c5c7739ce3452a8de97d6b6baf882cea3cbb9ef5
   1/*
   2 * Copyright (C) 2005 Junio C Hamano
   3 */
   4#include "cache.h"
   5#include "config.h"
   6#include "tempfile.h"
   7#include "quote.h"
   8#include "diff.h"
   9#include "diffcore.h"
  10#include "delta.h"
  11#include "xdiff-interface.h"
  12#include "color.h"
  13#include "attr.h"
  14#include "run-command.h"
  15#include "utf8.h"
  16#include "object-store.h"
  17#include "userdiff.h"
  18#include "submodule-config.h"
  19#include "submodule.h"
  20#include "hashmap.h"
  21#include "ll-merge.h"
  22#include "string-list.h"
  23#include "argv-array.h"
  24#include "graph.h"
  25#include "packfile.h"
  26#include "help.h"
  27
  28#ifdef NO_FAST_WORKING_DIRECTORY
  29#define FAST_WORKING_DIRECTORY 0
  30#else
  31#define FAST_WORKING_DIRECTORY 1
  32#endif
  33
  34static int diff_detect_rename_default;
  35static int diff_indent_heuristic = 1;
  36static int diff_rename_limit_default = 400;
  37static int diff_suppress_blank_empty;
  38static int diff_use_color_default = -1;
  39static int diff_color_moved_default;
  40static int diff_color_moved_ws_default;
  41static int diff_context_default = 3;
  42static int diff_interhunk_context_default;
  43static const char *diff_word_regex_cfg;
  44static const char *external_diff_cmd_cfg;
  45static const char *diff_order_file_cfg;
  46int diff_auto_refresh_index = 1;
  47static int diff_mnemonic_prefix;
  48static int diff_no_prefix;
  49static int diff_stat_graph_width;
  50static int diff_dirstat_permille_default = 30;
  51static struct diff_options default_diff_options;
  52static long diff_algorithm;
  53static unsigned ws_error_highlight_default = WSEH_NEW;
  54
  55static char diff_colors[][COLOR_MAXLEN] = {
  56        GIT_COLOR_RESET,
  57        GIT_COLOR_NORMAL,       /* CONTEXT */
  58        GIT_COLOR_BOLD,         /* METAINFO */
  59        GIT_COLOR_CYAN,         /* FRAGINFO */
  60        GIT_COLOR_RED,          /* OLD */
  61        GIT_COLOR_GREEN,        /* NEW */
  62        GIT_COLOR_YELLOW,       /* COMMIT */
  63        GIT_COLOR_BG_RED,       /* WHITESPACE */
  64        GIT_COLOR_NORMAL,       /* FUNCINFO */
  65        GIT_COLOR_BOLD_MAGENTA, /* OLD_MOVED */
  66        GIT_COLOR_BOLD_BLUE,    /* OLD_MOVED ALTERNATIVE */
  67        GIT_COLOR_FAINT,        /* OLD_MOVED_DIM */
  68        GIT_COLOR_FAINT_ITALIC, /* OLD_MOVED_ALTERNATIVE_DIM */
  69        GIT_COLOR_BOLD_CYAN,    /* NEW_MOVED */
  70        GIT_COLOR_BOLD_YELLOW,  /* NEW_MOVED ALTERNATIVE */
  71        GIT_COLOR_FAINT,        /* NEW_MOVED_DIM */
  72        GIT_COLOR_FAINT_ITALIC, /* NEW_MOVED_ALTERNATIVE_DIM */
  73        GIT_COLOR_FAINT,        /* CONTEXT_DIM */
  74        GIT_COLOR_FAINT_RED,    /* OLD_DIM */
  75        GIT_COLOR_FAINT_GREEN,  /* NEW_DIM */
  76        GIT_COLOR_BOLD,         /* CONTEXT_BOLD */
  77        GIT_COLOR_BOLD_RED,     /* OLD_BOLD */
  78        GIT_COLOR_BOLD_GREEN,   /* NEW_BOLD */
  79};
  80
  81static const char *color_diff_slots[] = {
  82        [DIFF_CONTEXT]                = "context",
  83        [DIFF_METAINFO]               = "meta",
  84        [DIFF_FRAGINFO]               = "frag",
  85        [DIFF_FILE_OLD]               = "old",
  86        [DIFF_FILE_NEW]               = "new",
  87        [DIFF_COMMIT]                 = "commit",
  88        [DIFF_WHITESPACE]             = "whitespace",
  89        [DIFF_FUNCINFO]               = "func",
  90        [DIFF_FILE_OLD_MOVED]         = "oldMoved",
  91        [DIFF_FILE_OLD_MOVED_ALT]     = "oldMovedAlternative",
  92        [DIFF_FILE_OLD_MOVED_DIM]     = "oldMovedDimmed",
  93        [DIFF_FILE_OLD_MOVED_ALT_DIM] = "oldMovedAlternativeDimmed",
  94        [DIFF_FILE_NEW_MOVED]         = "newMoved",
  95        [DIFF_FILE_NEW_MOVED_ALT]     = "newMovedAlternative",
  96        [DIFF_FILE_NEW_MOVED_DIM]     = "newMovedDimmed",
  97        [DIFF_FILE_NEW_MOVED_ALT_DIM] = "newMovedAlternativeDimmed",
  98        [DIFF_CONTEXT_DIM]            = "contextDimmed",
  99        [DIFF_FILE_OLD_DIM]           = "oldDimmed",
 100        [DIFF_FILE_NEW_DIM]           = "newDimmed",
 101        [DIFF_CONTEXT_BOLD]           = "contextBold",
 102        [DIFF_FILE_OLD_BOLD]          = "oldBold",
 103        [DIFF_FILE_NEW_BOLD]          = "newBold",
 104};
 105
 106static NORETURN void die_want_option(const char *option_name)
 107{
 108        die(_("option '%s' requires a value"), option_name);
 109}
 110
 111define_list_config_array_extra(color_diff_slots, {"plain"});
 112
 113static int parse_diff_color_slot(const char *var)
 114{
 115        if (!strcasecmp(var, "plain"))
 116                return DIFF_CONTEXT;
 117        return LOOKUP_CONFIG(color_diff_slots, var);
 118}
 119
 120static int parse_dirstat_params(struct diff_options *options, const char *params_string,
 121                                struct strbuf *errmsg)
 122{
 123        char *params_copy = xstrdup(params_string);
 124        struct string_list params = STRING_LIST_INIT_NODUP;
 125        int ret = 0;
 126        int i;
 127
 128        if (*params_copy)
 129                string_list_split_in_place(&params, params_copy, ',', -1);
 130        for (i = 0; i < params.nr; i++) {
 131                const char *p = params.items[i].string;
 132                if (!strcmp(p, "changes")) {
 133                        options->flags.dirstat_by_line = 0;
 134                        options->flags.dirstat_by_file = 0;
 135                } else if (!strcmp(p, "lines")) {
 136                        options->flags.dirstat_by_line = 1;
 137                        options->flags.dirstat_by_file = 0;
 138                } else if (!strcmp(p, "files")) {
 139                        options->flags.dirstat_by_line = 0;
 140                        options->flags.dirstat_by_file = 1;
 141                } else if (!strcmp(p, "noncumulative")) {
 142                        options->flags.dirstat_cumulative = 0;
 143                } else if (!strcmp(p, "cumulative")) {
 144                        options->flags.dirstat_cumulative = 1;
 145                } else if (isdigit(*p)) {
 146                        char *end;
 147                        int permille = strtoul(p, &end, 10) * 10;
 148                        if (*end == '.' && isdigit(*++end)) {
 149                                /* only use first digit */
 150                                permille += *end - '0';
 151                                /* .. and ignore any further digits */
 152                                while (isdigit(*++end))
 153                                        ; /* nothing */
 154                        }
 155                        if (!*end)
 156                                options->dirstat_permille = permille;
 157                        else {
 158                                strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%s'\n"),
 159                                            p);
 160                                ret++;
 161                        }
 162                } else {
 163                        strbuf_addf(errmsg, _("  Unknown dirstat parameter '%s'\n"), p);
 164                        ret++;
 165                }
 166
 167        }
 168        string_list_clear(&params, 0);
 169        free(params_copy);
 170        return ret;
 171}
 172
 173static int parse_submodule_params(struct diff_options *options, const char *value)
 174{
 175        if (!strcmp(value, "log"))
 176                options->submodule_format = DIFF_SUBMODULE_LOG;
 177        else if (!strcmp(value, "short"))
 178                options->submodule_format = DIFF_SUBMODULE_SHORT;
 179        else if (!strcmp(value, "diff"))
 180                options->submodule_format = DIFF_SUBMODULE_INLINE_DIFF;
 181        else
 182                return -1;
 183        return 0;
 184}
 185
 186int git_config_rename(const char *var, const char *value)
 187{
 188        if (!value)
 189                return DIFF_DETECT_RENAME;
 190        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 191                return  DIFF_DETECT_COPY;
 192        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 193}
 194
 195long parse_algorithm_value(const char *value)
 196{
 197        if (!value)
 198                return -1;
 199        else if (!strcasecmp(value, "myers") || !strcasecmp(value, "default"))
 200                return 0;
 201        else if (!strcasecmp(value, "minimal"))
 202                return XDF_NEED_MINIMAL;
 203        else if (!strcasecmp(value, "patience"))
 204                return XDF_PATIENCE_DIFF;
 205        else if (!strcasecmp(value, "histogram"))
 206                return XDF_HISTOGRAM_DIFF;
 207        return -1;
 208}
 209
 210static int parse_one_token(const char **arg, const char *token)
 211{
 212        const char *rest;
 213        if (skip_prefix(*arg, token, &rest) && (!*rest || *rest == ',')) {
 214                *arg = rest;
 215                return 1;
 216        }
 217        return 0;
 218}
 219
 220static int parse_ws_error_highlight(const char *arg)
 221{
 222        const char *orig_arg = arg;
 223        unsigned val = 0;
 224
 225        while (*arg) {
 226                if (parse_one_token(&arg, "none"))
 227                        val = 0;
 228                else if (parse_one_token(&arg, "default"))
 229                        val = WSEH_NEW;
 230                else if (parse_one_token(&arg, "all"))
 231                        val = WSEH_NEW | WSEH_OLD | WSEH_CONTEXT;
 232                else if (parse_one_token(&arg, "new"))
 233                        val |= WSEH_NEW;
 234                else if (parse_one_token(&arg, "old"))
 235                        val |= WSEH_OLD;
 236                else if (parse_one_token(&arg, "context"))
 237                        val |= WSEH_CONTEXT;
 238                else {
 239                        return -1 - (int)(arg - orig_arg);
 240                }
 241                if (*arg)
 242                        arg++;
 243        }
 244        return val;
 245}
 246
 247/*
 248 * These are to give UI layer defaults.
 249 * The core-level commands such as git-diff-files should
 250 * never be affected by the setting of diff.renames
 251 * the user happens to have in the configuration file.
 252 */
 253void init_diff_ui_defaults(void)
 254{
 255        diff_detect_rename_default = DIFF_DETECT_RENAME;
 256}
 257
 258int git_diff_heuristic_config(const char *var, const char *value, void *cb)
 259{
 260        if (!strcmp(var, "diff.indentheuristic"))
 261                diff_indent_heuristic = git_config_bool(var, value);
 262        return 0;
 263}
 264
 265static int parse_color_moved(const char *arg)
 266{
 267        switch (git_parse_maybe_bool(arg)) {
 268        case 0:
 269                return COLOR_MOVED_NO;
 270        case 1:
 271                return COLOR_MOVED_DEFAULT;
 272        default:
 273                break;
 274        }
 275
 276        if (!strcmp(arg, "no"))
 277                return COLOR_MOVED_NO;
 278        else if (!strcmp(arg, "plain"))
 279                return COLOR_MOVED_PLAIN;
 280        else if (!strcmp(arg, "blocks"))
 281                return COLOR_MOVED_BLOCKS;
 282        else if (!strcmp(arg, "zebra"))
 283                return COLOR_MOVED_ZEBRA;
 284        else if (!strcmp(arg, "default"))
 285                return COLOR_MOVED_DEFAULT;
 286        else if (!strcmp(arg, "dimmed_zebra"))
 287                return COLOR_MOVED_ZEBRA_DIM;
 288        else
 289                return error(_("color moved setting must be one of 'no', 'default', 'blocks', 'zebra', 'dimmed_zebra', 'plain'"));
 290}
 291
 292static int parse_color_moved_ws(const char *arg)
 293{
 294        int ret = 0;
 295        struct string_list l = STRING_LIST_INIT_DUP;
 296        struct string_list_item *i;
 297
 298        string_list_split(&l, arg, ',', -1);
 299
 300        for_each_string_list_item(i, &l) {
 301                struct strbuf sb = STRBUF_INIT;
 302                strbuf_addstr(&sb, i->string);
 303                strbuf_trim(&sb);
 304
 305                if (!strcmp(sb.buf, "ignore-space-change"))
 306                        ret |= XDF_IGNORE_WHITESPACE_CHANGE;
 307                else if (!strcmp(sb.buf, "ignore-space-at-eol"))
 308                        ret |= XDF_IGNORE_WHITESPACE_AT_EOL;
 309                else if (!strcmp(sb.buf, "ignore-all-space"))
 310                        ret |= XDF_IGNORE_WHITESPACE;
 311                else if (!strcmp(sb.buf, "allow-indentation-change"))
 312                        ret |= COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE;
 313                else
 314                        error(_("ignoring unknown color-moved-ws mode '%s'"), sb.buf);
 315
 316                strbuf_release(&sb);
 317        }
 318
 319        if ((ret & COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) &&
 320            (ret & XDF_WHITESPACE_FLAGS))
 321                die(_("color-moved-ws: allow-indentation-change cannot be combined with other white space modes"));
 322
 323        string_list_clear(&l, 0);
 324
 325        return ret;
 326}
 327
 328int git_diff_ui_config(const char *var, const char *value, void *cb)
 329{
 330        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 331                diff_use_color_default = git_config_colorbool(var, value);
 332                return 0;
 333        }
 334        if (!strcmp(var, "diff.colormoved")) {
 335                int cm = parse_color_moved(value);
 336                if (cm < 0)
 337                        return -1;
 338                diff_color_moved_default = cm;
 339                return 0;
 340        }
 341        if (!strcmp(var, "diff.colormovedws")) {
 342                int cm = parse_color_moved_ws(value);
 343                if (cm < 0)
 344                        return -1;
 345                diff_color_moved_ws_default = cm;
 346                return 0;
 347        }
 348        if (!strcmp(var, "diff.context")) {
 349                diff_context_default = git_config_int(var, value);
 350                if (diff_context_default < 0)
 351                        return -1;
 352                return 0;
 353        }
 354        if (!strcmp(var, "diff.interhunkcontext")) {
 355                diff_interhunk_context_default = git_config_int(var, value);
 356                if (diff_interhunk_context_default < 0)
 357                        return -1;
 358                return 0;
 359        }
 360        if (!strcmp(var, "diff.renames")) {
 361                diff_detect_rename_default = git_config_rename(var, value);
 362                return 0;
 363        }
 364        if (!strcmp(var, "diff.autorefreshindex")) {
 365                diff_auto_refresh_index = git_config_bool(var, value);
 366                return 0;
 367        }
 368        if (!strcmp(var, "diff.mnemonicprefix")) {
 369                diff_mnemonic_prefix = git_config_bool(var, value);
 370                return 0;
 371        }
 372        if (!strcmp(var, "diff.noprefix")) {
 373                diff_no_prefix = git_config_bool(var, value);
 374                return 0;
 375        }
 376        if (!strcmp(var, "diff.statgraphwidth")) {
 377                diff_stat_graph_width = git_config_int(var, value);
 378                return 0;
 379        }
 380        if (!strcmp(var, "diff.external"))
 381                return git_config_string(&external_diff_cmd_cfg, var, value);
 382        if (!strcmp(var, "diff.wordregex"))
 383                return git_config_string(&diff_word_regex_cfg, var, value);
 384        if (!strcmp(var, "diff.orderfile"))
 385                return git_config_pathname(&diff_order_file_cfg, var, value);
 386
 387        if (!strcmp(var, "diff.ignoresubmodules"))
 388                handle_ignore_submodules_arg(&default_diff_options, value);
 389
 390        if (!strcmp(var, "diff.submodule")) {
 391                if (parse_submodule_params(&default_diff_options, value))
 392                        warning(_("Unknown value for 'diff.submodule' config variable: '%s'"),
 393                                value);
 394                return 0;
 395        }
 396
 397        if (!strcmp(var, "diff.algorithm")) {
 398                diff_algorithm = parse_algorithm_value(value);
 399                if (diff_algorithm < 0)
 400                        return -1;
 401                return 0;
 402        }
 403
 404        if (!strcmp(var, "diff.wserrorhighlight")) {
 405                int val = parse_ws_error_highlight(value);
 406                if (val < 0)
 407                        return -1;
 408                ws_error_highlight_default = val;
 409                return 0;
 410        }
 411
 412        if (git_color_config(var, value, cb) < 0)
 413                return -1;
 414
 415        return git_diff_basic_config(var, value, cb);
 416}
 417
 418int git_diff_basic_config(const char *var, const char *value, void *cb)
 419{
 420        const char *name;
 421
 422        if (!strcmp(var, "diff.renamelimit")) {
 423                diff_rename_limit_default = git_config_int(var, value);
 424                return 0;
 425        }
 426
 427        if (userdiff_config(var, value) < 0)
 428                return -1;
 429
 430        if (skip_prefix(var, "diff.color.", &name) ||
 431            skip_prefix(var, "color.diff.", &name)) {
 432                int slot = parse_diff_color_slot(name);
 433                if (slot < 0)
 434                        return 0;
 435                if (!value)
 436                        return config_error_nonbool(var);
 437                return color_parse(value, diff_colors[slot]);
 438        }
 439
 440        /* like GNU diff's --suppress-blank-empty option  */
 441        if (!strcmp(var, "diff.suppressblankempty") ||
 442                        /* for backwards compatibility */
 443                        !strcmp(var, "diff.suppress-blank-empty")) {
 444                diff_suppress_blank_empty = git_config_bool(var, value);
 445                return 0;
 446        }
 447
 448        if (!strcmp(var, "diff.dirstat")) {
 449                struct strbuf errmsg = STRBUF_INIT;
 450                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 451                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 452                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 453                                errmsg.buf);
 454                strbuf_release(&errmsg);
 455                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 456                return 0;
 457        }
 458
 459        if (git_diff_heuristic_config(var, value, cb) < 0)
 460                return -1;
 461
 462        return git_default_config(var, value, cb);
 463}
 464
 465static char *quote_two(const char *one, const char *two)
 466{
 467        int need_one = quote_c_style(one, NULL, NULL, 1);
 468        int need_two = quote_c_style(two, NULL, NULL, 1);
 469        struct strbuf res = STRBUF_INIT;
 470
 471        if (need_one + need_two) {
 472                strbuf_addch(&res, '"');
 473                quote_c_style(one, &res, NULL, 1);
 474                quote_c_style(two, &res, NULL, 1);
 475                strbuf_addch(&res, '"');
 476        } else {
 477                strbuf_addstr(&res, one);
 478                strbuf_addstr(&res, two);
 479        }
 480        return strbuf_detach(&res, NULL);
 481}
 482
 483static const char *external_diff(void)
 484{
 485        static const char *external_diff_cmd = NULL;
 486        static int done_preparing = 0;
 487
 488        if (done_preparing)
 489                return external_diff_cmd;
 490        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 491        if (!external_diff_cmd)
 492                external_diff_cmd = external_diff_cmd_cfg;
 493        done_preparing = 1;
 494        return external_diff_cmd;
 495}
 496
 497/*
 498 * Keep track of files used for diffing. Sometimes such an entry
 499 * refers to a temporary file, sometimes to an existing file, and
 500 * sometimes to "/dev/null".
 501 */
 502static struct diff_tempfile {
 503        /*
 504         * filename external diff should read from, or NULL if this
 505         * entry is currently not in use:
 506         */
 507        const char *name;
 508
 509        char hex[GIT_MAX_HEXSZ + 1];
 510        char mode[10];
 511
 512        /*
 513         * If this diff_tempfile instance refers to a temporary file,
 514         * this tempfile object is used to manage its lifetime.
 515         */
 516        struct tempfile *tempfile;
 517} diff_temp[2];
 518
 519struct emit_callback {
 520        int color_diff;
 521        unsigned ws_rule;
 522        int blank_at_eof_in_preimage;
 523        int blank_at_eof_in_postimage;
 524        int lno_in_preimage;
 525        int lno_in_postimage;
 526        const char **label_path;
 527        struct diff_words_data *diff_words;
 528        struct diff_options *opt;
 529        struct strbuf *header;
 530};
 531
 532static int count_lines(const char *data, int size)
 533{
 534        int count, ch, completely_empty = 1, nl_just_seen = 0;
 535        count = 0;
 536        while (0 < size--) {
 537                ch = *data++;
 538                if (ch == '\n') {
 539                        count++;
 540                        nl_just_seen = 1;
 541                        completely_empty = 0;
 542                }
 543                else {
 544                        nl_just_seen = 0;
 545                        completely_empty = 0;
 546                }
 547        }
 548        if (completely_empty)
 549                return 0;
 550        if (!nl_just_seen)
 551                count++; /* no trailing newline */
 552        return count;
 553}
 554
 555static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 556{
 557        if (!DIFF_FILE_VALID(one)) {
 558                mf->ptr = (char *)""; /* does not matter */
 559                mf->size = 0;
 560                return 0;
 561        }
 562        else if (diff_populate_filespec(one, 0))
 563                return -1;
 564
 565        mf->ptr = one->data;
 566        mf->size = one->size;
 567        return 0;
 568}
 569
 570/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 571static unsigned long diff_filespec_size(struct diff_filespec *one)
 572{
 573        if (!DIFF_FILE_VALID(one))
 574                return 0;
 575        diff_populate_filespec(one, CHECK_SIZE_ONLY);
 576        return one->size;
 577}
 578
 579static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 580{
 581        char *ptr = mf->ptr;
 582        long size = mf->size;
 583        int cnt = 0;
 584
 585        if (!size)
 586                return cnt;
 587        ptr += size - 1; /* pointing at the very end */
 588        if (*ptr != '\n')
 589                ; /* incomplete line */
 590        else
 591                ptr--; /* skip the last LF */
 592        while (mf->ptr < ptr) {
 593                char *prev_eol;
 594                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 595                        if (*prev_eol == '\n')
 596                                break;
 597                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 598                        break;
 599                cnt++;
 600                ptr = prev_eol - 1;
 601        }
 602        return cnt;
 603}
 604
 605static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 606                               struct emit_callback *ecbdata)
 607{
 608        int l1, l2, at;
 609        unsigned ws_rule = ecbdata->ws_rule;
 610        l1 = count_trailing_blank(mf1, ws_rule);
 611        l2 = count_trailing_blank(mf2, ws_rule);
 612        if (l2 <= l1) {
 613                ecbdata->blank_at_eof_in_preimage = 0;
 614                ecbdata->blank_at_eof_in_postimage = 0;
 615                return;
 616        }
 617        at = count_lines(mf1->ptr, mf1->size);
 618        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 619
 620        at = count_lines(mf2->ptr, mf2->size);
 621        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 622}
 623
 624static void emit_line_0(struct diff_options *o,
 625                        const char *set_sign, const char *set, unsigned reverse, const char *reset,
 626                        int first, const char *line, int len)
 627{
 628        int has_trailing_newline, has_trailing_carriage_return;
 629        int needs_reset = 0; /* at the end of the line */
 630        FILE *file = o->file;
 631
 632        fputs(diff_line_prefix(o), file);
 633
 634        has_trailing_newline = (len > 0 && line[len-1] == '\n');
 635        if (has_trailing_newline)
 636                len--;
 637
 638        has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 639        if (has_trailing_carriage_return)
 640                len--;
 641
 642        if (!len && !first)
 643                goto end_of_line;
 644
 645        if (reverse && want_color(o->use_color)) {
 646                fputs(GIT_COLOR_REVERSE, file);
 647                needs_reset = 1;
 648        }
 649
 650        if (set_sign) {
 651                fputs(set_sign, file);
 652                needs_reset = 1;
 653        }
 654
 655        if (first)
 656                fputc(first, file);
 657
 658        if (!len)
 659                goto end_of_line;
 660
 661        if (set) {
 662                if (set_sign && set != set_sign)
 663                        fputs(reset, file);
 664                fputs(set, file);
 665                needs_reset = 1;
 666        }
 667        fwrite(line, len, 1, file);
 668        needs_reset = 1; /* 'line' may contain color codes. */
 669
 670end_of_line:
 671        if (needs_reset)
 672                fputs(reset, file);
 673        if (has_trailing_carriage_return)
 674                fputc('\r', file);
 675        if (has_trailing_newline)
 676                fputc('\n', file);
 677}
 678
 679static void emit_line(struct diff_options *o, const char *set, const char *reset,
 680                      const char *line, int len)
 681{
 682        emit_line_0(o, set, NULL, 0, reset, 0, line, len);
 683}
 684
 685enum diff_symbol {
 686        DIFF_SYMBOL_BINARY_DIFF_HEADER,
 687        DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
 688        DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
 689        DIFF_SYMBOL_BINARY_DIFF_BODY,
 690        DIFF_SYMBOL_BINARY_DIFF_FOOTER,
 691        DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
 692        DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
 693        DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
 694        DIFF_SYMBOL_STATS_LINE,
 695        DIFF_SYMBOL_WORD_DIFF,
 696        DIFF_SYMBOL_STAT_SEP,
 697        DIFF_SYMBOL_SUMMARY,
 698        DIFF_SYMBOL_SUBMODULE_ADD,
 699        DIFF_SYMBOL_SUBMODULE_DEL,
 700        DIFF_SYMBOL_SUBMODULE_UNTRACKED,
 701        DIFF_SYMBOL_SUBMODULE_MODIFIED,
 702        DIFF_SYMBOL_SUBMODULE_HEADER,
 703        DIFF_SYMBOL_SUBMODULE_ERROR,
 704        DIFF_SYMBOL_SUBMODULE_PIPETHROUGH,
 705        DIFF_SYMBOL_REWRITE_DIFF,
 706        DIFF_SYMBOL_BINARY_FILES,
 707        DIFF_SYMBOL_HEADER,
 708        DIFF_SYMBOL_FILEPAIR_PLUS,
 709        DIFF_SYMBOL_FILEPAIR_MINUS,
 710        DIFF_SYMBOL_WORDS_PORCELAIN,
 711        DIFF_SYMBOL_WORDS,
 712        DIFF_SYMBOL_CONTEXT,
 713        DIFF_SYMBOL_CONTEXT_INCOMPLETE,
 714        DIFF_SYMBOL_PLUS,
 715        DIFF_SYMBOL_MINUS,
 716        DIFF_SYMBOL_NO_LF_EOF,
 717        DIFF_SYMBOL_CONTEXT_FRAGINFO,
 718        DIFF_SYMBOL_CONTEXT_MARKER,
 719        DIFF_SYMBOL_SEPARATOR
 720};
 721/*
 722 * Flags for content lines:
 723 * 0..12 are whitespace rules
 724 * 13-15 are WSEH_NEW | WSEH_OLD | WSEH_CONTEXT
 725 * 16 is marking if the line is blank at EOF
 726 */
 727#define DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF      (1<<16)
 728#define DIFF_SYMBOL_MOVED_LINE                  (1<<17)
 729#define DIFF_SYMBOL_MOVED_LINE_ALT              (1<<18)
 730#define DIFF_SYMBOL_MOVED_LINE_UNINTERESTING    (1<<19)
 731#define DIFF_SYMBOL_CONTENT_WS_MASK (WSEH_NEW | WSEH_OLD | WSEH_CONTEXT | WS_RULE_MASK)
 732
 733/*
 734 * This struct is used when we need to buffer the output of the diff output.
 735 *
 736 * NEEDSWORK: Instead of storing a copy of the line, add an offset pointer
 737 * into the pre/post image file. This pointer could be a union with the
 738 * line pointer. By storing an offset into the file instead of the literal line,
 739 * we can decrease the memory footprint for the buffered output. At first we
 740 * may want to only have indirection for the content lines, but we could also
 741 * enhance the state for emitting prefabricated lines, e.g. the similarity
 742 * score line or hunk/file headers would only need to store a number or path
 743 * and then the output can be constructed later on depending on state.
 744 */
 745struct emitted_diff_symbol {
 746        const char *line;
 747        int len;
 748        int flags;
 749        enum diff_symbol s;
 750};
 751#define EMITTED_DIFF_SYMBOL_INIT {NULL}
 752
 753struct emitted_diff_symbols {
 754        struct emitted_diff_symbol *buf;
 755        int nr, alloc;
 756};
 757#define EMITTED_DIFF_SYMBOLS_INIT {NULL, 0, 0}
 758
 759static void append_emitted_diff_symbol(struct diff_options *o,
 760                                       struct emitted_diff_symbol *e)
 761{
 762        struct emitted_diff_symbol *f;
 763
 764        ALLOC_GROW(o->emitted_symbols->buf,
 765                   o->emitted_symbols->nr + 1,
 766                   o->emitted_symbols->alloc);
 767        f = &o->emitted_symbols->buf[o->emitted_symbols->nr++];
 768
 769        memcpy(f, e, sizeof(struct emitted_diff_symbol));
 770        f->line = e->line ? xmemdupz(e->line, e->len) : NULL;
 771}
 772
 773struct moved_entry {
 774        struct hashmap_entry ent;
 775        const struct emitted_diff_symbol *es;
 776        struct moved_entry *next_line;
 777        struct ws_delta *wsd;
 778};
 779
 780/**
 781 * The struct ws_delta holds white space differences between moved lines, i.e.
 782 * between '+' and '-' lines that have been detected to be a move.
 783 * The string contains the difference in leading white spaces, before the
 784 * rest of the line is compared using the white space config for move
 785 * coloring. The current_longer indicates if the first string in the
 786 * comparision is longer than the second.
 787 */
 788struct ws_delta {
 789        char *string;
 790        unsigned int current_longer : 1;
 791};
 792#define WS_DELTA_INIT { NULL, 0 }
 793
 794static int compute_ws_delta(const struct emitted_diff_symbol *a,
 795                             const struct emitted_diff_symbol *b,
 796                             struct ws_delta *out)
 797{
 798        const struct emitted_diff_symbol *longer =  a->len > b->len ? a : b;
 799        const struct emitted_diff_symbol *shorter = a->len > b->len ? b : a;
 800        int d = longer->len - shorter->len;
 801
 802        out->string = xmemdupz(longer->line, d);
 803        out->current_longer = (a == longer);
 804
 805        return !strncmp(longer->line + d, shorter->line, shorter->len);
 806}
 807
 808static int cmp_in_block_with_wsd(const struct diff_options *o,
 809                                 const struct moved_entry *cur,
 810                                 const struct moved_entry *match,
 811                                 struct moved_entry *pmb,
 812                                 int n)
 813{
 814        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
 815        int al = cur->es->len, cl = l->len;
 816        const char *a = cur->es->line,
 817                   *b = match->es->line,
 818                   *c = l->line;
 819
 820        int wslen;
 821
 822        /*
 823         * We need to check if 'cur' is equal to 'match'.
 824         * As those are from the same (+/-) side, we do not need to adjust for
 825         * indent changes. However these were found using fuzzy matching
 826         * so we do have to check if they are equal.
 827         */
 828        if (strcmp(a, b))
 829                return 1;
 830
 831        if (!pmb->wsd)
 832                /*
 833                 * No white space delta was carried forward? This can happen
 834                 * when we exit early in this function and do not carry
 835                 * forward ws.
 836                 */
 837                return 1;
 838
 839        /*
 840         * The indent changes of the block are known and carried forward in
 841         * pmb->wsd; however we need to check if the indent changes of the
 842         * current line are still the same as before.
 843         *
 844         * To do so we need to compare 'l' to 'cur', adjusting the
 845         * one of them for the white spaces, depending which was longer.
 846         */
 847
 848        wslen = strlen(pmb->wsd->string);
 849        if (pmb->wsd->current_longer) {
 850                c += wslen;
 851                cl -= wslen;
 852        } else {
 853                a += wslen;
 854                al -= wslen;
 855        }
 856
 857        if (strcmp(a, c))
 858                return 1;
 859
 860        return 0;
 861}
 862
 863static int moved_entry_cmp(const void *hashmap_cmp_fn_data,
 864                           const void *entry,
 865                           const void *entry_or_key,
 866                           const void *keydata)
 867{
 868        const struct diff_options *diffopt = hashmap_cmp_fn_data;
 869        const struct moved_entry *a = entry;
 870        const struct moved_entry *b = entry_or_key;
 871        unsigned flags = diffopt->color_moved_ws_handling
 872                         & XDF_WHITESPACE_FLAGS;
 873
 874        if (diffopt->color_moved_ws_handling &
 875            COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
 876                /*
 877                 * As there is not specific white space config given,
 878                 * we'd need to check for a new block, so ignore all
 879                 * white space. The setup of the white space
 880                 * configuration for the next block is done else where
 881                 */
 882                flags |= XDF_IGNORE_WHITESPACE;
 883
 884        return !xdiff_compare_lines(a->es->line, a->es->len,
 885                                    b->es->line, b->es->len,
 886                                    flags);
 887}
 888
 889static struct moved_entry *prepare_entry(struct diff_options *o,
 890                                         int line_no)
 891{
 892        struct moved_entry *ret = xmalloc(sizeof(*ret));
 893        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[line_no];
 894        unsigned flags = o->color_moved_ws_handling & XDF_WHITESPACE_FLAGS;
 895
 896        ret->ent.hash = xdiff_hash_string(l->line, l->len, flags);
 897        ret->es = l;
 898        ret->next_line = NULL;
 899        ret->wsd = NULL;
 900
 901        return ret;
 902}
 903
 904static void add_lines_to_move_detection(struct diff_options *o,
 905                                        struct hashmap *add_lines,
 906                                        struct hashmap *del_lines)
 907{
 908        struct moved_entry *prev_line = NULL;
 909
 910        int n;
 911        for (n = 0; n < o->emitted_symbols->nr; n++) {
 912                struct hashmap *hm;
 913                struct moved_entry *key;
 914
 915                switch (o->emitted_symbols->buf[n].s) {
 916                case DIFF_SYMBOL_PLUS:
 917                        hm = add_lines;
 918                        break;
 919                case DIFF_SYMBOL_MINUS:
 920                        hm = del_lines;
 921                        break;
 922                default:
 923                        prev_line = NULL;
 924                        continue;
 925                }
 926
 927                key = prepare_entry(o, n);
 928                if (prev_line && prev_line->es->s == o->emitted_symbols->buf[n].s)
 929                        prev_line->next_line = key;
 930
 931                hashmap_add(hm, key);
 932                prev_line = key;
 933        }
 934}
 935
 936static void pmb_advance_or_null(struct diff_options *o,
 937                                struct moved_entry *match,
 938                                struct hashmap *hm,
 939                                struct moved_entry **pmb,
 940                                int pmb_nr)
 941{
 942        int i;
 943        for (i = 0; i < pmb_nr; i++) {
 944                struct moved_entry *prev = pmb[i];
 945                struct moved_entry *cur = (prev && prev->next_line) ?
 946                                prev->next_line : NULL;
 947                if (cur && !hm->cmpfn(o, cur, match, NULL)) {
 948                        pmb[i] = cur;
 949                } else {
 950                        pmb[i] = NULL;
 951                }
 952        }
 953}
 954
 955static void pmb_advance_or_null_multi_match(struct diff_options *o,
 956                                            struct moved_entry *match,
 957                                            struct hashmap *hm,
 958                                            struct moved_entry **pmb,
 959                                            int pmb_nr, int n)
 960{
 961        int i;
 962        char *got_match = xcalloc(1, pmb_nr);
 963
 964        for (; match; match = hashmap_get_next(hm, match)) {
 965                for (i = 0; i < pmb_nr; i++) {
 966                        struct moved_entry *prev = pmb[i];
 967                        struct moved_entry *cur = (prev && prev->next_line) ?
 968                                        prev->next_line : NULL;
 969                        if (!cur)
 970                                continue;
 971                        if (!cmp_in_block_with_wsd(o, cur, match, pmb[i], n))
 972                                got_match[i] |= 1;
 973                }
 974        }
 975
 976        for (i = 0; i < pmb_nr; i++) {
 977                if (got_match[i]) {
 978                        /* Carry the white space delta forward */
 979                        pmb[i]->next_line->wsd = pmb[i]->wsd;
 980                        pmb[i] = pmb[i]->next_line;
 981                } else
 982                        pmb[i] = NULL;
 983        }
 984}
 985
 986static int shrink_potential_moved_blocks(struct moved_entry **pmb,
 987                                         int pmb_nr)
 988{
 989        int lp, rp;
 990
 991        /* Shrink the set of potential block to the remaining running */
 992        for (lp = 0, rp = pmb_nr - 1; lp <= rp;) {
 993                while (lp < pmb_nr && pmb[lp])
 994                        lp++;
 995                /* lp points at the first NULL now */
 996
 997                while (rp > -1 && !pmb[rp])
 998                        rp--;
 999                /* rp points at the last non-NULL */
1000
1001                if (lp < pmb_nr && rp > -1 && lp < rp) {
1002                        pmb[lp] = pmb[rp];
1003                        if (pmb[rp]->wsd) {
1004                                free(pmb[rp]->wsd->string);
1005                                FREE_AND_NULL(pmb[rp]->wsd);
1006                        }
1007                        pmb[rp] = NULL;
1008                        rp--;
1009                        lp++;
1010                }
1011        }
1012
1013        /* Remember the number of running sets */
1014        return rp + 1;
1015}
1016
1017/*
1018 * If o->color_moved is COLOR_MOVED_PLAIN, this function does nothing.
1019 *
1020 * Otherwise, if the last block has fewer alphanumeric characters than
1021 * COLOR_MOVED_MIN_ALNUM_COUNT, unset DIFF_SYMBOL_MOVED_LINE on all lines in
1022 * that block.
1023 *
1024 * The last block consists of the (n - block_length)'th line up to but not
1025 * including the nth line.
1026 *
1027 * NEEDSWORK: This uses the same heuristic as blame_entry_score() in blame.c.
1028 * Think of a way to unify them.
1029 */
1030static void adjust_last_block(struct diff_options *o, int n, int block_length)
1031{
1032        int i, alnum_count = 0;
1033        if (o->color_moved == COLOR_MOVED_PLAIN)
1034                return;
1035        for (i = 1; i < block_length + 1; i++) {
1036                const char *c = o->emitted_symbols->buf[n - i].line;
1037                for (; *c; c++) {
1038                        if (!isalnum(*c))
1039                                continue;
1040                        alnum_count++;
1041                        if (alnum_count >= COLOR_MOVED_MIN_ALNUM_COUNT)
1042                                return;
1043                }
1044        }
1045        for (i = 1; i < block_length + 1; i++)
1046                o->emitted_symbols->buf[n - i].flags &= ~DIFF_SYMBOL_MOVED_LINE;
1047}
1048
1049/* Find blocks of moved code, delegate actual coloring decision to helper */
1050static void mark_color_as_moved(struct diff_options *o,
1051                                struct hashmap *add_lines,
1052                                struct hashmap *del_lines)
1053{
1054        struct moved_entry **pmb = NULL; /* potentially moved blocks */
1055        int pmb_nr = 0, pmb_alloc = 0;
1056        int n, flipped_block = 1, block_length = 0;
1057
1058
1059        for (n = 0; n < o->emitted_symbols->nr; n++) {
1060                struct hashmap *hm = NULL;
1061                struct moved_entry *key;
1062                struct moved_entry *match = NULL;
1063                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
1064
1065                switch (l->s) {
1066                case DIFF_SYMBOL_PLUS:
1067                        hm = del_lines;
1068                        key = prepare_entry(o, n);
1069                        match = hashmap_get(hm, key, NULL);
1070                        free(key);
1071                        break;
1072                case DIFF_SYMBOL_MINUS:
1073                        hm = add_lines;
1074                        key = prepare_entry(o, n);
1075                        match = hashmap_get(hm, key, NULL);
1076                        free(key);
1077                        break;
1078                default:
1079                        flipped_block = 1;
1080                }
1081
1082                if (!match) {
1083                        adjust_last_block(o, n, block_length);
1084                        pmb_nr = 0;
1085                        block_length = 0;
1086                        continue;
1087                }
1088
1089                l->flags |= DIFF_SYMBOL_MOVED_LINE;
1090
1091                if (o->color_moved == COLOR_MOVED_PLAIN)
1092                        continue;
1093
1094                if (o->color_moved_ws_handling &
1095                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
1096                        pmb_advance_or_null_multi_match(o, match, hm, pmb, pmb_nr, n);
1097                else
1098                        pmb_advance_or_null(o, match, hm, pmb, pmb_nr);
1099
1100                pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
1101
1102                if (pmb_nr == 0) {
1103                        /*
1104                         * The current line is the start of a new block.
1105                         * Setup the set of potential blocks.
1106                         */
1107                        for (; match; match = hashmap_get_next(hm, match)) {
1108                                ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
1109                                if (o->color_moved_ws_handling &
1110                                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) {
1111                                        struct ws_delta *wsd = xmalloc(sizeof(*match->wsd));
1112                                        if (compute_ws_delta(l, match->es, wsd)) {
1113                                                match->wsd = wsd;
1114                                                pmb[pmb_nr++] = match;
1115                                        } else
1116                                                free(wsd);
1117                                } else {
1118                                        pmb[pmb_nr++] = match;
1119                                }
1120                        }
1121
1122                        flipped_block = (flipped_block + 1) % 2;
1123
1124                        adjust_last_block(o, n, block_length);
1125                        block_length = 0;
1126                }
1127
1128                block_length++;
1129
1130                if (flipped_block && o->color_moved != COLOR_MOVED_BLOCKS)
1131                        l->flags |= DIFF_SYMBOL_MOVED_LINE_ALT;
1132        }
1133        adjust_last_block(o, n, block_length);
1134
1135        free(pmb);
1136}
1137
1138#define DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK \
1139  (DIFF_SYMBOL_MOVED_LINE | DIFF_SYMBOL_MOVED_LINE_ALT)
1140static void dim_moved_lines(struct diff_options *o)
1141{
1142        int n;
1143        for (n = 0; n < o->emitted_symbols->nr; n++) {
1144                struct emitted_diff_symbol *prev = (n != 0) ?
1145                                &o->emitted_symbols->buf[n - 1] : NULL;
1146                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
1147                struct emitted_diff_symbol *next =
1148                                (n < o->emitted_symbols->nr - 1) ?
1149                                &o->emitted_symbols->buf[n + 1] : NULL;
1150
1151                /* Not a plus or minus line? */
1152                if (l->s != DIFF_SYMBOL_PLUS && l->s != DIFF_SYMBOL_MINUS)
1153                        continue;
1154
1155                /* Not a moved line? */
1156                if (!(l->flags & DIFF_SYMBOL_MOVED_LINE))
1157                        continue;
1158
1159                /*
1160                 * If prev or next are not a plus or minus line,
1161                 * pretend they don't exist
1162                 */
1163                if (prev && prev->s != DIFF_SYMBOL_PLUS &&
1164                            prev->s != DIFF_SYMBOL_MINUS)
1165                        prev = NULL;
1166                if (next && next->s != DIFF_SYMBOL_PLUS &&
1167                            next->s != DIFF_SYMBOL_MINUS)
1168                        next = NULL;
1169
1170                /* Inside a block? */
1171                if ((prev &&
1172                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
1173                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK)) &&
1174                    (next &&
1175                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
1176                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK))) {
1177                        l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1178                        continue;
1179                }
1180
1181                /* Check if we are at an interesting bound: */
1182                if (prev && (prev->flags & DIFF_SYMBOL_MOVED_LINE) &&
1183                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1184                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1185                        continue;
1186                if (next && (next->flags & DIFF_SYMBOL_MOVED_LINE) &&
1187                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1188                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1189                        continue;
1190
1191                /*
1192                 * The boundary to prev and next are not interesting,
1193                 * so this line is not interesting as a whole
1194                 */
1195                l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1196        }
1197}
1198
1199static void emit_line_ws_markup(struct diff_options *o,
1200                                const char *set_sign, const char *set,
1201                                const char *reset,
1202                                char sign, const char *line, int len,
1203                                unsigned ws_rule, int blank_at_eof)
1204{
1205        const char *ws = NULL;
1206
1207        if (o->ws_error_highlight & ws_rule) {
1208                ws = diff_get_color_opt(o, DIFF_WHITESPACE);
1209                if (!*ws)
1210                        ws = NULL;
1211        }
1212
1213        if (!ws && !set_sign)
1214                emit_line_0(o, set, NULL, 0, reset, sign, line, len);
1215        else if (!ws) {
1216                emit_line_0(o, set_sign, set, !!set_sign, reset, sign, line, len);
1217        } else if (blank_at_eof)
1218                /* Blank line at EOF - paint '+' as well */
1219                emit_line_0(o, ws, NULL, 0, reset, sign, line, len);
1220        else {
1221                /* Emit just the prefix, then the rest. */
1222                emit_line_0(o, set_sign ? set_sign : set, NULL, !!set_sign, reset,
1223                            sign, "", 0);
1224                ws_check_emit(line, len, ws_rule,
1225                              o->file, set, reset, ws);
1226        }
1227}
1228
1229static void emit_diff_symbol_from_struct(struct diff_options *o,
1230                                         struct emitted_diff_symbol *eds)
1231{
1232        static const char *nneof = " No newline at end of file\n";
1233        const char *context, *reset, *set, *set_sign, *meta, *fraginfo;
1234        struct strbuf sb = STRBUF_INIT;
1235
1236        enum diff_symbol s = eds->s;
1237        const char *line = eds->line;
1238        int len = eds->len;
1239        unsigned flags = eds->flags;
1240
1241        switch (s) {
1242        case DIFF_SYMBOL_NO_LF_EOF:
1243                context = diff_get_color_opt(o, DIFF_CONTEXT);
1244                reset = diff_get_color_opt(o, DIFF_RESET);
1245                putc('\n', o->file);
1246                emit_line_0(o, context, NULL, 0, reset, '\\',
1247                            nneof, strlen(nneof));
1248                break;
1249        case DIFF_SYMBOL_SUBMODULE_HEADER:
1250        case DIFF_SYMBOL_SUBMODULE_ERROR:
1251        case DIFF_SYMBOL_SUBMODULE_PIPETHROUGH:
1252        case DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES:
1253        case DIFF_SYMBOL_SUMMARY:
1254        case DIFF_SYMBOL_STATS_LINE:
1255        case DIFF_SYMBOL_BINARY_DIFF_BODY:
1256        case DIFF_SYMBOL_CONTEXT_FRAGINFO:
1257                emit_line(o, "", "", line, len);
1258                break;
1259        case DIFF_SYMBOL_CONTEXT_INCOMPLETE:
1260        case DIFF_SYMBOL_CONTEXT_MARKER:
1261                context = diff_get_color_opt(o, DIFF_CONTEXT);
1262                reset = diff_get_color_opt(o, DIFF_RESET);
1263                emit_line(o, context, reset, line, len);
1264                break;
1265        case DIFF_SYMBOL_SEPARATOR:
1266                fprintf(o->file, "%s%c",
1267                        diff_line_prefix(o),
1268                        o->line_termination);
1269                break;
1270        case DIFF_SYMBOL_CONTEXT:
1271                set = diff_get_color_opt(o, DIFF_CONTEXT);
1272                reset = diff_get_color_opt(o, DIFF_RESET);
1273                set_sign = NULL;
1274                if (o->flags.dual_color_diffed_diffs) {
1275                        char c = !len ? 0 : line[0];
1276
1277                        if (c == '+')
1278                                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1279                        else if (c == '@')
1280                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1281                        else if (c == '-')
1282                                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1283                }
1284                emit_line_ws_markup(o, set_sign, set, reset, ' ', line, len,
1285                                    flags & (DIFF_SYMBOL_CONTENT_WS_MASK), 0);
1286                break;
1287        case DIFF_SYMBOL_PLUS:
1288                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1289                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1290                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1291                case DIFF_SYMBOL_MOVED_LINE |
1292                     DIFF_SYMBOL_MOVED_LINE_ALT |
1293                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1294                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT_DIM);
1295                        break;
1296                case DIFF_SYMBOL_MOVED_LINE |
1297                     DIFF_SYMBOL_MOVED_LINE_ALT:
1298                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT);
1299                        break;
1300                case DIFF_SYMBOL_MOVED_LINE |
1301                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1302                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_DIM);
1303                        break;
1304                case DIFF_SYMBOL_MOVED_LINE:
1305                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED);
1306                        break;
1307                default:
1308                        set = diff_get_color_opt(o, DIFF_FILE_NEW);
1309                }
1310                reset = diff_get_color_opt(o, DIFF_RESET);
1311                if (!o->flags.dual_color_diffed_diffs)
1312                        set_sign = NULL;
1313                else {
1314                        char c = !len ? 0 : line[0];
1315
1316                        set_sign = set;
1317                        if (c == '-')
1318                                set = diff_get_color_opt(o, DIFF_FILE_OLD_BOLD);
1319                        else if (c == '@')
1320                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1321                        else if (c == '+')
1322                                set = diff_get_color_opt(o, DIFF_FILE_NEW_BOLD);
1323                        else
1324                                set = diff_get_color_opt(o, DIFF_CONTEXT_BOLD);
1325                        flags &= ~DIFF_SYMBOL_CONTENT_WS_MASK;
1326                }
1327                emit_line_ws_markup(o, set_sign, set, reset, '+', line, len,
1328                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK,
1329                                    flags & DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF);
1330                break;
1331        case DIFF_SYMBOL_MINUS:
1332                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1333                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1334                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1335                case DIFF_SYMBOL_MOVED_LINE |
1336                     DIFF_SYMBOL_MOVED_LINE_ALT |
1337                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1338                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT_DIM);
1339                        break;
1340                case DIFF_SYMBOL_MOVED_LINE |
1341                     DIFF_SYMBOL_MOVED_LINE_ALT:
1342                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT);
1343                        break;
1344                case DIFF_SYMBOL_MOVED_LINE |
1345                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1346                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_DIM);
1347                        break;
1348                case DIFF_SYMBOL_MOVED_LINE:
1349                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED);
1350                        break;
1351                default:
1352                        set = diff_get_color_opt(o, DIFF_FILE_OLD);
1353                }
1354                reset = diff_get_color_opt(o, DIFF_RESET);
1355                if (!o->flags.dual_color_diffed_diffs)
1356                        set_sign = NULL;
1357                else {
1358                        char c = !len ? 0 : line[0];
1359
1360                        set_sign = set;
1361                        if (c == '+')
1362                                set = diff_get_color_opt(o, DIFF_FILE_NEW_DIM);
1363                        else if (c == '@')
1364                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1365                        else if (c == '-')
1366                                set = diff_get_color_opt(o, DIFF_FILE_OLD_DIM);
1367                        else
1368                                set = diff_get_color_opt(o, DIFF_CONTEXT_DIM);
1369                }
1370                emit_line_ws_markup(o, set_sign, set, reset, '-', line, len,
1371                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK, 0);
1372                break;
1373        case DIFF_SYMBOL_WORDS_PORCELAIN:
1374                context = diff_get_color_opt(o, DIFF_CONTEXT);
1375                reset = diff_get_color_opt(o, DIFF_RESET);
1376                emit_line(o, context, reset, line, len);
1377                fputs("~\n", o->file);
1378                break;
1379        case DIFF_SYMBOL_WORDS:
1380                context = diff_get_color_opt(o, DIFF_CONTEXT);
1381                reset = diff_get_color_opt(o, DIFF_RESET);
1382                /*
1383                 * Skip the prefix character, if any.  With
1384                 * diff_suppress_blank_empty, there may be
1385                 * none.
1386                 */
1387                if (line[0] != '\n') {
1388                        line++;
1389                        len--;
1390                }
1391                emit_line(o, context, reset, line, len);
1392                break;
1393        case DIFF_SYMBOL_FILEPAIR_PLUS:
1394                meta = diff_get_color_opt(o, DIFF_METAINFO);
1395                reset = diff_get_color_opt(o, DIFF_RESET);
1396                fprintf(o->file, "%s%s+++ %s%s%s\n", diff_line_prefix(o), meta,
1397                        line, reset,
1398                        strchr(line, ' ') ? "\t" : "");
1399                break;
1400        case DIFF_SYMBOL_FILEPAIR_MINUS:
1401                meta = diff_get_color_opt(o, DIFF_METAINFO);
1402                reset = diff_get_color_opt(o, DIFF_RESET);
1403                fprintf(o->file, "%s%s--- %s%s%s\n", diff_line_prefix(o), meta,
1404                        line, reset,
1405                        strchr(line, ' ') ? "\t" : "");
1406                break;
1407        case DIFF_SYMBOL_BINARY_FILES:
1408        case DIFF_SYMBOL_HEADER:
1409                fprintf(o->file, "%s", line);
1410                break;
1411        case DIFF_SYMBOL_BINARY_DIFF_HEADER:
1412                fprintf(o->file, "%sGIT binary patch\n", diff_line_prefix(o));
1413                break;
1414        case DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA:
1415                fprintf(o->file, "%sdelta %s\n", diff_line_prefix(o), line);
1416                break;
1417        case DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL:
1418                fprintf(o->file, "%sliteral %s\n", diff_line_prefix(o), line);
1419                break;
1420        case DIFF_SYMBOL_BINARY_DIFF_FOOTER:
1421                fputs(diff_line_prefix(o), o->file);
1422                fputc('\n', o->file);
1423                break;
1424        case DIFF_SYMBOL_REWRITE_DIFF:
1425                fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
1426                reset = diff_get_color_opt(o, DIFF_RESET);
1427                emit_line(o, fraginfo, reset, line, len);
1428                break;
1429        case DIFF_SYMBOL_SUBMODULE_ADD:
1430                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1431                reset = diff_get_color_opt(o, DIFF_RESET);
1432                emit_line(o, set, reset, line, len);
1433                break;
1434        case DIFF_SYMBOL_SUBMODULE_DEL:
1435                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1436                reset = diff_get_color_opt(o, DIFF_RESET);
1437                emit_line(o, set, reset, line, len);
1438                break;
1439        case DIFF_SYMBOL_SUBMODULE_UNTRACKED:
1440                fprintf(o->file, "%sSubmodule %s contains untracked content\n",
1441                        diff_line_prefix(o), line);
1442                break;
1443        case DIFF_SYMBOL_SUBMODULE_MODIFIED:
1444                fprintf(o->file, "%sSubmodule %s contains modified content\n",
1445                        diff_line_prefix(o), line);
1446                break;
1447        case DIFF_SYMBOL_STATS_SUMMARY_NO_FILES:
1448                emit_line(o, "", "", " 0 files changed\n",
1449                          strlen(" 0 files changed\n"));
1450                break;
1451        case DIFF_SYMBOL_STATS_SUMMARY_ABBREV:
1452                emit_line(o, "", "", " ...\n", strlen(" ...\n"));
1453                break;
1454        case DIFF_SYMBOL_WORD_DIFF:
1455                fprintf(o->file, "%.*s", len, line);
1456                break;
1457        case DIFF_SYMBOL_STAT_SEP:
1458                fputs(o->stat_sep, o->file);
1459                break;
1460        default:
1461                BUG("unknown diff symbol");
1462        }
1463        strbuf_release(&sb);
1464}
1465
1466static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
1467                             const char *line, int len, unsigned flags)
1468{
1469        struct emitted_diff_symbol e = {line, len, flags, s};
1470
1471        if (o->emitted_symbols)
1472                append_emitted_diff_symbol(o, &e);
1473        else
1474                emit_diff_symbol_from_struct(o, &e);
1475}
1476
1477void diff_emit_submodule_del(struct diff_options *o, const char *line)
1478{
1479        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_DEL, line, strlen(line), 0);
1480}
1481
1482void diff_emit_submodule_add(struct diff_options *o, const char *line)
1483{
1484        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ADD, line, strlen(line), 0);
1485}
1486
1487void diff_emit_submodule_untracked(struct diff_options *o, const char *path)
1488{
1489        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_UNTRACKED,
1490                         path, strlen(path), 0);
1491}
1492
1493void diff_emit_submodule_modified(struct diff_options *o, const char *path)
1494{
1495        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_MODIFIED,
1496                         path, strlen(path), 0);
1497}
1498
1499void diff_emit_submodule_header(struct diff_options *o, const char *header)
1500{
1501        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_HEADER,
1502                         header, strlen(header), 0);
1503}
1504
1505void diff_emit_submodule_error(struct diff_options *o, const char *err)
1506{
1507        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ERROR, err, strlen(err), 0);
1508}
1509
1510void diff_emit_submodule_pipethrough(struct diff_options *o,
1511                                     const char *line, int len)
1512{
1513        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_PIPETHROUGH, line, len, 0);
1514}
1515
1516static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
1517{
1518        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
1519              ecbdata->blank_at_eof_in_preimage &&
1520              ecbdata->blank_at_eof_in_postimage &&
1521              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
1522              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
1523                return 0;
1524        return ws_blank_line(line, len, ecbdata->ws_rule);
1525}
1526
1527static void emit_add_line(const char *reset,
1528                          struct emit_callback *ecbdata,
1529                          const char *line, int len)
1530{
1531        unsigned flags = WSEH_NEW | ecbdata->ws_rule;
1532        if (new_blank_line_at_eof(ecbdata, line, len))
1533                flags |= DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF;
1534
1535        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_PLUS, line, len, flags);
1536}
1537
1538static void emit_del_line(const char *reset,
1539                          struct emit_callback *ecbdata,
1540                          const char *line, int len)
1541{
1542        unsigned flags = WSEH_OLD | ecbdata->ws_rule;
1543        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_MINUS, line, len, flags);
1544}
1545
1546static void emit_context_line(const char *reset,
1547                              struct emit_callback *ecbdata,
1548                              const char *line, int len)
1549{
1550        unsigned flags = WSEH_CONTEXT | ecbdata->ws_rule;
1551        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_CONTEXT, line, len, flags);
1552}
1553
1554static void emit_hunk_header(struct emit_callback *ecbdata,
1555                             const char *line, int len)
1556{
1557        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
1558        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
1559        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
1560        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1561        const char *reverse = ecbdata->color_diff ? GIT_COLOR_REVERSE : "";
1562        static const char atat[2] = { '@', '@' };
1563        const char *cp, *ep;
1564        struct strbuf msgbuf = STRBUF_INIT;
1565        int org_len = len;
1566        int i = 1;
1567
1568        /*
1569         * As a hunk header must begin with "@@ -<old>, +<new> @@",
1570         * it always is at least 10 bytes long.
1571         */
1572        if (len < 10 ||
1573            memcmp(line, atat, 2) ||
1574            !(ep = memmem(line + 2, len - 2, atat, 2))) {
1575                emit_diff_symbol(ecbdata->opt,
1576                                 DIFF_SYMBOL_CONTEXT_MARKER, line, len, 0);
1577                return;
1578        }
1579        ep += 2; /* skip over @@ */
1580
1581        /* The hunk header in fraginfo color */
1582        if (ecbdata->opt->flags.dual_color_diffed_diffs)
1583                strbuf_addstr(&msgbuf, reverse);
1584        strbuf_addstr(&msgbuf, frag);
1585        strbuf_add(&msgbuf, line, ep - line);
1586        strbuf_addstr(&msgbuf, reset);
1587
1588        /*
1589         * trailing "\r\n"
1590         */
1591        for ( ; i < 3; i++)
1592                if (line[len - i] == '\r' || line[len - i] == '\n')
1593                        len--;
1594
1595        /* blank before the func header */
1596        for (cp = ep; ep - line < len; ep++)
1597                if (*ep != ' ' && *ep != '\t')
1598                        break;
1599        if (ep != cp) {
1600                strbuf_addstr(&msgbuf, context);
1601                strbuf_add(&msgbuf, cp, ep - cp);
1602                strbuf_addstr(&msgbuf, reset);
1603        }
1604
1605        if (ep < line + len) {
1606                strbuf_addstr(&msgbuf, func);
1607                strbuf_add(&msgbuf, ep, line + len - ep);
1608                strbuf_addstr(&msgbuf, reset);
1609        }
1610
1611        strbuf_add(&msgbuf, line + len, org_len - len);
1612        strbuf_complete_line(&msgbuf);
1613        emit_diff_symbol(ecbdata->opt,
1614                         DIFF_SYMBOL_CONTEXT_FRAGINFO, msgbuf.buf, msgbuf.len, 0);
1615        strbuf_release(&msgbuf);
1616}
1617
1618static struct diff_tempfile *claim_diff_tempfile(void) {
1619        int i;
1620        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
1621                if (!diff_temp[i].name)
1622                        return diff_temp + i;
1623        BUG("diff is failing to clean up its tempfiles");
1624}
1625
1626static void remove_tempfile(void)
1627{
1628        int i;
1629        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
1630                if (is_tempfile_active(diff_temp[i].tempfile))
1631                        delete_tempfile(&diff_temp[i].tempfile);
1632                diff_temp[i].name = NULL;
1633        }
1634}
1635
1636static void add_line_count(struct strbuf *out, int count)
1637{
1638        switch (count) {
1639        case 0:
1640                strbuf_addstr(out, "0,0");
1641                break;
1642        case 1:
1643                strbuf_addstr(out, "1");
1644                break;
1645        default:
1646                strbuf_addf(out, "1,%d", count);
1647                break;
1648        }
1649}
1650
1651static void emit_rewrite_lines(struct emit_callback *ecb,
1652                               int prefix, const char *data, int size)
1653{
1654        const char *endp = NULL;
1655        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
1656
1657        while (0 < size) {
1658                int len;
1659
1660                endp = memchr(data, '\n', size);
1661                len = endp ? (endp - data + 1) : size;
1662                if (prefix != '+') {
1663                        ecb->lno_in_preimage++;
1664                        emit_del_line(reset, ecb, data, len);
1665                } else {
1666                        ecb->lno_in_postimage++;
1667                        emit_add_line(reset, ecb, data, len);
1668                }
1669                size -= len;
1670                data += len;
1671        }
1672        if (!endp)
1673                emit_diff_symbol(ecb->opt, DIFF_SYMBOL_NO_LF_EOF, NULL, 0, 0);
1674}
1675
1676static void emit_rewrite_diff(const char *name_a,
1677                              const char *name_b,
1678                              struct diff_filespec *one,
1679                              struct diff_filespec *two,
1680                              struct userdiff_driver *textconv_one,
1681                              struct userdiff_driver *textconv_two,
1682                              struct diff_options *o)
1683{
1684        int lc_a, lc_b;
1685        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
1686        const char *a_prefix, *b_prefix;
1687        char *data_one, *data_two;
1688        size_t size_one, size_two;
1689        struct emit_callback ecbdata;
1690        struct strbuf out = STRBUF_INIT;
1691
1692        if (diff_mnemonic_prefix && o->flags.reverse_diff) {
1693                a_prefix = o->b_prefix;
1694                b_prefix = o->a_prefix;
1695        } else {
1696                a_prefix = o->a_prefix;
1697                b_prefix = o->b_prefix;
1698        }
1699
1700        name_a += (*name_a == '/');
1701        name_b += (*name_b == '/');
1702
1703        strbuf_reset(&a_name);
1704        strbuf_reset(&b_name);
1705        quote_two_c_style(&a_name, a_prefix, name_a, 0);
1706        quote_two_c_style(&b_name, b_prefix, name_b, 0);
1707
1708        size_one = fill_textconv(textconv_one, one, &data_one);
1709        size_two = fill_textconv(textconv_two, two, &data_two);
1710
1711        memset(&ecbdata, 0, sizeof(ecbdata));
1712        ecbdata.color_diff = want_color(o->use_color);
1713        ecbdata.ws_rule = whitespace_rule(name_b);
1714        ecbdata.opt = o;
1715        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
1716                mmfile_t mf1, mf2;
1717                mf1.ptr = (char *)data_one;
1718                mf2.ptr = (char *)data_two;
1719                mf1.size = size_one;
1720                mf2.size = size_two;
1721                check_blank_at_eof(&mf1, &mf2, &ecbdata);
1722        }
1723        ecbdata.lno_in_preimage = 1;
1724        ecbdata.lno_in_postimage = 1;
1725
1726        lc_a = count_lines(data_one, size_one);
1727        lc_b = count_lines(data_two, size_two);
1728
1729        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
1730                         a_name.buf, a_name.len, 0);
1731        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
1732                         b_name.buf, b_name.len, 0);
1733
1734        strbuf_addstr(&out, "@@ -");
1735        if (!o->irreversible_delete)
1736                add_line_count(&out, lc_a);
1737        else
1738                strbuf_addstr(&out, "?,?");
1739        strbuf_addstr(&out, " +");
1740        add_line_count(&out, lc_b);
1741        strbuf_addstr(&out, " @@\n");
1742        emit_diff_symbol(o, DIFF_SYMBOL_REWRITE_DIFF, out.buf, out.len, 0);
1743        strbuf_release(&out);
1744
1745        if (lc_a && !o->irreversible_delete)
1746                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
1747        if (lc_b)
1748                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
1749        if (textconv_one)
1750                free((char *)data_one);
1751        if (textconv_two)
1752                free((char *)data_two);
1753}
1754
1755struct diff_words_buffer {
1756        mmfile_t text;
1757        unsigned long alloc;
1758        struct diff_words_orig {
1759                const char *begin, *end;
1760        } *orig;
1761        int orig_nr, orig_alloc;
1762};
1763
1764static void diff_words_append(char *line, unsigned long len,
1765                struct diff_words_buffer *buffer)
1766{
1767        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
1768        line++;
1769        len--;
1770        memcpy(buffer->text.ptr + buffer->text.size, line, len);
1771        buffer->text.size += len;
1772        buffer->text.ptr[buffer->text.size] = '\0';
1773}
1774
1775struct diff_words_style_elem {
1776        const char *prefix;
1777        const char *suffix;
1778        const char *color; /* NULL; filled in by the setup code if
1779                            * color is enabled */
1780};
1781
1782struct diff_words_style {
1783        enum diff_words_type type;
1784        struct diff_words_style_elem new_word, old_word, ctx;
1785        const char *newline;
1786};
1787
1788static struct diff_words_style diff_words_styles[] = {
1789        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
1790        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
1791        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
1792};
1793
1794struct diff_words_data {
1795        struct diff_words_buffer minus, plus;
1796        const char *current_plus;
1797        int last_minus;
1798        struct diff_options *opt;
1799        regex_t *word_regex;
1800        enum diff_words_type type;
1801        struct diff_words_style *style;
1802};
1803
1804static int fn_out_diff_words_write_helper(struct diff_options *o,
1805                                          struct diff_words_style_elem *st_el,
1806                                          const char *newline,
1807                                          size_t count, const char *buf)
1808{
1809        int print = 0;
1810        struct strbuf sb = STRBUF_INIT;
1811
1812        while (count) {
1813                char *p = memchr(buf, '\n', count);
1814                if (print)
1815                        strbuf_addstr(&sb, diff_line_prefix(o));
1816
1817                if (p != buf) {
1818                        const char *reset = st_el->color && *st_el->color ?
1819                                            GIT_COLOR_RESET : NULL;
1820                        if (st_el->color && *st_el->color)
1821                                strbuf_addstr(&sb, st_el->color);
1822                        strbuf_addstr(&sb, st_el->prefix);
1823                        strbuf_add(&sb, buf, p ? p - buf : count);
1824                        strbuf_addstr(&sb, st_el->suffix);
1825                        if (reset)
1826                                strbuf_addstr(&sb, reset);
1827                }
1828                if (!p)
1829                        goto out;
1830
1831                strbuf_addstr(&sb, newline);
1832                count -= p + 1 - buf;
1833                buf = p + 1;
1834                print = 1;
1835                if (count) {
1836                        emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1837                                         sb.buf, sb.len, 0);
1838                        strbuf_reset(&sb);
1839                }
1840        }
1841
1842out:
1843        if (sb.len)
1844                emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1845                                 sb.buf, sb.len, 0);
1846        strbuf_release(&sb);
1847        return 0;
1848}
1849
1850/*
1851 * '--color-words' algorithm can be described as:
1852 *
1853 *   1. collect the minus/plus lines of a diff hunk, divided into
1854 *      minus-lines and plus-lines;
1855 *
1856 *   2. break both minus-lines and plus-lines into words and
1857 *      place them into two mmfile_t with one word for each line;
1858 *
1859 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
1860 *
1861 * And for the common parts of the both file, we output the plus side text.
1862 * diff_words->current_plus is used to trace the current position of the plus file
1863 * which printed. diff_words->last_minus is used to trace the last minus word
1864 * printed.
1865 *
1866 * For '--graph' to work with '--color-words', we need to output the graph prefix
1867 * on each line of color words output. Generally, there are two conditions on
1868 * which we should output the prefix.
1869 *
1870 *   1. diff_words->last_minus == 0 &&
1871 *      diff_words->current_plus == diff_words->plus.text.ptr
1872 *
1873 *      that is: the plus text must start as a new line, and if there is no minus
1874 *      word printed, a graph prefix must be printed.
1875 *
1876 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
1877 *      *(diff_words->current_plus - 1) == '\n'
1878 *
1879 *      that is: a graph prefix must be printed following a '\n'
1880 */
1881static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
1882{
1883        if ((diff_words->last_minus == 0 &&
1884                diff_words->current_plus == diff_words->plus.text.ptr) ||
1885                (diff_words->current_plus > diff_words->plus.text.ptr &&
1886                *(diff_words->current_plus - 1) == '\n')) {
1887                return 1;
1888        } else {
1889                return 0;
1890        }
1891}
1892
1893static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
1894{
1895        struct diff_words_data *diff_words = priv;
1896        struct diff_words_style *style = diff_words->style;
1897        int minus_first, minus_len, plus_first, plus_len;
1898        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
1899        struct diff_options *opt = diff_words->opt;
1900        const char *line_prefix;
1901
1902        if (line[0] != '@' || parse_hunk_header(line, len,
1903                        &minus_first, &minus_len, &plus_first, &plus_len))
1904                return;
1905
1906        assert(opt);
1907        line_prefix = diff_line_prefix(opt);
1908
1909        /* POSIX requires that first be decremented by one if len == 0... */
1910        if (minus_len) {
1911                minus_begin = diff_words->minus.orig[minus_first].begin;
1912                minus_end =
1913                        diff_words->minus.orig[minus_first + minus_len - 1].end;
1914        } else
1915                minus_begin = minus_end =
1916                        diff_words->minus.orig[minus_first].end;
1917
1918        if (plus_len) {
1919                plus_begin = diff_words->plus.orig[plus_first].begin;
1920                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
1921        } else
1922                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
1923
1924        if (color_words_output_graph_prefix(diff_words)) {
1925                fputs(line_prefix, diff_words->opt->file);
1926        }
1927        if (diff_words->current_plus != plus_begin) {
1928                fn_out_diff_words_write_helper(diff_words->opt,
1929                                &style->ctx, style->newline,
1930                                plus_begin - diff_words->current_plus,
1931                                diff_words->current_plus);
1932        }
1933        if (minus_begin != minus_end) {
1934                fn_out_diff_words_write_helper(diff_words->opt,
1935                                &style->old_word, style->newline,
1936                                minus_end - minus_begin, minus_begin);
1937        }
1938        if (plus_begin != plus_end) {
1939                fn_out_diff_words_write_helper(diff_words->opt,
1940                                &style->new_word, style->newline,
1941                                plus_end - plus_begin, plus_begin);
1942        }
1943
1944        diff_words->current_plus = plus_end;
1945        diff_words->last_minus = minus_first;
1946}
1947
1948/* This function starts looking at *begin, and returns 0 iff a word was found. */
1949static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
1950                int *begin, int *end)
1951{
1952        if (word_regex && *begin < buffer->size) {
1953                regmatch_t match[1];
1954                if (!regexec_buf(word_regex, buffer->ptr + *begin,
1955                                 buffer->size - *begin, 1, match, 0)) {
1956                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
1957                                        '\n', match[0].rm_eo - match[0].rm_so);
1958                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
1959                        *begin += match[0].rm_so;
1960                        return *begin >= *end;
1961                }
1962                return -1;
1963        }
1964
1965        /* find the next word */
1966        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
1967                (*begin)++;
1968        if (*begin >= buffer->size)
1969                return -1;
1970
1971        /* find the end of the word */
1972        *end = *begin + 1;
1973        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
1974                (*end)++;
1975
1976        return 0;
1977}
1978
1979/*
1980 * This function splits the words in buffer->text, stores the list with
1981 * newline separator into out, and saves the offsets of the original words
1982 * in buffer->orig.
1983 */
1984static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
1985                regex_t *word_regex)
1986{
1987        int i, j;
1988        long alloc = 0;
1989
1990        out->size = 0;
1991        out->ptr = NULL;
1992
1993        /* fake an empty "0th" word */
1994        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
1995        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
1996        buffer->orig_nr = 1;
1997
1998        for (i = 0; i < buffer->text.size; i++) {
1999                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
2000                        return;
2001
2002                /* store original boundaries */
2003                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
2004                                buffer->orig_alloc);
2005                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
2006                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
2007                buffer->orig_nr++;
2008
2009                /* store one word */
2010                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
2011                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
2012                out->ptr[out->size + j - i] = '\n';
2013                out->size += j - i + 1;
2014
2015                i = j - 1;
2016        }
2017}
2018
2019/* this executes the word diff on the accumulated buffers */
2020static void diff_words_show(struct diff_words_data *diff_words)
2021{
2022        xpparam_t xpp;
2023        xdemitconf_t xecfg;
2024        mmfile_t minus, plus;
2025        struct diff_words_style *style = diff_words->style;
2026
2027        struct diff_options *opt = diff_words->opt;
2028        const char *line_prefix;
2029
2030        assert(opt);
2031        line_prefix = diff_line_prefix(opt);
2032
2033        /* special case: only removal */
2034        if (!diff_words->plus.text.size) {
2035                emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
2036                                 line_prefix, strlen(line_prefix), 0);
2037                fn_out_diff_words_write_helper(diff_words->opt,
2038                        &style->old_word, style->newline,
2039                        diff_words->minus.text.size,
2040                        diff_words->minus.text.ptr);
2041                diff_words->minus.text.size = 0;
2042                return;
2043        }
2044
2045        diff_words->current_plus = diff_words->plus.text.ptr;
2046        diff_words->last_minus = 0;
2047
2048        memset(&xpp, 0, sizeof(xpp));
2049        memset(&xecfg, 0, sizeof(xecfg));
2050        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
2051        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
2052        xpp.flags = 0;
2053        /* as only the hunk header will be parsed, we need a 0-context */
2054        xecfg.ctxlen = 0;
2055        if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
2056                          &xpp, &xecfg))
2057                die("unable to generate word diff");
2058        free(minus.ptr);
2059        free(plus.ptr);
2060        if (diff_words->current_plus != diff_words->plus.text.ptr +
2061                        diff_words->plus.text.size) {
2062                if (color_words_output_graph_prefix(diff_words))
2063                        emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
2064                                         line_prefix, strlen(line_prefix), 0);
2065                fn_out_diff_words_write_helper(diff_words->opt,
2066                        &style->ctx, style->newline,
2067                        diff_words->plus.text.ptr + diff_words->plus.text.size
2068                        - diff_words->current_plus, diff_words->current_plus);
2069        }
2070        diff_words->minus.text.size = diff_words->plus.text.size = 0;
2071}
2072
2073/* In "color-words" mode, show word-diff of words accumulated in the buffer */
2074static void diff_words_flush(struct emit_callback *ecbdata)
2075{
2076        struct diff_options *wo = ecbdata->diff_words->opt;
2077
2078        if (ecbdata->diff_words->minus.text.size ||
2079            ecbdata->diff_words->plus.text.size)
2080                diff_words_show(ecbdata->diff_words);
2081
2082        if (wo->emitted_symbols) {
2083                struct diff_options *o = ecbdata->opt;
2084                struct emitted_diff_symbols *wol = wo->emitted_symbols;
2085                int i;
2086
2087                /*
2088                 * NEEDSWORK:
2089                 * Instead of appending each, concat all words to a line?
2090                 */
2091                for (i = 0; i < wol->nr; i++)
2092                        append_emitted_diff_symbol(o, &wol->buf[i]);
2093
2094                for (i = 0; i < wol->nr; i++)
2095                        free((void *)wol->buf[i].line);
2096
2097                wol->nr = 0;
2098        }
2099}
2100
2101static void diff_filespec_load_driver(struct diff_filespec *one)
2102{
2103        /* Use already-loaded driver */
2104        if (one->driver)
2105                return;
2106
2107        if (S_ISREG(one->mode))
2108                one->driver = userdiff_find_by_path(one->path);
2109
2110        /* Fallback to default settings */
2111        if (!one->driver)
2112                one->driver = userdiff_find_by_name("default");
2113}
2114
2115static const char *userdiff_word_regex(struct diff_filespec *one)
2116{
2117        diff_filespec_load_driver(one);
2118        return one->driver->word_regex;
2119}
2120
2121static void init_diff_words_data(struct emit_callback *ecbdata,
2122                                 struct diff_options *orig_opts,
2123                                 struct diff_filespec *one,
2124                                 struct diff_filespec *two)
2125{
2126        int i;
2127        struct diff_options *o = xmalloc(sizeof(struct diff_options));
2128        memcpy(o, orig_opts, sizeof(struct diff_options));
2129
2130        ecbdata->diff_words =
2131                xcalloc(1, sizeof(struct diff_words_data));
2132        ecbdata->diff_words->type = o->word_diff;
2133        ecbdata->diff_words->opt = o;
2134
2135        if (orig_opts->emitted_symbols)
2136                o->emitted_symbols =
2137                        xcalloc(1, sizeof(struct emitted_diff_symbols));
2138
2139        if (!o->word_regex)
2140                o->word_regex = userdiff_word_regex(one);
2141        if (!o->word_regex)
2142                o->word_regex = userdiff_word_regex(two);
2143        if (!o->word_regex)
2144                o->word_regex = diff_word_regex_cfg;
2145        if (o->word_regex) {
2146                ecbdata->diff_words->word_regex = (regex_t *)
2147                        xmalloc(sizeof(regex_t));
2148                if (regcomp(ecbdata->diff_words->word_regex,
2149                            o->word_regex,
2150                            REG_EXTENDED | REG_NEWLINE))
2151                        die ("Invalid regular expression: %s",
2152                             o->word_regex);
2153        }
2154        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2155                if (o->word_diff == diff_words_styles[i].type) {
2156                        ecbdata->diff_words->style =
2157                                &diff_words_styles[i];
2158                        break;
2159                }
2160        }
2161        if (want_color(o->use_color)) {
2162                struct diff_words_style *st = ecbdata->diff_words->style;
2163                st->old_word.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2164                st->new_word.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2165                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
2166        }
2167}
2168
2169static void free_diff_words_data(struct emit_callback *ecbdata)
2170{
2171        if (ecbdata->diff_words) {
2172                diff_words_flush(ecbdata);
2173                free (ecbdata->diff_words->opt->emitted_symbols);
2174                free (ecbdata->diff_words->opt);
2175                free (ecbdata->diff_words->minus.text.ptr);
2176                free (ecbdata->diff_words->minus.orig);
2177                free (ecbdata->diff_words->plus.text.ptr);
2178                free (ecbdata->diff_words->plus.orig);
2179                if (ecbdata->diff_words->word_regex) {
2180                        regfree(ecbdata->diff_words->word_regex);
2181                        free(ecbdata->diff_words->word_regex);
2182                }
2183                FREE_AND_NULL(ecbdata->diff_words);
2184        }
2185}
2186
2187const char *diff_get_color(int diff_use_color, enum color_diff ix)
2188{
2189        if (want_color(diff_use_color))
2190                return diff_colors[ix];
2191        return "";
2192}
2193
2194const char *diff_line_prefix(struct diff_options *opt)
2195{
2196        struct strbuf *msgbuf;
2197        if (!opt->output_prefix)
2198                return "";
2199
2200        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
2201        return msgbuf->buf;
2202}
2203
2204static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
2205{
2206        const char *cp;
2207        unsigned long allot;
2208        size_t l = len;
2209
2210        cp = line;
2211        allot = l;
2212        while (0 < l) {
2213                (void) utf8_width(&cp, &l);
2214                if (!cp)
2215                        break; /* truncated in the middle? */
2216        }
2217        return allot - l;
2218}
2219
2220static void find_lno(const char *line, struct emit_callback *ecbdata)
2221{
2222        const char *p;
2223        ecbdata->lno_in_preimage = 0;
2224        ecbdata->lno_in_postimage = 0;
2225        p = strchr(line, '-');
2226        if (!p)
2227                return; /* cannot happen */
2228        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
2229        p = strchr(p, '+');
2230        if (!p)
2231                return; /* cannot happen */
2232        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
2233}
2234
2235static void fn_out_consume(void *priv, char *line, unsigned long len)
2236{
2237        struct emit_callback *ecbdata = priv;
2238        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
2239        struct diff_options *o = ecbdata->opt;
2240
2241        o->found_changes = 1;
2242
2243        if (ecbdata->header) {
2244                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
2245                                 ecbdata->header->buf, ecbdata->header->len, 0);
2246                strbuf_reset(ecbdata->header);
2247                ecbdata->header = NULL;
2248        }
2249
2250        if (ecbdata->label_path[0]) {
2251                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
2252                                 ecbdata->label_path[0],
2253                                 strlen(ecbdata->label_path[0]), 0);
2254                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
2255                                 ecbdata->label_path[1],
2256                                 strlen(ecbdata->label_path[1]), 0);
2257                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
2258        }
2259
2260        if (diff_suppress_blank_empty
2261            && len == 2 && line[0] == ' ' && line[1] == '\n') {
2262                line[0] = '\n';
2263                len = 1;
2264        }
2265
2266        if (line[0] == '@') {
2267                if (ecbdata->diff_words)
2268                        diff_words_flush(ecbdata);
2269                len = sane_truncate_line(ecbdata, line, len);
2270                find_lno(line, ecbdata);
2271                emit_hunk_header(ecbdata, line, len);
2272                return;
2273        }
2274
2275        if (ecbdata->diff_words) {
2276                enum diff_symbol s =
2277                        ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN ?
2278                        DIFF_SYMBOL_WORDS_PORCELAIN : DIFF_SYMBOL_WORDS;
2279                if (line[0] == '-') {
2280                        diff_words_append(line, len,
2281                                          &ecbdata->diff_words->minus);
2282                        return;
2283                } else if (line[0] == '+') {
2284                        diff_words_append(line, len,
2285                                          &ecbdata->diff_words->plus);
2286                        return;
2287                } else if (starts_with(line, "\\ ")) {
2288                        /*
2289                         * Eat the "no newline at eof" marker as if we
2290                         * saw a "+" or "-" line with nothing on it,
2291                         * and return without diff_words_flush() to
2292                         * defer processing. If this is the end of
2293                         * preimage, more "+" lines may come after it.
2294                         */
2295                        return;
2296                }
2297                diff_words_flush(ecbdata);
2298                emit_diff_symbol(o, s, line, len, 0);
2299                return;
2300        }
2301
2302        switch (line[0]) {
2303        case '+':
2304                ecbdata->lno_in_postimage++;
2305                emit_add_line(reset, ecbdata, line + 1, len - 1);
2306                break;
2307        case '-':
2308                ecbdata->lno_in_preimage++;
2309                emit_del_line(reset, ecbdata, line + 1, len - 1);
2310                break;
2311        case ' ':
2312                ecbdata->lno_in_postimage++;
2313                ecbdata->lno_in_preimage++;
2314                emit_context_line(reset, ecbdata, line + 1, len - 1);
2315                break;
2316        default:
2317                /* incomplete line at the end */
2318                ecbdata->lno_in_preimage++;
2319                emit_diff_symbol(o, DIFF_SYMBOL_CONTEXT_INCOMPLETE,
2320                                 line, len, 0);
2321                break;
2322        }
2323}
2324
2325static void pprint_rename(struct strbuf *name, const char *a, const char *b)
2326{
2327        const char *old_name = a;
2328        const char *new_name = b;
2329        int pfx_length, sfx_length;
2330        int pfx_adjust_for_slash;
2331        int len_a = strlen(a);
2332        int len_b = strlen(b);
2333        int a_midlen, b_midlen;
2334        int qlen_a = quote_c_style(a, NULL, NULL, 0);
2335        int qlen_b = quote_c_style(b, NULL, NULL, 0);
2336
2337        if (qlen_a || qlen_b) {
2338                quote_c_style(a, name, NULL, 0);
2339                strbuf_addstr(name, " => ");
2340                quote_c_style(b, name, NULL, 0);
2341                return;
2342        }
2343
2344        /* Find common prefix */
2345        pfx_length = 0;
2346        while (*old_name && *new_name && *old_name == *new_name) {
2347                if (*old_name == '/')
2348                        pfx_length = old_name - a + 1;
2349                old_name++;
2350                new_name++;
2351        }
2352
2353        /* Find common suffix */
2354        old_name = a + len_a;
2355        new_name = b + len_b;
2356        sfx_length = 0;
2357        /*
2358         * If there is a common prefix, it must end in a slash.  In
2359         * that case we let this loop run 1 into the prefix to see the
2360         * same slash.
2361         *
2362         * If there is no common prefix, we cannot do this as it would
2363         * underrun the input strings.
2364         */
2365        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
2366        while (a + pfx_length - pfx_adjust_for_slash <= old_name &&
2367               b + pfx_length - pfx_adjust_for_slash <= new_name &&
2368               *old_name == *new_name) {
2369                if (*old_name == '/')
2370                        sfx_length = len_a - (old_name - a);
2371                old_name--;
2372                new_name--;
2373        }
2374
2375        /*
2376         * pfx{mid-a => mid-b}sfx
2377         * {pfx-a => pfx-b}sfx
2378         * pfx{sfx-a => sfx-b}
2379         * name-a => name-b
2380         */
2381        a_midlen = len_a - pfx_length - sfx_length;
2382        b_midlen = len_b - pfx_length - sfx_length;
2383        if (a_midlen < 0)
2384                a_midlen = 0;
2385        if (b_midlen < 0)
2386                b_midlen = 0;
2387
2388        strbuf_grow(name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
2389        if (pfx_length + sfx_length) {
2390                strbuf_add(name, a, pfx_length);
2391                strbuf_addch(name, '{');
2392        }
2393        strbuf_add(name, a + pfx_length, a_midlen);
2394        strbuf_addstr(name, " => ");
2395        strbuf_add(name, b + pfx_length, b_midlen);
2396        if (pfx_length + sfx_length) {
2397                strbuf_addch(name, '}');
2398                strbuf_add(name, a + len_a - sfx_length, sfx_length);
2399        }
2400}
2401
2402struct diffstat_t {
2403        int nr;
2404        int alloc;
2405        struct diffstat_file {
2406                char *from_name;
2407                char *name;
2408                char *print_name;
2409                const char *comments;
2410                unsigned is_unmerged:1;
2411                unsigned is_binary:1;
2412                unsigned is_renamed:1;
2413                unsigned is_interesting:1;
2414                uintmax_t added, deleted;
2415        } **files;
2416};
2417
2418static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
2419                                          const char *name_a,
2420                                          const char *name_b)
2421{
2422        struct diffstat_file *x;
2423        x = xcalloc(1, sizeof(*x));
2424        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
2425        diffstat->files[diffstat->nr++] = x;
2426        if (name_b) {
2427                x->from_name = xstrdup(name_a);
2428                x->name = xstrdup(name_b);
2429                x->is_renamed = 1;
2430        }
2431        else {
2432                x->from_name = NULL;
2433                x->name = xstrdup(name_a);
2434        }
2435        return x;
2436}
2437
2438static void diffstat_consume(void *priv, char *line, unsigned long len)
2439{
2440        struct diffstat_t *diffstat = priv;
2441        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
2442
2443        if (line[0] == '+')
2444                x->added++;
2445        else if (line[0] == '-')
2446                x->deleted++;
2447}
2448
2449const char mime_boundary_leader[] = "------------";
2450
2451static int scale_linear(int it, int width, int max_change)
2452{
2453        if (!it)
2454                return 0;
2455        /*
2456         * make sure that at least one '-' or '+' is printed if
2457         * there is any change to this path. The easiest way is to
2458         * scale linearly as if the alloted width is one column shorter
2459         * than it is, and then add 1 to the result.
2460         */
2461        return 1 + (it * (width - 1) / max_change);
2462}
2463
2464static void show_graph(struct strbuf *out, char ch, int cnt,
2465                       const char *set, const char *reset)
2466{
2467        if (cnt <= 0)
2468                return;
2469        strbuf_addstr(out, set);
2470        strbuf_addchars(out, ch, cnt);
2471        strbuf_addstr(out, reset);
2472}
2473
2474static void fill_print_name(struct diffstat_file *file)
2475{
2476        struct strbuf pname = STRBUF_INIT;
2477
2478        if (file->print_name)
2479                return;
2480
2481        if (file->is_renamed)
2482                pprint_rename(&pname, file->from_name, file->name);
2483        else
2484                quote_c_style(file->name, &pname, NULL, 0);
2485
2486        if (file->comments)
2487                strbuf_addf(&pname, " (%s)", file->comments);
2488
2489        file->print_name = strbuf_detach(&pname, NULL);
2490}
2491
2492static void print_stat_summary_inserts_deletes(struct diff_options *options,
2493                int files, int insertions, int deletions)
2494{
2495        struct strbuf sb = STRBUF_INIT;
2496
2497        if (!files) {
2498                assert(insertions == 0 && deletions == 0);
2499                emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
2500                                 NULL, 0, 0);
2501                return;
2502        }
2503
2504        strbuf_addf(&sb,
2505                    (files == 1) ? " %d file changed" : " %d files changed",
2506                    files);
2507
2508        /*
2509         * For binary diff, the caller may want to print "x files
2510         * changed" with insertions == 0 && deletions == 0.
2511         *
2512         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
2513         * is probably less confusing (i.e skip over "2 files changed
2514         * but nothing about added/removed lines? Is this a bug in Git?").
2515         */
2516        if (insertions || deletions == 0) {
2517                strbuf_addf(&sb,
2518                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
2519                            insertions);
2520        }
2521
2522        if (deletions || insertions == 0) {
2523                strbuf_addf(&sb,
2524                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
2525                            deletions);
2526        }
2527        strbuf_addch(&sb, '\n');
2528        emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
2529                         sb.buf, sb.len, 0);
2530        strbuf_release(&sb);
2531}
2532
2533void print_stat_summary(FILE *fp, int files,
2534                        int insertions, int deletions)
2535{
2536        struct diff_options o;
2537        memset(&o, 0, sizeof(o));
2538        o.file = fp;
2539
2540        print_stat_summary_inserts_deletes(&o, files, insertions, deletions);
2541}
2542
2543static void show_stats(struct diffstat_t *data, struct diff_options *options)
2544{
2545        int i, len, add, del, adds = 0, dels = 0;
2546        uintmax_t max_change = 0, max_len = 0;
2547        int total_files = data->nr, count;
2548        int width, name_width, graph_width, number_width = 0, bin_width = 0;
2549        const char *reset, *add_c, *del_c;
2550        int extra_shown = 0;
2551        const char *line_prefix = diff_line_prefix(options);
2552        struct strbuf out = STRBUF_INIT;
2553
2554        if (data->nr == 0)
2555                return;
2556
2557        count = options->stat_count ? options->stat_count : data->nr;
2558
2559        reset = diff_get_color_opt(options, DIFF_RESET);
2560        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
2561        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
2562
2563        /*
2564         * Find the longest filename and max number of changes
2565         */
2566        for (i = 0; (i < count) && (i < data->nr); i++) {
2567                struct diffstat_file *file = data->files[i];
2568                uintmax_t change = file->added + file->deleted;
2569
2570                if (!file->is_interesting && (change == 0)) {
2571                        count++; /* not shown == room for one more */
2572                        continue;
2573                }
2574                fill_print_name(file);
2575                len = strlen(file->print_name);
2576                if (max_len < len)
2577                        max_len = len;
2578
2579                if (file->is_unmerged) {
2580                        /* "Unmerged" is 8 characters */
2581                        bin_width = bin_width < 8 ? 8 : bin_width;
2582                        continue;
2583                }
2584                if (file->is_binary) {
2585                        /* "Bin XXX -> YYY bytes" */
2586                        int w = 14 + decimal_width(file->added)
2587                                + decimal_width(file->deleted);
2588                        bin_width = bin_width < w ? w : bin_width;
2589                        /* Display change counts aligned with "Bin" */
2590                        number_width = 3;
2591                        continue;
2592                }
2593
2594                if (max_change < change)
2595                        max_change = change;
2596        }
2597        count = i; /* where we can stop scanning in data->files[] */
2598
2599        /*
2600         * We have width = stat_width or term_columns() columns total.
2601         * We want a maximum of min(max_len, stat_name_width) for the name part.
2602         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
2603         * We also need 1 for " " and 4 + decimal_width(max_change)
2604         * for " | NNNN " and one the empty column at the end, altogether
2605         * 6 + decimal_width(max_change).
2606         *
2607         * If there's not enough space, we will use the smaller of
2608         * stat_name_width (if set) and 5/8*width for the filename,
2609         * and the rest for constant elements + graph part, but no more
2610         * than stat_graph_width for the graph part.
2611         * (5/8 gives 50 for filename and 30 for the constant parts + graph
2612         * for the standard terminal size).
2613         *
2614         * In other words: stat_width limits the maximum width, and
2615         * stat_name_width fixes the maximum width of the filename,
2616         * and is also used to divide available columns if there
2617         * aren't enough.
2618         *
2619         * Binary files are displayed with "Bin XXX -> YYY bytes"
2620         * instead of the change count and graph. This part is treated
2621         * similarly to the graph part, except that it is not
2622         * "scaled". If total width is too small to accommodate the
2623         * guaranteed minimum width of the filename part and the
2624         * separators and this message, this message will "overflow"
2625         * making the line longer than the maximum width.
2626         */
2627
2628        if (options->stat_width == -1)
2629                width = term_columns() - strlen(line_prefix);
2630        else
2631                width = options->stat_width ? options->stat_width : 80;
2632        number_width = decimal_width(max_change) > number_width ?
2633                decimal_width(max_change) : number_width;
2634
2635        if (options->stat_graph_width == -1)
2636                options->stat_graph_width = diff_stat_graph_width;
2637
2638        /*
2639         * Guarantee 3/8*16==6 for the graph part
2640         * and 5/8*16==10 for the filename part
2641         */
2642        if (width < 16 + 6 + number_width)
2643                width = 16 + 6 + number_width;
2644
2645        /*
2646         * First assign sizes that are wanted, ignoring available width.
2647         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
2648         * starting from "XXX" should fit in graph_width.
2649         */
2650        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
2651        if (options->stat_graph_width &&
2652            options->stat_graph_width < graph_width)
2653                graph_width = options->stat_graph_width;
2654
2655        name_width = (options->stat_name_width > 0 &&
2656                      options->stat_name_width < max_len) ?
2657                options->stat_name_width : max_len;
2658
2659        /*
2660         * Adjust adjustable widths not to exceed maximum width
2661         */
2662        if (name_width + number_width + 6 + graph_width > width) {
2663                if (graph_width > width * 3/8 - number_width - 6) {
2664                        graph_width = width * 3/8 - number_width - 6;
2665                        if (graph_width < 6)
2666                                graph_width = 6;
2667                }
2668
2669                if (options->stat_graph_width &&
2670                    graph_width > options->stat_graph_width)
2671                        graph_width = options->stat_graph_width;
2672                if (name_width > width - number_width - 6 - graph_width)
2673                        name_width = width - number_width - 6 - graph_width;
2674                else
2675                        graph_width = width - number_width - 6 - name_width;
2676        }
2677
2678        /*
2679         * From here name_width is the width of the name area,
2680         * and graph_width is the width of the graph area.
2681         * max_change is used to scale graph properly.
2682         */
2683        for (i = 0; i < count; i++) {
2684                const char *prefix = "";
2685                struct diffstat_file *file = data->files[i];
2686                char *name = file->print_name;
2687                uintmax_t added = file->added;
2688                uintmax_t deleted = file->deleted;
2689                int name_len;
2690
2691                if (!file->is_interesting && (added + deleted == 0))
2692                        continue;
2693
2694                /*
2695                 * "scale" the filename
2696                 */
2697                len = name_width;
2698                name_len = strlen(name);
2699                if (name_width < name_len) {
2700                        char *slash;
2701                        prefix = "...";
2702                        len -= 3;
2703                        name += name_len - len;
2704                        slash = strchr(name, '/');
2705                        if (slash)
2706                                name = slash;
2707                }
2708
2709                if (file->is_binary) {
2710                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2711                        strbuf_addf(&out, " %*s", number_width, "Bin");
2712                        if (!added && !deleted) {
2713                                strbuf_addch(&out, '\n');
2714                                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2715                                                 out.buf, out.len, 0);
2716                                strbuf_reset(&out);
2717                                continue;
2718                        }
2719                        strbuf_addf(&out, " %s%"PRIuMAX"%s",
2720                                del_c, deleted, reset);
2721                        strbuf_addstr(&out, " -> ");
2722                        strbuf_addf(&out, "%s%"PRIuMAX"%s",
2723                                add_c, added, reset);
2724                        strbuf_addstr(&out, " bytes\n");
2725                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2726                                         out.buf, out.len, 0);
2727                        strbuf_reset(&out);
2728                        continue;
2729                }
2730                else if (file->is_unmerged) {
2731                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2732                        strbuf_addstr(&out, " Unmerged\n");
2733                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2734                                         out.buf, out.len, 0);
2735                        strbuf_reset(&out);
2736                        continue;
2737                }
2738
2739                /*
2740                 * scale the add/delete
2741                 */
2742                add = added;
2743                del = deleted;
2744
2745                if (graph_width <= max_change) {
2746                        int total = scale_linear(add + del, graph_width, max_change);
2747                        if (total < 2 && add && del)
2748                                /* width >= 2 due to the sanity check */
2749                                total = 2;
2750                        if (add < del) {
2751                                add = scale_linear(add, graph_width, max_change);
2752                                del = total - add;
2753                        } else {
2754                                del = scale_linear(del, graph_width, max_change);
2755                                add = total - del;
2756                        }
2757                }
2758                strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2759                strbuf_addf(&out, " %*"PRIuMAX"%s",
2760                        number_width, added + deleted,
2761                        added + deleted ? " " : "");
2762                show_graph(&out, '+', add, add_c, reset);
2763                show_graph(&out, '-', del, del_c, reset);
2764                strbuf_addch(&out, '\n');
2765                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2766                                 out.buf, out.len, 0);
2767                strbuf_reset(&out);
2768        }
2769
2770        for (i = 0; i < data->nr; i++) {
2771                struct diffstat_file *file = data->files[i];
2772                uintmax_t added = file->added;
2773                uintmax_t deleted = file->deleted;
2774
2775                if (file->is_unmerged ||
2776                    (!file->is_interesting && (added + deleted == 0))) {
2777                        total_files--;
2778                        continue;
2779                }
2780
2781                if (!file->is_binary) {
2782                        adds += added;
2783                        dels += deleted;
2784                }
2785                if (i < count)
2786                        continue;
2787                if (!extra_shown)
2788                        emit_diff_symbol(options,
2789                                         DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
2790                                         NULL, 0, 0);
2791                extra_shown = 1;
2792        }
2793
2794        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2795        strbuf_release(&out);
2796}
2797
2798static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
2799{
2800        int i, adds = 0, dels = 0, total_files = data->nr;
2801
2802        if (data->nr == 0)
2803                return;
2804
2805        for (i = 0; i < data->nr; i++) {
2806                int added = data->files[i]->added;
2807                int deleted = data->files[i]->deleted;
2808
2809                if (data->files[i]->is_unmerged ||
2810                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
2811                        total_files--;
2812                } else if (!data->files[i]->is_binary) { /* don't count bytes */
2813                        adds += added;
2814                        dels += deleted;
2815                }
2816        }
2817        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2818}
2819
2820static void show_numstat(struct diffstat_t *data, struct diff_options *options)
2821{
2822        int i;
2823
2824        if (data->nr == 0)
2825                return;
2826
2827        for (i = 0; i < data->nr; i++) {
2828                struct diffstat_file *file = data->files[i];
2829
2830                fprintf(options->file, "%s", diff_line_prefix(options));
2831
2832                if (file->is_binary)
2833                        fprintf(options->file, "-\t-\t");
2834                else
2835                        fprintf(options->file,
2836                                "%"PRIuMAX"\t%"PRIuMAX"\t",
2837                                file->added, file->deleted);
2838                if (options->line_termination) {
2839                        fill_print_name(file);
2840                        if (!file->is_renamed)
2841                                write_name_quoted(file->name, options->file,
2842                                                  options->line_termination);
2843                        else {
2844                                fputs(file->print_name, options->file);
2845                                putc(options->line_termination, options->file);
2846                        }
2847                } else {
2848                        if (file->is_renamed) {
2849                                putc('\0', options->file);
2850                                write_name_quoted(file->from_name, options->file, '\0');
2851                        }
2852                        write_name_quoted(file->name, options->file, '\0');
2853                }
2854        }
2855}
2856
2857struct dirstat_file {
2858        const char *name;
2859        unsigned long changed;
2860};
2861
2862struct dirstat_dir {
2863        struct dirstat_file *files;
2864        int alloc, nr, permille, cumulative;
2865};
2866
2867static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
2868                unsigned long changed, const char *base, int baselen)
2869{
2870        unsigned long sum_changes = 0;
2871        unsigned int sources = 0;
2872        const char *line_prefix = diff_line_prefix(opt);
2873
2874        while (dir->nr) {
2875                struct dirstat_file *f = dir->files;
2876                int namelen = strlen(f->name);
2877                unsigned long changes;
2878                char *slash;
2879
2880                if (namelen < baselen)
2881                        break;
2882                if (memcmp(f->name, base, baselen))
2883                        break;
2884                slash = strchr(f->name + baselen, '/');
2885                if (slash) {
2886                        int newbaselen = slash + 1 - f->name;
2887                        changes = gather_dirstat(opt, dir, changed, f->name, newbaselen);
2888                        sources++;
2889                } else {
2890                        changes = f->changed;
2891                        dir->files++;
2892                        dir->nr--;
2893                        sources += 2;
2894                }
2895                sum_changes += changes;
2896        }
2897
2898        /*
2899         * We don't report dirstat's for
2900         *  - the top level
2901         *  - or cases where everything came from a single directory
2902         *    under this directory (sources == 1).
2903         */
2904        if (baselen && sources != 1) {
2905                if (sum_changes) {
2906                        int permille = sum_changes * 1000 / changed;
2907                        if (permille >= dir->permille) {
2908                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
2909                                        permille / 10, permille % 10, baselen, base);
2910                                if (!dir->cumulative)
2911                                        return 0;
2912                        }
2913                }
2914        }
2915        return sum_changes;
2916}
2917
2918static int dirstat_compare(const void *_a, const void *_b)
2919{
2920        const struct dirstat_file *a = _a;
2921        const struct dirstat_file *b = _b;
2922        return strcmp(a->name, b->name);
2923}
2924
2925static void show_dirstat(struct diff_options *options)
2926{
2927        int i;
2928        unsigned long changed;
2929        struct dirstat_dir dir;
2930        struct diff_queue_struct *q = &diff_queued_diff;
2931
2932        dir.files = NULL;
2933        dir.alloc = 0;
2934        dir.nr = 0;
2935        dir.permille = options->dirstat_permille;
2936        dir.cumulative = options->flags.dirstat_cumulative;
2937
2938        changed = 0;
2939        for (i = 0; i < q->nr; i++) {
2940                struct diff_filepair *p = q->queue[i];
2941                const char *name;
2942                unsigned long copied, added, damage;
2943                int content_changed;
2944
2945                name = p->two->path ? p->two->path : p->one->path;
2946
2947                if (p->one->oid_valid && p->two->oid_valid)
2948                        content_changed = oidcmp(&p->one->oid, &p->two->oid);
2949                else
2950                        content_changed = 1;
2951
2952                if (!content_changed) {
2953                        /*
2954                         * The SHA1 has not changed, so pre-/post-content is
2955                         * identical. We can therefore skip looking at the
2956                         * file contents altogether.
2957                         */
2958                        damage = 0;
2959                        goto found_damage;
2960                }
2961
2962                if (options->flags.dirstat_by_file) {
2963                        /*
2964                         * In --dirstat-by-file mode, we don't really need to
2965                         * look at the actual file contents at all.
2966                         * The fact that the SHA1 changed is enough for us to
2967                         * add this file to the list of results
2968                         * (with each file contributing equal damage).
2969                         */
2970                        damage = 1;
2971                        goto found_damage;
2972                }
2973
2974                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
2975                        diff_populate_filespec(p->one, 0);
2976                        diff_populate_filespec(p->two, 0);
2977                        diffcore_count_changes(p->one, p->two, NULL, NULL,
2978                                               &copied, &added);
2979                        diff_free_filespec_data(p->one);
2980                        diff_free_filespec_data(p->two);
2981                } else if (DIFF_FILE_VALID(p->one)) {
2982                        diff_populate_filespec(p->one, CHECK_SIZE_ONLY);
2983                        copied = added = 0;
2984                        diff_free_filespec_data(p->one);
2985                } else if (DIFF_FILE_VALID(p->two)) {
2986                        diff_populate_filespec(p->two, CHECK_SIZE_ONLY);
2987                        copied = 0;
2988                        added = p->two->size;
2989                        diff_free_filespec_data(p->two);
2990                } else
2991                        continue;
2992
2993                /*
2994                 * Original minus copied is the removed material,
2995                 * added is the new material.  They are both damages
2996                 * made to the preimage.
2997                 * If the resulting damage is zero, we know that
2998                 * diffcore_count_changes() considers the two entries to
2999                 * be identical, but since content_changed is true, we
3000                 * know that there must have been _some_ kind of change,
3001                 * so we force all entries to have damage > 0.
3002                 */
3003                damage = (p->one->size - copied) + added;
3004                if (!damage)
3005                        damage = 1;
3006
3007found_damage:
3008                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
3009                dir.files[dir.nr].name = name;
3010                dir.files[dir.nr].changed = damage;
3011                changed += damage;
3012                dir.nr++;
3013        }
3014
3015        /* This can happen even with many files, if everything was renames */
3016        if (!changed)
3017                return;
3018
3019        /* Show all directories with more than x% of the changes */
3020        QSORT(dir.files, dir.nr, dirstat_compare);
3021        gather_dirstat(options, &dir, changed, "", 0);
3022}
3023
3024static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
3025{
3026        int i;
3027        unsigned long changed;
3028        struct dirstat_dir dir;
3029
3030        if (data->nr == 0)
3031                return;
3032
3033        dir.files = NULL;
3034        dir.alloc = 0;
3035        dir.nr = 0;
3036        dir.permille = options->dirstat_permille;
3037        dir.cumulative = options->flags.dirstat_cumulative;
3038
3039        changed = 0;
3040        for (i = 0; i < data->nr; i++) {
3041                struct diffstat_file *file = data->files[i];
3042                unsigned long damage = file->added + file->deleted;
3043                if (file->is_binary)
3044                        /*
3045                         * binary files counts bytes, not lines. Must find some
3046                         * way to normalize binary bytes vs. textual lines.
3047                         * The following heuristic assumes that there are 64
3048                         * bytes per "line".
3049                         * This is stupid and ugly, but very cheap...
3050                         */
3051                        damage = DIV_ROUND_UP(damage, 64);
3052                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
3053                dir.files[dir.nr].name = file->name;
3054                dir.files[dir.nr].changed = damage;
3055                changed += damage;
3056                dir.nr++;
3057        }
3058
3059        /* This can happen even with many files, if everything was renames */
3060        if (!changed)
3061                return;
3062
3063        /* Show all directories with more than x% of the changes */
3064        QSORT(dir.files, dir.nr, dirstat_compare);
3065        gather_dirstat(options, &dir, changed, "", 0);
3066}
3067
3068static void free_diffstat_info(struct diffstat_t *diffstat)
3069{
3070        int i;
3071        for (i = 0; i < diffstat->nr; i++) {
3072                struct diffstat_file *f = diffstat->files[i];
3073                free(f->print_name);
3074                free(f->name);
3075                free(f->from_name);
3076                free(f);
3077        }
3078        free(diffstat->files);
3079}
3080
3081struct checkdiff_t {
3082        const char *filename;
3083        int lineno;
3084        int conflict_marker_size;
3085        struct diff_options *o;
3086        unsigned ws_rule;
3087        unsigned status;
3088};
3089
3090static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
3091{
3092        char firstchar;
3093        int cnt;
3094
3095        if (len < marker_size + 1)
3096                return 0;
3097        firstchar = line[0];
3098        switch (firstchar) {
3099        case '=': case '>': case '<': case '|':
3100                break;
3101        default:
3102                return 0;
3103        }
3104        for (cnt = 1; cnt < marker_size; cnt++)
3105                if (line[cnt] != firstchar)
3106                        return 0;
3107        /* line[1] thru line[marker_size-1] are same as firstchar */
3108        if (len < marker_size + 1 || !isspace(line[marker_size]))
3109                return 0;
3110        return 1;
3111}
3112
3113static void checkdiff_consume(void *priv, char *line, unsigned long len)
3114{
3115        struct checkdiff_t *data = priv;
3116        int marker_size = data->conflict_marker_size;
3117        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
3118        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
3119        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
3120        char *err;
3121        const char *line_prefix;
3122
3123        assert(data->o);
3124        line_prefix = diff_line_prefix(data->o);
3125
3126        if (line[0] == '+') {
3127                unsigned bad;
3128                data->lineno++;
3129                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
3130                        data->status |= 1;
3131                        fprintf(data->o->file,
3132                                "%s%s:%d: leftover conflict marker\n",
3133                                line_prefix, data->filename, data->lineno);
3134                }
3135                bad = ws_check(line + 1, len - 1, data->ws_rule);
3136                if (!bad)
3137                        return;
3138                data->status |= bad;
3139                err = whitespace_error_string(bad);
3140                fprintf(data->o->file, "%s%s:%d: %s.\n",
3141                        line_prefix, data->filename, data->lineno, err);
3142                free(err);
3143                emit_line(data->o, set, reset, line, 1);
3144                ws_check_emit(line + 1, len - 1, data->ws_rule,
3145                              data->o->file, set, reset, ws);
3146        } else if (line[0] == ' ') {
3147                data->lineno++;
3148        } else if (line[0] == '@') {
3149                char *plus = strchr(line, '+');
3150                if (plus)
3151                        data->lineno = strtol(plus, NULL, 10) - 1;
3152                else
3153                        die("invalid diff");
3154        }
3155}
3156
3157static unsigned char *deflate_it(char *data,
3158                                 unsigned long size,
3159                                 unsigned long *result_size)
3160{
3161        int bound;
3162        unsigned char *deflated;
3163        git_zstream stream;
3164
3165        git_deflate_init(&stream, zlib_compression_level);
3166        bound = git_deflate_bound(&stream, size);
3167        deflated = xmalloc(bound);
3168        stream.next_out = deflated;
3169        stream.avail_out = bound;
3170
3171        stream.next_in = (unsigned char *)data;
3172        stream.avail_in = size;
3173        while (git_deflate(&stream, Z_FINISH) == Z_OK)
3174                ; /* nothing */
3175        git_deflate_end(&stream);
3176        *result_size = stream.total_out;
3177        return deflated;
3178}
3179
3180static void emit_binary_diff_body(struct diff_options *o,
3181                                  mmfile_t *one, mmfile_t *two)
3182{
3183        void *cp;
3184        void *delta;
3185        void *deflated;
3186        void *data;
3187        unsigned long orig_size;
3188        unsigned long delta_size;
3189        unsigned long deflate_size;
3190        unsigned long data_size;
3191
3192        /* We could do deflated delta, or we could do just deflated two,
3193         * whichever is smaller.
3194         */
3195        delta = NULL;
3196        deflated = deflate_it(two->ptr, two->size, &deflate_size);
3197        if (one->size && two->size) {
3198                delta = diff_delta(one->ptr, one->size,
3199                                   two->ptr, two->size,
3200                                   &delta_size, deflate_size);
3201                if (delta) {
3202                        void *to_free = delta;
3203                        orig_size = delta_size;
3204                        delta = deflate_it(delta, delta_size, &delta_size);
3205                        free(to_free);
3206                }
3207        }
3208
3209        if (delta && delta_size < deflate_size) {
3210                char *s = xstrfmt("%lu", orig_size);
3211                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
3212                                 s, strlen(s), 0);
3213                free(s);
3214                free(deflated);
3215                data = delta;
3216                data_size = delta_size;
3217        } else {
3218                char *s = xstrfmt("%lu", two->size);
3219                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
3220                                 s, strlen(s), 0);
3221                free(s);
3222                free(delta);
3223                data = deflated;
3224                data_size = deflate_size;
3225        }
3226
3227        /* emit data encoded in base85 */
3228        cp = data;
3229        while (data_size) {
3230                int len;
3231                int bytes = (52 < data_size) ? 52 : data_size;
3232                char line[71];
3233                data_size -= bytes;
3234                if (bytes <= 26)
3235                        line[0] = bytes + 'A' - 1;
3236                else
3237                        line[0] = bytes - 26 + 'a' - 1;
3238                encode_85(line + 1, cp, bytes);
3239                cp = (char *) cp + bytes;
3240
3241                len = strlen(line);
3242                line[len++] = '\n';
3243                line[len] = '\0';
3244
3245                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_BODY,
3246                                 line, len, 0);
3247        }
3248        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_FOOTER, NULL, 0, 0);
3249        free(data);
3250}
3251
3252static void emit_binary_diff(struct diff_options *o,
3253                             mmfile_t *one, mmfile_t *two)
3254{
3255        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER, NULL, 0, 0);
3256        emit_binary_diff_body(o, one, two);
3257        emit_binary_diff_body(o, two, one);
3258}
3259
3260int diff_filespec_is_binary(struct diff_filespec *one)
3261{
3262        if (one->is_binary == -1) {
3263                diff_filespec_load_driver(one);
3264                if (one->driver->binary != -1)
3265                        one->is_binary = one->driver->binary;
3266                else {
3267                        if (!one->data && DIFF_FILE_VALID(one))
3268                                diff_populate_filespec(one, CHECK_BINARY);
3269                        if (one->is_binary == -1 && one->data)
3270                                one->is_binary = buffer_is_binary(one->data,
3271                                                one->size);
3272                        if (one->is_binary == -1)
3273                                one->is_binary = 0;
3274                }
3275        }
3276        return one->is_binary;
3277}
3278
3279static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
3280{
3281        diff_filespec_load_driver(one);
3282        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
3283}
3284
3285void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
3286{
3287        if (!options->a_prefix)
3288                options->a_prefix = a;
3289        if (!options->b_prefix)
3290                options->b_prefix = b;
3291}
3292
3293struct userdiff_driver *get_textconv(struct diff_filespec *one)
3294{
3295        if (!DIFF_FILE_VALID(one))
3296                return NULL;
3297
3298        diff_filespec_load_driver(one);
3299        return userdiff_get_textconv(one->driver);
3300}
3301
3302static void builtin_diff(const char *name_a,
3303                         const char *name_b,
3304                         struct diff_filespec *one,
3305                         struct diff_filespec *two,
3306                         const char *xfrm_msg,
3307                         int must_show_header,
3308                         struct diff_options *o,
3309                         int complete_rewrite)
3310{
3311        mmfile_t mf1, mf2;
3312        const char *lbl[2];
3313        char *a_one, *b_two;
3314        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
3315        const char *reset = diff_get_color_opt(o, DIFF_RESET);
3316        const char *a_prefix, *b_prefix;
3317        struct userdiff_driver *textconv_one = NULL;
3318        struct userdiff_driver *textconv_two = NULL;
3319        struct strbuf header = STRBUF_INIT;
3320        const char *line_prefix = diff_line_prefix(o);
3321
3322        diff_set_mnemonic_prefix(o, "a/", "b/");
3323        if (o->flags.reverse_diff) {
3324                a_prefix = o->b_prefix;
3325                b_prefix = o->a_prefix;
3326        } else {
3327                a_prefix = o->a_prefix;
3328                b_prefix = o->b_prefix;
3329        }
3330
3331        if (o->submodule_format == DIFF_SUBMODULE_LOG &&
3332            (!one->mode || S_ISGITLINK(one->mode)) &&
3333            (!two->mode || S_ISGITLINK(two->mode))) {
3334                show_submodule_summary(o, one->path ? one->path : two->path,
3335                                &one->oid, &two->oid,
3336                                two->dirty_submodule);
3337                return;
3338        } else if (o->submodule_format == DIFF_SUBMODULE_INLINE_DIFF &&
3339                   (!one->mode || S_ISGITLINK(one->mode)) &&
3340                   (!two->mode || S_ISGITLINK(two->mode))) {
3341                show_submodule_inline_diff(o, one->path ? one->path : two->path,
3342                                &one->oid, &two->oid,
3343                                two->dirty_submodule);
3344                return;
3345        }
3346
3347        if (o->flags.allow_textconv) {
3348                textconv_one = get_textconv(one);
3349                textconv_two = get_textconv(two);
3350        }
3351
3352        /* Never use a non-valid filename anywhere if at all possible */
3353        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
3354        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
3355
3356        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
3357        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
3358        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
3359        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
3360        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
3361        if (lbl[0][0] == '/') {
3362                /* /dev/null */
3363                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
3364                if (xfrm_msg)
3365                        strbuf_addstr(&header, xfrm_msg);
3366                must_show_header = 1;
3367        }
3368        else if (lbl[1][0] == '/') {
3369                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
3370                if (xfrm_msg)
3371                        strbuf_addstr(&header, xfrm_msg);
3372                must_show_header = 1;
3373        }
3374        else {
3375                if (one->mode != two->mode) {
3376                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
3377                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
3378                        must_show_header = 1;
3379                }
3380                if (xfrm_msg)
3381                        strbuf_addstr(&header, xfrm_msg);
3382
3383                /*
3384                 * we do not run diff between different kind
3385                 * of objects.
3386                 */
3387                if ((one->mode ^ two->mode) & S_IFMT)
3388                        goto free_ab_and_return;
3389                if (complete_rewrite &&
3390                    (textconv_one || !diff_filespec_is_binary(one)) &&
3391                    (textconv_two || !diff_filespec_is_binary(two))) {
3392                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3393                                         header.buf, header.len, 0);
3394                        strbuf_reset(&header);
3395                        emit_rewrite_diff(name_a, name_b, one, two,
3396                                                textconv_one, textconv_two, o);
3397                        o->found_changes = 1;
3398                        goto free_ab_and_return;
3399                }
3400        }
3401
3402        if (o->irreversible_delete && lbl[1][0] == '/') {
3403                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf,
3404                                 header.len, 0);
3405                strbuf_reset(&header);
3406                goto free_ab_and_return;
3407        } else if (!o->flags.text &&
3408            ( (!textconv_one && diff_filespec_is_binary(one)) ||
3409              (!textconv_two && diff_filespec_is_binary(two)) )) {
3410                struct strbuf sb = STRBUF_INIT;
3411                if (!one->data && !two->data &&
3412                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
3413                    !o->flags.binary) {
3414                        if (!oidcmp(&one->oid, &two->oid)) {
3415                                if (must_show_header)
3416                                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3417                                                         header.buf, header.len,
3418                                                         0);
3419                                goto free_ab_and_return;
3420                        }
3421                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3422                                         header.buf, header.len, 0);
3423                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3424                                    diff_line_prefix(o), lbl[0], lbl[1]);
3425                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3426                                         sb.buf, sb.len, 0);
3427                        strbuf_release(&sb);
3428                        goto free_ab_and_return;
3429                }
3430                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3431                        die("unable to read files to diff");
3432                /* Quite common confusing case */
3433                if (mf1.size == mf2.size &&
3434                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
3435                        if (must_show_header)
3436                                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3437                                                 header.buf, header.len, 0);
3438                        goto free_ab_and_return;
3439                }
3440                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf, header.len, 0);
3441                strbuf_reset(&header);
3442                if (o->flags.binary)
3443                        emit_binary_diff(o, &mf1, &mf2);
3444                else {
3445                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3446                                    diff_line_prefix(o), lbl[0], lbl[1]);
3447                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3448                                         sb.buf, sb.len, 0);
3449                        strbuf_release(&sb);
3450                }
3451                o->found_changes = 1;
3452        } else {
3453                /* Crazy xdl interfaces.. */
3454                const char *diffopts = getenv("GIT_DIFF_OPTS");
3455                const char *v;
3456                xpparam_t xpp;
3457                xdemitconf_t xecfg;
3458                struct emit_callback ecbdata;
3459                const struct userdiff_funcname *pe;
3460
3461                if (must_show_header) {
3462                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3463                                         header.buf, header.len, 0);
3464                        strbuf_reset(&header);
3465                }
3466
3467                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
3468                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
3469
3470                pe = diff_funcname_pattern(one);
3471                if (!pe)
3472                        pe = diff_funcname_pattern(two);
3473
3474                memset(&xpp, 0, sizeof(xpp));
3475                memset(&xecfg, 0, sizeof(xecfg));
3476                memset(&ecbdata, 0, sizeof(ecbdata));
3477                if (o->flags.suppress_diff_headers)
3478                        lbl[0] = NULL;
3479                ecbdata.label_path = lbl;
3480                ecbdata.color_diff = want_color(o->use_color);
3481                ecbdata.ws_rule = whitespace_rule(name_b);
3482                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
3483                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3484                ecbdata.opt = o;
3485                if (header.len && !o->flags.suppress_diff_headers)
3486                        ecbdata.header = &header;
3487                xpp.flags = o->xdl_opts;
3488                xpp.anchors = o->anchors;
3489                xpp.anchors_nr = o->anchors_nr;
3490                xecfg.ctxlen = o->context;
3491                xecfg.interhunkctxlen = o->interhunkcontext;
3492                xecfg.flags = XDL_EMIT_FUNCNAMES;
3493                if (o->flags.funccontext)
3494                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
3495                if (pe)
3496                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
3497                if (!diffopts)
3498                        ;
3499                else if (skip_prefix(diffopts, "--unified=", &v))
3500                        xecfg.ctxlen = strtoul(v, NULL, 10);
3501                else if (skip_prefix(diffopts, "-u", &v))
3502                        xecfg.ctxlen = strtoul(v, NULL, 10);
3503                if (o->word_diff)
3504                        init_diff_words_data(&ecbdata, o, one, two);
3505                if (xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
3506                                  &xpp, &xecfg))
3507                        die("unable to generate diff for %s", one->path);
3508                if (o->word_diff)
3509                        free_diff_words_data(&ecbdata);
3510                if (textconv_one)
3511                        free(mf1.ptr);
3512                if (textconv_two)
3513                        free(mf2.ptr);
3514                xdiff_clear_find_func(&xecfg);
3515        }
3516
3517 free_ab_and_return:
3518        strbuf_release(&header);
3519        diff_free_filespec_data(one);
3520        diff_free_filespec_data(two);
3521        free(a_one);
3522        free(b_two);
3523        return;
3524}
3525
3526static char *get_compact_summary(const struct diff_filepair *p, int is_renamed)
3527{
3528        if (!is_renamed) {
3529                if (p->status == DIFF_STATUS_ADDED) {
3530                        if (S_ISLNK(p->two->mode))
3531                                return "new +l";
3532                        else if ((p->two->mode & 0777) == 0755)
3533                                return "new +x";
3534                        else
3535                                return "new";
3536                } else if (p->status == DIFF_STATUS_DELETED)
3537                        return "gone";
3538        }
3539        if (S_ISLNK(p->one->mode) && !S_ISLNK(p->two->mode))
3540                return "mode -l";
3541        else if (!S_ISLNK(p->one->mode) && S_ISLNK(p->two->mode))
3542                return "mode +l";
3543        else if ((p->one->mode & 0777) == 0644 &&
3544                 (p->two->mode & 0777) == 0755)
3545                return "mode +x";
3546        else if ((p->one->mode & 0777) == 0755 &&
3547                 (p->two->mode & 0777) == 0644)
3548                return "mode -x";
3549        return NULL;
3550}
3551
3552static void builtin_diffstat(const char *name_a, const char *name_b,
3553                             struct diff_filespec *one,
3554                             struct diff_filespec *two,
3555                             struct diffstat_t *diffstat,
3556                             struct diff_options *o,
3557                             struct diff_filepair *p)
3558{
3559        mmfile_t mf1, mf2;
3560        struct diffstat_file *data;
3561        int same_contents;
3562        int complete_rewrite = 0;
3563
3564        if (!DIFF_PAIR_UNMERGED(p)) {
3565                if (p->status == DIFF_STATUS_MODIFIED && p->score)
3566                        complete_rewrite = 1;
3567        }
3568
3569        data = diffstat_add(diffstat, name_a, name_b);
3570        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
3571        if (o->flags.stat_with_summary)
3572                data->comments = get_compact_summary(p, data->is_renamed);
3573
3574        if (!one || !two) {
3575                data->is_unmerged = 1;
3576                return;
3577        }
3578
3579        same_contents = !oidcmp(&one->oid, &two->oid);
3580
3581        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
3582                data->is_binary = 1;
3583                if (same_contents) {
3584                        data->added = 0;
3585                        data->deleted = 0;
3586                } else {
3587                        data->added = diff_filespec_size(two);
3588                        data->deleted = diff_filespec_size(one);
3589                }
3590        }
3591
3592        else if (complete_rewrite) {
3593                diff_populate_filespec(one, 0);
3594                diff_populate_filespec(two, 0);
3595                data->deleted = count_lines(one->data, one->size);
3596                data->added = count_lines(two->data, two->size);
3597        }
3598
3599        else if (!same_contents) {
3600                /* Crazy xdl interfaces.. */
3601                xpparam_t xpp;
3602                xdemitconf_t xecfg;
3603
3604                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3605                        die("unable to read files to diff");
3606
3607                memset(&xpp, 0, sizeof(xpp));
3608                memset(&xecfg, 0, sizeof(xecfg));
3609                xpp.flags = o->xdl_opts;
3610                xpp.anchors = o->anchors;
3611                xpp.anchors_nr = o->anchors_nr;
3612                xecfg.ctxlen = o->context;
3613                xecfg.interhunkctxlen = o->interhunkcontext;
3614                if (xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
3615                                  &xpp, &xecfg))
3616                        die("unable to generate diffstat for %s", one->path);
3617        }
3618
3619        diff_free_filespec_data(one);
3620        diff_free_filespec_data(two);
3621}
3622
3623static void builtin_checkdiff(const char *name_a, const char *name_b,
3624                              const char *attr_path,
3625                              struct diff_filespec *one,
3626                              struct diff_filespec *two,
3627                              struct diff_options *o)
3628{
3629        mmfile_t mf1, mf2;
3630        struct checkdiff_t data;
3631
3632        if (!two)
3633                return;
3634
3635        memset(&data, 0, sizeof(data));
3636        data.filename = name_b ? name_b : name_a;
3637        data.lineno = 0;
3638        data.o = o;
3639        data.ws_rule = whitespace_rule(attr_path);
3640        data.conflict_marker_size = ll_merge_marker_size(attr_path);
3641
3642        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3643                die("unable to read files to diff");
3644
3645        /*
3646         * All the other codepaths check both sides, but not checking
3647         * the "old" side here is deliberate.  We are checking the newly
3648         * introduced changes, and as long as the "new" side is text, we
3649         * can and should check what it introduces.
3650         */
3651        if (diff_filespec_is_binary(two))
3652                goto free_and_return;
3653        else {
3654                /* Crazy xdl interfaces.. */
3655                xpparam_t xpp;
3656                xdemitconf_t xecfg;
3657
3658                memset(&xpp, 0, sizeof(xpp));
3659                memset(&xecfg, 0, sizeof(xecfg));
3660                xecfg.ctxlen = 1; /* at least one context line */
3661                xpp.flags = 0;
3662                if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
3663                                  &xpp, &xecfg))
3664                        die("unable to generate checkdiff for %s", one->path);
3665
3666                if (data.ws_rule & WS_BLANK_AT_EOF) {
3667                        struct emit_callback ecbdata;
3668                        int blank_at_eof;
3669
3670                        ecbdata.ws_rule = data.ws_rule;
3671                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3672                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
3673
3674                        if (blank_at_eof) {
3675                                static char *err;
3676                                if (!err)
3677                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
3678                                fprintf(o->file, "%s:%d: %s.\n",
3679                                        data.filename, blank_at_eof, err);
3680                                data.status = 1; /* report errors */
3681                        }
3682                }
3683        }
3684 free_and_return:
3685        diff_free_filespec_data(one);
3686        diff_free_filespec_data(two);
3687        if (data.status)
3688                o->flags.check_failed = 1;
3689}
3690
3691struct diff_filespec *alloc_filespec(const char *path)
3692{
3693        struct diff_filespec *spec;
3694
3695        FLEXPTR_ALLOC_STR(spec, path, path);
3696        spec->count = 1;
3697        spec->is_binary = -1;
3698        return spec;
3699}
3700
3701void free_filespec(struct diff_filespec *spec)
3702{
3703        if (!--spec->count) {
3704                diff_free_filespec_data(spec);
3705                free(spec);
3706        }
3707}
3708
3709void fill_filespec(struct diff_filespec *spec, const struct object_id *oid,
3710                   int oid_valid, unsigned short mode)
3711{
3712        if (mode) {
3713                spec->mode = canon_mode(mode);
3714                oidcpy(&spec->oid, oid);
3715                spec->oid_valid = oid_valid;
3716        }
3717}
3718
3719/*
3720 * Given a name and sha1 pair, if the index tells us the file in
3721 * the work tree has that object contents, return true, so that
3722 * prepare_temp_file() does not have to inflate and extract.
3723 */
3724static int reuse_worktree_file(const char *name, const struct object_id *oid, int want_file)
3725{
3726        const struct cache_entry *ce;
3727        struct stat st;
3728        int pos, len;
3729
3730        /*
3731         * We do not read the cache ourselves here, because the
3732         * benchmark with my previous version that always reads cache
3733         * shows that it makes things worse for diff-tree comparing
3734         * two linux-2.6 kernel trees in an already checked out work
3735         * tree.  This is because most diff-tree comparisons deal with
3736         * only a small number of files, while reading the cache is
3737         * expensive for a large project, and its cost outweighs the
3738         * savings we get by not inflating the object to a temporary
3739         * file.  Practically, this code only helps when we are used
3740         * by diff-cache --cached, which does read the cache before
3741         * calling us.
3742         */
3743        if (!active_cache)
3744                return 0;
3745
3746        /* We want to avoid the working directory if our caller
3747         * doesn't need the data in a normal file, this system
3748         * is rather slow with its stat/open/mmap/close syscalls,
3749         * and the object is contained in a pack file.  The pack
3750         * is probably already open and will be faster to obtain
3751         * the data through than the working directory.  Loose
3752         * objects however would tend to be slower as they need
3753         * to be individually opened and inflated.
3754         */
3755        if (!FAST_WORKING_DIRECTORY && !want_file && has_object_pack(oid))
3756                return 0;
3757
3758        /*
3759         * Similarly, if we'd have to convert the file contents anyway, that
3760         * makes the optimization not worthwhile.
3761         */
3762        if (!want_file && would_convert_to_git(&the_index, name))
3763                return 0;
3764
3765        len = strlen(name);
3766        pos = cache_name_pos(name, len);
3767        if (pos < 0)
3768                return 0;
3769        ce = active_cache[pos];
3770
3771        /*
3772         * This is not the sha1 we are looking for, or
3773         * unreusable because it is not a regular file.
3774         */
3775        if (oidcmp(oid, &ce->oid) || !S_ISREG(ce->ce_mode))
3776                return 0;
3777
3778        /*
3779         * If ce is marked as "assume unchanged", there is no
3780         * guarantee that work tree matches what we are looking for.
3781         */
3782        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
3783                return 0;
3784
3785        /*
3786         * If ce matches the file in the work tree, we can reuse it.
3787         */
3788        if (ce_uptodate(ce) ||
3789            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
3790                return 1;
3791
3792        return 0;
3793}
3794
3795static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
3796{
3797        struct strbuf buf = STRBUF_INIT;
3798        char *dirty = "";
3799
3800        /* Are we looking at the work tree? */
3801        if (s->dirty_submodule)
3802                dirty = "-dirty";
3803
3804        strbuf_addf(&buf, "Subproject commit %s%s\n",
3805                    oid_to_hex(&s->oid), dirty);
3806        s->size = buf.len;
3807        if (size_only) {
3808                s->data = NULL;
3809                strbuf_release(&buf);
3810        } else {
3811                s->data = strbuf_detach(&buf, NULL);
3812                s->should_free = 1;
3813        }
3814        return 0;
3815}
3816
3817/*
3818 * While doing rename detection and pickaxe operation, we may need to
3819 * grab the data for the blob (or file) for our own in-core comparison.
3820 * diff_filespec has data and size fields for this purpose.
3821 */
3822int diff_populate_filespec(struct diff_filespec *s, unsigned int flags)
3823{
3824        int size_only = flags & CHECK_SIZE_ONLY;
3825        int err = 0;
3826        int conv_flags = global_conv_flags_eol;
3827        /*
3828         * demote FAIL to WARN to allow inspecting the situation
3829         * instead of refusing.
3830         */
3831        if (conv_flags & CONV_EOL_RNDTRP_DIE)
3832                conv_flags = CONV_EOL_RNDTRP_WARN;
3833
3834        if (!DIFF_FILE_VALID(s))
3835                die("internal error: asking to populate invalid file.");
3836        if (S_ISDIR(s->mode))
3837                return -1;
3838
3839        if (s->data)
3840                return 0;
3841
3842        if (size_only && 0 < s->size)
3843                return 0;
3844
3845        if (S_ISGITLINK(s->mode))
3846                return diff_populate_gitlink(s, size_only);
3847
3848        if (!s->oid_valid ||
3849            reuse_worktree_file(s->path, &s->oid, 0)) {
3850                struct strbuf buf = STRBUF_INIT;
3851                struct stat st;
3852                int fd;
3853
3854                if (lstat(s->path, &st) < 0) {
3855                err_empty:
3856                        err = -1;
3857                empty:
3858                        s->data = (char *)"";
3859                        s->size = 0;
3860                        return err;
3861                }
3862                s->size = xsize_t(st.st_size);
3863                if (!s->size)
3864                        goto empty;
3865                if (S_ISLNK(st.st_mode)) {
3866                        struct strbuf sb = STRBUF_INIT;
3867
3868                        if (strbuf_readlink(&sb, s->path, s->size))
3869                                goto err_empty;
3870                        s->size = sb.len;
3871                        s->data = strbuf_detach(&sb, NULL);
3872                        s->should_free = 1;
3873                        return 0;
3874                }
3875
3876                /*
3877                 * Even if the caller would be happy with getting
3878                 * only the size, we cannot return early at this
3879                 * point if the path requires us to run the content
3880                 * conversion.
3881                 */
3882                if (size_only && !would_convert_to_git(&the_index, s->path))
3883                        return 0;
3884
3885                /*
3886                 * Note: this check uses xsize_t(st.st_size) that may
3887                 * not be the true size of the blob after it goes
3888                 * through convert_to_git().  This may not strictly be
3889                 * correct, but the whole point of big_file_threshold
3890                 * and is_binary check being that we want to avoid
3891                 * opening the file and inspecting the contents, this
3892                 * is probably fine.
3893                 */
3894                if ((flags & CHECK_BINARY) &&
3895                    s->size > big_file_threshold && s->is_binary == -1) {
3896                        s->is_binary = 1;
3897                        return 0;
3898                }
3899                fd = open(s->path, O_RDONLY);
3900                if (fd < 0)
3901                        goto err_empty;
3902                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
3903                close(fd);
3904                s->should_munmap = 1;
3905
3906                /*
3907                 * Convert from working tree format to canonical git format
3908                 */
3909                if (convert_to_git(&the_index, s->path, s->data, s->size, &buf, conv_flags)) {
3910                        size_t size = 0;
3911                        munmap(s->data, s->size);
3912                        s->should_munmap = 0;
3913                        s->data = strbuf_detach(&buf, &size);
3914                        s->size = size;
3915                        s->should_free = 1;
3916                }
3917        }
3918        else {
3919                enum object_type type;
3920                if (size_only || (flags & CHECK_BINARY)) {
3921                        type = oid_object_info(the_repository, &s->oid,
3922                                               &s->size);
3923                        if (type < 0)
3924                                die("unable to read %s",
3925                                    oid_to_hex(&s->oid));
3926                        if (size_only)
3927                                return 0;
3928                        if (s->size > big_file_threshold && s->is_binary == -1) {
3929                                s->is_binary = 1;
3930                                return 0;
3931                        }
3932                }
3933                s->data = read_object_file(&s->oid, &type, &s->size);
3934                if (!s->data)
3935                        die("unable to read %s", oid_to_hex(&s->oid));
3936                s->should_free = 1;
3937        }
3938        return 0;
3939}
3940
3941void diff_free_filespec_blob(struct diff_filespec *s)
3942{
3943        if (s->should_free)
3944                free(s->data);
3945        else if (s->should_munmap)
3946                munmap(s->data, s->size);
3947
3948        if (s->should_free || s->should_munmap) {
3949                s->should_free = s->should_munmap = 0;
3950                s->data = NULL;
3951        }
3952}
3953
3954void diff_free_filespec_data(struct diff_filespec *s)
3955{
3956        diff_free_filespec_blob(s);
3957        FREE_AND_NULL(s->cnt_data);
3958}
3959
3960static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
3961                           void *blob,
3962                           unsigned long size,
3963                           const struct object_id *oid,
3964                           int mode)
3965{
3966        struct strbuf buf = STRBUF_INIT;
3967        struct strbuf tempfile = STRBUF_INIT;
3968        char *path_dup = xstrdup(path);
3969        const char *base = basename(path_dup);
3970
3971        /* Generate "XXXXXX_basename.ext" */
3972        strbuf_addstr(&tempfile, "XXXXXX_");
3973        strbuf_addstr(&tempfile, base);
3974
3975        temp->tempfile = mks_tempfile_ts(tempfile.buf, strlen(base) + 1);
3976        if (!temp->tempfile)
3977                die_errno("unable to create temp-file");
3978        if (convert_to_working_tree(path,
3979                        (const char *)blob, (size_t)size, &buf)) {
3980                blob = buf.buf;
3981                size = buf.len;
3982        }
3983        if (write_in_full(temp->tempfile->fd, blob, size) < 0 ||
3984            close_tempfile_gently(temp->tempfile))
3985                die_errno("unable to write temp-file");
3986        temp->name = get_tempfile_path(temp->tempfile);
3987        oid_to_hex_r(temp->hex, oid);
3988        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
3989        strbuf_release(&buf);
3990        strbuf_release(&tempfile);
3991        free(path_dup);
3992}
3993
3994static struct diff_tempfile *prepare_temp_file(const char *name,
3995                struct diff_filespec *one)
3996{
3997        struct diff_tempfile *temp = claim_diff_tempfile();
3998
3999        if (!DIFF_FILE_VALID(one)) {
4000        not_a_valid_file:
4001                /* A '-' entry produces this for file-2, and
4002                 * a '+' entry produces this for file-1.
4003                 */
4004                temp->name = "/dev/null";
4005                xsnprintf(temp->hex, sizeof(temp->hex), ".");
4006                xsnprintf(temp->mode, sizeof(temp->mode), ".");
4007                return temp;
4008        }
4009
4010        if (!S_ISGITLINK(one->mode) &&
4011            (!one->oid_valid ||
4012             reuse_worktree_file(name, &one->oid, 1))) {
4013                struct stat st;
4014                if (lstat(name, &st) < 0) {
4015                        if (errno == ENOENT)
4016                                goto not_a_valid_file;
4017                        die_errno("stat(%s)", name);
4018                }
4019                if (S_ISLNK(st.st_mode)) {
4020                        struct strbuf sb = STRBUF_INIT;
4021                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
4022                                die_errno("readlink(%s)", name);
4023                        prep_temp_blob(name, temp, sb.buf, sb.len,
4024                                       (one->oid_valid ?
4025                                        &one->oid : &null_oid),
4026                                       (one->oid_valid ?
4027                                        one->mode : S_IFLNK));
4028                        strbuf_release(&sb);
4029                }
4030                else {
4031                        /* we can borrow from the file in the work tree */
4032                        temp->name = name;
4033                        if (!one->oid_valid)
4034                                oid_to_hex_r(temp->hex, &null_oid);
4035                        else
4036                                oid_to_hex_r(temp->hex, &one->oid);
4037                        /* Even though we may sometimes borrow the
4038                         * contents from the work tree, we always want
4039                         * one->mode.  mode is trustworthy even when
4040                         * !(one->oid_valid), as long as
4041                         * DIFF_FILE_VALID(one).
4042                         */
4043                        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
4044                }
4045                return temp;
4046        }
4047        else {
4048                if (diff_populate_filespec(one, 0))
4049                        die("cannot read data blob for %s", one->path);
4050                prep_temp_blob(name, temp, one->data, one->size,
4051                               &one->oid, one->mode);
4052        }
4053        return temp;
4054}
4055
4056static void add_external_diff_name(struct argv_array *argv,
4057                                   const char *name,
4058                                   struct diff_filespec *df)
4059{
4060        struct diff_tempfile *temp = prepare_temp_file(name, df);
4061        argv_array_push(argv, temp->name);
4062        argv_array_push(argv, temp->hex);
4063        argv_array_push(argv, temp->mode);
4064}
4065
4066/* An external diff command takes:
4067 *
4068 * diff-cmd name infile1 infile1-sha1 infile1-mode \
4069 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
4070 *
4071 */
4072static void run_external_diff(const char *pgm,
4073                              const char *name,
4074                              const char *other,
4075                              struct diff_filespec *one,
4076                              struct diff_filespec *two,
4077                              const char *xfrm_msg,
4078                              int complete_rewrite,
4079                              struct diff_options *o)
4080{
4081        struct argv_array argv = ARGV_ARRAY_INIT;
4082        struct argv_array env = ARGV_ARRAY_INIT;
4083        struct diff_queue_struct *q = &diff_queued_diff;
4084
4085        argv_array_push(&argv, pgm);
4086        argv_array_push(&argv, name);
4087
4088        if (one && two) {
4089                add_external_diff_name(&argv, name, one);
4090                if (!other)
4091                        add_external_diff_name(&argv, name, two);
4092                else {
4093                        add_external_diff_name(&argv, other, two);
4094                        argv_array_push(&argv, other);
4095                        argv_array_push(&argv, xfrm_msg);
4096                }
4097        }
4098
4099        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
4100        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
4101
4102        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
4103                die(_("external diff died, stopping at %s"), name);
4104
4105        remove_tempfile();
4106        argv_array_clear(&argv);
4107        argv_array_clear(&env);
4108}
4109
4110static int similarity_index(struct diff_filepair *p)
4111{
4112        return p->score * 100 / MAX_SCORE;
4113}
4114
4115static const char *diff_abbrev_oid(const struct object_id *oid, int abbrev)
4116{
4117        if (startup_info->have_repository)
4118                return find_unique_abbrev(oid, abbrev);
4119        else {
4120                char *hex = oid_to_hex(oid);
4121                if (abbrev < 0)
4122                        abbrev = FALLBACK_DEFAULT_ABBREV;
4123                if (abbrev > the_hash_algo->hexsz)
4124                        BUG("oid abbreviation out of range: %d", abbrev);
4125                if (abbrev)
4126                        hex[abbrev] = '\0';
4127                return hex;
4128        }
4129}
4130
4131static void fill_metainfo(struct strbuf *msg,
4132                          const char *name,
4133                          const char *other,
4134                          struct diff_filespec *one,
4135                          struct diff_filespec *two,
4136                          struct diff_options *o,
4137                          struct diff_filepair *p,
4138                          int *must_show_header,
4139                          int use_color)
4140{
4141        const char *set = diff_get_color(use_color, DIFF_METAINFO);
4142        const char *reset = diff_get_color(use_color, DIFF_RESET);
4143        const char *line_prefix = diff_line_prefix(o);
4144
4145        *must_show_header = 1;
4146        strbuf_init(msg, PATH_MAX * 2 + 300);
4147        switch (p->status) {
4148        case DIFF_STATUS_COPIED:
4149                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4150                            line_prefix, set, similarity_index(p));
4151                strbuf_addf(msg, "%s\n%s%scopy from ",
4152                            reset,  line_prefix, set);
4153                quote_c_style(name, msg, NULL, 0);
4154                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
4155                quote_c_style(other, msg, NULL, 0);
4156                strbuf_addf(msg, "%s\n", reset);
4157                break;
4158        case DIFF_STATUS_RENAMED:
4159                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4160                            line_prefix, set, similarity_index(p));
4161                strbuf_addf(msg, "%s\n%s%srename from ",
4162                            reset, line_prefix, set);
4163                quote_c_style(name, msg, NULL, 0);
4164                strbuf_addf(msg, "%s\n%s%srename to ",
4165                            reset, line_prefix, set);
4166                quote_c_style(other, msg, NULL, 0);
4167                strbuf_addf(msg, "%s\n", reset);
4168                break;
4169        case DIFF_STATUS_MODIFIED:
4170                if (p->score) {
4171                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
4172                                    line_prefix,
4173                                    set, similarity_index(p), reset);
4174                        break;
4175                }
4176                /* fallthru */
4177        default:
4178                *must_show_header = 0;
4179        }
4180        if (one && two && oidcmp(&one->oid, &two->oid)) {
4181                const unsigned hexsz = the_hash_algo->hexsz;
4182                int abbrev = o->flags.full_index ? hexsz : DEFAULT_ABBREV;
4183
4184                if (o->flags.binary) {
4185                        mmfile_t mf;
4186                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
4187                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
4188                                abbrev = hexsz;
4189                }
4190                strbuf_addf(msg, "%s%sindex %s..%s", line_prefix, set,
4191                            diff_abbrev_oid(&one->oid, abbrev),
4192                            diff_abbrev_oid(&two->oid, abbrev));
4193                if (one->mode == two->mode)
4194                        strbuf_addf(msg, " %06o", one->mode);
4195                strbuf_addf(msg, "%s\n", reset);
4196        }
4197}
4198
4199static void run_diff_cmd(const char *pgm,
4200                         const char *name,
4201                         const char *other,
4202                         const char *attr_path,
4203                         struct diff_filespec *one,
4204                         struct diff_filespec *two,
4205                         struct strbuf *msg,
4206                         struct diff_options *o,
4207                         struct diff_filepair *p)
4208{
4209        const char *xfrm_msg = NULL;
4210        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
4211        int must_show_header = 0;
4212
4213
4214        if (o->flags.allow_external) {
4215                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
4216                if (drv && drv->external)
4217                        pgm = drv->external;
4218        }
4219
4220        if (msg) {
4221                /*
4222                 * don't use colors when the header is intended for an
4223                 * external diff driver
4224                 */
4225                fill_metainfo(msg, name, other, one, two, o, p,
4226                              &must_show_header,
4227                              want_color(o->use_color) && !pgm);
4228                xfrm_msg = msg->len ? msg->buf : NULL;
4229        }
4230
4231        if (pgm) {
4232                run_external_diff(pgm, name, other, one, two, xfrm_msg,
4233                                  complete_rewrite, o);
4234                return;
4235        }
4236        if (one && two)
4237                builtin_diff(name, other ? other : name,
4238                             one, two, xfrm_msg, must_show_header,
4239                             o, complete_rewrite);
4240        else
4241                fprintf(o->file, "* Unmerged path %s\n", name);
4242}
4243
4244static void diff_fill_oid_info(struct diff_filespec *one)
4245{
4246        if (DIFF_FILE_VALID(one)) {
4247                if (!one->oid_valid) {
4248                        struct stat st;
4249                        if (one->is_stdin) {
4250                                oidclr(&one->oid);
4251                                return;
4252                        }
4253                        if (lstat(one->path, &st) < 0)
4254                                die_errno("stat '%s'", one->path);
4255                        if (index_path(&one->oid, one->path, &st, 0))
4256                                die("cannot hash %s", one->path);
4257                }
4258        }
4259        else
4260                oidclr(&one->oid);
4261}
4262
4263static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
4264{
4265        /* Strip the prefix but do not molest /dev/null and absolute paths */
4266        if (*namep && **namep != '/') {
4267                *namep += prefix_length;
4268                if (**namep == '/')
4269                        ++*namep;
4270        }
4271        if (*otherp && **otherp != '/') {
4272                *otherp += prefix_length;
4273                if (**otherp == '/')
4274                        ++*otherp;
4275        }
4276}
4277
4278static void run_diff(struct diff_filepair *p, struct diff_options *o)
4279{
4280        const char *pgm = external_diff();
4281        struct strbuf msg;
4282        struct diff_filespec *one = p->one;
4283        struct diff_filespec *two = p->two;
4284        const char *name;
4285        const char *other;
4286        const char *attr_path;
4287
4288        name  = one->path;
4289        other = (strcmp(name, two->path) ? two->path : NULL);
4290        attr_path = name;
4291        if (o->prefix_length)
4292                strip_prefix(o->prefix_length, &name, &other);
4293
4294        if (!o->flags.allow_external)
4295                pgm = NULL;
4296
4297        if (DIFF_PAIR_UNMERGED(p)) {
4298                run_diff_cmd(pgm, name, NULL, attr_path,
4299                             NULL, NULL, NULL, o, p);
4300                return;
4301        }
4302
4303        diff_fill_oid_info(one);
4304        diff_fill_oid_info(two);
4305
4306        if (!pgm &&
4307            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
4308            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
4309                /*
4310                 * a filepair that changes between file and symlink
4311                 * needs to be split into deletion and creation.
4312                 */
4313                struct diff_filespec *null = alloc_filespec(two->path);
4314                run_diff_cmd(NULL, name, other, attr_path,
4315                             one, null, &msg, o, p);
4316                free(null);
4317                strbuf_release(&msg);
4318
4319                null = alloc_filespec(one->path);
4320                run_diff_cmd(NULL, name, other, attr_path,
4321                             null, two, &msg, o, p);
4322                free(null);
4323        }
4324        else
4325                run_diff_cmd(pgm, name, other, attr_path,
4326                             one, two, &msg, o, p);
4327
4328        strbuf_release(&msg);
4329}
4330
4331static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
4332                         struct diffstat_t *diffstat)
4333{
4334        const char *name;
4335        const char *other;
4336
4337        if (DIFF_PAIR_UNMERGED(p)) {
4338                /* unmerged */
4339                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, p);
4340                return;
4341        }
4342
4343        name = p->one->path;
4344        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4345
4346        if (o->prefix_length)
4347                strip_prefix(o->prefix_length, &name, &other);
4348
4349        diff_fill_oid_info(p->one);
4350        diff_fill_oid_info(p->two);
4351
4352        builtin_diffstat(name, other, p->one, p->two, diffstat, o, p);
4353}
4354
4355static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
4356{
4357        const char *name;
4358        const char *other;
4359        const char *attr_path;
4360
4361        if (DIFF_PAIR_UNMERGED(p)) {
4362                /* unmerged */
4363                return;
4364        }
4365
4366        name = p->one->path;
4367        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4368        attr_path = other ? other : name;
4369
4370        if (o->prefix_length)
4371                strip_prefix(o->prefix_length, &name, &other);
4372
4373        diff_fill_oid_info(p->one);
4374        diff_fill_oid_info(p->two);
4375
4376        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
4377}
4378
4379void diff_setup(struct diff_options *options)
4380{
4381        memcpy(options, &default_diff_options, sizeof(*options));
4382
4383        options->file = stdout;
4384
4385        options->abbrev = DEFAULT_ABBREV;
4386        options->line_termination = '\n';
4387        options->break_opt = -1;
4388        options->rename_limit = -1;
4389        options->dirstat_permille = diff_dirstat_permille_default;
4390        options->context = diff_context_default;
4391        options->interhunkcontext = diff_interhunk_context_default;
4392        options->ws_error_highlight = ws_error_highlight_default;
4393        options->flags.rename_empty = 1;
4394        options->objfind = NULL;
4395
4396        /* pathchange left =NULL by default */
4397        options->change = diff_change;
4398        options->add_remove = diff_addremove;
4399        options->use_color = diff_use_color_default;
4400        options->detect_rename = diff_detect_rename_default;
4401        options->xdl_opts |= diff_algorithm;
4402        if (diff_indent_heuristic)
4403                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4404
4405        options->orderfile = diff_order_file_cfg;
4406
4407        if (diff_no_prefix) {
4408                options->a_prefix = options->b_prefix = "";
4409        } else if (!diff_mnemonic_prefix) {
4410                options->a_prefix = "a/";
4411                options->b_prefix = "b/";
4412        }
4413
4414        options->color_moved = diff_color_moved_default;
4415        options->color_moved_ws_handling = diff_color_moved_ws_default;
4416}
4417
4418void diff_setup_done(struct diff_options *options)
4419{
4420        unsigned check_mask = DIFF_FORMAT_NAME |
4421                              DIFF_FORMAT_NAME_STATUS |
4422                              DIFF_FORMAT_CHECKDIFF |
4423                              DIFF_FORMAT_NO_OUTPUT;
4424        /*
4425         * This must be signed because we're comparing against a potentially
4426         * negative value.
4427         */
4428        const int hexsz = the_hash_algo->hexsz;
4429
4430        if (options->set_default)
4431                options->set_default(options);
4432
4433        if (HAS_MULTI_BITS(options->output_format & check_mask))
4434                die(_("--name-only, --name-status, --check and -s are mutually exclusive"));
4435
4436        if (HAS_MULTI_BITS(options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK))
4437                die(_("-G, -S and --find-object are mutually exclusive"));
4438
4439        /*
4440         * Most of the time we can say "there are changes"
4441         * only by checking if there are changed paths, but
4442         * --ignore-whitespace* options force us to look
4443         * inside contents.
4444         */
4445
4446        if ((options->xdl_opts & XDF_WHITESPACE_FLAGS))
4447                options->flags.diff_from_contents = 1;
4448        else
4449                options->flags.diff_from_contents = 0;
4450
4451        if (options->flags.find_copies_harder)
4452                options->detect_rename = DIFF_DETECT_COPY;
4453
4454        if (!options->flags.relative_name)
4455                options->prefix = NULL;
4456        if (options->prefix)
4457                options->prefix_length = strlen(options->prefix);
4458        else
4459                options->prefix_length = 0;
4460
4461        if (options->output_format & (DIFF_FORMAT_NAME |
4462                                      DIFF_FORMAT_NAME_STATUS |
4463                                      DIFF_FORMAT_CHECKDIFF |
4464                                      DIFF_FORMAT_NO_OUTPUT))
4465                options->output_format &= ~(DIFF_FORMAT_RAW |
4466                                            DIFF_FORMAT_NUMSTAT |
4467                                            DIFF_FORMAT_DIFFSTAT |
4468                                            DIFF_FORMAT_SHORTSTAT |
4469                                            DIFF_FORMAT_DIRSTAT |
4470                                            DIFF_FORMAT_SUMMARY |
4471                                            DIFF_FORMAT_PATCH);
4472
4473        /*
4474         * These cases always need recursive; we do not drop caller-supplied
4475         * recursive bits for other formats here.
4476         */
4477        if (options->output_format & (DIFF_FORMAT_PATCH |
4478                                      DIFF_FORMAT_NUMSTAT |
4479                                      DIFF_FORMAT_DIFFSTAT |
4480                                      DIFF_FORMAT_SHORTSTAT |
4481                                      DIFF_FORMAT_DIRSTAT |
4482                                      DIFF_FORMAT_SUMMARY |
4483                                      DIFF_FORMAT_CHECKDIFF))
4484                options->flags.recursive = 1;
4485        /*
4486         * Also pickaxe would not work very well if you do not say recursive
4487         */
4488        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
4489                options->flags.recursive = 1;
4490        /*
4491         * When patches are generated, submodules diffed against the work tree
4492         * must be checked for dirtiness too so it can be shown in the output
4493         */
4494        if (options->output_format & DIFF_FORMAT_PATCH)
4495                options->flags.dirty_submodules = 1;
4496
4497        if (options->detect_rename && options->rename_limit < 0)
4498                options->rename_limit = diff_rename_limit_default;
4499        if (options->setup & DIFF_SETUP_USE_CACHE) {
4500                if (!active_cache)
4501                        /* read-cache does not die even when it fails
4502                         * so it is safe for us to do this here.  Also
4503                         * it does not smudge active_cache or active_nr
4504                         * when it fails, so we do not have to worry about
4505                         * cleaning it up ourselves either.
4506                         */
4507                        read_cache();
4508        }
4509        if (hexsz < options->abbrev)
4510                options->abbrev = hexsz; /* full */
4511
4512        /*
4513         * It does not make sense to show the first hit we happened
4514         * to have found.  It does not make sense not to return with
4515         * exit code in such a case either.
4516         */
4517        if (options->flags.quick) {
4518                options->output_format = DIFF_FORMAT_NO_OUTPUT;
4519                options->flags.exit_with_status = 1;
4520        }
4521
4522        options->diff_path_counter = 0;
4523
4524        if (options->flags.follow_renames && options->pathspec.nr != 1)
4525                die(_("--follow requires exactly one pathspec"));
4526
4527        if (!options->use_color || external_diff())
4528                options->color_moved = 0;
4529}
4530
4531static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
4532{
4533        char c, *eq;
4534        int len;
4535
4536        if (*arg != '-')
4537                return 0;
4538        c = *++arg;
4539        if (!c)
4540                return 0;
4541        if (c == arg_short) {
4542                c = *++arg;
4543                if (!c)
4544                        return 1;
4545                if (val && isdigit(c)) {
4546                        char *end;
4547                        int n = strtoul(arg, &end, 10);
4548                        if (*end)
4549                                return 0;
4550                        *val = n;
4551                        return 1;
4552                }
4553                return 0;
4554        }
4555        if (c != '-')
4556                return 0;
4557        arg++;
4558        eq = strchrnul(arg, '=');
4559        len = eq - arg;
4560        if (!len || strncmp(arg, arg_long, len))
4561                return 0;
4562        if (*eq) {
4563                int n;
4564                char *end;
4565                if (!isdigit(*++eq))
4566                        return 0;
4567                n = strtoul(eq, &end, 10);
4568                if (*end)
4569                        return 0;
4570                *val = n;
4571        }
4572        return 1;
4573}
4574
4575static int diff_scoreopt_parse(const char *opt);
4576
4577static inline int short_opt(char opt, const char **argv,
4578                            const char **optarg)
4579{
4580        const char *arg = argv[0];
4581        if (arg[0] != '-' || arg[1] != opt)
4582                return 0;
4583        if (arg[2] != '\0') {
4584                *optarg = arg + 2;
4585                return 1;
4586        }
4587        if (!argv[1])
4588                die("Option '%c' requires a value", opt);
4589        *optarg = argv[1];
4590        return 2;
4591}
4592
4593int parse_long_opt(const char *opt, const char **argv,
4594                   const char **optarg)
4595{
4596        const char *arg = argv[0];
4597        if (!skip_prefix(arg, "--", &arg))
4598                return 0;
4599        if (!skip_prefix(arg, opt, &arg))
4600                return 0;
4601        if (*arg == '=') { /* stuck form: --option=value */
4602                *optarg = arg + 1;
4603                return 1;
4604        }
4605        if (*arg != '\0')
4606                return 0;
4607        /* separate form: --option value */
4608        if (!argv[1])
4609                die("Option '--%s' requires a value", opt);
4610        *optarg = argv[1];
4611        return 2;
4612}
4613
4614static int stat_opt(struct diff_options *options, const char **av)
4615{
4616        const char *arg = av[0];
4617        char *end;
4618        int width = options->stat_width;
4619        int name_width = options->stat_name_width;
4620        int graph_width = options->stat_graph_width;
4621        int count = options->stat_count;
4622        int argcount = 1;
4623
4624        if (!skip_prefix(arg, "--stat", &arg))
4625                BUG("stat option does not begin with --stat: %s", arg);
4626        end = (char *)arg;
4627
4628        switch (*arg) {
4629        case '-':
4630                if (skip_prefix(arg, "-width", &arg)) {
4631                        if (*arg == '=')
4632                                width = strtoul(arg + 1, &end, 10);
4633                        else if (!*arg && !av[1])
4634                                die_want_option("--stat-width");
4635                        else if (!*arg) {
4636                                width = strtoul(av[1], &end, 10);
4637                                argcount = 2;
4638                        }
4639                } else if (skip_prefix(arg, "-name-width", &arg)) {
4640                        if (*arg == '=')
4641                                name_width = strtoul(arg + 1, &end, 10);
4642                        else if (!*arg && !av[1])
4643                                die_want_option("--stat-name-width");
4644                        else if (!*arg) {
4645                                name_width = strtoul(av[1], &end, 10);
4646                                argcount = 2;
4647                        }
4648                } else if (skip_prefix(arg, "-graph-width", &arg)) {
4649                        if (*arg == '=')
4650                                graph_width = strtoul(arg + 1, &end, 10);
4651                        else if (!*arg && !av[1])
4652                                die_want_option("--stat-graph-width");
4653                        else if (!*arg) {
4654                                graph_width = strtoul(av[1], &end, 10);
4655                                argcount = 2;
4656                        }
4657                } else if (skip_prefix(arg, "-count", &arg)) {
4658                        if (*arg == '=')
4659                                count = strtoul(arg + 1, &end, 10);
4660                        else if (!*arg && !av[1])
4661                                die_want_option("--stat-count");
4662                        else if (!*arg) {
4663                                count = strtoul(av[1], &end, 10);
4664                                argcount = 2;
4665                        }
4666                }
4667                break;
4668        case '=':
4669                width = strtoul(arg+1, &end, 10);
4670                if (*end == ',')
4671                        name_width = strtoul(end+1, &end, 10);
4672                if (*end == ',')
4673                        count = strtoul(end+1, &end, 10);
4674        }
4675
4676        /* Important! This checks all the error cases! */
4677        if (*end)
4678                return 0;
4679        options->output_format |= DIFF_FORMAT_DIFFSTAT;
4680        options->stat_name_width = name_width;
4681        options->stat_graph_width = graph_width;
4682        options->stat_width = width;
4683        options->stat_count = count;
4684        return argcount;
4685}
4686
4687static int parse_dirstat_opt(struct diff_options *options, const char *params)
4688{
4689        struct strbuf errmsg = STRBUF_INIT;
4690        if (parse_dirstat_params(options, params, &errmsg))
4691                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
4692                    errmsg.buf);
4693        strbuf_release(&errmsg);
4694        /*
4695         * The caller knows a dirstat-related option is given from the command
4696         * line; allow it to say "return this_function();"
4697         */
4698        options->output_format |= DIFF_FORMAT_DIRSTAT;
4699        return 1;
4700}
4701
4702static int parse_submodule_opt(struct diff_options *options, const char *value)
4703{
4704        if (parse_submodule_params(options, value))
4705                die(_("Failed to parse --submodule option parameter: '%s'"),
4706                        value);
4707        return 1;
4708}
4709
4710static const char diff_status_letters[] = {
4711        DIFF_STATUS_ADDED,
4712        DIFF_STATUS_COPIED,
4713        DIFF_STATUS_DELETED,
4714        DIFF_STATUS_MODIFIED,
4715        DIFF_STATUS_RENAMED,
4716        DIFF_STATUS_TYPE_CHANGED,
4717        DIFF_STATUS_UNKNOWN,
4718        DIFF_STATUS_UNMERGED,
4719        DIFF_STATUS_FILTER_AON,
4720        DIFF_STATUS_FILTER_BROKEN,
4721        '\0',
4722};
4723
4724static unsigned int filter_bit['Z' + 1];
4725
4726static void prepare_filter_bits(void)
4727{
4728        int i;
4729
4730        if (!filter_bit[DIFF_STATUS_ADDED]) {
4731                for (i = 0; diff_status_letters[i]; i++)
4732                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
4733        }
4734}
4735
4736static unsigned filter_bit_tst(char status, const struct diff_options *opt)
4737{
4738        return opt->filter & filter_bit[(int) status];
4739}
4740
4741static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
4742{
4743        int i, optch;
4744
4745        prepare_filter_bits();
4746
4747        /*
4748         * If there is a negation e.g. 'd' in the input, and we haven't
4749         * initialized the filter field with another --diff-filter, start
4750         * from full set of bits, except for AON.
4751         */
4752        if (!opt->filter) {
4753                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4754                        if (optch < 'a' || 'z' < optch)
4755                                continue;
4756                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
4757                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
4758                        break;
4759                }
4760        }
4761
4762        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4763                unsigned int bit;
4764                int negate;
4765
4766                if ('a' <= optch && optch <= 'z') {
4767                        negate = 1;
4768                        optch = toupper(optch);
4769                } else {
4770                        negate = 0;
4771                }
4772
4773                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
4774                if (!bit)
4775                        return optarg[i];
4776                if (negate)
4777                        opt->filter &= ~bit;
4778                else
4779                        opt->filter |= bit;
4780        }
4781        return 0;
4782}
4783
4784static void enable_patch_output(int *fmt) {
4785        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
4786        *fmt |= DIFF_FORMAT_PATCH;
4787}
4788
4789static int parse_ws_error_highlight_opt(struct diff_options *opt, const char *arg)
4790{
4791        int val = parse_ws_error_highlight(arg);
4792
4793        if (val < 0) {
4794                error("unknown value after ws-error-highlight=%.*s",
4795                      -1 - val, arg);
4796                return 0;
4797        }
4798        opt->ws_error_highlight = val;
4799        return 1;
4800}
4801
4802static int parse_objfind_opt(struct diff_options *opt, const char *arg)
4803{
4804        struct object_id oid;
4805
4806        if (get_oid(arg, &oid))
4807                return error("unable to resolve '%s'", arg);
4808
4809        if (!opt->objfind)
4810                opt->objfind = xcalloc(1, sizeof(*opt->objfind));
4811
4812        opt->pickaxe_opts |= DIFF_PICKAXE_KIND_OBJFIND;
4813        opt->flags.recursive = 1;
4814        opt->flags.tree_in_recursive = 1;
4815        oidset_insert(opt->objfind, &oid);
4816        return 1;
4817}
4818
4819int diff_opt_parse(struct diff_options *options,
4820                   const char **av, int ac, const char *prefix)
4821{
4822        const char *arg = av[0];
4823        const char *optarg;
4824        int argcount;
4825
4826        if (!prefix)
4827                prefix = "";
4828
4829        /* Output format options */
4830        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
4831            || opt_arg(arg, 'U', "unified", &options->context))
4832                enable_patch_output(&options->output_format);
4833        else if (!strcmp(arg, "--raw"))
4834                options->output_format |= DIFF_FORMAT_RAW;
4835        else if (!strcmp(arg, "--patch-with-raw")) {
4836                enable_patch_output(&options->output_format);
4837                options->output_format |= DIFF_FORMAT_RAW;
4838        } else if (!strcmp(arg, "--numstat"))
4839                options->output_format |= DIFF_FORMAT_NUMSTAT;
4840        else if (!strcmp(arg, "--shortstat"))
4841                options->output_format |= DIFF_FORMAT_SHORTSTAT;
4842        else if (skip_prefix(arg, "-X", &arg) ||
4843                 skip_to_optional_arg(arg, "--dirstat", &arg))
4844                return parse_dirstat_opt(options, arg);
4845        else if (!strcmp(arg, "--cumulative"))
4846                return parse_dirstat_opt(options, "cumulative");
4847        else if (skip_to_optional_arg(arg, "--dirstat-by-file", &arg)) {
4848                parse_dirstat_opt(options, "files");
4849                return parse_dirstat_opt(options, arg);
4850        }
4851        else if (!strcmp(arg, "--check"))
4852                options->output_format |= DIFF_FORMAT_CHECKDIFF;
4853        else if (!strcmp(arg, "--summary"))
4854                options->output_format |= DIFF_FORMAT_SUMMARY;
4855        else if (!strcmp(arg, "--patch-with-stat")) {
4856                enable_patch_output(&options->output_format);
4857                options->output_format |= DIFF_FORMAT_DIFFSTAT;
4858        } else if (!strcmp(arg, "--name-only"))
4859                options->output_format |= DIFF_FORMAT_NAME;
4860        else if (!strcmp(arg, "--name-status"))
4861                options->output_format |= DIFF_FORMAT_NAME_STATUS;
4862        else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
4863                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
4864        else if (starts_with(arg, "--stat"))
4865                /* --stat, --stat-width, --stat-name-width, or --stat-count */
4866                return stat_opt(options, av);
4867        else if (!strcmp(arg, "--compact-summary")) {
4868                 options->flags.stat_with_summary = 1;
4869                 options->output_format |= DIFF_FORMAT_DIFFSTAT;
4870        } else if (!strcmp(arg, "--no-compact-summary"))
4871                 options->flags.stat_with_summary = 0;
4872
4873        /* renames options */
4874        else if (starts_with(arg, "-B") ||
4875                 skip_to_optional_arg(arg, "--break-rewrites", NULL)) {
4876                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
4877                        return error("invalid argument to -B: %s", arg+2);
4878        }
4879        else if (starts_with(arg, "-M") ||
4880                 skip_to_optional_arg(arg, "--find-renames", NULL)) {
4881                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4882                        return error("invalid argument to -M: %s", arg+2);
4883                options->detect_rename = DIFF_DETECT_RENAME;
4884        }
4885        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
4886                options->irreversible_delete = 1;
4887        }
4888        else if (starts_with(arg, "-C") ||
4889                 skip_to_optional_arg(arg, "--find-copies", NULL)) {
4890                if (options->detect_rename == DIFF_DETECT_COPY)
4891                        options->flags.find_copies_harder = 1;
4892                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4893                        return error("invalid argument to -C: %s", arg+2);
4894                options->detect_rename = DIFF_DETECT_COPY;
4895        }
4896        else if (!strcmp(arg, "--no-renames"))
4897                options->detect_rename = 0;
4898        else if (!strcmp(arg, "--rename-empty"))
4899                options->flags.rename_empty = 1;
4900        else if (!strcmp(arg, "--no-rename-empty"))
4901                options->flags.rename_empty = 0;
4902        else if (skip_to_optional_arg_default(arg, "--relative", &arg, NULL)) {
4903                options->flags.relative_name = 1;
4904                if (arg)
4905                        options->prefix = arg;
4906        }
4907
4908        /* xdiff options */
4909        else if (!strcmp(arg, "--minimal"))
4910                DIFF_XDL_SET(options, NEED_MINIMAL);
4911        else if (!strcmp(arg, "--no-minimal"))
4912                DIFF_XDL_CLR(options, NEED_MINIMAL);
4913        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
4914                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
4915        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
4916                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
4917        else if (!strcmp(arg, "--ignore-space-at-eol"))
4918                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
4919        else if (!strcmp(arg, "--ignore-cr-at-eol"))
4920                DIFF_XDL_SET(options, IGNORE_CR_AT_EOL);
4921        else if (!strcmp(arg, "--ignore-blank-lines"))
4922                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
4923        else if (!strcmp(arg, "--indent-heuristic"))
4924                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4925        else if (!strcmp(arg, "--no-indent-heuristic"))
4926                DIFF_XDL_CLR(options, INDENT_HEURISTIC);
4927        else if (!strcmp(arg, "--patience")) {
4928                int i;
4929                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4930                /*
4931                 * Both --patience and --anchored use PATIENCE_DIFF
4932                 * internally, so remove any anchors previously
4933                 * specified.
4934                 */
4935                for (i = 0; i < options->anchors_nr; i++)
4936                        free(options->anchors[i]);
4937                options->anchors_nr = 0;
4938        } else if (!strcmp(arg, "--histogram"))
4939                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
4940        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
4941                long value = parse_algorithm_value(optarg);
4942                if (value < 0)
4943                        return error("option diff-algorithm accepts \"myers\", "
4944                                     "\"minimal\", \"patience\" and \"histogram\"");
4945                /* clear out previous settings */
4946                DIFF_XDL_CLR(options, NEED_MINIMAL);
4947                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
4948                options->xdl_opts |= value;
4949                return argcount;
4950        } else if (skip_prefix(arg, "--anchored=", &arg)) {
4951                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4952                ALLOC_GROW(options->anchors, options->anchors_nr + 1,
4953                           options->anchors_alloc);
4954                options->anchors[options->anchors_nr++] = xstrdup(arg);
4955        }
4956
4957        /* flags options */
4958        else if (!strcmp(arg, "--binary")) {
4959                enable_patch_output(&options->output_format);
4960                options->flags.binary = 1;
4961        }
4962        else if (!strcmp(arg, "--full-index"))
4963                options->flags.full_index = 1;
4964        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
4965                options->flags.text = 1;
4966        else if (!strcmp(arg, "-R"))
4967                options->flags.reverse_diff = 1;
4968        else if (!strcmp(arg, "--find-copies-harder"))
4969                options->flags.find_copies_harder = 1;
4970        else if (!strcmp(arg, "--follow"))
4971                options->flags.follow_renames = 1;
4972        else if (!strcmp(arg, "--no-follow")) {
4973                options->flags.follow_renames = 0;
4974                options->flags.default_follow_renames = 0;
4975        } else if (skip_to_optional_arg_default(arg, "--color", &arg, "always")) {
4976                int value = git_config_colorbool(NULL, arg);
4977                if (value < 0)
4978                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
4979                options->use_color = value;
4980        }
4981        else if (!strcmp(arg, "--no-color"))
4982                options->use_color = 0;
4983        else if (!strcmp(arg, "--color-moved")) {
4984                if (diff_color_moved_default)
4985                        options->color_moved = diff_color_moved_default;
4986                if (options->color_moved == COLOR_MOVED_NO)
4987                        options->color_moved = COLOR_MOVED_DEFAULT;
4988        } else if (!strcmp(arg, "--no-color-moved"))
4989                options->color_moved = COLOR_MOVED_NO;
4990        else if (skip_prefix(arg, "--color-moved=", &arg)) {
4991                int cm = parse_color_moved(arg);
4992                if (cm < 0)
4993                        die("bad --color-moved argument: %s", arg);
4994                options->color_moved = cm;
4995        } else if (skip_prefix(arg, "--color-moved-ws=", &arg)) {
4996                options->color_moved_ws_handling = parse_color_moved_ws(arg);
4997        } else if (skip_to_optional_arg_default(arg, "--color-words", &options->word_regex, NULL)) {
4998                options->use_color = 1;
4999                options->word_diff = DIFF_WORDS_COLOR;
5000        }
5001        else if (!strcmp(arg, "--word-diff")) {
5002                if (options->word_diff == DIFF_WORDS_NONE)
5003                        options->word_diff = DIFF_WORDS_PLAIN;
5004        }
5005        else if (skip_prefix(arg, "--word-diff=", &arg)) {
5006                if (!strcmp(arg, "plain"))
5007                        options->word_diff = DIFF_WORDS_PLAIN;
5008                else if (!strcmp(arg, "color")) {
5009                        options->use_color = 1;
5010                        options->word_diff = DIFF_WORDS_COLOR;
5011                }
5012                else if (!strcmp(arg, "porcelain"))
5013                        options->word_diff = DIFF_WORDS_PORCELAIN;
5014                else if (!strcmp(arg, "none"))
5015                        options->word_diff = DIFF_WORDS_NONE;
5016                else
5017                        die("bad --word-diff argument: %s", arg);
5018        }
5019        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
5020                if (options->word_diff == DIFF_WORDS_NONE)
5021                        options->word_diff = DIFF_WORDS_PLAIN;
5022                options->word_regex = optarg;
5023                return argcount;
5024        }
5025        else if (!strcmp(arg, "--exit-code"))
5026                options->flags.exit_with_status = 1;
5027        else if (!strcmp(arg, "--quiet"))
5028                options->flags.quick = 1;
5029        else if (!strcmp(arg, "--ext-diff"))
5030                options->flags.allow_external = 1;
5031        else if (!strcmp(arg, "--no-ext-diff"))
5032                options->flags.allow_external = 0;
5033        else if (!strcmp(arg, "--textconv")) {
5034                options->flags.allow_textconv = 1;
5035                options->flags.textconv_set_via_cmdline = 1;
5036        } else if (!strcmp(arg, "--no-textconv"))
5037                options->flags.allow_textconv = 0;
5038        else if (skip_to_optional_arg_default(arg, "--ignore-submodules", &arg, "all")) {
5039                options->flags.override_submodule_config = 1;
5040                handle_ignore_submodules_arg(options, arg);
5041        } else if (skip_to_optional_arg_default(arg, "--submodule", &arg, "log"))
5042                return parse_submodule_opt(options, arg);
5043        else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
5044                return parse_ws_error_highlight_opt(options, arg);
5045        else if (!strcmp(arg, "--ita-invisible-in-index"))
5046                options->ita_invisible_in_index = 1;
5047        else if (!strcmp(arg, "--ita-visible-in-index"))
5048                options->ita_invisible_in_index = 0;
5049
5050        /* misc options */
5051        else if (!strcmp(arg, "-z"))
5052                options->line_termination = 0;
5053        else if ((argcount = short_opt('l', av, &optarg))) {
5054                options->rename_limit = strtoul(optarg, NULL, 10);
5055                return argcount;
5056        }
5057        else if ((argcount = short_opt('S', av, &optarg))) {
5058                options->pickaxe = optarg;
5059                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
5060                return argcount;
5061        } else if ((argcount = short_opt('G', av, &optarg))) {
5062                options->pickaxe = optarg;
5063                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
5064                return argcount;
5065        }
5066        else if (!strcmp(arg, "--pickaxe-all"))
5067                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
5068        else if (!strcmp(arg, "--pickaxe-regex"))
5069                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
5070        else if ((argcount = short_opt('O', av, &optarg))) {
5071                options->orderfile = prefix_filename(prefix, optarg);
5072                return argcount;
5073        } else if (skip_prefix(arg, "--find-object=", &arg))
5074                return parse_objfind_opt(options, arg);
5075        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
5076                int offending = parse_diff_filter_opt(optarg, options);
5077                if (offending)
5078                        die("unknown change class '%c' in --diff-filter=%s",
5079                            offending, optarg);
5080                return argcount;
5081        }
5082        else if (!strcmp(arg, "--no-abbrev"))
5083                options->abbrev = 0;
5084        else if (!strcmp(arg, "--abbrev"))
5085                options->abbrev = DEFAULT_ABBREV;
5086        else if (skip_prefix(arg, "--abbrev=", &arg)) {
5087                options->abbrev = strtoul(arg, NULL, 10);
5088                if (options->abbrev < MINIMUM_ABBREV)
5089                        options->abbrev = MINIMUM_ABBREV;
5090                else if (the_hash_algo->hexsz < options->abbrev)
5091                        options->abbrev = the_hash_algo->hexsz;
5092        }
5093        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
5094                options->a_prefix = optarg;
5095                return argcount;
5096        }
5097        else if ((argcount = parse_long_opt("line-prefix", av, &optarg))) {
5098                options->line_prefix = optarg;
5099                options->line_prefix_length = strlen(options->line_prefix);
5100                graph_setup_line_prefix(options);
5101                return argcount;
5102        }
5103        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
5104                options->b_prefix = optarg;
5105                return argcount;
5106        }
5107        else if (!strcmp(arg, "--no-prefix"))
5108                options->a_prefix = options->b_prefix = "";
5109        else if (opt_arg(arg, '\0', "inter-hunk-context",
5110                         &options->interhunkcontext))
5111                ;
5112        else if (!strcmp(arg, "-W"))
5113                options->flags.funccontext = 1;
5114        else if (!strcmp(arg, "--function-context"))
5115                options->flags.funccontext = 1;
5116        else if (!strcmp(arg, "--no-function-context"))
5117                options->flags.funccontext = 0;
5118        else if ((argcount = parse_long_opt("output", av, &optarg))) {
5119                char *path = prefix_filename(prefix, optarg);
5120                options->file = xfopen(path, "w");
5121                options->close_file = 1;
5122                if (options->use_color != GIT_COLOR_ALWAYS)
5123                        options->use_color = GIT_COLOR_NEVER;
5124                free(path);
5125                return argcount;
5126        } else
5127                return 0;
5128        return 1;
5129}
5130
5131int parse_rename_score(const char **cp_p)
5132{
5133        unsigned long num, scale;
5134        int ch, dot;
5135        const char *cp = *cp_p;
5136
5137        num = 0;
5138        scale = 1;
5139        dot = 0;
5140        for (;;) {
5141                ch = *cp;
5142                if ( !dot && ch == '.' ) {
5143                        scale = 1;
5144                        dot = 1;
5145                } else if ( ch == '%' ) {
5146                        scale = dot ? scale*100 : 100;
5147                        cp++;   /* % is always at the end */
5148                        break;
5149                } else if ( ch >= '0' && ch <= '9' ) {
5150                        if ( scale < 100000 ) {
5151                                scale *= 10;
5152                                num = (num*10) + (ch-'0');
5153                        }
5154                } else {
5155                        break;
5156                }
5157                cp++;
5158        }
5159        *cp_p = cp;
5160
5161        /* user says num divided by scale and we say internally that
5162         * is MAX_SCORE * num / scale.
5163         */
5164        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
5165}
5166
5167static int diff_scoreopt_parse(const char *opt)
5168{
5169        int opt1, opt2, cmd;
5170
5171        if (*opt++ != '-')
5172                return -1;
5173        cmd = *opt++;
5174        if (cmd == '-') {
5175                /* convert the long-form arguments into short-form versions */
5176                if (skip_prefix(opt, "break-rewrites", &opt)) {
5177                        if (*opt == 0 || *opt++ == '=')
5178                                cmd = 'B';
5179                } else if (skip_prefix(opt, "find-copies", &opt)) {
5180                        if (*opt == 0 || *opt++ == '=')
5181                                cmd = 'C';
5182                } else if (skip_prefix(opt, "find-renames", &opt)) {
5183                        if (*opt == 0 || *opt++ == '=')
5184                                cmd = 'M';
5185                }
5186        }
5187        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
5188                return -1; /* that is not a -M, -C, or -B option */
5189
5190        opt1 = parse_rename_score(&opt);
5191        if (cmd != 'B')
5192                opt2 = 0;
5193        else {
5194                if (*opt == 0)
5195                        opt2 = 0;
5196                else if (*opt != '/')
5197                        return -1; /* we expect -B80/99 or -B80 */
5198                else {
5199                        opt++;
5200                        opt2 = parse_rename_score(&opt);
5201                }
5202        }
5203        if (*opt != 0)
5204                return -1;
5205        return opt1 | (opt2 << 16);
5206}
5207
5208struct diff_queue_struct diff_queued_diff;
5209
5210void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
5211{
5212        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
5213        queue->queue[queue->nr++] = dp;
5214}
5215
5216struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
5217                                 struct diff_filespec *one,
5218                                 struct diff_filespec *two)
5219{
5220        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
5221        dp->one = one;
5222        dp->two = two;
5223        if (queue)
5224                diff_q(queue, dp);
5225        return dp;
5226}
5227
5228void diff_free_filepair(struct diff_filepair *p)
5229{
5230        free_filespec(p->one);
5231        free_filespec(p->two);
5232        free(p);
5233}
5234
5235const char *diff_aligned_abbrev(const struct object_id *oid, int len)
5236{
5237        int abblen;
5238        const char *abbrev;
5239
5240        /* Do we want all 40 hex characters? */
5241        if (len == the_hash_algo->hexsz)
5242                return oid_to_hex(oid);
5243
5244        /* An abbreviated value is fine, possibly followed by an ellipsis. */
5245        abbrev = diff_abbrev_oid(oid, len);
5246
5247        if (!print_sha1_ellipsis())
5248                return abbrev;
5249
5250        abblen = strlen(abbrev);
5251
5252        /*
5253         * In well-behaved cases, where the abbreviated result is the
5254         * same as the requested length, append three dots after the
5255         * abbreviation (hence the whole logic is limited to the case
5256         * where abblen < 37); when the actual abbreviated result is a
5257         * bit longer than the requested length, we reduce the number
5258         * of dots so that they match the well-behaved ones.  However,
5259         * if the actual abbreviation is longer than the requested
5260         * length by more than three, we give up on aligning, and add
5261         * three dots anyway, to indicate that the output is not the
5262         * full object name.  Yes, this may be suboptimal, but this
5263         * appears only in "diff --raw --abbrev" output and it is not
5264         * worth the effort to change it now.  Note that this would
5265         * likely to work fine when the automatic sizing of default
5266         * abbreviation length is used--we would be fed -1 in "len" in
5267         * that case, and will end up always appending three-dots, but
5268         * the automatic sizing is supposed to give abblen that ensures
5269         * uniqueness across all objects (statistically speaking).
5270         */
5271        if (abblen < the_hash_algo->hexsz - 3) {
5272                static char hex[GIT_MAX_HEXSZ + 1];
5273                if (len < abblen && abblen <= len + 2)
5274                        xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
5275                else
5276                        xsnprintf(hex, sizeof(hex), "%s...", abbrev);
5277                return hex;
5278        }
5279
5280        return oid_to_hex(oid);
5281}
5282
5283static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
5284{
5285        int line_termination = opt->line_termination;
5286        int inter_name_termination = line_termination ? '\t' : '\0';
5287
5288        fprintf(opt->file, "%s", diff_line_prefix(opt));
5289        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
5290                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
5291                        diff_aligned_abbrev(&p->one->oid, opt->abbrev));
5292                fprintf(opt->file, "%s ",
5293                        diff_aligned_abbrev(&p->two->oid, opt->abbrev));
5294        }
5295        if (p->score) {
5296                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
5297                        inter_name_termination);
5298        } else {
5299                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
5300        }
5301
5302        if (p->status == DIFF_STATUS_COPIED ||
5303            p->status == DIFF_STATUS_RENAMED) {
5304                const char *name_a, *name_b;
5305                name_a = p->one->path;
5306                name_b = p->two->path;
5307                strip_prefix(opt->prefix_length, &name_a, &name_b);
5308                write_name_quoted(name_a, opt->file, inter_name_termination);
5309                write_name_quoted(name_b, opt->file, line_termination);
5310        } else {
5311                const char *name_a, *name_b;
5312                name_a = p->one->mode ? p->one->path : p->two->path;
5313                name_b = NULL;
5314                strip_prefix(opt->prefix_length, &name_a, &name_b);
5315                write_name_quoted(name_a, opt->file, line_termination);
5316        }
5317}
5318
5319int diff_unmodified_pair(struct diff_filepair *p)
5320{
5321        /* This function is written stricter than necessary to support
5322         * the currently implemented transformers, but the idea is to
5323         * let transformers to produce diff_filepairs any way they want,
5324         * and filter and clean them up here before producing the output.
5325         */
5326        struct diff_filespec *one = p->one, *two = p->two;
5327
5328        if (DIFF_PAIR_UNMERGED(p))
5329                return 0; /* unmerged is interesting */
5330
5331        /* deletion, addition, mode or type change
5332         * and rename are all interesting.
5333         */
5334        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
5335            DIFF_PAIR_MODE_CHANGED(p) ||
5336            strcmp(one->path, two->path))
5337                return 0;
5338
5339        /* both are valid and point at the same path.  that is, we are
5340         * dealing with a change.
5341         */
5342        if (one->oid_valid && two->oid_valid &&
5343            !oidcmp(&one->oid, &two->oid) &&
5344            !one->dirty_submodule && !two->dirty_submodule)
5345                return 1; /* no change */
5346        if (!one->oid_valid && !two->oid_valid)
5347                return 1; /* both look at the same file on the filesystem. */
5348        return 0;
5349}
5350
5351static void diff_flush_patch(struct diff_filepair *p, 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; /* no tree diffs in patch format */
5359
5360        run_diff(p, o);
5361}
5362
5363static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
5364                            struct diffstat_t *diffstat)
5365{
5366        if (diff_unmodified_pair(p))
5367                return;
5368
5369        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5370            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5371                return; /* no useful stat for tree diffs */
5372
5373        run_diffstat(p, o, diffstat);
5374}
5375
5376static void diff_flush_checkdiff(struct diff_filepair *p,
5377                struct diff_options *o)
5378{
5379        if (diff_unmodified_pair(p))
5380                return;
5381
5382        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5383            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5384                return; /* nothing to check in tree diffs */
5385
5386        run_checkdiff(p, o);
5387}
5388
5389int diff_queue_is_empty(void)
5390{
5391        struct diff_queue_struct *q = &diff_queued_diff;
5392        int i;
5393        for (i = 0; i < q->nr; i++)
5394                if (!diff_unmodified_pair(q->queue[i]))
5395                        return 0;
5396        return 1;
5397}
5398
5399#if DIFF_DEBUG
5400void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
5401{
5402        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
5403                x, one ? one : "",
5404                s->path,
5405                DIFF_FILE_VALID(s) ? "valid" : "invalid",
5406                s->mode,
5407                s->oid_valid ? oid_to_hex(&s->oid) : "");
5408        fprintf(stderr, "queue[%d] %s size %lu\n",
5409                x, one ? one : "",
5410                s->size);
5411}
5412
5413void diff_debug_filepair(const struct diff_filepair *p, int i)
5414{
5415        diff_debug_filespec(p->one, i, "one");
5416        diff_debug_filespec(p->two, i, "two");
5417        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
5418                p->score, p->status ? p->status : '?',
5419                p->one->rename_used, p->broken_pair);
5420}
5421
5422void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
5423{
5424        int i;
5425        if (msg)
5426                fprintf(stderr, "%s\n", msg);
5427        fprintf(stderr, "q->nr = %d\n", q->nr);
5428        for (i = 0; i < q->nr; i++) {
5429                struct diff_filepair *p = q->queue[i];
5430                diff_debug_filepair(p, i);
5431        }
5432}
5433#endif
5434
5435static void diff_resolve_rename_copy(void)
5436{
5437        int i;
5438        struct diff_filepair *p;
5439        struct diff_queue_struct *q = &diff_queued_diff;
5440
5441        diff_debug_queue("resolve-rename-copy", q);
5442
5443        for (i = 0; i < q->nr; i++) {
5444                p = q->queue[i];
5445                p->status = 0; /* undecided */
5446                if (DIFF_PAIR_UNMERGED(p))
5447                        p->status = DIFF_STATUS_UNMERGED;
5448                else if (!DIFF_FILE_VALID(p->one))
5449                        p->status = DIFF_STATUS_ADDED;
5450                else if (!DIFF_FILE_VALID(p->two))
5451                        p->status = DIFF_STATUS_DELETED;
5452                else if (DIFF_PAIR_TYPE_CHANGED(p))
5453                        p->status = DIFF_STATUS_TYPE_CHANGED;
5454
5455                /* from this point on, we are dealing with a pair
5456                 * whose both sides are valid and of the same type, i.e.
5457                 * either in-place edit or rename/copy edit.
5458                 */
5459                else if (DIFF_PAIR_RENAME(p)) {
5460                        /*
5461                         * A rename might have re-connected a broken
5462                         * pair up, causing the pathnames to be the
5463                         * same again. If so, that's not a rename at
5464                         * all, just a modification..
5465                         *
5466                         * Otherwise, see if this source was used for
5467                         * multiple renames, in which case we decrement
5468                         * the count, and call it a copy.
5469                         */
5470                        if (!strcmp(p->one->path, p->two->path))
5471                                p->status = DIFF_STATUS_MODIFIED;
5472                        else if (--p->one->rename_used > 0)
5473                                p->status = DIFF_STATUS_COPIED;
5474                        else
5475                                p->status = DIFF_STATUS_RENAMED;
5476                }
5477                else if (oidcmp(&p->one->oid, &p->two->oid) ||
5478                         p->one->mode != p->two->mode ||
5479                         p->one->dirty_submodule ||
5480                         p->two->dirty_submodule ||
5481                         is_null_oid(&p->one->oid))
5482                        p->status = DIFF_STATUS_MODIFIED;
5483                else {
5484                        /* This is a "no-change" entry and should not
5485                         * happen anymore, but prepare for broken callers.
5486                         */
5487                        error("feeding unmodified %s to diffcore",
5488                              p->one->path);
5489                        p->status = DIFF_STATUS_UNKNOWN;
5490                }
5491        }
5492        diff_debug_queue("resolve-rename-copy done", q);
5493}
5494
5495static int check_pair_status(struct diff_filepair *p)
5496{
5497        switch (p->status) {
5498        case DIFF_STATUS_UNKNOWN:
5499                return 0;
5500        case 0:
5501                die("internal error in diff-resolve-rename-copy");
5502        default:
5503                return 1;
5504        }
5505}
5506
5507static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
5508{
5509        int fmt = opt->output_format;
5510
5511        if (fmt & DIFF_FORMAT_CHECKDIFF)
5512                diff_flush_checkdiff(p, opt);
5513        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
5514                diff_flush_raw(p, opt);
5515        else if (fmt & DIFF_FORMAT_NAME) {
5516                const char *name_a, *name_b;
5517                name_a = p->two->path;
5518                name_b = NULL;
5519                strip_prefix(opt->prefix_length, &name_a, &name_b);
5520                fprintf(opt->file, "%s", diff_line_prefix(opt));
5521                write_name_quoted(name_a, opt->file, opt->line_termination);
5522        }
5523}
5524
5525static void show_file_mode_name(struct diff_options *opt, const char *newdelete, struct diff_filespec *fs)
5526{
5527        struct strbuf sb = STRBUF_INIT;
5528        if (fs->mode)
5529                strbuf_addf(&sb, " %s mode %06o ", newdelete, fs->mode);
5530        else
5531                strbuf_addf(&sb, " %s ", newdelete);
5532
5533        quote_c_style(fs->path, &sb, NULL, 0);
5534        strbuf_addch(&sb, '\n');
5535        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5536                         sb.buf, sb.len, 0);
5537        strbuf_release(&sb);
5538}
5539
5540static void show_mode_change(struct diff_options *opt, struct diff_filepair *p,
5541                int show_name)
5542{
5543        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
5544                struct strbuf sb = STRBUF_INIT;
5545                strbuf_addf(&sb, " mode change %06o => %06o",
5546                            p->one->mode, p->two->mode);
5547                if (show_name) {
5548                        strbuf_addch(&sb, ' ');
5549                        quote_c_style(p->two->path, &sb, NULL, 0);
5550                }
5551                strbuf_addch(&sb, '\n');
5552                emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5553                                 sb.buf, sb.len, 0);
5554                strbuf_release(&sb);
5555        }
5556}
5557
5558static void show_rename_copy(struct diff_options *opt, const char *renamecopy,
5559                struct diff_filepair *p)
5560{
5561        struct strbuf sb = STRBUF_INIT;
5562        struct strbuf names = STRBUF_INIT;
5563
5564        pprint_rename(&names, p->one->path, p->two->path);
5565        strbuf_addf(&sb, " %s %s (%d%%)\n",
5566                    renamecopy, names.buf, similarity_index(p));
5567        strbuf_release(&names);
5568        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5569                                 sb.buf, sb.len, 0);
5570        show_mode_change(opt, p, 0);
5571        strbuf_release(&sb);
5572}
5573
5574static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
5575{
5576        switch(p->status) {
5577        case DIFF_STATUS_DELETED:
5578                show_file_mode_name(opt, "delete", p->one);
5579                break;
5580        case DIFF_STATUS_ADDED:
5581                show_file_mode_name(opt, "create", p->two);
5582                break;
5583        case DIFF_STATUS_COPIED:
5584                show_rename_copy(opt, "copy", p);
5585                break;
5586        case DIFF_STATUS_RENAMED:
5587                show_rename_copy(opt, "rename", p);
5588                break;
5589        default:
5590                if (p->score) {
5591                        struct strbuf sb = STRBUF_INIT;
5592                        strbuf_addstr(&sb, " rewrite ");
5593                        quote_c_style(p->two->path, &sb, NULL, 0);
5594                        strbuf_addf(&sb, " (%d%%)\n", similarity_index(p));
5595                        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5596                                         sb.buf, sb.len, 0);
5597                        strbuf_release(&sb);
5598                }
5599                show_mode_change(opt, p, !p->score);
5600                break;
5601        }
5602}
5603
5604struct patch_id_t {
5605        git_SHA_CTX *ctx;
5606        int patchlen;
5607};
5608
5609static int remove_space(char *line, int len)
5610{
5611        int i;
5612        char *dst = line;
5613        unsigned char c;
5614
5615        for (i = 0; i < len; i++)
5616                if (!isspace((c = line[i])))
5617                        *dst++ = c;
5618
5619        return dst - line;
5620}
5621
5622static void patch_id_consume(void *priv, char *line, unsigned long len)
5623{
5624        struct patch_id_t *data = priv;
5625        int new_len;
5626
5627        /* Ignore line numbers when computing the SHA1 of the patch */
5628        if (starts_with(line, "@@ -"))
5629                return;
5630
5631        new_len = remove_space(line, len);
5632
5633        git_SHA1_Update(data->ctx, line, new_len);
5634        data->patchlen += new_len;
5635}
5636
5637static void patch_id_add_string(git_SHA_CTX *ctx, const char *str)
5638{
5639        git_SHA1_Update(ctx, str, strlen(str));
5640}
5641
5642static void patch_id_add_mode(git_SHA_CTX *ctx, unsigned mode)
5643{
5644        /* large enough for 2^32 in octal */
5645        char buf[12];
5646        int len = xsnprintf(buf, sizeof(buf), "%06o", mode);
5647        git_SHA1_Update(ctx, buf, len);
5648}
5649
5650/* returns 0 upon success, and writes result into sha1 */
5651static int diff_get_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5652{
5653        struct diff_queue_struct *q = &diff_queued_diff;
5654        int i;
5655        git_SHA_CTX ctx;
5656        struct patch_id_t data;
5657
5658        git_SHA1_Init(&ctx);
5659        memset(&data, 0, sizeof(struct patch_id_t));
5660        data.ctx = &ctx;
5661
5662        for (i = 0; i < q->nr; i++) {
5663                xpparam_t xpp;
5664                xdemitconf_t xecfg;
5665                mmfile_t mf1, mf2;
5666                struct diff_filepair *p = q->queue[i];
5667                int len1, len2;
5668
5669                memset(&xpp, 0, sizeof(xpp));
5670                memset(&xecfg, 0, sizeof(xecfg));
5671                if (p->status == 0)
5672                        return error("internal diff status error");
5673                if (p->status == DIFF_STATUS_UNKNOWN)
5674                        continue;
5675                if (diff_unmodified_pair(p))
5676                        continue;
5677                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5678                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5679                        continue;
5680                if (DIFF_PAIR_UNMERGED(p))
5681                        continue;
5682
5683                diff_fill_oid_info(p->one);
5684                diff_fill_oid_info(p->two);
5685
5686                len1 = remove_space(p->one->path, strlen(p->one->path));
5687                len2 = remove_space(p->two->path, strlen(p->two->path));
5688                patch_id_add_string(&ctx, "diff--git");
5689                patch_id_add_string(&ctx, "a/");
5690                git_SHA1_Update(&ctx, p->one->path, len1);
5691                patch_id_add_string(&ctx, "b/");
5692                git_SHA1_Update(&ctx, p->two->path, len2);
5693
5694                if (p->one->mode == 0) {
5695                        patch_id_add_string(&ctx, "newfilemode");
5696                        patch_id_add_mode(&ctx, p->two->mode);
5697                        patch_id_add_string(&ctx, "---/dev/null");
5698                        patch_id_add_string(&ctx, "+++b/");
5699                        git_SHA1_Update(&ctx, p->two->path, len2);
5700                } else if (p->two->mode == 0) {
5701                        patch_id_add_string(&ctx, "deletedfilemode");
5702                        patch_id_add_mode(&ctx, p->one->mode);
5703                        patch_id_add_string(&ctx, "---a/");
5704                        git_SHA1_Update(&ctx, p->one->path, len1);
5705                        patch_id_add_string(&ctx, "+++/dev/null");
5706                } else {
5707                        patch_id_add_string(&ctx, "---a/");
5708                        git_SHA1_Update(&ctx, p->one->path, len1);
5709                        patch_id_add_string(&ctx, "+++b/");
5710                        git_SHA1_Update(&ctx, p->two->path, len2);
5711                }
5712
5713                if (diff_header_only)
5714                        continue;
5715
5716                if (fill_mmfile(&mf1, p->one) < 0 ||
5717                    fill_mmfile(&mf2, p->two) < 0)
5718                        return error("unable to read files to diff");
5719
5720                if (diff_filespec_is_binary(p->one) ||
5721                    diff_filespec_is_binary(p->two)) {
5722                        git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
5723                                        GIT_SHA1_HEXSZ);
5724                        git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
5725                                        GIT_SHA1_HEXSZ);
5726                        continue;
5727                }
5728
5729                xpp.flags = 0;
5730                xecfg.ctxlen = 3;
5731                xecfg.flags = 0;
5732                if (xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
5733                                  &xpp, &xecfg))
5734                        return error("unable to generate patch-id diff for %s",
5735                                     p->one->path);
5736        }
5737
5738        git_SHA1_Final(oid->hash, &ctx);
5739        return 0;
5740}
5741
5742int diff_flush_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5743{
5744        struct diff_queue_struct *q = &diff_queued_diff;
5745        int i;
5746        int result = diff_get_patch_id(options, oid, diff_header_only);
5747
5748        for (i = 0; i < q->nr; i++)
5749                diff_free_filepair(q->queue[i]);
5750
5751        free(q->queue);
5752        DIFF_QUEUE_CLEAR(q);
5753
5754        return result;
5755}
5756
5757static int is_summary_empty(const struct diff_queue_struct *q)
5758{
5759        int i;
5760
5761        for (i = 0; i < q->nr; i++) {
5762                const struct diff_filepair *p = q->queue[i];
5763
5764                switch (p->status) {
5765                case DIFF_STATUS_DELETED:
5766                case DIFF_STATUS_ADDED:
5767                case DIFF_STATUS_COPIED:
5768                case DIFF_STATUS_RENAMED:
5769                        return 0;
5770                default:
5771                        if (p->score)
5772                                return 0;
5773                        if (p->one->mode && p->two->mode &&
5774                            p->one->mode != p->two->mode)
5775                                return 0;
5776                        break;
5777                }
5778        }
5779        return 1;
5780}
5781
5782static const char rename_limit_warning[] =
5783N_("inexact rename detection was skipped due to too many files.");
5784
5785static const char degrade_cc_to_c_warning[] =
5786N_("only found copies from modified paths due to too many files.");
5787
5788static const char rename_limit_advice[] =
5789N_("you may want to set your %s variable to at least "
5790   "%d and retry the command.");
5791
5792void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
5793{
5794        fflush(stdout);
5795        if (degraded_cc)
5796                warning(_(degrade_cc_to_c_warning));
5797        else if (needed)
5798                warning(_(rename_limit_warning));
5799        else
5800                return;
5801        if (0 < needed)
5802                warning(_(rename_limit_advice), varname, needed);
5803}
5804
5805static void diff_flush_patch_all_file_pairs(struct diff_options *o)
5806{
5807        int i;
5808        static struct emitted_diff_symbols esm = EMITTED_DIFF_SYMBOLS_INIT;
5809        struct diff_queue_struct *q = &diff_queued_diff;
5810
5811        if (WSEH_NEW & WS_RULE_MASK)
5812                BUG("WS rules bit mask overlaps with diff symbol flags");
5813
5814        if (o->color_moved)
5815                o->emitted_symbols = &esm;
5816
5817        for (i = 0; i < q->nr; i++) {
5818                struct diff_filepair *p = q->queue[i];
5819                if (check_pair_status(p))
5820                        diff_flush_patch(p, o);
5821        }
5822
5823        if (o->emitted_symbols) {
5824                if (o->color_moved) {
5825                        struct hashmap add_lines, del_lines;
5826
5827                        if (o->color_moved_ws_handling &
5828                            COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
5829                                o->color_moved_ws_handling |= XDF_IGNORE_WHITESPACE;
5830
5831                        hashmap_init(&del_lines, moved_entry_cmp, o, 0);
5832                        hashmap_init(&add_lines, moved_entry_cmp, o, 0);
5833
5834                        add_lines_to_move_detection(o, &add_lines, &del_lines);
5835                        mark_color_as_moved(o, &add_lines, &del_lines);
5836                        if (o->color_moved == COLOR_MOVED_ZEBRA_DIM)
5837                                dim_moved_lines(o);
5838
5839                        hashmap_free(&add_lines, 0);
5840                        hashmap_free(&del_lines, 0);
5841                }
5842
5843                for (i = 0; i < esm.nr; i++)
5844                        emit_diff_symbol_from_struct(o, &esm.buf[i]);
5845
5846                for (i = 0; i < esm.nr; i++)
5847                        free((void *)esm.buf[i].line);
5848        }
5849        esm.nr = 0;
5850}
5851
5852void diff_flush(struct diff_options *options)
5853{
5854        struct diff_queue_struct *q = &diff_queued_diff;
5855        int i, output_format = options->output_format;
5856        int separator = 0;
5857        int dirstat_by_line = 0;
5858
5859        /*
5860         * Order: raw, stat, summary, patch
5861         * or:    name/name-status/checkdiff (other bits clear)
5862         */
5863        if (!q->nr)
5864                goto free_queue;
5865
5866        if (output_format & (DIFF_FORMAT_RAW |
5867                             DIFF_FORMAT_NAME |
5868                             DIFF_FORMAT_NAME_STATUS |
5869                             DIFF_FORMAT_CHECKDIFF)) {
5870                for (i = 0; i < q->nr; i++) {
5871                        struct diff_filepair *p = q->queue[i];
5872                        if (check_pair_status(p))
5873                                flush_one_pair(p, options);
5874                }
5875                separator++;
5876        }
5877
5878        if (output_format & DIFF_FORMAT_DIRSTAT && options->flags.dirstat_by_line)
5879                dirstat_by_line = 1;
5880
5881        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
5882            dirstat_by_line) {
5883                struct diffstat_t diffstat;
5884
5885                memset(&diffstat, 0, sizeof(struct diffstat_t));
5886                for (i = 0; i < q->nr; i++) {
5887                        struct diff_filepair *p = q->queue[i];
5888                        if (check_pair_status(p))
5889                                diff_flush_stat(p, options, &diffstat);
5890                }
5891                if (output_format & DIFF_FORMAT_NUMSTAT)
5892                        show_numstat(&diffstat, options);
5893                if (output_format & DIFF_FORMAT_DIFFSTAT)
5894                        show_stats(&diffstat, options);
5895                if (output_format & DIFF_FORMAT_SHORTSTAT)
5896                        show_shortstats(&diffstat, options);
5897                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
5898                        show_dirstat_by_line(&diffstat, options);
5899                free_diffstat_info(&diffstat);
5900                separator++;
5901        }
5902        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
5903                show_dirstat(options);
5904
5905        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
5906                for (i = 0; i < q->nr; i++) {
5907                        diff_summary(options, q->queue[i]);
5908                }
5909                separator++;
5910        }
5911
5912        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
5913            options->flags.exit_with_status &&
5914            options->flags.diff_from_contents) {
5915                /*
5916                 * run diff_flush_patch for the exit status. setting
5917                 * options->file to /dev/null should be safe, because we
5918                 * aren't supposed to produce any output anyway.
5919                 */
5920                if (options->close_file)
5921                        fclose(options->file);
5922                options->file = xfopen("/dev/null", "w");
5923                options->close_file = 1;
5924                options->color_moved = 0;
5925                for (i = 0; i < q->nr; i++) {
5926                        struct diff_filepair *p = q->queue[i];
5927                        if (check_pair_status(p))
5928                                diff_flush_patch(p, options);
5929                        if (options->found_changes)
5930                                break;
5931                }
5932        }
5933
5934        if (output_format & DIFF_FORMAT_PATCH) {
5935                if (separator) {
5936                        emit_diff_symbol(options, DIFF_SYMBOL_SEPARATOR, NULL, 0, 0);
5937                        if (options->stat_sep)
5938                                /* attach patch instead of inline */
5939                                emit_diff_symbol(options, DIFF_SYMBOL_STAT_SEP,
5940                                                 NULL, 0, 0);
5941                }
5942
5943                diff_flush_patch_all_file_pairs(options);
5944        }
5945
5946        if (output_format & DIFF_FORMAT_CALLBACK)
5947                options->format_callback(q, options, options->format_callback_data);
5948
5949        for (i = 0; i < q->nr; i++)
5950                diff_free_filepair(q->queue[i]);
5951free_queue:
5952        free(q->queue);
5953        DIFF_QUEUE_CLEAR(q);
5954        if (options->close_file)
5955                fclose(options->file);
5956
5957        /*
5958         * Report the content-level differences with HAS_CHANGES;
5959         * diff_addremove/diff_change does not set the bit when
5960         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
5961         */
5962        if (options->flags.diff_from_contents) {
5963                if (options->found_changes)
5964                        options->flags.has_changes = 1;
5965                else
5966                        options->flags.has_changes = 0;
5967        }
5968}
5969
5970static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
5971{
5972        return (((p->status == DIFF_STATUS_MODIFIED) &&
5973                 ((p->score &&
5974                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
5975                  (!p->score &&
5976                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
5977                ((p->status != DIFF_STATUS_MODIFIED) &&
5978                 filter_bit_tst(p->status, options)));
5979}
5980
5981static void diffcore_apply_filter(struct diff_options *options)
5982{
5983        int i;
5984        struct diff_queue_struct *q = &diff_queued_diff;
5985        struct diff_queue_struct outq;
5986
5987        DIFF_QUEUE_CLEAR(&outq);
5988
5989        if (!options->filter)
5990                return;
5991
5992        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
5993                int found;
5994                for (i = found = 0; !found && i < q->nr; i++) {
5995                        if (match_filter(options, q->queue[i]))
5996                                found++;
5997                }
5998                if (found)
5999                        return;
6000
6001                /* otherwise we will clear the whole queue
6002                 * by copying the empty outq at the end of this
6003                 * function, but first clear the current entries
6004                 * in the queue.
6005                 */
6006                for (i = 0; i < q->nr; i++)
6007                        diff_free_filepair(q->queue[i]);
6008        }
6009        else {
6010                /* Only the matching ones */
6011                for (i = 0; i < q->nr; i++) {
6012                        struct diff_filepair *p = q->queue[i];
6013                        if (match_filter(options, p))
6014                                diff_q(&outq, p);
6015                        else
6016                                diff_free_filepair(p);
6017                }
6018        }
6019        free(q->queue);
6020        *q = outq;
6021}
6022
6023/* Check whether two filespecs with the same mode and size are identical */
6024static int diff_filespec_is_identical(struct diff_filespec *one,
6025                                      struct diff_filespec *two)
6026{
6027        if (S_ISGITLINK(one->mode))
6028                return 0;
6029        if (diff_populate_filespec(one, 0))
6030                return 0;
6031        if (diff_populate_filespec(two, 0))
6032                return 0;
6033        return !memcmp(one->data, two->data, one->size);
6034}
6035
6036static int diff_filespec_check_stat_unmatch(struct diff_filepair *p)
6037{
6038        if (p->done_skip_stat_unmatch)
6039                return p->skip_stat_unmatch_result;
6040
6041        p->done_skip_stat_unmatch = 1;
6042        p->skip_stat_unmatch_result = 0;
6043        /*
6044         * 1. Entries that come from stat info dirtiness
6045         *    always have both sides (iow, not create/delete),
6046         *    one side of the object name is unknown, with
6047         *    the same mode and size.  Keep the ones that
6048         *    do not match these criteria.  They have real
6049         *    differences.
6050         *
6051         * 2. At this point, the file is known to be modified,
6052         *    with the same mode and size, and the object
6053         *    name of one side is unknown.  Need to inspect
6054         *    the identical contents.
6055         */
6056        if (!DIFF_FILE_VALID(p->one) || /* (1) */
6057            !DIFF_FILE_VALID(p->two) ||
6058            (p->one->oid_valid && p->two->oid_valid) ||
6059            (p->one->mode != p->two->mode) ||
6060            diff_populate_filespec(p->one, CHECK_SIZE_ONLY) ||
6061            diff_populate_filespec(p->two, CHECK_SIZE_ONLY) ||
6062            (p->one->size != p->two->size) ||
6063            !diff_filespec_is_identical(p->one, p->two)) /* (2) */
6064                p->skip_stat_unmatch_result = 1;
6065        return p->skip_stat_unmatch_result;
6066}
6067
6068static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
6069{
6070        int i;
6071        struct diff_queue_struct *q = &diff_queued_diff;
6072        struct diff_queue_struct outq;
6073        DIFF_QUEUE_CLEAR(&outq);
6074
6075        for (i = 0; i < q->nr; i++) {
6076                struct diff_filepair *p = q->queue[i];
6077
6078                if (diff_filespec_check_stat_unmatch(p))
6079                        diff_q(&outq, p);
6080                else {
6081                        /*
6082                         * The caller can subtract 1 from skip_stat_unmatch
6083                         * to determine how many paths were dirty only
6084                         * due to stat info mismatch.
6085                         */
6086                        if (!diffopt->flags.no_index)
6087                                diffopt->skip_stat_unmatch++;
6088                        diff_free_filepair(p);
6089                }
6090        }
6091        free(q->queue);
6092        *q = outq;
6093}
6094
6095static int diffnamecmp(const void *a_, const void *b_)
6096{
6097        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
6098        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
6099        const char *name_a, *name_b;
6100
6101        name_a = a->one ? a->one->path : a->two->path;
6102        name_b = b->one ? b->one->path : b->two->path;
6103        return strcmp(name_a, name_b);
6104}
6105
6106void diffcore_fix_diff_index(struct diff_options *options)
6107{
6108        struct diff_queue_struct *q = &diff_queued_diff;
6109        QSORT(q->queue, q->nr, diffnamecmp);
6110}
6111
6112void diffcore_std(struct diff_options *options)
6113{
6114        /* NOTE please keep the following in sync with diff_tree_combined() */
6115        if (options->skip_stat_unmatch)
6116                diffcore_skip_stat_unmatch(options);
6117        if (!options->found_follow) {
6118                /* See try_to_follow_renames() in tree-diff.c */
6119                if (options->break_opt != -1)
6120                        diffcore_break(options->break_opt);
6121                if (options->detect_rename)
6122                        diffcore_rename(options);
6123                if (options->break_opt != -1)
6124                        diffcore_merge_broken();
6125        }
6126        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
6127                diffcore_pickaxe(options);
6128        if (options->orderfile)
6129                diffcore_order(options->orderfile);
6130        if (!options->found_follow)
6131                /* See try_to_follow_renames() in tree-diff.c */
6132                diff_resolve_rename_copy();
6133        diffcore_apply_filter(options);
6134
6135        if (diff_queued_diff.nr && !options->flags.diff_from_contents)
6136                options->flags.has_changes = 1;
6137        else
6138                options->flags.has_changes = 0;
6139
6140        options->found_follow = 0;
6141}
6142
6143int diff_result_code(struct diff_options *opt, int status)
6144{
6145        int result = 0;
6146
6147        diff_warn_rename_limit("diff.renameLimit",
6148                               opt->needed_rename_limit,
6149                               opt->degraded_cc_to_c);
6150        if (!opt->flags.exit_with_status &&
6151            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
6152                return status;
6153        if (opt->flags.exit_with_status &&
6154            opt->flags.has_changes)
6155                result |= 01;
6156        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
6157            opt->flags.check_failed)
6158                result |= 02;
6159        return result;
6160}
6161
6162int diff_can_quit_early(struct diff_options *opt)
6163{
6164        return (opt->flags.quick &&
6165                !opt->filter &&
6166                opt->flags.has_changes);
6167}
6168
6169/*
6170 * Shall changes to this submodule be ignored?
6171 *
6172 * Submodule changes can be configured to be ignored separately for each path,
6173 * but that configuration can be overridden from the command line.
6174 */
6175static int is_submodule_ignored(const char *path, struct diff_options *options)
6176{
6177        int ignored = 0;
6178        struct diff_flags orig_flags = options->flags;
6179        if (!options->flags.override_submodule_config)
6180                set_diffopt_flags_from_submodule_config(options, path);
6181        if (options->flags.ignore_submodules)
6182                ignored = 1;
6183        options->flags = orig_flags;
6184        return ignored;
6185}
6186
6187void diff_addremove(struct diff_options *options,
6188                    int addremove, unsigned mode,
6189                    const struct object_id *oid,
6190                    int oid_valid,
6191                    const char *concatpath, unsigned dirty_submodule)
6192{
6193        struct diff_filespec *one, *two;
6194
6195        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
6196                return;
6197
6198        /* This may look odd, but it is a preparation for
6199         * feeding "there are unchanged files which should
6200         * not produce diffs, but when you are doing copy
6201         * detection you would need them, so here they are"
6202         * entries to the diff-core.  They will be prefixed
6203         * with something like '=' or '*' (I haven't decided
6204         * which but should not make any difference).
6205         * Feeding the same new and old to diff_change()
6206         * also has the same effect.
6207         * Before the final output happens, they are pruned after
6208         * merged into rename/copy pairs as appropriate.
6209         */
6210        if (options->flags.reverse_diff)
6211                addremove = (addremove == '+' ? '-' :
6212                             addremove == '-' ? '+' : addremove);
6213
6214        if (options->prefix &&
6215            strncmp(concatpath, options->prefix, options->prefix_length))
6216                return;
6217
6218        one = alloc_filespec(concatpath);
6219        two = alloc_filespec(concatpath);
6220
6221        if (addremove != '+')
6222                fill_filespec(one, oid, oid_valid, mode);
6223        if (addremove != '-') {
6224                fill_filespec(two, oid, oid_valid, mode);
6225                two->dirty_submodule = dirty_submodule;
6226        }
6227
6228        diff_queue(&diff_queued_diff, one, two);
6229        if (!options->flags.diff_from_contents)
6230                options->flags.has_changes = 1;
6231}
6232
6233void diff_change(struct diff_options *options,
6234                 unsigned old_mode, unsigned new_mode,
6235                 const struct object_id *old_oid,
6236                 const struct object_id *new_oid,
6237                 int old_oid_valid, int new_oid_valid,
6238                 const char *concatpath,
6239                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
6240{
6241        struct diff_filespec *one, *two;
6242        struct diff_filepair *p;
6243
6244        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
6245            is_submodule_ignored(concatpath, options))
6246                return;
6247
6248        if (options->flags.reverse_diff) {
6249                SWAP(old_mode, new_mode);
6250                SWAP(old_oid, new_oid);
6251                SWAP(old_oid_valid, new_oid_valid);
6252                SWAP(old_dirty_submodule, new_dirty_submodule);
6253        }
6254
6255        if (options->prefix &&
6256            strncmp(concatpath, options->prefix, options->prefix_length))
6257                return;
6258
6259        one = alloc_filespec(concatpath);
6260        two = alloc_filespec(concatpath);
6261        fill_filespec(one, old_oid, old_oid_valid, old_mode);
6262        fill_filespec(two, new_oid, new_oid_valid, new_mode);
6263        one->dirty_submodule = old_dirty_submodule;
6264        two->dirty_submodule = new_dirty_submodule;
6265        p = diff_queue(&diff_queued_diff, one, two);
6266
6267        if (options->flags.diff_from_contents)
6268                return;
6269
6270        if (options->flags.quick && options->skip_stat_unmatch &&
6271            !diff_filespec_check_stat_unmatch(p))
6272                return;
6273
6274        options->flags.has_changes = 1;
6275}
6276
6277struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
6278{
6279        struct diff_filepair *pair;
6280        struct diff_filespec *one, *two;
6281
6282        if (options->prefix &&
6283            strncmp(path, options->prefix, options->prefix_length))
6284                return NULL;
6285
6286        one = alloc_filespec(path);
6287        two = alloc_filespec(path);
6288        pair = diff_queue(&diff_queued_diff, one, two);
6289        pair->is_unmerged = 1;
6290        return pair;
6291}
6292
6293static char *run_textconv(const char *pgm, struct diff_filespec *spec,
6294                size_t *outsize)
6295{
6296        struct diff_tempfile *temp;
6297        const char *argv[3];
6298        const char **arg = argv;
6299        struct child_process child = CHILD_PROCESS_INIT;
6300        struct strbuf buf = STRBUF_INIT;
6301        int err = 0;
6302
6303        temp = prepare_temp_file(spec->path, spec);
6304        *arg++ = pgm;
6305        *arg++ = temp->name;
6306        *arg = NULL;
6307
6308        child.use_shell = 1;
6309        child.argv = argv;
6310        child.out = -1;
6311        if (start_command(&child)) {
6312                remove_tempfile();
6313                return NULL;
6314        }
6315
6316        if (strbuf_read(&buf, child.out, 0) < 0)
6317                err = error("error reading from textconv command '%s'", pgm);
6318        close(child.out);
6319
6320        if (finish_command(&child) || err) {
6321                strbuf_release(&buf);
6322                remove_tempfile();
6323                return NULL;
6324        }
6325        remove_tempfile();
6326
6327        return strbuf_detach(&buf, outsize);
6328}
6329
6330size_t fill_textconv(struct userdiff_driver *driver,
6331                     struct diff_filespec *df,
6332                     char **outbuf)
6333{
6334        size_t size;
6335
6336        if (!driver) {
6337                if (!DIFF_FILE_VALID(df)) {
6338                        *outbuf = "";
6339                        return 0;
6340                }
6341                if (diff_populate_filespec(df, 0))
6342                        die("unable to read files to diff");
6343                *outbuf = df->data;
6344                return df->size;
6345        }
6346
6347        if (!driver->textconv)
6348                BUG("fill_textconv called with non-textconv driver");
6349
6350        if (driver->textconv_cache && df->oid_valid) {
6351                *outbuf = notes_cache_get(driver->textconv_cache,
6352                                          &df->oid,
6353                                          &size);
6354                if (*outbuf)
6355                        return size;
6356        }
6357
6358        *outbuf = run_textconv(driver->textconv, df, &size);
6359        if (!*outbuf)
6360                die("unable to read files to diff");
6361
6362        if (driver->textconv_cache && df->oid_valid) {
6363                /* ignore errors, as we might be in a readonly repository */
6364                notes_cache_put(driver->textconv_cache, &df->oid, *outbuf,
6365                                size);
6366                /*
6367                 * we could save up changes and flush them all at the end,
6368                 * but we would need an extra call after all diffing is done.
6369                 * Since generating a cache entry is the slow path anyway,
6370                 * this extra overhead probably isn't a big deal.
6371                 */
6372                notes_cache_write(driver->textconv_cache);
6373        }
6374
6375        return size;
6376}
6377
6378int textconv_object(const char *path,
6379                    unsigned mode,
6380                    const struct object_id *oid,
6381                    int oid_valid,
6382                    char **buf,
6383                    unsigned long *buf_size)
6384{
6385        struct diff_filespec *df;
6386        struct userdiff_driver *textconv;
6387
6388        df = alloc_filespec(path);
6389        fill_filespec(df, oid, oid_valid, mode);
6390        textconv = get_textconv(df);
6391        if (!textconv) {
6392                free_filespec(df);
6393                return 0;
6394        }
6395
6396        *buf_size = fill_textconv(textconv, df, buf);
6397        free_filespec(df);
6398        return 1;
6399}
6400
6401void setup_diff_pager(struct diff_options *opt)
6402{
6403        /*
6404         * If the user asked for our exit code, then either they want --quiet
6405         * or --exit-code. We should definitely not bother with a pager in the
6406         * former case, as we will generate no output. Since we still properly
6407         * report our exit code even when a pager is run, we _could_ run a
6408         * pager with --exit-code. But since we have not done so historically,
6409         * and because it is easy to find people oneline advising "git diff
6410         * --exit-code" in hooks and other scripts, we do not do so.
6411         */
6412        if (!opt->flags.exit_with_status &&
6413            check_pager_config("diff") != 0)
6414                setup_pager();
6415}