diff.con commit diff-parseopt: convert --summary (70a3041)
   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 "parse-options.h"
  27#include "help.h"
  28
  29#ifdef NO_FAST_WORKING_DIRECTORY
  30#define FAST_WORKING_DIRECTORY 0
  31#else
  32#define FAST_WORKING_DIRECTORY 1
  33#endif
  34
  35static int diff_detect_rename_default;
  36static int diff_indent_heuristic = 1;
  37static int diff_rename_limit_default = 400;
  38static int diff_suppress_blank_empty;
  39static int diff_use_color_default = -1;
  40static int diff_color_moved_default;
  41static int diff_color_moved_ws_default;
  42static int diff_context_default = 3;
  43static int diff_interhunk_context_default;
  44static const char *diff_word_regex_cfg;
  45static const char *external_diff_cmd_cfg;
  46static const char *diff_order_file_cfg;
  47int diff_auto_refresh_index = 1;
  48static int diff_mnemonic_prefix;
  49static int diff_no_prefix;
  50static int diff_stat_graph_width;
  51static int diff_dirstat_permille_default = 30;
  52static struct diff_options default_diff_options;
  53static long diff_algorithm;
  54static unsigned ws_error_highlight_default = WSEH_NEW;
  55
  56static char diff_colors[][COLOR_MAXLEN] = {
  57        GIT_COLOR_RESET,
  58        GIT_COLOR_NORMAL,       /* CONTEXT */
  59        GIT_COLOR_BOLD,         /* METAINFO */
  60        GIT_COLOR_CYAN,         /* FRAGINFO */
  61        GIT_COLOR_RED,          /* OLD */
  62        GIT_COLOR_GREEN,        /* NEW */
  63        GIT_COLOR_YELLOW,       /* COMMIT */
  64        GIT_COLOR_BG_RED,       /* WHITESPACE */
  65        GIT_COLOR_NORMAL,       /* FUNCINFO */
  66        GIT_COLOR_BOLD_MAGENTA, /* OLD_MOVED */
  67        GIT_COLOR_BOLD_BLUE,    /* OLD_MOVED ALTERNATIVE */
  68        GIT_COLOR_FAINT,        /* OLD_MOVED_DIM */
  69        GIT_COLOR_FAINT_ITALIC, /* OLD_MOVED_ALTERNATIVE_DIM */
  70        GIT_COLOR_BOLD_CYAN,    /* NEW_MOVED */
  71        GIT_COLOR_BOLD_YELLOW,  /* NEW_MOVED ALTERNATIVE */
  72        GIT_COLOR_FAINT,        /* NEW_MOVED_DIM */
  73        GIT_COLOR_FAINT_ITALIC, /* NEW_MOVED_ALTERNATIVE_DIM */
  74        GIT_COLOR_FAINT,        /* CONTEXT_DIM */
  75        GIT_COLOR_FAINT_RED,    /* OLD_DIM */
  76        GIT_COLOR_FAINT_GREEN,  /* NEW_DIM */
  77        GIT_COLOR_BOLD,         /* CONTEXT_BOLD */
  78        GIT_COLOR_BOLD_RED,     /* OLD_BOLD */
  79        GIT_COLOR_BOLD_GREEN,   /* NEW_BOLD */
  80};
  81
  82static const char *color_diff_slots[] = {
  83        [DIFF_CONTEXT]                = "context",
  84        [DIFF_METAINFO]               = "meta",
  85        [DIFF_FRAGINFO]               = "frag",
  86        [DIFF_FILE_OLD]               = "old",
  87        [DIFF_FILE_NEW]               = "new",
  88        [DIFF_COMMIT]                 = "commit",
  89        [DIFF_WHITESPACE]             = "whitespace",
  90        [DIFF_FUNCINFO]               = "func",
  91        [DIFF_FILE_OLD_MOVED]         = "oldMoved",
  92        [DIFF_FILE_OLD_MOVED_ALT]     = "oldMovedAlternative",
  93        [DIFF_FILE_OLD_MOVED_DIM]     = "oldMovedDimmed",
  94        [DIFF_FILE_OLD_MOVED_ALT_DIM] = "oldMovedAlternativeDimmed",
  95        [DIFF_FILE_NEW_MOVED]         = "newMoved",
  96        [DIFF_FILE_NEW_MOVED_ALT]     = "newMovedAlternative",
  97        [DIFF_FILE_NEW_MOVED_DIM]     = "newMovedDimmed",
  98        [DIFF_FILE_NEW_MOVED_ALT_DIM] = "newMovedAlternativeDimmed",
  99        [DIFF_CONTEXT_DIM]            = "contextDimmed",
 100        [DIFF_FILE_OLD_DIM]           = "oldDimmed",
 101        [DIFF_FILE_NEW_DIM]           = "newDimmed",
 102        [DIFF_CONTEXT_BOLD]           = "contextBold",
 103        [DIFF_FILE_OLD_BOLD]          = "oldBold",
 104        [DIFF_FILE_NEW_BOLD]          = "newBold",
 105};
 106
 107static NORETURN void die_want_option(const char *option_name)
 108{
 109        die(_("option '%s' requires a value"), option_name);
 110}
 111
 112define_list_config_array_extra(color_diff_slots, {"plain"});
 113
 114static int parse_diff_color_slot(const char *var)
 115{
 116        if (!strcasecmp(var, "plain"))
 117                return DIFF_CONTEXT;
 118        return LOOKUP_CONFIG(color_diff_slots, var);
 119}
 120
 121static int parse_dirstat_params(struct diff_options *options, const char *params_string,
 122                                struct strbuf *errmsg)
 123{
 124        char *params_copy = xstrdup(params_string);
 125        struct string_list params = STRING_LIST_INIT_NODUP;
 126        int ret = 0;
 127        int i;
 128
 129        if (*params_copy)
 130                string_list_split_in_place(&params, params_copy, ',', -1);
 131        for (i = 0; i < params.nr; i++) {
 132                const char *p = params.items[i].string;
 133                if (!strcmp(p, "changes")) {
 134                        options->flags.dirstat_by_line = 0;
 135                        options->flags.dirstat_by_file = 0;
 136                } else if (!strcmp(p, "lines")) {
 137                        options->flags.dirstat_by_line = 1;
 138                        options->flags.dirstat_by_file = 0;
 139                } else if (!strcmp(p, "files")) {
 140                        options->flags.dirstat_by_line = 0;
 141                        options->flags.dirstat_by_file = 1;
 142                } else if (!strcmp(p, "noncumulative")) {
 143                        options->flags.dirstat_cumulative = 0;
 144                } else if (!strcmp(p, "cumulative")) {
 145                        options->flags.dirstat_cumulative = 1;
 146                } else if (isdigit(*p)) {
 147                        char *end;
 148                        int permille = strtoul(p, &end, 10) * 10;
 149                        if (*end == '.' && isdigit(*++end)) {
 150                                /* only use first digit */
 151                                permille += *end - '0';
 152                                /* .. and ignore any further digits */
 153                                while (isdigit(*++end))
 154                                        ; /* nothing */
 155                        }
 156                        if (!*end)
 157                                options->dirstat_permille = permille;
 158                        else {
 159                                strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%s'\n"),
 160                                            p);
 161                                ret++;
 162                        }
 163                } else {
 164                        strbuf_addf(errmsg, _("  Unknown dirstat parameter '%s'\n"), p);
 165                        ret++;
 166                }
 167
 168        }
 169        string_list_clear(&params, 0);
 170        free(params_copy);
 171        return ret;
 172}
 173
 174static int parse_submodule_params(struct diff_options *options, const char *value)
 175{
 176        if (!strcmp(value, "log"))
 177                options->submodule_format = DIFF_SUBMODULE_LOG;
 178        else if (!strcmp(value, "short"))
 179                options->submodule_format = DIFF_SUBMODULE_SHORT;
 180        else if (!strcmp(value, "diff"))
 181                options->submodule_format = DIFF_SUBMODULE_INLINE_DIFF;
 182        else
 183                return -1;
 184        return 0;
 185}
 186
 187int git_config_rename(const char *var, const char *value)
 188{
 189        if (!value)
 190                return DIFF_DETECT_RENAME;
 191        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 192                return  DIFF_DETECT_COPY;
 193        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 194}
 195
 196long parse_algorithm_value(const char *value)
 197{
 198        if (!value)
 199                return -1;
 200        else if (!strcasecmp(value, "myers") || !strcasecmp(value, "default"))
 201                return 0;
 202        else if (!strcasecmp(value, "minimal"))
 203                return XDF_NEED_MINIMAL;
 204        else if (!strcasecmp(value, "patience"))
 205                return XDF_PATIENCE_DIFF;
 206        else if (!strcasecmp(value, "histogram"))
 207                return XDF_HISTOGRAM_DIFF;
 208        return -1;
 209}
 210
 211static int parse_one_token(const char **arg, const char *token)
 212{
 213        const char *rest;
 214        if (skip_prefix(*arg, token, &rest) && (!*rest || *rest == ',')) {
 215                *arg = rest;
 216                return 1;
 217        }
 218        return 0;
 219}
 220
 221static int parse_ws_error_highlight(const char *arg)
 222{
 223        const char *orig_arg = arg;
 224        unsigned val = 0;
 225
 226        while (*arg) {
 227                if (parse_one_token(&arg, "none"))
 228                        val = 0;
 229                else if (parse_one_token(&arg, "default"))
 230                        val = WSEH_NEW;
 231                else if (parse_one_token(&arg, "all"))
 232                        val = WSEH_NEW | WSEH_OLD | WSEH_CONTEXT;
 233                else if (parse_one_token(&arg, "new"))
 234                        val |= WSEH_NEW;
 235                else if (parse_one_token(&arg, "old"))
 236                        val |= WSEH_OLD;
 237                else if (parse_one_token(&arg, "context"))
 238                        val |= WSEH_CONTEXT;
 239                else {
 240                        return -1 - (int)(arg - orig_arg);
 241                }
 242                if (*arg)
 243                        arg++;
 244        }
 245        return val;
 246}
 247
 248/*
 249 * These are to give UI layer defaults.
 250 * The core-level commands such as git-diff-files should
 251 * never be affected by the setting of diff.renames
 252 * the user happens to have in the configuration file.
 253 */
 254void init_diff_ui_defaults(void)
 255{
 256        diff_detect_rename_default = DIFF_DETECT_RENAME;
 257}
 258
 259int git_diff_heuristic_config(const char *var, const char *value, void *cb)
 260{
 261        if (!strcmp(var, "diff.indentheuristic"))
 262                diff_indent_heuristic = git_config_bool(var, value);
 263        return 0;
 264}
 265
 266static int parse_color_moved(const char *arg)
 267{
 268        switch (git_parse_maybe_bool(arg)) {
 269        case 0:
 270                return COLOR_MOVED_NO;
 271        case 1:
 272                return COLOR_MOVED_DEFAULT;
 273        default:
 274                break;
 275        }
 276
 277        if (!strcmp(arg, "no"))
 278                return COLOR_MOVED_NO;
 279        else if (!strcmp(arg, "plain"))
 280                return COLOR_MOVED_PLAIN;
 281        else if (!strcmp(arg, "blocks"))
 282                return COLOR_MOVED_BLOCKS;
 283        else if (!strcmp(arg, "zebra"))
 284                return COLOR_MOVED_ZEBRA;
 285        else if (!strcmp(arg, "default"))
 286                return COLOR_MOVED_DEFAULT;
 287        else if (!strcmp(arg, "dimmed-zebra"))
 288                return COLOR_MOVED_ZEBRA_DIM;
 289        else if (!strcmp(arg, "dimmed_zebra"))
 290                return COLOR_MOVED_ZEBRA_DIM;
 291        else
 292                return error(_("color moved setting must be one of 'no', 'default', 'blocks', 'zebra', 'dimmed-zebra', 'plain'"));
 293}
 294
 295static unsigned parse_color_moved_ws(const char *arg)
 296{
 297        int ret = 0;
 298        struct string_list l = STRING_LIST_INIT_DUP;
 299        struct string_list_item *i;
 300
 301        string_list_split(&l, arg, ',', -1);
 302
 303        for_each_string_list_item(i, &l) {
 304                struct strbuf sb = STRBUF_INIT;
 305                strbuf_addstr(&sb, i->string);
 306                strbuf_trim(&sb);
 307
 308                if (!strcmp(sb.buf, "ignore-space-change"))
 309                        ret |= XDF_IGNORE_WHITESPACE_CHANGE;
 310                else if (!strcmp(sb.buf, "ignore-space-at-eol"))
 311                        ret |= XDF_IGNORE_WHITESPACE_AT_EOL;
 312                else if (!strcmp(sb.buf, "ignore-all-space"))
 313                        ret |= XDF_IGNORE_WHITESPACE;
 314                else if (!strcmp(sb.buf, "allow-indentation-change"))
 315                        ret |= COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE;
 316                else {
 317                        ret |= COLOR_MOVED_WS_ERROR;
 318                        error(_("unknown color-moved-ws mode '%s', possible values are 'ignore-space-change', 'ignore-space-at-eol', 'ignore-all-space', 'allow-indentation-change'"), sb.buf);
 319                }
 320
 321                strbuf_release(&sb);
 322        }
 323
 324        if ((ret & COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) &&
 325            (ret & XDF_WHITESPACE_FLAGS)) {
 326                error(_("color-moved-ws: allow-indentation-change cannot be combined with other white space modes"));
 327                ret |= COLOR_MOVED_WS_ERROR;
 328        }
 329
 330        string_list_clear(&l, 0);
 331
 332        return ret;
 333}
 334
 335int git_diff_ui_config(const char *var, const char *value, void *cb)
 336{
 337        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 338                diff_use_color_default = git_config_colorbool(var, value);
 339                return 0;
 340        }
 341        if (!strcmp(var, "diff.colormoved")) {
 342                int cm = parse_color_moved(value);
 343                if (cm < 0)
 344                        return -1;
 345                diff_color_moved_default = cm;
 346                return 0;
 347        }
 348        if (!strcmp(var, "diff.colormovedws")) {
 349                unsigned cm = parse_color_moved_ws(value);
 350                if (cm & COLOR_MOVED_WS_ERROR)
 351                        return -1;
 352                diff_color_moved_ws_default = cm;
 353                return 0;
 354        }
 355        if (!strcmp(var, "diff.context")) {
 356                diff_context_default = git_config_int(var, value);
 357                if (diff_context_default < 0)
 358                        return -1;
 359                return 0;
 360        }
 361        if (!strcmp(var, "diff.interhunkcontext")) {
 362                diff_interhunk_context_default = git_config_int(var, value);
 363                if (diff_interhunk_context_default < 0)
 364                        return -1;
 365                return 0;
 366        }
 367        if (!strcmp(var, "diff.renames")) {
 368                diff_detect_rename_default = git_config_rename(var, value);
 369                return 0;
 370        }
 371        if (!strcmp(var, "diff.autorefreshindex")) {
 372                diff_auto_refresh_index = git_config_bool(var, value);
 373                return 0;
 374        }
 375        if (!strcmp(var, "diff.mnemonicprefix")) {
 376                diff_mnemonic_prefix = git_config_bool(var, value);
 377                return 0;
 378        }
 379        if (!strcmp(var, "diff.noprefix")) {
 380                diff_no_prefix = git_config_bool(var, value);
 381                return 0;
 382        }
 383        if (!strcmp(var, "diff.statgraphwidth")) {
 384                diff_stat_graph_width = git_config_int(var, value);
 385                return 0;
 386        }
 387        if (!strcmp(var, "diff.external"))
 388                return git_config_string(&external_diff_cmd_cfg, var, value);
 389        if (!strcmp(var, "diff.wordregex"))
 390                return git_config_string(&diff_word_regex_cfg, var, value);
 391        if (!strcmp(var, "diff.orderfile"))
 392                return git_config_pathname(&diff_order_file_cfg, var, value);
 393
 394        if (!strcmp(var, "diff.ignoresubmodules"))
 395                handle_ignore_submodules_arg(&default_diff_options, value);
 396
 397        if (!strcmp(var, "diff.submodule")) {
 398                if (parse_submodule_params(&default_diff_options, value))
 399                        warning(_("Unknown value for 'diff.submodule' config variable: '%s'"),
 400                                value);
 401                return 0;
 402        }
 403
 404        if (!strcmp(var, "diff.algorithm")) {
 405                diff_algorithm = parse_algorithm_value(value);
 406                if (diff_algorithm < 0)
 407                        return -1;
 408                return 0;
 409        }
 410
 411        if (!strcmp(var, "diff.wserrorhighlight")) {
 412                int val = parse_ws_error_highlight(value);
 413                if (val < 0)
 414                        return -1;
 415                ws_error_highlight_default = val;
 416                return 0;
 417        }
 418
 419        if (git_color_config(var, value, cb) < 0)
 420                return -1;
 421
 422        return git_diff_basic_config(var, value, cb);
 423}
 424
 425int git_diff_basic_config(const char *var, const char *value, void *cb)
 426{
 427        const char *name;
 428
 429        if (!strcmp(var, "diff.renamelimit")) {
 430                diff_rename_limit_default = git_config_int(var, value);
 431                return 0;
 432        }
 433
 434        if (userdiff_config(var, value) < 0)
 435                return -1;
 436
 437        if (skip_prefix(var, "diff.color.", &name) ||
 438            skip_prefix(var, "color.diff.", &name)) {
 439                int slot = parse_diff_color_slot(name);
 440                if (slot < 0)
 441                        return 0;
 442                if (!value)
 443                        return config_error_nonbool(var);
 444                return color_parse(value, diff_colors[slot]);
 445        }
 446
 447        /* like GNU diff's --suppress-blank-empty option  */
 448        if (!strcmp(var, "diff.suppressblankempty") ||
 449                        /* for backwards compatibility */
 450                        !strcmp(var, "diff.suppress-blank-empty")) {
 451                diff_suppress_blank_empty = git_config_bool(var, value);
 452                return 0;
 453        }
 454
 455        if (!strcmp(var, "diff.dirstat")) {
 456                struct strbuf errmsg = STRBUF_INIT;
 457                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 458                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 459                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 460                                errmsg.buf);
 461                strbuf_release(&errmsg);
 462                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 463                return 0;
 464        }
 465
 466        if (git_diff_heuristic_config(var, value, cb) < 0)
 467                return -1;
 468
 469        return git_default_config(var, value, cb);
 470}
 471
 472static char *quote_two(const char *one, const char *two)
 473{
 474        int need_one = quote_c_style(one, NULL, NULL, 1);
 475        int need_two = quote_c_style(two, NULL, NULL, 1);
 476        struct strbuf res = STRBUF_INIT;
 477
 478        if (need_one + need_two) {
 479                strbuf_addch(&res, '"');
 480                quote_c_style(one, &res, NULL, 1);
 481                quote_c_style(two, &res, NULL, 1);
 482                strbuf_addch(&res, '"');
 483        } else {
 484                strbuf_addstr(&res, one);
 485                strbuf_addstr(&res, two);
 486        }
 487        return strbuf_detach(&res, NULL);
 488}
 489
 490static const char *external_diff(void)
 491{
 492        static const char *external_diff_cmd = NULL;
 493        static int done_preparing = 0;
 494
 495        if (done_preparing)
 496                return external_diff_cmd;
 497        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 498        if (!external_diff_cmd)
 499                external_diff_cmd = external_diff_cmd_cfg;
 500        done_preparing = 1;
 501        return external_diff_cmd;
 502}
 503
 504/*
 505 * Keep track of files used for diffing. Sometimes such an entry
 506 * refers to a temporary file, sometimes to an existing file, and
 507 * sometimes to "/dev/null".
 508 */
 509static struct diff_tempfile {
 510        /*
 511         * filename external diff should read from, or NULL if this
 512         * entry is currently not in use:
 513         */
 514        const char *name;
 515
 516        char hex[GIT_MAX_HEXSZ + 1];
 517        char mode[10];
 518
 519        /*
 520         * If this diff_tempfile instance refers to a temporary file,
 521         * this tempfile object is used to manage its lifetime.
 522         */
 523        struct tempfile *tempfile;
 524} diff_temp[2];
 525
 526struct emit_callback {
 527        int color_diff;
 528        unsigned ws_rule;
 529        int blank_at_eof_in_preimage;
 530        int blank_at_eof_in_postimage;
 531        int lno_in_preimage;
 532        int lno_in_postimage;
 533        const char **label_path;
 534        struct diff_words_data *diff_words;
 535        struct diff_options *opt;
 536        struct strbuf *header;
 537};
 538
 539static int count_lines(const char *data, int size)
 540{
 541        int count, ch, completely_empty = 1, nl_just_seen = 0;
 542        count = 0;
 543        while (0 < size--) {
 544                ch = *data++;
 545                if (ch == '\n') {
 546                        count++;
 547                        nl_just_seen = 1;
 548                        completely_empty = 0;
 549                }
 550                else {
 551                        nl_just_seen = 0;
 552                        completely_empty = 0;
 553                }
 554        }
 555        if (completely_empty)
 556                return 0;
 557        if (!nl_just_seen)
 558                count++; /* no trailing newline */
 559        return count;
 560}
 561
 562static int fill_mmfile(struct repository *r, mmfile_t *mf,
 563                       struct diff_filespec *one)
 564{
 565        if (!DIFF_FILE_VALID(one)) {
 566                mf->ptr = (char *)""; /* does not matter */
 567                mf->size = 0;
 568                return 0;
 569        }
 570        else if (diff_populate_filespec(r, one, 0))
 571                return -1;
 572
 573        mf->ptr = one->data;
 574        mf->size = one->size;
 575        return 0;
 576}
 577
 578/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 579static unsigned long diff_filespec_size(struct repository *r,
 580                                        struct diff_filespec *one)
 581{
 582        if (!DIFF_FILE_VALID(one))
 583                return 0;
 584        diff_populate_filespec(r, one, CHECK_SIZE_ONLY);
 585        return one->size;
 586}
 587
 588static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 589{
 590        char *ptr = mf->ptr;
 591        long size = mf->size;
 592        int cnt = 0;
 593
 594        if (!size)
 595                return cnt;
 596        ptr += size - 1; /* pointing at the very end */
 597        if (*ptr != '\n')
 598                ; /* incomplete line */
 599        else
 600                ptr--; /* skip the last LF */
 601        while (mf->ptr < ptr) {
 602                char *prev_eol;
 603                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 604                        if (*prev_eol == '\n')
 605                                break;
 606                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 607                        break;
 608                cnt++;
 609                ptr = prev_eol - 1;
 610        }
 611        return cnt;
 612}
 613
 614static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 615                               struct emit_callback *ecbdata)
 616{
 617        int l1, l2, at;
 618        unsigned ws_rule = ecbdata->ws_rule;
 619        l1 = count_trailing_blank(mf1, ws_rule);
 620        l2 = count_trailing_blank(mf2, ws_rule);
 621        if (l2 <= l1) {
 622                ecbdata->blank_at_eof_in_preimage = 0;
 623                ecbdata->blank_at_eof_in_postimage = 0;
 624                return;
 625        }
 626        at = count_lines(mf1->ptr, mf1->size);
 627        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 628
 629        at = count_lines(mf2->ptr, mf2->size);
 630        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 631}
 632
 633static void emit_line_0(struct diff_options *o,
 634                        const char *set_sign, const char *set, unsigned reverse, const char *reset,
 635                        int first, const char *line, int len)
 636{
 637        int has_trailing_newline, has_trailing_carriage_return;
 638        int needs_reset = 0; /* at the end of the line */
 639        FILE *file = o->file;
 640
 641        fputs(diff_line_prefix(o), file);
 642
 643        has_trailing_newline = (len > 0 && line[len-1] == '\n');
 644        if (has_trailing_newline)
 645                len--;
 646
 647        has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 648        if (has_trailing_carriage_return)
 649                len--;
 650
 651        if (!len && !first)
 652                goto end_of_line;
 653
 654        if (reverse && want_color(o->use_color)) {
 655                fputs(GIT_COLOR_REVERSE, file);
 656                needs_reset = 1;
 657        }
 658
 659        if (set_sign) {
 660                fputs(set_sign, file);
 661                needs_reset = 1;
 662        }
 663
 664        if (first)
 665                fputc(first, file);
 666
 667        if (!len)
 668                goto end_of_line;
 669
 670        if (set) {
 671                if (set_sign && set != set_sign)
 672                        fputs(reset, file);
 673                fputs(set, file);
 674                needs_reset = 1;
 675        }
 676        fwrite(line, len, 1, file);
 677        needs_reset = 1; /* 'line' may contain color codes. */
 678
 679end_of_line:
 680        if (needs_reset)
 681                fputs(reset, file);
 682        if (has_trailing_carriage_return)
 683                fputc('\r', file);
 684        if (has_trailing_newline)
 685                fputc('\n', file);
 686}
 687
 688static void emit_line(struct diff_options *o, const char *set, const char *reset,
 689                      const char *line, int len)
 690{
 691        emit_line_0(o, set, NULL, 0, reset, 0, line, len);
 692}
 693
 694enum diff_symbol {
 695        DIFF_SYMBOL_BINARY_DIFF_HEADER,
 696        DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
 697        DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
 698        DIFF_SYMBOL_BINARY_DIFF_BODY,
 699        DIFF_SYMBOL_BINARY_DIFF_FOOTER,
 700        DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
 701        DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
 702        DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
 703        DIFF_SYMBOL_STATS_LINE,
 704        DIFF_SYMBOL_WORD_DIFF,
 705        DIFF_SYMBOL_STAT_SEP,
 706        DIFF_SYMBOL_SUMMARY,
 707        DIFF_SYMBOL_SUBMODULE_ADD,
 708        DIFF_SYMBOL_SUBMODULE_DEL,
 709        DIFF_SYMBOL_SUBMODULE_UNTRACKED,
 710        DIFF_SYMBOL_SUBMODULE_MODIFIED,
 711        DIFF_SYMBOL_SUBMODULE_HEADER,
 712        DIFF_SYMBOL_SUBMODULE_ERROR,
 713        DIFF_SYMBOL_SUBMODULE_PIPETHROUGH,
 714        DIFF_SYMBOL_REWRITE_DIFF,
 715        DIFF_SYMBOL_BINARY_FILES,
 716        DIFF_SYMBOL_HEADER,
 717        DIFF_SYMBOL_FILEPAIR_PLUS,
 718        DIFF_SYMBOL_FILEPAIR_MINUS,
 719        DIFF_SYMBOL_WORDS_PORCELAIN,
 720        DIFF_SYMBOL_WORDS,
 721        DIFF_SYMBOL_CONTEXT,
 722        DIFF_SYMBOL_CONTEXT_INCOMPLETE,
 723        DIFF_SYMBOL_PLUS,
 724        DIFF_SYMBOL_MINUS,
 725        DIFF_SYMBOL_NO_LF_EOF,
 726        DIFF_SYMBOL_CONTEXT_FRAGINFO,
 727        DIFF_SYMBOL_CONTEXT_MARKER,
 728        DIFF_SYMBOL_SEPARATOR
 729};
 730/*
 731 * Flags for content lines:
 732 * 0..12 are whitespace rules
 733 * 13-15 are WSEH_NEW | WSEH_OLD | WSEH_CONTEXT
 734 * 16 is marking if the line is blank at EOF
 735 */
 736#define DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF      (1<<16)
 737#define DIFF_SYMBOL_MOVED_LINE                  (1<<17)
 738#define DIFF_SYMBOL_MOVED_LINE_ALT              (1<<18)
 739#define DIFF_SYMBOL_MOVED_LINE_UNINTERESTING    (1<<19)
 740#define DIFF_SYMBOL_CONTENT_WS_MASK (WSEH_NEW | WSEH_OLD | WSEH_CONTEXT | WS_RULE_MASK)
 741
 742/*
 743 * This struct is used when we need to buffer the output of the diff output.
 744 *
 745 * NEEDSWORK: Instead of storing a copy of the line, add an offset pointer
 746 * into the pre/post image file. This pointer could be a union with the
 747 * line pointer. By storing an offset into the file instead of the literal line,
 748 * we can decrease the memory footprint for the buffered output. At first we
 749 * may want to only have indirection for the content lines, but we could also
 750 * enhance the state for emitting prefabricated lines, e.g. the similarity
 751 * score line or hunk/file headers would only need to store a number or path
 752 * and then the output can be constructed later on depending on state.
 753 */
 754struct emitted_diff_symbol {
 755        const char *line;
 756        int len;
 757        int flags;
 758        enum diff_symbol s;
 759};
 760#define EMITTED_DIFF_SYMBOL_INIT {NULL}
 761
 762struct emitted_diff_symbols {
 763        struct emitted_diff_symbol *buf;
 764        int nr, alloc;
 765};
 766#define EMITTED_DIFF_SYMBOLS_INIT {NULL, 0, 0}
 767
 768static void append_emitted_diff_symbol(struct diff_options *o,
 769                                       struct emitted_diff_symbol *e)
 770{
 771        struct emitted_diff_symbol *f;
 772
 773        ALLOC_GROW(o->emitted_symbols->buf,
 774                   o->emitted_symbols->nr + 1,
 775                   o->emitted_symbols->alloc);
 776        f = &o->emitted_symbols->buf[o->emitted_symbols->nr++];
 777
 778        memcpy(f, e, sizeof(struct emitted_diff_symbol));
 779        f->line = e->line ? xmemdupz(e->line, e->len) : NULL;
 780}
 781
 782struct moved_entry {
 783        struct hashmap_entry ent;
 784        const struct emitted_diff_symbol *es;
 785        struct moved_entry *next_line;
 786};
 787
 788/**
 789 * The struct ws_delta holds white space differences between moved lines, i.e.
 790 * between '+' and '-' lines that have been detected to be a move.
 791 * The string contains the difference in leading white spaces, before the
 792 * rest of the line is compared using the white space config for move
 793 * coloring. The current_longer indicates if the first string in the
 794 * comparision is longer than the second.
 795 */
 796struct ws_delta {
 797        char *string;
 798        unsigned int current_longer : 1;
 799};
 800#define WS_DELTA_INIT { NULL, 0 }
 801
 802struct moved_block {
 803        struct moved_entry *match;
 804        struct ws_delta wsd;
 805};
 806
 807static void moved_block_clear(struct moved_block *b)
 808{
 809        FREE_AND_NULL(b->wsd.string);
 810        b->match = NULL;
 811}
 812
 813static int compute_ws_delta(const struct emitted_diff_symbol *a,
 814                             const struct emitted_diff_symbol *b,
 815                             struct ws_delta *out)
 816{
 817        const struct emitted_diff_symbol *longer =  a->len > b->len ? a : b;
 818        const struct emitted_diff_symbol *shorter = a->len > b->len ? b : a;
 819        int d = longer->len - shorter->len;
 820
 821        if (strncmp(longer->line + d, shorter->line, shorter->len))
 822                return 0;
 823
 824        out->string = xmemdupz(longer->line, d);
 825        out->current_longer = (a == longer);
 826
 827        return 1;
 828}
 829
 830static int cmp_in_block_with_wsd(const struct diff_options *o,
 831                                 const struct moved_entry *cur,
 832                                 const struct moved_entry *match,
 833                                 struct moved_block *pmb,
 834                                 int n)
 835{
 836        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
 837        int al = cur->es->len, cl = l->len;
 838        const char *a = cur->es->line,
 839                   *b = match->es->line,
 840                   *c = l->line;
 841
 842        int wslen;
 843
 844        /*
 845         * We need to check if 'cur' is equal to 'match'.
 846         * As those are from the same (+/-) side, we do not need to adjust for
 847         * indent changes. However these were found using fuzzy matching
 848         * so we do have to check if they are equal.
 849         */
 850        if (strcmp(a, b))
 851                return 1;
 852
 853        if (!pmb->wsd.string)
 854                /*
 855                 * The white space delta is not active? This can happen
 856                 * when we exit early in this function.
 857                 */
 858                return 1;
 859
 860        /*
 861         * The indent changes of the block are known and stored in
 862         * pmb->wsd; however we need to check if the indent changes of the
 863         * current line are still the same as before.
 864         *
 865         * To do so we need to compare 'l' to 'cur', adjusting the
 866         * one of them for the white spaces, depending which was longer.
 867         */
 868
 869        wslen = strlen(pmb->wsd.string);
 870        if (pmb->wsd.current_longer) {
 871                c += wslen;
 872                cl -= wslen;
 873        } else {
 874                a += wslen;
 875                al -= wslen;
 876        }
 877
 878        if (al != cl || memcmp(a, c, al))
 879                return 1;
 880
 881        return 0;
 882}
 883
 884static int moved_entry_cmp(const void *hashmap_cmp_fn_data,
 885                           const void *entry,
 886                           const void *entry_or_key,
 887                           const void *keydata)
 888{
 889        const struct diff_options *diffopt = hashmap_cmp_fn_data;
 890        const struct moved_entry *a = entry;
 891        const struct moved_entry *b = entry_or_key;
 892        unsigned flags = diffopt->color_moved_ws_handling
 893                         & XDF_WHITESPACE_FLAGS;
 894
 895        if (diffopt->color_moved_ws_handling &
 896            COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
 897                /*
 898                 * As there is not specific white space config given,
 899                 * we'd need to check for a new block, so ignore all
 900                 * white space. The setup of the white space
 901                 * configuration for the next block is done else where
 902                 */
 903                flags |= XDF_IGNORE_WHITESPACE;
 904
 905        return !xdiff_compare_lines(a->es->line, a->es->len,
 906                                    b->es->line, b->es->len,
 907                                    flags);
 908}
 909
 910static struct moved_entry *prepare_entry(struct diff_options *o,
 911                                         int line_no)
 912{
 913        struct moved_entry *ret = xmalloc(sizeof(*ret));
 914        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[line_no];
 915        unsigned flags = o->color_moved_ws_handling & XDF_WHITESPACE_FLAGS;
 916
 917        ret->ent.hash = xdiff_hash_string(l->line, l->len, flags);
 918        ret->es = l;
 919        ret->next_line = NULL;
 920
 921        return ret;
 922}
 923
 924static void add_lines_to_move_detection(struct diff_options *o,
 925                                        struct hashmap *add_lines,
 926                                        struct hashmap *del_lines)
 927{
 928        struct moved_entry *prev_line = NULL;
 929
 930        int n;
 931        for (n = 0; n < o->emitted_symbols->nr; n++) {
 932                struct hashmap *hm;
 933                struct moved_entry *key;
 934
 935                switch (o->emitted_symbols->buf[n].s) {
 936                case DIFF_SYMBOL_PLUS:
 937                        hm = add_lines;
 938                        break;
 939                case DIFF_SYMBOL_MINUS:
 940                        hm = del_lines;
 941                        break;
 942                default:
 943                        prev_line = NULL;
 944                        continue;
 945                }
 946
 947                key = prepare_entry(o, n);
 948                if (prev_line && prev_line->es->s == o->emitted_symbols->buf[n].s)
 949                        prev_line->next_line = key;
 950
 951                hashmap_add(hm, key);
 952                prev_line = key;
 953        }
 954}
 955
 956static void pmb_advance_or_null(struct diff_options *o,
 957                                struct moved_entry *match,
 958                                struct hashmap *hm,
 959                                struct moved_block *pmb,
 960                                int pmb_nr)
 961{
 962        int i;
 963        for (i = 0; i < pmb_nr; i++) {
 964                struct moved_entry *prev = pmb[i].match;
 965                struct moved_entry *cur = (prev && prev->next_line) ?
 966                                prev->next_line : NULL;
 967                if (cur && !hm->cmpfn(o, cur, match, NULL)) {
 968                        pmb[i].match = cur;
 969                } else {
 970                        pmb[i].match = NULL;
 971                }
 972        }
 973}
 974
 975static void pmb_advance_or_null_multi_match(struct diff_options *o,
 976                                            struct moved_entry *match,
 977                                            struct hashmap *hm,
 978                                            struct moved_block *pmb,
 979                                            int pmb_nr, int n)
 980{
 981        int i;
 982        char *got_match = xcalloc(1, pmb_nr);
 983
 984        for (; match; match = hashmap_get_next(hm, match)) {
 985                for (i = 0; i < pmb_nr; i++) {
 986                        struct moved_entry *prev = pmb[i].match;
 987                        struct moved_entry *cur = (prev && prev->next_line) ?
 988                                        prev->next_line : NULL;
 989                        if (!cur)
 990                                continue;
 991                        if (!cmp_in_block_with_wsd(o, cur, match, &pmb[i], n))
 992                                got_match[i] |= 1;
 993                }
 994        }
 995
 996        for (i = 0; i < pmb_nr; i++) {
 997                if (got_match[i]) {
 998                        /* Advance to the next line */
 999                        pmb[i].match = pmb[i].match->next_line;
1000                } else {
1001                        moved_block_clear(&pmb[i]);
1002                }
1003        }
1004
1005        free(got_match);
1006}
1007
1008static int shrink_potential_moved_blocks(struct moved_block *pmb,
1009                                         int pmb_nr)
1010{
1011        int lp, rp;
1012
1013        /* Shrink the set of potential block to the remaining running */
1014        for (lp = 0, rp = pmb_nr - 1; lp <= rp;) {
1015                while (lp < pmb_nr && pmb[lp].match)
1016                        lp++;
1017                /* lp points at the first NULL now */
1018
1019                while (rp > -1 && !pmb[rp].match)
1020                        rp--;
1021                /* rp points at the last non-NULL */
1022
1023                if (lp < pmb_nr && rp > -1 && lp < rp) {
1024                        pmb[lp] = pmb[rp];
1025                        pmb[rp].match = NULL;
1026                        pmb[rp].wsd.string = NULL;
1027                        rp--;
1028                        lp++;
1029                }
1030        }
1031
1032        /* Remember the number of running sets */
1033        return rp + 1;
1034}
1035
1036/*
1037 * If o->color_moved is COLOR_MOVED_PLAIN, this function does nothing.
1038 *
1039 * Otherwise, if the last block has fewer alphanumeric characters than
1040 * COLOR_MOVED_MIN_ALNUM_COUNT, unset DIFF_SYMBOL_MOVED_LINE on all lines in
1041 * that block.
1042 *
1043 * The last block consists of the (n - block_length)'th line up to but not
1044 * including the nth line.
1045 *
1046 * NEEDSWORK: This uses the same heuristic as blame_entry_score() in blame.c.
1047 * Think of a way to unify them.
1048 */
1049static void adjust_last_block(struct diff_options *o, int n, int block_length)
1050{
1051        int i, alnum_count = 0;
1052        if (o->color_moved == COLOR_MOVED_PLAIN)
1053                return;
1054        for (i = 1; i < block_length + 1; i++) {
1055                const char *c = o->emitted_symbols->buf[n - i].line;
1056                for (; *c; c++) {
1057                        if (!isalnum(*c))
1058                                continue;
1059                        alnum_count++;
1060                        if (alnum_count >= COLOR_MOVED_MIN_ALNUM_COUNT)
1061                                return;
1062                }
1063        }
1064        for (i = 1; i < block_length + 1; i++)
1065                o->emitted_symbols->buf[n - i].flags &= ~DIFF_SYMBOL_MOVED_LINE;
1066}
1067
1068/* Find blocks of moved code, delegate actual coloring decision to helper */
1069static void mark_color_as_moved(struct diff_options *o,
1070                                struct hashmap *add_lines,
1071                                struct hashmap *del_lines)
1072{
1073        struct moved_block *pmb = NULL; /* potentially moved blocks */
1074        int pmb_nr = 0, pmb_alloc = 0;
1075        int n, flipped_block = 1, block_length = 0;
1076
1077
1078        for (n = 0; n < o->emitted_symbols->nr; n++) {
1079                struct hashmap *hm = NULL;
1080                struct moved_entry *key;
1081                struct moved_entry *match = NULL;
1082                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
1083
1084                switch (l->s) {
1085                case DIFF_SYMBOL_PLUS:
1086                        hm = del_lines;
1087                        key = prepare_entry(o, n);
1088                        match = hashmap_get(hm, key, NULL);
1089                        free(key);
1090                        break;
1091                case DIFF_SYMBOL_MINUS:
1092                        hm = add_lines;
1093                        key = prepare_entry(o, n);
1094                        match = hashmap_get(hm, key, NULL);
1095                        free(key);
1096                        break;
1097                default:
1098                        flipped_block = 1;
1099                }
1100
1101                if (!match) {
1102                        int i;
1103
1104                        adjust_last_block(o, n, block_length);
1105                        for(i = 0; i < pmb_nr; i++)
1106                                moved_block_clear(&pmb[i]);
1107                        pmb_nr = 0;
1108                        block_length = 0;
1109                        continue;
1110                }
1111
1112                l->flags |= DIFF_SYMBOL_MOVED_LINE;
1113
1114                if (o->color_moved == COLOR_MOVED_PLAIN)
1115                        continue;
1116
1117                if (o->color_moved_ws_handling &
1118                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
1119                        pmb_advance_or_null_multi_match(o, match, hm, pmb, pmb_nr, n);
1120                else
1121                        pmb_advance_or_null(o, match, hm, pmb, pmb_nr);
1122
1123                pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
1124
1125                if (pmb_nr == 0) {
1126                        /*
1127                         * The current line is the start of a new block.
1128                         * Setup the set of potential blocks.
1129                         */
1130                        for (; match; match = hashmap_get_next(hm, match)) {
1131                                ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
1132                                if (o->color_moved_ws_handling &
1133                                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) {
1134                                        if (compute_ws_delta(l, match->es,
1135                                                             &pmb[pmb_nr].wsd))
1136                                                pmb[pmb_nr++].match = match;
1137                                } else {
1138                                        pmb[pmb_nr].wsd.string = NULL;
1139                                        pmb[pmb_nr++].match = match;
1140                                }
1141                        }
1142
1143                        flipped_block = (flipped_block + 1) % 2;
1144
1145                        adjust_last_block(o, n, block_length);
1146                        block_length = 0;
1147                }
1148
1149                block_length++;
1150
1151                if (flipped_block && o->color_moved != COLOR_MOVED_BLOCKS)
1152                        l->flags |= DIFF_SYMBOL_MOVED_LINE_ALT;
1153        }
1154        adjust_last_block(o, n, block_length);
1155
1156        for(n = 0; n < pmb_nr; n++)
1157                moved_block_clear(&pmb[n]);
1158        free(pmb);
1159}
1160
1161#define DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK \
1162  (DIFF_SYMBOL_MOVED_LINE | DIFF_SYMBOL_MOVED_LINE_ALT)
1163static void dim_moved_lines(struct diff_options *o)
1164{
1165        int n;
1166        for (n = 0; n < o->emitted_symbols->nr; n++) {
1167                struct emitted_diff_symbol *prev = (n != 0) ?
1168                                &o->emitted_symbols->buf[n - 1] : NULL;
1169                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
1170                struct emitted_diff_symbol *next =
1171                                (n < o->emitted_symbols->nr - 1) ?
1172                                &o->emitted_symbols->buf[n + 1] : NULL;
1173
1174                /* Not a plus or minus line? */
1175                if (l->s != DIFF_SYMBOL_PLUS && l->s != DIFF_SYMBOL_MINUS)
1176                        continue;
1177
1178                /* Not a moved line? */
1179                if (!(l->flags & DIFF_SYMBOL_MOVED_LINE))
1180                        continue;
1181
1182                /*
1183                 * If prev or next are not a plus or minus line,
1184                 * pretend they don't exist
1185                 */
1186                if (prev && prev->s != DIFF_SYMBOL_PLUS &&
1187                            prev->s != DIFF_SYMBOL_MINUS)
1188                        prev = NULL;
1189                if (next && next->s != DIFF_SYMBOL_PLUS &&
1190                            next->s != DIFF_SYMBOL_MINUS)
1191                        next = NULL;
1192
1193                /* Inside a block? */
1194                if ((prev &&
1195                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
1196                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK)) &&
1197                    (next &&
1198                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
1199                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK))) {
1200                        l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1201                        continue;
1202                }
1203
1204                /* Check if we are at an interesting bound: */
1205                if (prev && (prev->flags & DIFF_SYMBOL_MOVED_LINE) &&
1206                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1207                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1208                        continue;
1209                if (next && (next->flags & DIFF_SYMBOL_MOVED_LINE) &&
1210                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1211                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1212                        continue;
1213
1214                /*
1215                 * The boundary to prev and next are not interesting,
1216                 * so this line is not interesting as a whole
1217                 */
1218                l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1219        }
1220}
1221
1222static void emit_line_ws_markup(struct diff_options *o,
1223                                const char *set_sign, const char *set,
1224                                const char *reset,
1225                                int sign_index, const char *line, int len,
1226                                unsigned ws_rule, int blank_at_eof)
1227{
1228        const char *ws = NULL;
1229        int sign = o->output_indicators[sign_index];
1230
1231        if (o->ws_error_highlight & ws_rule) {
1232                ws = diff_get_color_opt(o, DIFF_WHITESPACE);
1233                if (!*ws)
1234                        ws = NULL;
1235        }
1236
1237        if (!ws && !set_sign)
1238                emit_line_0(o, set, NULL, 0, reset, sign, line, len);
1239        else if (!ws) {
1240                emit_line_0(o, set_sign, set, !!set_sign, reset, sign, line, len);
1241        } else if (blank_at_eof)
1242                /* Blank line at EOF - paint '+' as well */
1243                emit_line_0(o, ws, NULL, 0, reset, sign, line, len);
1244        else {
1245                /* Emit just the prefix, then the rest. */
1246                emit_line_0(o, set_sign ? set_sign : set, NULL, !!set_sign, reset,
1247                            sign, "", 0);
1248                ws_check_emit(line, len, ws_rule,
1249                              o->file, set, reset, ws);
1250        }
1251}
1252
1253static void emit_diff_symbol_from_struct(struct diff_options *o,
1254                                         struct emitted_diff_symbol *eds)
1255{
1256        static const char *nneof = " No newline at end of file\n";
1257        const char *context, *reset, *set, *set_sign, *meta, *fraginfo;
1258        struct strbuf sb = STRBUF_INIT;
1259
1260        enum diff_symbol s = eds->s;
1261        const char *line = eds->line;
1262        int len = eds->len;
1263        unsigned flags = eds->flags;
1264
1265        switch (s) {
1266        case DIFF_SYMBOL_NO_LF_EOF:
1267                context = diff_get_color_opt(o, DIFF_CONTEXT);
1268                reset = diff_get_color_opt(o, DIFF_RESET);
1269                putc('\n', o->file);
1270                emit_line_0(o, context, NULL, 0, reset, '\\',
1271                            nneof, strlen(nneof));
1272                break;
1273        case DIFF_SYMBOL_SUBMODULE_HEADER:
1274        case DIFF_SYMBOL_SUBMODULE_ERROR:
1275        case DIFF_SYMBOL_SUBMODULE_PIPETHROUGH:
1276        case DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES:
1277        case DIFF_SYMBOL_SUMMARY:
1278        case DIFF_SYMBOL_STATS_LINE:
1279        case DIFF_SYMBOL_BINARY_DIFF_BODY:
1280        case DIFF_SYMBOL_CONTEXT_FRAGINFO:
1281                emit_line(o, "", "", line, len);
1282                break;
1283        case DIFF_SYMBOL_CONTEXT_INCOMPLETE:
1284        case DIFF_SYMBOL_CONTEXT_MARKER:
1285                context = diff_get_color_opt(o, DIFF_CONTEXT);
1286                reset = diff_get_color_opt(o, DIFF_RESET);
1287                emit_line(o, context, reset, line, len);
1288                break;
1289        case DIFF_SYMBOL_SEPARATOR:
1290                fprintf(o->file, "%s%c",
1291                        diff_line_prefix(o),
1292                        o->line_termination);
1293                break;
1294        case DIFF_SYMBOL_CONTEXT:
1295                set = diff_get_color_opt(o, DIFF_CONTEXT);
1296                reset = diff_get_color_opt(o, DIFF_RESET);
1297                set_sign = NULL;
1298                if (o->flags.dual_color_diffed_diffs) {
1299                        char c = !len ? 0 : line[0];
1300
1301                        if (c == '+')
1302                                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1303                        else if (c == '@')
1304                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1305                        else if (c == '-')
1306                                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1307                }
1308                emit_line_ws_markup(o, set_sign, set, reset,
1309                                    OUTPUT_INDICATOR_CONTEXT, line, len,
1310                                    flags & (DIFF_SYMBOL_CONTENT_WS_MASK), 0);
1311                break;
1312        case DIFF_SYMBOL_PLUS:
1313                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1314                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1315                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1316                case DIFF_SYMBOL_MOVED_LINE |
1317                     DIFF_SYMBOL_MOVED_LINE_ALT |
1318                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1319                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT_DIM);
1320                        break;
1321                case DIFF_SYMBOL_MOVED_LINE |
1322                     DIFF_SYMBOL_MOVED_LINE_ALT:
1323                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT);
1324                        break;
1325                case DIFF_SYMBOL_MOVED_LINE |
1326                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1327                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_DIM);
1328                        break;
1329                case DIFF_SYMBOL_MOVED_LINE:
1330                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED);
1331                        break;
1332                default:
1333                        set = diff_get_color_opt(o, DIFF_FILE_NEW);
1334                }
1335                reset = diff_get_color_opt(o, DIFF_RESET);
1336                if (!o->flags.dual_color_diffed_diffs)
1337                        set_sign = NULL;
1338                else {
1339                        char c = !len ? 0 : line[0];
1340
1341                        set_sign = set;
1342                        if (c == '-')
1343                                set = diff_get_color_opt(o, DIFF_FILE_OLD_BOLD);
1344                        else if (c == '@')
1345                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1346                        else if (c == '+')
1347                                set = diff_get_color_opt(o, DIFF_FILE_NEW_BOLD);
1348                        else
1349                                set = diff_get_color_opt(o, DIFF_CONTEXT_BOLD);
1350                        flags &= ~DIFF_SYMBOL_CONTENT_WS_MASK;
1351                }
1352                emit_line_ws_markup(o, set_sign, set, reset,
1353                                    OUTPUT_INDICATOR_NEW, line, len,
1354                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK,
1355                                    flags & DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF);
1356                break;
1357        case DIFF_SYMBOL_MINUS:
1358                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1359                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1360                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1361                case DIFF_SYMBOL_MOVED_LINE |
1362                     DIFF_SYMBOL_MOVED_LINE_ALT |
1363                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1364                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT_DIM);
1365                        break;
1366                case DIFF_SYMBOL_MOVED_LINE |
1367                     DIFF_SYMBOL_MOVED_LINE_ALT:
1368                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT);
1369                        break;
1370                case DIFF_SYMBOL_MOVED_LINE |
1371                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1372                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_DIM);
1373                        break;
1374                case DIFF_SYMBOL_MOVED_LINE:
1375                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED);
1376                        break;
1377                default:
1378                        set = diff_get_color_opt(o, DIFF_FILE_OLD);
1379                }
1380                reset = diff_get_color_opt(o, DIFF_RESET);
1381                if (!o->flags.dual_color_diffed_diffs)
1382                        set_sign = NULL;
1383                else {
1384                        char c = !len ? 0 : line[0];
1385
1386                        set_sign = set;
1387                        if (c == '+')
1388                                set = diff_get_color_opt(o, DIFF_FILE_NEW_DIM);
1389                        else if (c == '@')
1390                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1391                        else if (c == '-')
1392                                set = diff_get_color_opt(o, DIFF_FILE_OLD_DIM);
1393                        else
1394                                set = diff_get_color_opt(o, DIFF_CONTEXT_DIM);
1395                }
1396                emit_line_ws_markup(o, set_sign, set, reset,
1397                                    OUTPUT_INDICATOR_OLD, line, len,
1398                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK, 0);
1399                break;
1400        case DIFF_SYMBOL_WORDS_PORCELAIN:
1401                context = diff_get_color_opt(o, DIFF_CONTEXT);
1402                reset = diff_get_color_opt(o, DIFF_RESET);
1403                emit_line(o, context, reset, line, len);
1404                fputs("~\n", o->file);
1405                break;
1406        case DIFF_SYMBOL_WORDS:
1407                context = diff_get_color_opt(o, DIFF_CONTEXT);
1408                reset = diff_get_color_opt(o, DIFF_RESET);
1409                /*
1410                 * Skip the prefix character, if any.  With
1411                 * diff_suppress_blank_empty, there may be
1412                 * none.
1413                 */
1414                if (line[0] != '\n') {
1415                        line++;
1416                        len--;
1417                }
1418                emit_line(o, context, reset, line, len);
1419                break;
1420        case DIFF_SYMBOL_FILEPAIR_PLUS:
1421                meta = diff_get_color_opt(o, DIFF_METAINFO);
1422                reset = diff_get_color_opt(o, DIFF_RESET);
1423                fprintf(o->file, "%s%s+++ %s%s%s\n", diff_line_prefix(o), meta,
1424                        line, reset,
1425                        strchr(line, ' ') ? "\t" : "");
1426                break;
1427        case DIFF_SYMBOL_FILEPAIR_MINUS:
1428                meta = diff_get_color_opt(o, DIFF_METAINFO);
1429                reset = diff_get_color_opt(o, DIFF_RESET);
1430                fprintf(o->file, "%s%s--- %s%s%s\n", diff_line_prefix(o), meta,
1431                        line, reset,
1432                        strchr(line, ' ') ? "\t" : "");
1433                break;
1434        case DIFF_SYMBOL_BINARY_FILES:
1435        case DIFF_SYMBOL_HEADER:
1436                fprintf(o->file, "%s", line);
1437                break;
1438        case DIFF_SYMBOL_BINARY_DIFF_HEADER:
1439                fprintf(o->file, "%sGIT binary patch\n", diff_line_prefix(o));
1440                break;
1441        case DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA:
1442                fprintf(o->file, "%sdelta %s\n", diff_line_prefix(o), line);
1443                break;
1444        case DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL:
1445                fprintf(o->file, "%sliteral %s\n", diff_line_prefix(o), line);
1446                break;
1447        case DIFF_SYMBOL_BINARY_DIFF_FOOTER:
1448                fputs(diff_line_prefix(o), o->file);
1449                fputc('\n', o->file);
1450                break;
1451        case DIFF_SYMBOL_REWRITE_DIFF:
1452                fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
1453                reset = diff_get_color_opt(o, DIFF_RESET);
1454                emit_line(o, fraginfo, reset, line, len);
1455                break;
1456        case DIFF_SYMBOL_SUBMODULE_ADD:
1457                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1458                reset = diff_get_color_opt(o, DIFF_RESET);
1459                emit_line(o, set, reset, line, len);
1460                break;
1461        case DIFF_SYMBOL_SUBMODULE_DEL:
1462                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1463                reset = diff_get_color_opt(o, DIFF_RESET);
1464                emit_line(o, set, reset, line, len);
1465                break;
1466        case DIFF_SYMBOL_SUBMODULE_UNTRACKED:
1467                fprintf(o->file, "%sSubmodule %s contains untracked content\n",
1468                        diff_line_prefix(o), line);
1469                break;
1470        case DIFF_SYMBOL_SUBMODULE_MODIFIED:
1471                fprintf(o->file, "%sSubmodule %s contains modified content\n",
1472                        diff_line_prefix(o), line);
1473                break;
1474        case DIFF_SYMBOL_STATS_SUMMARY_NO_FILES:
1475                emit_line(o, "", "", " 0 files changed\n",
1476                          strlen(" 0 files changed\n"));
1477                break;
1478        case DIFF_SYMBOL_STATS_SUMMARY_ABBREV:
1479                emit_line(o, "", "", " ...\n", strlen(" ...\n"));
1480                break;
1481        case DIFF_SYMBOL_WORD_DIFF:
1482                fprintf(o->file, "%.*s", len, line);
1483                break;
1484        case DIFF_SYMBOL_STAT_SEP:
1485                fputs(o->stat_sep, o->file);
1486                break;
1487        default:
1488                BUG("unknown diff symbol");
1489        }
1490        strbuf_release(&sb);
1491}
1492
1493static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
1494                             const char *line, int len, unsigned flags)
1495{
1496        struct emitted_diff_symbol e = {line, len, flags, s};
1497
1498        if (o->emitted_symbols)
1499                append_emitted_diff_symbol(o, &e);
1500        else
1501                emit_diff_symbol_from_struct(o, &e);
1502}
1503
1504void diff_emit_submodule_del(struct diff_options *o, const char *line)
1505{
1506        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_DEL, line, strlen(line), 0);
1507}
1508
1509void diff_emit_submodule_add(struct diff_options *o, const char *line)
1510{
1511        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ADD, line, strlen(line), 0);
1512}
1513
1514void diff_emit_submodule_untracked(struct diff_options *o, const char *path)
1515{
1516        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_UNTRACKED,
1517                         path, strlen(path), 0);
1518}
1519
1520void diff_emit_submodule_modified(struct diff_options *o, const char *path)
1521{
1522        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_MODIFIED,
1523                         path, strlen(path), 0);
1524}
1525
1526void diff_emit_submodule_header(struct diff_options *o, const char *header)
1527{
1528        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_HEADER,
1529                         header, strlen(header), 0);
1530}
1531
1532void diff_emit_submodule_error(struct diff_options *o, const char *err)
1533{
1534        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ERROR, err, strlen(err), 0);
1535}
1536
1537void diff_emit_submodule_pipethrough(struct diff_options *o,
1538                                     const char *line, int len)
1539{
1540        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_PIPETHROUGH, line, len, 0);
1541}
1542
1543static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
1544{
1545        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
1546              ecbdata->blank_at_eof_in_preimage &&
1547              ecbdata->blank_at_eof_in_postimage &&
1548              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
1549              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
1550                return 0;
1551        return ws_blank_line(line, len, ecbdata->ws_rule);
1552}
1553
1554static void emit_add_line(const char *reset,
1555                          struct emit_callback *ecbdata,
1556                          const char *line, int len)
1557{
1558        unsigned flags = WSEH_NEW | ecbdata->ws_rule;
1559        if (new_blank_line_at_eof(ecbdata, line, len))
1560                flags |= DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF;
1561
1562        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_PLUS, line, len, flags);
1563}
1564
1565static void emit_del_line(const char *reset,
1566                          struct emit_callback *ecbdata,
1567                          const char *line, int len)
1568{
1569        unsigned flags = WSEH_OLD | ecbdata->ws_rule;
1570        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_MINUS, line, len, flags);
1571}
1572
1573static void emit_context_line(const char *reset,
1574                              struct emit_callback *ecbdata,
1575                              const char *line, int len)
1576{
1577        unsigned flags = WSEH_CONTEXT | ecbdata->ws_rule;
1578        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_CONTEXT, line, len, flags);
1579}
1580
1581static void emit_hunk_header(struct emit_callback *ecbdata,
1582                             const char *line, int len)
1583{
1584        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
1585        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
1586        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
1587        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1588        const char *reverse = ecbdata->color_diff ? GIT_COLOR_REVERSE : "";
1589        static const char atat[2] = { '@', '@' };
1590        const char *cp, *ep;
1591        struct strbuf msgbuf = STRBUF_INIT;
1592        int org_len = len;
1593        int i = 1;
1594
1595        /*
1596         * As a hunk header must begin with "@@ -<old>, +<new> @@",
1597         * it always is at least 10 bytes long.
1598         */
1599        if (len < 10 ||
1600            memcmp(line, atat, 2) ||
1601            !(ep = memmem(line + 2, len - 2, atat, 2))) {
1602                emit_diff_symbol(ecbdata->opt,
1603                                 DIFF_SYMBOL_CONTEXT_MARKER, line, len, 0);
1604                return;
1605        }
1606        ep += 2; /* skip over @@ */
1607
1608        /* The hunk header in fraginfo color */
1609        if (ecbdata->opt->flags.dual_color_diffed_diffs)
1610                strbuf_addstr(&msgbuf, reverse);
1611        strbuf_addstr(&msgbuf, frag);
1612        strbuf_add(&msgbuf, line, ep - line);
1613        strbuf_addstr(&msgbuf, reset);
1614
1615        /*
1616         * trailing "\r\n"
1617         */
1618        for ( ; i < 3; i++)
1619                if (line[len - i] == '\r' || line[len - i] == '\n')
1620                        len--;
1621
1622        /* blank before the func header */
1623        for (cp = ep; ep - line < len; ep++)
1624                if (*ep != ' ' && *ep != '\t')
1625                        break;
1626        if (ep != cp) {
1627                strbuf_addstr(&msgbuf, context);
1628                strbuf_add(&msgbuf, cp, ep - cp);
1629                strbuf_addstr(&msgbuf, reset);
1630        }
1631
1632        if (ep < line + len) {
1633                strbuf_addstr(&msgbuf, func);
1634                strbuf_add(&msgbuf, ep, line + len - ep);
1635                strbuf_addstr(&msgbuf, reset);
1636        }
1637
1638        strbuf_add(&msgbuf, line + len, org_len - len);
1639        strbuf_complete_line(&msgbuf);
1640        emit_diff_symbol(ecbdata->opt,
1641                         DIFF_SYMBOL_CONTEXT_FRAGINFO, msgbuf.buf, msgbuf.len, 0);
1642        strbuf_release(&msgbuf);
1643}
1644
1645static struct diff_tempfile *claim_diff_tempfile(void)
1646{
1647        int i;
1648        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
1649                if (!diff_temp[i].name)
1650                        return diff_temp + i;
1651        BUG("diff is failing to clean up its tempfiles");
1652}
1653
1654static void remove_tempfile(void)
1655{
1656        int i;
1657        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
1658                if (is_tempfile_active(diff_temp[i].tempfile))
1659                        delete_tempfile(&diff_temp[i].tempfile);
1660                diff_temp[i].name = NULL;
1661        }
1662}
1663
1664static void add_line_count(struct strbuf *out, int count)
1665{
1666        switch (count) {
1667        case 0:
1668                strbuf_addstr(out, "0,0");
1669                break;
1670        case 1:
1671                strbuf_addstr(out, "1");
1672                break;
1673        default:
1674                strbuf_addf(out, "1,%d", count);
1675                break;
1676        }
1677}
1678
1679static void emit_rewrite_lines(struct emit_callback *ecb,
1680                               int prefix, const char *data, int size)
1681{
1682        const char *endp = NULL;
1683        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
1684
1685        while (0 < size) {
1686                int len;
1687
1688                endp = memchr(data, '\n', size);
1689                len = endp ? (endp - data + 1) : size;
1690                if (prefix != '+') {
1691                        ecb->lno_in_preimage++;
1692                        emit_del_line(reset, ecb, data, len);
1693                } else {
1694                        ecb->lno_in_postimage++;
1695                        emit_add_line(reset, ecb, data, len);
1696                }
1697                size -= len;
1698                data += len;
1699        }
1700        if (!endp)
1701                emit_diff_symbol(ecb->opt, DIFF_SYMBOL_NO_LF_EOF, NULL, 0, 0);
1702}
1703
1704static void emit_rewrite_diff(const char *name_a,
1705                              const char *name_b,
1706                              struct diff_filespec *one,
1707                              struct diff_filespec *two,
1708                              struct userdiff_driver *textconv_one,
1709                              struct userdiff_driver *textconv_two,
1710                              struct diff_options *o)
1711{
1712        int lc_a, lc_b;
1713        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
1714        const char *a_prefix, *b_prefix;
1715        char *data_one, *data_two;
1716        size_t size_one, size_two;
1717        struct emit_callback ecbdata;
1718        struct strbuf out = STRBUF_INIT;
1719
1720        if (diff_mnemonic_prefix && o->flags.reverse_diff) {
1721                a_prefix = o->b_prefix;
1722                b_prefix = o->a_prefix;
1723        } else {
1724                a_prefix = o->a_prefix;
1725                b_prefix = o->b_prefix;
1726        }
1727
1728        name_a += (*name_a == '/');
1729        name_b += (*name_b == '/');
1730
1731        strbuf_reset(&a_name);
1732        strbuf_reset(&b_name);
1733        quote_two_c_style(&a_name, a_prefix, name_a, 0);
1734        quote_two_c_style(&b_name, b_prefix, name_b, 0);
1735
1736        size_one = fill_textconv(o->repo, textconv_one, one, &data_one);
1737        size_two = fill_textconv(o->repo, textconv_two, two, &data_two);
1738
1739        memset(&ecbdata, 0, sizeof(ecbdata));
1740        ecbdata.color_diff = want_color(o->use_color);
1741        ecbdata.ws_rule = whitespace_rule(o->repo->index, name_b);
1742        ecbdata.opt = o;
1743        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
1744                mmfile_t mf1, mf2;
1745                mf1.ptr = (char *)data_one;
1746                mf2.ptr = (char *)data_two;
1747                mf1.size = size_one;
1748                mf2.size = size_two;
1749                check_blank_at_eof(&mf1, &mf2, &ecbdata);
1750        }
1751        ecbdata.lno_in_preimage = 1;
1752        ecbdata.lno_in_postimage = 1;
1753
1754        lc_a = count_lines(data_one, size_one);
1755        lc_b = count_lines(data_two, size_two);
1756
1757        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
1758                         a_name.buf, a_name.len, 0);
1759        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
1760                         b_name.buf, b_name.len, 0);
1761
1762        strbuf_addstr(&out, "@@ -");
1763        if (!o->irreversible_delete)
1764                add_line_count(&out, lc_a);
1765        else
1766                strbuf_addstr(&out, "?,?");
1767        strbuf_addstr(&out, " +");
1768        add_line_count(&out, lc_b);
1769        strbuf_addstr(&out, " @@\n");
1770        emit_diff_symbol(o, DIFF_SYMBOL_REWRITE_DIFF, out.buf, out.len, 0);
1771        strbuf_release(&out);
1772
1773        if (lc_a && !o->irreversible_delete)
1774                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
1775        if (lc_b)
1776                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
1777        if (textconv_one)
1778                free((char *)data_one);
1779        if (textconv_two)
1780                free((char *)data_two);
1781}
1782
1783struct diff_words_buffer {
1784        mmfile_t text;
1785        unsigned long alloc;
1786        struct diff_words_orig {
1787                const char *begin, *end;
1788        } *orig;
1789        int orig_nr, orig_alloc;
1790};
1791
1792static void diff_words_append(char *line, unsigned long len,
1793                struct diff_words_buffer *buffer)
1794{
1795        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
1796        line++;
1797        len--;
1798        memcpy(buffer->text.ptr + buffer->text.size, line, len);
1799        buffer->text.size += len;
1800        buffer->text.ptr[buffer->text.size] = '\0';
1801}
1802
1803struct diff_words_style_elem {
1804        const char *prefix;
1805        const char *suffix;
1806        const char *color; /* NULL; filled in by the setup code if
1807                            * color is enabled */
1808};
1809
1810struct diff_words_style {
1811        enum diff_words_type type;
1812        struct diff_words_style_elem new_word, old_word, ctx;
1813        const char *newline;
1814};
1815
1816static struct diff_words_style diff_words_styles[] = {
1817        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
1818        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
1819        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
1820};
1821
1822struct diff_words_data {
1823        struct diff_words_buffer minus, plus;
1824        const char *current_plus;
1825        int last_minus;
1826        struct diff_options *opt;
1827        regex_t *word_regex;
1828        enum diff_words_type type;
1829        struct diff_words_style *style;
1830};
1831
1832static int fn_out_diff_words_write_helper(struct diff_options *o,
1833                                          struct diff_words_style_elem *st_el,
1834                                          const char *newline,
1835                                          size_t count, const char *buf)
1836{
1837        int print = 0;
1838        struct strbuf sb = STRBUF_INIT;
1839
1840        while (count) {
1841                char *p = memchr(buf, '\n', count);
1842                if (print)
1843                        strbuf_addstr(&sb, diff_line_prefix(o));
1844
1845                if (p != buf) {
1846                        const char *reset = st_el->color && *st_el->color ?
1847                                            GIT_COLOR_RESET : NULL;
1848                        if (st_el->color && *st_el->color)
1849                                strbuf_addstr(&sb, st_el->color);
1850                        strbuf_addstr(&sb, st_el->prefix);
1851                        strbuf_add(&sb, buf, p ? p - buf : count);
1852                        strbuf_addstr(&sb, st_el->suffix);
1853                        if (reset)
1854                                strbuf_addstr(&sb, reset);
1855                }
1856                if (!p)
1857                        goto out;
1858
1859                strbuf_addstr(&sb, newline);
1860                count -= p + 1 - buf;
1861                buf = p + 1;
1862                print = 1;
1863                if (count) {
1864                        emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1865                                         sb.buf, sb.len, 0);
1866                        strbuf_reset(&sb);
1867                }
1868        }
1869
1870out:
1871        if (sb.len)
1872                emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1873                                 sb.buf, sb.len, 0);
1874        strbuf_release(&sb);
1875        return 0;
1876}
1877
1878/*
1879 * '--color-words' algorithm can be described as:
1880 *
1881 *   1. collect the minus/plus lines of a diff hunk, divided into
1882 *      minus-lines and plus-lines;
1883 *
1884 *   2. break both minus-lines and plus-lines into words and
1885 *      place them into two mmfile_t with one word for each line;
1886 *
1887 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
1888 *
1889 * And for the common parts of the both file, we output the plus side text.
1890 * diff_words->current_plus is used to trace the current position of the plus file
1891 * which printed. diff_words->last_minus is used to trace the last minus word
1892 * printed.
1893 *
1894 * For '--graph' to work with '--color-words', we need to output the graph prefix
1895 * on each line of color words output. Generally, there are two conditions on
1896 * which we should output the prefix.
1897 *
1898 *   1. diff_words->last_minus == 0 &&
1899 *      diff_words->current_plus == diff_words->plus.text.ptr
1900 *
1901 *      that is: the plus text must start as a new line, and if there is no minus
1902 *      word printed, a graph prefix must be printed.
1903 *
1904 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
1905 *      *(diff_words->current_plus - 1) == '\n'
1906 *
1907 *      that is: a graph prefix must be printed following a '\n'
1908 */
1909static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
1910{
1911        if ((diff_words->last_minus == 0 &&
1912                diff_words->current_plus == diff_words->plus.text.ptr) ||
1913                (diff_words->current_plus > diff_words->plus.text.ptr &&
1914                *(diff_words->current_plus - 1) == '\n')) {
1915                return 1;
1916        } else {
1917                return 0;
1918        }
1919}
1920
1921static void fn_out_diff_words_aux(void *priv,
1922                                  long minus_first, long minus_len,
1923                                  long plus_first, long plus_len,
1924                                  const char *func, long funclen)
1925{
1926        struct diff_words_data *diff_words = priv;
1927        struct diff_words_style *style = diff_words->style;
1928        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
1929        struct diff_options *opt = diff_words->opt;
1930        const char *line_prefix;
1931
1932        assert(opt);
1933        line_prefix = diff_line_prefix(opt);
1934
1935        /* POSIX requires that first be decremented by one if len == 0... */
1936        if (minus_len) {
1937                minus_begin = diff_words->minus.orig[minus_first].begin;
1938                minus_end =
1939                        diff_words->minus.orig[minus_first + minus_len - 1].end;
1940        } else
1941                minus_begin = minus_end =
1942                        diff_words->minus.orig[minus_first].end;
1943
1944        if (plus_len) {
1945                plus_begin = diff_words->plus.orig[plus_first].begin;
1946                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
1947        } else
1948                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
1949
1950        if (color_words_output_graph_prefix(diff_words)) {
1951                fputs(line_prefix, diff_words->opt->file);
1952        }
1953        if (diff_words->current_plus != plus_begin) {
1954                fn_out_diff_words_write_helper(diff_words->opt,
1955                                &style->ctx, style->newline,
1956                                plus_begin - diff_words->current_plus,
1957                                diff_words->current_plus);
1958        }
1959        if (minus_begin != minus_end) {
1960                fn_out_diff_words_write_helper(diff_words->opt,
1961                                &style->old_word, style->newline,
1962                                minus_end - minus_begin, minus_begin);
1963        }
1964        if (plus_begin != plus_end) {
1965                fn_out_diff_words_write_helper(diff_words->opt,
1966                                &style->new_word, style->newline,
1967                                plus_end - plus_begin, plus_begin);
1968        }
1969
1970        diff_words->current_plus = plus_end;
1971        diff_words->last_minus = minus_first;
1972}
1973
1974/* This function starts looking at *begin, and returns 0 iff a word was found. */
1975static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
1976                int *begin, int *end)
1977{
1978        if (word_regex && *begin < buffer->size) {
1979                regmatch_t match[1];
1980                if (!regexec_buf(word_regex, buffer->ptr + *begin,
1981                                 buffer->size - *begin, 1, match, 0)) {
1982                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
1983                                        '\n', match[0].rm_eo - match[0].rm_so);
1984                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
1985                        *begin += match[0].rm_so;
1986                        return *begin >= *end;
1987                }
1988                return -1;
1989        }
1990
1991        /* find the next word */
1992        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
1993                (*begin)++;
1994        if (*begin >= buffer->size)
1995                return -1;
1996
1997        /* find the end of the word */
1998        *end = *begin + 1;
1999        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
2000                (*end)++;
2001
2002        return 0;
2003}
2004
2005/*
2006 * This function splits the words in buffer->text, stores the list with
2007 * newline separator into out, and saves the offsets of the original words
2008 * in buffer->orig.
2009 */
2010static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
2011                regex_t *word_regex)
2012{
2013        int i, j;
2014        long alloc = 0;
2015
2016        out->size = 0;
2017        out->ptr = NULL;
2018
2019        /* fake an empty "0th" word */
2020        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
2021        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
2022        buffer->orig_nr = 1;
2023
2024        for (i = 0; i < buffer->text.size; i++) {
2025                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
2026                        return;
2027
2028                /* store original boundaries */
2029                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
2030                                buffer->orig_alloc);
2031                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
2032                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
2033                buffer->orig_nr++;
2034
2035                /* store one word */
2036                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
2037                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
2038                out->ptr[out->size + j - i] = '\n';
2039                out->size += j - i + 1;
2040
2041                i = j - 1;
2042        }
2043}
2044
2045/* this executes the word diff on the accumulated buffers */
2046static void diff_words_show(struct diff_words_data *diff_words)
2047{
2048        xpparam_t xpp;
2049        xdemitconf_t xecfg;
2050        mmfile_t minus, plus;
2051        struct diff_words_style *style = diff_words->style;
2052
2053        struct diff_options *opt = diff_words->opt;
2054        const char *line_prefix;
2055
2056        assert(opt);
2057        line_prefix = diff_line_prefix(opt);
2058
2059        /* special case: only removal */
2060        if (!diff_words->plus.text.size) {
2061                emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
2062                                 line_prefix, strlen(line_prefix), 0);
2063                fn_out_diff_words_write_helper(diff_words->opt,
2064                        &style->old_word, style->newline,
2065                        diff_words->minus.text.size,
2066                        diff_words->minus.text.ptr);
2067                diff_words->minus.text.size = 0;
2068                return;
2069        }
2070
2071        diff_words->current_plus = diff_words->plus.text.ptr;
2072        diff_words->last_minus = 0;
2073
2074        memset(&xpp, 0, sizeof(xpp));
2075        memset(&xecfg, 0, sizeof(xecfg));
2076        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
2077        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
2078        xpp.flags = 0;
2079        /* as only the hunk header will be parsed, we need a 0-context */
2080        xecfg.ctxlen = 0;
2081        if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, NULL,
2082                          diff_words, &xpp, &xecfg))
2083                die("unable to generate word diff");
2084        free(minus.ptr);
2085        free(plus.ptr);
2086        if (diff_words->current_plus != diff_words->plus.text.ptr +
2087                        diff_words->plus.text.size) {
2088                if (color_words_output_graph_prefix(diff_words))
2089                        emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
2090                                         line_prefix, strlen(line_prefix), 0);
2091                fn_out_diff_words_write_helper(diff_words->opt,
2092                        &style->ctx, style->newline,
2093                        diff_words->plus.text.ptr + diff_words->plus.text.size
2094                        - diff_words->current_plus, diff_words->current_plus);
2095        }
2096        diff_words->minus.text.size = diff_words->plus.text.size = 0;
2097}
2098
2099/* In "color-words" mode, show word-diff of words accumulated in the buffer */
2100static void diff_words_flush(struct emit_callback *ecbdata)
2101{
2102        struct diff_options *wo = ecbdata->diff_words->opt;
2103
2104        if (ecbdata->diff_words->minus.text.size ||
2105            ecbdata->diff_words->plus.text.size)
2106                diff_words_show(ecbdata->diff_words);
2107
2108        if (wo->emitted_symbols) {
2109                struct diff_options *o = ecbdata->opt;
2110                struct emitted_diff_symbols *wol = wo->emitted_symbols;
2111                int i;
2112
2113                /*
2114                 * NEEDSWORK:
2115                 * Instead of appending each, concat all words to a line?
2116                 */
2117                for (i = 0; i < wol->nr; i++)
2118                        append_emitted_diff_symbol(o, &wol->buf[i]);
2119
2120                for (i = 0; i < wol->nr; i++)
2121                        free((void *)wol->buf[i].line);
2122
2123                wol->nr = 0;
2124        }
2125}
2126
2127static void diff_filespec_load_driver(struct diff_filespec *one,
2128                                      struct index_state *istate)
2129{
2130        /* Use already-loaded driver */
2131        if (one->driver)
2132                return;
2133
2134        if (S_ISREG(one->mode))
2135                one->driver = userdiff_find_by_path(istate, one->path);
2136
2137        /* Fallback to default settings */
2138        if (!one->driver)
2139                one->driver = userdiff_find_by_name("default");
2140}
2141
2142static const char *userdiff_word_regex(struct diff_filespec *one,
2143                                       struct index_state *istate)
2144{
2145        diff_filespec_load_driver(one, istate);
2146        return one->driver->word_regex;
2147}
2148
2149static void init_diff_words_data(struct emit_callback *ecbdata,
2150                                 struct diff_options *orig_opts,
2151                                 struct diff_filespec *one,
2152                                 struct diff_filespec *two)
2153{
2154        int i;
2155        struct diff_options *o = xmalloc(sizeof(struct diff_options));
2156        memcpy(o, orig_opts, sizeof(struct diff_options));
2157
2158        ecbdata->diff_words =
2159                xcalloc(1, sizeof(struct diff_words_data));
2160        ecbdata->diff_words->type = o->word_diff;
2161        ecbdata->diff_words->opt = o;
2162
2163        if (orig_opts->emitted_symbols)
2164                o->emitted_symbols =
2165                        xcalloc(1, sizeof(struct emitted_diff_symbols));
2166
2167        if (!o->word_regex)
2168                o->word_regex = userdiff_word_regex(one, o->repo->index);
2169        if (!o->word_regex)
2170                o->word_regex = userdiff_word_regex(two, o->repo->index);
2171        if (!o->word_regex)
2172                o->word_regex = diff_word_regex_cfg;
2173        if (o->word_regex) {
2174                ecbdata->diff_words->word_regex = (regex_t *)
2175                        xmalloc(sizeof(regex_t));
2176                if (regcomp(ecbdata->diff_words->word_regex,
2177                            o->word_regex,
2178                            REG_EXTENDED | REG_NEWLINE))
2179                        die("invalid regular expression: %s",
2180                            o->word_regex);
2181        }
2182        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2183                if (o->word_diff == diff_words_styles[i].type) {
2184                        ecbdata->diff_words->style =
2185                                &diff_words_styles[i];
2186                        break;
2187                }
2188        }
2189        if (want_color(o->use_color)) {
2190                struct diff_words_style *st = ecbdata->diff_words->style;
2191                st->old_word.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2192                st->new_word.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2193                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
2194        }
2195}
2196
2197static void free_diff_words_data(struct emit_callback *ecbdata)
2198{
2199        if (ecbdata->diff_words) {
2200                diff_words_flush(ecbdata);
2201                free (ecbdata->diff_words->opt->emitted_symbols);
2202                free (ecbdata->diff_words->opt);
2203                free (ecbdata->diff_words->minus.text.ptr);
2204                free (ecbdata->diff_words->minus.orig);
2205                free (ecbdata->diff_words->plus.text.ptr);
2206                free (ecbdata->diff_words->plus.orig);
2207                if (ecbdata->diff_words->word_regex) {
2208                        regfree(ecbdata->diff_words->word_regex);
2209                        free(ecbdata->diff_words->word_regex);
2210                }
2211                FREE_AND_NULL(ecbdata->diff_words);
2212        }
2213}
2214
2215const char *diff_get_color(int diff_use_color, enum color_diff ix)
2216{
2217        if (want_color(diff_use_color))
2218                return diff_colors[ix];
2219        return "";
2220}
2221
2222const char *diff_line_prefix(struct diff_options *opt)
2223{
2224        struct strbuf *msgbuf;
2225        if (!opt->output_prefix)
2226                return "";
2227
2228        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
2229        return msgbuf->buf;
2230}
2231
2232static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
2233{
2234        const char *cp;
2235        unsigned long allot;
2236        size_t l = len;
2237
2238        cp = line;
2239        allot = l;
2240        while (0 < l) {
2241                (void) utf8_width(&cp, &l);
2242                if (!cp)
2243                        break; /* truncated in the middle? */
2244        }
2245        return allot - l;
2246}
2247
2248static void find_lno(const char *line, struct emit_callback *ecbdata)
2249{
2250        const char *p;
2251        ecbdata->lno_in_preimage = 0;
2252        ecbdata->lno_in_postimage = 0;
2253        p = strchr(line, '-');
2254        if (!p)
2255                return; /* cannot happen */
2256        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
2257        p = strchr(p, '+');
2258        if (!p)
2259                return; /* cannot happen */
2260        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
2261}
2262
2263static void fn_out_consume(void *priv, char *line, unsigned long len)
2264{
2265        struct emit_callback *ecbdata = priv;
2266        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
2267        struct diff_options *o = ecbdata->opt;
2268
2269        o->found_changes = 1;
2270
2271        if (ecbdata->header) {
2272                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
2273                                 ecbdata->header->buf, ecbdata->header->len, 0);
2274                strbuf_reset(ecbdata->header);
2275                ecbdata->header = NULL;
2276        }
2277
2278        if (ecbdata->label_path[0]) {
2279                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
2280                                 ecbdata->label_path[0],
2281                                 strlen(ecbdata->label_path[0]), 0);
2282                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
2283                                 ecbdata->label_path[1],
2284                                 strlen(ecbdata->label_path[1]), 0);
2285                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
2286        }
2287
2288        if (diff_suppress_blank_empty
2289            && len == 2 && line[0] == ' ' && line[1] == '\n') {
2290                line[0] = '\n';
2291                len = 1;
2292        }
2293
2294        if (line[0] == '@') {
2295                if (ecbdata->diff_words)
2296                        diff_words_flush(ecbdata);
2297                len = sane_truncate_line(ecbdata, line, len);
2298                find_lno(line, ecbdata);
2299                emit_hunk_header(ecbdata, line, len);
2300                return;
2301        }
2302
2303        if (ecbdata->diff_words) {
2304                enum diff_symbol s =
2305                        ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN ?
2306                        DIFF_SYMBOL_WORDS_PORCELAIN : DIFF_SYMBOL_WORDS;
2307                if (line[0] == '-') {
2308                        diff_words_append(line, len,
2309                                          &ecbdata->diff_words->minus);
2310                        return;
2311                } else if (line[0] == '+') {
2312                        diff_words_append(line, len,
2313                                          &ecbdata->diff_words->plus);
2314                        return;
2315                } else if (starts_with(line, "\\ ")) {
2316                        /*
2317                         * Eat the "no newline at eof" marker as if we
2318                         * saw a "+" or "-" line with nothing on it,
2319                         * and return without diff_words_flush() to
2320                         * defer processing. If this is the end of
2321                         * preimage, more "+" lines may come after it.
2322                         */
2323                        return;
2324                }
2325                diff_words_flush(ecbdata);
2326                emit_diff_symbol(o, s, line, len, 0);
2327                return;
2328        }
2329
2330        switch (line[0]) {
2331        case '+':
2332                ecbdata->lno_in_postimage++;
2333                emit_add_line(reset, ecbdata, line + 1, len - 1);
2334                break;
2335        case '-':
2336                ecbdata->lno_in_preimage++;
2337                emit_del_line(reset, ecbdata, line + 1, len - 1);
2338                break;
2339        case ' ':
2340                ecbdata->lno_in_postimage++;
2341                ecbdata->lno_in_preimage++;
2342                emit_context_line(reset, ecbdata, line + 1, len - 1);
2343                break;
2344        default:
2345                /* incomplete line at the end */
2346                ecbdata->lno_in_preimage++;
2347                emit_diff_symbol(o, DIFF_SYMBOL_CONTEXT_INCOMPLETE,
2348                                 line, len, 0);
2349                break;
2350        }
2351}
2352
2353static void pprint_rename(struct strbuf *name, const char *a, const char *b)
2354{
2355        const char *old_name = a;
2356        const char *new_name = b;
2357        int pfx_length, sfx_length;
2358        int pfx_adjust_for_slash;
2359        int len_a = strlen(a);
2360        int len_b = strlen(b);
2361        int a_midlen, b_midlen;
2362        int qlen_a = quote_c_style(a, NULL, NULL, 0);
2363        int qlen_b = quote_c_style(b, NULL, NULL, 0);
2364
2365        if (qlen_a || qlen_b) {
2366                quote_c_style(a, name, NULL, 0);
2367                strbuf_addstr(name, " => ");
2368                quote_c_style(b, name, NULL, 0);
2369                return;
2370        }
2371
2372        /* Find common prefix */
2373        pfx_length = 0;
2374        while (*old_name && *new_name && *old_name == *new_name) {
2375                if (*old_name == '/')
2376                        pfx_length = old_name - a + 1;
2377                old_name++;
2378                new_name++;
2379        }
2380
2381        /* Find common suffix */
2382        old_name = a + len_a;
2383        new_name = b + len_b;
2384        sfx_length = 0;
2385        /*
2386         * If there is a common prefix, it must end in a slash.  In
2387         * that case we let this loop run 1 into the prefix to see the
2388         * same slash.
2389         *
2390         * If there is no common prefix, we cannot do this as it would
2391         * underrun the input strings.
2392         */
2393        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
2394        while (a + pfx_length - pfx_adjust_for_slash <= old_name &&
2395               b + pfx_length - pfx_adjust_for_slash <= new_name &&
2396               *old_name == *new_name) {
2397                if (*old_name == '/')
2398                        sfx_length = len_a - (old_name - a);
2399                old_name--;
2400                new_name--;
2401        }
2402
2403        /*
2404         * pfx{mid-a => mid-b}sfx
2405         * {pfx-a => pfx-b}sfx
2406         * pfx{sfx-a => sfx-b}
2407         * name-a => name-b
2408         */
2409        a_midlen = len_a - pfx_length - sfx_length;
2410        b_midlen = len_b - pfx_length - sfx_length;
2411        if (a_midlen < 0)
2412                a_midlen = 0;
2413        if (b_midlen < 0)
2414                b_midlen = 0;
2415
2416        strbuf_grow(name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
2417        if (pfx_length + sfx_length) {
2418                strbuf_add(name, a, pfx_length);
2419                strbuf_addch(name, '{');
2420        }
2421        strbuf_add(name, a + pfx_length, a_midlen);
2422        strbuf_addstr(name, " => ");
2423        strbuf_add(name, b + pfx_length, b_midlen);
2424        if (pfx_length + sfx_length) {
2425                strbuf_addch(name, '}');
2426                strbuf_add(name, a + len_a - sfx_length, sfx_length);
2427        }
2428}
2429
2430struct diffstat_t {
2431        int nr;
2432        int alloc;
2433        struct diffstat_file {
2434                char *from_name;
2435                char *name;
2436                char *print_name;
2437                const char *comments;
2438                unsigned is_unmerged:1;
2439                unsigned is_binary:1;
2440                unsigned is_renamed:1;
2441                unsigned is_interesting:1;
2442                uintmax_t added, deleted;
2443        } **files;
2444};
2445
2446static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
2447                                          const char *name_a,
2448                                          const char *name_b)
2449{
2450        struct diffstat_file *x;
2451        x = xcalloc(1, sizeof(*x));
2452        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
2453        diffstat->files[diffstat->nr++] = x;
2454        if (name_b) {
2455                x->from_name = xstrdup(name_a);
2456                x->name = xstrdup(name_b);
2457                x->is_renamed = 1;
2458        }
2459        else {
2460                x->from_name = NULL;
2461                x->name = xstrdup(name_a);
2462        }
2463        return x;
2464}
2465
2466static void diffstat_consume(void *priv, char *line, unsigned long len)
2467{
2468        struct diffstat_t *diffstat = priv;
2469        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
2470
2471        if (line[0] == '+')
2472                x->added++;
2473        else if (line[0] == '-')
2474                x->deleted++;
2475}
2476
2477const char mime_boundary_leader[] = "------------";
2478
2479static int scale_linear(int it, int width, int max_change)
2480{
2481        if (!it)
2482                return 0;
2483        /*
2484         * make sure that at least one '-' or '+' is printed if
2485         * there is any change to this path. The easiest way is to
2486         * scale linearly as if the alloted width is one column shorter
2487         * than it is, and then add 1 to the result.
2488         */
2489        return 1 + (it * (width - 1) / max_change);
2490}
2491
2492static void show_graph(struct strbuf *out, char ch, int cnt,
2493                       const char *set, const char *reset)
2494{
2495        if (cnt <= 0)
2496                return;
2497        strbuf_addstr(out, set);
2498        strbuf_addchars(out, ch, cnt);
2499        strbuf_addstr(out, reset);
2500}
2501
2502static void fill_print_name(struct diffstat_file *file)
2503{
2504        struct strbuf pname = STRBUF_INIT;
2505
2506        if (file->print_name)
2507                return;
2508
2509        if (file->is_renamed)
2510                pprint_rename(&pname, file->from_name, file->name);
2511        else
2512                quote_c_style(file->name, &pname, NULL, 0);
2513
2514        if (file->comments)
2515                strbuf_addf(&pname, " (%s)", file->comments);
2516
2517        file->print_name = strbuf_detach(&pname, NULL);
2518}
2519
2520static void print_stat_summary_inserts_deletes(struct diff_options *options,
2521                int files, int insertions, int deletions)
2522{
2523        struct strbuf sb = STRBUF_INIT;
2524
2525        if (!files) {
2526                assert(insertions == 0 && deletions == 0);
2527                emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
2528                                 NULL, 0, 0);
2529                return;
2530        }
2531
2532        strbuf_addf(&sb,
2533                    (files == 1) ? " %d file changed" : " %d files changed",
2534                    files);
2535
2536        /*
2537         * For binary diff, the caller may want to print "x files
2538         * changed" with insertions == 0 && deletions == 0.
2539         *
2540         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
2541         * is probably less confusing (i.e skip over "2 files changed
2542         * but nothing about added/removed lines? Is this a bug in Git?").
2543         */
2544        if (insertions || deletions == 0) {
2545                strbuf_addf(&sb,
2546                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
2547                            insertions);
2548        }
2549
2550        if (deletions || insertions == 0) {
2551                strbuf_addf(&sb,
2552                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
2553                            deletions);
2554        }
2555        strbuf_addch(&sb, '\n');
2556        emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
2557                         sb.buf, sb.len, 0);
2558        strbuf_release(&sb);
2559}
2560
2561void print_stat_summary(FILE *fp, int files,
2562                        int insertions, int deletions)
2563{
2564        struct diff_options o;
2565        memset(&o, 0, sizeof(o));
2566        o.file = fp;
2567
2568        print_stat_summary_inserts_deletes(&o, files, insertions, deletions);
2569}
2570
2571static void show_stats(struct diffstat_t *data, struct diff_options *options)
2572{
2573        int i, len, add, del, adds = 0, dels = 0;
2574        uintmax_t max_change = 0, max_len = 0;
2575        int total_files = data->nr, count;
2576        int width, name_width, graph_width, number_width = 0, bin_width = 0;
2577        const char *reset, *add_c, *del_c;
2578        int extra_shown = 0;
2579        const char *line_prefix = diff_line_prefix(options);
2580        struct strbuf out = STRBUF_INIT;
2581
2582        if (data->nr == 0)
2583                return;
2584
2585        count = options->stat_count ? options->stat_count : data->nr;
2586
2587        reset = diff_get_color_opt(options, DIFF_RESET);
2588        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
2589        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
2590
2591        /*
2592         * Find the longest filename and max number of changes
2593         */
2594        for (i = 0; (i < count) && (i < data->nr); i++) {
2595                struct diffstat_file *file = data->files[i];
2596                uintmax_t change = file->added + file->deleted;
2597
2598                if (!file->is_interesting && (change == 0)) {
2599                        count++; /* not shown == room for one more */
2600                        continue;
2601                }
2602                fill_print_name(file);
2603                len = strlen(file->print_name);
2604                if (max_len < len)
2605                        max_len = len;
2606
2607                if (file->is_unmerged) {
2608                        /* "Unmerged" is 8 characters */
2609                        bin_width = bin_width < 8 ? 8 : bin_width;
2610                        continue;
2611                }
2612                if (file->is_binary) {
2613                        /* "Bin XXX -> YYY bytes" */
2614                        int w = 14 + decimal_width(file->added)
2615                                + decimal_width(file->deleted);
2616                        bin_width = bin_width < w ? w : bin_width;
2617                        /* Display change counts aligned with "Bin" */
2618                        number_width = 3;
2619                        continue;
2620                }
2621
2622                if (max_change < change)
2623                        max_change = change;
2624        }
2625        count = i; /* where we can stop scanning in data->files[] */
2626
2627        /*
2628         * We have width = stat_width or term_columns() columns total.
2629         * We want a maximum of min(max_len, stat_name_width) for the name part.
2630         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
2631         * We also need 1 for " " and 4 + decimal_width(max_change)
2632         * for " | NNNN " and one the empty column at the end, altogether
2633         * 6 + decimal_width(max_change).
2634         *
2635         * If there's not enough space, we will use the smaller of
2636         * stat_name_width (if set) and 5/8*width for the filename,
2637         * and the rest for constant elements + graph part, but no more
2638         * than stat_graph_width for the graph part.
2639         * (5/8 gives 50 for filename and 30 for the constant parts + graph
2640         * for the standard terminal size).
2641         *
2642         * In other words: stat_width limits the maximum width, and
2643         * stat_name_width fixes the maximum width of the filename,
2644         * and is also used to divide available columns if there
2645         * aren't enough.
2646         *
2647         * Binary files are displayed with "Bin XXX -> YYY bytes"
2648         * instead of the change count and graph. This part is treated
2649         * similarly to the graph part, except that it is not
2650         * "scaled". If total width is too small to accommodate the
2651         * guaranteed minimum width of the filename part and the
2652         * separators and this message, this message will "overflow"
2653         * making the line longer than the maximum width.
2654         */
2655
2656        if (options->stat_width == -1)
2657                width = term_columns() - strlen(line_prefix);
2658        else
2659                width = options->stat_width ? options->stat_width : 80;
2660        number_width = decimal_width(max_change) > number_width ?
2661                decimal_width(max_change) : number_width;
2662
2663        if (options->stat_graph_width == -1)
2664                options->stat_graph_width = diff_stat_graph_width;
2665
2666        /*
2667         * Guarantee 3/8*16==6 for the graph part
2668         * and 5/8*16==10 for the filename part
2669         */
2670        if (width < 16 + 6 + number_width)
2671                width = 16 + 6 + number_width;
2672
2673        /*
2674         * First assign sizes that are wanted, ignoring available width.
2675         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
2676         * starting from "XXX" should fit in graph_width.
2677         */
2678        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
2679        if (options->stat_graph_width &&
2680            options->stat_graph_width < graph_width)
2681                graph_width = options->stat_graph_width;
2682
2683        name_width = (options->stat_name_width > 0 &&
2684                      options->stat_name_width < max_len) ?
2685                options->stat_name_width : max_len;
2686
2687        /*
2688         * Adjust adjustable widths not to exceed maximum width
2689         */
2690        if (name_width + number_width + 6 + graph_width > width) {
2691                if (graph_width > width * 3/8 - number_width - 6) {
2692                        graph_width = width * 3/8 - number_width - 6;
2693                        if (graph_width < 6)
2694                                graph_width = 6;
2695                }
2696
2697                if (options->stat_graph_width &&
2698                    graph_width > options->stat_graph_width)
2699                        graph_width = options->stat_graph_width;
2700                if (name_width > width - number_width - 6 - graph_width)
2701                        name_width = width - number_width - 6 - graph_width;
2702                else
2703                        graph_width = width - number_width - 6 - name_width;
2704        }
2705
2706        /*
2707         * From here name_width is the width of the name area,
2708         * and graph_width is the width of the graph area.
2709         * max_change is used to scale graph properly.
2710         */
2711        for (i = 0; i < count; i++) {
2712                const char *prefix = "";
2713                struct diffstat_file *file = data->files[i];
2714                char *name = file->print_name;
2715                uintmax_t added = file->added;
2716                uintmax_t deleted = file->deleted;
2717                int name_len;
2718
2719                if (!file->is_interesting && (added + deleted == 0))
2720                        continue;
2721
2722                /*
2723                 * "scale" the filename
2724                 */
2725                len = name_width;
2726                name_len = strlen(name);
2727                if (name_width < name_len) {
2728                        char *slash;
2729                        prefix = "...";
2730                        len -= 3;
2731                        name += name_len - len;
2732                        slash = strchr(name, '/');
2733                        if (slash)
2734                                name = slash;
2735                }
2736
2737                if (file->is_binary) {
2738                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2739                        strbuf_addf(&out, " %*s", number_width, "Bin");
2740                        if (!added && !deleted) {
2741                                strbuf_addch(&out, '\n');
2742                                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2743                                                 out.buf, out.len, 0);
2744                                strbuf_reset(&out);
2745                                continue;
2746                        }
2747                        strbuf_addf(&out, " %s%"PRIuMAX"%s",
2748                                del_c, deleted, reset);
2749                        strbuf_addstr(&out, " -> ");
2750                        strbuf_addf(&out, "%s%"PRIuMAX"%s",
2751                                add_c, added, reset);
2752                        strbuf_addstr(&out, " bytes\n");
2753                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2754                                         out.buf, out.len, 0);
2755                        strbuf_reset(&out);
2756                        continue;
2757                }
2758                else if (file->is_unmerged) {
2759                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2760                        strbuf_addstr(&out, " Unmerged\n");
2761                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2762                                         out.buf, out.len, 0);
2763                        strbuf_reset(&out);
2764                        continue;
2765                }
2766
2767                /*
2768                 * scale the add/delete
2769                 */
2770                add = added;
2771                del = deleted;
2772
2773                if (graph_width <= max_change) {
2774                        int total = scale_linear(add + del, graph_width, max_change);
2775                        if (total < 2 && add && del)
2776                                /* width >= 2 due to the sanity check */
2777                                total = 2;
2778                        if (add < del) {
2779                                add = scale_linear(add, graph_width, max_change);
2780                                del = total - add;
2781                        } else {
2782                                del = scale_linear(del, graph_width, max_change);
2783                                add = total - del;
2784                        }
2785                }
2786                strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2787                strbuf_addf(&out, " %*"PRIuMAX"%s",
2788                        number_width, added + deleted,
2789                        added + deleted ? " " : "");
2790                show_graph(&out, '+', add, add_c, reset);
2791                show_graph(&out, '-', del, del_c, reset);
2792                strbuf_addch(&out, '\n');
2793                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2794                                 out.buf, out.len, 0);
2795                strbuf_reset(&out);
2796        }
2797
2798        for (i = 0; i < data->nr; i++) {
2799                struct diffstat_file *file = data->files[i];
2800                uintmax_t added = file->added;
2801                uintmax_t deleted = file->deleted;
2802
2803                if (file->is_unmerged ||
2804                    (!file->is_interesting && (added + deleted == 0))) {
2805                        total_files--;
2806                        continue;
2807                }
2808
2809                if (!file->is_binary) {
2810                        adds += added;
2811                        dels += deleted;
2812                }
2813                if (i < count)
2814                        continue;
2815                if (!extra_shown)
2816                        emit_diff_symbol(options,
2817                                         DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
2818                                         NULL, 0, 0);
2819                extra_shown = 1;
2820        }
2821
2822        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2823        strbuf_release(&out);
2824}
2825
2826static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
2827{
2828        int i, adds = 0, dels = 0, total_files = data->nr;
2829
2830        if (data->nr == 0)
2831                return;
2832
2833        for (i = 0; i < data->nr; i++) {
2834                int added = data->files[i]->added;
2835                int deleted = data->files[i]->deleted;
2836
2837                if (data->files[i]->is_unmerged ||
2838                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
2839                        total_files--;
2840                } else if (!data->files[i]->is_binary) { /* don't count bytes */
2841                        adds += added;
2842                        dels += deleted;
2843                }
2844        }
2845        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2846}
2847
2848static void show_numstat(struct diffstat_t *data, struct diff_options *options)
2849{
2850        int i;
2851
2852        if (data->nr == 0)
2853                return;
2854
2855        for (i = 0; i < data->nr; i++) {
2856                struct diffstat_file *file = data->files[i];
2857
2858                fprintf(options->file, "%s", diff_line_prefix(options));
2859
2860                if (file->is_binary)
2861                        fprintf(options->file, "-\t-\t");
2862                else
2863                        fprintf(options->file,
2864                                "%"PRIuMAX"\t%"PRIuMAX"\t",
2865                                file->added, file->deleted);
2866                if (options->line_termination) {
2867                        fill_print_name(file);
2868                        if (!file->is_renamed)
2869                                write_name_quoted(file->name, options->file,
2870                                                  options->line_termination);
2871                        else {
2872                                fputs(file->print_name, options->file);
2873                                putc(options->line_termination, options->file);
2874                        }
2875                } else {
2876                        if (file->is_renamed) {
2877                                putc('\0', options->file);
2878                                write_name_quoted(file->from_name, options->file, '\0');
2879                        }
2880                        write_name_quoted(file->name, options->file, '\0');
2881                }
2882        }
2883}
2884
2885struct dirstat_file {
2886        const char *name;
2887        unsigned long changed;
2888};
2889
2890struct dirstat_dir {
2891        struct dirstat_file *files;
2892        int alloc, nr, permille, cumulative;
2893};
2894
2895static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
2896                unsigned long changed, const char *base, int baselen)
2897{
2898        unsigned long sum_changes = 0;
2899        unsigned int sources = 0;
2900        const char *line_prefix = diff_line_prefix(opt);
2901
2902        while (dir->nr) {
2903                struct dirstat_file *f = dir->files;
2904                int namelen = strlen(f->name);
2905                unsigned long changes;
2906                char *slash;
2907
2908                if (namelen < baselen)
2909                        break;
2910                if (memcmp(f->name, base, baselen))
2911                        break;
2912                slash = strchr(f->name + baselen, '/');
2913                if (slash) {
2914                        int newbaselen = slash + 1 - f->name;
2915                        changes = gather_dirstat(opt, dir, changed, f->name, newbaselen);
2916                        sources++;
2917                } else {
2918                        changes = f->changed;
2919                        dir->files++;
2920                        dir->nr--;
2921                        sources += 2;
2922                }
2923                sum_changes += changes;
2924        }
2925
2926        /*
2927         * We don't report dirstat's for
2928         *  - the top level
2929         *  - or cases where everything came from a single directory
2930         *    under this directory (sources == 1).
2931         */
2932        if (baselen && sources != 1) {
2933                if (sum_changes) {
2934                        int permille = sum_changes * 1000 / changed;
2935                        if (permille >= dir->permille) {
2936                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
2937                                        permille / 10, permille % 10, baselen, base);
2938                                if (!dir->cumulative)
2939                                        return 0;
2940                        }
2941                }
2942        }
2943        return sum_changes;
2944}
2945
2946static int dirstat_compare(const void *_a, const void *_b)
2947{
2948        const struct dirstat_file *a = _a;
2949        const struct dirstat_file *b = _b;
2950        return strcmp(a->name, b->name);
2951}
2952
2953static void show_dirstat(struct diff_options *options)
2954{
2955        int i;
2956        unsigned long changed;
2957        struct dirstat_dir dir;
2958        struct diff_queue_struct *q = &diff_queued_diff;
2959
2960        dir.files = NULL;
2961        dir.alloc = 0;
2962        dir.nr = 0;
2963        dir.permille = options->dirstat_permille;
2964        dir.cumulative = options->flags.dirstat_cumulative;
2965
2966        changed = 0;
2967        for (i = 0; i < q->nr; i++) {
2968                struct diff_filepair *p = q->queue[i];
2969                const char *name;
2970                unsigned long copied, added, damage;
2971
2972                name = p->two->path ? p->two->path : p->one->path;
2973
2974                if (p->one->oid_valid && p->two->oid_valid &&
2975                    oideq(&p->one->oid, &p->two->oid)) {
2976                        /*
2977                         * The SHA1 has not changed, so pre-/post-content is
2978                         * identical. We can therefore skip looking at the
2979                         * file contents altogether.
2980                         */
2981                        damage = 0;
2982                        goto found_damage;
2983                }
2984
2985                if (options->flags.dirstat_by_file) {
2986                        /*
2987                         * In --dirstat-by-file mode, we don't really need to
2988                         * look at the actual file contents at all.
2989                         * The fact that the SHA1 changed is enough for us to
2990                         * add this file to the list of results
2991                         * (with each file contributing equal damage).
2992                         */
2993                        damage = 1;
2994                        goto found_damage;
2995                }
2996
2997                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
2998                        diff_populate_filespec(options->repo, p->one, 0);
2999                        diff_populate_filespec(options->repo, p->two, 0);
3000                        diffcore_count_changes(options->repo,
3001                                               p->one, p->two, NULL, NULL,
3002                                               &copied, &added);
3003                        diff_free_filespec_data(p->one);
3004                        diff_free_filespec_data(p->two);
3005                } else if (DIFF_FILE_VALID(p->one)) {
3006                        diff_populate_filespec(options->repo, p->one, CHECK_SIZE_ONLY);
3007                        copied = added = 0;
3008                        diff_free_filespec_data(p->one);
3009                } else if (DIFF_FILE_VALID(p->two)) {
3010                        diff_populate_filespec(options->repo, p->two, CHECK_SIZE_ONLY);
3011                        copied = 0;
3012                        added = p->two->size;
3013                        diff_free_filespec_data(p->two);
3014                } else
3015                        continue;
3016
3017                /*
3018                 * Original minus copied is the removed material,
3019                 * added is the new material.  They are both damages
3020                 * made to the preimage.
3021                 * If the resulting damage is zero, we know that
3022                 * diffcore_count_changes() considers the two entries to
3023                 * be identical, but since the oid changed, we
3024                 * know that there must have been _some_ kind of change,
3025                 * so we force all entries to have damage > 0.
3026                 */
3027                damage = (p->one->size - copied) + added;
3028                if (!damage)
3029                        damage = 1;
3030
3031found_damage:
3032                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
3033                dir.files[dir.nr].name = name;
3034                dir.files[dir.nr].changed = damage;
3035                changed += damage;
3036                dir.nr++;
3037        }
3038
3039        /* This can happen even with many files, if everything was renames */
3040        if (!changed)
3041                return;
3042
3043        /* Show all directories with more than x% of the changes */
3044        QSORT(dir.files, dir.nr, dirstat_compare);
3045        gather_dirstat(options, &dir, changed, "", 0);
3046}
3047
3048static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
3049{
3050        int i;
3051        unsigned long changed;
3052        struct dirstat_dir dir;
3053
3054        if (data->nr == 0)
3055                return;
3056
3057        dir.files = NULL;
3058        dir.alloc = 0;
3059        dir.nr = 0;
3060        dir.permille = options->dirstat_permille;
3061        dir.cumulative = options->flags.dirstat_cumulative;
3062
3063        changed = 0;
3064        for (i = 0; i < data->nr; i++) {
3065                struct diffstat_file *file = data->files[i];
3066                unsigned long damage = file->added + file->deleted;
3067                if (file->is_binary)
3068                        /*
3069                         * binary files counts bytes, not lines. Must find some
3070                         * way to normalize binary bytes vs. textual lines.
3071                         * The following heuristic assumes that there are 64
3072                         * bytes per "line".
3073                         * This is stupid and ugly, but very cheap...
3074                         */
3075                        damage = DIV_ROUND_UP(damage, 64);
3076                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
3077                dir.files[dir.nr].name = file->name;
3078                dir.files[dir.nr].changed = damage;
3079                changed += damage;
3080                dir.nr++;
3081        }
3082
3083        /* This can happen even with many files, if everything was renames */
3084        if (!changed)
3085                return;
3086
3087        /* Show all directories with more than x% of the changes */
3088        QSORT(dir.files, dir.nr, dirstat_compare);
3089        gather_dirstat(options, &dir, changed, "", 0);
3090}
3091
3092static void free_diffstat_info(struct diffstat_t *diffstat)
3093{
3094        int i;
3095        for (i = 0; i < diffstat->nr; i++) {
3096                struct diffstat_file *f = diffstat->files[i];
3097                free(f->print_name);
3098                free(f->name);
3099                free(f->from_name);
3100                free(f);
3101        }
3102        free(diffstat->files);
3103}
3104
3105struct checkdiff_t {
3106        const char *filename;
3107        int lineno;
3108        int conflict_marker_size;
3109        struct diff_options *o;
3110        unsigned ws_rule;
3111        unsigned status;
3112};
3113
3114static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
3115{
3116        char firstchar;
3117        int cnt;
3118
3119        if (len < marker_size + 1)
3120                return 0;
3121        firstchar = line[0];
3122        switch (firstchar) {
3123        case '=': case '>': case '<': case '|':
3124                break;
3125        default:
3126                return 0;
3127        }
3128        for (cnt = 1; cnt < marker_size; cnt++)
3129                if (line[cnt] != firstchar)
3130                        return 0;
3131        /* line[1] thru line[marker_size-1] are same as firstchar */
3132        if (len < marker_size + 1 || !isspace(line[marker_size]))
3133                return 0;
3134        return 1;
3135}
3136
3137static void checkdiff_consume_hunk(void *priv,
3138                                   long ob, long on, long nb, long nn,
3139                                   const char *func, long funclen)
3140
3141{
3142        struct checkdiff_t *data = priv;
3143        data->lineno = nb - 1;
3144}
3145
3146static void checkdiff_consume(void *priv, char *line, unsigned long len)
3147{
3148        struct checkdiff_t *data = priv;
3149        int marker_size = data->conflict_marker_size;
3150        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
3151        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
3152        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
3153        char *err;
3154        const char *line_prefix;
3155
3156        assert(data->o);
3157        line_prefix = diff_line_prefix(data->o);
3158
3159        if (line[0] == '+') {
3160                unsigned bad;
3161                data->lineno++;
3162                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
3163                        data->status |= 1;
3164                        fprintf(data->o->file,
3165                                "%s%s:%d: leftover conflict marker\n",
3166                                line_prefix, data->filename, data->lineno);
3167                }
3168                bad = ws_check(line + 1, len - 1, data->ws_rule);
3169                if (!bad)
3170                        return;
3171                data->status |= bad;
3172                err = whitespace_error_string(bad);
3173                fprintf(data->o->file, "%s%s:%d: %s.\n",
3174                        line_prefix, data->filename, data->lineno, err);
3175                free(err);
3176                emit_line(data->o, set, reset, line, 1);
3177                ws_check_emit(line + 1, len - 1, data->ws_rule,
3178                              data->o->file, set, reset, ws);
3179        } else if (line[0] == ' ') {
3180                data->lineno++;
3181        }
3182}
3183
3184static unsigned char *deflate_it(char *data,
3185                                 unsigned long size,
3186                                 unsigned long *result_size)
3187{
3188        int bound;
3189        unsigned char *deflated;
3190        git_zstream stream;
3191
3192        git_deflate_init(&stream, zlib_compression_level);
3193        bound = git_deflate_bound(&stream, size);
3194        deflated = xmalloc(bound);
3195        stream.next_out = deflated;
3196        stream.avail_out = bound;
3197
3198        stream.next_in = (unsigned char *)data;
3199        stream.avail_in = size;
3200        while (git_deflate(&stream, Z_FINISH) == Z_OK)
3201                ; /* nothing */
3202        git_deflate_end(&stream);
3203        *result_size = stream.total_out;
3204        return deflated;
3205}
3206
3207static void emit_binary_diff_body(struct diff_options *o,
3208                                  mmfile_t *one, mmfile_t *two)
3209{
3210        void *cp;
3211        void *delta;
3212        void *deflated;
3213        void *data;
3214        unsigned long orig_size;
3215        unsigned long delta_size;
3216        unsigned long deflate_size;
3217        unsigned long data_size;
3218
3219        /* We could do deflated delta, or we could do just deflated two,
3220         * whichever is smaller.
3221         */
3222        delta = NULL;
3223        deflated = deflate_it(two->ptr, two->size, &deflate_size);
3224        if (one->size && two->size) {
3225                delta = diff_delta(one->ptr, one->size,
3226                                   two->ptr, two->size,
3227                                   &delta_size, deflate_size);
3228                if (delta) {
3229                        void *to_free = delta;
3230                        orig_size = delta_size;
3231                        delta = deflate_it(delta, delta_size, &delta_size);
3232                        free(to_free);
3233                }
3234        }
3235
3236        if (delta && delta_size < deflate_size) {
3237                char *s = xstrfmt("%"PRIuMAX , (uintmax_t)orig_size);
3238                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
3239                                 s, strlen(s), 0);
3240                free(s);
3241                free(deflated);
3242                data = delta;
3243                data_size = delta_size;
3244        } else {
3245                char *s = xstrfmt("%lu", two->size);
3246                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
3247                                 s, strlen(s), 0);
3248                free(s);
3249                free(delta);
3250                data = deflated;
3251                data_size = deflate_size;
3252        }
3253
3254        /* emit data encoded in base85 */
3255        cp = data;
3256        while (data_size) {
3257                int len;
3258                int bytes = (52 < data_size) ? 52 : data_size;
3259                char line[71];
3260                data_size -= bytes;
3261                if (bytes <= 26)
3262                        line[0] = bytes + 'A' - 1;
3263                else
3264                        line[0] = bytes - 26 + 'a' - 1;
3265                encode_85(line + 1, cp, bytes);
3266                cp = (char *) cp + bytes;
3267
3268                len = strlen(line);
3269                line[len++] = '\n';
3270                line[len] = '\0';
3271
3272                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_BODY,
3273                                 line, len, 0);
3274        }
3275        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_FOOTER, NULL, 0, 0);
3276        free(data);
3277}
3278
3279static void emit_binary_diff(struct diff_options *o,
3280                             mmfile_t *one, mmfile_t *two)
3281{
3282        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER, NULL, 0, 0);
3283        emit_binary_diff_body(o, one, two);
3284        emit_binary_diff_body(o, two, one);
3285}
3286
3287int diff_filespec_is_binary(struct repository *r,
3288                            struct diff_filespec *one)
3289{
3290        if (one->is_binary == -1) {
3291                diff_filespec_load_driver(one, r->index);
3292                if (one->driver->binary != -1)
3293                        one->is_binary = one->driver->binary;
3294                else {
3295                        if (!one->data && DIFF_FILE_VALID(one))
3296                                diff_populate_filespec(r, one, CHECK_BINARY);
3297                        if (one->is_binary == -1 && one->data)
3298                                one->is_binary = buffer_is_binary(one->data,
3299                                                one->size);
3300                        if (one->is_binary == -1)
3301                                one->is_binary = 0;
3302                }
3303        }
3304        return one->is_binary;
3305}
3306
3307static const struct userdiff_funcname *
3308diff_funcname_pattern(struct diff_options *o, struct diff_filespec *one)
3309{
3310        diff_filespec_load_driver(one, o->repo->index);
3311        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
3312}
3313
3314void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
3315{
3316        if (!options->a_prefix)
3317                options->a_prefix = a;
3318        if (!options->b_prefix)
3319                options->b_prefix = b;
3320}
3321
3322struct userdiff_driver *get_textconv(struct repository *r,
3323                                     struct diff_filespec *one)
3324{
3325        if (!DIFF_FILE_VALID(one))
3326                return NULL;
3327
3328        diff_filespec_load_driver(one, r->index);
3329        return userdiff_get_textconv(r, one->driver);
3330}
3331
3332static void builtin_diff(const char *name_a,
3333                         const char *name_b,
3334                         struct diff_filespec *one,
3335                         struct diff_filespec *two,
3336                         const char *xfrm_msg,
3337                         int must_show_header,
3338                         struct diff_options *o,
3339                         int complete_rewrite)
3340{
3341        mmfile_t mf1, mf2;
3342        const char *lbl[2];
3343        char *a_one, *b_two;
3344        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
3345        const char *reset = diff_get_color_opt(o, DIFF_RESET);
3346        const char *a_prefix, *b_prefix;
3347        struct userdiff_driver *textconv_one = NULL;
3348        struct userdiff_driver *textconv_two = NULL;
3349        struct strbuf header = STRBUF_INIT;
3350        const char *line_prefix = diff_line_prefix(o);
3351
3352        diff_set_mnemonic_prefix(o, "a/", "b/");
3353        if (o->flags.reverse_diff) {
3354                a_prefix = o->b_prefix;
3355                b_prefix = o->a_prefix;
3356        } else {
3357                a_prefix = o->a_prefix;
3358                b_prefix = o->b_prefix;
3359        }
3360
3361        if (o->submodule_format == DIFF_SUBMODULE_LOG &&
3362            (!one->mode || S_ISGITLINK(one->mode)) &&
3363            (!two->mode || S_ISGITLINK(two->mode))) {
3364                show_submodule_summary(o, one->path ? one->path : two->path,
3365                                &one->oid, &two->oid,
3366                                two->dirty_submodule);
3367                return;
3368        } else if (o->submodule_format == DIFF_SUBMODULE_INLINE_DIFF &&
3369                   (!one->mode || S_ISGITLINK(one->mode)) &&
3370                   (!two->mode || S_ISGITLINK(two->mode))) {
3371                show_submodule_inline_diff(o, one->path ? one->path : two->path,
3372                                &one->oid, &two->oid,
3373                                two->dirty_submodule);
3374                return;
3375        }
3376
3377        if (o->flags.allow_textconv) {
3378                textconv_one = get_textconv(o->repo, one);
3379                textconv_two = get_textconv(o->repo, two);
3380        }
3381
3382        /* Never use a non-valid filename anywhere if at all possible */
3383        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
3384        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
3385
3386        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
3387        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
3388        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
3389        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
3390        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
3391        if (lbl[0][0] == '/') {
3392                /* /dev/null */
3393                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
3394                if (xfrm_msg)
3395                        strbuf_addstr(&header, xfrm_msg);
3396                must_show_header = 1;
3397        }
3398        else if (lbl[1][0] == '/') {
3399                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
3400                if (xfrm_msg)
3401                        strbuf_addstr(&header, xfrm_msg);
3402                must_show_header = 1;
3403        }
3404        else {
3405                if (one->mode != two->mode) {
3406                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
3407                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
3408                        must_show_header = 1;
3409                }
3410                if (xfrm_msg)
3411                        strbuf_addstr(&header, xfrm_msg);
3412
3413                /*
3414                 * we do not run diff between different kind
3415                 * of objects.
3416                 */
3417                if ((one->mode ^ two->mode) & S_IFMT)
3418                        goto free_ab_and_return;
3419                if (complete_rewrite &&
3420                    (textconv_one || !diff_filespec_is_binary(o->repo, one)) &&
3421                    (textconv_two || !diff_filespec_is_binary(o->repo, two))) {
3422                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3423                                         header.buf, header.len, 0);
3424                        strbuf_reset(&header);
3425                        emit_rewrite_diff(name_a, name_b, one, two,
3426                                          textconv_one, textconv_two, o);
3427                        o->found_changes = 1;
3428                        goto free_ab_and_return;
3429                }
3430        }
3431
3432        if (o->irreversible_delete && lbl[1][0] == '/') {
3433                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf,
3434                                 header.len, 0);
3435                strbuf_reset(&header);
3436                goto free_ab_and_return;
3437        } else if (!o->flags.text &&
3438                   ( (!textconv_one && diff_filespec_is_binary(o->repo, one)) ||
3439                     (!textconv_two && diff_filespec_is_binary(o->repo, two)) )) {
3440                struct strbuf sb = STRBUF_INIT;
3441                if (!one->data && !two->data &&
3442                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
3443                    !o->flags.binary) {
3444                        if (oideq(&one->oid, &two->oid)) {
3445                                if (must_show_header)
3446                                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3447                                                         header.buf, header.len,
3448                                                         0);
3449                                goto free_ab_and_return;
3450                        }
3451                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3452                                         header.buf, header.len, 0);
3453                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3454                                    diff_line_prefix(o), lbl[0], lbl[1]);
3455                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3456                                         sb.buf, sb.len, 0);
3457                        strbuf_release(&sb);
3458                        goto free_ab_and_return;
3459                }
3460                if (fill_mmfile(o->repo, &mf1, one) < 0 ||
3461                    fill_mmfile(o->repo, &mf2, two) < 0)
3462                        die("unable to read files to diff");
3463                /* Quite common confusing case */
3464                if (mf1.size == mf2.size &&
3465                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
3466                        if (must_show_header)
3467                                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3468                                                 header.buf, header.len, 0);
3469                        goto free_ab_and_return;
3470                }
3471                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf, header.len, 0);
3472                strbuf_reset(&header);
3473                if (o->flags.binary)
3474                        emit_binary_diff(o, &mf1, &mf2);
3475                else {
3476                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3477                                    diff_line_prefix(o), lbl[0], lbl[1]);
3478                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3479                                         sb.buf, sb.len, 0);
3480                        strbuf_release(&sb);
3481                }
3482                o->found_changes = 1;
3483        } else {
3484                /* Crazy xdl interfaces.. */
3485                const char *diffopts = getenv("GIT_DIFF_OPTS");
3486                const char *v;
3487                xpparam_t xpp;
3488                xdemitconf_t xecfg;
3489                struct emit_callback ecbdata;
3490                const struct userdiff_funcname *pe;
3491
3492                if (must_show_header) {
3493                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3494                                         header.buf, header.len, 0);
3495                        strbuf_reset(&header);
3496                }
3497
3498                mf1.size = fill_textconv(o->repo, textconv_one, one, &mf1.ptr);
3499                mf2.size = fill_textconv(o->repo, textconv_two, two, &mf2.ptr);
3500
3501                pe = diff_funcname_pattern(o, one);
3502                if (!pe)
3503                        pe = diff_funcname_pattern(o, two);
3504
3505                memset(&xpp, 0, sizeof(xpp));
3506                memset(&xecfg, 0, sizeof(xecfg));
3507                memset(&ecbdata, 0, sizeof(ecbdata));
3508                if (o->flags.suppress_diff_headers)
3509                        lbl[0] = NULL;
3510                ecbdata.label_path = lbl;
3511                ecbdata.color_diff = want_color(o->use_color);
3512                ecbdata.ws_rule = whitespace_rule(o->repo->index, name_b);
3513                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
3514                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3515                ecbdata.opt = o;
3516                if (header.len && !o->flags.suppress_diff_headers)
3517                        ecbdata.header = &header;
3518                xpp.flags = o->xdl_opts;
3519                xpp.anchors = o->anchors;
3520                xpp.anchors_nr = o->anchors_nr;
3521                xecfg.ctxlen = o->context;
3522                xecfg.interhunkctxlen = o->interhunkcontext;
3523                xecfg.flags = XDL_EMIT_FUNCNAMES;
3524                if (o->flags.funccontext)
3525                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
3526                if (pe)
3527                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
3528                if (!diffopts)
3529                        ;
3530                else if (skip_prefix(diffopts, "--unified=", &v))
3531                        xecfg.ctxlen = strtoul(v, NULL, 10);
3532                else if (skip_prefix(diffopts, "-u", &v))
3533                        xecfg.ctxlen = strtoul(v, NULL, 10);
3534                if (o->word_diff)
3535                        init_diff_words_data(&ecbdata, o, one, two);
3536                if (xdi_diff_outf(&mf1, &mf2, NULL, fn_out_consume,
3537                                  &ecbdata, &xpp, &xecfg))
3538                        die("unable to generate diff for %s", one->path);
3539                if (o->word_diff)
3540                        free_diff_words_data(&ecbdata);
3541                if (textconv_one)
3542                        free(mf1.ptr);
3543                if (textconv_two)
3544                        free(mf2.ptr);
3545                xdiff_clear_find_func(&xecfg);
3546        }
3547
3548 free_ab_and_return:
3549        strbuf_release(&header);
3550        diff_free_filespec_data(one);
3551        diff_free_filespec_data(two);
3552        free(a_one);
3553        free(b_two);
3554        return;
3555}
3556
3557static char *get_compact_summary(const struct diff_filepair *p, int is_renamed)
3558{
3559        if (!is_renamed) {
3560                if (p->status == DIFF_STATUS_ADDED) {
3561                        if (S_ISLNK(p->two->mode))
3562                                return "new +l";
3563                        else if ((p->two->mode & 0777) == 0755)
3564                                return "new +x";
3565                        else
3566                                return "new";
3567                } else if (p->status == DIFF_STATUS_DELETED)
3568                        return "gone";
3569        }
3570        if (S_ISLNK(p->one->mode) && !S_ISLNK(p->two->mode))
3571                return "mode -l";
3572        else if (!S_ISLNK(p->one->mode) && S_ISLNK(p->two->mode))
3573                return "mode +l";
3574        else if ((p->one->mode & 0777) == 0644 &&
3575                 (p->two->mode & 0777) == 0755)
3576                return "mode +x";
3577        else if ((p->one->mode & 0777) == 0755 &&
3578                 (p->two->mode & 0777) == 0644)
3579                return "mode -x";
3580        return NULL;
3581}
3582
3583static void builtin_diffstat(const char *name_a, const char *name_b,
3584                             struct diff_filespec *one,
3585                             struct diff_filespec *two,
3586                             struct diffstat_t *diffstat,
3587                             struct diff_options *o,
3588                             struct diff_filepair *p)
3589{
3590        mmfile_t mf1, mf2;
3591        struct diffstat_file *data;
3592        int same_contents;
3593        int complete_rewrite = 0;
3594
3595        if (!DIFF_PAIR_UNMERGED(p)) {
3596                if (p->status == DIFF_STATUS_MODIFIED && p->score)
3597                        complete_rewrite = 1;
3598        }
3599
3600        data = diffstat_add(diffstat, name_a, name_b);
3601        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
3602        if (o->flags.stat_with_summary)
3603                data->comments = get_compact_summary(p, data->is_renamed);
3604
3605        if (!one || !two) {
3606                data->is_unmerged = 1;
3607                return;
3608        }
3609
3610        same_contents = oideq(&one->oid, &two->oid);
3611
3612        if (diff_filespec_is_binary(o->repo, one) ||
3613            diff_filespec_is_binary(o->repo, two)) {
3614                data->is_binary = 1;
3615                if (same_contents) {
3616                        data->added = 0;
3617                        data->deleted = 0;
3618                } else {
3619                        data->added = diff_filespec_size(o->repo, two);
3620                        data->deleted = diff_filespec_size(o->repo, one);
3621                }
3622        }
3623
3624        else if (complete_rewrite) {
3625                diff_populate_filespec(o->repo, one, 0);
3626                diff_populate_filespec(o->repo, two, 0);
3627                data->deleted = count_lines(one->data, one->size);
3628                data->added = count_lines(two->data, two->size);
3629        }
3630
3631        else if (!same_contents) {
3632                /* Crazy xdl interfaces.. */
3633                xpparam_t xpp;
3634                xdemitconf_t xecfg;
3635
3636                if (fill_mmfile(o->repo, &mf1, one) < 0 ||
3637                    fill_mmfile(o->repo, &mf2, two) < 0)
3638                        die("unable to read files to diff");
3639
3640                memset(&xpp, 0, sizeof(xpp));
3641                memset(&xecfg, 0, sizeof(xecfg));
3642                xpp.flags = o->xdl_opts;
3643                xpp.anchors = o->anchors;
3644                xpp.anchors_nr = o->anchors_nr;
3645                xecfg.ctxlen = o->context;
3646                xecfg.interhunkctxlen = o->interhunkcontext;
3647                if (xdi_diff_outf(&mf1, &mf2, discard_hunk_line,
3648                                  diffstat_consume, diffstat, &xpp, &xecfg))
3649                        die("unable to generate diffstat for %s", one->path);
3650        }
3651
3652        diff_free_filespec_data(one);
3653        diff_free_filespec_data(two);
3654}
3655
3656static void builtin_checkdiff(const char *name_a, const char *name_b,
3657                              const char *attr_path,
3658                              struct diff_filespec *one,
3659                              struct diff_filespec *two,
3660                              struct diff_options *o)
3661{
3662        mmfile_t mf1, mf2;
3663        struct checkdiff_t data;
3664
3665        if (!two)
3666                return;
3667
3668        memset(&data, 0, sizeof(data));
3669        data.filename = name_b ? name_b : name_a;
3670        data.lineno = 0;
3671        data.o = o;
3672        data.ws_rule = whitespace_rule(o->repo->index, attr_path);
3673        data.conflict_marker_size = ll_merge_marker_size(o->repo->index, attr_path);
3674
3675        if (fill_mmfile(o->repo, &mf1, one) < 0 ||
3676            fill_mmfile(o->repo, &mf2, two) < 0)
3677                die("unable to read files to diff");
3678
3679        /*
3680         * All the other codepaths check both sides, but not checking
3681         * the "old" side here is deliberate.  We are checking the newly
3682         * introduced changes, and as long as the "new" side is text, we
3683         * can and should check what it introduces.
3684         */
3685        if (diff_filespec_is_binary(o->repo, two))
3686                goto free_and_return;
3687        else {
3688                /* Crazy xdl interfaces.. */
3689                xpparam_t xpp;
3690                xdemitconf_t xecfg;
3691
3692                memset(&xpp, 0, sizeof(xpp));
3693                memset(&xecfg, 0, sizeof(xecfg));
3694                xecfg.ctxlen = 1; /* at least one context line */
3695                xpp.flags = 0;
3696                if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume_hunk,
3697                                  checkdiff_consume, &data,
3698                                  &xpp, &xecfg))
3699                        die("unable to generate checkdiff for %s", one->path);
3700
3701                if (data.ws_rule & WS_BLANK_AT_EOF) {
3702                        struct emit_callback ecbdata;
3703                        int blank_at_eof;
3704
3705                        ecbdata.ws_rule = data.ws_rule;
3706                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3707                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
3708
3709                        if (blank_at_eof) {
3710                                static char *err;
3711                                if (!err)
3712                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
3713                                fprintf(o->file, "%s:%d: %s.\n",
3714                                        data.filename, blank_at_eof, err);
3715                                data.status = 1; /* report errors */
3716                        }
3717                }
3718        }
3719 free_and_return:
3720        diff_free_filespec_data(one);
3721        diff_free_filespec_data(two);
3722        if (data.status)
3723                o->flags.check_failed = 1;
3724}
3725
3726struct diff_filespec *alloc_filespec(const char *path)
3727{
3728        struct diff_filespec *spec;
3729
3730        FLEXPTR_ALLOC_STR(spec, path, path);
3731        spec->count = 1;
3732        spec->is_binary = -1;
3733        return spec;
3734}
3735
3736void free_filespec(struct diff_filespec *spec)
3737{
3738        if (!--spec->count) {
3739                diff_free_filespec_data(spec);
3740                free(spec);
3741        }
3742}
3743
3744void fill_filespec(struct diff_filespec *spec, const struct object_id *oid,
3745                   int oid_valid, unsigned short mode)
3746{
3747        if (mode) {
3748                spec->mode = canon_mode(mode);
3749                oidcpy(&spec->oid, oid);
3750                spec->oid_valid = oid_valid;
3751        }
3752}
3753
3754/*
3755 * Given a name and sha1 pair, if the index tells us the file in
3756 * the work tree has that object contents, return true, so that
3757 * prepare_temp_file() does not have to inflate and extract.
3758 */
3759static int reuse_worktree_file(struct index_state *istate,
3760                               const char *name,
3761                               const struct object_id *oid,
3762                               int want_file)
3763{
3764        const struct cache_entry *ce;
3765        struct stat st;
3766        int pos, len;
3767
3768        /*
3769         * We do not read the cache ourselves here, because the
3770         * benchmark with my previous version that always reads cache
3771         * shows that it makes things worse for diff-tree comparing
3772         * two linux-2.6 kernel trees in an already checked out work
3773         * tree.  This is because most diff-tree comparisons deal with
3774         * only a small number of files, while reading the cache is
3775         * expensive for a large project, and its cost outweighs the
3776         * savings we get by not inflating the object to a temporary
3777         * file.  Practically, this code only helps when we are used
3778         * by diff-cache --cached, which does read the cache before
3779         * calling us.
3780         */
3781        if (!istate->cache)
3782                return 0;
3783
3784        /* We want to avoid the working directory if our caller
3785         * doesn't need the data in a normal file, this system
3786         * is rather slow with its stat/open/mmap/close syscalls,
3787         * and the object is contained in a pack file.  The pack
3788         * is probably already open and will be faster to obtain
3789         * the data through than the working directory.  Loose
3790         * objects however would tend to be slower as they need
3791         * to be individually opened and inflated.
3792         */
3793        if (!FAST_WORKING_DIRECTORY && !want_file && has_object_pack(oid))
3794                return 0;
3795
3796        /*
3797         * Similarly, if we'd have to convert the file contents anyway, that
3798         * makes the optimization not worthwhile.
3799         */
3800        if (!want_file && would_convert_to_git(istate, name))
3801                return 0;
3802
3803        len = strlen(name);
3804        pos = index_name_pos(istate, name, len);
3805        if (pos < 0)
3806                return 0;
3807        ce = istate->cache[pos];
3808
3809        /*
3810         * This is not the sha1 we are looking for, or
3811         * unreusable because it is not a regular file.
3812         */
3813        if (!oideq(oid, &ce->oid) || !S_ISREG(ce->ce_mode))
3814                return 0;
3815
3816        /*
3817         * If ce is marked as "assume unchanged", there is no
3818         * guarantee that work tree matches what we are looking for.
3819         */
3820        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
3821                return 0;
3822
3823        /*
3824         * If ce matches the file in the work tree, we can reuse it.
3825         */
3826        if (ce_uptodate(ce) ||
3827            (!lstat(name, &st) && !ie_match_stat(istate, ce, &st, 0)))
3828                return 1;
3829
3830        return 0;
3831}
3832
3833static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
3834{
3835        struct strbuf buf = STRBUF_INIT;
3836        char *dirty = "";
3837
3838        /* Are we looking at the work tree? */
3839        if (s->dirty_submodule)
3840                dirty = "-dirty";
3841
3842        strbuf_addf(&buf, "Subproject commit %s%s\n",
3843                    oid_to_hex(&s->oid), dirty);
3844        s->size = buf.len;
3845        if (size_only) {
3846                s->data = NULL;
3847                strbuf_release(&buf);
3848        } else {
3849                s->data = strbuf_detach(&buf, NULL);
3850                s->should_free = 1;
3851        }
3852        return 0;
3853}
3854
3855/*
3856 * While doing rename detection and pickaxe operation, we may need to
3857 * grab the data for the blob (or file) for our own in-core comparison.
3858 * diff_filespec has data and size fields for this purpose.
3859 */
3860int diff_populate_filespec(struct repository *r,
3861                           struct diff_filespec *s,
3862                           unsigned int flags)
3863{
3864        int size_only = flags & CHECK_SIZE_ONLY;
3865        int err = 0;
3866        int conv_flags = global_conv_flags_eol;
3867        /*
3868         * demote FAIL to WARN to allow inspecting the situation
3869         * instead of refusing.
3870         */
3871        if (conv_flags & CONV_EOL_RNDTRP_DIE)
3872                conv_flags = CONV_EOL_RNDTRP_WARN;
3873
3874        if (!DIFF_FILE_VALID(s))
3875                die("internal error: asking to populate invalid file.");
3876        if (S_ISDIR(s->mode))
3877                return -1;
3878
3879        if (s->data)
3880                return 0;
3881
3882        if (size_only && 0 < s->size)
3883                return 0;
3884
3885        if (S_ISGITLINK(s->mode))
3886                return diff_populate_gitlink(s, size_only);
3887
3888        if (!s->oid_valid ||
3889            reuse_worktree_file(r->index, s->path, &s->oid, 0)) {
3890                struct strbuf buf = STRBUF_INIT;
3891                struct stat st;
3892                int fd;
3893
3894                if (lstat(s->path, &st) < 0) {
3895                err_empty:
3896                        err = -1;
3897                empty:
3898                        s->data = (char *)"";
3899                        s->size = 0;
3900                        return err;
3901                }
3902                s->size = xsize_t(st.st_size);
3903                if (!s->size)
3904                        goto empty;
3905                if (S_ISLNK(st.st_mode)) {
3906                        struct strbuf sb = STRBUF_INIT;
3907
3908                        if (strbuf_readlink(&sb, s->path, s->size))
3909                                goto err_empty;
3910                        s->size = sb.len;
3911                        s->data = strbuf_detach(&sb, NULL);
3912                        s->should_free = 1;
3913                        return 0;
3914                }
3915
3916                /*
3917                 * Even if the caller would be happy with getting
3918                 * only the size, we cannot return early at this
3919                 * point if the path requires us to run the content
3920                 * conversion.
3921                 */
3922                if (size_only && !would_convert_to_git(r->index, s->path))
3923                        return 0;
3924
3925                /*
3926                 * Note: this check uses xsize_t(st.st_size) that may
3927                 * not be the true size of the blob after it goes
3928                 * through convert_to_git().  This may not strictly be
3929                 * correct, but the whole point of big_file_threshold
3930                 * and is_binary check being that we want to avoid
3931                 * opening the file and inspecting the contents, this
3932                 * is probably fine.
3933                 */
3934                if ((flags & CHECK_BINARY) &&
3935                    s->size > big_file_threshold && s->is_binary == -1) {
3936                        s->is_binary = 1;
3937                        return 0;
3938                }
3939                fd = open(s->path, O_RDONLY);
3940                if (fd < 0)
3941                        goto err_empty;
3942                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
3943                close(fd);
3944                s->should_munmap = 1;
3945
3946                /*
3947                 * Convert from working tree format to canonical git format
3948                 */
3949                if (convert_to_git(r->index, s->path, s->data, s->size, &buf, conv_flags)) {
3950                        size_t size = 0;
3951                        munmap(s->data, s->size);
3952                        s->should_munmap = 0;
3953                        s->data = strbuf_detach(&buf, &size);
3954                        s->size = size;
3955                        s->should_free = 1;
3956                }
3957        }
3958        else {
3959                enum object_type type;
3960                if (size_only || (flags & CHECK_BINARY)) {
3961                        type = oid_object_info(r, &s->oid, &s->size);
3962                        if (type < 0)
3963                                die("unable to read %s",
3964                                    oid_to_hex(&s->oid));
3965                        if (size_only)
3966                                return 0;
3967                        if (s->size > big_file_threshold && s->is_binary == -1) {
3968                                s->is_binary = 1;
3969                                return 0;
3970                        }
3971                }
3972                s->data = read_object_file(&s->oid, &type, &s->size);
3973                if (!s->data)
3974                        die("unable to read %s", oid_to_hex(&s->oid));
3975                s->should_free = 1;
3976        }
3977        return 0;
3978}
3979
3980void diff_free_filespec_blob(struct diff_filespec *s)
3981{
3982        if (s->should_free)
3983                free(s->data);
3984        else if (s->should_munmap)
3985                munmap(s->data, s->size);
3986
3987        if (s->should_free || s->should_munmap) {
3988                s->should_free = s->should_munmap = 0;
3989                s->data = NULL;
3990        }
3991}
3992
3993void diff_free_filespec_data(struct diff_filespec *s)
3994{
3995        diff_free_filespec_blob(s);
3996        FREE_AND_NULL(s->cnt_data);
3997}
3998
3999static void prep_temp_blob(struct index_state *istate,
4000                           const char *path, struct diff_tempfile *temp,
4001                           void *blob,
4002                           unsigned long size,
4003                           const struct object_id *oid,
4004                           int mode)
4005{
4006        struct strbuf buf = STRBUF_INIT;
4007        struct strbuf tempfile = STRBUF_INIT;
4008        char *path_dup = xstrdup(path);
4009        const char *base = basename(path_dup);
4010
4011        /* Generate "XXXXXX_basename.ext" */
4012        strbuf_addstr(&tempfile, "XXXXXX_");
4013        strbuf_addstr(&tempfile, base);
4014
4015        temp->tempfile = mks_tempfile_ts(tempfile.buf, strlen(base) + 1);
4016        if (!temp->tempfile)
4017                die_errno("unable to create temp-file");
4018        if (convert_to_working_tree(istate, path,
4019                        (const char *)blob, (size_t)size, &buf)) {
4020                blob = buf.buf;
4021                size = buf.len;
4022        }
4023        if (write_in_full(temp->tempfile->fd, blob, size) < 0 ||
4024            close_tempfile_gently(temp->tempfile))
4025                die_errno("unable to write temp-file");
4026        temp->name = get_tempfile_path(temp->tempfile);
4027        oid_to_hex_r(temp->hex, oid);
4028        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
4029        strbuf_release(&buf);
4030        strbuf_release(&tempfile);
4031        free(path_dup);
4032}
4033
4034static struct diff_tempfile *prepare_temp_file(struct repository *r,
4035                                               const char *name,
4036                                               struct diff_filespec *one)
4037{
4038        struct diff_tempfile *temp = claim_diff_tempfile();
4039
4040        if (!DIFF_FILE_VALID(one)) {
4041        not_a_valid_file:
4042                /* A '-' entry produces this for file-2, and
4043                 * a '+' entry produces this for file-1.
4044                 */
4045                temp->name = "/dev/null";
4046                xsnprintf(temp->hex, sizeof(temp->hex), ".");
4047                xsnprintf(temp->mode, sizeof(temp->mode), ".");
4048                return temp;
4049        }
4050
4051        if (!S_ISGITLINK(one->mode) &&
4052            (!one->oid_valid ||
4053             reuse_worktree_file(r->index, name, &one->oid, 1))) {
4054                struct stat st;
4055                if (lstat(name, &st) < 0) {
4056                        if (errno == ENOENT)
4057                                goto not_a_valid_file;
4058                        die_errno("stat(%s)", name);
4059                }
4060                if (S_ISLNK(st.st_mode)) {
4061                        struct strbuf sb = STRBUF_INIT;
4062                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
4063                                die_errno("readlink(%s)", name);
4064                        prep_temp_blob(r->index, name, temp, sb.buf, sb.len,
4065                                       (one->oid_valid ?
4066                                        &one->oid : &null_oid),
4067                                       (one->oid_valid ?
4068                                        one->mode : S_IFLNK));
4069                        strbuf_release(&sb);
4070                }
4071                else {
4072                        /* we can borrow from the file in the work tree */
4073                        temp->name = name;
4074                        if (!one->oid_valid)
4075                                oid_to_hex_r(temp->hex, &null_oid);
4076                        else
4077                                oid_to_hex_r(temp->hex, &one->oid);
4078                        /* Even though we may sometimes borrow the
4079                         * contents from the work tree, we always want
4080                         * one->mode.  mode is trustworthy even when
4081                         * !(one->oid_valid), as long as
4082                         * DIFF_FILE_VALID(one).
4083                         */
4084                        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
4085                }
4086                return temp;
4087        }
4088        else {
4089                if (diff_populate_filespec(r, one, 0))
4090                        die("cannot read data blob for %s", one->path);
4091                prep_temp_blob(r->index, name, temp,
4092                               one->data, one->size,
4093                               &one->oid, one->mode);
4094        }
4095        return temp;
4096}
4097
4098static void add_external_diff_name(struct repository *r,
4099                                   struct argv_array *argv,
4100                                   const char *name,
4101                                   struct diff_filespec *df)
4102{
4103        struct diff_tempfile *temp = prepare_temp_file(r, name, df);
4104        argv_array_push(argv, temp->name);
4105        argv_array_push(argv, temp->hex);
4106        argv_array_push(argv, temp->mode);
4107}
4108
4109/* An external diff command takes:
4110 *
4111 * diff-cmd name infile1 infile1-sha1 infile1-mode \
4112 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
4113 *
4114 */
4115static void run_external_diff(const char *pgm,
4116                              const char *name,
4117                              const char *other,
4118                              struct diff_filespec *one,
4119                              struct diff_filespec *two,
4120                              const char *xfrm_msg,
4121                              int complete_rewrite,
4122                              struct diff_options *o)
4123{
4124        struct argv_array argv = ARGV_ARRAY_INIT;
4125        struct argv_array env = ARGV_ARRAY_INIT;
4126        struct diff_queue_struct *q = &diff_queued_diff;
4127
4128        argv_array_push(&argv, pgm);
4129        argv_array_push(&argv, name);
4130
4131        if (one && two) {
4132                add_external_diff_name(o->repo, &argv, name, one);
4133                if (!other)
4134                        add_external_diff_name(o->repo, &argv, name, two);
4135                else {
4136                        add_external_diff_name(o->repo, &argv, other, two);
4137                        argv_array_push(&argv, other);
4138                        argv_array_push(&argv, xfrm_msg);
4139                }
4140        }
4141
4142        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
4143        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
4144
4145        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
4146                die(_("external diff died, stopping at %s"), name);
4147
4148        remove_tempfile();
4149        argv_array_clear(&argv);
4150        argv_array_clear(&env);
4151}
4152
4153static int similarity_index(struct diff_filepair *p)
4154{
4155        return p->score * 100 / MAX_SCORE;
4156}
4157
4158static const char *diff_abbrev_oid(const struct object_id *oid, int abbrev)
4159{
4160        if (startup_info->have_repository)
4161                return find_unique_abbrev(oid, abbrev);
4162        else {
4163                char *hex = oid_to_hex(oid);
4164                if (abbrev < 0)
4165                        abbrev = FALLBACK_DEFAULT_ABBREV;
4166                if (abbrev > the_hash_algo->hexsz)
4167                        BUG("oid abbreviation out of range: %d", abbrev);
4168                if (abbrev)
4169                        hex[abbrev] = '\0';
4170                return hex;
4171        }
4172}
4173
4174static void fill_metainfo(struct strbuf *msg,
4175                          const char *name,
4176                          const char *other,
4177                          struct diff_filespec *one,
4178                          struct diff_filespec *two,
4179                          struct diff_options *o,
4180                          struct diff_filepair *p,
4181                          int *must_show_header,
4182                          int use_color)
4183{
4184        const char *set = diff_get_color(use_color, DIFF_METAINFO);
4185        const char *reset = diff_get_color(use_color, DIFF_RESET);
4186        const char *line_prefix = diff_line_prefix(o);
4187
4188        *must_show_header = 1;
4189        strbuf_init(msg, PATH_MAX * 2 + 300);
4190        switch (p->status) {
4191        case DIFF_STATUS_COPIED:
4192                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4193                            line_prefix, set, similarity_index(p));
4194                strbuf_addf(msg, "%s\n%s%scopy from ",
4195                            reset,  line_prefix, set);
4196                quote_c_style(name, msg, NULL, 0);
4197                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
4198                quote_c_style(other, msg, NULL, 0);
4199                strbuf_addf(msg, "%s\n", reset);
4200                break;
4201        case DIFF_STATUS_RENAMED:
4202                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4203                            line_prefix, set, similarity_index(p));
4204                strbuf_addf(msg, "%s\n%s%srename from ",
4205                            reset, line_prefix, set);
4206                quote_c_style(name, msg, NULL, 0);
4207                strbuf_addf(msg, "%s\n%s%srename to ",
4208                            reset, line_prefix, set);
4209                quote_c_style(other, msg, NULL, 0);
4210                strbuf_addf(msg, "%s\n", reset);
4211                break;
4212        case DIFF_STATUS_MODIFIED:
4213                if (p->score) {
4214                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
4215                                    line_prefix,
4216                                    set, similarity_index(p), reset);
4217                        break;
4218                }
4219                /* fallthru */
4220        default:
4221                *must_show_header = 0;
4222        }
4223        if (one && two && !oideq(&one->oid, &two->oid)) {
4224                const unsigned hexsz = the_hash_algo->hexsz;
4225                int abbrev = o->flags.full_index ? hexsz : DEFAULT_ABBREV;
4226
4227                if (o->flags.binary) {
4228                        mmfile_t mf;
4229                        if ((!fill_mmfile(o->repo, &mf, one) &&
4230                             diff_filespec_is_binary(o->repo, one)) ||
4231                            (!fill_mmfile(o->repo, &mf, two) &&
4232                             diff_filespec_is_binary(o->repo, two)))
4233                                abbrev = hexsz;
4234                }
4235                strbuf_addf(msg, "%s%sindex %s..%s", line_prefix, set,
4236                            diff_abbrev_oid(&one->oid, abbrev),
4237                            diff_abbrev_oid(&two->oid, abbrev));
4238                if (one->mode == two->mode)
4239                        strbuf_addf(msg, " %06o", one->mode);
4240                strbuf_addf(msg, "%s\n", reset);
4241        }
4242}
4243
4244static void run_diff_cmd(const char *pgm,
4245                         const char *name,
4246                         const char *other,
4247                         const char *attr_path,
4248                         struct diff_filespec *one,
4249                         struct diff_filespec *two,
4250                         struct strbuf *msg,
4251                         struct diff_options *o,
4252                         struct diff_filepair *p)
4253{
4254        const char *xfrm_msg = NULL;
4255        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
4256        int must_show_header = 0;
4257
4258
4259        if (o->flags.allow_external) {
4260                struct userdiff_driver *drv;
4261
4262                drv = userdiff_find_by_path(o->repo->index, attr_path);
4263                if (drv && drv->external)
4264                        pgm = drv->external;
4265        }
4266
4267        if (msg) {
4268                /*
4269                 * don't use colors when the header is intended for an
4270                 * external diff driver
4271                 */
4272                fill_metainfo(msg, name, other, one, two, o, p,
4273                              &must_show_header,
4274                              want_color(o->use_color) && !pgm);
4275                xfrm_msg = msg->len ? msg->buf : NULL;
4276        }
4277
4278        if (pgm) {
4279                run_external_diff(pgm, name, other, one, two, xfrm_msg,
4280                                  complete_rewrite, o);
4281                return;
4282        }
4283        if (one && two)
4284                builtin_diff(name, other ? other : name,
4285                             one, two, xfrm_msg, must_show_header,
4286                             o, complete_rewrite);
4287        else
4288                fprintf(o->file, "* Unmerged path %s\n", name);
4289}
4290
4291static void diff_fill_oid_info(struct diff_filespec *one, struct index_state *istate)
4292{
4293        if (DIFF_FILE_VALID(one)) {
4294                if (!one->oid_valid) {
4295                        struct stat st;
4296                        if (one->is_stdin) {
4297                                oidclr(&one->oid);
4298                                return;
4299                        }
4300                        if (lstat(one->path, &st) < 0)
4301                                die_errno("stat '%s'", one->path);
4302                        if (index_path(istate, &one->oid, one->path, &st, 0))
4303                                die("cannot hash %s", one->path);
4304                }
4305        }
4306        else
4307                oidclr(&one->oid);
4308}
4309
4310static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
4311{
4312        /* Strip the prefix but do not molest /dev/null and absolute paths */
4313        if (*namep && !is_absolute_path(*namep)) {
4314                *namep += prefix_length;
4315                if (**namep == '/')
4316                        ++*namep;
4317        }
4318        if (*otherp && !is_absolute_path(*otherp)) {
4319                *otherp += prefix_length;
4320                if (**otherp == '/')
4321                        ++*otherp;
4322        }
4323}
4324
4325static void run_diff(struct diff_filepair *p, struct diff_options *o)
4326{
4327        const char *pgm = external_diff();
4328        struct strbuf msg;
4329        struct diff_filespec *one = p->one;
4330        struct diff_filespec *two = p->two;
4331        const char *name;
4332        const char *other;
4333        const char *attr_path;
4334
4335        name  = one->path;
4336        other = (strcmp(name, two->path) ? two->path : NULL);
4337        attr_path = name;
4338        if (o->prefix_length)
4339                strip_prefix(o->prefix_length, &name, &other);
4340
4341        if (!o->flags.allow_external)
4342                pgm = NULL;
4343
4344        if (DIFF_PAIR_UNMERGED(p)) {
4345                run_diff_cmd(pgm, name, NULL, attr_path,
4346                             NULL, NULL, NULL, o, p);
4347                return;
4348        }
4349
4350        diff_fill_oid_info(one, o->repo->index);
4351        diff_fill_oid_info(two, o->repo->index);
4352
4353        if (!pgm &&
4354            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
4355            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
4356                /*
4357                 * a filepair that changes between file and symlink
4358                 * needs to be split into deletion and creation.
4359                 */
4360                struct diff_filespec *null = alloc_filespec(two->path);
4361                run_diff_cmd(NULL, name, other, attr_path,
4362                             one, null, &msg,
4363                             o, p);
4364                free(null);
4365                strbuf_release(&msg);
4366
4367                null = alloc_filespec(one->path);
4368                run_diff_cmd(NULL, name, other, attr_path,
4369                             null, two, &msg, o, p);
4370                free(null);
4371        }
4372        else
4373                run_diff_cmd(pgm, name, other, attr_path,
4374                             one, two, &msg, o, p);
4375
4376        strbuf_release(&msg);
4377}
4378
4379static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
4380                         struct diffstat_t *diffstat)
4381{
4382        const char *name;
4383        const char *other;
4384
4385        if (DIFF_PAIR_UNMERGED(p)) {
4386                /* unmerged */
4387                builtin_diffstat(p->one->path, NULL, NULL, NULL,
4388                                 diffstat, o, p);
4389                return;
4390        }
4391
4392        name = p->one->path;
4393        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4394
4395        if (o->prefix_length)
4396                strip_prefix(o->prefix_length, &name, &other);
4397
4398        diff_fill_oid_info(p->one, o->repo->index);
4399        diff_fill_oid_info(p->two, o->repo->index);
4400
4401        builtin_diffstat(name, other, p->one, p->two,
4402                         diffstat, o, p);
4403}
4404
4405static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
4406{
4407        const char *name;
4408        const char *other;
4409        const char *attr_path;
4410
4411        if (DIFF_PAIR_UNMERGED(p)) {
4412                /* unmerged */
4413                return;
4414        }
4415
4416        name = p->one->path;
4417        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4418        attr_path = other ? other : name;
4419
4420        if (o->prefix_length)
4421                strip_prefix(o->prefix_length, &name, &other);
4422
4423        diff_fill_oid_info(p->one, o->repo->index);
4424        diff_fill_oid_info(p->two, o->repo->index);
4425
4426        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
4427}
4428
4429static void prep_parse_options(struct diff_options *options);
4430
4431void repo_diff_setup(struct repository *r, struct diff_options *options)
4432{
4433        memcpy(options, &default_diff_options, sizeof(*options));
4434
4435        options->file = stdout;
4436        options->repo = r;
4437
4438        options->output_indicators[OUTPUT_INDICATOR_NEW] = '+';
4439        options->output_indicators[OUTPUT_INDICATOR_OLD] = '-';
4440        options->output_indicators[OUTPUT_INDICATOR_CONTEXT] = ' ';
4441        options->abbrev = DEFAULT_ABBREV;
4442        options->line_termination = '\n';
4443        options->break_opt = -1;
4444        options->rename_limit = -1;
4445        options->dirstat_permille = diff_dirstat_permille_default;
4446        options->context = diff_context_default;
4447        options->interhunkcontext = diff_interhunk_context_default;
4448        options->ws_error_highlight = ws_error_highlight_default;
4449        options->flags.rename_empty = 1;
4450        options->objfind = NULL;
4451
4452        /* pathchange left =NULL by default */
4453        options->change = diff_change;
4454        options->add_remove = diff_addremove;
4455        options->use_color = diff_use_color_default;
4456        options->detect_rename = diff_detect_rename_default;
4457        options->xdl_opts |= diff_algorithm;
4458        if (diff_indent_heuristic)
4459                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4460
4461        options->orderfile = diff_order_file_cfg;
4462
4463        if (diff_no_prefix) {
4464                options->a_prefix = options->b_prefix = "";
4465        } else if (!diff_mnemonic_prefix) {
4466                options->a_prefix = "a/";
4467                options->b_prefix = "b/";
4468        }
4469
4470        options->color_moved = diff_color_moved_default;
4471        options->color_moved_ws_handling = diff_color_moved_ws_default;
4472
4473        prep_parse_options(options);
4474}
4475
4476void diff_setup_done(struct diff_options *options)
4477{
4478        unsigned check_mask = DIFF_FORMAT_NAME |
4479                              DIFF_FORMAT_NAME_STATUS |
4480                              DIFF_FORMAT_CHECKDIFF |
4481                              DIFF_FORMAT_NO_OUTPUT;
4482        /*
4483         * This must be signed because we're comparing against a potentially
4484         * negative value.
4485         */
4486        const int hexsz = the_hash_algo->hexsz;
4487
4488        if (options->set_default)
4489                options->set_default(options);
4490
4491        if (HAS_MULTI_BITS(options->output_format & check_mask))
4492                die(_("--name-only, --name-status, --check and -s are mutually exclusive"));
4493
4494        if (HAS_MULTI_BITS(options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK))
4495                die(_("-G, -S and --find-object are mutually exclusive"));
4496
4497        /*
4498         * Most of the time we can say "there are changes"
4499         * only by checking if there are changed paths, but
4500         * --ignore-whitespace* options force us to look
4501         * inside contents.
4502         */
4503
4504        if ((options->xdl_opts & XDF_WHITESPACE_FLAGS))
4505                options->flags.diff_from_contents = 1;
4506        else
4507                options->flags.diff_from_contents = 0;
4508
4509        if (options->flags.find_copies_harder)
4510                options->detect_rename = DIFF_DETECT_COPY;
4511
4512        if (!options->flags.relative_name)
4513                options->prefix = NULL;
4514        if (options->prefix)
4515                options->prefix_length = strlen(options->prefix);
4516        else
4517                options->prefix_length = 0;
4518
4519        if (options->output_format & (DIFF_FORMAT_NAME |
4520                                      DIFF_FORMAT_NAME_STATUS |
4521                                      DIFF_FORMAT_CHECKDIFF |
4522                                      DIFF_FORMAT_NO_OUTPUT))
4523                options->output_format &= ~(DIFF_FORMAT_RAW |
4524                                            DIFF_FORMAT_NUMSTAT |
4525                                            DIFF_FORMAT_DIFFSTAT |
4526                                            DIFF_FORMAT_SHORTSTAT |
4527                                            DIFF_FORMAT_DIRSTAT |
4528                                            DIFF_FORMAT_SUMMARY |
4529                                            DIFF_FORMAT_PATCH);
4530
4531        /*
4532         * These cases always need recursive; we do not drop caller-supplied
4533         * recursive bits for other formats here.
4534         */
4535        if (options->output_format & (DIFF_FORMAT_PATCH |
4536                                      DIFF_FORMAT_NUMSTAT |
4537                                      DIFF_FORMAT_DIFFSTAT |
4538                                      DIFF_FORMAT_SHORTSTAT |
4539                                      DIFF_FORMAT_DIRSTAT |
4540                                      DIFF_FORMAT_SUMMARY |
4541                                      DIFF_FORMAT_CHECKDIFF))
4542                options->flags.recursive = 1;
4543        /*
4544         * Also pickaxe would not work very well if you do not say recursive
4545         */
4546        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
4547                options->flags.recursive = 1;
4548        /*
4549         * When patches are generated, submodules diffed against the work tree
4550         * must be checked for dirtiness too so it can be shown in the output
4551         */
4552        if (options->output_format & DIFF_FORMAT_PATCH)
4553                options->flags.dirty_submodules = 1;
4554
4555        if (options->detect_rename && options->rename_limit < 0)
4556                options->rename_limit = diff_rename_limit_default;
4557        if (hexsz < options->abbrev)
4558                options->abbrev = hexsz; /* full */
4559
4560        /*
4561         * It does not make sense to show the first hit we happened
4562         * to have found.  It does not make sense not to return with
4563         * exit code in such a case either.
4564         */
4565        if (options->flags.quick) {
4566                options->output_format = DIFF_FORMAT_NO_OUTPUT;
4567                options->flags.exit_with_status = 1;
4568        }
4569
4570        options->diff_path_counter = 0;
4571
4572        if (options->flags.follow_renames && options->pathspec.nr != 1)
4573                die(_("--follow requires exactly one pathspec"));
4574
4575        if (!options->use_color || external_diff())
4576                options->color_moved = 0;
4577
4578        FREE_AND_NULL(options->parseopts);
4579}
4580
4581static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
4582{
4583        char c, *eq;
4584        int len;
4585
4586        if (*arg != '-')
4587                return 0;
4588        c = *++arg;
4589        if (!c)
4590                return 0;
4591        if (c == arg_short) {
4592                c = *++arg;
4593                if (!c)
4594                        return 1;
4595                if (val && isdigit(c)) {
4596                        char *end;
4597                        int n = strtoul(arg, &end, 10);
4598                        if (*end)
4599                                return 0;
4600                        *val = n;
4601                        return 1;
4602                }
4603                return 0;
4604        }
4605        if (c != '-')
4606                return 0;
4607        arg++;
4608        eq = strchrnul(arg, '=');
4609        len = eq - arg;
4610        if (!len || strncmp(arg, arg_long, len))
4611                return 0;
4612        if (*eq) {
4613                int n;
4614                char *end;
4615                if (!isdigit(*++eq))
4616                        return 0;
4617                n = strtoul(eq, &end, 10);
4618                if (*end)
4619                        return 0;
4620                *val = n;
4621        }
4622        return 1;
4623}
4624
4625static int diff_scoreopt_parse(const char *opt);
4626
4627static inline int short_opt(char opt, const char **argv,
4628                            const char **optarg)
4629{
4630        const char *arg = argv[0];
4631        if (arg[0] != '-' || arg[1] != opt)
4632                return 0;
4633        if (arg[2] != '\0') {
4634                *optarg = arg + 2;
4635                return 1;
4636        }
4637        if (!argv[1])
4638                die("Option '%c' requires a value", opt);
4639        *optarg = argv[1];
4640        return 2;
4641}
4642
4643int parse_long_opt(const char *opt, const char **argv,
4644                   const char **optarg)
4645{
4646        const char *arg = argv[0];
4647        if (!skip_prefix(arg, "--", &arg))
4648                return 0;
4649        if (!skip_prefix(arg, opt, &arg))
4650                return 0;
4651        if (*arg == '=') { /* stuck form: --option=value */
4652                *optarg = arg + 1;
4653                return 1;
4654        }
4655        if (*arg != '\0')
4656                return 0;
4657        /* separate form: --option value */
4658        if (!argv[1])
4659                die("Option '--%s' requires a value", opt);
4660        *optarg = argv[1];
4661        return 2;
4662}
4663
4664static int stat_opt(struct diff_options *options, const char **av)
4665{
4666        const char *arg = av[0];
4667        char *end;
4668        int width = options->stat_width;
4669        int name_width = options->stat_name_width;
4670        int graph_width = options->stat_graph_width;
4671        int count = options->stat_count;
4672        int argcount = 1;
4673
4674        if (!skip_prefix(arg, "--stat", &arg))
4675                BUG("stat option does not begin with --stat: %s", arg);
4676        end = (char *)arg;
4677
4678        switch (*arg) {
4679        case '-':
4680                if (skip_prefix(arg, "-width", &arg)) {
4681                        if (*arg == '=')
4682                                width = strtoul(arg + 1, &end, 10);
4683                        else if (!*arg && !av[1])
4684                                die_want_option("--stat-width");
4685                        else if (!*arg) {
4686                                width = strtoul(av[1], &end, 10);
4687                                argcount = 2;
4688                        }
4689                } else if (skip_prefix(arg, "-name-width", &arg)) {
4690                        if (*arg == '=')
4691                                name_width = strtoul(arg + 1, &end, 10);
4692                        else if (!*arg && !av[1])
4693                                die_want_option("--stat-name-width");
4694                        else if (!*arg) {
4695                                name_width = strtoul(av[1], &end, 10);
4696                                argcount = 2;
4697                        }
4698                } else if (skip_prefix(arg, "-graph-width", &arg)) {
4699                        if (*arg == '=')
4700                                graph_width = strtoul(arg + 1, &end, 10);
4701                        else if (!*arg && !av[1])
4702                                die_want_option("--stat-graph-width");
4703                        else if (!*arg) {
4704                                graph_width = strtoul(av[1], &end, 10);
4705                                argcount = 2;
4706                        }
4707                } else if (skip_prefix(arg, "-count", &arg)) {
4708                        if (*arg == '=')
4709                                count = strtoul(arg + 1, &end, 10);
4710                        else if (!*arg && !av[1])
4711                                die_want_option("--stat-count");
4712                        else if (!*arg) {
4713                                count = strtoul(av[1], &end, 10);
4714                                argcount = 2;
4715                        }
4716                }
4717                break;
4718        case '=':
4719                width = strtoul(arg+1, &end, 10);
4720                if (*end == ',')
4721                        name_width = strtoul(end+1, &end, 10);
4722                if (*end == ',')
4723                        count = strtoul(end+1, &end, 10);
4724        }
4725
4726        /* Important! This checks all the error cases! */
4727        if (*end)
4728                return 0;
4729        options->output_format |= DIFF_FORMAT_DIFFSTAT;
4730        options->stat_name_width = name_width;
4731        options->stat_graph_width = graph_width;
4732        options->stat_width = width;
4733        options->stat_count = count;
4734        return argcount;
4735}
4736
4737static int parse_dirstat_opt(struct diff_options *options, const char *params)
4738{
4739        struct strbuf errmsg = STRBUF_INIT;
4740        if (parse_dirstat_params(options, params, &errmsg))
4741                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
4742                    errmsg.buf);
4743        strbuf_release(&errmsg);
4744        /*
4745         * The caller knows a dirstat-related option is given from the command
4746         * line; allow it to say "return this_function();"
4747         */
4748        options->output_format |= DIFF_FORMAT_DIRSTAT;
4749        return 1;
4750}
4751
4752static int parse_submodule_opt(struct diff_options *options, const char *value)
4753{
4754        if (parse_submodule_params(options, value))
4755                die(_("Failed to parse --submodule option parameter: '%s'"),
4756                        value);
4757        return 1;
4758}
4759
4760static const char diff_status_letters[] = {
4761        DIFF_STATUS_ADDED,
4762        DIFF_STATUS_COPIED,
4763        DIFF_STATUS_DELETED,
4764        DIFF_STATUS_MODIFIED,
4765        DIFF_STATUS_RENAMED,
4766        DIFF_STATUS_TYPE_CHANGED,
4767        DIFF_STATUS_UNKNOWN,
4768        DIFF_STATUS_UNMERGED,
4769        DIFF_STATUS_FILTER_AON,
4770        DIFF_STATUS_FILTER_BROKEN,
4771        '\0',
4772};
4773
4774static unsigned int filter_bit['Z' + 1];
4775
4776static void prepare_filter_bits(void)
4777{
4778        int i;
4779
4780        if (!filter_bit[DIFF_STATUS_ADDED]) {
4781                for (i = 0; diff_status_letters[i]; i++)
4782                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
4783        }
4784}
4785
4786static unsigned filter_bit_tst(char status, const struct diff_options *opt)
4787{
4788        return opt->filter & filter_bit[(int) status];
4789}
4790
4791static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
4792{
4793        int i, optch;
4794
4795        prepare_filter_bits();
4796
4797        /*
4798         * If there is a negation e.g. 'd' in the input, and we haven't
4799         * initialized the filter field with another --diff-filter, start
4800         * from full set of bits, except for AON.
4801         */
4802        if (!opt->filter) {
4803                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4804                        if (optch < 'a' || 'z' < optch)
4805                                continue;
4806                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
4807                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
4808                        break;
4809                }
4810        }
4811
4812        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4813                unsigned int bit;
4814                int negate;
4815
4816                if ('a' <= optch && optch <= 'z') {
4817                        negate = 1;
4818                        optch = toupper(optch);
4819                } else {
4820                        negate = 0;
4821                }
4822
4823                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
4824                if (!bit)
4825                        return optarg[i];
4826                if (negate)
4827                        opt->filter &= ~bit;
4828                else
4829                        opt->filter |= bit;
4830        }
4831        return 0;
4832}
4833
4834static void enable_patch_output(int *fmt)
4835{
4836        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
4837        *fmt |= DIFF_FORMAT_PATCH;
4838}
4839
4840static int parse_ws_error_highlight_opt(struct diff_options *opt, const char *arg)
4841{
4842        int val = parse_ws_error_highlight(arg);
4843
4844        if (val < 0) {
4845                error("unknown value after ws-error-highlight=%.*s",
4846                      -1 - val, arg);
4847                return 0;
4848        }
4849        opt->ws_error_highlight = val;
4850        return 1;
4851}
4852
4853static int parse_objfind_opt(struct diff_options *opt, const char *arg)
4854{
4855        struct object_id oid;
4856
4857        if (get_oid(arg, &oid))
4858                return error("unable to resolve '%s'", arg);
4859
4860        if (!opt->objfind)
4861                opt->objfind = xcalloc(1, sizeof(*opt->objfind));
4862
4863        opt->pickaxe_opts |= DIFF_PICKAXE_KIND_OBJFIND;
4864        opt->flags.recursive = 1;
4865        opt->flags.tree_in_recursive = 1;
4866        oidset_insert(opt->objfind, &oid);
4867        return 1;
4868}
4869
4870static int diff_opt_dirstat(const struct option *opt,
4871                            const char *arg, int unset)
4872{
4873        struct diff_options *options = opt->value;
4874
4875        BUG_ON_OPT_NEG(unset);
4876        if (!strcmp(opt->long_name, "cumulative")) {
4877                if (arg)
4878                        BUG("how come --cumulative take a value?");
4879                arg = "cumulative";
4880        } else if (!strcmp(opt->long_name, "dirstat-by-file"))
4881                parse_dirstat_opt(options, "files");
4882        parse_dirstat_opt(options, arg ? arg : "");
4883        return 0;
4884}
4885
4886static int diff_opt_unified(const struct option *opt,
4887                            const char *arg, int unset)
4888{
4889        struct diff_options *options = opt->value;
4890        char *s;
4891
4892        BUG_ON_OPT_NEG(unset);
4893
4894        options->context = strtol(arg, &s, 10);
4895        if (*s)
4896                return error(_("%s expects a numerical value"), "--unified");
4897        enable_patch_output(&options->output_format);
4898
4899        return 0;
4900}
4901
4902static void prep_parse_options(struct diff_options *options)
4903{
4904        struct option parseopts[] = {
4905                OPT_GROUP(N_("Diff output format options")),
4906                OPT_BITOP('p', "patch", &options->output_format,
4907                          N_("generate patch"),
4908                          DIFF_FORMAT_PATCH, DIFF_FORMAT_NO_OUTPUT),
4909                OPT_BITOP('u', NULL, &options->output_format,
4910                          N_("generate patch"),
4911                          DIFF_FORMAT_PATCH, DIFF_FORMAT_NO_OUTPUT),
4912                OPT_CALLBACK_F('U', "unified", options, N_("<n>"),
4913                               N_("generate diffs with <n> lines context"),
4914                               PARSE_OPT_NONEG, diff_opt_unified),
4915                OPT_BOOL('W', "function-context", &options->flags.funccontext,
4916                         N_("generate diffs with <n> lines context")),
4917                OPT_BIT_F(0, "raw", &options->output_format,
4918                          N_("generate the diff in raw format"),
4919                          DIFF_FORMAT_RAW, PARSE_OPT_NONEG),
4920                OPT_BITOP(0, "patch-with-raw", &options->output_format,
4921                          N_("synonym for '-p --raw'"),
4922                          DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW,
4923                          DIFF_FORMAT_NO_OUTPUT),
4924                OPT_BIT_F(0, "numstat", &options->output_format,
4925                          N_("machine friendly --stat"),
4926                          DIFF_FORMAT_NUMSTAT, PARSE_OPT_NONEG),
4927                OPT_BIT_F(0, "shortstat", &options->output_format,
4928                          N_("output only the last line of --stat"),
4929                          DIFF_FORMAT_SHORTSTAT, PARSE_OPT_NONEG),
4930                OPT_CALLBACK_F('X', "dirstat", options, N_("<param1,param2>..."),
4931                               N_("output the distribution of relative amount of changes for each sub-directory"),
4932                               PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
4933                               diff_opt_dirstat),
4934                OPT_CALLBACK_F(0, "cumulative", options, NULL,
4935                               N_("synonym for --dirstat=cumulative"),
4936                               PARSE_OPT_NONEG | PARSE_OPT_NOARG,
4937                               diff_opt_dirstat),
4938                OPT_CALLBACK_F(0, "dirstat-by-file", options, N_("<param1,param2>..."),
4939                               N_("synonym for --dirstat=files,param1,param2..."),
4940                               PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
4941                               diff_opt_dirstat),
4942                OPT_BIT_F(0, "check", &options->output_format,
4943                          N_("warn if changes introduce conflict markers or whitespace errors"),
4944                          DIFF_FORMAT_CHECKDIFF, PARSE_OPT_NONEG),
4945                OPT_BIT_F(0, "summary", &options->output_format,
4946                          N_("condensed summary such as creations, renames and mode changes"),
4947                          DIFF_FORMAT_SUMMARY, PARSE_OPT_NONEG),
4948                OPT_END()
4949        };
4950
4951        ALLOC_ARRAY(options->parseopts, ARRAY_SIZE(parseopts));
4952        memcpy(options->parseopts, parseopts, sizeof(parseopts));
4953}
4954
4955int diff_opt_parse(struct diff_options *options,
4956                   const char **av, int ac, const char *prefix)
4957{
4958        const char *arg = av[0];
4959        const char *optarg;
4960        int argcount;
4961
4962        if (!prefix)
4963                prefix = "";
4964
4965        ac = parse_options(ac, av, prefix, options->parseopts, NULL,
4966                           PARSE_OPT_KEEP_DASHDASH |
4967                           PARSE_OPT_KEEP_UNKNOWN |
4968                           PARSE_OPT_NO_INTERNAL_HELP |
4969                           PARSE_OPT_ONE_SHOT |
4970                           PARSE_OPT_STOP_AT_NON_OPTION);
4971
4972        if (ac)
4973                return ac;
4974
4975        /* Output format options */
4976        if (!strcmp(arg, "--patch-with-stat")) {
4977                enable_patch_output(&options->output_format);
4978                options->output_format |= DIFF_FORMAT_DIFFSTAT;
4979        } else if (!strcmp(arg, "--name-only"))
4980                options->output_format |= DIFF_FORMAT_NAME;
4981        else if (!strcmp(arg, "--name-status"))
4982                options->output_format |= DIFF_FORMAT_NAME_STATUS;
4983        else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
4984                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
4985        else if (starts_with(arg, "--stat"))
4986                /* --stat, --stat-width, --stat-name-width, or --stat-count */
4987                return stat_opt(options, av);
4988        else if (!strcmp(arg, "--compact-summary")) {
4989                 options->flags.stat_with_summary = 1;
4990                 options->output_format |= DIFF_FORMAT_DIFFSTAT;
4991        } else if (!strcmp(arg, "--no-compact-summary"))
4992                 options->flags.stat_with_summary = 0;
4993        else if (skip_prefix(arg, "--output-indicator-new=", &arg))
4994                options->output_indicators[OUTPUT_INDICATOR_NEW] = arg[0];
4995        else if (skip_prefix(arg, "--output-indicator-old=", &arg))
4996                options->output_indicators[OUTPUT_INDICATOR_OLD] = arg[0];
4997        else if (skip_prefix(arg, "--output-indicator-context=", &arg))
4998                options->output_indicators[OUTPUT_INDICATOR_CONTEXT] = arg[0];
4999
5000        /* renames options */
5001        else if (starts_with(arg, "-B") ||
5002                 skip_to_optional_arg(arg, "--break-rewrites", NULL)) {
5003                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
5004                        return error("invalid argument to -B: %s", arg+2);
5005        }
5006        else if (starts_with(arg, "-M") ||
5007                 skip_to_optional_arg(arg, "--find-renames", NULL)) {
5008                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
5009                        return error("invalid argument to -M: %s", arg+2);
5010                options->detect_rename = DIFF_DETECT_RENAME;
5011        }
5012        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
5013                options->irreversible_delete = 1;
5014        }
5015        else if (starts_with(arg, "-C") ||
5016                 skip_to_optional_arg(arg, "--find-copies", NULL)) {
5017                if (options->detect_rename == DIFF_DETECT_COPY)
5018                        options->flags.find_copies_harder = 1;
5019                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
5020                        return error("invalid argument to -C: %s", arg+2);
5021                options->detect_rename = DIFF_DETECT_COPY;
5022        }
5023        else if (!strcmp(arg, "--no-renames"))
5024                options->detect_rename = 0;
5025        else if (!strcmp(arg, "--rename-empty"))
5026                options->flags.rename_empty = 1;
5027        else if (!strcmp(arg, "--no-rename-empty"))
5028                options->flags.rename_empty = 0;
5029        else if (skip_to_optional_arg_default(arg, "--relative", &arg, NULL)) {
5030                options->flags.relative_name = 1;
5031                if (arg)
5032                        options->prefix = arg;
5033        }
5034
5035        /* xdiff options */
5036        else if (!strcmp(arg, "--minimal"))
5037                DIFF_XDL_SET(options, NEED_MINIMAL);
5038        else if (!strcmp(arg, "--no-minimal"))
5039                DIFF_XDL_CLR(options, NEED_MINIMAL);
5040        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
5041                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
5042        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
5043                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
5044        else if (!strcmp(arg, "--ignore-space-at-eol"))
5045                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
5046        else if (!strcmp(arg, "--ignore-cr-at-eol"))
5047                DIFF_XDL_SET(options, IGNORE_CR_AT_EOL);
5048        else if (!strcmp(arg, "--ignore-blank-lines"))
5049                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
5050        else if (!strcmp(arg, "--indent-heuristic"))
5051                DIFF_XDL_SET(options, INDENT_HEURISTIC);
5052        else if (!strcmp(arg, "--no-indent-heuristic"))
5053                DIFF_XDL_CLR(options, INDENT_HEURISTIC);
5054        else if (!strcmp(arg, "--patience")) {
5055                int i;
5056                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
5057                /*
5058                 * Both --patience and --anchored use PATIENCE_DIFF
5059                 * internally, so remove any anchors previously
5060                 * specified.
5061                 */
5062                for (i = 0; i < options->anchors_nr; i++)
5063                        free(options->anchors[i]);
5064                options->anchors_nr = 0;
5065        } else if (!strcmp(arg, "--histogram"))
5066                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
5067        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
5068                long value = parse_algorithm_value(optarg);
5069                if (value < 0)
5070                        return error("option diff-algorithm accepts \"myers\", "
5071                                     "\"minimal\", \"patience\" and \"histogram\"");
5072                /* clear out previous settings */
5073                DIFF_XDL_CLR(options, NEED_MINIMAL);
5074                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
5075                options->xdl_opts |= value;
5076                return argcount;
5077        } else if (skip_prefix(arg, "--anchored=", &arg)) {
5078                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
5079                ALLOC_GROW(options->anchors, options->anchors_nr + 1,
5080                           options->anchors_alloc);
5081                options->anchors[options->anchors_nr++] = xstrdup(arg);
5082        }
5083
5084        /* flags options */
5085        else if (!strcmp(arg, "--binary")) {
5086                enable_patch_output(&options->output_format);
5087                options->flags.binary = 1;
5088        }
5089        else if (!strcmp(arg, "--full-index"))
5090                options->flags.full_index = 1;
5091        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
5092                options->flags.text = 1;
5093        else if (!strcmp(arg, "-R"))
5094                options->flags.reverse_diff = 1;
5095        else if (!strcmp(arg, "--find-copies-harder"))
5096                options->flags.find_copies_harder = 1;
5097        else if (!strcmp(arg, "--follow"))
5098                options->flags.follow_renames = 1;
5099        else if (!strcmp(arg, "--no-follow")) {
5100                options->flags.follow_renames = 0;
5101                options->flags.default_follow_renames = 0;
5102        } else if (skip_to_optional_arg_default(arg, "--color", &arg, "always")) {
5103                int value = git_config_colorbool(NULL, arg);
5104                if (value < 0)
5105                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
5106                options->use_color = value;
5107        }
5108        else if (!strcmp(arg, "--no-color"))
5109                options->use_color = 0;
5110        else if (!strcmp(arg, "--color-moved")) {
5111                if (diff_color_moved_default)
5112                        options->color_moved = diff_color_moved_default;
5113                if (options->color_moved == COLOR_MOVED_NO)
5114                        options->color_moved = COLOR_MOVED_DEFAULT;
5115        } else if (!strcmp(arg, "--no-color-moved"))
5116                options->color_moved = COLOR_MOVED_NO;
5117        else if (skip_prefix(arg, "--color-moved=", &arg)) {
5118                int cm = parse_color_moved(arg);
5119                if (cm < 0)
5120                        return error("bad --color-moved argument: %s", arg);
5121                options->color_moved = cm;
5122        } else if (skip_prefix(arg, "--color-moved-ws=", &arg)) {
5123                unsigned cm = parse_color_moved_ws(arg);
5124                if (cm & COLOR_MOVED_WS_ERROR)
5125                        return -1;
5126                options->color_moved_ws_handling = cm;
5127        } else if (skip_to_optional_arg_default(arg, "--color-words", &options->word_regex, NULL)) {
5128                options->use_color = 1;
5129                options->word_diff = DIFF_WORDS_COLOR;
5130        }
5131        else if (!strcmp(arg, "--word-diff")) {
5132                if (options->word_diff == DIFF_WORDS_NONE)
5133                        options->word_diff = DIFF_WORDS_PLAIN;
5134        }
5135        else if (skip_prefix(arg, "--word-diff=", &arg)) {
5136                if (!strcmp(arg, "plain"))
5137                        options->word_diff = DIFF_WORDS_PLAIN;
5138                else if (!strcmp(arg, "color")) {
5139                        options->use_color = 1;
5140                        options->word_diff = DIFF_WORDS_COLOR;
5141                }
5142                else if (!strcmp(arg, "porcelain"))
5143                        options->word_diff = DIFF_WORDS_PORCELAIN;
5144                else if (!strcmp(arg, "none"))
5145                        options->word_diff = DIFF_WORDS_NONE;
5146                else
5147                        die("bad --word-diff argument: %s", arg);
5148        }
5149        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
5150                if (options->word_diff == DIFF_WORDS_NONE)
5151                        options->word_diff = DIFF_WORDS_PLAIN;
5152                options->word_regex = optarg;
5153                return argcount;
5154        }
5155        else if (!strcmp(arg, "--exit-code"))
5156                options->flags.exit_with_status = 1;
5157        else if (!strcmp(arg, "--quiet"))
5158                options->flags.quick = 1;
5159        else if (!strcmp(arg, "--ext-diff"))
5160                options->flags.allow_external = 1;
5161        else if (!strcmp(arg, "--no-ext-diff"))
5162                options->flags.allow_external = 0;
5163        else if (!strcmp(arg, "--textconv")) {
5164                options->flags.allow_textconv = 1;
5165                options->flags.textconv_set_via_cmdline = 1;
5166        } else if (!strcmp(arg, "--no-textconv"))
5167                options->flags.allow_textconv = 0;
5168        else if (skip_to_optional_arg_default(arg, "--ignore-submodules", &arg, "all")) {
5169                options->flags.override_submodule_config = 1;
5170                handle_ignore_submodules_arg(options, arg);
5171        } else if (skip_to_optional_arg_default(arg, "--submodule", &arg, "log"))
5172                return parse_submodule_opt(options, arg);
5173        else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
5174                return parse_ws_error_highlight_opt(options, arg);
5175        else if (!strcmp(arg, "--ita-invisible-in-index"))
5176                options->ita_invisible_in_index = 1;
5177        else if (!strcmp(arg, "--ita-visible-in-index"))
5178                options->ita_invisible_in_index = 0;
5179
5180        /* misc options */
5181        else if (!strcmp(arg, "-z"))
5182                options->line_termination = 0;
5183        else if ((argcount = short_opt('l', av, &optarg))) {
5184                options->rename_limit = strtoul(optarg, NULL, 10);
5185                return argcount;
5186        }
5187        else if ((argcount = short_opt('S', av, &optarg))) {
5188                options->pickaxe = optarg;
5189                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
5190                return argcount;
5191        } else if ((argcount = short_opt('G', av, &optarg))) {
5192                options->pickaxe = optarg;
5193                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
5194                return argcount;
5195        }
5196        else if (!strcmp(arg, "--pickaxe-all"))
5197                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
5198        else if (!strcmp(arg, "--pickaxe-regex"))
5199                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
5200        else if ((argcount = short_opt('O', av, &optarg))) {
5201                options->orderfile = prefix_filename(prefix, optarg);
5202                return argcount;
5203        } else if (skip_prefix(arg, "--find-object=", &arg))
5204                return parse_objfind_opt(options, arg);
5205        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
5206                int offending = parse_diff_filter_opt(optarg, options);
5207                if (offending)
5208                        die("unknown change class '%c' in --diff-filter=%s",
5209                            offending, optarg);
5210                return argcount;
5211        }
5212        else if (!strcmp(arg, "--no-abbrev"))
5213                options->abbrev = 0;
5214        else if (!strcmp(arg, "--abbrev"))
5215                options->abbrev = DEFAULT_ABBREV;
5216        else if (skip_prefix(arg, "--abbrev=", &arg)) {
5217                options->abbrev = strtoul(arg, NULL, 10);
5218                if (options->abbrev < MINIMUM_ABBREV)
5219                        options->abbrev = MINIMUM_ABBREV;
5220                else if (the_hash_algo->hexsz < options->abbrev)
5221                        options->abbrev = the_hash_algo->hexsz;
5222        }
5223        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
5224                options->a_prefix = optarg;
5225                return argcount;
5226        }
5227        else if ((argcount = parse_long_opt("line-prefix", av, &optarg))) {
5228                options->line_prefix = optarg;
5229                options->line_prefix_length = strlen(options->line_prefix);
5230                graph_setup_line_prefix(options);
5231                return argcount;
5232        }
5233        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
5234                options->b_prefix = optarg;
5235                return argcount;
5236        }
5237        else if (!strcmp(arg, "--no-prefix"))
5238                options->a_prefix = options->b_prefix = "";
5239        else if (opt_arg(arg, '\0', "inter-hunk-context",
5240                         &options->interhunkcontext))
5241                ;
5242        else if ((argcount = parse_long_opt("output", av, &optarg))) {
5243                char *path = prefix_filename(prefix, optarg);
5244                options->file = xfopen(path, "w");
5245                options->close_file = 1;
5246                if (options->use_color != GIT_COLOR_ALWAYS)
5247                        options->use_color = GIT_COLOR_NEVER;
5248                free(path);
5249                return argcount;
5250        } else
5251                return 0;
5252        return 1;
5253}
5254
5255int parse_rename_score(const char **cp_p)
5256{
5257        unsigned long num, scale;
5258        int ch, dot;
5259        const char *cp = *cp_p;
5260
5261        num = 0;
5262        scale = 1;
5263        dot = 0;
5264        for (;;) {
5265                ch = *cp;
5266                if ( !dot && ch == '.' ) {
5267                        scale = 1;
5268                        dot = 1;
5269                } else if ( ch == '%' ) {
5270                        scale = dot ? scale*100 : 100;
5271                        cp++;   /* % is always at the end */
5272                        break;
5273                } else if ( ch >= '0' && ch <= '9' ) {
5274                        if ( scale < 100000 ) {
5275                                scale *= 10;
5276                                num = (num*10) + (ch-'0');
5277                        }
5278                } else {
5279                        break;
5280                }
5281                cp++;
5282        }
5283        *cp_p = cp;
5284
5285        /* user says num divided by scale and we say internally that
5286         * is MAX_SCORE * num / scale.
5287         */
5288        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
5289}
5290
5291static int diff_scoreopt_parse(const char *opt)
5292{
5293        int opt1, opt2, cmd;
5294
5295        if (*opt++ != '-')
5296                return -1;
5297        cmd = *opt++;
5298        if (cmd == '-') {
5299                /* convert the long-form arguments into short-form versions */
5300                if (skip_prefix(opt, "break-rewrites", &opt)) {
5301                        if (*opt == 0 || *opt++ == '=')
5302                                cmd = 'B';
5303                } else if (skip_prefix(opt, "find-copies", &opt)) {
5304                        if (*opt == 0 || *opt++ == '=')
5305                                cmd = 'C';
5306                } else if (skip_prefix(opt, "find-renames", &opt)) {
5307                        if (*opt == 0 || *opt++ == '=')
5308                                cmd = 'M';
5309                }
5310        }
5311        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
5312                return -1; /* that is not a -M, -C, or -B option */
5313
5314        opt1 = parse_rename_score(&opt);
5315        if (cmd != 'B')
5316                opt2 = 0;
5317        else {
5318                if (*opt == 0)
5319                        opt2 = 0;
5320                else if (*opt != '/')
5321                        return -1; /* we expect -B80/99 or -B80 */
5322                else {
5323                        opt++;
5324                        opt2 = parse_rename_score(&opt);
5325                }
5326        }
5327        if (*opt != 0)
5328                return -1;
5329        return opt1 | (opt2 << 16);
5330}
5331
5332struct diff_queue_struct diff_queued_diff;
5333
5334void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
5335{
5336        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
5337        queue->queue[queue->nr++] = dp;
5338}
5339
5340struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
5341                                 struct diff_filespec *one,
5342                                 struct diff_filespec *two)
5343{
5344        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
5345        dp->one = one;
5346        dp->two = two;
5347        if (queue)
5348                diff_q(queue, dp);
5349        return dp;
5350}
5351
5352void diff_free_filepair(struct diff_filepair *p)
5353{
5354        free_filespec(p->one);
5355        free_filespec(p->two);
5356        free(p);
5357}
5358
5359const char *diff_aligned_abbrev(const struct object_id *oid, int len)
5360{
5361        int abblen;
5362        const char *abbrev;
5363
5364        /* Do we want all 40 hex characters? */
5365        if (len == the_hash_algo->hexsz)
5366                return oid_to_hex(oid);
5367
5368        /* An abbreviated value is fine, possibly followed by an ellipsis. */
5369        abbrev = diff_abbrev_oid(oid, len);
5370
5371        if (!print_sha1_ellipsis())
5372                return abbrev;
5373
5374        abblen = strlen(abbrev);
5375
5376        /*
5377         * In well-behaved cases, where the abbreviated result is the
5378         * same as the requested length, append three dots after the
5379         * abbreviation (hence the whole logic is limited to the case
5380         * where abblen < 37); when the actual abbreviated result is a
5381         * bit longer than the requested length, we reduce the number
5382         * of dots so that they match the well-behaved ones.  However,
5383         * if the actual abbreviation is longer than the requested
5384         * length by more than three, we give up on aligning, and add
5385         * three dots anyway, to indicate that the output is not the
5386         * full object name.  Yes, this may be suboptimal, but this
5387         * appears only in "diff --raw --abbrev" output and it is not
5388         * worth the effort to change it now.  Note that this would
5389         * likely to work fine when the automatic sizing of default
5390         * abbreviation length is used--we would be fed -1 in "len" in
5391         * that case, and will end up always appending three-dots, but
5392         * the automatic sizing is supposed to give abblen that ensures
5393         * uniqueness across all objects (statistically speaking).
5394         */
5395        if (abblen < the_hash_algo->hexsz - 3) {
5396                static char hex[GIT_MAX_HEXSZ + 1];
5397                if (len < abblen && abblen <= len + 2)
5398                        xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
5399                else
5400                        xsnprintf(hex, sizeof(hex), "%s...", abbrev);
5401                return hex;
5402        }
5403
5404        return oid_to_hex(oid);
5405}
5406
5407static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
5408{
5409        int line_termination = opt->line_termination;
5410        int inter_name_termination = line_termination ? '\t' : '\0';
5411
5412        fprintf(opt->file, "%s", diff_line_prefix(opt));
5413        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
5414                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
5415                        diff_aligned_abbrev(&p->one->oid, opt->abbrev));
5416                fprintf(opt->file, "%s ",
5417                        diff_aligned_abbrev(&p->two->oid, opt->abbrev));
5418        }
5419        if (p->score) {
5420                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
5421                        inter_name_termination);
5422        } else {
5423                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
5424        }
5425
5426        if (p->status == DIFF_STATUS_COPIED ||
5427            p->status == DIFF_STATUS_RENAMED) {
5428                const char *name_a, *name_b;
5429                name_a = p->one->path;
5430                name_b = p->two->path;
5431                strip_prefix(opt->prefix_length, &name_a, &name_b);
5432                write_name_quoted(name_a, opt->file, inter_name_termination);
5433                write_name_quoted(name_b, opt->file, line_termination);
5434        } else {
5435                const char *name_a, *name_b;
5436                name_a = p->one->mode ? p->one->path : p->two->path;
5437                name_b = NULL;
5438                strip_prefix(opt->prefix_length, &name_a, &name_b);
5439                write_name_quoted(name_a, opt->file, line_termination);
5440        }
5441}
5442
5443int diff_unmodified_pair(struct diff_filepair *p)
5444{
5445        /* This function is written stricter than necessary to support
5446         * the currently implemented transformers, but the idea is to
5447         * let transformers to produce diff_filepairs any way they want,
5448         * and filter and clean them up here before producing the output.
5449         */
5450        struct diff_filespec *one = p->one, *two = p->two;
5451
5452        if (DIFF_PAIR_UNMERGED(p))
5453                return 0; /* unmerged is interesting */
5454
5455        /* deletion, addition, mode or type change
5456         * and rename are all interesting.
5457         */
5458        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
5459            DIFF_PAIR_MODE_CHANGED(p) ||
5460            strcmp(one->path, two->path))
5461                return 0;
5462
5463        /* both are valid and point at the same path.  that is, we are
5464         * dealing with a change.
5465         */
5466        if (one->oid_valid && two->oid_valid &&
5467            oideq(&one->oid, &two->oid) &&
5468            !one->dirty_submodule && !two->dirty_submodule)
5469                return 1; /* no change */
5470        if (!one->oid_valid && !two->oid_valid)
5471                return 1; /* both look at the same file on the filesystem. */
5472        return 0;
5473}
5474
5475static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
5476{
5477        if (diff_unmodified_pair(p))
5478                return;
5479
5480        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5481            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5482                return; /* no tree diffs in patch format */
5483
5484        run_diff(p, o);
5485}
5486
5487static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
5488                            struct diffstat_t *diffstat)
5489{
5490        if (diff_unmodified_pair(p))
5491                return;
5492
5493        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5494            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5495                return; /* no useful stat for tree diffs */
5496
5497        run_diffstat(p, o, diffstat);
5498}
5499
5500static void diff_flush_checkdiff(struct diff_filepair *p,
5501                struct diff_options *o)
5502{
5503        if (diff_unmodified_pair(p))
5504                return;
5505
5506        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5507            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5508                return; /* nothing to check in tree diffs */
5509
5510        run_checkdiff(p, o);
5511}
5512
5513int diff_queue_is_empty(void)
5514{
5515        struct diff_queue_struct *q = &diff_queued_diff;
5516        int i;
5517        for (i = 0; i < q->nr; i++)
5518                if (!diff_unmodified_pair(q->queue[i]))
5519                        return 0;
5520        return 1;
5521}
5522
5523#if DIFF_DEBUG
5524void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
5525{
5526        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
5527                x, one ? one : "",
5528                s->path,
5529                DIFF_FILE_VALID(s) ? "valid" : "invalid",
5530                s->mode,
5531                s->oid_valid ? oid_to_hex(&s->oid) : "");
5532        fprintf(stderr, "queue[%d] %s size %lu\n",
5533                x, one ? one : "",
5534                s->size);
5535}
5536
5537void diff_debug_filepair(const struct diff_filepair *p, int i)
5538{
5539        diff_debug_filespec(p->one, i, "one");
5540        diff_debug_filespec(p->two, i, "two");
5541        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
5542                p->score, p->status ? p->status : '?',
5543                p->one->rename_used, p->broken_pair);
5544}
5545
5546void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
5547{
5548        int i;
5549        if (msg)
5550                fprintf(stderr, "%s\n", msg);
5551        fprintf(stderr, "q->nr = %d\n", q->nr);
5552        for (i = 0; i < q->nr; i++) {
5553                struct diff_filepair *p = q->queue[i];
5554                diff_debug_filepair(p, i);
5555        }
5556}
5557#endif
5558
5559static void diff_resolve_rename_copy(void)
5560{
5561        int i;
5562        struct diff_filepair *p;
5563        struct diff_queue_struct *q = &diff_queued_diff;
5564
5565        diff_debug_queue("resolve-rename-copy", q);
5566
5567        for (i = 0; i < q->nr; i++) {
5568                p = q->queue[i];
5569                p->status = 0; /* undecided */
5570                if (DIFF_PAIR_UNMERGED(p))
5571                        p->status = DIFF_STATUS_UNMERGED;
5572                else if (!DIFF_FILE_VALID(p->one))
5573                        p->status = DIFF_STATUS_ADDED;
5574                else if (!DIFF_FILE_VALID(p->two))
5575                        p->status = DIFF_STATUS_DELETED;
5576                else if (DIFF_PAIR_TYPE_CHANGED(p))
5577                        p->status = DIFF_STATUS_TYPE_CHANGED;
5578
5579                /* from this point on, we are dealing with a pair
5580                 * whose both sides are valid and of the same type, i.e.
5581                 * either in-place edit or rename/copy edit.
5582                 */
5583                else if (DIFF_PAIR_RENAME(p)) {
5584                        /*
5585                         * A rename might have re-connected a broken
5586                         * pair up, causing the pathnames to be the
5587                         * same again. If so, that's not a rename at
5588                         * all, just a modification..
5589                         *
5590                         * Otherwise, see if this source was used for
5591                         * multiple renames, in which case we decrement
5592                         * the count, and call it a copy.
5593                         */
5594                        if (!strcmp(p->one->path, p->two->path))
5595                                p->status = DIFF_STATUS_MODIFIED;
5596                        else if (--p->one->rename_used > 0)
5597                                p->status = DIFF_STATUS_COPIED;
5598                        else
5599                                p->status = DIFF_STATUS_RENAMED;
5600                }
5601                else if (!oideq(&p->one->oid, &p->two->oid) ||
5602                         p->one->mode != p->two->mode ||
5603                         p->one->dirty_submodule ||
5604                         p->two->dirty_submodule ||
5605                         is_null_oid(&p->one->oid))
5606                        p->status = DIFF_STATUS_MODIFIED;
5607                else {
5608                        /* This is a "no-change" entry and should not
5609                         * happen anymore, but prepare for broken callers.
5610                         */
5611                        error("feeding unmodified %s to diffcore",
5612                              p->one->path);
5613                        p->status = DIFF_STATUS_UNKNOWN;
5614                }
5615        }
5616        diff_debug_queue("resolve-rename-copy done", q);
5617}
5618
5619static int check_pair_status(struct diff_filepair *p)
5620{
5621        switch (p->status) {
5622        case DIFF_STATUS_UNKNOWN:
5623                return 0;
5624        case 0:
5625                die("internal error in diff-resolve-rename-copy");
5626        default:
5627                return 1;
5628        }
5629}
5630
5631static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
5632{
5633        int fmt = opt->output_format;
5634
5635        if (fmt & DIFF_FORMAT_CHECKDIFF)
5636                diff_flush_checkdiff(p, opt);
5637        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
5638                diff_flush_raw(p, opt);
5639        else if (fmt & DIFF_FORMAT_NAME) {
5640                const char *name_a, *name_b;
5641                name_a = p->two->path;
5642                name_b = NULL;
5643                strip_prefix(opt->prefix_length, &name_a, &name_b);
5644                fprintf(opt->file, "%s", diff_line_prefix(opt));
5645                write_name_quoted(name_a, opt->file, opt->line_termination);
5646        }
5647}
5648
5649static void show_file_mode_name(struct diff_options *opt, const char *newdelete, struct diff_filespec *fs)
5650{
5651        struct strbuf sb = STRBUF_INIT;
5652        if (fs->mode)
5653                strbuf_addf(&sb, " %s mode %06o ", newdelete, fs->mode);
5654        else
5655                strbuf_addf(&sb, " %s ", newdelete);
5656
5657        quote_c_style(fs->path, &sb, NULL, 0);
5658        strbuf_addch(&sb, '\n');
5659        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5660                         sb.buf, sb.len, 0);
5661        strbuf_release(&sb);
5662}
5663
5664static void show_mode_change(struct diff_options *opt, struct diff_filepair *p,
5665                int show_name)
5666{
5667        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
5668                struct strbuf sb = STRBUF_INIT;
5669                strbuf_addf(&sb, " mode change %06o => %06o",
5670                            p->one->mode, p->two->mode);
5671                if (show_name) {
5672                        strbuf_addch(&sb, ' ');
5673                        quote_c_style(p->two->path, &sb, NULL, 0);
5674                }
5675                strbuf_addch(&sb, '\n');
5676                emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5677                                 sb.buf, sb.len, 0);
5678                strbuf_release(&sb);
5679        }
5680}
5681
5682static void show_rename_copy(struct diff_options *opt, const char *renamecopy,
5683                struct diff_filepair *p)
5684{
5685        struct strbuf sb = STRBUF_INIT;
5686        struct strbuf names = STRBUF_INIT;
5687
5688        pprint_rename(&names, p->one->path, p->two->path);
5689        strbuf_addf(&sb, " %s %s (%d%%)\n",
5690                    renamecopy, names.buf, similarity_index(p));
5691        strbuf_release(&names);
5692        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5693                                 sb.buf, sb.len, 0);
5694        show_mode_change(opt, p, 0);
5695        strbuf_release(&sb);
5696}
5697
5698static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
5699{
5700        switch(p->status) {
5701        case DIFF_STATUS_DELETED:
5702                show_file_mode_name(opt, "delete", p->one);
5703                break;
5704        case DIFF_STATUS_ADDED:
5705                show_file_mode_name(opt, "create", p->two);
5706                break;
5707        case DIFF_STATUS_COPIED:
5708                show_rename_copy(opt, "copy", p);
5709                break;
5710        case DIFF_STATUS_RENAMED:
5711                show_rename_copy(opt, "rename", p);
5712                break;
5713        default:
5714                if (p->score) {
5715                        struct strbuf sb = STRBUF_INIT;
5716                        strbuf_addstr(&sb, " rewrite ");
5717                        quote_c_style(p->two->path, &sb, NULL, 0);
5718                        strbuf_addf(&sb, " (%d%%)\n", similarity_index(p));
5719                        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5720                                         sb.buf, sb.len, 0);
5721                        strbuf_release(&sb);
5722                }
5723                show_mode_change(opt, p, !p->score);
5724                break;
5725        }
5726}
5727
5728struct patch_id_t {
5729        git_SHA_CTX *ctx;
5730        int patchlen;
5731};
5732
5733static int remove_space(char *line, int len)
5734{
5735        int i;
5736        char *dst = line;
5737        unsigned char c;
5738
5739        for (i = 0; i < len; i++)
5740                if (!isspace((c = line[i])))
5741                        *dst++ = c;
5742
5743        return dst - line;
5744}
5745
5746static void patch_id_consume(void *priv, char *line, unsigned long len)
5747{
5748        struct patch_id_t *data = priv;
5749        int new_len;
5750
5751        new_len = remove_space(line, len);
5752
5753        git_SHA1_Update(data->ctx, line, new_len);
5754        data->patchlen += new_len;
5755}
5756
5757static void patch_id_add_string(git_SHA_CTX *ctx, const char *str)
5758{
5759        git_SHA1_Update(ctx, str, strlen(str));
5760}
5761
5762static void patch_id_add_mode(git_SHA_CTX *ctx, unsigned mode)
5763{
5764        /* large enough for 2^32 in octal */
5765        char buf[12];
5766        int len = xsnprintf(buf, sizeof(buf), "%06o", mode);
5767        git_SHA1_Update(ctx, buf, len);
5768}
5769
5770/* returns 0 upon success, and writes result into sha1 */
5771static int diff_get_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5772{
5773        struct diff_queue_struct *q = &diff_queued_diff;
5774        int i;
5775        git_SHA_CTX ctx;
5776        struct patch_id_t data;
5777
5778        git_SHA1_Init(&ctx);
5779        memset(&data, 0, sizeof(struct patch_id_t));
5780        data.ctx = &ctx;
5781
5782        for (i = 0; i < q->nr; i++) {
5783                xpparam_t xpp;
5784                xdemitconf_t xecfg;
5785                mmfile_t mf1, mf2;
5786                struct diff_filepair *p = q->queue[i];
5787                int len1, len2;
5788
5789                memset(&xpp, 0, sizeof(xpp));
5790                memset(&xecfg, 0, sizeof(xecfg));
5791                if (p->status == 0)
5792                        return error("internal diff status error");
5793                if (p->status == DIFF_STATUS_UNKNOWN)
5794                        continue;
5795                if (diff_unmodified_pair(p))
5796                        continue;
5797                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5798                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5799                        continue;
5800                if (DIFF_PAIR_UNMERGED(p))
5801                        continue;
5802
5803                diff_fill_oid_info(p->one, options->repo->index);
5804                diff_fill_oid_info(p->two, options->repo->index);
5805
5806                len1 = remove_space(p->one->path, strlen(p->one->path));
5807                len2 = remove_space(p->two->path, strlen(p->two->path));
5808                patch_id_add_string(&ctx, "diff--git");
5809                patch_id_add_string(&ctx, "a/");
5810                git_SHA1_Update(&ctx, p->one->path, len1);
5811                patch_id_add_string(&ctx, "b/");
5812                git_SHA1_Update(&ctx, p->two->path, len2);
5813
5814                if (p->one->mode == 0) {
5815                        patch_id_add_string(&ctx, "newfilemode");
5816                        patch_id_add_mode(&ctx, p->two->mode);
5817                        patch_id_add_string(&ctx, "---/dev/null");
5818                        patch_id_add_string(&ctx, "+++b/");
5819                        git_SHA1_Update(&ctx, p->two->path, len2);
5820                } else if (p->two->mode == 0) {
5821                        patch_id_add_string(&ctx, "deletedfilemode");
5822                        patch_id_add_mode(&ctx, p->one->mode);
5823                        patch_id_add_string(&ctx, "---a/");
5824                        git_SHA1_Update(&ctx, p->one->path, len1);
5825                        patch_id_add_string(&ctx, "+++/dev/null");
5826                } else {
5827                        patch_id_add_string(&ctx, "---a/");
5828                        git_SHA1_Update(&ctx, p->one->path, len1);
5829                        patch_id_add_string(&ctx, "+++b/");
5830                        git_SHA1_Update(&ctx, p->two->path, len2);
5831                }
5832
5833                if (diff_header_only)
5834                        continue;
5835
5836                if (fill_mmfile(options->repo, &mf1, p->one) < 0 ||
5837                    fill_mmfile(options->repo, &mf2, p->two) < 0)
5838                        return error("unable to read files to diff");
5839
5840                if (diff_filespec_is_binary(options->repo, p->one) ||
5841                    diff_filespec_is_binary(options->repo, p->two)) {
5842                        git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
5843                                        GIT_SHA1_HEXSZ);
5844                        git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
5845                                        GIT_SHA1_HEXSZ);
5846                        continue;
5847                }
5848
5849                xpp.flags = 0;
5850                xecfg.ctxlen = 3;
5851                xecfg.flags = 0;
5852                if (xdi_diff_outf(&mf1, &mf2, discard_hunk_line,
5853                                  patch_id_consume, &data, &xpp, &xecfg))
5854                        return error("unable to generate patch-id diff for %s",
5855                                     p->one->path);
5856        }
5857
5858        git_SHA1_Final(oid->hash, &ctx);
5859        return 0;
5860}
5861
5862int diff_flush_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5863{
5864        struct diff_queue_struct *q = &diff_queued_diff;
5865        int i;
5866        int result = diff_get_patch_id(options, oid, diff_header_only);
5867
5868        for (i = 0; i < q->nr; i++)
5869                diff_free_filepair(q->queue[i]);
5870
5871        free(q->queue);
5872        DIFF_QUEUE_CLEAR(q);
5873
5874        return result;
5875}
5876
5877static int is_summary_empty(const struct diff_queue_struct *q)
5878{
5879        int i;
5880
5881        for (i = 0; i < q->nr; i++) {
5882                const struct diff_filepair *p = q->queue[i];
5883
5884                switch (p->status) {
5885                case DIFF_STATUS_DELETED:
5886                case DIFF_STATUS_ADDED:
5887                case DIFF_STATUS_COPIED:
5888                case DIFF_STATUS_RENAMED:
5889                        return 0;
5890                default:
5891                        if (p->score)
5892                                return 0;
5893                        if (p->one->mode && p->two->mode &&
5894                            p->one->mode != p->two->mode)
5895                                return 0;
5896                        break;
5897                }
5898        }
5899        return 1;
5900}
5901
5902static const char rename_limit_warning[] =
5903N_("inexact rename detection was skipped due to too many files.");
5904
5905static const char degrade_cc_to_c_warning[] =
5906N_("only found copies from modified paths due to too many files.");
5907
5908static const char rename_limit_advice[] =
5909N_("you may want to set your %s variable to at least "
5910   "%d and retry the command.");
5911
5912void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
5913{
5914        fflush(stdout);
5915        if (degraded_cc)
5916                warning(_(degrade_cc_to_c_warning));
5917        else if (needed)
5918                warning(_(rename_limit_warning));
5919        else
5920                return;
5921        if (0 < needed)
5922                warning(_(rename_limit_advice), varname, needed);
5923}
5924
5925static void diff_flush_patch_all_file_pairs(struct diff_options *o)
5926{
5927        int i;
5928        static struct emitted_diff_symbols esm = EMITTED_DIFF_SYMBOLS_INIT;
5929        struct diff_queue_struct *q = &diff_queued_diff;
5930
5931        if (WSEH_NEW & WS_RULE_MASK)
5932                BUG("WS rules bit mask overlaps with diff symbol flags");
5933
5934        if (o->color_moved)
5935                o->emitted_symbols = &esm;
5936
5937        for (i = 0; i < q->nr; i++) {
5938                struct diff_filepair *p = q->queue[i];
5939                if (check_pair_status(p))
5940                        diff_flush_patch(p, o);
5941        }
5942
5943        if (o->emitted_symbols) {
5944                if (o->color_moved) {
5945                        struct hashmap add_lines, del_lines;
5946
5947                        if (o->color_moved_ws_handling &
5948                            COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
5949                                o->color_moved_ws_handling |= XDF_IGNORE_WHITESPACE;
5950
5951                        hashmap_init(&del_lines, moved_entry_cmp, o, 0);
5952                        hashmap_init(&add_lines, moved_entry_cmp, o, 0);
5953
5954                        add_lines_to_move_detection(o, &add_lines, &del_lines);
5955                        mark_color_as_moved(o, &add_lines, &del_lines);
5956                        if (o->color_moved == COLOR_MOVED_ZEBRA_DIM)
5957                                dim_moved_lines(o);
5958
5959                        hashmap_free(&add_lines, 1);
5960                        hashmap_free(&del_lines, 1);
5961                }
5962
5963                for (i = 0; i < esm.nr; i++)
5964                        emit_diff_symbol_from_struct(o, &esm.buf[i]);
5965
5966                for (i = 0; i < esm.nr; i++)
5967                        free((void *)esm.buf[i].line);
5968        }
5969        esm.nr = 0;
5970}
5971
5972void diff_flush(struct diff_options *options)
5973{
5974        struct diff_queue_struct *q = &diff_queued_diff;
5975        int i, output_format = options->output_format;
5976        int separator = 0;
5977        int dirstat_by_line = 0;
5978
5979        /*
5980         * Order: raw, stat, summary, patch
5981         * or:    name/name-status/checkdiff (other bits clear)
5982         */
5983        if (!q->nr)
5984                goto free_queue;
5985
5986        if (output_format & (DIFF_FORMAT_RAW |
5987                             DIFF_FORMAT_NAME |
5988                             DIFF_FORMAT_NAME_STATUS |
5989                             DIFF_FORMAT_CHECKDIFF)) {
5990                for (i = 0; i < q->nr; i++) {
5991                        struct diff_filepair *p = q->queue[i];
5992                        if (check_pair_status(p))
5993                                flush_one_pair(p, options);
5994                }
5995                separator++;
5996        }
5997
5998        if (output_format & DIFF_FORMAT_DIRSTAT && options->flags.dirstat_by_line)
5999                dirstat_by_line = 1;
6000
6001        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
6002            dirstat_by_line) {
6003                struct diffstat_t diffstat;
6004
6005                memset(&diffstat, 0, sizeof(struct diffstat_t));
6006                for (i = 0; i < q->nr; i++) {
6007                        struct diff_filepair *p = q->queue[i];
6008                        if (check_pair_status(p))
6009                                diff_flush_stat(p, options, &diffstat);
6010                }
6011                if (output_format & DIFF_FORMAT_NUMSTAT)
6012                        show_numstat(&diffstat, options);
6013                if (output_format & DIFF_FORMAT_DIFFSTAT)
6014                        show_stats(&diffstat, options);
6015                if (output_format & DIFF_FORMAT_SHORTSTAT)
6016                        show_shortstats(&diffstat, options);
6017                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
6018                        show_dirstat_by_line(&diffstat, options);
6019                free_diffstat_info(&diffstat);
6020                separator++;
6021        }
6022        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
6023                show_dirstat(options);
6024
6025        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
6026                for (i = 0; i < q->nr; i++) {
6027                        diff_summary(options, q->queue[i]);
6028                }
6029                separator++;
6030        }
6031
6032        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
6033            options->flags.exit_with_status &&
6034            options->flags.diff_from_contents) {
6035                /*
6036                 * run diff_flush_patch for the exit status. setting
6037                 * options->file to /dev/null should be safe, because we
6038                 * aren't supposed to produce any output anyway.
6039                 */
6040                if (options->close_file)
6041                        fclose(options->file);
6042                options->file = xfopen("/dev/null", "w");
6043                options->close_file = 1;
6044                options->color_moved = 0;
6045                for (i = 0; i < q->nr; i++) {
6046                        struct diff_filepair *p = q->queue[i];
6047                        if (check_pair_status(p))
6048                                diff_flush_patch(p, options);
6049                        if (options->found_changes)
6050                                break;
6051                }
6052        }
6053
6054        if (output_format & DIFF_FORMAT_PATCH) {
6055                if (separator) {
6056                        emit_diff_symbol(options, DIFF_SYMBOL_SEPARATOR, NULL, 0, 0);
6057                        if (options->stat_sep)
6058                                /* attach patch instead of inline */
6059                                emit_diff_symbol(options, DIFF_SYMBOL_STAT_SEP,
6060                                                 NULL, 0, 0);
6061                }
6062
6063                diff_flush_patch_all_file_pairs(options);
6064        }
6065
6066        if (output_format & DIFF_FORMAT_CALLBACK)
6067                options->format_callback(q, options, options->format_callback_data);
6068
6069        for (i = 0; i < q->nr; i++)
6070                diff_free_filepair(q->queue[i]);
6071free_queue:
6072        free(q->queue);
6073        DIFF_QUEUE_CLEAR(q);
6074        if (options->close_file)
6075                fclose(options->file);
6076
6077        /*
6078         * Report the content-level differences with HAS_CHANGES;
6079         * diff_addremove/diff_change does not set the bit when
6080         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
6081         */
6082        if (options->flags.diff_from_contents) {
6083                if (options->found_changes)
6084                        options->flags.has_changes = 1;
6085                else
6086                        options->flags.has_changes = 0;
6087        }
6088}
6089
6090static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
6091{
6092        return (((p->status == DIFF_STATUS_MODIFIED) &&
6093                 ((p->score &&
6094                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
6095                  (!p->score &&
6096                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
6097                ((p->status != DIFF_STATUS_MODIFIED) &&
6098                 filter_bit_tst(p->status, options)));
6099}
6100
6101static void diffcore_apply_filter(struct diff_options *options)
6102{
6103        int i;
6104        struct diff_queue_struct *q = &diff_queued_diff;
6105        struct diff_queue_struct outq;
6106
6107        DIFF_QUEUE_CLEAR(&outq);
6108
6109        if (!options->filter)
6110                return;
6111
6112        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
6113                int found;
6114                for (i = found = 0; !found && i < q->nr; i++) {
6115                        if (match_filter(options, q->queue[i]))
6116                                found++;
6117                }
6118                if (found)
6119                        return;
6120
6121                /* otherwise we will clear the whole queue
6122                 * by copying the empty outq at the end of this
6123                 * function, but first clear the current entries
6124                 * in the queue.
6125                 */
6126                for (i = 0; i < q->nr; i++)
6127                        diff_free_filepair(q->queue[i]);
6128        }
6129        else {
6130                /* Only the matching ones */
6131                for (i = 0; i < q->nr; i++) {
6132                        struct diff_filepair *p = q->queue[i];
6133                        if (match_filter(options, p))
6134                                diff_q(&outq, p);
6135                        else
6136                                diff_free_filepair(p);
6137                }
6138        }
6139        free(q->queue);
6140        *q = outq;
6141}
6142
6143/* Check whether two filespecs with the same mode and size are identical */
6144static int diff_filespec_is_identical(struct repository *r,
6145                                      struct diff_filespec *one,
6146                                      struct diff_filespec *two)
6147{
6148        if (S_ISGITLINK(one->mode))
6149                return 0;
6150        if (diff_populate_filespec(r, one, 0))
6151                return 0;
6152        if (diff_populate_filespec(r, two, 0))
6153                return 0;
6154        return !memcmp(one->data, two->data, one->size);
6155}
6156
6157static int diff_filespec_check_stat_unmatch(struct repository *r,
6158                                            struct diff_filepair *p)
6159{
6160        if (p->done_skip_stat_unmatch)
6161                return p->skip_stat_unmatch_result;
6162
6163        p->done_skip_stat_unmatch = 1;
6164        p->skip_stat_unmatch_result = 0;
6165        /*
6166         * 1. Entries that come from stat info dirtiness
6167         *    always have both sides (iow, not create/delete),
6168         *    one side of the object name is unknown, with
6169         *    the same mode and size.  Keep the ones that
6170         *    do not match these criteria.  They have real
6171         *    differences.
6172         *
6173         * 2. At this point, the file is known to be modified,
6174         *    with the same mode and size, and the object
6175         *    name of one side is unknown.  Need to inspect
6176         *    the identical contents.
6177         */
6178        if (!DIFF_FILE_VALID(p->one) || /* (1) */
6179            !DIFF_FILE_VALID(p->two) ||
6180            (p->one->oid_valid && p->two->oid_valid) ||
6181            (p->one->mode != p->two->mode) ||
6182            diff_populate_filespec(r, p->one, CHECK_SIZE_ONLY) ||
6183            diff_populate_filespec(r, p->two, CHECK_SIZE_ONLY) ||
6184            (p->one->size != p->two->size) ||
6185            !diff_filespec_is_identical(r, p->one, p->two)) /* (2) */
6186                p->skip_stat_unmatch_result = 1;
6187        return p->skip_stat_unmatch_result;
6188}
6189
6190static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
6191{
6192        int i;
6193        struct diff_queue_struct *q = &diff_queued_diff;
6194        struct diff_queue_struct outq;
6195        DIFF_QUEUE_CLEAR(&outq);
6196
6197        for (i = 0; i < q->nr; i++) {
6198                struct diff_filepair *p = q->queue[i];
6199
6200                if (diff_filespec_check_stat_unmatch(diffopt->repo, p))
6201                        diff_q(&outq, p);
6202                else {
6203                        /*
6204                         * The caller can subtract 1 from skip_stat_unmatch
6205                         * to determine how many paths were dirty only
6206                         * due to stat info mismatch.
6207                         */
6208                        if (!diffopt->flags.no_index)
6209                                diffopt->skip_stat_unmatch++;
6210                        diff_free_filepair(p);
6211                }
6212        }
6213        free(q->queue);
6214        *q = outq;
6215}
6216
6217static int diffnamecmp(const void *a_, const void *b_)
6218{
6219        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
6220        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
6221        const char *name_a, *name_b;
6222
6223        name_a = a->one ? a->one->path : a->two->path;
6224        name_b = b->one ? b->one->path : b->two->path;
6225        return strcmp(name_a, name_b);
6226}
6227
6228void diffcore_fix_diff_index(struct diff_options *options)
6229{
6230        struct diff_queue_struct *q = &diff_queued_diff;
6231        QSORT(q->queue, q->nr, diffnamecmp);
6232}
6233
6234void diffcore_std(struct diff_options *options)
6235{
6236        /* NOTE please keep the following in sync with diff_tree_combined() */
6237        if (options->skip_stat_unmatch)
6238                diffcore_skip_stat_unmatch(options);
6239        if (!options->found_follow) {
6240                /* See try_to_follow_renames() in tree-diff.c */
6241                if (options->break_opt != -1)
6242                        diffcore_break(options->repo,
6243                                       options->break_opt);
6244                if (options->detect_rename)
6245                        diffcore_rename(options);
6246                if (options->break_opt != -1)
6247                        diffcore_merge_broken();
6248        }
6249        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
6250                diffcore_pickaxe(options);
6251        if (options->orderfile)
6252                diffcore_order(options->orderfile);
6253        if (!options->found_follow)
6254                /* See try_to_follow_renames() in tree-diff.c */
6255                diff_resolve_rename_copy();
6256        diffcore_apply_filter(options);
6257
6258        if (diff_queued_diff.nr && !options->flags.diff_from_contents)
6259                options->flags.has_changes = 1;
6260        else
6261                options->flags.has_changes = 0;
6262
6263        options->found_follow = 0;
6264}
6265
6266int diff_result_code(struct diff_options *opt, int status)
6267{
6268        int result = 0;
6269
6270        diff_warn_rename_limit("diff.renameLimit",
6271                               opt->needed_rename_limit,
6272                               opt->degraded_cc_to_c);
6273        if (!opt->flags.exit_with_status &&
6274            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
6275                return status;
6276        if (opt->flags.exit_with_status &&
6277            opt->flags.has_changes)
6278                result |= 01;
6279        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
6280            opt->flags.check_failed)
6281                result |= 02;
6282        return result;
6283}
6284
6285int diff_can_quit_early(struct diff_options *opt)
6286{
6287        return (opt->flags.quick &&
6288                !opt->filter &&
6289                opt->flags.has_changes);
6290}
6291
6292/*
6293 * Shall changes to this submodule be ignored?
6294 *
6295 * Submodule changes can be configured to be ignored separately for each path,
6296 * but that configuration can be overridden from the command line.
6297 */
6298static int is_submodule_ignored(const char *path, struct diff_options *options)
6299{
6300        int ignored = 0;
6301        struct diff_flags orig_flags = options->flags;
6302        if (!options->flags.override_submodule_config)
6303                set_diffopt_flags_from_submodule_config(options, path);
6304        if (options->flags.ignore_submodules)
6305                ignored = 1;
6306        options->flags = orig_flags;
6307        return ignored;
6308}
6309
6310void diff_addremove(struct diff_options *options,
6311                    int addremove, unsigned mode,
6312                    const struct object_id *oid,
6313                    int oid_valid,
6314                    const char *concatpath, unsigned dirty_submodule)
6315{
6316        struct diff_filespec *one, *two;
6317
6318        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
6319                return;
6320
6321        /* This may look odd, but it is a preparation for
6322         * feeding "there are unchanged files which should
6323         * not produce diffs, but when you are doing copy
6324         * detection you would need them, so here they are"
6325         * entries to the diff-core.  They will be prefixed
6326         * with something like '=' or '*' (I haven't decided
6327         * which but should not make any difference).
6328         * Feeding the same new and old to diff_change()
6329         * also has the same effect.
6330         * Before the final output happens, they are pruned after
6331         * merged into rename/copy pairs as appropriate.
6332         */
6333        if (options->flags.reverse_diff)
6334                addremove = (addremove == '+' ? '-' :
6335                             addremove == '-' ? '+' : addremove);
6336
6337        if (options->prefix &&
6338            strncmp(concatpath, options->prefix, options->prefix_length))
6339                return;
6340
6341        one = alloc_filespec(concatpath);
6342        two = alloc_filespec(concatpath);
6343
6344        if (addremove != '+')
6345                fill_filespec(one, oid, oid_valid, mode);
6346        if (addremove != '-') {
6347                fill_filespec(two, oid, oid_valid, mode);
6348                two->dirty_submodule = dirty_submodule;
6349        }
6350
6351        diff_queue(&diff_queued_diff, one, two);
6352        if (!options->flags.diff_from_contents)
6353                options->flags.has_changes = 1;
6354}
6355
6356void diff_change(struct diff_options *options,
6357                 unsigned old_mode, unsigned new_mode,
6358                 const struct object_id *old_oid,
6359                 const struct object_id *new_oid,
6360                 int old_oid_valid, int new_oid_valid,
6361                 const char *concatpath,
6362                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
6363{
6364        struct diff_filespec *one, *two;
6365        struct diff_filepair *p;
6366
6367        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
6368            is_submodule_ignored(concatpath, options))
6369                return;
6370
6371        if (options->flags.reverse_diff) {
6372                SWAP(old_mode, new_mode);
6373                SWAP(old_oid, new_oid);
6374                SWAP(old_oid_valid, new_oid_valid);
6375                SWAP(old_dirty_submodule, new_dirty_submodule);
6376        }
6377
6378        if (options->prefix &&
6379            strncmp(concatpath, options->prefix, options->prefix_length))
6380                return;
6381
6382        one = alloc_filespec(concatpath);
6383        two = alloc_filespec(concatpath);
6384        fill_filespec(one, old_oid, old_oid_valid, old_mode);
6385        fill_filespec(two, new_oid, new_oid_valid, new_mode);
6386        one->dirty_submodule = old_dirty_submodule;
6387        two->dirty_submodule = new_dirty_submodule;
6388        p = diff_queue(&diff_queued_diff, one, two);
6389
6390        if (options->flags.diff_from_contents)
6391                return;
6392
6393        if (options->flags.quick && options->skip_stat_unmatch &&
6394            !diff_filespec_check_stat_unmatch(options->repo, p))
6395                return;
6396
6397        options->flags.has_changes = 1;
6398}
6399
6400struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
6401{
6402        struct diff_filepair *pair;
6403        struct diff_filespec *one, *two;
6404
6405        if (options->prefix &&
6406            strncmp(path, options->prefix, options->prefix_length))
6407                return NULL;
6408
6409        one = alloc_filespec(path);
6410        two = alloc_filespec(path);
6411        pair = diff_queue(&diff_queued_diff, one, two);
6412        pair->is_unmerged = 1;
6413        return pair;
6414}
6415
6416static char *run_textconv(struct repository *r,
6417                          const char *pgm,
6418                          struct diff_filespec *spec,
6419                          size_t *outsize)
6420{
6421        struct diff_tempfile *temp;
6422        const char *argv[3];
6423        const char **arg = argv;
6424        struct child_process child = CHILD_PROCESS_INIT;
6425        struct strbuf buf = STRBUF_INIT;
6426        int err = 0;
6427
6428        temp = prepare_temp_file(r, spec->path, spec);
6429        *arg++ = pgm;
6430        *arg++ = temp->name;
6431        *arg = NULL;
6432
6433        child.use_shell = 1;
6434        child.argv = argv;
6435        child.out = -1;
6436        if (start_command(&child)) {
6437                remove_tempfile();
6438                return NULL;
6439        }
6440
6441        if (strbuf_read(&buf, child.out, 0) < 0)
6442                err = error("error reading from textconv command '%s'", pgm);
6443        close(child.out);
6444
6445        if (finish_command(&child) || err) {
6446                strbuf_release(&buf);
6447                remove_tempfile();
6448                return NULL;
6449        }
6450        remove_tempfile();
6451
6452        return strbuf_detach(&buf, outsize);
6453}
6454
6455size_t fill_textconv(struct repository *r,
6456                     struct userdiff_driver *driver,
6457                     struct diff_filespec *df,
6458                     char **outbuf)
6459{
6460        size_t size;
6461
6462        if (!driver) {
6463                if (!DIFF_FILE_VALID(df)) {
6464                        *outbuf = "";
6465                        return 0;
6466                }
6467                if (diff_populate_filespec(r, df, 0))
6468                        die("unable to read files to diff");
6469                *outbuf = df->data;
6470                return df->size;
6471        }
6472
6473        if (!driver->textconv)
6474                BUG("fill_textconv called with non-textconv driver");
6475
6476        if (driver->textconv_cache && df->oid_valid) {
6477                *outbuf = notes_cache_get(driver->textconv_cache,
6478                                          &df->oid,
6479                                          &size);
6480                if (*outbuf)
6481                        return size;
6482        }
6483
6484        *outbuf = run_textconv(r, driver->textconv, df, &size);
6485        if (!*outbuf)
6486                die("unable to read files to diff");
6487
6488        if (driver->textconv_cache && df->oid_valid) {
6489                /* ignore errors, as we might be in a readonly repository */
6490                notes_cache_put(driver->textconv_cache, &df->oid, *outbuf,
6491                                size);
6492                /*
6493                 * we could save up changes and flush them all at the end,
6494                 * but we would need an extra call after all diffing is done.
6495                 * Since generating a cache entry is the slow path anyway,
6496                 * this extra overhead probably isn't a big deal.
6497                 */
6498                notes_cache_write(driver->textconv_cache);
6499        }
6500
6501        return size;
6502}
6503
6504int textconv_object(struct repository *r,
6505                    const char *path,
6506                    unsigned mode,
6507                    const struct object_id *oid,
6508                    int oid_valid,
6509                    char **buf,
6510                    unsigned long *buf_size)
6511{
6512        struct diff_filespec *df;
6513        struct userdiff_driver *textconv;
6514
6515        df = alloc_filespec(path);
6516        fill_filespec(df, oid, oid_valid, mode);
6517        textconv = get_textconv(r, df);
6518        if (!textconv) {
6519                free_filespec(df);
6520                return 0;
6521        }
6522
6523        *buf_size = fill_textconv(r, textconv, df, buf);
6524        free_filespec(df);
6525        return 1;
6526}
6527
6528void setup_diff_pager(struct diff_options *opt)
6529{
6530        /*
6531         * If the user asked for our exit code, then either they want --quiet
6532         * or --exit-code. We should definitely not bother with a pager in the
6533         * former case, as we will generate no output. Since we still properly
6534         * report our exit code even when a pager is run, we _could_ run a
6535         * pager with --exit-code. But since we have not done so historically,
6536         * and because it is easy to find people oneline advising "git diff
6537         * --exit-code" in hooks and other scripts, we do not do so.
6538         */
6539        if (!opt->flags.exit_with_status &&
6540            check_pager_config("diff") != 0)
6541                setup_pager();
6542}