5256b9eabc903db2a1290ac786032285cd9cda1c
   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, 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 nofirst;
 634        FILE *file = o->file;
 635
 636        if (first)
 637                fputs(diff_line_prefix(o), file);
 638        else if (!len)
 639                return;
 640
 641        if (len == 0) {
 642                has_trailing_newline = (first == '\n');
 643                has_trailing_carriage_return = (!has_trailing_newline &&
 644                                                (first == '\r'));
 645                nofirst = has_trailing_newline || has_trailing_carriage_return;
 646        } else {
 647                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 648                if (has_trailing_newline)
 649                        len--;
 650                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 651                if (has_trailing_carriage_return)
 652                        len--;
 653                nofirst = 0;
 654        }
 655
 656        if (len || !nofirst) {
 657                if (reverse && want_color(o->use_color))
 658                        fputs(GIT_COLOR_REVERSE, file);
 659                fputs(set, file);
 660                if (first && !nofirst)
 661                        fputc(first, file);
 662                fwrite(line, len, 1, file);
 663                fputs(reset, file);
 664        }
 665        if (has_trailing_carriage_return)
 666                fputc('\r', file);
 667        if (has_trailing_newline)
 668                fputc('\n', file);
 669}
 670
 671static void emit_line(struct diff_options *o, const char *set, const char *reset,
 672                      const char *line, int len)
 673{
 674        emit_line_0(o, set, 0, reset, line[0], line+1, len-1);
 675}
 676
 677enum diff_symbol {
 678        DIFF_SYMBOL_BINARY_DIFF_HEADER,
 679        DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
 680        DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
 681        DIFF_SYMBOL_BINARY_DIFF_BODY,
 682        DIFF_SYMBOL_BINARY_DIFF_FOOTER,
 683        DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
 684        DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
 685        DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
 686        DIFF_SYMBOL_STATS_LINE,
 687        DIFF_SYMBOL_WORD_DIFF,
 688        DIFF_SYMBOL_STAT_SEP,
 689        DIFF_SYMBOL_SUMMARY,
 690        DIFF_SYMBOL_SUBMODULE_ADD,
 691        DIFF_SYMBOL_SUBMODULE_DEL,
 692        DIFF_SYMBOL_SUBMODULE_UNTRACKED,
 693        DIFF_SYMBOL_SUBMODULE_MODIFIED,
 694        DIFF_SYMBOL_SUBMODULE_HEADER,
 695        DIFF_SYMBOL_SUBMODULE_ERROR,
 696        DIFF_SYMBOL_SUBMODULE_PIPETHROUGH,
 697        DIFF_SYMBOL_REWRITE_DIFF,
 698        DIFF_SYMBOL_BINARY_FILES,
 699        DIFF_SYMBOL_HEADER,
 700        DIFF_SYMBOL_FILEPAIR_PLUS,
 701        DIFF_SYMBOL_FILEPAIR_MINUS,
 702        DIFF_SYMBOL_WORDS_PORCELAIN,
 703        DIFF_SYMBOL_WORDS,
 704        DIFF_SYMBOL_CONTEXT,
 705        DIFF_SYMBOL_CONTEXT_INCOMPLETE,
 706        DIFF_SYMBOL_PLUS,
 707        DIFF_SYMBOL_MINUS,
 708        DIFF_SYMBOL_NO_LF_EOF,
 709        DIFF_SYMBOL_CONTEXT_FRAGINFO,
 710        DIFF_SYMBOL_CONTEXT_MARKER,
 711        DIFF_SYMBOL_SEPARATOR
 712};
 713/*
 714 * Flags for content lines:
 715 * 0..12 are whitespace rules
 716 * 13-15 are WSEH_NEW | WSEH_OLD | WSEH_CONTEXT
 717 * 16 is marking if the line is blank at EOF
 718 */
 719#define DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF      (1<<16)
 720#define DIFF_SYMBOL_MOVED_LINE                  (1<<17)
 721#define DIFF_SYMBOL_MOVED_LINE_ALT              (1<<18)
 722#define DIFF_SYMBOL_MOVED_LINE_UNINTERESTING    (1<<19)
 723#define DIFF_SYMBOL_CONTENT_WS_MASK (WSEH_NEW | WSEH_OLD | WSEH_CONTEXT | WS_RULE_MASK)
 724
 725/*
 726 * This struct is used when we need to buffer the output of the diff output.
 727 *
 728 * NEEDSWORK: Instead of storing a copy of the line, add an offset pointer
 729 * into the pre/post image file. This pointer could be a union with the
 730 * line pointer. By storing an offset into the file instead of the literal line,
 731 * we can decrease the memory footprint for the buffered output. At first we
 732 * may want to only have indirection for the content lines, but we could also
 733 * enhance the state for emitting prefabricated lines, e.g. the similarity
 734 * score line or hunk/file headers would only need to store a number or path
 735 * and then the output can be constructed later on depending on state.
 736 */
 737struct emitted_diff_symbol {
 738        const char *line;
 739        int len;
 740        int flags;
 741        enum diff_symbol s;
 742};
 743#define EMITTED_DIFF_SYMBOL_INIT {NULL}
 744
 745struct emitted_diff_symbols {
 746        struct emitted_diff_symbol *buf;
 747        int nr, alloc;
 748};
 749#define EMITTED_DIFF_SYMBOLS_INIT {NULL, 0, 0}
 750
 751static void append_emitted_diff_symbol(struct diff_options *o,
 752                                       struct emitted_diff_symbol *e)
 753{
 754        struct emitted_diff_symbol *f;
 755
 756        ALLOC_GROW(o->emitted_symbols->buf,
 757                   o->emitted_symbols->nr + 1,
 758                   o->emitted_symbols->alloc);
 759        f = &o->emitted_symbols->buf[o->emitted_symbols->nr++];
 760
 761        memcpy(f, e, sizeof(struct emitted_diff_symbol));
 762        f->line = e->line ? xmemdupz(e->line, e->len) : NULL;
 763}
 764
 765struct moved_entry {
 766        struct hashmap_entry ent;
 767        const struct emitted_diff_symbol *es;
 768        struct moved_entry *next_line;
 769        struct ws_delta *wsd;
 770};
 771
 772/**
 773 * The struct ws_delta holds white space differences between moved lines, i.e.
 774 * between '+' and '-' lines that have been detected to be a move.
 775 * The string contains the difference in leading white spaces, before the
 776 * rest of the line is compared using the white space config for move
 777 * coloring. The current_longer indicates if the first string in the
 778 * comparision is longer than the second.
 779 */
 780struct ws_delta {
 781        char *string;
 782        unsigned int current_longer : 1;
 783};
 784#define WS_DELTA_INIT { NULL, 0 }
 785
 786static int compute_ws_delta(const struct emitted_diff_symbol *a,
 787                             const struct emitted_diff_symbol *b,
 788                             struct ws_delta *out)
 789{
 790        const struct emitted_diff_symbol *longer =  a->len > b->len ? a : b;
 791        const struct emitted_diff_symbol *shorter = a->len > b->len ? b : a;
 792        int d = longer->len - shorter->len;
 793
 794        out->string = xmemdupz(longer->line, d);
 795        out->current_longer = (a == longer);
 796
 797        return !strncmp(longer->line + d, shorter->line, shorter->len);
 798}
 799
 800static int cmp_in_block_with_wsd(const struct diff_options *o,
 801                                 const struct moved_entry *cur,
 802                                 const struct moved_entry *match,
 803                                 struct moved_entry *pmb,
 804                                 int n)
 805{
 806        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
 807        int al = cur->es->len, cl = l->len;
 808        const char *a = cur->es->line,
 809                   *b = match->es->line,
 810                   *c = l->line;
 811
 812        int wslen;
 813
 814        /*
 815         * We need to check if 'cur' is equal to 'match'.
 816         * As those are from the same (+/-) side, we do not need to adjust for
 817         * indent changes. However these were found using fuzzy matching
 818         * so we do have to check if they are equal.
 819         */
 820        if (strcmp(a, b))
 821                return 1;
 822
 823        if (!pmb->wsd)
 824                /*
 825                 * No white space delta was carried forward? This can happen
 826                 * when we exit early in this function and do not carry
 827                 * forward ws.
 828                 */
 829                return 1;
 830
 831        /*
 832         * The indent changes of the block are known and carried forward in
 833         * pmb->wsd; however we need to check if the indent changes of the
 834         * current line are still the same as before.
 835         *
 836         * To do so we need to compare 'l' to 'cur', adjusting the
 837         * one of them for the white spaces, depending which was longer.
 838         */
 839
 840        wslen = strlen(pmb->wsd->string);
 841        if (pmb->wsd->current_longer) {
 842                c += wslen;
 843                cl -= wslen;
 844        } else {
 845                a += wslen;
 846                al -= wslen;
 847        }
 848
 849        if (strcmp(a, c))
 850                return 1;
 851
 852        return 0;
 853}
 854
 855static int moved_entry_cmp(const void *hashmap_cmp_fn_data,
 856                           const void *entry,
 857                           const void *entry_or_key,
 858                           const void *keydata)
 859{
 860        const struct diff_options *diffopt = hashmap_cmp_fn_data;
 861        const struct moved_entry *a = entry;
 862        const struct moved_entry *b = entry_or_key;
 863        unsigned flags = diffopt->color_moved_ws_handling
 864                         & XDF_WHITESPACE_FLAGS;
 865
 866        if (diffopt->color_moved_ws_handling &
 867            COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
 868                /*
 869                 * As there is not specific white space config given,
 870                 * we'd need to check for a new block, so ignore all
 871                 * white space. The setup of the white space
 872                 * configuration for the next block is done else where
 873                 */
 874                flags |= XDF_IGNORE_WHITESPACE;
 875
 876        return !xdiff_compare_lines(a->es->line, a->es->len,
 877                                    b->es->line, b->es->len,
 878                                    flags);
 879}
 880
 881static struct moved_entry *prepare_entry(struct diff_options *o,
 882                                         int line_no)
 883{
 884        struct moved_entry *ret = xmalloc(sizeof(*ret));
 885        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[line_no];
 886        unsigned flags = o->color_moved_ws_handling & XDF_WHITESPACE_FLAGS;
 887
 888        ret->ent.hash = xdiff_hash_string(l->line, l->len, flags);
 889        ret->es = l;
 890        ret->next_line = NULL;
 891        ret->wsd = NULL;
 892
 893        return ret;
 894}
 895
 896static void add_lines_to_move_detection(struct diff_options *o,
 897                                        struct hashmap *add_lines,
 898                                        struct hashmap *del_lines)
 899{
 900        struct moved_entry *prev_line = NULL;
 901
 902        int n;
 903        for (n = 0; n < o->emitted_symbols->nr; n++) {
 904                struct hashmap *hm;
 905                struct moved_entry *key;
 906
 907                switch (o->emitted_symbols->buf[n].s) {
 908                case DIFF_SYMBOL_PLUS:
 909                        hm = add_lines;
 910                        break;
 911                case DIFF_SYMBOL_MINUS:
 912                        hm = del_lines;
 913                        break;
 914                default:
 915                        prev_line = NULL;
 916                        continue;
 917                }
 918
 919                key = prepare_entry(o, n);
 920                if (prev_line && prev_line->es->s == o->emitted_symbols->buf[n].s)
 921                        prev_line->next_line = key;
 922
 923                hashmap_add(hm, key);
 924                prev_line = key;
 925        }
 926}
 927
 928static void pmb_advance_or_null(struct diff_options *o,
 929                                struct moved_entry *match,
 930                                struct hashmap *hm,
 931                                struct moved_entry **pmb,
 932                                int pmb_nr)
 933{
 934        int i;
 935        for (i = 0; i < pmb_nr; i++) {
 936                struct moved_entry *prev = pmb[i];
 937                struct moved_entry *cur = (prev && prev->next_line) ?
 938                                prev->next_line : NULL;
 939                if (cur && !hm->cmpfn(o, cur, match, NULL)) {
 940                        pmb[i] = cur;
 941                } else {
 942                        pmb[i] = NULL;
 943                }
 944        }
 945}
 946
 947static void pmb_advance_or_null_multi_match(struct diff_options *o,
 948                                            struct moved_entry *match,
 949                                            struct hashmap *hm,
 950                                            struct moved_entry **pmb,
 951                                            int pmb_nr, int n)
 952{
 953        int i;
 954        char *got_match = xcalloc(1, pmb_nr);
 955
 956        for (; match; match = hashmap_get_next(hm, match)) {
 957                for (i = 0; i < pmb_nr; i++) {
 958                        struct moved_entry *prev = pmb[i];
 959                        struct moved_entry *cur = (prev && prev->next_line) ?
 960                                        prev->next_line : NULL;
 961                        if (!cur)
 962                                continue;
 963                        if (!cmp_in_block_with_wsd(o, cur, match, pmb[i], n))
 964                                got_match[i] |= 1;
 965                }
 966        }
 967
 968        for (i = 0; i < pmb_nr; i++) {
 969                if (got_match[i]) {
 970                        /* Carry the white space delta forward */
 971                        pmb[i]->next_line->wsd = pmb[i]->wsd;
 972                        pmb[i] = pmb[i]->next_line;
 973                } else
 974                        pmb[i] = NULL;
 975        }
 976}
 977
 978static int shrink_potential_moved_blocks(struct moved_entry **pmb,
 979                                         int pmb_nr)
 980{
 981        int lp, rp;
 982
 983        /* Shrink the set of potential block to the remaining running */
 984        for (lp = 0, rp = pmb_nr - 1; lp <= rp;) {
 985                while (lp < pmb_nr && pmb[lp])
 986                        lp++;
 987                /* lp points at the first NULL now */
 988
 989                while (rp > -1 && !pmb[rp])
 990                        rp--;
 991                /* rp points at the last non-NULL */
 992
 993                if (lp < pmb_nr && rp > -1 && lp < rp) {
 994                        pmb[lp] = pmb[rp];
 995                        if (pmb[rp]->wsd) {
 996                                free(pmb[rp]->wsd->string);
 997                                FREE_AND_NULL(pmb[rp]->wsd);
 998                        }
 999                        pmb[rp] = NULL;
1000                        rp--;
1001                        lp++;
1002                }
1003        }
1004
1005        /* Remember the number of running sets */
1006        return rp + 1;
1007}
1008
1009/*
1010 * If o->color_moved is COLOR_MOVED_PLAIN, this function does nothing.
1011 *
1012 * Otherwise, if the last block has fewer alphanumeric characters than
1013 * COLOR_MOVED_MIN_ALNUM_COUNT, unset DIFF_SYMBOL_MOVED_LINE on all lines in
1014 * that block.
1015 *
1016 * The last block consists of the (n - block_length)'th line up to but not
1017 * including the nth line.
1018 *
1019 * NEEDSWORK: This uses the same heuristic as blame_entry_score() in blame.c.
1020 * Think of a way to unify them.
1021 */
1022static void adjust_last_block(struct diff_options *o, int n, int block_length)
1023{
1024        int i, alnum_count = 0;
1025        if (o->color_moved == COLOR_MOVED_PLAIN)
1026                return;
1027        for (i = 1; i < block_length + 1; i++) {
1028                const char *c = o->emitted_symbols->buf[n - i].line;
1029                for (; *c; c++) {
1030                        if (!isalnum(*c))
1031                                continue;
1032                        alnum_count++;
1033                        if (alnum_count >= COLOR_MOVED_MIN_ALNUM_COUNT)
1034                                return;
1035                }
1036        }
1037        for (i = 1; i < block_length + 1; i++)
1038                o->emitted_symbols->buf[n - i].flags &= ~DIFF_SYMBOL_MOVED_LINE;
1039}
1040
1041/* Find blocks of moved code, delegate actual coloring decision to helper */
1042static void mark_color_as_moved(struct diff_options *o,
1043                                struct hashmap *add_lines,
1044                                struct hashmap *del_lines)
1045{
1046        struct moved_entry **pmb = NULL; /* potentially moved blocks */
1047        int pmb_nr = 0, pmb_alloc = 0;
1048        int n, flipped_block = 1, block_length = 0;
1049
1050
1051        for (n = 0; n < o->emitted_symbols->nr; n++) {
1052                struct hashmap *hm = NULL;
1053                struct moved_entry *key;
1054                struct moved_entry *match = NULL;
1055                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
1056
1057                switch (l->s) {
1058                case DIFF_SYMBOL_PLUS:
1059                        hm = del_lines;
1060                        key = prepare_entry(o, n);
1061                        match = hashmap_get(hm, key, NULL);
1062                        free(key);
1063                        break;
1064                case DIFF_SYMBOL_MINUS:
1065                        hm = add_lines;
1066                        key = prepare_entry(o, n);
1067                        match = hashmap_get(hm, key, NULL);
1068                        free(key);
1069                        break;
1070                default:
1071                        flipped_block = 1;
1072                }
1073
1074                if (!match) {
1075                        adjust_last_block(o, n, block_length);
1076                        pmb_nr = 0;
1077                        block_length = 0;
1078                        continue;
1079                }
1080
1081                l->flags |= DIFF_SYMBOL_MOVED_LINE;
1082
1083                if (o->color_moved == COLOR_MOVED_PLAIN)
1084                        continue;
1085
1086                if (o->color_moved_ws_handling &
1087                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
1088                        pmb_advance_or_null_multi_match(o, match, hm, pmb, pmb_nr, n);
1089                else
1090                        pmb_advance_or_null(o, match, hm, pmb, pmb_nr);
1091
1092                pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
1093
1094                if (pmb_nr == 0) {
1095                        /*
1096                         * The current line is the start of a new block.
1097                         * Setup the set of potential blocks.
1098                         */
1099                        for (; match; match = hashmap_get_next(hm, match)) {
1100                                ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
1101                                if (o->color_moved_ws_handling &
1102                                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) {
1103                                        struct ws_delta *wsd = xmalloc(sizeof(*match->wsd));
1104                                        if (compute_ws_delta(l, match->es, wsd)) {
1105                                                match->wsd = wsd;
1106                                                pmb[pmb_nr++] = match;
1107                                        } else
1108                                                free(wsd);
1109                                } else {
1110                                        pmb[pmb_nr++] = match;
1111                                }
1112                        }
1113
1114                        flipped_block = (flipped_block + 1) % 2;
1115
1116                        adjust_last_block(o, n, block_length);
1117                        block_length = 0;
1118                }
1119
1120                block_length++;
1121
1122                if (flipped_block && o->color_moved != COLOR_MOVED_BLOCKS)
1123                        l->flags |= DIFF_SYMBOL_MOVED_LINE_ALT;
1124        }
1125        adjust_last_block(o, n, block_length);
1126
1127        free(pmb);
1128}
1129
1130#define DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK \
1131  (DIFF_SYMBOL_MOVED_LINE | DIFF_SYMBOL_MOVED_LINE_ALT)
1132static void dim_moved_lines(struct diff_options *o)
1133{
1134        int n;
1135        for (n = 0; n < o->emitted_symbols->nr; n++) {
1136                struct emitted_diff_symbol *prev = (n != 0) ?
1137                                &o->emitted_symbols->buf[n - 1] : NULL;
1138                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
1139                struct emitted_diff_symbol *next =
1140                                (n < o->emitted_symbols->nr - 1) ?
1141                                &o->emitted_symbols->buf[n + 1] : NULL;
1142
1143                /* Not a plus or minus line? */
1144                if (l->s != DIFF_SYMBOL_PLUS && l->s != DIFF_SYMBOL_MINUS)
1145                        continue;
1146
1147                /* Not a moved line? */
1148                if (!(l->flags & DIFF_SYMBOL_MOVED_LINE))
1149                        continue;
1150
1151                /*
1152                 * If prev or next are not a plus or minus line,
1153                 * pretend they don't exist
1154                 */
1155                if (prev && prev->s != DIFF_SYMBOL_PLUS &&
1156                            prev->s != DIFF_SYMBOL_MINUS)
1157                        prev = NULL;
1158                if (next && next->s != DIFF_SYMBOL_PLUS &&
1159                            next->s != DIFF_SYMBOL_MINUS)
1160                        next = NULL;
1161
1162                /* Inside a block? */
1163                if ((prev &&
1164                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
1165                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK)) &&
1166                    (next &&
1167                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
1168                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK))) {
1169                        l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1170                        continue;
1171                }
1172
1173                /* Check if we are at an interesting bound: */
1174                if (prev && (prev->flags & DIFF_SYMBOL_MOVED_LINE) &&
1175                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1176                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1177                        continue;
1178                if (next && (next->flags & DIFF_SYMBOL_MOVED_LINE) &&
1179                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1180                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1181                        continue;
1182
1183                /*
1184                 * The boundary to prev and next are not interesting,
1185                 * so this line is not interesting as a whole
1186                 */
1187                l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1188        }
1189}
1190
1191static void emit_line_ws_markup(struct diff_options *o,
1192                                const char *set, const char *reset,
1193                                const char *line, int len,
1194                                const char *set_sign, char sign,
1195                                unsigned ws_rule, int blank_at_eof)
1196{
1197        const char *ws = NULL;
1198
1199        if (o->ws_error_highlight & ws_rule) {
1200                ws = diff_get_color_opt(o, DIFF_WHITESPACE);
1201                if (!*ws)
1202                        ws = NULL;
1203        }
1204
1205        if (!ws && !set_sign)
1206                emit_line_0(o, set, 0, reset, sign, line, len);
1207        else if (!ws) {
1208                /* Emit just the prefix, then the rest. */
1209                emit_line_0(o, set_sign ? set_sign : set, !!set_sign, reset,
1210                            sign, "", 0);
1211                emit_line_0(o, set, 0, reset, 0, line, len);
1212        } else if (blank_at_eof)
1213                /* Blank line at EOF - paint '+' as well */
1214                emit_line_0(o, ws, 0, reset, sign, line, len);
1215        else {
1216                /* Emit just the prefix, then the rest. */
1217                emit_line_0(o, set_sign ? set_sign : set, !!set_sign, reset,
1218                            sign, "", 0);
1219                ws_check_emit(line, len, ws_rule,
1220                              o->file, set, reset, ws);
1221        }
1222}
1223
1224static void emit_diff_symbol_from_struct(struct diff_options *o,
1225                                         struct emitted_diff_symbol *eds)
1226{
1227        static const char *nneof = " No newline at end of file\n";
1228        const char *context, *reset, *set, *set_sign, *meta, *fraginfo;
1229        struct strbuf sb = STRBUF_INIT;
1230
1231        enum diff_symbol s = eds->s;
1232        const char *line = eds->line;
1233        int len = eds->len;
1234        unsigned flags = eds->flags;
1235
1236        switch (s) {
1237        case DIFF_SYMBOL_NO_LF_EOF:
1238                context = diff_get_color_opt(o, DIFF_CONTEXT);
1239                reset = diff_get_color_opt(o, DIFF_RESET);
1240                putc('\n', o->file);
1241                emit_line_0(o, context, 0, reset, '\\',
1242                            nneof, strlen(nneof));
1243                break;
1244        case DIFF_SYMBOL_SUBMODULE_HEADER:
1245        case DIFF_SYMBOL_SUBMODULE_ERROR:
1246        case DIFF_SYMBOL_SUBMODULE_PIPETHROUGH:
1247        case DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES:
1248        case DIFF_SYMBOL_SUMMARY:
1249        case DIFF_SYMBOL_STATS_LINE:
1250        case DIFF_SYMBOL_BINARY_DIFF_BODY:
1251        case DIFF_SYMBOL_CONTEXT_FRAGINFO:
1252                emit_line(o, "", "", line, len);
1253                break;
1254        case DIFF_SYMBOL_CONTEXT_INCOMPLETE:
1255        case DIFF_SYMBOL_CONTEXT_MARKER:
1256                context = diff_get_color_opt(o, DIFF_CONTEXT);
1257                reset = diff_get_color_opt(o, DIFF_RESET);
1258                emit_line(o, context, reset, line, len);
1259                break;
1260        case DIFF_SYMBOL_SEPARATOR:
1261                fprintf(o->file, "%s%c",
1262                        diff_line_prefix(o),
1263                        o->line_termination);
1264                break;
1265        case DIFF_SYMBOL_CONTEXT:
1266                set = diff_get_color_opt(o, DIFF_CONTEXT);
1267                reset = diff_get_color_opt(o, DIFF_RESET);
1268                set_sign = NULL;
1269                if (o->flags.dual_color_diffed_diffs) {
1270                        char c = !len ? 0 : line[0];
1271
1272                        if (c == '+')
1273                                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1274                        else if (c == '@')
1275                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1276                        else if (c == '-')
1277                                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1278                }
1279                emit_line_ws_markup(o, set, reset, line, len, set_sign, ' ',
1280                                    flags & (DIFF_SYMBOL_CONTENT_WS_MASK), 0);
1281                break;
1282        case DIFF_SYMBOL_PLUS:
1283                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1284                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1285                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1286                case DIFF_SYMBOL_MOVED_LINE |
1287                     DIFF_SYMBOL_MOVED_LINE_ALT |
1288                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1289                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT_DIM);
1290                        break;
1291                case DIFF_SYMBOL_MOVED_LINE |
1292                     DIFF_SYMBOL_MOVED_LINE_ALT:
1293                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT);
1294                        break;
1295                case DIFF_SYMBOL_MOVED_LINE |
1296                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1297                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_DIM);
1298                        break;
1299                case DIFF_SYMBOL_MOVED_LINE:
1300                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED);
1301                        break;
1302                default:
1303                        set = diff_get_color_opt(o, DIFF_FILE_NEW);
1304                }
1305                reset = diff_get_color_opt(o, DIFF_RESET);
1306                if (!o->flags.dual_color_diffed_diffs)
1307                        set_sign = NULL;
1308                else {
1309                        char c = !len ? 0 : line[0];
1310
1311                        set_sign = set;
1312                        if (c == '-')
1313                                set = diff_get_color_opt(o, DIFF_FILE_OLD_BOLD);
1314                        else if (c == '@')
1315                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1316                        else if (c == '+')
1317                                set = diff_get_color_opt(o, DIFF_FILE_NEW_BOLD);
1318                        else
1319                                set = diff_get_color_opt(o, DIFF_CONTEXT_BOLD);
1320                        flags &= ~DIFF_SYMBOL_CONTENT_WS_MASK;
1321                }
1322                emit_line_ws_markup(o, set, reset, line, len, set_sign, '+',
1323                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK,
1324                                    flags & DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF);
1325                break;
1326        case DIFF_SYMBOL_MINUS:
1327                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1328                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1329                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1330                case DIFF_SYMBOL_MOVED_LINE |
1331                     DIFF_SYMBOL_MOVED_LINE_ALT |
1332                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1333                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT_DIM);
1334                        break;
1335                case DIFF_SYMBOL_MOVED_LINE |
1336                     DIFF_SYMBOL_MOVED_LINE_ALT:
1337                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT);
1338                        break;
1339                case DIFF_SYMBOL_MOVED_LINE |
1340                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1341                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_DIM);
1342                        break;
1343                case DIFF_SYMBOL_MOVED_LINE:
1344                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED);
1345                        break;
1346                default:
1347                        set = diff_get_color_opt(o, DIFF_FILE_OLD);
1348                }
1349                reset = diff_get_color_opt(o, DIFF_RESET);
1350                if (!o->flags.dual_color_diffed_diffs)
1351                        set_sign = NULL;
1352                else {
1353                        char c = !len ? 0 : line[0];
1354
1355                        set_sign = set;
1356                        if (c == '+')
1357                                set = diff_get_color_opt(o, DIFF_FILE_NEW_DIM);
1358                        else if (c == '@')
1359                                set = diff_get_color_opt(o, DIFF_FRAGINFO);
1360                        else if (c == '-')
1361                                set = diff_get_color_opt(o, DIFF_FILE_OLD_DIM);
1362                        else
1363                                set = diff_get_color_opt(o, DIFF_CONTEXT_DIM);
1364                }
1365                emit_line_ws_markup(o, set, reset, line, len, set_sign, '-',
1366                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK, 0);
1367                break;
1368        case DIFF_SYMBOL_WORDS_PORCELAIN:
1369                context = diff_get_color_opt(o, DIFF_CONTEXT);
1370                reset = diff_get_color_opt(o, DIFF_RESET);
1371                emit_line(o, context, reset, line, len);
1372                fputs("~\n", o->file);
1373                break;
1374        case DIFF_SYMBOL_WORDS:
1375                context = diff_get_color_opt(o, DIFF_CONTEXT);
1376                reset = diff_get_color_opt(o, DIFF_RESET);
1377                /*
1378                 * Skip the prefix character, if any.  With
1379                 * diff_suppress_blank_empty, there may be
1380                 * none.
1381                 */
1382                if (line[0] != '\n') {
1383                        line++;
1384                        len--;
1385                }
1386                emit_line(o, context, reset, line, len);
1387                break;
1388        case DIFF_SYMBOL_FILEPAIR_PLUS:
1389                meta = diff_get_color_opt(o, DIFF_METAINFO);
1390                reset = diff_get_color_opt(o, DIFF_RESET);
1391                fprintf(o->file, "%s%s+++ %s%s%s\n", diff_line_prefix(o), meta,
1392                        line, reset,
1393                        strchr(line, ' ') ? "\t" : "");
1394                break;
1395        case DIFF_SYMBOL_FILEPAIR_MINUS:
1396                meta = diff_get_color_opt(o, DIFF_METAINFO);
1397                reset = diff_get_color_opt(o, DIFF_RESET);
1398                fprintf(o->file, "%s%s--- %s%s%s\n", diff_line_prefix(o), meta,
1399                        line, reset,
1400                        strchr(line, ' ') ? "\t" : "");
1401                break;
1402        case DIFF_SYMBOL_BINARY_FILES:
1403        case DIFF_SYMBOL_HEADER:
1404                fprintf(o->file, "%s", line);
1405                break;
1406        case DIFF_SYMBOL_BINARY_DIFF_HEADER:
1407                fprintf(o->file, "%sGIT binary patch\n", diff_line_prefix(o));
1408                break;
1409        case DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA:
1410                fprintf(o->file, "%sdelta %s\n", diff_line_prefix(o), line);
1411                break;
1412        case DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL:
1413                fprintf(o->file, "%sliteral %s\n", diff_line_prefix(o), line);
1414                break;
1415        case DIFF_SYMBOL_BINARY_DIFF_FOOTER:
1416                fputs(diff_line_prefix(o), o->file);
1417                fputc('\n', o->file);
1418                break;
1419        case DIFF_SYMBOL_REWRITE_DIFF:
1420                fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
1421                reset = diff_get_color_opt(o, DIFF_RESET);
1422                emit_line(o, fraginfo, reset, line, len);
1423                break;
1424        case DIFF_SYMBOL_SUBMODULE_ADD:
1425                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1426                reset = diff_get_color_opt(o, DIFF_RESET);
1427                emit_line(o, set, reset, line, len);
1428                break;
1429        case DIFF_SYMBOL_SUBMODULE_DEL:
1430                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1431                reset = diff_get_color_opt(o, DIFF_RESET);
1432                emit_line(o, set, reset, line, len);
1433                break;
1434        case DIFF_SYMBOL_SUBMODULE_UNTRACKED:
1435                fprintf(o->file, "%sSubmodule %s contains untracked content\n",
1436                        diff_line_prefix(o), line);
1437                break;
1438        case DIFF_SYMBOL_SUBMODULE_MODIFIED:
1439                fprintf(o->file, "%sSubmodule %s contains modified content\n",
1440                        diff_line_prefix(o), line);
1441                break;
1442        case DIFF_SYMBOL_STATS_SUMMARY_NO_FILES:
1443                emit_line(o, "", "", " 0 files changed\n",
1444                          strlen(" 0 files changed\n"));
1445                break;
1446        case DIFF_SYMBOL_STATS_SUMMARY_ABBREV:
1447                emit_line(o, "", "", " ...\n", strlen(" ...\n"));
1448                break;
1449        case DIFF_SYMBOL_WORD_DIFF:
1450                fprintf(o->file, "%.*s", len, line);
1451                break;
1452        case DIFF_SYMBOL_STAT_SEP:
1453                fputs(o->stat_sep, o->file);
1454                break;
1455        default:
1456                BUG("unknown diff symbol");
1457        }
1458        strbuf_release(&sb);
1459}
1460
1461static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
1462                             const char *line, int len, unsigned flags)
1463{
1464        struct emitted_diff_symbol e = {line, len, flags, s};
1465
1466        if (o->emitted_symbols)
1467                append_emitted_diff_symbol(o, &e);
1468        else
1469                emit_diff_symbol_from_struct(o, &e);
1470}
1471
1472void diff_emit_submodule_del(struct diff_options *o, const char *line)
1473{
1474        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_DEL, line, strlen(line), 0);
1475}
1476
1477void diff_emit_submodule_add(struct diff_options *o, const char *line)
1478{
1479        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ADD, line, strlen(line), 0);
1480}
1481
1482void diff_emit_submodule_untracked(struct diff_options *o, const char *path)
1483{
1484        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_UNTRACKED,
1485                         path, strlen(path), 0);
1486}
1487
1488void diff_emit_submodule_modified(struct diff_options *o, const char *path)
1489{
1490        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_MODIFIED,
1491                         path, strlen(path), 0);
1492}
1493
1494void diff_emit_submodule_header(struct diff_options *o, const char *header)
1495{
1496        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_HEADER,
1497                         header, strlen(header), 0);
1498}
1499
1500void diff_emit_submodule_error(struct diff_options *o, const char *err)
1501{
1502        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ERROR, err, strlen(err), 0);
1503}
1504
1505void diff_emit_submodule_pipethrough(struct diff_options *o,
1506                                     const char *line, int len)
1507{
1508        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_PIPETHROUGH, line, len, 0);
1509}
1510
1511static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
1512{
1513        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
1514              ecbdata->blank_at_eof_in_preimage &&
1515              ecbdata->blank_at_eof_in_postimage &&
1516              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
1517              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
1518                return 0;
1519        return ws_blank_line(line, len, ecbdata->ws_rule);
1520}
1521
1522static void emit_add_line(const char *reset,
1523                          struct emit_callback *ecbdata,
1524                          const char *line, int len)
1525{
1526        unsigned flags = WSEH_NEW | ecbdata->ws_rule;
1527        if (new_blank_line_at_eof(ecbdata, line, len))
1528                flags |= DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF;
1529
1530        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_PLUS, line, len, flags);
1531}
1532
1533static void emit_del_line(const char *reset,
1534                          struct emit_callback *ecbdata,
1535                          const char *line, int len)
1536{
1537        unsigned flags = WSEH_OLD | ecbdata->ws_rule;
1538        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_MINUS, line, len, flags);
1539}
1540
1541static void emit_context_line(const char *reset,
1542                              struct emit_callback *ecbdata,
1543                              const char *line, int len)
1544{
1545        unsigned flags = WSEH_CONTEXT | ecbdata->ws_rule;
1546        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_CONTEXT, line, len, flags);
1547}
1548
1549static void emit_hunk_header(struct emit_callback *ecbdata,
1550                             const char *line, int len)
1551{
1552        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
1553        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
1554        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
1555        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1556        const char *reverse = ecbdata->color_diff ? GIT_COLOR_REVERSE : "";
1557        static const char atat[2] = { '@', '@' };
1558        const char *cp, *ep;
1559        struct strbuf msgbuf = STRBUF_INIT;
1560        int org_len = len;
1561        int i = 1;
1562
1563        /*
1564         * As a hunk header must begin with "@@ -<old>, +<new> @@",
1565         * it always is at least 10 bytes long.
1566         */
1567        if (len < 10 ||
1568            memcmp(line, atat, 2) ||
1569            !(ep = memmem(line + 2, len - 2, atat, 2))) {
1570                emit_diff_symbol(ecbdata->opt,
1571                                 DIFF_SYMBOL_CONTEXT_MARKER, line, len, 0);
1572                return;
1573        }
1574        ep += 2; /* skip over @@ */
1575
1576        /* The hunk header in fraginfo color */
1577        if (ecbdata->opt->flags.dual_color_diffed_diffs)
1578                strbuf_addstr(&msgbuf, reverse);
1579        strbuf_addstr(&msgbuf, frag);
1580        strbuf_add(&msgbuf, line, ep - line);
1581        strbuf_addstr(&msgbuf, reset);
1582
1583        /*
1584         * trailing "\r\n"
1585         */
1586        for ( ; i < 3; i++)
1587                if (line[len - i] == '\r' || line[len - i] == '\n')
1588                        len--;
1589
1590        /* blank before the func header */
1591        for (cp = ep; ep - line < len; ep++)
1592                if (*ep != ' ' && *ep != '\t')
1593                        break;
1594        if (ep != cp) {
1595                strbuf_addstr(&msgbuf, context);
1596                strbuf_add(&msgbuf, cp, ep - cp);
1597                strbuf_addstr(&msgbuf, reset);
1598        }
1599
1600        if (ep < line + len) {
1601                strbuf_addstr(&msgbuf, func);
1602                strbuf_add(&msgbuf, ep, line + len - ep);
1603                strbuf_addstr(&msgbuf, reset);
1604        }
1605
1606        strbuf_add(&msgbuf, line + len, org_len - len);
1607        strbuf_complete_line(&msgbuf);
1608        emit_diff_symbol(ecbdata->opt,
1609                         DIFF_SYMBOL_CONTEXT_FRAGINFO, msgbuf.buf, msgbuf.len, 0);
1610        strbuf_release(&msgbuf);
1611}
1612
1613static struct diff_tempfile *claim_diff_tempfile(void) {
1614        int i;
1615        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
1616                if (!diff_temp[i].name)
1617                        return diff_temp + i;
1618        BUG("diff is failing to clean up its tempfiles");
1619}
1620
1621static void remove_tempfile(void)
1622{
1623        int i;
1624        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
1625                if (is_tempfile_active(diff_temp[i].tempfile))
1626                        delete_tempfile(&diff_temp[i].tempfile);
1627                diff_temp[i].name = NULL;
1628        }
1629}
1630
1631static void add_line_count(struct strbuf *out, int count)
1632{
1633        switch (count) {
1634        case 0:
1635                strbuf_addstr(out, "0,0");
1636                break;
1637        case 1:
1638                strbuf_addstr(out, "1");
1639                break;
1640        default:
1641                strbuf_addf(out, "1,%d", count);
1642                break;
1643        }
1644}
1645
1646static void emit_rewrite_lines(struct emit_callback *ecb,
1647                               int prefix, const char *data, int size)
1648{
1649        const char *endp = NULL;
1650        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
1651
1652        while (0 < size) {
1653                int len;
1654
1655                endp = memchr(data, '\n', size);
1656                len = endp ? (endp - data + 1) : size;
1657                if (prefix != '+') {
1658                        ecb->lno_in_preimage++;
1659                        emit_del_line(reset, ecb, data, len);
1660                } else {
1661                        ecb->lno_in_postimage++;
1662                        emit_add_line(reset, ecb, data, len);
1663                }
1664                size -= len;
1665                data += len;
1666        }
1667        if (!endp)
1668                emit_diff_symbol(ecb->opt, DIFF_SYMBOL_NO_LF_EOF, NULL, 0, 0);
1669}
1670
1671static void emit_rewrite_diff(const char *name_a,
1672                              const char *name_b,
1673                              struct diff_filespec *one,
1674                              struct diff_filespec *two,
1675                              struct userdiff_driver *textconv_one,
1676                              struct userdiff_driver *textconv_two,
1677                              struct diff_options *o)
1678{
1679        int lc_a, lc_b;
1680        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
1681        const char *a_prefix, *b_prefix;
1682        char *data_one, *data_two;
1683        size_t size_one, size_two;
1684        struct emit_callback ecbdata;
1685        struct strbuf out = STRBUF_INIT;
1686
1687        if (diff_mnemonic_prefix && o->flags.reverse_diff) {
1688                a_prefix = o->b_prefix;
1689                b_prefix = o->a_prefix;
1690        } else {
1691                a_prefix = o->a_prefix;
1692                b_prefix = o->b_prefix;
1693        }
1694
1695        name_a += (*name_a == '/');
1696        name_b += (*name_b == '/');
1697
1698        strbuf_reset(&a_name);
1699        strbuf_reset(&b_name);
1700        quote_two_c_style(&a_name, a_prefix, name_a, 0);
1701        quote_two_c_style(&b_name, b_prefix, name_b, 0);
1702
1703        size_one = fill_textconv(o->repo, textconv_one, one, &data_one);
1704        size_two = fill_textconv(o->repo, textconv_two, two, &data_two);
1705
1706        memset(&ecbdata, 0, sizeof(ecbdata));
1707        ecbdata.color_diff = want_color(o->use_color);
1708        ecbdata.ws_rule = whitespace_rule(name_b);
1709        ecbdata.opt = o;
1710        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
1711                mmfile_t mf1, mf2;
1712                mf1.ptr = (char *)data_one;
1713                mf2.ptr = (char *)data_two;
1714                mf1.size = size_one;
1715                mf2.size = size_two;
1716                check_blank_at_eof(&mf1, &mf2, &ecbdata);
1717        }
1718        ecbdata.lno_in_preimage = 1;
1719        ecbdata.lno_in_postimage = 1;
1720
1721        lc_a = count_lines(data_one, size_one);
1722        lc_b = count_lines(data_two, size_two);
1723
1724        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
1725                         a_name.buf, a_name.len, 0);
1726        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
1727                         b_name.buf, b_name.len, 0);
1728
1729        strbuf_addstr(&out, "@@ -");
1730        if (!o->irreversible_delete)
1731                add_line_count(&out, lc_a);
1732        else
1733                strbuf_addstr(&out, "?,?");
1734        strbuf_addstr(&out, " +");
1735        add_line_count(&out, lc_b);
1736        strbuf_addstr(&out, " @@\n");
1737        emit_diff_symbol(o, DIFF_SYMBOL_REWRITE_DIFF, out.buf, out.len, 0);
1738        strbuf_release(&out);
1739
1740        if (lc_a && !o->irreversible_delete)
1741                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
1742        if (lc_b)
1743                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
1744        if (textconv_one)
1745                free((char *)data_one);
1746        if (textconv_two)
1747                free((char *)data_two);
1748}
1749
1750struct diff_words_buffer {
1751        mmfile_t text;
1752        unsigned long alloc;
1753        struct diff_words_orig {
1754                const char *begin, *end;
1755        } *orig;
1756        int orig_nr, orig_alloc;
1757};
1758
1759static void diff_words_append(char *line, unsigned long len,
1760                struct diff_words_buffer *buffer)
1761{
1762        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
1763        line++;
1764        len--;
1765        memcpy(buffer->text.ptr + buffer->text.size, line, len);
1766        buffer->text.size += len;
1767        buffer->text.ptr[buffer->text.size] = '\0';
1768}
1769
1770struct diff_words_style_elem {
1771        const char *prefix;
1772        const char *suffix;
1773        const char *color; /* NULL; filled in by the setup code if
1774                            * color is enabled */
1775};
1776
1777struct diff_words_style {
1778        enum diff_words_type type;
1779        struct diff_words_style_elem new_word, old_word, ctx;
1780        const char *newline;
1781};
1782
1783static struct diff_words_style diff_words_styles[] = {
1784        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
1785        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
1786        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
1787};
1788
1789struct diff_words_data {
1790        struct diff_words_buffer minus, plus;
1791        const char *current_plus;
1792        int last_minus;
1793        struct diff_options *opt;
1794        regex_t *word_regex;
1795        enum diff_words_type type;
1796        struct diff_words_style *style;
1797};
1798
1799static int fn_out_diff_words_write_helper(struct diff_options *o,
1800                                          struct diff_words_style_elem *st_el,
1801                                          const char *newline,
1802                                          size_t count, const char *buf)
1803{
1804        int print = 0;
1805        struct strbuf sb = STRBUF_INIT;
1806
1807        while (count) {
1808                char *p = memchr(buf, '\n', count);
1809                if (print)
1810                        strbuf_addstr(&sb, diff_line_prefix(o));
1811
1812                if (p != buf) {
1813                        const char *reset = st_el->color && *st_el->color ?
1814                                            GIT_COLOR_RESET : NULL;
1815                        if (st_el->color && *st_el->color)
1816                                strbuf_addstr(&sb, st_el->color);
1817                        strbuf_addstr(&sb, st_el->prefix);
1818                        strbuf_add(&sb, buf, p ? p - buf : count);
1819                        strbuf_addstr(&sb, st_el->suffix);
1820                        if (reset)
1821                                strbuf_addstr(&sb, reset);
1822                }
1823                if (!p)
1824                        goto out;
1825
1826                strbuf_addstr(&sb, newline);
1827                count -= p + 1 - buf;
1828                buf = p + 1;
1829                print = 1;
1830                if (count) {
1831                        emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1832                                         sb.buf, sb.len, 0);
1833                        strbuf_reset(&sb);
1834                }
1835        }
1836
1837out:
1838        if (sb.len)
1839                emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1840                                 sb.buf, sb.len, 0);
1841        strbuf_release(&sb);
1842        return 0;
1843}
1844
1845/*
1846 * '--color-words' algorithm can be described as:
1847 *
1848 *   1. collect the minus/plus lines of a diff hunk, divided into
1849 *      minus-lines and plus-lines;
1850 *
1851 *   2. break both minus-lines and plus-lines into words and
1852 *      place them into two mmfile_t with one word for each line;
1853 *
1854 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
1855 *
1856 * And for the common parts of the both file, we output the plus side text.
1857 * diff_words->current_plus is used to trace the current position of the plus file
1858 * which printed. diff_words->last_minus is used to trace the last minus word
1859 * printed.
1860 *
1861 * For '--graph' to work with '--color-words', we need to output the graph prefix
1862 * on each line of color words output. Generally, there are two conditions on
1863 * which we should output the prefix.
1864 *
1865 *   1. diff_words->last_minus == 0 &&
1866 *      diff_words->current_plus == diff_words->plus.text.ptr
1867 *
1868 *      that is: the plus text must start as a new line, and if there is no minus
1869 *      word printed, a graph prefix must be printed.
1870 *
1871 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
1872 *      *(diff_words->current_plus - 1) == '\n'
1873 *
1874 *      that is: a graph prefix must be printed following a '\n'
1875 */
1876static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
1877{
1878        if ((diff_words->last_minus == 0 &&
1879                diff_words->current_plus == diff_words->plus.text.ptr) ||
1880                (diff_words->current_plus > diff_words->plus.text.ptr &&
1881                *(diff_words->current_plus - 1) == '\n')) {
1882                return 1;
1883        } else {
1884                return 0;
1885        }
1886}
1887
1888static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
1889{
1890        struct diff_words_data *diff_words = priv;
1891        struct diff_words_style *style = diff_words->style;
1892        int minus_first, minus_len, plus_first, plus_len;
1893        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
1894        struct diff_options *opt = diff_words->opt;
1895        const char *line_prefix;
1896
1897        if (line[0] != '@' || parse_hunk_header(line, len,
1898                        &minus_first, &minus_len, &plus_first, &plus_len))
1899                return;
1900
1901        assert(opt);
1902        line_prefix = diff_line_prefix(opt);
1903
1904        /* POSIX requires that first be decremented by one if len == 0... */
1905        if (minus_len) {
1906                minus_begin = diff_words->minus.orig[minus_first].begin;
1907                minus_end =
1908                        diff_words->minus.orig[minus_first + minus_len - 1].end;
1909        } else
1910                minus_begin = minus_end =
1911                        diff_words->minus.orig[minus_first].end;
1912
1913        if (plus_len) {
1914                plus_begin = diff_words->plus.orig[plus_first].begin;
1915                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
1916        } else
1917                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
1918
1919        if (color_words_output_graph_prefix(diff_words)) {
1920                fputs(line_prefix, diff_words->opt->file);
1921        }
1922        if (diff_words->current_plus != plus_begin) {
1923                fn_out_diff_words_write_helper(diff_words->opt,
1924                                &style->ctx, style->newline,
1925                                plus_begin - diff_words->current_plus,
1926                                diff_words->current_plus);
1927        }
1928        if (minus_begin != minus_end) {
1929                fn_out_diff_words_write_helper(diff_words->opt,
1930                                &style->old_word, style->newline,
1931                                minus_end - minus_begin, minus_begin);
1932        }
1933        if (plus_begin != plus_end) {
1934                fn_out_diff_words_write_helper(diff_words->opt,
1935                                &style->new_word, style->newline,
1936                                plus_end - plus_begin, plus_begin);
1937        }
1938
1939        diff_words->current_plus = plus_end;
1940        diff_words->last_minus = minus_first;
1941}
1942
1943/* This function starts looking at *begin, and returns 0 iff a word was found. */
1944static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
1945                int *begin, int *end)
1946{
1947        if (word_regex && *begin < buffer->size) {
1948                regmatch_t match[1];
1949                if (!regexec_buf(word_regex, buffer->ptr + *begin,
1950                                 buffer->size - *begin, 1, match, 0)) {
1951                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
1952                                        '\n', match[0].rm_eo - match[0].rm_so);
1953                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
1954                        *begin += match[0].rm_so;
1955                        return *begin >= *end;
1956                }
1957                return -1;
1958        }
1959
1960        /* find the next word */
1961        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
1962                (*begin)++;
1963        if (*begin >= buffer->size)
1964                return -1;
1965
1966        /* find the end of the word */
1967        *end = *begin + 1;
1968        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
1969                (*end)++;
1970
1971        return 0;
1972}
1973
1974/*
1975 * This function splits the words in buffer->text, stores the list with
1976 * newline separator into out, and saves the offsets of the original words
1977 * in buffer->orig.
1978 */
1979static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
1980                regex_t *word_regex)
1981{
1982        int i, j;
1983        long alloc = 0;
1984
1985        out->size = 0;
1986        out->ptr = NULL;
1987
1988        /* fake an empty "0th" word */
1989        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
1990        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
1991        buffer->orig_nr = 1;
1992
1993        for (i = 0; i < buffer->text.size; i++) {
1994                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
1995                        return;
1996
1997                /* store original boundaries */
1998                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
1999                                buffer->orig_alloc);
2000                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
2001                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
2002                buffer->orig_nr++;
2003
2004                /* store one word */
2005                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
2006                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
2007                out->ptr[out->size + j - i] = '\n';
2008                out->size += j - i + 1;
2009
2010                i = j - 1;
2011        }
2012}
2013
2014/* this executes the word diff on the accumulated buffers */
2015static void diff_words_show(struct diff_words_data *diff_words)
2016{
2017        xpparam_t xpp;
2018        xdemitconf_t xecfg;
2019        mmfile_t minus, plus;
2020        struct diff_words_style *style = diff_words->style;
2021
2022        struct diff_options *opt = diff_words->opt;
2023        const char *line_prefix;
2024
2025        assert(opt);
2026        line_prefix = diff_line_prefix(opt);
2027
2028        /* special case: only removal */
2029        if (!diff_words->plus.text.size) {
2030                emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
2031                                 line_prefix, strlen(line_prefix), 0);
2032                fn_out_diff_words_write_helper(diff_words->opt,
2033                        &style->old_word, style->newline,
2034                        diff_words->minus.text.size,
2035                        diff_words->minus.text.ptr);
2036                diff_words->minus.text.size = 0;
2037                return;
2038        }
2039
2040        diff_words->current_plus = diff_words->plus.text.ptr;
2041        diff_words->last_minus = 0;
2042
2043        memset(&xpp, 0, sizeof(xpp));
2044        memset(&xecfg, 0, sizeof(xecfg));
2045        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
2046        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
2047        xpp.flags = 0;
2048        /* as only the hunk header will be parsed, we need a 0-context */
2049        xecfg.ctxlen = 0;
2050        if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
2051                          &xpp, &xecfg))
2052                die("unable to generate word diff");
2053        free(minus.ptr);
2054        free(plus.ptr);
2055        if (diff_words->current_plus != diff_words->plus.text.ptr +
2056                        diff_words->plus.text.size) {
2057                if (color_words_output_graph_prefix(diff_words))
2058                        emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
2059                                         line_prefix, strlen(line_prefix), 0);
2060                fn_out_diff_words_write_helper(diff_words->opt,
2061                        &style->ctx, style->newline,
2062                        diff_words->plus.text.ptr + diff_words->plus.text.size
2063                        - diff_words->current_plus, diff_words->current_plus);
2064        }
2065        diff_words->minus.text.size = diff_words->plus.text.size = 0;
2066}
2067
2068/* In "color-words" mode, show word-diff of words accumulated in the buffer */
2069static void diff_words_flush(struct emit_callback *ecbdata)
2070{
2071        struct diff_options *wo = ecbdata->diff_words->opt;
2072
2073        if (ecbdata->diff_words->minus.text.size ||
2074            ecbdata->diff_words->plus.text.size)
2075                diff_words_show(ecbdata->diff_words);
2076
2077        if (wo->emitted_symbols) {
2078                struct diff_options *o = ecbdata->opt;
2079                struct emitted_diff_symbols *wol = wo->emitted_symbols;
2080                int i;
2081
2082                /*
2083                 * NEEDSWORK:
2084                 * Instead of appending each, concat all words to a line?
2085                 */
2086                for (i = 0; i < wol->nr; i++)
2087                        append_emitted_diff_symbol(o, &wol->buf[i]);
2088
2089                for (i = 0; i < wol->nr; i++)
2090                        free((void *)wol->buf[i].line);
2091
2092                wol->nr = 0;
2093        }
2094}
2095
2096static void diff_filespec_load_driver(struct diff_filespec *one,
2097                                      struct index_state *istate)
2098{
2099        /* Use already-loaded driver */
2100        if (one->driver)
2101                return;
2102
2103        if (S_ISREG(one->mode))
2104                one->driver = userdiff_find_by_path(istate, one->path);
2105
2106        /* Fallback to default settings */
2107        if (!one->driver)
2108                one->driver = userdiff_find_by_name("default");
2109}
2110
2111static const char *userdiff_word_regex(struct diff_filespec *one,
2112                                       struct index_state *istate)
2113{
2114        diff_filespec_load_driver(one, istate);
2115        return one->driver->word_regex;
2116}
2117
2118static void init_diff_words_data(struct emit_callback *ecbdata,
2119                                 struct diff_options *orig_opts,
2120                                 struct diff_filespec *one,
2121                                 struct diff_filespec *two)
2122{
2123        int i;
2124        struct diff_options *o = xmalloc(sizeof(struct diff_options));
2125        memcpy(o, orig_opts, sizeof(struct diff_options));
2126
2127        ecbdata->diff_words =
2128                xcalloc(1, sizeof(struct diff_words_data));
2129        ecbdata->diff_words->type = o->word_diff;
2130        ecbdata->diff_words->opt = o;
2131
2132        if (orig_opts->emitted_symbols)
2133                o->emitted_symbols =
2134                        xcalloc(1, sizeof(struct emitted_diff_symbols));
2135
2136        if (!o->word_regex)
2137                o->word_regex = userdiff_word_regex(one, o->repo->index);
2138        if (!o->word_regex)
2139                o->word_regex = userdiff_word_regex(two, o->repo->index);
2140        if (!o->word_regex)
2141                o->word_regex = diff_word_regex_cfg;
2142        if (o->word_regex) {
2143                ecbdata->diff_words->word_regex = (regex_t *)
2144                        xmalloc(sizeof(regex_t));
2145                if (regcomp(ecbdata->diff_words->word_regex,
2146                            o->word_regex,
2147                            REG_EXTENDED | REG_NEWLINE))
2148                        die("invalid regular expression: %s",
2149                            o->word_regex);
2150        }
2151        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2152                if (o->word_diff == diff_words_styles[i].type) {
2153                        ecbdata->diff_words->style =
2154                                &diff_words_styles[i];
2155                        break;
2156                }
2157        }
2158        if (want_color(o->use_color)) {
2159                struct diff_words_style *st = ecbdata->diff_words->style;
2160                st->old_word.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2161                st->new_word.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2162                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
2163        }
2164}
2165
2166static void free_diff_words_data(struct emit_callback *ecbdata)
2167{
2168        if (ecbdata->diff_words) {
2169                diff_words_flush(ecbdata);
2170                free (ecbdata->diff_words->opt->emitted_symbols);
2171                free (ecbdata->diff_words->opt);
2172                free (ecbdata->diff_words->minus.text.ptr);
2173                free (ecbdata->diff_words->minus.orig);
2174                free (ecbdata->diff_words->plus.text.ptr);
2175                free (ecbdata->diff_words->plus.orig);
2176                if (ecbdata->diff_words->word_regex) {
2177                        regfree(ecbdata->diff_words->word_regex);
2178                        free(ecbdata->diff_words->word_regex);
2179                }
2180                FREE_AND_NULL(ecbdata->diff_words);
2181        }
2182}
2183
2184const char *diff_get_color(int diff_use_color, enum color_diff ix)
2185{
2186        if (want_color(diff_use_color))
2187                return diff_colors[ix];
2188        return "";
2189}
2190
2191const char *diff_line_prefix(struct diff_options *opt)
2192{
2193        struct strbuf *msgbuf;
2194        if (!opt->output_prefix)
2195                return "";
2196
2197        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
2198        return msgbuf->buf;
2199}
2200
2201static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
2202{
2203        const char *cp;
2204        unsigned long allot;
2205        size_t l = len;
2206
2207        cp = line;
2208        allot = l;
2209        while (0 < l) {
2210                (void) utf8_width(&cp, &l);
2211                if (!cp)
2212                        break; /* truncated in the middle? */
2213        }
2214        return allot - l;
2215}
2216
2217static void find_lno(const char *line, struct emit_callback *ecbdata)
2218{
2219        const char *p;
2220        ecbdata->lno_in_preimage = 0;
2221        ecbdata->lno_in_postimage = 0;
2222        p = strchr(line, '-');
2223        if (!p)
2224                return; /* cannot happen */
2225        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
2226        p = strchr(p, '+');
2227        if (!p)
2228                return; /* cannot happen */
2229        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
2230}
2231
2232static void fn_out_consume(void *priv, char *line, unsigned long len)
2233{
2234        struct emit_callback *ecbdata = priv;
2235        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
2236        struct diff_options *o = ecbdata->opt;
2237
2238        o->found_changes = 1;
2239
2240        if (ecbdata->header) {
2241                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
2242                                 ecbdata->header->buf, ecbdata->header->len, 0);
2243                strbuf_reset(ecbdata->header);
2244                ecbdata->header = NULL;
2245        }
2246
2247        if (ecbdata->label_path[0]) {
2248                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
2249                                 ecbdata->label_path[0],
2250                                 strlen(ecbdata->label_path[0]), 0);
2251                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
2252                                 ecbdata->label_path[1],
2253                                 strlen(ecbdata->label_path[1]), 0);
2254                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
2255        }
2256
2257        if (diff_suppress_blank_empty
2258            && len == 2 && line[0] == ' ' && line[1] == '\n') {
2259                line[0] = '\n';
2260                len = 1;
2261        }
2262
2263        if (line[0] == '@') {
2264                if (ecbdata->diff_words)
2265                        diff_words_flush(ecbdata);
2266                len = sane_truncate_line(ecbdata, line, len);
2267                find_lno(line, ecbdata);
2268                emit_hunk_header(ecbdata, line, len);
2269                return;
2270        }
2271
2272        if (ecbdata->diff_words) {
2273                enum diff_symbol s =
2274                        ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN ?
2275                        DIFF_SYMBOL_WORDS_PORCELAIN : DIFF_SYMBOL_WORDS;
2276                if (line[0] == '-') {
2277                        diff_words_append(line, len,
2278                                          &ecbdata->diff_words->minus);
2279                        return;
2280                } else if (line[0] == '+') {
2281                        diff_words_append(line, len,
2282                                          &ecbdata->diff_words->plus);
2283                        return;
2284                } else if (starts_with(line, "\\ ")) {
2285                        /*
2286                         * Eat the "no newline at eof" marker as if we
2287                         * saw a "+" or "-" line with nothing on it,
2288                         * and return without diff_words_flush() to
2289                         * defer processing. If this is the end of
2290                         * preimage, more "+" lines may come after it.
2291                         */
2292                        return;
2293                }
2294                diff_words_flush(ecbdata);
2295                emit_diff_symbol(o, s, line, len, 0);
2296                return;
2297        }
2298
2299        switch (line[0]) {
2300        case '+':
2301                ecbdata->lno_in_postimage++;
2302                emit_add_line(reset, ecbdata, line + 1, len - 1);
2303                break;
2304        case '-':
2305                ecbdata->lno_in_preimage++;
2306                emit_del_line(reset, ecbdata, line + 1, len - 1);
2307                break;
2308        case ' ':
2309                ecbdata->lno_in_postimage++;
2310                ecbdata->lno_in_preimage++;
2311                emit_context_line(reset, ecbdata, line + 1, len - 1);
2312                break;
2313        default:
2314                /* incomplete line at the end */
2315                ecbdata->lno_in_preimage++;
2316                emit_diff_symbol(o, DIFF_SYMBOL_CONTEXT_INCOMPLETE,
2317                                 line, len, 0);
2318                break;
2319        }
2320}
2321
2322static void pprint_rename(struct strbuf *name, const char *a, const char *b)
2323{
2324        const char *old_name = a;
2325        const char *new_name = b;
2326        int pfx_length, sfx_length;
2327        int pfx_adjust_for_slash;
2328        int len_a = strlen(a);
2329        int len_b = strlen(b);
2330        int a_midlen, b_midlen;
2331        int qlen_a = quote_c_style(a, NULL, NULL, 0);
2332        int qlen_b = quote_c_style(b, NULL, NULL, 0);
2333
2334        if (qlen_a || qlen_b) {
2335                quote_c_style(a, name, NULL, 0);
2336                strbuf_addstr(name, " => ");
2337                quote_c_style(b, name, NULL, 0);
2338                return;
2339        }
2340
2341        /* Find common prefix */
2342        pfx_length = 0;
2343        while (*old_name && *new_name && *old_name == *new_name) {
2344                if (*old_name == '/')
2345                        pfx_length = old_name - a + 1;
2346                old_name++;
2347                new_name++;
2348        }
2349
2350        /* Find common suffix */
2351        old_name = a + len_a;
2352        new_name = b + len_b;
2353        sfx_length = 0;
2354        /*
2355         * If there is a common prefix, it must end in a slash.  In
2356         * that case we let this loop run 1 into the prefix to see the
2357         * same slash.
2358         *
2359         * If there is no common prefix, we cannot do this as it would
2360         * underrun the input strings.
2361         */
2362        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
2363        while (a + pfx_length - pfx_adjust_for_slash <= old_name &&
2364               b + pfx_length - pfx_adjust_for_slash <= new_name &&
2365               *old_name == *new_name) {
2366                if (*old_name == '/')
2367                        sfx_length = len_a - (old_name - a);
2368                old_name--;
2369                new_name--;
2370        }
2371
2372        /*
2373         * pfx{mid-a => mid-b}sfx
2374         * {pfx-a => pfx-b}sfx
2375         * pfx{sfx-a => sfx-b}
2376         * name-a => name-b
2377         */
2378        a_midlen = len_a - pfx_length - sfx_length;
2379        b_midlen = len_b - pfx_length - sfx_length;
2380        if (a_midlen < 0)
2381                a_midlen = 0;
2382        if (b_midlen < 0)
2383                b_midlen = 0;
2384
2385        strbuf_grow(name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
2386        if (pfx_length + sfx_length) {
2387                strbuf_add(name, a, pfx_length);
2388                strbuf_addch(name, '{');
2389        }
2390        strbuf_add(name, a + pfx_length, a_midlen);
2391        strbuf_addstr(name, " => ");
2392        strbuf_add(name, b + pfx_length, b_midlen);
2393        if (pfx_length + sfx_length) {
2394                strbuf_addch(name, '}');
2395                strbuf_add(name, a + len_a - sfx_length, sfx_length);
2396        }
2397}
2398
2399struct diffstat_t {
2400        int nr;
2401        int alloc;
2402        struct diffstat_file {
2403                char *from_name;
2404                char *name;
2405                char *print_name;
2406                const char *comments;
2407                unsigned is_unmerged:1;
2408                unsigned is_binary:1;
2409                unsigned is_renamed:1;
2410                unsigned is_interesting:1;
2411                uintmax_t added, deleted;
2412        } **files;
2413};
2414
2415static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
2416                                          const char *name_a,
2417                                          const char *name_b)
2418{
2419        struct diffstat_file *x;
2420        x = xcalloc(1, sizeof(*x));
2421        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
2422        diffstat->files[diffstat->nr++] = x;
2423        if (name_b) {
2424                x->from_name = xstrdup(name_a);
2425                x->name = xstrdup(name_b);
2426                x->is_renamed = 1;
2427        }
2428        else {
2429                x->from_name = NULL;
2430                x->name = xstrdup(name_a);
2431        }
2432        return x;
2433}
2434
2435static void diffstat_consume(void *priv, char *line, unsigned long len)
2436{
2437        struct diffstat_t *diffstat = priv;
2438        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
2439
2440        if (line[0] == '+')
2441                x->added++;
2442        else if (line[0] == '-')
2443                x->deleted++;
2444}
2445
2446const char mime_boundary_leader[] = "------------";
2447
2448static int scale_linear(int it, int width, int max_change)
2449{
2450        if (!it)
2451                return 0;
2452        /*
2453         * make sure that at least one '-' or '+' is printed if
2454         * there is any change to this path. The easiest way is to
2455         * scale linearly as if the alloted width is one column shorter
2456         * than it is, and then add 1 to the result.
2457         */
2458        return 1 + (it * (width - 1) / max_change);
2459}
2460
2461static void show_graph(struct strbuf *out, char ch, int cnt,
2462                       const char *set, const char *reset)
2463{
2464        if (cnt <= 0)
2465                return;
2466        strbuf_addstr(out, set);
2467        strbuf_addchars(out, ch, cnt);
2468        strbuf_addstr(out, reset);
2469}
2470
2471static void fill_print_name(struct diffstat_file *file)
2472{
2473        struct strbuf pname = STRBUF_INIT;
2474
2475        if (file->print_name)
2476                return;
2477
2478        if (file->is_renamed)
2479                pprint_rename(&pname, file->from_name, file->name);
2480        else
2481                quote_c_style(file->name, &pname, NULL, 0);
2482
2483        if (file->comments)
2484                strbuf_addf(&pname, " (%s)", file->comments);
2485
2486        file->print_name = strbuf_detach(&pname, NULL);
2487}
2488
2489static void print_stat_summary_inserts_deletes(struct diff_options *options,
2490                int files, int insertions, int deletions)
2491{
2492        struct strbuf sb = STRBUF_INIT;
2493
2494        if (!files) {
2495                assert(insertions == 0 && deletions == 0);
2496                emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
2497                                 NULL, 0, 0);
2498                return;
2499        }
2500
2501        strbuf_addf(&sb,
2502                    (files == 1) ? " %d file changed" : " %d files changed",
2503                    files);
2504
2505        /*
2506         * For binary diff, the caller may want to print "x files
2507         * changed" with insertions == 0 && deletions == 0.
2508         *
2509         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
2510         * is probably less confusing (i.e skip over "2 files changed
2511         * but nothing about added/removed lines? Is this a bug in Git?").
2512         */
2513        if (insertions || deletions == 0) {
2514                strbuf_addf(&sb,
2515                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
2516                            insertions);
2517        }
2518
2519        if (deletions || insertions == 0) {
2520                strbuf_addf(&sb,
2521                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
2522                            deletions);
2523        }
2524        strbuf_addch(&sb, '\n');
2525        emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
2526                         sb.buf, sb.len, 0);
2527        strbuf_release(&sb);
2528}
2529
2530void print_stat_summary(FILE *fp, int files,
2531                        int insertions, int deletions)
2532{
2533        struct diff_options o;
2534        memset(&o, 0, sizeof(o));
2535        o.file = fp;
2536
2537        print_stat_summary_inserts_deletes(&o, files, insertions, deletions);
2538}
2539
2540static void show_stats(struct diffstat_t *data, struct diff_options *options)
2541{
2542        int i, len, add, del, adds = 0, dels = 0;
2543        uintmax_t max_change = 0, max_len = 0;
2544        int total_files = data->nr, count;
2545        int width, name_width, graph_width, number_width = 0, bin_width = 0;
2546        const char *reset, *add_c, *del_c;
2547        int extra_shown = 0;
2548        const char *line_prefix = diff_line_prefix(options);
2549        struct strbuf out = STRBUF_INIT;
2550
2551        if (data->nr == 0)
2552                return;
2553
2554        count = options->stat_count ? options->stat_count : data->nr;
2555
2556        reset = diff_get_color_opt(options, DIFF_RESET);
2557        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
2558        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
2559
2560        /*
2561         * Find the longest filename and max number of changes
2562         */
2563        for (i = 0; (i < count) && (i < data->nr); i++) {
2564                struct diffstat_file *file = data->files[i];
2565                uintmax_t change = file->added + file->deleted;
2566
2567                if (!file->is_interesting && (change == 0)) {
2568                        count++; /* not shown == room for one more */
2569                        continue;
2570                }
2571                fill_print_name(file);
2572                len = strlen(file->print_name);
2573                if (max_len < len)
2574                        max_len = len;
2575
2576                if (file->is_unmerged) {
2577                        /* "Unmerged" is 8 characters */
2578                        bin_width = bin_width < 8 ? 8 : bin_width;
2579                        continue;
2580                }
2581                if (file->is_binary) {
2582                        /* "Bin XXX -> YYY bytes" */
2583                        int w = 14 + decimal_width(file->added)
2584                                + decimal_width(file->deleted);
2585                        bin_width = bin_width < w ? w : bin_width;
2586                        /* Display change counts aligned with "Bin" */
2587                        number_width = 3;
2588                        continue;
2589                }
2590
2591                if (max_change < change)
2592                        max_change = change;
2593        }
2594        count = i; /* where we can stop scanning in data->files[] */
2595
2596        /*
2597         * We have width = stat_width or term_columns() columns total.
2598         * We want a maximum of min(max_len, stat_name_width) for the name part.
2599         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
2600         * We also need 1 for " " and 4 + decimal_width(max_change)
2601         * for " | NNNN " and one the empty column at the end, altogether
2602         * 6 + decimal_width(max_change).
2603         *
2604         * If there's not enough space, we will use the smaller of
2605         * stat_name_width (if set) and 5/8*width for the filename,
2606         * and the rest for constant elements + graph part, but no more
2607         * than stat_graph_width for the graph part.
2608         * (5/8 gives 50 for filename and 30 for the constant parts + graph
2609         * for the standard terminal size).
2610         *
2611         * In other words: stat_width limits the maximum width, and
2612         * stat_name_width fixes the maximum width of the filename,
2613         * and is also used to divide available columns if there
2614         * aren't enough.
2615         *
2616         * Binary files are displayed with "Bin XXX -> YYY bytes"
2617         * instead of the change count and graph. This part is treated
2618         * similarly to the graph part, except that it is not
2619         * "scaled". If total width is too small to accommodate the
2620         * guaranteed minimum width of the filename part and the
2621         * separators and this message, this message will "overflow"
2622         * making the line longer than the maximum width.
2623         */
2624
2625        if (options->stat_width == -1)
2626                width = term_columns() - strlen(line_prefix);
2627        else
2628                width = options->stat_width ? options->stat_width : 80;
2629        number_width = decimal_width(max_change) > number_width ?
2630                decimal_width(max_change) : number_width;
2631
2632        if (options->stat_graph_width == -1)
2633                options->stat_graph_width = diff_stat_graph_width;
2634
2635        /*
2636         * Guarantee 3/8*16==6 for the graph part
2637         * and 5/8*16==10 for the filename part
2638         */
2639        if (width < 16 + 6 + number_width)
2640                width = 16 + 6 + number_width;
2641
2642        /*
2643         * First assign sizes that are wanted, ignoring available width.
2644         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
2645         * starting from "XXX" should fit in graph_width.
2646         */
2647        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
2648        if (options->stat_graph_width &&
2649            options->stat_graph_width < graph_width)
2650                graph_width = options->stat_graph_width;
2651
2652        name_width = (options->stat_name_width > 0 &&
2653                      options->stat_name_width < max_len) ?
2654                options->stat_name_width : max_len;
2655
2656        /*
2657         * Adjust adjustable widths not to exceed maximum width
2658         */
2659        if (name_width + number_width + 6 + graph_width > width) {
2660                if (graph_width > width * 3/8 - number_width - 6) {
2661                        graph_width = width * 3/8 - number_width - 6;
2662                        if (graph_width < 6)
2663                                graph_width = 6;
2664                }
2665
2666                if (options->stat_graph_width &&
2667                    graph_width > options->stat_graph_width)
2668                        graph_width = options->stat_graph_width;
2669                if (name_width > width - number_width - 6 - graph_width)
2670                        name_width = width - number_width - 6 - graph_width;
2671                else
2672                        graph_width = width - number_width - 6 - name_width;
2673        }
2674
2675        /*
2676         * From here name_width is the width of the name area,
2677         * and graph_width is the width of the graph area.
2678         * max_change is used to scale graph properly.
2679         */
2680        for (i = 0; i < count; i++) {
2681                const char *prefix = "";
2682                struct diffstat_file *file = data->files[i];
2683                char *name = file->print_name;
2684                uintmax_t added = file->added;
2685                uintmax_t deleted = file->deleted;
2686                int name_len;
2687
2688                if (!file->is_interesting && (added + deleted == 0))
2689                        continue;
2690
2691                /*
2692                 * "scale" the filename
2693                 */
2694                len = name_width;
2695                name_len = strlen(name);
2696                if (name_width < name_len) {
2697                        char *slash;
2698                        prefix = "...";
2699                        len -= 3;
2700                        name += name_len - len;
2701                        slash = strchr(name, '/');
2702                        if (slash)
2703                                name = slash;
2704                }
2705
2706                if (file->is_binary) {
2707                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2708                        strbuf_addf(&out, " %*s", number_width, "Bin");
2709                        if (!added && !deleted) {
2710                                strbuf_addch(&out, '\n');
2711                                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2712                                                 out.buf, out.len, 0);
2713                                strbuf_reset(&out);
2714                                continue;
2715                        }
2716                        strbuf_addf(&out, " %s%"PRIuMAX"%s",
2717                                del_c, deleted, reset);
2718                        strbuf_addstr(&out, " -> ");
2719                        strbuf_addf(&out, "%s%"PRIuMAX"%s",
2720                                add_c, added, reset);
2721                        strbuf_addstr(&out, " bytes\n");
2722                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2723                                         out.buf, out.len, 0);
2724                        strbuf_reset(&out);
2725                        continue;
2726                }
2727                else if (file->is_unmerged) {
2728                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2729                        strbuf_addstr(&out, " Unmerged\n");
2730                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2731                                         out.buf, out.len, 0);
2732                        strbuf_reset(&out);
2733                        continue;
2734                }
2735
2736                /*
2737                 * scale the add/delete
2738                 */
2739                add = added;
2740                del = deleted;
2741
2742                if (graph_width <= max_change) {
2743                        int total = scale_linear(add + del, graph_width, max_change);
2744                        if (total < 2 && add && del)
2745                                /* width >= 2 due to the sanity check */
2746                                total = 2;
2747                        if (add < del) {
2748                                add = scale_linear(add, graph_width, max_change);
2749                                del = total - add;
2750                        } else {
2751                                del = scale_linear(del, graph_width, max_change);
2752                                add = total - del;
2753                        }
2754                }
2755                strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2756                strbuf_addf(&out, " %*"PRIuMAX"%s",
2757                        number_width, added + deleted,
2758                        added + deleted ? " " : "");
2759                show_graph(&out, '+', add, add_c, reset);
2760                show_graph(&out, '-', del, del_c, reset);
2761                strbuf_addch(&out, '\n');
2762                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2763                                 out.buf, out.len, 0);
2764                strbuf_reset(&out);
2765        }
2766
2767        for (i = 0; i < data->nr; i++) {
2768                struct diffstat_file *file = data->files[i];
2769                uintmax_t added = file->added;
2770                uintmax_t deleted = file->deleted;
2771
2772                if (file->is_unmerged ||
2773                    (!file->is_interesting && (added + deleted == 0))) {
2774                        total_files--;
2775                        continue;
2776                }
2777
2778                if (!file->is_binary) {
2779                        adds += added;
2780                        dels += deleted;
2781                }
2782                if (i < count)
2783                        continue;
2784                if (!extra_shown)
2785                        emit_diff_symbol(options,
2786                                         DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
2787                                         NULL, 0, 0);
2788                extra_shown = 1;
2789        }
2790
2791        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2792        strbuf_release(&out);
2793}
2794
2795static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
2796{
2797        int i, adds = 0, dels = 0, total_files = data->nr;
2798
2799        if (data->nr == 0)
2800                return;
2801
2802        for (i = 0; i < data->nr; i++) {
2803                int added = data->files[i]->added;
2804                int deleted = data->files[i]->deleted;
2805
2806                if (data->files[i]->is_unmerged ||
2807                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
2808                        total_files--;
2809                } else if (!data->files[i]->is_binary) { /* don't count bytes */
2810                        adds += added;
2811                        dels += deleted;
2812                }
2813        }
2814        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2815}
2816
2817static void show_numstat(struct diffstat_t *data, struct diff_options *options)
2818{
2819        int i;
2820
2821        if (data->nr == 0)
2822                return;
2823
2824        for (i = 0; i < data->nr; i++) {
2825                struct diffstat_file *file = data->files[i];
2826
2827                fprintf(options->file, "%s", diff_line_prefix(options));
2828
2829                if (file->is_binary)
2830                        fprintf(options->file, "-\t-\t");
2831                else
2832                        fprintf(options->file,
2833                                "%"PRIuMAX"\t%"PRIuMAX"\t",
2834                                file->added, file->deleted);
2835                if (options->line_termination) {
2836                        fill_print_name(file);
2837                        if (!file->is_renamed)
2838                                write_name_quoted(file->name, options->file,
2839                                                  options->line_termination);
2840                        else {
2841                                fputs(file->print_name, options->file);
2842                                putc(options->line_termination, options->file);
2843                        }
2844                } else {
2845                        if (file->is_renamed) {
2846                                putc('\0', options->file);
2847                                write_name_quoted(file->from_name, options->file, '\0');
2848                        }
2849                        write_name_quoted(file->name, options->file, '\0');
2850                }
2851        }
2852}
2853
2854struct dirstat_file {
2855        const char *name;
2856        unsigned long changed;
2857};
2858
2859struct dirstat_dir {
2860        struct dirstat_file *files;
2861        int alloc, nr, permille, cumulative;
2862};
2863
2864static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
2865                unsigned long changed, const char *base, int baselen)
2866{
2867        unsigned long sum_changes = 0;
2868        unsigned int sources = 0;
2869        const char *line_prefix = diff_line_prefix(opt);
2870
2871        while (dir->nr) {
2872                struct dirstat_file *f = dir->files;
2873                int namelen = strlen(f->name);
2874                unsigned long changes;
2875                char *slash;
2876
2877                if (namelen < baselen)
2878                        break;
2879                if (memcmp(f->name, base, baselen))
2880                        break;
2881                slash = strchr(f->name + baselen, '/');
2882                if (slash) {
2883                        int newbaselen = slash + 1 - f->name;
2884                        changes = gather_dirstat(opt, dir, changed, f->name, newbaselen);
2885                        sources++;
2886                } else {
2887                        changes = f->changed;
2888                        dir->files++;
2889                        dir->nr--;
2890                        sources += 2;
2891                }
2892                sum_changes += changes;
2893        }
2894
2895        /*
2896         * We don't report dirstat's for
2897         *  - the top level
2898         *  - or cases where everything came from a single directory
2899         *    under this directory (sources == 1).
2900         */
2901        if (baselen && sources != 1) {
2902                if (sum_changes) {
2903                        int permille = sum_changes * 1000 / changed;
2904                        if (permille >= dir->permille) {
2905                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
2906                                        permille / 10, permille % 10, baselen, base);
2907                                if (!dir->cumulative)
2908                                        return 0;
2909                        }
2910                }
2911        }
2912        return sum_changes;
2913}
2914
2915static int dirstat_compare(const void *_a, const void *_b)
2916{
2917        const struct dirstat_file *a = _a;
2918        const struct dirstat_file *b = _b;
2919        return strcmp(a->name, b->name);
2920}
2921
2922static void show_dirstat(struct diff_options *options)
2923{
2924        int i;
2925        unsigned long changed;
2926        struct dirstat_dir dir;
2927        struct diff_queue_struct *q = &diff_queued_diff;
2928
2929        dir.files = NULL;
2930        dir.alloc = 0;
2931        dir.nr = 0;
2932        dir.permille = options->dirstat_permille;
2933        dir.cumulative = options->flags.dirstat_cumulative;
2934
2935        changed = 0;
2936        for (i = 0; i < q->nr; i++) {
2937                struct diff_filepair *p = q->queue[i];
2938                const char *name;
2939                unsigned long copied, added, damage;
2940                int content_changed;
2941
2942                name = p->two->path ? p->two->path : p->one->path;
2943
2944                if (p->one->oid_valid && p->two->oid_valid)
2945                        content_changed = oidcmp(&p->one->oid, &p->two->oid);
2946                else
2947                        content_changed = 1;
2948
2949                if (!content_changed) {
2950                        /*
2951                         * The SHA1 has not changed, so pre-/post-content is
2952                         * identical. We can therefore skip looking at the
2953                         * file contents altogether.
2954                         */
2955                        damage = 0;
2956                        goto found_damage;
2957                }
2958
2959                if (options->flags.dirstat_by_file) {
2960                        /*
2961                         * In --dirstat-by-file mode, we don't really need to
2962                         * look at the actual file contents at all.
2963                         * The fact that the SHA1 changed is enough for us to
2964                         * add this file to the list of results
2965                         * (with each file contributing equal damage).
2966                         */
2967                        damage = 1;
2968                        goto found_damage;
2969                }
2970
2971                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
2972                        diff_populate_filespec(options->repo, p->one, 0);
2973                        diff_populate_filespec(options->repo, p->two, 0);
2974                        diffcore_count_changes(options->repo,
2975                                               p->one, p->two, NULL, NULL,
2976                                               &copied, &added);
2977                        diff_free_filespec_data(p->one);
2978                        diff_free_filespec_data(p->two);
2979                } else if (DIFF_FILE_VALID(p->one)) {
2980                        diff_populate_filespec(options->repo, p->one, CHECK_SIZE_ONLY);
2981                        copied = added = 0;
2982                        diff_free_filespec_data(p->one);
2983                } else if (DIFF_FILE_VALID(p->two)) {
2984                        diff_populate_filespec(options->repo, p->two, CHECK_SIZE_ONLY);
2985                        copied = 0;
2986                        added = p->two->size;
2987                        diff_free_filespec_data(p->two);
2988                } else
2989                        continue;
2990
2991                /*
2992                 * Original minus copied is the removed material,
2993                 * added is the new material.  They are both damages
2994                 * made to the preimage.
2995                 * If the resulting damage is zero, we know that
2996                 * diffcore_count_changes() considers the two entries to
2997                 * be identical, but since content_changed is true, we
2998                 * know that there must have been _some_ kind of change,
2999                 * so we force all entries to have damage > 0.
3000                 */
3001                damage = (p->one->size - copied) + added;
3002                if (!damage)
3003                        damage = 1;
3004
3005found_damage:
3006                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
3007                dir.files[dir.nr].name = name;
3008                dir.files[dir.nr].changed = damage;
3009                changed += damage;
3010                dir.nr++;
3011        }
3012
3013        /* This can happen even with many files, if everything was renames */
3014        if (!changed)
3015                return;
3016
3017        /* Show all directories with more than x% of the changes */
3018        QSORT(dir.files, dir.nr, dirstat_compare);
3019        gather_dirstat(options, &dir, changed, "", 0);
3020}
3021
3022static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
3023{
3024        int i;
3025        unsigned long changed;
3026        struct dirstat_dir dir;
3027
3028        if (data->nr == 0)
3029                return;
3030
3031        dir.files = NULL;
3032        dir.alloc = 0;
3033        dir.nr = 0;
3034        dir.permille = options->dirstat_permille;
3035        dir.cumulative = options->flags.dirstat_cumulative;
3036
3037        changed = 0;
3038        for (i = 0; i < data->nr; i++) {
3039                struct diffstat_file *file = data->files[i];
3040                unsigned long damage = file->added + file->deleted;
3041                if (file->is_binary)
3042                        /*
3043                         * binary files counts bytes, not lines. Must find some
3044                         * way to normalize binary bytes vs. textual lines.
3045                         * The following heuristic assumes that there are 64
3046                         * bytes per "line".
3047                         * This is stupid and ugly, but very cheap...
3048                         */
3049                        damage = DIV_ROUND_UP(damage, 64);
3050                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
3051                dir.files[dir.nr].name = file->name;
3052                dir.files[dir.nr].changed = damage;
3053                changed += damage;
3054                dir.nr++;
3055        }
3056
3057        /* This can happen even with many files, if everything was renames */
3058        if (!changed)
3059                return;
3060
3061        /* Show all directories with more than x% of the changes */
3062        QSORT(dir.files, dir.nr, dirstat_compare);
3063        gather_dirstat(options, &dir, changed, "", 0);
3064}
3065
3066static void free_diffstat_info(struct diffstat_t *diffstat)
3067{
3068        int i;
3069        for (i = 0; i < diffstat->nr; i++) {
3070                struct diffstat_file *f = diffstat->files[i];
3071                free(f->print_name);
3072                free(f->name);
3073                free(f->from_name);
3074                free(f);
3075        }
3076        free(diffstat->files);
3077}
3078
3079struct checkdiff_t {
3080        const char *filename;
3081        int lineno;
3082        int conflict_marker_size;
3083        struct diff_options *o;
3084        unsigned ws_rule;
3085        unsigned status;
3086};
3087
3088static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
3089{
3090        char firstchar;
3091        int cnt;
3092
3093        if (len < marker_size + 1)
3094                return 0;
3095        firstchar = line[0];
3096        switch (firstchar) {
3097        case '=': case '>': case '<': case '|':
3098                break;
3099        default:
3100                return 0;
3101        }
3102        for (cnt = 1; cnt < marker_size; cnt++)
3103                if (line[cnt] != firstchar)
3104                        return 0;
3105        /* line[1] thru line[marker_size-1] are same as firstchar */
3106        if (len < marker_size + 1 || !isspace(line[marker_size]))
3107                return 0;
3108        return 1;
3109}
3110
3111static void checkdiff_consume(void *priv, char *line, unsigned long len)
3112{
3113        struct checkdiff_t *data = priv;
3114        int marker_size = data->conflict_marker_size;
3115        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
3116        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
3117        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
3118        char *err;
3119        const char *line_prefix;
3120
3121        assert(data->o);
3122        line_prefix = diff_line_prefix(data->o);
3123
3124        if (line[0] == '+') {
3125                unsigned bad;
3126                data->lineno++;
3127                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
3128                        data->status |= 1;
3129                        fprintf(data->o->file,
3130                                "%s%s:%d: leftover conflict marker\n",
3131                                line_prefix, data->filename, data->lineno);
3132                }
3133                bad = ws_check(line + 1, len - 1, data->ws_rule);
3134                if (!bad)
3135                        return;
3136                data->status |= bad;
3137                err = whitespace_error_string(bad);
3138                fprintf(data->o->file, "%s%s:%d: %s.\n",
3139                        line_prefix, data->filename, data->lineno, err);
3140                free(err);
3141                emit_line(data->o, set, reset, line, 1);
3142                ws_check_emit(line + 1, len - 1, data->ws_rule,
3143                              data->o->file, set, reset, ws);
3144        } else if (line[0] == ' ') {
3145                data->lineno++;
3146        } else if (line[0] == '@') {
3147                char *plus = strchr(line, '+');
3148                if (plus)
3149                        data->lineno = strtol(plus, NULL, 10) - 1;
3150                else
3151                        die("invalid diff");
3152        }
3153}
3154
3155static unsigned char *deflate_it(char *data,
3156                                 unsigned long size,
3157                                 unsigned long *result_size)
3158{
3159        int bound;
3160        unsigned char *deflated;
3161        git_zstream stream;
3162
3163        git_deflate_init(&stream, zlib_compression_level);
3164        bound = git_deflate_bound(&stream, size);
3165        deflated = xmalloc(bound);
3166        stream.next_out = deflated;
3167        stream.avail_out = bound;
3168
3169        stream.next_in = (unsigned char *)data;
3170        stream.avail_in = size;
3171        while (git_deflate(&stream, Z_FINISH) == Z_OK)
3172                ; /* nothing */
3173        git_deflate_end(&stream);
3174        *result_size = stream.total_out;
3175        return deflated;
3176}
3177
3178static void emit_binary_diff_body(struct diff_options *o,
3179                                  mmfile_t *one, mmfile_t *two)
3180{
3181        void *cp;
3182        void *delta;
3183        void *deflated;
3184        void *data;
3185        unsigned long orig_size;
3186        unsigned long delta_size;
3187        unsigned long deflate_size;
3188        unsigned long data_size;
3189
3190        /* We could do deflated delta, or we could do just deflated two,
3191         * whichever is smaller.
3192         */
3193        delta = NULL;
3194        deflated = deflate_it(two->ptr, two->size, &deflate_size);
3195        if (one->size && two->size) {
3196                delta = diff_delta(one->ptr, one->size,
3197                                   two->ptr, two->size,
3198                                   &delta_size, deflate_size);
3199                if (delta) {
3200                        void *to_free = delta;
3201                        orig_size = delta_size;
3202                        delta = deflate_it(delta, delta_size, &delta_size);
3203                        free(to_free);
3204                }
3205        }
3206
3207        if (delta && delta_size < deflate_size) {
3208                char *s = xstrfmt("%lu", orig_size);
3209                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
3210                                 s, strlen(s), 0);
3211                free(s);
3212                free(deflated);
3213                data = delta;
3214                data_size = delta_size;
3215        } else {
3216                char *s = xstrfmt("%lu", two->size);
3217                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
3218                                 s, strlen(s), 0);
3219                free(s);
3220                free(delta);
3221                data = deflated;
3222                data_size = deflate_size;
3223        }
3224
3225        /* emit data encoded in base85 */
3226        cp = data;
3227        while (data_size) {
3228                int len;
3229                int bytes = (52 < data_size) ? 52 : data_size;
3230                char line[71];
3231                data_size -= bytes;
3232                if (bytes <= 26)
3233                        line[0] = bytes + 'A' - 1;
3234                else
3235                        line[0] = bytes - 26 + 'a' - 1;
3236                encode_85(line + 1, cp, bytes);
3237                cp = (char *) cp + bytes;
3238
3239                len = strlen(line);
3240                line[len++] = '\n';
3241                line[len] = '\0';
3242
3243                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_BODY,
3244                                 line, len, 0);
3245        }
3246        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_FOOTER, NULL, 0, 0);
3247        free(data);
3248}
3249
3250static void emit_binary_diff(struct diff_options *o,
3251                             mmfile_t *one, mmfile_t *two)
3252{
3253        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER, NULL, 0, 0);
3254        emit_binary_diff_body(o, one, two);
3255        emit_binary_diff_body(o, two, one);
3256}
3257
3258int diff_filespec_is_binary(struct repository *r,
3259                            struct diff_filespec *one)
3260{
3261        if (one->is_binary == -1) {
3262                diff_filespec_load_driver(one, r->index);
3263                if (one->driver->binary != -1)
3264                        one->is_binary = one->driver->binary;
3265                else {
3266                        if (!one->data && DIFF_FILE_VALID(one))
3267                                diff_populate_filespec(r, one, CHECK_BINARY);
3268                        if (one->is_binary == -1 && one->data)
3269                                one->is_binary = buffer_is_binary(one->data,
3270                                                one->size);
3271                        if (one->is_binary == -1)
3272                                one->is_binary = 0;
3273                }
3274        }
3275        return one->is_binary;
3276}
3277
3278static const struct userdiff_funcname *
3279diff_funcname_pattern(struct diff_options *o, struct diff_filespec *one)
3280{
3281        diff_filespec_load_driver(one, o->repo->index);
3282        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
3283}
3284
3285void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
3286{
3287        if (!options->a_prefix)
3288                options->a_prefix = a;
3289        if (!options->b_prefix)
3290                options->b_prefix = b;
3291}
3292
3293struct userdiff_driver *get_textconv(struct index_state *istate,
3294                                     struct diff_filespec *one)
3295{
3296        if (!DIFF_FILE_VALID(one))
3297                return NULL;
3298
3299        diff_filespec_load_driver(one, istate);
3300        return userdiff_get_textconv(one->driver);
3301}
3302
3303static void builtin_diff(const char *name_a,
3304                         const char *name_b,
3305                         struct diff_filespec *one,
3306                         struct diff_filespec *two,
3307                         const char *xfrm_msg,
3308                         int must_show_header,
3309                         struct diff_options *o,
3310                         int complete_rewrite)
3311{
3312        mmfile_t mf1, mf2;
3313        const char *lbl[2];
3314        char *a_one, *b_two;
3315        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
3316        const char *reset = diff_get_color_opt(o, DIFF_RESET);
3317        const char *a_prefix, *b_prefix;
3318        struct userdiff_driver *textconv_one = NULL;
3319        struct userdiff_driver *textconv_two = NULL;
3320        struct strbuf header = STRBUF_INIT;
3321        const char *line_prefix = diff_line_prefix(o);
3322
3323        diff_set_mnemonic_prefix(o, "a/", "b/");
3324        if (o->flags.reverse_diff) {
3325                a_prefix = o->b_prefix;
3326                b_prefix = o->a_prefix;
3327        } else {
3328                a_prefix = o->a_prefix;
3329                b_prefix = o->b_prefix;
3330        }
3331
3332        if (o->submodule_format == DIFF_SUBMODULE_LOG &&
3333            (!one->mode || S_ISGITLINK(one->mode)) &&
3334            (!two->mode || S_ISGITLINK(two->mode))) {
3335                show_submodule_summary(o, one->path ? one->path : two->path,
3336                                &one->oid, &two->oid,
3337                                two->dirty_submodule);
3338                return;
3339        } else if (o->submodule_format == DIFF_SUBMODULE_INLINE_DIFF &&
3340                   (!one->mode || S_ISGITLINK(one->mode)) &&
3341                   (!two->mode || S_ISGITLINK(two->mode))) {
3342                show_submodule_inline_diff(o, one->path ? one->path : two->path,
3343                                &one->oid, &two->oid,
3344                                two->dirty_submodule);
3345                return;
3346        }
3347
3348        if (o->flags.allow_textconv) {
3349                textconv_one = get_textconv(o->repo->index, one);
3350                textconv_two = get_textconv(o->repo->index, two);
3351        }
3352
3353        /* Never use a non-valid filename anywhere if at all possible */
3354        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
3355        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
3356
3357        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
3358        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
3359        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
3360        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
3361        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
3362        if (lbl[0][0] == '/') {
3363                /* /dev/null */
3364                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
3365                if (xfrm_msg)
3366                        strbuf_addstr(&header, xfrm_msg);
3367                must_show_header = 1;
3368        }
3369        else if (lbl[1][0] == '/') {
3370                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
3371                if (xfrm_msg)
3372                        strbuf_addstr(&header, xfrm_msg);
3373                must_show_header = 1;
3374        }
3375        else {
3376                if (one->mode != two->mode) {
3377                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
3378                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
3379                        must_show_header = 1;
3380                }
3381                if (xfrm_msg)
3382                        strbuf_addstr(&header, xfrm_msg);
3383
3384                /*
3385                 * we do not run diff between different kind
3386                 * of objects.
3387                 */
3388                if ((one->mode ^ two->mode) & S_IFMT)
3389                        goto free_ab_and_return;
3390                if (complete_rewrite &&
3391                    (textconv_one || !diff_filespec_is_binary(o->repo, one)) &&
3392                    (textconv_two || !diff_filespec_is_binary(o->repo, two))) {
3393                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3394                                         header.buf, header.len, 0);
3395                        strbuf_reset(&header);
3396                        emit_rewrite_diff(name_a, name_b, one, two,
3397                                          textconv_one, textconv_two, o);
3398                        o->found_changes = 1;
3399                        goto free_ab_and_return;
3400                }
3401        }
3402
3403        if (o->irreversible_delete && lbl[1][0] == '/') {
3404                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf,
3405                                 header.len, 0);
3406                strbuf_reset(&header);
3407                goto free_ab_and_return;
3408        } else if (!o->flags.text &&
3409                   ( (!textconv_one && diff_filespec_is_binary(o->repo, one)) ||
3410                     (!textconv_two && diff_filespec_is_binary(o->repo, two)) )) {
3411                struct strbuf sb = STRBUF_INIT;
3412                if (!one->data && !two->data &&
3413                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
3414                    !o->flags.binary) {
3415                        if (!oidcmp(&one->oid, &two->oid)) {
3416                                if (must_show_header)
3417                                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3418                                                         header.buf, header.len,
3419                                                         0);
3420                                goto free_ab_and_return;
3421                        }
3422                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3423                                         header.buf, header.len, 0);
3424                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3425                                    diff_line_prefix(o), lbl[0], lbl[1]);
3426                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3427                                         sb.buf, sb.len, 0);
3428                        strbuf_release(&sb);
3429                        goto free_ab_and_return;
3430                }
3431                if (fill_mmfile(o->repo, &mf1, one) < 0 ||
3432                    fill_mmfile(o->repo, &mf2, two) < 0)
3433                        die("unable to read files to diff");
3434                /* Quite common confusing case */
3435                if (mf1.size == mf2.size &&
3436                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
3437                        if (must_show_header)
3438                                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3439                                                 header.buf, header.len, 0);
3440                        goto free_ab_and_return;
3441                }
3442                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf, header.len, 0);
3443                strbuf_reset(&header);
3444                if (o->flags.binary)
3445                        emit_binary_diff(o, &mf1, &mf2);
3446                else {
3447                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3448                                    diff_line_prefix(o), lbl[0], lbl[1]);
3449                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3450                                         sb.buf, sb.len, 0);
3451                        strbuf_release(&sb);
3452                }
3453                o->found_changes = 1;
3454        } else {
3455                /* Crazy xdl interfaces.. */
3456                const char *diffopts = getenv("GIT_DIFF_OPTS");
3457                const char *v;
3458                xpparam_t xpp;
3459                xdemitconf_t xecfg;
3460                struct emit_callback ecbdata;
3461                const struct userdiff_funcname *pe;
3462
3463                if (must_show_header) {
3464                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3465                                         header.buf, header.len, 0);
3466                        strbuf_reset(&header);
3467                }
3468
3469                mf1.size = fill_textconv(o->repo, textconv_one, one, &mf1.ptr);
3470                mf2.size = fill_textconv(o->repo, textconv_two, two, &mf2.ptr);
3471
3472                pe = diff_funcname_pattern(o, one);
3473                if (!pe)
3474                        pe = diff_funcname_pattern(o, two);
3475
3476                memset(&xpp, 0, sizeof(xpp));
3477                memset(&xecfg, 0, sizeof(xecfg));
3478                memset(&ecbdata, 0, sizeof(ecbdata));
3479                if (o->flags.suppress_diff_headers)
3480                        lbl[0] = NULL;
3481                ecbdata.label_path = lbl;
3482                ecbdata.color_diff = want_color(o->use_color);
3483                ecbdata.ws_rule = whitespace_rule(name_b);
3484                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
3485                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3486                ecbdata.opt = o;
3487                if (header.len && !o->flags.suppress_diff_headers)
3488                        ecbdata.header = &header;
3489                xpp.flags = o->xdl_opts;
3490                xpp.anchors = o->anchors;
3491                xpp.anchors_nr = o->anchors_nr;
3492                xecfg.ctxlen = o->context;
3493                xecfg.interhunkctxlen = o->interhunkcontext;
3494                xecfg.flags = XDL_EMIT_FUNCNAMES;
3495                if (o->flags.funccontext)
3496                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
3497                if (pe)
3498                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
3499                if (!diffopts)
3500                        ;
3501                else if (skip_prefix(diffopts, "--unified=", &v))
3502                        xecfg.ctxlen = strtoul(v, NULL, 10);
3503                else if (skip_prefix(diffopts, "-u", &v))
3504                        xecfg.ctxlen = strtoul(v, NULL, 10);
3505                if (o->word_diff)
3506                        init_diff_words_data(&ecbdata, o, one, two);
3507                if (xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
3508                                  &xpp, &xecfg))
3509                        die("unable to generate diff for %s", one->path);
3510                if (o->word_diff)
3511                        free_diff_words_data(&ecbdata);
3512                if (textconv_one)
3513                        free(mf1.ptr);
3514                if (textconv_two)
3515                        free(mf2.ptr);
3516                xdiff_clear_find_func(&xecfg);
3517        }
3518
3519 free_ab_and_return:
3520        strbuf_release(&header);
3521        diff_free_filespec_data(one);
3522        diff_free_filespec_data(two);
3523        free(a_one);
3524        free(b_two);
3525        return;
3526}
3527
3528static char *get_compact_summary(const struct diff_filepair *p, int is_renamed)
3529{
3530        if (!is_renamed) {
3531                if (p->status == DIFF_STATUS_ADDED) {
3532                        if (S_ISLNK(p->two->mode))
3533                                return "new +l";
3534                        else if ((p->two->mode & 0777) == 0755)
3535                                return "new +x";
3536                        else
3537                                return "new";
3538                } else if (p->status == DIFF_STATUS_DELETED)
3539                        return "gone";
3540        }
3541        if (S_ISLNK(p->one->mode) && !S_ISLNK(p->two->mode))
3542                return "mode -l";
3543        else if (!S_ISLNK(p->one->mode) && S_ISLNK(p->two->mode))
3544                return "mode +l";
3545        else if ((p->one->mode & 0777) == 0644 &&
3546                 (p->two->mode & 0777) == 0755)
3547                return "mode +x";
3548        else if ((p->one->mode & 0777) == 0755 &&
3549                 (p->two->mode & 0777) == 0644)
3550                return "mode -x";
3551        return NULL;
3552}
3553
3554static void builtin_diffstat(const char *name_a, const char *name_b,
3555                             struct diff_filespec *one,
3556                             struct diff_filespec *two,
3557                             struct diffstat_t *diffstat,
3558                             struct diff_options *o,
3559                             struct diff_filepair *p)
3560{
3561        mmfile_t mf1, mf2;
3562        struct diffstat_file *data;
3563        int same_contents;
3564        int complete_rewrite = 0;
3565
3566        if (!DIFF_PAIR_UNMERGED(p)) {
3567                if (p->status == DIFF_STATUS_MODIFIED && p->score)
3568                        complete_rewrite = 1;
3569        }
3570
3571        data = diffstat_add(diffstat, name_a, name_b);
3572        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
3573        if (o->flags.stat_with_summary)
3574                data->comments = get_compact_summary(p, data->is_renamed);
3575
3576        if (!one || !two) {
3577                data->is_unmerged = 1;
3578                return;
3579        }
3580
3581        same_contents = !oidcmp(&one->oid, &two->oid);
3582
3583        if (diff_filespec_is_binary(o->repo, one) ||
3584            diff_filespec_is_binary(o->repo, two)) {
3585                data->is_binary = 1;
3586                if (same_contents) {
3587                        data->added = 0;
3588                        data->deleted = 0;
3589                } else {
3590                        data->added = diff_filespec_size(o->repo, two);
3591                        data->deleted = diff_filespec_size(o->repo, one);
3592                }
3593        }
3594
3595        else if (complete_rewrite) {
3596                diff_populate_filespec(o->repo, one, 0);
3597                diff_populate_filespec(o->repo, two, 0);
3598                data->deleted = count_lines(one->data, one->size);
3599                data->added = count_lines(two->data, two->size);
3600        }
3601
3602        else if (!same_contents) {
3603                /* Crazy xdl interfaces.. */
3604                xpparam_t xpp;
3605                xdemitconf_t xecfg;
3606
3607                if (fill_mmfile(o->repo, &mf1, one) < 0 ||
3608                    fill_mmfile(o->repo, &mf2, two) < 0)
3609                        die("unable to read files to diff");
3610
3611                memset(&xpp, 0, sizeof(xpp));
3612                memset(&xecfg, 0, sizeof(xecfg));
3613                xpp.flags = o->xdl_opts;
3614                xpp.anchors = o->anchors;
3615                xpp.anchors_nr = o->anchors_nr;
3616                xecfg.ctxlen = o->context;
3617                xecfg.interhunkctxlen = o->interhunkcontext;
3618                if (xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
3619                                  &xpp, &xecfg))
3620                        die("unable to generate diffstat for %s", one->path);
3621        }
3622
3623        diff_free_filespec_data(one);
3624        diff_free_filespec_data(two);
3625}
3626
3627static void builtin_checkdiff(const char *name_a, const char *name_b,
3628                              const char *attr_path,
3629                              struct diff_filespec *one,
3630                              struct diff_filespec *two,
3631                              struct diff_options *o)
3632{
3633        mmfile_t mf1, mf2;
3634        struct checkdiff_t data;
3635
3636        if (!two)
3637                return;
3638
3639        memset(&data, 0, sizeof(data));
3640        data.filename = name_b ? name_b : name_a;
3641        data.lineno = 0;
3642        data.o = o;
3643        data.ws_rule = whitespace_rule(attr_path);
3644        data.conflict_marker_size = ll_merge_marker_size(o->repo->index, attr_path);
3645
3646        if (fill_mmfile(o->repo, &mf1, one) < 0 ||
3647            fill_mmfile(o->repo, &mf2, two) < 0)
3648                die("unable to read files to diff");
3649
3650        /*
3651         * All the other codepaths check both sides, but not checking
3652         * the "old" side here is deliberate.  We are checking the newly
3653         * introduced changes, and as long as the "new" side is text, we
3654         * can and should check what it introduces.
3655         */
3656        if (diff_filespec_is_binary(o->repo, two))
3657                goto free_and_return;
3658        else {
3659                /* Crazy xdl interfaces.. */
3660                xpparam_t xpp;
3661                xdemitconf_t xecfg;
3662
3663                memset(&xpp, 0, sizeof(xpp));
3664                memset(&xecfg, 0, sizeof(xecfg));
3665                xecfg.ctxlen = 1; /* at least one context line */
3666                xpp.flags = 0;
3667                if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
3668                                  &xpp, &xecfg))
3669                        die("unable to generate checkdiff for %s", one->path);
3670
3671                if (data.ws_rule & WS_BLANK_AT_EOF) {
3672                        struct emit_callback ecbdata;
3673                        int blank_at_eof;
3674
3675                        ecbdata.ws_rule = data.ws_rule;
3676                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3677                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
3678
3679                        if (blank_at_eof) {
3680                                static char *err;
3681                                if (!err)
3682                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
3683                                fprintf(o->file, "%s:%d: %s.\n",
3684                                        data.filename, blank_at_eof, err);
3685                                data.status = 1; /* report errors */
3686                        }
3687                }
3688        }
3689 free_and_return:
3690        diff_free_filespec_data(one);
3691        diff_free_filespec_data(two);
3692        if (data.status)
3693                o->flags.check_failed = 1;
3694}
3695
3696struct diff_filespec *alloc_filespec(const char *path)
3697{
3698        struct diff_filespec *spec;
3699
3700        FLEXPTR_ALLOC_STR(spec, path, path);
3701        spec->count = 1;
3702        spec->is_binary = -1;
3703        return spec;
3704}
3705
3706void free_filespec(struct diff_filespec *spec)
3707{
3708        if (!--spec->count) {
3709                diff_free_filespec_data(spec);
3710                free(spec);
3711        }
3712}
3713
3714void fill_filespec(struct diff_filespec *spec, const struct object_id *oid,
3715                   int oid_valid, unsigned short mode)
3716{
3717        if (mode) {
3718                spec->mode = canon_mode(mode);
3719                oidcpy(&spec->oid, oid);
3720                spec->oid_valid = oid_valid;
3721        }
3722}
3723
3724/*
3725 * Given a name and sha1 pair, if the index tells us the file in
3726 * the work tree has that object contents, return true, so that
3727 * prepare_temp_file() does not have to inflate and extract.
3728 */
3729static int reuse_worktree_file(struct index_state *istate,
3730                               const char *name,
3731                               const struct object_id *oid,
3732                               int want_file)
3733{
3734        const struct cache_entry *ce;
3735        struct stat st;
3736        int pos, len;
3737
3738        /*
3739         * We do not read the cache ourselves here, because the
3740         * benchmark with my previous version that always reads cache
3741         * shows that it makes things worse for diff-tree comparing
3742         * two linux-2.6 kernel trees in an already checked out work
3743         * tree.  This is because most diff-tree comparisons deal with
3744         * only a small number of files, while reading the cache is
3745         * expensive for a large project, and its cost outweighs the
3746         * savings we get by not inflating the object to a temporary
3747         * file.  Practically, this code only helps when we are used
3748         * by diff-cache --cached, which does read the cache before
3749         * calling us.
3750         */
3751        if (!istate->cache)
3752                return 0;
3753
3754        /* We want to avoid the working directory if our caller
3755         * doesn't need the data in a normal file, this system
3756         * is rather slow with its stat/open/mmap/close syscalls,
3757         * and the object is contained in a pack file.  The pack
3758         * is probably already open and will be faster to obtain
3759         * the data through than the working directory.  Loose
3760         * objects however would tend to be slower as they need
3761         * to be individually opened and inflated.
3762         */
3763        if (!FAST_WORKING_DIRECTORY && !want_file && has_object_pack(oid))
3764                return 0;
3765
3766        /*
3767         * Similarly, if we'd have to convert the file contents anyway, that
3768         * makes the optimization not worthwhile.
3769         */
3770        if (!want_file && would_convert_to_git(istate, name))
3771                return 0;
3772
3773        len = strlen(name);
3774        pos = index_name_pos(istate, name, len);
3775        if (pos < 0)
3776                return 0;
3777        ce = istate->cache[pos];
3778
3779        /*
3780         * This is not the sha1 we are looking for, or
3781         * unreusable because it is not a regular file.
3782         */
3783        if (oidcmp(oid, &ce->oid) || !S_ISREG(ce->ce_mode))
3784                return 0;
3785
3786        /*
3787         * If ce is marked as "assume unchanged", there is no
3788         * guarantee that work tree matches what we are looking for.
3789         */
3790        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
3791                return 0;
3792
3793        /*
3794         * If ce matches the file in the work tree, we can reuse it.
3795         */
3796        if (ce_uptodate(ce) ||
3797            (!lstat(name, &st) && !ie_match_stat(istate, ce, &st, 0)))
3798                return 1;
3799
3800        return 0;
3801}
3802
3803static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
3804{
3805        struct strbuf buf = STRBUF_INIT;
3806        char *dirty = "";
3807
3808        /* Are we looking at the work tree? */
3809        if (s->dirty_submodule)
3810                dirty = "-dirty";
3811
3812        strbuf_addf(&buf, "Subproject commit %s%s\n",
3813                    oid_to_hex(&s->oid), dirty);
3814        s->size = buf.len;
3815        if (size_only) {
3816                s->data = NULL;
3817                strbuf_release(&buf);
3818        } else {
3819                s->data = strbuf_detach(&buf, NULL);
3820                s->should_free = 1;
3821        }
3822        return 0;
3823}
3824
3825/*
3826 * While doing rename detection and pickaxe operation, we may need to
3827 * grab the data for the blob (or file) for our own in-core comparison.
3828 * diff_filespec has data and size fields for this purpose.
3829 */
3830int diff_populate_filespec(struct repository *r,
3831                           struct diff_filespec *s,
3832                           unsigned int flags)
3833{
3834        int size_only = flags & CHECK_SIZE_ONLY;
3835        int err = 0;
3836        int conv_flags = global_conv_flags_eol;
3837        /*
3838         * demote FAIL to WARN to allow inspecting the situation
3839         * instead of refusing.
3840         */
3841        if (conv_flags & CONV_EOL_RNDTRP_DIE)
3842                conv_flags = CONV_EOL_RNDTRP_WARN;
3843
3844        if (!DIFF_FILE_VALID(s))
3845                die("internal error: asking to populate invalid file.");
3846        if (S_ISDIR(s->mode))
3847                return -1;
3848
3849        if (s->data)
3850                return 0;
3851
3852        if (size_only && 0 < s->size)
3853                return 0;
3854
3855        if (S_ISGITLINK(s->mode))
3856                return diff_populate_gitlink(s, size_only);
3857
3858        if (!s->oid_valid ||
3859            reuse_worktree_file(r->index, s->path, &s->oid, 0)) {
3860                struct strbuf buf = STRBUF_INIT;
3861                struct stat st;
3862                int fd;
3863
3864                if (lstat(s->path, &st) < 0) {
3865                err_empty:
3866                        err = -1;
3867                empty:
3868                        s->data = (char *)"";
3869                        s->size = 0;
3870                        return err;
3871                }
3872                s->size = xsize_t(st.st_size);
3873                if (!s->size)
3874                        goto empty;
3875                if (S_ISLNK(st.st_mode)) {
3876                        struct strbuf sb = STRBUF_INIT;
3877
3878                        if (strbuf_readlink(&sb, s->path, s->size))
3879                                goto err_empty;
3880                        s->size = sb.len;
3881                        s->data = strbuf_detach(&sb, NULL);
3882                        s->should_free = 1;
3883                        return 0;
3884                }
3885
3886                /*
3887                 * Even if the caller would be happy with getting
3888                 * only the size, we cannot return early at this
3889                 * point if the path requires us to run the content
3890                 * conversion.
3891                 */
3892                if (size_only && !would_convert_to_git(r->index, s->path))
3893                        return 0;
3894
3895                /*
3896                 * Note: this check uses xsize_t(st.st_size) that may
3897                 * not be the true size of the blob after it goes
3898                 * through convert_to_git().  This may not strictly be
3899                 * correct, but the whole point of big_file_threshold
3900                 * and is_binary check being that we want to avoid
3901                 * opening the file and inspecting the contents, this
3902                 * is probably fine.
3903                 */
3904                if ((flags & CHECK_BINARY) &&
3905                    s->size > big_file_threshold && s->is_binary == -1) {
3906                        s->is_binary = 1;
3907                        return 0;
3908                }
3909                fd = open(s->path, O_RDONLY);
3910                if (fd < 0)
3911                        goto err_empty;
3912                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
3913                close(fd);
3914                s->should_munmap = 1;
3915
3916                /*
3917                 * Convert from working tree format to canonical git format
3918                 */
3919                if (convert_to_git(r->index, s->path, s->data, s->size, &buf, conv_flags)) {
3920                        size_t size = 0;
3921                        munmap(s->data, s->size);
3922                        s->should_munmap = 0;
3923                        s->data = strbuf_detach(&buf, &size);
3924                        s->size = size;
3925                        s->should_free = 1;
3926                }
3927        }
3928        else {
3929                enum object_type type;
3930                if (size_only || (flags & CHECK_BINARY)) {
3931                        type = oid_object_info(r, &s->oid, &s->size);
3932                        if (type < 0)
3933                                die("unable to read %s",
3934                                    oid_to_hex(&s->oid));
3935                        if (size_only)
3936                                return 0;
3937                        if (s->size > big_file_threshold && s->is_binary == -1) {
3938                                s->is_binary = 1;
3939                                return 0;
3940                        }
3941                }
3942                s->data = read_object_file(&s->oid, &type, &s->size);
3943                if (!s->data)
3944                        die("unable to read %s", oid_to_hex(&s->oid));
3945                s->should_free = 1;
3946        }
3947        return 0;
3948}
3949
3950void diff_free_filespec_blob(struct diff_filespec *s)
3951{
3952        if (s->should_free)
3953                free(s->data);
3954        else if (s->should_munmap)
3955                munmap(s->data, s->size);
3956
3957        if (s->should_free || s->should_munmap) {
3958                s->should_free = s->should_munmap = 0;
3959                s->data = NULL;
3960        }
3961}
3962
3963void diff_free_filespec_data(struct diff_filespec *s)
3964{
3965        diff_free_filespec_blob(s);
3966        FREE_AND_NULL(s->cnt_data);
3967}
3968
3969static void prep_temp_blob(struct index_state *istate,
3970                           const char *path, struct diff_tempfile *temp,
3971                           void *blob,
3972                           unsigned long size,
3973                           const struct object_id *oid,
3974                           int mode)
3975{
3976        struct strbuf buf = STRBUF_INIT;
3977        struct strbuf tempfile = STRBUF_INIT;
3978        char *path_dup = xstrdup(path);
3979        const char *base = basename(path_dup);
3980
3981        /* Generate "XXXXXX_basename.ext" */
3982        strbuf_addstr(&tempfile, "XXXXXX_");
3983        strbuf_addstr(&tempfile, base);
3984
3985        temp->tempfile = mks_tempfile_ts(tempfile.buf, strlen(base) + 1);
3986        if (!temp->tempfile)
3987                die_errno("unable to create temp-file");
3988        if (convert_to_working_tree(istate, path,
3989                        (const char *)blob, (size_t)size, &buf)) {
3990                blob = buf.buf;
3991                size = buf.len;
3992        }
3993        if (write_in_full(temp->tempfile->fd, blob, size) < 0 ||
3994            close_tempfile_gently(temp->tempfile))
3995                die_errno("unable to write temp-file");
3996        temp->name = get_tempfile_path(temp->tempfile);
3997        oid_to_hex_r(temp->hex, oid);
3998        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
3999        strbuf_release(&buf);
4000        strbuf_release(&tempfile);
4001        free(path_dup);
4002}
4003
4004static struct diff_tempfile *prepare_temp_file(struct repository *r,
4005                                               const char *name,
4006                                               struct diff_filespec *one)
4007{
4008        struct diff_tempfile *temp = claim_diff_tempfile();
4009
4010        if (!DIFF_FILE_VALID(one)) {
4011        not_a_valid_file:
4012                /* A '-' entry produces this for file-2, and
4013                 * a '+' entry produces this for file-1.
4014                 */
4015                temp->name = "/dev/null";
4016                xsnprintf(temp->hex, sizeof(temp->hex), ".");
4017                xsnprintf(temp->mode, sizeof(temp->mode), ".");
4018                return temp;
4019        }
4020
4021        if (!S_ISGITLINK(one->mode) &&
4022            (!one->oid_valid ||
4023             reuse_worktree_file(r->index, name, &one->oid, 1))) {
4024                struct stat st;
4025                if (lstat(name, &st) < 0) {
4026                        if (errno == ENOENT)
4027                                goto not_a_valid_file;
4028                        die_errno("stat(%s)", name);
4029                }
4030                if (S_ISLNK(st.st_mode)) {
4031                        struct strbuf sb = STRBUF_INIT;
4032                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
4033                                die_errno("readlink(%s)", name);
4034                        prep_temp_blob(r->index, name, temp, sb.buf, sb.len,
4035                                       (one->oid_valid ?
4036                                        &one->oid : &null_oid),
4037                                       (one->oid_valid ?
4038                                        one->mode : S_IFLNK));
4039                        strbuf_release(&sb);
4040                }
4041                else {
4042                        /* we can borrow from the file in the work tree */
4043                        temp->name = name;
4044                        if (!one->oid_valid)
4045                                oid_to_hex_r(temp->hex, &null_oid);
4046                        else
4047                                oid_to_hex_r(temp->hex, &one->oid);
4048                        /* Even though we may sometimes borrow the
4049                         * contents from the work tree, we always want
4050                         * one->mode.  mode is trustworthy even when
4051                         * !(one->oid_valid), as long as
4052                         * DIFF_FILE_VALID(one).
4053                         */
4054                        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
4055                }
4056                return temp;
4057        }
4058        else {
4059                if (diff_populate_filespec(r, one, 0))
4060                        die("cannot read data blob for %s", one->path);
4061                prep_temp_blob(r->index, name, temp,
4062                               one->data, one->size,
4063                               &one->oid, one->mode);
4064        }
4065        return temp;
4066}
4067
4068static void add_external_diff_name(struct repository *r,
4069                                   struct argv_array *argv,
4070                                   const char *name,
4071                                   struct diff_filespec *df)
4072{
4073        struct diff_tempfile *temp = prepare_temp_file(r, name, df);
4074        argv_array_push(argv, temp->name);
4075        argv_array_push(argv, temp->hex);
4076        argv_array_push(argv, temp->mode);
4077}
4078
4079/* An external diff command takes:
4080 *
4081 * diff-cmd name infile1 infile1-sha1 infile1-mode \
4082 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
4083 *
4084 */
4085static void run_external_diff(const char *pgm,
4086                              const char *name,
4087                              const char *other,
4088                              struct diff_filespec *one,
4089                              struct diff_filespec *two,
4090                              const char *xfrm_msg,
4091                              int complete_rewrite,
4092                              struct diff_options *o)
4093{
4094        struct argv_array argv = ARGV_ARRAY_INIT;
4095        struct argv_array env = ARGV_ARRAY_INIT;
4096        struct diff_queue_struct *q = &diff_queued_diff;
4097
4098        argv_array_push(&argv, pgm);
4099        argv_array_push(&argv, name);
4100
4101        if (one && two) {
4102                add_external_diff_name(o->repo, &argv, name, one);
4103                if (!other)
4104                        add_external_diff_name(o->repo, &argv, name, two);
4105                else {
4106                        add_external_diff_name(o->repo, &argv, other, two);
4107                        argv_array_push(&argv, other);
4108                        argv_array_push(&argv, xfrm_msg);
4109                }
4110        }
4111
4112        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
4113        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
4114
4115        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
4116                die(_("external diff died, stopping at %s"), name);
4117
4118        remove_tempfile();
4119        argv_array_clear(&argv);
4120        argv_array_clear(&env);
4121}
4122
4123static int similarity_index(struct diff_filepair *p)
4124{
4125        return p->score * 100 / MAX_SCORE;
4126}
4127
4128static const char *diff_abbrev_oid(const struct object_id *oid, int abbrev)
4129{
4130        if (startup_info->have_repository)
4131                return find_unique_abbrev(oid, abbrev);
4132        else {
4133                char *hex = oid_to_hex(oid);
4134                if (abbrev < 0)
4135                        abbrev = FALLBACK_DEFAULT_ABBREV;
4136                if (abbrev > the_hash_algo->hexsz)
4137                        BUG("oid abbreviation out of range: %d", abbrev);
4138                if (abbrev)
4139                        hex[abbrev] = '\0';
4140                return hex;
4141        }
4142}
4143
4144static void fill_metainfo(struct strbuf *msg,
4145                          const char *name,
4146                          const char *other,
4147                          struct diff_filespec *one,
4148                          struct diff_filespec *two,
4149                          struct diff_options *o,
4150                          struct diff_filepair *p,
4151                          int *must_show_header,
4152                          int use_color)
4153{
4154        const char *set = diff_get_color(use_color, DIFF_METAINFO);
4155        const char *reset = diff_get_color(use_color, DIFF_RESET);
4156        const char *line_prefix = diff_line_prefix(o);
4157
4158        *must_show_header = 1;
4159        strbuf_init(msg, PATH_MAX * 2 + 300);
4160        switch (p->status) {
4161        case DIFF_STATUS_COPIED:
4162                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4163                            line_prefix, set, similarity_index(p));
4164                strbuf_addf(msg, "%s\n%s%scopy from ",
4165                            reset,  line_prefix, set);
4166                quote_c_style(name, msg, NULL, 0);
4167                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
4168                quote_c_style(other, msg, NULL, 0);
4169                strbuf_addf(msg, "%s\n", reset);
4170                break;
4171        case DIFF_STATUS_RENAMED:
4172                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4173                            line_prefix, set, similarity_index(p));
4174                strbuf_addf(msg, "%s\n%s%srename from ",
4175                            reset, line_prefix, set);
4176                quote_c_style(name, msg, NULL, 0);
4177                strbuf_addf(msg, "%s\n%s%srename to ",
4178                            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_MODIFIED:
4183                if (p->score) {
4184                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
4185                                    line_prefix,
4186                                    set, similarity_index(p), reset);
4187                        break;
4188                }
4189                /* fallthru */
4190        default:
4191                *must_show_header = 0;
4192        }
4193        if (one && two && oidcmp(&one->oid, &two->oid)) {
4194                const unsigned hexsz = the_hash_algo->hexsz;
4195                int abbrev = o->flags.full_index ? hexsz : DEFAULT_ABBREV;
4196
4197                if (o->flags.binary) {
4198                        mmfile_t mf;
4199                        if ((!fill_mmfile(o->repo, &mf, one) &&
4200                             diff_filespec_is_binary(o->repo, one)) ||
4201                            (!fill_mmfile(o->repo, &mf, two) &&
4202                             diff_filespec_is_binary(o->repo, two)))
4203                                abbrev = hexsz;
4204                }
4205                strbuf_addf(msg, "%s%sindex %s..%s", line_prefix, set,
4206                            diff_abbrev_oid(&one->oid, abbrev),
4207                            diff_abbrev_oid(&two->oid, abbrev));
4208                if (one->mode == two->mode)
4209                        strbuf_addf(msg, " %06o", one->mode);
4210                strbuf_addf(msg, "%s\n", reset);
4211        }
4212}
4213
4214static void run_diff_cmd(const char *pgm,
4215                         const char *name,
4216                         const char *other,
4217                         const char *attr_path,
4218                         struct diff_filespec *one,
4219                         struct diff_filespec *two,
4220                         struct strbuf *msg,
4221                         struct diff_options *o,
4222                         struct diff_filepair *p)
4223{
4224        const char *xfrm_msg = NULL;
4225        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
4226        int must_show_header = 0;
4227
4228
4229        if (o->flags.allow_external) {
4230                struct userdiff_driver *drv;
4231
4232                drv = userdiff_find_by_path(o->repo->index, attr_path);
4233                if (drv && drv->external)
4234                        pgm = drv->external;
4235        }
4236
4237        if (msg) {
4238                /*
4239                 * don't use colors when the header is intended for an
4240                 * external diff driver
4241                 */
4242                fill_metainfo(msg, name, other, one, two, o, p,
4243                              &must_show_header,
4244                              want_color(o->use_color) && !pgm);
4245                xfrm_msg = msg->len ? msg->buf : NULL;
4246        }
4247
4248        if (pgm) {
4249                run_external_diff(pgm, name, other, one, two, xfrm_msg,
4250                                  complete_rewrite, o);
4251                return;
4252        }
4253        if (one && two)
4254                builtin_diff(name, other ? other : name,
4255                             one, two, xfrm_msg, must_show_header,
4256                             o, complete_rewrite);
4257        else
4258                fprintf(o->file, "* Unmerged path %s\n", name);
4259}
4260
4261static void diff_fill_oid_info(struct diff_filespec *one, struct index_state *istate)
4262{
4263        if (DIFF_FILE_VALID(one)) {
4264                if (!one->oid_valid) {
4265                        struct stat st;
4266                        if (one->is_stdin) {
4267                                oidclr(&one->oid);
4268                                return;
4269                        }
4270                        if (lstat(one->path, &st) < 0)
4271                                die_errno("stat '%s'", one->path);
4272                        if (index_path(istate, &one->oid, one->path, &st, 0))
4273                                die("cannot hash %s", one->path);
4274                }
4275        }
4276        else
4277                oidclr(&one->oid);
4278}
4279
4280static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
4281{
4282        /* Strip the prefix but do not molest /dev/null and absolute paths */
4283        if (*namep && **namep != '/') {
4284                *namep += prefix_length;
4285                if (**namep == '/')
4286                        ++*namep;
4287        }
4288        if (*otherp && **otherp != '/') {
4289                *otherp += prefix_length;
4290                if (**otherp == '/')
4291                        ++*otherp;
4292        }
4293}
4294
4295static void run_diff(struct diff_filepair *p, struct diff_options *o)
4296{
4297        const char *pgm = external_diff();
4298        struct strbuf msg;
4299        struct diff_filespec *one = p->one;
4300        struct diff_filespec *two = p->two;
4301        const char *name;
4302        const char *other;
4303        const char *attr_path;
4304
4305        name  = one->path;
4306        other = (strcmp(name, two->path) ? two->path : NULL);
4307        attr_path = name;
4308        if (o->prefix_length)
4309                strip_prefix(o->prefix_length, &name, &other);
4310
4311        if (!o->flags.allow_external)
4312                pgm = NULL;
4313
4314        if (DIFF_PAIR_UNMERGED(p)) {
4315                run_diff_cmd(pgm, name, NULL, attr_path,
4316                             NULL, NULL, NULL, o, p);
4317                return;
4318        }
4319
4320        diff_fill_oid_info(one, o->repo->index);
4321        diff_fill_oid_info(two, o->repo->index);
4322
4323        if (!pgm &&
4324            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
4325            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
4326                /*
4327                 * a filepair that changes between file and symlink
4328                 * needs to be split into deletion and creation.
4329                 */
4330                struct diff_filespec *null = alloc_filespec(two->path);
4331                run_diff_cmd(NULL, name, other, attr_path,
4332                             one, null, &msg,
4333                             o, p);
4334                free(null);
4335                strbuf_release(&msg);
4336
4337                null = alloc_filespec(one->path);
4338                run_diff_cmd(NULL, name, other, attr_path,
4339                             null, two, &msg, o, p);
4340                free(null);
4341        }
4342        else
4343                run_diff_cmd(pgm, name, other, attr_path,
4344                             one, two, &msg, o, p);
4345
4346        strbuf_release(&msg);
4347}
4348
4349static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
4350                         struct diffstat_t *diffstat)
4351{
4352        const char *name;
4353        const char *other;
4354
4355        if (DIFF_PAIR_UNMERGED(p)) {
4356                /* unmerged */
4357                builtin_diffstat(p->one->path, NULL, NULL, NULL,
4358                                 diffstat, o, p);
4359                return;
4360        }
4361
4362        name = p->one->path;
4363        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4364
4365        if (o->prefix_length)
4366                strip_prefix(o->prefix_length, &name, &other);
4367
4368        diff_fill_oid_info(p->one, o->repo->index);
4369        diff_fill_oid_info(p->two, o->repo->index);
4370
4371        builtin_diffstat(name, other, p->one, p->two,
4372                         diffstat, o, p);
4373}
4374
4375static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
4376{
4377        const char *name;
4378        const char *other;
4379        const char *attr_path;
4380
4381        if (DIFF_PAIR_UNMERGED(p)) {
4382                /* unmerged */
4383                return;
4384        }
4385
4386        name = p->one->path;
4387        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4388        attr_path = other ? other : name;
4389
4390        if (o->prefix_length)
4391                strip_prefix(o->prefix_length, &name, &other);
4392
4393        diff_fill_oid_info(p->one, o->repo->index);
4394        diff_fill_oid_info(p->two, o->repo->index);
4395
4396        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
4397}
4398
4399void repo_diff_setup(struct repository *r, struct diff_options *options)
4400{
4401        memcpy(options, &default_diff_options, sizeof(*options));
4402
4403        options->file = stdout;
4404        options->repo = r;
4405
4406        options->abbrev = DEFAULT_ABBREV;
4407        options->line_termination = '\n';
4408        options->break_opt = -1;
4409        options->rename_limit = -1;
4410        options->dirstat_permille = diff_dirstat_permille_default;
4411        options->context = diff_context_default;
4412        options->interhunkcontext = diff_interhunk_context_default;
4413        options->ws_error_highlight = ws_error_highlight_default;
4414        options->flags.rename_empty = 1;
4415        options->objfind = NULL;
4416
4417        /* pathchange left =NULL by default */
4418        options->change = diff_change;
4419        options->add_remove = diff_addremove;
4420        options->use_color = diff_use_color_default;
4421        options->detect_rename = diff_detect_rename_default;
4422        options->xdl_opts |= diff_algorithm;
4423        if (diff_indent_heuristic)
4424                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4425
4426        options->orderfile = diff_order_file_cfg;
4427
4428        if (diff_no_prefix) {
4429                options->a_prefix = options->b_prefix = "";
4430        } else if (!diff_mnemonic_prefix) {
4431                options->a_prefix = "a/";
4432                options->b_prefix = "b/";
4433        }
4434
4435        options->color_moved = diff_color_moved_default;
4436        options->color_moved_ws_handling = diff_color_moved_ws_default;
4437}
4438
4439void diff_setup_done(struct diff_options *options)
4440{
4441        unsigned check_mask = DIFF_FORMAT_NAME |
4442                              DIFF_FORMAT_NAME_STATUS |
4443                              DIFF_FORMAT_CHECKDIFF |
4444                              DIFF_FORMAT_NO_OUTPUT;
4445        /*
4446         * This must be signed because we're comparing against a potentially
4447         * negative value.
4448         */
4449        const int hexsz = the_hash_algo->hexsz;
4450
4451        if (options->set_default)
4452                options->set_default(options);
4453
4454        if (HAS_MULTI_BITS(options->output_format & check_mask))
4455                die(_("--name-only, --name-status, --check and -s are mutually exclusive"));
4456
4457        if (HAS_MULTI_BITS(options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK))
4458                die(_("-G, -S and --find-object are mutually exclusive"));
4459
4460        /*
4461         * Most of the time we can say "there are changes"
4462         * only by checking if there are changed paths, but
4463         * --ignore-whitespace* options force us to look
4464         * inside contents.
4465         */
4466
4467        if ((options->xdl_opts & XDF_WHITESPACE_FLAGS))
4468                options->flags.diff_from_contents = 1;
4469        else
4470                options->flags.diff_from_contents = 0;
4471
4472        if (options->flags.find_copies_harder)
4473                options->detect_rename = DIFF_DETECT_COPY;
4474
4475        if (!options->flags.relative_name)
4476                options->prefix = NULL;
4477        if (options->prefix)
4478                options->prefix_length = strlen(options->prefix);
4479        else
4480                options->prefix_length = 0;
4481
4482        if (options->output_format & (DIFF_FORMAT_NAME |
4483                                      DIFF_FORMAT_NAME_STATUS |
4484                                      DIFF_FORMAT_CHECKDIFF |
4485                                      DIFF_FORMAT_NO_OUTPUT))
4486                options->output_format &= ~(DIFF_FORMAT_RAW |
4487                                            DIFF_FORMAT_NUMSTAT |
4488                                            DIFF_FORMAT_DIFFSTAT |
4489                                            DIFF_FORMAT_SHORTSTAT |
4490                                            DIFF_FORMAT_DIRSTAT |
4491                                            DIFF_FORMAT_SUMMARY |
4492                                            DIFF_FORMAT_PATCH);
4493
4494        /*
4495         * These cases always need recursive; we do not drop caller-supplied
4496         * recursive bits for other formats here.
4497         */
4498        if (options->output_format & (DIFF_FORMAT_PATCH |
4499                                      DIFF_FORMAT_NUMSTAT |
4500                                      DIFF_FORMAT_DIFFSTAT |
4501                                      DIFF_FORMAT_SHORTSTAT |
4502                                      DIFF_FORMAT_DIRSTAT |
4503                                      DIFF_FORMAT_SUMMARY |
4504                                      DIFF_FORMAT_CHECKDIFF))
4505                options->flags.recursive = 1;
4506        /*
4507         * Also pickaxe would not work very well if you do not say recursive
4508         */
4509        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
4510                options->flags.recursive = 1;
4511        /*
4512         * When patches are generated, submodules diffed against the work tree
4513         * must be checked for dirtiness too so it can be shown in the output
4514         */
4515        if (options->output_format & DIFF_FORMAT_PATCH)
4516                options->flags.dirty_submodules = 1;
4517
4518        if (options->detect_rename && options->rename_limit < 0)
4519                options->rename_limit = diff_rename_limit_default;
4520        if (hexsz < options->abbrev)
4521                options->abbrev = hexsz; /* full */
4522
4523        /*
4524         * It does not make sense to show the first hit we happened
4525         * to have found.  It does not make sense not to return with
4526         * exit code in such a case either.
4527         */
4528        if (options->flags.quick) {
4529                options->output_format = DIFF_FORMAT_NO_OUTPUT;
4530                options->flags.exit_with_status = 1;
4531        }
4532
4533        options->diff_path_counter = 0;
4534
4535        if (options->flags.follow_renames && options->pathspec.nr != 1)
4536                die(_("--follow requires exactly one pathspec"));
4537
4538        if (!options->use_color || external_diff())
4539                options->color_moved = 0;
4540}
4541
4542static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
4543{
4544        char c, *eq;
4545        int len;
4546
4547        if (*arg != '-')
4548                return 0;
4549        c = *++arg;
4550        if (!c)
4551                return 0;
4552        if (c == arg_short) {
4553                c = *++arg;
4554                if (!c)
4555                        return 1;
4556                if (val && isdigit(c)) {
4557                        char *end;
4558                        int n = strtoul(arg, &end, 10);
4559                        if (*end)
4560                                return 0;
4561                        *val = n;
4562                        return 1;
4563                }
4564                return 0;
4565        }
4566        if (c != '-')
4567                return 0;
4568        arg++;
4569        eq = strchrnul(arg, '=');
4570        len = eq - arg;
4571        if (!len || strncmp(arg, arg_long, len))
4572                return 0;
4573        if (*eq) {
4574                int n;
4575                char *end;
4576                if (!isdigit(*++eq))
4577                        return 0;
4578                n = strtoul(eq, &end, 10);
4579                if (*end)
4580                        return 0;
4581                *val = n;
4582        }
4583        return 1;
4584}
4585
4586static int diff_scoreopt_parse(const char *opt);
4587
4588static inline int short_opt(char opt, const char **argv,
4589                            const char **optarg)
4590{
4591        const char *arg = argv[0];
4592        if (arg[0] != '-' || arg[1] != opt)
4593                return 0;
4594        if (arg[2] != '\0') {
4595                *optarg = arg + 2;
4596                return 1;
4597        }
4598        if (!argv[1])
4599                die("Option '%c' requires a value", opt);
4600        *optarg = argv[1];
4601        return 2;
4602}
4603
4604int parse_long_opt(const char *opt, const char **argv,
4605                   const char **optarg)
4606{
4607        const char *arg = argv[0];
4608        if (!skip_prefix(arg, "--", &arg))
4609                return 0;
4610        if (!skip_prefix(arg, opt, &arg))
4611                return 0;
4612        if (*arg == '=') { /* stuck form: --option=value */
4613                *optarg = arg + 1;
4614                return 1;
4615        }
4616        if (*arg != '\0')
4617                return 0;
4618        /* separate form: --option value */
4619        if (!argv[1])
4620                die("Option '--%s' requires a value", opt);
4621        *optarg = argv[1];
4622        return 2;
4623}
4624
4625static int stat_opt(struct diff_options *options, const char **av)
4626{
4627        const char *arg = av[0];
4628        char *end;
4629        int width = options->stat_width;
4630        int name_width = options->stat_name_width;
4631        int graph_width = options->stat_graph_width;
4632        int count = options->stat_count;
4633        int argcount = 1;
4634
4635        if (!skip_prefix(arg, "--stat", &arg))
4636                BUG("stat option does not begin with --stat: %s", arg);
4637        end = (char *)arg;
4638
4639        switch (*arg) {
4640        case '-':
4641                if (skip_prefix(arg, "-width", &arg)) {
4642                        if (*arg == '=')
4643                                width = strtoul(arg + 1, &end, 10);
4644                        else if (!*arg && !av[1])
4645                                die_want_option("--stat-width");
4646                        else if (!*arg) {
4647                                width = strtoul(av[1], &end, 10);
4648                                argcount = 2;
4649                        }
4650                } else if (skip_prefix(arg, "-name-width", &arg)) {
4651                        if (*arg == '=')
4652                                name_width = strtoul(arg + 1, &end, 10);
4653                        else if (!*arg && !av[1])
4654                                die_want_option("--stat-name-width");
4655                        else if (!*arg) {
4656                                name_width = strtoul(av[1], &end, 10);
4657                                argcount = 2;
4658                        }
4659                } else if (skip_prefix(arg, "-graph-width", &arg)) {
4660                        if (*arg == '=')
4661                                graph_width = strtoul(arg + 1, &end, 10);
4662                        else if (!*arg && !av[1])
4663                                die_want_option("--stat-graph-width");
4664                        else if (!*arg) {
4665                                graph_width = strtoul(av[1], &end, 10);
4666                                argcount = 2;
4667                        }
4668                } else if (skip_prefix(arg, "-count", &arg)) {
4669                        if (*arg == '=')
4670                                count = strtoul(arg + 1, &end, 10);
4671                        else if (!*arg && !av[1])
4672                                die_want_option("--stat-count");
4673                        else if (!*arg) {
4674                                count = strtoul(av[1], &end, 10);
4675                                argcount = 2;
4676                        }
4677                }
4678                break;
4679        case '=':
4680                width = strtoul(arg+1, &end, 10);
4681                if (*end == ',')
4682                        name_width = strtoul(end+1, &end, 10);
4683                if (*end == ',')
4684                        count = strtoul(end+1, &end, 10);
4685        }
4686
4687        /* Important! This checks all the error cases! */
4688        if (*end)
4689                return 0;
4690        options->output_format |= DIFF_FORMAT_DIFFSTAT;
4691        options->stat_name_width = name_width;
4692        options->stat_graph_width = graph_width;
4693        options->stat_width = width;
4694        options->stat_count = count;
4695        return argcount;
4696}
4697
4698static int parse_dirstat_opt(struct diff_options *options, const char *params)
4699{
4700        struct strbuf errmsg = STRBUF_INIT;
4701        if (parse_dirstat_params(options, params, &errmsg))
4702                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
4703                    errmsg.buf);
4704        strbuf_release(&errmsg);
4705        /*
4706         * The caller knows a dirstat-related option is given from the command
4707         * line; allow it to say "return this_function();"
4708         */
4709        options->output_format |= DIFF_FORMAT_DIRSTAT;
4710        return 1;
4711}
4712
4713static int parse_submodule_opt(struct diff_options *options, const char *value)
4714{
4715        if (parse_submodule_params(options, value))
4716                die(_("Failed to parse --submodule option parameter: '%s'"),
4717                        value);
4718        return 1;
4719}
4720
4721static const char diff_status_letters[] = {
4722        DIFF_STATUS_ADDED,
4723        DIFF_STATUS_COPIED,
4724        DIFF_STATUS_DELETED,
4725        DIFF_STATUS_MODIFIED,
4726        DIFF_STATUS_RENAMED,
4727        DIFF_STATUS_TYPE_CHANGED,
4728        DIFF_STATUS_UNKNOWN,
4729        DIFF_STATUS_UNMERGED,
4730        DIFF_STATUS_FILTER_AON,
4731        DIFF_STATUS_FILTER_BROKEN,
4732        '\0',
4733};
4734
4735static unsigned int filter_bit['Z' + 1];
4736
4737static void prepare_filter_bits(void)
4738{
4739        int i;
4740
4741        if (!filter_bit[DIFF_STATUS_ADDED]) {
4742                for (i = 0; diff_status_letters[i]; i++)
4743                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
4744        }
4745}
4746
4747static unsigned filter_bit_tst(char status, const struct diff_options *opt)
4748{
4749        return opt->filter & filter_bit[(int) status];
4750}
4751
4752static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
4753{
4754        int i, optch;
4755
4756        prepare_filter_bits();
4757
4758        /*
4759         * If there is a negation e.g. 'd' in the input, and we haven't
4760         * initialized the filter field with another --diff-filter, start
4761         * from full set of bits, except for AON.
4762         */
4763        if (!opt->filter) {
4764                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4765                        if (optch < 'a' || 'z' < optch)
4766                                continue;
4767                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
4768                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
4769                        break;
4770                }
4771        }
4772
4773        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4774                unsigned int bit;
4775                int negate;
4776
4777                if ('a' <= optch && optch <= 'z') {
4778                        negate = 1;
4779                        optch = toupper(optch);
4780                } else {
4781                        negate = 0;
4782                }
4783
4784                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
4785                if (!bit)
4786                        return optarg[i];
4787                if (negate)
4788                        opt->filter &= ~bit;
4789                else
4790                        opt->filter |= bit;
4791        }
4792        return 0;
4793}
4794
4795static void enable_patch_output(int *fmt) {
4796        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
4797        *fmt |= DIFF_FORMAT_PATCH;
4798}
4799
4800static int parse_ws_error_highlight_opt(struct diff_options *opt, const char *arg)
4801{
4802        int val = parse_ws_error_highlight(arg);
4803
4804        if (val < 0) {
4805                error("unknown value after ws-error-highlight=%.*s",
4806                      -1 - val, arg);
4807                return 0;
4808        }
4809        opt->ws_error_highlight = val;
4810        return 1;
4811}
4812
4813static int parse_objfind_opt(struct diff_options *opt, const char *arg)
4814{
4815        struct object_id oid;
4816
4817        if (get_oid(arg, &oid))
4818                return error("unable to resolve '%s'", arg);
4819
4820        if (!opt->objfind)
4821                opt->objfind = xcalloc(1, sizeof(*opt->objfind));
4822
4823        opt->pickaxe_opts |= DIFF_PICKAXE_KIND_OBJFIND;
4824        opt->flags.recursive = 1;
4825        opt->flags.tree_in_recursive = 1;
4826        oidset_insert(opt->objfind, &oid);
4827        return 1;
4828}
4829
4830int diff_opt_parse(struct diff_options *options,
4831                   const char **av, int ac, const char *prefix)
4832{
4833        const char *arg = av[0];
4834        const char *optarg;
4835        int argcount;
4836
4837        if (!prefix)
4838                prefix = "";
4839
4840        /* Output format options */
4841        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
4842            || opt_arg(arg, 'U', "unified", &options->context))
4843                enable_patch_output(&options->output_format);
4844        else if (!strcmp(arg, "--raw"))
4845                options->output_format |= DIFF_FORMAT_RAW;
4846        else if (!strcmp(arg, "--patch-with-raw")) {
4847                enable_patch_output(&options->output_format);
4848                options->output_format |= DIFF_FORMAT_RAW;
4849        } else if (!strcmp(arg, "--numstat"))
4850                options->output_format |= DIFF_FORMAT_NUMSTAT;
4851        else if (!strcmp(arg, "--shortstat"))
4852                options->output_format |= DIFF_FORMAT_SHORTSTAT;
4853        else if (skip_prefix(arg, "-X", &arg) ||
4854                 skip_to_optional_arg(arg, "--dirstat", &arg))
4855                return parse_dirstat_opt(options, arg);
4856        else if (!strcmp(arg, "--cumulative"))
4857                return parse_dirstat_opt(options, "cumulative");
4858        else if (skip_to_optional_arg(arg, "--dirstat-by-file", &arg)) {
4859                parse_dirstat_opt(options, "files");
4860                return parse_dirstat_opt(options, arg);
4861        }
4862        else if (!strcmp(arg, "--check"))
4863                options->output_format |= DIFF_FORMAT_CHECKDIFF;
4864        else if (!strcmp(arg, "--summary"))
4865                options->output_format |= DIFF_FORMAT_SUMMARY;
4866        else if (!strcmp(arg, "--patch-with-stat")) {
4867                enable_patch_output(&options->output_format);
4868                options->output_format |= DIFF_FORMAT_DIFFSTAT;
4869        } else if (!strcmp(arg, "--name-only"))
4870                options->output_format |= DIFF_FORMAT_NAME;
4871        else if (!strcmp(arg, "--name-status"))
4872                options->output_format |= DIFF_FORMAT_NAME_STATUS;
4873        else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
4874                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
4875        else if (starts_with(arg, "--stat"))
4876                /* --stat, --stat-width, --stat-name-width, or --stat-count */
4877                return stat_opt(options, av);
4878        else if (!strcmp(arg, "--compact-summary")) {
4879                 options->flags.stat_with_summary = 1;
4880                 options->output_format |= DIFF_FORMAT_DIFFSTAT;
4881        } else if (!strcmp(arg, "--no-compact-summary"))
4882                 options->flags.stat_with_summary = 0;
4883
4884        /* renames options */
4885        else if (starts_with(arg, "-B") ||
4886                 skip_to_optional_arg(arg, "--break-rewrites", NULL)) {
4887                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
4888                        return error("invalid argument to -B: %s", arg+2);
4889        }
4890        else if (starts_with(arg, "-M") ||
4891                 skip_to_optional_arg(arg, "--find-renames", NULL)) {
4892                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4893                        return error("invalid argument to -M: %s", arg+2);
4894                options->detect_rename = DIFF_DETECT_RENAME;
4895        }
4896        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
4897                options->irreversible_delete = 1;
4898        }
4899        else if (starts_with(arg, "-C") ||
4900                 skip_to_optional_arg(arg, "--find-copies", NULL)) {
4901                if (options->detect_rename == DIFF_DETECT_COPY)
4902                        options->flags.find_copies_harder = 1;
4903                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4904                        return error("invalid argument to -C: %s", arg+2);
4905                options->detect_rename = DIFF_DETECT_COPY;
4906        }
4907        else if (!strcmp(arg, "--no-renames"))
4908                options->detect_rename = 0;
4909        else if (!strcmp(arg, "--rename-empty"))
4910                options->flags.rename_empty = 1;
4911        else if (!strcmp(arg, "--no-rename-empty"))
4912                options->flags.rename_empty = 0;
4913        else if (skip_to_optional_arg_default(arg, "--relative", &arg, NULL)) {
4914                options->flags.relative_name = 1;
4915                if (arg)
4916                        options->prefix = arg;
4917        }
4918
4919        /* xdiff options */
4920        else if (!strcmp(arg, "--minimal"))
4921                DIFF_XDL_SET(options, NEED_MINIMAL);
4922        else if (!strcmp(arg, "--no-minimal"))
4923                DIFF_XDL_CLR(options, NEED_MINIMAL);
4924        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
4925                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
4926        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
4927                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
4928        else if (!strcmp(arg, "--ignore-space-at-eol"))
4929                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
4930        else if (!strcmp(arg, "--ignore-cr-at-eol"))
4931                DIFF_XDL_SET(options, IGNORE_CR_AT_EOL);
4932        else if (!strcmp(arg, "--ignore-blank-lines"))
4933                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
4934        else if (!strcmp(arg, "--indent-heuristic"))
4935                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4936        else if (!strcmp(arg, "--no-indent-heuristic"))
4937                DIFF_XDL_CLR(options, INDENT_HEURISTIC);
4938        else if (!strcmp(arg, "--patience")) {
4939                int i;
4940                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4941                /*
4942                 * Both --patience and --anchored use PATIENCE_DIFF
4943                 * internally, so remove any anchors previously
4944                 * specified.
4945                 */
4946                for (i = 0; i < options->anchors_nr; i++)
4947                        free(options->anchors[i]);
4948                options->anchors_nr = 0;
4949        } else if (!strcmp(arg, "--histogram"))
4950                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
4951        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
4952                long value = parse_algorithm_value(optarg);
4953                if (value < 0)
4954                        return error("option diff-algorithm accepts \"myers\", "
4955                                     "\"minimal\", \"patience\" and \"histogram\"");
4956                /* clear out previous settings */
4957                DIFF_XDL_CLR(options, NEED_MINIMAL);
4958                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
4959                options->xdl_opts |= value;
4960                return argcount;
4961        } else if (skip_prefix(arg, "--anchored=", &arg)) {
4962                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4963                ALLOC_GROW(options->anchors, options->anchors_nr + 1,
4964                           options->anchors_alloc);
4965                options->anchors[options->anchors_nr++] = xstrdup(arg);
4966        }
4967
4968        /* flags options */
4969        else if (!strcmp(arg, "--binary")) {
4970                enable_patch_output(&options->output_format);
4971                options->flags.binary = 1;
4972        }
4973        else if (!strcmp(arg, "--full-index"))
4974                options->flags.full_index = 1;
4975        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
4976                options->flags.text = 1;
4977        else if (!strcmp(arg, "-R"))
4978                options->flags.reverse_diff = 1;
4979        else if (!strcmp(arg, "--find-copies-harder"))
4980                options->flags.find_copies_harder = 1;
4981        else if (!strcmp(arg, "--follow"))
4982                options->flags.follow_renames = 1;
4983        else if (!strcmp(arg, "--no-follow")) {
4984                options->flags.follow_renames = 0;
4985                options->flags.default_follow_renames = 0;
4986        } else if (skip_to_optional_arg_default(arg, "--color", &arg, "always")) {
4987                int value = git_config_colorbool(NULL, arg);
4988                if (value < 0)
4989                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
4990                options->use_color = value;
4991        }
4992        else if (!strcmp(arg, "--no-color"))
4993                options->use_color = 0;
4994        else if (!strcmp(arg, "--color-moved")) {
4995                if (diff_color_moved_default)
4996                        options->color_moved = diff_color_moved_default;
4997                if (options->color_moved == COLOR_MOVED_NO)
4998                        options->color_moved = COLOR_MOVED_DEFAULT;
4999        } else if (!strcmp(arg, "--no-color-moved"))
5000                options->color_moved = COLOR_MOVED_NO;
5001        else if (skip_prefix(arg, "--color-moved=", &arg)) {
5002                int cm = parse_color_moved(arg);
5003                if (cm < 0)
5004                        die("bad --color-moved argument: %s", arg);
5005                options->color_moved = cm;
5006        } else if (skip_prefix(arg, "--color-moved-ws=", &arg)) {
5007                options->color_moved_ws_handling = parse_color_moved_ws(arg);
5008        } else if (skip_to_optional_arg_default(arg, "--color-words", &options->word_regex, NULL)) {
5009                options->use_color = 1;
5010                options->word_diff = DIFF_WORDS_COLOR;
5011        }
5012        else if (!strcmp(arg, "--word-diff")) {
5013                if (options->word_diff == DIFF_WORDS_NONE)
5014                        options->word_diff = DIFF_WORDS_PLAIN;
5015        }
5016        else if (skip_prefix(arg, "--word-diff=", &arg)) {
5017                if (!strcmp(arg, "plain"))
5018                        options->word_diff = DIFF_WORDS_PLAIN;
5019                else if (!strcmp(arg, "color")) {
5020                        options->use_color = 1;
5021                        options->word_diff = DIFF_WORDS_COLOR;
5022                }
5023                else if (!strcmp(arg, "porcelain"))
5024                        options->word_diff = DIFF_WORDS_PORCELAIN;
5025                else if (!strcmp(arg, "none"))
5026                        options->word_diff = DIFF_WORDS_NONE;
5027                else
5028                        die("bad --word-diff argument: %s", arg);
5029        }
5030        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
5031                if (options->word_diff == DIFF_WORDS_NONE)
5032                        options->word_diff = DIFF_WORDS_PLAIN;
5033                options->word_regex = optarg;
5034                return argcount;
5035        }
5036        else if (!strcmp(arg, "--exit-code"))
5037                options->flags.exit_with_status = 1;
5038        else if (!strcmp(arg, "--quiet"))
5039                options->flags.quick = 1;
5040        else if (!strcmp(arg, "--ext-diff"))
5041                options->flags.allow_external = 1;
5042        else if (!strcmp(arg, "--no-ext-diff"))
5043                options->flags.allow_external = 0;
5044        else if (!strcmp(arg, "--textconv")) {
5045                options->flags.allow_textconv = 1;
5046                options->flags.textconv_set_via_cmdline = 1;
5047        } else if (!strcmp(arg, "--no-textconv"))
5048                options->flags.allow_textconv = 0;
5049        else if (skip_to_optional_arg_default(arg, "--ignore-submodules", &arg, "all")) {
5050                options->flags.override_submodule_config = 1;
5051                handle_ignore_submodules_arg(options, arg);
5052        } else if (skip_to_optional_arg_default(arg, "--submodule", &arg, "log"))
5053                return parse_submodule_opt(options, arg);
5054        else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
5055                return parse_ws_error_highlight_opt(options, arg);
5056        else if (!strcmp(arg, "--ita-invisible-in-index"))
5057                options->ita_invisible_in_index = 1;
5058        else if (!strcmp(arg, "--ita-visible-in-index"))
5059                options->ita_invisible_in_index = 0;
5060
5061        /* misc options */
5062        else if (!strcmp(arg, "-z"))
5063                options->line_termination = 0;
5064        else if ((argcount = short_opt('l', av, &optarg))) {
5065                options->rename_limit = strtoul(optarg, NULL, 10);
5066                return argcount;
5067        }
5068        else if ((argcount = short_opt('S', av, &optarg))) {
5069                options->pickaxe = optarg;
5070                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
5071                return argcount;
5072        } else if ((argcount = short_opt('G', av, &optarg))) {
5073                options->pickaxe = optarg;
5074                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
5075                return argcount;
5076        }
5077        else if (!strcmp(arg, "--pickaxe-all"))
5078                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
5079        else if (!strcmp(arg, "--pickaxe-regex"))
5080                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
5081        else if ((argcount = short_opt('O', av, &optarg))) {
5082                options->orderfile = prefix_filename(prefix, optarg);
5083                return argcount;
5084        } else if (skip_prefix(arg, "--find-object=", &arg))
5085                return parse_objfind_opt(options, arg);
5086        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
5087                int offending = parse_diff_filter_opt(optarg, options);
5088                if (offending)
5089                        die("unknown change class '%c' in --diff-filter=%s",
5090                            offending, optarg);
5091                return argcount;
5092        }
5093        else if (!strcmp(arg, "--no-abbrev"))
5094                options->abbrev = 0;
5095        else if (!strcmp(arg, "--abbrev"))
5096                options->abbrev = DEFAULT_ABBREV;
5097        else if (skip_prefix(arg, "--abbrev=", &arg)) {
5098                options->abbrev = strtoul(arg, NULL, 10);
5099                if (options->abbrev < MINIMUM_ABBREV)
5100                        options->abbrev = MINIMUM_ABBREV;
5101                else if (the_hash_algo->hexsz < options->abbrev)
5102                        options->abbrev = the_hash_algo->hexsz;
5103        }
5104        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
5105                options->a_prefix = optarg;
5106                return argcount;
5107        }
5108        else if ((argcount = parse_long_opt("line-prefix", av, &optarg))) {
5109                options->line_prefix = optarg;
5110                options->line_prefix_length = strlen(options->line_prefix);
5111                graph_setup_line_prefix(options);
5112                return argcount;
5113        }
5114        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
5115                options->b_prefix = optarg;
5116                return argcount;
5117        }
5118        else if (!strcmp(arg, "--no-prefix"))
5119                options->a_prefix = options->b_prefix = "";
5120        else if (opt_arg(arg, '\0', "inter-hunk-context",
5121                         &options->interhunkcontext))
5122                ;
5123        else if (!strcmp(arg, "-W"))
5124                options->flags.funccontext = 1;
5125        else if (!strcmp(arg, "--function-context"))
5126                options->flags.funccontext = 1;
5127        else if (!strcmp(arg, "--no-function-context"))
5128                options->flags.funccontext = 0;
5129        else if ((argcount = parse_long_opt("output", av, &optarg))) {
5130                char *path = prefix_filename(prefix, optarg);
5131                options->file = xfopen(path, "w");
5132                options->close_file = 1;
5133                if (options->use_color != GIT_COLOR_ALWAYS)
5134                        options->use_color = GIT_COLOR_NEVER;
5135                free(path);
5136                return argcount;
5137        } else
5138                return 0;
5139        return 1;
5140}
5141
5142int parse_rename_score(const char **cp_p)
5143{
5144        unsigned long num, scale;
5145        int ch, dot;
5146        const char *cp = *cp_p;
5147
5148        num = 0;
5149        scale = 1;
5150        dot = 0;
5151        for (;;) {
5152                ch = *cp;
5153                if ( !dot && ch == '.' ) {
5154                        scale = 1;
5155                        dot = 1;
5156                } else if ( ch == '%' ) {
5157                        scale = dot ? scale*100 : 100;
5158                        cp++;   /* % is always at the end */
5159                        break;
5160                } else if ( ch >= '0' && ch <= '9' ) {
5161                        if ( scale < 100000 ) {
5162                                scale *= 10;
5163                                num = (num*10) + (ch-'0');
5164                        }
5165                } else {
5166                        break;
5167                }
5168                cp++;
5169        }
5170        *cp_p = cp;
5171
5172        /* user says num divided by scale and we say internally that
5173         * is MAX_SCORE * num / scale.
5174         */
5175        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
5176}
5177
5178static int diff_scoreopt_parse(const char *opt)
5179{
5180        int opt1, opt2, cmd;
5181
5182        if (*opt++ != '-')
5183                return -1;
5184        cmd = *opt++;
5185        if (cmd == '-') {
5186                /* convert the long-form arguments into short-form versions */
5187                if (skip_prefix(opt, "break-rewrites", &opt)) {
5188                        if (*opt == 0 || *opt++ == '=')
5189                                cmd = 'B';
5190                } else if (skip_prefix(opt, "find-copies", &opt)) {
5191                        if (*opt == 0 || *opt++ == '=')
5192                                cmd = 'C';
5193                } else if (skip_prefix(opt, "find-renames", &opt)) {
5194                        if (*opt == 0 || *opt++ == '=')
5195                                cmd = 'M';
5196                }
5197        }
5198        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
5199                return -1; /* that is not a -M, -C, or -B option */
5200
5201        opt1 = parse_rename_score(&opt);
5202        if (cmd != 'B')
5203                opt2 = 0;
5204        else {
5205                if (*opt == 0)
5206                        opt2 = 0;
5207                else if (*opt != '/')
5208                        return -1; /* we expect -B80/99 or -B80 */
5209                else {
5210                        opt++;
5211                        opt2 = parse_rename_score(&opt);
5212                }
5213        }
5214        if (*opt != 0)
5215                return -1;
5216        return opt1 | (opt2 << 16);
5217}
5218
5219struct diff_queue_struct diff_queued_diff;
5220
5221void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
5222{
5223        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
5224        queue->queue[queue->nr++] = dp;
5225}
5226
5227struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
5228                                 struct diff_filespec *one,
5229                                 struct diff_filespec *two)
5230{
5231        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
5232        dp->one = one;
5233        dp->two = two;
5234        if (queue)
5235                diff_q(queue, dp);
5236        return dp;
5237}
5238
5239void diff_free_filepair(struct diff_filepair *p)
5240{
5241        free_filespec(p->one);
5242        free_filespec(p->two);
5243        free(p);
5244}
5245
5246const char *diff_aligned_abbrev(const struct object_id *oid, int len)
5247{
5248        int abblen;
5249        const char *abbrev;
5250
5251        /* Do we want all 40 hex characters? */
5252        if (len == the_hash_algo->hexsz)
5253                return oid_to_hex(oid);
5254
5255        /* An abbreviated value is fine, possibly followed by an ellipsis. */
5256        abbrev = diff_abbrev_oid(oid, len);
5257
5258        if (!print_sha1_ellipsis())
5259                return abbrev;
5260
5261        abblen = strlen(abbrev);
5262
5263        /*
5264         * In well-behaved cases, where the abbreviated result is the
5265         * same as the requested length, append three dots after the
5266         * abbreviation (hence the whole logic is limited to the case
5267         * where abblen < 37); when the actual abbreviated result is a
5268         * bit longer than the requested length, we reduce the number
5269         * of dots so that they match the well-behaved ones.  However,
5270         * if the actual abbreviation is longer than the requested
5271         * length by more than three, we give up on aligning, and add
5272         * three dots anyway, to indicate that the output is not the
5273         * full object name.  Yes, this may be suboptimal, but this
5274         * appears only in "diff --raw --abbrev" output and it is not
5275         * worth the effort to change it now.  Note that this would
5276         * likely to work fine when the automatic sizing of default
5277         * abbreviation length is used--we would be fed -1 in "len" in
5278         * that case, and will end up always appending three-dots, but
5279         * the automatic sizing is supposed to give abblen that ensures
5280         * uniqueness across all objects (statistically speaking).
5281         */
5282        if (abblen < the_hash_algo->hexsz - 3) {
5283                static char hex[GIT_MAX_HEXSZ + 1];
5284                if (len < abblen && abblen <= len + 2)
5285                        xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
5286                else
5287                        xsnprintf(hex, sizeof(hex), "%s...", abbrev);
5288                return hex;
5289        }
5290
5291        return oid_to_hex(oid);
5292}
5293
5294static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
5295{
5296        int line_termination = opt->line_termination;
5297        int inter_name_termination = line_termination ? '\t' : '\0';
5298
5299        fprintf(opt->file, "%s", diff_line_prefix(opt));
5300        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
5301                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
5302                        diff_aligned_abbrev(&p->one->oid, opt->abbrev));
5303                fprintf(opt->file, "%s ",
5304                        diff_aligned_abbrev(&p->two->oid, opt->abbrev));
5305        }
5306        if (p->score) {
5307                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
5308                        inter_name_termination);
5309        } else {
5310                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
5311        }
5312
5313        if (p->status == DIFF_STATUS_COPIED ||
5314            p->status == DIFF_STATUS_RENAMED) {
5315                const char *name_a, *name_b;
5316                name_a = p->one->path;
5317                name_b = p->two->path;
5318                strip_prefix(opt->prefix_length, &name_a, &name_b);
5319                write_name_quoted(name_a, opt->file, inter_name_termination);
5320                write_name_quoted(name_b, opt->file, line_termination);
5321        } else {
5322                const char *name_a, *name_b;
5323                name_a = p->one->mode ? p->one->path : p->two->path;
5324                name_b = NULL;
5325                strip_prefix(opt->prefix_length, &name_a, &name_b);
5326                write_name_quoted(name_a, opt->file, line_termination);
5327        }
5328}
5329
5330int diff_unmodified_pair(struct diff_filepair *p)
5331{
5332        /* This function is written stricter than necessary to support
5333         * the currently implemented transformers, but the idea is to
5334         * let transformers to produce diff_filepairs any way they want,
5335         * and filter and clean them up here before producing the output.
5336         */
5337        struct diff_filespec *one = p->one, *two = p->two;
5338
5339        if (DIFF_PAIR_UNMERGED(p))
5340                return 0; /* unmerged is interesting */
5341
5342        /* deletion, addition, mode or type change
5343         * and rename are all interesting.
5344         */
5345        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
5346            DIFF_PAIR_MODE_CHANGED(p) ||
5347            strcmp(one->path, two->path))
5348                return 0;
5349
5350        /* both are valid and point at the same path.  that is, we are
5351         * dealing with a change.
5352         */
5353        if (one->oid_valid && two->oid_valid &&
5354            !oidcmp(&one->oid, &two->oid) &&
5355            !one->dirty_submodule && !two->dirty_submodule)
5356                return 1; /* no change */
5357        if (!one->oid_valid && !two->oid_valid)
5358                return 1; /* both look at the same file on the filesystem. */
5359        return 0;
5360}
5361
5362static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
5363{
5364        if (diff_unmodified_pair(p))
5365                return;
5366
5367        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5368            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5369                return; /* no tree diffs in patch format */
5370
5371        run_diff(p, o);
5372}
5373
5374static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
5375                            struct diffstat_t *diffstat)
5376{
5377        if (diff_unmodified_pair(p))
5378                return;
5379
5380        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5381            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5382                return; /* no useful stat for tree diffs */
5383
5384        run_diffstat(p, o, diffstat);
5385}
5386
5387static void diff_flush_checkdiff(struct diff_filepair *p,
5388                struct diff_options *o)
5389{
5390        if (diff_unmodified_pair(p))
5391                return;
5392
5393        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5394            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5395                return; /* nothing to check in tree diffs */
5396
5397        run_checkdiff(p, o);
5398}
5399
5400int diff_queue_is_empty(void)
5401{
5402        struct diff_queue_struct *q = &diff_queued_diff;
5403        int i;
5404        for (i = 0; i < q->nr; i++)
5405                if (!diff_unmodified_pair(q->queue[i]))
5406                        return 0;
5407        return 1;
5408}
5409
5410#if DIFF_DEBUG
5411void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
5412{
5413        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
5414                x, one ? one : "",
5415                s->path,
5416                DIFF_FILE_VALID(s) ? "valid" : "invalid",
5417                s->mode,
5418                s->oid_valid ? oid_to_hex(&s->oid) : "");
5419        fprintf(stderr, "queue[%d] %s size %lu\n",
5420                x, one ? one : "",
5421                s->size);
5422}
5423
5424void diff_debug_filepair(const struct diff_filepair *p, int i)
5425{
5426        diff_debug_filespec(p->one, i, "one");
5427        diff_debug_filespec(p->two, i, "two");
5428        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
5429                p->score, p->status ? p->status : '?',
5430                p->one->rename_used, p->broken_pair);
5431}
5432
5433void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
5434{
5435        int i;
5436        if (msg)
5437                fprintf(stderr, "%s\n", msg);
5438        fprintf(stderr, "q->nr = %d\n", q->nr);
5439        for (i = 0; i < q->nr; i++) {
5440                struct diff_filepair *p = q->queue[i];
5441                diff_debug_filepair(p, i);
5442        }
5443}
5444#endif
5445
5446static void diff_resolve_rename_copy(void)
5447{
5448        int i;
5449        struct diff_filepair *p;
5450        struct diff_queue_struct *q = &diff_queued_diff;
5451
5452        diff_debug_queue("resolve-rename-copy", q);
5453
5454        for (i = 0; i < q->nr; i++) {
5455                p = q->queue[i];
5456                p->status = 0; /* undecided */
5457                if (DIFF_PAIR_UNMERGED(p))
5458                        p->status = DIFF_STATUS_UNMERGED;
5459                else if (!DIFF_FILE_VALID(p->one))
5460                        p->status = DIFF_STATUS_ADDED;
5461                else if (!DIFF_FILE_VALID(p->two))
5462                        p->status = DIFF_STATUS_DELETED;
5463                else if (DIFF_PAIR_TYPE_CHANGED(p))
5464                        p->status = DIFF_STATUS_TYPE_CHANGED;
5465
5466                /* from this point on, we are dealing with a pair
5467                 * whose both sides are valid and of the same type, i.e.
5468                 * either in-place edit or rename/copy edit.
5469                 */
5470                else if (DIFF_PAIR_RENAME(p)) {
5471                        /*
5472                         * A rename might have re-connected a broken
5473                         * pair up, causing the pathnames to be the
5474                         * same again. If so, that's not a rename at
5475                         * all, just a modification..
5476                         *
5477                         * Otherwise, see if this source was used for
5478                         * multiple renames, in which case we decrement
5479                         * the count, and call it a copy.
5480                         */
5481                        if (!strcmp(p->one->path, p->two->path))
5482                                p->status = DIFF_STATUS_MODIFIED;
5483                        else if (--p->one->rename_used > 0)
5484                                p->status = DIFF_STATUS_COPIED;
5485                        else
5486                                p->status = DIFF_STATUS_RENAMED;
5487                }
5488                else if (oidcmp(&p->one->oid, &p->two->oid) ||
5489                         p->one->mode != p->two->mode ||
5490                         p->one->dirty_submodule ||
5491                         p->two->dirty_submodule ||
5492                         is_null_oid(&p->one->oid))
5493                        p->status = DIFF_STATUS_MODIFIED;
5494                else {
5495                        /* This is a "no-change" entry and should not
5496                         * happen anymore, but prepare for broken callers.
5497                         */
5498                        error("feeding unmodified %s to diffcore",
5499                              p->one->path);
5500                        p->status = DIFF_STATUS_UNKNOWN;
5501                }
5502        }
5503        diff_debug_queue("resolve-rename-copy done", q);
5504}
5505
5506static int check_pair_status(struct diff_filepair *p)
5507{
5508        switch (p->status) {
5509        case DIFF_STATUS_UNKNOWN:
5510                return 0;
5511        case 0:
5512                die("internal error in diff-resolve-rename-copy");
5513        default:
5514                return 1;
5515        }
5516}
5517
5518static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
5519{
5520        int fmt = opt->output_format;
5521
5522        if (fmt & DIFF_FORMAT_CHECKDIFF)
5523                diff_flush_checkdiff(p, opt);
5524        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
5525                diff_flush_raw(p, opt);
5526        else if (fmt & DIFF_FORMAT_NAME) {
5527                const char *name_a, *name_b;
5528                name_a = p->two->path;
5529                name_b = NULL;
5530                strip_prefix(opt->prefix_length, &name_a, &name_b);
5531                fprintf(opt->file, "%s", diff_line_prefix(opt));
5532                write_name_quoted(name_a, opt->file, opt->line_termination);
5533        }
5534}
5535
5536static void show_file_mode_name(struct diff_options *opt, const char *newdelete, struct diff_filespec *fs)
5537{
5538        struct strbuf sb = STRBUF_INIT;
5539        if (fs->mode)
5540                strbuf_addf(&sb, " %s mode %06o ", newdelete, fs->mode);
5541        else
5542                strbuf_addf(&sb, " %s ", newdelete);
5543
5544        quote_c_style(fs->path, &sb, NULL, 0);
5545        strbuf_addch(&sb, '\n');
5546        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5547                         sb.buf, sb.len, 0);
5548        strbuf_release(&sb);
5549}
5550
5551static void show_mode_change(struct diff_options *opt, struct diff_filepair *p,
5552                int show_name)
5553{
5554        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
5555                struct strbuf sb = STRBUF_INIT;
5556                strbuf_addf(&sb, " mode change %06o => %06o",
5557                            p->one->mode, p->two->mode);
5558                if (show_name) {
5559                        strbuf_addch(&sb, ' ');
5560                        quote_c_style(p->two->path, &sb, NULL, 0);
5561                }
5562                strbuf_addch(&sb, '\n');
5563                emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5564                                 sb.buf, sb.len, 0);
5565                strbuf_release(&sb);
5566        }
5567}
5568
5569static void show_rename_copy(struct diff_options *opt, const char *renamecopy,
5570                struct diff_filepair *p)
5571{
5572        struct strbuf sb = STRBUF_INIT;
5573        struct strbuf names = STRBUF_INIT;
5574
5575        pprint_rename(&names, p->one->path, p->two->path);
5576        strbuf_addf(&sb, " %s %s (%d%%)\n",
5577                    renamecopy, names.buf, similarity_index(p));
5578        strbuf_release(&names);
5579        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5580                                 sb.buf, sb.len, 0);
5581        show_mode_change(opt, p, 0);
5582        strbuf_release(&sb);
5583}
5584
5585static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
5586{
5587        switch(p->status) {
5588        case DIFF_STATUS_DELETED:
5589                show_file_mode_name(opt, "delete", p->one);
5590                break;
5591        case DIFF_STATUS_ADDED:
5592                show_file_mode_name(opt, "create", p->two);
5593                break;
5594        case DIFF_STATUS_COPIED:
5595                show_rename_copy(opt, "copy", p);
5596                break;
5597        case DIFF_STATUS_RENAMED:
5598                show_rename_copy(opt, "rename", p);
5599                break;
5600        default:
5601                if (p->score) {
5602                        struct strbuf sb = STRBUF_INIT;
5603                        strbuf_addstr(&sb, " rewrite ");
5604                        quote_c_style(p->two->path, &sb, NULL, 0);
5605                        strbuf_addf(&sb, " (%d%%)\n", similarity_index(p));
5606                        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5607                                         sb.buf, sb.len, 0);
5608                        strbuf_release(&sb);
5609                }
5610                show_mode_change(opt, p, !p->score);
5611                break;
5612        }
5613}
5614
5615struct patch_id_t {
5616        git_SHA_CTX *ctx;
5617        int patchlen;
5618};
5619
5620static int remove_space(char *line, int len)
5621{
5622        int i;
5623        char *dst = line;
5624        unsigned char c;
5625
5626        for (i = 0; i < len; i++)
5627                if (!isspace((c = line[i])))
5628                        *dst++ = c;
5629
5630        return dst - line;
5631}
5632
5633static void patch_id_consume(void *priv, char *line, unsigned long len)
5634{
5635        struct patch_id_t *data = priv;
5636        int new_len;
5637
5638        /* Ignore line numbers when computing the SHA1 of the patch */
5639        if (starts_with(line, "@@ -"))
5640                return;
5641
5642        new_len = remove_space(line, len);
5643
5644        git_SHA1_Update(data->ctx, line, new_len);
5645        data->patchlen += new_len;
5646}
5647
5648static void patch_id_add_string(git_SHA_CTX *ctx, const char *str)
5649{
5650        git_SHA1_Update(ctx, str, strlen(str));
5651}
5652
5653static void patch_id_add_mode(git_SHA_CTX *ctx, unsigned mode)
5654{
5655        /* large enough for 2^32 in octal */
5656        char buf[12];
5657        int len = xsnprintf(buf, sizeof(buf), "%06o", mode);
5658        git_SHA1_Update(ctx, buf, len);
5659}
5660
5661/* returns 0 upon success, and writes result into sha1 */
5662static int diff_get_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5663{
5664        struct diff_queue_struct *q = &diff_queued_diff;
5665        int i;
5666        git_SHA_CTX ctx;
5667        struct patch_id_t data;
5668
5669        git_SHA1_Init(&ctx);
5670        memset(&data, 0, sizeof(struct patch_id_t));
5671        data.ctx = &ctx;
5672
5673        for (i = 0; i < q->nr; i++) {
5674                xpparam_t xpp;
5675                xdemitconf_t xecfg;
5676                mmfile_t mf1, mf2;
5677                struct diff_filepair *p = q->queue[i];
5678                int len1, len2;
5679
5680                memset(&xpp, 0, sizeof(xpp));
5681                memset(&xecfg, 0, sizeof(xecfg));
5682                if (p->status == 0)
5683                        return error("internal diff status error");
5684                if (p->status == DIFF_STATUS_UNKNOWN)
5685                        continue;
5686                if (diff_unmodified_pair(p))
5687                        continue;
5688                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5689                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5690                        continue;
5691                if (DIFF_PAIR_UNMERGED(p))
5692                        continue;
5693
5694                diff_fill_oid_info(p->one, options->repo->index);
5695                diff_fill_oid_info(p->two, options->repo->index);
5696
5697                len1 = remove_space(p->one->path, strlen(p->one->path));
5698                len2 = remove_space(p->two->path, strlen(p->two->path));
5699                patch_id_add_string(&ctx, "diff--git");
5700                patch_id_add_string(&ctx, "a/");
5701                git_SHA1_Update(&ctx, p->one->path, len1);
5702                patch_id_add_string(&ctx, "b/");
5703                git_SHA1_Update(&ctx, p->two->path, len2);
5704
5705                if (p->one->mode == 0) {
5706                        patch_id_add_string(&ctx, "newfilemode");
5707                        patch_id_add_mode(&ctx, p->two->mode);
5708                        patch_id_add_string(&ctx, "---/dev/null");
5709                        patch_id_add_string(&ctx, "+++b/");
5710                        git_SHA1_Update(&ctx, p->two->path, len2);
5711                } else if (p->two->mode == 0) {
5712                        patch_id_add_string(&ctx, "deletedfilemode");
5713                        patch_id_add_mode(&ctx, p->one->mode);
5714                        patch_id_add_string(&ctx, "---a/");
5715                        git_SHA1_Update(&ctx, p->one->path, len1);
5716                        patch_id_add_string(&ctx, "+++/dev/null");
5717                } else {
5718                        patch_id_add_string(&ctx, "---a/");
5719                        git_SHA1_Update(&ctx, p->one->path, len1);
5720                        patch_id_add_string(&ctx, "+++b/");
5721                        git_SHA1_Update(&ctx, p->two->path, len2);
5722                }
5723
5724                if (diff_header_only)
5725                        continue;
5726
5727                if (fill_mmfile(options->repo, &mf1, p->one) < 0 ||
5728                    fill_mmfile(options->repo, &mf2, p->two) < 0)
5729                        return error("unable to read files to diff");
5730
5731                if (diff_filespec_is_binary(options->repo, p->one) ||
5732                    diff_filespec_is_binary(options->repo, p->two)) {
5733                        git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
5734                                        GIT_SHA1_HEXSZ);
5735                        git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
5736                                        GIT_SHA1_HEXSZ);
5737                        continue;
5738                }
5739
5740                xpp.flags = 0;
5741                xecfg.ctxlen = 3;
5742                xecfg.flags = 0;
5743                if (xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
5744                                  &xpp, &xecfg))
5745                        return error("unable to generate patch-id diff for %s",
5746                                     p->one->path);
5747        }
5748
5749        git_SHA1_Final(oid->hash, &ctx);
5750        return 0;
5751}
5752
5753int diff_flush_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5754{
5755        struct diff_queue_struct *q = &diff_queued_diff;
5756        int i;
5757        int result = diff_get_patch_id(options, oid, diff_header_only);
5758
5759        for (i = 0; i < q->nr; i++)
5760                diff_free_filepair(q->queue[i]);
5761
5762        free(q->queue);
5763        DIFF_QUEUE_CLEAR(q);
5764
5765        return result;
5766}
5767
5768static int is_summary_empty(const struct diff_queue_struct *q)
5769{
5770        int i;
5771
5772        for (i = 0; i < q->nr; i++) {
5773                const struct diff_filepair *p = q->queue[i];
5774
5775                switch (p->status) {
5776                case DIFF_STATUS_DELETED:
5777                case DIFF_STATUS_ADDED:
5778                case DIFF_STATUS_COPIED:
5779                case DIFF_STATUS_RENAMED:
5780                        return 0;
5781                default:
5782                        if (p->score)
5783                                return 0;
5784                        if (p->one->mode && p->two->mode &&
5785                            p->one->mode != p->two->mode)
5786                                return 0;
5787                        break;
5788                }
5789        }
5790        return 1;
5791}
5792
5793static const char rename_limit_warning[] =
5794N_("inexact rename detection was skipped due to too many files.");
5795
5796static const char degrade_cc_to_c_warning[] =
5797N_("only found copies from modified paths due to too many files.");
5798
5799static const char rename_limit_advice[] =
5800N_("you may want to set your %s variable to at least "
5801   "%d and retry the command.");
5802
5803void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
5804{
5805        fflush(stdout);
5806        if (degraded_cc)
5807                warning(_(degrade_cc_to_c_warning));
5808        else if (needed)
5809                warning(_(rename_limit_warning));
5810        else
5811                return;
5812        if (0 < needed)
5813                warning(_(rename_limit_advice), varname, needed);
5814}
5815
5816static void diff_flush_patch_all_file_pairs(struct diff_options *o)
5817{
5818        int i;
5819        static struct emitted_diff_symbols esm = EMITTED_DIFF_SYMBOLS_INIT;
5820        struct diff_queue_struct *q = &diff_queued_diff;
5821
5822        if (WSEH_NEW & WS_RULE_MASK)
5823                BUG("WS rules bit mask overlaps with diff symbol flags");
5824
5825        if (o->color_moved)
5826                o->emitted_symbols = &esm;
5827
5828        for (i = 0; i < q->nr; i++) {
5829                struct diff_filepair *p = q->queue[i];
5830                if (check_pair_status(p))
5831                        diff_flush_patch(p, o);
5832        }
5833
5834        if (o->emitted_symbols) {
5835                if (o->color_moved) {
5836                        struct hashmap add_lines, del_lines;
5837
5838                        if (o->color_moved_ws_handling &
5839                            COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
5840                                o->color_moved_ws_handling |= XDF_IGNORE_WHITESPACE;
5841
5842                        hashmap_init(&del_lines, moved_entry_cmp, o, 0);
5843                        hashmap_init(&add_lines, moved_entry_cmp, o, 0);
5844
5845                        add_lines_to_move_detection(o, &add_lines, &del_lines);
5846                        mark_color_as_moved(o, &add_lines, &del_lines);
5847                        if (o->color_moved == COLOR_MOVED_ZEBRA_DIM)
5848                                dim_moved_lines(o);
5849
5850                        hashmap_free(&add_lines, 0);
5851                        hashmap_free(&del_lines, 0);
5852                }
5853
5854                for (i = 0; i < esm.nr; i++)
5855                        emit_diff_symbol_from_struct(o, &esm.buf[i]);
5856
5857                for (i = 0; i < esm.nr; i++)
5858                        free((void *)esm.buf[i].line);
5859        }
5860        esm.nr = 0;
5861}
5862
5863void diff_flush(struct diff_options *options)
5864{
5865        struct diff_queue_struct *q = &diff_queued_diff;
5866        int i, output_format = options->output_format;
5867        int separator = 0;
5868        int dirstat_by_line = 0;
5869
5870        /*
5871         * Order: raw, stat, summary, patch
5872         * or:    name/name-status/checkdiff (other bits clear)
5873         */
5874        if (!q->nr)
5875                goto free_queue;
5876
5877        if (output_format & (DIFF_FORMAT_RAW |
5878                             DIFF_FORMAT_NAME |
5879                             DIFF_FORMAT_NAME_STATUS |
5880                             DIFF_FORMAT_CHECKDIFF)) {
5881                for (i = 0; i < q->nr; i++) {
5882                        struct diff_filepair *p = q->queue[i];
5883                        if (check_pair_status(p))
5884                                flush_one_pair(p, options);
5885                }
5886                separator++;
5887        }
5888
5889        if (output_format & DIFF_FORMAT_DIRSTAT && options->flags.dirstat_by_line)
5890                dirstat_by_line = 1;
5891
5892        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
5893            dirstat_by_line) {
5894                struct diffstat_t diffstat;
5895
5896                memset(&diffstat, 0, sizeof(struct diffstat_t));
5897                for (i = 0; i < q->nr; i++) {
5898                        struct diff_filepair *p = q->queue[i];
5899                        if (check_pair_status(p))
5900                                diff_flush_stat(p, options, &diffstat);
5901                }
5902                if (output_format & DIFF_FORMAT_NUMSTAT)
5903                        show_numstat(&diffstat, options);
5904                if (output_format & DIFF_FORMAT_DIFFSTAT)
5905                        show_stats(&diffstat, options);
5906                if (output_format & DIFF_FORMAT_SHORTSTAT)
5907                        show_shortstats(&diffstat, options);
5908                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
5909                        show_dirstat_by_line(&diffstat, options);
5910                free_diffstat_info(&diffstat);
5911                separator++;
5912        }
5913        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
5914                show_dirstat(options);
5915
5916        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
5917                for (i = 0; i < q->nr; i++) {
5918                        diff_summary(options, q->queue[i]);
5919                }
5920                separator++;
5921        }
5922
5923        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
5924            options->flags.exit_with_status &&
5925            options->flags.diff_from_contents) {
5926                /*
5927                 * run diff_flush_patch for the exit status. setting
5928                 * options->file to /dev/null should be safe, because we
5929                 * aren't supposed to produce any output anyway.
5930                 */
5931                if (options->close_file)
5932                        fclose(options->file);
5933                options->file = xfopen("/dev/null", "w");
5934                options->close_file = 1;
5935                options->color_moved = 0;
5936                for (i = 0; i < q->nr; i++) {
5937                        struct diff_filepair *p = q->queue[i];
5938                        if (check_pair_status(p))
5939                                diff_flush_patch(p, options);
5940                        if (options->found_changes)
5941                                break;
5942                }
5943        }
5944
5945        if (output_format & DIFF_FORMAT_PATCH) {
5946                if (separator) {
5947                        emit_diff_symbol(options, DIFF_SYMBOL_SEPARATOR, NULL, 0, 0);
5948                        if (options->stat_sep)
5949                                /* attach patch instead of inline */
5950                                emit_diff_symbol(options, DIFF_SYMBOL_STAT_SEP,
5951                                                 NULL, 0, 0);
5952                }
5953
5954                diff_flush_patch_all_file_pairs(options);
5955        }
5956
5957        if (output_format & DIFF_FORMAT_CALLBACK)
5958                options->format_callback(q, options, options->format_callback_data);
5959
5960        for (i = 0; i < q->nr; i++)
5961                diff_free_filepair(q->queue[i]);
5962free_queue:
5963        free(q->queue);
5964        DIFF_QUEUE_CLEAR(q);
5965        if (options->close_file)
5966                fclose(options->file);
5967
5968        /*
5969         * Report the content-level differences with HAS_CHANGES;
5970         * diff_addremove/diff_change does not set the bit when
5971         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
5972         */
5973        if (options->flags.diff_from_contents) {
5974                if (options->found_changes)
5975                        options->flags.has_changes = 1;
5976                else
5977                        options->flags.has_changes = 0;
5978        }
5979}
5980
5981static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
5982{
5983        return (((p->status == DIFF_STATUS_MODIFIED) &&
5984                 ((p->score &&
5985                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
5986                  (!p->score &&
5987                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
5988                ((p->status != DIFF_STATUS_MODIFIED) &&
5989                 filter_bit_tst(p->status, options)));
5990}
5991
5992static void diffcore_apply_filter(struct diff_options *options)
5993{
5994        int i;
5995        struct diff_queue_struct *q = &diff_queued_diff;
5996        struct diff_queue_struct outq;
5997
5998        DIFF_QUEUE_CLEAR(&outq);
5999
6000        if (!options->filter)
6001                return;
6002
6003        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
6004                int found;
6005                for (i = found = 0; !found && i < q->nr; i++) {
6006                        if (match_filter(options, q->queue[i]))
6007                                found++;
6008                }
6009                if (found)
6010                        return;
6011
6012                /* otherwise we will clear the whole queue
6013                 * by copying the empty outq at the end of this
6014                 * function, but first clear the current entries
6015                 * in the queue.
6016                 */
6017                for (i = 0; i < q->nr; i++)
6018                        diff_free_filepair(q->queue[i]);
6019        }
6020        else {
6021                /* Only the matching ones */
6022                for (i = 0; i < q->nr; i++) {
6023                        struct diff_filepair *p = q->queue[i];
6024                        if (match_filter(options, p))
6025                                diff_q(&outq, p);
6026                        else
6027                                diff_free_filepair(p);
6028                }
6029        }
6030        free(q->queue);
6031        *q = outq;
6032}
6033
6034/* Check whether two filespecs with the same mode and size are identical */
6035static int diff_filespec_is_identical(struct repository *r,
6036                                      struct diff_filespec *one,
6037                                      struct diff_filespec *two)
6038{
6039        if (S_ISGITLINK(one->mode))
6040                return 0;
6041        if (diff_populate_filespec(r, one, 0))
6042                return 0;
6043        if (diff_populate_filespec(r, two, 0))
6044                return 0;
6045        return !memcmp(one->data, two->data, one->size);
6046}
6047
6048static int diff_filespec_check_stat_unmatch(struct repository *r,
6049                                            struct diff_filepair *p)
6050{
6051        if (p->done_skip_stat_unmatch)
6052                return p->skip_stat_unmatch_result;
6053
6054        p->done_skip_stat_unmatch = 1;
6055        p->skip_stat_unmatch_result = 0;
6056        /*
6057         * 1. Entries that come from stat info dirtiness
6058         *    always have both sides (iow, not create/delete),
6059         *    one side of the object name is unknown, with
6060         *    the same mode and size.  Keep the ones that
6061         *    do not match these criteria.  They have real
6062         *    differences.
6063         *
6064         * 2. At this point, the file is known to be modified,
6065         *    with the same mode and size, and the object
6066         *    name of one side is unknown.  Need to inspect
6067         *    the identical contents.
6068         */
6069        if (!DIFF_FILE_VALID(p->one) || /* (1) */
6070            !DIFF_FILE_VALID(p->two) ||
6071            (p->one->oid_valid && p->two->oid_valid) ||
6072            (p->one->mode != p->two->mode) ||
6073            diff_populate_filespec(r, p->one, CHECK_SIZE_ONLY) ||
6074            diff_populate_filespec(r, p->two, CHECK_SIZE_ONLY) ||
6075            (p->one->size != p->two->size) ||
6076            !diff_filespec_is_identical(r, p->one, p->two)) /* (2) */
6077                p->skip_stat_unmatch_result = 1;
6078        return p->skip_stat_unmatch_result;
6079}
6080
6081static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
6082{
6083        int i;
6084        struct diff_queue_struct *q = &diff_queued_diff;
6085        struct diff_queue_struct outq;
6086        DIFF_QUEUE_CLEAR(&outq);
6087
6088        for (i = 0; i < q->nr; i++) {
6089                struct diff_filepair *p = q->queue[i];
6090
6091                if (diff_filespec_check_stat_unmatch(diffopt->repo, p))
6092                        diff_q(&outq, p);
6093                else {
6094                        /*
6095                         * The caller can subtract 1 from skip_stat_unmatch
6096                         * to determine how many paths were dirty only
6097                         * due to stat info mismatch.
6098                         */
6099                        if (!diffopt->flags.no_index)
6100                                diffopt->skip_stat_unmatch++;
6101                        diff_free_filepair(p);
6102                }
6103        }
6104        free(q->queue);
6105        *q = outq;
6106}
6107
6108static int diffnamecmp(const void *a_, const void *b_)
6109{
6110        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
6111        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
6112        const char *name_a, *name_b;
6113
6114        name_a = a->one ? a->one->path : a->two->path;
6115        name_b = b->one ? b->one->path : b->two->path;
6116        return strcmp(name_a, name_b);
6117}
6118
6119void diffcore_fix_diff_index(struct diff_options *options)
6120{
6121        struct diff_queue_struct *q = &diff_queued_diff;
6122        QSORT(q->queue, q->nr, diffnamecmp);
6123}
6124
6125void diffcore_std(struct diff_options *options)
6126{
6127        /* NOTE please keep the following in sync with diff_tree_combined() */
6128        if (options->skip_stat_unmatch)
6129                diffcore_skip_stat_unmatch(options);
6130        if (!options->found_follow) {
6131                /* See try_to_follow_renames() in tree-diff.c */
6132                if (options->break_opt != -1)
6133                        diffcore_break(options->repo,
6134                                       options->break_opt);
6135                if (options->detect_rename)
6136                        diffcore_rename(options);
6137                if (options->break_opt != -1)
6138                        diffcore_merge_broken();
6139        }
6140        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
6141                diffcore_pickaxe(options);
6142        if (options->orderfile)
6143                diffcore_order(options->orderfile);
6144        if (!options->found_follow)
6145                /* See try_to_follow_renames() in tree-diff.c */
6146                diff_resolve_rename_copy();
6147        diffcore_apply_filter(options);
6148
6149        if (diff_queued_diff.nr && !options->flags.diff_from_contents)
6150                options->flags.has_changes = 1;
6151        else
6152                options->flags.has_changes = 0;
6153
6154        options->found_follow = 0;
6155}
6156
6157int diff_result_code(struct diff_options *opt, int status)
6158{
6159        int result = 0;
6160
6161        diff_warn_rename_limit("diff.renameLimit",
6162                               opt->needed_rename_limit,
6163                               opt->degraded_cc_to_c);
6164        if (!opt->flags.exit_with_status &&
6165            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
6166                return status;
6167        if (opt->flags.exit_with_status &&
6168            opt->flags.has_changes)
6169                result |= 01;
6170        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
6171            opt->flags.check_failed)
6172                result |= 02;
6173        return result;
6174}
6175
6176int diff_can_quit_early(struct diff_options *opt)
6177{
6178        return (opt->flags.quick &&
6179                !opt->filter &&
6180                opt->flags.has_changes);
6181}
6182
6183/*
6184 * Shall changes to this submodule be ignored?
6185 *
6186 * Submodule changes can be configured to be ignored separately for each path,
6187 * but that configuration can be overridden from the command line.
6188 */
6189static int is_submodule_ignored(const char *path, struct diff_options *options)
6190{
6191        int ignored = 0;
6192        struct diff_flags orig_flags = options->flags;
6193        if (!options->flags.override_submodule_config)
6194                set_diffopt_flags_from_submodule_config(options, path);
6195        if (options->flags.ignore_submodules)
6196                ignored = 1;
6197        options->flags = orig_flags;
6198        return ignored;
6199}
6200
6201void diff_addremove(struct diff_options *options,
6202                    int addremove, unsigned mode,
6203                    const struct object_id *oid,
6204                    int oid_valid,
6205                    const char *concatpath, unsigned dirty_submodule)
6206{
6207        struct diff_filespec *one, *two;
6208
6209        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
6210                return;
6211
6212        /* This may look odd, but it is a preparation for
6213         * feeding "there are unchanged files which should
6214         * not produce diffs, but when you are doing copy
6215         * detection you would need them, so here they are"
6216         * entries to the diff-core.  They will be prefixed
6217         * with something like '=' or '*' (I haven't decided
6218         * which but should not make any difference).
6219         * Feeding the same new and old to diff_change()
6220         * also has the same effect.
6221         * Before the final output happens, they are pruned after
6222         * merged into rename/copy pairs as appropriate.
6223         */
6224        if (options->flags.reverse_diff)
6225                addremove = (addremove == '+' ? '-' :
6226                             addremove == '-' ? '+' : addremove);
6227
6228        if (options->prefix &&
6229            strncmp(concatpath, options->prefix, options->prefix_length))
6230                return;
6231
6232        one = alloc_filespec(concatpath);
6233        two = alloc_filespec(concatpath);
6234
6235        if (addremove != '+')
6236                fill_filespec(one, oid, oid_valid, mode);
6237        if (addremove != '-') {
6238                fill_filespec(two, oid, oid_valid, mode);
6239                two->dirty_submodule = dirty_submodule;
6240        }
6241
6242        diff_queue(&diff_queued_diff, one, two);
6243        if (!options->flags.diff_from_contents)
6244                options->flags.has_changes = 1;
6245}
6246
6247void diff_change(struct diff_options *options,
6248                 unsigned old_mode, unsigned new_mode,
6249                 const struct object_id *old_oid,
6250                 const struct object_id *new_oid,
6251                 int old_oid_valid, int new_oid_valid,
6252                 const char *concatpath,
6253                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
6254{
6255        struct diff_filespec *one, *two;
6256        struct diff_filepair *p;
6257
6258        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
6259            is_submodule_ignored(concatpath, options))
6260                return;
6261
6262        if (options->flags.reverse_diff) {
6263                SWAP(old_mode, new_mode);
6264                SWAP(old_oid, new_oid);
6265                SWAP(old_oid_valid, new_oid_valid);
6266                SWAP(old_dirty_submodule, new_dirty_submodule);
6267        }
6268
6269        if (options->prefix &&
6270            strncmp(concatpath, options->prefix, options->prefix_length))
6271                return;
6272
6273        one = alloc_filespec(concatpath);
6274        two = alloc_filespec(concatpath);
6275        fill_filespec(one, old_oid, old_oid_valid, old_mode);
6276        fill_filespec(two, new_oid, new_oid_valid, new_mode);
6277        one->dirty_submodule = old_dirty_submodule;
6278        two->dirty_submodule = new_dirty_submodule;
6279        p = diff_queue(&diff_queued_diff, one, two);
6280
6281        if (options->flags.diff_from_contents)
6282                return;
6283
6284        if (options->flags.quick && options->skip_stat_unmatch &&
6285            !diff_filespec_check_stat_unmatch(options->repo, p))
6286                return;
6287
6288        options->flags.has_changes = 1;
6289}
6290
6291struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
6292{
6293        struct diff_filepair *pair;
6294        struct diff_filespec *one, *two;
6295
6296        if (options->prefix &&
6297            strncmp(path, options->prefix, options->prefix_length))
6298                return NULL;
6299
6300        one = alloc_filespec(path);
6301        two = alloc_filespec(path);
6302        pair = diff_queue(&diff_queued_diff, one, two);
6303        pair->is_unmerged = 1;
6304        return pair;
6305}
6306
6307static char *run_textconv(struct repository *r,
6308                          const char *pgm,
6309                          struct diff_filespec *spec,
6310                          size_t *outsize)
6311{
6312        struct diff_tempfile *temp;
6313        const char *argv[3];
6314        const char **arg = argv;
6315        struct child_process child = CHILD_PROCESS_INIT;
6316        struct strbuf buf = STRBUF_INIT;
6317        int err = 0;
6318
6319        temp = prepare_temp_file(r, spec->path, spec);
6320        *arg++ = pgm;
6321        *arg++ = temp->name;
6322        *arg = NULL;
6323
6324        child.use_shell = 1;
6325        child.argv = argv;
6326        child.out = -1;
6327        if (start_command(&child)) {
6328                remove_tempfile();
6329                return NULL;
6330        }
6331
6332        if (strbuf_read(&buf, child.out, 0) < 0)
6333                err = error("error reading from textconv command '%s'", pgm);
6334        close(child.out);
6335
6336        if (finish_command(&child) || err) {
6337                strbuf_release(&buf);
6338                remove_tempfile();
6339                return NULL;
6340        }
6341        remove_tempfile();
6342
6343        return strbuf_detach(&buf, outsize);
6344}
6345
6346size_t fill_textconv(struct repository *r,
6347                     struct userdiff_driver *driver,
6348                     struct diff_filespec *df,
6349                     char **outbuf)
6350{
6351        size_t size;
6352
6353        if (!driver) {
6354                if (!DIFF_FILE_VALID(df)) {
6355                        *outbuf = "";
6356                        return 0;
6357                }
6358                if (diff_populate_filespec(r, df, 0))
6359                        die("unable to read files to diff");
6360                *outbuf = df->data;
6361                return df->size;
6362        }
6363
6364        if (!driver->textconv)
6365                BUG("fill_textconv called with non-textconv driver");
6366
6367        if (driver->textconv_cache && df->oid_valid) {
6368                *outbuf = notes_cache_get(driver->textconv_cache,
6369                                          &df->oid,
6370                                          &size);
6371                if (*outbuf)
6372                        return size;
6373        }
6374
6375        *outbuf = run_textconv(r, driver->textconv, df, &size);
6376        if (!*outbuf)
6377                die("unable to read files to diff");
6378
6379        if (driver->textconv_cache && df->oid_valid) {
6380                /* ignore errors, as we might be in a readonly repository */
6381                notes_cache_put(driver->textconv_cache, &df->oid, *outbuf,
6382                                size);
6383                /*
6384                 * we could save up changes and flush them all at the end,
6385                 * but we would need an extra call after all diffing is done.
6386                 * Since generating a cache entry is the slow path anyway,
6387                 * this extra overhead probably isn't a big deal.
6388                 */
6389                notes_cache_write(driver->textconv_cache);
6390        }
6391
6392        return size;
6393}
6394
6395int textconv_object(struct repository *r,
6396                    const char *path,
6397                    unsigned mode,
6398                    const struct object_id *oid,
6399                    int oid_valid,
6400                    char **buf,
6401                    unsigned long *buf_size)
6402{
6403        struct diff_filespec *df;
6404        struct userdiff_driver *textconv;
6405
6406        df = alloc_filespec(path);
6407        fill_filespec(df, oid, oid_valid, mode);
6408        textconv = get_textconv(r->index, df);
6409        if (!textconv) {
6410                free_filespec(df);
6411                return 0;
6412        }
6413
6414        *buf_size = fill_textconv(r, textconv, df, buf);
6415        free_filespec(df);
6416        return 1;
6417}
6418
6419void setup_diff_pager(struct diff_options *opt)
6420{
6421        /*
6422         * If the user asked for our exit code, then either they want --quiet
6423         * or --exit-code. We should definitely not bother with a pager in the
6424         * former case, as we will generate no output. Since we still properly
6425         * report our exit code even when a pager is run, we _could_ run a
6426         * pager with --exit-code. But since we have not done so historically,
6427         * and because it is easy to find people oneline advising "git diff
6428         * --exit-code" in hooks and other scripts, we do not do so.
6429         */
6430        if (!opt->flags.exit_with_status &&
6431            check_pager_config("diff") != 0)
6432                setup_pager();
6433}