diff.con commit Merge branch 'jt/fetch-tips-in-partial-clone' (a1e9dff)
   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        struct ws_delta *wsd;
 782};
 783
 784/**
 785 * The struct ws_delta holds white space differences between moved lines, i.e.
 786 * between '+' and '-' lines that have been detected to be a move.
 787 * The string contains the difference in leading white spaces, before the
 788 * rest of the line is compared using the white space config for move
 789 * coloring. The current_longer indicates if the first string in the
 790 * comparision is longer than the second.
 791 */
 792struct ws_delta {
 793        char *string;
 794        unsigned int current_longer : 1;
 795};
 796#define WS_DELTA_INIT { NULL, 0 }
 797
 798static int compute_ws_delta(const struct emitted_diff_symbol *a,
 799                             const struct emitted_diff_symbol *b,
 800                             struct ws_delta *out)
 801{
 802        const struct emitted_diff_symbol *longer =  a->len > b->len ? a : b;
 803        const struct emitted_diff_symbol *shorter = a->len > b->len ? b : a;
 804        int d = longer->len - shorter->len;
 805
 806        out->string = xmemdupz(longer->line, d);
 807        out->current_longer = (a == longer);
 808
 809        return !strncmp(longer->line + d, shorter->line, shorter->len);
 810}
 811
 812static int cmp_in_block_with_wsd(const struct diff_options *o,
 813                                 const struct moved_entry *cur,
 814                                 const struct moved_entry *match,
 815                                 struct moved_entry *pmb,
 816                                 int n)
 817{
 818        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
 819        int al = cur->es->len, cl = l->len;
 820        const char *a = cur->es->line,
 821                   *b = match->es->line,
 822                   *c = l->line;
 823
 824        int wslen;
 825
 826        /*
 827         * We need to check if 'cur' is equal to 'match'.
 828         * As those are from the same (+/-) side, we do not need to adjust for
 829         * indent changes. However these were found using fuzzy matching
 830         * so we do have to check if they are equal.
 831         */
 832        if (strcmp(a, b))
 833                return 1;
 834
 835        if (!pmb->wsd)
 836                /*
 837                 * No white space delta was carried forward? This can happen
 838                 * when we exit early in this function and do not carry
 839                 * forward ws.
 840                 */
 841                return 1;
 842
 843        /*
 844         * The indent changes of the block are known and carried forward in
 845         * pmb->wsd; however we need to check if the indent changes of the
 846         * current line are still the same as before.
 847         *
 848         * To do so we need to compare 'l' to 'cur', adjusting the
 849         * one of them for the white spaces, depending which was longer.
 850         */
 851
 852        wslen = strlen(pmb->wsd->string);
 853        if (pmb->wsd->current_longer) {
 854                c += wslen;
 855                cl -= wslen;
 856        } else {
 857                a += wslen;
 858                al -= wslen;
 859        }
 860
 861        if (strcmp(a, c))
 862                return 1;
 863
 864        return 0;
 865}
 866
 867static int moved_entry_cmp(const void *hashmap_cmp_fn_data,
 868                           const void *entry,
 869                           const void *entry_or_key,
 870                           const void *keydata)
 871{
 872        const struct diff_options *diffopt = hashmap_cmp_fn_data;
 873        const struct moved_entry *a = entry;
 874        const struct moved_entry *b = entry_or_key;
 875        unsigned flags = diffopt->color_moved_ws_handling
 876                         & XDF_WHITESPACE_FLAGS;
 877
 878        if (diffopt->color_moved_ws_handling &
 879            COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
 880                /*
 881                 * As there is not specific white space config given,
 882                 * we'd need to check for a new block, so ignore all
 883                 * white space. The setup of the white space
 884                 * configuration for the next block is done else where
 885                 */
 886                flags |= XDF_IGNORE_WHITESPACE;
 887
 888        return !xdiff_compare_lines(a->es->line, a->es->len,
 889                                    b->es->line, b->es->len,
 890                                    flags);
 891}
 892
 893static struct moved_entry *prepare_entry(struct diff_options *o,
 894                                         int line_no)
 895{
 896        struct moved_entry *ret = xmalloc(sizeof(*ret));
 897        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[line_no];
 898        unsigned flags = o->color_moved_ws_handling & XDF_WHITESPACE_FLAGS;
 899
 900        ret->ent.hash = xdiff_hash_string(l->line, l->len, flags);
 901        ret->es = l;
 902        ret->next_line = NULL;
 903        ret->wsd = NULL;
 904
 905        return ret;
 906}
 907
 908static void add_lines_to_move_detection(struct diff_options *o,
 909                                        struct hashmap *add_lines,
 910                                        struct hashmap *del_lines)
 911{
 912        struct moved_entry *prev_line = NULL;
 913
 914        int n;
 915        for (n = 0; n < o->emitted_symbols->nr; n++) {
 916                struct hashmap *hm;
 917                struct moved_entry *key;
 918
 919                switch (o->emitted_symbols->buf[n].s) {
 920                case DIFF_SYMBOL_PLUS:
 921                        hm = add_lines;
 922                        break;
 923                case DIFF_SYMBOL_MINUS:
 924                        hm = del_lines;
 925                        break;
 926                default:
 927                        prev_line = NULL;
 928                        continue;
 929                }
 930
 931                key = prepare_entry(o, n);
 932                if (prev_line && prev_line->es->s == o->emitted_symbols->buf[n].s)
 933                        prev_line->next_line = key;
 934
 935                hashmap_add(hm, key);
 936                prev_line = key;
 937        }
 938}
 939
 940static void pmb_advance_or_null(struct diff_options *o,
 941                                struct moved_entry *match,
 942                                struct hashmap *hm,
 943                                struct moved_entry **pmb,
 944                                int pmb_nr)
 945{
 946        int i;
 947        for (i = 0; i < pmb_nr; i++) {
 948                struct moved_entry *prev = pmb[i];
 949                struct moved_entry *cur = (prev && prev->next_line) ?
 950                                prev->next_line : NULL;
 951                if (cur && !hm->cmpfn(o, cur, match, NULL)) {
 952                        pmb[i] = cur;
 953                } else {
 954                        pmb[i] = NULL;
 955                }
 956        }
 957}
 958
 959static void pmb_advance_or_null_multi_match(struct diff_options *o,
 960                                            struct moved_entry *match,
 961                                            struct hashmap *hm,
 962                                            struct moved_entry **pmb,
 963                                            int pmb_nr, int n)
 964{
 965        int i;
 966        char *got_match = xcalloc(1, pmb_nr);
 967
 968        for (; match; match = hashmap_get_next(hm, match)) {
 969                for (i = 0; i < pmb_nr; i++) {
 970                        struct moved_entry *prev = pmb[i];
 971                        struct moved_entry *cur = (prev && prev->next_line) ?
 972                                        prev->next_line : NULL;
 973                        if (!cur)
 974                                continue;
 975                        if (!cmp_in_block_with_wsd(o, cur, match, pmb[i], n))
 976                                got_match[i] |= 1;
 977                }
 978        }
 979
 980        for (i = 0; i < pmb_nr; i++) {
 981                if (got_match[i]) {
 982                        /* Carry the white space delta forward */
 983                        pmb[i]->next_line->wsd = pmb[i]->wsd;
 984                        pmb[i] = pmb[i]->next_line;
 985                } else {
 986                        if (pmb[i]->wsd) {
 987                                free(pmb[i]->wsd->string);
 988                                FREE_AND_NULL(pmb[i]->wsd);
 989                        }
 990                        pmb[i] = NULL;
 991                }
 992        }
 993}
 994
 995static int shrink_potential_moved_blocks(struct moved_entry **pmb,
 996                                         int pmb_nr)
 997{
 998        int lp, rp;
 999
1000        /* Shrink the set of potential block to the remaining running */
1001        for (lp = 0, rp = pmb_nr - 1; lp <= rp;) {
1002                while (lp < pmb_nr && pmb[lp])
1003                        lp++;
1004                /* lp points at the first NULL now */
1005
1006                while (rp > -1 && !pmb[rp])
1007                        rp--;
1008                /* rp points at the last non-NULL */
1009
1010                if (lp < pmb_nr && rp > -1 && lp < rp) {
1011                        pmb[lp] = pmb[rp];
1012                        pmb[rp] = NULL;
1013                        rp--;
1014                        lp++;
1015                }
1016        }
1017
1018        /* Remember the number of running sets */
1019        return rp + 1;
1020}
1021
1022/*
1023 * If o->color_moved is COLOR_MOVED_PLAIN, this function does nothing.
1024 *
1025 * Otherwise, if the last block has fewer alphanumeric characters than
1026 * COLOR_MOVED_MIN_ALNUM_COUNT, unset DIFF_SYMBOL_MOVED_LINE on all lines in
1027 * that block.
1028 *
1029 * The last block consists of the (n - block_length)'th line up to but not
1030 * including the nth line.
1031 *
1032 * NEEDSWORK: This uses the same heuristic as blame_entry_score() in blame.c.
1033 * Think of a way to unify them.
1034 */
1035static void adjust_last_block(struct diff_options *o, int n, int block_length)
1036{
1037        int i, alnum_count = 0;
1038        if (o->color_moved == COLOR_MOVED_PLAIN)
1039                return;
1040        for (i = 1; i < block_length + 1; i++) {
1041                const char *c = o->emitted_symbols->buf[n - i].line;
1042                for (; *c; c++) {
1043                        if (!isalnum(*c))
1044                                continue;
1045                        alnum_count++;
1046                        if (alnum_count >= COLOR_MOVED_MIN_ALNUM_COUNT)
1047                                return;
1048                }
1049        }
1050        for (i = 1; i < block_length + 1; i++)
1051                o->emitted_symbols->buf[n - i].flags &= ~DIFF_SYMBOL_MOVED_LINE;
1052}
1053
1054/* Find blocks of moved code, delegate actual coloring decision to helper */
1055static void mark_color_as_moved(struct diff_options *o,
1056                                struct hashmap *add_lines,
1057                                struct hashmap *del_lines)
1058{
1059        struct moved_entry **pmb = NULL; /* potentially moved blocks */
1060        int pmb_nr = 0, pmb_alloc = 0;
1061        int n, flipped_block = 1, block_length = 0;
1062
1063
1064        for (n = 0; n < o->emitted_symbols->nr; n++) {
1065                struct hashmap *hm = NULL;
1066                struct moved_entry *key;
1067                struct moved_entry *match = NULL;
1068                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
1069
1070                switch (l->s) {
1071                case DIFF_SYMBOL_PLUS:
1072                        hm = del_lines;
1073                        key = prepare_entry(o, n);
1074                        match = hashmap_get(hm, key, NULL);
1075                        free(key);
1076                        break;
1077                case DIFF_SYMBOL_MINUS:
1078                        hm = add_lines;
1079                        key = prepare_entry(o, n);
1080                        match = hashmap_get(hm, key, NULL);
1081                        free(key);
1082                        break;
1083                default:
1084                        flipped_block = 1;
1085                }
1086
1087                if (!match) {
1088                        adjust_last_block(o, n, block_length);
1089                        pmb_nr = 0;
1090                        block_length = 0;
1091                        continue;
1092                }
1093
1094                l->flags |= DIFF_SYMBOL_MOVED_LINE;
1095
1096                if (o->color_moved == COLOR_MOVED_PLAIN)
1097                        continue;
1098
1099                if (o->color_moved_ws_handling &
1100                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
1101                        pmb_advance_or_null_multi_match(o, match, hm, pmb, pmb_nr, n);
1102                else
1103                        pmb_advance_or_null(o, match, hm, pmb, pmb_nr);
1104
1105                pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
1106
1107                if (pmb_nr == 0) {
1108                        /*
1109                         * The current line is the start of a new block.
1110                         * Setup the set of potential blocks.
1111                         */
1112                        for (; match; match = hashmap_get_next(hm, match)) {
1113                                ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
1114                                if (o->color_moved_ws_handling &
1115                                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) {
1116                                        struct ws_delta *wsd = xmalloc(sizeof(*match->wsd));
1117                                        if (compute_ws_delta(l, match->es, wsd)) {
1118                                                match->wsd = wsd;
1119                                                pmb[pmb_nr++] = match;
1120                                        } else
1121                                                free(wsd);
1122                                } else {
1123                                        pmb[pmb_nr++] = match;
1124                                }
1125                        }
1126
1127                        flipped_block = (flipped_block + 1) % 2;
1128
1129                        adjust_last_block(o, n, block_length);
1130                        block_length = 0;
1131                }
1132
1133                block_length++;
1134
1135                if (flipped_block && o->color_moved != COLOR_MOVED_BLOCKS)
1136                        l->flags |= DIFF_SYMBOL_MOVED_LINE_ALT;
1137        }
1138        adjust_last_block(o, n, block_length);
1139
1140        free(pmb);
1141}
1142
1143#define DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK \
1144  (DIFF_SYMBOL_MOVED_LINE | DIFF_SYMBOL_MOVED_LINE_ALT)
1145static void dim_moved_lines(struct diff_options *o)
1146{
1147        int n;
1148        for (n = 0; n < o->emitted_symbols->nr; n++) {
1149                struct emitted_diff_symbol *prev = (n != 0) ?
1150                                &o->emitted_symbols->buf[n - 1] : NULL;
1151                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
1152                struct emitted_diff_symbol *next =
1153                                (n < o->emitted_symbols->nr - 1) ?
1154                                &o->emitted_symbols->buf[n + 1] : NULL;
1155
1156                /* Not a plus or minus line? */
1157                if (l->s != DIFF_SYMBOL_PLUS && l->s != DIFF_SYMBOL_MINUS)
1158                        continue;
1159
1160                /* Not a moved line? */
1161                if (!(l->flags & DIFF_SYMBOL_MOVED_LINE))
1162                        continue;
1163
1164                /*
1165                 * If prev or next are not a plus or minus line,
1166                 * pretend they don't exist
1167                 */
1168                if (prev && prev->s != DIFF_SYMBOL_PLUS &&
1169                            prev->s != DIFF_SYMBOL_MINUS)
1170                        prev = NULL;
1171                if (next && next->s != DIFF_SYMBOL_PLUS &&
1172                            next->s != DIFF_SYMBOL_MINUS)
1173                        next = NULL;
1174
1175                /* Inside a block? */
1176                if ((prev &&
1177                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
1178                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK)) &&
1179                    (next &&
1180                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
1181                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK))) {
1182                        l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1183                        continue;
1184                }
1185
1186                /* Check if we are at an interesting bound: */
1187                if (prev && (prev->flags & DIFF_SYMBOL_MOVED_LINE) &&
1188                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1189                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1190                        continue;
1191                if (next && (next->flags & DIFF_SYMBOL_MOVED_LINE) &&
1192                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1193                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1194                        continue;
1195
1196                /*
1197                 * The boundary to prev and next are not interesting,
1198                 * so this line is not interesting as a whole
1199                 */
1200                l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1201        }
1202}
1203
1204static void emit_line_ws_markup(struct diff_options *o,
1205                                const char *set_sign, const char *set,
1206                                const char *reset,
1207                                char sign, const char *line, int len,
1208                                unsigned ws_rule, int blank_at_eof)
1209{
1210        const char *ws = NULL;
1211
1212        if (o->ws_error_highlight & ws_rule) {
1213                ws = diff_get_color_opt(o, DIFF_WHITESPACE);
1214                if (!*ws)
1215                        ws = NULL;
1216        }
1217
1218        if (!ws && !set_sign)
1219                emit_line_0(o, set, NULL, 0, reset, sign, line, len);
1220        else if (!ws) {
1221                emit_line_0(o, set_sign, set, !!set_sign, reset, sign, line, len);
1222        } else if (blank_at_eof)
1223                /* Blank line at EOF - paint '+' as well */
1224                emit_line_0(o, ws, NULL, 0, reset, sign, line, len);
1225        else {
1226                /* Emit just the prefix, then the rest. */
1227                emit_line_0(o, set_sign ? set_sign : set, NULL, !!set_sign, reset,
1228                            sign, "", 0);
1229                ws_check_emit(line, len, ws_rule,
1230                              o->file, set, reset, ws);
1231        }
1232}
1233
1234static void emit_diff_symbol_from_struct(struct diff_options *o,
1235                                         struct emitted_diff_symbol *eds)
1236{
1237        static const char *nneof = " No newline at end of file\n";
1238        const char *context, *reset, *set, *set_sign, *meta, *fraginfo;
1239        struct strbuf sb = STRBUF_INIT;
1240
1241        enum diff_symbol s = eds->s;
1242        const char *line = eds->line;
1243        int len = eds->len;
1244        unsigned flags = eds->flags;
1245
1246        switch (s) {
1247        case DIFF_SYMBOL_NO_LF_EOF:
1248                context = diff_get_color_opt(o, DIFF_CONTEXT);
1249                reset = diff_get_color_opt(o, DIFF_RESET);
1250                putc('\n', o->file);
1251                emit_line_0(o, context, NULL, 0, reset, '\\',
1252                            nneof, strlen(nneof));
1253                break;
1254        case DIFF_SYMBOL_SUBMODULE_HEADER:
1255        case DIFF_SYMBOL_SUBMODULE_ERROR:
1256        case DIFF_SYMBOL_SUBMODULE_PIPETHROUGH:
1257        case DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES:
1258        case DIFF_SYMBOL_SUMMARY:
1259        case DIFF_SYMBOL_STATS_LINE:
1260        case DIFF_SYMBOL_BINARY_DIFF_BODY:
1261        case DIFF_SYMBOL_CONTEXT_FRAGINFO:
1262                emit_line(o, "", "", line, len);
1263                break;
1264        case DIFF_SYMBOL_CONTEXT_INCOMPLETE:
1265        case DIFF_SYMBOL_CONTEXT_MARKER:
1266                context = diff_get_color_opt(o, DIFF_CONTEXT);
1267                reset = diff_get_color_opt(o, DIFF_RESET);
1268                emit_line(o, context, reset, line, len);
1269                break;
1270        case DIFF_SYMBOL_SEPARATOR:
1271                fprintf(o->file, "%s%c",
1272                        diff_line_prefix(o),
1273                        o->line_termination);
1274                break;
1275        case DIFF_SYMBOL_CONTEXT:
1276                set = diff_get_color_opt(o, DIFF_CONTEXT);
1277                reset = diff_get_color_opt(o, DIFF_RESET);
1278                set_sign = NULL;
1279                if (o->flags.dual_color_diffed_diffs) {
1280                        char c = !len ? 0 : line[0];
1281
1282                        if (c == '+')
1283                                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1284                        else if (c == '@')
1285                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1286                        else if (c == '-')
1287                                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1288                }
1289                emit_line_ws_markup(o, set_sign, set, reset,
1290                                    o->output_indicators[OUTPUT_INDICATOR_CONTEXT],
1291                                    line, len,
1292                                    flags & (DIFF_SYMBOL_CONTENT_WS_MASK), 0);
1293                break;
1294        case DIFF_SYMBOL_PLUS:
1295                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1296                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1297                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1298                case DIFF_SYMBOL_MOVED_LINE |
1299                     DIFF_SYMBOL_MOVED_LINE_ALT |
1300                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1301                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT_DIM);
1302                        break;
1303                case DIFF_SYMBOL_MOVED_LINE |
1304                     DIFF_SYMBOL_MOVED_LINE_ALT:
1305                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT);
1306                        break;
1307                case DIFF_SYMBOL_MOVED_LINE |
1308                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1309                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_DIM);
1310                        break;
1311                case DIFF_SYMBOL_MOVED_LINE:
1312                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED);
1313                        break;
1314                default:
1315                        set = diff_get_color_opt(o, DIFF_FILE_NEW);
1316                }
1317                reset = diff_get_color_opt(o, DIFF_RESET);
1318                if (!o->flags.dual_color_diffed_diffs)
1319                        set_sign = NULL;
1320                else {
1321                        char c = !len ? 0 : line[0];
1322
1323                        set_sign = set;
1324                        if (c == '-')
1325                                set = diff_get_color_opt(o, DIFF_FILE_OLD_BOLD);
1326                        else if (c == '@')
1327                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1328                        else if (c == '+')
1329                                set = diff_get_color_opt(o, DIFF_FILE_NEW_BOLD);
1330                        else
1331                                set = diff_get_color_opt(o, DIFF_CONTEXT_BOLD);
1332                        flags &= ~DIFF_SYMBOL_CONTENT_WS_MASK;
1333                }
1334                emit_line_ws_markup(o, set_sign, set, reset,
1335                                    o->output_indicators[OUTPUT_INDICATOR_NEW],
1336                                    line, len,
1337                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK,
1338                                    flags & DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF);
1339                break;
1340        case DIFF_SYMBOL_MINUS:
1341                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1342                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1343                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1344                case DIFF_SYMBOL_MOVED_LINE |
1345                     DIFF_SYMBOL_MOVED_LINE_ALT |
1346                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1347                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT_DIM);
1348                        break;
1349                case DIFF_SYMBOL_MOVED_LINE |
1350                     DIFF_SYMBOL_MOVED_LINE_ALT:
1351                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT);
1352                        break;
1353                case DIFF_SYMBOL_MOVED_LINE |
1354                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1355                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_DIM);
1356                        break;
1357                case DIFF_SYMBOL_MOVED_LINE:
1358                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED);
1359                        break;
1360                default:
1361                        set = diff_get_color_opt(o, DIFF_FILE_OLD);
1362                }
1363                reset = diff_get_color_opt(o, DIFF_RESET);
1364                if (!o->flags.dual_color_diffed_diffs)
1365                        set_sign = NULL;
1366                else {
1367                        char c = !len ? 0 : line[0];
1368
1369                        set_sign = set;
1370                        if (c == '+')
1371                                set = diff_get_color_opt(o, DIFF_FILE_NEW_DIM);
1372                        else if (c == '@')
1373                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1374                        else if (c == '-')
1375                                set = diff_get_color_opt(o, DIFF_FILE_OLD_DIM);
1376                        else
1377                                set = diff_get_color_opt(o, DIFF_CONTEXT_DIM);
1378                }
1379                emit_line_ws_markup(o, set_sign, set, reset,
1380                                    o->output_indicators[OUTPUT_INDICATOR_OLD],
1381                                    line, len,
1382                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK, 0);
1383                break;
1384        case DIFF_SYMBOL_WORDS_PORCELAIN:
1385                context = diff_get_color_opt(o, DIFF_CONTEXT);
1386                reset = diff_get_color_opt(o, DIFF_RESET);
1387                emit_line(o, context, reset, line, len);
1388                fputs("~\n", o->file);
1389                break;
1390        case DIFF_SYMBOL_WORDS:
1391                context = diff_get_color_opt(o, DIFF_CONTEXT);
1392                reset = diff_get_color_opt(o, DIFF_RESET);
1393                /*
1394                 * Skip the prefix character, if any.  With
1395                 * diff_suppress_blank_empty, there may be
1396                 * none.
1397                 */
1398                if (line[0] != '\n') {
1399                        line++;
1400                        len--;
1401                }
1402                emit_line(o, context, reset, line, len);
1403                break;
1404        case DIFF_SYMBOL_FILEPAIR_PLUS:
1405                meta = diff_get_color_opt(o, DIFF_METAINFO);
1406                reset = diff_get_color_opt(o, DIFF_RESET);
1407                fprintf(o->file, "%s%s+++ %s%s%s\n", diff_line_prefix(o), meta,
1408                        line, reset,
1409                        strchr(line, ' ') ? "\t" : "");
1410                break;
1411        case DIFF_SYMBOL_FILEPAIR_MINUS:
1412                meta = diff_get_color_opt(o, DIFF_METAINFO);
1413                reset = diff_get_color_opt(o, DIFF_RESET);
1414                fprintf(o->file, "%s%s--- %s%s%s\n", diff_line_prefix(o), meta,
1415                        line, reset,
1416                        strchr(line, ' ') ? "\t" : "");
1417                break;
1418        case DIFF_SYMBOL_BINARY_FILES:
1419        case DIFF_SYMBOL_HEADER:
1420                fprintf(o->file, "%s", line);
1421                break;
1422        case DIFF_SYMBOL_BINARY_DIFF_HEADER:
1423                fprintf(o->file, "%sGIT binary patch\n", diff_line_prefix(o));
1424                break;
1425        case DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA:
1426                fprintf(o->file, "%sdelta %s\n", diff_line_prefix(o), line);
1427                break;
1428        case DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL:
1429                fprintf(o->file, "%sliteral %s\n", diff_line_prefix(o), line);
1430                break;
1431        case DIFF_SYMBOL_BINARY_DIFF_FOOTER:
1432                fputs(diff_line_prefix(o), o->file);
1433                fputc('\n', o->file);
1434                break;
1435        case DIFF_SYMBOL_REWRITE_DIFF:
1436                fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
1437                reset = diff_get_color_opt(o, DIFF_RESET);
1438                emit_line(o, fraginfo, reset, line, len);
1439                break;
1440        case DIFF_SYMBOL_SUBMODULE_ADD:
1441                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1442                reset = diff_get_color_opt(o, DIFF_RESET);
1443                emit_line(o, set, reset, line, len);
1444                break;
1445        case DIFF_SYMBOL_SUBMODULE_DEL:
1446                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1447                reset = diff_get_color_opt(o, DIFF_RESET);
1448                emit_line(o, set, reset, line, len);
1449                break;
1450        case DIFF_SYMBOL_SUBMODULE_UNTRACKED:
1451                fprintf(o->file, "%sSubmodule %s contains untracked content\n",
1452                        diff_line_prefix(o), line);
1453                break;
1454        case DIFF_SYMBOL_SUBMODULE_MODIFIED:
1455                fprintf(o->file, "%sSubmodule %s contains modified content\n",
1456                        diff_line_prefix(o), line);
1457                break;
1458        case DIFF_SYMBOL_STATS_SUMMARY_NO_FILES:
1459                emit_line(o, "", "", " 0 files changed\n",
1460                          strlen(" 0 files changed\n"));
1461                break;
1462        case DIFF_SYMBOL_STATS_SUMMARY_ABBREV:
1463                emit_line(o, "", "", " ...\n", strlen(" ...\n"));
1464                break;
1465        case DIFF_SYMBOL_WORD_DIFF:
1466                fprintf(o->file, "%.*s", len, line);
1467                break;
1468        case DIFF_SYMBOL_STAT_SEP:
1469                fputs(o->stat_sep, o->file);
1470                break;
1471        default:
1472                BUG("unknown diff symbol");
1473        }
1474        strbuf_release(&sb);
1475}
1476
1477static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
1478                             const char *line, int len, unsigned flags)
1479{
1480        struct emitted_diff_symbol e = {line, len, flags, s};
1481
1482        if (o->emitted_symbols)
1483                append_emitted_diff_symbol(o, &e);
1484        else
1485                emit_diff_symbol_from_struct(o, &e);
1486}
1487
1488void diff_emit_submodule_del(struct diff_options *o, const char *line)
1489{
1490        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_DEL, line, strlen(line), 0);
1491}
1492
1493void diff_emit_submodule_add(struct diff_options *o, const char *line)
1494{
1495        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ADD, line, strlen(line), 0);
1496}
1497
1498void diff_emit_submodule_untracked(struct diff_options *o, const char *path)
1499{
1500        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_UNTRACKED,
1501                         path, strlen(path), 0);
1502}
1503
1504void diff_emit_submodule_modified(struct diff_options *o, const char *path)
1505{
1506        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_MODIFIED,
1507                         path, strlen(path), 0);
1508}
1509
1510void diff_emit_submodule_header(struct diff_options *o, const char *header)
1511{
1512        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_HEADER,
1513                         header, strlen(header), 0);
1514}
1515
1516void diff_emit_submodule_error(struct diff_options *o, const char *err)
1517{
1518        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ERROR, err, strlen(err), 0);
1519}
1520
1521void diff_emit_submodule_pipethrough(struct diff_options *o,
1522                                     const char *line, int len)
1523{
1524        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_PIPETHROUGH, line, len, 0);
1525}
1526
1527static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
1528{
1529        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
1530              ecbdata->blank_at_eof_in_preimage &&
1531              ecbdata->blank_at_eof_in_postimage &&
1532              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
1533              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
1534                return 0;
1535        return ws_blank_line(line, len, ecbdata->ws_rule);
1536}
1537
1538static void emit_add_line(const char *reset,
1539                          struct emit_callback *ecbdata,
1540                          const char *line, int len)
1541{
1542        unsigned flags = WSEH_NEW | ecbdata->ws_rule;
1543        if (new_blank_line_at_eof(ecbdata, line, len))
1544                flags |= DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF;
1545
1546        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_PLUS, line, len, flags);
1547}
1548
1549static void emit_del_line(const char *reset,
1550                          struct emit_callback *ecbdata,
1551                          const char *line, int len)
1552{
1553        unsigned flags = WSEH_OLD | ecbdata->ws_rule;
1554        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_MINUS, line, len, flags);
1555}
1556
1557static void emit_context_line(const char *reset,
1558                              struct emit_callback *ecbdata,
1559                              const char *line, int len)
1560{
1561        unsigned flags = WSEH_CONTEXT | ecbdata->ws_rule;
1562        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_CONTEXT, line, len, flags);
1563}
1564
1565static void emit_hunk_header(struct emit_callback *ecbdata,
1566                             const char *line, int len)
1567{
1568        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
1569        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
1570        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
1571        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1572        const char *reverse = ecbdata->color_diff ? GIT_COLOR_REVERSE : "";
1573        static const char atat[2] = { '@', '@' };
1574        const char *cp, *ep;
1575        struct strbuf msgbuf = STRBUF_INIT;
1576        int org_len = len;
1577        int i = 1;
1578
1579        /*
1580         * As a hunk header must begin with "@@ -<old>, +<new> @@",
1581         * it always is at least 10 bytes long.
1582         */
1583        if (len < 10 ||
1584            memcmp(line, atat, 2) ||
1585            !(ep = memmem(line + 2, len - 2, atat, 2))) {
1586                emit_diff_symbol(ecbdata->opt,
1587                                 DIFF_SYMBOL_CONTEXT_MARKER, line, len, 0);
1588                return;
1589        }
1590        ep += 2; /* skip over @@ */
1591
1592        /* The hunk header in fraginfo color */
1593        if (ecbdata->opt->flags.dual_color_diffed_diffs)
1594                strbuf_addstr(&msgbuf, reverse);
1595        strbuf_addstr(&msgbuf, frag);
1596        strbuf_add(&msgbuf, line, ep - line);
1597        strbuf_addstr(&msgbuf, reset);
1598
1599        /*
1600         * trailing "\r\n"
1601         */
1602        for ( ; i < 3; i++)
1603                if (line[len - i] == '\r' || line[len - i] == '\n')
1604                        len--;
1605
1606        /* blank before the func header */
1607        for (cp = ep; ep - line < len; ep++)
1608                if (*ep != ' ' && *ep != '\t')
1609                        break;
1610        if (ep != cp) {
1611                strbuf_addstr(&msgbuf, context);
1612                strbuf_add(&msgbuf, cp, ep - cp);
1613                strbuf_addstr(&msgbuf, reset);
1614        }
1615
1616        if (ep < line + len) {
1617                strbuf_addstr(&msgbuf, func);
1618                strbuf_add(&msgbuf, ep, line + len - ep);
1619                strbuf_addstr(&msgbuf, reset);
1620        }
1621
1622        strbuf_add(&msgbuf, line + len, org_len - len);
1623        strbuf_complete_line(&msgbuf);
1624        emit_diff_symbol(ecbdata->opt,
1625                         DIFF_SYMBOL_CONTEXT_FRAGINFO, msgbuf.buf, msgbuf.len, 0);
1626        strbuf_release(&msgbuf);
1627}
1628
1629static struct diff_tempfile *claim_diff_tempfile(void) {
1630        int i;
1631        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
1632                if (!diff_temp[i].name)
1633                        return diff_temp + i;
1634        BUG("diff is failing to clean up its tempfiles");
1635}
1636
1637static void remove_tempfile(void)
1638{
1639        int i;
1640        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
1641                if (is_tempfile_active(diff_temp[i].tempfile))
1642                        delete_tempfile(&diff_temp[i].tempfile);
1643                diff_temp[i].name = NULL;
1644        }
1645}
1646
1647static void add_line_count(struct strbuf *out, int count)
1648{
1649        switch (count) {
1650        case 0:
1651                strbuf_addstr(out, "0,0");
1652                break;
1653        case 1:
1654                strbuf_addstr(out, "1");
1655                break;
1656        default:
1657                strbuf_addf(out, "1,%d", count);
1658                break;
1659        }
1660}
1661
1662static void emit_rewrite_lines(struct emit_callback *ecb,
1663                               int prefix, const char *data, int size)
1664{
1665        const char *endp = NULL;
1666        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
1667
1668        while (0 < size) {
1669                int len;
1670
1671                endp = memchr(data, '\n', size);
1672                len = endp ? (endp - data + 1) : size;
1673                if (prefix != '+') {
1674                        ecb->lno_in_preimage++;
1675                        emit_del_line(reset, ecb, data, len);
1676                } else {
1677                        ecb->lno_in_postimage++;
1678                        emit_add_line(reset, ecb, data, len);
1679                }
1680                size -= len;
1681                data += len;
1682        }
1683        if (!endp)
1684                emit_diff_symbol(ecb->opt, DIFF_SYMBOL_NO_LF_EOF, NULL, 0, 0);
1685}
1686
1687static void emit_rewrite_diff(const char *name_a,
1688                              const char *name_b,
1689                              struct diff_filespec *one,
1690                              struct diff_filespec *two,
1691                              struct userdiff_driver *textconv_one,
1692                              struct userdiff_driver *textconv_two,
1693                              struct diff_options *o)
1694{
1695        int lc_a, lc_b;
1696        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
1697        const char *a_prefix, *b_prefix;
1698        char *data_one, *data_two;
1699        size_t size_one, size_two;
1700        struct emit_callback ecbdata;
1701        struct strbuf out = STRBUF_INIT;
1702
1703        if (diff_mnemonic_prefix && o->flags.reverse_diff) {
1704                a_prefix = o->b_prefix;
1705                b_prefix = o->a_prefix;
1706        } else {
1707                a_prefix = o->a_prefix;
1708                b_prefix = o->b_prefix;
1709        }
1710
1711        name_a += (*name_a == '/');
1712        name_b += (*name_b == '/');
1713
1714        strbuf_reset(&a_name);
1715        strbuf_reset(&b_name);
1716        quote_two_c_style(&a_name, a_prefix, name_a, 0);
1717        quote_two_c_style(&b_name, b_prefix, name_b, 0);
1718
1719        size_one = fill_textconv(o->repo, textconv_one, one, &data_one);
1720        size_two = fill_textconv(o->repo, textconv_two, two, &data_two);
1721
1722        memset(&ecbdata, 0, sizeof(ecbdata));
1723        ecbdata.color_diff = want_color(o->use_color);
1724        ecbdata.ws_rule = whitespace_rule(o->repo->index, name_b);
1725        ecbdata.opt = o;
1726        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
1727                mmfile_t mf1, mf2;
1728                mf1.ptr = (char *)data_one;
1729                mf2.ptr = (char *)data_two;
1730                mf1.size = size_one;
1731                mf2.size = size_two;
1732                check_blank_at_eof(&mf1, &mf2, &ecbdata);
1733        }
1734        ecbdata.lno_in_preimage = 1;
1735        ecbdata.lno_in_postimage = 1;
1736
1737        lc_a = count_lines(data_one, size_one);
1738        lc_b = count_lines(data_two, size_two);
1739
1740        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
1741                         a_name.buf, a_name.len, 0);
1742        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
1743                         b_name.buf, b_name.len, 0);
1744
1745        strbuf_addstr(&out, "@@ -");
1746        if (!o->irreversible_delete)
1747                add_line_count(&out, lc_a);
1748        else
1749                strbuf_addstr(&out, "?,?");
1750        strbuf_addstr(&out, " +");
1751        add_line_count(&out, lc_b);
1752        strbuf_addstr(&out, " @@\n");
1753        emit_diff_symbol(o, DIFF_SYMBOL_REWRITE_DIFF, out.buf, out.len, 0);
1754        strbuf_release(&out);
1755
1756        if (lc_a && !o->irreversible_delete)
1757                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
1758        if (lc_b)
1759                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
1760        if (textconv_one)
1761                free((char *)data_one);
1762        if (textconv_two)
1763                free((char *)data_two);
1764}
1765
1766struct diff_words_buffer {
1767        mmfile_t text;
1768        unsigned long alloc;
1769        struct diff_words_orig {
1770                const char *begin, *end;
1771        } *orig;
1772        int orig_nr, orig_alloc;
1773};
1774
1775static void diff_words_append(char *line, unsigned long len,
1776                struct diff_words_buffer *buffer)
1777{
1778        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
1779        line++;
1780        len--;
1781        memcpy(buffer->text.ptr + buffer->text.size, line, len);
1782        buffer->text.size += len;
1783        buffer->text.ptr[buffer->text.size] = '\0';
1784}
1785
1786struct diff_words_style_elem {
1787        const char *prefix;
1788        const char *suffix;
1789        const char *color; /* NULL; filled in by the setup code if
1790                            * color is enabled */
1791};
1792
1793struct diff_words_style {
1794        enum diff_words_type type;
1795        struct diff_words_style_elem new_word, old_word, ctx;
1796        const char *newline;
1797};
1798
1799static struct diff_words_style diff_words_styles[] = {
1800        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
1801        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
1802        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
1803};
1804
1805struct diff_words_data {
1806        struct diff_words_buffer minus, plus;
1807        const char *current_plus;
1808        int last_minus;
1809        struct diff_options *opt;
1810        regex_t *word_regex;
1811        enum diff_words_type type;
1812        struct diff_words_style *style;
1813};
1814
1815static int fn_out_diff_words_write_helper(struct diff_options *o,
1816                                          struct diff_words_style_elem *st_el,
1817                                          const char *newline,
1818                                          size_t count, const char *buf)
1819{
1820        int print = 0;
1821        struct strbuf sb = STRBUF_INIT;
1822
1823        while (count) {
1824                char *p = memchr(buf, '\n', count);
1825                if (print)
1826                        strbuf_addstr(&sb, diff_line_prefix(o));
1827
1828                if (p != buf) {
1829                        const char *reset = st_el->color && *st_el->color ?
1830                                            GIT_COLOR_RESET : NULL;
1831                        if (st_el->color && *st_el->color)
1832                                strbuf_addstr(&sb, st_el->color);
1833                        strbuf_addstr(&sb, st_el->prefix);
1834                        strbuf_add(&sb, buf, p ? p - buf : count);
1835                        strbuf_addstr(&sb, st_el->suffix);
1836                        if (reset)
1837                                strbuf_addstr(&sb, reset);
1838                }
1839                if (!p)
1840                        goto out;
1841
1842                strbuf_addstr(&sb, newline);
1843                count -= p + 1 - buf;
1844                buf = p + 1;
1845                print = 1;
1846                if (count) {
1847                        emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1848                                         sb.buf, sb.len, 0);
1849                        strbuf_reset(&sb);
1850                }
1851        }
1852
1853out:
1854        if (sb.len)
1855                emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1856                                 sb.buf, sb.len, 0);
1857        strbuf_release(&sb);
1858        return 0;
1859}
1860
1861/*
1862 * '--color-words' algorithm can be described as:
1863 *
1864 *   1. collect the minus/plus lines of a diff hunk, divided into
1865 *      minus-lines and plus-lines;
1866 *
1867 *   2. break both minus-lines and plus-lines into words and
1868 *      place them into two mmfile_t with one word for each line;
1869 *
1870 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
1871 *
1872 * And for the common parts of the both file, we output the plus side text.
1873 * diff_words->current_plus is used to trace the current position of the plus file
1874 * which printed. diff_words->last_minus is used to trace the last minus word
1875 * printed.
1876 *
1877 * For '--graph' to work with '--color-words', we need to output the graph prefix
1878 * on each line of color words output. Generally, there are two conditions on
1879 * which we should output the prefix.
1880 *
1881 *   1. diff_words->last_minus == 0 &&
1882 *      diff_words->current_plus == diff_words->plus.text.ptr
1883 *
1884 *      that is: the plus text must start as a new line, and if there is no minus
1885 *      word printed, a graph prefix must be printed.
1886 *
1887 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
1888 *      *(diff_words->current_plus - 1) == '\n'
1889 *
1890 *      that is: a graph prefix must be printed following a '\n'
1891 */
1892static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
1893{
1894        if ((diff_words->last_minus == 0 &&
1895                diff_words->current_plus == diff_words->plus.text.ptr) ||
1896                (diff_words->current_plus > diff_words->plus.text.ptr &&
1897                *(diff_words->current_plus - 1) == '\n')) {
1898                return 1;
1899        } else {
1900                return 0;
1901        }
1902}
1903
1904static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
1905{
1906        struct diff_words_data *diff_words = priv;
1907        struct diff_words_style *style = diff_words->style;
1908        int minus_first, minus_len, plus_first, plus_len;
1909        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
1910        struct diff_options *opt = diff_words->opt;
1911        const char *line_prefix;
1912
1913        if (line[0] != '@' || parse_hunk_header(line, len,
1914                        &minus_first, &minus_len, &plus_first, &plus_len))
1915                return;
1916
1917        assert(opt);
1918        line_prefix = diff_line_prefix(opt);
1919
1920        /* POSIX requires that first be decremented by one if len == 0... */
1921        if (minus_len) {
1922                minus_begin = diff_words->minus.orig[minus_first].begin;
1923                minus_end =
1924                        diff_words->minus.orig[minus_first + minus_len - 1].end;
1925        } else
1926                minus_begin = minus_end =
1927                        diff_words->minus.orig[minus_first].end;
1928
1929        if (plus_len) {
1930                plus_begin = diff_words->plus.orig[plus_first].begin;
1931                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
1932        } else
1933                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
1934
1935        if (color_words_output_graph_prefix(diff_words)) {
1936                fputs(line_prefix, diff_words->opt->file);
1937        }
1938        if (diff_words->current_plus != plus_begin) {
1939                fn_out_diff_words_write_helper(diff_words->opt,
1940                                &style->ctx, style->newline,
1941                                plus_begin - diff_words->current_plus,
1942                                diff_words->current_plus);
1943        }
1944        if (minus_begin != minus_end) {
1945                fn_out_diff_words_write_helper(diff_words->opt,
1946                                &style->old_word, style->newline,
1947                                minus_end - minus_begin, minus_begin);
1948        }
1949        if (plus_begin != plus_end) {
1950                fn_out_diff_words_write_helper(diff_words->opt,
1951                                &style->new_word, style->newline,
1952                                plus_end - plus_begin, plus_begin);
1953        }
1954
1955        diff_words->current_plus = plus_end;
1956        diff_words->last_minus = minus_first;
1957}
1958
1959/* This function starts looking at *begin, and returns 0 iff a word was found. */
1960static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
1961                int *begin, int *end)
1962{
1963        if (word_regex && *begin < buffer->size) {
1964                regmatch_t match[1];
1965                if (!regexec_buf(word_regex, buffer->ptr + *begin,
1966                                 buffer->size - *begin, 1, match, 0)) {
1967                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
1968                                        '\n', match[0].rm_eo - match[0].rm_so);
1969                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
1970                        *begin += match[0].rm_so;
1971                        return *begin >= *end;
1972                }
1973                return -1;
1974        }
1975
1976        /* find the next word */
1977        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
1978                (*begin)++;
1979        if (*begin >= buffer->size)
1980                return -1;
1981
1982        /* find the end of the word */
1983        *end = *begin + 1;
1984        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
1985                (*end)++;
1986
1987        return 0;
1988}
1989
1990/*
1991 * This function splits the words in buffer->text, stores the list with
1992 * newline separator into out, and saves the offsets of the original words
1993 * in buffer->orig.
1994 */
1995static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
1996                regex_t *word_regex)
1997{
1998        int i, j;
1999        long alloc = 0;
2000
2001        out->size = 0;
2002        out->ptr = NULL;
2003
2004        /* fake an empty "0th" word */
2005        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
2006        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
2007        buffer->orig_nr = 1;
2008
2009        for (i = 0; i < buffer->text.size; i++) {
2010                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
2011                        return;
2012
2013                /* store original boundaries */
2014                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
2015                                buffer->orig_alloc);
2016                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
2017                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
2018                buffer->orig_nr++;
2019
2020                /* store one word */
2021                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
2022                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
2023                out->ptr[out->size + j - i] = '\n';
2024                out->size += j - i + 1;
2025
2026                i = j - 1;
2027        }
2028}
2029
2030/* this executes the word diff on the accumulated buffers */
2031static void diff_words_show(struct diff_words_data *diff_words)
2032{
2033        xpparam_t xpp;
2034        xdemitconf_t xecfg;
2035        mmfile_t minus, plus;
2036        struct diff_words_style *style = diff_words->style;
2037
2038        struct diff_options *opt = diff_words->opt;
2039        const char *line_prefix;
2040
2041        assert(opt);
2042        line_prefix = diff_line_prefix(opt);
2043
2044        /* special case: only removal */
2045        if (!diff_words->plus.text.size) {
2046                emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
2047                                 line_prefix, strlen(line_prefix), 0);
2048                fn_out_diff_words_write_helper(diff_words->opt,
2049                        &style->old_word, style->newline,
2050                        diff_words->minus.text.size,
2051                        diff_words->minus.text.ptr);
2052                diff_words->minus.text.size = 0;
2053                return;
2054        }
2055
2056        diff_words->current_plus = diff_words->plus.text.ptr;
2057        diff_words->last_minus = 0;
2058
2059        memset(&xpp, 0, sizeof(xpp));
2060        memset(&xecfg, 0, sizeof(xecfg));
2061        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
2062        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
2063        xpp.flags = 0;
2064        /* as only the hunk header will be parsed, we need a 0-context */
2065        xecfg.ctxlen = 0;
2066        if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
2067                          &xpp, &xecfg))
2068                die("unable to generate word diff");
2069        free(minus.ptr);
2070        free(plus.ptr);
2071        if (diff_words->current_plus != diff_words->plus.text.ptr +
2072                        diff_words->plus.text.size) {
2073                if (color_words_output_graph_prefix(diff_words))
2074                        emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
2075                                         line_prefix, strlen(line_prefix), 0);
2076                fn_out_diff_words_write_helper(diff_words->opt,
2077                        &style->ctx, style->newline,
2078                        diff_words->plus.text.ptr + diff_words->plus.text.size
2079                        - diff_words->current_plus, diff_words->current_plus);
2080        }
2081        diff_words->minus.text.size = diff_words->plus.text.size = 0;
2082}
2083
2084/* In "color-words" mode, show word-diff of words accumulated in the buffer */
2085static void diff_words_flush(struct emit_callback *ecbdata)
2086{
2087        struct diff_options *wo = ecbdata->diff_words->opt;
2088
2089        if (ecbdata->diff_words->minus.text.size ||
2090            ecbdata->diff_words->plus.text.size)
2091                diff_words_show(ecbdata->diff_words);
2092
2093        if (wo->emitted_symbols) {
2094                struct diff_options *o = ecbdata->opt;
2095                struct emitted_diff_symbols *wol = wo->emitted_symbols;
2096                int i;
2097
2098                /*
2099                 * NEEDSWORK:
2100                 * Instead of appending each, concat all words to a line?
2101                 */
2102                for (i = 0; i < wol->nr; i++)
2103                        append_emitted_diff_symbol(o, &wol->buf[i]);
2104
2105                for (i = 0; i < wol->nr; i++)
2106                        free((void *)wol->buf[i].line);
2107
2108                wol->nr = 0;
2109        }
2110}
2111
2112static void diff_filespec_load_driver(struct diff_filespec *one,
2113                                      struct index_state *istate)
2114{
2115        /* Use already-loaded driver */
2116        if (one->driver)
2117                return;
2118
2119        if (S_ISREG(one->mode))
2120                one->driver = userdiff_find_by_path(istate, one->path);
2121
2122        /* Fallback to default settings */
2123        if (!one->driver)
2124                one->driver = userdiff_find_by_name("default");
2125}
2126
2127static const char *userdiff_word_regex(struct diff_filespec *one,
2128                                       struct index_state *istate)
2129{
2130        diff_filespec_load_driver(one, istate);
2131        return one->driver->word_regex;
2132}
2133
2134static void init_diff_words_data(struct emit_callback *ecbdata,
2135                                 struct diff_options *orig_opts,
2136                                 struct diff_filespec *one,
2137                                 struct diff_filespec *two)
2138{
2139        int i;
2140        struct diff_options *o = xmalloc(sizeof(struct diff_options));
2141        memcpy(o, orig_opts, sizeof(struct diff_options));
2142
2143        ecbdata->diff_words =
2144                xcalloc(1, sizeof(struct diff_words_data));
2145        ecbdata->diff_words->type = o->word_diff;
2146        ecbdata->diff_words->opt = o;
2147
2148        if (orig_opts->emitted_symbols)
2149                o->emitted_symbols =
2150                        xcalloc(1, sizeof(struct emitted_diff_symbols));
2151
2152        if (!o->word_regex)
2153                o->word_regex = userdiff_word_regex(one, o->repo->index);
2154        if (!o->word_regex)
2155                o->word_regex = userdiff_word_regex(two, o->repo->index);
2156        if (!o->word_regex)
2157                o->word_regex = diff_word_regex_cfg;
2158        if (o->word_regex) {
2159                ecbdata->diff_words->word_regex = (regex_t *)
2160                        xmalloc(sizeof(regex_t));
2161                if (regcomp(ecbdata->diff_words->word_regex,
2162                            o->word_regex,
2163                            REG_EXTENDED | REG_NEWLINE))
2164                        die("invalid regular expression: %s",
2165                            o->word_regex);
2166        }
2167        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2168                if (o->word_diff == diff_words_styles[i].type) {
2169                        ecbdata->diff_words->style =
2170                                &diff_words_styles[i];
2171                        break;
2172                }
2173        }
2174        if (want_color(o->use_color)) {
2175                struct diff_words_style *st = ecbdata->diff_words->style;
2176                st->old_word.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2177                st->new_word.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2178                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
2179        }
2180}
2181
2182static void free_diff_words_data(struct emit_callback *ecbdata)
2183{
2184        if (ecbdata->diff_words) {
2185                diff_words_flush(ecbdata);
2186                free (ecbdata->diff_words->opt->emitted_symbols);
2187                free (ecbdata->diff_words->opt);
2188                free (ecbdata->diff_words->minus.text.ptr);
2189                free (ecbdata->diff_words->minus.orig);
2190                free (ecbdata->diff_words->plus.text.ptr);
2191                free (ecbdata->diff_words->plus.orig);
2192                if (ecbdata->diff_words->word_regex) {
2193                        regfree(ecbdata->diff_words->word_regex);
2194                        free(ecbdata->diff_words->word_regex);
2195                }
2196                FREE_AND_NULL(ecbdata->diff_words);
2197        }
2198}
2199
2200const char *diff_get_color(int diff_use_color, enum color_diff ix)
2201{
2202        if (want_color(diff_use_color))
2203                return diff_colors[ix];
2204        return "";
2205}
2206
2207const char *diff_line_prefix(struct diff_options *opt)
2208{
2209        struct strbuf *msgbuf;
2210        if (!opt->output_prefix)
2211                return "";
2212
2213        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
2214        return msgbuf->buf;
2215}
2216
2217static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
2218{
2219        const char *cp;
2220        unsigned long allot;
2221        size_t l = len;
2222
2223        cp = line;
2224        allot = l;
2225        while (0 < l) {
2226                (void) utf8_width(&cp, &l);
2227                if (!cp)
2228                        break; /* truncated in the middle? */
2229        }
2230        return allot - l;
2231}
2232
2233static void find_lno(const char *line, struct emit_callback *ecbdata)
2234{
2235        const char *p;
2236        ecbdata->lno_in_preimage = 0;
2237        ecbdata->lno_in_postimage = 0;
2238        p = strchr(line, '-');
2239        if (!p)
2240                return; /* cannot happen */
2241        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
2242        p = strchr(p, '+');
2243        if (!p)
2244                return; /* cannot happen */
2245        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
2246}
2247
2248static void fn_out_consume(void *priv, char *line, unsigned long len)
2249{
2250        struct emit_callback *ecbdata = priv;
2251        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
2252        struct diff_options *o = ecbdata->opt;
2253
2254        o->found_changes = 1;
2255
2256        if (ecbdata->header) {
2257                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
2258                                 ecbdata->header->buf, ecbdata->header->len, 0);
2259                strbuf_reset(ecbdata->header);
2260                ecbdata->header = NULL;
2261        }
2262
2263        if (ecbdata->label_path[0]) {
2264                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
2265                                 ecbdata->label_path[0],
2266                                 strlen(ecbdata->label_path[0]), 0);
2267                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
2268                                 ecbdata->label_path[1],
2269                                 strlen(ecbdata->label_path[1]), 0);
2270                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
2271        }
2272
2273        if (diff_suppress_blank_empty
2274            && len == 2 && line[0] == ' ' && line[1] == '\n') {
2275                line[0] = '\n';
2276                len = 1;
2277        }
2278
2279        if (line[0] == '@') {
2280                if (ecbdata->diff_words)
2281                        diff_words_flush(ecbdata);
2282                len = sane_truncate_line(ecbdata, line, len);
2283                find_lno(line, ecbdata);
2284                emit_hunk_header(ecbdata, line, len);
2285                return;
2286        }
2287
2288        if (ecbdata->diff_words) {
2289                enum diff_symbol s =
2290                        ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN ?
2291                        DIFF_SYMBOL_WORDS_PORCELAIN : DIFF_SYMBOL_WORDS;
2292                if (line[0] == '-') {
2293                        diff_words_append(line, len,
2294                                          &ecbdata->diff_words->minus);
2295                        return;
2296                } else if (line[0] == '+') {
2297                        diff_words_append(line, len,
2298                                          &ecbdata->diff_words->plus);
2299                        return;
2300                } else if (starts_with(line, "\\ ")) {
2301                        /*
2302                         * Eat the "no newline at eof" marker as if we
2303                         * saw a "+" or "-" line with nothing on it,
2304                         * and return without diff_words_flush() to
2305                         * defer processing. If this is the end of
2306                         * preimage, more "+" lines may come after it.
2307                         */
2308                        return;
2309                }
2310                diff_words_flush(ecbdata);
2311                emit_diff_symbol(o, s, line, len, 0);
2312                return;
2313        }
2314
2315        switch (line[0]) {
2316        case '+':
2317                ecbdata->lno_in_postimage++;
2318                emit_add_line(reset, ecbdata, line + 1, len - 1);
2319                break;
2320        case '-':
2321                ecbdata->lno_in_preimage++;
2322                emit_del_line(reset, ecbdata, line + 1, len - 1);
2323                break;
2324        case ' ':
2325                ecbdata->lno_in_postimage++;
2326                ecbdata->lno_in_preimage++;
2327                emit_context_line(reset, ecbdata, line + 1, len - 1);
2328                break;
2329        default:
2330                /* incomplete line at the end */
2331                ecbdata->lno_in_preimage++;
2332                emit_diff_symbol(o, DIFF_SYMBOL_CONTEXT_INCOMPLETE,
2333                                 line, len, 0);
2334                break;
2335        }
2336}
2337
2338static void pprint_rename(struct strbuf *name, const char *a, const char *b)
2339{
2340        const char *old_name = a;
2341        const char *new_name = b;
2342        int pfx_length, sfx_length;
2343        int pfx_adjust_for_slash;
2344        int len_a = strlen(a);
2345        int len_b = strlen(b);
2346        int a_midlen, b_midlen;
2347        int qlen_a = quote_c_style(a, NULL, NULL, 0);
2348        int qlen_b = quote_c_style(b, NULL, NULL, 0);
2349
2350        if (qlen_a || qlen_b) {
2351                quote_c_style(a, name, NULL, 0);
2352                strbuf_addstr(name, " => ");
2353                quote_c_style(b, name, NULL, 0);
2354                return;
2355        }
2356
2357        /* Find common prefix */
2358        pfx_length = 0;
2359        while (*old_name && *new_name && *old_name == *new_name) {
2360                if (*old_name == '/')
2361                        pfx_length = old_name - a + 1;
2362                old_name++;
2363                new_name++;
2364        }
2365
2366        /* Find common suffix */
2367        old_name = a + len_a;
2368        new_name = b + len_b;
2369        sfx_length = 0;
2370        /*
2371         * If there is a common prefix, it must end in a slash.  In
2372         * that case we let this loop run 1 into the prefix to see the
2373         * same slash.
2374         *
2375         * If there is no common prefix, we cannot do this as it would
2376         * underrun the input strings.
2377         */
2378        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
2379        while (a + pfx_length - pfx_adjust_for_slash <= old_name &&
2380               b + pfx_length - pfx_adjust_for_slash <= new_name &&
2381               *old_name == *new_name) {
2382                if (*old_name == '/')
2383                        sfx_length = len_a - (old_name - a);
2384                old_name--;
2385                new_name--;
2386        }
2387
2388        /*
2389         * pfx{mid-a => mid-b}sfx
2390         * {pfx-a => pfx-b}sfx
2391         * pfx{sfx-a => sfx-b}
2392         * name-a => name-b
2393         */
2394        a_midlen = len_a - pfx_length - sfx_length;
2395        b_midlen = len_b - pfx_length - sfx_length;
2396        if (a_midlen < 0)
2397                a_midlen = 0;
2398        if (b_midlen < 0)
2399                b_midlen = 0;
2400
2401        strbuf_grow(name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
2402        if (pfx_length + sfx_length) {
2403                strbuf_add(name, a, pfx_length);
2404                strbuf_addch(name, '{');
2405        }
2406        strbuf_add(name, a + pfx_length, a_midlen);
2407        strbuf_addstr(name, " => ");
2408        strbuf_add(name, b + pfx_length, b_midlen);
2409        if (pfx_length + sfx_length) {
2410                strbuf_addch(name, '}');
2411                strbuf_add(name, a + len_a - sfx_length, sfx_length);
2412        }
2413}
2414
2415struct diffstat_t {
2416        int nr;
2417        int alloc;
2418        struct diffstat_file {
2419                char *from_name;
2420                char *name;
2421                char *print_name;
2422                const char *comments;
2423                unsigned is_unmerged:1;
2424                unsigned is_binary:1;
2425                unsigned is_renamed:1;
2426                unsigned is_interesting:1;
2427                uintmax_t added, deleted;
2428        } **files;
2429};
2430
2431static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
2432                                          const char *name_a,
2433                                          const char *name_b)
2434{
2435        struct diffstat_file *x;
2436        x = xcalloc(1, sizeof(*x));
2437        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
2438        diffstat->files[diffstat->nr++] = x;
2439        if (name_b) {
2440                x->from_name = xstrdup(name_a);
2441                x->name = xstrdup(name_b);
2442                x->is_renamed = 1;
2443        }
2444        else {
2445                x->from_name = NULL;
2446                x->name = xstrdup(name_a);
2447        }
2448        return x;
2449}
2450
2451static void diffstat_consume(void *priv, char *line, unsigned long len)
2452{
2453        struct diffstat_t *diffstat = priv;
2454        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
2455
2456        if (line[0] == '+')
2457                x->added++;
2458        else if (line[0] == '-')
2459                x->deleted++;
2460}
2461
2462const char mime_boundary_leader[] = "------------";
2463
2464static int scale_linear(int it, int width, int max_change)
2465{
2466        if (!it)
2467                return 0;
2468        /*
2469         * make sure that at least one '-' or '+' is printed if
2470         * there is any change to this path. The easiest way is to
2471         * scale linearly as if the alloted width is one column shorter
2472         * than it is, and then add 1 to the result.
2473         */
2474        return 1 + (it * (width - 1) / max_change);
2475}
2476
2477static void show_graph(struct strbuf *out, char ch, int cnt,
2478                       const char *set, const char *reset)
2479{
2480        if (cnt <= 0)
2481                return;
2482        strbuf_addstr(out, set);
2483        strbuf_addchars(out, ch, cnt);
2484        strbuf_addstr(out, reset);
2485}
2486
2487static void fill_print_name(struct diffstat_file *file)
2488{
2489        struct strbuf pname = STRBUF_INIT;
2490
2491        if (file->print_name)
2492                return;
2493
2494        if (file->is_renamed)
2495                pprint_rename(&pname, file->from_name, file->name);
2496        else
2497                quote_c_style(file->name, &pname, NULL, 0);
2498
2499        if (file->comments)
2500                strbuf_addf(&pname, " (%s)", file->comments);
2501
2502        file->print_name = strbuf_detach(&pname, NULL);
2503}
2504
2505static void print_stat_summary_inserts_deletes(struct diff_options *options,
2506                int files, int insertions, int deletions)
2507{
2508        struct strbuf sb = STRBUF_INIT;
2509
2510        if (!files) {
2511                assert(insertions == 0 && deletions == 0);
2512                emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
2513                                 NULL, 0, 0);
2514                return;
2515        }
2516
2517        strbuf_addf(&sb,
2518                    (files == 1) ? " %d file changed" : " %d files changed",
2519                    files);
2520
2521        /*
2522         * For binary diff, the caller may want to print "x files
2523         * changed" with insertions == 0 && deletions == 0.
2524         *
2525         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
2526         * is probably less confusing (i.e skip over "2 files changed
2527         * but nothing about added/removed lines? Is this a bug in Git?").
2528         */
2529        if (insertions || deletions == 0) {
2530                strbuf_addf(&sb,
2531                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
2532                            insertions);
2533        }
2534
2535        if (deletions || insertions == 0) {
2536                strbuf_addf(&sb,
2537                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
2538                            deletions);
2539        }
2540        strbuf_addch(&sb, '\n');
2541        emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
2542                         sb.buf, sb.len, 0);
2543        strbuf_release(&sb);
2544}
2545
2546void print_stat_summary(FILE *fp, int files,
2547                        int insertions, int deletions)
2548{
2549        struct diff_options o;
2550        memset(&o, 0, sizeof(o));
2551        o.file = fp;
2552
2553        print_stat_summary_inserts_deletes(&o, files, insertions, deletions);
2554}
2555
2556static void show_stats(struct diffstat_t *data, struct diff_options *options)
2557{
2558        int i, len, add, del, adds = 0, dels = 0;
2559        uintmax_t max_change = 0, max_len = 0;
2560        int total_files = data->nr, count;
2561        int width, name_width, graph_width, number_width = 0, bin_width = 0;
2562        const char *reset, *add_c, *del_c;
2563        int extra_shown = 0;
2564        const char *line_prefix = diff_line_prefix(options);
2565        struct strbuf out = STRBUF_INIT;
2566
2567        if (data->nr == 0)
2568                return;
2569
2570        count = options->stat_count ? options->stat_count : data->nr;
2571
2572        reset = diff_get_color_opt(options, DIFF_RESET);
2573        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
2574        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
2575
2576        /*
2577         * Find the longest filename and max number of changes
2578         */
2579        for (i = 0; (i < count) && (i < data->nr); i++) {
2580                struct diffstat_file *file = data->files[i];
2581                uintmax_t change = file->added + file->deleted;
2582
2583                if (!file->is_interesting && (change == 0)) {
2584                        count++; /* not shown == room for one more */
2585                        continue;
2586                }
2587                fill_print_name(file);
2588                len = strlen(file->print_name);
2589                if (max_len < len)
2590                        max_len = len;
2591
2592                if (file->is_unmerged) {
2593                        /* "Unmerged" is 8 characters */
2594                        bin_width = bin_width < 8 ? 8 : bin_width;
2595                        continue;
2596                }
2597                if (file->is_binary) {
2598                        /* "Bin XXX -> YYY bytes" */
2599                        int w = 14 + decimal_width(file->added)
2600                                + decimal_width(file->deleted);
2601                        bin_width = bin_width < w ? w : bin_width;
2602                        /* Display change counts aligned with "Bin" */
2603                        number_width = 3;
2604                        continue;
2605                }
2606
2607                if (max_change < change)
2608                        max_change = change;
2609        }
2610        count = i; /* where we can stop scanning in data->files[] */
2611
2612        /*
2613         * We have width = stat_width or term_columns() columns total.
2614         * We want a maximum of min(max_len, stat_name_width) for the name part.
2615         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
2616         * We also need 1 for " " and 4 + decimal_width(max_change)
2617         * for " | NNNN " and one the empty column at the end, altogether
2618         * 6 + decimal_width(max_change).
2619         *
2620         * If there's not enough space, we will use the smaller of
2621         * stat_name_width (if set) and 5/8*width for the filename,
2622         * and the rest for constant elements + graph part, but no more
2623         * than stat_graph_width for the graph part.
2624         * (5/8 gives 50 for filename and 30 for the constant parts + graph
2625         * for the standard terminal size).
2626         *
2627         * In other words: stat_width limits the maximum width, and
2628         * stat_name_width fixes the maximum width of the filename,
2629         * and is also used to divide available columns if there
2630         * aren't enough.
2631         *
2632         * Binary files are displayed with "Bin XXX -> YYY bytes"
2633         * instead of the change count and graph. This part is treated
2634         * similarly to the graph part, except that it is not
2635         * "scaled". If total width is too small to accommodate the
2636         * guaranteed minimum width of the filename part and the
2637         * separators and this message, this message will "overflow"
2638         * making the line longer than the maximum width.
2639         */
2640
2641        if (options->stat_width == -1)
2642                width = term_columns() - strlen(line_prefix);
2643        else
2644                width = options->stat_width ? options->stat_width : 80;
2645        number_width = decimal_width(max_change) > number_width ?
2646                decimal_width(max_change) : number_width;
2647
2648        if (options->stat_graph_width == -1)
2649                options->stat_graph_width = diff_stat_graph_width;
2650
2651        /*
2652         * Guarantee 3/8*16==6 for the graph part
2653         * and 5/8*16==10 for the filename part
2654         */
2655        if (width < 16 + 6 + number_width)
2656                width = 16 + 6 + number_width;
2657
2658        /*
2659         * First assign sizes that are wanted, ignoring available width.
2660         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
2661         * starting from "XXX" should fit in graph_width.
2662         */
2663        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
2664        if (options->stat_graph_width &&
2665            options->stat_graph_width < graph_width)
2666                graph_width = options->stat_graph_width;
2667
2668        name_width = (options->stat_name_width > 0 &&
2669                      options->stat_name_width < max_len) ?
2670                options->stat_name_width : max_len;
2671
2672        /*
2673         * Adjust adjustable widths not to exceed maximum width
2674         */
2675        if (name_width + number_width + 6 + graph_width > width) {
2676                if (graph_width > width * 3/8 - number_width - 6) {
2677                        graph_width = width * 3/8 - number_width - 6;
2678                        if (graph_width < 6)
2679                                graph_width = 6;
2680                }
2681
2682                if (options->stat_graph_width &&
2683                    graph_width > options->stat_graph_width)
2684                        graph_width = options->stat_graph_width;
2685                if (name_width > width - number_width - 6 - graph_width)
2686                        name_width = width - number_width - 6 - graph_width;
2687                else
2688                        graph_width = width - number_width - 6 - name_width;
2689        }
2690
2691        /*
2692         * From here name_width is the width of the name area,
2693         * and graph_width is the width of the graph area.
2694         * max_change is used to scale graph properly.
2695         */
2696        for (i = 0; i < count; i++) {
2697                const char *prefix = "";
2698                struct diffstat_file *file = data->files[i];
2699                char *name = file->print_name;
2700                uintmax_t added = file->added;
2701                uintmax_t deleted = file->deleted;
2702                int name_len;
2703
2704                if (!file->is_interesting && (added + deleted == 0))
2705                        continue;
2706
2707                /*
2708                 * "scale" the filename
2709                 */
2710                len = name_width;
2711                name_len = strlen(name);
2712                if (name_width < name_len) {
2713                        char *slash;
2714                        prefix = "...";
2715                        len -= 3;
2716                        name += name_len - len;
2717                        slash = strchr(name, '/');
2718                        if (slash)
2719                                name = slash;
2720                }
2721
2722                if (file->is_binary) {
2723                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2724                        strbuf_addf(&out, " %*s", number_width, "Bin");
2725                        if (!added && !deleted) {
2726                                strbuf_addch(&out, '\n');
2727                                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2728                                                 out.buf, out.len, 0);
2729                                strbuf_reset(&out);
2730                                continue;
2731                        }
2732                        strbuf_addf(&out, " %s%"PRIuMAX"%s",
2733                                del_c, deleted, reset);
2734                        strbuf_addstr(&out, " -> ");
2735                        strbuf_addf(&out, "%s%"PRIuMAX"%s",
2736                                add_c, added, reset);
2737                        strbuf_addstr(&out, " bytes\n");
2738                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2739                                         out.buf, out.len, 0);
2740                        strbuf_reset(&out);
2741                        continue;
2742                }
2743                else if (file->is_unmerged) {
2744                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2745                        strbuf_addstr(&out, " Unmerged\n");
2746                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2747                                         out.buf, out.len, 0);
2748                        strbuf_reset(&out);
2749                        continue;
2750                }
2751
2752                /*
2753                 * scale the add/delete
2754                 */
2755                add = added;
2756                del = deleted;
2757
2758                if (graph_width <= max_change) {
2759                        int total = scale_linear(add + del, graph_width, max_change);
2760                        if (total < 2 && add && del)
2761                                /* width >= 2 due to the sanity check */
2762                                total = 2;
2763                        if (add < del) {
2764                                add = scale_linear(add, graph_width, max_change);
2765                                del = total - add;
2766                        } else {
2767                                del = scale_linear(del, graph_width, max_change);
2768                                add = total - del;
2769                        }
2770                }
2771                strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2772                strbuf_addf(&out, " %*"PRIuMAX"%s",
2773                        number_width, added + deleted,
2774                        added + deleted ? " " : "");
2775                show_graph(&out, '+', add, add_c, reset);
2776                show_graph(&out, '-', del, del_c, reset);
2777                strbuf_addch(&out, '\n');
2778                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2779                                 out.buf, out.len, 0);
2780                strbuf_reset(&out);
2781        }
2782
2783        for (i = 0; i < data->nr; i++) {
2784                struct diffstat_file *file = data->files[i];
2785                uintmax_t added = file->added;
2786                uintmax_t deleted = file->deleted;
2787
2788                if (file->is_unmerged ||
2789                    (!file->is_interesting && (added + deleted == 0))) {
2790                        total_files--;
2791                        continue;
2792                }
2793
2794                if (!file->is_binary) {
2795                        adds += added;
2796                        dels += deleted;
2797                }
2798                if (i < count)
2799                        continue;
2800                if (!extra_shown)
2801                        emit_diff_symbol(options,
2802                                         DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
2803                                         NULL, 0, 0);
2804                extra_shown = 1;
2805        }
2806
2807        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2808        strbuf_release(&out);
2809}
2810
2811static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
2812{
2813        int i, adds = 0, dels = 0, total_files = data->nr;
2814
2815        if (data->nr == 0)
2816                return;
2817
2818        for (i = 0; i < data->nr; i++) {
2819                int added = data->files[i]->added;
2820                int deleted = data->files[i]->deleted;
2821
2822                if (data->files[i]->is_unmerged ||
2823                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
2824                        total_files--;
2825                } else if (!data->files[i]->is_binary) { /* don't count bytes */
2826                        adds += added;
2827                        dels += deleted;
2828                }
2829        }
2830        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2831}
2832
2833static void show_numstat(struct diffstat_t *data, struct diff_options *options)
2834{
2835        int i;
2836
2837        if (data->nr == 0)
2838                return;
2839
2840        for (i = 0; i < data->nr; i++) {
2841                struct diffstat_file *file = data->files[i];
2842
2843                fprintf(options->file, "%s", diff_line_prefix(options));
2844
2845                if (file->is_binary)
2846                        fprintf(options->file, "-\t-\t");
2847                else
2848                        fprintf(options->file,
2849                                "%"PRIuMAX"\t%"PRIuMAX"\t",
2850                                file->added, file->deleted);
2851                if (options->line_termination) {
2852                        fill_print_name(file);
2853                        if (!file->is_renamed)
2854                                write_name_quoted(file->name, options->file,
2855                                                  options->line_termination);
2856                        else {
2857                                fputs(file->print_name, options->file);
2858                                putc(options->line_termination, options->file);
2859                        }
2860                } else {
2861                        if (file->is_renamed) {
2862                                putc('\0', options->file);
2863                                write_name_quoted(file->from_name, options->file, '\0');
2864                        }
2865                        write_name_quoted(file->name, options->file, '\0');
2866                }
2867        }
2868}
2869
2870struct dirstat_file {
2871        const char *name;
2872        unsigned long changed;
2873};
2874
2875struct dirstat_dir {
2876        struct dirstat_file *files;
2877        int alloc, nr, permille, cumulative;
2878};
2879
2880static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
2881                unsigned long changed, const char *base, int baselen)
2882{
2883        unsigned long sum_changes = 0;
2884        unsigned int sources = 0;
2885        const char *line_prefix = diff_line_prefix(opt);
2886
2887        while (dir->nr) {
2888                struct dirstat_file *f = dir->files;
2889                int namelen = strlen(f->name);
2890                unsigned long changes;
2891                char *slash;
2892
2893                if (namelen < baselen)
2894                        break;
2895                if (memcmp(f->name, base, baselen))
2896                        break;
2897                slash = strchr(f->name + baselen, '/');
2898                if (slash) {
2899                        int newbaselen = slash + 1 - f->name;
2900                        changes = gather_dirstat(opt, dir, changed, f->name, newbaselen);
2901                        sources++;
2902                } else {
2903                        changes = f->changed;
2904                        dir->files++;
2905                        dir->nr--;
2906                        sources += 2;
2907                }
2908                sum_changes += changes;
2909        }
2910
2911        /*
2912         * We don't report dirstat's for
2913         *  - the top level
2914         *  - or cases where everything came from a single directory
2915         *    under this directory (sources == 1).
2916         */
2917        if (baselen && sources != 1) {
2918                if (sum_changes) {
2919                        int permille = sum_changes * 1000 / changed;
2920                        if (permille >= dir->permille) {
2921                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
2922                                        permille / 10, permille % 10, baselen, base);
2923                                if (!dir->cumulative)
2924                                        return 0;
2925                        }
2926                }
2927        }
2928        return sum_changes;
2929}
2930
2931static int dirstat_compare(const void *_a, const void *_b)
2932{
2933        const struct dirstat_file *a = _a;
2934        const struct dirstat_file *b = _b;
2935        return strcmp(a->name, b->name);
2936}
2937
2938static void show_dirstat(struct diff_options *options)
2939{
2940        int i;
2941        unsigned long changed;
2942        struct dirstat_dir dir;
2943        struct diff_queue_struct *q = &diff_queued_diff;
2944
2945        dir.files = NULL;
2946        dir.alloc = 0;
2947        dir.nr = 0;
2948        dir.permille = options->dirstat_permille;
2949        dir.cumulative = options->flags.dirstat_cumulative;
2950
2951        changed = 0;
2952        for (i = 0; i < q->nr; i++) {
2953                struct diff_filepair *p = q->queue[i];
2954                const char *name;
2955                unsigned long copied, added, damage;
2956
2957                name = p->two->path ? p->two->path : p->one->path;
2958
2959                if (p->one->oid_valid && p->two->oid_valid &&
2960                    oideq(&p->one->oid, &p->two->oid)) {
2961                        /*
2962                         * The SHA1 has not changed, so pre-/post-content is
2963                         * identical. We can therefore skip looking at the
2964                         * file contents altogether.
2965                         */
2966                        damage = 0;
2967                        goto found_damage;
2968                }
2969
2970                if (options->flags.dirstat_by_file) {
2971                        /*
2972                         * In --dirstat-by-file mode, we don't really need to
2973                         * look at the actual file contents at all.
2974                         * The fact that the SHA1 changed is enough for us to
2975                         * add this file to the list of results
2976                         * (with each file contributing equal damage).
2977                         */
2978                        damage = 1;
2979                        goto found_damage;
2980                }
2981
2982                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
2983                        diff_populate_filespec(options->repo, p->one, 0);
2984                        diff_populate_filespec(options->repo, p->two, 0);
2985                        diffcore_count_changes(options->repo,
2986                                               p->one, p->two, NULL, NULL,
2987                                               &copied, &added);
2988                        diff_free_filespec_data(p->one);
2989                        diff_free_filespec_data(p->two);
2990                } else if (DIFF_FILE_VALID(p->one)) {
2991                        diff_populate_filespec(options->repo, p->one, CHECK_SIZE_ONLY);
2992                        copied = added = 0;
2993                        diff_free_filespec_data(p->one);
2994                } else if (DIFF_FILE_VALID(p->two)) {
2995                        diff_populate_filespec(options->repo, p->two, CHECK_SIZE_ONLY);
2996                        copied = 0;
2997                        added = p->two->size;
2998                        diff_free_filespec_data(p->two);
2999                } else
3000                        continue;
3001
3002                /*
3003                 * Original minus copied is the removed material,
3004                 * added is the new material.  They are both damages
3005                 * made to the preimage.
3006                 * If the resulting damage is zero, we know that
3007                 * diffcore_count_changes() considers the two entries to
3008                 * be identical, but since the oid changed, we
3009                 * know that there must have been _some_ kind of change,
3010                 * so we force all entries to have damage > 0.
3011                 */
3012                damage = (p->one->size - copied) + added;
3013                if (!damage)
3014                        damage = 1;
3015
3016found_damage:
3017                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
3018                dir.files[dir.nr].name = name;
3019                dir.files[dir.nr].changed = damage;
3020                changed += damage;
3021                dir.nr++;
3022        }
3023
3024        /* This can happen even with many files, if everything was renames */
3025        if (!changed)
3026                return;
3027
3028        /* Show all directories with more than x% of the changes */
3029        QSORT(dir.files, dir.nr, dirstat_compare);
3030        gather_dirstat(options, &dir, changed, "", 0);
3031}
3032
3033static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
3034{
3035        int i;
3036        unsigned long changed;
3037        struct dirstat_dir dir;
3038
3039        if (data->nr == 0)
3040                return;
3041
3042        dir.files = NULL;
3043        dir.alloc = 0;
3044        dir.nr = 0;
3045        dir.permille = options->dirstat_permille;
3046        dir.cumulative = options->flags.dirstat_cumulative;
3047
3048        changed = 0;
3049        for (i = 0; i < data->nr; i++) {
3050                struct diffstat_file *file = data->files[i];
3051                unsigned long damage = file->added + file->deleted;
3052                if (file->is_binary)
3053                        /*
3054                         * binary files counts bytes, not lines. Must find some
3055                         * way to normalize binary bytes vs. textual lines.
3056                         * The following heuristic assumes that there are 64
3057                         * bytes per "line".
3058                         * This is stupid and ugly, but very cheap...
3059                         */
3060                        damage = DIV_ROUND_UP(damage, 64);
3061                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
3062                dir.files[dir.nr].name = file->name;
3063                dir.files[dir.nr].changed = damage;
3064                changed += damage;
3065                dir.nr++;
3066        }
3067
3068        /* This can happen even with many files, if everything was renames */
3069        if (!changed)
3070                return;
3071
3072        /* Show all directories with more than x% of the changes */
3073        QSORT(dir.files, dir.nr, dirstat_compare);
3074        gather_dirstat(options, &dir, changed, "", 0);
3075}
3076
3077static void free_diffstat_info(struct diffstat_t *diffstat)
3078{
3079        int i;
3080        for (i = 0; i < diffstat->nr; i++) {
3081                struct diffstat_file *f = diffstat->files[i];
3082                free(f->print_name);
3083                free(f->name);
3084                free(f->from_name);
3085                free(f);
3086        }
3087        free(diffstat->files);
3088}
3089
3090struct checkdiff_t {
3091        const char *filename;
3092        int lineno;
3093        int conflict_marker_size;
3094        struct diff_options *o;
3095        unsigned ws_rule;
3096        unsigned status;
3097};
3098
3099static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
3100{
3101        char firstchar;
3102        int cnt;
3103
3104        if (len < marker_size + 1)
3105                return 0;
3106        firstchar = line[0];
3107        switch (firstchar) {
3108        case '=': case '>': case '<': case '|':
3109                break;
3110        default:
3111                return 0;
3112        }
3113        for (cnt = 1; cnt < marker_size; cnt++)
3114                if (line[cnt] != firstchar)
3115                        return 0;
3116        /* line[1] thru line[marker_size-1] are same as firstchar */
3117        if (len < marker_size + 1 || !isspace(line[marker_size]))
3118                return 0;
3119        return 1;
3120}
3121
3122static void checkdiff_consume(void *priv, char *line, unsigned long len)
3123{
3124        struct checkdiff_t *data = priv;
3125        int marker_size = data->conflict_marker_size;
3126        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
3127        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
3128        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
3129        char *err;
3130        const char *line_prefix;
3131
3132        assert(data->o);
3133        line_prefix = diff_line_prefix(data->o);
3134
3135        if (line[0] == '+') {
3136                unsigned bad;
3137                data->lineno++;
3138                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
3139                        data->status |= 1;
3140                        fprintf(data->o->file,
3141                                "%s%s:%d: leftover conflict marker\n",
3142                                line_prefix, data->filename, data->lineno);
3143                }
3144                bad = ws_check(line + 1, len - 1, data->ws_rule);
3145                if (!bad)
3146                        return;
3147                data->status |= bad;
3148                err = whitespace_error_string(bad);
3149                fprintf(data->o->file, "%s%s:%d: %s.\n",
3150                        line_prefix, data->filename, data->lineno, err);
3151                free(err);
3152                emit_line(data->o, set, reset, line, 1);
3153                ws_check_emit(line + 1, len - 1, data->ws_rule,
3154                              data->o->file, set, reset, ws);
3155        } else if (line[0] == ' ') {
3156                data->lineno++;
3157        } else if (line[0] == '@') {
3158                char *plus = strchr(line, '+');
3159                if (plus)
3160                        data->lineno = strtol(plus, NULL, 10) - 1;
3161                else
3162                        die("invalid diff");
3163        }
3164}
3165
3166static unsigned char *deflate_it(char *data,
3167                                 unsigned long size,
3168                                 unsigned long *result_size)
3169{
3170        int bound;
3171        unsigned char *deflated;
3172        git_zstream stream;
3173
3174        git_deflate_init(&stream, zlib_compression_level);
3175        bound = git_deflate_bound(&stream, size);
3176        deflated = xmalloc(bound);
3177        stream.next_out = deflated;
3178        stream.avail_out = bound;
3179
3180        stream.next_in = (unsigned char *)data;
3181        stream.avail_in = size;
3182        while (git_deflate(&stream, Z_FINISH) == Z_OK)
3183                ; /* nothing */
3184        git_deflate_end(&stream);
3185        *result_size = stream.total_out;
3186        return deflated;
3187}
3188
3189static void emit_binary_diff_body(struct diff_options *o,
3190                                  mmfile_t *one, mmfile_t *two)
3191{
3192        void *cp;
3193        void *delta;
3194        void *deflated;
3195        void *data;
3196        unsigned long orig_size;
3197        unsigned long delta_size;
3198        unsigned long deflate_size;
3199        unsigned long data_size;
3200
3201        /* We could do deflated delta, or we could do just deflated two,
3202         * whichever is smaller.
3203         */
3204        delta = NULL;
3205        deflated = deflate_it(two->ptr, two->size, &deflate_size);
3206        if (one->size && two->size) {
3207                delta = diff_delta(one->ptr, one->size,
3208                                   two->ptr, two->size,
3209                                   &delta_size, deflate_size);
3210                if (delta) {
3211                        void *to_free = delta;
3212                        orig_size = delta_size;
3213                        delta = deflate_it(delta, delta_size, &delta_size);
3214                        free(to_free);
3215                }
3216        }
3217
3218        if (delta && delta_size < deflate_size) {
3219                char *s = xstrfmt("%lu", orig_size);
3220                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
3221                                 s, strlen(s), 0);
3222                free(s);
3223                free(deflated);
3224                data = delta;
3225                data_size = delta_size;
3226        } else {
3227                char *s = xstrfmt("%lu", two->size);
3228                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
3229                                 s, strlen(s), 0);
3230                free(s);
3231                free(delta);
3232                data = deflated;
3233                data_size = deflate_size;
3234        }
3235
3236        /* emit data encoded in base85 */
3237        cp = data;
3238        while (data_size) {
3239                int len;
3240                int bytes = (52 < data_size) ? 52 : data_size;
3241                char line[71];
3242                data_size -= bytes;
3243                if (bytes <= 26)
3244                        line[0] = bytes + 'A' - 1;
3245                else
3246                        line[0] = bytes - 26 + 'a' - 1;
3247                encode_85(line + 1, cp, bytes);
3248                cp = (char *) cp + bytes;
3249
3250                len = strlen(line);
3251                line[len++] = '\n';
3252                line[len] = '\0';
3253
3254                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_BODY,
3255                                 line, len, 0);
3256        }
3257        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_FOOTER, NULL, 0, 0);
3258        free(data);
3259}
3260
3261static void emit_binary_diff(struct diff_options *o,
3262                             mmfile_t *one, mmfile_t *two)
3263{
3264        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER, NULL, 0, 0);
3265        emit_binary_diff_body(o, one, two);
3266        emit_binary_diff_body(o, two, one);
3267}
3268
3269int diff_filespec_is_binary(struct repository *r,
3270                            struct diff_filespec *one)
3271{
3272        if (one->is_binary == -1) {
3273                diff_filespec_load_driver(one, r->index);
3274                if (one->driver->binary != -1)
3275                        one->is_binary = one->driver->binary;
3276                else {
3277                        if (!one->data && DIFF_FILE_VALID(one))
3278                                diff_populate_filespec(r, one, CHECK_BINARY);
3279                        if (one->is_binary == -1 && one->data)
3280                                one->is_binary = buffer_is_binary(one->data,
3281                                                one->size);
3282                        if (one->is_binary == -1)
3283                                one->is_binary = 0;
3284                }
3285        }
3286        return one->is_binary;
3287}
3288
3289static const struct userdiff_funcname *
3290diff_funcname_pattern(struct diff_options *o, struct diff_filespec *one)
3291{
3292        diff_filespec_load_driver(one, o->repo->index);
3293        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
3294}
3295
3296void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
3297{
3298        if (!options->a_prefix)
3299                options->a_prefix = a;
3300        if (!options->b_prefix)
3301                options->b_prefix = b;
3302}
3303
3304struct userdiff_driver *get_textconv(struct index_state *istate,
3305                                     struct diff_filespec *one)
3306{
3307        if (!DIFF_FILE_VALID(one))
3308                return NULL;
3309
3310        diff_filespec_load_driver(one, istate);
3311        return userdiff_get_textconv(one->driver);
3312}
3313
3314static void builtin_diff(const char *name_a,
3315                         const char *name_b,
3316                         struct diff_filespec *one,
3317                         struct diff_filespec *two,
3318                         const char *xfrm_msg,
3319                         int must_show_header,
3320                         struct diff_options *o,
3321                         int complete_rewrite)
3322{
3323        mmfile_t mf1, mf2;
3324        const char *lbl[2];
3325        char *a_one, *b_two;
3326        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
3327        const char *reset = diff_get_color_opt(o, DIFF_RESET);
3328        const char *a_prefix, *b_prefix;
3329        struct userdiff_driver *textconv_one = NULL;
3330        struct userdiff_driver *textconv_two = NULL;
3331        struct strbuf header = STRBUF_INIT;
3332        const char *line_prefix = diff_line_prefix(o);
3333
3334        diff_set_mnemonic_prefix(o, "a/", "b/");
3335        if (o->flags.reverse_diff) {
3336                a_prefix = o->b_prefix;
3337                b_prefix = o->a_prefix;
3338        } else {
3339                a_prefix = o->a_prefix;
3340                b_prefix = o->b_prefix;
3341        }
3342
3343        if (o->submodule_format == DIFF_SUBMODULE_LOG &&
3344            (!one->mode || S_ISGITLINK(one->mode)) &&
3345            (!two->mode || S_ISGITLINK(two->mode))) {
3346                show_submodule_summary(o, one->path ? one->path : two->path,
3347                                &one->oid, &two->oid,
3348                                two->dirty_submodule);
3349                return;
3350        } else if (o->submodule_format == DIFF_SUBMODULE_INLINE_DIFF &&
3351                   (!one->mode || S_ISGITLINK(one->mode)) &&
3352                   (!two->mode || S_ISGITLINK(two->mode))) {
3353                show_submodule_inline_diff(o, one->path ? one->path : two->path,
3354                                &one->oid, &two->oid,
3355                                two->dirty_submodule);
3356                return;
3357        }
3358
3359        if (o->flags.allow_textconv) {
3360                textconv_one = get_textconv(o->repo->index, one);
3361                textconv_two = get_textconv(o->repo->index, two);
3362        }
3363
3364        /* Never use a non-valid filename anywhere if at all possible */
3365        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
3366        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
3367
3368        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
3369        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
3370        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
3371        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
3372        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
3373        if (lbl[0][0] == '/') {
3374                /* /dev/null */
3375                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
3376                if (xfrm_msg)
3377                        strbuf_addstr(&header, xfrm_msg);
3378                must_show_header = 1;
3379        }
3380        else if (lbl[1][0] == '/') {
3381                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
3382                if (xfrm_msg)
3383                        strbuf_addstr(&header, xfrm_msg);
3384                must_show_header = 1;
3385        }
3386        else {
3387                if (one->mode != two->mode) {
3388                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
3389                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
3390                        must_show_header = 1;
3391                }
3392                if (xfrm_msg)
3393                        strbuf_addstr(&header, xfrm_msg);
3394
3395                /*
3396                 * we do not run diff between different kind
3397                 * of objects.
3398                 */
3399                if ((one->mode ^ two->mode) & S_IFMT)
3400                        goto free_ab_and_return;
3401                if (complete_rewrite &&
3402                    (textconv_one || !diff_filespec_is_binary(o->repo, one)) &&
3403                    (textconv_two || !diff_filespec_is_binary(o->repo, two))) {
3404                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3405                                         header.buf, header.len, 0);
3406                        strbuf_reset(&header);
3407                        emit_rewrite_diff(name_a, name_b, one, two,
3408                                          textconv_one, textconv_two, o);
3409                        o->found_changes = 1;
3410                        goto free_ab_and_return;
3411                }
3412        }
3413
3414        if (o->irreversible_delete && lbl[1][0] == '/') {
3415                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf,
3416                                 header.len, 0);
3417                strbuf_reset(&header);
3418                goto free_ab_and_return;
3419        } else if (!o->flags.text &&
3420                   ( (!textconv_one && diff_filespec_is_binary(o->repo, one)) ||
3421                     (!textconv_two && diff_filespec_is_binary(o->repo, two)) )) {
3422                struct strbuf sb = STRBUF_INIT;
3423                if (!one->data && !two->data &&
3424                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
3425                    !o->flags.binary) {
3426                        if (oideq(&one->oid, &two->oid)) {
3427                                if (must_show_header)
3428                                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3429                                                         header.buf, header.len,
3430                                                         0);
3431                                goto free_ab_and_return;
3432                        }
3433                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3434                                         header.buf, header.len, 0);
3435                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3436                                    diff_line_prefix(o), lbl[0], lbl[1]);
3437                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3438                                         sb.buf, sb.len, 0);
3439                        strbuf_release(&sb);
3440                        goto free_ab_and_return;
3441                }
3442                if (fill_mmfile(o->repo, &mf1, one) < 0 ||
3443                    fill_mmfile(o->repo, &mf2, two) < 0)
3444                        die("unable to read files to diff");
3445                /* Quite common confusing case */
3446                if (mf1.size == mf2.size &&
3447                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
3448                        if (must_show_header)
3449                                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3450                                                 header.buf, header.len, 0);
3451                        goto free_ab_and_return;
3452                }
3453                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf, header.len, 0);
3454                strbuf_reset(&header);
3455                if (o->flags.binary)
3456                        emit_binary_diff(o, &mf1, &mf2);
3457                else {
3458                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3459                                    diff_line_prefix(o), lbl[0], lbl[1]);
3460                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3461                                         sb.buf, sb.len, 0);
3462                        strbuf_release(&sb);
3463                }
3464                o->found_changes = 1;
3465        } else {
3466                /* Crazy xdl interfaces.. */
3467                const char *diffopts = getenv("GIT_DIFF_OPTS");
3468                const char *v;
3469                xpparam_t xpp;
3470                xdemitconf_t xecfg;
3471                struct emit_callback ecbdata;
3472                const struct userdiff_funcname *pe;
3473
3474                if (must_show_header) {
3475                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3476                                         header.buf, header.len, 0);
3477                        strbuf_reset(&header);
3478                }
3479
3480                mf1.size = fill_textconv(o->repo, textconv_one, one, &mf1.ptr);
3481                mf2.size = fill_textconv(o->repo, textconv_two, two, &mf2.ptr);
3482
3483                pe = diff_funcname_pattern(o, one);
3484                if (!pe)
3485                        pe = diff_funcname_pattern(o, two);
3486
3487                memset(&xpp, 0, sizeof(xpp));
3488                memset(&xecfg, 0, sizeof(xecfg));
3489                memset(&ecbdata, 0, sizeof(ecbdata));
3490                if (o->flags.suppress_diff_headers)
3491                        lbl[0] = NULL;
3492                ecbdata.label_path = lbl;
3493                ecbdata.color_diff = want_color(o->use_color);
3494                ecbdata.ws_rule = whitespace_rule(o->repo->index, name_b);
3495                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
3496                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3497                ecbdata.opt = o;
3498                if (header.len && !o->flags.suppress_diff_headers)
3499                        ecbdata.header = &header;
3500                xpp.flags = o->xdl_opts;
3501                xpp.anchors = o->anchors;
3502                xpp.anchors_nr = o->anchors_nr;
3503                xecfg.ctxlen = o->context;
3504                xecfg.interhunkctxlen = o->interhunkcontext;
3505                xecfg.flags = XDL_EMIT_FUNCNAMES;
3506                if (o->flags.funccontext)
3507                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
3508                if (pe)
3509                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
3510                if (!diffopts)
3511                        ;
3512                else if (skip_prefix(diffopts, "--unified=", &v))
3513                        xecfg.ctxlen = strtoul(v, NULL, 10);
3514                else if (skip_prefix(diffopts, "-u", &v))
3515                        xecfg.ctxlen = strtoul(v, NULL, 10);
3516                if (o->word_diff)
3517                        init_diff_words_data(&ecbdata, o, one, two);
3518                if (xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
3519                                  &xpp, &xecfg))
3520                        die("unable to generate diff for %s", one->path);
3521                if (o->word_diff)
3522                        free_diff_words_data(&ecbdata);
3523                if (textconv_one)
3524                        free(mf1.ptr);
3525                if (textconv_two)
3526                        free(mf2.ptr);
3527                xdiff_clear_find_func(&xecfg);
3528        }
3529
3530 free_ab_and_return:
3531        strbuf_release(&header);
3532        diff_free_filespec_data(one);
3533        diff_free_filespec_data(two);
3534        free(a_one);
3535        free(b_two);
3536        return;
3537}
3538
3539static char *get_compact_summary(const struct diff_filepair *p, int is_renamed)
3540{
3541        if (!is_renamed) {
3542                if (p->status == DIFF_STATUS_ADDED) {
3543                        if (S_ISLNK(p->two->mode))
3544                                return "new +l";
3545                        else if ((p->two->mode & 0777) == 0755)
3546                                return "new +x";
3547                        else
3548                                return "new";
3549                } else if (p->status == DIFF_STATUS_DELETED)
3550                        return "gone";
3551        }
3552        if (S_ISLNK(p->one->mode) && !S_ISLNK(p->two->mode))
3553                return "mode -l";
3554        else if (!S_ISLNK(p->one->mode) && S_ISLNK(p->two->mode))
3555                return "mode +l";
3556        else if ((p->one->mode & 0777) == 0644 &&
3557                 (p->two->mode & 0777) == 0755)
3558                return "mode +x";
3559        else if ((p->one->mode & 0777) == 0755 &&
3560                 (p->two->mode & 0777) == 0644)
3561                return "mode -x";
3562        return NULL;
3563}
3564
3565static void builtin_diffstat(const char *name_a, const char *name_b,
3566                             struct diff_filespec *one,
3567                             struct diff_filespec *two,
3568                             struct diffstat_t *diffstat,
3569                             struct diff_options *o,
3570                             struct diff_filepair *p)
3571{
3572        mmfile_t mf1, mf2;
3573        struct diffstat_file *data;
3574        int same_contents;
3575        int complete_rewrite = 0;
3576
3577        if (!DIFF_PAIR_UNMERGED(p)) {
3578                if (p->status == DIFF_STATUS_MODIFIED && p->score)
3579                        complete_rewrite = 1;
3580        }
3581
3582        data = diffstat_add(diffstat, name_a, name_b);
3583        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
3584        if (o->flags.stat_with_summary)
3585                data->comments = get_compact_summary(p, data->is_renamed);
3586
3587        if (!one || !two) {
3588                data->is_unmerged = 1;
3589                return;
3590        }
3591
3592        same_contents = oideq(&one->oid, &two->oid);
3593
3594        if (diff_filespec_is_binary(o->repo, one) ||
3595            diff_filespec_is_binary(o->repo, two)) {
3596                data->is_binary = 1;
3597                if (same_contents) {
3598                        data->added = 0;
3599                        data->deleted = 0;
3600                } else {
3601                        data->added = diff_filespec_size(o->repo, two);
3602                        data->deleted = diff_filespec_size(o->repo, one);
3603                }
3604        }
3605
3606        else if (complete_rewrite) {
3607                diff_populate_filespec(o->repo, one, 0);
3608                diff_populate_filespec(o->repo, two, 0);
3609                data->deleted = count_lines(one->data, one->size);
3610                data->added = count_lines(two->data, two->size);
3611        }
3612
3613        else if (!same_contents) {
3614                /* Crazy xdl interfaces.. */
3615                xpparam_t xpp;
3616                xdemitconf_t xecfg;
3617
3618                if (fill_mmfile(o->repo, &mf1, one) < 0 ||
3619                    fill_mmfile(o->repo, &mf2, two) < 0)
3620                        die("unable to read files to diff");
3621
3622                memset(&xpp, 0, sizeof(xpp));
3623                memset(&xecfg, 0, sizeof(xecfg));
3624                xpp.flags = o->xdl_opts;
3625                xpp.anchors = o->anchors;
3626                xpp.anchors_nr = o->anchors_nr;
3627                xecfg.ctxlen = o->context;
3628                xecfg.interhunkctxlen = o->interhunkcontext;
3629                if (xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
3630                                  &xpp, &xecfg))
3631                        die("unable to generate diffstat for %s", one->path);
3632        }
3633
3634        diff_free_filespec_data(one);
3635        diff_free_filespec_data(two);
3636}
3637
3638static void builtin_checkdiff(const char *name_a, const char *name_b,
3639                              const char *attr_path,
3640                              struct diff_filespec *one,
3641                              struct diff_filespec *two,
3642                              struct diff_options *o)
3643{
3644        mmfile_t mf1, mf2;
3645        struct checkdiff_t data;
3646
3647        if (!two)
3648                return;
3649
3650        memset(&data, 0, sizeof(data));
3651        data.filename = name_b ? name_b : name_a;
3652        data.lineno = 0;
3653        data.o = o;
3654        data.ws_rule = whitespace_rule(o->repo->index, attr_path);
3655        data.conflict_marker_size = ll_merge_marker_size(o->repo->index, attr_path);
3656
3657        if (fill_mmfile(o->repo, &mf1, one) < 0 ||
3658            fill_mmfile(o->repo, &mf2, two) < 0)
3659                die("unable to read files to diff");
3660
3661        /*
3662         * All the other codepaths check both sides, but not checking
3663         * the "old" side here is deliberate.  We are checking the newly
3664         * introduced changes, and as long as the "new" side is text, we
3665         * can and should check what it introduces.
3666         */
3667        if (diff_filespec_is_binary(o->repo, two))
3668                goto free_and_return;
3669        else {
3670                /* Crazy xdl interfaces.. */
3671                xpparam_t xpp;
3672                xdemitconf_t xecfg;
3673
3674                memset(&xpp, 0, sizeof(xpp));
3675                memset(&xecfg, 0, sizeof(xecfg));
3676                xecfg.ctxlen = 1; /* at least one context line */
3677                xpp.flags = 0;
3678                if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
3679                                  &xpp, &xecfg))
3680                        die("unable to generate checkdiff for %s", one->path);
3681
3682                if (data.ws_rule & WS_BLANK_AT_EOF) {
3683                        struct emit_callback ecbdata;
3684                        int blank_at_eof;
3685
3686                        ecbdata.ws_rule = data.ws_rule;
3687                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3688                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
3689
3690                        if (blank_at_eof) {
3691                                static char *err;
3692                                if (!err)
3693                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
3694                                fprintf(o->file, "%s:%d: %s.\n",
3695                                        data.filename, blank_at_eof, err);
3696                                data.status = 1; /* report errors */
3697                        }
3698                }
3699        }
3700 free_and_return:
3701        diff_free_filespec_data(one);
3702        diff_free_filespec_data(two);
3703        if (data.status)
3704                o->flags.check_failed = 1;
3705}
3706
3707struct diff_filespec *alloc_filespec(const char *path)
3708{
3709        struct diff_filespec *spec;
3710
3711        FLEXPTR_ALLOC_STR(spec, path, path);
3712        spec->count = 1;
3713        spec->is_binary = -1;
3714        return spec;
3715}
3716
3717void free_filespec(struct diff_filespec *spec)
3718{
3719        if (!--spec->count) {
3720                diff_free_filespec_data(spec);
3721                free(spec);
3722        }
3723}
3724
3725void fill_filespec(struct diff_filespec *spec, const struct object_id *oid,
3726                   int oid_valid, unsigned short mode)
3727{
3728        if (mode) {
3729                spec->mode = canon_mode(mode);
3730                oidcpy(&spec->oid, oid);
3731                spec->oid_valid = oid_valid;
3732        }
3733}
3734
3735/*
3736 * Given a name and sha1 pair, if the index tells us the file in
3737 * the work tree has that object contents, return true, so that
3738 * prepare_temp_file() does not have to inflate and extract.
3739 */
3740static int reuse_worktree_file(struct index_state *istate,
3741                               const char *name,
3742                               const struct object_id *oid,
3743                               int want_file)
3744{
3745        const struct cache_entry *ce;
3746        struct stat st;
3747        int pos, len;
3748
3749        /*
3750         * We do not read the cache ourselves here, because the
3751         * benchmark with my previous version that always reads cache
3752         * shows that it makes things worse for diff-tree comparing
3753         * two linux-2.6 kernel trees in an already checked out work
3754         * tree.  This is because most diff-tree comparisons deal with
3755         * only a small number of files, while reading the cache is
3756         * expensive for a large project, and its cost outweighs the
3757         * savings we get by not inflating the object to a temporary
3758         * file.  Practically, this code only helps when we are used
3759         * by diff-cache --cached, which does read the cache before
3760         * calling us.
3761         */
3762        if (!istate->cache)
3763                return 0;
3764
3765        /* We want to avoid the working directory if our caller
3766         * doesn't need the data in a normal file, this system
3767         * is rather slow with its stat/open/mmap/close syscalls,
3768         * and the object is contained in a pack file.  The pack
3769         * is probably already open and will be faster to obtain
3770         * the data through than the working directory.  Loose
3771         * objects however would tend to be slower as they need
3772         * to be individually opened and inflated.
3773         */
3774        if (!FAST_WORKING_DIRECTORY && !want_file && has_object_pack(oid))
3775                return 0;
3776
3777        /*
3778         * Similarly, if we'd have to convert the file contents anyway, that
3779         * makes the optimization not worthwhile.
3780         */
3781        if (!want_file && would_convert_to_git(istate, name))
3782                return 0;
3783
3784        len = strlen(name);
3785        pos = index_name_pos(istate, name, len);
3786        if (pos < 0)
3787                return 0;
3788        ce = istate->cache[pos];
3789
3790        /*
3791         * This is not the sha1 we are looking for, or
3792         * unreusable because it is not a regular file.
3793         */
3794        if (!oideq(oid, &ce->oid) || !S_ISREG(ce->ce_mode))
3795                return 0;
3796
3797        /*
3798         * If ce is marked as "assume unchanged", there is no
3799         * guarantee that work tree matches what we are looking for.
3800         */
3801        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
3802                return 0;
3803
3804        /*
3805         * If ce matches the file in the work tree, we can reuse it.
3806         */
3807        if (ce_uptodate(ce) ||
3808            (!lstat(name, &st) && !ie_match_stat(istate, ce, &st, 0)))
3809                return 1;
3810
3811        return 0;
3812}
3813
3814static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
3815{
3816        struct strbuf buf = STRBUF_INIT;
3817        char *dirty = "";
3818
3819        /* Are we looking at the work tree? */
3820        if (s->dirty_submodule)
3821                dirty = "-dirty";
3822
3823        strbuf_addf(&buf, "Subproject commit %s%s\n",
3824                    oid_to_hex(&s->oid), dirty);
3825        s->size = buf.len;
3826        if (size_only) {
3827                s->data = NULL;
3828                strbuf_release(&buf);
3829        } else {
3830                s->data = strbuf_detach(&buf, NULL);
3831                s->should_free = 1;
3832        }
3833        return 0;
3834}
3835
3836/*
3837 * While doing rename detection and pickaxe operation, we may need to
3838 * grab the data for the blob (or file) for our own in-core comparison.
3839 * diff_filespec has data and size fields for this purpose.
3840 */
3841int diff_populate_filespec(struct repository *r,
3842                           struct diff_filespec *s,
3843                           unsigned int flags)
3844{
3845        int size_only = flags & CHECK_SIZE_ONLY;
3846        int err = 0;
3847        int conv_flags = global_conv_flags_eol;
3848        /*
3849         * demote FAIL to WARN to allow inspecting the situation
3850         * instead of refusing.
3851         */
3852        if (conv_flags & CONV_EOL_RNDTRP_DIE)
3853                conv_flags = CONV_EOL_RNDTRP_WARN;
3854
3855        if (!DIFF_FILE_VALID(s))
3856                die("internal error: asking to populate invalid file.");
3857        if (S_ISDIR(s->mode))
3858                return -1;
3859
3860        if (s->data)
3861                return 0;
3862
3863        if (size_only && 0 < s->size)
3864                return 0;
3865
3866        if (S_ISGITLINK(s->mode))
3867                return diff_populate_gitlink(s, size_only);
3868
3869        if (!s->oid_valid ||
3870            reuse_worktree_file(r->index, s->path, &s->oid, 0)) {
3871                struct strbuf buf = STRBUF_INIT;
3872                struct stat st;
3873                int fd;
3874
3875                if (lstat(s->path, &st) < 0) {
3876                err_empty:
3877                        err = -1;
3878                empty:
3879                        s->data = (char *)"";
3880                        s->size = 0;
3881                        return err;
3882                }
3883                s->size = xsize_t(st.st_size);
3884                if (!s->size)
3885                        goto empty;
3886                if (S_ISLNK(st.st_mode)) {
3887                        struct strbuf sb = STRBUF_INIT;
3888
3889                        if (strbuf_readlink(&sb, s->path, s->size))
3890                                goto err_empty;
3891                        s->size = sb.len;
3892                        s->data = strbuf_detach(&sb, NULL);
3893                        s->should_free = 1;
3894                        return 0;
3895                }
3896
3897                /*
3898                 * Even if the caller would be happy with getting
3899                 * only the size, we cannot return early at this
3900                 * point if the path requires us to run the content
3901                 * conversion.
3902                 */
3903                if (size_only && !would_convert_to_git(r->index, s->path))
3904                        return 0;
3905
3906                /*
3907                 * Note: this check uses xsize_t(st.st_size) that may
3908                 * not be the true size of the blob after it goes
3909                 * through convert_to_git().  This may not strictly be
3910                 * correct, but the whole point of big_file_threshold
3911                 * and is_binary check being that we want to avoid
3912                 * opening the file and inspecting the contents, this
3913                 * is probably fine.
3914                 */
3915                if ((flags & CHECK_BINARY) &&
3916                    s->size > big_file_threshold && s->is_binary == -1) {
3917                        s->is_binary = 1;
3918                        return 0;
3919                }
3920                fd = open(s->path, O_RDONLY);
3921                if (fd < 0)
3922                        goto err_empty;
3923                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
3924                close(fd);
3925                s->should_munmap = 1;
3926
3927                /*
3928                 * Convert from working tree format to canonical git format
3929                 */
3930                if (convert_to_git(r->index, s->path, s->data, s->size, &buf, conv_flags)) {
3931                        size_t size = 0;
3932                        munmap(s->data, s->size);
3933                        s->should_munmap = 0;
3934                        s->data = strbuf_detach(&buf, &size);
3935                        s->size = size;
3936                        s->should_free = 1;
3937                }
3938        }
3939        else {
3940                enum object_type type;
3941                if (size_only || (flags & CHECK_BINARY)) {
3942                        type = oid_object_info(r, &s->oid, &s->size);
3943                        if (type < 0)
3944                                die("unable to read %s",
3945                                    oid_to_hex(&s->oid));
3946                        if (size_only)
3947                                return 0;
3948                        if (s->size > big_file_threshold && s->is_binary == -1) {
3949                                s->is_binary = 1;
3950                                return 0;
3951                        }
3952                }
3953                s->data = read_object_file(&s->oid, &type, &s->size);
3954                if (!s->data)
3955                        die("unable to read %s", oid_to_hex(&s->oid));
3956                s->should_free = 1;
3957        }
3958        return 0;
3959}
3960
3961void diff_free_filespec_blob(struct diff_filespec *s)
3962{
3963        if (s->should_free)
3964                free(s->data);
3965        else if (s->should_munmap)
3966                munmap(s->data, s->size);
3967
3968        if (s->should_free || s->should_munmap) {
3969                s->should_free = s->should_munmap = 0;
3970                s->data = NULL;
3971        }
3972}
3973
3974void diff_free_filespec_data(struct diff_filespec *s)
3975{
3976        diff_free_filespec_blob(s);
3977        FREE_AND_NULL(s->cnt_data);
3978}
3979
3980static void prep_temp_blob(struct index_state *istate,
3981                           const char *path, struct diff_tempfile *temp,
3982                           void *blob,
3983                           unsigned long size,
3984                           const struct object_id *oid,
3985                           int mode)
3986{
3987        struct strbuf buf = STRBUF_INIT;
3988        struct strbuf tempfile = STRBUF_INIT;
3989        char *path_dup = xstrdup(path);
3990        const char *base = basename(path_dup);
3991
3992        /* Generate "XXXXXX_basename.ext" */
3993        strbuf_addstr(&tempfile, "XXXXXX_");
3994        strbuf_addstr(&tempfile, base);
3995
3996        temp->tempfile = mks_tempfile_ts(tempfile.buf, strlen(base) + 1);
3997        if (!temp->tempfile)
3998                die_errno("unable to create temp-file");
3999        if (convert_to_working_tree(istate, path,
4000                        (const char *)blob, (size_t)size, &buf)) {
4001                blob = buf.buf;
4002                size = buf.len;
4003        }
4004        if (write_in_full(temp->tempfile->fd, blob, size) < 0 ||
4005            close_tempfile_gently(temp->tempfile))
4006                die_errno("unable to write temp-file");
4007        temp->name = get_tempfile_path(temp->tempfile);
4008        oid_to_hex_r(temp->hex, oid);
4009        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
4010        strbuf_release(&buf);
4011        strbuf_release(&tempfile);
4012        free(path_dup);
4013}
4014
4015static struct diff_tempfile *prepare_temp_file(struct repository *r,
4016                                               const char *name,
4017                                               struct diff_filespec *one)
4018{
4019        struct diff_tempfile *temp = claim_diff_tempfile();
4020
4021        if (!DIFF_FILE_VALID(one)) {
4022        not_a_valid_file:
4023                /* A '-' entry produces this for file-2, and
4024                 * a '+' entry produces this for file-1.
4025                 */
4026                temp->name = "/dev/null";
4027                xsnprintf(temp->hex, sizeof(temp->hex), ".");
4028                xsnprintf(temp->mode, sizeof(temp->mode), ".");
4029                return temp;
4030        }
4031
4032        if (!S_ISGITLINK(one->mode) &&
4033            (!one->oid_valid ||
4034             reuse_worktree_file(r->index, name, &one->oid, 1))) {
4035                struct stat st;
4036                if (lstat(name, &st) < 0) {
4037                        if (errno == ENOENT)
4038                                goto not_a_valid_file;
4039                        die_errno("stat(%s)", name);
4040                }
4041                if (S_ISLNK(st.st_mode)) {
4042                        struct strbuf sb = STRBUF_INIT;
4043                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
4044                                die_errno("readlink(%s)", name);
4045                        prep_temp_blob(r->index, name, temp, sb.buf, sb.len,
4046                                       (one->oid_valid ?
4047                                        &one->oid : &null_oid),
4048                                       (one->oid_valid ?
4049                                        one->mode : S_IFLNK));
4050                        strbuf_release(&sb);
4051                }
4052                else {
4053                        /* we can borrow from the file in the work tree */
4054                        temp->name = name;
4055                        if (!one->oid_valid)
4056                                oid_to_hex_r(temp->hex, &null_oid);
4057                        else
4058                                oid_to_hex_r(temp->hex, &one->oid);
4059                        /* Even though we may sometimes borrow the
4060                         * contents from the work tree, we always want
4061                         * one->mode.  mode is trustworthy even when
4062                         * !(one->oid_valid), as long as
4063                         * DIFF_FILE_VALID(one).
4064                         */
4065                        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
4066                }
4067                return temp;
4068        }
4069        else {
4070                if (diff_populate_filespec(r, one, 0))
4071                        die("cannot read data blob for %s", one->path);
4072                prep_temp_blob(r->index, name, temp,
4073                               one->data, one->size,
4074                               &one->oid, one->mode);
4075        }
4076        return temp;
4077}
4078
4079static void add_external_diff_name(struct repository *r,
4080                                   struct argv_array *argv,
4081                                   const char *name,
4082                                   struct diff_filespec *df)
4083{
4084        struct diff_tempfile *temp = prepare_temp_file(r, name, df);
4085        argv_array_push(argv, temp->name);
4086        argv_array_push(argv, temp->hex);
4087        argv_array_push(argv, temp->mode);
4088}
4089
4090/* An external diff command takes:
4091 *
4092 * diff-cmd name infile1 infile1-sha1 infile1-mode \
4093 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
4094 *
4095 */
4096static void run_external_diff(const char *pgm,
4097                              const char *name,
4098                              const char *other,
4099                              struct diff_filespec *one,
4100                              struct diff_filespec *two,
4101                              const char *xfrm_msg,
4102                              int complete_rewrite,
4103                              struct diff_options *o)
4104{
4105        struct argv_array argv = ARGV_ARRAY_INIT;
4106        struct argv_array env = ARGV_ARRAY_INIT;
4107        struct diff_queue_struct *q = &diff_queued_diff;
4108
4109        argv_array_push(&argv, pgm);
4110        argv_array_push(&argv, name);
4111
4112        if (one && two) {
4113                add_external_diff_name(o->repo, &argv, name, one);
4114                if (!other)
4115                        add_external_diff_name(o->repo, &argv, name, two);
4116                else {
4117                        add_external_diff_name(o->repo, &argv, other, two);
4118                        argv_array_push(&argv, other);
4119                        argv_array_push(&argv, xfrm_msg);
4120                }
4121        }
4122
4123        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
4124        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
4125
4126        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
4127                die(_("external diff died, stopping at %s"), name);
4128
4129        remove_tempfile();
4130        argv_array_clear(&argv);
4131        argv_array_clear(&env);
4132}
4133
4134static int similarity_index(struct diff_filepair *p)
4135{
4136        return p->score * 100 / MAX_SCORE;
4137}
4138
4139static const char *diff_abbrev_oid(const struct object_id *oid, int abbrev)
4140{
4141        if (startup_info->have_repository)
4142                return find_unique_abbrev(oid, abbrev);
4143        else {
4144                char *hex = oid_to_hex(oid);
4145                if (abbrev < 0)
4146                        abbrev = FALLBACK_DEFAULT_ABBREV;
4147                if (abbrev > the_hash_algo->hexsz)
4148                        BUG("oid abbreviation out of range: %d", abbrev);
4149                if (abbrev)
4150                        hex[abbrev] = '\0';
4151                return hex;
4152        }
4153}
4154
4155static void fill_metainfo(struct strbuf *msg,
4156                          const char *name,
4157                          const char *other,
4158                          struct diff_filespec *one,
4159                          struct diff_filespec *two,
4160                          struct diff_options *o,
4161                          struct diff_filepair *p,
4162                          int *must_show_header,
4163                          int use_color)
4164{
4165        const char *set = diff_get_color(use_color, DIFF_METAINFO);
4166        const char *reset = diff_get_color(use_color, DIFF_RESET);
4167        const char *line_prefix = diff_line_prefix(o);
4168
4169        *must_show_header = 1;
4170        strbuf_init(msg, PATH_MAX * 2 + 300);
4171        switch (p->status) {
4172        case DIFF_STATUS_COPIED:
4173                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4174                            line_prefix, set, similarity_index(p));
4175                strbuf_addf(msg, "%s\n%s%scopy from ",
4176                            reset,  line_prefix, set);
4177                quote_c_style(name, msg, NULL, 0);
4178                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
4179                quote_c_style(other, msg, NULL, 0);
4180                strbuf_addf(msg, "%s\n", reset);
4181                break;
4182        case DIFF_STATUS_RENAMED:
4183                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4184                            line_prefix, set, similarity_index(p));
4185                strbuf_addf(msg, "%s\n%s%srename from ",
4186                            reset, line_prefix, set);
4187                quote_c_style(name, msg, NULL, 0);
4188                strbuf_addf(msg, "%s\n%s%srename to ",
4189                            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_MODIFIED:
4194                if (p->score) {
4195                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
4196                                    line_prefix,
4197                                    set, similarity_index(p), reset);
4198                        break;
4199                }
4200                /* fallthru */
4201        default:
4202                *must_show_header = 0;
4203        }
4204        if (one && two && !oideq(&one->oid, &two->oid)) {
4205                const unsigned hexsz = the_hash_algo->hexsz;
4206                int abbrev = o->flags.full_index ? hexsz : DEFAULT_ABBREV;
4207
4208                if (o->flags.binary) {
4209                        mmfile_t mf;
4210                        if ((!fill_mmfile(o->repo, &mf, one) &&
4211                             diff_filespec_is_binary(o->repo, one)) ||
4212                            (!fill_mmfile(o->repo, &mf, two) &&
4213                             diff_filespec_is_binary(o->repo, two)))
4214                                abbrev = hexsz;
4215                }
4216                strbuf_addf(msg, "%s%sindex %s..%s", line_prefix, set,
4217                            diff_abbrev_oid(&one->oid, abbrev),
4218                            diff_abbrev_oid(&two->oid, abbrev));
4219                if (one->mode == two->mode)
4220                        strbuf_addf(msg, " %06o", one->mode);
4221                strbuf_addf(msg, "%s\n", reset);
4222        }
4223}
4224
4225static void run_diff_cmd(const char *pgm,
4226                         const char *name,
4227                         const char *other,
4228                         const char *attr_path,
4229                         struct diff_filespec *one,
4230                         struct diff_filespec *two,
4231                         struct strbuf *msg,
4232                         struct diff_options *o,
4233                         struct diff_filepair *p)
4234{
4235        const char *xfrm_msg = NULL;
4236        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
4237        int must_show_header = 0;
4238
4239
4240        if (o->flags.allow_external) {
4241                struct userdiff_driver *drv;
4242
4243                drv = userdiff_find_by_path(o->repo->index, attr_path);
4244                if (drv && drv->external)
4245                        pgm = drv->external;
4246        }
4247
4248        if (msg) {
4249                /*
4250                 * don't use colors when the header is intended for an
4251                 * external diff driver
4252                 */
4253                fill_metainfo(msg, name, other, one, two, o, p,
4254                              &must_show_header,
4255                              want_color(o->use_color) && !pgm);
4256                xfrm_msg = msg->len ? msg->buf : NULL;
4257        }
4258
4259        if (pgm) {
4260                run_external_diff(pgm, name, other, one, two, xfrm_msg,
4261                                  complete_rewrite, o);
4262                return;
4263        }
4264        if (one && two)
4265                builtin_diff(name, other ? other : name,
4266                             one, two, xfrm_msg, must_show_header,
4267                             o, complete_rewrite);
4268        else
4269                fprintf(o->file, "* Unmerged path %s\n", name);
4270}
4271
4272static void diff_fill_oid_info(struct diff_filespec *one, struct index_state *istate)
4273{
4274        if (DIFF_FILE_VALID(one)) {
4275                if (!one->oid_valid) {
4276                        struct stat st;
4277                        if (one->is_stdin) {
4278                                oidclr(&one->oid);
4279                                return;
4280                        }
4281                        if (lstat(one->path, &st) < 0)
4282                                die_errno("stat '%s'", one->path);
4283                        if (index_path(istate, &one->oid, one->path, &st, 0))
4284                                die("cannot hash %s", one->path);
4285                }
4286        }
4287        else
4288                oidclr(&one->oid);
4289}
4290
4291static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
4292{
4293        /* Strip the prefix but do not molest /dev/null and absolute paths */
4294        if (*namep && **namep != '/') {
4295                *namep += prefix_length;
4296                if (**namep == '/')
4297                        ++*namep;
4298        }
4299        if (*otherp && **otherp != '/') {
4300                *otherp += prefix_length;
4301                if (**otherp == '/')
4302                        ++*otherp;
4303        }
4304}
4305
4306static void run_diff(struct diff_filepair *p, struct diff_options *o)
4307{
4308        const char *pgm = external_diff();
4309        struct strbuf msg;
4310        struct diff_filespec *one = p->one;
4311        struct diff_filespec *two = p->two;
4312        const char *name;
4313        const char *other;
4314        const char *attr_path;
4315
4316        name  = one->path;
4317        other = (strcmp(name, two->path) ? two->path : NULL);
4318        attr_path = name;
4319        if (o->prefix_length)
4320                strip_prefix(o->prefix_length, &name, &other);
4321
4322        if (!o->flags.allow_external)
4323                pgm = NULL;
4324
4325        if (DIFF_PAIR_UNMERGED(p)) {
4326                run_diff_cmd(pgm, name, NULL, attr_path,
4327                             NULL, NULL, NULL, o, p);
4328                return;
4329        }
4330
4331        diff_fill_oid_info(one, o->repo->index);
4332        diff_fill_oid_info(two, o->repo->index);
4333
4334        if (!pgm &&
4335            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
4336            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
4337                /*
4338                 * a filepair that changes between file and symlink
4339                 * needs to be split into deletion and creation.
4340                 */
4341                struct diff_filespec *null = alloc_filespec(two->path);
4342                run_diff_cmd(NULL, name, other, attr_path,
4343                             one, null, &msg,
4344                             o, p);
4345                free(null);
4346                strbuf_release(&msg);
4347
4348                null = alloc_filespec(one->path);
4349                run_diff_cmd(NULL, name, other, attr_path,
4350                             null, two, &msg, o, p);
4351                free(null);
4352        }
4353        else
4354                run_diff_cmd(pgm, name, other, attr_path,
4355                             one, two, &msg, o, p);
4356
4357        strbuf_release(&msg);
4358}
4359
4360static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
4361                         struct diffstat_t *diffstat)
4362{
4363        const char *name;
4364        const char *other;
4365
4366        if (DIFF_PAIR_UNMERGED(p)) {
4367                /* unmerged */
4368                builtin_diffstat(p->one->path, NULL, NULL, NULL,
4369                                 diffstat, o, p);
4370                return;
4371        }
4372
4373        name = p->one->path;
4374        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4375
4376        if (o->prefix_length)
4377                strip_prefix(o->prefix_length, &name, &other);
4378
4379        diff_fill_oid_info(p->one, o->repo->index);
4380        diff_fill_oid_info(p->two, o->repo->index);
4381
4382        builtin_diffstat(name, other, p->one, p->two,
4383                         diffstat, o, p);
4384}
4385
4386static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
4387{
4388        const char *name;
4389        const char *other;
4390        const char *attr_path;
4391
4392        if (DIFF_PAIR_UNMERGED(p)) {
4393                /* unmerged */
4394                return;
4395        }
4396
4397        name = p->one->path;
4398        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4399        attr_path = other ? other : name;
4400
4401        if (o->prefix_length)
4402                strip_prefix(o->prefix_length, &name, &other);
4403
4404        diff_fill_oid_info(p->one, o->repo->index);
4405        diff_fill_oid_info(p->two, o->repo->index);
4406
4407        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
4408}
4409
4410void repo_diff_setup(struct repository *r, struct diff_options *options)
4411{
4412        memcpy(options, &default_diff_options, sizeof(*options));
4413
4414        options->file = stdout;
4415        options->repo = r;
4416
4417        options->output_indicators[OUTPUT_INDICATOR_NEW] = '+';
4418        options->output_indicators[OUTPUT_INDICATOR_OLD] = '-';
4419        options->output_indicators[OUTPUT_INDICATOR_CONTEXT] = ' ';
4420        options->abbrev = DEFAULT_ABBREV;
4421        options->line_termination = '\n';
4422        options->break_opt = -1;
4423        options->rename_limit = -1;
4424        options->dirstat_permille = diff_dirstat_permille_default;
4425        options->context = diff_context_default;
4426        options->interhunkcontext = diff_interhunk_context_default;
4427        options->ws_error_highlight = ws_error_highlight_default;
4428        options->flags.rename_empty = 1;
4429        options->objfind = NULL;
4430
4431        /* pathchange left =NULL by default */
4432        options->change = diff_change;
4433        options->add_remove = diff_addremove;
4434        options->use_color = diff_use_color_default;
4435        options->detect_rename = diff_detect_rename_default;
4436        options->xdl_opts |= diff_algorithm;
4437        if (diff_indent_heuristic)
4438                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4439
4440        options->orderfile = diff_order_file_cfg;
4441
4442        if (diff_no_prefix) {
4443                options->a_prefix = options->b_prefix = "";
4444        } else if (!diff_mnemonic_prefix) {
4445                options->a_prefix = "a/";
4446                options->b_prefix = "b/";
4447        }
4448
4449        options->color_moved = diff_color_moved_default;
4450        options->color_moved_ws_handling = diff_color_moved_ws_default;
4451}
4452
4453void diff_setup_done(struct diff_options *options)
4454{
4455        unsigned check_mask = DIFF_FORMAT_NAME |
4456                              DIFF_FORMAT_NAME_STATUS |
4457                              DIFF_FORMAT_CHECKDIFF |
4458                              DIFF_FORMAT_NO_OUTPUT;
4459        /*
4460         * This must be signed because we're comparing against a potentially
4461         * negative value.
4462         */
4463        const int hexsz = the_hash_algo->hexsz;
4464
4465        if (options->set_default)
4466                options->set_default(options);
4467
4468        if (HAS_MULTI_BITS(options->output_format & check_mask))
4469                die(_("--name-only, --name-status, --check and -s are mutually exclusive"));
4470
4471        if (HAS_MULTI_BITS(options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK))
4472                die(_("-G, -S and --find-object are mutually exclusive"));
4473
4474        /*
4475         * Most of the time we can say "there are changes"
4476         * only by checking if there are changed paths, but
4477         * --ignore-whitespace* options force us to look
4478         * inside contents.
4479         */
4480
4481        if ((options->xdl_opts & XDF_WHITESPACE_FLAGS))
4482                options->flags.diff_from_contents = 1;
4483        else
4484                options->flags.diff_from_contents = 0;
4485
4486        if (options->flags.find_copies_harder)
4487                options->detect_rename = DIFF_DETECT_COPY;
4488
4489        if (!options->flags.relative_name)
4490                options->prefix = NULL;
4491        if (options->prefix)
4492                options->prefix_length = strlen(options->prefix);
4493        else
4494                options->prefix_length = 0;
4495
4496        if (options->output_format & (DIFF_FORMAT_NAME |
4497                                      DIFF_FORMAT_NAME_STATUS |
4498                                      DIFF_FORMAT_CHECKDIFF |
4499                                      DIFF_FORMAT_NO_OUTPUT))
4500                options->output_format &= ~(DIFF_FORMAT_RAW |
4501                                            DIFF_FORMAT_NUMSTAT |
4502                                            DIFF_FORMAT_DIFFSTAT |
4503                                            DIFF_FORMAT_SHORTSTAT |
4504                                            DIFF_FORMAT_DIRSTAT |
4505                                            DIFF_FORMAT_SUMMARY |
4506                                            DIFF_FORMAT_PATCH);
4507
4508        /*
4509         * These cases always need recursive; we do not drop caller-supplied
4510         * recursive bits for other formats here.
4511         */
4512        if (options->output_format & (DIFF_FORMAT_PATCH |
4513                                      DIFF_FORMAT_NUMSTAT |
4514                                      DIFF_FORMAT_DIFFSTAT |
4515                                      DIFF_FORMAT_SHORTSTAT |
4516                                      DIFF_FORMAT_DIRSTAT |
4517                                      DIFF_FORMAT_SUMMARY |
4518                                      DIFF_FORMAT_CHECKDIFF))
4519                options->flags.recursive = 1;
4520        /*
4521         * Also pickaxe would not work very well if you do not say recursive
4522         */
4523        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
4524                options->flags.recursive = 1;
4525        /*
4526         * When patches are generated, submodules diffed against the work tree
4527         * must be checked for dirtiness too so it can be shown in the output
4528         */
4529        if (options->output_format & DIFF_FORMAT_PATCH)
4530                options->flags.dirty_submodules = 1;
4531
4532        if (options->detect_rename && options->rename_limit < 0)
4533                options->rename_limit = diff_rename_limit_default;
4534        if (hexsz < options->abbrev)
4535                options->abbrev = hexsz; /* full */
4536
4537        /*
4538         * It does not make sense to show the first hit we happened
4539         * to have found.  It does not make sense not to return with
4540         * exit code in such a case either.
4541         */
4542        if (options->flags.quick) {
4543                options->output_format = DIFF_FORMAT_NO_OUTPUT;
4544                options->flags.exit_with_status = 1;
4545        }
4546
4547        options->diff_path_counter = 0;
4548
4549        if (options->flags.follow_renames && options->pathspec.nr != 1)
4550                die(_("--follow requires exactly one pathspec"));
4551
4552        if (!options->use_color || external_diff())
4553                options->color_moved = 0;
4554}
4555
4556static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
4557{
4558        char c, *eq;
4559        int len;
4560
4561        if (*arg != '-')
4562                return 0;
4563        c = *++arg;
4564        if (!c)
4565                return 0;
4566        if (c == arg_short) {
4567                c = *++arg;
4568                if (!c)
4569                        return 1;
4570                if (val && isdigit(c)) {
4571                        char *end;
4572                        int n = strtoul(arg, &end, 10);
4573                        if (*end)
4574                                return 0;
4575                        *val = n;
4576                        return 1;
4577                }
4578                return 0;
4579        }
4580        if (c != '-')
4581                return 0;
4582        arg++;
4583        eq = strchrnul(arg, '=');
4584        len = eq - arg;
4585        if (!len || strncmp(arg, arg_long, len))
4586                return 0;
4587        if (*eq) {
4588                int n;
4589                char *end;
4590                if (!isdigit(*++eq))
4591                        return 0;
4592                n = strtoul(eq, &end, 10);
4593                if (*end)
4594                        return 0;
4595                *val = n;
4596        }
4597        return 1;
4598}
4599
4600static int diff_scoreopt_parse(const char *opt);
4601
4602static inline int short_opt(char opt, const char **argv,
4603                            const char **optarg)
4604{
4605        const char *arg = argv[0];
4606        if (arg[0] != '-' || arg[1] != opt)
4607                return 0;
4608        if (arg[2] != '\0') {
4609                *optarg = arg + 2;
4610                return 1;
4611        }
4612        if (!argv[1])
4613                die("Option '%c' requires a value", opt);
4614        *optarg = argv[1];
4615        return 2;
4616}
4617
4618int parse_long_opt(const char *opt, const char **argv,
4619                   const char **optarg)
4620{
4621        const char *arg = argv[0];
4622        if (!skip_prefix(arg, "--", &arg))
4623                return 0;
4624        if (!skip_prefix(arg, opt, &arg))
4625                return 0;
4626        if (*arg == '=') { /* stuck form: --option=value */
4627                *optarg = arg + 1;
4628                return 1;
4629        }
4630        if (*arg != '\0')
4631                return 0;
4632        /* separate form: --option value */
4633        if (!argv[1])
4634                die("Option '--%s' requires a value", opt);
4635        *optarg = argv[1];
4636        return 2;
4637}
4638
4639static int stat_opt(struct diff_options *options, const char **av)
4640{
4641        const char *arg = av[0];
4642        char *end;
4643        int width = options->stat_width;
4644        int name_width = options->stat_name_width;
4645        int graph_width = options->stat_graph_width;
4646        int count = options->stat_count;
4647        int argcount = 1;
4648
4649        if (!skip_prefix(arg, "--stat", &arg))
4650                BUG("stat option does not begin with --stat: %s", arg);
4651        end = (char *)arg;
4652
4653        switch (*arg) {
4654        case '-':
4655                if (skip_prefix(arg, "-width", &arg)) {
4656                        if (*arg == '=')
4657                                width = strtoul(arg + 1, &end, 10);
4658                        else if (!*arg && !av[1])
4659                                die_want_option("--stat-width");
4660                        else if (!*arg) {
4661                                width = strtoul(av[1], &end, 10);
4662                                argcount = 2;
4663                        }
4664                } else if (skip_prefix(arg, "-name-width", &arg)) {
4665                        if (*arg == '=')
4666                                name_width = strtoul(arg + 1, &end, 10);
4667                        else if (!*arg && !av[1])
4668                                die_want_option("--stat-name-width");
4669                        else if (!*arg) {
4670                                name_width = strtoul(av[1], &end, 10);
4671                                argcount = 2;
4672                        }
4673                } else if (skip_prefix(arg, "-graph-width", &arg)) {
4674                        if (*arg == '=')
4675                                graph_width = strtoul(arg + 1, &end, 10);
4676                        else if (!*arg && !av[1])
4677                                die_want_option("--stat-graph-width");
4678                        else if (!*arg) {
4679                                graph_width = strtoul(av[1], &end, 10);
4680                                argcount = 2;
4681                        }
4682                } else if (skip_prefix(arg, "-count", &arg)) {
4683                        if (*arg == '=')
4684                                count = strtoul(arg + 1, &end, 10);
4685                        else if (!*arg && !av[1])
4686                                die_want_option("--stat-count");
4687                        else if (!*arg) {
4688                                count = strtoul(av[1], &end, 10);
4689                                argcount = 2;
4690                        }
4691                }
4692                break;
4693        case '=':
4694                width = strtoul(arg+1, &end, 10);
4695                if (*end == ',')
4696                        name_width = strtoul(end+1, &end, 10);
4697                if (*end == ',')
4698                        count = strtoul(end+1, &end, 10);
4699        }
4700
4701        /* Important! This checks all the error cases! */
4702        if (*end)
4703                return 0;
4704        options->output_format |= DIFF_FORMAT_DIFFSTAT;
4705        options->stat_name_width = name_width;
4706        options->stat_graph_width = graph_width;
4707        options->stat_width = width;
4708        options->stat_count = count;
4709        return argcount;
4710}
4711
4712static int parse_dirstat_opt(struct diff_options *options, const char *params)
4713{
4714        struct strbuf errmsg = STRBUF_INIT;
4715        if (parse_dirstat_params(options, params, &errmsg))
4716                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
4717                    errmsg.buf);
4718        strbuf_release(&errmsg);
4719        /*
4720         * The caller knows a dirstat-related option is given from the command
4721         * line; allow it to say "return this_function();"
4722         */
4723        options->output_format |= DIFF_FORMAT_DIRSTAT;
4724        return 1;
4725}
4726
4727static int parse_submodule_opt(struct diff_options *options, const char *value)
4728{
4729        if (parse_submodule_params(options, value))
4730                die(_("Failed to parse --submodule option parameter: '%s'"),
4731                        value);
4732        return 1;
4733}
4734
4735static const char diff_status_letters[] = {
4736        DIFF_STATUS_ADDED,
4737        DIFF_STATUS_COPIED,
4738        DIFF_STATUS_DELETED,
4739        DIFF_STATUS_MODIFIED,
4740        DIFF_STATUS_RENAMED,
4741        DIFF_STATUS_TYPE_CHANGED,
4742        DIFF_STATUS_UNKNOWN,
4743        DIFF_STATUS_UNMERGED,
4744        DIFF_STATUS_FILTER_AON,
4745        DIFF_STATUS_FILTER_BROKEN,
4746        '\0',
4747};
4748
4749static unsigned int filter_bit['Z' + 1];
4750
4751static void prepare_filter_bits(void)
4752{
4753        int i;
4754
4755        if (!filter_bit[DIFF_STATUS_ADDED]) {
4756                for (i = 0; diff_status_letters[i]; i++)
4757                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
4758        }
4759}
4760
4761static unsigned filter_bit_tst(char status, const struct diff_options *opt)
4762{
4763        return opt->filter & filter_bit[(int) status];
4764}
4765
4766static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
4767{
4768        int i, optch;
4769
4770        prepare_filter_bits();
4771
4772        /*
4773         * If there is a negation e.g. 'd' in the input, and we haven't
4774         * initialized the filter field with another --diff-filter, start
4775         * from full set of bits, except for AON.
4776         */
4777        if (!opt->filter) {
4778                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4779                        if (optch < 'a' || 'z' < optch)
4780                                continue;
4781                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
4782                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
4783                        break;
4784                }
4785        }
4786
4787        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4788                unsigned int bit;
4789                int negate;
4790
4791                if ('a' <= optch && optch <= 'z') {
4792                        negate = 1;
4793                        optch = toupper(optch);
4794                } else {
4795                        negate = 0;
4796                }
4797
4798                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
4799                if (!bit)
4800                        return optarg[i];
4801                if (negate)
4802                        opt->filter &= ~bit;
4803                else
4804                        opt->filter |= bit;
4805        }
4806        return 0;
4807}
4808
4809static void enable_patch_output(int *fmt) {
4810        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
4811        *fmt |= DIFF_FORMAT_PATCH;
4812}
4813
4814static int parse_ws_error_highlight_opt(struct diff_options *opt, const char *arg)
4815{
4816        int val = parse_ws_error_highlight(arg);
4817
4818        if (val < 0) {
4819                error("unknown value after ws-error-highlight=%.*s",
4820                      -1 - val, arg);
4821                return 0;
4822        }
4823        opt->ws_error_highlight = val;
4824        return 1;
4825}
4826
4827static int parse_objfind_opt(struct diff_options *opt, const char *arg)
4828{
4829        struct object_id oid;
4830
4831        if (get_oid(arg, &oid))
4832                return error("unable to resolve '%s'", arg);
4833
4834        if (!opt->objfind)
4835                opt->objfind = xcalloc(1, sizeof(*opt->objfind));
4836
4837        opt->pickaxe_opts |= DIFF_PICKAXE_KIND_OBJFIND;
4838        opt->flags.recursive = 1;
4839        opt->flags.tree_in_recursive = 1;
4840        oidset_insert(opt->objfind, &oid);
4841        return 1;
4842}
4843
4844int diff_opt_parse(struct diff_options *options,
4845                   const char **av, int ac, const char *prefix)
4846{
4847        const char *arg = av[0];
4848        const char *optarg;
4849        int argcount;
4850
4851        if (!prefix)
4852                prefix = "";
4853
4854        /* Output format options */
4855        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
4856            || opt_arg(arg, 'U', "unified", &options->context))
4857                enable_patch_output(&options->output_format);
4858        else if (!strcmp(arg, "--raw"))
4859                options->output_format |= DIFF_FORMAT_RAW;
4860        else if (!strcmp(arg, "--patch-with-raw")) {
4861                enable_patch_output(&options->output_format);
4862                options->output_format |= DIFF_FORMAT_RAW;
4863        } else if (!strcmp(arg, "--numstat"))
4864                options->output_format |= DIFF_FORMAT_NUMSTAT;
4865        else if (!strcmp(arg, "--shortstat"))
4866                options->output_format |= DIFF_FORMAT_SHORTSTAT;
4867        else if (skip_prefix(arg, "-X", &arg) ||
4868                 skip_to_optional_arg(arg, "--dirstat", &arg))
4869                return parse_dirstat_opt(options, arg);
4870        else if (!strcmp(arg, "--cumulative"))
4871                return parse_dirstat_opt(options, "cumulative");
4872        else if (skip_to_optional_arg(arg, "--dirstat-by-file", &arg)) {
4873                parse_dirstat_opt(options, "files");
4874                return parse_dirstat_opt(options, arg);
4875        }
4876        else if (!strcmp(arg, "--check"))
4877                options->output_format |= DIFF_FORMAT_CHECKDIFF;
4878        else if (!strcmp(arg, "--summary"))
4879                options->output_format |= DIFF_FORMAT_SUMMARY;
4880        else if (!strcmp(arg, "--patch-with-stat")) {
4881                enable_patch_output(&options->output_format);
4882                options->output_format |= DIFF_FORMAT_DIFFSTAT;
4883        } else if (!strcmp(arg, "--name-only"))
4884                options->output_format |= DIFF_FORMAT_NAME;
4885        else if (!strcmp(arg, "--name-status"))
4886                options->output_format |= DIFF_FORMAT_NAME_STATUS;
4887        else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
4888                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
4889        else if (starts_with(arg, "--stat"))
4890                /* --stat, --stat-width, --stat-name-width, or --stat-count */
4891                return stat_opt(options, av);
4892        else if (!strcmp(arg, "--compact-summary")) {
4893                 options->flags.stat_with_summary = 1;
4894                 options->output_format |= DIFF_FORMAT_DIFFSTAT;
4895        } else if (!strcmp(arg, "--no-compact-summary"))
4896                 options->flags.stat_with_summary = 0;
4897        else if (skip_prefix(arg, "--output-indicator-new=", &arg))
4898                options->output_indicators[OUTPUT_INDICATOR_NEW] = arg[0];
4899        else if (skip_prefix(arg, "--output-indicator-old=", &arg))
4900                options->output_indicators[OUTPUT_INDICATOR_OLD] = arg[0];
4901        else if (skip_prefix(arg, "--output-indicator-context=", &arg))
4902                options->output_indicators[OUTPUT_INDICATOR_CONTEXT] = arg[0];
4903
4904        /* renames options */
4905        else if (starts_with(arg, "-B") ||
4906                 skip_to_optional_arg(arg, "--break-rewrites", NULL)) {
4907                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
4908                        return error("invalid argument to -B: %s", arg+2);
4909        }
4910        else if (starts_with(arg, "-M") ||
4911                 skip_to_optional_arg(arg, "--find-renames", NULL)) {
4912                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4913                        return error("invalid argument to -M: %s", arg+2);
4914                options->detect_rename = DIFF_DETECT_RENAME;
4915        }
4916        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
4917                options->irreversible_delete = 1;
4918        }
4919        else if (starts_with(arg, "-C") ||
4920                 skip_to_optional_arg(arg, "--find-copies", NULL)) {
4921                if (options->detect_rename == DIFF_DETECT_COPY)
4922                        options->flags.find_copies_harder = 1;
4923                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4924                        return error("invalid argument to -C: %s", arg+2);
4925                options->detect_rename = DIFF_DETECT_COPY;
4926        }
4927        else if (!strcmp(arg, "--no-renames"))
4928                options->detect_rename = 0;
4929        else if (!strcmp(arg, "--rename-empty"))
4930                options->flags.rename_empty = 1;
4931        else if (!strcmp(arg, "--no-rename-empty"))
4932                options->flags.rename_empty = 0;
4933        else if (skip_to_optional_arg_default(arg, "--relative", &arg, NULL)) {
4934                options->flags.relative_name = 1;
4935                if (arg)
4936                        options->prefix = arg;
4937        }
4938
4939        /* xdiff options */
4940        else if (!strcmp(arg, "--minimal"))
4941                DIFF_XDL_SET(options, NEED_MINIMAL);
4942        else if (!strcmp(arg, "--no-minimal"))
4943                DIFF_XDL_CLR(options, NEED_MINIMAL);
4944        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
4945                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
4946        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
4947                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
4948        else if (!strcmp(arg, "--ignore-space-at-eol"))
4949                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
4950        else if (!strcmp(arg, "--ignore-cr-at-eol"))
4951                DIFF_XDL_SET(options, IGNORE_CR_AT_EOL);
4952        else if (!strcmp(arg, "--ignore-blank-lines"))
4953                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
4954        else if (!strcmp(arg, "--indent-heuristic"))
4955                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4956        else if (!strcmp(arg, "--no-indent-heuristic"))
4957                DIFF_XDL_CLR(options, INDENT_HEURISTIC);
4958        else if (!strcmp(arg, "--patience")) {
4959                int i;
4960                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4961                /*
4962                 * Both --patience and --anchored use PATIENCE_DIFF
4963                 * internally, so remove any anchors previously
4964                 * specified.
4965                 */
4966                for (i = 0; i < options->anchors_nr; i++)
4967                        free(options->anchors[i]);
4968                options->anchors_nr = 0;
4969        } else if (!strcmp(arg, "--histogram"))
4970                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
4971        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
4972                long value = parse_algorithm_value(optarg);
4973                if (value < 0)
4974                        return error("option diff-algorithm accepts \"myers\", "
4975                                     "\"minimal\", \"patience\" and \"histogram\"");
4976                /* clear out previous settings */
4977                DIFF_XDL_CLR(options, NEED_MINIMAL);
4978                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
4979                options->xdl_opts |= value;
4980                return argcount;
4981        } else if (skip_prefix(arg, "--anchored=", &arg)) {
4982                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4983                ALLOC_GROW(options->anchors, options->anchors_nr + 1,
4984                           options->anchors_alloc);
4985                options->anchors[options->anchors_nr++] = xstrdup(arg);
4986        }
4987
4988        /* flags options */
4989        else if (!strcmp(arg, "--binary")) {
4990                enable_patch_output(&options->output_format);
4991                options->flags.binary = 1;
4992        }
4993        else if (!strcmp(arg, "--full-index"))
4994                options->flags.full_index = 1;
4995        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
4996                options->flags.text = 1;
4997        else if (!strcmp(arg, "-R"))
4998                options->flags.reverse_diff = 1;
4999        else if (!strcmp(arg, "--find-copies-harder"))
5000                options->flags.find_copies_harder = 1;
5001        else if (!strcmp(arg, "--follow"))
5002                options->flags.follow_renames = 1;
5003        else if (!strcmp(arg, "--no-follow")) {
5004                options->flags.follow_renames = 0;
5005                options->flags.default_follow_renames = 0;
5006        } else if (skip_to_optional_arg_default(arg, "--color", &arg, "always")) {
5007                int value = git_config_colorbool(NULL, arg);
5008                if (value < 0)
5009                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
5010                options->use_color = value;
5011        }
5012        else if (!strcmp(arg, "--no-color"))
5013                options->use_color = 0;
5014        else if (!strcmp(arg, "--color-moved")) {
5015                if (diff_color_moved_default)
5016                        options->color_moved = diff_color_moved_default;
5017                if (options->color_moved == COLOR_MOVED_NO)
5018                        options->color_moved = COLOR_MOVED_DEFAULT;
5019        } else if (!strcmp(arg, "--no-color-moved"))
5020                options->color_moved = COLOR_MOVED_NO;
5021        else if (skip_prefix(arg, "--color-moved=", &arg)) {
5022                int cm = parse_color_moved(arg);
5023                if (cm < 0)
5024                        die("bad --color-moved argument: %s", arg);
5025                options->color_moved = cm;
5026        } else if (skip_prefix(arg, "--color-moved-ws=", &arg)) {
5027                options->color_moved_ws_handling = parse_color_moved_ws(arg);
5028        } else if (skip_to_optional_arg_default(arg, "--color-words", &options->word_regex, NULL)) {
5029                options->use_color = 1;
5030                options->word_diff = DIFF_WORDS_COLOR;
5031        }
5032        else if (!strcmp(arg, "--word-diff")) {
5033                if (options->word_diff == DIFF_WORDS_NONE)
5034                        options->word_diff = DIFF_WORDS_PLAIN;
5035        }
5036        else if (skip_prefix(arg, "--word-diff=", &arg)) {
5037                if (!strcmp(arg, "plain"))
5038                        options->word_diff = DIFF_WORDS_PLAIN;
5039                else if (!strcmp(arg, "color")) {
5040                        options->use_color = 1;
5041                        options->word_diff = DIFF_WORDS_COLOR;
5042                }
5043                else if (!strcmp(arg, "porcelain"))
5044                        options->word_diff = DIFF_WORDS_PORCELAIN;
5045                else if (!strcmp(arg, "none"))
5046                        options->word_diff = DIFF_WORDS_NONE;
5047                else
5048                        die("bad --word-diff argument: %s", arg);
5049        }
5050        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
5051                if (options->word_diff == DIFF_WORDS_NONE)
5052                        options->word_diff = DIFF_WORDS_PLAIN;
5053                options->word_regex = optarg;
5054                return argcount;
5055        }
5056        else if (!strcmp(arg, "--exit-code"))
5057                options->flags.exit_with_status = 1;
5058        else if (!strcmp(arg, "--quiet"))
5059                options->flags.quick = 1;
5060        else if (!strcmp(arg, "--ext-diff"))
5061                options->flags.allow_external = 1;
5062        else if (!strcmp(arg, "--no-ext-diff"))
5063                options->flags.allow_external = 0;
5064        else if (!strcmp(arg, "--textconv")) {
5065                options->flags.allow_textconv = 1;
5066                options->flags.textconv_set_via_cmdline = 1;
5067        } else if (!strcmp(arg, "--no-textconv"))
5068                options->flags.allow_textconv = 0;
5069        else if (skip_to_optional_arg_default(arg, "--ignore-submodules", &arg, "all")) {
5070                options->flags.override_submodule_config = 1;
5071                handle_ignore_submodules_arg(options, arg);
5072        } else if (skip_to_optional_arg_default(arg, "--submodule", &arg, "log"))
5073                return parse_submodule_opt(options, arg);
5074        else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
5075                return parse_ws_error_highlight_opt(options, arg);
5076        else if (!strcmp(arg, "--ita-invisible-in-index"))
5077                options->ita_invisible_in_index = 1;
5078        else if (!strcmp(arg, "--ita-visible-in-index"))
5079                options->ita_invisible_in_index = 0;
5080
5081        /* misc options */
5082        else if (!strcmp(arg, "-z"))
5083                options->line_termination = 0;
5084        else if ((argcount = short_opt('l', av, &optarg))) {
5085                options->rename_limit = strtoul(optarg, NULL, 10);
5086                return argcount;
5087        }
5088        else if ((argcount = short_opt('S', av, &optarg))) {
5089                options->pickaxe = optarg;
5090                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
5091                return argcount;
5092        } else if ((argcount = short_opt('G', av, &optarg))) {
5093                options->pickaxe = optarg;
5094                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
5095                return argcount;
5096        }
5097        else if (!strcmp(arg, "--pickaxe-all"))
5098                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
5099        else if (!strcmp(arg, "--pickaxe-regex"))
5100                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
5101        else if ((argcount = short_opt('O', av, &optarg))) {
5102                options->orderfile = prefix_filename(prefix, optarg);
5103                return argcount;
5104        } else if (skip_prefix(arg, "--find-object=", &arg))
5105                return parse_objfind_opt(options, arg);
5106        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
5107                int offending = parse_diff_filter_opt(optarg, options);
5108                if (offending)
5109                        die("unknown change class '%c' in --diff-filter=%s",
5110                            offending, optarg);
5111                return argcount;
5112        }
5113        else if (!strcmp(arg, "--no-abbrev"))
5114                options->abbrev = 0;
5115        else if (!strcmp(arg, "--abbrev"))
5116                options->abbrev = DEFAULT_ABBREV;
5117        else if (skip_prefix(arg, "--abbrev=", &arg)) {
5118                options->abbrev = strtoul(arg, NULL, 10);
5119                if (options->abbrev < MINIMUM_ABBREV)
5120                        options->abbrev = MINIMUM_ABBREV;
5121                else if (the_hash_algo->hexsz < options->abbrev)
5122                        options->abbrev = the_hash_algo->hexsz;
5123        }
5124        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
5125                options->a_prefix = optarg;
5126                return argcount;
5127        }
5128        else if ((argcount = parse_long_opt("line-prefix", av, &optarg))) {
5129                options->line_prefix = optarg;
5130                options->line_prefix_length = strlen(options->line_prefix);
5131                graph_setup_line_prefix(options);
5132                return argcount;
5133        }
5134        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
5135                options->b_prefix = optarg;
5136                return argcount;
5137        }
5138        else if (!strcmp(arg, "--no-prefix"))
5139                options->a_prefix = options->b_prefix = "";
5140        else if (opt_arg(arg, '\0', "inter-hunk-context",
5141                         &options->interhunkcontext))
5142                ;
5143        else if (!strcmp(arg, "-W"))
5144                options->flags.funccontext = 1;
5145        else if (!strcmp(arg, "--function-context"))
5146                options->flags.funccontext = 1;
5147        else if (!strcmp(arg, "--no-function-context"))
5148                options->flags.funccontext = 0;
5149        else if ((argcount = parse_long_opt("output", av, &optarg))) {
5150                char *path = prefix_filename(prefix, optarg);
5151                options->file = xfopen(path, "w");
5152                options->close_file = 1;
5153                if (options->use_color != GIT_COLOR_ALWAYS)
5154                        options->use_color = GIT_COLOR_NEVER;
5155                free(path);
5156                return argcount;
5157        } else
5158                return 0;
5159        return 1;
5160}
5161
5162int parse_rename_score(const char **cp_p)
5163{
5164        unsigned long num, scale;
5165        int ch, dot;
5166        const char *cp = *cp_p;
5167
5168        num = 0;
5169        scale = 1;
5170        dot = 0;
5171        for (;;) {
5172                ch = *cp;
5173                if ( !dot && ch == '.' ) {
5174                        scale = 1;
5175                        dot = 1;
5176                } else if ( ch == '%' ) {
5177                        scale = dot ? scale*100 : 100;
5178                        cp++;   /* % is always at the end */
5179                        break;
5180                } else if ( ch >= '0' && ch <= '9' ) {
5181                        if ( scale < 100000 ) {
5182                                scale *= 10;
5183                                num = (num*10) + (ch-'0');
5184                        }
5185                } else {
5186                        break;
5187                }
5188                cp++;
5189        }
5190        *cp_p = cp;
5191
5192        /* user says num divided by scale and we say internally that
5193         * is MAX_SCORE * num / scale.
5194         */
5195        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
5196}
5197
5198static int diff_scoreopt_parse(const char *opt)
5199{
5200        int opt1, opt2, cmd;
5201
5202        if (*opt++ != '-')
5203                return -1;
5204        cmd = *opt++;
5205        if (cmd == '-') {
5206                /* convert the long-form arguments into short-form versions */
5207                if (skip_prefix(opt, "break-rewrites", &opt)) {
5208                        if (*opt == 0 || *opt++ == '=')
5209                                cmd = 'B';
5210                } else if (skip_prefix(opt, "find-copies", &opt)) {
5211                        if (*opt == 0 || *opt++ == '=')
5212                                cmd = 'C';
5213                } else if (skip_prefix(opt, "find-renames", &opt)) {
5214                        if (*opt == 0 || *opt++ == '=')
5215                                cmd = 'M';
5216                }
5217        }
5218        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
5219                return -1; /* that is not a -M, -C, or -B option */
5220
5221        opt1 = parse_rename_score(&opt);
5222        if (cmd != 'B')
5223                opt2 = 0;
5224        else {
5225                if (*opt == 0)
5226                        opt2 = 0;
5227                else if (*opt != '/')
5228                        return -1; /* we expect -B80/99 or -B80 */
5229                else {
5230                        opt++;
5231                        opt2 = parse_rename_score(&opt);
5232                }
5233        }
5234        if (*opt != 0)
5235                return -1;
5236        return opt1 | (opt2 << 16);
5237}
5238
5239struct diff_queue_struct diff_queued_diff;
5240
5241void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
5242{
5243        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
5244        queue->queue[queue->nr++] = dp;
5245}
5246
5247struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
5248                                 struct diff_filespec *one,
5249                                 struct diff_filespec *two)
5250{
5251        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
5252        dp->one = one;
5253        dp->two = two;
5254        if (queue)
5255                diff_q(queue, dp);
5256        return dp;
5257}
5258
5259void diff_free_filepair(struct diff_filepair *p)
5260{
5261        free_filespec(p->one);
5262        free_filespec(p->two);
5263        free(p);
5264}
5265
5266const char *diff_aligned_abbrev(const struct object_id *oid, int len)
5267{
5268        int abblen;
5269        const char *abbrev;
5270
5271        /* Do we want all 40 hex characters? */
5272        if (len == the_hash_algo->hexsz)
5273                return oid_to_hex(oid);
5274
5275        /* An abbreviated value is fine, possibly followed by an ellipsis. */
5276        abbrev = diff_abbrev_oid(oid, len);
5277
5278        if (!print_sha1_ellipsis())
5279                return abbrev;
5280
5281        abblen = strlen(abbrev);
5282
5283        /*
5284         * In well-behaved cases, where the abbreviated result is the
5285         * same as the requested length, append three dots after the
5286         * abbreviation (hence the whole logic is limited to the case
5287         * where abblen < 37); when the actual abbreviated result is a
5288         * bit longer than the requested length, we reduce the number
5289         * of dots so that they match the well-behaved ones.  However,
5290         * if the actual abbreviation is longer than the requested
5291         * length by more than three, we give up on aligning, and add
5292         * three dots anyway, to indicate that the output is not the
5293         * full object name.  Yes, this may be suboptimal, but this
5294         * appears only in "diff --raw --abbrev" output and it is not
5295         * worth the effort to change it now.  Note that this would
5296         * likely to work fine when the automatic sizing of default
5297         * abbreviation length is used--we would be fed -1 in "len" in
5298         * that case, and will end up always appending three-dots, but
5299         * the automatic sizing is supposed to give abblen that ensures
5300         * uniqueness across all objects (statistically speaking).
5301         */
5302        if (abblen < the_hash_algo->hexsz - 3) {
5303                static char hex[GIT_MAX_HEXSZ + 1];
5304                if (len < abblen && abblen <= len + 2)
5305                        xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
5306                else
5307                        xsnprintf(hex, sizeof(hex), "%s...", abbrev);
5308                return hex;
5309        }
5310
5311        return oid_to_hex(oid);
5312}
5313
5314static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
5315{
5316        int line_termination = opt->line_termination;
5317        int inter_name_termination = line_termination ? '\t' : '\0';
5318
5319        fprintf(opt->file, "%s", diff_line_prefix(opt));
5320        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
5321                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
5322                        diff_aligned_abbrev(&p->one->oid, opt->abbrev));
5323                fprintf(opt->file, "%s ",
5324                        diff_aligned_abbrev(&p->two->oid, opt->abbrev));
5325        }
5326        if (p->score) {
5327                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
5328                        inter_name_termination);
5329        } else {
5330                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
5331        }
5332
5333        if (p->status == DIFF_STATUS_COPIED ||
5334            p->status == DIFF_STATUS_RENAMED) {
5335                const char *name_a, *name_b;
5336                name_a = p->one->path;
5337                name_b = p->two->path;
5338                strip_prefix(opt->prefix_length, &name_a, &name_b);
5339                write_name_quoted(name_a, opt->file, inter_name_termination);
5340                write_name_quoted(name_b, opt->file, line_termination);
5341        } else {
5342                const char *name_a, *name_b;
5343                name_a = p->one->mode ? p->one->path : p->two->path;
5344                name_b = NULL;
5345                strip_prefix(opt->prefix_length, &name_a, &name_b);
5346                write_name_quoted(name_a, opt->file, line_termination);
5347        }
5348}
5349
5350int diff_unmodified_pair(struct diff_filepair *p)
5351{
5352        /* This function is written stricter than necessary to support
5353         * the currently implemented transformers, but the idea is to
5354         * let transformers to produce diff_filepairs any way they want,
5355         * and filter and clean them up here before producing the output.
5356         */
5357        struct diff_filespec *one = p->one, *two = p->two;
5358
5359        if (DIFF_PAIR_UNMERGED(p))
5360                return 0; /* unmerged is interesting */
5361
5362        /* deletion, addition, mode or type change
5363         * and rename are all interesting.
5364         */
5365        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
5366            DIFF_PAIR_MODE_CHANGED(p) ||
5367            strcmp(one->path, two->path))
5368                return 0;
5369
5370        /* both are valid and point at the same path.  that is, we are
5371         * dealing with a change.
5372         */
5373        if (one->oid_valid && two->oid_valid &&
5374            oideq(&one->oid, &two->oid) &&
5375            !one->dirty_submodule && !two->dirty_submodule)
5376                return 1; /* no change */
5377        if (!one->oid_valid && !two->oid_valid)
5378                return 1; /* both look at the same file on the filesystem. */
5379        return 0;
5380}
5381
5382static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
5383{
5384        if (diff_unmodified_pair(p))
5385                return;
5386
5387        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5388            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5389                return; /* no tree diffs in patch format */
5390
5391        run_diff(p, o);
5392}
5393
5394static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
5395                            struct diffstat_t *diffstat)
5396{
5397        if (diff_unmodified_pair(p))
5398                return;
5399
5400        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5401            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5402                return; /* no useful stat for tree diffs */
5403
5404        run_diffstat(p, o, diffstat);
5405}
5406
5407static void diff_flush_checkdiff(struct diff_filepair *p,
5408                struct diff_options *o)
5409{
5410        if (diff_unmodified_pair(p))
5411                return;
5412
5413        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5414            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5415                return; /* nothing to check in tree diffs */
5416
5417        run_checkdiff(p, o);
5418}
5419
5420int diff_queue_is_empty(void)
5421{
5422        struct diff_queue_struct *q = &diff_queued_diff;
5423        int i;
5424        for (i = 0; i < q->nr; i++)
5425                if (!diff_unmodified_pair(q->queue[i]))
5426                        return 0;
5427        return 1;
5428}
5429
5430#if DIFF_DEBUG
5431void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
5432{
5433        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
5434                x, one ? one : "",
5435                s->path,
5436                DIFF_FILE_VALID(s) ? "valid" : "invalid",
5437                s->mode,
5438                s->oid_valid ? oid_to_hex(&s->oid) : "");
5439        fprintf(stderr, "queue[%d] %s size %lu\n",
5440                x, one ? one : "",
5441                s->size);
5442}
5443
5444void diff_debug_filepair(const struct diff_filepair *p, int i)
5445{
5446        diff_debug_filespec(p->one, i, "one");
5447        diff_debug_filespec(p->two, i, "two");
5448        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
5449                p->score, p->status ? p->status : '?',
5450                p->one->rename_used, p->broken_pair);
5451}
5452
5453void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
5454{
5455        int i;
5456        if (msg)
5457                fprintf(stderr, "%s\n", msg);
5458        fprintf(stderr, "q->nr = %d\n", q->nr);
5459        for (i = 0; i < q->nr; i++) {
5460                struct diff_filepair *p = q->queue[i];
5461                diff_debug_filepair(p, i);
5462        }
5463}
5464#endif
5465
5466static void diff_resolve_rename_copy(void)
5467{
5468        int i;
5469        struct diff_filepair *p;
5470        struct diff_queue_struct *q = &diff_queued_diff;
5471
5472        diff_debug_queue("resolve-rename-copy", q);
5473
5474        for (i = 0; i < q->nr; i++) {
5475                p = q->queue[i];
5476                p->status = 0; /* undecided */
5477                if (DIFF_PAIR_UNMERGED(p))
5478                        p->status = DIFF_STATUS_UNMERGED;
5479                else if (!DIFF_FILE_VALID(p->one))
5480                        p->status = DIFF_STATUS_ADDED;
5481                else if (!DIFF_FILE_VALID(p->two))
5482                        p->status = DIFF_STATUS_DELETED;
5483                else if (DIFF_PAIR_TYPE_CHANGED(p))
5484                        p->status = DIFF_STATUS_TYPE_CHANGED;
5485
5486                /* from this point on, we are dealing with a pair
5487                 * whose both sides are valid and of the same type, i.e.
5488                 * either in-place edit or rename/copy edit.
5489                 */
5490                else if (DIFF_PAIR_RENAME(p)) {
5491                        /*
5492                         * A rename might have re-connected a broken
5493                         * pair up, causing the pathnames to be the
5494                         * same again. If so, that's not a rename at
5495                         * all, just a modification..
5496                         *
5497                         * Otherwise, see if this source was used for
5498                         * multiple renames, in which case we decrement
5499                         * the count, and call it a copy.
5500                         */
5501                        if (!strcmp(p->one->path, p->two->path))
5502                                p->status = DIFF_STATUS_MODIFIED;
5503                        else if (--p->one->rename_used > 0)
5504                                p->status = DIFF_STATUS_COPIED;
5505                        else
5506                                p->status = DIFF_STATUS_RENAMED;
5507                }
5508                else if (!oideq(&p->one->oid, &p->two->oid) ||
5509                         p->one->mode != p->two->mode ||
5510                         p->one->dirty_submodule ||
5511                         p->two->dirty_submodule ||
5512                         is_null_oid(&p->one->oid))
5513                        p->status = DIFF_STATUS_MODIFIED;
5514                else {
5515                        /* This is a "no-change" entry and should not
5516                         * happen anymore, but prepare for broken callers.
5517                         */
5518                        error("feeding unmodified %s to diffcore",
5519                              p->one->path);
5520                        p->status = DIFF_STATUS_UNKNOWN;
5521                }
5522        }
5523        diff_debug_queue("resolve-rename-copy done", q);
5524}
5525
5526static int check_pair_status(struct diff_filepair *p)
5527{
5528        switch (p->status) {
5529        case DIFF_STATUS_UNKNOWN:
5530                return 0;
5531        case 0:
5532                die("internal error in diff-resolve-rename-copy");
5533        default:
5534                return 1;
5535        }
5536}
5537
5538static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
5539{
5540        int fmt = opt->output_format;
5541
5542        if (fmt & DIFF_FORMAT_CHECKDIFF)
5543                diff_flush_checkdiff(p, opt);
5544        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
5545                diff_flush_raw(p, opt);
5546        else if (fmt & DIFF_FORMAT_NAME) {
5547                const char *name_a, *name_b;
5548                name_a = p->two->path;
5549                name_b = NULL;
5550                strip_prefix(opt->prefix_length, &name_a, &name_b);
5551                fprintf(opt->file, "%s", diff_line_prefix(opt));
5552                write_name_quoted(name_a, opt->file, opt->line_termination);
5553        }
5554}
5555
5556static void show_file_mode_name(struct diff_options *opt, const char *newdelete, struct diff_filespec *fs)
5557{
5558        struct strbuf sb = STRBUF_INIT;
5559        if (fs->mode)
5560                strbuf_addf(&sb, " %s mode %06o ", newdelete, fs->mode);
5561        else
5562                strbuf_addf(&sb, " %s ", newdelete);
5563
5564        quote_c_style(fs->path, &sb, NULL, 0);
5565        strbuf_addch(&sb, '\n');
5566        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5567                         sb.buf, sb.len, 0);
5568        strbuf_release(&sb);
5569}
5570
5571static void show_mode_change(struct diff_options *opt, struct diff_filepair *p,
5572                int show_name)
5573{
5574        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
5575                struct strbuf sb = STRBUF_INIT;
5576                strbuf_addf(&sb, " mode change %06o => %06o",
5577                            p->one->mode, p->two->mode);
5578                if (show_name) {
5579                        strbuf_addch(&sb, ' ');
5580                        quote_c_style(p->two->path, &sb, NULL, 0);
5581                }
5582                strbuf_addch(&sb, '\n');
5583                emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5584                                 sb.buf, sb.len, 0);
5585                strbuf_release(&sb);
5586        }
5587}
5588
5589static void show_rename_copy(struct diff_options *opt, const char *renamecopy,
5590                struct diff_filepair *p)
5591{
5592        struct strbuf sb = STRBUF_INIT;
5593        struct strbuf names = STRBUF_INIT;
5594
5595        pprint_rename(&names, p->one->path, p->two->path);
5596        strbuf_addf(&sb, " %s %s (%d%%)\n",
5597                    renamecopy, names.buf, similarity_index(p));
5598        strbuf_release(&names);
5599        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5600                                 sb.buf, sb.len, 0);
5601        show_mode_change(opt, p, 0);
5602        strbuf_release(&sb);
5603}
5604
5605static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
5606{
5607        switch(p->status) {
5608        case DIFF_STATUS_DELETED:
5609                show_file_mode_name(opt, "delete", p->one);
5610                break;
5611        case DIFF_STATUS_ADDED:
5612                show_file_mode_name(opt, "create", p->two);
5613                break;
5614        case DIFF_STATUS_COPIED:
5615                show_rename_copy(opt, "copy", p);
5616                break;
5617        case DIFF_STATUS_RENAMED:
5618                show_rename_copy(opt, "rename", p);
5619                break;
5620        default:
5621                if (p->score) {
5622                        struct strbuf sb = STRBUF_INIT;
5623                        strbuf_addstr(&sb, " rewrite ");
5624                        quote_c_style(p->two->path, &sb, NULL, 0);
5625                        strbuf_addf(&sb, " (%d%%)\n", similarity_index(p));
5626                        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5627                                         sb.buf, sb.len, 0);
5628                        strbuf_release(&sb);
5629                }
5630                show_mode_change(opt, p, !p->score);
5631                break;
5632        }
5633}
5634
5635struct patch_id_t {
5636        git_SHA_CTX *ctx;
5637        int patchlen;
5638};
5639
5640static int remove_space(char *line, int len)
5641{
5642        int i;
5643        char *dst = line;
5644        unsigned char c;
5645
5646        for (i = 0; i < len; i++)
5647                if (!isspace((c = line[i])))
5648                        *dst++ = c;
5649
5650        return dst - line;
5651}
5652
5653static void patch_id_consume(void *priv, char *line, unsigned long len)
5654{
5655        struct patch_id_t *data = priv;
5656        int new_len;
5657
5658        /* Ignore line numbers when computing the SHA1 of the patch */
5659        if (starts_with(line, "@@ -"))
5660                return;
5661
5662        new_len = remove_space(line, len);
5663
5664        git_SHA1_Update(data->ctx, line, new_len);
5665        data->patchlen += new_len;
5666}
5667
5668static void patch_id_add_string(git_SHA_CTX *ctx, const char *str)
5669{
5670        git_SHA1_Update(ctx, str, strlen(str));
5671}
5672
5673static void patch_id_add_mode(git_SHA_CTX *ctx, unsigned mode)
5674{
5675        /* large enough for 2^32 in octal */
5676        char buf[12];
5677        int len = xsnprintf(buf, sizeof(buf), "%06o", mode);
5678        git_SHA1_Update(ctx, buf, len);
5679}
5680
5681/* returns 0 upon success, and writes result into sha1 */
5682static int diff_get_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5683{
5684        struct diff_queue_struct *q = &diff_queued_diff;
5685        int i;
5686        git_SHA_CTX ctx;
5687        struct patch_id_t data;
5688
5689        git_SHA1_Init(&ctx);
5690        memset(&data, 0, sizeof(struct patch_id_t));
5691        data.ctx = &ctx;
5692
5693        for (i = 0; i < q->nr; i++) {
5694                xpparam_t xpp;
5695                xdemitconf_t xecfg;
5696                mmfile_t mf1, mf2;
5697                struct diff_filepair *p = q->queue[i];
5698                int len1, len2;
5699
5700                memset(&xpp, 0, sizeof(xpp));
5701                memset(&xecfg, 0, sizeof(xecfg));
5702                if (p->status == 0)
5703                        return error("internal diff status error");
5704                if (p->status == DIFF_STATUS_UNKNOWN)
5705                        continue;
5706                if (diff_unmodified_pair(p))
5707                        continue;
5708                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5709                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5710                        continue;
5711                if (DIFF_PAIR_UNMERGED(p))
5712                        continue;
5713
5714                diff_fill_oid_info(p->one, options->repo->index);
5715                diff_fill_oid_info(p->two, options->repo->index);
5716
5717                len1 = remove_space(p->one->path, strlen(p->one->path));
5718                len2 = remove_space(p->two->path, strlen(p->two->path));
5719                patch_id_add_string(&ctx, "diff--git");
5720                patch_id_add_string(&ctx, "a/");
5721                git_SHA1_Update(&ctx, p->one->path, len1);
5722                patch_id_add_string(&ctx, "b/");
5723                git_SHA1_Update(&ctx, p->two->path, len2);
5724
5725                if (p->one->mode == 0) {
5726                        patch_id_add_string(&ctx, "newfilemode");
5727                        patch_id_add_mode(&ctx, p->two->mode);
5728                        patch_id_add_string(&ctx, "---/dev/null");
5729                        patch_id_add_string(&ctx, "+++b/");
5730                        git_SHA1_Update(&ctx, p->two->path, len2);
5731                } else if (p->two->mode == 0) {
5732                        patch_id_add_string(&ctx, "deletedfilemode");
5733                        patch_id_add_mode(&ctx, p->one->mode);
5734                        patch_id_add_string(&ctx, "---a/");
5735                        git_SHA1_Update(&ctx, p->one->path, len1);
5736                        patch_id_add_string(&ctx, "+++/dev/null");
5737                } else {
5738                        patch_id_add_string(&ctx, "---a/");
5739                        git_SHA1_Update(&ctx, p->one->path, len1);
5740                        patch_id_add_string(&ctx, "+++b/");
5741                        git_SHA1_Update(&ctx, p->two->path, len2);
5742                }
5743
5744                if (diff_header_only)
5745                        continue;
5746
5747                if (fill_mmfile(options->repo, &mf1, p->one) < 0 ||
5748                    fill_mmfile(options->repo, &mf2, p->two) < 0)
5749                        return error("unable to read files to diff");
5750
5751                if (diff_filespec_is_binary(options->repo, p->one) ||
5752                    diff_filespec_is_binary(options->repo, p->two)) {
5753                        git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
5754                                        GIT_SHA1_HEXSZ);
5755                        git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
5756                                        GIT_SHA1_HEXSZ);
5757                        continue;
5758                }
5759
5760                xpp.flags = 0;
5761                xecfg.ctxlen = 3;
5762                xecfg.flags = 0;
5763                if (xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
5764                                  &xpp, &xecfg))
5765                        return error("unable to generate patch-id diff for %s",
5766                                     p->one->path);
5767        }
5768
5769        git_SHA1_Final(oid->hash, &ctx);
5770        return 0;
5771}
5772
5773int diff_flush_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5774{
5775        struct diff_queue_struct *q = &diff_queued_diff;
5776        int i;
5777        int result = diff_get_patch_id(options, oid, diff_header_only);
5778
5779        for (i = 0; i < q->nr; i++)
5780                diff_free_filepair(q->queue[i]);
5781
5782        free(q->queue);
5783        DIFF_QUEUE_CLEAR(q);
5784
5785        return result;
5786}
5787
5788static int is_summary_empty(const struct diff_queue_struct *q)
5789{
5790        int i;
5791
5792        for (i = 0; i < q->nr; i++) {
5793                const struct diff_filepair *p = q->queue[i];
5794
5795                switch (p->status) {
5796                case DIFF_STATUS_DELETED:
5797                case DIFF_STATUS_ADDED:
5798                case DIFF_STATUS_COPIED:
5799                case DIFF_STATUS_RENAMED:
5800                        return 0;
5801                default:
5802                        if (p->score)
5803                                return 0;
5804                        if (p->one->mode && p->two->mode &&
5805                            p->one->mode != p->two->mode)
5806                                return 0;
5807                        break;
5808                }
5809        }
5810        return 1;
5811}
5812
5813static const char rename_limit_warning[] =
5814N_("inexact rename detection was skipped due to too many files.");
5815
5816static const char degrade_cc_to_c_warning[] =
5817N_("only found copies from modified paths due to too many files.");
5818
5819static const char rename_limit_advice[] =
5820N_("you may want to set your %s variable to at least "
5821   "%d and retry the command.");
5822
5823void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
5824{
5825        fflush(stdout);
5826        if (degraded_cc)
5827                warning(_(degrade_cc_to_c_warning));
5828        else if (needed)
5829                warning(_(rename_limit_warning));
5830        else
5831                return;
5832        if (0 < needed)
5833                warning(_(rename_limit_advice), varname, needed);
5834}
5835
5836static void diff_flush_patch_all_file_pairs(struct diff_options *o)
5837{
5838        int i;
5839        static struct emitted_diff_symbols esm = EMITTED_DIFF_SYMBOLS_INIT;
5840        struct diff_queue_struct *q = &diff_queued_diff;
5841
5842        if (WSEH_NEW & WS_RULE_MASK)
5843                BUG("WS rules bit mask overlaps with diff symbol flags");
5844
5845        if (o->color_moved)
5846                o->emitted_symbols = &esm;
5847
5848        for (i = 0; i < q->nr; i++) {
5849                struct diff_filepair *p = q->queue[i];
5850                if (check_pair_status(p))
5851                        diff_flush_patch(p, o);
5852        }
5853
5854        if (o->emitted_symbols) {
5855                if (o->color_moved) {
5856                        struct hashmap add_lines, del_lines;
5857
5858                        if (o->color_moved_ws_handling &
5859                            COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
5860                                o->color_moved_ws_handling |= XDF_IGNORE_WHITESPACE;
5861
5862                        hashmap_init(&del_lines, moved_entry_cmp, o, 0);
5863                        hashmap_init(&add_lines, moved_entry_cmp, o, 0);
5864
5865                        add_lines_to_move_detection(o, &add_lines, &del_lines);
5866                        mark_color_as_moved(o, &add_lines, &del_lines);
5867                        if (o->color_moved == COLOR_MOVED_ZEBRA_DIM)
5868                                dim_moved_lines(o);
5869
5870                        hashmap_free(&add_lines, 0);
5871                        hashmap_free(&del_lines, 0);
5872                }
5873
5874                for (i = 0; i < esm.nr; i++)
5875                        emit_diff_symbol_from_struct(o, &esm.buf[i]);
5876
5877                for (i = 0; i < esm.nr; i++)
5878                        free((void *)esm.buf[i].line);
5879        }
5880        esm.nr = 0;
5881}
5882
5883void diff_flush(struct diff_options *options)
5884{
5885        struct diff_queue_struct *q = &diff_queued_diff;
5886        int i, output_format = options->output_format;
5887        int separator = 0;
5888        int dirstat_by_line = 0;
5889
5890        /*
5891         * Order: raw, stat, summary, patch
5892         * or:    name/name-status/checkdiff (other bits clear)
5893         */
5894        if (!q->nr)
5895                goto free_queue;
5896
5897        if (output_format & (DIFF_FORMAT_RAW |
5898                             DIFF_FORMAT_NAME |
5899                             DIFF_FORMAT_NAME_STATUS |
5900                             DIFF_FORMAT_CHECKDIFF)) {
5901                for (i = 0; i < q->nr; i++) {
5902                        struct diff_filepair *p = q->queue[i];
5903                        if (check_pair_status(p))
5904                                flush_one_pair(p, options);
5905                }
5906                separator++;
5907        }
5908
5909        if (output_format & DIFF_FORMAT_DIRSTAT && options->flags.dirstat_by_line)
5910                dirstat_by_line = 1;
5911
5912        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
5913            dirstat_by_line) {
5914                struct diffstat_t diffstat;
5915
5916                memset(&diffstat, 0, sizeof(struct diffstat_t));
5917                for (i = 0; i < q->nr; i++) {
5918                        struct diff_filepair *p = q->queue[i];
5919                        if (check_pair_status(p))
5920                                diff_flush_stat(p, options, &diffstat);
5921                }
5922                if (output_format & DIFF_FORMAT_NUMSTAT)
5923                        show_numstat(&diffstat, options);
5924                if (output_format & DIFF_FORMAT_DIFFSTAT)
5925                        show_stats(&diffstat, options);
5926                if (output_format & DIFF_FORMAT_SHORTSTAT)
5927                        show_shortstats(&diffstat, options);
5928                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
5929                        show_dirstat_by_line(&diffstat, options);
5930                free_diffstat_info(&diffstat);
5931                separator++;
5932        }
5933        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
5934                show_dirstat(options);
5935
5936        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
5937                for (i = 0; i < q->nr; i++) {
5938                        diff_summary(options, q->queue[i]);
5939                }
5940                separator++;
5941        }
5942
5943        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
5944            options->flags.exit_with_status &&
5945            options->flags.diff_from_contents) {
5946                /*
5947                 * run diff_flush_patch for the exit status. setting
5948                 * options->file to /dev/null should be safe, because we
5949                 * aren't supposed to produce any output anyway.
5950                 */
5951                if (options->close_file)
5952                        fclose(options->file);
5953                options->file = xfopen("/dev/null", "w");
5954                options->close_file = 1;
5955                options->color_moved = 0;
5956                for (i = 0; i < q->nr; i++) {
5957                        struct diff_filepair *p = q->queue[i];
5958                        if (check_pair_status(p))
5959                                diff_flush_patch(p, options);
5960                        if (options->found_changes)
5961                                break;
5962                }
5963        }
5964
5965        if (output_format & DIFF_FORMAT_PATCH) {
5966                if (separator) {
5967                        emit_diff_symbol(options, DIFF_SYMBOL_SEPARATOR, NULL, 0, 0);
5968                        if (options->stat_sep)
5969                                /* attach patch instead of inline */
5970                                emit_diff_symbol(options, DIFF_SYMBOL_STAT_SEP,
5971                                                 NULL, 0, 0);
5972                }
5973
5974                diff_flush_patch_all_file_pairs(options);
5975        }
5976
5977        if (output_format & DIFF_FORMAT_CALLBACK)
5978                options->format_callback(q, options, options->format_callback_data);
5979
5980        for (i = 0; i < q->nr; i++)
5981                diff_free_filepair(q->queue[i]);
5982free_queue:
5983        free(q->queue);
5984        DIFF_QUEUE_CLEAR(q);
5985        if (options->close_file)
5986                fclose(options->file);
5987
5988        /*
5989         * Report the content-level differences with HAS_CHANGES;
5990         * diff_addremove/diff_change does not set the bit when
5991         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
5992         */
5993        if (options->flags.diff_from_contents) {
5994                if (options->found_changes)
5995                        options->flags.has_changes = 1;
5996                else
5997                        options->flags.has_changes = 0;
5998        }
5999}
6000
6001static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
6002{
6003        return (((p->status == DIFF_STATUS_MODIFIED) &&
6004                 ((p->score &&
6005                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
6006                  (!p->score &&
6007                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
6008                ((p->status != DIFF_STATUS_MODIFIED) &&
6009                 filter_bit_tst(p->status, options)));
6010}
6011
6012static void diffcore_apply_filter(struct diff_options *options)
6013{
6014        int i;
6015        struct diff_queue_struct *q = &diff_queued_diff;
6016        struct diff_queue_struct outq;
6017
6018        DIFF_QUEUE_CLEAR(&outq);
6019
6020        if (!options->filter)
6021                return;
6022
6023        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
6024                int found;
6025                for (i = found = 0; !found && i < q->nr; i++) {
6026                        if (match_filter(options, q->queue[i]))
6027                                found++;
6028                }
6029                if (found)
6030                        return;
6031
6032                /* otherwise we will clear the whole queue
6033                 * by copying the empty outq at the end of this
6034                 * function, but first clear the current entries
6035                 * in the queue.
6036                 */
6037                for (i = 0; i < q->nr; i++)
6038                        diff_free_filepair(q->queue[i]);
6039        }
6040        else {
6041                /* Only the matching ones */
6042                for (i = 0; i < q->nr; i++) {
6043                        struct diff_filepair *p = q->queue[i];
6044                        if (match_filter(options, p))
6045                                diff_q(&outq, p);
6046                        else
6047                                diff_free_filepair(p);
6048                }
6049        }
6050        free(q->queue);
6051        *q = outq;
6052}
6053
6054/* Check whether two filespecs with the same mode and size are identical */
6055static int diff_filespec_is_identical(struct repository *r,
6056                                      struct diff_filespec *one,
6057                                      struct diff_filespec *two)
6058{
6059        if (S_ISGITLINK(one->mode))
6060                return 0;
6061        if (diff_populate_filespec(r, one, 0))
6062                return 0;
6063        if (diff_populate_filespec(r, two, 0))
6064                return 0;
6065        return !memcmp(one->data, two->data, one->size);
6066}
6067
6068static int diff_filespec_check_stat_unmatch(struct repository *r,
6069                                            struct diff_filepair *p)
6070{
6071        if (p->done_skip_stat_unmatch)
6072                return p->skip_stat_unmatch_result;
6073
6074        p->done_skip_stat_unmatch = 1;
6075        p->skip_stat_unmatch_result = 0;
6076        /*
6077         * 1. Entries that come from stat info dirtiness
6078         *    always have both sides (iow, not create/delete),
6079         *    one side of the object name is unknown, with
6080         *    the same mode and size.  Keep the ones that
6081         *    do not match these criteria.  They have real
6082         *    differences.
6083         *
6084         * 2. At this point, the file is known to be modified,
6085         *    with the same mode and size, and the object
6086         *    name of one side is unknown.  Need to inspect
6087         *    the identical contents.
6088         */
6089        if (!DIFF_FILE_VALID(p->one) || /* (1) */
6090            !DIFF_FILE_VALID(p->two) ||
6091            (p->one->oid_valid && p->two->oid_valid) ||
6092            (p->one->mode != p->two->mode) ||
6093            diff_populate_filespec(r, p->one, CHECK_SIZE_ONLY) ||
6094            diff_populate_filespec(r, p->two, CHECK_SIZE_ONLY) ||
6095            (p->one->size != p->two->size) ||
6096            !diff_filespec_is_identical(r, p->one, p->two)) /* (2) */
6097                p->skip_stat_unmatch_result = 1;
6098        return p->skip_stat_unmatch_result;
6099}
6100
6101static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
6102{
6103        int i;
6104        struct diff_queue_struct *q = &diff_queued_diff;
6105        struct diff_queue_struct outq;
6106        DIFF_QUEUE_CLEAR(&outq);
6107
6108        for (i = 0; i < q->nr; i++) {
6109                struct diff_filepair *p = q->queue[i];
6110
6111                if (diff_filespec_check_stat_unmatch(diffopt->repo, p))
6112                        diff_q(&outq, p);
6113                else {
6114                        /*
6115                         * The caller can subtract 1 from skip_stat_unmatch
6116                         * to determine how many paths were dirty only
6117                         * due to stat info mismatch.
6118                         */
6119                        if (!diffopt->flags.no_index)
6120                                diffopt->skip_stat_unmatch++;
6121                        diff_free_filepair(p);
6122                }
6123        }
6124        free(q->queue);
6125        *q = outq;
6126}
6127
6128static int diffnamecmp(const void *a_, const void *b_)
6129{
6130        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
6131        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
6132        const char *name_a, *name_b;
6133
6134        name_a = a->one ? a->one->path : a->two->path;
6135        name_b = b->one ? b->one->path : b->two->path;
6136        return strcmp(name_a, name_b);
6137}
6138
6139void diffcore_fix_diff_index(struct diff_options *options)
6140{
6141        struct diff_queue_struct *q = &diff_queued_diff;
6142        QSORT(q->queue, q->nr, diffnamecmp);
6143}
6144
6145void diffcore_std(struct diff_options *options)
6146{
6147        /* NOTE please keep the following in sync with diff_tree_combined() */
6148        if (options->skip_stat_unmatch)
6149                diffcore_skip_stat_unmatch(options);
6150        if (!options->found_follow) {
6151                /* See try_to_follow_renames() in tree-diff.c */
6152                if (options->break_opt != -1)
6153                        diffcore_break(options->repo,
6154                                       options->break_opt);
6155                if (options->detect_rename)
6156                        diffcore_rename(options);
6157                if (options->break_opt != -1)
6158                        diffcore_merge_broken();
6159        }
6160        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
6161                diffcore_pickaxe(options);
6162        if (options->orderfile)
6163                diffcore_order(options->orderfile);
6164        if (!options->found_follow)
6165                /* See try_to_follow_renames() in tree-diff.c */
6166                diff_resolve_rename_copy();
6167        diffcore_apply_filter(options);
6168
6169        if (diff_queued_diff.nr && !options->flags.diff_from_contents)
6170                options->flags.has_changes = 1;
6171        else
6172                options->flags.has_changes = 0;
6173
6174        options->found_follow = 0;
6175}
6176
6177int diff_result_code(struct diff_options *opt, int status)
6178{
6179        int result = 0;
6180
6181        diff_warn_rename_limit("diff.renameLimit",
6182                               opt->needed_rename_limit,
6183                               opt->degraded_cc_to_c);
6184        if (!opt->flags.exit_with_status &&
6185            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
6186                return status;
6187        if (opt->flags.exit_with_status &&
6188            opt->flags.has_changes)
6189                result |= 01;
6190        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
6191            opt->flags.check_failed)
6192                result |= 02;
6193        return result;
6194}
6195
6196int diff_can_quit_early(struct diff_options *opt)
6197{
6198        return (opt->flags.quick &&
6199                !opt->filter &&
6200                opt->flags.has_changes);
6201}
6202
6203/*
6204 * Shall changes to this submodule be ignored?
6205 *
6206 * Submodule changes can be configured to be ignored separately for each path,
6207 * but that configuration can be overridden from the command line.
6208 */
6209static int is_submodule_ignored(const char *path, struct diff_options *options)
6210{
6211        int ignored = 0;
6212        struct diff_flags orig_flags = options->flags;
6213        if (!options->flags.override_submodule_config)
6214                set_diffopt_flags_from_submodule_config(options, path);
6215        if (options->flags.ignore_submodules)
6216                ignored = 1;
6217        options->flags = orig_flags;
6218        return ignored;
6219}
6220
6221void diff_addremove(struct diff_options *options,
6222                    int addremove, unsigned mode,
6223                    const struct object_id *oid,
6224                    int oid_valid,
6225                    const char *concatpath, unsigned dirty_submodule)
6226{
6227        struct diff_filespec *one, *two;
6228
6229        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
6230                return;
6231
6232        /* This may look odd, but it is a preparation for
6233         * feeding "there are unchanged files which should
6234         * not produce diffs, but when you are doing copy
6235         * detection you would need them, so here they are"
6236         * entries to the diff-core.  They will be prefixed
6237         * with something like '=' or '*' (I haven't decided
6238         * which but should not make any difference).
6239         * Feeding the same new and old to diff_change()
6240         * also has the same effect.
6241         * Before the final output happens, they are pruned after
6242         * merged into rename/copy pairs as appropriate.
6243         */
6244        if (options->flags.reverse_diff)
6245                addremove = (addremove == '+' ? '-' :
6246                             addremove == '-' ? '+' : addremove);
6247
6248        if (options->prefix &&
6249            strncmp(concatpath, options->prefix, options->prefix_length))
6250                return;
6251
6252        one = alloc_filespec(concatpath);
6253        two = alloc_filespec(concatpath);
6254
6255        if (addremove != '+')
6256                fill_filespec(one, oid, oid_valid, mode);
6257        if (addremove != '-') {
6258                fill_filespec(two, oid, oid_valid, mode);
6259                two->dirty_submodule = dirty_submodule;
6260        }
6261
6262        diff_queue(&diff_queued_diff, one, two);
6263        if (!options->flags.diff_from_contents)
6264                options->flags.has_changes = 1;
6265}
6266
6267void diff_change(struct diff_options *options,
6268                 unsigned old_mode, unsigned new_mode,
6269                 const struct object_id *old_oid,
6270                 const struct object_id *new_oid,
6271                 int old_oid_valid, int new_oid_valid,
6272                 const char *concatpath,
6273                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
6274{
6275        struct diff_filespec *one, *two;
6276        struct diff_filepair *p;
6277
6278        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
6279            is_submodule_ignored(concatpath, options))
6280                return;
6281
6282        if (options->flags.reverse_diff) {
6283                SWAP(old_mode, new_mode);
6284                SWAP(old_oid, new_oid);
6285                SWAP(old_oid_valid, new_oid_valid);
6286                SWAP(old_dirty_submodule, new_dirty_submodule);
6287        }
6288
6289        if (options->prefix &&
6290            strncmp(concatpath, options->prefix, options->prefix_length))
6291                return;
6292
6293        one = alloc_filespec(concatpath);
6294        two = alloc_filespec(concatpath);
6295        fill_filespec(one, old_oid, old_oid_valid, old_mode);
6296        fill_filespec(two, new_oid, new_oid_valid, new_mode);
6297        one->dirty_submodule = old_dirty_submodule;
6298        two->dirty_submodule = new_dirty_submodule;
6299        p = diff_queue(&diff_queued_diff, one, two);
6300
6301        if (options->flags.diff_from_contents)
6302                return;
6303
6304        if (options->flags.quick && options->skip_stat_unmatch &&
6305            !diff_filespec_check_stat_unmatch(options->repo, p))
6306                return;
6307
6308        options->flags.has_changes = 1;
6309}
6310
6311struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
6312{
6313        struct diff_filepair *pair;
6314        struct diff_filespec *one, *two;
6315
6316        if (options->prefix &&
6317            strncmp(path, options->prefix, options->prefix_length))
6318                return NULL;
6319
6320        one = alloc_filespec(path);
6321        two = alloc_filespec(path);
6322        pair = diff_queue(&diff_queued_diff, one, two);
6323        pair->is_unmerged = 1;
6324        return pair;
6325}
6326
6327static char *run_textconv(struct repository *r,
6328                          const char *pgm,
6329                          struct diff_filespec *spec,
6330                          size_t *outsize)
6331{
6332        struct diff_tempfile *temp;
6333        const char *argv[3];
6334        const char **arg = argv;
6335        struct child_process child = CHILD_PROCESS_INIT;
6336        struct strbuf buf = STRBUF_INIT;
6337        int err = 0;
6338
6339        temp = prepare_temp_file(r, spec->path, spec);
6340        *arg++ = pgm;
6341        *arg++ = temp->name;
6342        *arg = NULL;
6343
6344        child.use_shell = 1;
6345        child.argv = argv;
6346        child.out = -1;
6347        if (start_command(&child)) {
6348                remove_tempfile();
6349                return NULL;
6350        }
6351
6352        if (strbuf_read(&buf, child.out, 0) < 0)
6353                err = error("error reading from textconv command '%s'", pgm);
6354        close(child.out);
6355
6356        if (finish_command(&child) || err) {
6357                strbuf_release(&buf);
6358                remove_tempfile();
6359                return NULL;
6360        }
6361        remove_tempfile();
6362
6363        return strbuf_detach(&buf, outsize);
6364}
6365
6366size_t fill_textconv(struct repository *r,
6367                     struct userdiff_driver *driver,
6368                     struct diff_filespec *df,
6369                     char **outbuf)
6370{
6371        size_t size;
6372
6373        if (!driver) {
6374                if (!DIFF_FILE_VALID(df)) {
6375                        *outbuf = "";
6376                        return 0;
6377                }
6378                if (diff_populate_filespec(r, df, 0))
6379                        die("unable to read files to diff");
6380                *outbuf = df->data;
6381                return df->size;
6382        }
6383
6384        if (!driver->textconv)
6385                BUG("fill_textconv called with non-textconv driver");
6386
6387        if (driver->textconv_cache && df->oid_valid) {
6388                *outbuf = notes_cache_get(driver->textconv_cache,
6389                                          &df->oid,
6390                                          &size);
6391                if (*outbuf)
6392                        return size;
6393        }
6394
6395        *outbuf = run_textconv(r, driver->textconv, df, &size);
6396        if (!*outbuf)
6397                die("unable to read files to diff");
6398
6399        if (driver->textconv_cache && df->oid_valid) {
6400                /* ignore errors, as we might be in a readonly repository */
6401                notes_cache_put(driver->textconv_cache, &df->oid, *outbuf,
6402                                size);
6403                /*
6404                 * we could save up changes and flush them all at the end,
6405                 * but we would need an extra call after all diffing is done.
6406                 * Since generating a cache entry is the slow path anyway,
6407                 * this extra overhead probably isn't a big deal.
6408                 */
6409                notes_cache_write(driver->textconv_cache);
6410        }
6411
6412        return size;
6413}
6414
6415int textconv_object(struct repository *r,
6416                    const char *path,
6417                    unsigned mode,
6418                    const struct object_id *oid,
6419                    int oid_valid,
6420                    char **buf,
6421                    unsigned long *buf_size)
6422{
6423        struct diff_filespec *df;
6424        struct userdiff_driver *textconv;
6425
6426        df = alloc_filespec(path);
6427        fill_filespec(df, oid, oid_valid, mode);
6428        textconv = get_textconv(r->index, df);
6429        if (!textconv) {
6430                free_filespec(df);
6431                return 0;
6432        }
6433
6434        *buf_size = fill_textconv(r, textconv, df, buf);
6435        free_filespec(df);
6436        return 1;
6437}
6438
6439void setup_diff_pager(struct diff_options *opt)
6440{
6441        /*
6442         * If the user asked for our exit code, then either they want --quiet
6443         * or --exit-code. We should definitely not bother with a pager in the
6444         * former case, as we will generate no output. Since we still properly
6445         * report our exit code even when a pager is run, we _could_ run a
6446         * pager with --exit-code. But since we have not done so historically,
6447         * and because it is easy to find people oneline advising "git diff
6448         * --exit-code" in hooks and other scripts, we do not do so.
6449         */
6450        if (!opt->flags.exit_with_status &&
6451            check_pager_config("diff") != 0)
6452                setup_pager();
6453}