff_queue_struct *q = &diff_queued_diff;
4058
4059        argv_array_push(&argv, pgm);
4060        argv_array_push(&argv, name);
4061
4062        if (one && two) {
4063                add_external_diff_name(&argv, name, one);
4064                if (!other)
4065                        add_external_diff_name(&argv, name, two);
4066                else {
4067                        add_external_diff_name(&argv, other, two);
4068                        argv_array_push(&argv, other);
4069                        argv_array_push(&argv, xfrm_msg);
4070                }
4071        }
4072
4073        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
4074        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
4075
4076        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
4077                die(_("external diff died, stopping at %s"), name);
4078
4079        remove_tempfile();
4080        argv_array_clear(&argv);
4081        argv_array_clear(&env);
4082}
4083
4084static int similarity_index(struct diff_filepair *p)
4085{
4086        return p->score * 100 / MAX_SCORE;
4087}
4088
4089static const char *diff_abbrev_oid(const struct object_id *oid, int abbrev)
4090{
4091        if (startup_info->have_repository)
4092                return find_unique_abbrev(oid, abbrev);
4093        else {
4094                char *hex = oid_to_hex(oid);
4095                if (abbrev < 0)
4096                        abbrev = FALLBACK_DEFAULT_ABBREV;
4097                if (abbrev > the_hash_algo->hexsz)
4098                        BUG("oid abbreviation out of range: %d", abbrev);
4099                if (abbrev)
4100                        hex[abbrev] = '\0';
4101                return hex;
4102        }
4103}
4104
4105static void fill_metainfo(struct strbuf *msg,
4106                          const char *name,
4107                          const char *other,
4108                          struct diff_filespec *one,
4109                          struct diff_filespec *two,
4110                          struct diff_options *o,
4111                          struct diff_filepair *p,
4112                          int *must_show_header,
4113                          int use_color)
4114{
4115        const char *set = diff_get_color(use_color, DIFF_METAINFO);
4116        const char *reset = diff_get_color(use_color, DIFF_RESET);
4117        const char *line_prefix = diff_line_prefix(o);
4118
4119        *must_show_header = 1;
4120        strbuf_init(msg, PATH_MAX * 2 + 300);
4121        switch (p->status) {
4122        case DIFF_STATUS_COPIED:
4123                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4124                            line_prefix, set, similarity_index(p));
4125                strbuf_addf(msg, "%s\n%s%scopy from ",
4126                            reset,  line_prefix, set);
4127                quote_c_style(name, msg, NULL, 0);
4128                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
4129                quote_c_style(other, msg, NULL, 0);
4130                strbuf_addf(msg, "%s\n", reset);
4131                break;
4132        case DIFF_STATUS_RENAMED:
4133                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4134                            line_prefix, set, similarity_index(p));
4135                strbuf_addf(msg, "%s\n%s%srename from ",
4136                            reset, line_prefix, set);
4137                quote_c_style(name, msg, NULL, 0);
4138                strbuf_addf(msg, "%s\n%s%srename to ",
4139                            reset, line_prefix, set);
4140                quote_c_style(other, msg, NULL, 0);
4141                strbuf_addf(msg, "%s\n", reset);
4142                break;
4143        case DIFF_STATUS_MODIFIED:
4144                if (p->score) {
4145                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
4146                                    line_prefix,
4147                                    set, similarity_index(p), reset);
4148                        break;
4149                }
4150                /* fallthru */
4151        default:
4152                *must_show_header = 0;
4153        }
4154        if (one && two && oidcmp(&one->oid, &two->oid)) {
4155                const unsigned hexsz = the_hash_algo->hexsz;
4156                int abbrev = o->flags.full_index ? hexsz : DEFAULT_ABBREV;
4157
4158                if (o->flags.binary) {
4159                        mmfile_t mf;
4160                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
4161                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
4162                                abbrev = hexsz;
4163                }
4164                strbuf_addf(msg, "%s%sindex %s..%s", line_prefix, set,
4165                            diff_abbrev_oid(&one->oid, abbrev),
4166                            diff_abbrev_oid(&two->oid, abbrev));
4167                if (one->mode == two->mode)
4168                        strbuf_addf(msg, " %06o", one->mode);
4169                strbuf_addf(msg, "%s\n", reset);
4170        }
4171}
4172
4173static void run_diff_cmd(const char *pgm,
4174                         const char *name,
4175                         const char *other,
4176                         const char *attr_path,
4177                         struct diff_filespec *one,
4178                         struct diff_filespec *two,
4179                         struct strbuf *msg,
4180                         struct diff_options *o,
4181                         struct diff_filepair *p)
4182{
4183        const char *xfrm_msg = NULL;
4184        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
4185        int must_show_header = 0;
4186
4187
4188        if (o->flags.allow_external) {
4189                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
4190                if (drv && drv->external)
4191                        pgm = drv->external;
4192        }
4193
4194        if (msg) {
4195                /*
4196                 * don't use colors when the header is intended for an
4197                 * external diff driver
4198                 */
4199                fill_metainfo(msg, name, other, one, two, o, p,
4200                              &must_show_header,
4201                              want_color(o->use_color) && !pgm);
4202                xfrm_msg = msg->len ? msg->buf : NULL;
4203        }
4204
4205        if (pgm) {
4206                run_external_diff(pgm, name, other, one, two, xfrm_msg,
4207                                  complete_rewrite, o);
4208                return;
4209        }
4210        if (one && two)
4211                builtin_diff(name, other ? other : name,
4212                             one, two, xfrm_msg, must_show_header,
4213                             o, complete_rewrite);
4214        else
4215                fprintf(o->file, "* Unmerged path %s\n", name);
4216}
4217
4218static void diff_fill_oid_info(struct diff_filespec *one)
4219{
4220        if (DIFF_FILE_VALID(one)) {
4221                if (!one->oid_valid) {
4222                        struct stat st;
4223                        if (one->is_stdin) {
4224                                oidclr(&one->oid);
4225                                return;
4226                        }
4227                        if (lstat(one->path, &st) < 0)
4228                                die_errno("stat '%s'", one->path);
4229                        if (index_path(&one->oid, one->path, &st, 0))
4230                                die("cannot hash %s", one->path);
4231                }
4232        }
4233        else
4234                oidclr(&one->oid);
4235}
4236
4237static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
4238{
4239        /* Strip the prefix but do not molest /dev/null and absolute paths */
4240        if (*namep && **namep != '/') {
4241                *namep += prefix_length;
4242                if (**namep == '/')
4243                        ++*namep;
4244        }
4245        if (*otherp && **otherp != '/') {
4246                *otherp += prefix_length;
4247                if (**otherp == '/')
4248                        ++*otherp;
4249        }
4250}
4251
4252static void run_diff(struct diff_filepair *p, struct diff_options *o)
4253{
4254        const char *pgm = external_diff();
4255        struct strbuf msg;
4256        struct diff_filespec *one = p->one;
4257        struct diff_filespec *two = p->two;
4258        const char *name;
4259        const char *other;
4260        const char *attr_path;
4261
4262        name  = one->path;
4263        other = (strcmp(name, two->path) ? two->path : NULL);
4264        attr_path = name;
4265        if (o->prefix_length)
4266                strip_prefix(o->prefix_length, &name, &other);
4267
4268        if (!o->flags.allow_external)
4269                pgm = NULL;
4270
4271        if (DIFF_PAIR_UNMERGED(p)) {
4272                run_diff_cmd(pgm, name, NULL, attr_path,
4273                             NULL, NULL, NULL, o, p);
4274                return;
4275        }
4276
4277        diff_fill_oid_info(one);
4278        diff_fill_oid_info(two);
4279
4280        if (!pgm &&
4281            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
4282            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
4283                /*
4284                 * a filepair that changes between file and symlink
4285                 * needs to be split into deletion and creation.
4286                 */
4287                struct diff_filespec *null = alloc_filespec(two->path);
4288                run_diff_cmd(NULL, name, other, attr_path,
4289                             one, null, &msg, o, p);
4290                free(null);
4291                strbuf_release(&msg);
4292
4293                null = alloc_filespec(one->path);
4294                run_diff_cmd(NULL, name, other, attr_path,
4295                             null, two, &msg, o, p);
4296                free(null);
4297        }
4298        else
4299                run_diff_cmd(pgm, name, other, attr_path,
4300                             one, two, &msg, o, p);
4301
4302        strbuf_release(&msg);
4303}
4304
4305static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
4306                         struct diffstat_t *diffstat)
4307{
4308        const char *name;
4309        const char *other;
4310
4311        if (DIFF_PAIR_UNMERGED(p)) {
4312                /* unmerged */
4313                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, p);
4314                return;
4315        }
4316
4317        name = p->one->path;
4318        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4319
4320        if (o->prefix_length)
4321                strip_prefix(o->prefix_length, &name, &other);
4322
4323        diff_fill_oid_info(p->one);
4324        diff_fill_oid_info(p->two);
4325
4326        builtin_diffstat(name, other, p->one, p->two, diffstat, o, p);
4327}
4328
4329static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
4330{
4331        const char *name;
4332        const char *other;
4333        const char *attr_path;
4334
4335        if (DIFF_PAIR_UNMERGED(p)) {
4336                /* unmerged */
4337                return;
4338        }
4339
4340        name = p->one->path;
4341        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4342        attr_path = other ? other : name;
4343
4344        if (o->prefix_length)
4345                strip_prefix(o->prefix_length, &name, &other);
4346
4347        diff_fill_oid_info(p->one);
4348        diff_fill_oid_info(p->two);
4349
4350        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
4351}
4352
4353void diff_setup(struct diff_options *options)
4354{
4355        memcpy(options, &default_diff_options, sizeof(*options));
4356
4357        options->file = stdout;
4358
4359        options->abbrev = DEFAULT_ABBREV;
4360        options->line_termination = '\n';
4361        options->break_opt = -1;
4362        options->rename_limit = -1;
4363        options->dirstat_permille = diff_dirstat_permille_default;
4364        options->context = diff_context_default;
4365        options->interhunkcontext = diff_interhunk_context_default;
4366        options->ws_error_highlight = ws_error_highlight_default;
4367        options->flags.rename_empty = 1;
4368        options->objfind = NULL;
4369
4370        /* pathchange left =NULL by default */
4371        options->change = diff_change;
4372        options->add_remove = diff_addremove;
4373        options->use_color = diff_use_color_default;
4374        options->detect_rename = diff_detect_rename_default;
4375        options->xdl_opts |= diff_algorithm;
4376        if (diff_indent_heuristic)
4377                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4378
4379        options->orderfile = diff_order_file_cfg;
4380
4381        if (diff_no_prefix) {
4382                options->a_prefix = options->b_prefix = "";
4383        } else if (!diff_mnemonic_prefix) {
4384                options->a_prefix = "a/";
4385                options->b_prefix = "b/";
4386        }
4387
4388        options->color_moved = diff_color_moved_default;
4389        options->color_moved_ws_handling = diff_color_moved_ws_default;
4390}
4391
4392void diff_setup_done(struct diff_options *options)
4393{
4394        unsigned check_mask = DIFF_FORMAT_NAME |
4395                              DIFF_FORMAT_NAME_STATUS |
4396                              DIFF_FORMAT_CHECKDIFF |
4397                              DIFF_FORMAT_NO_OUTPUT;
4398        /*
4399         * This must be signed because we're comparing against a potentially
4400         * negative value.
4401         */
4402        const int hexsz = the_hash_algo->hexsz;
4403
4404        if (options->set_default)
4405                options->set_default(options);
4406
4407        if (HAS_MULTI_BITS(options->output_format & check_mask))
4408                die(_("--name-only, --name-status, --check and -s are mutually exclusive"));
4409
4410        if (HAS_MULTI_BITS(options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK))
4411                die(_("-G, -S and --find-object are mutually exclusive"));
4412
4413        /*
4414         * Most of the time we can say "there are changes"
4415         * only by checking if there are changed paths, but
4416         * --ignore-whitespace* options force us to look
4417         * inside contents.
4418         */
4419
4420        if ((options->xdl_opts & XDF_WHITESPACE_FLAGS))
4421                options->flags.diff_from_contents = 1;
4422        else
4423                options->flags.diff_from_contents = 0;
4424
4425        if (options->flags.find_copies_harder)
4426                options->detect_rename = DIFF_DETECT_COPY;
4427
4428        if (!options->flags.relative_name)
4429                options->prefix = NULL;
4430        if (options->prefix)
4431                options->prefix_length = strlen(options->prefix);
4432        else
4433                options->prefix_length = 0;
4434
4435        if (options->output_format & (DIFF_FORMAT_NAME |
4436                                      DIFF_FORMAT_NAME_STATUS |
4437                                      DIFF_FORMAT_CHECKDIFF |
4438                                      DIFF_FORMAT_NO_OUTPUT))
4439                options->output_format &= ~(DIFF_FORMAT_RAW |
4440                                            DIFF_FORMAT_NUMSTAT |
4441                                            DIFF_FORMAT_DIFFSTAT |
4442                                            DIFF_FORMAT_SHORTSTAT |
4443                                            DIFF_FORMAT_DIRSTAT |
4444                                            DIFF_FORMAT_SUMMARY |
4445                                            DIFF_FORMAT_PATCH);
4446
4447        /*
4448         * These cases always need recursive; we do not drop caller-supplied
4449         * recursive bits for other formats here.
4450         */
4451        if (options->output_format & (DIFF_FORMAT_PATCH |
4452                                      DIFF_FORMAT_NUMSTAT |
4453                                      DIFF_FORMAT_DIFFSTAT |
4454                                      DIFF_FORMAT_SHORTSTAT |
4455                                      DIFF_FORMAT_DIRSTAT |
4456                                      DIFF_FORMAT_SUMMARY |
4457                                      DIFF_FORMAT_CHECKDIFF))
4458                options->flags.recursive = 1;
4459        /*
4460         * Also pickaxe would not work very well if you do not say recursive
4461         */
4462        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
4463                options->flags.recursive = 1;
4464        /*
4465         * When patches are generated, submodules diffed against the work tree
4466         * must be checked for dirtiness too so it can be shown in the output
4467         */
4468        if (options->output_format & DIFF_FORMAT_PATCH)
4469                options->flags.dirty_submodules = 1;
4470
4471        if (options->detect_rename && options->rename_limit < 0)
4472                options->rename_limit = diff_rename_limit_default;
4473        if (options->setup & DIFF_SETUP_USE_CACHE) {
4474                if (!active_cache)
4475                        /* read-cache does not die even when it fails
4476                         * so it is safe for us to do this here.  Also
4477                         * it does not smudge active_cache or active_nr
4478                         * when it fails, so we do not have to worry about
4479                         * cleaning it up ourselves either.
4480                         */
4481                        read_cache();
4482        }
4483        if (hexsz < options->abbrev)
4484                options->abbrev = hexsz; /* full */
4485
4486        /*
4487         * It does not make sense to show the first hit we happened
4488         * to have found.  It does not make sense not to return with
4489         * exit code in such a case either.
4490         */
4491        if (options->flags.quick) {
4492                options->output_format = DIFF_FORMAT_NO_OUTPUT;
4493                options->flags.exit_with_status = 1;
4494        }
4495
4496        options->diff_path_counter = 0;
4497
4498        if (options->flags.follow_renames && options->pathspec.nr != 1)
4499                die(_("--follow requires exactly one pathspec"));
4500
4501        if (!options->use_color || external_diff())
4502                options->color_moved = 0;
4503}
4504
4505static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
4506{
4507        char c, *eq;
4508        int len;
4509
4510        if (*arg != '-')
4511                return 0;
4512        c = *++arg;
4513        if (!c)
4514                return 0;
4515        if (c == arg_short) {
4516                c = *++arg;
4517                if (!c)
4518                        return 1;
4519                if (val && isdigit(c)) {
4520                        char *end;
4521                        int n = strtoul(arg, &end, 10);
4522                        if (*end)
4523                                return 0;
4524                        *val = n;
4525                        return 1;
4526                }
4527                return 0;
4528        }
4529        if (c != '-')
4530                return 0;
4531        arg++;
4532        eq = strchrnul(arg, '=');
4533        len = eq - arg;
4534        if (!len || strncmp(arg, arg_long, len))
4535                return 0;
4536        if (*eq) {
4537                int n;
4538                char *end;
4539                if (!isdigit(*++eq))
4540                        return 0;
4541                n = strtoul(eq, &end, 10);
4542                if (*end)
4543                        return 0;
4544                *val = n;
4545        }
4546        return 1;
4547}
4548
4549static int diff_scoreopt_parse(const char *opt);
4550
4551static inline int short_opt(char opt, const char **argv,
4552                            const char **optarg)
4553{
4554        const char *arg = argv[0];
4555        if (arg[0] != '-' || arg[1] != opt)
4556                return 0;
4557        if (arg[2] != '\0') {
4558                *optarg = arg + 2;
4559                return 1;
4560        }
4561        if (!argv[1])
4562                die("Option '%c' requires a value", opt);
4563        *optarg = argv[1];
4564        return 2;
4565}
4566
4567int parse_long_opt(const char *opt, const char **argv,
4568                   const char **optarg)
4569{
4570        const char *arg = argv[0];
4571        if (!skip_prefix(arg, "--", &arg))
4572                return 0;
4573        if (!skip_prefix(arg, opt, &arg))
4574                return 0;
4575        if (*arg == '=') { /* stuck form: --option=value */
4576                *optarg = arg + 1;
4577                return 1;
4578        }
4579        if (*arg != '\0')
4580                return 0;
4581        /* separate form: --option value */
4582        if (!argv[1])
4583                die("Option '--%s' requires a value", opt);
4584        *optarg = argv[1];
4585        return 2;
4586}
4587
4588static int stat_opt(struct diff_options *options, const char **av)
4589{
4590        const char *arg = av[0];
4591        char *end;
4592        int width = options->stat_width;
4593        int name_width = options->stat_name_width;
4594        int graph_width = options->stat_graph_width;
4595        int count = options->stat_count;
4596        int argcount = 1;
4597
4598        if (!skip_prefix(arg, "--stat", &arg))
4599                BUG("stat option does not begin with --stat: %s", arg);
4600        end = (char *)arg;
4601
4602        switch (*arg) {
4603        case '-':
4604                if (skip_prefix(arg, "-width", &arg)) {
4605                        if (*arg == '=')
4606                                width = strtoul(arg + 1, &end, 10);
4607                        else if (!*arg && !av[1])
4608                                die_want_option("--stat-width");
4609                        else if (!*arg) {
4610                                width = strtoul(av[1], &end, 10);
4611                                argcount = 2;
4612                        }
4613                } else if (skip_prefix(arg, "-name-width", &arg)) {
4614                        if (*arg == '=')
4615                                name_width = strtoul(arg + 1, &end, 10);
4616                        else if (!*arg && !av[1])
4617                                die_want_option("--stat-name-width");
4618                        else if (!*arg) {
4619                                name_width = strtoul(av[1], &end, 10);
4620                                argcount = 2;
4621                        }
4622                } else if (skip_prefix(arg, "-graph-width", &arg)) {
4623                        if (*arg == '=')
4624                                graph_width = strtoul(arg + 1, &end, 10);
4625                        else if (!*arg && !av[1])
4626                                die_want_option("--stat-graph-width");
4627                        else if (!*arg) {
4628                                graph_width = strtoul(av[1], &end, 10);
4629                                argcount = 2;
4630                        }
4631                } else if (skip_prefix(arg, "-count", &arg)) {
4632                        if (*arg == '=')
4633                                count = strtoul(arg + 1, &end, 10);
4634                        else if (!*arg && !av[1])
4635                                die_want_option("--stat-count");
4636                        else if (!*arg) {
4637                                count = strtoul(av[1], &end, 10);
4638                                argcount = 2;
4639                        }
4640                }
4641                break;
4642        case '=':
4643                width = strtoul(arg+1, &end, 10);
4644                if (*end == ',')
4645                        name_width = strtoul(end+1, &end, 10);
4646                if (*end == ',')
4647                        count = strtoul(end+1, &end, 10);
4648        }
4649
4650        /* Important! This checks all the error cases! */
4651        if (*end)
4652                return 0;
4653        options->output_format |= DIFF_FORMAT_DIFFSTAT;
4654        options->stat_name_width = name_width;
4655        options->stat_graph_width = graph_width;
4656        options->stat_width = width;
4657        options->stat_count = count;
4658        return argcount;
4659}
4660
4661static int parse_dirstat_opt(struct diff_options *options, const char *params)
4662{
4663        struct strbuf errmsg = STRBUF_INIT;
4664        if (parse_dirstat_params(options, params, &errmsg))
4665                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
4666                    errmsg.buf);
4667        strbuf_release(&errmsg);
4668        /*
4669         * The caller knows a dirstat-related option is given from the command
4670         * line; allow it to say "return this_function();"
4671         */
4672        options->output_format |= DIFF_FORMAT_DIRSTAT;
4673        return 1;
4674}
4675
4676static int parse_submodule_opt(struct diff_options *options, const char *value)
4677{
4678        if (parse_submodule_params(options, value))
4679                die(_("Failed to parse --submodule option parameter: '%s'"),
4680                        value);
4681        return 1;
4682}
4683
4684static const char diff_status_letters[] = {
4685        DIFF_STATUS_ADDED,
4686        DIFF_STATUS_COPIED,
4687        DIFF_STATUS_DELETED,
4688        DIFF_STATUS_MODIFIED,
4689        DIFF_STATUS_RENAMED,
4690        DIFF_STATUS_TYPE_CHANGED,
4691        DIFF_STATUS_UNKNOWN,
4692        DIFF_STATUS_UNMERGED,
4693        DIFF_STATUS_FILTER_AON,
4694        DIFF_STATUS_FILTER_BROKEN,
4695        '\0',
4696};
4697
4698static unsigned int filter_bit['Z' + 1];
4699
4700static void prepare_filter_bits(void)
4701{
4702        int i;
4703
4704        if (!filter_bit[DIFF_STATUS_ADDED]) {
4705                for (i = 0; diff_status_letters[i]; i++)
4706                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
4707        }
4708}
4709
4710static unsigned filter_bit_tst(char status, const struct diff_options *opt)
4711{
4712        return opt->filter & filter_bit[(int) status];
4713}
4714
4715static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
4716{
4717        int i, optch;
4718
4719        prepare_filter_bits();
4720
4721        /*
4722         * If there is a negation e.g. 'd' in the input, and we haven't
4723         * initialized the filter field with another --diff-filter, start
4724         * from full set of bits, except for AON.
4725         */
4726        if (!opt->filter) {
4727                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4728                        if (optch < 'a' || 'z' < optch)
4729                                continue;
4730                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
4731                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
4732                        break;
4733                }
4734        }
4735
4736        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4737                unsigned int bit;
4738                int negate;
4739
4740                if ('a' <= optch && optch <= 'z') {
4741                        negate = 1;
4742                        optch = toupper(optch);
4743                } else {
4744                        negate = 0;
4745                }
4746
4747                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
4748                if (!bit)
4749                        return optarg[i];
4750                if (negate)
4751                        opt->filter &= ~bit;
4752                else
4753                        opt->filter |= bit;
4754        }
4755        return 0;
4756}
4757
4758static void enable_patch_output(int *fmt) {
4759        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
4760        *fmt |= DIFF_FORMAT_PATCH;
4761}
4762
4763static int parse_ws_error_highlight_opt(struct diff_options *opt, const char *arg)
4764{
4765        int val = parse_ws_error_highlight(arg);
4766
4767        if (val < 0) {
4768                error("unknown value after ws-error-highlight=%.*s",
4769                      -1 - val, arg);
4770                return 0;
4771        }
4772        opt->ws_error_highlight = val;
4773        return 1;
4774}
4775
4776static int parse_objfind_opt(struct diff_options *opt, const char *arg)
4777{
4778        struct object_id oid;
4779
4780        if (get_oid(arg, &oid))
4781                return error("unable to resolve '%s'", arg);
4782
4783        if (!opt->objfind)
4784                opt->objfind = xcalloc(1, sizeof(*opt->objfind));
4785
4786        opt->pickaxe_opts |= DIFF_PICKAXE_KIND_OBJFIND;
4787        opt->flags.recursive = 1;
4788        opt->flags.tree_in_recursive = 1;
4789        oidset_insert(opt->objfind, &oid);
4790        return 1;
4791}
4792
4793int diff_opt_parse(struct diff_options *options,
4794                   const char **av, int ac, const char *prefix)
4795{
4796        const char *arg = av[0];
4797        const char *optarg;
4798        int argcount;
4799
4800        if (!prefix)
4801                prefix = "";
4802
4803        /* Output format options */
4804        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
4805            || opt_arg(arg, 'U', "unified", &options->context))
4806                enable_patch_output(&options->output_format);
4807        else if (!strcmp(arg, "--raw"))
4808                options->output_format |= DIFF_FORMAT_RAW;
4809        else if (!strcmp(arg, "--patch-with-raw")) {
4810                enable_patch_output(&options->output_format);
4811                options->output_format |= DIFF_FORMAT_RAW;
4812        } else if (!strcmp(arg, "--numstat"))
4813                options->output_format |= DIFF_FORMAT_NUMSTAT;
4814        else if (!strcmp(arg, "--shortstat"))
4815                options->output_format |= DIFF_FORMAT_SHORTSTAT;
4816        else if (skip_prefix(arg, "-X", &arg) ||
4817                 skip_to_optional_arg(arg, "--dirstat", &arg))
4818                return parse_dirstat_opt(options, arg);
4819        else if (!strcmp(arg, "--cumulative"))
4820                return parse_dirstat_opt(options, "cumulative");
4821        else if (skip_to_optional_arg(arg, "--dirstat-by-file", &arg)) {
4822                parse_dirstat_opt(options, "files");
4823                return parse_dirstat_opt(options, arg);
4824        }
4825        else if (!strcmp(arg, "--check"))
4826                options->output_format |= DIFF_FORMAT_CHECKDIFF;
4827        else if (!strcmp(arg, "--summary"))
4828                options->output_format |= DIFF_FORMAT_SUMMARY;
4829        else if (!strcmp(arg, "--patch-with-stat")) {
4830                enable_patch_output(&options->output_format);
4831                options->output_format |= DIFF_FORMAT_DIFFSTAT;
4832        } else if (!strcmp(arg, "--name-only"))
4833                options->output_format |= DIFF_FORMAT_NAME;
4834        else if (!strcmp(arg, "--name-status"))
4835                options->output_format |= DIFF_FORMAT_NAME_STATUS;
4836        else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
4837                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
4838        else if (starts_with(arg, "--stat"))
4839                /* --stat, --stat-width, --stat-name-width, or --stat-count */
4840                return stat_opt(options, av);
4841        else if (!strcmp(arg, "--compact-summary")) {
4842                 options->flags.stat_with_summary = 1;
4843                 options->output_format |= DIFF_FORMAT_DIFFSTAT;
4844        } else if (!strcmp(arg, "--no-compact-summary"))
4845                 options->flags.stat_with_summary = 0;
4846
4847        /* renames options */
4848        else if (starts_with(arg, "-B") ||
4849                 skip_to_optional_arg(arg, "--break-rewrites", NULL)) {
4850                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
4851                        return error("invalid argument to -B: %s", arg+2);
4852        }
4853        else if (starts_with(arg, "-M") ||
4854                 skip_to_optional_arg(arg, "--find-renames", NULL)) {
4855                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4856                        return error("invalid argument to -M: %s", arg+2);
4857                options->detect_rename = DIFF_DETECT_RENAME;
4858        }
4859        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
4860                options->irreversible_delete = 1;
4861        }
4862        else if (starts_with(arg, "-C") ||
4863                 skip_to_optional_arg(arg, "--find-copies", NULL)) {
4864                if (options->detect_rename == DIFF_DETECT_COPY)
4865                        options->flags.find_copies_harder = 1;
4866                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4867                        return error("invalid argument to -C: %s", arg+2);
4868                options->detect_rename = DIFF_DETECT_COPY;
4869        }
4870        else if (!strcmp(arg, "--no-renames"))
4871                options->detect_rename = 0;
4872        else if (!strcmp(arg, "--rename-empty"))
4873                options->flags.rename_empty = 1;
4874        else if (!strcmp(arg, "--no-rename-empty"))
4875                options->flags.rename_empty = 0;
4876        else if (skip_to_optional_arg_default(arg, "--relative", &arg, NULL)) {
4877                options->flags.relative_name = 1;
4878                if (arg)
4879                        options->prefix = arg;
4880        }
4881
4882        /* xdiff options */
4883        else if (!strcmp(arg, "--minimal"))
4884                DIFF_XDL_SET(options, NEED_MINIMAL);
4885        else if (!strcmp(arg, "--no-minimal"))
4886                DIFF_XDL_CLR(options, NEED_MINIMAL);
4887        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
4888                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
4889        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
4890                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
4891        else if (!strcmp(arg, "--ignore-space-at-eol"))
4892                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
4893        else if (!strcmp(arg, "--ignore-cr-at-eol"))
4894                DIFF_XDL_SET(options, IGNORE_CR_AT_EOL);
4895        else if (!strcmp(arg, "--ignore-blank-lines"))
4896                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
4897        else if (!strcmp(arg, "--indent-heuristic"))
4898                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4899        else if (!strcmp(arg, "--no-indent-heuristic"))
4900                DIFF_XDL_CLR(options, INDENT_HEURISTIC);
4901        else if (!strcmp(arg, "--patience")) {
4902                int i;
4903                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4904                /*
4905                 * Both --patience and --anchored use PATIENCE_DIFF
4906                 * internally, so remove any anchors previously
4907                 * specified.
4908                 */
4909                for (i = 0; i < options->anchors_nr; i++)
4910                        free(options->anchors[i]);
4911                options->anchors_nr = 0;
4912        } else if (!strcmp(arg, "--histogram"))
4913                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
4914        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
4915                long value = parse_algorithm_value(optarg);
4916                if (value < 0)
4917                        return error("option diff-algorithm accepts \"myers\", "
4918                                     "\"minimal\", \"patience\" and \"histogram\"");
4919                /* clear out previous settings */
4920                DIFF_XDL_CLR(options, NEED_MINIMAL);
4921                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
4922                options->xdl_opts |= value;
4923                return argcount;
4924        } else if (skip_prefix(arg, "--anchored=", &arg)) {
4925                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4926                ALLOC_GROW(options->anchors, options->anchors_nr + 1,
4927                           options->anchors_alloc);
4928                options->anchors[options->anchors_nr++] = xstrdup(arg);
4929        }
4930
4931        /* flags options */
4932        else if (!strcmp(arg, "--binary")) {
4933                enable_patch_output(&options->output_format);
4934                options->flags.binary = 1;
4935        }
4936        else if (!strcmp(arg, "--full-index"))
4937                options->flags.full_index = 1;
4938        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
4939                options->flags.text = 1;
4940        else if (!strcmp(arg, "-R"))
4941                options->flags.reverse_diff = 1;
4942        else if (!strcmp(arg, "--find-copies-harder"))
4943                options->flags.find_copies_harder = 1;
4944        else if (!strcmp(arg, "--follow"))
4945                options->flags.follow_renames = 1;
4946        else if (!strcmp(arg, "--no-follow")) {
4947                options->flags.follow_renames = 0;
4948                options->flags.default_follow_renames = 0;
4949        } else if (skip_to_optional_arg_default(arg, "--color", &arg, "always")) {
4950                int value = git_config_colorbool(NULL, arg);
4951                if (value < 0)
4952                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
4953                options->use_color = value;
4954        }
4955        else if (!strcmp(arg, "--no-color"))
4956                options->use_color = 0;
4957        else if (!strcmp(arg, "--color-moved")) {
4958                if (diff_color_moved_default)
4959                        options->color_moved = diff_color_moved_default;
4960                if (options->color_moved == COLOR_MOVED_NO)
4961                        options->color_moved = COLOR_MOVED_DEFAULT;
4962        } else if (!strcmp(arg, "--no-color-moved"))
4963                options->color_moved = COLOR_MOVED_NO;
4964        else if (skip_prefix(arg, "--color-moved=", &arg)) {
4965                int cm = parse_color_moved(arg);
4966                if (cm < 0)
4967                        die("bad --color-moved argument: %s", arg);
4968                options->color_moved = cm;
4969        } else if (skip_prefix(arg, "--color-moved-ws=", &arg)) {
4970                options->color_moved_ws_handling = parse_color_moved_ws(arg);
4971        } else if (skip_to_optional_arg_default(arg, "--color-words", &options->word_regex, NULL)) {
4972                options->use_color = 1;
4973                options->word_diff = DIFF_WORDS_COLOR;
4974        }
4975        else if (!strcmp(arg, "--word-diff")) {
4976                if (options->word_diff == DIFF_WORDS_NONE)
4977                        options->word_diff = DIFF_WORDS_PLAIN;
4978        }
4979        else if (skip_prefix(arg, "--word-diff=", &arg)) {
4980                if (!strcmp(arg, "plain"))
4981                        options->word_diff = DIFF_WORDS_PLAIN;
4982                else if (!strcmp(arg, "color")) {
4983                        options->use_color = 1;
4984                        options->word_diff = DIFF_WORDS_COLOR;
4985                }
4986                else if (!strcmp(arg, "porcelain"))
4987                        options->word_diff = DIFF_WORDS_PORCELAIN;
4988                else if (!strcmp(arg, "none"))
4989                        options->word_diff = DIFF_WORDS_NONE;
4990                else
4991                        die("bad --word-diff argument: %s", arg);
4992        }
4993        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
4994                if (options->word_diff == DIFF_WORDS_NONE)
4995                        options->word_diff = DIFF_WORDS_PLAIN;
4996                options->word_regex = optarg;
4997                return argcount;
4998        }
4999        else if (!strcmp(arg, "--exit-code"))
5000                options->flags.exit_with_status = 1;
5001        else if (!strcmp(arg, "--quiet"))
5002                options->flags.quick = 1;
5003        else if (!strcmp(arg, "--ext-diff"))
5004                options->flags.allow_external = 1;
5005        else if (!strcmp(arg, "--no-ext-diff"))
5006                options->flags.allow_external = 0;
5007        else if (!strcmp(arg, "--textconv")) {
5008                options->flags.allow_textconv = 1;
5009                options->flags.textconv_set_via_cmdline = 1;
5010        } else if (!strcmp(arg, "--no-textconv"))
5011                options->flags.allow_textconv = 0;
5012        else if (skip_to_optional_arg_default(arg, "--ignore-submodules", &arg, "all")) {
5013                options->flags.override_submodule_config = 1;
5014                handle_ignore_submodules_arg(options, arg);
5015        } else if (skip_to_optional_arg_default(arg, "--submodule", &arg, "log"))
5016                return parse_submodule_opt(options, arg);
5017        else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
5018                return parse_ws_error_highlight_opt(options, arg);
5019        else if (!strcmp(arg, "--ita-invisible-in-index"))
5020                options->ita_invisible_in_index = 1;
5021        else if (!strcmp(arg, "--ita-visible-in-index"))
5022                options->ita_invisible_in_index = 0;
5023
5024        /* misc options */
5025        else if (!strcmp(arg, "-z"))
5026                options->line_termination = 0;
5027        else if ((argcount = short_opt('l', av, &optarg))) {
5028                options->rename_limit = strtoul(optarg, NULL, 10);
5029                return argcount;
5030        }
5031        else if ((argcount = short_opt('S', av, &optarg))) {
5032                options->pickaxe = optarg;
5033                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
5034                return argcount;
5035        } else if ((argcount = short_opt('G', av, &optarg))) {
5036                options->pickaxe = optarg;
5037                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
5038                return argcount;
5039        }
5040        else if (!strcmp(arg, "--pickaxe-all"))
5041                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
5042        else if (!strcmp(arg, "--pickaxe-regex"))
5043                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
5044        else if ((argcount = short_opt('O', av, &optarg))) {
5045                options->orderfile = prefix_filename(prefix, optarg);
5046                return argcount;
5047        } else if (skip_prefix(arg, "--find-object=", &arg))
5048                return parse_objfind_opt(options, arg);
5049        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
5050                int offending = parse_diff_filter_opt(optarg, options);
5051                if (offending)
5052                        die("unknown change class '%c' in --diff-filter=%s",
5053                            offending, optarg);
5054                return argcount;
5055        }
5056        else if (!strcmp(arg, "--no-abbrev"))
5057                options->abbrev = 0;
5058        else if (!strcmp(arg, "--abbrev"))
5059                options->abbrev = DEFAULT_ABBREV;
5060        else if (skip_prefix(arg, "--abbrev=", &arg)) {
5061                options->abbrev = strtoul(arg, NULL, 10);
5062                if (options->abbrev < MINIMUM_ABBREV)
5063                        options->abbrev = MINIMUM_ABBREV;
5064                else if (the_hash_algo->hexsz < options->abbrev)
5065                        options->abbrev = the_hash_algo->hexsz;
5066        }
5067        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
5068                options->a_prefix = optarg;
5069                return argcount;
5070        }
5071        else if ((argcount = parse_long_opt("line-prefix", av, &optarg))) {
5072                options->line_prefix = optarg;
5073                options->line_prefix_length = strlen(options->line_prefix);
5074                graph_setup_line_prefix(options);
5075                return argcount;
5076        }
5077        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
5078                options->b_prefix = optarg;
5079                return argcount;
5080        }
5081        else if (!strcmp(arg, "--no-prefix"))
5082                options->a_prefix = options->b_prefix = "";
5083        else if (opt_arg(arg, '\0', "inter-hunk-context",
5084                         &options->interhunkcontext))
5085                ;
5086        else if (!strcmp(arg, "-W"))
5087                options->flags.funccontext = 1;
5088        else if (!strcmp(arg, "--function-context"))
5089                options->flags.funccontext = 1;
5090        else if (!strcmp(arg, "--no-function-context"))
5091                options->flags.funccontext = 0;
5092        else if ((argcount = parse_long_opt("output", av, &optarg))) {
5093                char *path = prefix_filename(prefix, optarg);
5094                options->file = xfopen(path, "w");
5095                options->close_file = 1;
5096                if (options->use_color != GIT_COLOR_ALWAYS)
5097                        options->use_color = GIT_COLOR_NEVER;
5098                free(path);
5099                return argcount;
5100        } else
5101                return 0;
5102        return 1;
5103}
5104
5105int parse_rename_score(const char **cp_p)
5106{
5107        unsigned long num, scale;
5108        int ch, dot;
5109        const char *cp = *cp_p;
5110
5111        num = 0;
5112        scale = 1;
5113        dot = 0;
5114        for (;;) {
5115                ch = *cp;
5116                if ( !dot && ch == '.' ) {
5117                        scale = 1;
5118                        dot = 1;
5119                } else if ( ch == '%' ) {
5120                        scale = dot ? scale*100 : 100;
5121                        cp++;   /* % is always at the end */
5122                        break;
5123                } else if ( ch >= '0' && ch <= '9' ) {
5124                        if ( scale < 100000 ) {
5125                                scale *= 10;
5126                                num = (num*10) + (ch-'0');
5127                        }
5128                } else {
5129                        break;
5130                }
5131                cp++;
5132        }
5133        *cp_p = cp;
5134
5135        /* user says num divided by scale and we say internally that
5136         * is MAX_SCORE * num / scale.
5137         */
5138        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
5139}
5140
5141static int diff_scoreopt_parse(const char *opt)
5142{
5143        int opt1, opt2, cmd;
5144
5145        if (*opt++ != '-')
5146                return -1;
5147        cmd = *opt++;
5148        if (cmd == '-') {
5149                /* convert the long-form arguments into short-form versions */
5150                if (skip_prefix(opt, "break-rewrites", &opt)) {
5151                        if (*opt == 0 || *opt++ == '=')
5152                                cmd = 'B';
5153                } else if (skip_prefix(opt, "find-copies", &opt)) {
5154                        if (*opt == 0 || *opt++ == '=')
5155                                cmd = 'C';
5156                } else if (skip_prefix(opt, "find-renames", &opt)) {
5157                        if (*opt == 0 || *opt++ == '=')
5158                                cmd = 'M';
5159                }
5160        }
5161        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
5162                return -1; /* that is not a -M, -C, or -B option */
5163
5164        opt1 = parse_rename_score(&opt);
5165        if (cmd != 'B')
5166                opt2 = 0;
5167        else {
5168                if (*opt == 0)
5169                        opt2 = 0;
5170                else if (*opt != '/')
5171                        return -1; /* we expect -B80/99 or -B80 */
5172                else {
5173                        opt++;
5174                        opt2 = parse_rename_score(&opt);
5175                }
5176        }
5177        if (*opt != 0)
5178                return -1;
5179        return opt1 | (opt2 << 16);
5180}
5181
5182struct diff_queue_struct diff_queued_diff;
5183
5184void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
5185{
5186        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
5187        queue->queue[queue->nr++] = dp;
5188}
5189
5190struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
5191                                 struct diff_filespec *one,
5192                                 struct diff_filespec *two)
5193{
5194        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
5195        dp->one = one;
5196        dp->two = two;
5197        if (queue)
5198                diff_q(queue, dp);
5199        return dp;
5200}
5201
5202void diff_free_filepair(struct diff_filepair *p)
5203{
5204        free_filespec(p->one);
5205        free_filespec(p->two);
5206        free(p);
5207}
5208
5209const char *diff_aligned_abbrev(const struct object_id *oid, int len)
5210{
5211        int abblen;
5212        const char *abbrev;
5213
5214        /* Do we want all 40 hex characters? */
5215        if (len == the_hash_algo->hexsz)
5216                return oid_to_hex(oid);
5217
5218        /* An abbreviated value is fine, possibly followed by an ellipsis. */
5219        abbrev = diff_abbrev_oid(oid, len);
5220
5221        if (!print_sha1_ellipsis())
5222                return abbrev;
5223
5224        abblen = strlen(abbrev);
5225
5226        /*
5227         * In well-behaved cases, where the abbreviated result is the
5228         * same as the requested length, append three dots after the
5229         * abbreviation (hence the whole logic is limited to the case
5230         * where abblen < 37); when the actual abbreviated result is a
5231         * bit longer than the requested length, we reduce the number
5232         * of dots so that they match the well-behaved ones.  However,
5233         * if the actual abbreviation is longer than the requested
5234         * length by more than three, we give up on aligning, and add
5235         * three dots anyway, to indicate that the output is not the
5236         * full object name.  Yes, this may be suboptimal, but this
5237         * appears only in "diff --raw --abbrev" output and it is not
5238         * worth the effort to change it now.  Note that this would
5239         * likely to work fine when the automatic sizing of default
5240         * abbreviation length is used--we would be fed -1 in "len" in
5241         * that case, and will end up always appending three-dots, but
5242         * the automatic sizing is supposed to give abblen that ensures
5243         * uniqueness across all objects (statistically speaking).
5244         */
5245        if (abblen < the_hash_algo->hexsz - 3) {
5246                static char hex[GIT_MAX_HEXSZ + 1];
5247                if (len < abblen && abblen <= len + 2)
5248                        xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
5249                else
5250                        xsnprintf(hex, sizeof(hex), "%s...", abbrev);
5251                return hex;
5252        }
5253
5254        return oid_to_hex(oid);
5255}
5256
5257static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
5258{
5259        int line_termination = opt->line_termination;
5260        int inter_name_termination = line_termination ? '\t' : '\0';
5261
5262        fprintf(opt->file, "%s", diff_line_prefix(opt));
5263        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
5264                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
5265                        diff_aligned_abbrev(&p->one->oid, opt->abbrev));
5266                fprintf(opt->file, "%s ",
5267                        diff_aligned_abbrev(&p->two->oid, opt->abbrev));
5268        }
5269        if (p->score) {
5270                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
5271                        inter_name_termination);
5272        } else {
5273                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
5274        }
5275
5276        if (p->status == DIFF_STATUS_COPIED ||
5277            p->status == DIFF_STATUS_RENAMED) {
5278                const char *name_a, *name_b;
5279                name_a = p->one->path;
5280                name_b = p->two->path;
5281                strip_prefix(opt->prefix_length, &name_a, &name_b);
5282                write_name_quoted(name_a, opt->file, inter_name_termination);
5283                write_name_quoted(name_b, opt->file, line_termination);
5284        } else {
5285                const char *name_a, *name_b;
5286                name_a = p->one->mode ? p->one->path : p->two->path;
5287                name_b = NULL;
5288                strip_prefix(opt->prefix_length, &name_a, &name_b);
5289                write_name_quoted(name_a, opt->file, line_termination);
5290        }
5291}
5292
5293int diff_unmodified_pair(struct diff_filepair *p)
5294{
5295        /* This function is written stricter than necessary to support
5296         * the currently implemented transformers, but the idea is to
5297         * let transformers to produce diff_filepairs any way they want,
5298         * and filter and clean them up here before producing the output.
5299         */
5300        struct diff_filespec *one = p->one, *two = p->two;
5301
5302        if (DIFF_PAIR_UNMERGED(p))
5303                return 0; /* unmerged is interesting */
5304
5305        /* deletion, addition, mode or type change
5306         * and rename are all interesting.
5307         */
5308        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
5309            DIFF_PAIR_MODE_CHANGED(p) ||
5310            strcmp(one->path, two->path))
5311                return 0;
5312
5313        /* both are valid and point at the same path.  that is, we are
5314         * dealing with a change.
5315         */
5316        if (one->oid_valid && two->oid_valid &&
5317            !oidcmp(&one->oid, &two->oid) &&
5318            !one->dirty_submodule && !two->dirty_submodule)
5319                return 1; /* no change */
5320        if (!one->oid_valid && !two->oid_valid)
5321                return 1; /* both look at the same file on the filesystem. */
5322        return 0;
5323}
5324
5325static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
5326{
5327        if (diff_unmodified_pair(p))
5328                return;
5329
5330        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5331            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5332                return; /* no tree diffs in patch format */
5333
5334        run_diff(p, o);
5335}
5336
5337static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
5338                            struct diffstat_t *diffstat)
5339{
5340        if (diff_unmodified_pair(p))
5341                return;
5342
5343        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5344            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5345                return; /* no useful stat for tree diffs */
5346
5347        run_diffstat(p, o, diffstat);
5348}
5349
5350static void diff_flush_checkdiff(struct diff_filepair *p,
5351                struct diff_options *o)
5352{
5353        if (diff_unmodified_pair(p))
5354                return;
5355
5356        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5357            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5358                return; /* nothing to check in tree diffs */
5359
5360        run_checkdiff(p, o);
5361}
5362
5363int diff_queue_is_empty(void)
5364{
5365        struct diff_queue_struct *q = &diff_queued_diff;
5366        int i;
5367        for (i = 0; i < q->nr; i++)
5368                if (!diff_unmodified_pair(q->queue[i]))
5369                        return 0;
5370        return 1;
5371}
5372
5373#if DIFF_DEBUG
5374void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
5375{
5376        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
5377                x, one ? one : "",
5378                s->path,
5379                DIFF_FILE_VALID(s) ? "valid" : "invalid",
5380                s->mode,
5381                s->oid_valid ? oid_to_hex(&s->oid) : "");
5382        fprintf(stderr, "queue[%d] %s size %lu\n",
5383                x, one ? one : "",
5384                s->size);
5385}
5386
5387void diff_debug_filepair(const struct diff_filepair *p, int i)
5388{
5389        diff_debug_filespec(p->one, i, "one");
5390        diff_debug_filespec(p->two, i, "two");
5391        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
5392                p->score, p->status ? p->status : '?',
5393                p->one->rename_used, p->broken_pair);
5394}
5395
5396void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
5397{
5398        int i;
5399        if (msg)
5400                fprintf(stderr, "%s\n", msg);
5401        fprintf(stderr, "q->nr = %d\n", q->nr);
5402        for (i = 0; i < q->nr; i++) {
5403                struct diff_filepair *p = q->queue[i];
5404                diff_debug_filepair(p, i);
5405        }
5406}
5407#endif
5408
5409static void diff_resolve_rename_copy(void)
5410{
5411        int i;
5412        struct diff_filepair *p;
5413        struct diff_queue_struct *q = &diff_queued_diff;
5414
5415        diff_debug_queue("resolve-rename-copy", q);
5416
5417        for (i = 0; i < q->nr; i++) {
5418                p = q->queue[i];
5419                p->status = 0; /* undecided */
5420                if (DIFF_PAIR_UNMERGED(p))
5421                        p->status = DIFF_STATUS_UNMERGED;
5422                else if (!DIFF_FILE_VALID(p->one))
5423                        p->status = DIFF_STATUS_ADDED;
5424                else if (!DIFF_FILE_VALID(p->two))
5425                        p->status = DIFF_STATUS_DELETED;
5426                else if (DIFF_PAIR_TYPE_CHANGED(p))
5427                        p->status = DIFF_STATUS_TYPE_CHANGED;
5428
5429                /* from this point on, we are dealing with a pair
5430                 * whose both sides are valid and of the same type, i.e.
5431                 * either in-place edit or rename/copy edit.
5432                 */
5433                else if (DIFF_PAIR_RENAME(p)) {
5434                        /*
5435                         * A rename might have re-connected a broken
5436                         * pair up, causing the pathnames to be the
5437                         * same again. If so, that's not a rename at
5438                         * all, just a modification..
5439                         *
5440                         * Otherwise, see if this source was used for
5441                         * multiple renames, in which case we decrement
5442                         * the count, and call it a copy.
5443                         */
5444                        if (!strcmp(p->one->path, p->two->path))
5445                                p->status = DIFF_STATUS_MODIFIED;
5446                        else if (--p->one->rename_used > 0)
5447                                p->status = DIFF_STATUS_COPIED;
5448                        else
5449                                p->status = DIFF_STATUS_RENAMED;
5450                }
5451                else if (oidcmp(&p->one->oid, &p->two->oid) ||
5452                         p->one->mode != p->two->mode ||
5453                         p->one->dirty_submodule ||
5454                         p->two->dirty_submodule ||
5455                         is_null_oid(&p->one->oid))
5456                        p->status = DIFF_STATUS_MODIFIED;
5457                else {
5458                        /* This is a "no-change" entry and should not
5459                         * happen anymore, but prepare for broken callers.
5460                         */
5461                        error("feeding unmodified %s to diffcore",
5462                              p->one->path);
5463                        p->status = DIFF_STATUS_UNKNOWN;
5464                }
5465        }
5466        diff_debug_queue("resolve-rename-copy done", q);
5467}
5468
5469static int check_pair_status(struct diff_filepair *p)
5470{
5471        switch (p->status) {
5472        case DIFF_STATUS_UNKNOWN:
5473                return 0;
5474        case 0:
5475                die("internal error in diff-resolve-rename-copy");
5476        default:
5477                return 1;
5478        }
5479}
5480
5481static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
5482{
5483        int fmt = opt->output_format;
5484
5485        if (fmt & DIFF_FORMAT_CHECKDIFF)
5486                diff_flush_checkdiff(p, opt);
5487        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
5488                diff_flush_raw(p, opt);
5489        else if (fmt & DIFF_FORMAT_NAME) {
5490                const char *name_a, *name_b;
5491                name_a = p->two->path;
5492                name_b = NULL;
5493                strip_prefix(opt->prefix_length, &name_a, &name_b);
5494                fprintf(opt->file, "%s", diff_line_prefix(opt));
5495                write_name_quoted(name_a, opt->file, opt->line_termination);
5496        }
5497}
5498
5499static void show_file_mode_name(struct diff_options *opt, const char *newdelete, struct diff_filespec *fs)
5500{
5501        struct strbuf sb = STRBUF_INIT;
5502        if (fs->mode)
5503                strbuf_addf(&sb, " %s mode %06o ", newdelete, fs->mode);
5504        else
5505                strbuf_addf(&sb, " %s ", newdelete);
5506
5507        quote_c_style(fs->path, &sb, NULL, 0);
5508        strbuf_addch(&sb, '\n');
5509        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5510                         sb.buf, sb.len, 0);
5511        strbuf_release(&sb);
5512}
5513
5514static void show_mode_change(struct diff_options *opt, struct diff_filepair *p,
5515                int show_name)
5516{
5517        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
5518                struct strbuf sb = STRBUF_INIT;
5519                strbuf_addf(&sb, " mode change %06o => %06o",
5520                            p->one->mode, p->two->mode);
5521                if (show_name) {
5522                        strbuf_addch(&sb, ' ');
5523                        quote_c_style(p->two->path, &sb, NULL, 0);
5524                }
5525                strbuf_addch(&sb, '\n');
5526                emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5527                                 sb.buf, sb.len, 0);
5528                strbuf_release(&sb);
5529        }
5530}
5531
5532static void show_rename_copy(struct diff_options *opt, const char *renamecopy,
5533                struct diff_filepair *p)
5534{
5535        struct strbuf sb = STRBUF_INIT;
5536        struct strbuf names = STRBUF_INIT;
5537
5538        pprint_rename(&names, p->one->path, p->two->path);
5539        strbuf_addf(&sb, " %s %s (%d%%)\n",
5540                    renamecopy, names.buf, similarity_index(p));
5541        strbuf_release(&names);
5542        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5543                                 sb.buf, sb.len, 0);
5544        show_mode_change(opt, p, 0);
5545        strbuf_release(&sb);
5546}
5547
5548static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
5549{
5550        switch(p->status) {
5551        case DIFF_STATUS_DELETED:
5552                show_file_mode_name(opt, "delete", p->one);
5553                break;
5554        case DIFF_STATUS_ADDED:
5555                show_file_mode_name(opt, "create", p->two);
5556                break;
5557        case DIFF_STATUS_COPIED:
5558                show_rename_copy(opt, "copy", p);
5559                break;
5560        case DIFF_STATUS_RENAMED:
5561                show_rename_copy(opt, "rename", p);
5562                break;
5563        default:
5564                if (p->score) {
5565                        struct strbuf sb = STRBUF_INIT;
5566                        strbuf_addstr(&sb, " rewrite ");
5567                        quote_c_style(p->two->path, &sb, NULL, 0);
5568                        strbuf_addf(&sb, " (%d%%)\n", similarity_index(p));
5569                        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5570                                         sb.buf, sb.len, 0);
5571                        strbuf_release(&sb);
5572                }
5573                show_mode_change(opt, p, !p->score);
5574                break;
5575        }
5576}
5577
5578struct patch_id_t {
5579        git_SHA_CTX *ctx;
5580        int patchlen;
5581};
5582
5583static int remove_space(char *line, int len)
5584{
5585        int i;
5586        char *dst = line;
5587        unsigned char c;
5588
5589        for (i = 0; i < len; i++)
5590                if (!isspace((c = line[i])))
5591                        *dst++ = c;
5592
5593        return dst - line;
5594}
5595
5596static void patch_id_consume(void *priv, char *line, unsigned long len)
5597{
5598        struct patch_id_t *data = priv;
5599        int new_len;
5600
5601        /* Ignore line numbers when computing the SHA1 of the patch */
5602        if (starts_with(line, "@@ -"))
5603                return;
5604
5605        new_len = remove_space(line, len);
5606
5607        git_SHA1_Update(data->ctx, line, new_len);
5608        data->patchlen += new_len;
5609}
5610
5611static void patch_id_add_string(git_SHA_CTX *ctx, const char *str)
5612{
5613        git_SHA1_Update(ctx, str, strlen(str));
5614}
5615
5616static void patch_id_add_mode(git_SHA_CTX *ctx, unsigned mode)
5617{
5618        /* large enough for 2^32 in octal */
5619        char buf[12];
5620        int len = xsnprintf(buf, sizeof(buf), "%06o", mode);
5621        git_SHA1_Update(ctx, buf, len);
5622}
5623
5624/* returns 0 upon success, and writes result into sha1 */
5625static int diff_get_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5626{
5627        struct diff_queue_struct *q = &diff_queued_diff;
5628        int i;
5629        git_SHA_CTX ctx;
5630        struct patch_id_t data;
5631
5632        git_SHA1_Init(&ctx);
5633        memset(&data, 0, sizeof(struct patch_id_t));
5634        data.ctx = &ctx;
5635
5636        for (i = 0; i < q->nr; i++) {
5637                xpparam_t xpp;
5638                xdemitconf_t xecfg;
5639                mmfile_t mf1, mf2;
5640                struct diff_filepair *p = q->queue[i];
5641                int len1, len2;
5642
5643                memset(&xpp, 0, sizeof(xpp));
5644                memset(&xecfg, 0, sizeof(xecfg));
5645                if (p->status == 0)
5646                        return error("internal diff status error");
5647                if (p->status == DIFF_STATUS_UNKNOWN)
5648                        continue;
5649                if (diff_unmodified_pair(p))
5650                        continue;
5651                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5652                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5653                        continue;
5654                if (DIFF_PAIR_UNMERGED(p))
5655                        continue;
5656
5657                diff_fill_oid_info(p->one);
5658                diff_fill_oid_info(p->two);
5659
5660                len1 = remove_space(p->one->path, strlen(p->one->path));
5661                len2 = remove_space(p->two->path, strlen(p->two->path));
5662                patch_id_add_string(&ctx, "diff--git");
5663                patch_id_add_string(&ctx, "a/");
5664                git_SHA1_Update(&ctx, p->one->path, len1);
5665                patch_id_add_string(&ctx, "b/");
5666                git_SHA1_Update(&ctx, p->two->path, len2);
5667
5668                if (p->one->mode == 0) {
5669                        patch_id_add_string(&ctx, "newfilemode");
5670                        patch_id_add_mode(&ctx, p->two->mode);
5671                        patch_id_add_string(&ctx, "---/dev/null");
5672                        patch_id_add_string(&ctx, "+++b/");
5673                        git_SHA1_Update(&ctx, p->two->path, len2);
5674                } else if (p->two->mode == 0) {
5675                        patch_id_add_string(&ctx, "deletedfilemode");
5676                        patch_id_add_mode(&ctx, p->one->mode);
5677                        patch_id_add_string(&ctx, "---a/");
5678                        git_SHA1_Update(&ctx, p->one->path, len1);
5679                        patch_id_add_string(&ctx, "+++/dev/null");
5680                } else {
5681                        patch_id_add_string(&ctx, "---a/");
5682                        git_SHA1_Update(&ctx, p->one->path, len1);
5683                        patch_id_add_string(&ctx, "+++b/");
5684                        git_SHA1_Update(&ctx, p->two->path, len2);
5685                }
5686
5687                if (diff_header_only)
5688                        continue;
5689
5690                if (fill_mmfile(&mf1, p->one) < 0 ||
5691                    fill_mmfile(&mf2, p->two) < 0)
5692                        return error("unable to read files to diff");
5693
5694                if (diff_filespec_is_binary(p->one) ||
5695                    diff_filespec_is_binary(p->two)) {
5696                        git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
5697                                        GIT_SHA1_HEXSZ);
5698                        git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
5699                                        GIT_SHA1_HEXSZ);
5700                        continue;
5701                }
5702
5703                xpp.flags = 0;
5704                xecfg.ctxlen = 3;
5705                xecfg.flags = 0;
5706                if (xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
5707                                  &xpp, &xecfg))
5708                        return error("unable to generate patch-id diff for %s",
5709                                     p->one->path);
5710        }
5711
5712        git_SHA1_Final(oid->hash, &ctx);
5713        return 0;
5714}
5715
5716int diff_flush_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5717{
5718        struct diff_queue_struct *q = &diff_queued_diff;
5719        int i;
5720        int result = diff_get_patch_id(options, oid, diff_header_only);
5721
5722        for (i = 0; i < q->nr; i++)
5723                diff_free_filepair(q->queue[i]);
5724
5725        free(q->queue);
5726        DIFF_QUEUE_CLEAR(q);
5727
5728        return result;
5729}
5730
5731static int is_summary_empty(const struct diff_queue_struct *q)
5732{
5733        int i;
5734
5735        for (i = 0; i < q->nr; i++) {
5736                const struct diff_filepair *p = q->queue[i];
5737
5738                switch (p->status) {
5739                case DIFF_STATUS_DELETED:
5740                case DIFF_STATUS_ADDED:
5741                case DIFF_STATUS_COPIED:
5742                case DIFF_STATUS_RENAMED:
5743                        return 0;
5744                default:
5745                        if (p->score)
5746                                return 0;
5747                        if (p->one->mode && p->two->mode &&
5748                            p->one->mode != p->two->mode)
5749                                return 0;
5750                        break;
5751                }
5752        }
5753        return 1;
5754}
5755
5756static const char rename_limit_warning[] =
5757N_("inexact rename detection was skipped due to too many files.");
5758
5759static const char degrade_cc_to_c_warning[] =
5760N_("only found copies from modified paths due to too many files.");
5761
5762static const char rename_limit_advice[] =
5763N_("you may want to set your %s variable to at least "
5764   "%d and retry the command.");
5765
5766void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
5767{
5768        fflush(stdout);
5769        if (degraded_cc)
5770                warning(_(degrade_cc_to_c_warning));
5771        else if (needed)
5772                warning(_(rename_limit_warning));
5773        else
5774                return;
5775        if (0 < needed)
5776                warning(_(rename_limit_advice), varname, needed);
5777}
5778
5779static void diff_flush_patch_all_file_pairs(struct diff_options *o)
5780{
5781        int i;
5782        static struct emitted_diff_symbols esm = EMITTED_DIFF_SYMBOLS_INIT;
5783        struct diff_queue_struct *q = &diff_queued_diff;
5784
5785        if (WSEH_NEW & WS_RULE_MASK)
5786                BUG("WS rules bit mask overlaps with diff symbol flags");
5787
5788        if (o->color_moved)
5789                o->emitted_symbols = &esm;
5790
5791        for (i = 0; i < q->nr; i++) {
5792                struct diff_filepair *p = q->queue[i];
5793                if (check_pair_status(p))
5794                        diff_flush_patch(p, o);
5795        }
5796
5797        if (o->emitted_symbols) {
5798                if (o->color_moved) {
5799                        struct hashmap add_lines, del_lines;
5800
5801                        if (o->color_moved_ws_handling &
5802                            COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
5803                                o->color_moved_ws_handling |= XDF_IGNORE_WHITESPACE;
5804
5805                        hashmap_init(&del_lines, moved_entry_cmp, o, 0);
5806                        hashmap_init(&add_lines, moved_entry_cmp, o, 0);
5807
5808                        add_lines_to_move_detection(o, &add_lines, &del_lines);
5809                        mark_color_as_moved(o, &add_lines, &del_lines);
5810                        if (o->color_moved == COLOR_MOVED_ZEBRA_DIM)
5811                                dim_moved_lines(o);
5812
5813                        hashmap_free(&add_lines, 0);
5814                        hashmap_free(&del_lines, 0);
5815                }
5816
5817                for (i = 0; i < esm.nr; i++)
5818                        emit_diff_symbol_from_struct(o, &esm.buf[i]);
5819
5820                for (i = 0; i < esm.nr; i++)
5821                        free((void *)esm.buf[i].line);
5822        }
5823        esm.nr = 0;
5824}
5825
5826void diff_flush(struct diff_options *options)
5827{
5828        struct diff_queue_struct *q = &diff_queued_diff;
5829        int i, output_format = options->output_format;
5830        int separator = 0;
5831        int dirstat_by_line = 0;
5832
5833        /*
5834         * Order: raw, stat, summary, patch
5835         * or:    name/name-status/checkdiff (other bits clear)
5836         */
5837        if (!q->nr)
5838                goto free_queue;
5839
5840        if (output_format & (DIFF_FORMAT_RAW |
5841                             DIFF_FORMAT_NAME |
5842                             DIFF_FORMAT_NAME_STATUS |
5843                             DIFF_FORMAT_CHECKDIFF)) {
5844                for (i = 0; i < q->nr; i++) {
5845                        struct diff_filepair *p = q->queue[i];
5846                        if (check_pair_status(p))
5847                                flush_one_pair(p, options);
5848                }
5849                separator++;
5850        }
5851
5852        if (output_format & DIFF_FORMAT_DIRSTAT && options->flags.dirstat_by_line)
5853                dirstat_by_line = 1;
5854
5855        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
5856            dirstat_by_line) {
5857                struct diffstat_t diffstat;
5858
5859                memset(&diffstat, 0, sizeof(struct diffstat_t));
5860                for (i = 0; i < q->nr; i++) {
5861                        struct diff_filepair *p = q->queue[i];
5862                        if (check_pair_status(p))
5863                                diff_flush_stat(p, options, &diffstat);
5864                }
5865                if (output_format & DIFF_FORMAT_NUMSTAT)
5866                        show_numstat(&diffstat, options);
5867                if (output_format & DIFF_FORMAT_DIFFSTAT)
5868                        show_stats(&diffstat, options);
5869                if (output_format & DIFF_FORMAT_SHORTSTAT)
5870                        show_shortstats(&diffstat, options);
5871                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
5872                        show_dirstat_by_line(&diffstat, options);
5873                free_diffstat_info(&diffstat);
5874                separator++;
5875        }
5876        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
5877                show_dirstat(options);
5878
5879        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
5880                for (i = 0; i < q->nr; i++) {
5881                        diff_summary(options, q->queue[i]);
5882                }
5883                separator++;
5884        }
5885
5886        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
5887            options->flags.exit_with_status &&
5888            options->flags.diff_from_contents) {
5889                /*
5890                 * run diff_flush_patch for the exit status. setting
5891                 * options->file to /dev/null should be safe, because we
5892                 * aren't supposed to produce any output anyway.
5893                 */
5894                if (options->close_file)
5895                        fclose(options->file);
5896                options->file = xfopen("/dev/null", "w");
5897                options->close_file = 1;
5898                options->color_moved = 0;
5899                for (i = 0; i < q->nr; i++) {
5900                        struct diff_filepair *p = q->queue[i];
5901                        if (check_pair_status(p))
5902                                diff_flush_patch(p, options);
5903                        if (options->found_changes)
5904                                break;
5905                }
5906        }
5907
5908        if (output_format & DIFF_FORMAT_PATCH) {
5909                if (separator) {
5910                        emit_diff_symbol(options, DIFF_SYMBOL_SEPARATOR, NULL, 0, 0);
5911                        if (options->stat_sep)
5912                                /* attach patch instead of inline */
5913                                emit_diff_symbol(options, DIFF_SYMBOL_STAT_SEP,
5914                                                 NULL, 0, 0);
5915                }
5916
5917                diff_flush_patch_all_file_pairs(options);
5918        }
5919
5920        if (output_format & DIFF_FORMAT_CALLBACK)
5921                options->format_callback(q, options, options->format_callback_data);
5922
5923        for (i = 0; i < q->nr; i++)
5924                diff_free_filepair(q->queue[i]);
5925free_queue:
5926        free(q->queue);
5927        DIFF_QUEUE_CLEAR(q);
5928        if (options->close_file)
5929                fclose(options->file);
5930
5931        /*
5932         * Report the content-level differences with HAS_CHANGES;
5933         * diff_addremove/diff_change does not set the bit when
5934         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
5935         */
5936        if (options->flags.diff_from_contents) {
5937                if (options->found_changes)
5938                        options->flags.has_changes = 1;
5939                else
5940                        options->flags.has_changes = 0;
5941        }
5942}
5943
5944static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
5945{
5946        return (((p->status == DIFF_STATUS_MODIFIED) &&
5947                 ((p->score &&
5948                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
5949                  (!p->score &&
5950                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
5951                ((p->status != DIFF_STATUS_MODIFIED) &&
5952                 filter_bit_tst(p->status, options)));
5953}
5954
5955static void diffcore_apply_filter(struct diff_options *options)
5956{
5957        int i;
5958        struct diff_queue_struct *q = &diff_queued_diff;
5959        struct diff_queue_struct outq;
5960
5961        DIFF_QUEUE_CLEAR(&outq);
5962
5963        if (!options->filter)
5964                return;
5965
5966        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
5967                int found;
5968                for (i = found = 0; !found && i < q->nr; i++) {
5969                        if (match_filter(options, q->queue[i]))
5970                                found++;
5971                }
5972                if (found)
5973                        return;
5974
5975                /* otherwise we will clear the whole queue
5976                 * by copying the empty outq at the end of this
5977                 * function, but first clear the current entries
5978                 * in the queue.
5979                 */
5980                for (i = 0; i < q->nr; i++)
5981                        diff_free_filepair(q->queue[i]);
5982        }
5983        else {
5984                /* Only the matching ones */
5985                for (i = 0; i < q->nr; i++) {
5986                        struct diff_filepair *p = q->queue[i];
5987                        if (match_filter(options, p))
5988                                diff_q(&outq, p);
5989                        else
5990                                diff_free_filepair(p);
5991                }
5992        }
5993        free(q->queue);
5994        *q = outq;
5995}
5996
5997/* Check whether two filespecs with the same mode and size are identical */
5998static int diff_filespec_is_identical(struct diff_filespec *one,
5999                                      struct diff_filespec *two)
6000{
6001        if (S_ISGITLINK(one->mode))
6002                return 0;
6003        if (diff_populate_filespec(one, 0))
6004                return 0;
6005        if (diff_populate_filespec(two, 0))
6006                return 0;
6007        return !memcmp(one->data, two->data, one->size);
6008}
6009
6010static int diff_filespec_check_stat_unmatch(struct diff_filepair *p)
6011{
6012        if (p->done_skip_stat_unmatch)
6013                return p->skip_stat_unmatch_result;
6014
6015        p->done_skip_stat_unmatch = 1;
6016        p->skip_stat_unmatch_result = 0;
6017        /*
6018         * 1. Entries that come from stat info dirtiness
6019         *    always have both sides (iow, not create/delete),
6020         *    one side of the object name is unknown, with
6021         *    the same mode and size.  Keep the ones that
6022         *    do not match these criteria.  They have real
6023         *    differences.
6024         *
6025         * 2. At this point, the file is known to be modified,
6026         *    with the same mode and size, and the object
6027         *    name of one side is unknown.  Need to inspect
6028         *    the identical contents.
6029         */
6030        if (!DIFF_FILE_VALID(p->one) || /* (1) */
6031            !DIFF_FILE_VALID(p->two) ||
6032            (p->one->oid_valid && p->two->oid_valid) ||
6033            (p->one->mode != p->two->mode) ||
6034            diff_populate_filespec(p->one, CHECK_SIZE_ONLY) ||
6035            diff_populate_filespec(p->two, CHECK_SIZE_ONLY) ||
6036            (p->one->size != p->two->size) ||
6037            !diff_filespec_is_identical(p->one, p->two)) /* (2) */
6038                p->skip_stat_unmatch_result = 1;
6039        return p->skip_stat_unmatch_result;
6040}
6041
6042static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
6043{
6044        int i;
6045        struct diff_queue_struct *q = &diff_queued_diff;
6046        struct diff_queue_struct outq;
6047        DIFF_QUEUE_CLEAR(&outq);
6048
6049        for (i = 0; i < q->nr; i++) {
6050                struct diff_filepair *p = q->queue[i];
6051
6052                if (diff_filespec_check_stat_unmatch(p))
6053                        diff_q(&outq, p);
6054                else {
6055                        /*
6056                         * The caller can subtract 1 from skip_stat_unmatch
6057                         * to determine how many paths were dirty only
6058                         * due to stat info mismatch.
6059                         */
6060                        if (!diffopt->flags.no_index)
6061                                diffopt->skip_stat_unmatch++;
6062                        diff_free_filepair(p);
6063                }
6064        }
6065        free(q->queue);
6066        *q = outq;
6067}
6068
6069static int diffnamecmp(const void *a_, const void *b_)
6070{
6071        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
6072        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
6073        const char *name_a, *name_b;
6074
6075        name_a = a->one ? a->one->path : a->two->path;
6076        name_b = b->one ? b->one->path : b->two->path;
6077        return strcmp(name_a, name_b);
6078}
6079
6080void diffcore_fix_diff_index(struct diff_options *options)
6081{
6082        struct diff_queue_struct *q = &diff_queued_diff;
6083        QSORT(q->queue, q->nr, diffnamecmp);
6084}
6085
6086void diffcore_std(struct diff_options *options)
6087{
6088        /* NOTE please keep the following in sync with diff_tree_combined() */
6089        if (options->skip_stat_unmatch)
6090                diffcore_skip_stat_unmatch(options);
6091        if (!options->found_follow) {
6092                /* See try_to_follow_renames() in tree-diff.c */
6093                if (options->break_opt != -1)
6094                        diffcore_break(options->break_opt);
6095                if (options->detect_rename)
6096                        diffcore_rename(options);
6097                if (options->break_opt != -1)
6098                        diffcore_merge_broken();
6099        }
6100        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
6101                diffcore_pickaxe(options);
6102        if (options->orderfile)
6103                diffcore_order(options->orderfile);
6104        if (!options->found_follow)
6105                /* See try_to_follow_renames() in tree-diff.c */
6106                diff_resolve_rename_copy();
6107        diffcore_apply_filter(options);
6108
6109        if (diff_queued_diff.nr && !options->flags.diff_from_contents)
6110                options->flags.has_changes = 1;
6111        else
6112                options->flags.has_changes = 0;
6113
6114        options->found_follow = 0;
6115}
6116
6117int diff_result_code(struct diff_options *opt, int status)
6118{
6119        int result = 0;
6120
6121        diff_warn_rename_limit("diff.renameLimit",
6122                               opt->needed_rename_limit,
6123                               opt->degraded_cc_to_c);
6124        if (!opt->flags.exit_with_status &&
6125            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
6126                return status;
6127        if (opt->flags.exit_with_status &&
6128            opt->flags.has_changes)
6129                result |= 01;
6130        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
6131            opt->flags.check_failed)
6132                result |= 02;
6133        return result;
6134}
6135
6136int diff_can_quit_early(struct diff_options *opt)
6137{
6138        return (opt->flags.quick &&
6139                !opt->filter &&
6140                opt->flags.has_changes);
6141}
6142
6143/*
6144 * Shall changes to this submodule be ignored?
6145 *
6146 * Submodule changes can be configured to be ignored separately for each path,
6147 * but that configuration can be overridden from the command line.
6148 */
6149static int is_submodule_ignored(const char *path, struct diff_options *options)
6150{
6151        int ignored = 0;
6152        struct diff_flags orig_flags = options->flags;
6153        if (!options->flags.override_submodule_config)
6154                set_diffopt_flags_from_submodule_config(options, path);
6155        if (options->flags.ignore_submodules)
6156                ignored = 1;
6157        options->flags = orig_flags;
6158        return ignored;
6159}
6160
6161void diff_addremove(struct diff_options *options,
6162                    int addremove, unsigned mode,
6163                    const struct object_id *oid,
6164                    int oid_valid,
6165                    const char *concatpath, unsigned dirty_submodule)
6166{
6167        struct diff_filespec *one, *two;
6168
6169        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
6170                return;
6171
6172        /* This may look odd, but it is a preparation for
6173         * feeding "there are unchanged files which should
6174         * not produce diffs, but when you are doing copy
6175         * detection you would need them, so here they are"
6176         * entries to the diff-core.  They will be prefixed
6177         * with something like '=' or '*' (I haven't decided
6178         * which but should not make any difference).
6179         * Feeding the same new and old to diff_change()
6180         * also has the same effect.
6181         * Before the final output happens, they are pruned after
6182         * merged into rename/copy pairs as appropriate.
6183         */
6184        if (options->flags.reverse_diff)
6185                addremove = (addremove == '+' ? '-' :
6186                             addremove == '-' ? '+' : addremove);
6187
6188        if (options->prefix &&
6189            strncmp(concatpath, options->prefix, options->prefix_length))
6190                return;
6191
6192        one = alloc_filespec(concatpath);
6193        two = alloc_filespec(concatpath);
6194
6195        if (addremove != '+')
6196                fill_filespec(one, oid, oid_valid, mode);
6197        if (addremove != '-') {
6198                fill_filespec(two, oid, oid_valid, mode);
6199                two->dirty_submodule = dirty_submodule;
6200        }
6201
6202        diff_queue(&diff_queued_diff, one, two);
6203        if (!options->flags.diff_from_contents)
6204                options->flags.has_changes = 1;
6205}
6206
6207void diff_change(struct diff_options *options,
6208                 unsigned old_mode, unsigned new_mode,
6209                 const struct object_id *old_oid,
6210                 const struct object_id *new_oid,
6211                 int old_oid_valid, int new_oid_valid,
6212                 const char *concatpath,
6213                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
6214{
6215        struct diff_filespec *one, *two;
6216        struct diff_filepair *p;
6217
6218        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
6219            is_submodule_ignored(concatpath, options))
6220                return;
6221
6222        if (options->flags.reverse_diff) {
6223                SWAP(old_mode, new_mode);
6224                SWAP(old_oid, new_oid);
6225                SWAP(old_oid_valid, new_oid_valid);
6226                SWAP(old_dirty_submodule, new_dirty_submodule);
6227        }
6228
6229        if (options->prefix &&
6230            strncmp(concatpath, options->prefix, options->prefix_length))
6231                return;
6232
6233        one = alloc_filespec(concatpath);
6234        two = alloc_filespec(concatpath);
6235        fill_filespec(one, old_oid, old_oid_valid, old_mode);
6236        fill_filespec(two, new_oid, new_oid_valid, new_mode);
6237        one->dirty_submodule = old_dirty_submodule;
6238        two->dirty_submodule = new_dirty_submodule;
6239        p = diff_queue(&diff_queued_diff, one, two);
6240
6241        if (options->flags.diff_from_contents)
6242                return;
6243
6244        if (options->flags.quick && options->skip_stat_unmatch &&
6245            !diff_filespec_check_stat_unmatch(p))
6246                return;
6247
6248        options->flags.has_changes = 1;
6249}
6250
6251struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
6252{
6253        struct diff_filepair *pair;
6254        struct diff_filespec *one, *two;
6255
6256        if (options->prefix &&
6257            strncmp(path, options->prefix, options->prefix_length))
6258                return NULL;
6259
6260        one = alloc_filespec(path);
6261        two = alloc_filespec(path);
6262        pair = diff_queue(&diff_queued_diff, one, two);
6263        pair->is_unmerged = 1;
6264        return pair;
6265}
6266
6267static char *run_textconv(const char *pgm, struct diff_filespec *spec,
6268                size_t *outsize)
6269{
6270        struct diff_tempfile *temp;
6271        const char *argv[3];
6272        const char **arg = argv;
6273        struct child_process child = CHILD_PROCESS_INIT;
6274        struct strbuf buf = STRBUF_INIT;
6275        int err = 0;
6276
6277        temp = prepare_temp_file(spec->path, spec);
6278        *arg++ = pgm;
6279        *arg++ = temp->name;
6280        *arg = NULL;
6281
6282        child.use_shell = 1;
6283        child.argv = argv;
6284        child.out = -1;
6285        if (start_command(&child)) {
6286                remove_tempfile();
6287                return NULL;
6288        }
6289
6290        if (strbuf_read(&buf, child.out, 0) < 0)
6291                err = error("error reading from textconv command '%s'", pgm);
6292        close(child.out);
6293
6294        if (finish_command(&child) || err) {
6295                strbuf_release(&buf);
6296                remove_tempfile();
6297                return NULL;
6298        }
6299        remove_tempfile();
6300
6301        return strbuf_detach(&buf, outsize);
6302}
6303
6304size_t fill_textconv(struct userdiff_driver *driver,
6305                     struct diff_filespec *df,
6306                     char **outbuf)
6307{
6308        size_t size;
6309
6310        if (!driver) {
6311                if (!DIFF_FILE_VALID(df)) {
6312                        *outbuf = "";
6313                        return 0;
6314                }
6315                if (diff_populate_filespec(df, 0))
6316                        die("unable to read files to diff");
6317                *outbuf = df->data;
6318                return df->size;
6319        }
6320
6321        if (!driver->textconv)
6322                BUG("fill_textconv called with non-textconv driver");
6323
6324        if (driver->textconv_cache && df->oid_valid) {
6325                *outbuf = notes_cache_get(driver->textconv_cache,
6326                                          &df->oid,
6327                                          &size);
6328                if (*outbuf)
6329                        return size;
6330        }
6331
6332        *outbuf = run_textconv(driver->textconv, df, &size);
6333        if (!*outbuf)
6334                die("unable to read files to diff");
6335
6336        if (driver->textconv_cache && df->oid_valid) {
6337                /* ignore errors, as we might be in a readonly repository */
6338                notes_cache_put(driver->textconv_cache, &df->oid, *outbuf,
6339                                size);
6340                /*
6341                 * we could save up changes and flush them all at the end,
6342                 * but we would need an extra call after all diffing is done.
6343                 * Since generating a cache entry is the slow path anyway,
6344                 * this extra overhead probably isn't a big deal.
6345                 */
6346                notes_cache_write(driver->textconv_cache);
6347        }
6348
6349        return size;
6350}
6351
6352int textconv_object(const char *path,
6353                    unsigned mode,
6354                    const struct object_id *oid,
6355                    int oid_valid,
6356                    char **buf,
6357                    unsigned long *buf_size)
6358{
6359        struct diff_filespec *df;
6360        struct userdiff_driver *textconv;
6361
6362        df = alloc_filespec(path);
6363        fill_filespec(df, oid, oid_valid, mode);
6364        textconv = get_textconv(df);
6365        if (!textconv) {
6366                free_filespec(df);
6367                return 0;
6368        }
6369
6370        *buf_size = fill_textconv(textconv, df, buf);
6371        free_filespec(df);
6372        return 1;
6373}
6374
6375void setup_diff_pager(struct diff_options *opt)
6376{
6377        /*
6378         * If the user asked for our exit code, then either they want --quiet
6379         * or --exit-code. We should definitely not bother with a pager in the
6380         * former case, as we will generate no output. Since we still properly
6381         * report our exit code even when a pager is run, we _could_ run a
6382         * pager with --exit-code. But since we have not done so historically,
6383         * and because it is easy to find people oneline advising "git diff
6384         * --exit-code" in hooks and other scripts, we do not do so.
6385         */
6386        if (!opt->flags.exit_with_status &&
6387            check_pager_config("diff") != 0)
6388                setup_pager();
6389}