diff.con commit Merge branch 'ds/reachable' (f2d1c83)
   1/*
   2 * Copyright (C) 2005 Junio C Hamano
   3 */
   4#include "cache.h"
   5#include "config.h"
   6#include "tempfile.h"
   7#include "quote.h"
   8#include "diff.h"
   9#include "diffcore.h"
  10#include "delta.h"
  11#include "xdiff-interface.h"
  12#include "color.h"
  13#include "attr.h"
  14#include "run-command.h"
  15#include "utf8.h"
  16#include "object-store.h"
  17#include "userdiff.h"
  18#include "submodule-config.h"
  19#include "submodule.h"
  20#include "hashmap.h"
  21#include "ll-merge.h"
  22#include "string-list.h"
  23#include "argv-array.h"
  24#include "graph.h"
  25#include "packfile.h"
  26#include "help.h"
  27
  28#ifdef NO_FAST_WORKING_DIRECTORY
  29#define FAST_WORKING_DIRECTORY 0
  30#else
  31#define FAST_WORKING_DIRECTORY 1
  32#endif
  33
  34static int diff_detect_rename_default;
  35static int diff_indent_heuristic = 1;
  36static int diff_rename_limit_default = 400;
  37static int diff_suppress_blank_empty;
  38static int diff_use_color_default = -1;
  39static int diff_color_moved_default;
  40static int diff_color_moved_ws_default;
  41static int diff_context_default = 3;
  42static int diff_interhunk_context_default;
  43static const char *diff_word_regex_cfg;
  44static const char *external_diff_cmd_cfg;
  45static const char *diff_order_file_cfg;
  46int diff_auto_refresh_index = 1;
  47static int diff_mnemonic_prefix;
  48static int diff_no_prefix;
  49static int diff_stat_graph_width;
  50static int diff_dirstat_permille_default = 30;
  51static struct diff_options default_diff_options;
  52static long diff_algorithm;
  53static unsigned ws_error_highlight_default = WSEH_NEW;
  54
  55static char diff_colors[][COLOR_MAXLEN] = {
  56        GIT_COLOR_RESET,
  57        GIT_COLOR_NORMAL,       /* CONTEXT */
  58        GIT_COLOR_BOLD,         /* METAINFO */
  59        GIT_COLOR_CYAN,         /* FRAGINFO */
  60        GIT_COLOR_RED,          /* OLD */
  61        GIT_COLOR_GREEN,        /* NEW */
  62        GIT_COLOR_YELLOW,       /* COMMIT */
  63        GIT_COLOR_BG_RED,       /* WHITESPACE */
  64        GIT_COLOR_NORMAL,       /* FUNCINFO */
  65        GIT_COLOR_BOLD_MAGENTA, /* OLD_MOVED */
  66        GIT_COLOR_BOLD_BLUE,    /* OLD_MOVED ALTERNATIVE */
  67        GIT_COLOR_FAINT,        /* OLD_MOVED_DIM */
  68        GIT_COLOR_FAINT_ITALIC, /* OLD_MOVED_ALTERNATIVE_DIM */
  69        GIT_COLOR_BOLD_CYAN,    /* NEW_MOVED */
  70        GIT_COLOR_BOLD_YELLOW,  /* NEW_MOVED ALTERNATIVE */
  71        GIT_COLOR_FAINT,        /* NEW_MOVED_DIM */
  72        GIT_COLOR_FAINT_ITALIC, /* NEW_MOVED_ALTERNATIVE_DIM */
  73        GIT_COLOR_FAINT,        /* CONTEXT_DIM */
  74        GIT_COLOR_FAINT_RED,    /* OLD_DIM */
  75        GIT_COLOR_FAINT_GREEN,  /* NEW_DIM */
  76        GIT_COLOR_BOLD,         /* CONTEXT_BOLD */
  77        GIT_COLOR_BOLD_RED,     /* OLD_BOLD */
  78        GIT_COLOR_BOLD_GREEN,   /* NEW_BOLD */
  79};
  80
  81static const char *color_diff_slots[] = {
  82        [DIFF_CONTEXT]                = "context",
  83        [DIFF_METAINFO]               = "meta",
  84        [DIFF_FRAGINFO]               = "frag",
  85        [DIFF_FILE_OLD]               = "old",
  86        [DIFF_FILE_NEW]               = "new",
  87        [DIFF_COMMIT]                 = "commit",
  88        [DIFF_WHITESPACE]             = "whitespace",
  89        [DIFF_FUNCINFO]               = "func",
  90        [DIFF_FILE_OLD_MOVED]         = "oldMoved",
  91        [DIFF_FILE_OLD_MOVED_ALT]     = "oldMovedAlternative",
  92        [DIFF_FILE_OLD_MOVED_DIM]     = "oldMovedDimmed",
  93        [DIFF_FILE_OLD_MOVED_ALT_DIM] = "oldMovedAlternativeDimmed",
  94        [DIFF_FILE_NEW_MOVED]         = "newMoved",
  95        [DIFF_FILE_NEW_MOVED_ALT]     = "newMovedAlternative",
  96        [DIFF_FILE_NEW_MOVED_DIM]     = "newMovedDimmed",
  97        [DIFF_FILE_NEW_MOVED_ALT_DIM] = "newMovedAlternativeDimmed",
  98        [DIFF_CONTEXT_DIM]            = "contextDimmed",
  99        [DIFF_FILE_OLD_DIM]           = "oldDimmed",
 100        [DIFF_FILE_NEW_DIM]           = "newDimmed",
 101        [DIFF_CONTEXT_BOLD]           = "contextBold",
 102        [DIFF_FILE_OLD_BOLD]          = "oldBold",
 103        [DIFF_FILE_NEW_BOLD]          = "newBold",
 104};
 105
 106static NORETURN void die_want_option(const char *option_name)
 107{
 108        die(_("option '%s' requires a value"), option_name);
 109}
 110
 111define_list_config_array_extra(color_diff_slots, {"plain"});
 112
 113static int parse_diff_color_slot(const char *var)
 114{
 115        if (!strcasecmp(var, "plain"))
 116                return DIFF_CONTEXT;
 117        return LOOKUP_CONFIG(color_diff_slots, var);
 118}
 119
 120static int parse_dirstat_params(struct diff_options *options, const char *params_string,
 121                                struct strbuf *errmsg)
 122{
 123        char *params_copy = xstrdup(params_string);
 124        struct string_list params = STRING_LIST_INIT_NODUP;
 125        int ret = 0;
 126        int i;
 127
 128        if (*params_copy)
 129                string_list_split_in_place(&params, params_copy, ',', -1);
 130        for (i = 0; i < params.nr; i++) {
 131                const char *p = params.items[i].string;
 132                if (!strcmp(p, "changes")) {
 133                        options->flags.dirstat_by_line = 0;
 134                        options->flags.dirstat_by_file = 0;
 135                } else if (!strcmp(p, "lines")) {
 136                        options->flags.dirstat_by_line = 1;
 137                        options->flags.dirstat_by_file = 0;
 138                } else if (!strcmp(p, "files")) {
 139                        options->flags.dirstat_by_line = 0;
 140                        options->flags.dirstat_by_file = 1;
 141                } else if (!strcmp(p, "noncumulative")) {
 142                        options->flags.dirstat_cumulative = 0;
 143                } else if (!strcmp(p, "cumulative")) {
 144                        options->flags.dirstat_cumulative = 1;
 145                } else if (isdigit(*p)) {
 146                        char *end;
 147                        int permille = strtoul(p, &end, 10) * 10;
 148                        if (*end == '.' && isdigit(*++end)) {
 149                                /* only use first digit */
 150                                permille += *end - '0';
 151                                /* .. and ignore any further digits */
 152                                while (isdigit(*++end))
 153                                        ; /* nothing */
 154                        }
 155                        if (!*end)
 156                                options->dirstat_permille = permille;
 157                        else {
 158                                strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%s'\n"),
 159                                            p);
 160                                ret++;
 161                        }
 162                } else {
 163                        strbuf_addf(errmsg, _("  Unknown dirstat parameter '%s'\n"), p);
 164                        ret++;
 165                }
 166
 167        }
 168        string_list_clear(&params, 0);
 169        free(params_copy);
 170        return ret;
 171}
 172
 173static int parse_submodule_params(struct diff_options *options, const char *value)
 174{
 175        if (!strcmp(value, "log"))
 176                options->submodule_format = DIFF_SUBMODULE_LOG;
 177        else if (!strcmp(value, "short"))
 178                options->submodule_format = DIFF_SUBMODULE_SHORT;
 179        else if (!strcmp(value, "diff"))
 180                options->submodule_format = DIFF_SUBMODULE_INLINE_DIFF;
 181        else
 182                return -1;
 183        return 0;
 184}
 185
 186int git_config_rename(const char *var, const char *value)
 187{
 188        if (!value)
 189                return DIFF_DETECT_RENAME;
 190        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 191                return  DIFF_DETECT_COPY;
 192        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 193}
 194
 195long parse_algorithm_value(const char *value)
 196{
 197        if (!value)
 198                return -1;
 199        else if (!strcasecmp(value, "myers") || !strcasecmp(value, "default"))
 200                return 0;
 201        else if (!strcasecmp(value, "minimal"))
 202                return XDF_NEED_MINIMAL;
 203        else if (!strcasecmp(value, "patience"))
 204                return XDF_PATIENCE_DIFF;
 205        else if (!strcasecmp(value, "histogram"))
 206                return XDF_HISTOGRAM_DIFF;
 207        return -1;
 208}
 209
 210static int parse_one_token(const char **arg, const char *token)
 211{
 212        const char *rest;
 213        if (skip_prefix(*arg, token, &rest) && (!*rest || *rest == ',')) {
 214                *arg = rest;
 215                return 1;
 216        }
 217        return 0;
 218}
 219
 220static int parse_ws_error_highlight(const char *arg)
 221{
 222        const char *orig_arg = arg;
 223        unsigned val = 0;
 224
 225        while (*arg) {
 226                if (parse_one_token(&arg, "none"))
 227                        val = 0;
 228                else if (parse_one_token(&arg, "default"))
 229                        val = WSEH_NEW;
 230                else if (parse_one_token(&arg, "all"))
 231                        val = WSEH_NEW | WSEH_OLD | WSEH_CONTEXT;
 232                else if (parse_one_token(&arg, "new"))
 233                        val |= WSEH_NEW;
 234                else if (parse_one_token(&arg, "old"))
 235                        val |= WSEH_OLD;
 236                else if (parse_one_token(&arg, "context"))
 237                        val |= WSEH_CONTEXT;
 238                else {
 239                        return -1 - (int)(arg - orig_arg);
 240                }
 241                if (*arg)
 242                        arg++;
 243        }
 244        return val;
 245}
 246
 247/*
 248 * These are to give UI layer defaults.
 249 * The core-level commands such as git-diff-files should
 250 * never be affected by the setting of diff.renames
 251 * the user happens to have in the configuration file.
 252 */
 253void init_diff_ui_defaults(void)
 254{
 255        diff_detect_rename_default = DIFF_DETECT_RENAME;
 256}
 257
 258int git_diff_heuristic_config(const char *var, const char *value, void *cb)
 259{
 260        if (!strcmp(var, "diff.indentheuristic"))
 261                diff_indent_heuristic = git_config_bool(var, value);
 262        return 0;
 263}
 264
 265static int parse_color_moved(const char *arg)
 266{
 267        switch (git_parse_maybe_bool(arg)) {
 268        case 0:
 269                return COLOR_MOVED_NO;
 270        case 1:
 271                return COLOR_MOVED_DEFAULT;
 272        default:
 273                break;
 274        }
 275
 276        if (!strcmp(arg, "no"))
 277                return COLOR_MOVED_NO;
 278        else if (!strcmp(arg, "plain"))
 279                return COLOR_MOVED_PLAIN;
 280        else if (!strcmp(arg, "blocks"))
 281                return COLOR_MOVED_BLOCKS;
 282        else if (!strcmp(arg, "zebra"))
 283                return COLOR_MOVED_ZEBRA;
 284        else if (!strcmp(arg, "default"))
 285                return COLOR_MOVED_DEFAULT;
 286        else if (!strcmp(arg, "dimmed-zebra"))
 287                return COLOR_MOVED_ZEBRA_DIM;
 288        else if (!strcmp(arg, "dimmed_zebra"))
 289                return COLOR_MOVED_ZEBRA_DIM;
 290        else
 291                return error(_("color moved setting must be one of 'no', 'default', 'blocks', 'zebra', 'dimmed-zebra', 'plain'"));
 292}
 293
 294static int parse_color_moved_ws(const char *arg)
 295{
 296        int ret = 0;
 297        struct string_list l = STRING_LIST_INIT_DUP;
 298        struct string_list_item *i;
 299
 300        string_list_split(&l, arg, ',', -1);
 301
 302        for_each_string_list_item(i, &l) {
 303                struct strbuf sb = STRBUF_INIT;
 304                strbuf_addstr(&sb, i->string);
 305                strbuf_trim(&sb);
 306
 307                if (!strcmp(sb.buf, "ignore-space-change"))
 308                        ret |= XDF_IGNORE_WHITESPACE_CHANGE;
 309                else if (!strcmp(sb.buf, "ignore-space-at-eol"))
 310                        ret |= XDF_IGNORE_WHITESPACE_AT_EOL;
 311                else if (!strcmp(sb.buf, "ignore-all-space"))
 312                        ret |= XDF_IGNORE_WHITESPACE;
 313                else if (!strcmp(sb.buf, "allow-indentation-change"))
 314                        ret |= COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE;
 315                else
 316                        error(_("ignoring unknown color-moved-ws mode '%s'"), sb.buf);
 317
 318                strbuf_release(&sb);
 319        }
 320
 321        if ((ret & COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) &&
 322            (ret & XDF_WHITESPACE_FLAGS))
 323                die(_("color-moved-ws: allow-indentation-change cannot be combined with other white space modes"));
 324
 325        string_list_clear(&l, 0);
 326
 327        return ret;
 328}
 329
 330int git_diff_ui_config(const char *var, const char *value, void *cb)
 331{
 332        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 333                diff_use_color_default = git_config_colorbool(var, value);
 334                return 0;
 335        }
 336        if (!strcmp(var, "diff.colormoved")) {
 337                int cm = parse_color_moved(value);
 338                if (cm < 0)
 339                        return -1;
 340                diff_color_moved_default = cm;
 341                return 0;
 342        }
 343        if (!strcmp(var, "diff.colormovedws")) {
 344                int cm = parse_color_moved_ws(value);
 345                if (cm < 0)
 346                        return -1;
 347                diff_color_moved_ws_default = cm;
 348                return 0;
 349        }
 350        if (!strcmp(var, "diff.context")) {
 351                diff_context_default = git_config_int(var, value);
 352                if (diff_context_default < 0)
 353                        return -1;
 354                return 0;
 355        }
 356        if (!strcmp(var, "diff.interhunkcontext")) {
 357                diff_interhunk_context_default = git_config_int(var, value);
 358                if (diff_interhunk_context_default < 0)
 359                        return -1;
 360                return 0;
 361        }
 362        if (!strcmp(var, "diff.renames")) {
 363                diff_detect_rename_default = git_config_rename(var, value);
 364                return 0;
 365        }
 366        if (!strcmp(var, "diff.autorefreshindex")) {
 367                diff_auto_refresh_index = git_config_bool(var, value);
 368                return 0;
 369        }
 370        if (!strcmp(var, "diff.mnemonicprefix")) {
 371                diff_mnemonic_prefix = git_config_bool(var, value);
 372                return 0;
 373        }
 374        if (!strcmp(var, "diff.noprefix")) {
 375                diff_no_prefix = git_config_bool(var, value);
 376                return 0;
 377        }
 378        if (!strcmp(var, "diff.statgraphwidth")) {
 379                diff_stat_graph_width = git_config_int(var, value);
 380                return 0;
 381        }
 382        if (!strcmp(var, "diff.external"))
 383                return git_config_string(&external_diff_cmd_cfg, var, value);
 384        if (!strcmp(var, "diff.wordregex"))
 385                return git_config_string(&diff_word_regex_cfg, var, value);
 386        if (!strcmp(var, "diff.orderfile"))
 387                return git_config_pathname(&diff_order_file_cfg, var, value);
 388
 389        if (!strcmp(var, "diff.ignoresubmodules"))
 390                handle_ignore_submodules_arg(&default_diff_options, value);
 391
 392        if (!strcmp(var, "diff.submodule")) {
 393                if (parse_submodule_params(&default_diff_options, value))
 394                        warning(_("Unknown value for 'diff.submodule' config variable: '%s'"),
 395                                value);
 396                return 0;
 397        }
 398
 399        if (!strcmp(var, "diff.algorithm")) {
 400                diff_algorithm = parse_algorithm_value(value);
 401                if (diff_algorithm < 0)
 402                        return -1;
 403                return 0;
 404        }
 405
 406        if (!strcmp(var, "diff.wserrorhighlight")) {
 407                int val = parse_ws_error_highlight(value);
 408                if (val < 0)
 409                        return -1;
 410                ws_error_highlight_default = val;
 411                return 0;
 412        }
 413
 414        if (git_color_config(var, value, cb) < 0)
 415                return -1;
 416
 417        return git_diff_basic_config(var, value, cb);
 418}
 419
 420int git_diff_basic_config(const char *var, const char *value, void *cb)
 421{
 422        const char *name;
 423
 424        if (!strcmp(var, "diff.renamelimit")) {
 425                diff_rename_limit_default = git_config_int(var, value);
 426                return 0;
 427        }
 428
 429        if (userdiff_config(var, value) < 0)
 430                return -1;
 431
 432        if (skip_prefix(var, "diff.color.", &name) ||
 433            skip_prefix(var, "color.diff.", &name)) {
 434                int slot = parse_diff_color_slot(name);
 435                if (slot < 0)
 436                        return 0;
 437                if (!value)
 438                        return config_error_nonbool(var);
 439                return color_parse(value, diff_colors[slot]);
 440        }
 441
 442        /* like GNU diff's --suppress-blank-empty option  */
 443        if (!strcmp(var, "diff.suppressblankempty") ||
 444                        /* for backwards compatibility */
 445                        !strcmp(var, "diff.suppress-blank-empty")) {
 446                diff_suppress_blank_empty = git_config_bool(var, value);
 447                return 0;
 448        }
 449
 450        if (!strcmp(var, "diff.dirstat")) {
 451                struct strbuf errmsg = STRBUF_INIT;
 452                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 453                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 454                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 455                                errmsg.buf);
 456                strbuf_release(&errmsg);
 457                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 458                return 0;
 459        }
 460
 461        if (git_diff_heuristic_config(var, value, cb) < 0)
 462                return -1;
 463
 464        return git_default_config(var, value, cb);
 465}
 466
 467static char *quote_two(const char *one, const char *two)
 468{
 469        int need_one = quote_c_style(one, NULL, NULL, 1);
 470        int need_two = quote_c_style(two, NULL, NULL, 1);
 471        struct strbuf res = STRBUF_INIT;
 472
 473        if (need_one + need_two) {
 474                strbuf_addch(&res, '"');
 475                quote_c_style(one, &res, NULL, 1);
 476                quote_c_style(two, &res, NULL, 1);
 477                strbuf_addch(&res, '"');
 478        } else {
 479                strbuf_addstr(&res, one);
 480                strbuf_addstr(&res, two);
 481        }
 482        return strbuf_detach(&res, NULL);
 483}
 484
 485static const char *external_diff(void)
 486{
 487        static const char *external_diff_cmd = NULL;
 488        static int done_preparing = 0;
 489
 490        if (done_preparing)
 491                return external_diff_cmd;
 492        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 493        if (!external_diff_cmd)
 494                external_diff_cmd = external_diff_cmd_cfg;
 495        done_preparing = 1;
 496        return external_diff_cmd;
 497}
 498
 499/*
 500 * Keep track of files used for diffing. Sometimes such an entry
 501 * refers to a temporary file, sometimes to an existing file, and
 502 * sometimes to "/dev/null".
 503 */
 504static struct diff_tempfile {
 505        /*
 506         * filename external diff should read from, or NULL if this
 507         * entry is currently not in use:
 508         */
 509        const char *name;
 510
 511        char hex[GIT_MAX_HEXSZ + 1];
 512        char mode[10];
 513
 514        /*
 515         * If this diff_tempfile instance refers to a temporary file,
 516         * this tempfile object is used to manage its lifetime.
 517         */
 518        struct tempfile *tempfile;
 519} diff_temp[2];
 520
 521struct emit_callback {
 522        int color_diff;
 523        unsigned ws_rule;
 524        int blank_at_eof_in_preimage;
 525        int blank_at_eof_in_postimage;
 526        int lno_in_preimage;
 527        int lno_in_postimage;
 528        const char **label_path;
 529        struct diff_words_data *diff_words;
 530        struct diff_options *opt;
 531        struct strbuf *header;
 532};
 533
 534static int count_lines(const char *data, int size)
 535{
 536        int count, ch, completely_empty = 1, nl_just_seen = 0;
 537        count = 0;
 538        while (0 < size--) {
 539                ch = *data++;
 540                if (ch == '\n') {
 541                        count++;
 542                        nl_just_seen = 1;
 543                        completely_empty = 0;
 544                }
 545                else {
 546                        nl_just_seen = 0;
 547                        completely_empty = 0;
 548                }
 549        }
 550        if (completely_empty)
 551                return 0;
 552        if (!nl_just_seen)
 553                count++; /* no trailing newline */
 554        return count;
 555}
 556
 557static int fill_mmfile(struct repository *r, mmfile_t *mf,
 558                       struct diff_filespec *one)
 559{
 560        if (!DIFF_FILE_VALID(one)) {
 561                mf->ptr = (char *)""; /* does not matter */
 562                mf->size = 0;
 563                return 0;
 564        }
 565        else if (diff_populate_filespec(r, one, 0))
 566                return -1;
 567
 568        mf->ptr = one->data;
 569        mf->size = one->size;
 570        return 0;
 571}
 572
 573/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 574static unsigned long diff_filespec_size(struct repository *r,
 575                                        struct diff_filespec *one)
 576{
 577        if (!DIFF_FILE_VALID(one))
 578                return 0;
 579        diff_populate_filespec(r, one, CHECK_SIZE_ONLY);
 580        return one->size;
 581}
 582
 583static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 584{
 585        char *ptr = mf->ptr;
 586        long size = mf->size;
 587        int cnt = 0;
 588
 589        if (!size)
 590                return cnt;
 591        ptr += size - 1; /* pointing at the very end */
 592        if (*ptr != '\n')
 593                ; /* incomplete line */
 594        else
 595                ptr--; /* skip the last LF */
 596        while (mf->ptr < ptr) {
 597                char *prev_eol;
 598                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 599                        if (*prev_eol == '\n')
 600                                break;
 601                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 602                        break;
 603                cnt++;
 604                ptr = prev_eol - 1;
 605        }
 606        return cnt;
 607}
 608
 609static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 610                               struct emit_callback *ecbdata)
 611{
 612        int l1, l2, at;
 613        unsigned ws_rule = ecbdata->ws_rule;
 614        l1 = count_trailing_blank(mf1, ws_rule);
 615        l2 = count_trailing_blank(mf2, ws_rule);
 616        if (l2 <= l1) {
 617                ecbdata->blank_at_eof_in_preimage = 0;
 618                ecbdata->blank_at_eof_in_postimage = 0;
 619                return;
 620        }
 621        at = count_lines(mf1->ptr, mf1->size);
 622        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 623
 624        at = count_lines(mf2->ptr, mf2->size);
 625        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 626}
 627
 628static void emit_line_0(struct diff_options *o,
 629                        const char *set_sign, const char *set, unsigned reverse, const char *reset,
 630                        int first, const char *line, int len)
 631{
 632        int has_trailing_newline, has_trailing_carriage_return;
 633        int needs_reset = 0; /* at the end of the line */
 634        FILE *file = o->file;
 635
 636        fputs(diff_line_prefix(o), file);
 637
 638        has_trailing_newline = (len > 0 && line[len-1] == '\n');
 639        if (has_trailing_newline)
 640                len--;
 641
 642        has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 643        if (has_trailing_carriage_return)
 644                len--;
 645
 646        if (!len && !first)
 647                goto end_of_line;
 648
 649        if (reverse && want_color(o->use_color)) {
 650                fputs(GIT_COLOR_REVERSE, file);
 651                needs_reset = 1;
 652        }
 653
 654        if (set_sign) {
 655                fputs(set_sign, file);
 656                needs_reset = 1;
 657        }
 658
 659        if (first)
 660                fputc(first, file);
 661
 662        if (!len)
 663                goto end_of_line;
 664
 665        if (set) {
 666                if (set_sign && set != set_sign)
 667                        fputs(reset, file);
 668                fputs(set, file);
 669                needs_reset = 1;
 670        }
 671        fwrite(line, len, 1, file);
 672        needs_reset = 1; /* 'line' may contain color codes. */
 673
 674end_of_line:
 675        if (needs_reset)
 676                fputs(reset, file);
 677        if (has_trailing_carriage_return)
 678                fputc('\r', file);
 679        if (has_trailing_newline)
 680                fputc('\n', file);
 681}
 682
 683static void emit_line(struct diff_options *o, const char *set, const char *reset,
 684                      const char *line, int len)
 685{
 686        emit_line_0(o, set, NULL, 0, reset, 0, line, len);
 687}
 688
 689enum diff_symbol {
 690        DIFF_SYMBOL_BINARY_DIFF_HEADER,
 691        DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
 692        DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
 693        DIFF_SYMBOL_BINARY_DIFF_BODY,
 694        DIFF_SYMBOL_BINARY_DIFF_FOOTER,
 695        DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
 696        DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
 697        DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
 698        DIFF_SYMBOL_STATS_LINE,
 699        DIFF_SYMBOL_WORD_DIFF,
 700        DIFF_SYMBOL_STAT_SEP,
 701        DIFF_SYMBOL_SUMMARY,
 702        DIFF_SYMBOL_SUBMODULE_ADD,
 703        DIFF_SYMBOL_SUBMODULE_DEL,
 704        DIFF_SYMBOL_SUBMODULE_UNTRACKED,
 705        DIFF_SYMBOL_SUBMODULE_MODIFIED,
 706        DIFF_SYMBOL_SUBMODULE_HEADER,
 707        DIFF_SYMBOL_SUBMODULE_ERROR,
 708        DIFF_SYMBOL_SUBMODULE_PIPETHROUGH,
 709        DIFF_SYMBOL_REWRITE_DIFF,
 710        DIFF_SYMBOL_BINARY_FILES,
 711        DIFF_SYMBOL_HEADER,
 712        DIFF_SYMBOL_FILEPAIR_PLUS,
 713        DIFF_SYMBOL_FILEPAIR_MINUS,
 714        DIFF_SYMBOL_WORDS_PORCELAIN,
 715        DIFF_SYMBOL_WORDS,
 716        DIFF_SYMBOL_CONTEXT,
 717        DIFF_SYMBOL_CONTEXT_INCOMPLETE,
 718        DIFF_SYMBOL_PLUS,
 719        DIFF_SYMBOL_MINUS,
 720        DIFF_SYMBOL_NO_LF_EOF,
 721        DIFF_SYMBOL_CONTEXT_FRAGINFO,
 722        DIFF_SYMBOL_CONTEXT_MARKER,
 723        DIFF_SYMBOL_SEPARATOR
 724};
 725/*
 726 * Flags for content lines:
 727 * 0..12 are whitespace rules
 728 * 13-15 are WSEH_NEW | WSEH_OLD | WSEH_CONTEXT
 729 * 16 is marking if the line is blank at EOF
 730 */
 731#define DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF      (1<<16)
 732#define DIFF_SYMBOL_MOVED_LINE                  (1<<17)
 733#define DIFF_SYMBOL_MOVED_LINE_ALT              (1<<18)
 734#define DIFF_SYMBOL_MOVED_LINE_UNINTERESTING    (1<<19)
 735#define DIFF_SYMBOL_CONTENT_WS_MASK (WSEH_NEW | WSEH_OLD | WSEH_CONTEXT | WS_RULE_MASK)
 736
 737/*
 738 * This struct is used when we need to buffer the output of the diff output.
 739 *
 740 * NEEDSWORK: Instead of storing a copy of the line, add an offset pointer
 741 * into the pre/post image file. This pointer could be a union with the
 742 * line pointer. By storing an offset into the file instead of the literal line,
 743 * we can decrease the memory footprint for the buffered output. At first we
 744 * may want to only have indirection for the content lines, but we could also
 745 * enhance the state for emitting prefabricated lines, e.g. the similarity
 746 * score line or hunk/file headers would only need to store a number or path
 747 * and then the output can be constructed later on depending on state.
 748 */
 749struct emitted_diff_symbol {
 750        const char *line;
 751        int len;
 752        int flags;
 753        enum diff_symbol s;
 754};
 755#define EMITTED_DIFF_SYMBOL_INIT {NULL}
 756
 757struct emitted_diff_symbols {
 758        struct emitted_diff_symbol *buf;
 759        int nr, alloc;
 760};
 761#define EMITTED_DIFF_SYMBOLS_INIT {NULL, 0, 0}
 762
 763static void append_emitted_diff_symbol(struct diff_options *o,
 764                                       struct emitted_diff_symbol *e)
 765{
 766        struct emitted_diff_symbol *f;
 767
 768        ALLOC_GROW(o->emitted_symbols->buf,
 769                   o->emitted_symbols->nr + 1,
 770                   o->emitted_symbols->alloc);
 771        f = &o->emitted_symbols->buf[o->emitted_symbols->nr++];
 772
 773        memcpy(f, e, sizeof(struct emitted_diff_symbol));
 774        f->line = e->line ? xmemdupz(e->line, e->len) : NULL;
 775}
 776
 777struct moved_entry {
 778        struct hashmap_entry ent;
 779        const struct emitted_diff_symbol *es;
 780        struct moved_entry *next_line;
 781};
 782
 783/**
 784 * The struct ws_delta holds white space differences between moved lines, i.e.
 785 * between '+' and '-' lines that have been detected to be a move.
 786 * The string contains the difference in leading white spaces, before the
 787 * rest of the line is compared using the white space config for move
 788 * coloring. The current_longer indicates if the first string in the
 789 * comparision is longer than the second.
 790 */
 791struct ws_delta {
 792        char *string;
 793        unsigned int current_longer : 1;
 794};
 795#define WS_DELTA_INIT { NULL, 0 }
 796
 797struct moved_block {
 798        struct moved_entry *match;
 799        struct ws_delta wsd;
 800};
 801
 802static void moved_block_clear(struct moved_block *b)
 803{
 804        FREE_AND_NULL(b->wsd.string);
 805        b->match = NULL;
 806}
 807
 808static int compute_ws_delta(const struct emitted_diff_symbol *a,
 809                             const struct emitted_diff_symbol *b,
 810                             struct ws_delta *out)
 811{
 812        const struct emitted_diff_symbol *longer =  a->len > b->len ? a : b;
 813        const struct emitted_diff_symbol *shorter = a->len > b->len ? b : a;
 814        int d = longer->len - shorter->len;
 815
 816        if (strncmp(longer->line + d, shorter->line, shorter->len))
 817                return 0;
 818
 819        out->string = xmemdupz(longer->line, d);
 820        out->current_longer = (a == longer);
 821
 822        return 1;
 823}
 824
 825static int cmp_in_block_with_wsd(const struct diff_options *o,
 826                                 const struct moved_entry *cur,
 827                                 const struct moved_entry *match,
 828                                 struct moved_block *pmb,
 829                                 int n)
 830{
 831        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
 832        int al = cur->es->len, cl = l->len;
 833        const char *a = cur->es->line,
 834                   *b = match->es->line,
 835                   *c = l->line;
 836
 837        int wslen;
 838
 839        /*
 840         * We need to check if 'cur' is equal to 'match'.
 841         * As those are from the same (+/-) side, we do not need to adjust for
 842         * indent changes. However these were found using fuzzy matching
 843         * so we do have to check if they are equal.
 844         */
 845        if (strcmp(a, b))
 846                return 1;
 847
 848        if (!pmb->wsd.string)
 849                /*
 850                 * The white space delta is not active? This can happen
 851                 * when we exit early in this function.
 852                 */
 853                return 1;
 854
 855        /*
 856         * The indent changes of the block are known and stored in
 857         * pmb->wsd; however we need to check if the indent changes of the
 858         * current line are still the same as before.
 859         *
 860         * To do so we need to compare 'l' to 'cur', adjusting the
 861         * one of them for the white spaces, depending which was longer.
 862         */
 863
 864        wslen = strlen(pmb->wsd.string);
 865        if (pmb->wsd.current_longer) {
 866                c += wslen;
 867                cl -= wslen;
 868        } else {
 869                a += wslen;
 870                al -= wslen;
 871        }
 872
 873        if (al != cl || memcmp(a, c, al))
 874                return 1;
 875
 876        return 0;
 877}
 878
 879static int moved_entry_cmp(const void *hashmap_cmp_fn_data,
 880                           const void *entry,
 881                           const void *entry_or_key,
 882                           const void *keydata)
 883{
 884        const struct diff_options *diffopt = hashmap_cmp_fn_data;
 885        const struct moved_entry *a = entry;
 886        const struct moved_entry *b = entry_or_key;
 887        unsigned flags = diffopt->color_moved_ws_handling
 888                         & XDF_WHITESPACE_FLAGS;
 889
 890        if (diffopt->color_moved_ws_handling &
 891            COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
 892                /*
 893                 * As there is not specific white space config given,
 894                 * we'd need to check for a new block, so ignore all
 895                 * white space. The setup of the white space
 896                 * configuration for the next block is done else where
 897                 */
 898                flags |= XDF_IGNORE_WHITESPACE;
 899
 900        return !xdiff_compare_lines(a->es->line, a->es->len,
 901                                    b->es->line, b->es->len,
 902                                    flags);
 903}
 904
 905static struct moved_entry *prepare_entry(struct diff_options *o,
 906                                         int line_no)
 907{
 908        struct moved_entry *ret = xmalloc(sizeof(*ret));
 909        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[line_no];
 910        unsigned flags = o->color_moved_ws_handling & XDF_WHITESPACE_FLAGS;
 911
 912        ret->ent.hash = xdiff_hash_string(l->line, l->len, flags);
 913        ret->es = l;
 914        ret->next_line = NULL;
 915
 916        return ret;
 917}
 918
 919static void add_lines_to_move_detection(struct diff_options *o,
 920                                        struct hashmap *add_lines,
 921                                        struct hashmap *del_lines)
 922{
 923        struct moved_entry *prev_line = NULL;
 924
 925        int n;
 926        for (n = 0; n < o->emitted_symbols->nr; n++) {
 927                struct hashmap *hm;
 928                struct moved_entry *key;
 929
 930                switch (o->emitted_symbols->buf[n].s) {
 931                case DIFF_SYMBOL_PLUS:
 932                        hm = add_lines;
 933                        break;
 934                case DIFF_SYMBOL_MINUS:
 935                        hm = del_lines;
 936                        break;
 937                default:
 938                        prev_line = NULL;
 939                        continue;
 940                }
 941
 942                key = prepare_entry(o, n);
 943                if (prev_line && prev_line->es->s == o->emitted_symbols->buf[n].s)
 944                        prev_line->next_line = key;
 945
 946                hashmap_add(hm, key);
 947                prev_line = key;
 948        }
 949}
 950
 951static void pmb_advance_or_null(struct diff_options *o,
 952                                struct moved_entry *match,
 953                                struct hashmap *hm,
 954                                struct moved_block *pmb,
 955                                int pmb_nr)
 956{
 957        int i;
 958        for (i = 0; i < pmb_nr; i++) {
 959                struct moved_entry *prev = pmb[i].match;
 960                struct moved_entry *cur = (prev && prev->next_line) ?
 961                                prev->next_line : NULL;
 962                if (cur && !hm->cmpfn(o, cur, match, NULL)) {
 963                        pmb[i].match = cur;
 964                } else {
 965                        pmb[i].match = NULL;
 966                }
 967        }
 968}
 969
 970static void pmb_advance_or_null_multi_match(struct diff_options *o,
 971                                            struct moved_entry *match,
 972                                            struct hashmap *hm,
 973                                            struct moved_block *pmb,
 974                                            int pmb_nr, int n)
 975{
 976        int i;
 977        char *got_match = xcalloc(1, pmb_nr);
 978
 979        for (; match; match = hashmap_get_next(hm, match)) {
 980                for (i = 0; i < pmb_nr; i++) {
 981                        struct moved_entry *prev = pmb[i].match;
 982                        struct moved_entry *cur = (prev && prev->next_line) ?
 983                                        prev->next_line : NULL;
 984                        if (!cur)
 985                                continue;
 986                        if (!cmp_in_block_with_wsd(o, cur, match, &pmb[i], n))
 987                                got_match[i] |= 1;
 988                }
 989        }
 990
 991        for (i = 0; i < pmb_nr; i++) {
 992                if (got_match[i]) {
 993                        /* Advance to the next line */
 994                        pmb[i].match = pmb[i].match->next_line;
 995                } else {
 996                        moved_block_clear(&pmb[i]);
 997                }
 998        }
 999
1000        free(got_match);
1001}
1002
1003static int shrink_potential_moved_blocks(struct moved_block *pmb,
1004                                         int pmb_nr)
1005{
1006        int lp, rp;
1007
1008        /* Shrink the set of potential block to the remaining running */
1009        for (lp = 0, rp = pmb_nr - 1; lp <= rp;) {
1010                while (lp < pmb_nr && pmb[lp].match)
1011                        lp++;
1012                /* lp points at the first NULL now */
1013
1014                while (rp > -1 && !pmb[rp].match)
1015                        rp--;
1016                /* rp points at the last non-NULL */
1017
1018                if (lp < pmb_nr && rp > -1 && lp < rp) {
1019                        pmb[lp] = pmb[rp];
1020                        pmb[rp].match = NULL;
1021                        pmb[rp].wsd.string = NULL;
1022                        rp--;
1023                        lp++;
1024                }
1025        }
1026
1027        /* Remember the number of running sets */
1028        return rp + 1;
1029}
1030
1031/*
1032 * If o->color_moved is COLOR_MOVED_PLAIN, this function does nothing.
1033 *
1034 * Otherwise, if the last block has fewer alphanumeric characters than
1035 * COLOR_MOVED_MIN_ALNUM_COUNT, unset DIFF_SYMBOL_MOVED_LINE on all lines in
1036 * that block.
1037 *
1038 * The last block consists of the (n - block_length)'th line up to but not
1039 * including the nth line.
1040 *
1041 * NEEDSWORK: This uses the same heuristic as blame_entry_score() in blame.c.
1042 * Think of a way to unify them.
1043 */
1044static void adjust_last_block(struct diff_options *o, int n, int block_length)
1045{
1046        int i, alnum_count = 0;
1047        if (o->color_moved == COLOR_MOVED_PLAIN)
1048                return;
1049        for (i = 1; i < block_length + 1; i++) {
1050                const char *c = o->emitted_symbols->buf[n - i].line;
1051                for (; *c; c++) {
1052                        if (!isalnum(*c))
1053                                continue;
1054                        alnum_count++;
1055                        if (alnum_count >= COLOR_MOVED_MIN_ALNUM_COUNT)
1056                                return;
1057                }
1058        }
1059        for (i = 1; i < block_length + 1; i++)
1060                o->emitted_symbols->buf[n - i].flags &= ~DIFF_SYMBOL_MOVED_LINE;
1061}
1062
1063/* Find blocks of moved code, delegate actual coloring decision to helper */
1064static void mark_color_as_moved(struct diff_options *o,
1065                                struct hashmap *add_lines,
1066                                struct hashmap *del_lines)
1067{
1068        struct moved_block *pmb = NULL; /* potentially moved blocks */
1069        int pmb_nr = 0, pmb_alloc = 0;
1070        int n, flipped_block = 1, block_length = 0;
1071
1072
1073        for (n = 0; n < o->emitted_symbols->nr; n++) {
1074                struct hashmap *hm = NULL;
1075                struct moved_entry *key;
1076                struct moved_entry *match = NULL;
1077                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
1078
1079                switch (l->s) {
1080                case DIFF_SYMBOL_PLUS:
1081                        hm = del_lines;
1082                        key = prepare_entry(o, n);
1083                        match = hashmap_get(hm, key, NULL);
1084                        free(key);
1085                        break;
1086                case DIFF_SYMBOL_MINUS:
1087                        hm = add_lines;
1088                        key = prepare_entry(o, n);
1089                        match = hashmap_get(hm, key, NULL);
1090                        free(key);
1091                        break;
1092                default:
1093                        flipped_block = 1;
1094                }
1095
1096                if (!match) {
1097                        int i;
1098
1099                        adjust_last_block(o, n, block_length);
1100                        for(i = 0; i < pmb_nr; i++)
1101                                moved_block_clear(&pmb[i]);
1102                        pmb_nr = 0;
1103                        block_length = 0;
1104                        continue;
1105                }
1106
1107                l->flags |= DIFF_SYMBOL_MOVED_LINE;
1108
1109                if (o->color_moved == COLOR_MOVED_PLAIN)
1110                        continue;
1111
1112                if (o->color_moved_ws_handling &
1113                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
1114                        pmb_advance_or_null_multi_match(o, match, hm, pmb, pmb_nr, n);
1115                else
1116                        pmb_advance_or_null(o, match, hm, pmb, pmb_nr);
1117
1118                pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
1119
1120                if (pmb_nr == 0) {
1121                        /*
1122                         * The current line is the start of a new block.
1123                         * Setup the set of potential blocks.
1124                         */
1125                        for (; match; match = hashmap_get_next(hm, match)) {
1126                                ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
1127                                if (o->color_moved_ws_handling &
1128                                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) {
1129                                        if (compute_ws_delta(l, match->es,
1130                                                             &pmb[pmb_nr].wsd))
1131                                                pmb[pmb_nr++].match = match;
1132                                } else {
1133                                        pmb[pmb_nr].wsd.string = NULL;
1134                                        pmb[pmb_nr++].match = match;
1135                                }
1136                        }
1137
1138                        flipped_block = (flipped_block + 1) % 2;
1139
1140                        adjust_last_block(o, n, block_length);
1141                        block_length = 0;
1142                }
1143
1144                block_length++;
1145
1146                if (flipped_block && o->color_moved != COLOR_MOVED_BLOCKS)
1147                        l->flags |= DIFF_SYMBOL_MOVED_LINE_ALT;
1148        }
1149        adjust_last_block(o, n, block_length);
1150
1151        for(n = 0; n < pmb_nr; n++)
1152                moved_block_clear(&pmb[n]);
1153        free(pmb);
1154}
1155
1156#define DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK \
1157  (DIFF_SYMBOL_MOVED_LINE | DIFF_SYMBOL_MOVED_LINE_ALT)
1158static void dim_moved_lines(struct diff_options *o)
1159{
1160        int n;
1161        for (n = 0; n < o->emitted_symbols->nr; n++) {
1162                struct emitted_diff_symbol *prev = (n != 0) ?
1163                                &o->emitted_symbols->buf[n - 1] : NULL;
1164                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
1165                struct emitted_diff_symbol *next =
1166                                (n < o->emitted_symbols->nr - 1) ?
1167                                &o->emitted_symbols->buf[n + 1] : NULL;
1168
1169                /* Not a plus or minus line? */
1170                if (l->s != DIFF_SYMBOL_PLUS && l->s != DIFF_SYMBOL_MINUS)
1171                        continue;
1172
1173                /* Not a moved line? */
1174                if (!(l->flags & DIFF_SYMBOL_MOVED_LINE))
1175                        continue;
1176
1177                /*
1178                 * If prev or next are not a plus or minus line,
1179                 * pretend they don't exist
1180                 */
1181                if (prev && prev->s != DIFF_SYMBOL_PLUS &&
1182                            prev->s != DIFF_SYMBOL_MINUS)
1183                        prev = NULL;
1184                if (next && next->s != DIFF_SYMBOL_PLUS &&
1185                            next->s != DIFF_SYMBOL_MINUS)
1186                        next = NULL;
1187
1188                /* Inside a block? */
1189                if ((prev &&
1190                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
1191                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK)) &&
1192                    (next &&
1193                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
1194                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK))) {
1195                        l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1196                        continue;
1197                }
1198
1199                /* Check if we are at an interesting bound: */
1200                if (prev && (prev->flags & DIFF_SYMBOL_MOVED_LINE) &&
1201                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1202                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1203                        continue;
1204                if (next && (next->flags & DIFF_SYMBOL_MOVED_LINE) &&
1205                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1206                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1207                        continue;
1208
1209                /*
1210                 * The boundary to prev and next are not interesting,
1211                 * so this line is not interesting as a whole
1212                 */
1213                l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1214        }
1215}
1216
1217static void emit_line_ws_markup(struct diff_options *o,
1218                                const char *set_sign, const char *set,
1219                                const char *reset,
1220                                int sign_index, const char *line, int len,
1221                                unsigned ws_rule, int blank_at_eof)
1222{
1223        const char *ws = NULL;
1224        int sign = o->output_indicators[sign_index];
1225
1226        if (o->ws_error_highlight & ws_rule) {
1227                ws = diff_get_color_opt(o, DIFF_WHITESPACE);
1228                if (!*ws)
1229                        ws = NULL;
1230        }
1231
1232        if (!ws && !set_sign)
1233                emit_line_0(o, set, NULL, 0, reset, sign, line, len);
1234        else if (!ws) {
1235                emit_line_0(o, set_sign, set, !!set_sign, reset, sign, line, len);
1236        } else if (blank_at_eof)
1237                /* Blank line at EOF - paint '+' as well */
1238                emit_line_0(o, ws, NULL, 0, reset, sign, line, len);
1239        else {
1240                /* Emit just the prefix, then the rest. */
1241                emit_line_0(o, set_sign ? set_sign : set, NULL, !!set_sign, reset,
1242                            sign, "", 0);
1243                ws_check_emit(line, len, ws_rule,
1244                              o->file, set, reset, ws);
1245        }
1246}
1247
1248static void emit_diff_symbol_from_struct(struct diff_options *o,
1249                                         struct emitted_diff_symbol *eds)
1250{
1251        static const char *nneof = " No newline at end of file\n";
1252        const char *context, *reset, *set, *set_sign, *meta, *fraginfo;
1253        struct strbuf sb = STRBUF_INIT;
1254
1255        enum diff_symbol s = eds->s;
1256        const char *line = eds->line;
1257        int len = eds->len;
1258        unsigned flags = eds->flags;
1259
1260        switch (s) {
1261        case DIFF_SYMBOL_NO_LF_EOF:
1262                context = diff_get_color_opt(o, DIFF_CONTEXT);
1263                reset = diff_get_color_opt(o, DIFF_RESET);
1264                putc('\n', o->file);
1265                emit_line_0(o, context, NULL, 0, reset, '\\',
1266                            nneof, strlen(nneof));
1267                break;
1268        case DIFF_SYMBOL_SUBMODULE_HEADER:
1269        case DIFF_SYMBOL_SUBMODULE_ERROR:
1270        case DIFF_SYMBOL_SUBMODULE_PIPETHROUGH:
1271        case DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES:
1272        case DIFF_SYMBOL_SUMMARY:
1273        case DIFF_SYMBOL_STATS_LINE:
1274        case DIFF_SYMBOL_BINARY_DIFF_BODY:
1275        case DIFF_SYMBOL_CONTEXT_FRAGINFO:
1276                emit_line(o, "", "", line, len);
1277                break;
1278        case DIFF_SYMBOL_CONTEXT_INCOMPLETE:
1279        case DIFF_SYMBOL_CONTEXT_MARKER:
1280                context = diff_get_color_opt(o, DIFF_CONTEXT);
1281                reset = diff_get_color_opt(o, DIFF_RESET);
1282                emit_line(o, context, reset, line, len);
1283                break;
1284        case DIFF_SYMBOL_SEPARATOR:
1285                fprintf(o->file, "%s%c",
1286                        diff_line_prefix(o),
1287                        o->line_termination);
1288                break;
1289        case DIFF_SYMBOL_CONTEXT:
1290                set = diff_get_color_opt(o, DIFF_CONTEXT);
1291                reset = diff_get_color_opt(o, DIFF_RESET);
1292                set_sign = NULL;
1293                if (o->flags.dual_color_diffed_diffs) {
1294                        char c = !len ? 0 : line[0];
1295
1296                        if (c == '+')
1297                                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1298                        else if (c == '@')
1299                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1300                        else if (c == '-')
1301                                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1302                }
1303                emit_line_ws_markup(o, set_sign, set, reset,
1304                                    OUTPUT_INDICATOR_CONTEXT, line, len,
1305                                    flags & (DIFF_SYMBOL_CONTENT_WS_MASK), 0);
1306                break;
1307        case DIFF_SYMBOL_PLUS:
1308                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1309                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1310                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1311                case DIFF_SYMBOL_MOVED_LINE |
1312                     DIFF_SYMBOL_MOVED_LINE_ALT |
1313                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1314                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT_DIM);
1315                        break;
1316                case DIFF_SYMBOL_MOVED_LINE |
1317                     DIFF_SYMBOL_MOVED_LINE_ALT:
1318                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT);
1319                        break;
1320                case DIFF_SYMBOL_MOVED_LINE |
1321                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1322                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_DIM);
1323                        break;
1324                case DIFF_SYMBOL_MOVED_LINE:
1325                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED);
1326                        break;
1327                default:
1328                        set = diff_get_color_opt(o, DIFF_FILE_NEW);
1329                }
1330                reset = diff_get_color_opt(o, DIFF_RESET);
1331                if (!o->flags.dual_color_diffed_diffs)
1332                        set_sign = NULL;
1333                else {
1334                        char c = !len ? 0 : line[0];
1335
1336                        set_sign = set;
1337                        if (c == '-')
1338                                set = diff_get_color_opt(o, DIFF_FILE_OLD_BOLD);
1339                        else if (c == '@')
1340                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1341                        else if (c == '+')
1342                                set = diff_get_color_opt(o, DIFF_FILE_NEW_BOLD);
1343                        else
1344                                set = diff_get_color_opt(o, DIFF_CONTEXT_BOLD);
1345                        flags &= ~DIFF_SYMBOL_CONTENT_WS_MASK;
1346                }
1347                emit_line_ws_markup(o, set_sign, set, reset,
1348                                    OUTPUT_INDICATOR_NEW, line, len,
1349                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK,
1350                                    flags & DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF);
1351                break;
1352        case DIFF_SYMBOL_MINUS:
1353                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1354                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1355                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1356                case DIFF_SYMBOL_MOVED_LINE |
1357                     DIFF_SYMBOL_MOVED_LINE_ALT |
1358                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1359                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT_DIM);
1360                        break;
1361                case DIFF_SYMBOL_MOVED_LINE |
1362                     DIFF_SYMBOL_MOVED_LINE_ALT:
1363                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT);
1364                        break;
1365                case DIFF_SYMBOL_MOVED_LINE |
1366                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1367                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_DIM);
1368                        break;
1369                case DIFF_SYMBOL_MOVED_LINE:
1370                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED);
1371                        break;
1372                default:
1373                        set = diff_get_color_opt(o, DIFF_FILE_OLD);
1374                }
1375                reset = diff_get_color_opt(o, DIFF_RESET);
1376                if (!o->flags.dual_color_diffed_diffs)
1377                        set_sign = NULL;
1378                else {
1379                        char c = !len ? 0 : line[0];
1380
1381                        set_sign = set;
1382                        if (c == '+')
1383                                set = diff_get_color_opt(o, DIFF_FILE_NEW_DIM);
1384                        else if (c == '@')
1385                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1386                        else if (c == '-')
1387                                set = diff_get_color_opt(o, DIFF_FILE_OLD_DIM);
1388                        else
1389                                set = diff_get_color_opt(o, DIFF_CONTEXT_DIM);
1390                }
1391                emit_line_ws_markup(o, set_sign, set, reset,
1392                                    OUTPUT_INDICATOR_OLD, line, len,
1393                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK, 0);
1394                break;
1395        case DIFF_SYMBOL_WORDS_PORCELAIN:
1396                context = diff_get_color_opt(o, DIFF_CONTEXT);
1397                reset = diff_get_color_opt(o, DIFF_RESET);
1398                emit_line(o, context, reset, line, len);
1399                fputs("~\n", o->file);
1400                break;
1401        case DIFF_SYMBOL_WORDS:
1402                context = diff_get_color_opt(o, DIFF_CONTEXT);
1403                reset = diff_get_color_opt(o, DIFF_RESET);
1404                /*
1405                 * Skip the prefix character, if any.  With
1406                 * diff_suppress_blank_empty, there may be
1407                 * none.
1408                 */
1409                if (line[0] != '\n') {
1410                        line++;
1411                        len--;
1412                }
1413                emit_line(o, context, reset, line, len);
1414                break;
1415        case DIFF_SYMBOL_FILEPAIR_PLUS:
1416                meta = diff_get_color_opt(o, DIFF_METAINFO);
1417                reset = diff_get_color_opt(o, DIFF_RESET);
1418                fprintf(o->file, "%s%s+++ %s%s%s\n", diff_line_prefix(o), meta,
1419                        line, reset,
1420                        strchr(line, ' ') ? "\t" : "");
1421                break;
1422        case DIFF_SYMBOL_FILEPAIR_MINUS:
1423                meta = diff_get_color_opt(o, DIFF_METAINFO);
1424                reset = diff_get_color_opt(o, DIFF_RESET);
1425                fprintf(o->file, "%s%s--- %s%s%s\n", diff_line_prefix(o), meta,
1426                        line, reset,
1427                        strchr(line, ' ') ? "\t" : "");
1428                break;
1429        case DIFF_SYMBOL_BINARY_FILES:
1430        case DIFF_SYMBOL_HEADER:
1431                fprintf(o->file, "%s", line);
1432                break;
1433        case DIFF_SYMBOL_BINARY_DIFF_HEADER:
1434                fprintf(o->file, "%sGIT binary patch\n", diff_line_prefix(o));
1435                break;
1436        case DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA:
1437                fprintf(o->file, "%sdelta %s\n", diff_line_prefix(o), line);
1438                break;
1439        case DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL:
1440                fprintf(o->file, "%sliteral %s\n", diff_line_prefix(o), line);
1441                break;
1442        case DIFF_SYMBOL_BINARY_DIFF_FOOTER:
1443                fputs(diff_line_prefix(o), o->file);
1444                fputc('\n', o->file);
1445                break;
1446        case DIFF_SYMBOL_REWRITE_DIFF:
1447                fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
1448                reset = diff_get_color_opt(o, DIFF_RESET);
1449                emit_line(o, fraginfo, reset, line, len);
1450                break;
1451        case DIFF_SYMBOL_SUBMODULE_ADD:
1452                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1453                reset = diff_get_color_opt(o, DIFF_RESET);
1454                emit_line(o, set, reset, line, len);
1455                break;
1456        case DIFF_SYMBOL_SUBMODULE_DEL:
1457                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1458                reset = diff_get_color_opt(o, DIFF_RESET);
1459                emit_line(o, set, reset, line, len);
1460                break;
1461        case DIFF_SYMBOL_SUBMODULE_UNTRACKED:
1462                fprintf(o->file, "%sSubmodule %s contains untracked content\n",
1463                        diff_line_prefix(o), line);
1464                break;
1465        case DIFF_SYMBOL_SUBMODULE_MODIFIED:
1466                fprintf(o->file, "%sSubmodule %s contains modified content\n",
1467                        diff_line_prefix(o), line);
1468                break;
1469        case DIFF_SYMBOL_STATS_SUMMARY_NO_FILES:
1470                emit_line(o, "", "", " 0 files changed\n",
1471                          strlen(" 0 files changed\n"));
1472                break;
1473        case DIFF_SYMBOL_STATS_SUMMARY_ABBREV:
1474                emit_line(o, "", "", " ...\n", strlen(" ...\n"));
1475                break;
1476        case DIFF_SYMBOL_WORD_DIFF:
1477                fprintf(o->file, "%.*s", len, line);
1478                break;
1479        case DIFF_SYMBOL_STAT_SEP:
1480                fputs(o->stat_sep, o->file);
1481                break;
1482        default:
1483                BUG("unknown diff symbol");
1484        }
1485        strbuf_release(&sb);
1486}
1487
1488static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
1489                             const char *line, int len, unsigned flags)
1490{
1491        struct emitted_diff_symbol e = {line, len, flags, s};
1492
1493        if (o->emitted_symbols)
1494                append_emitted_diff_symbol(o, &e);
1495        else
1496                emit_diff_symbol_from_struct(o, &e);
1497}
1498
1499void diff_emit_submodule_del(struct diff_options *o, const char *line)
1500{
1501        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_DEL, line, strlen(line), 0);
1502}
1503
1504void diff_emit_submodule_add(struct diff_options *o, const char *line)
1505{
1506        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ADD, line, strlen(line), 0);
1507}
1508
1509void diff_emit_submodule_untracked(struct diff_options *o, const char *path)
1510{
1511        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_UNTRACKED,
1512                         path, strlen(path), 0);
1513}
1514
1515void diff_emit_submodule_modified(struct diff_options *o, const char *path)
1516{
1517        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_MODIFIED,
1518                         path, strlen(path), 0);
1519}
1520
1521void diff_emit_submodule_header(struct diff_options *o, const char *header)
1522{
1523        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_HEADER,
1524                         header, strlen(header), 0);
1525}
1526
1527void diff_emit_submodule_error(struct diff_options *o, const char *err)
1528{
1529        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ERROR, err, strlen(err), 0);
1530}
1531
1532void diff_emit_submodule_pipethrough(struct diff_options *o,
1533                                     const char *line, int len)
1534{
1535        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_PIPETHROUGH, line, len, 0);
1536}
1537
1538static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
1539{
1540        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
1541              ecbdata->blank_at_eof_in_preimage &&
1542              ecbdata->blank_at_eof_in_postimage &&
1543              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
1544              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
1545                return 0;
1546        return ws_blank_line(line, len, ecbdata->ws_rule);
1547}
1548
1549static void emit_add_line(const char *reset,
1550                          struct emit_callback *ecbdata,
1551                          const char *line, int len)
1552{
1553        unsigned flags = WSEH_NEW | ecbdata->ws_rule;
1554        if (new_blank_line_at_eof(ecbdata, line, len))
1555                flags |= DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF;
1556
1557        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_PLUS, line, len, flags);
1558}
1559
1560static void emit_del_line(const char *reset,
1561                          struct emit_callback *ecbdata,
1562                          const char *line, int len)
1563{
1564        unsigned flags = WSEH_OLD | ecbdata->ws_rule;
1565        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_MINUS, line, len, flags);
1566}
1567
1568static void emit_context_line(const char *reset,
1569                              struct emit_callback *ecbdata,
1570                              const char *line, int len)
1571{
1572        unsigned flags = WSEH_CONTEXT | ecbdata->ws_rule;
1573        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_CONTEXT, line, len, flags);
1574}
1575
1576static void emit_hunk_header(struct emit_callback *ecbdata,
1577                             const char *line, int len)
1578{
1579        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
1580        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
1581        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
1582        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1583        const char *reverse = ecbdata->color_diff ? GIT_COLOR_REVERSE : "";
1584        static const char atat[2] = { '@', '@' };
1585        const char *cp, *ep;
1586        struct strbuf msgbuf = STRBUF_INIT;
1587        int org_len = len;
1588        int i = 1;
1589
1590        /*
1591         * As a hunk header must begin with "@@ -<old>, +<new> @@",
1592         * it always is at least 10 bytes long.
1593         */
1594        if (len < 10 ||
1595            memcmp(line, atat, 2) ||
1596            !(ep = memmem(line + 2, len - 2, atat, 2))) {
1597                emit_diff_symbol(ecbdata->opt,
1598                                 DIFF_SYMBOL_CONTEXT_MARKER, line, len, 0);
1599                return;
1600        }
1601        ep += 2; /* skip over @@ */
1602
1603        /* The hunk header in fraginfo color */
1604        if (ecbdata->opt->flags.dual_color_diffed_diffs)
1605                strbuf_addstr(&msgbuf, reverse);
1606        strbuf_addstr(&msgbuf, frag);
1607        strbuf_add(&msgbuf, line, ep - line);
1608        strbuf_addstr(&msgbuf, reset);
1609
1610        /*
1611         * trailing "\r\n"
1612         */
1613        for ( ; i < 3; i++)
1614                if (line[len - i] == '\r' || line[len - i] == '\n')
1615                        len--;
1616
1617        /* blank before the func header */
1618        for (cp = ep; ep - line < len; ep++)
1619                if (*ep != ' ' && *ep != '\t')
1620                        break;
1621        if (ep != cp) {
1622                strbuf_addstr(&msgbuf, context);
1623                strbuf_add(&msgbuf, cp, ep - cp);
1624                strbuf_addstr(&msgbuf, reset);
1625        }
1626
1627        if (ep < line + len) {
1628                strbuf_addstr(&msgbuf, func);
1629                strbuf_add(&msgbuf, ep, line + len - ep);
1630                strbuf_addstr(&msgbuf, reset);
1631        }
1632
1633        strbuf_add(&msgbuf, line + len, org_len - len);
1634        strbuf_complete_line(&msgbuf);
1635        emit_diff_symbol(ecbdata->opt,
1636                         DIFF_SYMBOL_CONTEXT_FRAGINFO, msgbuf.buf, msgbuf.len, 0);
1637        strbuf_release(&msgbuf);
1638}
1639
1640static struct diff_tempfile *claim_diff_tempfile(void) {
1641        int i;
1642        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
1643                if (!diff_temp[i].name)
1644                        return diff_temp + i;
1645        BUG("diff is failing to clean up its tempfiles");
1646}
1647
1648static void remove_tempfile(void)
1649{
1650        int i;
1651        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
1652                if (is_tempfile_active(diff_temp[i].tempfile))
1653                        delete_tempfile(&diff_temp[i].tempfile);
1654                diff_temp[i].name = NULL;
1655        }
1656}
1657
1658static void add_line_count(struct strbuf *out, int count)
1659{
1660        switch (count) {
1661        case 0:
1662                strbuf_addstr(out, "0,0");
1663                break;
1664        case 1:
1665                strbuf_addstr(out, "1");
1666                break;
1667        default:
1668                strbuf_addf(out, "1,%d", count);
1669                break;
1670        }
1671}
1672
1673static void emit_rewrite_lines(struct emit_callback *ecb,
1674                               int prefix, const char *data, int size)
1675{
1676        const char *endp = NULL;
1677        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
1678
1679        while (0 < size) {
1680                int len;
1681
1682                endp = memchr(data, '\n', size);
1683                len = endp ? (endp - data + 1) : size;
1684                if (prefix != '+') {
1685                        ecb->lno_in_preimage++;
1686                        emit_del_line(reset, ecb, data, len);
1687                } else {
1688                        ecb->lno_in_postimage++;
1689                        emit_add_line(reset, ecb, data, len);
1690                }
1691                size -= len;
1692                data += len;
1693        }
1694        if (!endp)
1695                emit_diff_symbol(ecb->opt, DIFF_SYMBOL_NO_LF_EOF, NULL, 0, 0);
1696}
1697
1698static void emit_rewrite_diff(const char *name_a,
1699                              const char *name_b,
1700                              struct diff_filespec *one,
1701                              struct diff_filespec *two,
1702                              struct userdiff_driver *textconv_one,
1703                              struct userdiff_driver *textconv_two,
1704                              struct diff_options *o)
1705{
1706        int lc_a, lc_b;
1707        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
1708        const char *a_prefix, *b_prefix;
1709        char *data_one, *data_two;
1710        size_t size_one, size_two;
1711        struct emit_callback ecbdata;
1712        struct strbuf out = STRBUF_INIT;
1713
1714        if (diff_mnemonic_prefix && o->flags.reverse_diff) {
1715                a_prefix = o->b_prefix;
1716                b_prefix = o->a_prefix;
1717        } else {
1718                a_prefix = o->a_prefix;
1719                b_prefix = o->b_prefix;
1720        }
1721
1722        name_a += (*name_a == '/');
1723        name_b += (*name_b == '/');
1724
1725        strbuf_reset(&a_name);
1726        strbuf_reset(&b_name);
1727        quote_two_c_style(&a_name, a_prefix, name_a, 0);
1728        quote_two_c_style(&b_name, b_prefix, name_b, 0);
1729
1730        size_one = fill_textconv(o->repo, textconv_one, one, &data_one);
1731        size_two = fill_textconv(o->repo, textconv_two, two, &data_two);
1732
1733        memset(&ecbdata, 0, sizeof(ecbdata));
1734        ecbdata.color_diff = want_color(o->use_color);
1735        ecbdata.ws_rule = whitespace_rule(o->repo->index, name_b);
1736        ecbdata.opt = o;
1737        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
1738                mmfile_t mf1, mf2;
1739                mf1.ptr = (char *)data_one;
1740                mf2.ptr = (char *)data_two;
1741                mf1.size = size_one;
1742                mf2.size = size_two;
1743                check_blank_at_eof(&mf1, &mf2, &ecbdata);
1744        }
1745        ecbdata.lno_in_preimage = 1;
1746        ecbdata.lno_in_postimage = 1;
1747
1748        lc_a = count_lines(data_one, size_one);
1749        lc_b = count_lines(data_two, size_two);
1750
1751        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
1752                         a_name.buf, a_name.len, 0);
1753        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
1754                         b_name.buf, b_name.len, 0);
1755
1756        strbuf_addstr(&out, "@@ -");
1757        if (!o->irreversible_delete)
1758                add_line_count(&out, lc_a);
1759        else
1760                strbuf_addstr(&out, "?,?");
1761        strbuf_addstr(&out, " +");
1762        add_line_count(&out, lc_b);
1763        strbuf_addstr(&out, " @@\n");
1764        emit_diff_symbol(o, DIFF_SYMBOL_REWRITE_DIFF, out.buf, out.len, 0);
1765        strbuf_release(&out);
1766
1767        if (lc_a && !o->irreversible_delete)
1768                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
1769        if (lc_b)
1770                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
1771        if (textconv_one)
1772                free((char *)data_one);
1773        if (textconv_two)
1774                free((char *)data_two);
1775}
1776
1777struct diff_words_buffer {
1778        mmfile_t text;
1779        unsigned long alloc;
1780        struct diff_words_orig {
1781                const char *begin, *end;
1782        } *orig;
1783        int orig_nr, orig_alloc;
1784};
1785
1786static void diff_words_append(char *line, unsigned long len,
1787                struct diff_words_buffer *buffer)
1788{
1789        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
1790        line++;
1791        len--;
1792        memcpy(buffer->text.ptr + buffer->text.size, line, len);
1793        buffer->text.size += len;
1794        buffer->text.ptr[buffer->text.size] = '\0';
1795}
1796
1797struct diff_words_style_elem {
1798        const char *prefix;
1799        const char *suffix;
1800        const char *color; /* NULL; filled in by the setup code if
1801                            * color is enabled */
1802};
1803
1804struct diff_words_style {
1805        enum diff_words_type type;
1806        struct diff_words_style_elem new_word, old_word, ctx;
1807        const char *newline;
1808};
1809
1810static struct diff_words_style diff_words_styles[] = {
1811        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
1812        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
1813        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
1814};
1815
1816struct diff_words_data {
1817        struct diff_words_buffer minus, plus;
1818        const char *current_plus;
1819        int last_minus;
1820        struct diff_options *opt;
1821        regex_t *word_regex;
1822        enum diff_words_type type;
1823        struct diff_words_style *style;
1824};
1825
1826static int fn_out_diff_words_write_helper(struct diff_options *o,
1827                                          struct diff_words_style_elem *st_el,
1828                                          const char *newline,
1829                                          size_t count, const char *buf)
1830{
1831        int print = 0;
1832        struct strbuf sb = STRBUF_INIT;
1833
1834        while (count) {
1835                char *p = memchr(buf, '\n', count);
1836                if (print)
1837                        strbuf_addstr(&sb, diff_line_prefix(o));
1838
1839                if (p != buf) {
1840                        const char *reset = st_el->color && *st_el->color ?
1841                                            GIT_COLOR_RESET : NULL;
1842                        if (st_el->color && *st_el->color)
1843                                strbuf_addstr(&sb, st_el->color);
1844                        strbuf_addstr(&sb, st_el->prefix);
1845                        strbuf_add(&sb, buf, p ? p - buf : count);
1846                        strbuf_addstr(&sb, st_el->suffix);
1847                        if (reset)
1848                                strbuf_addstr(&sb, reset);
1849                }
1850                if (!p)
1851                        goto out;
1852
1853                strbuf_addstr(&sb, newline);
1854                count -= p + 1 - buf;
1855                buf = p + 1;
1856                print = 1;
1857                if (count) {
1858                        emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1859                                         sb.buf, sb.len, 0);
1860                        strbuf_reset(&sb);
1861                }
1862        }
1863
1864out:
1865        if (sb.len)
1866                emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1867                                 sb.buf, sb.len, 0);
1868        strbuf_release(&sb);
1869        return 0;
1870}
1871
1872/*
1873 * '--color-words' algorithm can be described as:
1874 *
1875 *   1. collect the minus/plus lines of a diff hunk, divided into
1876 *      minus-lines and plus-lines;
1877 *
1878 *   2. break both minus-lines and plus-lines into words and
1879 *      place them into two mmfile_t with one word for each line;
1880 *
1881 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
1882 *
1883 * And for the common parts of the both file, we output the plus side text.
1884 * diff_words->current_plus is used to trace the current position of the plus file
1885 * which printed. diff_words->last_minus is used to trace the last minus word
1886 * printed.
1887 *
1888 * For '--graph' to work with '--color-words', we need to output the graph prefix
1889 * on each line of color words output. Generally, there are two conditions on
1890 * which we should output the prefix.
1891 *
1892 *   1. diff_words->last_minus == 0 &&
1893 *      diff_words->current_plus == diff_words->plus.text.ptr
1894 *
1895 *      that is: the plus text must start as a new line, and if there is no minus
1896 *      word printed, a graph prefix must be printed.
1897 *
1898 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
1899 *      *(diff_words->current_plus - 1) == '\n'
1900 *
1901 *      that is: a graph prefix must be printed following a '\n'
1902 */
1903static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
1904{
1905        if ((diff_words->last_minus == 0 &&
1906                diff_words->current_plus == diff_words->plus.text.ptr) ||
1907                (diff_words->current_plus > diff_words->plus.text.ptr &&
1908                *(diff_words->current_plus - 1) == '\n')) {
1909                return 1;
1910        } else {
1911                return 0;
1912        }
1913}
1914
1915static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
1916{
1917        struct diff_words_data *diff_words = priv;
1918        struct diff_words_style *style = diff_words->style;
1919        int minus_first, minus_len, plus_first, plus_len;
1920        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
1921        struct diff_options *opt = diff_words->opt;
1922        const char *line_prefix;
1923
1924        if (line[0] != '@' || parse_hunk_header(line, len,
1925                        &minus_first, &minus_len, &plus_first, &plus_len))
1926                return;
1927
1928        assert(opt);
1929        line_prefix = diff_line_prefix(opt);
1930
1931        /* POSIX requires that first be decremented by one if len == 0... */
1932        if (minus_len) {
1933                minus_begin = diff_words->minus.orig[minus_first].begin;
1934                minus_end =
1935                        diff_words->minus.orig[minus_first + minus_len - 1].end;
1936        } else
1937                minus_begin = minus_end =
1938                        diff_words->minus.orig[minus_first].end;
1939
1940        if (plus_len) {
1941                plus_begin = diff_words->plus.orig[plus_first].begin;
1942                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
1943        } else
1944                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
1945
1946        if (color_words_output_graph_prefix(diff_words)) {
1947                fputs(line_prefix, diff_words->opt->file);
1948        }
1949        if (diff_words->current_plus != plus_begin) {
1950                fn_out_diff_words_write_helper(diff_words->opt,
1951                                &style->ctx, style->newline,
1952                                plus_begin - diff_words->current_plus,
1953                                diff_words->current_plus);
1954        }
1955        if (minus_begin != minus_end) {
1956                fn_out_diff_words_write_helper(diff_words->opt,
1957                                &style->old_word, style->newline,
1958                                minus_end - minus_begin, minus_begin);
1959        }
1960        if (plus_begin != plus_end) {
1961                fn_out_diff_words_write_helper(diff_words->opt,
1962                                &style->new_word, style->newline,
1963                                plus_end - plus_begin, plus_begin);
1964        }
1965
1966        diff_words->current_plus = plus_end;
1967        diff_words->last_minus = minus_first;
1968}
1969
1970/* This function starts looking at *begin, and returns 0 iff a word was found. */
1971static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
1972                int *begin, int *end)
1973{
1974        if (word_regex && *begin < buffer->size) {
1975                regmatch_t match[1];
1976                if (!regexec_buf(word_regex, buffer->ptr + *begin,
1977                                 buffer->size - *begin, 1, match, 0)) {
1978                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
1979                                        '\n', match[0].rm_eo - match[0].rm_so);
1980                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
1981                        *begin += match[0].rm_so;
1982                        return *begin >= *end;
1983                }
1984                return -1;
1985        }
1986
1987        /* find the next word */
1988        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
1989                (*begin)++;
1990        if (*begin >= buffer->size)
1991                return -1;
1992
1993        /* find the end of the word */
1994        *end = *begin + 1;
1995        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
1996                (*end)++;
1997
1998        return 0;
1999}
2000
2001/*
2002 * This function splits the words in buffer->text, stores the list with
2003 * newline separator into out, and saves the offsets of the original words
2004 * in buffer->orig.
2005 */
2006static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
2007                regex_t *word_regex)
2008{
2009        int i, j;
2010        long alloc = 0;
2011
2012        out->size = 0;
2013        out->ptr = NULL;
2014
2015        /* fake an empty "0th" word */
2016        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
2017        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
2018        buffer->orig_nr = 1;
2019
2020        for (i = 0; i < buffer->text.size; i++) {
2021                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
2022                        return;
2023
2024                /* store original boundaries */
2025                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
2026                                buffer->orig_alloc);
2027                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
2028                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
2029                buffer->orig_nr++;
2030
2031                /* store one word */
2032                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
2033                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
2034                out->ptr[out->size + j - i] = '\n';
2035                out->size += j - i + 1;
2036
2037                i = j - 1;
2038        }
2039}
2040
2041/* this executes the word diff on the accumulated buffers */
2042static void diff_words_show(struct diff_words_data *diff_words)
2043{
2044        xpparam_t xpp;
2045        xdemitconf_t xecfg;
2046        mmfile_t minus, plus;
2047        struct diff_words_style *style = diff_words->style;
2048
2049        struct diff_options *opt = diff_words->opt;
2050        const char *line_prefix;
2051
2052        assert(opt);
2053        line_prefix = diff_line_prefix(opt);
2054
2055        /* special case: only removal */
2056        if (!diff_words->plus.text.size) {
2057                emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
2058                                 line_prefix, strlen(line_prefix), 0);
2059                fn_out_diff_words_write_helper(diff_words->opt,
2060                        &style->old_word, style->newline,
2061                        diff_words->minus.text.size,
2062                        diff_words->minus.text.ptr);
2063                diff_words->minus.text.size = 0;
2064                return;
2065        }
2066
2067        diff_words->current_plus = diff_words->plus.text.ptr;
2068        diff_words->last_minus = 0;
2069
2070        memset(&xpp, 0, sizeof(xpp));
2071        memset(&xecfg, 0, sizeof(xecfg));
2072        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
2073        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
2074        xpp.flags = 0;
2075        /* as only the hunk header will be parsed, we need a 0-context */
2076        xecfg.ctxlen = 0;
2077        if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
2078                          &xpp, &xecfg))
2079                die("unable to generate word diff");
2080        free(minus.ptr);
2081        free(plus.ptr);
2082        if (diff_words->current_plus != diff_words->plus.text.ptr +
2083                        diff_words->plus.text.size) {
2084                if (color_words_output_graph_prefix(diff_words))
2085                        emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
2086                                         line_prefix, strlen(line_prefix), 0);
2087                fn_out_diff_words_write_helper(diff_words->opt,
2088                        &style->ctx, style->newline,
2089                        diff_words->plus.text.ptr + diff_words->plus.text.size
2090                        - diff_words->current_plus, diff_words->current_plus);
2091        }
2092        diff_words->minus.text.size = diff_words->plus.text.size = 0;
2093}
2094
2095/* In "color-words" mode, show word-diff of words accumulated in the buffer */
2096static void diff_words_flush(struct emit_callback *ecbdata)
2097{
2098        struct diff_options *wo = ecbdata->diff_words->opt;
2099
2100        if (ecbdata->diff_words->minus.text.size ||
2101            ecbdata->diff_words->plus.text.size)
2102                diff_words_show(ecbdata->diff_words);
2103
2104        if (wo->emitted_symbols) {
2105                struct diff_options *o = ecbdata->opt;
2106                struct emitted_diff_symbols *wol = wo->emitted_symbols;
2107                int i;
2108
2109                /*
2110                 * NEEDSWORK:
2111                 * Instead of appending each, concat all words to a line?
2112                 */
2113                for (i = 0; i < wol->nr; i++)
2114                        append_emitted_diff_symbol(o, &wol->buf[i]);
2115
2116                for (i = 0; i < wol->nr; i++)
2117                        free((void *)wol->buf[i].line);
2118
2119                wol->nr = 0;
2120        }
2121}
2122
2123static void diff_filespec_load_driver(struct diff_filespec *one,
2124                                      struct index_state *istate)
2125{
2126        /* Use already-loaded driver */
2127        if (one->driver)
2128                return;
2129
2130        if (S_ISREG(one->mode))
2131                one->driver = userdiff_find_by_path(istate, one->path);
2132
2133        /* Fallback to default settings */
2134        if (!one->driver)
2135                one->driver = userdiff_find_by_name("default");
2136}
2137
2138static const char *userdiff_word_regex(struct diff_filespec *one,
2139                                       struct index_state *istate)
2140{
2141        diff_filespec_load_driver(one, istate);
2142        return one->driver->word_regex;
2143}
2144
2145static void init_diff_words_data(struct emit_callback *ecbdata,
2146                                 struct diff_options *orig_opts,
2147                                 struct diff_filespec *one,
2148                                 struct diff_filespec *two)
2149{
2150        int i;
2151        struct diff_options *o = xmalloc(sizeof(struct diff_options));
2152        memcpy(o, orig_opts, sizeof(struct diff_options));
2153
2154        ecbdata->diff_words =
2155                xcalloc(1, sizeof(struct diff_words_data));
2156        ecbdata->diff_words->type = o->word_diff;
2157        ecbdata->diff_words->opt = o;
2158
2159        if (orig_opts->emitted_symbols)
2160                o->emitted_symbols =
2161                        xcalloc(1, sizeof(struct emitted_diff_symbols));
2162
2163        if (!o->word_regex)
2164                o->word_regex = userdiff_word_regex(one, o->repo->index);
2165        if (!o->word_regex)
2166                o->word_regex = userdiff_word_regex(two, o->repo->index);
2167        if (!o->word_regex)
2168                o->word_regex = diff_word_regex_cfg;
2169        if (o->word_regex) {
2170                ecbdata->diff_words->word_regex = (regex_t *)
2171                        xmalloc(sizeof(regex_t));
2172                if (regcomp(ecbdata->diff_words->word_regex,
2173                            o->word_regex,
2174                            REG_EXTENDED | REG_NEWLINE))
2175                        die("invalid regular expression: %s",
2176                            o->word_regex);
2177        }
2178        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2179                if (o->word_diff == diff_words_styles[i].type) {
2180                        ecbdata->diff_words->style =
2181                                &diff_words_styles[i];
2182                        break;
2183                }
2184        }
2185        if (want_color(o->use_color)) {
2186                struct diff_words_style *st = ecbdata->diff_words->style;
2187                st->old_word.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2188                st->new_word.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2189                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
2190        }
2191}
2192
2193static void free_diff_words_data(struct emit_callback *ecbdata)
2194{
2195        if (ecbdata->diff_words) {
2196                diff_words_flush(ecbdata);
2197                free (ecbdata->diff_words->opt->emitted_symbols);
2198                free (ecbdata->diff_words->opt);
2199                free (ecbdata->diff_words->minus.text.ptr);
2200                free (ecbdata->diff_words->minus.orig);
2201                free (ecbdata->diff_words->plus.text.ptr);
2202                free (ecbdata->diff_words->plus.orig);
2203                if (ecbdata->diff_words->word_regex) {
2204                        regfree(ecbdata->diff_words->word_regex);
2205                        free(ecbdata->diff_words->word_regex);
2206                }
2207                FREE_AND_NULL(ecbdata->diff_words);
2208        }
2209}
2210
2211const char *diff_get_color(int diff_use_color, enum color_diff ix)
2212{
2213        if (want_color(diff_use_color))
2214                return diff_colors[ix];
2215        return "";
2216}
2217
2218const char *diff_line_prefix(struct diff_options *opt)
2219{
2220        struct strbuf *msgbuf;
2221        if (!opt->output_prefix)
2222                return "";
2223
2224        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
2225        return msgbuf->buf;
2226}
2227
2228static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
2229{
2230        const char *cp;
2231        unsigned long allot;
2232        size_t l = len;
2233
2234        cp = line;
2235        allot = l;
2236        while (0 < l) {
2237                (void) utf8_width(&cp, &l);
2238                if (!cp)
2239                        break; /* truncated in the middle? */
2240        }
2241        return allot - l;
2242}
2243
2244static void find_lno(const char *line, struct emit_callback *ecbdata)
2245{
2246        const char *p;
2247        ecbdata->lno_in_preimage = 0;
2248        ecbdata->lno_in_postimage = 0;
2249        p = strchr(line, '-');
2250        if (!p)
2251                return; /* cannot happen */
2252        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
2253        p = strchr(p, '+');
2254        if (!p)
2255                return; /* cannot happen */
2256        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
2257}
2258
2259static void fn_out_consume(void *priv, char *line, unsigned long len)
2260{
2261        struct emit_callback *ecbdata = priv;
2262        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
2263        struct diff_options *o = ecbdata->opt;
2264
2265        o->found_changes = 1;
2266
2267        if (ecbdata->header) {
2268                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
2269                                 ecbdata->header->buf, ecbdata->header->len, 0);
2270                strbuf_reset(ecbdata->header);
2271                ecbdata->header = NULL;
2272        }
2273
2274        if (ecbdata->label_path[0]) {
2275                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
2276                                 ecbdata->label_path[0],
2277                                 strlen(ecbdata->label_path[0]), 0);
2278                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
2279                                 ecbdata->label_path[1],
2280                                 strlen(ecbdata->label_path[1]), 0);
2281                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
2282        }
2283
2284        if (diff_suppress_blank_empty
2285            && len == 2 && line[0] == ' ' && line[1] == '\n') {
2286                line[0] = '\n';
2287                len = 1;
2288        }
2289
2290        if (line[0] == '@') {
2291                if (ecbdata->diff_words)
2292                        diff_words_flush(ecbdata);
2293                len = sane_truncate_line(ecbdata, line, len);
2294                find_lno(line, ecbdata);
2295                emit_hunk_header(ecbdata, line, len);
2296                return;
2297        }
2298
2299        if (ecbdata->diff_words) {
2300                enum diff_symbol s =
2301                        ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN ?
2302                        DIFF_SYMBOL_WORDS_PORCELAIN : DIFF_SYMBOL_WORDS;
2303                if (line[0] == '-') {
2304                        diff_words_append(line, len,
2305                                          &ecbdata->diff_words->minus);
2306                        return;
2307                } else if (line[0] == '+') {
2308                        diff_words_append(line, len,
2309                                          &ecbdata->diff_words->plus);
2310                        return;
2311                } else if (starts_with(line, "\\ ")) {
2312                        /*
2313                         * Eat the "no newline at eof" marker as if we
2314                         * saw a "+" or "-" line with nothing on it,
2315                         * and return without diff_words_flush() to
2316                         * defer processing. If this is the end of
2317                         * preimage, more "+" lines may come after it.
2318                         */
2319                        return;
2320                }
2321                diff_words_flush(ecbdata);
2322                emit_diff_symbol(o, s, line, len, 0);
2323                return;
2324        }
2325
2326        switch (line[0]) {
2327        case '+':
2328                ecbdata->lno_in_postimage++;
2329                emit_add_line(reset, ecbdata, line + 1, len - 1);
2330                break;
2331        case '-':
2332                ecbdata->lno_in_preimage++;
2333                emit_del_line(reset, ecbdata, line + 1, len - 1);
2334                break;
2335        case ' ':
2336                ecbdata->lno_in_postimage++;
2337                ecbdata->lno_in_preimage++;
2338                emit_context_line(reset, ecbdata, line + 1, len - 1);
2339                break;
2340        default:
2341                /* incomplete line at the end */
2342                ecbdata->lno_in_preimage++;
2343                emit_diff_symbol(o, DIFF_SYMBOL_CONTEXT_INCOMPLETE,
2344                                 line, len, 0);
2345                break;
2346        }
2347}
2348
2349static void pprint_rename(struct strbuf *name, const char *a, const char *b)
2350{
2351        const char *old_name = a;
2352        const char *new_name = b;
2353        int pfx_length, sfx_length;
2354        int pfx_adjust_for_slash;
2355        int len_a = strlen(a);
2356        int len_b = strlen(b);
2357        int a_midlen, b_midlen;
2358        int qlen_a = quote_c_style(a, NULL, NULL, 0);
2359        int qlen_b = quote_c_style(b, NULL, NULL, 0);
2360
2361        if (qlen_a || qlen_b) {
2362                quote_c_style(a, name, NULL, 0);
2363                strbuf_addstr(name, " => ");
2364                quote_c_style(b, name, NULL, 0);
2365                return;
2366        }
2367
2368        /* Find common prefix */
2369        pfx_length = 0;
2370        while (*old_name && *new_name && *old_name == *new_name) {
2371                if (*old_name == '/')
2372                        pfx_length = old_name - a + 1;
2373                old_name++;
2374                new_name++;
2375        }
2376
2377        /* Find common suffix */
2378        old_name = a + len_a;
2379        new_name = b + len_b;
2380        sfx_length = 0;
2381        /*
2382         * If there is a common prefix, it must end in a slash.  In
2383         * that case we let this loop run 1 into the prefix to see the
2384         * same slash.
2385         *
2386         * If there is no common prefix, we cannot do this as it would
2387         * underrun the input strings.
2388         */
2389        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
2390        while (a + pfx_length - pfx_adjust_for_slash <= old_name &&
2391               b + pfx_length - pfx_adjust_for_slash <= new_name &&
2392               *old_name == *new_name) {
2393                if (*old_name == '/')
2394                        sfx_length = len_a - (old_name - a);
2395                old_name--;
2396                new_name--;
2397        }
2398
2399        /*
2400         * pfx{mid-a => mid-b}sfx
2401         * {pfx-a => pfx-b}sfx
2402         * pfx{sfx-a => sfx-b}
2403         * name-a => name-b
2404         */
2405        a_midlen = len_a - pfx_length - sfx_length;
2406        b_midlen = len_b - pfx_length - sfx_length;
2407        if (a_midlen < 0)
2408                a_midlen = 0;
2409        if (b_midlen < 0)
2410                b_midlen = 0;
2411
2412        strbuf_grow(name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
2413        if (pfx_length + sfx_length) {
2414                strbuf_add(name, a, pfx_length);
2415                strbuf_addch(name, '{');
2416        }
2417        strbuf_add(name, a + pfx_length, a_midlen);
2418        strbuf_addstr(name, " => ");
2419        strbuf_add(name, b + pfx_length, b_midlen);
2420        if (pfx_length + sfx_length) {
2421                strbuf_addch(name, '}');
2422                strbuf_add(name, a + len_a - sfx_length, sfx_length);
2423        }
2424}
2425
2426struct diffstat_t {
2427        int nr;
2428        int alloc;
2429        struct diffstat_file {
2430                char *from_name;
2431                char *name;
2432                char *print_name;
2433                const char *comments;
2434                unsigned is_unmerged:1;
2435                unsigned is_binary:1;
2436                unsigned is_renamed:1;
2437                unsigned is_interesting:1;
2438                uintmax_t added, deleted;
2439        } **files;
2440};
2441
2442static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
2443                                          const char *name_a,
2444                                          const char *name_b)
2445{
2446        struct diffstat_file *x;
2447        x = xcalloc(1, sizeof(*x));
2448        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
2449        diffstat->files[diffstat->nr++] = x;
2450        if (name_b) {
2451                x->from_name = xstrdup(name_a);
2452                x->name = xstrdup(name_b);
2453                x->is_renamed = 1;
2454        }
2455        else {
2456                x->from_name = NULL;
2457                x->name = xstrdup(name_a);
2458        }
2459        return x;
2460}
2461
2462static void diffstat_consume(void *priv, char *line, unsigned long len)
2463{
2464        struct diffstat_t *diffstat = priv;
2465        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
2466
2467        if (line[0] == '+')
2468                x->added++;
2469        else if (line[0] == '-')
2470                x->deleted++;
2471}
2472
2473const char mime_boundary_leader[] = "------------";
2474
2475static int scale_linear(int it, int width, int max_change)
2476{
2477        if (!it)
2478                return 0;
2479        /*
2480         * make sure that at least one '-' or '+' is printed if
2481         * there is any change to this path. The easiest way is to
2482         * scale linearly as if the alloted width is one column shorter
2483         * than it is, and then add 1 to the result.
2484         */
2485        return 1 + (it * (width - 1) / max_change);
2486}
2487
2488static void show_graph(struct strbuf *out, char ch, int cnt,
2489                       const char *set, const char *reset)
2490{
2491        if (cnt <= 0)
2492                return;
2493        strbuf_addstr(out, set);
2494        strbuf_addchars(out, ch, cnt);
2495        strbuf_addstr(out, reset);
2496}
2497
2498static void fill_print_name(struct diffstat_file *file)
2499{
2500        struct strbuf pname = STRBUF_INIT;
2501
2502        if (file->print_name)
2503                return;
2504
2505        if (file->is_renamed)
2506                pprint_rename(&pname, file->from_name, file->name);
2507        else
2508                quote_c_style(file->name, &pname, NULL, 0);
2509
2510        if (file->comments)
2511                strbuf_addf(&pname, " (%s)", file->comments);
2512
2513        file->print_name = strbuf_detach(&pname, NULL);
2514}
2515
2516static void print_stat_summary_inserts_deletes(struct diff_options *options,
2517                int files, int insertions, int deletions)
2518{
2519        struct strbuf sb = STRBUF_INIT;
2520
2521        if (!files) {
2522                assert(insertions == 0 && deletions == 0);
2523                emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
2524                                 NULL, 0, 0);
2525                return;
2526        }
2527
2528        strbuf_addf(&sb,
2529                    (files == 1) ? " %d file changed" : " %d files changed",
2530                    files);
2531
2532        /*
2533         * For binary diff, the caller may want to print "x files
2534         * changed" with insertions == 0 && deletions == 0.
2535         *
2536         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
2537         * is probably less confusing (i.e skip over "2 files changed
2538         * but nothing about added/removed lines? Is this a bug in Git?").
2539         */
2540        if (insertions || deletions == 0) {
2541                strbuf_addf(&sb,
2542                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
2543                            insertions);
2544        }
2545
2546        if (deletions || insertions == 0) {
2547                strbuf_addf(&sb,
2548                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
2549                            deletions);
2550        }
2551        strbuf_addch(&sb, '\n');
2552        emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
2553                         sb.buf, sb.len, 0);
2554        strbuf_release(&sb);
2555}
2556
2557void print_stat_summary(FILE *fp, int files,
2558                        int insertions, int deletions)
2559{
2560        struct diff_options o;
2561        memset(&o, 0, sizeof(o));
2562        o.file = fp;
2563
2564        print_stat_summary_inserts_deletes(&o, files, insertions, deletions);
2565}
2566
2567static void show_stats(struct diffstat_t *data, struct diff_options *options)
2568{
2569        int i, len, add, del, adds = 0, dels = 0;
2570        uintmax_t max_change = 0, max_len = 0;
2571        int total_files = data->nr, count;
2572        int width, name_width, graph_width, number_width = 0, bin_width = 0;
2573        const char *reset, *add_c, *del_c;
2574        int extra_shown = 0;
2575        const char *line_prefix = diff_line_prefix(options);
2576        struct strbuf out = STRBUF_INIT;
2577
2578        if (data->nr == 0)
2579                return;
2580
2581        count = options->stat_count ? options->stat_count : data->nr;
2582
2583        reset = diff_get_color_opt(options, DIFF_RESET);
2584        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
2585        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
2586
2587        /*
2588         * Find the longest filename and max number of changes
2589         */
2590        for (i = 0; (i < count) && (i < data->nr); i++) {
2591                struct diffstat_file *file = data->files[i];
2592                uintmax_t change = file->added + file->deleted;
2593
2594                if (!file->is_interesting && (change == 0)) {
2595                        count++; /* not shown == room for one more */
2596                        continue;
2597                }
2598                fill_print_name(file);
2599                len = strlen(file->print_name);
2600                if (max_len < len)
2601                        max_len = len;
2602
2603                if (file->is_unmerged) {
2604                        /* "Unmerged" is 8 characters */
2605                        bin_width = bin_width < 8 ? 8 : bin_width;
2606                        continue;
2607                }
2608                if (file->is_binary) {
2609                        /* "Bin XXX -> YYY bytes" */
2610                        int w = 14 + decimal_width(file->added)
2611                                + decimal_width(file->deleted);
2612                        bin_width = bin_width < w ? w : bin_width;
2613                        /* Display change counts aligned with "Bin" */
2614                        number_width = 3;
2615                        continue;
2616                }
2617
2618                if (max_change < change)
2619                        max_change = change;
2620        }
2621        count = i; /* where we can stop scanning in data->files[] */
2622
2623        /*
2624         * We have width = stat_width or term_columns() columns total.
2625         * We want a maximum of min(max_len, stat_name_width) for the name part.
2626         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
2627         * We also need 1 for " " and 4 + decimal_width(max_change)
2628         * for " | NNNN " and one the empty column at the end, altogether
2629         * 6 + decimal_width(max_change).
2630         *
2631         * If there's not enough space, we will use the smaller of
2632         * stat_name_width (if set) and 5/8*width for the filename,
2633         * and the rest for constant elements + graph part, but no more
2634         * than stat_graph_width for the graph part.
2635         * (5/8 gives 50 for filename and 30 for the constant parts + graph
2636         * for the standard terminal size).
2637         *
2638         * In other words: stat_width limits the maximum width, and
2639         * stat_name_width fixes the maximum width of the filename,
2640         * and is also used to divide available columns if there
2641         * aren't enough.
2642         *
2643         * Binary files are displayed with "Bin XXX -> YYY bytes"
2644         * instead of the change count and graph. This part is treated
2645         * similarly to the graph part, except that it is not
2646         * "scaled". If total width is too small to accommodate the
2647         * guaranteed minimum width of the filename part and the
2648         * separators and this message, this message will "overflow"
2649         * making the line longer than the maximum width.
2650         */
2651
2652        if (options->stat_width == -1)
2653                width = term_columns() - strlen(line_prefix);
2654        else
2655                width = options->stat_width ? options->stat_width : 80;
2656        number_width = decimal_width(max_change) > number_width ?
2657                decimal_width(max_change) : number_width;
2658
2659        if (options->stat_graph_width == -1)
2660                options->stat_graph_width = diff_stat_graph_width;
2661
2662        /*
2663         * Guarantee 3/8*16==6 for the graph part
2664         * and 5/8*16==10 for the filename part
2665         */
2666        if (width < 16 + 6 + number_width)
2667                width = 16 + 6 + number_width;
2668
2669        /*
2670         * First assign sizes that are wanted, ignoring available width.
2671         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
2672         * starting from "XXX" should fit in graph_width.
2673         */
2674        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
2675        if (options->stat_graph_width &&
2676            options->stat_graph_width < graph_width)
2677                graph_width = options->stat_graph_width;
2678
2679        name_width = (options->stat_name_width > 0 &&
2680                      options->stat_name_width < max_len) ?
2681                options->stat_name_width : max_len;
2682
2683        /*
2684         * Adjust adjustable widths not to exceed maximum width
2685         */
2686        if (name_width + number_width + 6 + graph_width > width) {
2687                if (graph_width > width * 3/8 - number_width - 6) {
2688                        graph_width = width * 3/8 - number_width - 6;
2689                        if (graph_width < 6)
2690                                graph_width = 6;
2691                }
2692
2693                if (options->stat_graph_width &&
2694                    graph_width > options->stat_graph_width)
2695                        graph_width = options->stat_graph_width;
2696                if (name_width > width - number_width - 6 - graph_width)
2697                        name_width = width - number_width - 6 - graph_width;
2698                else
2699                        graph_width = width - number_width - 6 - name_width;
2700        }
2701
2702        /*
2703         * From here name_width is the width of the name area,
2704         * and graph_width is the width of the graph area.
2705         * max_change is used to scale graph properly.
2706         */
2707        for (i = 0; i < count; i++) {
2708                const char *prefix = "";
2709                struct diffstat_file *file = data->files[i];
2710                char *name = file->print_name;
2711                uintmax_t added = file->added;
2712                uintmax_t deleted = file->deleted;
2713                int name_len;
2714
2715                if (!file->is_interesting && (added + deleted == 0))
2716                        continue;
2717
2718                /*
2719                 * "scale" the filename
2720                 */
2721                len = name_width;
2722                name_len = strlen(name);
2723                if (name_width < name_len) {
2724                        char *slash;
2725                        prefix = "...";
2726                        len -= 3;
2727                        name += name_len - len;
2728                        slash = strchr(name, '/');
2729                        if (slash)
2730                                name = slash;
2731                }
2732
2733                if (file->is_binary) {
2734                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2735                        strbuf_addf(&out, " %*s", number_width, "Bin");
2736                        if (!added && !deleted) {
2737                                strbuf_addch(&out, '\n');
2738                                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2739                                                 out.buf, out.len, 0);
2740                                strbuf_reset(&out);
2741                                continue;
2742                        }
2743                        strbuf_addf(&out, " %s%"PRIuMAX"%s",
2744                                del_c, deleted, reset);
2745                        strbuf_addstr(&out, " -> ");
2746                        strbuf_addf(&out, "%s%"PRIuMAX"%s",
2747                                add_c, added, reset);
2748                        strbuf_addstr(&out, " bytes\n");
2749                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2750                                         out.buf, out.len, 0);
2751                        strbuf_reset(&out);
2752                        continue;
2753                }
2754                else if (file->is_unmerged) {
2755                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2756                        strbuf_addstr(&out, " Unmerged\n");
2757                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2758                                         out.buf, out.len, 0);
2759                        strbuf_reset(&out);
2760                        continue;
2761                }
2762
2763                /*
2764                 * scale the add/delete
2765                 */
2766                add = added;
2767                del = deleted;
2768
2769                if (graph_width <= max_change) {
2770                        int total = scale_linear(add + del, graph_width, max_change);
2771                        if (total < 2 && add && del)
2772                                /* width >= 2 due to the sanity check */
2773                                total = 2;
2774                        if (add < del) {
2775                                add = scale_linear(add, graph_width, max_change);
2776                                del = total - add;
2777                        } else {
2778                                del = scale_linear(del, graph_width, max_change);
2779                                add = total - del;
2780                        }
2781                }
2782                strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2783                strbuf_addf(&out, " %*"PRIuMAX"%s",
2784                        number_width, added + deleted,
2785                        added + deleted ? " " : "");
2786                show_graph(&out, '+', add, add_c, reset);
2787                show_graph(&out, '-', del, del_c, reset);
2788                strbuf_addch(&out, '\n');
2789                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2790                                 out.buf, out.len, 0);
2791                strbuf_reset(&out);
2792        }
2793
2794        for (i = 0; i < data->nr; i++) {
2795                struct diffstat_file *file = data->files[i];
2796                uintmax_t added = file->added;
2797                uintmax_t deleted = file->deleted;
2798
2799                if (file->is_unmerged ||
2800                    (!file->is_interesting && (added + deleted == 0))) {
2801                        total_files--;
2802                        continue;
2803                }
2804
2805                if (!file->is_binary) {
2806                        adds += added;
2807                        dels += deleted;
2808                }
2809                if (i < count)
2810                        continue;
2811                if (!extra_shown)
2812                        emit_diff_symbol(options,
2813                                         DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
2814                                         NULL, 0, 0);
2815                extra_shown = 1;
2816        }
2817
2818        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2819        strbuf_release(&out);
2820}
2821
2822static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
2823{
2824        int i, adds = 0, dels = 0, total_files = data->nr;
2825
2826        if (data->nr == 0)
2827                return;
2828
2829        for (i = 0; i < data->nr; i++) {
2830                int added = data->files[i]->added;
2831                int deleted = data->files[i]->deleted;
2832
2833                if (data->files[i]->is_unmerged ||
2834                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
2835                        total_files--;
2836                } else if (!data->files[i]->is_binary) { /* don't count bytes */
2837                        adds += added;
2838                        dels += deleted;
2839                }
2840        }
2841        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2842}
2843
2844static void show_numstat(struct diffstat_t *data, struct diff_options *options)
2845{
2846        int i;
2847
2848        if (data->nr == 0)
2849                return;
2850
2851        for (i = 0; i < data->nr; i++) {
2852                struct diffstat_file *file = data->files[i];
2853
2854                fprintf(options->file, "%s", diff_line_prefix(options));
2855
2856                if (file->is_binary)
2857                        fprintf(options->file, "-\t-\t");
2858                else
2859                        fprintf(options->file,
2860                                "%"PRIuMAX"\t%"PRIuMAX"\t",
2861                                file->added, file->deleted);
2862                if (options->line_termination) {
2863                        fill_print_name(file);
2864                        if (!file->is_renamed)
2865                                write_name_quoted(file->name, options->file,
2866                                                  options->line_termination);
2867                        else {
2868                                fputs(file->print_name, options->file);
2869                                putc(options->line_termination, options->file);
2870                        }
2871                } else {
2872                        if (file->is_renamed) {
2873                                putc('\0', options->file);
2874                                write_name_quoted(file->from_name, options->file, '\0');
2875                        }
2876                        write_name_quoted(file->name, options->file, '\0');
2877                }
2878        }
2879}
2880
2881struct dirstat_file {
2882        const char *name;
2883        unsigned long changed;
2884};
2885
2886struct dirstat_dir {
2887        struct dirstat_file *files;
2888        int alloc, nr, permille, cumulative;
2889};
2890
2891static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
2892                unsigned long changed, const char *base, int baselen)
2893{
2894        unsigned long sum_changes = 0;
2895        unsigned int sources = 0;
2896        const char *line_prefix = diff_line_prefix(opt);
2897
2898        while (dir->nr) {
2899                struct dirstat_file *f = dir->files;
2900                int namelen = strlen(f->name);
2901                unsigned long changes;
2902                char *slash;
2903
2904                if (namelen < baselen)
2905                        break;
2906                if (memcmp(f->name, base, baselen))
2907                        break;
2908                slash = strchr(f->name + baselen, '/');
2909                if (slash) {
2910                        int newbaselen = slash + 1 - f->name;
2911                        changes = gather_dirstat(opt, dir, changed, f->name, newbaselen);
2912                        sources++;
2913                } else {
2914                        changes = f->changed;
2915                        dir->files++;
2916                        dir->nr--;
2917                        sources += 2;
2918                }
2919                sum_changes += changes;
2920        }
2921
2922        /*
2923         * We don't report dirstat's for
2924         *  - the top level
2925         *  - or cases where everything came from a single directory
2926         *    under this directory (sources == 1).
2927         */
2928        if (baselen && sources != 1) {
2929                if (sum_changes) {
2930                        int permille = sum_changes * 1000 / changed;
2931                        if (permille >= dir->permille) {
2932                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
2933                                        permille / 10, permille % 10, baselen, base);
2934                                if (!dir->cumulative)
2935                                        return 0;
2936                        }
2937                }
2938        }
2939        return sum_changes;
2940}
2941
2942static int dirstat_compare(const void *_a, const void *_b)
2943{
2944        const struct dirstat_file *a = _a;
2945        const struct dirstat_file *b = _b;
2946        return strcmp(a->name, b->name);
2947}
2948
2949static void show_dirstat(struct diff_options *options)
2950{
2951        int i;
2952        unsigned long changed;
2953        struct dirstat_dir dir;
2954        struct diff_queue_struct *q = &diff_queued_diff;
2955
2956        dir.files = NULL;
2957        dir.alloc = 0;
2958        dir.nr = 0;
2959        dir.permille = options->dirstat_permille;
2960        dir.cumulative = options->flags.dirstat_cumulative;
2961
2962        changed = 0;
2963        for (i = 0; i < q->nr; i++) {
2964                struct diff_filepair *p = q->queue[i];
2965                const char *name;
2966                unsigned long copied, added, damage;
2967
2968                name = p->two->path ? p->two->path : p->one->path;
2969
2970                if (p->one->oid_valid && p->two->oid_valid &&
2971                    oideq(&p->one->oid, &p->two->oid)) {
2972                        /*
2973                         * The SHA1 has not changed, so pre-/post-content is
2974                         * identical. We can therefore skip looking at the
2975                         * file contents altogether.
2976                         */
2977                        damage = 0;
2978                        goto found_damage;
2979                }
2980
2981                if (options->flags.dirstat_by_file) {
2982                        /*
2983                         * In --dirstat-by-file mode, we don't really need to
2984                         * look at the actual file contents at all.
2985                         * The fact that the SHA1 changed is enough for us to
2986                         * add this file to the list of results
2987                         * (with each file contributing equal damage).
2988                         */
2989                        damage = 1;
2990                        goto found_damage;
2991                }
2992
2993                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
2994                        diff_populate_filespec(options->repo, p->one, 0);
2995                        diff_populate_filespec(options->repo, p->two, 0);
2996                        diffcore_count_changes(options->repo,
2997                                               p->one, p->two, NULL, NULL,
2998                                               &copied, &added);
2999                        diff_free_filespec_data(p->one);
3000                        diff_free_filespec_data(p->two);
3001                } else if (DIFF_FILE_VALID(p->one)) {
3002                        diff_populate_filespec(options->repo, p->one, CHECK_SIZE_ONLY);
3003                        copied = added = 0;
3004                        diff_free_filespec_data(p->one);
3005                } else if (DIFF_FILE_VALID(p->two)) {
3006                        diff_populate_filespec(options->repo, p->two, CHECK_SIZE_ONLY);
3007                        copied = 0;
3008                        added = p->two->size;
3009                        diff_free_filespec_data(p->two);
3010                } else
3011                        continue;
3012
3013                /*
3014                 * Original minus copied is the removed material,
3015                 * added is the new material.  They are both damages
3016                 * made to the preimage.
3017                 * If the resulting damage is zero, we know that
3018                 * diffcore_count_changes() considers the two entries to
3019                 * be identical, but since the oid changed, we
3020                 * know that there must have been _some_ kind of change,
3021                 * so we force all entries to have damage > 0.
3022                 */
3023                damage = (p->one->size - copied) + added;
3024                if (!damage)
3025                        damage = 1;
3026
3027found_damage:
3028                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
3029                dir.files[dir.nr].name = name;
3030                dir.files[dir.nr].changed = damage;
3031                changed += damage;
3032                dir.nr++;
3033        }
3034
3035        /* This can happen even with many files, if everything was renames */
3036        if (!changed)
3037                return;
3038
3039        /* Show all directories with more than x% of the changes */
3040        QSORT(dir.files, dir.nr, dirstat_compare);
3041        gather_dirstat(options, &dir, changed, "", 0);
3042}
3043
3044static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
3045{
3046        int i;
3047        unsigned long changed;
3048        struct dirstat_dir dir;
3049
3050        if (data->nr == 0)
3051                return;
3052
3053        dir.files = NULL;
3054        dir.alloc = 0;
3055        dir.nr = 0;
3056        dir.permille = options->dirstat_permille;
3057        dir.cumulative = options->flags.dirstat_cumulative;
3058
3059        changed = 0;
3060        for (i = 0; i < data->nr; i++) {
3061                struct diffstat_file *file = data->files[i];
3062                unsigned long damage = file->added + file->deleted;
3063                if (file->is_binary)
3064                        /*
3065                         * binary files counts bytes, not lines. Must find some
3066                         * way to normalize binary bytes vs. textual lines.
3067                         * The following heuristic assumes that there are 64
3068                         * bytes per "line".
3069                         * This is stupid and ugly, but very cheap...
3070                         */
3071                        damage = DIV_ROUND_UP(damage, 64);
3072                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
3073                dir.files[dir.nr].name = file->name;
3074                dir.files[dir.nr].changed = damage;
3075                changed += damage;
3076                dir.nr++;
3077        }
3078
3079        /* This can happen even with many files, if everything was renames */
3080        if (!changed)
3081                return;
3082
3083        /* Show all directories with more than x% of the changes */
3084        QSORT(dir.files, dir.nr, dirstat_compare);
3085        gather_dirstat(options, &dir, changed, "", 0);
3086}
3087
3088static void free_diffstat_info(struct diffstat_t *diffstat)
3089{
3090        int i;
3091        for (i = 0; i < diffstat->nr; i++) {
3092                struct diffstat_file *f = diffstat->files[i];
3093                free(f->print_name);
3094                free(f->name);
3095                free(f->from_name);
3096                free(f);
3097        }
3098        free(diffstat->files);
3099}
3100
3101struct checkdiff_t {
3102        const char *filename;
3103        int lineno;
3104        int conflict_marker_size;
3105        struct diff_options *o;
3106        unsigned ws_rule;
3107        unsigned status;
3108};
3109
3110static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
3111{
3112        char firstchar;
3113        int cnt;
3114
3115        if (len < marker_size + 1)
3116                return 0;
3117        firstchar = line[0];
3118        switch (firstchar) {
3119        case '=': case '>': case '<': case '|':
3120                break;
3121        default:
3122                return 0;
3123        }
3124        for (cnt = 1; cnt < marker_size; cnt++)
3125                if (line[cnt] != firstchar)
3126                        return 0;
3127        /* line[1] thru line[marker_size-1] are same as firstchar */
3128        if (len < marker_size + 1 || !isspace(line[marker_size]))
3129                return 0;
3130        return 1;
3131}
3132
3133static void checkdiff_consume(void *priv, char *line, unsigned long len)
3134{
3135        struct checkdiff_t *data = priv;
3136        int marker_size = data->conflict_marker_size;
3137        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
3138        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
3139        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
3140        char *err;
3141        const char *line_prefix;
3142
3143        assert(data->o);
3144        line_prefix = diff_line_prefix(data->o);
3145
3146        if (line[0] == '+') {
3147                unsigned bad;
3148                data->lineno++;
3149                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
3150                        data->status |= 1;
3151                        fprintf(data->o->file,
3152                                "%s%s:%d: leftover conflict marker\n",
3153                                line_prefix, data->filename, data->lineno);
3154                }
3155                bad = ws_check(line + 1, len - 1, data->ws_rule);
3156                if (!bad)
3157                        return;
3158                data->status |= bad;
3159                err = whitespace_error_string(bad);
3160                fprintf(data->o->file, "%s%s:%d: %s.\n",
3161                        line_prefix, data->filename, data->lineno, err);
3162                free(err);
3163                emit_line(data->o, set, reset, line, 1);
3164                ws_check_emit(line + 1, len - 1, data->ws_rule,
3165                              data->o->file, set, reset, ws);
3166        } else if (line[0] == ' ') {
3167                data->lineno++;
3168        } else if (line[0] == '@') {
3169                char *plus = strchr(line, '+');
3170                if (plus)
3171                        data->lineno = strtol(plus, NULL, 10) - 1;
3172                else
3173                        die("invalid diff");
3174        }
3175}
3176
3177static unsigned char *deflate_it(char *data,
3178                                 unsigned long size,
3179                                 unsigned long *result_size)
3180{
3181        int bound;
3182        unsigned char *deflated;
3183        git_zstream stream;
3184
3185        git_deflate_init(&stream, zlib_compression_level);
3186        bound = git_deflate_bound(&stream, size);
3187        deflated = xmalloc(bound);
3188        stream.next_out = deflated;
3189        stream.avail_out = bound;
3190
3191        stream.next_in = (unsigned char *)data;
3192        stream.avail_in = size;
3193        while (git_deflate(&stream, Z_FINISH) == Z_OK)
3194                ; /* nothing */
3195        git_deflate_end(&stream);
3196        *result_size = stream.total_out;
3197        return deflated;
3198}
3199
3200static void emit_binary_diff_body(struct diff_options *o,
3201                                  mmfile_t *one, mmfile_t *two)
3202{
3203        void *cp;
3204        void *delta;
3205        void *deflated;
3206        void *data;
3207        unsigned long orig_size;
3208        unsigned long delta_size;
3209        unsigned long deflate_size;
3210        unsigned long data_size;
3211
3212        /* We could do deflated delta, or we could do just deflated two,
3213         * whichever is smaller.
3214         */
3215        delta = NULL;
3216        deflated = deflate_it(two->ptr, two->size, &deflate_size);
3217        if (one->size && two->size) {
3218                delta = diff_delta(one->ptr, one->size,
3219                                   two->ptr, two->size,
3220                                   &delta_size, deflate_size);
3221                if (delta) {
3222                        void *to_free = delta;
3223                        orig_size = delta_size;
3224                        delta = deflate_it(delta, delta_size, &delta_size);
3225                        free(to_free);
3226                }
3227        }
3228
3229        if (delta && delta_size < deflate_size) {
3230                char *s = xstrfmt("%lu", orig_size);
3231                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
3232                                 s, strlen(s), 0);
3233                free(s);
3234                free(deflated);
3235                data = delta;
3236                data_size = delta_size;
3237        } else {
3238                char *s = xstrfmt("%lu", two->size);
3239                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
3240                                 s, strlen(s), 0);
3241                free(s);
3242                free(delta);
3243                data = deflated;
3244                data_size = deflate_size;
3245        }
3246
3247        /* emit data encoded in base85 */
3248        cp = data;
3249        while (data_size) {
3250                int len;
3251                int bytes = (52 < data_size) ? 52 : data_size;
3252                char line[71];
3253                data_size -= bytes;
3254                if (bytes <= 26)
3255                        line[0] = bytes + 'A' - 1;
3256                else
3257                        line[0] = bytes - 26 + 'a' - 1;
3258                encode_85(line + 1, cp, bytes);
3259                cp = (char *) cp + bytes;
3260
3261                len = strlen(line);
3262                line[len++] = '\n';
3263                line[len] = '\0';
3264
3265                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_BODY,
3266                                 line, len, 0);
3267        }
3268        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_FOOTER, NULL, 0, 0);
3269        free(data);
3270}
3271
3272static void emit_binary_diff(struct diff_options *o,
3273                             mmfile_t *one, mmfile_t *two)
3274{
3275        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER, NULL, 0, 0);
3276        emit_binary_diff_body(o, one, two);
3277        emit_binary_diff_body(o, two, one);
3278}
3279
3280int diff_filespec_is_binary(struct repository *r,
3281                            struct diff_filespec *one)
3282{
3283        if (one->is_binary == -1) {
3284                diff_filespec_load_driver(one, r->index);
3285                if (one->driver->binary != -1)
3286                        one->is_binary = one->driver->binary;
3287                else {
3288                        if (!one->data && DIFF_FILE_VALID(one))
3289                                diff_populate_filespec(r, one, CHECK_BINARY);
3290                        if (one->is_binary == -1 && one->data)
3291                                one->is_binary = buffer_is_binary(one->data,
3292                                                one->size);
3293                        if (one->is_binary == -1)
3294                                one->is_binary = 0;
3295                }
3296        }
3297        return one->is_binary;
3298}
3299
3300static const struct userdiff_funcname *
3301diff_funcname_pattern(struct diff_options *o, struct diff_filespec *one)
3302{
3303        diff_filespec_load_driver(one, o->repo->index);
3304        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
3305}
3306
3307void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
3308{
3309        if (!options->a_prefix)
3310                options->a_prefix = a;
3311        if (!options->b_prefix)
3312                options->b_prefix = b;
3313}
3314
3315struct userdiff_driver *get_textconv(struct index_state *istate,
3316                                     struct diff_filespec *one)
3317{
3318        if (!DIFF_FILE_VALID(one))
3319                return NULL;
3320
3321        diff_filespec_load_driver(one, istate);
3322        return userdiff_get_textconv(one->driver);
3323}
3324
3325static void builtin_diff(const char *name_a,
3326                         const char *name_b,
3327                         struct diff_filespec *one,
3328                         struct diff_filespec *two,
3329                         const char *xfrm_msg,
3330                         int must_show_header,
3331                         struct diff_options *o,
3332                         int complete_rewrite)
3333{
3334        mmfile_t mf1, mf2;
3335        const char *lbl[2];
3336        char *a_one, *b_two;
3337        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
3338        const char *reset = diff_get_color_opt(o, DIFF_RESET);
3339        const char *a_prefix, *b_prefix;
3340        struct userdiff_driver *textconv_one = NULL;
3341        struct userdiff_driver *textconv_two = NULL;
3342        struct strbuf header = STRBUF_INIT;
3343        const char *line_prefix = diff_line_prefix(o);
3344
3345        diff_set_mnemonic_prefix(o, "a/", "b/");
3346        if (o->flags.reverse_diff) {
3347                a_prefix = o->b_prefix;
3348                b_prefix = o->a_prefix;
3349        } else {
3350                a_prefix = o->a_prefix;
3351                b_prefix = o->b_prefix;
3352        }
3353
3354        if (o->submodule_format == DIFF_SUBMODULE_LOG &&
3355            (!one->mode || S_ISGITLINK(one->mode)) &&
3356            (!two->mode || S_ISGITLINK(two->mode))) {
3357                show_submodule_summary(o, one->path ? one->path : two->path,
3358                                &one->oid, &two->oid,
3359                                two->dirty_submodule);
3360                return;
3361        } else if (o->submodule_format == DIFF_SUBMODULE_INLINE_DIFF &&
3362                   (!one->mode || S_ISGITLINK(one->mode)) &&
3363                   (!two->mode || S_ISGITLINK(two->mode))) {
3364                show_submodule_inline_diff(o, one->path ? one->path : two->path,
3365                                &one->oid, &two->oid,
3366                                two->dirty_submodule);
3367                return;
3368        }
3369
3370        if (o->flags.allow_textconv) {
3371                textconv_one = get_textconv(o->repo->index, one);
3372                textconv_two = get_textconv(o->repo->index, two);
3373        }
3374
3375        /* Never use a non-valid filename anywhere if at all possible */
3376        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
3377        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
3378
3379        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
3380        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
3381        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
3382        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
3383        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
3384        if (lbl[0][0] == '/') {
3385                /* /dev/null */
3386                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
3387                if (xfrm_msg)
3388                        strbuf_addstr(&header, xfrm_msg);
3389                must_show_header = 1;
3390        }
3391        else if (lbl[1][0] == '/') {
3392                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
3393                if (xfrm_msg)
3394                        strbuf_addstr(&header, xfrm_msg);
3395                must_show_header = 1;
3396        }
3397        else {
3398                if (one->mode != two->mode) {
3399                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
3400                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
3401                        must_show_header = 1;
3402                }
3403                if (xfrm_msg)
3404                        strbuf_addstr(&header, xfrm_msg);
3405
3406                /*
3407                 * we do not run diff between different kind
3408                 * of objects.
3409                 */
3410                if ((one->mode ^ two->mode) & S_IFMT)
3411                        goto free_ab_and_return;
3412                if (complete_rewrite &&
3413                    (textconv_one || !diff_filespec_is_binary(o->repo, one)) &&
3414                    (textconv_two || !diff_filespec_is_binary(o->repo, two))) {
3415                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3416                                         header.buf, header.len, 0);
3417                        strbuf_reset(&header);
3418                        emit_rewrite_diff(name_a, name_b, one, two,
3419                                          textconv_one, textconv_two, o);
3420                        o->found_changes = 1;
3421                        goto free_ab_and_return;
3422                }
3423        }
3424
3425        if (o->irreversible_delete && lbl[1][0] == '/') {
3426                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf,
3427                                 header.len, 0);
3428                strbuf_reset(&header);
3429                goto free_ab_and_return;
3430        } else if (!o->flags.text &&
3431                   ( (!textconv_one && diff_filespec_is_binary(o->repo, one)) ||
3432                     (!textconv_two && diff_filespec_is_binary(o->repo, two)) )) {
3433                struct strbuf sb = STRBUF_INIT;
3434                if (!one->data && !two->data &&
3435                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
3436                    !o->flags.binary) {
3437                        if (oideq(&one->oid, &two->oid)) {
3438                                if (must_show_header)
3439                                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3440                                                         header.buf, header.len,
3441                                                         0);
3442                                goto free_ab_and_return;
3443                        }
3444                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3445                                         header.buf, header.len, 0);
3446                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3447                                    diff_line_prefix(o), lbl[0], lbl[1]);
3448                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3449                                         sb.buf, sb.len, 0);
3450                        strbuf_release(&sb);
3451                        goto free_ab_and_return;
3452                }
3453                if (fill_mmfile(o->repo, &mf1, one) < 0 ||
3454                    fill_mmfile(o->repo, &mf2, two) < 0)
3455                        die("unable to read files to diff");
3456                /* Quite common confusing case */
3457                if (mf1.size == mf2.size &&
3458                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
3459                        if (must_show_header)
3460                                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3461                                                 header.buf, header.len, 0);
3462                        goto free_ab_and_return;
3463                }
3464                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf, header.len, 0);
3465                strbuf_reset(&header);
3466                if (o->flags.binary)
3467                        emit_binary_diff(o, &mf1, &mf2);
3468                else {
3469                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3470                                    diff_line_prefix(o), lbl[0], lbl[1]);
3471                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3472                                         sb.buf, sb.len, 0);
3473                        strbuf_release(&sb);
3474                }
3475                o->found_changes = 1;
3476        } else {
3477                /* Crazy xdl interfaces.. */
3478                const char *diffopts = getenv("GIT_DIFF_OPTS");
3479                const char *v;
3480                xpparam_t xpp;
3481                xdemitconf_t xecfg;
3482                struct emit_callback ecbdata;
3483                const struct userdiff_funcname *pe;
3484
3485                if (must_show_header) {
3486                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3487                                         header.buf, header.len, 0);
3488                        strbuf_reset(&header);
3489                }
3490
3491                mf1.size = fill_textconv(o->repo, textconv_one, one, &mf1.ptr);
3492                mf2.size = fill_textconv(o->repo, textconv_two, two, &mf2.ptr);
3493
3494                pe = diff_funcname_pattern(o, one);
3495                if (!pe)
3496                        pe = diff_funcname_pattern(o, two);
3497
3498                memset(&xpp, 0, sizeof(xpp));
3499                memset(&xecfg, 0, sizeof(xecfg));
3500                memset(&ecbdata, 0, sizeof(ecbdata));
3501                if (o->flags.suppress_diff_headers)
3502                        lbl[0] = NULL;
3503                ecbdata.label_path = lbl;
3504                ecbdata.color_diff = want_color(o->use_color);
3505                ecbdata.ws_rule = whitespace_rule(o->repo->index, name_b);
3506                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
3507                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3508                ecbdata.opt = o;
3509                if (header.len && !o->flags.suppress_diff_headers)
3510                        ecbdata.header = &header;
3511                xpp.flags = o->xdl_opts;
3512                xpp.anchors = o->anchors;
3513                xpp.anchors_nr = o->anchors_nr;
3514                xecfg.ctxlen = o->context;
3515                xecfg.interhunkctxlen = o->interhunkcontext;
3516                xecfg.flags = XDL_EMIT_FUNCNAMES;
3517                if (o->flags.funccontext)
3518                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
3519                if (pe)
3520                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
3521                if (!diffopts)
3522                        ;
3523                else if (skip_prefix(diffopts, "--unified=", &v))
3524                        xecfg.ctxlen = strtoul(v, NULL, 10);
3525                else if (skip_prefix(diffopts, "-u", &v))
3526                        xecfg.ctxlen = strtoul(v, NULL, 10);
3527                if (o->word_diff)
3528                        init_diff_words_data(&ecbdata, o, one, two);
3529                if (xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
3530                                  &xpp, &xecfg))
3531                        die("unable to generate diff for %s", one->path);
3532                if (o->word_diff)
3533                        free_diff_words_data(&ecbdata);
3534                if (textconv_one)
3535                        free(mf1.ptr);
3536                if (textconv_two)
3537                        free(mf2.ptr);
3538                xdiff_clear_find_func(&xecfg);
3539        }
3540
3541 free_ab_and_return:
3542        strbuf_release(&header);
3543        diff_free_filespec_data(one);
3544        diff_free_filespec_data(two);
3545        free(a_one);
3546        free(b_two);
3547        return;
3548}
3549
3550static char *get_compact_summary(const struct diff_filepair *p, int is_renamed)
3551{
3552        if (!is_renamed) {
3553                if (p->status == DIFF_STATUS_ADDED) {
3554                        if (S_ISLNK(p->two->mode))
3555                                return "new +l";
3556                        else if ((p->two->mode & 0777) == 0755)
3557                                return "new +x";
3558                        else
3559                                return "new";
3560                } else if (p->status == DIFF_STATUS_DELETED)
3561                        return "gone";
3562        }
3563        if (S_ISLNK(p->one->mode) && !S_ISLNK(p->two->mode))
3564                return "mode -l";
3565        else if (!S_ISLNK(p->one->mode) && S_ISLNK(p->two->mode))
3566                return "mode +l";
3567        else if ((p->one->mode & 0777) == 0644 &&
3568                 (p->two->mode & 0777) == 0755)
3569                return "mode +x";
3570        else if ((p->one->mode & 0777) == 0755 &&
3571                 (p->two->mode & 0777) == 0644)
3572                return "mode -x";
3573        return NULL;
3574}
3575
3576static void builtin_diffstat(const char *name_a, const char *name_b,
3577                             struct diff_filespec *one,
3578                             struct diff_filespec *two,
3579                             struct diffstat_t *diffstat,
3580                             struct diff_options *o,
3581                             struct diff_filepair *p)
3582{
3583        mmfile_t mf1, mf2;
3584        struct diffstat_file *data;
3585        int same_contents;
3586        int complete_rewrite = 0;
3587
3588        if (!DIFF_PAIR_UNMERGED(p)) {
3589                if (p->status == DIFF_STATUS_MODIFIED && p->score)
3590                        complete_rewrite = 1;
3591        }
3592
3593        data = diffstat_add(diffstat, name_a, name_b);
3594        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
3595        if (o->flags.stat_with_summary)
3596                data->comments = get_compact_summary(p, data->is_renamed);
3597
3598        if (!one || !two) {
3599                data->is_unmerged = 1;
3600                return;
3601        }
3602
3603        same_contents = oideq(&one->oid, &two->oid);
3604
3605        if (diff_filespec_is_binary(o->repo, one) ||
3606            diff_filespec_is_binary(o->repo, two)) {
3607                data->is_binary = 1;
3608                if (same_contents) {
3609                        data->added = 0;
3610                        data->deleted = 0;
3611                } else {
3612                        data->added = diff_filespec_size(o->repo, two);
3613                        data->deleted = diff_filespec_size(o->repo, one);
3614                }
3615        }
3616
3617        else if (complete_rewrite) {
3618                diff_populate_filespec(o->repo, one, 0);
3619                diff_populate_filespec(o->repo, two, 0);
3620                data->deleted = count_lines(one->data, one->size);
3621                data->added = count_lines(two->data, two->size);
3622        }
3623
3624        else if (!same_contents) {
3625                /* Crazy xdl interfaces.. */
3626                xpparam_t xpp;
3627                xdemitconf_t xecfg;
3628
3629                if (fill_mmfile(o->repo, &mf1, one) < 0 ||
3630                    fill_mmfile(o->repo, &mf2, two) < 0)
3631                        die("unable to read files to diff");
3632
3633                memset(&xpp, 0, sizeof(xpp));
3634                memset(&xecfg, 0, sizeof(xecfg));
3635                xpp.flags = o->xdl_opts;
3636                xpp.anchors = o->anchors;
3637                xpp.anchors_nr = o->anchors_nr;
3638                xecfg.ctxlen = o->context;
3639                xecfg.interhunkctxlen = o->interhunkcontext;
3640                if (xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
3641                                  &xpp, &xecfg))
3642                        die("unable to generate diffstat for %s", one->path);
3643        }
3644
3645        diff_free_filespec_data(one);
3646        diff_free_filespec_data(two);
3647}
3648
3649static void builtin_checkdiff(const char *name_a, const char *name_b,
3650                              const char *attr_path,
3651                              struct diff_filespec *one,
3652                              struct diff_filespec *two,
3653                              struct diff_options *o)
3654{
3655        mmfile_t mf1, mf2;
3656        struct checkdiff_t data;
3657
3658        if (!two)
3659                return;
3660
3661        memset(&data, 0, sizeof(data));
3662        data.filename = name_b ? name_b : name_a;
3663        data.lineno = 0;
3664        data.o = o;
3665        data.ws_rule = whitespace_rule(o->repo->index, attr_path);
3666        data.conflict_marker_size = ll_merge_marker_size(o->repo->index, attr_path);
3667
3668        if (fill_mmfile(o->repo, &mf1, one) < 0 ||
3669            fill_mmfile(o->repo, &mf2, two) < 0)
3670                die("unable to read files to diff");
3671
3672        /*
3673         * All the other codepaths check both sides, but not checking
3674         * the "old" side here is deliberate.  We are checking the newly
3675         * introduced changes, and as long as the "new" side is text, we
3676         * can and should check what it introduces.
3677         */
3678        if (diff_filespec_is_binary(o->repo, two))
3679                goto free_and_return;
3680        else {
3681                /* Crazy xdl interfaces.. */
3682                xpparam_t xpp;
3683                xdemitconf_t xecfg;
3684
3685                memset(&xpp, 0, sizeof(xpp));
3686                memset(&xecfg, 0, sizeof(xecfg));
3687                xecfg.ctxlen = 1; /* at least one context line */
3688                xpp.flags = 0;
3689                if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
3690                                  &xpp, &xecfg))
3691                        die("unable to generate checkdiff for %s", one->path);
3692
3693                if (data.ws_rule & WS_BLANK_AT_EOF) {
3694                        struct emit_callback ecbdata;
3695                        int blank_at_eof;
3696
3697                        ecbdata.ws_rule = data.ws_rule;
3698                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3699                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
3700
3701                        if (blank_at_eof) {
3702                                static char *err;
3703                                if (!err)
3704                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
3705                                fprintf(o->file, "%s:%d: %s.\n",
3706                                        data.filename, blank_at_eof, err);
3707                                data.status = 1; /* report errors */
3708                        }
3709                }
3710        }
3711 free_and_return:
3712        diff_free_filespec_data(one);
3713        diff_free_filespec_data(two);
3714        if (data.status)
3715                o->flags.check_failed = 1;
3716}
3717
3718struct diff_filespec *alloc_filespec(const char *path)
3719{
3720        struct diff_filespec *spec;
3721
3722        FLEXPTR_ALLOC_STR(spec, path, path);
3723        spec->count = 1;
3724        spec->is_binary = -1;
3725        return spec;
3726}
3727
3728void free_filespec(struct diff_filespec *spec)
3729{
3730        if (!--spec->count) {
3731                diff_free_filespec_data(spec);
3732                free(spec);
3733        }
3734}
3735
3736void fill_filespec(struct diff_filespec *spec, const struct object_id *oid,
3737                   int oid_valid, unsigned short mode)
3738{
3739        if (mode) {
3740                spec->mode = canon_mode(mode);
3741                oidcpy(&spec->oid, oid);
3742                spec->oid_valid = oid_valid;
3743        }
3744}
3745
3746/*
3747 * Given a name and sha1 pair, if the index tells us the file in
3748 * the work tree has that object contents, return true, so that
3749 * prepare_temp_file() does not have to inflate and extract.
3750 */
3751static int reuse_worktree_file(struct index_state *istate,
3752                               const char *name,
3753                               const struct object_id *oid,
3754                               int want_file)
3755{
3756        const struct cache_entry *ce;
3757        struct stat st;
3758        int pos, len;
3759
3760        /*
3761         * We do not read the cache ourselves here, because the
3762         * benchmark with my previous version that always reads cache
3763         * shows that it makes things worse for diff-tree comparing
3764         * two linux-2.6 kernel trees in an already checked out work
3765         * tree.  This is because most diff-tree comparisons deal with
3766         * only a small number of files, while reading the cache is
3767         * expensive for a large project, and its cost outweighs the
3768         * savings we get by not inflating the object to a temporary
3769         * file.  Practically, this code only helps when we are used
3770         * by diff-cache --cached, which does read the cache before
3771         * calling us.
3772         */
3773        if (!istate->cache)
3774                return 0;
3775
3776        /* We want to avoid the working directory if our caller
3777         * doesn't need the data in a normal file, this system
3778         * is rather slow with its stat/open/mmap/close syscalls,
3779         * and the object is contained in a pack file.  The pack
3780         * is probably already open and will be faster to obtain
3781         * the data through than the working directory.  Loose
3782         * objects however would tend to be slower as they need
3783         * to be individually opened and inflated.
3784         */
3785        if (!FAST_WORKING_DIRECTORY && !want_file && has_object_pack(oid))
3786                return 0;
3787
3788        /*
3789         * Similarly, if we'd have to convert the file contents anyway, that
3790         * makes the optimization not worthwhile.
3791         */
3792        if (!want_file && would_convert_to_git(istate, name))
3793                return 0;
3794
3795        len = strlen(name);
3796        pos = index_name_pos(istate, name, len);
3797        if (pos < 0)
3798                return 0;
3799        ce = istate->cache[pos];
3800
3801        /*
3802         * This is not the sha1 we are looking for, or
3803         * unreusable because it is not a regular file.
3804         */
3805        if (!oideq(oid, &ce->oid) || !S_ISREG(ce->ce_mode))
3806                return 0;
3807
3808        /*
3809         * If ce is marked as "assume unchanged", there is no
3810         * guarantee that work tree matches what we are looking for.
3811         */
3812        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
3813                return 0;
3814
3815        /*
3816         * If ce matches the file in the work tree, we can reuse it.
3817         */
3818        if (ce_uptodate(ce) ||
3819            (!lstat(name, &st) && !ie_match_stat(istate, ce, &st, 0)))
3820                return 1;
3821
3822        return 0;
3823}
3824
3825static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
3826{
3827        struct strbuf buf = STRBUF_INIT;
3828        char *dirty = "";
3829
3830        /* Are we looking at the work tree? */
3831        if (s->dirty_submodule)
3832                dirty = "-dirty";
3833
3834        strbuf_addf(&buf, "Subproject commit %s%s\n",
3835                    oid_to_hex(&s->oid), dirty);
3836        s->size = buf.len;
3837        if (size_only) {
3838                s->data = NULL;
3839                strbuf_release(&buf);
3840        } else {
3841                s->data = strbuf_detach(&buf, NULL);
3842                s->should_free = 1;
3843        }
3844        return 0;
3845}
3846
3847/*
3848 * While doing rename detection and pickaxe operation, we may need to
3849 * grab the data for the blob (or file) for our own in-core comparison.
3850 * diff_filespec has data and size fields for this purpose.
3851 */
3852int diff_populate_filespec(struct repository *r,
3853                           struct diff_filespec *s,
3854                           unsigned int flags)
3855{
3856        int size_only = flags & CHECK_SIZE_ONLY;
3857        int err = 0;
3858        int conv_flags = global_conv_flags_eol;
3859        /*
3860         * demote FAIL to WARN to allow inspecting the situation
3861         * instead of refusing.
3862         */
3863        if (conv_flags & CONV_EOL_RNDTRP_DIE)
3864                conv_flags = CONV_EOL_RNDTRP_WARN;
3865
3866        if (!DIFF_FILE_VALID(s))
3867                die("internal error: asking to populate invalid file.");
3868        if (S_ISDIR(s->mode))
3869                return -1;
3870
3871        if (s->data)
3872                return 0;
3873
3874        if (size_only && 0 < s->size)
3875                return 0;
3876
3877        if (S_ISGITLINK(s->mode))
3878                return diff_populate_gitlink(s, size_only);
3879
3880        if (!s->oid_valid ||
3881            reuse_worktree_file(r->index, s->path, &s->oid, 0)) {
3882                struct strbuf buf = STRBUF_INIT;
3883                struct stat st;
3884                int fd;
3885
3886                if (lstat(s->path, &st) < 0) {
3887                err_empty:
3888                        err = -1;
3889                empty:
3890                        s->data = (char *)"";
3891                        s->size = 0;
3892                        return err;
3893                }
3894                s->size = xsize_t(st.st_size);
3895                if (!s->size)
3896                        goto empty;
3897                if (S_ISLNK(st.st_mode)) {
3898                        struct strbuf sb = STRBUF_INIT;
3899
3900                        if (strbuf_readlink(&sb, s->path, s->size))
3901                                goto err_empty;
3902                        s->size = sb.len;
3903                        s->data = strbuf_detach(&sb, NULL);
3904                        s->should_free = 1;
3905                        return 0;
3906                }
3907
3908                /*
3909                 * Even if the caller would be happy with getting
3910                 * only the size, we cannot return early at this
3911                 * point if the path requires us to run the content
3912                 * conversion.
3913                 */
3914                if (size_only && !would_convert_to_git(r->index, s->path))
3915                        return 0;
3916
3917                /*
3918                 * Note: this check uses xsize_t(st.st_size) that may
3919                 * not be the true size of the blob after it goes
3920                 * through convert_to_git().  This may not strictly be
3921                 * correct, but the whole point of big_file_threshold
3922                 * and is_binary check being that we want to avoid
3923                 * opening the file and inspecting the contents, this
3924                 * is probably fine.
3925                 */
3926                if ((flags & CHECK_BINARY) &&
3927                    s->size > big_file_threshold && s->is_binary == -1) {
3928                        s->is_binary = 1;
3929                        return 0;
3930                }
3931                fd = open(s->path, O_RDONLY);
3932                if (fd < 0)
3933                        goto err_empty;
3934                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
3935                close(fd);
3936                s->should_munmap = 1;
3937
3938                /*
3939                 * Convert from working tree format to canonical git format
3940                 */
3941                if (convert_to_git(r->index, s->path, s->data, s->size, &buf, conv_flags)) {
3942                        size_t size = 0;
3943                        munmap(s->data, s->size);
3944                        s->should_munmap = 0;
3945                        s->data = strbuf_detach(&buf, &size);
3946                        s->size = size;
3947                        s->should_free = 1;
3948                }
3949        }
3950        else {
3951                enum object_type type;
3952                if (size_only || (flags & CHECK_BINARY)) {
3953                        type = oid_object_info(r, &s->oid, &s->size);
3954                        if (type < 0)
3955                                die("unable to read %s",
3956                                    oid_to_hex(&s->oid));
3957                        if (size_only)
3958                                return 0;
3959                        if (s->size > big_file_threshold && s->is_binary == -1) {
3960                                s->is_binary = 1;
3961                                return 0;
3962                        }
3963                }
3964                s->data = read_object_file(&s->oid, &type, &s->size);
3965                if (!s->data)
3966                        die("unable to read %s", oid_to_hex(&s->oid));
3967                s->should_free = 1;
3968        }
3969        return 0;
3970}
3971
3972void diff_free_filespec_blob(struct diff_filespec *s)
3973{
3974        if (s->should_free)
3975                free(s->data);
3976        else if (s->should_munmap)
3977                munmap(s->data, s->size);
3978
3979        if (s->should_free || s->should_munmap) {
3980                s->should_free = s->should_munmap = 0;
3981                s->data = NULL;
3982        }
3983}
3984
3985void diff_free_filespec_data(struct diff_filespec *s)
3986{
3987        diff_free_filespec_blob(s);
3988        FREE_AND_NULL(s->cnt_data);
3989}
3990
3991static void prep_temp_blob(struct index_state *istate,
3992                           const char *path, struct diff_tempfile *temp,
3993                           void *blob,
3994                           unsigned long size,
3995                           const struct object_id *oid,
3996                           int mode)
3997{
3998        struct strbuf buf = STRBUF_INIT;
3999        struct strbuf tempfile = STRBUF_INIT;
4000        char *path_dup = xstrdup(path);
4001        const char *base = basename(path_dup);
4002
4003        /* Generate "XXXXXX_basename.ext" */
4004        strbuf_addstr(&tempfile, "XXXXXX_");
4005        strbuf_addstr(&tempfile, base);
4006
4007        temp->tempfile = mks_tempfile_ts(tempfile.buf, strlen(base) + 1);
4008        if (!temp->tempfile)
4009                die_errno("unable to create temp-file");
4010        if (convert_to_working_tree(istate, path,
4011                        (const char *)blob, (size_t)size, &buf)) {
4012                blob = buf.buf;
4013                size = buf.len;
4014        }
4015        if (write_in_full(temp->tempfile->fd, blob, size) < 0 ||
4016            close_tempfile_gently(temp->tempfile))
4017                die_errno("unable to write temp-file");
4018        temp->name = get_tempfile_path(temp->tempfile);
4019        oid_to_hex_r(temp->hex, oid);
4020        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
4021        strbuf_release(&buf);
4022        strbuf_release(&tempfile);
4023        free(path_dup);
4024}
4025
4026static struct diff_tempfile *prepare_temp_file(struct repository *r,
4027                                               const char *name,
4028                                               struct diff_filespec *one)
4029{
4030        struct diff_tempfile *temp = claim_diff_tempfile();
4031
4032        if (!DIFF_FILE_VALID(one)) {
4033        not_a_valid_file:
4034                /* A '-' entry produces this for file-2, and
4035                 * a '+' entry produces this for file-1.
4036                 */
4037                temp->name = "/dev/null";
4038                xsnprintf(temp->hex, sizeof(temp->hex), ".");
4039                xsnprintf(temp->mode, sizeof(temp->mode), ".");
4040                return temp;
4041        }
4042
4043        if (!S_ISGITLINK(one->mode) &&
4044            (!one->oid_valid ||
4045             reuse_worktree_file(r->index, name, &one->oid, 1))) {
4046                struct stat st;
4047                if (lstat(name, &st) < 0) {
4048                        if (errno == ENOENT)
4049                                goto not_a_valid_file;
4050                        die_errno("stat(%s)", name);
4051                }
4052                if (S_ISLNK(st.st_mode)) {
4053                        struct strbuf sb = STRBUF_INIT;
4054                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
4055                                die_errno("readlink(%s)", name);
4056                        prep_temp_blob(r->index, name, temp, sb.buf, sb.len,
4057                                       (one->oid_valid ?
4058                                        &one->oid : &null_oid),
4059                                       (one->oid_valid ?
4060                                        one->mode : S_IFLNK));
4061                        strbuf_release(&sb);
4062                }
4063                else {
4064                        /* we can borrow from the file in the work tree */
4065                        temp->name = name;
4066                        if (!one->oid_valid)
4067                                oid_to_hex_r(temp->hex, &null_oid);
4068                        else
4069                                oid_to_hex_r(temp->hex, &one->oid);
4070                        /* Even though we may sometimes borrow the
4071                         * contents from the work tree, we always want
4072                         * one->mode.  mode is trustworthy even when
4073                         * !(one->oid_valid), as long as
4074                         * DIFF_FILE_VALID(one).
4075                         */
4076                        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
4077                }
4078                return temp;
4079        }
4080        else {
4081                if (diff_populate_filespec(r, one, 0))
4082                        die("cannot read data blob for %s", one->path);
4083                prep_temp_blob(r->index, name, temp,
4084                               one->data, one->size,
4085                               &one->oid, one->mode);
4086        }
4087        return temp;
4088}
4089
4090static void add_external_diff_name(struct repository *r,
4091                                   struct argv_array *argv,
4092                                   const char *name,
4093                                   struct diff_filespec *df)
4094{
4095        struct diff_tempfile *temp = prepare_temp_file(r, name, df);
4096        argv_array_push(argv, temp->name);
4097        argv_array_push(argv, temp->hex);
4098        argv_array_push(argv, temp->mode);
4099}
4100
4101/* An external diff command takes:
4102 *
4103 * diff-cmd name infile1 infile1-sha1 infile1-mode \
4104 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
4105 *
4106 */
4107static void run_external_diff(const char *pgm,
4108                              const char *name,
4109                              const char *other,
4110                              struct diff_filespec *one,
4111                              struct diff_filespec *two,
4112                              const char *xfrm_msg,
4113                              int complete_rewrite,
4114                              struct diff_options *o)
4115{
4116        struct argv_array argv = ARGV_ARRAY_INIT;
4117        struct argv_array env = ARGV_ARRAY_INIT;
4118        struct diff_queue_struct *q = &diff_queued_diff;
4119
4120        argv_array_push(&argv, pgm);
4121        argv_array_push(&argv, name);
4122
4123        if (one && two) {
4124                add_external_diff_name(o->repo, &argv, name, one);
4125                if (!other)
4126                        add_external_diff_name(o->repo, &argv, name, two);
4127                else {
4128                        add_external_diff_name(o->repo, &argv, other, two);
4129                        argv_array_push(&argv, other);
4130                        argv_array_push(&argv, xfrm_msg);
4131                }
4132        }
4133
4134        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
4135        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
4136
4137        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
4138                die(_("external diff died, stopping at %s"), name);
4139
4140        remove_tempfile();
4141        argv_array_clear(&argv);
4142        argv_array_clear(&env);
4143}
4144
4145static int similarity_index(struct diff_filepair *p)
4146{
4147        return p->score * 100 / MAX_SCORE;
4148}
4149
4150static const char *diff_abbrev_oid(const struct object_id *oid, int abbrev)
4151{
4152        if (startup_info->have_repository)
4153                return find_unique_abbrev(oid, abbrev);
4154        else {
4155                char *hex = oid_to_hex(oid);
4156                if (abbrev < 0)
4157                        abbrev = FALLBACK_DEFAULT_ABBREV;
4158                if (abbrev > the_hash_algo->hexsz)
4159                        BUG("oid abbreviation out of range: %d", abbrev);
4160                if (abbrev)
4161                        hex[abbrev] = '\0';
4162                return hex;
4163        }
4164}
4165
4166static void fill_metainfo(struct strbuf *msg,
4167                          const char *name,
4168                          const char *other,
4169                          struct diff_filespec *one,
4170                          struct diff_filespec *two,
4171                          struct diff_options *o,
4172                          struct diff_filepair *p,
4173                          int *must_show_header,
4174                          int use_color)
4175{
4176        const char *set = diff_get_color(use_color, DIFF_METAINFO);
4177        const char *reset = diff_get_color(use_color, DIFF_RESET);
4178        const char *line_prefix = diff_line_prefix(o);
4179
4180        *must_show_header = 1;
4181        strbuf_init(msg, PATH_MAX * 2 + 300);
4182        switch (p->status) {
4183        case DIFF_STATUS_COPIED:
4184                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4185                            line_prefix, set, similarity_index(p));
4186                strbuf_addf(msg, "%s\n%s%scopy from ",
4187                            reset,  line_prefix, set);
4188                quote_c_style(name, msg, NULL, 0);
4189                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
4190                quote_c_style(other, msg, NULL, 0);
4191                strbuf_addf(msg, "%s\n", reset);
4192                break;
4193        case DIFF_STATUS_RENAMED:
4194                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4195                            line_prefix, set, similarity_index(p));
4196                strbuf_addf(msg, "%s\n%s%srename from ",
4197                            reset, line_prefix, set);
4198                quote_c_style(name, msg, NULL, 0);
4199                strbuf_addf(msg, "%s\n%s%srename to ",
4200                            reset, line_prefix, set);
4201                quote_c_style(other, msg, NULL, 0);
4202                strbuf_addf(msg, "%s\n", reset);
4203                break;
4204        case DIFF_STATUS_MODIFIED:
4205                if (p->score) {
4206                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
4207                                    line_prefix,
4208                                    set, similarity_index(p), reset);
4209                        break;
4210                }
4211                /* fallthru */
4212        default:
4213                *must_show_header = 0;
4214        }
4215        if (one && two && !oideq(&one->oid, &two->oid)) {
4216                const unsigned hexsz = the_hash_algo->hexsz;
4217                int abbrev = o->flags.full_index ? hexsz : DEFAULT_ABBREV;
4218
4219                if (o->flags.binary) {
4220                        mmfile_t mf;
4221                        if ((!fill_mmfile(o->repo, &mf, one) &&
4222                             diff_filespec_is_binary(o->repo, one)) ||
4223                            (!fill_mmfile(o->repo, &mf, two) &&
4224                             diff_filespec_is_binary(o->repo, two)))
4225                                abbrev = hexsz;
4226                }
4227                strbuf_addf(msg, "%s%sindex %s..%s", line_prefix, set,
4228                            diff_abbrev_oid(&one->oid, abbrev),
4229                            diff_abbrev_oid(&two->oid, abbrev));
4230                if (one->mode == two->mode)
4231                        strbuf_addf(msg, " %06o", one->mode);
4232                strbuf_addf(msg, "%s\n", reset);
4233        }
4234}
4235
4236static void run_diff_cmd(const char *pgm,
4237                         const char *name,
4238                         const char *other,
4239                         const char *attr_path,
4240                         struct diff_filespec *one,
4241                         struct diff_filespec *two,
4242                         struct strbuf *msg,
4243                         struct diff_options *o,
4244                         struct diff_filepair *p)
4245{
4246        const char *xfrm_msg = NULL;
4247        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
4248        int must_show_header = 0;
4249
4250
4251        if (o->flags.allow_external) {
4252                struct userdiff_driver *drv;
4253
4254                drv = userdiff_find_by_path(o->repo->index, attr_path);
4255                if (drv && drv->external)
4256                        pgm = drv->external;
4257        }
4258
4259        if (msg) {
4260                /*
4261                 * don't use colors when the header is intended for an
4262                 * external diff driver
4263                 */
4264                fill_metainfo(msg, name, other, one, two, o, p,
4265                              &must_show_header,
4266                              want_color(o->use_color) && !pgm);
4267                xfrm_msg = msg->len ? msg->buf : NULL;
4268        }
4269
4270        if (pgm) {
4271                run_external_diff(pgm, name, other, one, two, xfrm_msg,
4272                                  complete_rewrite, o);
4273                return;
4274        }
4275        if (one && two)
4276                builtin_diff(name, other ? other : name,
4277                             one, two, xfrm_msg, must_show_header,
4278                             o, complete_rewrite);
4279        else
4280                fprintf(o->file, "* Unmerged path %s\n", name);
4281}
4282
4283static void diff_fill_oid_info(struct diff_filespec *one, struct index_state *istate)
4284{
4285        if (DIFF_FILE_VALID(one)) {
4286                if (!one->oid_valid) {
4287                        struct stat st;
4288                        if (one->is_stdin) {
4289                                oidclr(&one->oid);
4290                                return;
4291                        }
4292                        if (lstat(one->path, &st) < 0)
4293                                die_errno("stat '%s'", one->path);
4294                        if (index_path(istate, &one->oid, one->path, &st, 0))
4295                                die("cannot hash %s", one->path);
4296                }
4297        }
4298        else
4299                oidclr(&one->oid);
4300}
4301
4302static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
4303{
4304        /* Strip the prefix but do not molest /dev/null and absolute paths */
4305        if (*namep && !is_absolute_path(*namep)) {
4306                *namep += prefix_length;
4307                if (**namep == '/')
4308                        ++*namep;
4309        }
4310        if (*otherp && !is_absolute_path(*otherp)) {
4311                *otherp += prefix_length;
4312                if (**otherp == '/')
4313                        ++*otherp;
4314        }
4315}
4316
4317static void run_diff(struct diff_filepair *p, struct diff_options *o)
4318{
4319        const char *pgm = external_diff();
4320        struct strbuf msg;
4321        struct diff_filespec *one = p->one;
4322        struct diff_filespec *two = p->two;
4323        const char *name;
4324        const char *other;
4325        const char *attr_path;
4326
4327        name  = one->path;
4328        other = (strcmp(name, two->path) ? two->path : NULL);
4329        attr_path = name;
4330        if (o->prefix_length)
4331                strip_prefix(o->prefix_length, &name, &other);
4332
4333        if (!o->flags.allow_external)
4334                pgm = NULL;
4335
4336        if (DIFF_PAIR_UNMERGED(p)) {
4337                run_diff_cmd(pgm, name, NULL, attr_path,
4338                             NULL, NULL, NULL, o, p);
4339                return;
4340        }
4341
4342        diff_fill_oid_info(one, o->repo->index);
4343        diff_fill_oid_info(two, o->repo->index);
4344
4345        if (!pgm &&
4346            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
4347            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
4348                /*
4349                 * a filepair that changes between file and symlink
4350                 * needs to be split into deletion and creation.
4351                 */
4352                struct diff_filespec *null = alloc_filespec(two->path);
4353                run_diff_cmd(NULL, name, other, attr_path,
4354                             one, null, &msg,
4355                             o, p);
4356                free(null);
4357                strbuf_release(&msg);
4358
4359                null = alloc_filespec(one->path);
4360                run_diff_cmd(NULL, name, other, attr_path,
4361                             null, two, &msg, o, p);
4362                free(null);
4363        }
4364        else
4365                run_diff_cmd(pgm, name, other, attr_path,
4366                             one, two, &msg, o, p);
4367
4368        strbuf_release(&msg);
4369}
4370
4371static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
4372                         struct diffstat_t *diffstat)
4373{
4374        const char *name;
4375        const char *other;
4376
4377        if (DIFF_PAIR_UNMERGED(p)) {
4378                /* unmerged */
4379                builtin_diffstat(p->one->path, NULL, NULL, NULL,
4380                                 diffstat, o, p);
4381                return;
4382        }
4383
4384        name = p->one->path;
4385        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4386
4387        if (o->prefix_length)
4388                strip_prefix(o->prefix_length, &name, &other);
4389
4390        diff_fill_oid_info(p->one, o->repo->index);
4391        diff_fill_oid_info(p->two, o->repo->index);
4392
4393        builtin_diffstat(name, other, p->one, p->two,
4394                         diffstat, o, p);
4395}
4396
4397static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
4398{
4399        const char *name;
4400        const char *other;
4401        const char *attr_path;
4402
4403        if (DIFF_PAIR_UNMERGED(p)) {
4404                /* unmerged */
4405                return;
4406        }
4407
4408        name = p->one->path;
4409        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4410        attr_path = other ? other : name;
4411
4412        if (o->prefix_length)
4413                strip_prefix(o->prefix_length, &name, &other);
4414
4415        diff_fill_oid_info(p->one, o->repo->index);
4416        diff_fill_oid_info(p->two, o->repo->index);
4417
4418        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
4419}
4420
4421void repo_diff_setup(struct repository *r, struct diff_options *options)
4422{
4423        memcpy(options, &default_diff_options, sizeof(*options));
4424
4425        options->file = stdout;
4426        options->repo = r;
4427
4428        options->output_indicators[OUTPUT_INDICATOR_NEW] = '+';
4429        options->output_indicators[OUTPUT_INDICATOR_OLD] = '-';
4430        options->output_indicators[OUTPUT_INDICATOR_CONTEXT] = ' ';
4431        options->abbrev = DEFAULT_ABBREV;
4432        options->line_termination = '\n';
4433        options->break_opt = -1;
4434        options->rename_limit = -1;
4435        options->dirstat_permille = diff_dirstat_permille_default;
4436        options->context = diff_context_default;
4437        options->interhunkcontext = diff_interhunk_context_default;
4438        options->ws_error_highlight = ws_error_highlight_default;
4439        options->flags.rename_empty = 1;
4440        options->objfind = NULL;
4441
4442        /* pathchange left =NULL by default */
4443        options->change = diff_change;
4444        options->add_remove = diff_addremove;
4445        options->use_color = diff_use_color_default;
4446        options->detect_rename = diff_detect_rename_default;
4447        options->xdl_opts |= diff_algorithm;
4448        if (diff_indent_heuristic)
4449                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4450
4451        options->orderfile = diff_order_file_cfg;
4452
4453        if (diff_no_prefix) {
4454                options->a_prefix = options->b_prefix = "";
4455        } else if (!diff_mnemonic_prefix) {
4456                options->a_prefix = "a/";
4457                options->b_prefix = "b/";
4458        }
4459
4460        options->color_moved = diff_color_moved_default;
4461        options->color_moved_ws_handling = diff_color_moved_ws_default;
4462}
4463
4464void diff_setup_done(struct diff_options *options)
4465{
4466        unsigned check_mask = DIFF_FORMAT_NAME |
4467                              DIFF_FORMAT_NAME_STATUS |
4468                              DIFF_FORMAT_CHECKDIFF |
4469                              DIFF_FORMAT_NO_OUTPUT;
4470        /*
4471         * This must be signed because we're comparing against a potentially
4472         * negative value.
4473         */
4474        const int hexsz = the_hash_algo->hexsz;
4475
4476        if (options->set_default)
4477                options->set_default(options);
4478
4479        if (HAS_MULTI_BITS(options->output_format & check_mask))
4480                die(_("--name-only, --name-status, --check and -s are mutually exclusive"));
4481
4482        if (HAS_MULTI_BITS(options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK))
4483                die(_("-G, -S and --find-object are mutually exclusive"));
4484
4485        /*
4486         * Most of the time we can say "there are changes"
4487         * only by checking if there are changed paths, but
4488         * --ignore-whitespace* options force us to look
4489         * inside contents.
4490         */
4491
4492        if ((options->xdl_opts & XDF_WHITESPACE_FLAGS))
4493                options->flags.diff_from_contents = 1;
4494        else
4495                options->flags.diff_from_contents = 0;
4496
4497        if (options->flags.find_copies_harder)
4498                options->detect_rename = DIFF_DETECT_COPY;
4499
4500        if (!options->flags.relative_name)
4501                options->prefix = NULL;
4502        if (options->prefix)
4503                options->prefix_length = strlen(options->prefix);
4504        else
4505                options->prefix_length = 0;
4506
4507        if (options->output_format & (DIFF_FORMAT_NAME |
4508                                      DIFF_FORMAT_NAME_STATUS |
4509                                      DIFF_FORMAT_CHECKDIFF |
4510                                      DIFF_FORMAT_NO_OUTPUT))
4511                options->output_format &= ~(DIFF_FORMAT_RAW |
4512                                            DIFF_FORMAT_NUMSTAT |
4513                                            DIFF_FORMAT_DIFFSTAT |
4514                                            DIFF_FORMAT_SHORTSTAT |
4515                                            DIFF_FORMAT_DIRSTAT |
4516                                            DIFF_FORMAT_SUMMARY |
4517                                            DIFF_FORMAT_PATCH);
4518
4519        /*
4520         * These cases always need recursive; we do not drop caller-supplied
4521         * recursive bits for other formats here.
4522         */
4523        if (options->output_format & (DIFF_FORMAT_PATCH |
4524                                      DIFF_FORMAT_NUMSTAT |
4525                                      DIFF_FORMAT_DIFFSTAT |
4526                                      DIFF_FORMAT_SHORTSTAT |
4527                                      DIFF_FORMAT_DIRSTAT |
4528                                      DIFF_FORMAT_SUMMARY |
4529                                      DIFF_FORMAT_CHECKDIFF))
4530                options->flags.recursive = 1;
4531        /*
4532         * Also pickaxe would not work very well if you do not say recursive
4533         */
4534        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
4535                options->flags.recursive = 1;
4536        /*
4537         * When patches are generated, submodules diffed against the work tree
4538         * must be checked for dirtiness too so it can be shown in the output
4539         */
4540        if (options->output_format & DIFF_FORMAT_PATCH)
4541                options->flags.dirty_submodules = 1;
4542
4543        if (options->detect_rename && options->rename_limit < 0)
4544                options->rename_limit = diff_rename_limit_default;
4545        if (hexsz < options->abbrev)
4546                options->abbrev = hexsz; /* full */
4547
4548        /*
4549         * It does not make sense to show the first hit we happened
4550         * to have found.  It does not make sense not to return with
4551         * exit code in such a case either.
4552         */
4553        if (options->flags.quick) {
4554                options->output_format = DIFF_FORMAT_NO_OUTPUT;
4555                options->flags.exit_with_status = 1;
4556        }
4557
4558        options->diff_path_counter = 0;
4559
4560        if (options->flags.follow_renames && options->pathspec.nr != 1)
4561                die(_("--follow requires exactly one pathspec"));
4562
4563        if (!options->use_color || external_diff())
4564                options->color_moved = 0;
4565}
4566
4567static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
4568{
4569        char c, *eq;
4570        int len;
4571
4572        if (*arg != '-')
4573                return 0;
4574        c = *++arg;
4575        if (!c)
4576                return 0;
4577        if (c == arg_short) {
4578                c = *++arg;
4579                if (!c)
4580                        return 1;
4581                if (val && isdigit(c)) {
4582                        char *end;
4583                        int n = strtoul(arg, &end, 10);
4584                        if (*end)
4585                                return 0;
4586                        *val = n;
4587                        return 1;
4588                }
4589                return 0;
4590        }
4591        if (c != '-')
4592                return 0;
4593        arg++;
4594        eq = strchrnul(arg, '=');
4595        len = eq - arg;
4596        if (!len || strncmp(arg, arg_long, len))
4597                return 0;
4598        if (*eq) {
4599                int n;
4600                char *end;
4601                if (!isdigit(*++eq))
4602                        return 0;
4603                n = strtoul(eq, &end, 10);
4604                if (*end)
4605                        return 0;
4606                *val = n;
4607        }
4608        return 1;
4609}
4610
4611static int diff_scoreopt_parse(const char *opt);
4612
4613static inline int short_opt(char opt, const char **argv,
4614                            const char **optarg)
4615{
4616        const char *arg = argv[0];
4617        if (arg[0] != '-' || arg[1] != opt)
4618                return 0;
4619        if (arg[2] != '\0') {
4620                *optarg = arg + 2;
4621                return 1;
4622        }
4623        if (!argv[1])
4624                die("Option '%c' requires a value", opt);
4625        *optarg = argv[1];
4626        return 2;
4627}
4628
4629int parse_long_opt(const char *opt, const char **argv,
4630                   const char **optarg)
4631{
4632        const char *arg = argv[0];
4633        if (!skip_prefix(arg, "--", &arg))
4634                return 0;
4635        if (!skip_prefix(arg, opt, &arg))
4636                return 0;
4637        if (*arg == '=') { /* stuck form: --option=value */
4638                *optarg = arg + 1;
4639                return 1;
4640        }
4641        if (*arg != '\0')
4642                return 0;
4643        /* separate form: --option value */
4644        if (!argv[1])
4645                die("Option '--%s' requires a value", opt);
4646        *optarg = argv[1];
4647        return 2;
4648}
4649
4650static int stat_opt(struct diff_options *options, const char **av)
4651{
4652        const char *arg = av[0];
4653        char *end;
4654        int width = options->stat_width;
4655        int name_width = options->stat_name_width;
4656        int graph_width = options->stat_graph_width;
4657        int count = options->stat_count;
4658        int argcount = 1;
4659
4660        if (!skip_prefix(arg, "--stat", &arg))
4661                BUG("stat option does not begin with --stat: %s", arg);
4662        end = (char *)arg;
4663
4664        switch (*arg) {
4665        case '-':
4666                if (skip_prefix(arg, "-width", &arg)) {
4667                        if (*arg == '=')
4668                                width = strtoul(arg + 1, &end, 10);
4669                        else if (!*arg && !av[1])
4670                                die_want_option("--stat-width");
4671                        else if (!*arg) {
4672                                width = strtoul(av[1], &end, 10);
4673                                argcount = 2;
4674                        }
4675                } else if (skip_prefix(arg, "-name-width", &arg)) {
4676                        if (*arg == '=')
4677                                name_width = strtoul(arg + 1, &end, 10);
4678                        else if (!*arg && !av[1])
4679                                die_want_option("--stat-name-width");
4680                        else if (!*arg) {
4681                                name_width = strtoul(av[1], &end, 10);
4682                                argcount = 2;
4683                        }
4684                } else if (skip_prefix(arg, "-graph-width", &arg)) {
4685                        if (*arg == '=')
4686                                graph_width = strtoul(arg + 1, &end, 10);
4687                        else if (!*arg && !av[1])
4688                                die_want_option("--stat-graph-width");
4689                        else if (!*arg) {
4690                                graph_width = strtoul(av[1], &end, 10);
4691                                argcount = 2;
4692                        }
4693                } else if (skip_prefix(arg, "-count", &arg)) {
4694                        if (*arg == '=')
4695                                count = strtoul(arg + 1, &end, 10);
4696                        else if (!*arg && !av[1])
4697                                die_want_option("--stat-count");
4698                        else if (!*arg) {
4699                                count = strtoul(av[1], &end, 10);
4700                                argcount = 2;
4701                        }
4702                }
4703                break;
4704        case '=':
4705                width = strtoul(arg+1, &end, 10);
4706                if (*end == ',')
4707                        name_width = strtoul(end+1, &end, 10);
4708                if (*end == ',')
4709                        count = strtoul(end+1, &end, 10);
4710        }
4711
4712        /* Important! This checks all the error cases! */
4713        if (*end)
4714                return 0;
4715        options->output_format |= DIFF_FORMAT_DIFFSTAT;
4716        options->stat_name_width = name_width;
4717        options->stat_graph_width = graph_width;
4718        options->stat_width = width;
4719        options->stat_count = count;
4720        return argcount;
4721}
4722
4723static int parse_dirstat_opt(struct diff_options *options, const char *params)
4724{
4725        struct strbuf errmsg = STRBUF_INIT;
4726        if (parse_dirstat_params(options, params, &errmsg))
4727                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
4728                    errmsg.buf);
4729        strbuf_release(&errmsg);
4730        /*
4731         * The caller knows a dirstat-related option is given from the command
4732         * line; allow it to say "return this_function();"
4733         */
4734        options->output_format |= DIFF_FORMAT_DIRSTAT;
4735        return 1;
4736}
4737
4738static int parse_submodule_opt(struct diff_options *options, const char *value)
4739{
4740        if (parse_submodule_params(options, value))
4741                die(_("Failed to parse --submodule option parameter: '%s'"),
4742                        value);
4743        return 1;
4744}
4745
4746static const char diff_status_letters[] = {
4747        DIFF_STATUS_ADDED,
4748        DIFF_STATUS_COPIED,
4749        DIFF_STATUS_DELETED,
4750        DIFF_STATUS_MODIFIED,
4751        DIFF_STATUS_RENAMED,
4752        DIFF_STATUS_TYPE_CHANGED,
4753        DIFF_STATUS_UNKNOWN,
4754        DIFF_STATUS_UNMERGED,
4755        DIFF_STATUS_FILTER_AON,
4756        DIFF_STATUS_FILTER_BROKEN,
4757        '\0',
4758};
4759
4760static unsigned int filter_bit['Z' + 1];
4761
4762static void prepare_filter_bits(void)
4763{
4764        int i;
4765
4766        if (!filter_bit[DIFF_STATUS_ADDED]) {
4767                for (i = 0; diff_status_letters[i]; i++)
4768                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
4769        }
4770}
4771
4772static unsigned filter_bit_tst(char status, const struct diff_options *opt)
4773{
4774        return opt->filter & filter_bit[(int) status];
4775}
4776
4777static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
4778{
4779        int i, optch;
4780
4781        prepare_filter_bits();
4782
4783        /*
4784         * If there is a negation e.g. 'd' in the input, and we haven't
4785         * initialized the filter field with another --diff-filter, start
4786         * from full set of bits, except for AON.
4787         */
4788        if (!opt->filter) {
4789                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4790                        if (optch < 'a' || 'z' < optch)
4791                                continue;
4792                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
4793                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
4794                        break;
4795                }
4796        }
4797
4798        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4799                unsigned int bit;
4800                int negate;
4801
4802                if ('a' <= optch && optch <= 'z') {
4803                        negate = 1;
4804                        optch = toupper(optch);
4805                } else {
4806                        negate = 0;
4807                }
4808
4809                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
4810                if (!bit)
4811                        return optarg[i];
4812                if (negate)
4813                        opt->filter &= ~bit;
4814                else
4815                        opt->filter |= bit;
4816        }
4817        return 0;
4818}
4819
4820static void enable_patch_output(int *fmt) {
4821        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
4822        *fmt |= DIFF_FORMAT_PATCH;
4823}
4824
4825static int parse_ws_error_highlight_opt(struct diff_options *opt, const char *arg)
4826{
4827        int val = parse_ws_error_highlight(arg);
4828
4829        if (val < 0) {
4830                error("unknown value after ws-error-highlight=%.*s",
4831                      -1 - val, arg);
4832                return 0;
4833        }
4834        opt->ws_error_highlight = val;
4835        return 1;
4836}
4837
4838static int parse_objfind_opt(struct diff_options *opt, const char *arg)
4839{
4840        struct object_id oid;
4841
4842        if (get_oid(arg, &oid))
4843                return error("unable to resolve '%s'", arg);
4844
4845        if (!opt->objfind)
4846                opt->objfind = xcalloc(1, sizeof(*opt->objfind));
4847
4848        opt->pickaxe_opts |= DIFF_PICKAXE_KIND_OBJFIND;
4849        opt->flags.recursive = 1;
4850        opt->flags.tree_in_recursive = 1;
4851        oidset_insert(opt->objfind, &oid);
4852        return 1;
4853}
4854
4855int diff_opt_parse(struct diff_options *options,
4856                   const char **av, int ac, const char *prefix)
4857{
4858        const char *arg = av[0];
4859        const char *optarg;
4860        int argcount;
4861
4862        if (!prefix)
4863                prefix = "";
4864
4865        /* Output format options */
4866        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
4867            || opt_arg(arg, 'U', "unified", &options->context))
4868                enable_patch_output(&options->output_format);
4869        else if (!strcmp(arg, "--raw"))
4870                options->output_format |= DIFF_FORMAT_RAW;
4871        else if (!strcmp(arg, "--patch-with-raw")) {
4872                enable_patch_output(&options->output_format);
4873                options->output_format |= DIFF_FORMAT_RAW;
4874        } else if (!strcmp(arg, "--numstat"))
4875                options->output_format |= DIFF_FORMAT_NUMSTAT;
4876        else if (!strcmp(arg, "--shortstat"))
4877                options->output_format |= DIFF_FORMAT_SHORTSTAT;
4878        else if (skip_prefix(arg, "-X", &arg) ||
4879                 skip_to_optional_arg(arg, "--dirstat", &arg))
4880                return parse_dirstat_opt(options, arg);
4881        else if (!strcmp(arg, "--cumulative"))
4882                return parse_dirstat_opt(options, "cumulative");
4883        else if (skip_to_optional_arg(arg, "--dirstat-by-file", &arg)) {
4884                parse_dirstat_opt(options, "files");
4885                return parse_dirstat_opt(options, arg);
4886        }
4887        else if (!strcmp(arg, "--check"))
4888                options->output_format |= DIFF_FORMAT_CHECKDIFF;
4889        else if (!strcmp(arg, "--summary"))
4890                options->output_format |= DIFF_FORMAT_SUMMARY;
4891        else if (!strcmp(arg, "--patch-with-stat")) {
4892                enable_patch_output(&options->output_format);
4893                options->output_format |= DIFF_FORMAT_DIFFSTAT;
4894        } else if (!strcmp(arg, "--name-only"))
4895                options->output_format |= DIFF_FORMAT_NAME;
4896        else if (!strcmp(arg, "--name-status"))
4897                options->output_format |= DIFF_FORMAT_NAME_STATUS;
4898        else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
4899                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
4900        else if (starts_with(arg, "--stat"))
4901                /* --stat, --stat-width, --stat-name-width, or --stat-count */
4902                return stat_opt(options, av);
4903        else if (!strcmp(arg, "--compact-summary")) {
4904                 options->flags.stat_with_summary = 1;
4905                 options->output_format |= DIFF_FORMAT_DIFFSTAT;
4906        } else if (!strcmp(arg, "--no-compact-summary"))
4907                 options->flags.stat_with_summary = 0;
4908        else if (skip_prefix(arg, "--output-indicator-new=", &arg))
4909                options->output_indicators[OUTPUT_INDICATOR_NEW] = arg[0];
4910        else if (skip_prefix(arg, "--output-indicator-old=", &arg))
4911                options->output_indicators[OUTPUT_INDICATOR_OLD] = arg[0];
4912        else if (skip_prefix(arg, "--output-indicator-context=", &arg))
4913                options->output_indicators[OUTPUT_INDICATOR_CONTEXT] = arg[0];
4914
4915        /* renames options */
4916        else if (starts_with(arg, "-B") ||
4917                 skip_to_optional_arg(arg, "--break-rewrites", NULL)) {
4918                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
4919                        return error("invalid argument to -B: %s", arg+2);
4920        }
4921        else if (starts_with(arg, "-M") ||
4922                 skip_to_optional_arg(arg, "--find-renames", NULL)) {
4923                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4924                        return error("invalid argument to -M: %s", arg+2);
4925                options->detect_rename = DIFF_DETECT_RENAME;
4926        }
4927        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
4928                options->irreversible_delete = 1;
4929        }
4930        else if (starts_with(arg, "-C") ||
4931                 skip_to_optional_arg(arg, "--find-copies", NULL)) {
4932                if (options->detect_rename == DIFF_DETECT_COPY)
4933                        options->flags.find_copies_harder = 1;
4934                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4935                        return error("invalid argument to -C: %s", arg+2);
4936                options->detect_rename = DIFF_DETECT_COPY;
4937        }
4938        else if (!strcmp(arg, "--no-renames"))
4939                options->detect_rename = 0;
4940        else if (!strcmp(arg, "--rename-empty"))
4941                options->flags.rename_empty = 1;
4942        else if (!strcmp(arg, "--no-rename-empty"))
4943                options->flags.rename_empty = 0;
4944        else if (skip_to_optional_arg_default(arg, "--relative", &arg, NULL)) {
4945                options->flags.relative_name = 1;
4946                if (arg)
4947                        options->prefix = arg;
4948        }
4949
4950        /* xdiff options */
4951        else if (!strcmp(arg, "--minimal"))
4952                DIFF_XDL_SET(options, NEED_MINIMAL);
4953        else if (!strcmp(arg, "--no-minimal"))
4954                DIFF_XDL_CLR(options, NEED_MINIMAL);
4955        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
4956                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
4957        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
4958                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
4959        else if (!strcmp(arg, "--ignore-space-at-eol"))
4960                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
4961        else if (!strcmp(arg, "--ignore-cr-at-eol"))
4962                DIFF_XDL_SET(options, IGNORE_CR_AT_EOL);
4963        else if (!strcmp(arg, "--ignore-blank-lines"))
4964                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
4965        else if (!strcmp(arg, "--indent-heuristic"))
4966                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4967        else if (!strcmp(arg, "--no-indent-heuristic"))
4968                DIFF_XDL_CLR(options, INDENT_HEURISTIC);
4969        else if (!strcmp(arg, "--patience")) {
4970                int i;
4971                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4972                /*
4973                 * Both --patience and --anchored use PATIENCE_DIFF
4974                 * internally, so remove any anchors previously
4975                 * specified.
4976                 */
4977                for (i = 0; i < options->anchors_nr; i++)
4978                        free(options->anchors[i]);
4979                options->anchors_nr = 0;
4980        } else if (!strcmp(arg, "--histogram"))
4981                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
4982        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
4983                long value = parse_algorithm_value(optarg);
4984                if (value < 0)
4985                        return error("option diff-algorithm accepts \"myers\", "
4986                                     "\"minimal\", \"patience\" and \"histogram\"");
4987                /* clear out previous settings */
4988                DIFF_XDL_CLR(options, NEED_MINIMAL);
4989                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
4990                options->xdl_opts |= value;
4991                return argcount;
4992        } else if (skip_prefix(arg, "--anchored=", &arg)) {
4993                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4994                ALLOC_GROW(options->anchors, options->anchors_nr + 1,
4995                           options->anchors_alloc);
4996                options->anchors[options->anchors_nr++] = xstrdup(arg);
4997        }
4998
4999        /* flags options */
5000        else if (!strcmp(arg, "--binary")) {
5001                enable_patch_output(&options->output_format);
5002                options->flags.binary = 1;
5003        }
5004        else if (!strcmp(arg, "--full-index"))
5005                options->flags.full_index = 1;
5006        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
5007                options->flags.text = 1;
5008        else if (!strcmp(arg, "-R"))
5009                options->flags.reverse_diff = 1;
5010        else if (!strcmp(arg, "--find-copies-harder"))
5011                options->flags.find_copies_harder = 1;
5012        else if (!strcmp(arg, "--follow"))
5013                options->flags.follow_renames = 1;
5014        else if (!strcmp(arg, "--no-follow")) {
5015                options->flags.follow_renames = 0;
5016                options->flags.default_follow_renames = 0;
5017        } else if (skip_to_optional_arg_default(arg, "--color", &arg, "always")) {
5018                int value = git_config_colorbool(NULL, arg);
5019                if (value < 0)
5020                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
5021                options->use_color = value;
5022        }
5023        else if (!strcmp(arg, "--no-color"))
5024                options->use_color = 0;
5025        else if (!strcmp(arg, "--color-moved")) {
5026                if (diff_color_moved_default)
5027                        options->color_moved = diff_color_moved_default;
5028                if (options->color_moved == COLOR_MOVED_NO)
5029                        options->color_moved = COLOR_MOVED_DEFAULT;
5030        } else if (!strcmp(arg, "--no-color-moved"))
5031                options->color_moved = COLOR_MOVED_NO;
5032        else if (skip_prefix(arg, "--color-moved=", &arg)) {
5033                int cm = parse_color_moved(arg);
5034                if (cm < 0)
5035                        die("bad --color-moved argument: %s", arg);
5036                options->color_moved = cm;
5037        } else if (skip_prefix(arg, "--color-moved-ws=", &arg)) {
5038                options->color_moved_ws_handling = parse_color_moved_ws(arg);
5039        } else if (skip_to_optional_arg_default(arg, "--color-words", &options->word_regex, NULL)) {
5040                options->use_color = 1;
5041                options->word_diff = DIFF_WORDS_COLOR;
5042        }
5043        else if (!strcmp(arg, "--word-diff")) {
5044                if (options->word_diff == DIFF_WORDS_NONE)
5045                        options->word_diff = DIFF_WORDS_PLAIN;
5046        }
5047        else if (skip_prefix(arg, "--word-diff=", &arg)) {
5048                if (!strcmp(arg, "plain"))
5049                        options->word_diff = DIFF_WORDS_PLAIN;
5050                else if (!strcmp(arg, "color")) {
5051                        options->use_color = 1;
5052                        options->word_diff = DIFF_WORDS_COLOR;
5053                }
5054                else if (!strcmp(arg, "porcelain"))
5055                        options->word_diff = DIFF_WORDS_PORCELAIN;
5056                else if (!strcmp(arg, "none"))
5057                        options->word_diff = DIFF_WORDS_NONE;
5058                else
5059                        die("bad --word-diff argument: %s", arg);
5060        }
5061        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
5062                if (options->word_diff == DIFF_WORDS_NONE)
5063                        options->word_diff = DIFF_WORDS_PLAIN;
5064                options->word_regex = optarg;
5065                return argcount;
5066        }
5067        else if (!strcmp(arg, "--exit-code"))
5068                options->flags.exit_with_status = 1;
5069        else if (!strcmp(arg, "--quiet"))
5070                options->flags.quick = 1;
5071        else if (!strcmp(arg, "--ext-diff"))
5072                options->flags.allow_external = 1;
5073        else if (!strcmp(arg, "--no-ext-diff"))
5074                options->flags.allow_external = 0;
5075        else if (!strcmp(arg, "--textconv")) {
5076                options->flags.allow_textconv = 1;
5077                options->flags.textconv_set_via_cmdline = 1;
5078        } else if (!strcmp(arg, "--no-textconv"))
5079                options->flags.allow_textconv = 0;
5080        else if (skip_to_optional_arg_default(arg, "--ignore-submodules", &arg, "all")) {
5081                options->flags.override_submodule_config = 1;
5082                handle_ignore_submodules_arg(options, arg);
5083        } else if (skip_to_optional_arg_default(arg, "--submodule", &arg, "log"))
5084                return parse_submodule_opt(options, arg);
5085        else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
5086                return parse_ws_error_highlight_opt(options, arg);
5087        else if (!strcmp(arg, "--ita-invisible-in-index"))
5088                options->ita_invisible_in_index = 1;
5089        else if (!strcmp(arg, "--ita-visible-in-index"))
5090                options->ita_invisible_in_index = 0;
5091
5092        /* misc options */
5093        else if (!strcmp(arg, "-z"))
5094                options->line_termination = 0;
5095        else if ((argcount = short_opt('l', av, &optarg))) {
5096                options->rename_limit = strtoul(optarg, NULL, 10);
5097                return argcount;
5098        }
5099        else if ((argcount = short_opt('S', av, &optarg))) {
5100                options->pickaxe = optarg;
5101                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
5102                return argcount;
5103        } else if ((argcount = short_opt('G', av, &optarg))) {
5104                options->pickaxe = optarg;
5105                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
5106                return argcount;
5107        }
5108        else if (!strcmp(arg, "--pickaxe-all"))
5109                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
5110        else if (!strcmp(arg, "--pickaxe-regex"))
5111                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
5112        else if ((argcount = short_opt('O', av, &optarg))) {
5113                options->orderfile = prefix_filename(prefix, optarg);
5114                return argcount;
5115        } else if (skip_prefix(arg, "--find-object=", &arg))
5116                return parse_objfind_opt(options, arg);
5117        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
5118                int offending = parse_diff_filter_opt(optarg, options);
5119                if (offending)
5120                        die("unknown change class '%c' in --diff-filter=%s",
5121                            offending, optarg);
5122                return argcount;
5123        }
5124        else if (!strcmp(arg, "--no-abbrev"))
5125                options->abbrev = 0;
5126        else if (!strcmp(arg, "--abbrev"))
5127                options->abbrev = DEFAULT_ABBREV;
5128        else if (skip_prefix(arg, "--abbrev=", &arg)) {
5129                options->abbrev = strtoul(arg, NULL, 10);
5130                if (options->abbrev < MINIMUM_ABBREV)
5131                        options->abbrev = MINIMUM_ABBREV;
5132                else if (the_hash_algo->hexsz < options->abbrev)
5133                        options->abbrev = the_hash_algo->hexsz;
5134        }
5135        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
5136                options->a_prefix = optarg;
5137                return argcount;
5138        }
5139        else if ((argcount = parse_long_opt("line-prefix", av, &optarg))) {
5140                options->line_prefix = optarg;
5141                options->line_prefix_length = strlen(options->line_prefix);
5142                graph_setup_line_prefix(options);
5143                return argcount;
5144        }
5145        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
5146                options->b_prefix = optarg;
5147                return argcount;
5148        }
5149        else if (!strcmp(arg, "--no-prefix"))
5150                options->a_prefix = options->b_prefix = "";
5151        else if (opt_arg(arg, '\0', "inter-hunk-context",
5152                         &options->interhunkcontext))
5153                ;
5154        else if (!strcmp(arg, "-W"))
5155                options->flags.funccontext = 1;
5156        else if (!strcmp(arg, "--function-context"))
5157                options->flags.funccontext = 1;
5158        else if (!strcmp(arg, "--no-function-context"))
5159                options->flags.funccontext = 0;
5160        else if ((argcount = parse_long_opt("output", av, &optarg))) {
5161                char *path = prefix_filename(prefix, optarg);
5162                options->file = xfopen(path, "w");
5163                options->close_file = 1;
5164                if (options->use_color != GIT_COLOR_ALWAYS)
5165                        options->use_color = GIT_COLOR_NEVER;
5166                free(path);
5167                return argcount;
5168        } else
5169                return 0;
5170        return 1;
5171}
5172
5173int parse_rename_score(const char **cp_p)
5174{
5175        unsigned long num, scale;
5176        int ch, dot;
5177        const char *cp = *cp_p;
5178
5179        num = 0;
5180        scale = 1;
5181        dot = 0;
5182        for (;;) {
5183                ch = *cp;
5184                if ( !dot && ch == '.' ) {
5185                        scale = 1;
5186                        dot = 1;
5187                } else if ( ch == '%' ) {
5188                        scale = dot ? scale*100 : 100;
5189                        cp++;   /* % is always at the end */
5190                        break;
5191                } else if ( ch >= '0' && ch <= '9' ) {
5192                        if ( scale < 100000 ) {
5193                                scale *= 10;
5194                                num = (num*10) + (ch-'0');
5195                        }
5196                } else {
5197                        break;
5198                }
5199                cp++;
5200        }
5201        *cp_p = cp;
5202
5203        /* user says num divided by scale and we say internally that
5204         * is MAX_SCORE * num / scale.
5205         */
5206        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
5207}
5208
5209static int diff_scoreopt_parse(const char *opt)
5210{
5211        int opt1, opt2, cmd;
5212
5213        if (*opt++ != '-')
5214                return -1;
5215        cmd = *opt++;
5216        if (cmd == '-') {
5217                /* convert the long-form arguments into short-form versions */
5218                if (skip_prefix(opt, "break-rewrites", &opt)) {
5219                        if (*opt == 0 || *opt++ == '=')
5220                                cmd = 'B';
5221                } else if (skip_prefix(opt, "find-copies", &opt)) {
5222                        if (*opt == 0 || *opt++ == '=')
5223                                cmd = 'C';
5224                } else if (skip_prefix(opt, "find-renames", &opt)) {
5225                        if (*opt == 0 || *opt++ == '=')
5226                                cmd = 'M';
5227                }
5228        }
5229        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
5230                return -1; /* that is not a -M, -C, or -B option */
5231
5232        opt1 = parse_rename_score(&opt);
5233        if (cmd != 'B')
5234                opt2 = 0;
5235        else {
5236                if (*opt == 0)
5237                        opt2 = 0;
5238                else if (*opt != '/')
5239                        return -1; /* we expect -B80/99 or -B80 */
5240                else {
5241                        opt++;
5242                        opt2 = parse_rename_score(&opt);
5243                }
5244        }
5245        if (*opt != 0)
5246                return -1;
5247        return opt1 | (opt2 << 16);
5248}
5249
5250struct diff_queue_struct diff_queued_diff;
5251
5252void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
5253{
5254        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
5255        queue->queue[queue->nr++] = dp;
5256}
5257
5258struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
5259                                 struct diff_filespec *one,
5260                                 struct diff_filespec *two)
5261{
5262        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
5263        dp->one = one;
5264        dp->two = two;
5265        if (queue)
5266                diff_q(queue, dp);
5267        return dp;
5268}
5269
5270void diff_free_filepair(struct diff_filepair *p)
5271{
5272        free_filespec(p->one);
5273        free_filespec(p->two);
5274        free(p);
5275}
5276
5277const char *diff_aligned_abbrev(const struct object_id *oid, int len)
5278{
5279        int abblen;
5280        const char *abbrev;
5281
5282        /* Do we want all 40 hex characters? */
5283        if (len == the_hash_algo->hexsz)
5284                return oid_to_hex(oid);
5285
5286        /* An abbreviated value is fine, possibly followed by an ellipsis. */
5287        abbrev = diff_abbrev_oid(oid, len);
5288
5289        if (!print_sha1_ellipsis())
5290                return abbrev;
5291
5292        abblen = strlen(abbrev);
5293
5294        /*
5295         * In well-behaved cases, where the abbreviated result is the
5296         * same as the requested length, append three dots after the
5297         * abbreviation (hence the whole logic is limited to the case
5298         * where abblen < 37); when the actual abbreviated result is a
5299         * bit longer than the requested length, we reduce the number
5300         * of dots so that they match the well-behaved ones.  However,
5301         * if the actual abbreviation is longer than the requested
5302         * length by more than three, we give up on aligning, and add
5303         * three dots anyway, to indicate that the output is not the
5304         * full object name.  Yes, this may be suboptimal, but this
5305         * appears only in "diff --raw --abbrev" output and it is not
5306         * worth the effort to change it now.  Note that this would
5307         * likely to work fine when the automatic sizing of default
5308         * abbreviation length is used--we would be fed -1 in "len" in
5309         * that case, and will end up always appending three-dots, but
5310         * the automatic sizing is supposed to give abblen that ensures
5311         * uniqueness across all objects (statistically speaking).
5312         */
5313        if (abblen < the_hash_algo->hexsz - 3) {
5314                static char hex[GIT_MAX_HEXSZ + 1];
5315                if (len < abblen && abblen <= len + 2)
5316                        xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
5317                else
5318                        xsnprintf(hex, sizeof(hex), "%s...", abbrev);
5319                return hex;
5320        }
5321
5322        return oid_to_hex(oid);
5323}
5324
5325static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
5326{
5327        int line_termination = opt->line_termination;
5328        int inter_name_termination = line_termination ? '\t' : '\0';
5329
5330        fprintf(opt->file, "%s", diff_line_prefix(opt));
5331        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
5332                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
5333                        diff_aligned_abbrev(&p->one->oid, opt->abbrev));
5334                fprintf(opt->file, "%s ",
5335                        diff_aligned_abbrev(&p->two->oid, opt->abbrev));
5336        }
5337        if (p->score) {
5338                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
5339                        inter_name_termination);
5340        } else {
5341                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
5342        }
5343
5344        if (p->status == DIFF_STATUS_COPIED ||
5345            p->status == DIFF_STATUS_RENAMED) {
5346                const char *name_a, *name_b;
5347                name_a = p->one->path;
5348                name_b = p->two->path;
5349                strip_prefix(opt->prefix_length, &name_a, &name_b);
5350                write_name_quoted(name_a, opt->file, inter_name_termination);
5351                write_name_quoted(name_b, opt->file, line_termination);
5352        } else {
5353                const char *name_a, *name_b;
5354                name_a = p->one->mode ? p->one->path : p->two->path;
5355                name_b = NULL;
5356                strip_prefix(opt->prefix_length, &name_a, &name_b);
5357                write_name_quoted(name_a, opt->file, line_termination);
5358        }
5359}
5360
5361int diff_unmodified_pair(struct diff_filepair *p)
5362{
5363        /* This function is written stricter than necessary to support
5364         * the currently implemented transformers, but the idea is to
5365         * let transformers to produce diff_filepairs any way they want,
5366         * and filter and clean them up here before producing the output.
5367         */
5368        struct diff_filespec *one = p->one, *two = p->two;
5369
5370        if (DIFF_PAIR_UNMERGED(p))
5371                return 0; /* unmerged is interesting */
5372
5373        /* deletion, addition, mode or type change
5374         * and rename are all interesting.
5375         */
5376        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
5377            DIFF_PAIR_MODE_CHANGED(p) ||
5378            strcmp(one->path, two->path))
5379                return 0;
5380
5381        /* both are valid and point at the same path.  that is, we are
5382         * dealing with a change.
5383         */
5384        if (one->oid_valid && two->oid_valid &&
5385            oideq(&one->oid, &two->oid) &&
5386            !one->dirty_submodule && !two->dirty_submodule)
5387                return 1; /* no change */
5388        if (!one->oid_valid && !two->oid_valid)
5389                return 1; /* both look at the same file on the filesystem. */
5390        return 0;
5391}
5392
5393static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
5394{
5395        if (diff_unmodified_pair(p))
5396                return;
5397
5398        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5399            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5400                return; /* no tree diffs in patch format */
5401
5402        run_diff(p, o);
5403}
5404
5405static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
5406                            struct diffstat_t *diffstat)
5407{
5408        if (diff_unmodified_pair(p))
5409                return;
5410
5411        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5412            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5413                return; /* no useful stat for tree diffs */
5414
5415        run_diffstat(p, o, diffstat);
5416}
5417
5418static void diff_flush_checkdiff(struct diff_filepair *p,
5419                struct diff_options *o)
5420{
5421        if (diff_unmodified_pair(p))
5422                return;
5423
5424        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5425            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5426                return; /* nothing to check in tree diffs */
5427
5428        run_checkdiff(p, o);
5429}
5430
5431int diff_queue_is_empty(void)
5432{
5433        struct diff_queue_struct *q = &diff_queued_diff;
5434        int i;
5435        for (i = 0; i < q->nr; i++)
5436                if (!diff_unmodified_pair(q->queue[i]))
5437                        return 0;
5438        return 1;
5439}
5440
5441#if DIFF_DEBUG
5442void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
5443{
5444        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
5445                x, one ? one : "",
5446                s->path,
5447                DIFF_FILE_VALID(s) ? "valid" : "invalid",
5448                s->mode,
5449                s->oid_valid ? oid_to_hex(&s->oid) : "");
5450        fprintf(stderr, "queue[%d] %s size %lu\n",
5451                x, one ? one : "",
5452                s->size);
5453}
5454
5455void diff_debug_filepair(const struct diff_filepair *p, int i)
5456{
5457        diff_debug_filespec(p->one, i, "one");
5458        diff_debug_filespec(p->two, i, "two");
5459        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
5460                p->score, p->status ? p->status : '?',
5461                p->one->rename_used, p->broken_pair);
5462}
5463
5464void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
5465{
5466        int i;
5467        if (msg)
5468                fprintf(stderr, "%s\n", msg);
5469        fprintf(stderr, "q->nr = %d\n", q->nr);
5470        for (i = 0; i < q->nr; i++) {
5471                struct diff_filepair *p = q->queue[i];
5472                diff_debug_filepair(p, i);
5473        }
5474}
5475#endif
5476
5477static void diff_resolve_rename_copy(void)
5478{
5479        int i;
5480        struct diff_filepair *p;
5481        struct diff_queue_struct *q = &diff_queued_diff;
5482
5483        diff_debug_queue("resolve-rename-copy", q);
5484
5485        for (i = 0; i < q->nr; i++) {
5486                p = q->queue[i];
5487                p->status = 0; /* undecided */
5488                if (DIFF_PAIR_UNMERGED(p))
5489                        p->status = DIFF_STATUS_UNMERGED;
5490                else if (!DIFF_FILE_VALID(p->one))
5491                        p->status = DIFF_STATUS_ADDED;
5492                else if (!DIFF_FILE_VALID(p->two))
5493                        p->status = DIFF_STATUS_DELETED;
5494                else if (DIFF_PAIR_TYPE_CHANGED(p))
5495                        p->status = DIFF_STATUS_TYPE_CHANGED;
5496
5497                /* from this point on, we are dealing with a pair
5498                 * whose both sides are valid and of the same type, i.e.
5499                 * either in-place edit or rename/copy edit.
5500                 */
5501                else if (DIFF_PAIR_RENAME(p)) {
5502                        /*
5503                         * A rename might have re-connected a broken
5504                         * pair up, causing the pathnames to be the
5505                         * same again. If so, that's not a rename at
5506                         * all, just a modification..
5507                         *
5508                         * Otherwise, see if this source was used for
5509                         * multiple renames, in which case we decrement
5510                         * the count, and call it a copy.
5511                         */
5512                        if (!strcmp(p->one->path, p->two->path))
5513                                p->status = DIFF_STATUS_MODIFIED;
5514                        else if (--p->one->rename_used > 0)
5515                                p->status = DIFF_STATUS_COPIED;
5516                        else
5517                                p->status = DIFF_STATUS_RENAMED;
5518                }
5519                else if (!oideq(&p->one->oid, &p->two->oid) ||
5520                         p->one->mode != p->two->mode ||
5521                         p->one->dirty_submodule ||
5522                         p->two->dirty_submodule ||
5523                         is_null_oid(&p->one->oid))
5524                        p->status = DIFF_STATUS_MODIFIED;
5525                else {
5526                        /* This is a "no-change" entry and should not
5527                         * happen anymore, but prepare for broken callers.
5528                         */
5529                        error("feeding unmodified %s to diffcore",
5530                              p->one->path);
5531                        p->status = DIFF_STATUS_UNKNOWN;
5532                }
5533        }
5534        diff_debug_queue("resolve-rename-copy done", q);
5535}
5536
5537static int check_pair_status(struct diff_filepair *p)
5538{
5539        switch (p->status) {
5540        case DIFF_STATUS_UNKNOWN:
5541                return 0;
5542        case 0:
5543                die("internal error in diff-resolve-rename-copy");
5544        default:
5545                return 1;
5546        }
5547}
5548
5549static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
5550{
5551        int fmt = opt->output_format;
5552
5553        if (fmt & DIFF_FORMAT_CHECKDIFF)
5554                diff_flush_checkdiff(p, opt);
5555        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
5556                diff_flush_raw(p, opt);
5557        else if (fmt & DIFF_FORMAT_NAME) {
5558                const char *name_a, *name_b;
5559                name_a = p->two->path;
5560                name_b = NULL;
5561                strip_prefix(opt->prefix_length, &name_a, &name_b);
5562                fprintf(opt->file, "%s", diff_line_prefix(opt));
5563                write_name_quoted(name_a, opt->file, opt->line_termination);
5564        }
5565}
5566
5567static void show_file_mode_name(struct diff_options *opt, const char *newdelete, struct diff_filespec *fs)
5568{
5569        struct strbuf sb = STRBUF_INIT;
5570        if (fs->mode)
5571                strbuf_addf(&sb, " %s mode %06o ", newdelete, fs->mode);
5572        else
5573                strbuf_addf(&sb, " %s ", newdelete);
5574
5575        quote_c_style(fs->path, &sb, NULL, 0);
5576        strbuf_addch(&sb, '\n');
5577        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5578                         sb.buf, sb.len, 0);
5579        strbuf_release(&sb);
5580}
5581
5582static void show_mode_change(struct diff_options *opt, struct diff_filepair *p,
5583                int show_name)
5584{
5585        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
5586                struct strbuf sb = STRBUF_INIT;
5587                strbuf_addf(&sb, " mode change %06o => %06o",
5588                            p->one->mode, p->two->mode);
5589                if (show_name) {
5590                        strbuf_addch(&sb, ' ');
5591                        quote_c_style(p->two->path, &sb, NULL, 0);
5592                }
5593                strbuf_addch(&sb, '\n');
5594                emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5595                                 sb.buf, sb.len, 0);
5596                strbuf_release(&sb);
5597        }
5598}
5599
5600static void show_rename_copy(struct diff_options *opt, const char *renamecopy,
5601                struct diff_filepair *p)
5602{
5603        struct strbuf sb = STRBUF_INIT;
5604        struct strbuf names = STRBUF_INIT;
5605
5606        pprint_rename(&names, p->one->path, p->two->path);
5607        strbuf_addf(&sb, " %s %s (%d%%)\n",
5608                    renamecopy, names.buf, similarity_index(p));
5609        strbuf_release(&names);
5610        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5611                                 sb.buf, sb.len, 0);
5612        show_mode_change(opt, p, 0);
5613        strbuf_release(&sb);
5614}
5615
5616static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
5617{
5618        switch(p->status) {
5619        case DIFF_STATUS_DELETED:
5620                show_file_mode_name(opt, "delete", p->one);
5621                break;
5622        case DIFF_STATUS_ADDED:
5623                show_file_mode_name(opt, "create", p->two);
5624                break;
5625        case DIFF_STATUS_COPIED:
5626                show_rename_copy(opt, "copy", p);
5627                break;
5628        case DIFF_STATUS_RENAMED:
5629                show_rename_copy(opt, "rename", p);
5630                break;
5631        default:
5632                if (p->score) {
5633                        struct strbuf sb = STRBUF_INIT;
5634                        strbuf_addstr(&sb, " rewrite ");
5635                        quote_c_style(p->two->path, &sb, NULL, 0);
5636                        strbuf_addf(&sb, " (%d%%)\n", similarity_index(p));
5637                        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5638                                         sb.buf, sb.len, 0);
5639                        strbuf_release(&sb);
5640                }
5641                show_mode_change(opt, p, !p->score);
5642                break;
5643        }
5644}
5645
5646struct patch_id_t {
5647        git_SHA_CTX *ctx;
5648        int patchlen;
5649};
5650
5651static int remove_space(char *line, int len)
5652{
5653        int i;
5654        char *dst = line;
5655        unsigned char c;
5656
5657        for (i = 0; i < len; i++)
5658                if (!isspace((c = line[i])))
5659                        *dst++ = c;
5660
5661        return dst - line;
5662}
5663
5664static void patch_id_consume(void *priv, char *line, unsigned long len)
5665{
5666        struct patch_id_t *data = priv;
5667        int new_len;
5668
5669        /* Ignore line numbers when computing the SHA1 of the patch */
5670        if (starts_with(line, "@@ -"))
5671                return;
5672
5673        new_len = remove_space(line, len);
5674
5675        git_SHA1_Update(data->ctx, line, new_len);
5676        data->patchlen += new_len;
5677}
5678
5679static void patch_id_add_string(git_SHA_CTX *ctx, const char *str)
5680{
5681        git_SHA1_Update(ctx, str, strlen(str));
5682}
5683
5684static void patch_id_add_mode(git_SHA_CTX *ctx, unsigned mode)
5685{
5686        /* large enough for 2^32 in octal */
5687        char buf[12];
5688        int len = xsnprintf(buf, sizeof(buf), "%06o", mode);
5689        git_SHA1_Update(ctx, buf, len);
5690}
5691
5692/* returns 0 upon success, and writes result into sha1 */
5693static int diff_get_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5694{
5695        struct diff_queue_struct *q = &diff_queued_diff;
5696        int i;
5697        git_SHA_CTX ctx;
5698        struct patch_id_t data;
5699
5700        git_SHA1_Init(&ctx);
5701        memset(&data, 0, sizeof(struct patch_id_t));
5702        data.ctx = &ctx;
5703
5704        for (i = 0; i < q->nr; i++) {
5705                xpparam_t xpp;
5706                xdemitconf_t xecfg;
5707                mmfile_t mf1, mf2;
5708                struct diff_filepair *p = q->queue[i];
5709                int len1, len2;
5710
5711                memset(&xpp, 0, sizeof(xpp));
5712                memset(&xecfg, 0, sizeof(xecfg));
5713                if (p->status == 0)
5714                        return error("internal diff status error");
5715                if (p->status == DIFF_STATUS_UNKNOWN)
5716                        continue;
5717                if (diff_unmodified_pair(p))
5718                        continue;
5719                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5720                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5721                        continue;
5722                if (DIFF_PAIR_UNMERGED(p))
5723                        continue;
5724
5725                diff_fill_oid_info(p->one, options->repo->index);
5726                diff_fill_oid_info(p->two, options->repo->index);
5727
5728                len1 = remove_space(p->one->path, strlen(p->one->path));
5729                len2 = remove_space(p->two->path, strlen(p->two->path));
5730                patch_id_add_string(&ctx, "diff--git");
5731                patch_id_add_string(&ctx, "a/");
5732                git_SHA1_Update(&ctx, p->one->path, len1);
5733                patch_id_add_string(&ctx, "b/");
5734                git_SHA1_Update(&ctx, p->two->path, len2);
5735
5736                if (p->one->mode == 0) {
5737                        patch_id_add_string(&ctx, "newfilemode");
5738                        patch_id_add_mode(&ctx, p->two->mode);
5739                        patch_id_add_string(&ctx, "---/dev/null");
5740                        patch_id_add_string(&ctx, "+++b/");
5741                        git_SHA1_Update(&ctx, p->two->path, len2);
5742                } else if (p->two->mode == 0) {
5743                        patch_id_add_string(&ctx, "deletedfilemode");
5744                        patch_id_add_mode(&ctx, p->one->mode);
5745                        patch_id_add_string(&ctx, "---a/");
5746                        git_SHA1_Update(&ctx, p->one->path, len1);
5747                        patch_id_add_string(&ctx, "+++/dev/null");
5748                } else {
5749                        patch_id_add_string(&ctx, "---a/");
5750                        git_SHA1_Update(&ctx, p->one->path, len1);
5751                        patch_id_add_string(&ctx, "+++b/");
5752                        git_SHA1_Update(&ctx, p->two->path, len2);
5753                }
5754
5755                if (diff_header_only)
5756                        continue;
5757
5758                if (fill_mmfile(options->repo, &mf1, p->one) < 0 ||
5759                    fill_mmfile(options->repo, &mf2, p->two) < 0)
5760                        return error("unable to read files to diff");
5761
5762                if (diff_filespec_is_binary(options->repo, p->one) ||
5763                    diff_filespec_is_binary(options->repo, p->two)) {
5764                        git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
5765                                        GIT_SHA1_HEXSZ);
5766                        git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
5767                                        GIT_SHA1_HEXSZ);
5768                        continue;
5769                }
5770
5771                xpp.flags = 0;
5772                xecfg.ctxlen = 3;
5773                xecfg.flags = 0;
5774                if (xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
5775                                  &xpp, &xecfg))
5776                        return error("unable to generate patch-id diff for %s",
5777                                     p->one->path);
5778        }
5779
5780        git_SHA1_Final(oid->hash, &ctx);
5781        return 0;
5782}
5783
5784int diff_flush_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5785{
5786        struct diff_queue_struct *q = &diff_queued_diff;
5787        int i;
5788        int result = diff_get_patch_id(options, oid, diff_header_only);
5789
5790        for (i = 0; i < q->nr; i++)
5791                diff_free_filepair(q->queue[i]);
5792
5793        free(q->queue);
5794        DIFF_QUEUE_CLEAR(q);
5795
5796        return result;
5797}
5798
5799static int is_summary_empty(const struct diff_queue_struct *q)
5800{
5801        int i;
5802
5803        for (i = 0; i < q->nr; i++) {
5804                const struct diff_filepair *p = q->queue[i];
5805
5806                switch (p->status) {
5807                case DIFF_STATUS_DELETED:
5808                case DIFF_STATUS_ADDED:
5809                case DIFF_STATUS_COPIED:
5810                case DIFF_STATUS_RENAMED:
5811                        return 0;
5812                default:
5813                        if (p->score)
5814                                return 0;
5815                        if (p->one->mode && p->two->mode &&
5816                            p->one->mode != p->two->mode)
5817                                return 0;
5818                        break;
5819                }
5820        }
5821        return 1;
5822}
5823
5824static const char rename_limit_warning[] =
5825N_("inexact rename detection was skipped due to too many files.");
5826
5827static const char degrade_cc_to_c_warning[] =
5828N_("only found copies from modified paths due to too many files.");
5829
5830static const char rename_limit_advice[] =
5831N_("you may want to set your %s variable to at least "
5832   "%d and retry the command.");
5833
5834void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
5835{
5836        fflush(stdout);
5837        if (degraded_cc)
5838                warning(_(degrade_cc_to_c_warning));
5839        else if (needed)
5840                warning(_(rename_limit_warning));
5841        else
5842                return;
5843        if (0 < needed)
5844                warning(_(rename_limit_advice), varname, needed);
5845}
5846
5847static void diff_flush_patch_all_file_pairs(struct diff_options *o)
5848{
5849        int i;
5850        static struct emitted_diff_symbols esm = EMITTED_DIFF_SYMBOLS_INIT;
5851        struct diff_queue_struct *q = &diff_queued_diff;
5852
5853        if (WSEH_NEW & WS_RULE_MASK)
5854                BUG("WS rules bit mask overlaps with diff symbol flags");
5855
5856        if (o->color_moved)
5857                o->emitted_symbols = &esm;
5858
5859        for (i = 0; i < q->nr; i++) {
5860                struct diff_filepair *p = q->queue[i];
5861                if (check_pair_status(p))
5862                        diff_flush_patch(p, o);
5863        }
5864
5865        if (o->emitted_symbols) {
5866                if (o->color_moved) {
5867                        struct hashmap add_lines, del_lines;
5868
5869                        if (o->color_moved_ws_handling &
5870                            COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
5871                                o->color_moved_ws_handling |= XDF_IGNORE_WHITESPACE;
5872
5873                        hashmap_init(&del_lines, moved_entry_cmp, o, 0);
5874                        hashmap_init(&add_lines, moved_entry_cmp, o, 0);
5875
5876                        add_lines_to_move_detection(o, &add_lines, &del_lines);
5877                        mark_color_as_moved(o, &add_lines, &del_lines);
5878                        if (o->color_moved == COLOR_MOVED_ZEBRA_DIM)
5879                                dim_moved_lines(o);
5880
5881                        hashmap_free(&add_lines, 1);
5882                        hashmap_free(&del_lines, 1);
5883                }
5884
5885                for (i = 0; i < esm.nr; i++)
5886                        emit_diff_symbol_from_struct(o, &esm.buf[i]);
5887
5888                for (i = 0; i < esm.nr; i++)
5889                        free((void *)esm.buf[i].line);
5890        }
5891        esm.nr = 0;
5892}
5893
5894void diff_flush(struct diff_options *options)
5895{
5896        struct diff_queue_struct *q = &diff_queued_diff;
5897        int i, output_format = options->output_format;
5898        int separator = 0;
5899        int dirstat_by_line = 0;
5900
5901        /*
5902         * Order: raw, stat, summary, patch
5903         * or:    name/name-status/checkdiff (other bits clear)
5904         */
5905        if (!q->nr)
5906                goto free_queue;
5907
5908        if (output_format & (DIFF_FORMAT_RAW |
5909                             DIFF_FORMAT_NAME |
5910                             DIFF_FORMAT_NAME_STATUS |
5911                             DIFF_FORMAT_CHECKDIFF)) {
5912                for (i = 0; i < q->nr; i++) {
5913                        struct diff_filepair *p = q->queue[i];
5914                        if (check_pair_status(p))
5915                                flush_one_pair(p, options);
5916                }
5917                separator++;
5918        }
5919
5920        if (output_format & DIFF_FORMAT_DIRSTAT && options->flags.dirstat_by_line)
5921                dirstat_by_line = 1;
5922
5923        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
5924            dirstat_by_line) {
5925                struct diffstat_t diffstat;
5926
5927                memset(&diffstat, 0, sizeof(struct diffstat_t));
5928                for (i = 0; i < q->nr; i++) {
5929                        struct diff_filepair *p = q->queue[i];
5930                        if (check_pair_status(p))
5931                                diff_flush_stat(p, options, &diffstat);
5932                }
5933                if (output_format & DIFF_FORMAT_NUMSTAT)
5934                        show_numstat(&diffstat, options);
5935                if (output_format & DIFF_FORMAT_DIFFSTAT)
5936                        show_stats(&diffstat, options);
5937                if (output_format & DIFF_FORMAT_SHORTSTAT)
5938                        show_shortstats(&diffstat, options);
5939                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
5940                        show_dirstat_by_line(&diffstat, options);
5941                free_diffstat_info(&diffstat);
5942                separator++;
5943        }
5944        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
5945                show_dirstat(options);
5946
5947        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
5948                for (i = 0; i < q->nr; i++) {
5949                        diff_summary(options, q->queue[i]);
5950                }
5951                separator++;
5952        }
5953
5954        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
5955            options->flags.exit_with_status &&
5956            options->flags.diff_from_contents) {
5957                /*
5958                 * run diff_flush_patch for the exit status. setting
5959                 * options->file to /dev/null should be safe, because we
5960                 * aren't supposed to produce any output anyway.
5961                 */
5962                if (options->close_file)
5963                        fclose(options->file);
5964                options->file = xfopen("/dev/null", "w");
5965                options->close_file = 1;
5966                options->color_moved = 0;
5967                for (i = 0; i < q->nr; i++) {
5968                        struct diff_filepair *p = q->queue[i];
5969                        if (check_pair_status(p))
5970                                diff_flush_patch(p, options);
5971                        if (options->found_changes)
5972                                break;
5973                }
5974        }
5975
5976        if (output_format & DIFF_FORMAT_PATCH) {
5977                if (separator) {
5978                        emit_diff_symbol(options, DIFF_SYMBOL_SEPARATOR, NULL, 0, 0);
5979                        if (options->stat_sep)
5980                                /* attach patch instead of inline */
5981                                emit_diff_symbol(options, DIFF_SYMBOL_STAT_SEP,
5982                                                 NULL, 0, 0);
5983                }
5984
5985                diff_flush_patch_all_file_pairs(options);
5986        }
5987
5988        if (output_format & DIFF_FORMAT_CALLBACK)
5989                options->format_callback(q, options, options->format_callback_data);
5990
5991        for (i = 0; i < q->nr; i++)
5992                diff_free_filepair(q->queue[i]);
5993free_queue:
5994        free(q->queue);
5995        DIFF_QUEUE_CLEAR(q);
5996        if (options->close_file)
5997                fclose(options->file);
5998
5999        /*
6000         * Report the content-level differences with HAS_CHANGES;
6001         * diff_addremove/diff_change does not set the bit when
6002         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
6003         */
6004        if (options->flags.diff_from_contents) {
6005                if (options->found_changes)
6006                        options->flags.has_changes = 1;
6007                else
6008                        options->flags.has_changes = 0;
6009        }
6010}
6011
6012static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
6013{
6014        return (((p->status == DIFF_STATUS_MODIFIED) &&
6015                 ((p->score &&
6016                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
6017                  (!p->score &&
6018                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
6019                ((p->status != DIFF_STATUS_MODIFIED) &&
6020                 filter_bit_tst(p->status, options)));
6021}
6022
6023static void diffcore_apply_filter(struct diff_options *options)
6024{
6025        int i;
6026        struct diff_queue_struct *q = &diff_queued_diff;
6027        struct diff_queue_struct outq;
6028
6029        DIFF_QUEUE_CLEAR(&outq);
6030
6031        if (!options->filter)
6032                return;
6033
6034        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
6035                int found;
6036                for (i = found = 0; !found && i < q->nr; i++) {
6037                        if (match_filter(options, q->queue[i]))
6038                                found++;
6039                }
6040                if (found)
6041                        return;
6042
6043                /* otherwise we will clear the whole queue
6044                 * by copying the empty outq at the end of this
6045                 * function, but first clear the current entries
6046                 * in the queue.
6047                 */
6048                for (i = 0; i < q->nr; i++)
6049                        diff_free_filepair(q->queue[i]);
6050        }
6051        else {
6052                /* Only the matching ones */
6053                for (i = 0; i < q->nr; i++) {
6054                        struct diff_filepair *p = q->queue[i];
6055                        if (match_filter(options, p))
6056                                diff_q(&outq, p);
6057                        else
6058                                diff_free_filepair(p);
6059                }
6060        }
6061        free(q->queue);
6062        *q = outq;
6063}
6064
6065/* Check whether two filespecs with the same mode and size are identical */
6066static int diff_filespec_is_identical(struct repository *r,
6067                                      struct diff_filespec *one,
6068                                      struct diff_filespec *two)
6069{
6070        if (S_ISGITLINK(one->mode))
6071                return 0;
6072        if (diff_populate_filespec(r, one, 0))
6073                return 0;
6074        if (diff_populate_filespec(r, two, 0))
6075                return 0;
6076        return !memcmp(one->data, two->data, one->size);
6077}
6078
6079static int diff_filespec_check_stat_unmatch(struct repository *r,
6080                                            struct diff_filepair *p)
6081{
6082        if (p->done_skip_stat_unmatch)
6083                return p->skip_stat_unmatch_result;
6084
6085        p->done_skip_stat_unmatch = 1;
6086        p->skip_stat_unmatch_result = 0;
6087        /*
6088         * 1. Entries that come from stat info dirtiness
6089         *    always have both sides (iow, not create/delete),
6090         *    one side of the object name is unknown, with
6091         *    the same mode and size.  Keep the ones that
6092         *    do not match these criteria.  They have real
6093         *    differences.
6094         *
6095         * 2. At this point, the file is known to be modified,
6096         *    with the same mode and size, and the object
6097         *    name of one side is unknown.  Need to inspect
6098         *    the identical contents.
6099         */
6100        if (!DIFF_FILE_VALID(p->one) || /* (1) */
6101            !DIFF_FILE_VALID(p->two) ||
6102            (p->one->oid_valid && p->two->oid_valid) ||
6103            (p->one->mode != p->two->mode) ||
6104            diff_populate_filespec(r, p->one, CHECK_SIZE_ONLY) ||
6105            diff_populate_filespec(r, p->two, CHECK_SIZE_ONLY) ||
6106            (p->one->size != p->two->size) ||
6107            !diff_filespec_is_identical(r, p->one, p->two)) /* (2) */
6108                p->skip_stat_unmatch_result = 1;
6109        return p->skip_stat_unmatch_result;
6110}
6111
6112static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
6113{
6114        int i;
6115        struct diff_queue_struct *q = &diff_queued_diff;
6116        struct diff_queue_struct outq;
6117        DIFF_QUEUE_CLEAR(&outq);
6118
6119        for (i = 0; i < q->nr; i++) {
6120                struct diff_filepair *p = q->queue[i];
6121
6122                if (diff_filespec_check_stat_unmatch(diffopt->repo, p))
6123                        diff_q(&outq, p);
6124                else {
6125                        /*
6126                         * The caller can subtract 1 from skip_stat_unmatch
6127                         * to determine how many paths were dirty only
6128                         * due to stat info mismatch.
6129                         */
6130                        if (!diffopt->flags.no_index)
6131                                diffopt->skip_stat_unmatch++;
6132                        diff_free_filepair(p);
6133                }
6134        }
6135        free(q->queue);
6136        *q = outq;
6137}
6138
6139static int diffnamecmp(const void *a_, const void *b_)
6140{
6141        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
6142        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
6143        const char *name_a, *name_b;
6144
6145        name_a = a->one ? a->one->path : a->two->path;
6146        name_b = b->one ? b->one->path : b->two->path;
6147        return strcmp(name_a, name_b);
6148}
6149
6150void diffcore_fix_diff_index(struct diff_options *options)
6151{
6152        struct diff_queue_struct *q = &diff_queued_diff;
6153        QSORT(q->queue, q->nr, diffnamecmp);
6154}
6155
6156void diffcore_std(struct diff_options *options)
6157{
6158        /* NOTE please keep the following in sync with diff_tree_combined() */
6159        if (options->skip_stat_unmatch)
6160                diffcore_skip_stat_unmatch(options);
6161        if (!options->found_follow) {
6162                /* See try_to_follow_renames() in tree-diff.c */
6163                if (options->break_opt != -1)
6164                        diffcore_break(options->repo,
6165                                       options->break_opt);
6166                if (options->detect_rename)
6167                        diffcore_rename(options);
6168                if (options->break_opt != -1)
6169                        diffcore_merge_broken();
6170        }
6171        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
6172                diffcore_pickaxe(options);
6173        if (options->orderfile)
6174                diffcore_order(options->orderfile);
6175        if (!options->found_follow)
6176                /* See try_to_follow_renames() in tree-diff.c */
6177                diff_resolve_rename_copy();
6178        diffcore_apply_filter(options);
6179
6180        if (diff_queued_diff.nr && !options->flags.diff_from_contents)
6181                options->flags.has_changes = 1;
6182        else
6183                options->flags.has_changes = 0;
6184
6185        options->found_follow = 0;
6186}
6187
6188int diff_result_code(struct diff_options *opt, int status)
6189{
6190        int result = 0;
6191
6192        diff_warn_rename_limit("diff.renameLimit",
6193                               opt->needed_rename_limit,
6194                               opt->degraded_cc_to_c);
6195        if (!opt->flags.exit_with_status &&
6196            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
6197                return status;
6198        if (opt->flags.exit_with_status &&
6199            opt->flags.has_changes)
6200                result |= 01;
6201        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
6202            opt->flags.check_failed)
6203                result |= 02;
6204        return result;
6205}
6206
6207int diff_can_quit_early(struct diff_options *opt)
6208{
6209        return (opt->flags.quick &&
6210                !opt->filter &&
6211                opt->flags.has_changes);
6212}
6213
6214/*
6215 * Shall changes to this submodule be ignored?
6216 *
6217 * Submodule changes can be configured to be ignored separately for each path,
6218 * but that configuration can be overridden from the command line.
6219 */
6220static int is_submodule_ignored(const char *path, struct diff_options *options)
6221{
6222        int ignored = 0;
6223        struct diff_flags orig_flags = options->flags;
6224        if (!options->flags.override_submodule_config)
6225                set_diffopt_flags_from_submodule_config(options, path);
6226        if (options->flags.ignore_submodules)
6227                ignored = 1;
6228        options->flags = orig_flags;
6229        return ignored;
6230}
6231
6232void diff_addremove(struct diff_options *options,
6233                    int addremove, unsigned mode,
6234                    const struct object_id *oid,
6235                    int oid_valid,
6236                    const char *concatpath, unsigned dirty_submodule)
6237{
6238        struct diff_filespec *one, *two;
6239
6240        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
6241                return;
6242
6243        /* This may look odd, but it is a preparation for
6244         * feeding "there are unchanged files which should
6245         * not produce diffs, but when you are doing copy
6246         * detection you would need them, so here they are"
6247         * entries to the diff-core.  They will be prefixed
6248         * with something like '=' or '*' (I haven't decided
6249         * which but should not make any difference).
6250         * Feeding the same new and old to diff_change()
6251         * also has the same effect.
6252         * Before the final output happens, they are pruned after
6253         * merged into rename/copy pairs as appropriate.
6254         */
6255        if (options->flags.reverse_diff)
6256                addremove = (addremove == '+' ? '-' :
6257                             addremove == '-' ? '+' : addremove);
6258
6259        if (options->prefix &&
6260            strncmp(concatpath, options->prefix, options->prefix_length))
6261                return;
6262
6263        one = alloc_filespec(concatpath);
6264        two = alloc_filespec(concatpath);
6265
6266        if (addremove != '+')
6267                fill_filespec(one, oid, oid_valid, mode);
6268        if (addremove != '-') {
6269                fill_filespec(two, oid, oid_valid, mode);
6270                two->dirty_submodule = dirty_submodule;
6271        }
6272
6273        diff_queue(&diff_queued_diff, one, two);
6274        if (!options->flags.diff_from_contents)
6275                options->flags.has_changes = 1;
6276}
6277
6278void diff_change(struct diff_options *options,
6279                 unsigned old_mode, unsigned new_mode,
6280                 const struct object_id *old_oid,
6281                 const struct object_id *new_oid,
6282                 int old_oid_valid, int new_oid_valid,
6283                 const char *concatpath,
6284                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
6285{
6286        struct diff_filespec *one, *two;
6287        struct diff_filepair *p;
6288
6289        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
6290            is_submodule_ignored(concatpath, options))
6291                return;
6292
6293        if (options->flags.reverse_diff) {
6294                SWAP(old_mode, new_mode);
6295                SWAP(old_oid, new_oid);
6296                SWAP(old_oid_valid, new_oid_valid);
6297                SWAP(old_dirty_submodule, new_dirty_submodule);
6298        }
6299
6300        if (options->prefix &&
6301            strncmp(concatpath, options->prefix, options->prefix_length))
6302                return;
6303
6304        one = alloc_filespec(concatpath);
6305        two = alloc_filespec(concatpath);
6306        fill_filespec(one, old_oid, old_oid_valid, old_mode);
6307        fill_filespec(two, new_oid, new_oid_valid, new_mode);
6308        one->dirty_submodule = old_dirty_submodule;
6309        two->dirty_submodule = new_dirty_submodule;
6310        p = diff_queue(&diff_queued_diff, one, two);
6311
6312        if (options->flags.diff_from_contents)
6313                return;
6314
6315        if (options->flags.quick && options->skip_stat_unmatch &&
6316            !diff_filespec_check_stat_unmatch(options->repo, p))
6317                return;
6318
6319        options->flags.has_changes = 1;
6320}
6321
6322struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
6323{
6324        struct diff_filepair *pair;
6325        struct diff_filespec *one, *two;
6326
6327        if (options->prefix &&
6328            strncmp(path, options->prefix, options->prefix_length))
6329                return NULL;
6330
6331        one = alloc_filespec(path);
6332        two = alloc_filespec(path);
6333        pair = diff_queue(&diff_queued_diff, one, two);
6334        pair->is_unmerged = 1;
6335        return pair;
6336}
6337
6338static char *run_textconv(struct repository *r,
6339                          const char *pgm,
6340                          struct diff_filespec *spec,
6341                          size_t *outsize)
6342{
6343        struct diff_tempfile *temp;
6344        const char *argv[3];
6345        const char **arg = argv;
6346        struct child_process child = CHILD_PROCESS_INIT;
6347        struct strbuf buf = STRBUF_INIT;
6348        int err = 0;
6349
6350        temp = prepare_temp_file(r, spec->path, spec);
6351        *arg++ = pgm;
6352        *arg++ = temp->name;
6353        *arg = NULL;
6354
6355        child.use_shell = 1;
6356        child.argv = argv;
6357        child.out = -1;
6358        if (start_command(&child)) {
6359                remove_tempfile();
6360                return NULL;
6361        }
6362
6363        if (strbuf_read(&buf, child.out, 0) < 0)
6364                err = error("error reading from textconv command '%s'", pgm);
6365        close(child.out);
6366
6367        if (finish_command(&child) || err) {
6368                strbuf_release(&buf);
6369                remove_tempfile();
6370                return NULL;
6371        }
6372        remove_tempfile();
6373
6374        return strbuf_detach(&buf, outsize);
6375}
6376
6377size_t fill_textconv(struct repository *r,
6378                     struct userdiff_driver *driver,
6379                     struct diff_filespec *df,
6380                     char **outbuf)
6381{
6382        size_t size;
6383
6384        if (!driver) {
6385                if (!DIFF_FILE_VALID(df)) {
6386                        *outbuf = "";
6387                        return 0;
6388                }
6389                if (diff_populate_filespec(r, df, 0))
6390                        die("unable to read files to diff");
6391                *outbuf = df->data;
6392                return df->size;
6393        }
6394
6395        if (!driver->textconv)
6396                BUG("fill_textconv called with non-textconv driver");
6397
6398        if (driver->textconv_cache && df->oid_valid) {
6399                *outbuf = notes_cache_get(driver->textconv_cache,
6400                                          &df->oid,
6401                                          &size);
6402                if (*outbuf)
6403                        return size;
6404        }
6405
6406        *outbuf = run_textconv(r, driver->textconv, df, &size);
6407        if (!*outbuf)
6408                die("unable to read files to diff");
6409
6410        if (driver->textconv_cache && df->oid_valid) {
6411                /* ignore errors, as we might be in a readonly repository */
6412                notes_cache_put(driver->textconv_cache, &df->oid, *outbuf,
6413                                size);
6414                /*
6415                 * we could save up changes and flush them all at the end,
6416                 * but we would need an extra call after all diffing is done.
6417                 * Since generating a cache entry is the slow path anyway,
6418                 * this extra overhead probably isn't a big deal.
6419                 */
6420                notes_cache_write(driver->textconv_cache);
6421        }
6422
6423        return size;
6424}
6425
6426int textconv_object(struct repository *r,
6427                    const char *path,
6428                    unsigned mode,
6429                    const struct object_id *oid,
6430                    int oid_valid,
6431                    char **buf,
6432                    unsigned long *buf_size)
6433{
6434        struct diff_filespec *df;
6435        struct userdiff_driver *textconv;
6436
6437        df = alloc_filespec(path);
6438        fill_filespec(df, oid, oid_valid, mode);
6439        textconv = get_textconv(r->index, df);
6440        if (!textconv) {
6441                free_filespec(df);
6442                return 0;
6443        }
6444
6445        *buf_size = fill_textconv(r, textconv, df, buf);
6446        free_filespec(df);
6447        return 1;
6448}
6449
6450void setup_diff_pager(struct diff_options *opt)
6451{
6452        /*
6453         * If the user asked for our exit code, then either they want --quiet
6454         * or --exit-code. We should definitely not bother with a pager in the
6455         * former case, as we will generate no output. Since we still properly
6456         * report our exit code even when a pager is run, we _could_ run a
6457         * pager with --exit-code. But since we have not done so historically,
6458         * and because it is easy to find people oneline advising "git diff
6459         * --exit-code" in hooks and other scripts, we do not do so.
6460         */
6461        if (!opt->flags.exit_with_status &&
6462            check_pager_config("diff") != 0)
6463                setup_pager();
6464}