diff.con commit contrib/completion: add smerge to the mergetool completion candidates (f57b2ae)
   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
 107define_list_config_array_extra(color_diff_slots, {"plain"});
 108
 109static int parse_diff_color_slot(const char *var)
 110{
 111        if (!strcasecmp(var, "plain"))
 112                return DIFF_CONTEXT;
 113        return LOOKUP_CONFIG(color_diff_slots, var);
 114}
 115
 116static int parse_dirstat_params(struct diff_options *options, const char *params_string,
 117                                struct strbuf *errmsg)
 118{
 119        char *params_copy = xstrdup(params_string);
 120        struct string_list params = STRING_LIST_INIT_NODUP;
 121        int ret = 0;
 122        int i;
 123
 124        if (*params_copy)
 125                string_list_split_in_place(&params, params_copy, ',', -1);
 126        for (i = 0; i < params.nr; i++) {
 127                const char *p = params.items[i].string;
 128                if (!strcmp(p, "changes")) {
 129                        options->flags.dirstat_by_line = 0;
 130                        options->flags.dirstat_by_file = 0;
 131                } else if (!strcmp(p, "lines")) {
 132                        options->flags.dirstat_by_line = 1;
 133                        options->flags.dirstat_by_file = 0;
 134                } else if (!strcmp(p, "files")) {
 135                        options->flags.dirstat_by_line = 0;
 136                        options->flags.dirstat_by_file = 1;
 137                } else if (!strcmp(p, "noncumulative")) {
 138                        options->flags.dirstat_cumulative = 0;
 139                } else if (!strcmp(p, "cumulative")) {
 140                        options->flags.dirstat_cumulative = 1;
 141                } else if (isdigit(*p)) {
 142                        char *end;
 143                        int permille = strtoul(p, &end, 10) * 10;
 144                        if (*end == '.' && isdigit(*++end)) {
 145                                /* only use first digit */
 146                                permille += *end - '0';
 147                                /* .. and ignore any further digits */
 148                                while (isdigit(*++end))
 149                                        ; /* nothing */
 150                        }
 151                        if (!*end)
 152                                options->dirstat_permille = permille;
 153                        else {
 154                                strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%s'\n"),
 155                                            p);
 156                                ret++;
 157                        }
 158                } else {
 159                        strbuf_addf(errmsg, _("  Unknown dirstat parameter '%s'\n"), p);
 160                        ret++;
 161                }
 162
 163        }
 164        string_list_clear(&params, 0);
 165        free(params_copy);
 166        return ret;
 167}
 168
 169static int parse_submodule_params(struct diff_options *options, const char *value)
 170{
 171        if (!strcmp(value, "log"))
 172                options->submodule_format = DIFF_SUBMODULE_LOG;
 173        else if (!strcmp(value, "short"))
 174                options->submodule_format = DIFF_SUBMODULE_SHORT;
 175        else if (!strcmp(value, "diff"))
 176                options->submodule_format = DIFF_SUBMODULE_INLINE_DIFF;
 177        /*
 178         * Please update $__git_diff_submodule_formats in
 179         * git-completion.bash when you add new formats.
 180         */
 181        else
 182                return -1;
 183        return 0;
 184}
 185
 186int git_config_rename(const char *var, const char *value)
 187{
 188        if (!value)
 189                return DIFF_DETECT_RENAME;
 190        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 191                return  DIFF_DETECT_COPY;
 192        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 193}
 194
 195long parse_algorithm_value(const char *value)
 196{
 197        if (!value)
 198                return -1;
 199        else if (!strcasecmp(value, "myers") || !strcasecmp(value, "default"))
 200                return 0;
 201        else if (!strcasecmp(value, "minimal"))
 202                return XDF_NEED_MINIMAL;
 203        else if (!strcasecmp(value, "patience"))
 204                return XDF_PATIENCE_DIFF;
 205        else if (!strcasecmp(value, "histogram"))
 206                return XDF_HISTOGRAM_DIFF;
 207        /*
 208         * Please update $__git_diff_algorithms in git-completion.bash
 209         * when you add new algorithms.
 210         */
 211        return -1;
 212}
 213
 214static int parse_one_token(const char **arg, const char *token)
 215{
 216        const char *rest;
 217        if (skip_prefix(*arg, token, &rest) && (!*rest || *rest == ',')) {
 218                *arg = rest;
 219                return 1;
 220        }
 221        return 0;
 222}
 223
 224static int parse_ws_error_highlight(const char *arg)
 225{
 226        const char *orig_arg = arg;
 227        unsigned val = 0;
 228
 229        while (*arg) {
 230                if (parse_one_token(&arg, "none"))
 231                        val = 0;
 232                else if (parse_one_token(&arg, "default"))
 233                        val = WSEH_NEW;
 234                else if (parse_one_token(&arg, "all"))
 235                        val = WSEH_NEW | WSEH_OLD | WSEH_CONTEXT;
 236                else if (parse_one_token(&arg, "new"))
 237                        val |= WSEH_NEW;
 238                else if (parse_one_token(&arg, "old"))
 239                        val |= WSEH_OLD;
 240                else if (parse_one_token(&arg, "context"))
 241                        val |= WSEH_CONTEXT;
 242                else {
 243                        return -1 - (int)(arg - orig_arg);
 244                }
 245                if (*arg)
 246                        arg++;
 247        }
 248        return val;
 249}
 250
 251/*
 252 * These are to give UI layer defaults.
 253 * The core-level commands such as git-diff-files should
 254 * never be affected by the setting of diff.renames
 255 * the user happens to have in the configuration file.
 256 */
 257void init_diff_ui_defaults(void)
 258{
 259        diff_detect_rename_default = DIFF_DETECT_RENAME;
 260}
 261
 262int git_diff_heuristic_config(const char *var, const char *value, void *cb)
 263{
 264        if (!strcmp(var, "diff.indentheuristic"))
 265                diff_indent_heuristic = git_config_bool(var, value);
 266        return 0;
 267}
 268
 269static int parse_color_moved(const char *arg)
 270{
 271        switch (git_parse_maybe_bool(arg)) {
 272        case 0:
 273                return COLOR_MOVED_NO;
 274        case 1:
 275                return COLOR_MOVED_DEFAULT;
 276        default:
 277                break;
 278        }
 279
 280        if (!strcmp(arg, "no"))
 281                return COLOR_MOVED_NO;
 282        else if (!strcmp(arg, "plain"))
 283                return COLOR_MOVED_PLAIN;
 284        else if (!strcmp(arg, "blocks"))
 285                return COLOR_MOVED_BLOCKS;
 286        else if (!strcmp(arg, "zebra"))
 287                return COLOR_MOVED_ZEBRA;
 288        else if (!strcmp(arg, "default"))
 289                return COLOR_MOVED_DEFAULT;
 290        else if (!strcmp(arg, "dimmed-zebra"))
 291                return COLOR_MOVED_ZEBRA_DIM;
 292        else if (!strcmp(arg, "dimmed_zebra"))
 293                return COLOR_MOVED_ZEBRA_DIM;
 294        else
 295                return error(_("color moved setting must be one of 'no', 'default', 'blocks', 'zebra', 'dimmed-zebra', 'plain'"));
 296}
 297
 298static unsigned parse_color_moved_ws(const char *arg)
 299{
 300        int ret = 0;
 301        struct string_list l = STRING_LIST_INIT_DUP;
 302        struct string_list_item *i;
 303
 304        string_list_split(&l, arg, ',', -1);
 305
 306        for_each_string_list_item(i, &l) {
 307                struct strbuf sb = STRBUF_INIT;
 308                strbuf_addstr(&sb, i->string);
 309                strbuf_trim(&sb);
 310
 311                if (!strcmp(sb.buf, "no"))
 312                        ret = 0;
 313                else if (!strcmp(sb.buf, "ignore-space-change"))
 314                        ret |= XDF_IGNORE_WHITESPACE_CHANGE;
 315                else if (!strcmp(sb.buf, "ignore-space-at-eol"))
 316                        ret |= XDF_IGNORE_WHITESPACE_AT_EOL;
 317                else if (!strcmp(sb.buf, "ignore-all-space"))
 318                        ret |= XDF_IGNORE_WHITESPACE;
 319                else if (!strcmp(sb.buf, "allow-indentation-change"))
 320                        ret |= COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE;
 321                else {
 322                        ret |= COLOR_MOVED_WS_ERROR;
 323                        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);
 324                }
 325
 326                strbuf_release(&sb);
 327        }
 328
 329        if ((ret & COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) &&
 330            (ret & XDF_WHITESPACE_FLAGS)) {
 331                error(_("color-moved-ws: allow-indentation-change cannot be combined with other whitespace modes"));
 332                ret |= COLOR_MOVED_WS_ERROR;
 333        }
 334
 335        string_list_clear(&l, 0);
 336
 337        return ret;
 338}
 339
 340int git_diff_ui_config(const char *var, const char *value, void *cb)
 341{
 342        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 343                diff_use_color_default = git_config_colorbool(var, value);
 344                return 0;
 345        }
 346        if (!strcmp(var, "diff.colormoved")) {
 347                int cm = parse_color_moved(value);
 348                if (cm < 0)
 349                        return -1;
 350                diff_color_moved_default = cm;
 351                return 0;
 352        }
 353        if (!strcmp(var, "diff.colormovedws")) {
 354                unsigned cm = parse_color_moved_ws(value);
 355                if (cm & COLOR_MOVED_WS_ERROR)
 356                        return -1;
 357                diff_color_moved_ws_default = cm;
 358                return 0;
 359        }
 360        if (!strcmp(var, "diff.context")) {
 361                diff_context_default = git_config_int(var, value);
 362                if (diff_context_default < 0)
 363                        return -1;
 364                return 0;
 365        }
 366        if (!strcmp(var, "diff.interhunkcontext")) {
 367                diff_interhunk_context_default = git_config_int(var, value);
 368                if (diff_interhunk_context_default < 0)
 369                        return -1;
 370                return 0;
 371        }
 372        if (!strcmp(var, "diff.renames")) {
 373                diff_detect_rename_default = git_config_rename(var, value);
 374                return 0;
 375        }
 376        if (!strcmp(var, "diff.autorefreshindex")) {
 377                diff_auto_refresh_index = git_config_bool(var, value);
 378                return 0;
 379        }
 380        if (!strcmp(var, "diff.mnemonicprefix")) {
 381                diff_mnemonic_prefix = git_config_bool(var, value);
 382                return 0;
 383        }
 384        if (!strcmp(var, "diff.noprefix")) {
 385                diff_no_prefix = git_config_bool(var, value);
 386                return 0;
 387        }
 388        if (!strcmp(var, "diff.statgraphwidth")) {
 389                diff_stat_graph_width = git_config_int(var, value);
 390                return 0;
 391        }
 392        if (!strcmp(var, "diff.external"))
 393                return git_config_string(&external_diff_cmd_cfg, var, value);
 394        if (!strcmp(var, "diff.wordregex"))
 395                return git_config_string(&diff_word_regex_cfg, var, value);
 396        if (!strcmp(var, "diff.orderfile"))
 397                return git_config_pathname(&diff_order_file_cfg, var, value);
 398
 399        if (!strcmp(var, "diff.ignoresubmodules"))
 400                handle_ignore_submodules_arg(&default_diff_options, value);
 401
 402        if (!strcmp(var, "diff.submodule")) {
 403                if (parse_submodule_params(&default_diff_options, value))
 404                        warning(_("Unknown value for 'diff.submodule' config variable: '%s'"),
 405                                value);
 406                return 0;
 407        }
 408
 409        if (!strcmp(var, "diff.algorithm")) {
 410                diff_algorithm = parse_algorithm_value(value);
 411                if (diff_algorithm < 0)
 412                        return -1;
 413                return 0;
 414        }
 415
 416        if (!strcmp(var, "diff.wserrorhighlight")) {
 417                int val = parse_ws_error_highlight(value);
 418                if (val < 0)
 419                        return -1;
 420                ws_error_highlight_default = val;
 421                return 0;
 422        }
 423
 424        if (git_color_config(var, value, cb) < 0)
 425                return -1;
 426
 427        return git_diff_basic_config(var, value, cb);
 428}
 429
 430int git_diff_basic_config(const char *var, const char *value, void *cb)
 431{
 432        const char *name;
 433
 434        if (!strcmp(var, "diff.renamelimit")) {
 435                diff_rename_limit_default = git_config_int(var, value);
 436                return 0;
 437        }
 438
 439        if (userdiff_config(var, value) < 0)
 440                return -1;
 441
 442        if (skip_prefix(var, "diff.color.", &name) ||
 443            skip_prefix(var, "color.diff.", &name)) {
 444                int slot = parse_diff_color_slot(name);
 445                if (slot < 0)
 446                        return 0;
 447                if (!value)
 448                        return config_error_nonbool(var);
 449                return color_parse(value, diff_colors[slot]);
 450        }
 451
 452        /* like GNU diff's --suppress-blank-empty option  */
 453        if (!strcmp(var, "diff.suppressblankempty") ||
 454                        /* for backwards compatibility */
 455                        !strcmp(var, "diff.suppress-blank-empty")) {
 456                diff_suppress_blank_empty = git_config_bool(var, value);
 457                return 0;
 458        }
 459
 460        if (!strcmp(var, "diff.dirstat")) {
 461                struct strbuf errmsg = STRBUF_INIT;
 462                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 463                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 464                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 465                                errmsg.buf);
 466                strbuf_release(&errmsg);
 467                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 468                return 0;
 469        }
 470
 471        if (git_diff_heuristic_config(var, value, cb) < 0)
 472                return -1;
 473
 474        return git_default_config(var, value, cb);
 475}
 476
 477static char *quote_two(const char *one, const char *two)
 478{
 479        int need_one = quote_c_style(one, NULL, NULL, 1);
 480        int need_two = quote_c_style(two, NULL, NULL, 1);
 481        struct strbuf res = STRBUF_INIT;
 482
 483        if (need_one + need_two) {
 484                strbuf_addch(&res, '"');
 485                quote_c_style(one, &res, NULL, 1);
 486                quote_c_style(two, &res, NULL, 1);
 487                strbuf_addch(&res, '"');
 488        } else {
 489                strbuf_addstr(&res, one);
 490                strbuf_addstr(&res, two);
 491        }
 492        return strbuf_detach(&res, NULL);
 493}
 494
 495static const char *external_diff(void)
 496{
 497        static const char *external_diff_cmd = NULL;
 498        static int done_preparing = 0;
 499
 500        if (done_preparing)
 501                return external_diff_cmd;
 502        external_diff_cmd = xstrdup_or_null(getenv("GIT_EXTERNAL_DIFF"));
 503        if (!external_diff_cmd)
 504                external_diff_cmd = external_diff_cmd_cfg;
 505        done_preparing = 1;
 506        return external_diff_cmd;
 507}
 508
 509/*
 510 * Keep track of files used for diffing. Sometimes such an entry
 511 * refers to a temporary file, sometimes to an existing file, and
 512 * sometimes to "/dev/null".
 513 */
 514static struct diff_tempfile {
 515        /*
 516         * filename external diff should read from, or NULL if this
 517         * entry is currently not in use:
 518         */
 519        const char *name;
 520
 521        char hex[GIT_MAX_HEXSZ + 1];
 522        char mode[10];
 523
 524        /*
 525         * If this diff_tempfile instance refers to a temporary file,
 526         * this tempfile object is used to manage its lifetime.
 527         */
 528        struct tempfile *tempfile;
 529} diff_temp[2];
 530
 531struct emit_callback {
 532        int color_diff;
 533        unsigned ws_rule;
 534        int blank_at_eof_in_preimage;
 535        int blank_at_eof_in_postimage;
 536        int lno_in_preimage;
 537        int lno_in_postimage;
 538        const char **label_path;
 539        struct diff_words_data *diff_words;
 540        struct diff_options *opt;
 541        struct strbuf *header;
 542};
 543
 544static int count_lines(const char *data, int size)
 545{
 546        int count, ch, completely_empty = 1, nl_just_seen = 0;
 547        count = 0;
 548        while (0 < size--) {
 549                ch = *data++;
 550                if (ch == '\n') {
 551                        count++;
 552                        nl_just_seen = 1;
 553                        completely_empty = 0;
 554                }
 555                else {
 556                        nl_just_seen = 0;
 557                        completely_empty = 0;
 558                }
 559        }
 560        if (completely_empty)
 561                return 0;
 562        if (!nl_just_seen)
 563                count++; /* no trailing newline */
 564        return count;
 565}
 566
 567static int fill_mmfile(struct repository *r, mmfile_t *mf,
 568                       struct diff_filespec *one)
 569{
 570        if (!DIFF_FILE_VALID(one)) {
 571                mf->ptr = (char *)""; /* does not matter */
 572                mf->size = 0;
 573                return 0;
 574        }
 575        else if (diff_populate_filespec(r, one, 0))
 576                return -1;
 577
 578        mf->ptr = one->data;
 579        mf->size = one->size;
 580        return 0;
 581}
 582
 583/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 584static unsigned long diff_filespec_size(struct repository *r,
 585                                        struct diff_filespec *one)
 586{
 587        if (!DIFF_FILE_VALID(one))
 588                return 0;
 589        diff_populate_filespec(r, one, CHECK_SIZE_ONLY);
 590        return one->size;
 591}
 592
 593static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 594{
 595        char *ptr = mf->ptr;
 596        long size = mf->size;
 597        int cnt = 0;
 598
 599        if (!size)
 600                return cnt;
 601        ptr += size - 1; /* pointing at the very end */
 602        if (*ptr != '\n')
 603                ; /* incomplete line */
 604        else
 605                ptr--; /* skip the last LF */
 606        while (mf->ptr < ptr) {
 607                char *prev_eol;
 608                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 609                        if (*prev_eol == '\n')
 610                                break;
 611                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 612                        break;
 613                cnt++;
 614                ptr = prev_eol - 1;
 615        }
 616        return cnt;
 617}
 618
 619static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 620                               struct emit_callback *ecbdata)
 621{
 622        int l1, l2, at;
 623        unsigned ws_rule = ecbdata->ws_rule;
 624        l1 = count_trailing_blank(mf1, ws_rule);
 625        l2 = count_trailing_blank(mf2, ws_rule);
 626        if (l2 <= l1) {
 627                ecbdata->blank_at_eof_in_preimage = 0;
 628                ecbdata->blank_at_eof_in_postimage = 0;
 629                return;
 630        }
 631        at = count_lines(mf1->ptr, mf1->size);
 632        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 633
 634        at = count_lines(mf2->ptr, mf2->size);
 635        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 636}
 637
 638static void emit_line_0(struct diff_options *o,
 639                        const char *set_sign, const char *set, unsigned reverse, const char *reset,
 640                        int first, const char *line, int len)
 641{
 642        int has_trailing_newline, has_trailing_carriage_return;
 643        int needs_reset = 0; /* at the end of the line */
 644        FILE *file = o->file;
 645
 646        fputs(diff_line_prefix(o), file);
 647
 648        has_trailing_newline = (len > 0 && line[len-1] == '\n');
 649        if (has_trailing_newline)
 650                len--;
 651
 652        has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 653        if (has_trailing_carriage_return)
 654                len--;
 655
 656        if (!len && !first)
 657                goto end_of_line;
 658
 659        if (reverse && want_color(o->use_color)) {
 660                fputs(GIT_COLOR_REVERSE, file);
 661                needs_reset = 1;
 662        }
 663
 664        if (set_sign) {
 665                fputs(set_sign, file);
 666                needs_reset = 1;
 667        }
 668
 669        if (first)
 670                fputc(first, file);
 671
 672        if (!len)
 673                goto end_of_line;
 674
 675        if (set) {
 676                if (set_sign && set != set_sign)
 677                        fputs(reset, file);
 678                fputs(set, file);
 679                needs_reset = 1;
 680        }
 681        fwrite(line, len, 1, file);
 682        needs_reset = 1; /* 'line' may contain color codes. */
 683
 684end_of_line:
 685        if (needs_reset)
 686                fputs(reset, file);
 687        if (has_trailing_carriage_return)
 688                fputc('\r', file);
 689        if (has_trailing_newline)
 690                fputc('\n', file);
 691}
 692
 693static void emit_line(struct diff_options *o, const char *set, const char *reset,
 694                      const char *line, int len)
 695{
 696        emit_line_0(o, set, NULL, 0, reset, 0, line, len);
 697}
 698
 699enum diff_symbol {
 700        DIFF_SYMBOL_BINARY_DIFF_HEADER,
 701        DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
 702        DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
 703        DIFF_SYMBOL_BINARY_DIFF_BODY,
 704        DIFF_SYMBOL_BINARY_DIFF_FOOTER,
 705        DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
 706        DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
 707        DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
 708        DIFF_SYMBOL_STATS_LINE,
 709        DIFF_SYMBOL_WORD_DIFF,
 710        DIFF_SYMBOL_STAT_SEP,
 711        DIFF_SYMBOL_SUMMARY,
 712        DIFF_SYMBOL_SUBMODULE_ADD,
 713        DIFF_SYMBOL_SUBMODULE_DEL,
 714        DIFF_SYMBOL_SUBMODULE_UNTRACKED,
 715        DIFF_SYMBOL_SUBMODULE_MODIFIED,
 716        DIFF_SYMBOL_SUBMODULE_HEADER,
 717        DIFF_SYMBOL_SUBMODULE_ERROR,
 718        DIFF_SYMBOL_SUBMODULE_PIPETHROUGH,
 719        DIFF_SYMBOL_REWRITE_DIFF,
 720        DIFF_SYMBOL_BINARY_FILES,
 721        DIFF_SYMBOL_HEADER,
 722        DIFF_SYMBOL_FILEPAIR_PLUS,
 723        DIFF_SYMBOL_FILEPAIR_MINUS,
 724        DIFF_SYMBOL_WORDS_PORCELAIN,
 725        DIFF_SYMBOL_WORDS,
 726        DIFF_SYMBOL_CONTEXT,
 727        DIFF_SYMBOL_CONTEXT_INCOMPLETE,
 728        DIFF_SYMBOL_PLUS,
 729        DIFF_SYMBOL_MINUS,
 730        DIFF_SYMBOL_NO_LF_EOF,
 731        DIFF_SYMBOL_CONTEXT_FRAGINFO,
 732        DIFF_SYMBOL_CONTEXT_MARKER,
 733        DIFF_SYMBOL_SEPARATOR
 734};
 735/*
 736 * Flags for content lines:
 737 * 0..12 are whitespace rules
 738 * 13-15 are WSEH_NEW | WSEH_OLD | WSEH_CONTEXT
 739 * 16 is marking if the line is blank at EOF
 740 */
 741#define DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF      (1<<16)
 742#define DIFF_SYMBOL_MOVED_LINE                  (1<<17)
 743#define DIFF_SYMBOL_MOVED_LINE_ALT              (1<<18)
 744#define DIFF_SYMBOL_MOVED_LINE_UNINTERESTING    (1<<19)
 745#define DIFF_SYMBOL_CONTENT_WS_MASK (WSEH_NEW | WSEH_OLD | WSEH_CONTEXT | WS_RULE_MASK)
 746
 747/*
 748 * This struct is used when we need to buffer the output of the diff output.
 749 *
 750 * NEEDSWORK: Instead of storing a copy of the line, add an offset pointer
 751 * into the pre/post image file. This pointer could be a union with the
 752 * line pointer. By storing an offset into the file instead of the literal line,
 753 * we can decrease the memory footprint for the buffered output. At first we
 754 * may want to only have indirection for the content lines, but we could also
 755 * enhance the state for emitting prefabricated lines, e.g. the similarity
 756 * score line or hunk/file headers would only need to store a number or path
 757 * and then the output can be constructed later on depending on state.
 758 */
 759struct emitted_diff_symbol {
 760        const char *line;
 761        int len;
 762        int flags;
 763        int indent_off;   /* Offset to first non-whitespace character */
 764        int indent_width; /* The visual width of the indentation */
 765        enum diff_symbol s;
 766};
 767#define EMITTED_DIFF_SYMBOL_INIT {NULL}
 768
 769struct emitted_diff_symbols {
 770        struct emitted_diff_symbol *buf;
 771        int nr, alloc;
 772};
 773#define EMITTED_DIFF_SYMBOLS_INIT {NULL, 0, 0}
 774
 775static void append_emitted_diff_symbol(struct diff_options *o,
 776                                       struct emitted_diff_symbol *e)
 777{
 778        struct emitted_diff_symbol *f;
 779
 780        ALLOC_GROW(o->emitted_symbols->buf,
 781                   o->emitted_symbols->nr + 1,
 782                   o->emitted_symbols->alloc);
 783        f = &o->emitted_symbols->buf[o->emitted_symbols->nr++];
 784
 785        memcpy(f, e, sizeof(struct emitted_diff_symbol));
 786        f->line = e->line ? xmemdupz(e->line, e->len) : NULL;
 787}
 788
 789struct moved_entry {
 790        struct hashmap_entry ent;
 791        const struct emitted_diff_symbol *es;
 792        struct moved_entry *next_line;
 793};
 794
 795struct moved_block {
 796        struct moved_entry *match;
 797        int wsd; /* The whitespace delta of this block */
 798};
 799
 800static void moved_block_clear(struct moved_block *b)
 801{
 802        memset(b, 0, sizeof(*b));
 803}
 804
 805#define INDENT_BLANKLINE INT_MIN
 806
 807static void fill_es_indent_data(struct emitted_diff_symbol *es)
 808{
 809        unsigned int off = 0, i;
 810        int width = 0, tab_width = es->flags & WS_TAB_WIDTH_MASK;
 811        const char *s = es->line;
 812        const int len = es->len;
 813
 814        /* skip any \v \f \r at start of indentation */
 815        while (s[off] == '\f' || s[off] == '\v' ||
 816               (s[off] == '\r' && off < len - 1))
 817                off++;
 818
 819        /* calculate the visual width of indentation */
 820        while(1) {
 821                if (s[off] == ' ') {
 822                        width++;
 823                        off++;
 824                } else if (s[off] == '\t') {
 825                        width += tab_width - (width % tab_width);
 826                        while (s[++off] == '\t')
 827                                width += tab_width;
 828                } else {
 829                        break;
 830                }
 831        }
 832
 833        /* check if this line is blank */
 834        for (i = off; i < len; i++)
 835                if (!isspace(s[i]))
 836                    break;
 837
 838        if (i == len) {
 839                es->indent_width = INDENT_BLANKLINE;
 840                es->indent_off = len;
 841        } else {
 842                es->indent_off = off;
 843                es->indent_width = width;
 844        }
 845}
 846
 847static int compute_ws_delta(const struct emitted_diff_symbol *a,
 848                            const struct emitted_diff_symbol *b,
 849                            int *out)
 850{
 851        int a_len = a->len,
 852            b_len = b->len,
 853            a_off = a->indent_off,
 854            a_width = a->indent_width,
 855            b_off = b->indent_off,
 856            b_width = b->indent_width;
 857        int delta;
 858
 859        if (a_width == INDENT_BLANKLINE && b_width == INDENT_BLANKLINE) {
 860                *out = INDENT_BLANKLINE;
 861                return 1;
 862        }
 863
 864        if (a->s == DIFF_SYMBOL_PLUS)
 865                delta = a_width - b_width;
 866        else
 867                delta = b_width - a_width;
 868
 869        if (a_len - a_off != b_len - b_off ||
 870            memcmp(a->line + a_off, b->line + b_off, a_len - a_off))
 871                return 0;
 872
 873        *out = delta;
 874
 875        return 1;
 876}
 877
 878static int cmp_in_block_with_wsd(const struct diff_options *o,
 879                                 const struct moved_entry *cur,
 880                                 const struct moved_entry *match,
 881                                 struct moved_block *pmb,
 882                                 int n)
 883{
 884        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
 885        int al = cur->es->len, bl = match->es->len, cl = l->len;
 886        const char *a = cur->es->line,
 887                   *b = match->es->line,
 888                   *c = l->line;
 889        int a_off = cur->es->indent_off,
 890            a_width = cur->es->indent_width,
 891            c_off = l->indent_off,
 892            c_width = l->indent_width;
 893        int delta;
 894
 895        /*
 896         * We need to check if 'cur' is equal to 'match'.  As those
 897         * are from the same (+/-) side, we do not need to adjust for
 898         * indent changes. However these were found using fuzzy
 899         * matching so we do have to check if they are equal. Here we
 900         * just check the lengths. We delay calling memcmp() to check
 901         * the contents until later as if the length comparison for a
 902         * and c fails we can avoid the call all together.
 903         */
 904        if (al != bl)
 905                return 1;
 906
 907        /* If 'l' and 'cur' are both blank then they match. */
 908        if (a_width == INDENT_BLANKLINE && c_width == INDENT_BLANKLINE)
 909                return 0;
 910
 911        /*
 912         * The indent changes of the block are known and stored in pmb->wsd;
 913         * however we need to check if the indent changes of the current line
 914         * match those of the current block and that the text of 'l' and 'cur'
 915         * after the indentation match.
 916         */
 917        if (cur->es->s == DIFF_SYMBOL_PLUS)
 918                delta = a_width - c_width;
 919        else
 920                delta = c_width - a_width;
 921
 922        /*
 923         * If the previous lines of this block were all blank then set its
 924         * whitespace delta.
 925         */
 926        if (pmb->wsd == INDENT_BLANKLINE)
 927                pmb->wsd = delta;
 928
 929        return !(delta == pmb->wsd && al - a_off == cl - c_off &&
 930                 !memcmp(a, b, al) && !
 931                 memcmp(a + a_off, c + c_off, al - a_off));
 932}
 933
 934static int moved_entry_cmp(const void *hashmap_cmp_fn_data,
 935                           const void *entry,
 936                           const void *entry_or_key,
 937                           const void *keydata)
 938{
 939        const struct diff_options *diffopt = hashmap_cmp_fn_data;
 940        const struct moved_entry *a = entry;
 941        const struct moved_entry *b = entry_or_key;
 942        unsigned flags = diffopt->color_moved_ws_handling
 943                         & XDF_WHITESPACE_FLAGS;
 944
 945        if (diffopt->color_moved_ws_handling &
 946            COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
 947                /*
 948                 * As there is not specific white space config given,
 949                 * we'd need to check for a new block, so ignore all
 950                 * white space. The setup of the white space
 951                 * configuration for the next block is done else where
 952                 */
 953                flags |= XDF_IGNORE_WHITESPACE;
 954
 955        return !xdiff_compare_lines(a->es->line, a->es->len,
 956                                    b->es->line, b->es->len,
 957                                    flags);
 958}
 959
 960static struct moved_entry *prepare_entry(struct diff_options *o,
 961                                         int line_no)
 962{
 963        struct moved_entry *ret = xmalloc(sizeof(*ret));
 964        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[line_no];
 965        unsigned flags = o->color_moved_ws_handling & XDF_WHITESPACE_FLAGS;
 966
 967        ret->ent.hash = xdiff_hash_string(l->line, l->len, flags);
 968        ret->es = l;
 969        ret->next_line = NULL;
 970
 971        return ret;
 972}
 973
 974static void add_lines_to_move_detection(struct diff_options *o,
 975                                        struct hashmap *add_lines,
 976                                        struct hashmap *del_lines)
 977{
 978        struct moved_entry *prev_line = NULL;
 979
 980        int n;
 981        for (n = 0; n < o->emitted_symbols->nr; n++) {
 982                struct hashmap *hm;
 983                struct moved_entry *key;
 984
 985                switch (o->emitted_symbols->buf[n].s) {
 986                case DIFF_SYMBOL_PLUS:
 987                        hm = add_lines;
 988                        break;
 989                case DIFF_SYMBOL_MINUS:
 990                        hm = del_lines;
 991                        break;
 992                default:
 993                        prev_line = NULL;
 994                        continue;
 995                }
 996
 997                if (o->color_moved_ws_handling &
 998                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
 999                        fill_es_indent_data(&o->emitted_symbols->buf[n]);
1000                key = prepare_entry(o, n);
1001                if (prev_line && prev_line->es->s == o->emitted_symbols->buf[n].s)
1002                        prev_line->next_line = key;
1003
1004                hashmap_add(hm, key);
1005                prev_line = key;
1006        }
1007}
1008
1009static void pmb_advance_or_null(struct diff_options *o,
1010                                struct moved_entry *match,
1011                                struct hashmap *hm,
1012                                struct moved_block *pmb,
1013                                int pmb_nr)
1014{
1015        int i;
1016        for (i = 0; i < pmb_nr; i++) {
1017                struct moved_entry *prev = pmb[i].match;
1018                struct moved_entry *cur = (prev && prev->next_line) ?
1019                                prev->next_line : NULL;
1020                if (cur && !hm->cmpfn(o, cur, match, NULL)) {
1021                        pmb[i].match = cur;
1022                } else {
1023                        pmb[i].match = NULL;
1024                }
1025        }
1026}
1027
1028static void pmb_advance_or_null_multi_match(struct diff_options *o,
1029                                            struct moved_entry *match,
1030                                            struct hashmap *hm,
1031                                            struct moved_block *pmb,
1032                                            int pmb_nr, int n)
1033{
1034        int i;
1035        char *got_match = xcalloc(1, pmb_nr);
1036
1037        for (; match; match = hashmap_get_next(hm, match)) {
1038                for (i = 0; i < pmb_nr; i++) {
1039                        struct moved_entry *prev = pmb[i].match;
1040                        struct moved_entry *cur = (prev && prev->next_line) ?
1041                                        prev->next_line : NULL;
1042                        if (!cur)
1043                                continue;
1044                        if (!cmp_in_block_with_wsd(o, cur, match, &pmb[i], n))
1045                                got_match[i] |= 1;
1046                }
1047        }
1048
1049        for (i = 0; i < pmb_nr; i++) {
1050                if (got_match[i]) {
1051                        /* Advance to the next line */
1052                        pmb[i].match = pmb[i].match->next_line;
1053                } else {
1054                        moved_block_clear(&pmb[i]);
1055                }
1056        }
1057
1058        free(got_match);
1059}
1060
1061static int shrink_potential_moved_blocks(struct moved_block *pmb,
1062                                         int pmb_nr)
1063{
1064        int lp, rp;
1065
1066        /* Shrink the set of potential block to the remaining running */
1067        for (lp = 0, rp = pmb_nr - 1; lp <= rp;) {
1068                while (lp < pmb_nr && pmb[lp].match)
1069                        lp++;
1070                /* lp points at the first NULL now */
1071
1072                while (rp > -1 && !pmb[rp].match)
1073                        rp--;
1074                /* rp points at the last non-NULL */
1075
1076                if (lp < pmb_nr && rp > -1 && lp < rp) {
1077                        pmb[lp] = pmb[rp];
1078                        memset(&pmb[rp], 0, sizeof(pmb[rp]));
1079                        rp--;
1080                        lp++;
1081                }
1082        }
1083
1084        /* Remember the number of running sets */
1085        return rp + 1;
1086}
1087
1088/*
1089 * If o->color_moved is COLOR_MOVED_PLAIN, this function does nothing.
1090 *
1091 * Otherwise, if the last block has fewer alphanumeric characters than
1092 * COLOR_MOVED_MIN_ALNUM_COUNT, unset DIFF_SYMBOL_MOVED_LINE on all lines in
1093 * that block.
1094 *
1095 * The last block consists of the (n - block_length)'th line up to but not
1096 * including the nth line.
1097 *
1098 * Returns 0 if the last block is empty or is unset by this function, non zero
1099 * otherwise.
1100 *
1101 * NEEDSWORK: This uses the same heuristic as blame_entry_score() in blame.c.
1102 * Think of a way to unify them.
1103 */
1104static int adjust_last_block(struct diff_options *o, int n, int block_length)
1105{
1106        int i, alnum_count = 0;
1107        if (o->color_moved == COLOR_MOVED_PLAIN)
1108                return block_length;
1109        for (i = 1; i < block_length + 1; i++) {
1110                const char *c = o->emitted_symbols->buf[n - i].line;
1111                for (; *c; c++) {
1112                        if (!isalnum(*c))
1113                                continue;
1114                        alnum_count++;
1115                        if (alnum_count >= COLOR_MOVED_MIN_ALNUM_COUNT)
1116                                return 1;
1117                }
1118        }
1119        for (i = 1; i < block_length + 1; i++)
1120                o->emitted_symbols->buf[n - i].flags &= ~DIFF_SYMBOL_MOVED_LINE;
1121        return 0;
1122}
1123
1124/* Find blocks of moved code, delegate actual coloring decision to helper */
1125static void mark_color_as_moved(struct diff_options *o,
1126                                struct hashmap *add_lines,
1127                                struct hashmap *del_lines)
1128{
1129        struct moved_block *pmb = NULL; /* potentially moved blocks */
1130        int pmb_nr = 0, pmb_alloc = 0;
1131        int n, flipped_block = 0, block_length = 0;
1132
1133
1134        for (n = 0; n < o->emitted_symbols->nr; n++) {
1135                struct hashmap *hm = NULL;
1136                struct moved_entry *key;
1137                struct moved_entry *match = NULL;
1138                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
1139                enum diff_symbol last_symbol = 0;
1140
1141                switch (l->s) {
1142                case DIFF_SYMBOL_PLUS:
1143                        hm = del_lines;
1144                        key = prepare_entry(o, n);
1145                        match = hashmap_get(hm, key, NULL);
1146                        free(key);
1147                        break;
1148                case DIFF_SYMBOL_MINUS:
1149                        hm = add_lines;
1150                        key = prepare_entry(o, n);
1151                        match = hashmap_get(hm, key, NULL);
1152                        free(key);
1153                        break;
1154                default:
1155                        flipped_block = 0;
1156                }
1157
1158                if (!match) {
1159                        int i;
1160
1161                        adjust_last_block(o, n, block_length);
1162                        for(i = 0; i < pmb_nr; i++)
1163                                moved_block_clear(&pmb[i]);
1164                        pmb_nr = 0;
1165                        block_length = 0;
1166                        flipped_block = 0;
1167                        last_symbol = l->s;
1168                        continue;
1169                }
1170
1171                if (o->color_moved == COLOR_MOVED_PLAIN) {
1172                        last_symbol = l->s;
1173                        l->flags |= DIFF_SYMBOL_MOVED_LINE;
1174                        continue;
1175                }
1176
1177                if (o->color_moved_ws_handling &
1178                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
1179                        pmb_advance_or_null_multi_match(o, match, hm, pmb, pmb_nr, n);
1180                else
1181                        pmb_advance_or_null(o, match, hm, pmb, pmb_nr);
1182
1183                pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
1184
1185                if (pmb_nr == 0) {
1186                        /*
1187                         * The current line is the start of a new block.
1188                         * Setup the set of potential blocks.
1189                         */
1190                        for (; match; match = hashmap_get_next(hm, match)) {
1191                                ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
1192                                if (o->color_moved_ws_handling &
1193                                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) {
1194                                        if (compute_ws_delta(l, match->es,
1195                                                             &pmb[pmb_nr].wsd))
1196                                                pmb[pmb_nr++].match = match;
1197                                } else {
1198                                        pmb[pmb_nr].wsd = 0;
1199                                        pmb[pmb_nr++].match = match;
1200                                }
1201                        }
1202
1203                        if (adjust_last_block(o, n, block_length) &&
1204                            pmb_nr && last_symbol != l->s)
1205                                flipped_block = (flipped_block + 1) % 2;
1206                        else
1207                                flipped_block = 0;
1208
1209                        block_length = 0;
1210                }
1211
1212                if (pmb_nr) {
1213                        block_length++;
1214                        l->flags |= DIFF_SYMBOL_MOVED_LINE;
1215                        if (flipped_block && o->color_moved != COLOR_MOVED_BLOCKS)
1216                                l->flags |= DIFF_SYMBOL_MOVED_LINE_ALT;
1217                }
1218                last_symbol = l->s;
1219        }
1220        adjust_last_block(o, n, block_length);
1221
1222        for(n = 0; n < pmb_nr; n++)
1223                moved_block_clear(&pmb[n]);
1224        free(pmb);
1225}
1226
1227#define DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK \
1228  (DIFF_SYMBOL_MOVED_LINE | DIFF_SYMBOL_MOVED_LINE_ALT)
1229static void dim_moved_lines(struct diff_options *o)
1230{
1231        int n;
1232        for (n = 0; n < o->emitted_symbols->nr; n++) {
1233                struct emitted_diff_symbol *prev = (n != 0) ?
1234                                &o->emitted_symbols->buf[n - 1] : NULL;
1235                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
1236                struct emitted_diff_symbol *next =
1237                                (n < o->emitted_symbols->nr - 1) ?
1238                                &o->emitted_symbols->buf[n + 1] : NULL;
1239
1240                /* Not a plus or minus line? */
1241                if (l->s != DIFF_SYMBOL_PLUS && l->s != DIFF_SYMBOL_MINUS)
1242                        continue;
1243
1244                /* Not a moved line? */
1245                if (!(l->flags & DIFF_SYMBOL_MOVED_LINE))
1246                        continue;
1247
1248                /*
1249                 * If prev or next are not a plus or minus line,
1250                 * pretend they don't exist
1251                 */
1252                if (prev && prev->s != DIFF_SYMBOL_PLUS &&
1253                            prev->s != DIFF_SYMBOL_MINUS)
1254                        prev = NULL;
1255                if (next && next->s != DIFF_SYMBOL_PLUS &&
1256                            next->s != DIFF_SYMBOL_MINUS)
1257                        next = NULL;
1258
1259                /* Inside a block? */
1260                if ((prev &&
1261                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
1262                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK)) &&
1263                    (next &&
1264                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
1265                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK))) {
1266                        l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1267                        continue;
1268                }
1269
1270                /* Check if we are at an interesting bound: */
1271                if (prev && (prev->flags & DIFF_SYMBOL_MOVED_LINE) &&
1272                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1273                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1274                        continue;
1275                if (next && (next->flags & DIFF_SYMBOL_MOVED_LINE) &&
1276                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1277                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1278                        continue;
1279
1280                /*
1281                 * The boundary to prev and next are not interesting,
1282                 * so this line is not interesting as a whole
1283                 */
1284                l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1285        }
1286}
1287
1288static void emit_line_ws_markup(struct diff_options *o,
1289                                const char *set_sign, const char *set,
1290                                const char *reset,
1291                                int sign_index, const char *line, int len,
1292                                unsigned ws_rule, int blank_at_eof)
1293{
1294        const char *ws = NULL;
1295        int sign = o->output_indicators[sign_index];
1296
1297        if (o->ws_error_highlight & ws_rule) {
1298                ws = diff_get_color_opt(o, DIFF_WHITESPACE);
1299                if (!*ws)
1300                        ws = NULL;
1301        }
1302
1303        if (!ws && !set_sign)
1304                emit_line_0(o, set, NULL, 0, reset, sign, line, len);
1305        else if (!ws) {
1306                emit_line_0(o, set_sign, set, !!set_sign, reset, sign, line, len);
1307        } else if (blank_at_eof)
1308                /* Blank line at EOF - paint '+' as well */
1309                emit_line_0(o, ws, NULL, 0, reset, sign, line, len);
1310        else {
1311                /* Emit just the prefix, then the rest. */
1312                emit_line_0(o, set_sign ? set_sign : set, NULL, !!set_sign, reset,
1313                            sign, "", 0);
1314                ws_check_emit(line, len, ws_rule,
1315                              o->file, set, reset, ws);
1316        }
1317}
1318
1319static void emit_diff_symbol_from_struct(struct diff_options *o,
1320                                         struct emitted_diff_symbol *eds)
1321{
1322        static const char *nneof = " No newline at end of file\n";
1323        const char *context, *reset, *set, *set_sign, *meta, *fraginfo;
1324        struct strbuf sb = STRBUF_INIT;
1325
1326        enum diff_symbol s = eds->s;
1327        const char *line = eds->line;
1328        int len = eds->len;
1329        unsigned flags = eds->flags;
1330
1331        switch (s) {
1332        case DIFF_SYMBOL_NO_LF_EOF:
1333                context = diff_get_color_opt(o, DIFF_CONTEXT);
1334                reset = diff_get_color_opt(o, DIFF_RESET);
1335                putc('\n', o->file);
1336                emit_line_0(o, context, NULL, 0, reset, '\\',
1337                            nneof, strlen(nneof));
1338                break;
1339        case DIFF_SYMBOL_SUBMODULE_HEADER:
1340        case DIFF_SYMBOL_SUBMODULE_ERROR:
1341        case DIFF_SYMBOL_SUBMODULE_PIPETHROUGH:
1342        case DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES:
1343        case DIFF_SYMBOL_SUMMARY:
1344        case DIFF_SYMBOL_STATS_LINE:
1345        case DIFF_SYMBOL_BINARY_DIFF_BODY:
1346        case DIFF_SYMBOL_CONTEXT_FRAGINFO:
1347                emit_line(o, "", "", line, len);
1348                break;
1349        case DIFF_SYMBOL_CONTEXT_INCOMPLETE:
1350        case DIFF_SYMBOL_CONTEXT_MARKER:
1351                context = diff_get_color_opt(o, DIFF_CONTEXT);
1352                reset = diff_get_color_opt(o, DIFF_RESET);
1353                emit_line(o, context, reset, line, len);
1354                break;
1355        case DIFF_SYMBOL_SEPARATOR:
1356                fprintf(o->file, "%s%c",
1357                        diff_line_prefix(o),
1358                        o->line_termination);
1359                break;
1360        case DIFF_SYMBOL_CONTEXT:
1361                set = diff_get_color_opt(o, DIFF_CONTEXT);
1362                reset = diff_get_color_opt(o, DIFF_RESET);
1363                set_sign = NULL;
1364                if (o->flags.dual_color_diffed_diffs) {
1365                        char c = !len ? 0 : line[0];
1366
1367                        if (c == '+')
1368                                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1369                        else if (c == '@')
1370                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1371                        else if (c == '-')
1372                                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1373                }
1374                emit_line_ws_markup(o, set_sign, set, reset,
1375                                    OUTPUT_INDICATOR_CONTEXT, line, len,
1376                                    flags & (DIFF_SYMBOL_CONTENT_WS_MASK), 0);
1377                break;
1378        case DIFF_SYMBOL_PLUS:
1379                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1380                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1381                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1382                case DIFF_SYMBOL_MOVED_LINE |
1383                     DIFF_SYMBOL_MOVED_LINE_ALT |
1384                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1385                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT_DIM);
1386                        break;
1387                case DIFF_SYMBOL_MOVED_LINE |
1388                     DIFF_SYMBOL_MOVED_LINE_ALT:
1389                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT);
1390                        break;
1391                case DIFF_SYMBOL_MOVED_LINE |
1392                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1393                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_DIM);
1394                        break;
1395                case DIFF_SYMBOL_MOVED_LINE:
1396                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED);
1397                        break;
1398                default:
1399                        set = diff_get_color_opt(o, DIFF_FILE_NEW);
1400                }
1401                reset = diff_get_color_opt(o, DIFF_RESET);
1402                if (!o->flags.dual_color_diffed_diffs)
1403                        set_sign = NULL;
1404                else {
1405                        char c = !len ? 0 : line[0];
1406
1407                        set_sign = set;
1408                        if (c == '-')
1409                                set = diff_get_color_opt(o, DIFF_FILE_OLD_BOLD);
1410                        else if (c == '@')
1411                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1412                        else if (c == '+')
1413                                set = diff_get_color_opt(o, DIFF_FILE_NEW_BOLD);
1414                        else
1415                                set = diff_get_color_opt(o, DIFF_CONTEXT_BOLD);
1416                        flags &= ~DIFF_SYMBOL_CONTENT_WS_MASK;
1417                }
1418                emit_line_ws_markup(o, set_sign, set, reset,
1419                                    OUTPUT_INDICATOR_NEW, line, len,
1420                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK,
1421                                    flags & DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF);
1422                break;
1423        case DIFF_SYMBOL_MINUS:
1424                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1425                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1426                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1427                case DIFF_SYMBOL_MOVED_LINE |
1428                     DIFF_SYMBOL_MOVED_LINE_ALT |
1429                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1430                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT_DIM);
1431                        break;
1432                case DIFF_SYMBOL_MOVED_LINE |
1433                     DIFF_SYMBOL_MOVED_LINE_ALT:
1434                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT);
1435                        break;
1436                case DIFF_SYMBOL_MOVED_LINE |
1437                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1438                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_DIM);
1439                        break;
1440                case DIFF_SYMBOL_MOVED_LINE:
1441                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED);
1442                        break;
1443                default:
1444                        set = diff_get_color_opt(o, DIFF_FILE_OLD);
1445                }
1446                reset = diff_get_color_opt(o, DIFF_RESET);
1447                if (!o->flags.dual_color_diffed_diffs)
1448                        set_sign = NULL;
1449                else {
1450                        char c = !len ? 0 : line[0];
1451
1452                        set_sign = set;
1453                        if (c == '+')
1454                                set = diff_get_color_opt(o, DIFF_FILE_NEW_DIM);
1455                        else if (c == '@')
1456                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1457                        else if (c == '-')
1458                                set = diff_get_color_opt(o, DIFF_FILE_OLD_DIM);
1459                        else
1460                                set = diff_get_color_opt(o, DIFF_CONTEXT_DIM);
1461                }
1462                emit_line_ws_markup(o, set_sign, set, reset,
1463                                    OUTPUT_INDICATOR_OLD, line, len,
1464                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK, 0);
1465                break;
1466        case DIFF_SYMBOL_WORDS_PORCELAIN:
1467                context = diff_get_color_opt(o, DIFF_CONTEXT);
1468                reset = diff_get_color_opt(o, DIFF_RESET);
1469                emit_line(o, context, reset, line, len);
1470                fputs("~\n", o->file);
1471                break;
1472        case DIFF_SYMBOL_WORDS:
1473                context = diff_get_color_opt(o, DIFF_CONTEXT);
1474                reset = diff_get_color_opt(o, DIFF_RESET);
1475                /*
1476                 * Skip the prefix character, if any.  With
1477                 * diff_suppress_blank_empty, there may be
1478                 * none.
1479                 */
1480                if (line[0] != '\n') {
1481                        line++;
1482                        len--;
1483                }
1484                emit_line(o, context, reset, line, len);
1485                break;
1486        case DIFF_SYMBOL_FILEPAIR_PLUS:
1487                meta = diff_get_color_opt(o, DIFF_METAINFO);
1488                reset = diff_get_color_opt(o, DIFF_RESET);
1489                fprintf(o->file, "%s%s+++ %s%s%s\n", diff_line_prefix(o), meta,
1490                        line, reset,
1491                        strchr(line, ' ') ? "\t" : "");
1492                break;
1493        case DIFF_SYMBOL_FILEPAIR_MINUS:
1494                meta = diff_get_color_opt(o, DIFF_METAINFO);
1495                reset = diff_get_color_opt(o, DIFF_RESET);
1496                fprintf(o->file, "%s%s--- %s%s%s\n", diff_line_prefix(o), meta,
1497                        line, reset,
1498                        strchr(line, ' ') ? "\t" : "");
1499                break;
1500        case DIFF_SYMBOL_BINARY_FILES:
1501        case DIFF_SYMBOL_HEADER:
1502                fprintf(o->file, "%s", line);
1503                break;
1504        case DIFF_SYMBOL_BINARY_DIFF_HEADER:
1505                fprintf(o->file, "%sGIT binary patch\n", diff_line_prefix(o));
1506                break;
1507        case DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA:
1508                fprintf(o->file, "%sdelta %s\n", diff_line_prefix(o), line);
1509                break;
1510        case DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL:
1511                fprintf(o->file, "%sliteral %s\n", diff_line_prefix(o), line);
1512                break;
1513        case DIFF_SYMBOL_BINARY_DIFF_FOOTER:
1514                fputs(diff_line_prefix(o), o->file);
1515                fputc('\n', o->file);
1516                break;
1517        case DIFF_SYMBOL_REWRITE_DIFF:
1518                fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
1519                reset = diff_get_color_opt(o, DIFF_RESET);
1520                emit_line(o, fraginfo, reset, line, len);
1521                break;
1522        case DIFF_SYMBOL_SUBMODULE_ADD:
1523                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1524                reset = diff_get_color_opt(o, DIFF_RESET);
1525                emit_line(o, set, reset, line, len);
1526                break;
1527        case DIFF_SYMBOL_SUBMODULE_DEL:
1528                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1529                reset = diff_get_color_opt(o, DIFF_RESET);
1530                emit_line(o, set, reset, line, len);
1531                break;
1532        case DIFF_SYMBOL_SUBMODULE_UNTRACKED:
1533                fprintf(o->file, "%sSubmodule %s contains untracked content\n",
1534                        diff_line_prefix(o), line);
1535                break;
1536        case DIFF_SYMBOL_SUBMODULE_MODIFIED:
1537                fprintf(o->file, "%sSubmodule %s contains modified content\n",
1538                        diff_line_prefix(o), line);
1539                break;
1540        case DIFF_SYMBOL_STATS_SUMMARY_NO_FILES:
1541                emit_line(o, "", "", " 0 files changed\n",
1542                          strlen(" 0 files changed\n"));
1543                break;
1544        case DIFF_SYMBOL_STATS_SUMMARY_ABBREV:
1545                emit_line(o, "", "", " ...\n", strlen(" ...\n"));
1546                break;
1547        case DIFF_SYMBOL_WORD_DIFF:
1548                fprintf(o->file, "%.*s", len, line);
1549                break;
1550        case DIFF_SYMBOL_STAT_SEP:
1551                fputs(o->stat_sep, o->file);
1552                break;
1553        default:
1554                BUG("unknown diff symbol");
1555        }
1556        strbuf_release(&sb);
1557}
1558
1559static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
1560                             const char *line, int len, unsigned flags)
1561{
1562        struct emitted_diff_symbol e = {line, len, flags, 0, 0, s};
1563
1564        if (o->emitted_symbols)
1565                append_emitted_diff_symbol(o, &e);
1566        else
1567                emit_diff_symbol_from_struct(o, &e);
1568}
1569
1570void diff_emit_submodule_del(struct diff_options *o, const char *line)
1571{
1572        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_DEL, line, strlen(line), 0);
1573}
1574
1575void diff_emit_submodule_add(struct diff_options *o, const char *line)
1576{
1577        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ADD, line, strlen(line), 0);
1578}
1579
1580void diff_emit_submodule_untracked(struct diff_options *o, const char *path)
1581{
1582        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_UNTRACKED,
1583                         path, strlen(path), 0);
1584}
1585
1586void diff_emit_submodule_modified(struct diff_options *o, const char *path)
1587{
1588        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_MODIFIED,
1589                         path, strlen(path), 0);
1590}
1591
1592void diff_emit_submodule_header(struct diff_options *o, const char *header)
1593{
1594        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_HEADER,
1595                         header, strlen(header), 0);
1596}
1597
1598void diff_emit_submodule_error(struct diff_options *o, const char *err)
1599{
1600        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ERROR, err, strlen(err), 0);
1601}
1602
1603void diff_emit_submodule_pipethrough(struct diff_options *o,
1604                                     const char *line, int len)
1605{
1606        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_PIPETHROUGH, line, len, 0);
1607}
1608
1609static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
1610{
1611        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
1612              ecbdata->blank_at_eof_in_preimage &&
1613              ecbdata->blank_at_eof_in_postimage &&
1614              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
1615              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
1616                return 0;
1617        return ws_blank_line(line, len, ecbdata->ws_rule);
1618}
1619
1620static void emit_add_line(struct emit_callback *ecbdata,
1621                          const char *line, int len)
1622{
1623        unsigned flags = WSEH_NEW | ecbdata->ws_rule;
1624        if (new_blank_line_at_eof(ecbdata, line, len))
1625                flags |= DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF;
1626
1627        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_PLUS, line, len, flags);
1628}
1629
1630static void emit_del_line(struct emit_callback *ecbdata,
1631                          const char *line, int len)
1632{
1633        unsigned flags = WSEH_OLD | ecbdata->ws_rule;
1634        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_MINUS, line, len, flags);
1635}
1636
1637static void emit_context_line(struct emit_callback *ecbdata,
1638                              const char *line, int len)
1639{
1640        unsigned flags = WSEH_CONTEXT | ecbdata->ws_rule;
1641        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_CONTEXT, line, len, flags);
1642}
1643
1644static void emit_hunk_header(struct emit_callback *ecbdata,
1645                             const char *line, int len)
1646{
1647        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
1648        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
1649        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
1650        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1651        const char *reverse = ecbdata->color_diff ? GIT_COLOR_REVERSE : "";
1652        static const char atat[2] = { '@', '@' };
1653        const char *cp, *ep;
1654        struct strbuf msgbuf = STRBUF_INIT;
1655        int org_len = len;
1656        int i = 1;
1657
1658        /*
1659         * As a hunk header must begin with "@@ -<old>, +<new> @@",
1660         * it always is at least 10 bytes long.
1661         */
1662        if (len < 10 ||
1663            memcmp(line, atat, 2) ||
1664            !(ep = memmem(line + 2, len - 2, atat, 2))) {
1665                emit_diff_symbol(ecbdata->opt,
1666                                 DIFF_SYMBOL_CONTEXT_MARKER, line, len, 0);
1667                return;
1668        }
1669        ep += 2; /* skip over @@ */
1670
1671        /* The hunk header in fraginfo color */
1672        if (ecbdata->opt->flags.dual_color_diffed_diffs)
1673                strbuf_addstr(&msgbuf, reverse);
1674        strbuf_addstr(&msgbuf, frag);
1675        strbuf_add(&msgbuf, line, ep - line);
1676        strbuf_addstr(&msgbuf, reset);
1677
1678        /*
1679         * trailing "\r\n"
1680         */
1681        for ( ; i < 3; i++)
1682                if (line[len - i] == '\r' || line[len - i] == '\n')
1683                        len--;
1684
1685        /* blank before the func header */
1686        for (cp = ep; ep - line < len; ep++)
1687                if (*ep != ' ' && *ep != '\t')
1688                        break;
1689        if (ep != cp) {
1690                strbuf_addstr(&msgbuf, context);
1691                strbuf_add(&msgbuf, cp, ep - cp);
1692                strbuf_addstr(&msgbuf, reset);
1693        }
1694
1695        if (ep < line + len) {
1696                strbuf_addstr(&msgbuf, func);
1697                strbuf_add(&msgbuf, ep, line + len - ep);
1698                strbuf_addstr(&msgbuf, reset);
1699        }
1700
1701        strbuf_add(&msgbuf, line + len, org_len - len);
1702        strbuf_complete_line(&msgbuf);
1703        emit_diff_symbol(ecbdata->opt,
1704                         DIFF_SYMBOL_CONTEXT_FRAGINFO, msgbuf.buf, msgbuf.len, 0);
1705        strbuf_release(&msgbuf);
1706}
1707
1708static struct diff_tempfile *claim_diff_tempfile(void)
1709{
1710        int i;
1711        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
1712                if (!diff_temp[i].name)
1713                        return diff_temp + i;
1714        BUG("diff is failing to clean up its tempfiles");
1715}
1716
1717static void remove_tempfile(void)
1718{
1719        int i;
1720        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
1721                if (is_tempfile_active(diff_temp[i].tempfile))
1722                        delete_tempfile(&diff_temp[i].tempfile);
1723                diff_temp[i].name = NULL;
1724        }
1725}
1726
1727static void add_line_count(struct strbuf *out, int count)
1728{
1729        switch (count) {
1730        case 0:
1731                strbuf_addstr(out, "0,0");
1732                break;
1733        case 1:
1734                strbuf_addstr(out, "1");
1735                break;
1736        default:
1737                strbuf_addf(out, "1,%d", count);
1738                break;
1739        }
1740}
1741
1742static void emit_rewrite_lines(struct emit_callback *ecb,
1743                               int prefix, const char *data, int size)
1744{
1745        const char *endp = NULL;
1746
1747        while (0 < size) {
1748                int len;
1749
1750                endp = memchr(data, '\n', size);
1751                len = endp ? (endp - data + 1) : size;
1752                if (prefix != '+') {
1753                        ecb->lno_in_preimage++;
1754                        emit_del_line(ecb, data, len);
1755                } else {
1756                        ecb->lno_in_postimage++;
1757                        emit_add_line(ecb, data, len);
1758                }
1759                size -= len;
1760                data += len;
1761        }
1762        if (!endp)
1763                emit_diff_symbol(ecb->opt, DIFF_SYMBOL_NO_LF_EOF, NULL, 0, 0);
1764}
1765
1766static void emit_rewrite_diff(const char *name_a,
1767                              const char *name_b,
1768                              struct diff_filespec *one,
1769                              struct diff_filespec *two,
1770                              struct userdiff_driver *textconv_one,
1771                              struct userdiff_driver *textconv_two,
1772                              struct diff_options *o)
1773{
1774        int lc_a, lc_b;
1775        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
1776        const char *a_prefix, *b_prefix;
1777        char *data_one, *data_two;
1778        size_t size_one, size_two;
1779        struct emit_callback ecbdata;
1780        struct strbuf out = STRBUF_INIT;
1781
1782        if (diff_mnemonic_prefix && o->flags.reverse_diff) {
1783                a_prefix = o->b_prefix;
1784                b_prefix = o->a_prefix;
1785        } else {
1786                a_prefix = o->a_prefix;
1787                b_prefix = o->b_prefix;
1788        }
1789
1790        name_a += (*name_a == '/');
1791        name_b += (*name_b == '/');
1792
1793        strbuf_reset(&a_name);
1794        strbuf_reset(&b_name);
1795        quote_two_c_style(&a_name, a_prefix, name_a, 0);
1796        quote_two_c_style(&b_name, b_prefix, name_b, 0);
1797
1798        size_one = fill_textconv(o->repo, textconv_one, one, &data_one);
1799        size_two = fill_textconv(o->repo, textconv_two, two, &data_two);
1800
1801        memset(&ecbdata, 0, sizeof(ecbdata));
1802        ecbdata.color_diff = want_color(o->use_color);
1803        ecbdata.ws_rule = whitespace_rule(o->repo->index, name_b);
1804        ecbdata.opt = o;
1805        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
1806                mmfile_t mf1, mf2;
1807                mf1.ptr = (char *)data_one;
1808                mf2.ptr = (char *)data_two;
1809                mf1.size = size_one;
1810                mf2.size = size_two;
1811                check_blank_at_eof(&mf1, &mf2, &ecbdata);
1812        }
1813        ecbdata.lno_in_preimage = 1;
1814        ecbdata.lno_in_postimage = 1;
1815
1816        lc_a = count_lines(data_one, size_one);
1817        lc_b = count_lines(data_two, size_two);
1818
1819        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
1820                         a_name.buf, a_name.len, 0);
1821        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
1822                         b_name.buf, b_name.len, 0);
1823
1824        strbuf_addstr(&out, "@@ -");
1825        if (!o->irreversible_delete)
1826                add_line_count(&out, lc_a);
1827        else
1828                strbuf_addstr(&out, "?,?");
1829        strbuf_addstr(&out, " +");
1830        add_line_count(&out, lc_b);
1831        strbuf_addstr(&out, " @@\n");
1832        emit_diff_symbol(o, DIFF_SYMBOL_REWRITE_DIFF, out.buf, out.len, 0);
1833        strbuf_release(&out);
1834
1835        if (lc_a && !o->irreversible_delete)
1836                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
1837        if (lc_b)
1838                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
1839        if (textconv_one)
1840                free((char *)data_one);
1841        if (textconv_two)
1842                free((char *)data_two);
1843}
1844
1845struct diff_words_buffer {
1846        mmfile_t text;
1847        unsigned long alloc;
1848        struct diff_words_orig {
1849                const char *begin, *end;
1850        } *orig;
1851        int orig_nr, orig_alloc;
1852};
1853
1854static void diff_words_append(char *line, unsigned long len,
1855                struct diff_words_buffer *buffer)
1856{
1857        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
1858        line++;
1859        len--;
1860        memcpy(buffer->text.ptr + buffer->text.size, line, len);
1861        buffer->text.size += len;
1862        buffer->text.ptr[buffer->text.size] = '\0';
1863}
1864
1865struct diff_words_style_elem {
1866        const char *prefix;
1867        const char *suffix;
1868        const char *color; /* NULL; filled in by the setup code if
1869                            * color is enabled */
1870};
1871
1872struct diff_words_style {
1873        enum diff_words_type type;
1874        struct diff_words_style_elem new_word, old_word, ctx;
1875        const char *newline;
1876};
1877
1878static struct diff_words_style diff_words_styles[] = {
1879        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
1880        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
1881        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
1882};
1883
1884struct diff_words_data {
1885        struct diff_words_buffer minus, plus;
1886        const char *current_plus;
1887        int last_minus;
1888        struct diff_options *opt;
1889        regex_t *word_regex;
1890        enum diff_words_type type;
1891        struct diff_words_style *style;
1892};
1893
1894static int fn_out_diff_words_write_helper(struct diff_options *o,
1895                                          struct diff_words_style_elem *st_el,
1896                                          const char *newline,
1897                                          size_t count, const char *buf)
1898{
1899        int print = 0;
1900        struct strbuf sb = STRBUF_INIT;
1901
1902        while (count) {
1903                char *p = memchr(buf, '\n', count);
1904                if (print)
1905                        strbuf_addstr(&sb, diff_line_prefix(o));
1906
1907                if (p != buf) {
1908                        const char *reset = st_el->color && *st_el->color ?
1909                                            GIT_COLOR_RESET : NULL;
1910                        if (st_el->color && *st_el->color)
1911                                strbuf_addstr(&sb, st_el->color);
1912                        strbuf_addstr(&sb, st_el->prefix);
1913                        strbuf_add(&sb, buf, p ? p - buf : count);
1914                        strbuf_addstr(&sb, st_el->suffix);
1915                        if (reset)
1916                                strbuf_addstr(&sb, reset);
1917                }
1918                if (!p)
1919                        goto out;
1920
1921                strbuf_addstr(&sb, newline);
1922                count -= p + 1 - buf;
1923                buf = p + 1;
1924                print = 1;
1925                if (count) {
1926                        emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1927                                         sb.buf, sb.len, 0);
1928                        strbuf_reset(&sb);
1929                }
1930        }
1931
1932out:
1933        if (sb.len)
1934                emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1935                                 sb.buf, sb.len, 0);
1936        strbuf_release(&sb);
1937        return 0;
1938}
1939
1940/*
1941 * '--color-words' algorithm can be described as:
1942 *
1943 *   1. collect the minus/plus lines of a diff hunk, divided into
1944 *      minus-lines and plus-lines;
1945 *
1946 *   2. break both minus-lines and plus-lines into words and
1947 *      place them into two mmfile_t with one word for each line;
1948 *
1949 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
1950 *
1951 * And for the common parts of the both file, we output the plus side text.
1952 * diff_words->current_plus is used to trace the current position of the plus file
1953 * which printed. diff_words->last_minus is used to trace the last minus word
1954 * printed.
1955 *
1956 * For '--graph' to work with '--color-words', we need to output the graph prefix
1957 * on each line of color words output. Generally, there are two conditions on
1958 * which we should output the prefix.
1959 *
1960 *   1. diff_words->last_minus == 0 &&
1961 *      diff_words->current_plus == diff_words->plus.text.ptr
1962 *
1963 *      that is: the plus text must start as a new line, and if there is no minus
1964 *      word printed, a graph prefix must be printed.
1965 *
1966 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
1967 *      *(diff_words->current_plus - 1) == '\n'
1968 *
1969 *      that is: a graph prefix must be printed following a '\n'
1970 */
1971static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
1972{
1973        if ((diff_words->last_minus == 0 &&
1974                diff_words->current_plus == diff_words->plus.text.ptr) ||
1975                (diff_words->current_plus > diff_words->plus.text.ptr &&
1976                *(diff_words->current_plus - 1) == '\n')) {
1977                return 1;
1978        } else {
1979                return 0;
1980        }
1981}
1982
1983static void fn_out_diff_words_aux(void *priv,
1984                                  long minus_first, long minus_len,
1985                                  long plus_first, long plus_len,
1986                                  const char *func, long funclen)
1987{
1988        struct diff_words_data *diff_words = priv;
1989        struct diff_words_style *style = diff_words->style;
1990        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
1991        struct diff_options *opt = diff_words->opt;
1992        const char *line_prefix;
1993
1994        assert(opt);
1995        line_prefix = diff_line_prefix(opt);
1996
1997        /* POSIX requires that first be decremented by one if len == 0... */
1998        if (minus_len) {
1999                minus_begin = diff_words->minus.orig[minus_first].begin;
2000                minus_end =
2001                        diff_words->minus.orig[minus_first + minus_len - 1].end;
2002        } else
2003                minus_begin = minus_end =
2004                        diff_words->minus.orig[minus_first].end;
2005
2006        if (plus_len) {
2007                plus_begin = diff_words->plus.orig[plus_first].begin;
2008                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
2009        } else
2010                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
2011
2012        if (color_words_output_graph_prefix(diff_words)) {
2013                fputs(line_prefix, diff_words->opt->file);
2014        }
2015        if (diff_words->current_plus != plus_begin) {
2016                fn_out_diff_words_write_helper(diff_words->opt,
2017                                &style->ctx, style->newline,
2018                                plus_begin - diff_words->current_plus,
2019                                diff_words->current_plus);
2020        }
2021        if (minus_begin != minus_end) {
2022                fn_out_diff_words_write_helper(diff_words->opt,
2023                                &style->old_word, style->newline,
2024                                minus_end - minus_begin, minus_begin);
2025        }
2026        if (plus_begin != plus_end) {
2027                fn_out_diff_words_write_helper(diff_words->opt,
2028                                &style->new_word, style->newline,
2029                                plus_end - plus_begin, plus_begin);
2030        }
2031
2032        diff_words->current_plus = plus_end;
2033        diff_words->last_minus = minus_first;
2034}
2035
2036/* This function starts looking at *begin, and returns 0 iff a word was found. */
2037static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
2038                int *begin, int *end)
2039{
2040        if (word_regex && *begin < buffer->size) {
2041                regmatch_t match[1];
2042                if (!regexec_buf(word_regex, buffer->ptr + *begin,
2043                                 buffer->size - *begin, 1, match, 0)) {
2044                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
2045                                        '\n', match[0].rm_eo - match[0].rm_so);
2046                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
2047                        *begin += match[0].rm_so;
2048                        return *begin >= *end;
2049                }
2050                return -1;
2051        }
2052
2053        /* find the next word */
2054        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
2055                (*begin)++;
2056        if (*begin >= buffer->size)
2057                return -1;
2058
2059        /* find the end of the word */
2060        *end = *begin + 1;
2061        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
2062                (*end)++;
2063
2064        return 0;
2065}
2066
2067/*
2068 * This function splits the words in buffer->text, stores the list with
2069 * newline separator into out, and saves the offsets of the original words
2070 * in buffer->orig.
2071 */
2072static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
2073                regex_t *word_regex)
2074{
2075        int i, j;
2076        long alloc = 0;
2077
2078        out->size = 0;
2079        out->ptr = NULL;
2080
2081        /* fake an empty "0th" word */
2082        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
2083        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
2084        buffer->orig_nr = 1;
2085
2086        for (i = 0; i < buffer->text.size; i++) {
2087                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
2088                        return;
2089
2090                /* store original boundaries */
2091                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
2092                                buffer->orig_alloc);
2093                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
2094                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
2095                buffer->orig_nr++;
2096
2097                /* store one word */
2098                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
2099                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
2100                out->ptr[out->size + j - i] = '\n';
2101                out->size += j - i + 1;
2102
2103                i = j - 1;
2104        }
2105}
2106
2107/* this executes the word diff on the accumulated buffers */
2108static void diff_words_show(struct diff_words_data *diff_words)
2109{
2110        xpparam_t xpp;
2111        xdemitconf_t xecfg;
2112        mmfile_t minus, plus;
2113        struct diff_words_style *style = diff_words->style;
2114
2115        struct diff_options *opt = diff_words->opt;
2116        const char *line_prefix;
2117
2118        assert(opt);
2119        line_prefix = diff_line_prefix(opt);
2120
2121        /* special case: only removal */
2122        if (!diff_words->plus.text.size) {
2123                emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
2124                                 line_prefix, strlen(line_prefix), 0);
2125                fn_out_diff_words_write_helper(diff_words->opt,
2126                        &style->old_word, style->newline,
2127                        diff_words->minus.text.size,
2128                        diff_words->minus.text.ptr);
2129                diff_words->minus.text.size = 0;
2130                return;
2131        }
2132
2133        diff_words->current_plus = diff_words->plus.text.ptr;
2134        diff_words->last_minus = 0;
2135
2136        memset(&xpp, 0, sizeof(xpp));
2137        memset(&xecfg, 0, sizeof(xecfg));
2138        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
2139        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
2140        xpp.flags = 0;
2141        /* as only the hunk header will be parsed, we need a 0-context */
2142        xecfg.ctxlen = 0;
2143        if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, NULL,
2144                          diff_words, &xpp, &xecfg))
2145                die("unable to generate word diff");
2146        free(minus.ptr);
2147        free(plus.ptr);
2148        if (diff_words->current_plus != diff_words->plus.text.ptr +
2149                        diff_words->plus.text.size) {
2150                if (color_words_output_graph_prefix(diff_words))
2151                        emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
2152                                         line_prefix, strlen(line_prefix), 0);
2153                fn_out_diff_words_write_helper(diff_words->opt,
2154                        &style->ctx, style->newline,
2155                        diff_words->plus.text.ptr + diff_words->plus.text.size
2156                        - diff_words->current_plus, diff_words->current_plus);
2157        }
2158        diff_words->minus.text.size = diff_words->plus.text.size = 0;
2159}
2160
2161/* In "color-words" mode, show word-diff of words accumulated in the buffer */
2162static void diff_words_flush(struct emit_callback *ecbdata)
2163{
2164        struct diff_options *wo = ecbdata->diff_words->opt;
2165
2166        if (ecbdata->diff_words->minus.text.size ||
2167            ecbdata->diff_words->plus.text.size)
2168                diff_words_show(ecbdata->diff_words);
2169
2170        if (wo->emitted_symbols) {
2171                struct diff_options *o = ecbdata->opt;
2172                struct emitted_diff_symbols *wol = wo->emitted_symbols;
2173                int i;
2174
2175                /*
2176                 * NEEDSWORK:
2177                 * Instead of appending each, concat all words to a line?
2178                 */
2179                for (i = 0; i < wol->nr; i++)
2180                        append_emitted_diff_symbol(o, &wol->buf[i]);
2181
2182                for (i = 0; i < wol->nr; i++)
2183                        free((void *)wol->buf[i].line);
2184
2185                wol->nr = 0;
2186        }
2187}
2188
2189static void diff_filespec_load_driver(struct diff_filespec *one,
2190                                      struct index_state *istate)
2191{
2192        /* Use already-loaded driver */
2193        if (one->driver)
2194                return;
2195
2196        if (S_ISREG(one->mode))
2197                one->driver = userdiff_find_by_path(istate, one->path);
2198
2199        /* Fallback to default settings */
2200        if (!one->driver)
2201                one->driver = userdiff_find_by_name("default");
2202}
2203
2204static const char *userdiff_word_regex(struct diff_filespec *one,
2205                                       struct index_state *istate)
2206{
2207        diff_filespec_load_driver(one, istate);
2208        return one->driver->word_regex;
2209}
2210
2211static void init_diff_words_data(struct emit_callback *ecbdata,
2212                                 struct diff_options *orig_opts,
2213                                 struct diff_filespec *one,
2214                                 struct diff_filespec *two)
2215{
2216        int i;
2217        struct diff_options *o = xmalloc(sizeof(struct diff_options));
2218        memcpy(o, orig_opts, sizeof(struct diff_options));
2219
2220        ecbdata->diff_words =
2221                xcalloc(1, sizeof(struct diff_words_data));
2222        ecbdata->diff_words->type = o->word_diff;
2223        ecbdata->diff_words->opt = o;
2224
2225        if (orig_opts->emitted_symbols)
2226                o->emitted_symbols =
2227                        xcalloc(1, sizeof(struct emitted_diff_symbols));
2228
2229        if (!o->word_regex)
2230                o->word_regex = userdiff_word_regex(one, o->repo->index);
2231        if (!o->word_regex)
2232                o->word_regex = userdiff_word_regex(two, o->repo->index);
2233        if (!o->word_regex)
2234                o->word_regex = diff_word_regex_cfg;
2235        if (o->word_regex) {
2236                ecbdata->diff_words->word_regex = (regex_t *)
2237                        xmalloc(sizeof(regex_t));
2238                if (regcomp(ecbdata->diff_words->word_regex,
2239                            o->word_regex,
2240                            REG_EXTENDED | REG_NEWLINE))
2241                        die("invalid regular expression: %s",
2242                            o->word_regex);
2243        }
2244        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2245                if (o->word_diff == diff_words_styles[i].type) {
2246                        ecbdata->diff_words->style =
2247                                &diff_words_styles[i];
2248                        break;
2249                }
2250        }
2251        if (want_color(o->use_color)) {
2252                struct diff_words_style *st = ecbdata->diff_words->style;
2253                st->old_word.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2254                st->new_word.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2255                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
2256        }
2257}
2258
2259static void free_diff_words_data(struct emit_callback *ecbdata)
2260{
2261        if (ecbdata->diff_words) {
2262                diff_words_flush(ecbdata);
2263                free (ecbdata->diff_words->opt->emitted_symbols);
2264                free (ecbdata->diff_words->opt);
2265                free (ecbdata->diff_words->minus.text.ptr);
2266                free (ecbdata->diff_words->minus.orig);
2267                free (ecbdata->diff_words->plus.text.ptr);
2268                free (ecbdata->diff_words->plus.orig);
2269                if (ecbdata->diff_words->word_regex) {
2270                        regfree(ecbdata->diff_words->word_regex);
2271                        free(ecbdata->diff_words->word_regex);
2272                }
2273                FREE_AND_NULL(ecbdata->diff_words);
2274        }
2275}
2276
2277const char *diff_get_color(int diff_use_color, enum color_diff ix)
2278{
2279        if (want_color(diff_use_color))
2280                return diff_colors[ix];
2281        return "";
2282}
2283
2284const char *diff_line_prefix(struct diff_options *opt)
2285{
2286        struct strbuf *msgbuf;
2287        if (!opt->output_prefix)
2288                return "";
2289
2290        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
2291        return msgbuf->buf;
2292}
2293
2294static unsigned long sane_truncate_line(char *line, unsigned long len)
2295{
2296        const char *cp;
2297        unsigned long allot;
2298        size_t l = len;
2299
2300        cp = line;
2301        allot = l;
2302        while (0 < l) {
2303                (void) utf8_width(&cp, &l);
2304                if (!cp)
2305                        break; /* truncated in the middle? */
2306        }
2307        return allot - l;
2308}
2309
2310static void find_lno(const char *line, struct emit_callback *ecbdata)
2311{
2312        const char *p;
2313        ecbdata->lno_in_preimage = 0;
2314        ecbdata->lno_in_postimage = 0;
2315        p = strchr(line, '-');
2316        if (!p)
2317                return; /* cannot happen */
2318        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
2319        p = strchr(p, '+');
2320        if (!p)
2321                return; /* cannot happen */
2322        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
2323}
2324
2325static void fn_out_consume(void *priv, char *line, unsigned long len)
2326{
2327        struct emit_callback *ecbdata = priv;
2328        struct diff_options *o = ecbdata->opt;
2329
2330        o->found_changes = 1;
2331
2332        if (ecbdata->header) {
2333                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
2334                                 ecbdata->header->buf, ecbdata->header->len, 0);
2335                strbuf_reset(ecbdata->header);
2336                ecbdata->header = NULL;
2337        }
2338
2339        if (ecbdata->label_path[0]) {
2340                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
2341                                 ecbdata->label_path[0],
2342                                 strlen(ecbdata->label_path[0]), 0);
2343                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
2344                                 ecbdata->label_path[1],
2345                                 strlen(ecbdata->label_path[1]), 0);
2346                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
2347        }
2348
2349        if (diff_suppress_blank_empty
2350            && len == 2 && line[0] == ' ' && line[1] == '\n') {
2351                line[0] = '\n';
2352                len = 1;
2353        }
2354
2355        if (line[0] == '@') {
2356                if (ecbdata->diff_words)
2357                        diff_words_flush(ecbdata);
2358                len = sane_truncate_line(line, len);
2359                find_lno(line, ecbdata);
2360                emit_hunk_header(ecbdata, line, len);
2361                return;
2362        }
2363
2364        if (ecbdata->diff_words) {
2365                enum diff_symbol s =
2366                        ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN ?
2367                        DIFF_SYMBOL_WORDS_PORCELAIN : DIFF_SYMBOL_WORDS;
2368                if (line[0] == '-') {
2369                        diff_words_append(line, len,
2370                                          &ecbdata->diff_words->minus);
2371                        return;
2372                } else if (line[0] == '+') {
2373                        diff_words_append(line, len,
2374                                          &ecbdata->diff_words->plus);
2375                        return;
2376                } else if (starts_with(line, "\\ ")) {
2377                        /*
2378                         * Eat the "no newline at eof" marker as if we
2379                         * saw a "+" or "-" line with nothing on it,
2380                         * and return without diff_words_flush() to
2381                         * defer processing. If this is the end of
2382                         * preimage, more "+" lines may come after it.
2383                         */
2384                        return;
2385                }
2386                diff_words_flush(ecbdata);
2387                emit_diff_symbol(o, s, line, len, 0);
2388                return;
2389        }
2390
2391        switch (line[0]) {
2392        case '+':
2393                ecbdata->lno_in_postimage++;
2394                emit_add_line(ecbdata, line + 1, len - 1);
2395                break;
2396        case '-':
2397                ecbdata->lno_in_preimage++;
2398                emit_del_line(ecbdata, line + 1, len - 1);
2399                break;
2400        case ' ':
2401                ecbdata->lno_in_postimage++;
2402                ecbdata->lno_in_preimage++;
2403                emit_context_line(ecbdata, line + 1, len - 1);
2404                break;
2405        default:
2406                /* incomplete line at the end */
2407                ecbdata->lno_in_preimage++;
2408                emit_diff_symbol(o, DIFF_SYMBOL_CONTEXT_INCOMPLETE,
2409                                 line, len, 0);
2410                break;
2411        }
2412}
2413
2414static void pprint_rename(struct strbuf *name, const char *a, const char *b)
2415{
2416        const char *old_name = a;
2417        const char *new_name = b;
2418        int pfx_length, sfx_length;
2419        int pfx_adjust_for_slash;
2420        int len_a = strlen(a);
2421        int len_b = strlen(b);
2422        int a_midlen, b_midlen;
2423        int qlen_a = quote_c_style(a, NULL, NULL, 0);
2424        int qlen_b = quote_c_style(b, NULL, NULL, 0);
2425
2426        if (qlen_a || qlen_b) {
2427                quote_c_style(a, name, NULL, 0);
2428                strbuf_addstr(name, " => ");
2429                quote_c_style(b, name, NULL, 0);
2430                return;
2431        }
2432
2433        /* Find common prefix */
2434        pfx_length = 0;
2435        while (*old_name && *new_name && *old_name == *new_name) {
2436                if (*old_name == '/')
2437                        pfx_length = old_name - a + 1;
2438                old_name++;
2439                new_name++;
2440        }
2441
2442        /* Find common suffix */
2443        old_name = a + len_a;
2444        new_name = b + len_b;
2445        sfx_length = 0;
2446        /*
2447         * If there is a common prefix, it must end in a slash.  In
2448         * that case we let this loop run 1 into the prefix to see the
2449         * same slash.
2450         *
2451         * If there is no common prefix, we cannot do this as it would
2452         * underrun the input strings.
2453         */
2454        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
2455        while (a + pfx_length - pfx_adjust_for_slash <= old_name &&
2456               b + pfx_length - pfx_adjust_for_slash <= new_name &&
2457               *old_name == *new_name) {
2458                if (*old_name == '/')
2459                        sfx_length = len_a - (old_name - a);
2460                old_name--;
2461                new_name--;
2462        }
2463
2464        /*
2465         * pfx{mid-a => mid-b}sfx
2466         * {pfx-a => pfx-b}sfx
2467         * pfx{sfx-a => sfx-b}
2468         * name-a => name-b
2469         */
2470        a_midlen = len_a - pfx_length - sfx_length;
2471        b_midlen = len_b - pfx_length - sfx_length;
2472        if (a_midlen < 0)
2473                a_midlen = 0;
2474        if (b_midlen < 0)
2475                b_midlen = 0;
2476
2477        strbuf_grow(name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
2478        if (pfx_length + sfx_length) {
2479                strbuf_add(name, a, pfx_length);
2480                strbuf_addch(name, '{');
2481        }
2482        strbuf_add(name, a + pfx_length, a_midlen);
2483        strbuf_addstr(name, " => ");
2484        strbuf_add(name, b + pfx_length, b_midlen);
2485        if (pfx_length + sfx_length) {
2486                strbuf_addch(name, '}');
2487                strbuf_add(name, a + len_a - sfx_length, sfx_length);
2488        }
2489}
2490
2491struct diffstat_t {
2492        int nr;
2493        int alloc;
2494        struct diffstat_file {
2495                char *from_name;
2496                char *name;
2497                char *print_name;
2498                const char *comments;
2499                unsigned is_unmerged:1;
2500                unsigned is_binary:1;
2501                unsigned is_renamed:1;
2502                unsigned is_interesting:1;
2503                uintmax_t added, deleted;
2504        } **files;
2505};
2506
2507static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
2508                                          const char *name_a,
2509                                          const char *name_b)
2510{
2511        struct diffstat_file *x;
2512        x = xcalloc(1, sizeof(*x));
2513        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
2514        diffstat->files[diffstat->nr++] = x;
2515        if (name_b) {
2516                x->from_name = xstrdup(name_a);
2517                x->name = xstrdup(name_b);
2518                x->is_renamed = 1;
2519        }
2520        else {
2521                x->from_name = NULL;
2522                x->name = xstrdup(name_a);
2523        }
2524        return x;
2525}
2526
2527static void diffstat_consume(void *priv, char *line, unsigned long len)
2528{
2529        struct diffstat_t *diffstat = priv;
2530        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
2531
2532        if (line[0] == '+')
2533                x->added++;
2534        else if (line[0] == '-')
2535                x->deleted++;
2536}
2537
2538const char mime_boundary_leader[] = "------------";
2539
2540static int scale_linear(int it, int width, int max_change)
2541{
2542        if (!it)
2543                return 0;
2544        /*
2545         * make sure that at least one '-' or '+' is printed if
2546         * there is any change to this path. The easiest way is to
2547         * scale linearly as if the alloted width is one column shorter
2548         * than it is, and then add 1 to the result.
2549         */
2550        return 1 + (it * (width - 1) / max_change);
2551}
2552
2553static void show_graph(struct strbuf *out, char ch, int cnt,
2554                       const char *set, const char *reset)
2555{
2556        if (cnt <= 0)
2557                return;
2558        strbuf_addstr(out, set);
2559        strbuf_addchars(out, ch, cnt);
2560        strbuf_addstr(out, reset);
2561}
2562
2563static void fill_print_name(struct diffstat_file *file)
2564{
2565        struct strbuf pname = STRBUF_INIT;
2566
2567        if (file->print_name)
2568                return;
2569
2570        if (file->is_renamed)
2571                pprint_rename(&pname, file->from_name, file->name);
2572        else
2573                quote_c_style(file->name, &pname, NULL, 0);
2574
2575        if (file->comments)
2576                strbuf_addf(&pname, " (%s)", file->comments);
2577
2578        file->print_name = strbuf_detach(&pname, NULL);
2579}
2580
2581static void print_stat_summary_inserts_deletes(struct diff_options *options,
2582                int files, int insertions, int deletions)
2583{
2584        struct strbuf sb = STRBUF_INIT;
2585
2586        if (!files) {
2587                assert(insertions == 0 && deletions == 0);
2588                emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
2589                                 NULL, 0, 0);
2590                return;
2591        }
2592
2593        strbuf_addf(&sb,
2594                    (files == 1) ? " %d file changed" : " %d files changed",
2595                    files);
2596
2597        /*
2598         * For binary diff, the caller may want to print "x files
2599         * changed" with insertions == 0 && deletions == 0.
2600         *
2601         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
2602         * is probably less confusing (i.e skip over "2 files changed
2603         * but nothing about added/removed lines? Is this a bug in Git?").
2604         */
2605        if (insertions || deletions == 0) {
2606                strbuf_addf(&sb,
2607                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
2608                            insertions);
2609        }
2610
2611        if (deletions || insertions == 0) {
2612                strbuf_addf(&sb,
2613                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
2614                            deletions);
2615        }
2616        strbuf_addch(&sb, '\n');
2617        emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
2618                         sb.buf, sb.len, 0);
2619        strbuf_release(&sb);
2620}
2621
2622void print_stat_summary(FILE *fp, int files,
2623                        int insertions, int deletions)
2624{
2625        struct diff_options o;
2626        memset(&o, 0, sizeof(o));
2627        o.file = fp;
2628
2629        print_stat_summary_inserts_deletes(&o, files, insertions, deletions);
2630}
2631
2632static void show_stats(struct diffstat_t *data, struct diff_options *options)
2633{
2634        int i, len, add, del, adds = 0, dels = 0;
2635        uintmax_t max_change = 0, max_len = 0;
2636        int total_files = data->nr, count;
2637        int width, name_width, graph_width, number_width = 0, bin_width = 0;
2638        const char *reset, *add_c, *del_c;
2639        int extra_shown = 0;
2640        const char *line_prefix = diff_line_prefix(options);
2641        struct strbuf out = STRBUF_INIT;
2642
2643        if (data->nr == 0)
2644                return;
2645
2646        count = options->stat_count ? options->stat_count : data->nr;
2647
2648        reset = diff_get_color_opt(options, DIFF_RESET);
2649        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
2650        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
2651
2652        /*
2653         * Find the longest filename and max number of changes
2654         */
2655        for (i = 0; (i < count) && (i < data->nr); i++) {
2656                struct diffstat_file *file = data->files[i];
2657                uintmax_t change = file->added + file->deleted;
2658
2659                if (!file->is_interesting && (change == 0)) {
2660                        count++; /* not shown == room for one more */
2661                        continue;
2662                }
2663                fill_print_name(file);
2664                len = strlen(file->print_name);
2665                if (max_len < len)
2666                        max_len = len;
2667
2668                if (file->is_unmerged) {
2669                        /* "Unmerged" is 8 characters */
2670                        bin_width = bin_width < 8 ? 8 : bin_width;
2671                        continue;
2672                }
2673                if (file->is_binary) {
2674                        /* "Bin XXX -> YYY bytes" */
2675                        int w = 14 + decimal_width(file->added)
2676                                + decimal_width(file->deleted);
2677                        bin_width = bin_width < w ? w : bin_width;
2678                        /* Display change counts aligned with "Bin" */
2679                        number_width = 3;
2680                        continue;
2681                }
2682
2683                if (max_change < change)
2684                        max_change = change;
2685        }
2686        count = i; /* where we can stop scanning in data->files[] */
2687
2688        /*
2689         * We have width = stat_width or term_columns() columns total.
2690         * We want a maximum of min(max_len, stat_name_width) for the name part.
2691         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
2692         * We also need 1 for " " and 4 + decimal_width(max_change)
2693         * for " | NNNN " and one the empty column at the end, altogether
2694         * 6 + decimal_width(max_change).
2695         *
2696         * If there's not enough space, we will use the smaller of
2697         * stat_name_width (if set) and 5/8*width for the filename,
2698         * and the rest for constant elements + graph part, but no more
2699         * than stat_graph_width for the graph part.
2700         * (5/8 gives 50 for filename and 30 for the constant parts + graph
2701         * for the standard terminal size).
2702         *
2703         * In other words: stat_width limits the maximum width, and
2704         * stat_name_width fixes the maximum width of the filename,
2705         * and is also used to divide available columns if there
2706         * aren't enough.
2707         *
2708         * Binary files are displayed with "Bin XXX -> YYY bytes"
2709         * instead of the change count and graph. This part is treated
2710         * similarly to the graph part, except that it is not
2711         * "scaled". If total width is too small to accommodate the
2712         * guaranteed minimum width of the filename part and the
2713         * separators and this message, this message will "overflow"
2714         * making the line longer than the maximum width.
2715         */
2716
2717        if (options->stat_width == -1)
2718                width = term_columns() - strlen(line_prefix);
2719        else
2720                width = options->stat_width ? options->stat_width : 80;
2721        number_width = decimal_width(max_change) > number_width ?
2722                decimal_width(max_change) : number_width;
2723
2724        if (options->stat_graph_width == -1)
2725                options->stat_graph_width = diff_stat_graph_width;
2726
2727        /*
2728         * Guarantee 3/8*16==6 for the graph part
2729         * and 5/8*16==10 for the filename part
2730         */
2731        if (width < 16 + 6 + number_width)
2732                width = 16 + 6 + number_width;
2733
2734        /*
2735         * First assign sizes that are wanted, ignoring available width.
2736         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
2737         * starting from "XXX" should fit in graph_width.
2738         */
2739        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
2740        if (options->stat_graph_width &&
2741            options->stat_graph_width < graph_width)
2742                graph_width = options->stat_graph_width;
2743
2744        name_width = (options->stat_name_width > 0 &&
2745                      options->stat_name_width < max_len) ?
2746                options->stat_name_width : max_len;
2747
2748        /*
2749         * Adjust adjustable widths not to exceed maximum width
2750         */
2751        if (name_width + number_width + 6 + graph_width > width) {
2752                if (graph_width > width * 3/8 - number_width - 6) {
2753                        graph_width = width * 3/8 - number_width - 6;
2754                        if (graph_width < 6)
2755                                graph_width = 6;
2756                }
2757
2758                if (options->stat_graph_width &&
2759                    graph_width > options->stat_graph_width)
2760                        graph_width = options->stat_graph_width;
2761                if (name_width > width - number_width - 6 - graph_width)
2762                        name_width = width - number_width - 6 - graph_width;
2763                else
2764                        graph_width = width - number_width - 6 - name_width;
2765        }
2766
2767        /*
2768         * From here name_width is the width of the name area,
2769         * and graph_width is the width of the graph area.
2770         * max_change is used to scale graph properly.
2771         */
2772        for (i = 0; i < count; i++) {
2773                const char *prefix = "";
2774                struct diffstat_file *file = data->files[i];
2775                char *name = file->print_name;
2776                uintmax_t added = file->added;
2777                uintmax_t deleted = file->deleted;
2778                int name_len;
2779
2780                if (!file->is_interesting && (added + deleted == 0))
2781                        continue;
2782
2783                /*
2784                 * "scale" the filename
2785                 */
2786                len = name_width;
2787                name_len = strlen(name);
2788                if (name_width < name_len) {
2789                        char *slash;
2790                        prefix = "...";
2791                        len -= 3;
2792                        name += name_len - len;
2793                        slash = strchr(name, '/');
2794                        if (slash)
2795                                name = slash;
2796                }
2797
2798                if (file->is_binary) {
2799                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2800                        strbuf_addf(&out, " %*s", number_width, "Bin");
2801                        if (!added && !deleted) {
2802                                strbuf_addch(&out, '\n');
2803                                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2804                                                 out.buf, out.len, 0);
2805                                strbuf_reset(&out);
2806                                continue;
2807                        }
2808                        strbuf_addf(&out, " %s%"PRIuMAX"%s",
2809                                del_c, deleted, reset);
2810                        strbuf_addstr(&out, " -> ");
2811                        strbuf_addf(&out, "%s%"PRIuMAX"%s",
2812                                add_c, added, reset);
2813                        strbuf_addstr(&out, " bytes\n");
2814                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2815                                         out.buf, out.len, 0);
2816                        strbuf_reset(&out);
2817                        continue;
2818                }
2819                else if (file->is_unmerged) {
2820                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2821                        strbuf_addstr(&out, " Unmerged\n");
2822                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2823                                         out.buf, out.len, 0);
2824                        strbuf_reset(&out);
2825                        continue;
2826                }
2827
2828                /*
2829                 * scale the add/delete
2830                 */
2831                add = added;
2832                del = deleted;
2833
2834                if (graph_width <= max_change) {
2835                        int total = scale_linear(add + del, graph_width, max_change);
2836                        if (total < 2 && add && del)
2837                                /* width >= 2 due to the sanity check */
2838                                total = 2;
2839                        if (add < del) {
2840                                add = scale_linear(add, graph_width, max_change);
2841                                del = total - add;
2842                        } else {
2843                                del = scale_linear(del, graph_width, max_change);
2844                                add = total - del;
2845                        }
2846                }
2847                strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2848                strbuf_addf(&out, " %*"PRIuMAX"%s",
2849                        number_width, added + deleted,
2850                        added + deleted ? " " : "");
2851                show_graph(&out, '+', add, add_c, reset);
2852                show_graph(&out, '-', del, del_c, reset);
2853                strbuf_addch(&out, '\n');
2854                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2855                                 out.buf, out.len, 0);
2856                strbuf_reset(&out);
2857        }
2858
2859        for (i = 0; i < data->nr; i++) {
2860                struct diffstat_file *file = data->files[i];
2861                uintmax_t added = file->added;
2862                uintmax_t deleted = file->deleted;
2863
2864                if (file->is_unmerged ||
2865                    (!file->is_interesting && (added + deleted == 0))) {
2866                        total_files--;
2867                        continue;
2868                }
2869
2870                if (!file->is_binary) {
2871                        adds += added;
2872                        dels += deleted;
2873                }
2874                if (i < count)
2875                        continue;
2876                if (!extra_shown)
2877                        emit_diff_symbol(options,
2878                                         DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
2879                                         NULL, 0, 0);
2880                extra_shown = 1;
2881        }
2882
2883        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2884        strbuf_release(&out);
2885}
2886
2887static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
2888{
2889        int i, adds = 0, dels = 0, total_files = data->nr;
2890
2891        if (data->nr == 0)
2892                return;
2893
2894        for (i = 0; i < data->nr; i++) {
2895                int added = data->files[i]->added;
2896                int deleted = data->files[i]->deleted;
2897
2898                if (data->files[i]->is_unmerged ||
2899                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
2900                        total_files--;
2901                } else if (!data->files[i]->is_binary) { /* don't count bytes */
2902                        adds += added;
2903                        dels += deleted;
2904                }
2905        }
2906        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2907}
2908
2909static void show_numstat(struct diffstat_t *data, struct diff_options *options)
2910{
2911        int i;
2912
2913        if (data->nr == 0)
2914                return;
2915
2916        for (i = 0; i < data->nr; i++) {
2917                struct diffstat_file *file = data->files[i];
2918
2919                fprintf(options->file, "%s", diff_line_prefix(options));
2920
2921                if (file->is_binary)
2922                        fprintf(options->file, "-\t-\t");
2923                else
2924                        fprintf(options->file,
2925                                "%"PRIuMAX"\t%"PRIuMAX"\t",
2926                                file->added, file->deleted);
2927                if (options->line_termination) {
2928                        fill_print_name(file);
2929                        if (!file->is_renamed)
2930                                write_name_quoted(file->name, options->file,
2931                                                  options->line_termination);
2932                        else {
2933                                fputs(file->print_name, options->file);
2934                                putc(options->line_termination, options->file);
2935                        }
2936                } else {
2937                        if (file->is_renamed) {
2938                                putc('\0', options->file);
2939                                write_name_quoted(file->from_name, options->file, '\0');
2940                        }
2941                        write_name_quoted(file->name, options->file, '\0');
2942                }
2943        }
2944}
2945
2946struct dirstat_file {
2947        const char *name;
2948        unsigned long changed;
2949};
2950
2951struct dirstat_dir {
2952        struct dirstat_file *files;
2953        int alloc, nr, permille, cumulative;
2954};
2955
2956static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
2957                unsigned long changed, const char *base, int baselen)
2958{
2959        unsigned long sum_changes = 0;
2960        unsigned int sources = 0;
2961        const char *line_prefix = diff_line_prefix(opt);
2962
2963        while (dir->nr) {
2964                struct dirstat_file *f = dir->files;
2965                int namelen = strlen(f->name);
2966                unsigned long changes;
2967                char *slash;
2968
2969                if (namelen < baselen)
2970                        break;
2971                if (memcmp(f->name, base, baselen))
2972                        break;
2973                slash = strchr(f->name + baselen, '/');
2974                if (slash) {
2975                        int newbaselen = slash + 1 - f->name;
2976                        changes = gather_dirstat(opt, dir, changed, f->name, newbaselen);
2977                        sources++;
2978                } else {
2979                        changes = f->changed;
2980                        dir->files++;
2981                        dir->nr--;
2982                        sources += 2;
2983                }
2984                sum_changes += changes;
2985        }
2986
2987        /*
2988         * We don't report dirstat's for
2989         *  - the top level
2990         *  - or cases where everything came from a single directory
2991         *    under this directory (sources == 1).
2992         */
2993        if (baselen && sources != 1) {
2994                if (sum_changes) {
2995                        int permille = sum_changes * 1000 / changed;
2996                        if (permille >= dir->permille) {
2997                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
2998                                        permille / 10, permille % 10, baselen, base);
2999                                if (!dir->cumulative)
3000                                        return 0;
3001                        }
3002                }
3003        }
3004        return sum_changes;
3005}
3006
3007static int dirstat_compare(const void *_a, const void *_b)
3008{
3009        const struct dirstat_file *a = _a;
3010        const struct dirstat_file *b = _b;
3011        return strcmp(a->name, b->name);
3012}
3013
3014static void show_dirstat(struct diff_options *options)
3015{
3016        int i;
3017        unsigned long changed;
3018        struct dirstat_dir dir;
3019        struct diff_queue_struct *q = &diff_queued_diff;
3020
3021        dir.files = NULL;
3022        dir.alloc = 0;
3023        dir.nr = 0;
3024        dir.permille = options->dirstat_permille;
3025        dir.cumulative = options->flags.dirstat_cumulative;
3026
3027        changed = 0;
3028        for (i = 0; i < q->nr; i++) {
3029                struct diff_filepair *p = q->queue[i];
3030                const char *name;
3031                unsigned long copied, added, damage;
3032
3033                name = p->two->path ? p->two->path : p->one->path;
3034
3035                if (p->one->oid_valid && p->two->oid_valid &&
3036                    oideq(&p->one->oid, &p->two->oid)) {
3037                        /*
3038                         * The SHA1 has not changed, so pre-/post-content is
3039                         * identical. We can therefore skip looking at the
3040                         * file contents altogether.
3041                         */
3042                        damage = 0;
3043                        goto found_damage;
3044                }
3045
3046                if (options->flags.dirstat_by_file) {
3047                        /*
3048                         * In --dirstat-by-file mode, we don't really need to
3049                         * look at the actual file contents at all.
3050                         * The fact that the SHA1 changed is enough for us to
3051                         * add this file to the list of results
3052                         * (with each file contributing equal damage).
3053                         */
3054                        damage = 1;
3055                        goto found_damage;
3056                }
3057
3058                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
3059                        diff_populate_filespec(options->repo, p->one, 0);
3060                        diff_populate_filespec(options->repo, p->two, 0);
3061                        diffcore_count_changes(options->repo,
3062                                               p->one, p->two, NULL, NULL,
3063                                               &copied, &added);
3064                        diff_free_filespec_data(p->one);
3065                        diff_free_filespec_data(p->two);
3066                } else if (DIFF_FILE_VALID(p->one)) {
3067                        diff_populate_filespec(options->repo, p->one, CHECK_SIZE_ONLY);
3068                        copied = added = 0;
3069                        diff_free_filespec_data(p->one);
3070                } else if (DIFF_FILE_VALID(p->two)) {
3071                        diff_populate_filespec(options->repo, p->two, CHECK_SIZE_ONLY);
3072                        copied = 0;
3073                        added = p->two->size;
3074                        diff_free_filespec_data(p->two);
3075                } else
3076                        continue;
3077
3078                /*
3079                 * Original minus copied is the removed material,
3080                 * added is the new material.  They are both damages
3081                 * made to the preimage.
3082                 * If the resulting damage is zero, we know that
3083                 * diffcore_count_changes() considers the two entries to
3084                 * be identical, but since the oid changed, we
3085                 * know that there must have been _some_ kind of change,
3086                 * so we force all entries to have damage > 0.
3087                 */
3088                damage = (p->one->size - copied) + added;
3089                if (!damage)
3090                        damage = 1;
3091
3092found_damage:
3093                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
3094                dir.files[dir.nr].name = name;
3095                dir.files[dir.nr].changed = damage;
3096                changed += damage;
3097                dir.nr++;
3098        }
3099
3100        /* This can happen even with many files, if everything was renames */
3101        if (!changed)
3102                return;
3103
3104        /* Show all directories with more than x% of the changes */
3105        QSORT(dir.files, dir.nr, dirstat_compare);
3106        gather_dirstat(options, &dir, changed, "", 0);
3107}
3108
3109static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
3110{
3111        int i;
3112        unsigned long changed;
3113        struct dirstat_dir dir;
3114
3115        if (data->nr == 0)
3116                return;
3117
3118        dir.files = NULL;
3119        dir.alloc = 0;
3120        dir.nr = 0;
3121        dir.permille = options->dirstat_permille;
3122        dir.cumulative = options->flags.dirstat_cumulative;
3123
3124        changed = 0;
3125        for (i = 0; i < data->nr; i++) {
3126                struct diffstat_file *file = data->files[i];
3127                unsigned long damage = file->added + file->deleted;
3128                if (file->is_binary)
3129                        /*
3130                         * binary files counts bytes, not lines. Must find some
3131                         * way to normalize binary bytes vs. textual lines.
3132                         * The following heuristic assumes that there are 64
3133                         * bytes per "line".
3134                         * This is stupid and ugly, but very cheap...
3135                         */
3136                        damage = DIV_ROUND_UP(damage, 64);
3137                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
3138                dir.files[dir.nr].name = file->name;
3139                dir.files[dir.nr].changed = damage;
3140                changed += damage;
3141                dir.nr++;
3142        }
3143
3144        /* This can happen even with many files, if everything was renames */
3145        if (!changed)
3146                return;
3147
3148        /* Show all directories with more than x% of the changes */
3149        QSORT(dir.files, dir.nr, dirstat_compare);
3150        gather_dirstat(options, &dir, changed, "", 0);
3151}
3152
3153static void free_diffstat_info(struct diffstat_t *diffstat)
3154{
3155        int i;
3156        for (i = 0; i < diffstat->nr; i++) {
3157                struct diffstat_file *f = diffstat->files[i];
3158                free(f->print_name);
3159                free(f->name);
3160                free(f->from_name);
3161                free(f);
3162        }
3163        free(diffstat->files);
3164}
3165
3166struct checkdiff_t {
3167        const char *filename;
3168        int lineno;
3169        int conflict_marker_size;
3170        struct diff_options *o;
3171        unsigned ws_rule;
3172        unsigned status;
3173};
3174
3175static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
3176{
3177        char firstchar;
3178        int cnt;
3179
3180        if (len < marker_size + 1)
3181                return 0;
3182        firstchar = line[0];
3183        switch (firstchar) {
3184        case '=': case '>': case '<': case '|':
3185                break;
3186        default:
3187                return 0;
3188        }
3189        for (cnt = 1; cnt < marker_size; cnt++)
3190                if (line[cnt] != firstchar)
3191                        return 0;
3192        /* line[1] thru line[marker_size-1] are same as firstchar */
3193        if (len < marker_size + 1 || !isspace(line[marker_size]))
3194                return 0;
3195        return 1;
3196}
3197
3198static void checkdiff_consume_hunk(void *priv,
3199                                   long ob, long on, long nb, long nn,
3200                                   const char *func, long funclen)
3201
3202{
3203        struct checkdiff_t *data = priv;
3204        data->lineno = nb - 1;
3205}
3206
3207static void checkdiff_consume(void *priv, char *line, unsigned long len)
3208{
3209        struct checkdiff_t *data = priv;
3210        int marker_size = data->conflict_marker_size;
3211        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
3212        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
3213        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
3214        char *err;
3215        const char *line_prefix;
3216
3217        assert(data->o);
3218        line_prefix = diff_line_prefix(data->o);
3219
3220        if (line[0] == '+') {
3221                unsigned bad;
3222                data->lineno++;
3223                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
3224                        data->status |= 1;
3225                        fprintf(data->o->file,
3226                                "%s%s:%d: leftover conflict marker\n",
3227                                line_prefix, data->filename, data->lineno);
3228                }
3229                bad = ws_check(line + 1, len - 1, data->ws_rule);
3230                if (!bad)
3231                        return;
3232                data->status |= bad;
3233                err = whitespace_error_string(bad);
3234                fprintf(data->o->file, "%s%s:%d: %s.\n",
3235                        line_prefix, data->filename, data->lineno, err);
3236                free(err);
3237                emit_line(data->o, set, reset, line, 1);
3238                ws_check_emit(line + 1, len - 1, data->ws_rule,
3239                              data->o->file, set, reset, ws);
3240        } else if (line[0] == ' ') {
3241                data->lineno++;
3242        }
3243}
3244
3245static unsigned char *deflate_it(char *data,
3246                                 unsigned long size,
3247                                 unsigned long *result_size)
3248{
3249        int bound;
3250        unsigned char *deflated;
3251        git_zstream stream;
3252
3253        git_deflate_init(&stream, zlib_compression_level);
3254        bound = git_deflate_bound(&stream, size);
3255        deflated = xmalloc(bound);
3256        stream.next_out = deflated;
3257        stream.avail_out = bound;
3258
3259        stream.next_in = (unsigned char *)data;
3260        stream.avail_in = size;
3261        while (git_deflate(&stream, Z_FINISH) == Z_OK)
3262                ; /* nothing */
3263        git_deflate_end(&stream);
3264        *result_size = stream.total_out;
3265        return deflated;
3266}
3267
3268static void emit_binary_diff_body(struct diff_options *o,
3269                                  mmfile_t *one, mmfile_t *two)
3270{
3271        void *cp;
3272        void *delta;
3273        void *deflated;
3274        void *data;
3275        unsigned long orig_size;
3276        unsigned long delta_size;
3277        unsigned long deflate_size;
3278        unsigned long data_size;
3279
3280        /* We could do deflated delta, or we could do just deflated two,
3281         * whichever is smaller.
3282         */
3283        delta = NULL;
3284        deflated = deflate_it(two->ptr, two->size, &deflate_size);
3285        if (one->size && two->size) {
3286                delta = diff_delta(one->ptr, one->size,
3287                                   two->ptr, two->size,
3288                                   &delta_size, deflate_size);
3289                if (delta) {
3290                        void *to_free = delta;
3291                        orig_size = delta_size;
3292                        delta = deflate_it(delta, delta_size, &delta_size);
3293                        free(to_free);
3294                }
3295        }
3296
3297        if (delta && delta_size < deflate_size) {
3298                char *s = xstrfmt("%"PRIuMAX , (uintmax_t)orig_size);
3299                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
3300                                 s, strlen(s), 0);
3301                free(s);
3302                free(deflated);
3303                data = delta;
3304                data_size = delta_size;
3305        } else {
3306                char *s = xstrfmt("%lu", two->size);
3307                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
3308                                 s, strlen(s), 0);
3309                free(s);
3310                free(delta);
3311                data = deflated;
3312                data_size = deflate_size;
3313        }
3314
3315        /* emit data encoded in base85 */
3316        cp = data;
3317        while (data_size) {
3318                int len;
3319                int bytes = (52 < data_size) ? 52 : data_size;
3320                char line[71];
3321                data_size -= bytes;
3322                if (bytes <= 26)
3323                        line[0] = bytes + 'A' - 1;
3324                else
3325                        line[0] = bytes - 26 + 'a' - 1;
3326                encode_85(line + 1, cp, bytes);
3327                cp = (char *) cp + bytes;
3328
3329                len = strlen(line);
3330                line[len++] = '\n';
3331                line[len] = '\0';
3332
3333                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_BODY,
3334                                 line, len, 0);
3335        }
3336        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_FOOTER, NULL, 0, 0);
3337        free(data);
3338}
3339
3340static void emit_binary_diff(struct diff_options *o,
3341                             mmfile_t *one, mmfile_t *two)
3342{
3343        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER, NULL, 0, 0);
3344        emit_binary_diff_body(o, one, two);
3345        emit_binary_diff_body(o, two, one);
3346}
3347
3348int diff_filespec_is_binary(struct repository *r,
3349                            struct diff_filespec *one)
3350{
3351        if (one->is_binary == -1) {
3352                diff_filespec_load_driver(one, r->index);
3353                if (one->driver->binary != -1)
3354                        one->is_binary = one->driver->binary;
3355                else {
3356                        if (!one->data && DIFF_FILE_VALID(one))
3357                                diff_populate_filespec(r, one, CHECK_BINARY);
3358                        if (one->is_binary == -1 && one->data)
3359                                one->is_binary = buffer_is_binary(one->data,
3360                                                one->size);
3361                        if (one->is_binary == -1)
3362                                one->is_binary = 0;
3363                }
3364        }
3365        return one->is_binary;
3366}
3367
3368static const struct userdiff_funcname *
3369diff_funcname_pattern(struct diff_options *o, struct diff_filespec *one)
3370{
3371        diff_filespec_load_driver(one, o->repo->index);
3372        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
3373}
3374
3375void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
3376{
3377        if (!options->a_prefix)
3378                options->a_prefix = a;
3379        if (!options->b_prefix)
3380                options->b_prefix = b;
3381}
3382
3383struct userdiff_driver *get_textconv(struct repository *r,
3384                                     struct diff_filespec *one)
3385{
3386        if (!DIFF_FILE_VALID(one))
3387                return NULL;
3388
3389        diff_filespec_load_driver(one, r->index);
3390        return userdiff_get_textconv(r, one->driver);
3391}
3392
3393static void builtin_diff(const char *name_a,
3394                         const char *name_b,
3395                         struct diff_filespec *one,
3396                         struct diff_filespec *two,
3397                         const char *xfrm_msg,
3398                         int must_show_header,
3399                         struct diff_options *o,
3400                         int complete_rewrite)
3401{
3402        mmfile_t mf1, mf2;
3403        const char *lbl[2];
3404        char *a_one, *b_two;
3405        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
3406        const char *reset = diff_get_color_opt(o, DIFF_RESET);
3407        const char *a_prefix, *b_prefix;
3408        struct userdiff_driver *textconv_one = NULL;
3409        struct userdiff_driver *textconv_two = NULL;
3410        struct strbuf header = STRBUF_INIT;
3411        const char *line_prefix = diff_line_prefix(o);
3412
3413        diff_set_mnemonic_prefix(o, "a/", "b/");
3414        if (o->flags.reverse_diff) {
3415                a_prefix = o->b_prefix;
3416                b_prefix = o->a_prefix;
3417        } else {
3418                a_prefix = o->a_prefix;
3419                b_prefix = o->b_prefix;
3420        }
3421
3422        if (o->submodule_format == DIFF_SUBMODULE_LOG &&
3423            (!one->mode || S_ISGITLINK(one->mode)) &&
3424            (!two->mode || S_ISGITLINK(two->mode))) {
3425                show_submodule_summary(o, one->path ? one->path : two->path,
3426                                &one->oid, &two->oid,
3427                                two->dirty_submodule);
3428                return;
3429        } else if (o->submodule_format == DIFF_SUBMODULE_INLINE_DIFF &&
3430                   (!one->mode || S_ISGITLINK(one->mode)) &&
3431                   (!two->mode || S_ISGITLINK(two->mode))) {
3432                show_submodule_inline_diff(o, one->path ? one->path : two->path,
3433                                &one->oid, &two->oid,
3434                                two->dirty_submodule);
3435                return;
3436        }
3437
3438        if (o->flags.allow_textconv) {
3439                textconv_one = get_textconv(o->repo, one);
3440                textconv_two = get_textconv(o->repo, two);
3441        }
3442
3443        /* Never use a non-valid filename anywhere if at all possible */
3444        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
3445        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
3446
3447        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
3448        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
3449        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
3450        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
3451        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
3452        if (lbl[0][0] == '/') {
3453                /* /dev/null */
3454                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
3455                if (xfrm_msg)
3456                        strbuf_addstr(&header, xfrm_msg);
3457                must_show_header = 1;
3458        }
3459        else if (lbl[1][0] == '/') {
3460                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
3461                if (xfrm_msg)
3462                        strbuf_addstr(&header, xfrm_msg);
3463                must_show_header = 1;
3464        }
3465        else {
3466                if (one->mode != two->mode) {
3467                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
3468                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
3469                        must_show_header = 1;
3470                }
3471                if (xfrm_msg)
3472                        strbuf_addstr(&header, xfrm_msg);
3473
3474                /*
3475                 * we do not run diff between different kind
3476                 * of objects.
3477                 */
3478                if ((one->mode ^ two->mode) & S_IFMT)
3479                        goto free_ab_and_return;
3480                if (complete_rewrite &&
3481                    (textconv_one || !diff_filespec_is_binary(o->repo, one)) &&
3482                    (textconv_two || !diff_filespec_is_binary(o->repo, two))) {
3483                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3484                                         header.buf, header.len, 0);
3485                        strbuf_reset(&header);
3486                        emit_rewrite_diff(name_a, name_b, one, two,
3487                                          textconv_one, textconv_two, o);
3488                        o->found_changes = 1;
3489                        goto free_ab_and_return;
3490                }
3491        }
3492
3493        if (o->irreversible_delete && lbl[1][0] == '/') {
3494                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf,
3495                                 header.len, 0);
3496                strbuf_reset(&header);
3497                goto free_ab_and_return;
3498        } else if (!o->flags.text &&
3499                   ( (!textconv_one && diff_filespec_is_binary(o->repo, one)) ||
3500                     (!textconv_two && diff_filespec_is_binary(o->repo, two)) )) {
3501                struct strbuf sb = STRBUF_INIT;
3502                if (!one->data && !two->data &&
3503                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
3504                    !o->flags.binary) {
3505                        if (oideq(&one->oid, &two->oid)) {
3506                                if (must_show_header)
3507                                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3508                                                         header.buf, header.len,
3509                                                         0);
3510                                goto free_ab_and_return;
3511                        }
3512                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3513                                         header.buf, header.len, 0);
3514                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3515                                    diff_line_prefix(o), lbl[0], lbl[1]);
3516                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3517                                         sb.buf, sb.len, 0);
3518                        strbuf_release(&sb);
3519                        goto free_ab_and_return;
3520                }
3521                if (fill_mmfile(o->repo, &mf1, one) < 0 ||
3522                    fill_mmfile(o->repo, &mf2, two) < 0)
3523                        die("unable to read files to diff");
3524                /* Quite common confusing case */
3525                if (mf1.size == mf2.size &&
3526                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
3527                        if (must_show_header)
3528                                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3529                                                 header.buf, header.len, 0);
3530                        goto free_ab_and_return;
3531                }
3532                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf, header.len, 0);
3533                strbuf_reset(&header);
3534                if (o->flags.binary)
3535                        emit_binary_diff(o, &mf1, &mf2);
3536                else {
3537                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3538                                    diff_line_prefix(o), lbl[0], lbl[1]);
3539                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3540                                         sb.buf, sb.len, 0);
3541                        strbuf_release(&sb);
3542                }
3543                o->found_changes = 1;
3544        } else {
3545                /* Crazy xdl interfaces.. */
3546                const char *diffopts;
3547                const char *v;
3548                xpparam_t xpp;
3549                xdemitconf_t xecfg;
3550                struct emit_callback ecbdata;
3551                const struct userdiff_funcname *pe;
3552
3553                if (must_show_header) {
3554                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3555                                         header.buf, header.len, 0);
3556                        strbuf_reset(&header);
3557                }
3558
3559                mf1.size = fill_textconv(o->repo, textconv_one, one, &mf1.ptr);
3560                mf2.size = fill_textconv(o->repo, textconv_two, two, &mf2.ptr);
3561
3562                pe = diff_funcname_pattern(o, one);
3563                if (!pe)
3564                        pe = diff_funcname_pattern(o, two);
3565
3566                memset(&xpp, 0, sizeof(xpp));
3567                memset(&xecfg, 0, sizeof(xecfg));
3568                memset(&ecbdata, 0, sizeof(ecbdata));
3569                if (o->flags.suppress_diff_headers)
3570                        lbl[0] = NULL;
3571                ecbdata.label_path = lbl;
3572                ecbdata.color_diff = want_color(o->use_color);
3573                ecbdata.ws_rule = whitespace_rule(o->repo->index, name_b);
3574                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
3575                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3576                ecbdata.opt = o;
3577                if (header.len && !o->flags.suppress_diff_headers)
3578                        ecbdata.header = &header;
3579                xpp.flags = o->xdl_opts;
3580                xpp.anchors = o->anchors;
3581                xpp.anchors_nr = o->anchors_nr;
3582                xecfg.ctxlen = o->context;
3583                xecfg.interhunkctxlen = o->interhunkcontext;
3584                xecfg.flags = XDL_EMIT_FUNCNAMES;
3585                if (o->flags.funccontext)
3586                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
3587                if (pe)
3588                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
3589
3590                diffopts = getenv("GIT_DIFF_OPTS");
3591                if (!diffopts)
3592                        ;
3593                else if (skip_prefix(diffopts, "--unified=", &v))
3594                        xecfg.ctxlen = strtoul(v, NULL, 10);
3595                else if (skip_prefix(diffopts, "-u", &v))
3596                        xecfg.ctxlen = strtoul(v, NULL, 10);
3597
3598                if (o->word_diff)
3599                        init_diff_words_data(&ecbdata, o, one, two);
3600                if (xdi_diff_outf(&mf1, &mf2, NULL, fn_out_consume,
3601                                  &ecbdata, &xpp, &xecfg))
3602                        die("unable to generate diff for %s", one->path);
3603                if (o->word_diff)
3604                        free_diff_words_data(&ecbdata);
3605                if (textconv_one)
3606                        free(mf1.ptr);
3607                if (textconv_two)
3608                        free(mf2.ptr);
3609                xdiff_clear_find_func(&xecfg);
3610        }
3611
3612 free_ab_and_return:
3613        strbuf_release(&header);
3614        diff_free_filespec_data(one);
3615        diff_free_filespec_data(two);
3616        free(a_one);
3617        free(b_two);
3618        return;
3619}
3620
3621static char *get_compact_summary(const struct diff_filepair *p, int is_renamed)
3622{
3623        if (!is_renamed) {
3624                if (p->status == DIFF_STATUS_ADDED) {
3625                        if (S_ISLNK(p->two->mode))
3626                                return "new +l";
3627                        else if ((p->two->mode & 0777) == 0755)
3628                                return "new +x";
3629                        else
3630                                return "new";
3631                } else if (p->status == DIFF_STATUS_DELETED)
3632                        return "gone";
3633        }
3634        if (S_ISLNK(p->one->mode) && !S_ISLNK(p->two->mode))
3635                return "mode -l";
3636        else if (!S_ISLNK(p->one->mode) && S_ISLNK(p->two->mode))
3637                return "mode +l";
3638        else if ((p->one->mode & 0777) == 0644 &&
3639                 (p->two->mode & 0777) == 0755)
3640                return "mode +x";
3641        else if ((p->one->mode & 0777) == 0755 &&
3642                 (p->two->mode & 0777) == 0644)
3643                return "mode -x";
3644        return NULL;
3645}
3646
3647static void builtin_diffstat(const char *name_a, const char *name_b,
3648                             struct diff_filespec *one,
3649                             struct diff_filespec *two,
3650                             struct diffstat_t *diffstat,
3651                             struct diff_options *o,
3652                             struct diff_filepair *p)
3653{
3654        mmfile_t mf1, mf2;
3655        struct diffstat_file *data;
3656        int same_contents;
3657        int complete_rewrite = 0;
3658
3659        if (!DIFF_PAIR_UNMERGED(p)) {
3660                if (p->status == DIFF_STATUS_MODIFIED && p->score)
3661                        complete_rewrite = 1;
3662        }
3663
3664        data = diffstat_add(diffstat, name_a, name_b);
3665        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
3666        if (o->flags.stat_with_summary)
3667                data->comments = get_compact_summary(p, data->is_renamed);
3668
3669        if (!one || !two) {
3670                data->is_unmerged = 1;
3671                return;
3672        }
3673
3674        same_contents = oideq(&one->oid, &two->oid);
3675
3676        if (diff_filespec_is_binary(o->repo, one) ||
3677            diff_filespec_is_binary(o->repo, two)) {
3678                data->is_binary = 1;
3679                if (same_contents) {
3680                        data->added = 0;
3681                        data->deleted = 0;
3682                } else {
3683                        data->added = diff_filespec_size(o->repo, two);
3684                        data->deleted = diff_filespec_size(o->repo, one);
3685                }
3686        }
3687
3688        else if (complete_rewrite) {
3689                diff_populate_filespec(o->repo, one, 0);
3690                diff_populate_filespec(o->repo, two, 0);
3691                data->deleted = count_lines(one->data, one->size);
3692                data->added = count_lines(two->data, two->size);
3693        }
3694
3695        else if (!same_contents) {
3696                /* Crazy xdl interfaces.. */
3697                xpparam_t xpp;
3698                xdemitconf_t xecfg;
3699
3700                if (fill_mmfile(o->repo, &mf1, one) < 0 ||
3701                    fill_mmfile(o->repo, &mf2, two) < 0)
3702                        die("unable to read files to diff");
3703
3704                memset(&xpp, 0, sizeof(xpp));
3705                memset(&xecfg, 0, sizeof(xecfg));
3706                xpp.flags = o->xdl_opts;
3707                xpp.anchors = o->anchors;
3708                xpp.anchors_nr = o->anchors_nr;
3709                xecfg.ctxlen = o->context;
3710                xecfg.interhunkctxlen = o->interhunkcontext;
3711                if (xdi_diff_outf(&mf1, &mf2, discard_hunk_line,
3712                                  diffstat_consume, diffstat, &xpp, &xecfg))
3713                        die("unable to generate diffstat for %s", one->path);
3714        }
3715
3716        diff_free_filespec_data(one);
3717        diff_free_filespec_data(two);
3718}
3719
3720static void builtin_checkdiff(const char *name_a, const char *name_b,
3721                              const char *attr_path,
3722                              struct diff_filespec *one,
3723                              struct diff_filespec *two,
3724                              struct diff_options *o)
3725{
3726        mmfile_t mf1, mf2;
3727        struct checkdiff_t data;
3728
3729        if (!two)
3730                return;
3731
3732        memset(&data, 0, sizeof(data));
3733        data.filename = name_b ? name_b : name_a;
3734        data.lineno = 0;
3735        data.o = o;
3736        data.ws_rule = whitespace_rule(o->repo->index, attr_path);
3737        data.conflict_marker_size = ll_merge_marker_size(o->repo->index, attr_path);
3738
3739        if (fill_mmfile(o->repo, &mf1, one) < 0 ||
3740            fill_mmfile(o->repo, &mf2, two) < 0)
3741                die("unable to read files to diff");
3742
3743        /*
3744         * All the other codepaths check both sides, but not checking
3745         * the "old" side here is deliberate.  We are checking the newly
3746         * introduced changes, and as long as the "new" side is text, we
3747         * can and should check what it introduces.
3748         */
3749        if (diff_filespec_is_binary(o->repo, two))
3750                goto free_and_return;
3751        else {
3752                /* Crazy xdl interfaces.. */
3753                xpparam_t xpp;
3754                xdemitconf_t xecfg;
3755
3756                memset(&xpp, 0, sizeof(xpp));
3757                memset(&xecfg, 0, sizeof(xecfg));
3758                xecfg.ctxlen = 1; /* at least one context line */
3759                xpp.flags = 0;
3760                if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume_hunk,
3761                                  checkdiff_consume, &data,
3762                                  &xpp, &xecfg))
3763                        die("unable to generate checkdiff for %s", one->path);
3764
3765                if (data.ws_rule & WS_BLANK_AT_EOF) {
3766                        struct emit_callback ecbdata;
3767                        int blank_at_eof;
3768
3769                        ecbdata.ws_rule = data.ws_rule;
3770                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3771                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
3772
3773                        if (blank_at_eof) {
3774                                static char *err;
3775                                if (!err)
3776                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
3777                                fprintf(o->file, "%s:%d: %s.\n",
3778                                        data.filename, blank_at_eof, err);
3779                                data.status = 1; /* report errors */
3780                        }
3781                }
3782        }
3783 free_and_return:
3784        diff_free_filespec_data(one);
3785        diff_free_filespec_data(two);
3786        if (data.status)
3787                o->flags.check_failed = 1;
3788}
3789
3790struct diff_filespec *alloc_filespec(const char *path)
3791{
3792        struct diff_filespec *spec;
3793
3794        FLEXPTR_ALLOC_STR(spec, path, path);
3795        spec->count = 1;
3796        spec->is_binary = -1;
3797        return spec;
3798}
3799
3800void free_filespec(struct diff_filespec *spec)
3801{
3802        if (!--spec->count) {
3803                diff_free_filespec_data(spec);
3804                free(spec);
3805        }
3806}
3807
3808void fill_filespec(struct diff_filespec *spec, const struct object_id *oid,
3809                   int oid_valid, unsigned short mode)
3810{
3811        if (mode) {
3812                spec->mode = canon_mode(mode);
3813                oidcpy(&spec->oid, oid);
3814                spec->oid_valid = oid_valid;
3815        }
3816}
3817
3818/*
3819 * Given a name and sha1 pair, if the index tells us the file in
3820 * the work tree has that object contents, return true, so that
3821 * prepare_temp_file() does not have to inflate and extract.
3822 */
3823static int reuse_worktree_file(struct index_state *istate,
3824                               const char *name,
3825                               const struct object_id *oid,
3826                               int want_file)
3827{
3828        const struct cache_entry *ce;
3829        struct stat st;
3830        int pos, len;
3831
3832        /*
3833         * We do not read the cache ourselves here, because the
3834         * benchmark with my previous version that always reads cache
3835         * shows that it makes things worse for diff-tree comparing
3836         * two linux-2.6 kernel trees in an already checked out work
3837         * tree.  This is because most diff-tree comparisons deal with
3838         * only a small number of files, while reading the cache is
3839         * expensive for a large project, and its cost outweighs the
3840         * savings we get by not inflating the object to a temporary
3841         * file.  Practically, this code only helps when we are used
3842         * by diff-cache --cached, which does read the cache before
3843         * calling us.
3844         */
3845        if (!istate->cache)
3846                return 0;
3847
3848        /* We want to avoid the working directory if our caller
3849         * doesn't need the data in a normal file, this system
3850         * is rather slow with its stat/open/mmap/close syscalls,
3851         * and the object is contained in a pack file.  The pack
3852         * is probably already open and will be faster to obtain
3853         * the data through than the working directory.  Loose
3854         * objects however would tend to be slower as they need
3855         * to be individually opened and inflated.
3856         */
3857        if (!FAST_WORKING_DIRECTORY && !want_file && has_object_pack(oid))
3858                return 0;
3859
3860        /*
3861         * Similarly, if we'd have to convert the file contents anyway, that
3862         * makes the optimization not worthwhile.
3863         */
3864        if (!want_file && would_convert_to_git(istate, name))
3865                return 0;
3866
3867        len = strlen(name);
3868        pos = index_name_pos(istate, name, len);
3869        if (pos < 0)
3870                return 0;
3871        ce = istate->cache[pos];
3872
3873        /*
3874         * This is not the sha1 we are looking for, or
3875         * unreusable because it is not a regular file.
3876         */
3877        if (!oideq(oid, &ce->oid) || !S_ISREG(ce->ce_mode))
3878                return 0;
3879
3880        /*
3881         * If ce is marked as "assume unchanged", there is no
3882         * guarantee that work tree matches what we are looking for.
3883         */
3884        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
3885                return 0;
3886
3887        /*
3888         * If ce matches the file in the work tree, we can reuse it.
3889         */
3890        if (ce_uptodate(ce) ||
3891            (!lstat(name, &st) && !ie_match_stat(istate, ce, &st, 0)))
3892                return 1;
3893
3894        return 0;
3895}
3896
3897static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
3898{
3899        struct strbuf buf = STRBUF_INIT;
3900        char *dirty = "";
3901
3902        /* Are we looking at the work tree? */
3903        if (s->dirty_submodule)
3904                dirty = "-dirty";
3905
3906        strbuf_addf(&buf, "Subproject commit %s%s\n",
3907                    oid_to_hex(&s->oid), dirty);
3908        s->size = buf.len;
3909        if (size_only) {
3910                s->data = NULL;
3911                strbuf_release(&buf);
3912        } else {
3913                s->data = strbuf_detach(&buf, NULL);
3914                s->should_free = 1;
3915        }
3916        return 0;
3917}
3918
3919/*
3920 * While doing rename detection and pickaxe operation, we may need to
3921 * grab the data for the blob (or file) for our own in-core comparison.
3922 * diff_filespec has data and size fields for this purpose.
3923 */
3924int diff_populate_filespec(struct repository *r,
3925                           struct diff_filespec *s,
3926                           unsigned int flags)
3927{
3928        int size_only = flags & CHECK_SIZE_ONLY;
3929        int err = 0;
3930        int conv_flags = global_conv_flags_eol;
3931        /*
3932         * demote FAIL to WARN to allow inspecting the situation
3933         * instead of refusing.
3934         */
3935        if (conv_flags & CONV_EOL_RNDTRP_DIE)
3936                conv_flags = CONV_EOL_RNDTRP_WARN;
3937
3938        if (!DIFF_FILE_VALID(s))
3939                die("internal error: asking to populate invalid file.");
3940        if (S_ISDIR(s->mode))
3941                return -1;
3942
3943        if (s->data)
3944                return 0;
3945
3946        if (size_only && 0 < s->size)
3947                return 0;
3948
3949        if (S_ISGITLINK(s->mode))
3950                return diff_populate_gitlink(s, size_only);
3951
3952        if (!s->oid_valid ||
3953            reuse_worktree_file(r->index, s->path, &s->oid, 0)) {
3954                struct strbuf buf = STRBUF_INIT;
3955                struct stat st;
3956                int fd;
3957
3958                if (lstat(s->path, &st) < 0) {
3959                err_empty:
3960                        err = -1;
3961                empty:
3962                        s->data = (char *)"";
3963                        s->size = 0;
3964                        return err;
3965                }
3966                s->size = xsize_t(st.st_size);
3967                if (!s->size)
3968                        goto empty;
3969                if (S_ISLNK(st.st_mode)) {
3970                        struct strbuf sb = STRBUF_INIT;
3971
3972                        if (strbuf_readlink(&sb, s->path, s->size))
3973                                goto err_empty;
3974                        s->size = sb.len;
3975                        s->data = strbuf_detach(&sb, NULL);
3976                        s->should_free = 1;
3977                        return 0;
3978                }
3979
3980                /*
3981                 * Even if the caller would be happy with getting
3982                 * only the size, we cannot return early at this
3983                 * point if the path requires us to run the content
3984                 * conversion.
3985                 */
3986                if (size_only && !would_convert_to_git(r->index, s->path))
3987                        return 0;
3988
3989                /*
3990                 * Note: this check uses xsize_t(st.st_size) that may
3991                 * not be the true size of the blob after it goes
3992                 * through convert_to_git().  This may not strictly be
3993                 * correct, but the whole point of big_file_threshold
3994                 * and is_binary check being that we want to avoid
3995                 * opening the file and inspecting the contents, this
3996                 * is probably fine.
3997                 */
3998                if ((flags & CHECK_BINARY) &&
3999                    s->size > big_file_threshold && s->is_binary == -1) {
4000                        s->is_binary = 1;
4001                        return 0;
4002                }
4003                fd = open(s->path, O_RDONLY);
4004                if (fd < 0)
4005                        goto err_empty;
4006                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
4007                close(fd);
4008                s->should_munmap = 1;
4009
4010                /*
4011                 * Convert from working tree format to canonical git format
4012                 */
4013                if (convert_to_git(r->index, s->path, s->data, s->size, &buf, conv_flags)) {
4014                        size_t size = 0;
4015                        munmap(s->data, s->size);
4016                        s->should_munmap = 0;
4017                        s->data = strbuf_detach(&buf, &size);
4018                        s->size = size;
4019                        s->should_free = 1;
4020                }
4021        }
4022        else {
4023                enum object_type type;
4024                if (size_only || (flags & CHECK_BINARY)) {
4025                        type = oid_object_info(r, &s->oid, &s->size);
4026                        if (type < 0)
4027                                die("unable to read %s",
4028                                    oid_to_hex(&s->oid));
4029                        if (size_only)
4030                                return 0;
4031                        if (s->size > big_file_threshold && s->is_binary == -1) {
4032                                s->is_binary = 1;
4033                                return 0;
4034                        }
4035                }
4036                s->data = read_object_file(&s->oid, &type, &s->size);
4037                if (!s->data)
4038                        die("unable to read %s", oid_to_hex(&s->oid));
4039                s->should_free = 1;
4040        }
4041        return 0;
4042}
4043
4044void diff_free_filespec_blob(struct diff_filespec *s)
4045{
4046        if (s->should_free)
4047                free(s->data);
4048        else if (s->should_munmap)
4049                munmap(s->data, s->size);
4050
4051        if (s->should_free || s->should_munmap) {
4052                s->should_free = s->should_munmap = 0;
4053                s->data = NULL;
4054        }
4055}
4056
4057void diff_free_filespec_data(struct diff_filespec *s)
4058{
4059        diff_free_filespec_blob(s);
4060        FREE_AND_NULL(s->cnt_data);
4061}
4062
4063static void prep_temp_blob(struct index_state *istate,
4064                           const char *path, struct diff_tempfile *temp,
4065                           void *blob,
4066                           unsigned long size,
4067                           const struct object_id *oid,
4068                           int mode)
4069{
4070        struct strbuf buf = STRBUF_INIT;
4071        struct strbuf tempfile = STRBUF_INIT;
4072        char *path_dup = xstrdup(path);
4073        const char *base = basename(path_dup);
4074
4075        /* Generate "XXXXXX_basename.ext" */
4076        strbuf_addstr(&tempfile, "XXXXXX_");
4077        strbuf_addstr(&tempfile, base);
4078
4079        temp->tempfile = mks_tempfile_ts(tempfile.buf, strlen(base) + 1);
4080        if (!temp->tempfile)
4081                die_errno("unable to create temp-file");
4082        if (convert_to_working_tree(istate, path,
4083                        (const char *)blob, (size_t)size, &buf)) {
4084                blob = buf.buf;
4085                size = buf.len;
4086        }
4087        if (write_in_full(temp->tempfile->fd, blob, size) < 0 ||
4088            close_tempfile_gently(temp->tempfile))
4089                die_errno("unable to write temp-file");
4090        temp->name = get_tempfile_path(temp->tempfile);
4091        oid_to_hex_r(temp->hex, oid);
4092        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
4093        strbuf_release(&buf);
4094        strbuf_release(&tempfile);
4095        free(path_dup);
4096}
4097
4098static struct diff_tempfile *prepare_temp_file(struct repository *r,
4099                                               const char *name,
4100                                               struct diff_filespec *one)
4101{
4102        struct diff_tempfile *temp = claim_diff_tempfile();
4103
4104        if (!DIFF_FILE_VALID(one)) {
4105        not_a_valid_file:
4106                /* A '-' entry produces this for file-2, and
4107                 * a '+' entry produces this for file-1.
4108                 */
4109                temp->name = "/dev/null";
4110                xsnprintf(temp->hex, sizeof(temp->hex), ".");
4111                xsnprintf(temp->mode, sizeof(temp->mode), ".");
4112                return temp;
4113        }
4114
4115        if (!S_ISGITLINK(one->mode) &&
4116            (!one->oid_valid ||
4117             reuse_worktree_file(r->index, name, &one->oid, 1))) {
4118                struct stat st;
4119                if (lstat(name, &st) < 0) {
4120                        if (errno == ENOENT)
4121                                goto not_a_valid_file;
4122                        die_errno("stat(%s)", name);
4123                }
4124                if (S_ISLNK(st.st_mode)) {
4125                        struct strbuf sb = STRBUF_INIT;
4126                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
4127                                die_errno("readlink(%s)", name);
4128                        prep_temp_blob(r->index, name, temp, sb.buf, sb.len,
4129                                       (one->oid_valid ?
4130                                        &one->oid : &null_oid),
4131                                       (one->oid_valid ?
4132                                        one->mode : S_IFLNK));
4133                        strbuf_release(&sb);
4134                }
4135                else {
4136                        /* we can borrow from the file in the work tree */
4137                        temp->name = name;
4138                        if (!one->oid_valid)
4139                                oid_to_hex_r(temp->hex, &null_oid);
4140                        else
4141                                oid_to_hex_r(temp->hex, &one->oid);
4142                        /* Even though we may sometimes borrow the
4143                         * contents from the work tree, we always want
4144                         * one->mode.  mode is trustworthy even when
4145                         * !(one->oid_valid), as long as
4146                         * DIFF_FILE_VALID(one).
4147                         */
4148                        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
4149                }
4150                return temp;
4151        }
4152        else {
4153                if (diff_populate_filespec(r, one, 0))
4154                        die("cannot read data blob for %s", one->path);
4155                prep_temp_blob(r->index, name, temp,
4156                               one->data, one->size,
4157                               &one->oid, one->mode);
4158        }
4159        return temp;
4160}
4161
4162static void add_external_diff_name(struct repository *r,
4163                                   struct argv_array *argv,
4164                                   const char *name,
4165                                   struct diff_filespec *df)
4166{
4167        struct diff_tempfile *temp = prepare_temp_file(r, name, df);
4168        argv_array_push(argv, temp->name);
4169        argv_array_push(argv, temp->hex);
4170        argv_array_push(argv, temp->mode);
4171}
4172
4173/* An external diff command takes:
4174 *
4175 * diff-cmd name infile1 infile1-sha1 infile1-mode \
4176 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
4177 *
4178 */
4179static void run_external_diff(const char *pgm,
4180                              const char *name,
4181                              const char *other,
4182                              struct diff_filespec *one,
4183                              struct diff_filespec *two,
4184                              const char *xfrm_msg,
4185                              struct diff_options *o)
4186{
4187        struct argv_array argv = ARGV_ARRAY_INIT;
4188        struct argv_array env = ARGV_ARRAY_INIT;
4189        struct diff_queue_struct *q = &diff_queued_diff;
4190
4191        argv_array_push(&argv, pgm);
4192        argv_array_push(&argv, name);
4193
4194        if (one && two) {
4195                add_external_diff_name(o->repo, &argv, name, one);
4196                if (!other)
4197                        add_external_diff_name(o->repo, &argv, name, two);
4198                else {
4199                        add_external_diff_name(o->repo, &argv, other, two);
4200                        argv_array_push(&argv, other);
4201                        argv_array_push(&argv, xfrm_msg);
4202                }
4203        }
4204
4205        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
4206        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
4207
4208        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
4209                die(_("external diff died, stopping at %s"), name);
4210
4211        remove_tempfile();
4212        argv_array_clear(&argv);
4213        argv_array_clear(&env);
4214}
4215
4216static int similarity_index(struct diff_filepair *p)
4217{
4218        return p->score * 100 / MAX_SCORE;
4219}
4220
4221static const char *diff_abbrev_oid(const struct object_id *oid, int abbrev)
4222{
4223        if (startup_info->have_repository)
4224                return find_unique_abbrev(oid, abbrev);
4225        else {
4226                char *hex = oid_to_hex(oid);
4227                if (abbrev < 0)
4228                        abbrev = FALLBACK_DEFAULT_ABBREV;
4229                if (abbrev > the_hash_algo->hexsz)
4230                        BUG("oid abbreviation out of range: %d", abbrev);
4231                if (abbrev)
4232                        hex[abbrev] = '\0';
4233                return hex;
4234        }
4235}
4236
4237static void fill_metainfo(struct strbuf *msg,
4238                          const char *name,
4239                          const char *other,
4240                          struct diff_filespec *one,
4241                          struct diff_filespec *two,
4242                          struct diff_options *o,
4243                          struct diff_filepair *p,
4244                          int *must_show_header,
4245                          int use_color)
4246{
4247        const char *set = diff_get_color(use_color, DIFF_METAINFO);
4248        const char *reset = diff_get_color(use_color, DIFF_RESET);
4249        const char *line_prefix = diff_line_prefix(o);
4250
4251        *must_show_header = 1;
4252        strbuf_init(msg, PATH_MAX * 2 + 300);
4253        switch (p->status) {
4254        case DIFF_STATUS_COPIED:
4255                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4256                            line_prefix, set, similarity_index(p));
4257                strbuf_addf(msg, "%s\n%s%scopy from ",
4258                            reset,  line_prefix, set);
4259                quote_c_style(name, msg, NULL, 0);
4260                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
4261                quote_c_style(other, msg, NULL, 0);
4262                strbuf_addf(msg, "%s\n", reset);
4263                break;
4264        case DIFF_STATUS_RENAMED:
4265                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4266                            line_prefix, set, similarity_index(p));
4267                strbuf_addf(msg, "%s\n%s%srename from ",
4268                            reset, line_prefix, set);
4269                quote_c_style(name, msg, NULL, 0);
4270                strbuf_addf(msg, "%s\n%s%srename to ",
4271                            reset, line_prefix, set);
4272                quote_c_style(other, msg, NULL, 0);
4273                strbuf_addf(msg, "%s\n", reset);
4274                break;
4275        case DIFF_STATUS_MODIFIED:
4276                if (p->score) {
4277                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
4278                                    line_prefix,
4279                                    set, similarity_index(p), reset);
4280                        break;
4281                }
4282                /* fallthru */
4283        default:
4284                *must_show_header = 0;
4285        }
4286        if (one && two && !oideq(&one->oid, &two->oid)) {
4287                const unsigned hexsz = the_hash_algo->hexsz;
4288                int abbrev = o->flags.full_index ? hexsz : DEFAULT_ABBREV;
4289
4290                if (o->flags.binary) {
4291                        mmfile_t mf;
4292                        if ((!fill_mmfile(o->repo, &mf, one) &&
4293                             diff_filespec_is_binary(o->repo, one)) ||
4294                            (!fill_mmfile(o->repo, &mf, two) &&
4295                             diff_filespec_is_binary(o->repo, two)))
4296                                abbrev = hexsz;
4297                }
4298                strbuf_addf(msg, "%s%sindex %s..%s", line_prefix, set,
4299                            diff_abbrev_oid(&one->oid, abbrev),
4300                            diff_abbrev_oid(&two->oid, abbrev));
4301                if (one->mode == two->mode)
4302                        strbuf_addf(msg, " %06o", one->mode);
4303                strbuf_addf(msg, "%s\n", reset);
4304        }
4305}
4306
4307static void run_diff_cmd(const char *pgm,
4308                         const char *name,
4309                         const char *other,
4310                         const char *attr_path,
4311                         struct diff_filespec *one,
4312                         struct diff_filespec *two,
4313                         struct strbuf *msg,
4314                         struct diff_options *o,
4315                         struct diff_filepair *p)
4316{
4317        const char *xfrm_msg = NULL;
4318        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
4319        int must_show_header = 0;
4320
4321
4322        if (o->flags.allow_external) {
4323                struct userdiff_driver *drv;
4324
4325                drv = userdiff_find_by_path(o->repo->index, attr_path);
4326                if (drv && drv->external)
4327                        pgm = drv->external;
4328        }
4329
4330        if (msg) {
4331                /*
4332                 * don't use colors when the header is intended for an
4333                 * external diff driver
4334                 */
4335                fill_metainfo(msg, name, other, one, two, o, p,
4336                              &must_show_header,
4337                              want_color(o->use_color) && !pgm);
4338                xfrm_msg = msg->len ? msg->buf : NULL;
4339        }
4340
4341        if (pgm) {
4342                run_external_diff(pgm, name, other, one, two, xfrm_msg, o);
4343                return;
4344        }
4345        if (one && two)
4346                builtin_diff(name, other ? other : name,
4347                             one, two, xfrm_msg, must_show_header,
4348                             o, complete_rewrite);
4349        else
4350                fprintf(o->file, "* Unmerged path %s\n", name);
4351}
4352
4353static void diff_fill_oid_info(struct diff_filespec *one, struct index_state *istate)
4354{
4355        if (DIFF_FILE_VALID(one)) {
4356                if (!one->oid_valid) {
4357                        struct stat st;
4358                        if (one->is_stdin) {
4359                                oidclr(&one->oid);
4360                                return;
4361                        }
4362                        if (lstat(one->path, &st) < 0)
4363                                die_errno("stat '%s'", one->path);
4364                        if (index_path(istate, &one->oid, one->path, &st, 0))
4365                                die("cannot hash %s", one->path);
4366                }
4367        }
4368        else
4369                oidclr(&one->oid);
4370}
4371
4372static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
4373{
4374        /* Strip the prefix but do not molest /dev/null and absolute paths */
4375        if (*namep && !is_absolute_path(*namep)) {
4376                *namep += prefix_length;
4377                if (**namep == '/')
4378                        ++*namep;
4379        }
4380        if (*otherp && !is_absolute_path(*otherp)) {
4381                *otherp += prefix_length;
4382                if (**otherp == '/')
4383                        ++*otherp;
4384        }
4385}
4386
4387static void run_diff(struct diff_filepair *p, struct diff_options *o)
4388{
4389        const char *pgm = external_diff();
4390        struct strbuf msg;
4391        struct diff_filespec *one = p->one;
4392        struct diff_filespec *two = p->two;
4393        const char *name;
4394        const char *other;
4395        const char *attr_path;
4396
4397        name  = one->path;
4398        other = (strcmp(name, two->path) ? two->path : NULL);
4399        attr_path = name;
4400        if (o->prefix_length)
4401                strip_prefix(o->prefix_length, &name, &other);
4402
4403        if (!o->flags.allow_external)
4404                pgm = NULL;
4405
4406        if (DIFF_PAIR_UNMERGED(p)) {
4407                run_diff_cmd(pgm, name, NULL, attr_path,
4408                             NULL, NULL, NULL, o, p);
4409                return;
4410        }
4411
4412        diff_fill_oid_info(one, o->repo->index);
4413        diff_fill_oid_info(two, o->repo->index);
4414
4415        if (!pgm &&
4416            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
4417            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
4418                /*
4419                 * a filepair that changes between file and symlink
4420                 * needs to be split into deletion and creation.
4421                 */
4422                struct diff_filespec *null = alloc_filespec(two->path);
4423                run_diff_cmd(NULL, name, other, attr_path,
4424                             one, null, &msg,
4425                             o, p);
4426                free(null);
4427                strbuf_release(&msg);
4428
4429                null = alloc_filespec(one->path);
4430                run_diff_cmd(NULL, name, other, attr_path,
4431                             null, two, &msg, o, p);
4432                free(null);
4433        }
4434        else
4435                run_diff_cmd(pgm, name, other, attr_path,
4436                             one, two, &msg, o, p);
4437
4438        strbuf_release(&msg);
4439}
4440
4441static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
4442                         struct diffstat_t *diffstat)
4443{
4444        const char *name;
4445        const char *other;
4446
4447        if (DIFF_PAIR_UNMERGED(p)) {
4448                /* unmerged */
4449                builtin_diffstat(p->one->path, NULL, NULL, NULL,
4450                                 diffstat, o, p);
4451                return;
4452        }
4453
4454        name = p->one->path;
4455        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4456
4457        if (o->prefix_length)
4458                strip_prefix(o->prefix_length, &name, &other);
4459
4460        diff_fill_oid_info(p->one, o->repo->index);
4461        diff_fill_oid_info(p->two, o->repo->index);
4462
4463        builtin_diffstat(name, other, p->one, p->two,
4464                         diffstat, o, p);
4465}
4466
4467static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
4468{
4469        const char *name;
4470        const char *other;
4471        const char *attr_path;
4472
4473        if (DIFF_PAIR_UNMERGED(p)) {
4474                /* unmerged */
4475                return;
4476        }
4477
4478        name = p->one->path;
4479        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4480        attr_path = other ? other : name;
4481
4482        if (o->prefix_length)
4483                strip_prefix(o->prefix_length, &name, &other);
4484
4485        diff_fill_oid_info(p->one, o->repo->index);
4486        diff_fill_oid_info(p->two, o->repo->index);
4487
4488        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
4489}
4490
4491static void prep_parse_options(struct diff_options *options);
4492
4493void repo_diff_setup(struct repository *r, struct diff_options *options)
4494{
4495        memcpy(options, &default_diff_options, sizeof(*options));
4496
4497        options->file = stdout;
4498        options->repo = r;
4499
4500        options->output_indicators[OUTPUT_INDICATOR_NEW] = '+';
4501        options->output_indicators[OUTPUT_INDICATOR_OLD] = '-';
4502        options->output_indicators[OUTPUT_INDICATOR_CONTEXT] = ' ';
4503        options->abbrev = DEFAULT_ABBREV;
4504        options->line_termination = '\n';
4505        options->break_opt = -1;
4506        options->rename_limit = -1;
4507        options->dirstat_permille = diff_dirstat_permille_default;
4508        options->context = diff_context_default;
4509        options->interhunkcontext = diff_interhunk_context_default;
4510        options->ws_error_highlight = ws_error_highlight_default;
4511        options->flags.rename_empty = 1;
4512        options->objfind = NULL;
4513
4514        /* pathchange left =NULL by default */
4515        options->change = diff_change;
4516        options->add_remove = diff_addremove;
4517        options->use_color = diff_use_color_default;
4518        options->detect_rename = diff_detect_rename_default;
4519        options->xdl_opts |= diff_algorithm;
4520        if (diff_indent_heuristic)
4521                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4522
4523        options->orderfile = diff_order_file_cfg;
4524
4525        if (diff_no_prefix) {
4526                options->a_prefix = options->b_prefix = "";
4527        } else if (!diff_mnemonic_prefix) {
4528                options->a_prefix = "a/";
4529                options->b_prefix = "b/";
4530        }
4531
4532        options->color_moved = diff_color_moved_default;
4533        options->color_moved_ws_handling = diff_color_moved_ws_default;
4534
4535        prep_parse_options(options);
4536}
4537
4538void diff_setup_done(struct diff_options *options)
4539{
4540        unsigned check_mask = DIFF_FORMAT_NAME |
4541                              DIFF_FORMAT_NAME_STATUS |
4542                              DIFF_FORMAT_CHECKDIFF |
4543                              DIFF_FORMAT_NO_OUTPUT;
4544        /*
4545         * This must be signed because we're comparing against a potentially
4546         * negative value.
4547         */
4548        const int hexsz = the_hash_algo->hexsz;
4549
4550        if (options->set_default)
4551                options->set_default(options);
4552
4553        if (HAS_MULTI_BITS(options->output_format & check_mask))
4554                die(_("--name-only, --name-status, --check and -s are mutually exclusive"));
4555
4556        if (HAS_MULTI_BITS(options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK))
4557                die(_("-G, -S and --find-object are mutually exclusive"));
4558
4559        /*
4560         * Most of the time we can say "there are changes"
4561         * only by checking if there are changed paths, but
4562         * --ignore-whitespace* options force us to look
4563         * inside contents.
4564         */
4565
4566        if ((options->xdl_opts & XDF_WHITESPACE_FLAGS))
4567                options->flags.diff_from_contents = 1;
4568        else
4569                options->flags.diff_from_contents = 0;
4570
4571        if (options->flags.find_copies_harder)
4572                options->detect_rename = DIFF_DETECT_COPY;
4573
4574        if (!options->flags.relative_name)
4575                options->prefix = NULL;
4576        if (options->prefix)
4577                options->prefix_length = strlen(options->prefix);
4578        else
4579                options->prefix_length = 0;
4580
4581        if (options->output_format & (DIFF_FORMAT_NAME |
4582                                      DIFF_FORMAT_NAME_STATUS |
4583                                      DIFF_FORMAT_CHECKDIFF |
4584                                      DIFF_FORMAT_NO_OUTPUT))
4585                options->output_format &= ~(DIFF_FORMAT_RAW |
4586                                            DIFF_FORMAT_NUMSTAT |
4587                                            DIFF_FORMAT_DIFFSTAT |
4588                                            DIFF_FORMAT_SHORTSTAT |
4589                                            DIFF_FORMAT_DIRSTAT |
4590                                            DIFF_FORMAT_SUMMARY |
4591                                            DIFF_FORMAT_PATCH);
4592
4593        /*
4594         * These cases always need recursive; we do not drop caller-supplied
4595         * recursive bits for other formats here.
4596         */
4597        if (options->output_format & (DIFF_FORMAT_PATCH |
4598                                      DIFF_FORMAT_NUMSTAT |
4599                                      DIFF_FORMAT_DIFFSTAT |
4600                                      DIFF_FORMAT_SHORTSTAT |
4601                                      DIFF_FORMAT_DIRSTAT |
4602                                      DIFF_FORMAT_SUMMARY |
4603                                      DIFF_FORMAT_CHECKDIFF))
4604                options->flags.recursive = 1;
4605        /*
4606         * Also pickaxe would not work very well if you do not say recursive
4607         */
4608        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
4609                options->flags.recursive = 1;
4610        /*
4611         * When patches are generated, submodules diffed against the work tree
4612         * must be checked for dirtiness too so it can be shown in the output
4613         */
4614        if (options->output_format & DIFF_FORMAT_PATCH)
4615                options->flags.dirty_submodules = 1;
4616
4617        if (options->detect_rename && options->rename_limit < 0)
4618                options->rename_limit = diff_rename_limit_default;
4619        if (hexsz < options->abbrev)
4620                options->abbrev = hexsz; /* full */
4621
4622        /*
4623         * It does not make sense to show the first hit we happened
4624         * to have found.  It does not make sense not to return with
4625         * exit code in such a case either.
4626         */
4627        if (options->flags.quick) {
4628                options->output_format = DIFF_FORMAT_NO_OUTPUT;
4629                options->flags.exit_with_status = 1;
4630        }
4631
4632        options->diff_path_counter = 0;
4633
4634        if (options->flags.follow_renames && options->pathspec.nr != 1)
4635                die(_("--follow requires exactly one pathspec"));
4636
4637        if (!options->use_color || external_diff())
4638                options->color_moved = 0;
4639
4640        FREE_AND_NULL(options->parseopts);
4641}
4642
4643static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
4644{
4645        char c, *eq;
4646        int len;
4647
4648        if (*arg != '-')
4649                return 0;
4650        c = *++arg;
4651        if (!c)
4652                return 0;
4653        if (c == arg_short) {
4654                c = *++arg;
4655                if (!c)
4656                        return 1;
4657                if (val && isdigit(c)) {
4658                        char *end;
4659                        int n = strtoul(arg, &end, 10);
4660                        if (*end)
4661                                return 0;
4662                        *val = n;
4663                        return 1;
4664                }
4665                return 0;
4666        }
4667        if (c != '-')
4668                return 0;
4669        arg++;
4670        eq = strchrnul(arg, '=');
4671        len = eq - arg;
4672        if (!len || strncmp(arg, arg_long, len))
4673                return 0;
4674        if (*eq) {
4675                int n;
4676                char *end;
4677                if (!isdigit(*++eq))
4678                        return 0;
4679                n = strtoul(eq, &end, 10);
4680                if (*end)
4681                        return 0;
4682                *val = n;
4683        }
4684        return 1;
4685}
4686
4687static inline int short_opt(char opt, const char **argv,
4688                            const char **optarg)
4689{
4690        const char *arg = argv[0];
4691        if (arg[0] != '-' || arg[1] != opt)
4692                return 0;
4693        if (arg[2] != '\0') {
4694                *optarg = arg + 2;
4695                return 1;
4696        }
4697        if (!argv[1])
4698                die("Option '%c' requires a value", opt);
4699        *optarg = argv[1];
4700        return 2;
4701}
4702
4703int parse_long_opt(const char *opt, const char **argv,
4704                   const char **optarg)
4705{
4706        const char *arg = argv[0];
4707        if (!skip_prefix(arg, "--", &arg))
4708                return 0;
4709        if (!skip_prefix(arg, opt, &arg))
4710                return 0;
4711        if (*arg == '=') { /* stuck form: --option=value */
4712                *optarg = arg + 1;
4713                return 1;
4714        }
4715        if (*arg != '\0')
4716                return 0;
4717        /* separate form: --option value */
4718        if (!argv[1])
4719                die("Option '--%s' requires a value", opt);
4720        *optarg = argv[1];
4721        return 2;
4722}
4723
4724static int diff_opt_stat(const struct option *opt, const char *value, int unset)
4725{
4726        struct diff_options *options = opt->value;
4727        int width = options->stat_width;
4728        int name_width = options->stat_name_width;
4729        int graph_width = options->stat_graph_width;
4730        int count = options->stat_count;
4731        char *end;
4732
4733        BUG_ON_OPT_NEG(unset);
4734
4735        if (!strcmp(opt->long_name, "stat")) {
4736                if (value) {
4737                        width = strtoul(value, &end, 10);
4738                        if (*end == ',')
4739                                name_width = strtoul(end+1, &end, 10);
4740                        if (*end == ',')
4741                                count = strtoul(end+1, &end, 10);
4742                        if (*end)
4743                                return error(_("invalid --stat value: %s"), value);
4744                }
4745        } else if (!strcmp(opt->long_name, "stat-width")) {
4746                width = strtoul(value, &end, 10);
4747                if (*end)
4748                        return error(_("%s expects a numerical value"),
4749                                     opt->long_name);
4750        } else if (!strcmp(opt->long_name, "stat-name-width")) {
4751                name_width = strtoul(value, &end, 10);
4752                if (*end)
4753                        return error(_("%s expects a numerical value"),
4754                                     opt->long_name);
4755        } else if (!strcmp(opt->long_name, "stat-graph-width")) {
4756                graph_width = strtoul(value, &end, 10);
4757                if (*end)
4758                        return error(_("%s expects a numerical value"),
4759                                     opt->long_name);
4760        } else if (!strcmp(opt->long_name, "stat-count")) {
4761                count = strtoul(value, &end, 10);
4762                if (*end)
4763                        return error(_("%s expects a numerical value"),
4764                                     opt->long_name);
4765        } else
4766                BUG("%s should not get here", opt->long_name);
4767
4768        options->output_format |= DIFF_FORMAT_DIFFSTAT;
4769        options->stat_name_width = name_width;
4770        options->stat_graph_width = graph_width;
4771        options->stat_width = width;
4772        options->stat_count = count;
4773        return 0;
4774}
4775
4776static int parse_dirstat_opt(struct diff_options *options, const char *params)
4777{
4778        struct strbuf errmsg = STRBUF_INIT;
4779        if (parse_dirstat_params(options, params, &errmsg))
4780                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
4781                    errmsg.buf);
4782        strbuf_release(&errmsg);
4783        /*
4784         * The caller knows a dirstat-related option is given from the command
4785         * line; allow it to say "return this_function();"
4786         */
4787        options->output_format |= DIFF_FORMAT_DIRSTAT;
4788        return 1;
4789}
4790
4791static int parse_submodule_opt(struct diff_options *options, const char *value)
4792{
4793        if (parse_submodule_params(options, value))
4794                die(_("Failed to parse --submodule option parameter: '%s'"),
4795                        value);
4796        return 1;
4797}
4798
4799static const char diff_status_letters[] = {
4800        DIFF_STATUS_ADDED,
4801        DIFF_STATUS_COPIED,
4802        DIFF_STATUS_DELETED,
4803        DIFF_STATUS_MODIFIED,
4804        DIFF_STATUS_RENAMED,
4805        DIFF_STATUS_TYPE_CHANGED,
4806        DIFF_STATUS_UNKNOWN,
4807        DIFF_STATUS_UNMERGED,
4808        DIFF_STATUS_FILTER_AON,
4809        DIFF_STATUS_FILTER_BROKEN,
4810        '\0',
4811};
4812
4813static unsigned int filter_bit['Z' + 1];
4814
4815static void prepare_filter_bits(void)
4816{
4817        int i;
4818
4819        if (!filter_bit[DIFF_STATUS_ADDED]) {
4820                for (i = 0; diff_status_letters[i]; i++)
4821                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
4822        }
4823}
4824
4825static unsigned filter_bit_tst(char status, const struct diff_options *opt)
4826{
4827        return opt->filter & filter_bit[(int) status];
4828}
4829
4830static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
4831{
4832        int i, optch;
4833
4834        prepare_filter_bits();
4835
4836        /*
4837         * If there is a negation e.g. 'd' in the input, and we haven't
4838         * initialized the filter field with another --diff-filter, start
4839         * from full set of bits, except for AON.
4840         */
4841        if (!opt->filter) {
4842                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4843                        if (optch < 'a' || 'z' < optch)
4844                                continue;
4845                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
4846                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
4847                        break;
4848                }
4849        }
4850
4851        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4852                unsigned int bit;
4853                int negate;
4854
4855                if ('a' <= optch && optch <= 'z') {
4856                        negate = 1;
4857                        optch = toupper(optch);
4858                } else {
4859                        negate = 0;
4860                }
4861
4862                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
4863                if (!bit)
4864                        return optarg[i];
4865                if (negate)
4866                        opt->filter &= ~bit;
4867                else
4868                        opt->filter |= bit;
4869        }
4870        return 0;
4871}
4872
4873static void enable_patch_output(int *fmt)
4874{
4875        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
4876        *fmt |= DIFF_FORMAT_PATCH;
4877}
4878
4879static int parse_ws_error_highlight_opt(struct diff_options *opt, const char *arg)
4880{
4881        int val = parse_ws_error_highlight(arg);
4882
4883        if (val < 0) {
4884                error("unknown value after ws-error-highlight=%.*s",
4885                      -1 - val, arg);
4886                return 0;
4887        }
4888        opt->ws_error_highlight = val;
4889        return 1;
4890}
4891
4892static int parse_objfind_opt(struct diff_options *opt, const char *arg)
4893{
4894        struct object_id oid;
4895
4896        if (get_oid(arg, &oid))
4897                return error("unable to resolve '%s'", arg);
4898
4899        if (!opt->objfind)
4900                opt->objfind = xcalloc(1, sizeof(*opt->objfind));
4901
4902        opt->pickaxe_opts |= DIFF_PICKAXE_KIND_OBJFIND;
4903        opt->flags.recursive = 1;
4904        opt->flags.tree_in_recursive = 1;
4905        oidset_insert(opt->objfind, &oid);
4906        return 1;
4907}
4908
4909static int diff_opt_break_rewrites(const struct option *opt,
4910                                   const char *arg, int unset)
4911{
4912        int *break_opt = opt->value;
4913        int opt1, opt2;
4914
4915        BUG_ON_OPT_NEG(unset);
4916        if (!arg)
4917                arg = "";
4918        opt1 = parse_rename_score(&arg);
4919        if (*arg == 0)
4920                opt2 = 0;
4921        else if (*arg != '/')
4922                return error(_("%s expects <n>/<m> form"), opt->long_name);
4923        else {
4924                arg++;
4925                opt2 = parse_rename_score(&arg);
4926        }
4927        if (*arg != 0)
4928                return error(_("%s expects <n>/<m> form"), opt->long_name);
4929        *break_opt = opt1 | (opt2 << 16);
4930        return 0;
4931}
4932
4933static int diff_opt_char(const struct option *opt,
4934                         const char *arg, int unset)
4935{
4936        char *value = opt->value;
4937
4938        BUG_ON_OPT_NEG(unset);
4939        if (arg[1])
4940                return error(_("%s expects a character, got '%s'"),
4941                             opt->long_name, arg);
4942        *value = arg[0];
4943        return 0;
4944}
4945
4946static int diff_opt_compact_summary(const struct option *opt,
4947                                    const char *arg, int unset)
4948{
4949        struct diff_options *options = opt->value;
4950
4951        BUG_ON_OPT_ARG(arg);
4952        if (unset) {
4953                options->flags.stat_with_summary = 0;
4954        } else {
4955                options->flags.stat_with_summary = 1;
4956                options->output_format |= DIFF_FORMAT_DIFFSTAT;
4957        }
4958        return 0;
4959}
4960
4961static int diff_opt_dirstat(const struct option *opt,
4962                            const char *arg, int unset)
4963{
4964        struct diff_options *options = opt->value;
4965
4966        BUG_ON_OPT_NEG(unset);
4967        if (!strcmp(opt->long_name, "cumulative")) {
4968                if (arg)
4969                        BUG("how come --cumulative take a value?");
4970                arg = "cumulative";
4971        } else if (!strcmp(opt->long_name, "dirstat-by-file"))
4972                parse_dirstat_opt(options, "files");
4973        parse_dirstat_opt(options, arg ? arg : "");
4974        return 0;
4975}
4976
4977static int diff_opt_find_copies(const struct option *opt,
4978                                const char *arg, int unset)
4979{
4980        struct diff_options *options = opt->value;
4981
4982        BUG_ON_OPT_NEG(unset);
4983        if (!arg)
4984                arg = "";
4985        options->rename_score = parse_rename_score(&arg);
4986        if (*arg != 0)
4987                return error(_("invalid argument to %s"), opt->long_name);
4988
4989        if (options->detect_rename == DIFF_DETECT_COPY)
4990                options->flags.find_copies_harder = 1;
4991        else
4992                options->detect_rename = DIFF_DETECT_COPY;
4993
4994        return 0;
4995}
4996
4997static int diff_opt_find_renames(const struct option *opt,
4998                                 const char *arg, int unset)
4999{
5000        struct diff_options *options = opt->value;
5001
5002        BUG_ON_OPT_NEG(unset);
5003        if (!arg)
5004                arg = "";
5005        options->rename_score = parse_rename_score(&arg);
5006        if (*arg != 0)
5007                return error(_("invalid argument to %s"), opt->long_name);
5008
5009        options->detect_rename = DIFF_DETECT_RENAME;
5010        return 0;
5011}
5012
5013static enum parse_opt_result diff_opt_output(struct parse_opt_ctx_t *ctx,
5014                                             const struct option *opt,
5015                                             const char *arg, int unset)
5016{
5017        struct diff_options *options = opt->value;
5018        char *path;
5019
5020        BUG_ON_OPT_NEG(unset);
5021        path = prefix_filename(ctx->prefix, arg);
5022        options->file = xfopen(path, "w");
5023        options->close_file = 1;
5024        if (options->use_color != GIT_COLOR_ALWAYS)
5025                options->use_color = GIT_COLOR_NEVER;
5026        free(path);
5027        return 0;
5028}
5029
5030static int diff_opt_relative(const struct option *opt,
5031                             const char *arg, int unset)
5032{
5033        struct diff_options *options = opt->value;
5034
5035        BUG_ON_OPT_NEG(unset);
5036        options->flags.relative_name = 1;
5037        if (arg)
5038                options->prefix = arg;
5039        return 0;
5040}
5041
5042static int diff_opt_unified(const struct option *opt,
5043                            const char *arg, int unset)
5044{
5045        struct diff_options *options = opt->value;
5046        char *s;
5047
5048        BUG_ON_OPT_NEG(unset);
5049
5050        options->context = strtol(arg, &s, 10);
5051        if (*s)
5052                return error(_("%s expects a numerical value"), "--unified");
5053        enable_patch_output(&options->output_format);
5054
5055        return 0;
5056}
5057
5058static void prep_parse_options(struct diff_options *options)
5059{
5060        struct option parseopts[] = {
5061                OPT_GROUP(N_("Diff output format options")),
5062                OPT_BITOP('p', "patch", &options->output_format,
5063                          N_("generate patch"),
5064                          DIFF_FORMAT_PATCH, DIFF_FORMAT_NO_OUTPUT),
5065                OPT_BIT_F('s', "no-patch", &options->output_format,
5066                          N_("suppress diff output"),
5067                          DIFF_FORMAT_NO_OUTPUT, PARSE_OPT_NONEG),
5068                OPT_BITOP('u', NULL, &options->output_format,
5069                          N_("generate patch"),
5070                          DIFF_FORMAT_PATCH, DIFF_FORMAT_NO_OUTPUT),
5071                OPT_CALLBACK_F('U', "unified", options, N_("<n>"),
5072                               N_("generate diffs with <n> lines context"),
5073                               PARSE_OPT_NONEG, diff_opt_unified),
5074                OPT_BOOL('W', "function-context", &options->flags.funccontext,
5075                         N_("generate diffs with <n> lines context")),
5076                OPT_BIT_F(0, "raw", &options->output_format,
5077                          N_("generate the diff in raw format"),
5078                          DIFF_FORMAT_RAW, PARSE_OPT_NONEG),
5079                OPT_BITOP(0, "patch-with-raw", &options->output_format,
5080                          N_("synonym for '-p --raw'"),
5081                          DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW,
5082                          DIFF_FORMAT_NO_OUTPUT),
5083                OPT_BITOP(0, "patch-with-stat", &options->output_format,
5084                          N_("synonym for '-p --stat'"),
5085                          DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT,
5086                          DIFF_FORMAT_NO_OUTPUT),
5087                OPT_BIT_F(0, "numstat", &options->output_format,
5088                          N_("machine friendly --stat"),
5089                          DIFF_FORMAT_NUMSTAT, PARSE_OPT_NONEG),
5090                OPT_BIT_F(0, "shortstat", &options->output_format,
5091                          N_("output only the last line of --stat"),
5092                          DIFF_FORMAT_SHORTSTAT, PARSE_OPT_NONEG),
5093                OPT_CALLBACK_F('X', "dirstat", options, N_("<param1,param2>..."),
5094                               N_("output the distribution of relative amount of changes for each sub-directory"),
5095                               PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
5096                               diff_opt_dirstat),
5097                OPT_CALLBACK_F(0, "cumulative", options, NULL,
5098                               N_("synonym for --dirstat=cumulative"),
5099                               PARSE_OPT_NONEG | PARSE_OPT_NOARG,
5100                               diff_opt_dirstat),
5101                OPT_CALLBACK_F(0, "dirstat-by-file", options, N_("<param1,param2>..."),
5102                               N_("synonym for --dirstat=files,param1,param2..."),
5103                               PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
5104                               diff_opt_dirstat),
5105                OPT_BIT_F(0, "check", &options->output_format,
5106                          N_("warn if changes introduce conflict markers or whitespace errors"),
5107                          DIFF_FORMAT_CHECKDIFF, PARSE_OPT_NONEG),
5108                OPT_BIT_F(0, "summary", &options->output_format,
5109                          N_("condensed summary such as creations, renames and mode changes"),
5110                          DIFF_FORMAT_SUMMARY, PARSE_OPT_NONEG),
5111                OPT_BIT_F(0, "name-only", &options->output_format,
5112                          N_("show only names of changed files"),
5113                          DIFF_FORMAT_NAME, PARSE_OPT_NONEG),
5114                OPT_BIT_F(0, "name-status", &options->output_format,
5115                          N_("show only names and status of changed files"),
5116                          DIFF_FORMAT_NAME_STATUS, PARSE_OPT_NONEG),
5117                OPT_CALLBACK_F(0, "stat", options, N_("<width>[,<name-width>[,<count>]]"),
5118                               N_("generate diffstat"),
5119                               PARSE_OPT_NONEG | PARSE_OPT_OPTARG, diff_opt_stat),
5120                OPT_CALLBACK_F(0, "stat-width", options, N_("<width>"),
5121                               N_("generate diffstat with a given width"),
5122                               PARSE_OPT_NONEG, diff_opt_stat),
5123                OPT_CALLBACK_F(0, "stat-name-width", options, N_("<width>"),
5124                               N_("generate diffstat with a given name width"),
5125                               PARSE_OPT_NONEG, diff_opt_stat),
5126                OPT_CALLBACK_F(0, "stat-graph-width", options, N_("<width>"),
5127                               N_("generate diffstat with a given graph width"),
5128                               PARSE_OPT_NONEG, diff_opt_stat),
5129                OPT_CALLBACK_F(0, "stat-count", options, N_("<count>"),
5130                               N_("generate diffstat with limited lines"),
5131                               PARSE_OPT_NONEG, diff_opt_stat),
5132                OPT_CALLBACK_F(0, "compact-summary", options, NULL,
5133                               N_("generate compact summary in diffstat"),
5134                               PARSE_OPT_NOARG, diff_opt_compact_summary),
5135                OPT_CALLBACK_F(0, "output-indicator-new",
5136                               &options->output_indicators[OUTPUT_INDICATOR_NEW],
5137                               N_("<char>"),
5138                               N_("specify the character to indicate a new line instead of '+'"),
5139                               PARSE_OPT_NONEG, diff_opt_char),
5140                OPT_CALLBACK_F(0, "output-indicator-old",
5141                               &options->output_indicators[OUTPUT_INDICATOR_OLD],
5142                               N_("<char>"),
5143                               N_("specify the character to indicate an old line instead of '-'"),
5144                               PARSE_OPT_NONEG, diff_opt_char),
5145                OPT_CALLBACK_F(0, "output-indicator-context",
5146                               &options->output_indicators[OUTPUT_INDICATOR_CONTEXT],
5147                               N_("<char>"),
5148                               N_("specify the character to indicate a context instead of ' '"),
5149                               PARSE_OPT_NONEG, diff_opt_char),
5150
5151                OPT_GROUP(N_("Diff rename options")),
5152                OPT_CALLBACK_F('B', "break-rewrites", &options->break_opt, N_("<n>[/<m>]"),
5153                               N_("break complete rewrite changes into pairs of delete and create"),
5154                               PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
5155                               diff_opt_break_rewrites),
5156                OPT_CALLBACK_F('M', "find-renames", options, N_("<n>"),
5157                               N_("detect renames"),
5158                               PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
5159                               diff_opt_find_renames),
5160                OPT_SET_INT_F('D', "irreversible-delete", &options->irreversible_delete,
5161                              N_("omit the preimage for deletes"),
5162                              1, PARSE_OPT_NONEG),
5163                OPT_CALLBACK_F('C', "find-copies", options, N_("<n>"),
5164                               N_("detect copies"),
5165                               PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
5166                               diff_opt_find_copies),
5167                OPT_BOOL(0, "find-copies-harder", &options->flags.find_copies_harder,
5168                         N_("use unmodified files as source to find copies")),
5169                OPT_SET_INT_F(0, "no-renames", &options->detect_rename,
5170                              N_("disable rename detection"),
5171                              0, PARSE_OPT_NONEG),
5172                OPT_BOOL(0, "rename-empty", &options->flags.rename_empty,
5173                         N_("use empty blobs as rename source")),
5174
5175                OPT_GROUP(N_("Diff algorithm options")),
5176                OPT_BIT(0, "minimal", &options->xdl_opts,
5177                        N_("produce the smallest possible diff"),
5178                        XDF_NEED_MINIMAL),
5179                OPT_BIT_F('w', "ignore-all-space", &options->xdl_opts,
5180                          N_("ignore whitespace when comparing lines"),
5181                          XDF_IGNORE_WHITESPACE, PARSE_OPT_NONEG),
5182                OPT_BIT_F('b', "ignore-space-change", &options->xdl_opts,
5183                          N_("ignore changes in amount of whitespace"),
5184                          XDF_IGNORE_WHITESPACE_CHANGE, PARSE_OPT_NONEG),
5185                OPT_BIT_F(0, "ignore-space-at-eol", &options->xdl_opts,
5186                          N_("ignore changes in whitespace at EOL"),
5187                          XDF_IGNORE_WHITESPACE_AT_EOL, PARSE_OPT_NONEG),
5188                OPT_BIT_F(0, "ignore-cr-at-eol", &options->xdl_opts,
5189                          N_("ignore carrier-return at the end of line"),
5190                          XDF_IGNORE_CR_AT_EOL, PARSE_OPT_NONEG),
5191                OPT_BIT_F(0, "ignore-blank-lines", &options->xdl_opts,
5192                          N_("ignore changes whose lines are all blank"),
5193                          XDF_IGNORE_BLANK_LINES, PARSE_OPT_NONEG),
5194
5195                OPT_GROUP(N_("Diff other options")),
5196                OPT_CALLBACK_F(0, "relative", options, N_("<prefix>"),
5197                               N_("when run from subdir, exclude changes outside and show relative paths"),
5198                               PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
5199                               diff_opt_relative),
5200                { OPTION_CALLBACK, 0, "output", options, N_("<file>"),
5201                  N_("Output to a specific file"),
5202                  PARSE_OPT_NONEG, NULL, 0, diff_opt_output },
5203
5204                OPT_END()
5205        };
5206
5207        ALLOC_ARRAY(options->parseopts, ARRAY_SIZE(parseopts));
5208        memcpy(options->parseopts, parseopts, sizeof(parseopts));
5209}
5210
5211int diff_opt_parse(struct diff_options *options,
5212                   const char **av, int ac, const char *prefix)
5213{
5214        const char *arg = av[0];
5215        const char *optarg;
5216        int argcount;
5217
5218        if (!prefix)
5219                prefix = "";
5220
5221        ac = parse_options(ac, av, prefix, options->parseopts, NULL,
5222                           PARSE_OPT_KEEP_DASHDASH |
5223                           PARSE_OPT_KEEP_UNKNOWN |
5224                           PARSE_OPT_NO_INTERNAL_HELP |
5225                           PARSE_OPT_ONE_SHOT |
5226                           PARSE_OPT_STOP_AT_NON_OPTION);
5227
5228        if (ac)
5229                return ac;
5230
5231        /* xdiff options */
5232        if (!strcmp(arg, "--indent-heuristic"))
5233                DIFF_XDL_SET(options, INDENT_HEURISTIC);
5234        else if (!strcmp(arg, "--no-indent-heuristic"))
5235                DIFF_XDL_CLR(options, INDENT_HEURISTIC);
5236        else if (!strcmp(arg, "--patience")) {
5237                int i;
5238                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
5239                /*
5240                 * Both --patience and --anchored use PATIENCE_DIFF
5241                 * internally, so remove any anchors previously
5242                 * specified.
5243                 */
5244                for (i = 0; i < options->anchors_nr; i++)
5245                        free(options->anchors[i]);
5246                options->anchors_nr = 0;
5247        } else if (!strcmp(arg, "--histogram"))
5248                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
5249        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
5250                long value = parse_algorithm_value(optarg);
5251                if (value < 0)
5252                        return error("option diff-algorithm accepts \"myers\", "
5253                                     "\"minimal\", \"patience\" and \"histogram\"");
5254                /* clear out previous settings */
5255                DIFF_XDL_CLR(options, NEED_MINIMAL);
5256                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
5257                options->xdl_opts |= value;
5258                return argcount;
5259        } else if (skip_prefix(arg, "--anchored=", &arg)) {
5260                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
5261                ALLOC_GROW(options->anchors, options->anchors_nr + 1,
5262                           options->anchors_alloc);
5263                options->anchors[options->anchors_nr++] = xstrdup(arg);
5264        }
5265
5266        /* flags options */
5267        else if (!strcmp(arg, "--binary")) {
5268                enable_patch_output(&options->output_format);
5269                options->flags.binary = 1;
5270        }
5271        else if (!strcmp(arg, "--full-index"))
5272                options->flags.full_index = 1;
5273        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
5274                options->flags.text = 1;
5275        else if (!strcmp(arg, "-R"))
5276                options->flags.reverse_diff = 1;
5277        else if (!strcmp(arg, "--follow"))
5278                options->flags.follow_renames = 1;
5279        else if (!strcmp(arg, "--no-follow")) {
5280                options->flags.follow_renames = 0;
5281                options->flags.default_follow_renames = 0;
5282        } else if (skip_to_optional_arg_default(arg, "--color", &arg, "always")) {
5283                int value = git_config_colorbool(NULL, arg);
5284                if (value < 0)
5285                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
5286                options->use_color = value;
5287        }
5288        else if (!strcmp(arg, "--no-color"))
5289                options->use_color = 0;
5290        else if (!strcmp(arg, "--color-moved")) {
5291                if (diff_color_moved_default)
5292                        options->color_moved = diff_color_moved_default;
5293                if (options->color_moved == COLOR_MOVED_NO)
5294                        options->color_moved = COLOR_MOVED_DEFAULT;
5295        } else if (!strcmp(arg, "--no-color-moved"))
5296                options->color_moved = COLOR_MOVED_NO;
5297        else if (skip_prefix(arg, "--color-moved=", &arg)) {
5298                int cm = parse_color_moved(arg);
5299                if (cm < 0)
5300                        return error("bad --color-moved argument: %s", arg);
5301                options->color_moved = cm;
5302        } else if (!strcmp(arg, "--no-color-moved-ws")) {
5303                options->color_moved_ws_handling = 0;
5304        } else if (skip_prefix(arg, "--color-moved-ws=", &arg)) {
5305                unsigned cm = parse_color_moved_ws(arg);
5306                if (cm & COLOR_MOVED_WS_ERROR)
5307                        return -1;
5308                options->color_moved_ws_handling = cm;
5309        } else if (skip_to_optional_arg_default(arg, "--color-words", &options->word_regex, NULL)) {
5310                options->use_color = 1;
5311                options->word_diff = DIFF_WORDS_COLOR;
5312        }
5313        else if (!strcmp(arg, "--word-diff")) {
5314                if (options->word_diff == DIFF_WORDS_NONE)
5315                        options->word_diff = DIFF_WORDS_PLAIN;
5316        }
5317        else if (skip_prefix(arg, "--word-diff=", &arg)) {
5318                if (!strcmp(arg, "plain"))
5319                        options->word_diff = DIFF_WORDS_PLAIN;
5320                else if (!strcmp(arg, "color")) {
5321                        options->use_color = 1;
5322                        options->word_diff = DIFF_WORDS_COLOR;
5323                }
5324                else if (!strcmp(arg, "porcelain"))
5325                        options->word_diff = DIFF_WORDS_PORCELAIN;
5326                else if (!strcmp(arg, "none"))
5327                        options->word_diff = DIFF_WORDS_NONE;
5328                else
5329                        die("bad --word-diff argument: %s", arg);
5330        }
5331        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
5332                if (options->word_diff == DIFF_WORDS_NONE)
5333                        options->word_diff = DIFF_WORDS_PLAIN;
5334                options->word_regex = optarg;
5335                return argcount;
5336        }
5337        else if (!strcmp(arg, "--exit-code"))
5338                options->flags.exit_with_status = 1;
5339        else if (!strcmp(arg, "--quiet"))
5340                options->flags.quick = 1;
5341        else if (!strcmp(arg, "--ext-diff"))
5342                options->flags.allow_external = 1;
5343        else if (!strcmp(arg, "--no-ext-diff"))
5344                options->flags.allow_external = 0;
5345        else if (!strcmp(arg, "--textconv")) {
5346                options->flags.allow_textconv = 1;
5347                options->flags.textconv_set_via_cmdline = 1;
5348        } else if (!strcmp(arg, "--no-textconv"))
5349                options->flags.allow_textconv = 0;
5350        else if (skip_to_optional_arg_default(arg, "--ignore-submodules", &arg, "all")) {
5351                options->flags.override_submodule_config = 1;
5352                handle_ignore_submodules_arg(options, arg);
5353        } else if (skip_to_optional_arg_default(arg, "--submodule", &arg, "log"))
5354                return parse_submodule_opt(options, arg);
5355        else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
5356                return parse_ws_error_highlight_opt(options, arg);
5357        else if (!strcmp(arg, "--ita-invisible-in-index"))
5358                options->ita_invisible_in_index = 1;
5359        else if (!strcmp(arg, "--ita-visible-in-index"))
5360                options->ita_invisible_in_index = 0;
5361
5362        /* misc options */
5363        else if (!strcmp(arg, "-z"))
5364                options->line_termination = 0;
5365        else if ((argcount = short_opt('l', av, &optarg))) {
5366                options->rename_limit = strtoul(optarg, NULL, 10);
5367                return argcount;
5368        }
5369        else if ((argcount = short_opt('S', av, &optarg))) {
5370                options->pickaxe = optarg;
5371                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
5372                return argcount;
5373        } else if ((argcount = short_opt('G', av, &optarg))) {
5374                options->pickaxe = optarg;
5375                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
5376                return argcount;
5377        }
5378        else if (!strcmp(arg, "--pickaxe-all"))
5379                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
5380        else if (!strcmp(arg, "--pickaxe-regex"))
5381                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
5382        else if ((argcount = short_opt('O', av, &optarg))) {
5383                options->orderfile = prefix_filename(prefix, optarg);
5384                return argcount;
5385        } else if (skip_prefix(arg, "--find-object=", &arg))
5386                return parse_objfind_opt(options, arg);
5387        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
5388                int offending = parse_diff_filter_opt(optarg, options);
5389                if (offending)
5390                        die("unknown change class '%c' in --diff-filter=%s",
5391                            offending, optarg);
5392                return argcount;
5393        }
5394        else if (!strcmp(arg, "--no-abbrev"))
5395                options->abbrev = 0;
5396        else if (!strcmp(arg, "--abbrev"))
5397                options->abbrev = DEFAULT_ABBREV;
5398        else if (skip_prefix(arg, "--abbrev=", &arg)) {
5399                options->abbrev = strtoul(arg, NULL, 10);
5400                if (options->abbrev < MINIMUM_ABBREV)
5401                        options->abbrev = MINIMUM_ABBREV;
5402                else if (the_hash_algo->hexsz < options->abbrev)
5403                        options->abbrev = the_hash_algo->hexsz;
5404        }
5405        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
5406                options->a_prefix = optarg;
5407                return argcount;
5408        }
5409        else if ((argcount = parse_long_opt("line-prefix", av, &optarg))) {
5410                options->line_prefix = optarg;
5411                options->line_prefix_length = strlen(options->line_prefix);
5412                graph_setup_line_prefix(options);
5413                return argcount;
5414        }
5415        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
5416                options->b_prefix = optarg;
5417                return argcount;
5418        }
5419        else if (!strcmp(arg, "--no-prefix"))
5420                options->a_prefix = options->b_prefix = "";
5421        else if (opt_arg(arg, '\0', "inter-hunk-context",
5422                         &options->interhunkcontext))
5423                ;
5424        else
5425                return 0;
5426        return 1;
5427}
5428
5429int parse_rename_score(const char **cp_p)
5430{
5431        unsigned long num, scale;
5432        int ch, dot;
5433        const char *cp = *cp_p;
5434
5435        num = 0;
5436        scale = 1;
5437        dot = 0;
5438        for (;;) {
5439                ch = *cp;
5440                if ( !dot && ch == '.' ) {
5441                        scale = 1;
5442                        dot = 1;
5443                } else if ( ch == '%' ) {
5444                        scale = dot ? scale*100 : 100;
5445                        cp++;   /* % is always at the end */
5446                        break;
5447                } else if ( ch >= '0' && ch <= '9' ) {
5448                        if ( scale < 100000 ) {
5449                                scale *= 10;
5450                                num = (num*10) + (ch-'0');
5451                        }
5452                } else {
5453                        break;
5454                }
5455                cp++;
5456        }
5457        *cp_p = cp;
5458
5459        /* user says num divided by scale and we say internally that
5460         * is MAX_SCORE * num / scale.
5461         */
5462        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
5463}
5464
5465struct diff_queue_struct diff_queued_diff;
5466
5467void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
5468{
5469        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
5470        queue->queue[queue->nr++] = dp;
5471}
5472
5473struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
5474                                 struct diff_filespec *one,
5475                                 struct diff_filespec *two)
5476{
5477        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
5478        dp->one = one;
5479        dp->two = two;
5480        if (queue)
5481                diff_q(queue, dp);
5482        return dp;
5483}
5484
5485void diff_free_filepair(struct diff_filepair *p)
5486{
5487        free_filespec(p->one);
5488        free_filespec(p->two);
5489        free(p);
5490}
5491
5492const char *diff_aligned_abbrev(const struct object_id *oid, int len)
5493{
5494        int abblen;
5495        const char *abbrev;
5496
5497        /* Do we want all 40 hex characters? */
5498        if (len == the_hash_algo->hexsz)
5499                return oid_to_hex(oid);
5500
5501        /* An abbreviated value is fine, possibly followed by an ellipsis. */
5502        abbrev = diff_abbrev_oid(oid, len);
5503
5504        if (!print_sha1_ellipsis())
5505                return abbrev;
5506
5507        abblen = strlen(abbrev);
5508
5509        /*
5510         * In well-behaved cases, where the abbreviated result is the
5511         * same as the requested length, append three dots after the
5512         * abbreviation (hence the whole logic is limited to the case
5513         * where abblen < 37); when the actual abbreviated result is a
5514         * bit longer than the requested length, we reduce the number
5515         * of dots so that they match the well-behaved ones.  However,
5516         * if the actual abbreviation is longer than the requested
5517         * length by more than three, we give up on aligning, and add
5518         * three dots anyway, to indicate that the output is not the
5519         * full object name.  Yes, this may be suboptimal, but this
5520         * appears only in "diff --raw --abbrev" output and it is not
5521         * worth the effort to change it now.  Note that this would
5522         * likely to work fine when the automatic sizing of default
5523         * abbreviation length is used--we would be fed -1 in "len" in
5524         * that case, and will end up always appending three-dots, but
5525         * the automatic sizing is supposed to give abblen that ensures
5526         * uniqueness across all objects (statistically speaking).
5527         */
5528        if (abblen < the_hash_algo->hexsz - 3) {
5529                static char hex[GIT_MAX_HEXSZ + 1];
5530                if (len < abblen && abblen <= len + 2)
5531                        xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
5532                else
5533                        xsnprintf(hex, sizeof(hex), "%s...", abbrev);
5534                return hex;
5535        }
5536
5537        return oid_to_hex(oid);
5538}
5539
5540static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
5541{
5542        int line_termination = opt->line_termination;
5543        int inter_name_termination = line_termination ? '\t' : '\0';
5544
5545        fprintf(opt->file, "%s", diff_line_prefix(opt));
5546        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
5547                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
5548                        diff_aligned_abbrev(&p->one->oid, opt->abbrev));
5549                fprintf(opt->file, "%s ",
5550                        diff_aligned_abbrev(&p->two->oid, opt->abbrev));
5551        }
5552        if (p->score) {
5553                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
5554                        inter_name_termination);
5555        } else {
5556                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
5557        }
5558
5559        if (p->status == DIFF_STATUS_COPIED ||
5560            p->status == DIFF_STATUS_RENAMED) {
5561                const char *name_a, *name_b;
5562                name_a = p->one->path;
5563                name_b = p->two->path;
5564                strip_prefix(opt->prefix_length, &name_a, &name_b);
5565                write_name_quoted(name_a, opt->file, inter_name_termination);
5566                write_name_quoted(name_b, opt->file, line_termination);
5567        } else {
5568                const char *name_a, *name_b;
5569                name_a = p->one->mode ? p->one->path : p->two->path;
5570                name_b = NULL;
5571                strip_prefix(opt->prefix_length, &name_a, &name_b);
5572                write_name_quoted(name_a, opt->file, line_termination);
5573        }
5574}
5575
5576int diff_unmodified_pair(struct diff_filepair *p)
5577{
5578        /* This function is written stricter than necessary to support
5579         * the currently implemented transformers, but the idea is to
5580         * let transformers to produce diff_filepairs any way they want,
5581         * and filter and clean them up here before producing the output.
5582         */
5583        struct diff_filespec *one = p->one, *two = p->two;
5584
5585        if (DIFF_PAIR_UNMERGED(p))
5586                return 0; /* unmerged is interesting */
5587
5588        /* deletion, addition, mode or type change
5589         * and rename are all interesting.
5590         */
5591        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
5592            DIFF_PAIR_MODE_CHANGED(p) ||
5593            strcmp(one->path, two->path))
5594                return 0;
5595
5596        /* both are valid and point at the same path.  that is, we are
5597         * dealing with a change.
5598         */
5599        if (one->oid_valid && two->oid_valid &&
5600            oideq(&one->oid, &two->oid) &&
5601            !one->dirty_submodule && !two->dirty_submodule)
5602                return 1; /* no change */
5603        if (!one->oid_valid && !two->oid_valid)
5604                return 1; /* both look at the same file on the filesystem. */
5605        return 0;
5606}
5607
5608static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
5609{
5610        if (diff_unmodified_pair(p))
5611                return;
5612
5613        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5614            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5615                return; /* no tree diffs in patch format */
5616
5617        run_diff(p, o);
5618}
5619
5620static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
5621                            struct diffstat_t *diffstat)
5622{
5623        if (diff_unmodified_pair(p))
5624                return;
5625
5626        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5627            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5628                return; /* no useful stat for tree diffs */
5629
5630        run_diffstat(p, o, diffstat);
5631}
5632
5633static void diff_flush_checkdiff(struct diff_filepair *p,
5634                struct diff_options *o)
5635{
5636        if (diff_unmodified_pair(p))
5637                return;
5638
5639        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5640            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5641                return; /* nothing to check in tree diffs */
5642
5643        run_checkdiff(p, o);
5644}
5645
5646int diff_queue_is_empty(void)
5647{
5648        struct diff_queue_struct *q = &diff_queued_diff;
5649        int i;
5650        for (i = 0; i < q->nr; i++)
5651                if (!diff_unmodified_pair(q->queue[i]))
5652                        return 0;
5653        return 1;
5654}
5655
5656#if DIFF_DEBUG
5657void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
5658{
5659        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
5660                x, one ? one : "",
5661                s->path,
5662                DIFF_FILE_VALID(s) ? "valid" : "invalid",
5663                s->mode,
5664                s->oid_valid ? oid_to_hex(&s->oid) : "");
5665        fprintf(stderr, "queue[%d] %s size %lu\n",
5666                x, one ? one : "",
5667                s->size);
5668}
5669
5670void diff_debug_filepair(const struct diff_filepair *p, int i)
5671{
5672        diff_debug_filespec(p->one, i, "one");
5673        diff_debug_filespec(p->two, i, "two");
5674        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
5675                p->score, p->status ? p->status : '?',
5676                p->one->rename_used, p->broken_pair);
5677}
5678
5679void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
5680{
5681        int i;
5682        if (msg)
5683                fprintf(stderr, "%s\n", msg);
5684        fprintf(stderr, "q->nr = %d\n", q->nr);
5685        for (i = 0; i < q->nr; i++) {
5686                struct diff_filepair *p = q->queue[i];
5687                diff_debug_filepair(p, i);
5688        }
5689}
5690#endif
5691
5692static void diff_resolve_rename_copy(void)
5693{
5694        int i;
5695        struct diff_filepair *p;
5696        struct diff_queue_struct *q = &diff_queued_diff;
5697
5698        diff_debug_queue("resolve-rename-copy", q);
5699
5700        for (i = 0; i < q->nr; i++) {
5701                p = q->queue[i];
5702                p->status = 0; /* undecided */
5703                if (DIFF_PAIR_UNMERGED(p))
5704                        p->status = DIFF_STATUS_UNMERGED;
5705                else if (!DIFF_FILE_VALID(p->one))
5706                        p->status = DIFF_STATUS_ADDED;
5707                else if (!DIFF_FILE_VALID(p->two))
5708                        p->status = DIFF_STATUS_DELETED;
5709                else if (DIFF_PAIR_TYPE_CHANGED(p))
5710                        p->status = DIFF_STATUS_TYPE_CHANGED;
5711
5712                /* from this point on, we are dealing with a pair
5713                 * whose both sides are valid and of the same type, i.e.
5714                 * either in-place edit or rename/copy edit.
5715                 */
5716                else if (DIFF_PAIR_RENAME(p)) {
5717                        /*
5718                         * A rename might have re-connected a broken
5719                         * pair up, causing the pathnames to be the
5720                         * same again. If so, that's not a rename at
5721                         * all, just a modification..
5722                         *
5723                         * Otherwise, see if this source was used for
5724                         * multiple renames, in which case we decrement
5725                         * the count, and call it a copy.
5726                         */
5727                        if (!strcmp(p->one->path, p->two->path))
5728                                p->status = DIFF_STATUS_MODIFIED;
5729                        else if (--p->one->rename_used > 0)
5730                                p->status = DIFF_STATUS_COPIED;
5731                        else
5732                                p->status = DIFF_STATUS_RENAMED;
5733                }
5734                else if (!oideq(&p->one->oid, &p->two->oid) ||
5735                         p->one->mode != p->two->mode ||
5736                         p->one->dirty_submodule ||
5737                         p->two->dirty_submodule ||
5738                         is_null_oid(&p->one->oid))
5739                        p->status = DIFF_STATUS_MODIFIED;
5740                else {
5741                        /* This is a "no-change" entry and should not
5742                         * happen anymore, but prepare for broken callers.
5743                         */
5744                        error("feeding unmodified %s to diffcore",
5745                              p->one->path);
5746                        p->status = DIFF_STATUS_UNKNOWN;
5747                }
5748        }
5749        diff_debug_queue("resolve-rename-copy done", q);
5750}
5751
5752static int check_pair_status(struct diff_filepair *p)
5753{
5754        switch (p->status) {
5755        case DIFF_STATUS_UNKNOWN:
5756                return 0;
5757        case 0:
5758                die("internal error in diff-resolve-rename-copy");
5759        default:
5760                return 1;
5761        }
5762}
5763
5764static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
5765{
5766        int fmt = opt->output_format;
5767
5768        if (fmt & DIFF_FORMAT_CHECKDIFF)
5769                diff_flush_checkdiff(p, opt);
5770        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
5771                diff_flush_raw(p, opt);
5772        else if (fmt & DIFF_FORMAT_NAME) {
5773                const char *name_a, *name_b;
5774                name_a = p->two->path;
5775                name_b = NULL;
5776                strip_prefix(opt->prefix_length, &name_a, &name_b);
5777                fprintf(opt->file, "%s", diff_line_prefix(opt));
5778                write_name_quoted(name_a, opt->file, opt->line_termination);
5779        }
5780}
5781
5782static void show_file_mode_name(struct diff_options *opt, const char *newdelete, struct diff_filespec *fs)
5783{
5784        struct strbuf sb = STRBUF_INIT;
5785        if (fs->mode)
5786                strbuf_addf(&sb, " %s mode %06o ", newdelete, fs->mode);
5787        else
5788                strbuf_addf(&sb, " %s ", newdelete);
5789
5790        quote_c_style(fs->path, &sb, NULL, 0);
5791        strbuf_addch(&sb, '\n');
5792        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5793                         sb.buf, sb.len, 0);
5794        strbuf_release(&sb);
5795}
5796
5797static void show_mode_change(struct diff_options *opt, struct diff_filepair *p,
5798                int show_name)
5799{
5800        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
5801                struct strbuf sb = STRBUF_INIT;
5802                strbuf_addf(&sb, " mode change %06o => %06o",
5803                            p->one->mode, p->two->mode);
5804                if (show_name) {
5805                        strbuf_addch(&sb, ' ');
5806                        quote_c_style(p->two->path, &sb, NULL, 0);
5807                }
5808                strbuf_addch(&sb, '\n');
5809                emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5810                                 sb.buf, sb.len, 0);
5811                strbuf_release(&sb);
5812        }
5813}
5814
5815static void show_rename_copy(struct diff_options *opt, const char *renamecopy,
5816                struct diff_filepair *p)
5817{
5818        struct strbuf sb = STRBUF_INIT;
5819        struct strbuf names = STRBUF_INIT;
5820
5821        pprint_rename(&names, p->one->path, p->two->path);
5822        strbuf_addf(&sb, " %s %s (%d%%)\n",
5823                    renamecopy, names.buf, similarity_index(p));
5824        strbuf_release(&names);
5825        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5826                                 sb.buf, sb.len, 0);
5827        show_mode_change(opt, p, 0);
5828        strbuf_release(&sb);
5829}
5830
5831static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
5832{
5833        switch(p->status) {
5834        case DIFF_STATUS_DELETED:
5835                show_file_mode_name(opt, "delete", p->one);
5836                break;
5837        case DIFF_STATUS_ADDED:
5838                show_file_mode_name(opt, "create", p->two);
5839                break;
5840        case DIFF_STATUS_COPIED:
5841                show_rename_copy(opt, "copy", p);
5842                break;
5843        case DIFF_STATUS_RENAMED:
5844                show_rename_copy(opt, "rename", p);
5845                break;
5846        default:
5847                if (p->score) {
5848                        struct strbuf sb = STRBUF_INIT;
5849                        strbuf_addstr(&sb, " rewrite ");
5850                        quote_c_style(p->two->path, &sb, NULL, 0);
5851                        strbuf_addf(&sb, " (%d%%)\n", similarity_index(p));
5852                        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5853                                         sb.buf, sb.len, 0);
5854                        strbuf_release(&sb);
5855                }
5856                show_mode_change(opt, p, !p->score);
5857                break;
5858        }
5859}
5860
5861struct patch_id_t {
5862        git_SHA_CTX *ctx;
5863        int patchlen;
5864};
5865
5866static int remove_space(char *line, int len)
5867{
5868        int i;
5869        char *dst = line;
5870        unsigned char c;
5871
5872        for (i = 0; i < len; i++)
5873                if (!isspace((c = line[i])))
5874                        *dst++ = c;
5875
5876        return dst - line;
5877}
5878
5879static void patch_id_consume(void *priv, char *line, unsigned long len)
5880{
5881        struct patch_id_t *data = priv;
5882        int new_len;
5883
5884        new_len = remove_space(line, len);
5885
5886        git_SHA1_Update(data->ctx, line, new_len);
5887        data->patchlen += new_len;
5888}
5889
5890static void patch_id_add_string(git_SHA_CTX *ctx, const char *str)
5891{
5892        git_SHA1_Update(ctx, str, strlen(str));
5893}
5894
5895static void patch_id_add_mode(git_SHA_CTX *ctx, unsigned mode)
5896{
5897        /* large enough for 2^32 in octal */
5898        char buf[12];
5899        int len = xsnprintf(buf, sizeof(buf), "%06o", mode);
5900        git_SHA1_Update(ctx, buf, len);
5901}
5902
5903/* returns 0 upon success, and writes result into sha1 */
5904static int diff_get_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5905{
5906        struct diff_queue_struct *q = &diff_queued_diff;
5907        int i;
5908        git_SHA_CTX ctx;
5909        struct patch_id_t data;
5910
5911        git_SHA1_Init(&ctx);
5912        memset(&data, 0, sizeof(struct patch_id_t));
5913        data.ctx = &ctx;
5914
5915        for (i = 0; i < q->nr; i++) {
5916                xpparam_t xpp;
5917                xdemitconf_t xecfg;
5918                mmfile_t mf1, mf2;
5919                struct diff_filepair *p = q->queue[i];
5920                int len1, len2;
5921
5922                memset(&xpp, 0, sizeof(xpp));
5923                memset(&xecfg, 0, sizeof(xecfg));
5924                if (p->status == 0)
5925                        return error("internal diff status error");
5926                if (p->status == DIFF_STATUS_UNKNOWN)
5927                        continue;
5928                if (diff_unmodified_pair(p))
5929                        continue;
5930                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5931                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5932                        continue;
5933                if (DIFF_PAIR_UNMERGED(p))
5934                        continue;
5935
5936                diff_fill_oid_info(p->one, options->repo->index);
5937                diff_fill_oid_info(p->two, options->repo->index);
5938
5939                len1 = remove_space(p->one->path, strlen(p->one->path));
5940                len2 = remove_space(p->two->path, strlen(p->two->path));
5941                patch_id_add_string(&ctx, "diff--git");
5942                patch_id_add_string(&ctx, "a/");
5943                git_SHA1_Update(&ctx, p->one->path, len1);
5944                patch_id_add_string(&ctx, "b/");
5945                git_SHA1_Update(&ctx, p->two->path, len2);
5946
5947                if (p->one->mode == 0) {
5948                        patch_id_add_string(&ctx, "newfilemode");
5949                        patch_id_add_mode(&ctx, p->two->mode);
5950                        patch_id_add_string(&ctx, "---/dev/null");
5951                        patch_id_add_string(&ctx, "+++b/");
5952                        git_SHA1_Update(&ctx, p->two->path, len2);
5953                } else if (p->two->mode == 0) {
5954                        patch_id_add_string(&ctx, "deletedfilemode");
5955                        patch_id_add_mode(&ctx, p->one->mode);
5956                        patch_id_add_string(&ctx, "---a/");
5957                        git_SHA1_Update(&ctx, p->one->path, len1);
5958                        patch_id_add_string(&ctx, "+++/dev/null");
5959                } else {
5960                        patch_id_add_string(&ctx, "---a/");
5961                        git_SHA1_Update(&ctx, p->one->path, len1);
5962                        patch_id_add_string(&ctx, "+++b/");
5963                        git_SHA1_Update(&ctx, p->two->path, len2);
5964                }
5965
5966                if (diff_header_only)
5967                        continue;
5968
5969                if (fill_mmfile(options->repo, &mf1, p->one) < 0 ||
5970                    fill_mmfile(options->repo, &mf2, p->two) < 0)
5971                        return error("unable to read files to diff");
5972
5973                if (diff_filespec_is_binary(options->repo, p->one) ||
5974                    diff_filespec_is_binary(options->repo, p->two)) {
5975                        git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
5976                                        GIT_SHA1_HEXSZ);
5977                        git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
5978                                        GIT_SHA1_HEXSZ);
5979                        continue;
5980                }
5981
5982                xpp.flags = 0;
5983                xecfg.ctxlen = 3;
5984                xecfg.flags = 0;
5985                if (xdi_diff_outf(&mf1, &mf2, discard_hunk_line,
5986                                  patch_id_consume, &data, &xpp, &xecfg))
5987                        return error("unable to generate patch-id diff for %s",
5988                                     p->one->path);
5989        }
5990
5991        git_SHA1_Final(oid->hash, &ctx);
5992        return 0;
5993}
5994
5995int diff_flush_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5996{
5997        struct diff_queue_struct *q = &diff_queued_diff;
5998        int i;
5999        int result = diff_get_patch_id(options, oid, diff_header_only);
6000
6001        for (i = 0; i < q->nr; i++)
6002                diff_free_filepair(q->queue[i]);
6003
6004        free(q->queue);
6005        DIFF_QUEUE_CLEAR(q);
6006
6007        return result;
6008}
6009
6010static int is_summary_empty(const struct diff_queue_struct *q)
6011{
6012        int i;
6013
6014        for (i = 0; i < q->nr; i++) {
6015                const struct diff_filepair *p = q->queue[i];
6016
6017                switch (p->status) {
6018                case DIFF_STATUS_DELETED:
6019                case DIFF_STATUS_ADDED:
6020                case DIFF_STATUS_COPIED:
6021                case DIFF_STATUS_RENAMED:
6022                        return 0;
6023                default:
6024                        if (p->score)
6025                                return 0;
6026                        if (p->one->mode && p->two->mode &&
6027                            p->one->mode != p->two->mode)
6028                                return 0;
6029                        break;
6030                }
6031        }
6032        return 1;
6033}
6034
6035static const char rename_limit_warning[] =
6036N_("inexact rename detection was skipped due to too many files.");
6037
6038static const char degrade_cc_to_c_warning[] =
6039N_("only found copies from modified paths due to too many files.");
6040
6041static const char rename_limit_advice[] =
6042N_("you may want to set your %s variable to at least "
6043   "%d and retry the command.");
6044
6045void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
6046{
6047        fflush(stdout);
6048        if (degraded_cc)
6049                warning(_(degrade_cc_to_c_warning));
6050        else if (needed)
6051                warning(_(rename_limit_warning));
6052        else
6053                return;
6054        if (0 < needed)
6055                warning(_(rename_limit_advice), varname, needed);
6056}
6057
6058static void diff_flush_patch_all_file_pairs(struct diff_options *o)
6059{
6060        int i;
6061        static struct emitted_diff_symbols esm = EMITTED_DIFF_SYMBOLS_INIT;
6062        struct diff_queue_struct *q = &diff_queued_diff;
6063
6064        if (WSEH_NEW & WS_RULE_MASK)
6065                BUG("WS rules bit mask overlaps with diff symbol flags");
6066
6067        if (o->color_moved)
6068                o->emitted_symbols = &esm;
6069
6070        for (i = 0; i < q->nr; i++) {
6071                struct diff_filepair *p = q->queue[i];
6072                if (check_pair_status(p))
6073                        diff_flush_patch(p, o);
6074        }
6075
6076        if (o->emitted_symbols) {
6077                if (o->color_moved) {
6078                        struct hashmap add_lines, del_lines;
6079
6080                        if (o->color_moved_ws_handling &
6081                            COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
6082                                o->color_moved_ws_handling |= XDF_IGNORE_WHITESPACE;
6083
6084                        hashmap_init(&del_lines, moved_entry_cmp, o, 0);
6085                        hashmap_init(&add_lines, moved_entry_cmp, o, 0);
6086
6087                        add_lines_to_move_detection(o, &add_lines, &del_lines);
6088                        mark_color_as_moved(o, &add_lines, &del_lines);
6089                        if (o->color_moved == COLOR_MOVED_ZEBRA_DIM)
6090                                dim_moved_lines(o);
6091
6092                        hashmap_free(&add_lines, 1);
6093                        hashmap_free(&del_lines, 1);
6094                }
6095
6096                for (i = 0; i < esm.nr; i++)
6097                        emit_diff_symbol_from_struct(o, &esm.buf[i]);
6098
6099                for (i = 0; i < esm.nr; i++)
6100                        free((void *)esm.buf[i].line);
6101                esm.nr = 0;
6102
6103                o->emitted_symbols = NULL;
6104        }
6105}
6106
6107void diff_flush(struct diff_options *options)
6108{
6109        struct diff_queue_struct *q = &diff_queued_diff;
6110        int i, output_format = options->output_format;
6111        int separator = 0;
6112        int dirstat_by_line = 0;
6113
6114        /*
6115         * Order: raw, stat, summary, patch
6116         * or:    name/name-status/checkdiff (other bits clear)
6117         */
6118        if (!q->nr)
6119                goto free_queue;
6120
6121        if (output_format & (DIFF_FORMAT_RAW |
6122                             DIFF_FORMAT_NAME |
6123                             DIFF_FORMAT_NAME_STATUS |
6124                             DIFF_FORMAT_CHECKDIFF)) {
6125                for (i = 0; i < q->nr; i++) {
6126                        struct diff_filepair *p = q->queue[i];
6127                        if (check_pair_status(p))
6128                                flush_one_pair(p, options);
6129                }
6130                separator++;
6131        }
6132
6133        if (output_format & DIFF_FORMAT_DIRSTAT && options->flags.dirstat_by_line)
6134                dirstat_by_line = 1;
6135
6136        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
6137            dirstat_by_line) {
6138                struct diffstat_t diffstat;
6139
6140                memset(&diffstat, 0, sizeof(struct diffstat_t));
6141                for (i = 0; i < q->nr; i++) {
6142                        struct diff_filepair *p = q->queue[i];
6143                        if (check_pair_status(p))
6144                                diff_flush_stat(p, options, &diffstat);
6145                }
6146                if (output_format & DIFF_FORMAT_NUMSTAT)
6147                        show_numstat(&diffstat, options);
6148                if (output_format & DIFF_FORMAT_DIFFSTAT)
6149                        show_stats(&diffstat, options);
6150                if (output_format & DIFF_FORMAT_SHORTSTAT)
6151                        show_shortstats(&diffstat, options);
6152                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
6153                        show_dirstat_by_line(&diffstat, options);
6154                free_diffstat_info(&diffstat);
6155                separator++;
6156        }
6157        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
6158                show_dirstat(options);
6159
6160        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
6161                for (i = 0; i < q->nr; i++) {
6162                        diff_summary(options, q->queue[i]);
6163                }
6164                separator++;
6165        }
6166
6167        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
6168            options->flags.exit_with_status &&
6169            options->flags.diff_from_contents) {
6170                /*
6171                 * run diff_flush_patch for the exit status. setting
6172                 * options->file to /dev/null should be safe, because we
6173                 * aren't supposed to produce any output anyway.
6174                 */
6175                if (options->close_file)
6176                        fclose(options->file);
6177                options->file = xfopen("/dev/null", "w");
6178                options->close_file = 1;
6179                options->color_moved = 0;
6180                for (i = 0; i < q->nr; i++) {
6181                        struct diff_filepair *p = q->queue[i];
6182                        if (check_pair_status(p))
6183                                diff_flush_patch(p, options);
6184                        if (options->found_changes)
6185                                break;
6186                }
6187        }
6188
6189        if (output_format & DIFF_FORMAT_PATCH) {
6190                if (separator) {
6191                        emit_diff_symbol(options, DIFF_SYMBOL_SEPARATOR, NULL, 0, 0);
6192                        if (options->stat_sep)
6193                                /* attach patch instead of inline */
6194                                emit_diff_symbol(options, DIFF_SYMBOL_STAT_SEP,
6195                                                 NULL, 0, 0);
6196                }
6197
6198                diff_flush_patch_all_file_pairs(options);
6199        }
6200
6201        if (output_format & DIFF_FORMAT_CALLBACK)
6202                options->format_callback(q, options, options->format_callback_data);
6203
6204        for (i = 0; i < q->nr; i++)
6205                diff_free_filepair(q->queue[i]);
6206free_queue:
6207        free(q->queue);
6208        DIFF_QUEUE_CLEAR(q);
6209        if (options->close_file)
6210                fclose(options->file);
6211
6212        /*
6213         * Report the content-level differences with HAS_CHANGES;
6214         * diff_addremove/diff_change does not set the bit when
6215         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
6216         */
6217        if (options->flags.diff_from_contents) {
6218                if (options->found_changes)
6219                        options->flags.has_changes = 1;
6220                else
6221                        options->flags.has_changes = 0;
6222        }
6223}
6224
6225static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
6226{
6227        return (((p->status == DIFF_STATUS_MODIFIED) &&
6228                 ((p->score &&
6229                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
6230                  (!p->score &&
6231                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
6232                ((p->status != DIFF_STATUS_MODIFIED) &&
6233                 filter_bit_tst(p->status, options)));
6234}
6235
6236static void diffcore_apply_filter(struct diff_options *options)
6237{
6238        int i;
6239        struct diff_queue_struct *q = &diff_queued_diff;
6240        struct diff_queue_struct outq;
6241
6242        DIFF_QUEUE_CLEAR(&outq);
6243
6244        if (!options->filter)
6245                return;
6246
6247        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
6248                int found;
6249                for (i = found = 0; !found && i < q->nr; i++) {
6250                        if (match_filter(options, q->queue[i]))
6251                                found++;
6252                }
6253                if (found)
6254                        return;
6255
6256                /* otherwise we will clear the whole queue
6257                 * by copying the empty outq at the end of this
6258                 * function, but first clear the current entries
6259                 * in the queue.
6260                 */
6261                for (i = 0; i < q->nr; i++)
6262                        diff_free_filepair(q->queue[i]);
6263        }
6264        else {
6265                /* Only the matching ones */
6266                for (i = 0; i < q->nr; i++) {
6267                        struct diff_filepair *p = q->queue[i];
6268                        if (match_filter(options, p))
6269                                diff_q(&outq, p);
6270                        else
6271                                diff_free_filepair(p);
6272                }
6273        }
6274        free(q->queue);
6275        *q = outq;
6276}
6277
6278/* Check whether two filespecs with the same mode and size are identical */
6279static int diff_filespec_is_identical(struct repository *r,
6280                                      struct diff_filespec *one,
6281                                      struct diff_filespec *two)
6282{
6283        if (S_ISGITLINK(one->mode))
6284                return 0;
6285        if (diff_populate_filespec(r, one, 0))
6286                return 0;
6287        if (diff_populate_filespec(r, two, 0))
6288                return 0;
6289        return !memcmp(one->data, two->data, one->size);
6290}
6291
6292static int diff_filespec_check_stat_unmatch(struct repository *r,
6293                                            struct diff_filepair *p)
6294{
6295        if (p->done_skip_stat_unmatch)
6296                return p->skip_stat_unmatch_result;
6297
6298        p->done_skip_stat_unmatch = 1;
6299        p->skip_stat_unmatch_result = 0;
6300        /*
6301         * 1. Entries that come from stat info dirtiness
6302         *    always have both sides (iow, not create/delete),
6303         *    one side of the object name is unknown, with
6304         *    the same mode and size.  Keep the ones that
6305         *    do not match these criteria.  They have real
6306         *    differences.
6307         *
6308         * 2. At this point, the file is known to be modified,
6309         *    with the same mode and size, and the object
6310         *    name of one side is unknown.  Need to inspect
6311         *    the identical contents.
6312         */
6313        if (!DIFF_FILE_VALID(p->one) || /* (1) */
6314            !DIFF_FILE_VALID(p->two) ||
6315            (p->one->oid_valid && p->two->oid_valid) ||
6316            (p->one->mode != p->two->mode) ||
6317            diff_populate_filespec(r, p->one, CHECK_SIZE_ONLY) ||
6318            diff_populate_filespec(r, p->two, CHECK_SIZE_ONLY) ||
6319            (p->one->size != p->two->size) ||
6320            !diff_filespec_is_identical(r, p->one, p->two)) /* (2) */
6321                p->skip_stat_unmatch_result = 1;
6322        return p->skip_stat_unmatch_result;
6323}
6324
6325static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
6326{
6327        int i;
6328        struct diff_queue_struct *q = &diff_queued_diff;
6329        struct diff_queue_struct outq;
6330        DIFF_QUEUE_CLEAR(&outq);
6331
6332        for (i = 0; i < q->nr; i++) {
6333                struct diff_filepair *p = q->queue[i];
6334
6335                if (diff_filespec_check_stat_unmatch(diffopt->repo, p))
6336                        diff_q(&outq, p);
6337                else {
6338                        /*
6339                         * The caller can subtract 1 from skip_stat_unmatch
6340                         * to determine how many paths were dirty only
6341                         * due to stat info mismatch.
6342                         */
6343                        if (!diffopt->flags.no_index)
6344                                diffopt->skip_stat_unmatch++;
6345                        diff_free_filepair(p);
6346                }
6347        }
6348        free(q->queue);
6349        *q = outq;
6350}
6351
6352static int diffnamecmp(const void *a_, const void *b_)
6353{
6354        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
6355        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
6356        const char *name_a, *name_b;
6357
6358        name_a = a->one ? a->one->path : a->two->path;
6359        name_b = b->one ? b->one->path : b->two->path;
6360        return strcmp(name_a, name_b);
6361}
6362
6363void diffcore_fix_diff_index(void)
6364{
6365        struct diff_queue_struct *q = &diff_queued_diff;
6366        QSORT(q->queue, q->nr, diffnamecmp);
6367}
6368
6369void diffcore_std(struct diff_options *options)
6370{
6371        /* NOTE please keep the following in sync with diff_tree_combined() */
6372        if (options->skip_stat_unmatch)
6373                diffcore_skip_stat_unmatch(options);
6374        if (!options->found_follow) {
6375                /* See try_to_follow_renames() in tree-diff.c */
6376                if (options->break_opt != -1)
6377                        diffcore_break(options->repo,
6378                                       options->break_opt);
6379                if (options->detect_rename)
6380                        diffcore_rename(options);
6381                if (options->break_opt != -1)
6382                        diffcore_merge_broken();
6383        }
6384        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
6385                diffcore_pickaxe(options);
6386        if (options->orderfile)
6387                diffcore_order(options->orderfile);
6388        if (!options->found_follow)
6389                /* See try_to_follow_renames() in tree-diff.c */
6390                diff_resolve_rename_copy();
6391        diffcore_apply_filter(options);
6392
6393        if (diff_queued_diff.nr && !options->flags.diff_from_contents)
6394                options->flags.has_changes = 1;
6395        else
6396                options->flags.has_changes = 0;
6397
6398        options->found_follow = 0;
6399}
6400
6401int diff_result_code(struct diff_options *opt, int status)
6402{
6403        int result = 0;
6404
6405        diff_warn_rename_limit("diff.renameLimit",
6406                               opt->needed_rename_limit,
6407                               opt->degraded_cc_to_c);
6408        if (!opt->flags.exit_with_status &&
6409            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
6410                return status;
6411        if (opt->flags.exit_with_status &&
6412            opt->flags.has_changes)
6413                result |= 01;
6414        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
6415            opt->flags.check_failed)
6416                result |= 02;
6417        return result;
6418}
6419
6420int diff_can_quit_early(struct diff_options *opt)
6421{
6422        return (opt->flags.quick &&
6423                !opt->filter &&
6424                opt->flags.has_changes);
6425}
6426
6427/*
6428 * Shall changes to this submodule be ignored?
6429 *
6430 * Submodule changes can be configured to be ignored separately for each path,
6431 * but that configuration can be overridden from the command line.
6432 */
6433static int is_submodule_ignored(const char *path, struct diff_options *options)
6434{
6435        int ignored = 0;
6436        struct diff_flags orig_flags = options->flags;
6437        if (!options->flags.override_submodule_config)
6438                set_diffopt_flags_from_submodule_config(options, path);
6439        if (options->flags.ignore_submodules)
6440                ignored = 1;
6441        options->flags = orig_flags;
6442        return ignored;
6443}
6444
6445void diff_addremove(struct diff_options *options,
6446                    int addremove, unsigned mode,
6447                    const struct object_id *oid,
6448                    int oid_valid,
6449                    const char *concatpath, unsigned dirty_submodule)
6450{
6451        struct diff_filespec *one, *two;
6452
6453        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
6454                return;
6455
6456        /* This may look odd, but it is a preparation for
6457         * feeding "there are unchanged files which should
6458         * not produce diffs, but when you are doing copy
6459         * detection you would need them, so here they are"
6460         * entries to the diff-core.  They will be prefixed
6461         * with something like '=' or '*' (I haven't decided
6462         * which but should not make any difference).
6463         * Feeding the same new and old to diff_change()
6464         * also has the same effect.
6465         * Before the final output happens, they are pruned after
6466         * merged into rename/copy pairs as appropriate.
6467         */
6468        if (options->flags.reverse_diff)
6469                addremove = (addremove == '+' ? '-' :
6470                             addremove == '-' ? '+' : addremove);
6471
6472        if (options->prefix &&
6473            strncmp(concatpath, options->prefix, options->prefix_length))
6474                return;
6475
6476        one = alloc_filespec(concatpath);
6477        two = alloc_filespec(concatpath);
6478
6479        if (addremove != '+')
6480                fill_filespec(one, oid, oid_valid, mode);
6481        if (addremove != '-') {
6482                fill_filespec(two, oid, oid_valid, mode);
6483                two->dirty_submodule = dirty_submodule;
6484        }
6485
6486        diff_queue(&diff_queued_diff, one, two);
6487        if (!options->flags.diff_from_contents)
6488                options->flags.has_changes = 1;
6489}
6490
6491void diff_change(struct diff_options *options,
6492                 unsigned old_mode, unsigned new_mode,
6493                 const struct object_id *old_oid,
6494                 const struct object_id *new_oid,
6495                 int old_oid_valid, int new_oid_valid,
6496                 const char *concatpath,
6497                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
6498{
6499        struct diff_filespec *one, *two;
6500        struct diff_filepair *p;
6501
6502        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
6503            is_submodule_ignored(concatpath, options))
6504                return;
6505
6506        if (options->flags.reverse_diff) {
6507                SWAP(old_mode, new_mode);
6508                SWAP(old_oid, new_oid);
6509                SWAP(old_oid_valid, new_oid_valid);
6510                SWAP(old_dirty_submodule, new_dirty_submodule);
6511        }
6512
6513        if (options->prefix &&
6514            strncmp(concatpath, options->prefix, options->prefix_length))
6515                return;
6516
6517        one = alloc_filespec(concatpath);
6518        two = alloc_filespec(concatpath);
6519        fill_filespec(one, old_oid, old_oid_valid, old_mode);
6520        fill_filespec(two, new_oid, new_oid_valid, new_mode);
6521        one->dirty_submodule = old_dirty_submodule;
6522        two->dirty_submodule = new_dirty_submodule;
6523        p = diff_queue(&diff_queued_diff, one, two);
6524
6525        if (options->flags.diff_from_contents)
6526                return;
6527
6528        if (options->flags.quick && options->skip_stat_unmatch &&
6529            !diff_filespec_check_stat_unmatch(options->repo, p))
6530                return;
6531
6532        options->flags.has_changes = 1;
6533}
6534
6535struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
6536{
6537        struct diff_filepair *pair;
6538        struct diff_filespec *one, *two;
6539
6540        if (options->prefix &&
6541            strncmp(path, options->prefix, options->prefix_length))
6542                return NULL;
6543
6544        one = alloc_filespec(path);
6545        two = alloc_filespec(path);
6546        pair = diff_queue(&diff_queued_diff, one, two);
6547        pair->is_unmerged = 1;
6548        return pair;
6549}
6550
6551static char *run_textconv(struct repository *r,
6552                          const char *pgm,
6553                          struct diff_filespec *spec,
6554                          size_t *outsize)
6555{
6556        struct diff_tempfile *temp;
6557        const char *argv[3];
6558        const char **arg = argv;
6559        struct child_process child = CHILD_PROCESS_INIT;
6560        struct strbuf buf = STRBUF_INIT;
6561        int err = 0;
6562
6563        temp = prepare_temp_file(r, spec->path, spec);
6564        *arg++ = pgm;
6565        *arg++ = temp->name;
6566        *arg = NULL;
6567
6568        child.use_shell = 1;
6569        child.argv = argv;
6570        child.out = -1;
6571        if (start_command(&child)) {
6572                remove_tempfile();
6573                return NULL;
6574        }
6575
6576        if (strbuf_read(&buf, child.out, 0) < 0)
6577                err = error("error reading from textconv command '%s'", pgm);
6578        close(child.out);
6579
6580        if (finish_command(&child) || err) {
6581                strbuf_release(&buf);
6582                remove_tempfile();
6583                return NULL;
6584        }
6585        remove_tempfile();
6586
6587        return strbuf_detach(&buf, outsize);
6588}
6589
6590size_t fill_textconv(struct repository *r,
6591                     struct userdiff_driver *driver,
6592                     struct diff_filespec *df,
6593                     char **outbuf)
6594{
6595        size_t size;
6596
6597        if (!driver) {
6598                if (!DIFF_FILE_VALID(df)) {
6599                        *outbuf = "";
6600                        return 0;
6601                }
6602                if (diff_populate_filespec(r, df, 0))
6603                        die("unable to read files to diff");
6604                *outbuf = df->data;
6605                return df->size;
6606        }
6607
6608        if (!driver->textconv)
6609                BUG("fill_textconv called with non-textconv driver");
6610
6611        if (driver->textconv_cache && df->oid_valid) {
6612                *outbuf = notes_cache_get(driver->textconv_cache,
6613                                          &df->oid,
6614                                          &size);
6615                if (*outbuf)
6616                        return size;
6617        }
6618
6619        *outbuf = run_textconv(r, driver->textconv, df, &size);
6620        if (!*outbuf)
6621                die("unable to read files to diff");
6622
6623        if (driver->textconv_cache && df->oid_valid) {
6624                /* ignore errors, as we might be in a readonly repository */
6625                notes_cache_put(driver->textconv_cache, &df->oid, *outbuf,
6626                                size);
6627                /*
6628                 * we could save up changes and flush them all at the end,
6629                 * but we would need an extra call after all diffing is done.
6630                 * Since generating a cache entry is the slow path anyway,
6631                 * this extra overhead probably isn't a big deal.
6632                 */
6633                notes_cache_write(driver->textconv_cache);
6634        }
6635
6636        return size;
6637}
6638
6639int textconv_object(struct repository *r,
6640                    const char *path,
6641                    unsigned mode,
6642                    const struct object_id *oid,
6643                    int oid_valid,
6644                    char **buf,
6645                    unsigned long *buf_size)
6646{
6647        struct diff_filespec *df;
6648        struct userdiff_driver *textconv;
6649
6650        df = alloc_filespec(path);
6651        fill_filespec(df, oid, oid_valid, mode);
6652        textconv = get_textconv(r, df);
6653        if (!textconv) {
6654                free_filespec(df);
6655                return 0;
6656        }
6657
6658        *buf_size = fill_textconv(r, textconv, df, buf);
6659        free_filespec(df);
6660        return 1;
6661}
6662
6663void setup_diff_pager(struct diff_options *opt)
6664{
6665        /*
6666         * If the user asked for our exit code, then either they want --quiet
6667         * or --exit-code. We should definitely not bother with a pager in the
6668         * former case, as we will generate no output. Since we still properly
6669         * report our exit code even when a pager is run, we _could_ run a
6670         * pager with --exit-code. But since we have not done so historically,
6671         * and because it is easy to find people oneline advising "git diff
6672         * --exit-code" in hooks and other scripts, we do not do so.
6673         */
6674        if (!opt->flags.exit_with_status &&
6675            check_pager_config("diff") != 0)
6676                setup_pager();
6677}