7810a4733f8f230af54d1d8b8d96484ebea3a2bc
   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 "userdiff.h"
  17#include "submodule-config.h"
  18#include "submodule.h"
  19#include "hashmap.h"
  20#include "ll-merge.h"
  21#include "string-list.h"
  22#include "argv-array.h"
  23#include "graph.h"
  24#include "packfile.h"
  25
  26#ifdef NO_FAST_WORKING_DIRECTORY
  27#define FAST_WORKING_DIRECTORY 0
  28#else
  29#define FAST_WORKING_DIRECTORY 1
  30#endif
  31
  32static int diff_detect_rename_default;
  33static int diff_indent_heuristic = 1;
  34static int diff_rename_limit_default = 400;
  35static int diff_suppress_blank_empty;
  36static int diff_use_color_default = -1;
  37static int diff_color_moved_default;
  38static int diff_context_default = 3;
  39static int diff_interhunk_context_default;
  40static const char *diff_word_regex_cfg;
  41static const char *external_diff_cmd_cfg;
  42static const char *diff_order_file_cfg;
  43int diff_auto_refresh_index = 1;
  44static int diff_mnemonic_prefix;
  45static int diff_no_prefix;
  46static int diff_stat_graph_width;
  47static int diff_dirstat_permille_default = 30;
  48static struct diff_options default_diff_options;
  49static long diff_algorithm;
  50static unsigned ws_error_highlight_default = WSEH_NEW;
  51
  52static char diff_colors[][COLOR_MAXLEN] = {
  53        GIT_COLOR_RESET,
  54        GIT_COLOR_NORMAL,       /* CONTEXT */
  55        GIT_COLOR_BOLD,         /* METAINFO */
  56        GIT_COLOR_CYAN,         /* FRAGINFO */
  57        GIT_COLOR_RED,          /* OLD */
  58        GIT_COLOR_GREEN,        /* NEW */
  59        GIT_COLOR_YELLOW,       /* COMMIT */
  60        GIT_COLOR_BG_RED,       /* WHITESPACE */
  61        GIT_COLOR_NORMAL,       /* FUNCINFO */
  62        GIT_COLOR_BOLD_MAGENTA, /* OLD_MOVED */
  63        GIT_COLOR_BOLD_BLUE,    /* OLD_MOVED ALTERNATIVE */
  64        GIT_COLOR_FAINT,        /* OLD_MOVED_DIM */
  65        GIT_COLOR_FAINT_ITALIC, /* OLD_MOVED_ALTERNATIVE_DIM */
  66        GIT_COLOR_BOLD_CYAN,    /* NEW_MOVED */
  67        GIT_COLOR_BOLD_YELLOW,  /* NEW_MOVED ALTERNATIVE */
  68        GIT_COLOR_FAINT,        /* NEW_MOVED_DIM */
  69        GIT_COLOR_FAINT_ITALIC, /* NEW_MOVED_ALTERNATIVE_DIM */
  70};
  71
  72static NORETURN void die_want_option(const char *option_name)
  73{
  74        die(_("option '%s' requires a value"), option_name);
  75}
  76
  77static int parse_diff_color_slot(const char *var)
  78{
  79        if (!strcasecmp(var, "context") || !strcasecmp(var, "plain"))
  80                return DIFF_CONTEXT;
  81        if (!strcasecmp(var, "meta"))
  82                return DIFF_METAINFO;
  83        if (!strcasecmp(var, "frag"))
  84                return DIFF_FRAGINFO;
  85        if (!strcasecmp(var, "old"))
  86                return DIFF_FILE_OLD;
  87        if (!strcasecmp(var, "new"))
  88                return DIFF_FILE_NEW;
  89        if (!strcasecmp(var, "commit"))
  90                return DIFF_COMMIT;
  91        if (!strcasecmp(var, "whitespace"))
  92                return DIFF_WHITESPACE;
  93        if (!strcasecmp(var, "func"))
  94                return DIFF_FUNCINFO;
  95        if (!strcasecmp(var, "oldmoved"))
  96                return DIFF_FILE_OLD_MOVED;
  97        if (!strcasecmp(var, "oldmovedalternative"))
  98                return DIFF_FILE_OLD_MOVED_ALT;
  99        if (!strcasecmp(var, "oldmoveddimmed"))
 100                return DIFF_FILE_OLD_MOVED_DIM;
 101        if (!strcasecmp(var, "oldmovedalternativedimmed"))
 102                return DIFF_FILE_OLD_MOVED_ALT_DIM;
 103        if (!strcasecmp(var, "newmoved"))
 104                return DIFF_FILE_NEW_MOVED;
 105        if (!strcasecmp(var, "newmovedalternative"))
 106                return DIFF_FILE_NEW_MOVED_ALT;
 107        if (!strcasecmp(var, "newmoveddimmed"))
 108                return DIFF_FILE_NEW_MOVED_DIM;
 109        if (!strcasecmp(var, "newmovedalternativedimmed"))
 110                return DIFF_FILE_NEW_MOVED_ALT_DIM;
 111        return -1;
 112}
 113
 114static int parse_dirstat_params(struct diff_options *options, const char *params_string,
 115                                struct strbuf *errmsg)
 116{
 117        char *params_copy = xstrdup(params_string);
 118        struct string_list params = STRING_LIST_INIT_NODUP;
 119        int ret = 0;
 120        int i;
 121
 122        if (*params_copy)
 123                string_list_split_in_place(&params, params_copy, ',', -1);
 124        for (i = 0; i < params.nr; i++) {
 125                const char *p = params.items[i].string;
 126                if (!strcmp(p, "changes")) {
 127                        options->flags.dirstat_by_line = 0;
 128                        options->flags.dirstat_by_file = 0;
 129                } else if (!strcmp(p, "lines")) {
 130                        options->flags.dirstat_by_line = 1;
 131                        options->flags.dirstat_by_file = 0;
 132                } else if (!strcmp(p, "files")) {
 133                        options->flags.dirstat_by_line = 0;
 134                        options->flags.dirstat_by_file = 1;
 135                } else if (!strcmp(p, "noncumulative")) {
 136                        options->flags.dirstat_cumulative = 0;
 137                } else if (!strcmp(p, "cumulative")) {
 138                        options->flags.dirstat_cumulative = 1;
 139                } else if (isdigit(*p)) {
 140                        char *end;
 141                        int permille = strtoul(p, &end, 10) * 10;
 142                        if (*end == '.' && isdigit(*++end)) {
 143                                /* only use first digit */
 144                                permille += *end - '0';
 145                                /* .. and ignore any further digits */
 146                                while (isdigit(*++end))
 147                                        ; /* nothing */
 148                        }
 149                        if (!*end)
 150                                options->dirstat_permille = permille;
 151                        else {
 152                                strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%s'\n"),
 153                                            p);
 154                                ret++;
 155                        }
 156                } else {
 157                        strbuf_addf(errmsg, _("  Unknown dirstat parameter '%s'\n"), p);
 158                        ret++;
 159                }
 160
 161        }
 162        string_list_clear(&params, 0);
 163        free(params_copy);
 164        return ret;
 165}
 166
 167static int parse_submodule_params(struct diff_options *options, const char *value)
 168{
 169        if (!strcmp(value, "log"))
 170                options->submodule_format = DIFF_SUBMODULE_LOG;
 171        else if (!strcmp(value, "short"))
 172                options->submodule_format = DIFF_SUBMODULE_SHORT;
 173        else if (!strcmp(value, "diff"))
 174                options->submodule_format = DIFF_SUBMODULE_INLINE_DIFF;
 175        else
 176                return -1;
 177        return 0;
 178}
 179
 180static int git_config_rename(const char *var, const char *value)
 181{
 182        if (!value)
 183                return DIFF_DETECT_RENAME;
 184        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 185                return  DIFF_DETECT_COPY;
 186        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 187}
 188
 189long parse_algorithm_value(const char *value)
 190{
 191        if (!value)
 192                return -1;
 193        else if (!strcasecmp(value, "myers") || !strcasecmp(value, "default"))
 194                return 0;
 195        else if (!strcasecmp(value, "minimal"))
 196                return XDF_NEED_MINIMAL;
 197        else if (!strcasecmp(value, "patience"))
 198                return XDF_PATIENCE_DIFF;
 199        else if (!strcasecmp(value, "histogram"))
 200                return XDF_HISTOGRAM_DIFF;
 201        return -1;
 202}
 203
 204static int parse_one_token(const char **arg, const char *token)
 205{
 206        const char *rest;
 207        if (skip_prefix(*arg, token, &rest) && (!*rest || *rest == ',')) {
 208                *arg = rest;
 209                return 1;
 210        }
 211        return 0;
 212}
 213
 214static int parse_ws_error_highlight(const char *arg)
 215{
 216        const char *orig_arg = arg;
 217        unsigned val = 0;
 218
 219        while (*arg) {
 220                if (parse_one_token(&arg, "none"))
 221                        val = 0;
 222                else if (parse_one_token(&arg, "default"))
 223                        val = WSEH_NEW;
 224                else if (parse_one_token(&arg, "all"))
 225                        val = WSEH_NEW | WSEH_OLD | WSEH_CONTEXT;
 226                else if (parse_one_token(&arg, "new"))
 227                        val |= WSEH_NEW;
 228                else if (parse_one_token(&arg, "old"))
 229                        val |= WSEH_OLD;
 230                else if (parse_one_token(&arg, "context"))
 231                        val |= WSEH_CONTEXT;
 232                else {
 233                        return -1 - (int)(arg - orig_arg);
 234                }
 235                if (*arg)
 236                        arg++;
 237        }
 238        return val;
 239}
 240
 241/*
 242 * These are to give UI layer defaults.
 243 * The core-level commands such as git-diff-files should
 244 * never be affected by the setting of diff.renames
 245 * the user happens to have in the configuration file.
 246 */
 247void init_diff_ui_defaults(void)
 248{
 249        diff_detect_rename_default = DIFF_DETECT_RENAME;
 250}
 251
 252int git_diff_heuristic_config(const char *var, const char *value, void *cb)
 253{
 254        if (!strcmp(var, "diff.indentheuristic"))
 255                diff_indent_heuristic = git_config_bool(var, value);
 256        return 0;
 257}
 258
 259static int parse_color_moved(const char *arg)
 260{
 261        switch (git_parse_maybe_bool(arg)) {
 262        case 0:
 263                return COLOR_MOVED_NO;
 264        case 1:
 265                return COLOR_MOVED_DEFAULT;
 266        default:
 267                break;
 268        }
 269
 270        if (!strcmp(arg, "no"))
 271                return COLOR_MOVED_NO;
 272        else if (!strcmp(arg, "plain"))
 273                return COLOR_MOVED_PLAIN;
 274        else if (!strcmp(arg, "blocks"))
 275                return COLOR_MOVED_BLOCKS;
 276        else if (!strcmp(arg, "zebra"))
 277                return COLOR_MOVED_ZEBRA;
 278        else if (!strcmp(arg, "default"))
 279                return COLOR_MOVED_DEFAULT;
 280        else if (!strcmp(arg, "dimmed_zebra"))
 281                return COLOR_MOVED_ZEBRA_DIM;
 282        else
 283                return error(_("color moved setting must be one of 'no', 'default', 'blocks', 'zebra', 'dimmed_zebra', 'plain'"));
 284}
 285
 286static int parse_color_moved_ws(const char *arg)
 287{
 288        int ret = 0;
 289        struct string_list l = STRING_LIST_INIT_DUP;
 290        struct string_list_item *i;
 291
 292        string_list_split(&l, arg, ',', -1);
 293
 294        for_each_string_list_item(i, &l) {
 295                struct strbuf sb = STRBUF_INIT;
 296                strbuf_addstr(&sb, i->string);
 297                strbuf_trim(&sb);
 298
 299                if (!strcmp(sb.buf, "ignore-space-change"))
 300                        ret |= XDF_IGNORE_WHITESPACE_CHANGE;
 301                else if (!strcmp(sb.buf, "ignore-space-at-eol"))
 302                        ret |= XDF_IGNORE_WHITESPACE_AT_EOL;
 303                else if (!strcmp(sb.buf, "ignore-all-space"))
 304                        ret |= XDF_IGNORE_WHITESPACE;
 305                else if (!strcmp(sb.buf, "allow-indentation-change"))
 306                        ret |= COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE;
 307                else
 308                        error(_("ignoring unknown color-moved-ws mode '%s'"), sb.buf);
 309
 310                strbuf_release(&sb);
 311        }
 312
 313        if ((ret & COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) &&
 314            (ret & XDF_WHITESPACE_FLAGS))
 315                die(_("color-moved-ws: allow-indentation-change cannot be combined with other white space modes"));
 316
 317        string_list_clear(&l, 0);
 318
 319        return ret;
 320}
 321
 322int git_diff_ui_config(const char *var, const char *value, void *cb)
 323{
 324        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 325                diff_use_color_default = git_config_colorbool(var, value);
 326                return 0;
 327        }
 328        if (!strcmp(var, "diff.colormoved")) {
 329                int cm = parse_color_moved(value);
 330                if (cm < 0)
 331                        return -1;
 332                diff_color_moved_default = cm;
 333                return 0;
 334        }
 335        if (!strcmp(var, "diff.context")) {
 336                diff_context_default = git_config_int(var, value);
 337                if (diff_context_default < 0)
 338                        return -1;
 339                return 0;
 340        }
 341        if (!strcmp(var, "diff.interhunkcontext")) {
 342                diff_interhunk_context_default = git_config_int(var, value);
 343                if (diff_interhunk_context_default < 0)
 344                        return -1;
 345                return 0;
 346        }
 347        if (!strcmp(var, "diff.renames")) {
 348                diff_detect_rename_default = git_config_rename(var, value);
 349                return 0;
 350        }
 351        if (!strcmp(var, "diff.autorefreshindex")) {
 352                diff_auto_refresh_index = git_config_bool(var, value);
 353                return 0;
 354        }
 355        if (!strcmp(var, "diff.mnemonicprefix")) {
 356                diff_mnemonic_prefix = git_config_bool(var, value);
 357                return 0;
 358        }
 359        if (!strcmp(var, "diff.noprefix")) {
 360                diff_no_prefix = git_config_bool(var, value);
 361                return 0;
 362        }
 363        if (!strcmp(var, "diff.statgraphwidth")) {
 364                diff_stat_graph_width = git_config_int(var, value);
 365                return 0;
 366        }
 367        if (!strcmp(var, "diff.external"))
 368                return git_config_string(&external_diff_cmd_cfg, var, value);
 369        if (!strcmp(var, "diff.wordregex"))
 370                return git_config_string(&diff_word_regex_cfg, var, value);
 371        if (!strcmp(var, "diff.orderfile"))
 372                return git_config_pathname(&diff_order_file_cfg, var, value);
 373
 374        if (!strcmp(var, "diff.ignoresubmodules"))
 375                handle_ignore_submodules_arg(&default_diff_options, value);
 376
 377        if (!strcmp(var, "diff.submodule")) {
 378                if (parse_submodule_params(&default_diff_options, value))
 379                        warning(_("Unknown value for 'diff.submodule' config variable: '%s'"),
 380                                value);
 381                return 0;
 382        }
 383
 384        if (!strcmp(var, "diff.algorithm")) {
 385                diff_algorithm = parse_algorithm_value(value);
 386                if (diff_algorithm < 0)
 387                        return -1;
 388                return 0;
 389        }
 390
 391        if (!strcmp(var, "diff.wserrorhighlight")) {
 392                int val = parse_ws_error_highlight(value);
 393                if (val < 0)
 394                        return -1;
 395                ws_error_highlight_default = val;
 396                return 0;
 397        }
 398
 399        if (git_color_config(var, value, cb) < 0)
 400                return -1;
 401
 402        return git_diff_basic_config(var, value, cb);
 403}
 404
 405int git_diff_basic_config(const char *var, const char *value, void *cb)
 406{
 407        const char *name;
 408
 409        if (!strcmp(var, "diff.renamelimit")) {
 410                diff_rename_limit_default = git_config_int(var, value);
 411                return 0;
 412        }
 413
 414        if (userdiff_config(var, value) < 0)
 415                return -1;
 416
 417        if (skip_prefix(var, "diff.color.", &name) ||
 418            skip_prefix(var, "color.diff.", &name)) {
 419                int slot = parse_diff_color_slot(name);
 420                if (slot < 0)
 421                        return 0;
 422                if (!value)
 423                        return config_error_nonbool(var);
 424                return color_parse(value, diff_colors[slot]);
 425        }
 426
 427        /* like GNU diff's --suppress-blank-empty option  */
 428        if (!strcmp(var, "diff.suppressblankempty") ||
 429                        /* for backwards compatibility */
 430                        !strcmp(var, "diff.suppress-blank-empty")) {
 431                diff_suppress_blank_empty = git_config_bool(var, value);
 432                return 0;
 433        }
 434
 435        if (!strcmp(var, "diff.dirstat")) {
 436                struct strbuf errmsg = STRBUF_INIT;
 437                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 438                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 439                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 440                                errmsg.buf);
 441                strbuf_release(&errmsg);
 442                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 443                return 0;
 444        }
 445
 446        if (git_diff_heuristic_config(var, value, cb) < 0)
 447                return -1;
 448
 449        return git_default_config(var, value, cb);
 450}
 451
 452static char *quote_two(const char *one, const char *two)
 453{
 454        int need_one = quote_c_style(one, NULL, NULL, 1);
 455        int need_two = quote_c_style(two, NULL, NULL, 1);
 456        struct strbuf res = STRBUF_INIT;
 457
 458        if (need_one + need_two) {
 459                strbuf_addch(&res, '"');
 460                quote_c_style(one, &res, NULL, 1);
 461                quote_c_style(two, &res, NULL, 1);
 462                strbuf_addch(&res, '"');
 463        } else {
 464                strbuf_addstr(&res, one);
 465                strbuf_addstr(&res, two);
 466        }
 467        return strbuf_detach(&res, NULL);
 468}
 469
 470static const char *external_diff(void)
 471{
 472        static const char *external_diff_cmd = NULL;
 473        static int done_preparing = 0;
 474
 475        if (done_preparing)
 476                return external_diff_cmd;
 477        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 478        if (!external_diff_cmd)
 479                external_diff_cmd = external_diff_cmd_cfg;
 480        done_preparing = 1;
 481        return external_diff_cmd;
 482}
 483
 484/*
 485 * Keep track of files used for diffing. Sometimes such an entry
 486 * refers to a temporary file, sometimes to an existing file, and
 487 * sometimes to "/dev/null".
 488 */
 489static struct diff_tempfile {
 490        /*
 491         * filename external diff should read from, or NULL if this
 492         * entry is currently not in use:
 493         */
 494        const char *name;
 495
 496        char hex[GIT_MAX_HEXSZ + 1];
 497        char mode[10];
 498
 499        /*
 500         * If this diff_tempfile instance refers to a temporary file,
 501         * this tempfile object is used to manage its lifetime.
 502         */
 503        struct tempfile *tempfile;
 504} diff_temp[2];
 505
 506struct emit_callback {
 507        int color_diff;
 508        unsigned ws_rule;
 509        int blank_at_eof_in_preimage;
 510        int blank_at_eof_in_postimage;
 511        int lno_in_preimage;
 512        int lno_in_postimage;
 513        const char **label_path;
 514        struct diff_words_data *diff_words;
 515        struct diff_options *opt;
 516        struct strbuf *header;
 517};
 518
 519static int count_lines(const char *data, int size)
 520{
 521        int count, ch, completely_empty = 1, nl_just_seen = 0;
 522        count = 0;
 523        while (0 < size--) {
 524                ch = *data++;
 525                if (ch == '\n') {
 526                        count++;
 527                        nl_just_seen = 1;
 528                        completely_empty = 0;
 529                }
 530                else {
 531                        nl_just_seen = 0;
 532                        completely_empty = 0;
 533                }
 534        }
 535        if (completely_empty)
 536                return 0;
 537        if (!nl_just_seen)
 538                count++; /* no trailing newline */
 539        return count;
 540}
 541
 542static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 543{
 544        if (!DIFF_FILE_VALID(one)) {
 545                mf->ptr = (char *)""; /* does not matter */
 546                mf->size = 0;
 547                return 0;
 548        }
 549        else if (diff_populate_filespec(one, 0))
 550                return -1;
 551
 552        mf->ptr = one->data;
 553        mf->size = one->size;
 554        return 0;
 555}
 556
 557/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 558static unsigned long diff_filespec_size(struct diff_filespec *one)
 559{
 560        if (!DIFF_FILE_VALID(one))
 561                return 0;
 562        diff_populate_filespec(one, CHECK_SIZE_ONLY);
 563        return one->size;
 564}
 565
 566static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 567{
 568        char *ptr = mf->ptr;
 569        long size = mf->size;
 570        int cnt = 0;
 571
 572        if (!size)
 573                return cnt;
 574        ptr += size - 1; /* pointing at the very end */
 575        if (*ptr != '\n')
 576                ; /* incomplete line */
 577        else
 578                ptr--; /* skip the last LF */
 579        while (mf->ptr < ptr) {
 580                char *prev_eol;
 581                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 582                        if (*prev_eol == '\n')
 583                                break;
 584                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 585                        break;
 586                cnt++;
 587                ptr = prev_eol - 1;
 588        }
 589        return cnt;
 590}
 591
 592static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 593                               struct emit_callback *ecbdata)
 594{
 595        int l1, l2, at;
 596        unsigned ws_rule = ecbdata->ws_rule;
 597        l1 = count_trailing_blank(mf1, ws_rule);
 598        l2 = count_trailing_blank(mf2, ws_rule);
 599        if (l2 <= l1) {
 600                ecbdata->blank_at_eof_in_preimage = 0;
 601                ecbdata->blank_at_eof_in_postimage = 0;
 602                return;
 603        }
 604        at = count_lines(mf1->ptr, mf1->size);
 605        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 606
 607        at = count_lines(mf2->ptr, mf2->size);
 608        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 609}
 610
 611static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 612                        int first, const char *line, int len)
 613{
 614        int has_trailing_newline, has_trailing_carriage_return;
 615        int nofirst;
 616        FILE *file = o->file;
 617
 618        fputs(diff_line_prefix(o), file);
 619
 620        if (len == 0) {
 621                has_trailing_newline = (first == '\n');
 622                has_trailing_carriage_return = (!has_trailing_newline &&
 623                                                (first == '\r'));
 624                nofirst = has_trailing_newline || has_trailing_carriage_return;
 625        } else {
 626                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 627                if (has_trailing_newline)
 628                        len--;
 629                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 630                if (has_trailing_carriage_return)
 631                        len--;
 632                nofirst = 0;
 633        }
 634
 635        if (len || !nofirst) {
 636                fputs(set, file);
 637                if (!nofirst)
 638                        fputc(first, file);
 639                fwrite(line, len, 1, file);
 640                fputs(reset, file);
 641        }
 642        if (has_trailing_carriage_return)
 643                fputc('\r', file);
 644        if (has_trailing_newline)
 645                fputc('\n', file);
 646}
 647
 648static void emit_line(struct diff_options *o, const char *set, const char *reset,
 649                      const char *line, int len)
 650{
 651        emit_line_0(o, set, reset, line[0], line+1, len-1);
 652}
 653
 654enum diff_symbol {
 655        DIFF_SYMBOL_BINARY_DIFF_HEADER,
 656        DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
 657        DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
 658        DIFF_SYMBOL_BINARY_DIFF_BODY,
 659        DIFF_SYMBOL_BINARY_DIFF_FOOTER,
 660        DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
 661        DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
 662        DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
 663        DIFF_SYMBOL_STATS_LINE,
 664        DIFF_SYMBOL_WORD_DIFF,
 665        DIFF_SYMBOL_STAT_SEP,
 666        DIFF_SYMBOL_SUMMARY,
 667        DIFF_SYMBOL_SUBMODULE_ADD,
 668        DIFF_SYMBOL_SUBMODULE_DEL,
 669        DIFF_SYMBOL_SUBMODULE_UNTRACKED,
 670        DIFF_SYMBOL_SUBMODULE_MODIFIED,
 671        DIFF_SYMBOL_SUBMODULE_HEADER,
 672        DIFF_SYMBOL_SUBMODULE_ERROR,
 673        DIFF_SYMBOL_SUBMODULE_PIPETHROUGH,
 674        DIFF_SYMBOL_REWRITE_DIFF,
 675        DIFF_SYMBOL_BINARY_FILES,
 676        DIFF_SYMBOL_HEADER,
 677        DIFF_SYMBOL_FILEPAIR_PLUS,
 678        DIFF_SYMBOL_FILEPAIR_MINUS,
 679        DIFF_SYMBOL_WORDS_PORCELAIN,
 680        DIFF_SYMBOL_WORDS,
 681        DIFF_SYMBOL_CONTEXT,
 682        DIFF_SYMBOL_CONTEXT_INCOMPLETE,
 683        DIFF_SYMBOL_PLUS,
 684        DIFF_SYMBOL_MINUS,
 685        DIFF_SYMBOL_NO_LF_EOF,
 686        DIFF_SYMBOL_CONTEXT_FRAGINFO,
 687        DIFF_SYMBOL_CONTEXT_MARKER,
 688        DIFF_SYMBOL_SEPARATOR
 689};
 690/*
 691 * Flags for content lines:
 692 * 0..12 are whitespace rules
 693 * 13-15 are WSEH_NEW | WSEH_OLD | WSEH_CONTEXT
 694 * 16 is marking if the line is blank at EOF
 695 */
 696#define DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF      (1<<16)
 697#define DIFF_SYMBOL_MOVED_LINE                  (1<<17)
 698#define DIFF_SYMBOL_MOVED_LINE_ALT              (1<<18)
 699#define DIFF_SYMBOL_MOVED_LINE_UNINTERESTING    (1<<19)
 700#define DIFF_SYMBOL_CONTENT_WS_MASK (WSEH_NEW | WSEH_OLD | WSEH_CONTEXT | WS_RULE_MASK)
 701
 702/*
 703 * This struct is used when we need to buffer the output of the diff output.
 704 *
 705 * NEEDSWORK: Instead of storing a copy of the line, add an offset pointer
 706 * into the pre/post image file. This pointer could be a union with the
 707 * line pointer. By storing an offset into the file instead of the literal line,
 708 * we can decrease the memory footprint for the buffered output. At first we
 709 * may want to only have indirection for the content lines, but we could also
 710 * enhance the state for emitting prefabricated lines, e.g. the similarity
 711 * score line or hunk/file headers would only need to store a number or path
 712 * and then the output can be constructed later on depending on state.
 713 */
 714struct emitted_diff_symbol {
 715        const char *line;
 716        int len;
 717        int flags;
 718        enum diff_symbol s;
 719};
 720#define EMITTED_DIFF_SYMBOL_INIT {NULL}
 721
 722struct emitted_diff_symbols {
 723        struct emitted_diff_symbol *buf;
 724        int nr, alloc;
 725};
 726#define EMITTED_DIFF_SYMBOLS_INIT {NULL, 0, 0}
 727
 728static void append_emitted_diff_symbol(struct diff_options *o,
 729                                       struct emitted_diff_symbol *e)
 730{
 731        struct emitted_diff_symbol *f;
 732
 733        ALLOC_GROW(o->emitted_symbols->buf,
 734                   o->emitted_symbols->nr + 1,
 735                   o->emitted_symbols->alloc);
 736        f = &o->emitted_symbols->buf[o->emitted_symbols->nr++];
 737
 738        memcpy(f, e, sizeof(struct emitted_diff_symbol));
 739        f->line = e->line ? xmemdupz(e->line, e->len) : NULL;
 740}
 741
 742struct moved_entry {
 743        struct hashmap_entry ent;
 744        const struct emitted_diff_symbol *es;
 745        struct moved_entry *next_line;
 746        struct ws_delta *wsd;
 747};
 748
 749/**
 750 * The struct ws_delta holds white space differences between moved lines, i.e.
 751 * between '+' and '-' lines that have been detected to be a move.
 752 * The string contains the difference in leading white spaces, before the
 753 * rest of the line is compared using the white space config for move
 754 * coloring. The current_longer indicates if the first string in the
 755 * comparision is longer than the second.
 756 */
 757struct ws_delta {
 758        char *string;
 759        unsigned int current_longer : 1;
 760};
 761#define WS_DELTA_INIT { NULL, 0 }
 762
 763static int compute_ws_delta(const struct emitted_diff_symbol *a,
 764                             const struct emitted_diff_symbol *b,
 765                             struct ws_delta *out)
 766{
 767        const struct emitted_diff_symbol *longer =  a->len > b->len ? a : b;
 768        const struct emitted_diff_symbol *shorter = a->len > b->len ? b : a;
 769        int d = longer->len - shorter->len;
 770
 771        out->string = xmemdupz(longer->line, d);
 772        out->current_longer = (a == longer);
 773
 774        return !strncmp(longer->line + d, shorter->line, shorter->len);
 775}
 776
 777static int cmp_in_block_with_wsd(const struct diff_options *o,
 778                                 const struct moved_entry *cur,
 779                                 const struct moved_entry *match,
 780                                 struct moved_entry *pmb,
 781                                 int n)
 782{
 783        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
 784        int al = cur->es->len, cl = l->len;
 785        const char *a = cur->es->line,
 786                   *b = match->es->line,
 787                   *c = l->line;
 788
 789        int wslen;
 790
 791        /*
 792         * We need to check if 'cur' is equal to 'match'.
 793         * As those are from the same (+/-) side, we do not need to adjust for
 794         * indent changes. However these were found using fuzzy matching
 795         * so we do have to check if they are equal.
 796         */
 797        if (strcmp(a, b))
 798                return 1;
 799
 800        if (!pmb->wsd)
 801                /*
 802                 * No white space delta was carried forward? This can happen
 803                 * when we exit early in this function and do not carry
 804                 * forward ws.
 805                 */
 806                return 1;
 807
 808        /*
 809         * The indent changes of the block are known and carried forward in
 810         * pmb->wsd; however we need to check if the indent changes of the
 811         * current line are still the same as before.
 812         *
 813         * To do so we need to compare 'l' to 'cur', adjusting the
 814         * one of them for the white spaces, depending which was longer.
 815         */
 816
 817        wslen = strlen(pmb->wsd->string);
 818        if (pmb->wsd->current_longer) {
 819                c += wslen;
 820                cl -= wslen;
 821        } else {
 822                a += wslen;
 823                al -= wslen;
 824        }
 825
 826        if (strcmp(a, c))
 827                return 1;
 828
 829        return 0;
 830}
 831
 832static int moved_entry_cmp(const void *hashmap_cmp_fn_data,
 833                           const void *entry,
 834                           const void *entry_or_key,
 835                           const void *keydata)
 836{
 837        const struct diff_options *diffopt = hashmap_cmp_fn_data;
 838        const struct moved_entry *a = entry;
 839        const struct moved_entry *b = entry_or_key;
 840        unsigned flags = diffopt->color_moved_ws_handling
 841                         & XDF_WHITESPACE_FLAGS;
 842
 843        if (diffopt->color_moved_ws_handling &
 844            COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
 845                /*
 846                 * As there is not specific white space config given,
 847                 * we'd need to check for a new block, so ignore all
 848                 * white space. The setup of the white space
 849                 * configuration for the next block is done else where
 850                 */
 851                flags |= XDF_IGNORE_WHITESPACE;
 852
 853        return !xdiff_compare_lines(a->es->line, a->es->len,
 854                                    b->es->line, b->es->len,
 855                                    flags);
 856}
 857
 858static struct moved_entry *prepare_entry(struct diff_options *o,
 859                                         int line_no)
 860{
 861        struct moved_entry *ret = xmalloc(sizeof(*ret));
 862        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[line_no];
 863        unsigned flags = o->color_moved_ws_handling & XDF_WHITESPACE_FLAGS;
 864
 865        ret->ent.hash = xdiff_hash_string(l->line, l->len, flags);
 866        ret->es = l;
 867        ret->next_line = NULL;
 868        ret->wsd = NULL;
 869
 870        return ret;
 871}
 872
 873static void add_lines_to_move_detection(struct diff_options *o,
 874                                        struct hashmap *add_lines,
 875                                        struct hashmap *del_lines)
 876{
 877        struct moved_entry *prev_line = NULL;
 878
 879        int n;
 880        for (n = 0; n < o->emitted_symbols->nr; n++) {
 881                struct hashmap *hm;
 882                struct moved_entry *key;
 883
 884                switch (o->emitted_symbols->buf[n].s) {
 885                case DIFF_SYMBOL_PLUS:
 886                        hm = add_lines;
 887                        break;
 888                case DIFF_SYMBOL_MINUS:
 889                        hm = del_lines;
 890                        break;
 891                default:
 892                        prev_line = NULL;
 893                        continue;
 894                }
 895
 896                key = prepare_entry(o, n);
 897                if (prev_line && prev_line->es->s == o->emitted_symbols->buf[n].s)
 898                        prev_line->next_line = key;
 899
 900                hashmap_add(hm, key);
 901                prev_line = key;
 902        }
 903}
 904
 905static void pmb_advance_or_null(struct diff_options *o,
 906                                struct moved_entry *match,
 907                                struct hashmap *hm,
 908                                struct moved_entry **pmb,
 909                                int pmb_nr)
 910{
 911        int i;
 912        for (i = 0; i < pmb_nr; i++) {
 913                struct moved_entry *prev = pmb[i];
 914                struct moved_entry *cur = (prev && prev->next_line) ?
 915                                prev->next_line : NULL;
 916                if (cur && !hm->cmpfn(o, cur, match, NULL)) {
 917                        pmb[i] = cur;
 918                } else {
 919                        pmb[i] = NULL;
 920                }
 921        }
 922}
 923
 924static void pmb_advance_or_null_multi_match(struct diff_options *o,
 925                                            struct moved_entry *match,
 926                                            struct hashmap *hm,
 927                                            struct moved_entry **pmb,
 928                                            int pmb_nr, int n)
 929{
 930        int i;
 931        char *got_match = xcalloc(1, pmb_nr);
 932
 933        for (; match; match = hashmap_get_next(hm, match)) {
 934                for (i = 0; i < pmb_nr; i++) {
 935                        struct moved_entry *prev = pmb[i];
 936                        struct moved_entry *cur = (prev && prev->next_line) ?
 937                                        prev->next_line : NULL;
 938                        if (!cur)
 939                                continue;
 940                        if (!cmp_in_block_with_wsd(o, cur, match, pmb[i], n))
 941                                got_match[i] |= 1;
 942                }
 943        }
 944
 945        for (i = 0; i < pmb_nr; i++) {
 946                if (got_match[i]) {
 947                        /* Carry the white space delta forward */
 948                        pmb[i]->next_line->wsd = pmb[i]->wsd;
 949                        pmb[i] = pmb[i]->next_line;
 950                } else
 951                        pmb[i] = NULL;
 952        }
 953}
 954
 955static int shrink_potential_moved_blocks(struct moved_entry **pmb,
 956                                         int pmb_nr)
 957{
 958        int lp, rp;
 959
 960        /* Shrink the set of potential block to the remaining running */
 961        for (lp = 0, rp = pmb_nr - 1; lp <= rp;) {
 962                while (lp < pmb_nr && pmb[lp])
 963                        lp++;
 964                /* lp points at the first NULL now */
 965
 966                while (rp > -1 && !pmb[rp])
 967                        rp--;
 968                /* rp points at the last non-NULL */
 969
 970                if (lp < pmb_nr && rp > -1 && lp < rp) {
 971                        pmb[lp] = pmb[rp];
 972                        if (pmb[rp]->wsd) {
 973                                free(pmb[rp]->wsd->string);
 974                                FREE_AND_NULL(pmb[rp]->wsd);
 975                        }
 976                        pmb[rp] = NULL;
 977                        rp--;
 978                        lp++;
 979                }
 980        }
 981
 982        /* Remember the number of running sets */
 983        return rp + 1;
 984}
 985
 986/*
 987 * If o->color_moved is COLOR_MOVED_PLAIN, this function does nothing.
 988 *
 989 * Otherwise, if the last block has fewer alphanumeric characters than
 990 * COLOR_MOVED_MIN_ALNUM_COUNT, unset DIFF_SYMBOL_MOVED_LINE on all lines in
 991 * that block.
 992 *
 993 * The last block consists of the (n - block_length)'th line up to but not
 994 * including the nth line.
 995 *
 996 * NEEDSWORK: This uses the same heuristic as blame_entry_score() in blame.c.
 997 * Think of a way to unify them.
 998 */
 999static void adjust_last_block(struct diff_options *o, int n, int block_length)
1000{
1001        int i, alnum_count = 0;
1002        if (o->color_moved == COLOR_MOVED_PLAIN)
1003                return;
1004        for (i = 1; i < block_length + 1; i++) {
1005                const char *c = o->emitted_symbols->buf[n - i].line;
1006                for (; *c; c++) {
1007                        if (!isalnum(*c))
1008                                continue;
1009                        alnum_count++;
1010                        if (alnum_count >= COLOR_MOVED_MIN_ALNUM_COUNT)
1011                                return;
1012                }
1013        }
1014        for (i = 1; i < block_length + 1; i++)
1015                o->emitted_symbols->buf[n - i].flags &= ~DIFF_SYMBOL_MOVED_LINE;
1016}
1017
1018/* Find blocks of moved code, delegate actual coloring decision to helper */
1019static void mark_color_as_moved(struct diff_options *o,
1020                                struct hashmap *add_lines,
1021                                struct hashmap *del_lines)
1022{
1023        struct moved_entry **pmb = NULL; /* potentially moved blocks */
1024        int pmb_nr = 0, pmb_alloc = 0;
1025        int n, flipped_block = 1, block_length = 0;
1026
1027
1028        for (n = 0; n < o->emitted_symbols->nr; n++) {
1029                struct hashmap *hm = NULL;
1030                struct moved_entry *key;
1031                struct moved_entry *match = NULL;
1032                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
1033
1034                switch (l->s) {
1035                case DIFF_SYMBOL_PLUS:
1036                        hm = del_lines;
1037                        key = prepare_entry(o, n);
1038                        match = hashmap_get(hm, key, NULL);
1039                        free(key);
1040                        break;
1041                case DIFF_SYMBOL_MINUS:
1042                        hm = add_lines;
1043                        key = prepare_entry(o, n);
1044                        match = hashmap_get(hm, key, NULL);
1045                        free(key);
1046                        break;
1047                default:
1048                        flipped_block = 1;
1049                }
1050
1051                if (!match) {
1052                        adjust_last_block(o, n, block_length);
1053                        pmb_nr = 0;
1054                        block_length = 0;
1055                        continue;
1056                }
1057
1058                l->flags |= DIFF_SYMBOL_MOVED_LINE;
1059
1060                if (o->color_moved == COLOR_MOVED_PLAIN)
1061                        continue;
1062
1063                if (o->color_moved_ws_handling &
1064                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
1065                        pmb_advance_or_null_multi_match(o, match, hm, pmb, pmb_nr, n);
1066                else
1067                        pmb_advance_or_null(o, match, hm, pmb, pmb_nr);
1068
1069                pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
1070
1071                if (pmb_nr == 0) {
1072                        /*
1073                         * The current line is the start of a new block.
1074                         * Setup the set of potential blocks.
1075                         */
1076                        for (; match; match = hashmap_get_next(hm, match)) {
1077                                ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
1078                                if (o->color_moved_ws_handling &
1079                                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) {
1080                                        struct ws_delta *wsd = xmalloc(sizeof(*match->wsd));
1081                                        if (compute_ws_delta(l, match->es, wsd)) {
1082                                                match->wsd = wsd;
1083                                                pmb[pmb_nr++] = match;
1084                                        } else
1085                                                free(wsd);
1086                                } else {
1087                                        pmb[pmb_nr++] = match;
1088                                }
1089                        }
1090
1091                        flipped_block = (flipped_block + 1) % 2;
1092
1093                        adjust_last_block(o, n, block_length);
1094                        block_length = 0;
1095                }
1096
1097                block_length++;
1098
1099                if (flipped_block && o->color_moved != COLOR_MOVED_BLOCKS)
1100                        l->flags |= DIFF_SYMBOL_MOVED_LINE_ALT;
1101        }
1102        adjust_last_block(o, n, block_length);
1103
1104        free(pmb);
1105}
1106
1107#define DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK \
1108  (DIFF_SYMBOL_MOVED_LINE | DIFF_SYMBOL_MOVED_LINE_ALT)
1109static void dim_moved_lines(struct diff_options *o)
1110{
1111        int n;
1112        for (n = 0; n < o->emitted_symbols->nr; n++) {
1113                struct emitted_diff_symbol *prev = (n != 0) ?
1114                                &o->emitted_symbols->buf[n - 1] : NULL;
1115                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
1116                struct emitted_diff_symbol *next =
1117                                (n < o->emitted_symbols->nr - 1) ?
1118                                &o->emitted_symbols->buf[n + 1] : NULL;
1119
1120                /* Not a plus or minus line? */
1121                if (l->s != DIFF_SYMBOL_PLUS && l->s != DIFF_SYMBOL_MINUS)
1122                        continue;
1123
1124                /* Not a moved line? */
1125                if (!(l->flags & DIFF_SYMBOL_MOVED_LINE))
1126                        continue;
1127
1128                /*
1129                 * If prev or next are not a plus or minus line,
1130                 * pretend they don't exist
1131                 */
1132                if (prev && prev->s != DIFF_SYMBOL_PLUS &&
1133                            prev->s != DIFF_SYMBOL_MINUS)
1134                        prev = NULL;
1135                if (next && next->s != DIFF_SYMBOL_PLUS &&
1136                            next->s != DIFF_SYMBOL_MINUS)
1137                        next = NULL;
1138
1139                /* Inside a block? */
1140                if ((prev &&
1141                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
1142                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK)) &&
1143                    (next &&
1144                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
1145                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK))) {
1146                        l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1147                        continue;
1148                }
1149
1150                /* Check if we are at an interesting bound: */
1151                if (prev && (prev->flags & DIFF_SYMBOL_MOVED_LINE) &&
1152                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1153                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1154                        continue;
1155                if (next && (next->flags & DIFF_SYMBOL_MOVED_LINE) &&
1156                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
1157                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
1158                        continue;
1159
1160                /*
1161                 * The boundary to prev and next are not interesting,
1162                 * so this line is not interesting as a whole
1163                 */
1164                l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
1165        }
1166}
1167
1168static void emit_line_ws_markup(struct diff_options *o,
1169                                const char *set, const char *reset,
1170                                const char *line, int len, char sign,
1171                                unsigned ws_rule, int blank_at_eof)
1172{
1173        const char *ws = NULL;
1174
1175        if (o->ws_error_highlight & ws_rule) {
1176                ws = diff_get_color_opt(o, DIFF_WHITESPACE);
1177                if (!*ws)
1178                        ws = NULL;
1179        }
1180
1181        if (!ws)
1182                emit_line_0(o, set, reset, sign, line, len);
1183        else if (blank_at_eof)
1184                /* Blank line at EOF - paint '+' as well */
1185                emit_line_0(o, ws, reset, sign, line, len);
1186        else {
1187                /* Emit just the prefix, then the rest. */
1188                emit_line_0(o, set, reset, sign, "", 0);
1189                ws_check_emit(line, len, ws_rule,
1190                              o->file, set, reset, ws);
1191        }
1192}
1193
1194static void emit_diff_symbol_from_struct(struct diff_options *o,
1195                                         struct emitted_diff_symbol *eds)
1196{
1197        static const char *nneof = " No newline at end of file\n";
1198        const char *context, *reset, *set, *meta, *fraginfo;
1199        struct strbuf sb = STRBUF_INIT;
1200
1201        enum diff_symbol s = eds->s;
1202        const char *line = eds->line;
1203        int len = eds->len;
1204        unsigned flags = eds->flags;
1205
1206        switch (s) {
1207        case DIFF_SYMBOL_NO_LF_EOF:
1208                context = diff_get_color_opt(o, DIFF_CONTEXT);
1209                reset = diff_get_color_opt(o, DIFF_RESET);
1210                putc('\n', o->file);
1211                emit_line_0(o, context, reset, '\\',
1212                            nneof, strlen(nneof));
1213                break;
1214        case DIFF_SYMBOL_SUBMODULE_HEADER:
1215        case DIFF_SYMBOL_SUBMODULE_ERROR:
1216        case DIFF_SYMBOL_SUBMODULE_PIPETHROUGH:
1217        case DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES:
1218        case DIFF_SYMBOL_SUMMARY:
1219        case DIFF_SYMBOL_STATS_LINE:
1220        case DIFF_SYMBOL_BINARY_DIFF_BODY:
1221        case DIFF_SYMBOL_CONTEXT_FRAGINFO:
1222                emit_line(o, "", "", line, len);
1223                break;
1224        case DIFF_SYMBOL_CONTEXT_INCOMPLETE:
1225        case DIFF_SYMBOL_CONTEXT_MARKER:
1226                context = diff_get_color_opt(o, DIFF_CONTEXT);
1227                reset = diff_get_color_opt(o, DIFF_RESET);
1228                emit_line(o, context, reset, line, len);
1229                break;
1230        case DIFF_SYMBOL_SEPARATOR:
1231                fprintf(o->file, "%s%c",
1232                        diff_line_prefix(o),
1233                        o->line_termination);
1234                break;
1235        case DIFF_SYMBOL_CONTEXT:
1236                set = diff_get_color_opt(o, DIFF_CONTEXT);
1237                reset = diff_get_color_opt(o, DIFF_RESET);
1238                emit_line_ws_markup(o, set, reset, line, len, ' ',
1239                                    flags & (DIFF_SYMBOL_CONTENT_WS_MASK), 0);
1240                break;
1241        case DIFF_SYMBOL_PLUS:
1242                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1243                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1244                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1245                case DIFF_SYMBOL_MOVED_LINE |
1246                     DIFF_SYMBOL_MOVED_LINE_ALT |
1247                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1248                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT_DIM);
1249                        break;
1250                case DIFF_SYMBOL_MOVED_LINE |
1251                     DIFF_SYMBOL_MOVED_LINE_ALT:
1252                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT);
1253                        break;
1254                case DIFF_SYMBOL_MOVED_LINE |
1255                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1256                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_DIM);
1257                        break;
1258                case DIFF_SYMBOL_MOVED_LINE:
1259                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED);
1260                        break;
1261                default:
1262                        set = diff_get_color_opt(o, DIFF_FILE_NEW);
1263                }
1264                reset = diff_get_color_opt(o, DIFF_RESET);
1265                emit_line_ws_markup(o, set, reset, line, len, '+',
1266                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK,
1267                                    flags & DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF);
1268                break;
1269        case DIFF_SYMBOL_MINUS:
1270                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1271                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1272                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1273                case DIFF_SYMBOL_MOVED_LINE |
1274                     DIFF_SYMBOL_MOVED_LINE_ALT |
1275                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1276                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT_DIM);
1277                        break;
1278                case DIFF_SYMBOL_MOVED_LINE |
1279                     DIFF_SYMBOL_MOVED_LINE_ALT:
1280                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT);
1281                        break;
1282                case DIFF_SYMBOL_MOVED_LINE |
1283                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1284                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_DIM);
1285                        break;
1286                case DIFF_SYMBOL_MOVED_LINE:
1287                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED);
1288                        break;
1289                default:
1290                        set = diff_get_color_opt(o, DIFF_FILE_OLD);
1291                }
1292                reset = diff_get_color_opt(o, DIFF_RESET);
1293                emit_line_ws_markup(o, set, reset, line, len, '-',
1294                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK, 0);
1295                break;
1296        case DIFF_SYMBOL_WORDS_PORCELAIN:
1297                context = diff_get_color_opt(o, DIFF_CONTEXT);
1298                reset = diff_get_color_opt(o, DIFF_RESET);
1299                emit_line(o, context, reset, line, len);
1300                fputs("~\n", o->file);
1301                break;
1302        case DIFF_SYMBOL_WORDS:
1303                context = diff_get_color_opt(o, DIFF_CONTEXT);
1304                reset = diff_get_color_opt(o, DIFF_RESET);
1305                /*
1306                 * Skip the prefix character, if any.  With
1307                 * diff_suppress_blank_empty, there may be
1308                 * none.
1309                 */
1310                if (line[0] != '\n') {
1311                        line++;
1312                        len--;
1313                }
1314                emit_line(o, context, reset, line, len);
1315                break;
1316        case DIFF_SYMBOL_FILEPAIR_PLUS:
1317                meta = diff_get_color_opt(o, DIFF_METAINFO);
1318                reset = diff_get_color_opt(o, DIFF_RESET);
1319                fprintf(o->file, "%s%s+++ %s%s%s\n", diff_line_prefix(o), meta,
1320                        line, reset,
1321                        strchr(line, ' ') ? "\t" : "");
1322                break;
1323        case DIFF_SYMBOL_FILEPAIR_MINUS:
1324                meta = diff_get_color_opt(o, DIFF_METAINFO);
1325                reset = diff_get_color_opt(o, DIFF_RESET);
1326                fprintf(o->file, "%s%s--- %s%s%s\n", diff_line_prefix(o), meta,
1327                        line, reset,
1328                        strchr(line, ' ') ? "\t" : "");
1329                break;
1330        case DIFF_SYMBOL_BINARY_FILES:
1331        case DIFF_SYMBOL_HEADER:
1332                fprintf(o->file, "%s", line);
1333                break;
1334        case DIFF_SYMBOL_BINARY_DIFF_HEADER:
1335                fprintf(o->file, "%sGIT binary patch\n", diff_line_prefix(o));
1336                break;
1337        case DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA:
1338                fprintf(o->file, "%sdelta %s\n", diff_line_prefix(o), line);
1339                break;
1340        case DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL:
1341                fprintf(o->file, "%sliteral %s\n", diff_line_prefix(o), line);
1342                break;
1343        case DIFF_SYMBOL_BINARY_DIFF_FOOTER:
1344                fputs(diff_line_prefix(o), o->file);
1345                fputc('\n', o->file);
1346                break;
1347        case DIFF_SYMBOL_REWRITE_DIFF:
1348                fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
1349                reset = diff_get_color_opt(o, DIFF_RESET);
1350                emit_line(o, fraginfo, reset, line, len);
1351                break;
1352        case DIFF_SYMBOL_SUBMODULE_ADD:
1353                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1354                reset = diff_get_color_opt(o, DIFF_RESET);
1355                emit_line(o, set, reset, line, len);
1356                break;
1357        case DIFF_SYMBOL_SUBMODULE_DEL:
1358                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1359                reset = diff_get_color_opt(o, DIFF_RESET);
1360                emit_line(o, set, reset, line, len);
1361                break;
1362        case DIFF_SYMBOL_SUBMODULE_UNTRACKED:
1363                fprintf(o->file, "%sSubmodule %s contains untracked content\n",
1364                        diff_line_prefix(o), line);
1365                break;
1366        case DIFF_SYMBOL_SUBMODULE_MODIFIED:
1367                fprintf(o->file, "%sSubmodule %s contains modified content\n",
1368                        diff_line_prefix(o), line);
1369                break;
1370        case DIFF_SYMBOL_STATS_SUMMARY_NO_FILES:
1371                emit_line(o, "", "", " 0 files changed\n",
1372                          strlen(" 0 files changed\n"));
1373                break;
1374        case DIFF_SYMBOL_STATS_SUMMARY_ABBREV:
1375                emit_line(o, "", "", " ...\n", strlen(" ...\n"));
1376                break;
1377        case DIFF_SYMBOL_WORD_DIFF:
1378                fprintf(o->file, "%.*s", len, line);
1379                break;
1380        case DIFF_SYMBOL_STAT_SEP:
1381                fputs(o->stat_sep, o->file);
1382                break;
1383        default:
1384                die("BUG: unknown diff symbol");
1385        }
1386        strbuf_release(&sb);
1387}
1388
1389static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
1390                             const char *line, int len, unsigned flags)
1391{
1392        struct emitted_diff_symbol e = {line, len, flags, s};
1393
1394        if (o->emitted_symbols)
1395                append_emitted_diff_symbol(o, &e);
1396        else
1397                emit_diff_symbol_from_struct(o, &e);
1398}
1399
1400void diff_emit_submodule_del(struct diff_options *o, const char *line)
1401{
1402        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_DEL, line, strlen(line), 0);
1403}
1404
1405void diff_emit_submodule_add(struct diff_options *o, const char *line)
1406{
1407        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ADD, line, strlen(line), 0);
1408}
1409
1410void diff_emit_submodule_untracked(struct diff_options *o, const char *path)
1411{
1412        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_UNTRACKED,
1413                         path, strlen(path), 0);
1414}
1415
1416void diff_emit_submodule_modified(struct diff_options *o, const char *path)
1417{
1418        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_MODIFIED,
1419                         path, strlen(path), 0);
1420}
1421
1422void diff_emit_submodule_header(struct diff_options *o, const char *header)
1423{
1424        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_HEADER,
1425                         header, strlen(header), 0);
1426}
1427
1428void diff_emit_submodule_error(struct diff_options *o, const char *err)
1429{
1430        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ERROR, err, strlen(err), 0);
1431}
1432
1433void diff_emit_submodule_pipethrough(struct diff_options *o,
1434                                     const char *line, int len)
1435{
1436        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_PIPETHROUGH, line, len, 0);
1437}
1438
1439static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
1440{
1441        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
1442              ecbdata->blank_at_eof_in_preimage &&
1443              ecbdata->blank_at_eof_in_postimage &&
1444              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
1445              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
1446                return 0;
1447        return ws_blank_line(line, len, ecbdata->ws_rule);
1448}
1449
1450static void emit_add_line(const char *reset,
1451                          struct emit_callback *ecbdata,
1452                          const char *line, int len)
1453{
1454        unsigned flags = WSEH_NEW | ecbdata->ws_rule;
1455        if (new_blank_line_at_eof(ecbdata, line, len))
1456                flags |= DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF;
1457
1458        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_PLUS, line, len, flags);
1459}
1460
1461static void emit_del_line(const char *reset,
1462                          struct emit_callback *ecbdata,
1463                          const char *line, int len)
1464{
1465        unsigned flags = WSEH_OLD | ecbdata->ws_rule;
1466        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_MINUS, line, len, flags);
1467}
1468
1469static void emit_context_line(const char *reset,
1470                              struct emit_callback *ecbdata,
1471                              const char *line, int len)
1472{
1473        unsigned flags = WSEH_CONTEXT | ecbdata->ws_rule;
1474        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_CONTEXT, line, len, flags);
1475}
1476
1477static void emit_hunk_header(struct emit_callback *ecbdata,
1478                             const char *line, int len)
1479{
1480        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
1481        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
1482        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
1483        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1484        static const char atat[2] = { '@', '@' };
1485        const char *cp, *ep;
1486        struct strbuf msgbuf = STRBUF_INIT;
1487        int org_len = len;
1488        int i = 1;
1489
1490        /*
1491         * As a hunk header must begin with "@@ -<old>, +<new> @@",
1492         * it always is at least 10 bytes long.
1493         */
1494        if (len < 10 ||
1495            memcmp(line, atat, 2) ||
1496            !(ep = memmem(line + 2, len - 2, atat, 2))) {
1497                emit_diff_symbol(ecbdata->opt,
1498                                 DIFF_SYMBOL_CONTEXT_MARKER, line, len, 0);
1499                return;
1500        }
1501        ep += 2; /* skip over @@ */
1502
1503        /* The hunk header in fraginfo color */
1504        strbuf_addstr(&msgbuf, frag);
1505        strbuf_add(&msgbuf, line, ep - line);
1506        strbuf_addstr(&msgbuf, reset);
1507
1508        /*
1509         * trailing "\r\n"
1510         */
1511        for ( ; i < 3; i++)
1512                if (line[len - i] == '\r' || line[len - i] == '\n')
1513                        len--;
1514
1515        /* blank before the func header */
1516        for (cp = ep; ep - line < len; ep++)
1517                if (*ep != ' ' && *ep != '\t')
1518                        break;
1519        if (ep != cp) {
1520                strbuf_addstr(&msgbuf, context);
1521                strbuf_add(&msgbuf, cp, ep - cp);
1522                strbuf_addstr(&msgbuf, reset);
1523        }
1524
1525        if (ep < line + len) {
1526                strbuf_addstr(&msgbuf, func);
1527                strbuf_add(&msgbuf, ep, line + len - ep);
1528                strbuf_addstr(&msgbuf, reset);
1529        }
1530
1531        strbuf_add(&msgbuf, line + len, org_len - len);
1532        strbuf_complete_line(&msgbuf);
1533        emit_diff_symbol(ecbdata->opt,
1534                         DIFF_SYMBOL_CONTEXT_FRAGINFO, msgbuf.buf, msgbuf.len, 0);
1535        strbuf_release(&msgbuf);
1536}
1537
1538static struct diff_tempfile *claim_diff_tempfile(void) {
1539        int i;
1540        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
1541                if (!diff_temp[i].name)
1542                        return diff_temp + i;
1543        die("BUG: diff is failing to clean up its tempfiles");
1544}
1545
1546static void remove_tempfile(void)
1547{
1548        int i;
1549        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
1550                if (is_tempfile_active(diff_temp[i].tempfile))
1551                        delete_tempfile(&diff_temp[i].tempfile);
1552                diff_temp[i].name = NULL;
1553        }
1554}
1555
1556static void add_line_count(struct strbuf *out, int count)
1557{
1558        switch (count) {
1559        case 0:
1560                strbuf_addstr(out, "0,0");
1561                break;
1562        case 1:
1563                strbuf_addstr(out, "1");
1564                break;
1565        default:
1566                strbuf_addf(out, "1,%d", count);
1567                break;
1568        }
1569}
1570
1571static void emit_rewrite_lines(struct emit_callback *ecb,
1572                               int prefix, const char *data, int size)
1573{
1574        const char *endp = NULL;
1575        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
1576
1577        while (0 < size) {
1578                int len;
1579
1580                endp = memchr(data, '\n', size);
1581                len = endp ? (endp - data + 1) : size;
1582                if (prefix != '+') {
1583                        ecb->lno_in_preimage++;
1584                        emit_del_line(reset, ecb, data, len);
1585                } else {
1586                        ecb->lno_in_postimage++;
1587                        emit_add_line(reset, ecb, data, len);
1588                }
1589                size -= len;
1590                data += len;
1591        }
1592        if (!endp)
1593                emit_diff_symbol(ecb->opt, DIFF_SYMBOL_NO_LF_EOF, NULL, 0, 0);
1594}
1595
1596static void emit_rewrite_diff(const char *name_a,
1597                              const char *name_b,
1598                              struct diff_filespec *one,
1599                              struct diff_filespec *two,
1600                              struct userdiff_driver *textconv_one,
1601                              struct userdiff_driver *textconv_two,
1602                              struct diff_options *o)
1603{
1604        int lc_a, lc_b;
1605        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
1606        const char *a_prefix, *b_prefix;
1607        char *data_one, *data_two;
1608        size_t size_one, size_two;
1609        struct emit_callback ecbdata;
1610        struct strbuf out = STRBUF_INIT;
1611
1612        if (diff_mnemonic_prefix && o->flags.reverse_diff) {
1613                a_prefix = o->b_prefix;
1614                b_prefix = o->a_prefix;
1615        } else {
1616                a_prefix = o->a_prefix;
1617                b_prefix = o->b_prefix;
1618        }
1619
1620        name_a += (*name_a == '/');
1621        name_b += (*name_b == '/');
1622
1623        strbuf_reset(&a_name);
1624        strbuf_reset(&b_name);
1625        quote_two_c_style(&a_name, a_prefix, name_a, 0);
1626        quote_two_c_style(&b_name, b_prefix, name_b, 0);
1627
1628        size_one = fill_textconv(textconv_one, one, &data_one);
1629        size_two = fill_textconv(textconv_two, two, &data_two);
1630
1631        memset(&ecbdata, 0, sizeof(ecbdata));
1632        ecbdata.color_diff = want_color(o->use_color);
1633        ecbdata.ws_rule = whitespace_rule(name_b);
1634        ecbdata.opt = o;
1635        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
1636                mmfile_t mf1, mf2;
1637                mf1.ptr = (char *)data_one;
1638                mf2.ptr = (char *)data_two;
1639                mf1.size = size_one;
1640                mf2.size = size_two;
1641                check_blank_at_eof(&mf1, &mf2, &ecbdata);
1642        }
1643        ecbdata.lno_in_preimage = 1;
1644        ecbdata.lno_in_postimage = 1;
1645
1646        lc_a = count_lines(data_one, size_one);
1647        lc_b = count_lines(data_two, size_two);
1648
1649        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
1650                         a_name.buf, a_name.len, 0);
1651        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
1652                         b_name.buf, b_name.len, 0);
1653
1654        strbuf_addstr(&out, "@@ -");
1655        if (!o->irreversible_delete)
1656                add_line_count(&out, lc_a);
1657        else
1658                strbuf_addstr(&out, "?,?");
1659        strbuf_addstr(&out, " +");
1660        add_line_count(&out, lc_b);
1661        strbuf_addstr(&out, " @@\n");
1662        emit_diff_symbol(o, DIFF_SYMBOL_REWRITE_DIFF, out.buf, out.len, 0);
1663        strbuf_release(&out);
1664
1665        if (lc_a && !o->irreversible_delete)
1666                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
1667        if (lc_b)
1668                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
1669        if (textconv_one)
1670                free((char *)data_one);
1671        if (textconv_two)
1672                free((char *)data_two);
1673}
1674
1675struct diff_words_buffer {
1676        mmfile_t text;
1677        unsigned long alloc;
1678        struct diff_words_orig {
1679                const char *begin, *end;
1680        } *orig;
1681        int orig_nr, orig_alloc;
1682};
1683
1684static void diff_words_append(char *line, unsigned long len,
1685                struct diff_words_buffer *buffer)
1686{
1687        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
1688        line++;
1689        len--;
1690        memcpy(buffer->text.ptr + buffer->text.size, line, len);
1691        buffer->text.size += len;
1692        buffer->text.ptr[buffer->text.size] = '\0';
1693}
1694
1695struct diff_words_style_elem {
1696        const char *prefix;
1697        const char *suffix;
1698        const char *color; /* NULL; filled in by the setup code if
1699                            * color is enabled */
1700};
1701
1702struct diff_words_style {
1703        enum diff_words_type type;
1704        struct diff_words_style_elem new_word, old_word, ctx;
1705        const char *newline;
1706};
1707
1708static struct diff_words_style diff_words_styles[] = {
1709        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
1710        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
1711        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
1712};
1713
1714struct diff_words_data {
1715        struct diff_words_buffer minus, plus;
1716        const char *current_plus;
1717        int last_minus;
1718        struct diff_options *opt;
1719        regex_t *word_regex;
1720        enum diff_words_type type;
1721        struct diff_words_style *style;
1722};
1723
1724static int fn_out_diff_words_write_helper(struct diff_options *o,
1725                                          struct diff_words_style_elem *st_el,
1726                                          const char *newline,
1727                                          size_t count, const char *buf)
1728{
1729        int print = 0;
1730        struct strbuf sb = STRBUF_INIT;
1731
1732        while (count) {
1733                char *p = memchr(buf, '\n', count);
1734                if (print)
1735                        strbuf_addstr(&sb, diff_line_prefix(o));
1736
1737                if (p != buf) {
1738                        const char *reset = st_el->color && *st_el->color ?
1739                                            GIT_COLOR_RESET : NULL;
1740                        if (st_el->color && *st_el->color)
1741                                strbuf_addstr(&sb, st_el->color);
1742                        strbuf_addstr(&sb, st_el->prefix);
1743                        strbuf_add(&sb, buf, p ? p - buf : count);
1744                        strbuf_addstr(&sb, st_el->suffix);
1745                        if (reset)
1746                                strbuf_addstr(&sb, reset);
1747                }
1748                if (!p)
1749                        goto out;
1750
1751                strbuf_addstr(&sb, newline);
1752                count -= p + 1 - buf;
1753                buf = p + 1;
1754                print = 1;
1755                if (count) {
1756                        emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1757                                         sb.buf, sb.len, 0);
1758                        strbuf_reset(&sb);
1759                }
1760        }
1761
1762out:
1763        if (sb.len)
1764                emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1765                                 sb.buf, sb.len, 0);
1766        strbuf_release(&sb);
1767        return 0;
1768}
1769
1770/*
1771 * '--color-words' algorithm can be described as:
1772 *
1773 *   1. collect the minus/plus lines of a diff hunk, divided into
1774 *      minus-lines and plus-lines;
1775 *
1776 *   2. break both minus-lines and plus-lines into words and
1777 *      place them into two mmfile_t with one word for each line;
1778 *
1779 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
1780 *
1781 * And for the common parts of the both file, we output the plus side text.
1782 * diff_words->current_plus is used to trace the current position of the plus file
1783 * which printed. diff_words->last_minus is used to trace the last minus word
1784 * printed.
1785 *
1786 * For '--graph' to work with '--color-words', we need to output the graph prefix
1787 * on each line of color words output. Generally, there are two conditions on
1788 * which we should output the prefix.
1789 *
1790 *   1. diff_words->last_minus == 0 &&
1791 *      diff_words->current_plus == diff_words->plus.text.ptr
1792 *
1793 *      that is: the plus text must start as a new line, and if there is no minus
1794 *      word printed, a graph prefix must be printed.
1795 *
1796 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
1797 *      *(diff_words->current_plus - 1) == '\n'
1798 *
1799 *      that is: a graph prefix must be printed following a '\n'
1800 */
1801static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
1802{
1803        if ((diff_words->last_minus == 0 &&
1804                diff_words->current_plus == diff_words->plus.text.ptr) ||
1805                (diff_words->current_plus > diff_words->plus.text.ptr &&
1806                *(diff_words->current_plus - 1) == '\n')) {
1807                return 1;
1808        } else {
1809                return 0;
1810        }
1811}
1812
1813static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
1814{
1815        struct diff_words_data *diff_words = priv;
1816        struct diff_words_style *style = diff_words->style;
1817        int minus_first, minus_len, plus_first, plus_len;
1818        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
1819        struct diff_options *opt = diff_words->opt;
1820        const char *line_prefix;
1821
1822        if (line[0] != '@' || parse_hunk_header(line, len,
1823                        &minus_first, &minus_len, &plus_first, &plus_len))
1824                return;
1825
1826        assert(opt);
1827        line_prefix = diff_line_prefix(opt);
1828
1829        /* POSIX requires that first be decremented by one if len == 0... */
1830        if (minus_len) {
1831                minus_begin = diff_words->minus.orig[minus_first].begin;
1832                minus_end =
1833                        diff_words->minus.orig[minus_first + minus_len - 1].end;
1834        } else
1835                minus_begin = minus_end =
1836                        diff_words->minus.orig[minus_first].end;
1837
1838        if (plus_len) {
1839                plus_begin = diff_words->plus.orig[plus_first].begin;
1840                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
1841        } else
1842                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
1843
1844        if (color_words_output_graph_prefix(diff_words)) {
1845                fputs(line_prefix, diff_words->opt->file);
1846        }
1847        if (diff_words->current_plus != plus_begin) {
1848                fn_out_diff_words_write_helper(diff_words->opt,
1849                                &style->ctx, style->newline,
1850                                plus_begin - diff_words->current_plus,
1851                                diff_words->current_plus);
1852        }
1853        if (minus_begin != minus_end) {
1854                fn_out_diff_words_write_helper(diff_words->opt,
1855                                &style->old_word, style->newline,
1856                                minus_end - minus_begin, minus_begin);
1857        }
1858        if (plus_begin != plus_end) {
1859                fn_out_diff_words_write_helper(diff_words->opt,
1860                                &style->new_word, style->newline,
1861                                plus_end - plus_begin, plus_begin);
1862        }
1863
1864        diff_words->current_plus = plus_end;
1865        diff_words->last_minus = minus_first;
1866}
1867
1868/* This function starts looking at *begin, and returns 0 iff a word was found. */
1869static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
1870                int *begin, int *end)
1871{
1872        if (word_regex && *begin < buffer->size) {
1873                regmatch_t match[1];
1874                if (!regexec_buf(word_regex, buffer->ptr + *begin,
1875                                 buffer->size - *begin, 1, match, 0)) {
1876                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
1877                                        '\n', match[0].rm_eo - match[0].rm_so);
1878                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
1879                        *begin += match[0].rm_so;
1880                        return *begin >= *end;
1881                }
1882                return -1;
1883        }
1884
1885        /* find the next word */
1886        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
1887                (*begin)++;
1888        if (*begin >= buffer->size)
1889                return -1;
1890
1891        /* find the end of the word */
1892        *end = *begin + 1;
1893        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
1894                (*end)++;
1895
1896        return 0;
1897}
1898
1899/*
1900 * This function splits the words in buffer->text, stores the list with
1901 * newline separator into out, and saves the offsets of the original words
1902 * in buffer->orig.
1903 */
1904static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
1905                regex_t *word_regex)
1906{
1907        int i, j;
1908        long alloc = 0;
1909
1910        out->size = 0;
1911        out->ptr = NULL;
1912
1913        /* fake an empty "0th" word */
1914        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
1915        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
1916        buffer->orig_nr = 1;
1917
1918        for (i = 0; i < buffer->text.size; i++) {
1919                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
1920                        return;
1921
1922                /* store original boundaries */
1923                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
1924                                buffer->orig_alloc);
1925                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
1926                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
1927                buffer->orig_nr++;
1928
1929                /* store one word */
1930                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
1931                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
1932                out->ptr[out->size + j - i] = '\n';
1933                out->size += j - i + 1;
1934
1935                i = j - 1;
1936        }
1937}
1938
1939/* this executes the word diff on the accumulated buffers */
1940static void diff_words_show(struct diff_words_data *diff_words)
1941{
1942        xpparam_t xpp;
1943        xdemitconf_t xecfg;
1944        mmfile_t minus, plus;
1945        struct diff_words_style *style = diff_words->style;
1946
1947        struct diff_options *opt = diff_words->opt;
1948        const char *line_prefix;
1949
1950        assert(opt);
1951        line_prefix = diff_line_prefix(opt);
1952
1953        /* special case: only removal */
1954        if (!diff_words->plus.text.size) {
1955                emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
1956                                 line_prefix, strlen(line_prefix), 0);
1957                fn_out_diff_words_write_helper(diff_words->opt,
1958                        &style->old_word, style->newline,
1959                        diff_words->minus.text.size,
1960                        diff_words->minus.text.ptr);
1961                diff_words->minus.text.size = 0;
1962                return;
1963        }
1964
1965        diff_words->current_plus = diff_words->plus.text.ptr;
1966        diff_words->last_minus = 0;
1967
1968        memset(&xpp, 0, sizeof(xpp));
1969        memset(&xecfg, 0, sizeof(xecfg));
1970        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
1971        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
1972        xpp.flags = 0;
1973        /* as only the hunk header will be parsed, we need a 0-context */
1974        xecfg.ctxlen = 0;
1975        if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
1976                          &xpp, &xecfg))
1977                die("unable to generate word diff");
1978        free(minus.ptr);
1979        free(plus.ptr);
1980        if (diff_words->current_plus != diff_words->plus.text.ptr +
1981                        diff_words->plus.text.size) {
1982                if (color_words_output_graph_prefix(diff_words))
1983                        emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
1984                                         line_prefix, strlen(line_prefix), 0);
1985                fn_out_diff_words_write_helper(diff_words->opt,
1986                        &style->ctx, style->newline,
1987                        diff_words->plus.text.ptr + diff_words->plus.text.size
1988                        - diff_words->current_plus, diff_words->current_plus);
1989        }
1990        diff_words->minus.text.size = diff_words->plus.text.size = 0;
1991}
1992
1993/* In "color-words" mode, show word-diff of words accumulated in the buffer */
1994static void diff_words_flush(struct emit_callback *ecbdata)
1995{
1996        struct diff_options *wo = ecbdata->diff_words->opt;
1997
1998        if (ecbdata->diff_words->minus.text.size ||
1999            ecbdata->diff_words->plus.text.size)
2000                diff_words_show(ecbdata->diff_words);
2001
2002        if (wo->emitted_symbols) {
2003                struct diff_options *o = ecbdata->opt;
2004                struct emitted_diff_symbols *wol = wo->emitted_symbols;
2005                int i;
2006
2007                /*
2008                 * NEEDSWORK:
2009                 * Instead of appending each, concat all words to a line?
2010                 */
2011                for (i = 0; i < wol->nr; i++)
2012                        append_emitted_diff_symbol(o, &wol->buf[i]);
2013
2014                for (i = 0; i < wol->nr; i++)
2015                        free((void *)wol->buf[i].line);
2016
2017                wol->nr = 0;
2018        }
2019}
2020
2021static void diff_filespec_load_driver(struct diff_filespec *one)
2022{
2023        /* Use already-loaded driver */
2024        if (one->driver)
2025                return;
2026
2027        if (S_ISREG(one->mode))
2028                one->driver = userdiff_find_by_path(one->path);
2029
2030        /* Fallback to default settings */
2031        if (!one->driver)
2032                one->driver = userdiff_find_by_name("default");
2033}
2034
2035static const char *userdiff_word_regex(struct diff_filespec *one)
2036{
2037        diff_filespec_load_driver(one);
2038        return one->driver->word_regex;
2039}
2040
2041static void init_diff_words_data(struct emit_callback *ecbdata,
2042                                 struct diff_options *orig_opts,
2043                                 struct diff_filespec *one,
2044                                 struct diff_filespec *two)
2045{
2046        int i;
2047        struct diff_options *o = xmalloc(sizeof(struct diff_options));
2048        memcpy(o, orig_opts, sizeof(struct diff_options));
2049
2050        ecbdata->diff_words =
2051                xcalloc(1, sizeof(struct diff_words_data));
2052        ecbdata->diff_words->type = o->word_diff;
2053        ecbdata->diff_words->opt = o;
2054
2055        if (orig_opts->emitted_symbols)
2056                o->emitted_symbols =
2057                        xcalloc(1, sizeof(struct emitted_diff_symbols));
2058
2059        if (!o->word_regex)
2060                o->word_regex = userdiff_word_regex(one);
2061        if (!o->word_regex)
2062                o->word_regex = userdiff_word_regex(two);
2063        if (!o->word_regex)
2064                o->word_regex = diff_word_regex_cfg;
2065        if (o->word_regex) {
2066                ecbdata->diff_words->word_regex = (regex_t *)
2067                        xmalloc(sizeof(regex_t));
2068                if (regcomp(ecbdata->diff_words->word_regex,
2069                            o->word_regex,
2070                            REG_EXTENDED | REG_NEWLINE))
2071                        die ("Invalid regular expression: %s",
2072                             o->word_regex);
2073        }
2074        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2075                if (o->word_diff == diff_words_styles[i].type) {
2076                        ecbdata->diff_words->style =
2077                                &diff_words_styles[i];
2078                        break;
2079                }
2080        }
2081        if (want_color(o->use_color)) {
2082                struct diff_words_style *st = ecbdata->diff_words->style;
2083                st->old_word.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2084                st->new_word.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2085                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
2086        }
2087}
2088
2089static void free_diff_words_data(struct emit_callback *ecbdata)
2090{
2091        if (ecbdata->diff_words) {
2092                diff_words_flush(ecbdata);
2093                free (ecbdata->diff_words->opt->emitted_symbols);
2094                free (ecbdata->diff_words->opt);
2095                free (ecbdata->diff_words->minus.text.ptr);
2096                free (ecbdata->diff_words->minus.orig);
2097                free (ecbdata->diff_words->plus.text.ptr);
2098                free (ecbdata->diff_words->plus.orig);
2099                if (ecbdata->diff_words->word_regex) {
2100                        regfree(ecbdata->diff_words->word_regex);
2101                        free(ecbdata->diff_words->word_regex);
2102                }
2103                FREE_AND_NULL(ecbdata->diff_words);
2104        }
2105}
2106
2107const char *diff_get_color(int diff_use_color, enum color_diff ix)
2108{
2109        if (want_color(diff_use_color))
2110                return diff_colors[ix];
2111        return "";
2112}
2113
2114const char *diff_line_prefix(struct diff_options *opt)
2115{
2116        struct strbuf *msgbuf;
2117        if (!opt->output_prefix)
2118                return "";
2119
2120        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
2121        return msgbuf->buf;
2122}
2123
2124static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
2125{
2126        const char *cp;
2127        unsigned long allot;
2128        size_t l = len;
2129
2130        cp = line;
2131        allot = l;
2132        while (0 < l) {
2133                (void) utf8_width(&cp, &l);
2134                if (!cp)
2135                        break; /* truncated in the middle? */
2136        }
2137        return allot - l;
2138}
2139
2140static void find_lno(const char *line, struct emit_callback *ecbdata)
2141{
2142        const char *p;
2143        ecbdata->lno_in_preimage = 0;
2144        ecbdata->lno_in_postimage = 0;
2145        p = strchr(line, '-');
2146        if (!p)
2147                return; /* cannot happen */
2148        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
2149        p = strchr(p, '+');
2150        if (!p)
2151                return; /* cannot happen */
2152        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
2153}
2154
2155static void fn_out_consume(void *priv, char *line, unsigned long len)
2156{
2157        struct emit_callback *ecbdata = priv;
2158        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
2159        struct diff_options *o = ecbdata->opt;
2160
2161        o->found_changes = 1;
2162
2163        if (ecbdata->header) {
2164                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
2165                                 ecbdata->header->buf, ecbdata->header->len, 0);
2166                strbuf_reset(ecbdata->header);
2167                ecbdata->header = NULL;
2168        }
2169
2170        if (ecbdata->label_path[0]) {
2171                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
2172                                 ecbdata->label_path[0],
2173                                 strlen(ecbdata->label_path[0]), 0);
2174                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
2175                                 ecbdata->label_path[1],
2176                                 strlen(ecbdata->label_path[1]), 0);
2177                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
2178        }
2179
2180        if (diff_suppress_blank_empty
2181            && len == 2 && line[0] == ' ' && line[1] == '\n') {
2182                line[0] = '\n';
2183                len = 1;
2184        }
2185
2186        if (line[0] == '@') {
2187                if (ecbdata->diff_words)
2188                        diff_words_flush(ecbdata);
2189                len = sane_truncate_line(ecbdata, line, len);
2190                find_lno(line, ecbdata);
2191                emit_hunk_header(ecbdata, line, len);
2192                return;
2193        }
2194
2195        if (ecbdata->diff_words) {
2196                enum diff_symbol s =
2197                        ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN ?
2198                        DIFF_SYMBOL_WORDS_PORCELAIN : DIFF_SYMBOL_WORDS;
2199                if (line[0] == '-') {
2200                        diff_words_append(line, len,
2201                                          &ecbdata->diff_words->minus);
2202                        return;
2203                } else if (line[0] == '+') {
2204                        diff_words_append(line, len,
2205                                          &ecbdata->diff_words->plus);
2206                        return;
2207                } else if (starts_with(line, "\\ ")) {
2208                        /*
2209                         * Eat the "no newline at eof" marker as if we
2210                         * saw a "+" or "-" line with nothing on it,
2211                         * and return without diff_words_flush() to
2212                         * defer processing. If this is the end of
2213                         * preimage, more "+" lines may come after it.
2214                         */
2215                        return;
2216                }
2217                diff_words_flush(ecbdata);
2218                emit_diff_symbol(o, s, line, len, 0);
2219                return;
2220        }
2221
2222        switch (line[0]) {
2223        case '+':
2224                ecbdata->lno_in_postimage++;
2225                emit_add_line(reset, ecbdata, line + 1, len - 1);
2226                break;
2227        case '-':
2228                ecbdata->lno_in_preimage++;
2229                emit_del_line(reset, ecbdata, line + 1, len - 1);
2230                break;
2231        case ' ':
2232                ecbdata->lno_in_postimage++;
2233                ecbdata->lno_in_preimage++;
2234                emit_context_line(reset, ecbdata, line + 1, len - 1);
2235                break;
2236        default:
2237                /* incomplete line at the end */
2238                ecbdata->lno_in_preimage++;
2239                emit_diff_symbol(o, DIFF_SYMBOL_CONTEXT_INCOMPLETE,
2240                                 line, len, 0);
2241                break;
2242        }
2243}
2244
2245static void pprint_rename(struct strbuf *name, const char *a, const char *b)
2246{
2247        const char *old_name = a;
2248        const char *new_name = b;
2249        int pfx_length, sfx_length;
2250        int pfx_adjust_for_slash;
2251        int len_a = strlen(a);
2252        int len_b = strlen(b);
2253        int a_midlen, b_midlen;
2254        int qlen_a = quote_c_style(a, NULL, NULL, 0);
2255        int qlen_b = quote_c_style(b, NULL, NULL, 0);
2256
2257        if (qlen_a || qlen_b) {
2258                quote_c_style(a, name, NULL, 0);
2259                strbuf_addstr(name, " => ");
2260                quote_c_style(b, name, NULL, 0);
2261                return;
2262        }
2263
2264        /* Find common prefix */
2265        pfx_length = 0;
2266        while (*old_name && *new_name && *old_name == *new_name) {
2267                if (*old_name == '/')
2268                        pfx_length = old_name - a + 1;
2269                old_name++;
2270                new_name++;
2271        }
2272
2273        /* Find common suffix */
2274        old_name = a + len_a;
2275        new_name = b + len_b;
2276        sfx_length = 0;
2277        /*
2278         * If there is a common prefix, it must end in a slash.  In
2279         * that case we let this loop run 1 into the prefix to see the
2280         * same slash.
2281         *
2282         * If there is no common prefix, we cannot do this as it would
2283         * underrun the input strings.
2284         */
2285        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
2286        while (a + pfx_length - pfx_adjust_for_slash <= old_name &&
2287               b + pfx_length - pfx_adjust_for_slash <= new_name &&
2288               *old_name == *new_name) {
2289                if (*old_name == '/')
2290                        sfx_length = len_a - (old_name - a);
2291                old_name--;
2292                new_name--;
2293        }
2294
2295        /*
2296         * pfx{mid-a => mid-b}sfx
2297         * {pfx-a => pfx-b}sfx
2298         * pfx{sfx-a => sfx-b}
2299         * name-a => name-b
2300         */
2301        a_midlen = len_a - pfx_length - sfx_length;
2302        b_midlen = len_b - pfx_length - sfx_length;
2303        if (a_midlen < 0)
2304                a_midlen = 0;
2305        if (b_midlen < 0)
2306                b_midlen = 0;
2307
2308        strbuf_grow(name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
2309        if (pfx_length + sfx_length) {
2310                strbuf_add(name, a, pfx_length);
2311                strbuf_addch(name, '{');
2312        }
2313        strbuf_add(name, a + pfx_length, a_midlen);
2314        strbuf_addstr(name, " => ");
2315        strbuf_add(name, b + pfx_length, b_midlen);
2316        if (pfx_length + sfx_length) {
2317                strbuf_addch(name, '}');
2318                strbuf_add(name, a + len_a - sfx_length, sfx_length);
2319        }
2320}
2321
2322struct diffstat_t {
2323        int nr;
2324        int alloc;
2325        struct diffstat_file {
2326                char *from_name;
2327                char *name;
2328                char *print_name;
2329                const char *comments;
2330                unsigned is_unmerged:1;
2331                unsigned is_binary:1;
2332                unsigned is_renamed:1;
2333                unsigned is_interesting:1;
2334                uintmax_t added, deleted;
2335        } **files;
2336};
2337
2338static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
2339                                          const char *name_a,
2340                                          const char *name_b)
2341{
2342        struct diffstat_file *x;
2343        x = xcalloc(1, sizeof(*x));
2344        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
2345        diffstat->files[diffstat->nr++] = x;
2346        if (name_b) {
2347                x->from_name = xstrdup(name_a);
2348                x->name = xstrdup(name_b);
2349                x->is_renamed = 1;
2350        }
2351        else {
2352                x->from_name = NULL;
2353                x->name = xstrdup(name_a);
2354        }
2355        return x;
2356}
2357
2358static void diffstat_consume(void *priv, char *line, unsigned long len)
2359{
2360        struct diffstat_t *diffstat = priv;
2361        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
2362
2363        if (line[0] == '+')
2364                x->added++;
2365        else if (line[0] == '-')
2366                x->deleted++;
2367}
2368
2369const char mime_boundary_leader[] = "------------";
2370
2371static int scale_linear(int it, int width, int max_change)
2372{
2373        if (!it)
2374                return 0;
2375        /*
2376         * make sure that at least one '-' or '+' is printed if
2377         * there is any change to this path. The easiest way is to
2378         * scale linearly as if the alloted width is one column shorter
2379         * than it is, and then add 1 to the result.
2380         */
2381        return 1 + (it * (width - 1) / max_change);
2382}
2383
2384static void show_graph(struct strbuf *out, char ch, int cnt,
2385                       const char *set, const char *reset)
2386{
2387        if (cnt <= 0)
2388                return;
2389        strbuf_addstr(out, set);
2390        strbuf_addchars(out, ch, cnt);
2391        strbuf_addstr(out, reset);
2392}
2393
2394static void fill_print_name(struct diffstat_file *file)
2395{
2396        struct strbuf pname = STRBUF_INIT;
2397
2398        if (file->print_name)
2399                return;
2400
2401        if (file->is_renamed)
2402                pprint_rename(&pname, file->from_name, file->name);
2403        else
2404                quote_c_style(file->name, &pname, NULL, 0);
2405
2406        if (file->comments)
2407                strbuf_addf(&pname, " (%s)", file->comments);
2408
2409        file->print_name = strbuf_detach(&pname, NULL);
2410}
2411
2412static void print_stat_summary_inserts_deletes(struct diff_options *options,
2413                int files, int insertions, int deletions)
2414{
2415        struct strbuf sb = STRBUF_INIT;
2416
2417        if (!files) {
2418                assert(insertions == 0 && deletions == 0);
2419                emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
2420                                 NULL, 0, 0);
2421                return;
2422        }
2423
2424        strbuf_addf(&sb,
2425                    (files == 1) ? " %d file changed" : " %d files changed",
2426                    files);
2427
2428        /*
2429         * For binary diff, the caller may want to print "x files
2430         * changed" with insertions == 0 && deletions == 0.
2431         *
2432         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
2433         * is probably less confusing (i.e skip over "2 files changed
2434         * but nothing about added/removed lines? Is this a bug in Git?").
2435         */
2436        if (insertions || deletions == 0) {
2437                strbuf_addf(&sb,
2438                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
2439                            insertions);
2440        }
2441
2442        if (deletions || insertions == 0) {
2443                strbuf_addf(&sb,
2444                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
2445                            deletions);
2446        }
2447        strbuf_addch(&sb, '\n');
2448        emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
2449                         sb.buf, sb.len, 0);
2450        strbuf_release(&sb);
2451}
2452
2453void print_stat_summary(FILE *fp, int files,
2454                        int insertions, int deletions)
2455{
2456        struct diff_options o;
2457        memset(&o, 0, sizeof(o));
2458        o.file = fp;
2459
2460        print_stat_summary_inserts_deletes(&o, files, insertions, deletions);
2461}
2462
2463static void show_stats(struct diffstat_t *data, struct diff_options *options)
2464{
2465        int i, len, add, del, adds = 0, dels = 0;
2466        uintmax_t max_change = 0, max_len = 0;
2467        int total_files = data->nr, count;
2468        int width, name_width, graph_width, number_width = 0, bin_width = 0;
2469        const char *reset, *add_c, *del_c;
2470        int extra_shown = 0;
2471        const char *line_prefix = diff_line_prefix(options);
2472        struct strbuf out = STRBUF_INIT;
2473
2474        if (data->nr == 0)
2475                return;
2476
2477        count = options->stat_count ? options->stat_count : data->nr;
2478
2479        reset = diff_get_color_opt(options, DIFF_RESET);
2480        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
2481        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
2482
2483        /*
2484         * Find the longest filename and max number of changes
2485         */
2486        for (i = 0; (i < count) && (i < data->nr); i++) {
2487                struct diffstat_file *file = data->files[i];
2488                uintmax_t change = file->added + file->deleted;
2489
2490                if (!file->is_interesting && (change == 0)) {
2491                        count++; /* not shown == room for one more */
2492                        continue;
2493                }
2494                fill_print_name(file);
2495                len = strlen(file->print_name);
2496                if (max_len < len)
2497                        max_len = len;
2498
2499                if (file->is_unmerged) {
2500                        /* "Unmerged" is 8 characters */
2501                        bin_width = bin_width < 8 ? 8 : bin_width;
2502                        continue;
2503                }
2504                if (file->is_binary) {
2505                        /* "Bin XXX -> YYY bytes" */
2506                        int w = 14 + decimal_width(file->added)
2507                                + decimal_width(file->deleted);
2508                        bin_width = bin_width < w ? w : bin_width;
2509                        /* Display change counts aligned with "Bin" */
2510                        number_width = 3;
2511                        continue;
2512                }
2513
2514                if (max_change < change)
2515                        max_change = change;
2516        }
2517        count = i; /* where we can stop scanning in data->files[] */
2518
2519        /*
2520         * We have width = stat_width or term_columns() columns total.
2521         * We want a maximum of min(max_len, stat_name_width) for the name part.
2522         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
2523         * We also need 1 for " " and 4 + decimal_width(max_change)
2524         * for " | NNNN " and one the empty column at the end, altogether
2525         * 6 + decimal_width(max_change).
2526         *
2527         * If there's not enough space, we will use the smaller of
2528         * stat_name_width (if set) and 5/8*width for the filename,
2529         * and the rest for constant elements + graph part, but no more
2530         * than stat_graph_width for the graph part.
2531         * (5/8 gives 50 for filename and 30 for the constant parts + graph
2532         * for the standard terminal size).
2533         *
2534         * In other words: stat_width limits the maximum width, and
2535         * stat_name_width fixes the maximum width of the filename,
2536         * and is also used to divide available columns if there
2537         * aren't enough.
2538         *
2539         * Binary files are displayed with "Bin XXX -> YYY bytes"
2540         * instead of the change count and graph. This part is treated
2541         * similarly to the graph part, except that it is not
2542         * "scaled". If total width is too small to accommodate the
2543         * guaranteed minimum width of the filename part and the
2544         * separators and this message, this message will "overflow"
2545         * making the line longer than the maximum width.
2546         */
2547
2548        if (options->stat_width == -1)
2549                width = term_columns() - strlen(line_prefix);
2550        else
2551                width = options->stat_width ? options->stat_width : 80;
2552        number_width = decimal_width(max_change) > number_width ?
2553                decimal_width(max_change) : number_width;
2554
2555        if (options->stat_graph_width == -1)
2556                options->stat_graph_width = diff_stat_graph_width;
2557
2558        /*
2559         * Guarantee 3/8*16==6 for the graph part
2560         * and 5/8*16==10 for the filename part
2561         */
2562        if (width < 16 + 6 + number_width)
2563                width = 16 + 6 + number_width;
2564
2565        /*
2566         * First assign sizes that are wanted, ignoring available width.
2567         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
2568         * starting from "XXX" should fit in graph_width.
2569         */
2570        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
2571        if (options->stat_graph_width &&
2572            options->stat_graph_width < graph_width)
2573                graph_width = options->stat_graph_width;
2574
2575        name_width = (options->stat_name_width > 0 &&
2576                      options->stat_name_width < max_len) ?
2577                options->stat_name_width : max_len;
2578
2579        /*
2580         * Adjust adjustable widths not to exceed maximum width
2581         */
2582        if (name_width + number_width + 6 + graph_width > width) {
2583                if (graph_width > width * 3/8 - number_width - 6) {
2584                        graph_width = width * 3/8 - number_width - 6;
2585                        if (graph_width < 6)
2586                                graph_width = 6;
2587                }
2588
2589                if (options->stat_graph_width &&
2590                    graph_width > options->stat_graph_width)
2591                        graph_width = options->stat_graph_width;
2592                if (name_width > width - number_width - 6 - graph_width)
2593                        name_width = width - number_width - 6 - graph_width;
2594                else
2595                        graph_width = width - number_width - 6 - name_width;
2596        }
2597
2598        /*
2599         * From here name_width is the width of the name area,
2600         * and graph_width is the width of the graph area.
2601         * max_change is used to scale graph properly.
2602         */
2603        for (i = 0; i < count; i++) {
2604                const char *prefix = "";
2605                struct diffstat_file *file = data->files[i];
2606                char *name = file->print_name;
2607                uintmax_t added = file->added;
2608                uintmax_t deleted = file->deleted;
2609                int name_len;
2610
2611                if (!file->is_interesting && (added + deleted == 0))
2612                        continue;
2613
2614                /*
2615                 * "scale" the filename
2616                 */
2617                len = name_width;
2618                name_len = strlen(name);
2619                if (name_width < name_len) {
2620                        char *slash;
2621                        prefix = "...";
2622                        len -= 3;
2623                        name += name_len - len;
2624                        slash = strchr(name, '/');
2625                        if (slash)
2626                                name = slash;
2627                }
2628
2629                if (file->is_binary) {
2630                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2631                        strbuf_addf(&out, " %*s", number_width, "Bin");
2632                        if (!added && !deleted) {
2633                                strbuf_addch(&out, '\n');
2634                                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2635                                                 out.buf, out.len, 0);
2636                                strbuf_reset(&out);
2637                                continue;
2638                        }
2639                        strbuf_addf(&out, " %s%"PRIuMAX"%s",
2640                                del_c, deleted, reset);
2641                        strbuf_addstr(&out, " -> ");
2642                        strbuf_addf(&out, "%s%"PRIuMAX"%s",
2643                                add_c, added, reset);
2644                        strbuf_addstr(&out, " bytes\n");
2645                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2646                                         out.buf, out.len, 0);
2647                        strbuf_reset(&out);
2648                        continue;
2649                }
2650                else if (file->is_unmerged) {
2651                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2652                        strbuf_addstr(&out, " Unmerged\n");
2653                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2654                                         out.buf, out.len, 0);
2655                        strbuf_reset(&out);
2656                        continue;
2657                }
2658
2659                /*
2660                 * scale the add/delete
2661                 */
2662                add = added;
2663                del = deleted;
2664
2665                if (graph_width <= max_change) {
2666                        int total = scale_linear(add + del, graph_width, max_change);
2667                        if (total < 2 && add && del)
2668                                /* width >= 2 due to the sanity check */
2669                                total = 2;
2670                        if (add < del) {
2671                                add = scale_linear(add, graph_width, max_change);
2672                                del = total - add;
2673                        } else {
2674                                del = scale_linear(del, graph_width, max_change);
2675                                add = total - del;
2676                        }
2677                }
2678                strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2679                strbuf_addf(&out, " %*"PRIuMAX"%s",
2680                        number_width, added + deleted,
2681                        added + deleted ? " " : "");
2682                show_graph(&out, '+', add, add_c, reset);
2683                show_graph(&out, '-', del, del_c, reset);
2684                strbuf_addch(&out, '\n');
2685                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2686                                 out.buf, out.len, 0);
2687                strbuf_reset(&out);
2688        }
2689
2690        for (i = 0; i < data->nr; i++) {
2691                struct diffstat_file *file = data->files[i];
2692                uintmax_t added = file->added;
2693                uintmax_t deleted = file->deleted;
2694
2695                if (file->is_unmerged ||
2696                    (!file->is_interesting && (added + deleted == 0))) {
2697                        total_files--;
2698                        continue;
2699                }
2700
2701                if (!file->is_binary) {
2702                        adds += added;
2703                        dels += deleted;
2704                }
2705                if (i < count)
2706                        continue;
2707                if (!extra_shown)
2708                        emit_diff_symbol(options,
2709                                         DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
2710                                         NULL, 0, 0);
2711                extra_shown = 1;
2712        }
2713
2714        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2715        strbuf_release(&out);
2716}
2717
2718static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
2719{
2720        int i, adds = 0, dels = 0, total_files = data->nr;
2721
2722        if (data->nr == 0)
2723                return;
2724
2725        for (i = 0; i < data->nr; i++) {
2726                int added = data->files[i]->added;
2727                int deleted = data->files[i]->deleted;
2728
2729                if (data->files[i]->is_unmerged ||
2730                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
2731                        total_files--;
2732                } else if (!data->files[i]->is_binary) { /* don't count bytes */
2733                        adds += added;
2734                        dels += deleted;
2735                }
2736        }
2737        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2738}
2739
2740static void show_numstat(struct diffstat_t *data, struct diff_options *options)
2741{
2742        int i;
2743
2744        if (data->nr == 0)
2745                return;
2746
2747        for (i = 0; i < data->nr; i++) {
2748                struct diffstat_file *file = data->files[i];
2749
2750                fprintf(options->file, "%s", diff_line_prefix(options));
2751
2752                if (file->is_binary)
2753                        fprintf(options->file, "-\t-\t");
2754                else
2755                        fprintf(options->file,
2756                                "%"PRIuMAX"\t%"PRIuMAX"\t",
2757                                file->added, file->deleted);
2758                if (options->line_termination) {
2759                        fill_print_name(file);
2760                        if (!file->is_renamed)
2761                                write_name_quoted(file->name, options->file,
2762                                                  options->line_termination);
2763                        else {
2764                                fputs(file->print_name, options->file);
2765                                putc(options->line_termination, options->file);
2766                        }
2767                } else {
2768                        if (file->is_renamed) {
2769                                putc('\0', options->file);
2770                                write_name_quoted(file->from_name, options->file, '\0');
2771                        }
2772                        write_name_quoted(file->name, options->file, '\0');
2773                }
2774        }
2775}
2776
2777struct dirstat_file {
2778        const char *name;
2779        unsigned long changed;
2780};
2781
2782struct dirstat_dir {
2783        struct dirstat_file *files;
2784        int alloc, nr, permille, cumulative;
2785};
2786
2787static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
2788                unsigned long changed, const char *base, int baselen)
2789{
2790        unsigned long sum_changes = 0;
2791        unsigned int sources = 0;
2792        const char *line_prefix = diff_line_prefix(opt);
2793
2794        while (dir->nr) {
2795                struct dirstat_file *f = dir->files;
2796                int namelen = strlen(f->name);
2797                unsigned long changes;
2798                char *slash;
2799
2800                if (namelen < baselen)
2801                        break;
2802                if (memcmp(f->name, base, baselen))
2803                        break;
2804                slash = strchr(f->name + baselen, '/');
2805                if (slash) {
2806                        int newbaselen = slash + 1 - f->name;
2807                        changes = gather_dirstat(opt, dir, changed, f->name, newbaselen);
2808                        sources++;
2809                } else {
2810                        changes = f->changed;
2811                        dir->files++;
2812                        dir->nr--;
2813                        sources += 2;
2814                }
2815                sum_changes += changes;
2816        }
2817
2818        /*
2819         * We don't report dirstat's for
2820         *  - the top level
2821         *  - or cases where everything came from a single directory
2822         *    under this directory (sources == 1).
2823         */
2824        if (baselen && sources != 1) {
2825                if (sum_changes) {
2826                        int permille = sum_changes * 1000 / changed;
2827                        if (permille >= dir->permille) {
2828                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
2829                                        permille / 10, permille % 10, baselen, base);
2830                                if (!dir->cumulative)
2831                                        return 0;
2832                        }
2833                }
2834        }
2835        return sum_changes;
2836}
2837
2838static int dirstat_compare(const void *_a, const void *_b)
2839{
2840        const struct dirstat_file *a = _a;
2841        const struct dirstat_file *b = _b;
2842        return strcmp(a->name, b->name);
2843}
2844
2845static void show_dirstat(struct diff_options *options)
2846{
2847        int i;
2848        unsigned long changed;
2849        struct dirstat_dir dir;
2850        struct diff_queue_struct *q = &diff_queued_diff;
2851
2852        dir.files = NULL;
2853        dir.alloc = 0;
2854        dir.nr = 0;
2855        dir.permille = options->dirstat_permille;
2856        dir.cumulative = options->flags.dirstat_cumulative;
2857
2858        changed = 0;
2859        for (i = 0; i < q->nr; i++) {
2860                struct diff_filepair *p = q->queue[i];
2861                const char *name;
2862                unsigned long copied, added, damage;
2863                int content_changed;
2864
2865                name = p->two->path ? p->two->path : p->one->path;
2866
2867                if (p->one->oid_valid && p->two->oid_valid)
2868                        content_changed = oidcmp(&p->one->oid, &p->two->oid);
2869                else
2870                        content_changed = 1;
2871
2872                if (!content_changed) {
2873                        /*
2874                         * The SHA1 has not changed, so pre-/post-content is
2875                         * identical. We can therefore skip looking at the
2876                         * file contents altogether.
2877                         */
2878                        damage = 0;
2879                        goto found_damage;
2880                }
2881
2882                if (options->flags.dirstat_by_file) {
2883                        /*
2884                         * In --dirstat-by-file mode, we don't really need to
2885                         * look at the actual file contents at all.
2886                         * The fact that the SHA1 changed is enough for us to
2887                         * add this file to the list of results
2888                         * (with each file contributing equal damage).
2889                         */
2890                        damage = 1;
2891                        goto found_damage;
2892                }
2893
2894                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
2895                        diff_populate_filespec(p->one, 0);
2896                        diff_populate_filespec(p->two, 0);
2897                        diffcore_count_changes(p->one, p->two, NULL, NULL,
2898                                               &copied, &added);
2899                        diff_free_filespec_data(p->one);
2900                        diff_free_filespec_data(p->two);
2901                } else if (DIFF_FILE_VALID(p->one)) {
2902                        diff_populate_filespec(p->one, CHECK_SIZE_ONLY);
2903                        copied = added = 0;
2904                        diff_free_filespec_data(p->one);
2905                } else if (DIFF_FILE_VALID(p->two)) {
2906                        diff_populate_filespec(p->two, CHECK_SIZE_ONLY);
2907                        copied = 0;
2908                        added = p->two->size;
2909                        diff_free_filespec_data(p->two);
2910                } else
2911                        continue;
2912
2913                /*
2914                 * Original minus copied is the removed material,
2915                 * added is the new material.  They are both damages
2916                 * made to the preimage.
2917                 * If the resulting damage is zero, we know that
2918                 * diffcore_count_changes() considers the two entries to
2919                 * be identical, but since content_changed is true, we
2920                 * know that there must have been _some_ kind of change,
2921                 * so we force all entries to have damage > 0.
2922                 */
2923                damage = (p->one->size - copied) + added;
2924                if (!damage)
2925                        damage = 1;
2926
2927found_damage:
2928                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
2929                dir.files[dir.nr].name = name;
2930                dir.files[dir.nr].changed = damage;
2931                changed += damage;
2932                dir.nr++;
2933        }
2934
2935        /* This can happen even with many files, if everything was renames */
2936        if (!changed)
2937                return;
2938
2939        /* Show all directories with more than x% of the changes */
2940        QSORT(dir.files, dir.nr, dirstat_compare);
2941        gather_dirstat(options, &dir, changed, "", 0);
2942}
2943
2944static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
2945{
2946        int i;
2947        unsigned long changed;
2948        struct dirstat_dir dir;
2949
2950        if (data->nr == 0)
2951                return;
2952
2953        dir.files = NULL;
2954        dir.alloc = 0;
2955        dir.nr = 0;
2956        dir.permille = options->dirstat_permille;
2957        dir.cumulative = options->flags.dirstat_cumulative;
2958
2959        changed = 0;
2960        for (i = 0; i < data->nr; i++) {
2961                struct diffstat_file *file = data->files[i];
2962                unsigned long damage = file->added + file->deleted;
2963                if (file->is_binary)
2964                        /*
2965                         * binary files counts bytes, not lines. Must find some
2966                         * way to normalize binary bytes vs. textual lines.
2967                         * The following heuristic assumes that there are 64
2968                         * bytes per "line".
2969                         * This is stupid and ugly, but very cheap...
2970                         */
2971                        damage = DIV_ROUND_UP(damage, 64);
2972                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
2973                dir.files[dir.nr].name = file->name;
2974                dir.files[dir.nr].changed = damage;
2975                changed += damage;
2976                dir.nr++;
2977        }
2978
2979        /* This can happen even with many files, if everything was renames */
2980        if (!changed)
2981                return;
2982
2983        /* Show all directories with more than x% of the changes */
2984        QSORT(dir.files, dir.nr, dirstat_compare);
2985        gather_dirstat(options, &dir, changed, "", 0);
2986}
2987
2988static void free_diffstat_info(struct diffstat_t *diffstat)
2989{
2990        int i;
2991        for (i = 0; i < diffstat->nr; i++) {
2992                struct diffstat_file *f = diffstat->files[i];
2993                free(f->print_name);
2994                free(f->name);
2995                free(f->from_name);
2996                free(f);
2997        }
2998        free(diffstat->files);
2999}
3000
3001struct checkdiff_t {
3002        const char *filename;
3003        int lineno;
3004        int conflict_marker_size;
3005        struct diff_options *o;
3006        unsigned ws_rule;
3007        unsigned status;
3008};
3009
3010static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
3011{
3012        char firstchar;
3013        int cnt;
3014
3015        if (len < marker_size + 1)
3016                return 0;
3017        firstchar = line[0];
3018        switch (firstchar) {
3019        case '=': case '>': case '<': case '|':
3020                break;
3021        default:
3022                return 0;
3023        }
3024        for (cnt = 1; cnt < marker_size; cnt++)
3025                if (line[cnt] != firstchar)
3026                        return 0;
3027        /* line[1] thru line[marker_size-1] are same as firstchar */
3028        if (len < marker_size + 1 || !isspace(line[marker_size]))
3029                return 0;
3030        return 1;
3031}
3032
3033static void checkdiff_consume(void *priv, char *line, unsigned long len)
3034{
3035        struct checkdiff_t *data = priv;
3036        int marker_size = data->conflict_marker_size;
3037        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
3038        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
3039        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
3040        char *err;
3041        const char *line_prefix;
3042
3043        assert(data->o);
3044        line_prefix = diff_line_prefix(data->o);
3045
3046        if (line[0] == '+') {
3047                unsigned bad;
3048                data->lineno++;
3049                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
3050                        data->status |= 1;
3051                        fprintf(data->o->file,
3052                                "%s%s:%d: leftover conflict marker\n",
3053                                line_prefix, data->filename, data->lineno);
3054                }
3055                bad = ws_check(line + 1, len - 1, data->ws_rule);
3056                if (!bad)
3057                        return;
3058                data->status |= bad;
3059                err = whitespace_error_string(bad);
3060                fprintf(data->o->file, "%s%s:%d: %s.\n",
3061                        line_prefix, data->filename, data->lineno, err);
3062                free(err);
3063                emit_line(data->o, set, reset, line, 1);
3064                ws_check_emit(line + 1, len - 1, data->ws_rule,
3065                              data->o->file, set, reset, ws);
3066        } else if (line[0] == ' ') {
3067                data->lineno++;
3068        } else if (line[0] == '@') {
3069                char *plus = strchr(line, '+');
3070                if (plus)
3071                        data->lineno = strtol(plus, NULL, 10) - 1;
3072                else
3073                        die("invalid diff");
3074        }
3075}
3076
3077static unsigned char *deflate_it(char *data,
3078                                 unsigned long size,
3079                                 unsigned long *result_size)
3080{
3081        int bound;
3082        unsigned char *deflated;
3083        git_zstream stream;
3084
3085        git_deflate_init(&stream, zlib_compression_level);
3086        bound = git_deflate_bound(&stream, size);
3087        deflated = xmalloc(bound);
3088        stream.next_out = deflated;
3089        stream.avail_out = bound;
3090
3091        stream.next_in = (unsigned char *)data;
3092        stream.avail_in = size;
3093        while (git_deflate(&stream, Z_FINISH) == Z_OK)
3094                ; /* nothing */
3095        git_deflate_end(&stream);
3096        *result_size = stream.total_out;
3097        return deflated;
3098}
3099
3100static void emit_binary_diff_body(struct diff_options *o,
3101                                  mmfile_t *one, mmfile_t *two)
3102{
3103        void *cp;
3104        void *delta;
3105        void *deflated;
3106        void *data;
3107        unsigned long orig_size;
3108        unsigned long delta_size;
3109        unsigned long deflate_size;
3110        unsigned long data_size;
3111
3112        /* We could do deflated delta, or we could do just deflated two,
3113         * whichever is smaller.
3114         */
3115        delta = NULL;
3116        deflated = deflate_it(two->ptr, two->size, &deflate_size);
3117        if (one->size && two->size) {
3118                delta = diff_delta(one->ptr, one->size,
3119                                   two->ptr, two->size,
3120                                   &delta_size, deflate_size);
3121                if (delta) {
3122                        void *to_free = delta;
3123                        orig_size = delta_size;
3124                        delta = deflate_it(delta, delta_size, &delta_size);
3125                        free(to_free);
3126                }
3127        }
3128
3129        if (delta && delta_size < deflate_size) {
3130                char *s = xstrfmt("%lu", orig_size);
3131                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
3132                                 s, strlen(s), 0);
3133                free(s);
3134                free(deflated);
3135                data = delta;
3136                data_size = delta_size;
3137        } else {
3138                char *s = xstrfmt("%lu", two->size);
3139                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
3140                                 s, strlen(s), 0);
3141                free(s);
3142                free(delta);
3143                data = deflated;
3144                data_size = deflate_size;
3145        }
3146
3147        /* emit data encoded in base85 */
3148        cp = data;
3149        while (data_size) {
3150                int len;
3151                int bytes = (52 < data_size) ? 52 : data_size;
3152                char line[71];
3153                data_size -= bytes;
3154                if (bytes <= 26)
3155                        line[0] = bytes + 'A' - 1;
3156                else
3157                        line[0] = bytes - 26 + 'a' - 1;
3158                encode_85(line + 1, cp, bytes);
3159                cp = (char *) cp + bytes;
3160
3161                len = strlen(line);
3162                line[len++] = '\n';
3163                line[len] = '\0';
3164
3165                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_BODY,
3166                                 line, len, 0);
3167        }
3168        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_FOOTER, NULL, 0, 0);
3169        free(data);
3170}
3171
3172static void emit_binary_diff(struct diff_options *o,
3173                             mmfile_t *one, mmfile_t *two)
3174{
3175        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER, NULL, 0, 0);
3176        emit_binary_diff_body(o, one, two);
3177        emit_binary_diff_body(o, two, one);
3178}
3179
3180int diff_filespec_is_binary(struct diff_filespec *one)
3181{
3182        if (one->is_binary == -1) {
3183                diff_filespec_load_driver(one);
3184                if (one->driver->binary != -1)
3185                        one->is_binary = one->driver->binary;
3186                else {
3187                        if (!one->data && DIFF_FILE_VALID(one))
3188                                diff_populate_filespec(one, CHECK_BINARY);
3189                        if (one->is_binary == -1 && one->data)
3190                                one->is_binary = buffer_is_binary(one->data,
3191                                                one->size);
3192                        if (one->is_binary == -1)
3193                                one->is_binary = 0;
3194                }
3195        }
3196        return one->is_binary;
3197}
3198
3199static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
3200{
3201        diff_filespec_load_driver(one);
3202        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
3203}
3204
3205void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
3206{
3207        if (!options->a_prefix)
3208                options->a_prefix = a;
3209        if (!options->b_prefix)
3210                options->b_prefix = b;
3211}
3212
3213struct userdiff_driver *get_textconv(struct diff_filespec *one)
3214{
3215        if (!DIFF_FILE_VALID(one))
3216                return NULL;
3217
3218        diff_filespec_load_driver(one);
3219        return userdiff_get_textconv(one->driver);
3220}
3221
3222static void builtin_diff(const char *name_a,
3223                         const char *name_b,
3224                         struct diff_filespec *one,
3225                         struct diff_filespec *two,
3226                         const char *xfrm_msg,
3227                         int must_show_header,
3228                         struct diff_options *o,
3229                         int complete_rewrite)
3230{
3231        mmfile_t mf1, mf2;
3232        const char *lbl[2];
3233        char *a_one, *b_two;
3234        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
3235        const char *reset = diff_get_color_opt(o, DIFF_RESET);
3236        const char *a_prefix, *b_prefix;
3237        struct userdiff_driver *textconv_one = NULL;
3238        struct userdiff_driver *textconv_two = NULL;
3239        struct strbuf header = STRBUF_INIT;
3240        const char *line_prefix = diff_line_prefix(o);
3241
3242        diff_set_mnemonic_prefix(o, "a/", "b/");
3243        if (o->flags.reverse_diff) {
3244                a_prefix = o->b_prefix;
3245                b_prefix = o->a_prefix;
3246        } else {
3247                a_prefix = o->a_prefix;
3248                b_prefix = o->b_prefix;
3249        }
3250
3251        if (o->submodule_format == DIFF_SUBMODULE_LOG &&
3252            (!one->mode || S_ISGITLINK(one->mode)) &&
3253            (!two->mode || S_ISGITLINK(two->mode))) {
3254                show_submodule_summary(o, one->path ? one->path : two->path,
3255                                &one->oid, &two->oid,
3256                                two->dirty_submodule);
3257                return;
3258        } else if (o->submodule_format == DIFF_SUBMODULE_INLINE_DIFF &&
3259                   (!one->mode || S_ISGITLINK(one->mode)) &&
3260                   (!two->mode || S_ISGITLINK(two->mode))) {
3261                show_submodule_inline_diff(o, one->path ? one->path : two->path,
3262                                &one->oid, &two->oid,
3263                                two->dirty_submodule);
3264                return;
3265        }
3266
3267        if (o->flags.allow_textconv) {
3268                textconv_one = get_textconv(one);
3269                textconv_two = get_textconv(two);
3270        }
3271
3272        /* Never use a non-valid filename anywhere if at all possible */
3273        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
3274        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
3275
3276        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
3277        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
3278        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
3279        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
3280        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
3281        if (lbl[0][0] == '/') {
3282                /* /dev/null */
3283                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
3284                if (xfrm_msg)
3285                        strbuf_addstr(&header, xfrm_msg);
3286                must_show_header = 1;
3287        }
3288        else if (lbl[1][0] == '/') {
3289                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
3290                if (xfrm_msg)
3291                        strbuf_addstr(&header, xfrm_msg);
3292                must_show_header = 1;
3293        }
3294        else {
3295                if (one->mode != two->mode) {
3296                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
3297                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
3298                        must_show_header = 1;
3299                }
3300                if (xfrm_msg)
3301                        strbuf_addstr(&header, xfrm_msg);
3302
3303                /*
3304                 * we do not run diff between different kind
3305                 * of objects.
3306                 */
3307                if ((one->mode ^ two->mode) & S_IFMT)
3308                        goto free_ab_and_return;
3309                if (complete_rewrite &&
3310                    (textconv_one || !diff_filespec_is_binary(one)) &&
3311                    (textconv_two || !diff_filespec_is_binary(two))) {
3312                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3313                                         header.buf, header.len, 0);
3314                        strbuf_reset(&header);
3315                        emit_rewrite_diff(name_a, name_b, one, two,
3316                                                textconv_one, textconv_two, o);
3317                        o->found_changes = 1;
3318                        goto free_ab_and_return;
3319                }
3320        }
3321
3322        if (o->irreversible_delete && lbl[1][0] == '/') {
3323                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf,
3324                                 header.len, 0);
3325                strbuf_reset(&header);
3326                goto free_ab_and_return;
3327        } else if (!o->flags.text &&
3328            ( (!textconv_one && diff_filespec_is_binary(one)) ||
3329              (!textconv_two && diff_filespec_is_binary(two)) )) {
3330                struct strbuf sb = STRBUF_INIT;
3331                if (!one->data && !two->data &&
3332                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
3333                    !o->flags.binary) {
3334                        if (!oidcmp(&one->oid, &two->oid)) {
3335                                if (must_show_header)
3336                                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3337                                                         header.buf, header.len,
3338                                                         0);
3339                                goto free_ab_and_return;
3340                        }
3341                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3342                                         header.buf, header.len, 0);
3343                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3344                                    diff_line_prefix(o), lbl[0], lbl[1]);
3345                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3346                                         sb.buf, sb.len, 0);
3347                        strbuf_release(&sb);
3348                        goto free_ab_and_return;
3349                }
3350                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3351                        die("unable to read files to diff");
3352                /* Quite common confusing case */
3353                if (mf1.size == mf2.size &&
3354                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
3355                        if (must_show_header)
3356                                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3357                                                 header.buf, header.len, 0);
3358                        goto free_ab_and_return;
3359                }
3360                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf, header.len, 0);
3361                strbuf_reset(&header);
3362                if (o->flags.binary)
3363                        emit_binary_diff(o, &mf1, &mf2);
3364                else {
3365                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3366                                    diff_line_prefix(o), lbl[0], lbl[1]);
3367                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3368                                         sb.buf, sb.len, 0);
3369                        strbuf_release(&sb);
3370                }
3371                o->found_changes = 1;
3372        } else {
3373                /* Crazy xdl interfaces.. */
3374                const char *diffopts = getenv("GIT_DIFF_OPTS");
3375                const char *v;
3376                xpparam_t xpp;
3377                xdemitconf_t xecfg;
3378                struct emit_callback ecbdata;
3379                const struct userdiff_funcname *pe;
3380
3381                if (must_show_header) {
3382                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3383                                         header.buf, header.len, 0);
3384                        strbuf_reset(&header);
3385                }
3386
3387                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
3388                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
3389
3390                pe = diff_funcname_pattern(one);
3391                if (!pe)
3392                        pe = diff_funcname_pattern(two);
3393
3394                memset(&xpp, 0, sizeof(xpp));
3395                memset(&xecfg, 0, sizeof(xecfg));
3396                memset(&ecbdata, 0, sizeof(ecbdata));
3397                ecbdata.label_path = lbl;
3398                ecbdata.color_diff = want_color(o->use_color);
3399                ecbdata.ws_rule = whitespace_rule(name_b);
3400                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
3401                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3402                ecbdata.opt = o;
3403                ecbdata.header = header.len ? &header : NULL;
3404                xpp.flags = o->xdl_opts;
3405                xpp.anchors = o->anchors;
3406                xpp.anchors_nr = o->anchors_nr;
3407                xecfg.ctxlen = o->context;
3408                xecfg.interhunkctxlen = o->interhunkcontext;
3409                xecfg.flags = XDL_EMIT_FUNCNAMES;
3410                if (o->flags.funccontext)
3411                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
3412                if (pe)
3413                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
3414                if (!diffopts)
3415                        ;
3416                else if (skip_prefix(diffopts, "--unified=", &v))
3417                        xecfg.ctxlen = strtoul(v, NULL, 10);
3418                else if (skip_prefix(diffopts, "-u", &v))
3419                        xecfg.ctxlen = strtoul(v, NULL, 10);
3420                if (o->word_diff)
3421                        init_diff_words_data(&ecbdata, o, one, two);
3422                if (xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
3423                                  &xpp, &xecfg))
3424                        die("unable to generate diff for %s", one->path);
3425                if (o->word_diff)
3426                        free_diff_words_data(&ecbdata);
3427                if (textconv_one)
3428                        free(mf1.ptr);
3429                if (textconv_two)
3430                        free(mf2.ptr);
3431                xdiff_clear_find_func(&xecfg);
3432        }
3433
3434 free_ab_and_return:
3435        strbuf_release(&header);
3436        diff_free_filespec_data(one);
3437        diff_free_filespec_data(two);
3438        free(a_one);
3439        free(b_two);
3440        return;
3441}
3442
3443static char *get_compact_summary(const struct diff_filepair *p, int is_renamed)
3444{
3445        if (!is_renamed) {
3446                if (p->status == DIFF_STATUS_ADDED) {
3447                        if (S_ISLNK(p->two->mode))
3448                                return "new +l";
3449                        else if ((p->two->mode & 0777) == 0755)
3450                                return "new +x";
3451                        else
3452                                return "new";
3453                } else if (p->status == DIFF_STATUS_DELETED)
3454                        return "gone";
3455        }
3456        if (S_ISLNK(p->one->mode) && !S_ISLNK(p->two->mode))
3457                return "mode -l";
3458        else if (!S_ISLNK(p->one->mode) && S_ISLNK(p->two->mode))
3459                return "mode +l";
3460        else if ((p->one->mode & 0777) == 0644 &&
3461                 (p->two->mode & 0777) == 0755)
3462                return "mode +x";
3463        else if ((p->one->mode & 0777) == 0755 &&
3464                 (p->two->mode & 0777) == 0644)
3465                return "mode -x";
3466        return NULL;
3467}
3468
3469static void builtin_diffstat(const char *name_a, const char *name_b,
3470                             struct diff_filespec *one,
3471                             struct diff_filespec *two,
3472                             struct diffstat_t *diffstat,
3473                             struct diff_options *o,
3474                             struct diff_filepair *p)
3475{
3476        mmfile_t mf1, mf2;
3477        struct diffstat_file *data;
3478        int same_contents;
3479        int complete_rewrite = 0;
3480
3481        if (!DIFF_PAIR_UNMERGED(p)) {
3482                if (p->status == DIFF_STATUS_MODIFIED && p->score)
3483                        complete_rewrite = 1;
3484        }
3485
3486        data = diffstat_add(diffstat, name_a, name_b);
3487        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
3488        if (o->flags.stat_with_summary)
3489                data->comments = get_compact_summary(p, data->is_renamed);
3490
3491        if (!one || !two) {
3492                data->is_unmerged = 1;
3493                return;
3494        }
3495
3496        same_contents = !oidcmp(&one->oid, &two->oid);
3497
3498        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
3499                data->is_binary = 1;
3500                if (same_contents) {
3501                        data->added = 0;
3502                        data->deleted = 0;
3503                } else {
3504                        data->added = diff_filespec_size(two);
3505                        data->deleted = diff_filespec_size(one);
3506                }
3507        }
3508
3509        else if (complete_rewrite) {
3510                diff_populate_filespec(one, 0);
3511                diff_populate_filespec(two, 0);
3512                data->deleted = count_lines(one->data, one->size);
3513                data->added = count_lines(two->data, two->size);
3514        }
3515
3516        else if (!same_contents) {
3517                /* Crazy xdl interfaces.. */
3518                xpparam_t xpp;
3519                xdemitconf_t xecfg;
3520
3521                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3522                        die("unable to read files to diff");
3523
3524                memset(&xpp, 0, sizeof(xpp));
3525                memset(&xecfg, 0, sizeof(xecfg));
3526                xpp.flags = o->xdl_opts;
3527                xpp.anchors = o->anchors;
3528                xpp.anchors_nr = o->anchors_nr;
3529                xecfg.ctxlen = o->context;
3530                xecfg.interhunkctxlen = o->interhunkcontext;
3531                if (xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
3532                                  &xpp, &xecfg))
3533                        die("unable to generate diffstat for %s", one->path);
3534        }
3535
3536        diff_free_filespec_data(one);
3537        diff_free_filespec_data(two);
3538}
3539
3540static void builtin_checkdiff(const char *name_a, const char *name_b,
3541                              const char *attr_path,
3542                              struct diff_filespec *one,
3543                              struct diff_filespec *two,
3544                              struct diff_options *o)
3545{
3546        mmfile_t mf1, mf2;
3547        struct checkdiff_t data;
3548
3549        if (!two)
3550                return;
3551
3552        memset(&data, 0, sizeof(data));
3553        data.filename = name_b ? name_b : name_a;
3554        data.lineno = 0;
3555        data.o = o;
3556        data.ws_rule = whitespace_rule(attr_path);
3557        data.conflict_marker_size = ll_merge_marker_size(attr_path);
3558
3559        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3560                die("unable to read files to diff");
3561
3562        /*
3563         * All the other codepaths check both sides, but not checking
3564         * the "old" side here is deliberate.  We are checking the newly
3565         * introduced changes, and as long as the "new" side is text, we
3566         * can and should check what it introduces.
3567         */
3568        if (diff_filespec_is_binary(two))
3569                goto free_and_return;
3570        else {
3571                /* Crazy xdl interfaces.. */
3572                xpparam_t xpp;
3573                xdemitconf_t xecfg;
3574
3575                memset(&xpp, 0, sizeof(xpp));
3576                memset(&xecfg, 0, sizeof(xecfg));
3577                xecfg.ctxlen = 1; /* at least one context line */
3578                xpp.flags = 0;
3579                if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
3580                                  &xpp, &xecfg))
3581                        die("unable to generate checkdiff for %s", one->path);
3582
3583                if (data.ws_rule & WS_BLANK_AT_EOF) {
3584                        struct emit_callback ecbdata;
3585                        int blank_at_eof;
3586
3587                        ecbdata.ws_rule = data.ws_rule;
3588                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3589                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
3590
3591                        if (blank_at_eof) {
3592                                static char *err;
3593                                if (!err)
3594                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
3595                                fprintf(o->file, "%s:%d: %s.\n",
3596                                        data.filename, blank_at_eof, err);
3597                                data.status = 1; /* report errors */
3598                        }
3599                }
3600        }
3601 free_and_return:
3602        diff_free_filespec_data(one);
3603        diff_free_filespec_data(two);
3604        if (data.status)
3605                o->flags.check_failed = 1;
3606}
3607
3608struct diff_filespec *alloc_filespec(const char *path)
3609{
3610        struct diff_filespec *spec;
3611
3612        FLEXPTR_ALLOC_STR(spec, path, path);
3613        spec->count = 1;
3614        spec->is_binary = -1;
3615        return spec;
3616}
3617
3618void free_filespec(struct diff_filespec *spec)
3619{
3620        if (!--spec->count) {
3621                diff_free_filespec_data(spec);
3622                free(spec);
3623        }
3624}
3625
3626void fill_filespec(struct diff_filespec *spec, const struct object_id *oid,
3627                   int oid_valid, unsigned short mode)
3628{
3629        if (mode) {
3630                spec->mode = canon_mode(mode);
3631                oidcpy(&spec->oid, oid);
3632                spec->oid_valid = oid_valid;
3633        }
3634}
3635
3636/*
3637 * Given a name and sha1 pair, if the index tells us the file in
3638 * the work tree has that object contents, return true, so that
3639 * prepare_temp_file() does not have to inflate and extract.
3640 */
3641static int reuse_worktree_file(const char *name, const struct object_id *oid, int want_file)
3642{
3643        const struct cache_entry *ce;
3644        struct stat st;
3645        int pos, len;
3646
3647        /*
3648         * We do not read the cache ourselves here, because the
3649         * benchmark with my previous version that always reads cache
3650         * shows that it makes things worse for diff-tree comparing
3651         * two linux-2.6 kernel trees in an already checked out work
3652         * tree.  This is because most diff-tree comparisons deal with
3653         * only a small number of files, while reading the cache is
3654         * expensive for a large project, and its cost outweighs the
3655         * savings we get by not inflating the object to a temporary
3656         * file.  Practically, this code only helps when we are used
3657         * by diff-cache --cached, which does read the cache before
3658         * calling us.
3659         */
3660        if (!active_cache)
3661                return 0;
3662
3663        /* We want to avoid the working directory if our caller
3664         * doesn't need the data in a normal file, this system
3665         * is rather slow with its stat/open/mmap/close syscalls,
3666         * and the object is contained in a pack file.  The pack
3667         * is probably already open and will be faster to obtain
3668         * the data through than the working directory.  Loose
3669         * objects however would tend to be slower as they need
3670         * to be individually opened and inflated.
3671         */
3672        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(oid->hash))
3673                return 0;
3674
3675        /*
3676         * Similarly, if we'd have to convert the file contents anyway, that
3677         * makes the optimization not worthwhile.
3678         */
3679        if (!want_file && would_convert_to_git(&the_index, name))
3680                return 0;
3681
3682        len = strlen(name);
3683        pos = cache_name_pos(name, len);
3684        if (pos < 0)
3685                return 0;
3686        ce = active_cache[pos];
3687
3688        /*
3689         * This is not the sha1 we are looking for, or
3690         * unreusable because it is not a regular file.
3691         */
3692        if (oidcmp(oid, &ce->oid) || !S_ISREG(ce->ce_mode))
3693                return 0;
3694
3695        /*
3696         * If ce is marked as "assume unchanged", there is no
3697         * guarantee that work tree matches what we are looking for.
3698         */
3699        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
3700                return 0;
3701
3702        /*
3703         * If ce matches the file in the work tree, we can reuse it.
3704         */
3705        if (ce_uptodate(ce) ||
3706            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
3707                return 1;
3708
3709        return 0;
3710}
3711
3712static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
3713{
3714        struct strbuf buf = STRBUF_INIT;
3715        char *dirty = "";
3716
3717        /* Are we looking at the work tree? */
3718        if (s->dirty_submodule)
3719                dirty = "-dirty";
3720
3721        strbuf_addf(&buf, "Subproject commit %s%s\n",
3722                    oid_to_hex(&s->oid), dirty);
3723        s->size = buf.len;
3724        if (size_only) {
3725                s->data = NULL;
3726                strbuf_release(&buf);
3727        } else {
3728                s->data = strbuf_detach(&buf, NULL);
3729                s->should_free = 1;
3730        }
3731        return 0;
3732}
3733
3734/*
3735 * While doing rename detection and pickaxe operation, we may need to
3736 * grab the data for the blob (or file) for our own in-core comparison.
3737 * diff_filespec has data and size fields for this purpose.
3738 */
3739int diff_populate_filespec(struct diff_filespec *s, unsigned int flags)
3740{
3741        int size_only = flags & CHECK_SIZE_ONLY;
3742        int err = 0;
3743        int conv_flags = global_conv_flags_eol;
3744        /*
3745         * demote FAIL to WARN to allow inspecting the situation
3746         * instead of refusing.
3747         */
3748        if (conv_flags & CONV_EOL_RNDTRP_DIE)
3749                conv_flags = CONV_EOL_RNDTRP_WARN;
3750
3751        if (!DIFF_FILE_VALID(s))
3752                die("internal error: asking to populate invalid file.");
3753        if (S_ISDIR(s->mode))
3754                return -1;
3755
3756        if (s->data)
3757                return 0;
3758
3759        if (size_only && 0 < s->size)
3760                return 0;
3761
3762        if (S_ISGITLINK(s->mode))
3763                return diff_populate_gitlink(s, size_only);
3764
3765        if (!s->oid_valid ||
3766            reuse_worktree_file(s->path, &s->oid, 0)) {
3767                struct strbuf buf = STRBUF_INIT;
3768                struct stat st;
3769                int fd;
3770
3771                if (lstat(s->path, &st) < 0) {
3772                err_empty:
3773                        err = -1;
3774                empty:
3775                        s->data = (char *)"";
3776                        s->size = 0;
3777                        return err;
3778                }
3779                s->size = xsize_t(st.st_size);
3780                if (!s->size)
3781                        goto empty;
3782                if (S_ISLNK(st.st_mode)) {
3783                        struct strbuf sb = STRBUF_INIT;
3784
3785                        if (strbuf_readlink(&sb, s->path, s->size))
3786                                goto err_empty;
3787                        s->size = sb.len;
3788                        s->data = strbuf_detach(&sb, NULL);
3789                        s->should_free = 1;
3790                        return 0;
3791                }
3792
3793                /*
3794                 * Even if the caller would be happy with getting
3795                 * only the size, we cannot return early at this
3796                 * point if the path requires us to run the content
3797                 * conversion.
3798                 */
3799                if (size_only && !would_convert_to_git(&the_index, s->path))
3800                        return 0;
3801
3802                /*
3803                 * Note: this check uses xsize_t(st.st_size) that may
3804                 * not be the true size of the blob after it goes
3805                 * through convert_to_git().  This may not strictly be
3806                 * correct, but the whole point of big_file_threshold
3807                 * and is_binary check being that we want to avoid
3808                 * opening the file and inspecting the contents, this
3809                 * is probably fine.
3810                 */
3811                if ((flags & CHECK_BINARY) &&
3812                    s->size > big_file_threshold && s->is_binary == -1) {
3813                        s->is_binary = 1;
3814                        return 0;
3815                }
3816                fd = open(s->path, O_RDONLY);
3817                if (fd < 0)
3818                        goto err_empty;
3819                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
3820                close(fd);
3821                s->should_munmap = 1;
3822
3823                /*
3824                 * Convert from working tree format to canonical git format
3825                 */
3826                if (convert_to_git(&the_index, s->path, s->data, s->size, &buf, conv_flags)) {
3827                        size_t size = 0;
3828                        munmap(s->data, s->size);
3829                        s->should_munmap = 0;
3830                        s->data = strbuf_detach(&buf, &size);
3831                        s->size = size;
3832                        s->should_free = 1;
3833                }
3834        }
3835        else {
3836                enum object_type type;
3837                if (size_only || (flags & CHECK_BINARY)) {
3838                        type = oid_object_info(&s->oid, &s->size);
3839                        if (type < 0)
3840                                die("unable to read %s",
3841                                    oid_to_hex(&s->oid));
3842                        if (size_only)
3843                                return 0;
3844                        if (s->size > big_file_threshold && s->is_binary == -1) {
3845                                s->is_binary = 1;
3846                                return 0;
3847                        }
3848                }
3849                s->data = read_object_file(&s->oid, &type, &s->size);
3850                if (!s->data)
3851                        die("unable to read %s", oid_to_hex(&s->oid));
3852                s->should_free = 1;
3853        }
3854        return 0;
3855}
3856
3857void diff_free_filespec_blob(struct diff_filespec *s)
3858{
3859        if (s->should_free)
3860                free(s->data);
3861        else if (s->should_munmap)
3862                munmap(s->data, s->size);
3863
3864        if (s->should_free || s->should_munmap) {
3865                s->should_free = s->should_munmap = 0;
3866                s->data = NULL;
3867        }
3868}
3869
3870void diff_free_filespec_data(struct diff_filespec *s)
3871{
3872        diff_free_filespec_blob(s);
3873        FREE_AND_NULL(s->cnt_data);
3874}
3875
3876static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
3877                           void *blob,
3878                           unsigned long size,
3879                           const struct object_id *oid,
3880                           int mode)
3881{
3882        struct strbuf buf = STRBUF_INIT;
3883        struct strbuf tempfile = STRBUF_INIT;
3884        char *path_dup = xstrdup(path);
3885        const char *base = basename(path_dup);
3886
3887        /* Generate "XXXXXX_basename.ext" */
3888        strbuf_addstr(&tempfile, "XXXXXX_");
3889        strbuf_addstr(&tempfile, base);
3890
3891        temp->tempfile = mks_tempfile_ts(tempfile.buf, strlen(base) + 1);
3892        if (!temp->tempfile)
3893                die_errno("unable to create temp-file");
3894        if (convert_to_working_tree(path,
3895                        (const char *)blob, (size_t)size, &buf)) {
3896                blob = buf.buf;
3897                size = buf.len;
3898        }
3899        if (write_in_full(temp->tempfile->fd, blob, size) < 0 ||
3900            close_tempfile_gently(temp->tempfile))
3901                die_errno("unable to write temp-file");
3902        temp->name = get_tempfile_path(temp->tempfile);
3903        oid_to_hex_r(temp->hex, oid);
3904        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
3905        strbuf_release(&buf);
3906        strbuf_release(&tempfile);
3907        free(path_dup);
3908}
3909
3910static struct diff_tempfile *prepare_temp_file(const char *name,
3911                struct diff_filespec *one)
3912{
3913        struct diff_tempfile *temp = claim_diff_tempfile();
3914
3915        if (!DIFF_FILE_VALID(one)) {
3916        not_a_valid_file:
3917                /* A '-' entry produces this for file-2, and
3918                 * a '+' entry produces this for file-1.
3919                 */
3920                temp->name = "/dev/null";
3921                xsnprintf(temp->hex, sizeof(temp->hex), ".");
3922                xsnprintf(temp->mode, sizeof(temp->mode), ".");
3923                return temp;
3924        }
3925
3926        if (!S_ISGITLINK(one->mode) &&
3927            (!one->oid_valid ||
3928             reuse_worktree_file(name, &one->oid, 1))) {
3929                struct stat st;
3930                if (lstat(name, &st) < 0) {
3931                        if (errno == ENOENT)
3932                                goto not_a_valid_file;
3933                        die_errno("stat(%s)", name);
3934                }
3935                if (S_ISLNK(st.st_mode)) {
3936                        struct strbuf sb = STRBUF_INIT;
3937                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
3938                                die_errno("readlink(%s)", name);
3939                        prep_temp_blob(name, temp, sb.buf, sb.len,
3940                                       (one->oid_valid ?
3941                                        &one->oid : &null_oid),
3942                                       (one->oid_valid ?
3943                                        one->mode : S_IFLNK));
3944                        strbuf_release(&sb);
3945                }
3946                else {
3947                        /* we can borrow from the file in the work tree */
3948                        temp->name = name;
3949                        if (!one->oid_valid)
3950                                oid_to_hex_r(temp->hex, &null_oid);
3951                        else
3952                                oid_to_hex_r(temp->hex, &one->oid);
3953                        /* Even though we may sometimes borrow the
3954                         * contents from the work tree, we always want
3955                         * one->mode.  mode is trustworthy even when
3956                         * !(one->oid_valid), as long as
3957                         * DIFF_FILE_VALID(one).
3958                         */
3959                        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
3960                }
3961                return temp;
3962        }
3963        else {
3964                if (diff_populate_filespec(one, 0))
3965                        die("cannot read data blob for %s", one->path);
3966                prep_temp_blob(name, temp, one->data, one->size,
3967                               &one->oid, one->mode);
3968        }
3969        return temp;
3970}
3971
3972static void add_external_diff_name(struct argv_array *argv,
3973                                   const char *name,
3974                                   struct diff_filespec *df)
3975{
3976        struct diff_tempfile *temp = prepare_temp_file(name, df);
3977        argv_array_push(argv, temp->name);
3978        argv_array_push(argv, temp->hex);
3979        argv_array_push(argv, temp->mode);
3980}
3981
3982/* An external diff command takes:
3983 *
3984 * diff-cmd name infile1 infile1-sha1 infile1-mode \
3985 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
3986 *
3987 */
3988static void run_external_diff(const char *pgm,
3989                              const char *name,
3990                              const char *other,
3991                              struct diff_filespec *one,
3992                              struct diff_filespec *two,
3993                              const char *xfrm_msg,
3994                              int complete_rewrite,
3995                              struct diff_options *o)
3996{
3997        struct argv_array argv = ARGV_ARRAY_INIT;
3998        struct argv_array env = ARGV_ARRAY_INIT;
3999        struct diff_queue_struct *q = &diff_queued_diff;
4000
4001        argv_array_push(&argv, pgm);
4002        argv_array_push(&argv, name);
4003
4004        if (one && two) {
4005                add_external_diff_name(&argv, name, one);
4006                if (!other)
4007                        add_external_diff_name(&argv, name, two);
4008                else {
4009                        add_external_diff_name(&argv, other, two);
4010                        argv_array_push(&argv, other);
4011                        argv_array_push(&argv, xfrm_msg);
4012                }
4013        }
4014
4015        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
4016        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
4017
4018        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
4019                die(_("external diff died, stopping at %s"), name);
4020
4021        remove_tempfile();
4022        argv_array_clear(&argv);
4023        argv_array_clear(&env);
4024}
4025
4026static int similarity_index(struct diff_filepair *p)
4027{
4028        return p->score * 100 / MAX_SCORE;
4029}
4030
4031static const char *diff_abbrev_oid(const struct object_id *oid, int abbrev)
4032{
4033        if (startup_info->have_repository)
4034                return find_unique_abbrev(oid, abbrev);
4035        else {
4036                char *hex = oid_to_hex(oid);
4037                if (abbrev < 0)
4038                        abbrev = FALLBACK_DEFAULT_ABBREV;
4039                if (abbrev > GIT_SHA1_HEXSZ)
4040                        die("BUG: oid abbreviation out of range: %d", abbrev);
4041                if (abbrev)
4042                        hex[abbrev] = '\0';
4043                return hex;
4044        }
4045}
4046
4047static void fill_metainfo(struct strbuf *msg,
4048                          const char *name,
4049                          const char *other,
4050                          struct diff_filespec *one,
4051                          struct diff_filespec *two,
4052                          struct diff_options *o,
4053                          struct diff_filepair *p,
4054                          int *must_show_header,
4055                          int use_color)
4056{
4057        const char *set = diff_get_color(use_color, DIFF_METAINFO);
4058        const char *reset = diff_get_color(use_color, DIFF_RESET);
4059        const char *line_prefix = diff_line_prefix(o);
4060
4061        *must_show_header = 1;
4062        strbuf_init(msg, PATH_MAX * 2 + 300);
4063        switch (p->status) {
4064        case DIFF_STATUS_COPIED:
4065                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4066                            line_prefix, set, similarity_index(p));
4067                strbuf_addf(msg, "%s\n%s%scopy from ",
4068                            reset,  line_prefix, set);
4069                quote_c_style(name, msg, NULL, 0);
4070                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
4071                quote_c_style(other, msg, NULL, 0);
4072                strbuf_addf(msg, "%s\n", reset);
4073                break;
4074        case DIFF_STATUS_RENAMED:
4075                strbuf_addf(msg, "%s%ssimilarity index %d%%",
4076                            line_prefix, set, similarity_index(p));
4077                strbuf_addf(msg, "%s\n%s%srename from ",
4078                            reset, line_prefix, set);
4079                quote_c_style(name, msg, NULL, 0);
4080                strbuf_addf(msg, "%s\n%s%srename to ",
4081                            reset, line_prefix, set);
4082                quote_c_style(other, msg, NULL, 0);
4083                strbuf_addf(msg, "%s\n", reset);
4084                break;
4085        case DIFF_STATUS_MODIFIED:
4086                if (p->score) {
4087                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
4088                                    line_prefix,
4089                                    set, similarity_index(p), reset);
4090                        break;
4091                }
4092                /* fallthru */
4093        default:
4094                *must_show_header = 0;
4095        }
4096        if (one && two && oidcmp(&one->oid, &two->oid)) {
4097                int abbrev = o->flags.full_index ? 40 : DEFAULT_ABBREV;
4098
4099                if (o->flags.binary) {
4100                        mmfile_t mf;
4101                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
4102                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
4103                                abbrev = 40;
4104                }
4105                strbuf_addf(msg, "%s%sindex %s..%s", line_prefix, set,
4106                            diff_abbrev_oid(&one->oid, abbrev),
4107                            diff_abbrev_oid(&two->oid, abbrev));
4108                if (one->mode == two->mode)
4109                        strbuf_addf(msg, " %06o", one->mode);
4110                strbuf_addf(msg, "%s\n", reset);
4111        }
4112}
4113
4114static void run_diff_cmd(const char *pgm,
4115                         const char *name,
4116                         const char *other,
4117                         const char *attr_path,
4118                         struct diff_filespec *one,
4119                         struct diff_filespec *two,
4120                         struct strbuf *msg,
4121                         struct diff_options *o,
4122                         struct diff_filepair *p)
4123{
4124        const char *xfrm_msg = NULL;
4125        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
4126        int must_show_header = 0;
4127
4128
4129        if (o->flags.allow_external) {
4130                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
4131                if (drv && drv->external)
4132                        pgm = drv->external;
4133        }
4134
4135        if (msg) {
4136                /*
4137                 * don't use colors when the header is intended for an
4138                 * external diff driver
4139                 */
4140                fill_metainfo(msg, name, other, one, two, o, p,
4141                              &must_show_header,
4142                              want_color(o->use_color) && !pgm);
4143                xfrm_msg = msg->len ? msg->buf : NULL;
4144        }
4145
4146        if (pgm) {
4147                run_external_diff(pgm, name, other, one, two, xfrm_msg,
4148                                  complete_rewrite, o);
4149                return;
4150        }
4151        if (one && two)
4152                builtin_diff(name, other ? other : name,
4153                             one, two, xfrm_msg, must_show_header,
4154                             o, complete_rewrite);
4155        else
4156                fprintf(o->file, "* Unmerged path %s\n", name);
4157}
4158
4159static void diff_fill_oid_info(struct diff_filespec *one)
4160{
4161        if (DIFF_FILE_VALID(one)) {
4162                if (!one->oid_valid) {
4163                        struct stat st;
4164                        if (one->is_stdin) {
4165                                oidclr(&one->oid);
4166                                return;
4167                        }
4168                        if (lstat(one->path, &st) < 0)
4169                                die_errno("stat '%s'", one->path);
4170                        if (index_path(&one->oid, one->path, &st, 0))
4171                                die("cannot hash %s", one->path);
4172                }
4173        }
4174        else
4175                oidclr(&one->oid);
4176}
4177
4178static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
4179{
4180        /* Strip the prefix but do not molest /dev/null and absolute paths */
4181        if (*namep && **namep != '/') {
4182                *namep += prefix_length;
4183                if (**namep == '/')
4184                        ++*namep;
4185        }
4186        if (*otherp && **otherp != '/') {
4187                *otherp += prefix_length;
4188                if (**otherp == '/')
4189                        ++*otherp;
4190        }
4191}
4192
4193static void run_diff(struct diff_filepair *p, struct diff_options *o)
4194{
4195        const char *pgm = external_diff();
4196        struct strbuf msg;
4197        struct diff_filespec *one = p->one;
4198        struct diff_filespec *two = p->two;
4199        const char *name;
4200        const char *other;
4201        const char *attr_path;
4202
4203        name  = one->path;
4204        other = (strcmp(name, two->path) ? two->path : NULL);
4205        attr_path = name;
4206        if (o->prefix_length)
4207                strip_prefix(o->prefix_length, &name, &other);
4208
4209        if (!o->flags.allow_external)
4210                pgm = NULL;
4211
4212        if (DIFF_PAIR_UNMERGED(p)) {
4213                run_diff_cmd(pgm, name, NULL, attr_path,
4214                             NULL, NULL, NULL, o, p);
4215                return;
4216        }
4217
4218        diff_fill_oid_info(one);
4219        diff_fill_oid_info(two);
4220
4221        if (!pgm &&
4222            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
4223            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
4224                /*
4225                 * a filepair that changes between file and symlink
4226                 * needs to be split into deletion and creation.
4227                 */
4228                struct diff_filespec *null = alloc_filespec(two->path);
4229                run_diff_cmd(NULL, name, other, attr_path,
4230                             one, null, &msg, o, p);
4231                free(null);
4232                strbuf_release(&msg);
4233
4234                null = alloc_filespec(one->path);
4235                run_diff_cmd(NULL, name, other, attr_path,
4236                             null, two, &msg, o, p);
4237                free(null);
4238        }
4239        else
4240                run_diff_cmd(pgm, name, other, attr_path,
4241                             one, two, &msg, o, p);
4242
4243        strbuf_release(&msg);
4244}
4245
4246static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
4247                         struct diffstat_t *diffstat)
4248{
4249        const char *name;
4250        const char *other;
4251
4252        if (DIFF_PAIR_UNMERGED(p)) {
4253                /* unmerged */
4254                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, p);
4255                return;
4256        }
4257
4258        name = p->one->path;
4259        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4260
4261        if (o->prefix_length)
4262                strip_prefix(o->prefix_length, &name, &other);
4263
4264        diff_fill_oid_info(p->one);
4265        diff_fill_oid_info(p->two);
4266
4267        builtin_diffstat(name, other, p->one, p->two, diffstat, o, p);
4268}
4269
4270static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
4271{
4272        const char *name;
4273        const char *other;
4274        const char *attr_path;
4275
4276        if (DIFF_PAIR_UNMERGED(p)) {
4277                /* unmerged */
4278                return;
4279        }
4280
4281        name = p->one->path;
4282        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4283        attr_path = other ? other : name;
4284
4285        if (o->prefix_length)
4286                strip_prefix(o->prefix_length, &name, &other);
4287
4288        diff_fill_oid_info(p->one);
4289        diff_fill_oid_info(p->two);
4290
4291        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
4292}
4293
4294void diff_setup(struct diff_options *options)
4295{
4296        memcpy(options, &default_diff_options, sizeof(*options));
4297
4298        options->file = stdout;
4299
4300        options->abbrev = DEFAULT_ABBREV;
4301        options->line_termination = '\n';
4302        options->break_opt = -1;
4303        options->rename_limit = -1;
4304        options->dirstat_permille = diff_dirstat_permille_default;
4305        options->context = diff_context_default;
4306        options->interhunkcontext = diff_interhunk_context_default;
4307        options->ws_error_highlight = ws_error_highlight_default;
4308        options->flags.rename_empty = 1;
4309        options->objfind = NULL;
4310
4311        /* pathchange left =NULL by default */
4312        options->change = diff_change;
4313        options->add_remove = diff_addremove;
4314        options->use_color = diff_use_color_default;
4315        options->detect_rename = diff_detect_rename_default;
4316        options->xdl_opts |= diff_algorithm;
4317        if (diff_indent_heuristic)
4318                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4319
4320        options->orderfile = diff_order_file_cfg;
4321
4322        if (diff_no_prefix) {
4323                options->a_prefix = options->b_prefix = "";
4324        } else if (!diff_mnemonic_prefix) {
4325                options->a_prefix = "a/";
4326                options->b_prefix = "b/";
4327        }
4328
4329        options->color_moved = diff_color_moved_default;
4330}
4331
4332void diff_setup_done(struct diff_options *options)
4333{
4334        unsigned check_mask = DIFF_FORMAT_NAME |
4335                              DIFF_FORMAT_NAME_STATUS |
4336                              DIFF_FORMAT_CHECKDIFF |
4337                              DIFF_FORMAT_NO_OUTPUT;
4338
4339        if (options->set_default)
4340                options->set_default(options);
4341
4342        if (HAS_MULTI_BITS(options->output_format & check_mask))
4343                die(_("--name-only, --name-status, --check and -s are mutually exclusive"));
4344
4345        if (HAS_MULTI_BITS(options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK))
4346                die(_("-G, -S and --find-object are mutually exclusive"));
4347
4348        /*
4349         * Most of the time we can say "there are changes"
4350         * only by checking if there are changed paths, but
4351         * --ignore-whitespace* options force us to look
4352         * inside contents.
4353         */
4354
4355        if ((options->xdl_opts & XDF_WHITESPACE_FLAGS))
4356                options->flags.diff_from_contents = 1;
4357        else
4358                options->flags.diff_from_contents = 0;
4359
4360        if (options->flags.find_copies_harder)
4361                options->detect_rename = DIFF_DETECT_COPY;
4362
4363        if (!options->flags.relative_name)
4364                options->prefix = NULL;
4365        if (options->prefix)
4366                options->prefix_length = strlen(options->prefix);
4367        else
4368                options->prefix_length = 0;
4369
4370        if (options->output_format & (DIFF_FORMAT_NAME |
4371                                      DIFF_FORMAT_NAME_STATUS |
4372                                      DIFF_FORMAT_CHECKDIFF |
4373                                      DIFF_FORMAT_NO_OUTPUT))
4374                options->output_format &= ~(DIFF_FORMAT_RAW |
4375                                            DIFF_FORMAT_NUMSTAT |
4376                                            DIFF_FORMAT_DIFFSTAT |
4377                                            DIFF_FORMAT_SHORTSTAT |
4378                                            DIFF_FORMAT_DIRSTAT |
4379                                            DIFF_FORMAT_SUMMARY |
4380                                            DIFF_FORMAT_PATCH);
4381
4382        /*
4383         * These cases always need recursive; we do not drop caller-supplied
4384         * recursive bits for other formats here.
4385         */
4386        if (options->output_format & (DIFF_FORMAT_PATCH |
4387                                      DIFF_FORMAT_NUMSTAT |
4388                                      DIFF_FORMAT_DIFFSTAT |
4389                                      DIFF_FORMAT_SHORTSTAT |
4390                                      DIFF_FORMAT_DIRSTAT |
4391                                      DIFF_FORMAT_SUMMARY |
4392                                      DIFF_FORMAT_CHECKDIFF))
4393                options->flags.recursive = 1;
4394        /*
4395         * Also pickaxe would not work very well if you do not say recursive
4396         */
4397        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
4398                options->flags.recursive = 1;
4399        /*
4400         * When patches are generated, submodules diffed against the work tree
4401         * must be checked for dirtiness too so it can be shown in the output
4402         */
4403        if (options->output_format & DIFF_FORMAT_PATCH)
4404                options->flags.dirty_submodules = 1;
4405
4406        if (options->detect_rename && options->rename_limit < 0)
4407                options->rename_limit = diff_rename_limit_default;
4408        if (options->setup & DIFF_SETUP_USE_CACHE) {
4409                if (!active_cache)
4410                        /* read-cache does not die even when it fails
4411                         * so it is safe for us to do this here.  Also
4412                         * it does not smudge active_cache or active_nr
4413                         * when it fails, so we do not have to worry about
4414                         * cleaning it up ourselves either.
4415                         */
4416                        read_cache();
4417        }
4418        if (40 < options->abbrev)
4419                options->abbrev = 40; /* full */
4420
4421        /*
4422         * It does not make sense to show the first hit we happened
4423         * to have found.  It does not make sense not to return with
4424         * exit code in such a case either.
4425         */
4426        if (options->flags.quick) {
4427                options->output_format = DIFF_FORMAT_NO_OUTPUT;
4428                options->flags.exit_with_status = 1;
4429        }
4430
4431        options->diff_path_counter = 0;
4432
4433        if (options->flags.follow_renames && options->pathspec.nr != 1)
4434                die(_("--follow requires exactly one pathspec"));
4435
4436        if (!options->use_color || external_diff())
4437                options->color_moved = 0;
4438}
4439
4440static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
4441{
4442        char c, *eq;
4443        int len;
4444
4445        if (*arg != '-')
4446                return 0;
4447        c = *++arg;
4448        if (!c)
4449                return 0;
4450        if (c == arg_short) {
4451                c = *++arg;
4452                if (!c)
4453                        return 1;
4454                if (val && isdigit(c)) {
4455                        char *end;
4456                        int n = strtoul(arg, &end, 10);
4457                        if (*end)
4458                                return 0;
4459                        *val = n;
4460                        return 1;
4461                }
4462                return 0;
4463        }
4464        if (c != '-')
4465                return 0;
4466        arg++;
4467        eq = strchrnul(arg, '=');
4468        len = eq - arg;
4469        if (!len || strncmp(arg, arg_long, len))
4470                return 0;
4471        if (*eq) {
4472                int n;
4473                char *end;
4474                if (!isdigit(*++eq))
4475                        return 0;
4476                n = strtoul(eq, &end, 10);
4477                if (*end)
4478                        return 0;
4479                *val = n;
4480        }
4481        return 1;
4482}
4483
4484static int diff_scoreopt_parse(const char *opt);
4485
4486static inline int short_opt(char opt, const char **argv,
4487                            const char **optarg)
4488{
4489        const char *arg = argv[0];
4490        if (arg[0] != '-' || arg[1] != opt)
4491                return 0;
4492        if (arg[2] != '\0') {
4493                *optarg = arg + 2;
4494                return 1;
4495        }
4496        if (!argv[1])
4497                die("Option '%c' requires a value", opt);
4498        *optarg = argv[1];
4499        return 2;
4500}
4501
4502int parse_long_opt(const char *opt, const char **argv,
4503                   const char **optarg)
4504{
4505        const char *arg = argv[0];
4506        if (!skip_prefix(arg, "--", &arg))
4507                return 0;
4508        if (!skip_prefix(arg, opt, &arg))
4509                return 0;
4510        if (*arg == '=') { /* stuck form: --option=value */
4511                *optarg = arg + 1;
4512                return 1;
4513        }
4514        if (*arg != '\0')
4515                return 0;
4516        /* separate form: --option value */
4517        if (!argv[1])
4518                die("Option '--%s' requires a value", opt);
4519        *optarg = argv[1];
4520        return 2;
4521}
4522
4523static int stat_opt(struct diff_options *options, const char **av)
4524{
4525        const char *arg = av[0];
4526        char *end;
4527        int width = options->stat_width;
4528        int name_width = options->stat_name_width;
4529        int graph_width = options->stat_graph_width;
4530        int count = options->stat_count;
4531        int argcount = 1;
4532
4533        if (!skip_prefix(arg, "--stat", &arg))
4534                die("BUG: stat option does not begin with --stat: %s", arg);
4535        end = (char *)arg;
4536
4537        switch (*arg) {
4538        case '-':
4539                if (skip_prefix(arg, "-width", &arg)) {
4540                        if (*arg == '=')
4541                                width = strtoul(arg + 1, &end, 10);
4542                        else if (!*arg && !av[1])
4543                                die_want_option("--stat-width");
4544                        else if (!*arg) {
4545                                width = strtoul(av[1], &end, 10);
4546                                argcount = 2;
4547                        }
4548                } else if (skip_prefix(arg, "-name-width", &arg)) {
4549                        if (*arg == '=')
4550                                name_width = strtoul(arg + 1, &end, 10);
4551                        else if (!*arg && !av[1])
4552                                die_want_option("--stat-name-width");
4553                        else if (!*arg) {
4554                                name_width = strtoul(av[1], &end, 10);
4555                                argcount = 2;
4556                        }
4557                } else if (skip_prefix(arg, "-graph-width", &arg)) {
4558                        if (*arg == '=')
4559                                graph_width = strtoul(arg + 1, &end, 10);
4560                        else if (!*arg && !av[1])
4561                                die_want_option("--stat-graph-width");
4562                        else if (!*arg) {
4563                                graph_width = strtoul(av[1], &end, 10);
4564                                argcount = 2;
4565                        }
4566                } else if (skip_prefix(arg, "-count", &arg)) {
4567                        if (*arg == '=')
4568                                count = strtoul(arg + 1, &end, 10);
4569                        else if (!*arg && !av[1])
4570                                die_want_option("--stat-count");
4571                        else if (!*arg) {
4572                                count = strtoul(av[1], &end, 10);
4573                                argcount = 2;
4574                        }
4575                }
4576                break;
4577        case '=':
4578                width = strtoul(arg+1, &end, 10);
4579                if (*end == ',')
4580                        name_width = strtoul(end+1, &end, 10);
4581                if (*end == ',')
4582                        count = strtoul(end+1, &end, 10);
4583        }
4584
4585        /* Important! This checks all the error cases! */
4586        if (*end)
4587                return 0;
4588        options->output_format |= DIFF_FORMAT_DIFFSTAT;
4589        options->stat_name_width = name_width;
4590        options->stat_graph_width = graph_width;
4591        options->stat_width = width;
4592        options->stat_count = count;
4593        return argcount;
4594}
4595
4596static int parse_dirstat_opt(struct diff_options *options, const char *params)
4597{
4598        struct strbuf errmsg = STRBUF_INIT;
4599        if (parse_dirstat_params(options, params, &errmsg))
4600                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
4601                    errmsg.buf);
4602        strbuf_release(&errmsg);
4603        /*
4604         * The caller knows a dirstat-related option is given from the command
4605         * line; allow it to say "return this_function();"
4606         */
4607        options->output_format |= DIFF_FORMAT_DIRSTAT;
4608        return 1;
4609}
4610
4611static int parse_submodule_opt(struct diff_options *options, const char *value)
4612{
4613        if (parse_submodule_params(options, value))
4614                die(_("Failed to parse --submodule option parameter: '%s'"),
4615                        value);
4616        return 1;
4617}
4618
4619static const char diff_status_letters[] = {
4620        DIFF_STATUS_ADDED,
4621        DIFF_STATUS_COPIED,
4622        DIFF_STATUS_DELETED,
4623        DIFF_STATUS_MODIFIED,
4624        DIFF_STATUS_RENAMED,
4625        DIFF_STATUS_TYPE_CHANGED,
4626        DIFF_STATUS_UNKNOWN,
4627        DIFF_STATUS_UNMERGED,
4628        DIFF_STATUS_FILTER_AON,
4629        DIFF_STATUS_FILTER_BROKEN,
4630        '\0',
4631};
4632
4633static unsigned int filter_bit['Z' + 1];
4634
4635static void prepare_filter_bits(void)
4636{
4637        int i;
4638
4639        if (!filter_bit[DIFF_STATUS_ADDED]) {
4640                for (i = 0; diff_status_letters[i]; i++)
4641                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
4642        }
4643}
4644
4645static unsigned filter_bit_tst(char status, const struct diff_options *opt)
4646{
4647        return opt->filter & filter_bit[(int) status];
4648}
4649
4650static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
4651{
4652        int i, optch;
4653
4654        prepare_filter_bits();
4655
4656        /*
4657         * If there is a negation e.g. 'd' in the input, and we haven't
4658         * initialized the filter field with another --diff-filter, start
4659         * from full set of bits, except for AON.
4660         */
4661        if (!opt->filter) {
4662                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4663                        if (optch < 'a' || 'z' < optch)
4664                                continue;
4665                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
4666                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
4667                        break;
4668                }
4669        }
4670
4671        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4672                unsigned int bit;
4673                int negate;
4674
4675                if ('a' <= optch && optch <= 'z') {
4676                        negate = 1;
4677                        optch = toupper(optch);
4678                } else {
4679                        negate = 0;
4680                }
4681
4682                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
4683                if (!bit)
4684                        return optarg[i];
4685                if (negate)
4686                        opt->filter &= ~bit;
4687                else
4688                        opt->filter |= bit;
4689        }
4690        return 0;
4691}
4692
4693static void enable_patch_output(int *fmt) {
4694        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
4695        *fmt |= DIFF_FORMAT_PATCH;
4696}
4697
4698static int parse_ws_error_highlight_opt(struct diff_options *opt, const char *arg)
4699{
4700        int val = parse_ws_error_highlight(arg);
4701
4702        if (val < 0) {
4703                error("unknown value after ws-error-highlight=%.*s",
4704                      -1 - val, arg);
4705                return 0;
4706        }
4707        opt->ws_error_highlight = val;
4708        return 1;
4709}
4710
4711static int parse_objfind_opt(struct diff_options *opt, const char *arg)
4712{
4713        struct object_id oid;
4714
4715        if (get_oid(arg, &oid))
4716                return error("unable to resolve '%s'", arg);
4717
4718        if (!opt->objfind)
4719                opt->objfind = xcalloc(1, sizeof(*opt->objfind));
4720
4721        opt->pickaxe_opts |= DIFF_PICKAXE_KIND_OBJFIND;
4722        opt->flags.recursive = 1;
4723        opt->flags.tree_in_recursive = 1;
4724        oidset_insert(opt->objfind, &oid);
4725        return 1;
4726}
4727
4728int diff_opt_parse(struct diff_options *options,
4729                   const char **av, int ac, const char *prefix)
4730{
4731        const char *arg = av[0];
4732        const char *optarg;
4733        int argcount;
4734
4735        if (!prefix)
4736                prefix = "";
4737
4738        /* Output format options */
4739        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
4740            || opt_arg(arg, 'U', "unified", &options->context))
4741                enable_patch_output(&options->output_format);
4742        else if (!strcmp(arg, "--raw"))
4743                options->output_format |= DIFF_FORMAT_RAW;
4744        else if (!strcmp(arg, "--patch-with-raw")) {
4745                enable_patch_output(&options->output_format);
4746                options->output_format |= DIFF_FORMAT_RAW;
4747        } else if (!strcmp(arg, "--numstat"))
4748                options->output_format |= DIFF_FORMAT_NUMSTAT;
4749        else if (!strcmp(arg, "--shortstat"))
4750                options->output_format |= DIFF_FORMAT_SHORTSTAT;
4751        else if (skip_prefix(arg, "-X", &arg) ||
4752                 skip_to_optional_arg(arg, "--dirstat", &arg))
4753                return parse_dirstat_opt(options, arg);
4754        else if (!strcmp(arg, "--cumulative"))
4755                return parse_dirstat_opt(options, "cumulative");
4756        else if (skip_to_optional_arg(arg, "--dirstat-by-file", &arg)) {
4757                parse_dirstat_opt(options, "files");
4758                return parse_dirstat_opt(options, arg);
4759        }
4760        else if (!strcmp(arg, "--check"))
4761                options->output_format |= DIFF_FORMAT_CHECKDIFF;
4762        else if (!strcmp(arg, "--summary"))
4763                options->output_format |= DIFF_FORMAT_SUMMARY;
4764        else if (!strcmp(arg, "--patch-with-stat")) {
4765                enable_patch_output(&options->output_format);
4766                options->output_format |= DIFF_FORMAT_DIFFSTAT;
4767        } else if (!strcmp(arg, "--name-only"))
4768                options->output_format |= DIFF_FORMAT_NAME;
4769        else if (!strcmp(arg, "--name-status"))
4770                options->output_format |= DIFF_FORMAT_NAME_STATUS;
4771        else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
4772                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
4773        else if (starts_with(arg, "--stat"))
4774                /* --stat, --stat-width, --stat-name-width, or --stat-count */
4775                return stat_opt(options, av);
4776        else if (!strcmp(arg, "--compact-summary")) {
4777                 options->flags.stat_with_summary = 1;
4778                 options->output_format |= DIFF_FORMAT_DIFFSTAT;
4779        } else if (!strcmp(arg, "--no-compact-summary"))
4780                 options->flags.stat_with_summary = 0;
4781
4782        /* renames options */
4783        else if (starts_with(arg, "-B") ||
4784                 skip_to_optional_arg(arg, "--break-rewrites", NULL)) {
4785                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
4786                        return error("invalid argument to -B: %s", arg+2);
4787        }
4788        else if (starts_with(arg, "-M") ||
4789                 skip_to_optional_arg(arg, "--find-renames", NULL)) {
4790                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4791                        return error("invalid argument to -M: %s", arg+2);
4792                options->detect_rename = DIFF_DETECT_RENAME;
4793        }
4794        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
4795                options->irreversible_delete = 1;
4796        }
4797        else if (starts_with(arg, "-C") ||
4798                 skip_to_optional_arg(arg, "--find-copies", NULL)) {
4799                if (options->detect_rename == DIFF_DETECT_COPY)
4800                        options->flags.find_copies_harder = 1;
4801                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4802                        return error("invalid argument to -C: %s", arg+2);
4803                options->detect_rename = DIFF_DETECT_COPY;
4804        }
4805        else if (!strcmp(arg, "--no-renames"))
4806                options->detect_rename = 0;
4807        else if (!strcmp(arg, "--rename-empty"))
4808                options->flags.rename_empty = 1;
4809        else if (!strcmp(arg, "--no-rename-empty"))
4810                options->flags.rename_empty = 0;
4811        else if (skip_to_optional_arg_default(arg, "--relative", &arg, NULL)) {
4812                options->flags.relative_name = 1;
4813                if (arg)
4814                        options->prefix = arg;
4815        }
4816
4817        /* xdiff options */
4818        else if (!strcmp(arg, "--minimal"))
4819                DIFF_XDL_SET(options, NEED_MINIMAL);
4820        else if (!strcmp(arg, "--no-minimal"))
4821                DIFF_XDL_CLR(options, NEED_MINIMAL);
4822        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
4823                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
4824        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
4825                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
4826        else if (!strcmp(arg, "--ignore-space-at-eol"))
4827                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
4828        else if (!strcmp(arg, "--ignore-cr-at-eol"))
4829                DIFF_XDL_SET(options, IGNORE_CR_AT_EOL);
4830        else if (!strcmp(arg, "--ignore-blank-lines"))
4831                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
4832        else if (!strcmp(arg, "--indent-heuristic"))
4833                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4834        else if (!strcmp(arg, "--no-indent-heuristic"))
4835                DIFF_XDL_CLR(options, INDENT_HEURISTIC);
4836        else if (!strcmp(arg, "--patience")) {
4837                int i;
4838                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4839                /*
4840                 * Both --patience and --anchored use PATIENCE_DIFF
4841                 * internally, so remove any anchors previously
4842                 * specified.
4843                 */
4844                for (i = 0; i < options->anchors_nr; i++)
4845                        free(options->anchors[i]);
4846                options->anchors_nr = 0;
4847        } else if (!strcmp(arg, "--histogram"))
4848                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
4849        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
4850                long value = parse_algorithm_value(optarg);
4851                if (value < 0)
4852                        return error("option diff-algorithm accepts \"myers\", "
4853                                     "\"minimal\", \"patience\" and \"histogram\"");
4854                /* clear out previous settings */
4855                DIFF_XDL_CLR(options, NEED_MINIMAL);
4856                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
4857                options->xdl_opts |= value;
4858                return argcount;
4859        } else if (skip_prefix(arg, "--anchored=", &arg)) {
4860                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4861                ALLOC_GROW(options->anchors, options->anchors_nr + 1,
4862                           options->anchors_alloc);
4863                options->anchors[options->anchors_nr++] = xstrdup(arg);
4864        }
4865
4866        /* flags options */
4867        else if (!strcmp(arg, "--binary")) {
4868                enable_patch_output(&options->output_format);
4869                options->flags.binary = 1;
4870        }
4871        else if (!strcmp(arg, "--full-index"))
4872                options->flags.full_index = 1;
4873        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
4874                options->flags.text = 1;
4875        else if (!strcmp(arg, "-R"))
4876                options->flags.reverse_diff = 1;
4877        else if (!strcmp(arg, "--find-copies-harder"))
4878                options->flags.find_copies_harder = 1;
4879        else if (!strcmp(arg, "--follow"))
4880                options->flags.follow_renames = 1;
4881        else if (!strcmp(arg, "--no-follow")) {
4882                options->flags.follow_renames = 0;
4883                options->flags.default_follow_renames = 0;
4884        } else if (skip_to_optional_arg_default(arg, "--color", &arg, "always")) {
4885                int value = git_config_colorbool(NULL, arg);
4886                if (value < 0)
4887                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
4888                options->use_color = value;
4889        }
4890        else if (!strcmp(arg, "--no-color"))
4891                options->use_color = 0;
4892        else if (!strcmp(arg, "--color-moved")) {
4893                if (diff_color_moved_default)
4894                        options->color_moved = diff_color_moved_default;
4895                if (options->color_moved == COLOR_MOVED_NO)
4896                        options->color_moved = COLOR_MOVED_DEFAULT;
4897        } else if (!strcmp(arg, "--no-color-moved"))
4898                options->color_moved = COLOR_MOVED_NO;
4899        else if (skip_prefix(arg, "--color-moved=", &arg)) {
4900                int cm = parse_color_moved(arg);
4901                if (cm < 0)
4902                        die("bad --color-moved argument: %s", arg);
4903                options->color_moved = cm;
4904        } else if (skip_prefix(arg, "--color-moved-ws=", &arg)) {
4905                options->color_moved_ws_handling = parse_color_moved_ws(arg);
4906        } else if (skip_to_optional_arg_default(arg, "--color-words", &options->word_regex, NULL)) {
4907                options->use_color = 1;
4908                options->word_diff = DIFF_WORDS_COLOR;
4909        }
4910        else if (!strcmp(arg, "--word-diff")) {
4911                if (options->word_diff == DIFF_WORDS_NONE)
4912                        options->word_diff = DIFF_WORDS_PLAIN;
4913        }
4914        else if (skip_prefix(arg, "--word-diff=", &arg)) {
4915                if (!strcmp(arg, "plain"))
4916                        options->word_diff = DIFF_WORDS_PLAIN;
4917                else if (!strcmp(arg, "color")) {
4918                        options->use_color = 1;
4919                        options->word_diff = DIFF_WORDS_COLOR;
4920                }
4921                else if (!strcmp(arg, "porcelain"))
4922                        options->word_diff = DIFF_WORDS_PORCELAIN;
4923                else if (!strcmp(arg, "none"))
4924                        options->word_diff = DIFF_WORDS_NONE;
4925                else
4926                        die("bad --word-diff argument: %s", arg);
4927        }
4928        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
4929                if (options->word_diff == DIFF_WORDS_NONE)
4930                        options->word_diff = DIFF_WORDS_PLAIN;
4931                options->word_regex = optarg;
4932                return argcount;
4933        }
4934        else if (!strcmp(arg, "--exit-code"))
4935                options->flags.exit_with_status = 1;
4936        else if (!strcmp(arg, "--quiet"))
4937                options->flags.quick = 1;
4938        else if (!strcmp(arg, "--ext-diff"))
4939                options->flags.allow_external = 1;
4940        else if (!strcmp(arg, "--no-ext-diff"))
4941                options->flags.allow_external = 0;
4942        else if (!strcmp(arg, "--textconv")) {
4943                options->flags.allow_textconv = 1;
4944                options->flags.textconv_set_via_cmdline = 1;
4945        } else if (!strcmp(arg, "--no-textconv"))
4946                options->flags.allow_textconv = 0;
4947        else if (skip_to_optional_arg_default(arg, "--ignore-submodules", &arg, "all")) {
4948                options->flags.override_submodule_config = 1;
4949                handle_ignore_submodules_arg(options, arg);
4950        } else if (skip_to_optional_arg_default(arg, "--submodule", &arg, "log"))
4951                return parse_submodule_opt(options, arg);
4952        else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
4953                return parse_ws_error_highlight_opt(options, arg);
4954        else if (!strcmp(arg, "--ita-invisible-in-index"))
4955                options->ita_invisible_in_index = 1;
4956        else if (!strcmp(arg, "--ita-visible-in-index"))
4957                options->ita_invisible_in_index = 0;
4958
4959        /* misc options */
4960        else if (!strcmp(arg, "-z"))
4961                options->line_termination = 0;
4962        else if ((argcount = short_opt('l', av, &optarg))) {
4963                options->rename_limit = strtoul(optarg, NULL, 10);
4964                return argcount;
4965        }
4966        else if ((argcount = short_opt('S', av, &optarg))) {
4967                options->pickaxe = optarg;
4968                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
4969                return argcount;
4970        } else if ((argcount = short_opt('G', av, &optarg))) {
4971                options->pickaxe = optarg;
4972                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
4973                return argcount;
4974        }
4975        else if (!strcmp(arg, "--pickaxe-all"))
4976                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
4977        else if (!strcmp(arg, "--pickaxe-regex"))
4978                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
4979        else if ((argcount = short_opt('O', av, &optarg))) {
4980                options->orderfile = prefix_filename(prefix, optarg);
4981                return argcount;
4982        } else if (skip_prefix(arg, "--find-object=", &arg))
4983                return parse_objfind_opt(options, arg);
4984        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
4985                int offending = parse_diff_filter_opt(optarg, options);
4986                if (offending)
4987                        die("unknown change class '%c' in --diff-filter=%s",
4988                            offending, optarg);
4989                return argcount;
4990        }
4991        else if (!strcmp(arg, "--no-abbrev"))
4992                options->abbrev = 0;
4993        else if (!strcmp(arg, "--abbrev"))
4994                options->abbrev = DEFAULT_ABBREV;
4995        else if (skip_prefix(arg, "--abbrev=", &arg)) {
4996                options->abbrev = strtoul(arg, NULL, 10);
4997                if (options->abbrev < MINIMUM_ABBREV)
4998                        options->abbrev = MINIMUM_ABBREV;
4999                else if (40 < options->abbrev)
5000                        options->abbrev = 40;
5001        }
5002        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
5003                options->a_prefix = optarg;
5004                return argcount;
5005        }
5006        else if ((argcount = parse_long_opt("line-prefix", av, &optarg))) {
5007                options->line_prefix = optarg;
5008                options->line_prefix_length = strlen(options->line_prefix);
5009                graph_setup_line_prefix(options);
5010                return argcount;
5011        }
5012        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
5013                options->b_prefix = optarg;
5014                return argcount;
5015        }
5016        else if (!strcmp(arg, "--no-prefix"))
5017                options->a_prefix = options->b_prefix = "";
5018        else if (opt_arg(arg, '\0', "inter-hunk-context",
5019                         &options->interhunkcontext))
5020                ;
5021        else if (!strcmp(arg, "-W"))
5022                options->flags.funccontext = 1;
5023        else if (!strcmp(arg, "--function-context"))
5024                options->flags.funccontext = 1;
5025        else if (!strcmp(arg, "--no-function-context"))
5026                options->flags.funccontext = 0;
5027        else if ((argcount = parse_long_opt("output", av, &optarg))) {
5028                char *path = prefix_filename(prefix, optarg);
5029                options->file = xfopen(path, "w");
5030                options->close_file = 1;
5031                if (options->use_color != GIT_COLOR_ALWAYS)
5032                        options->use_color = GIT_COLOR_NEVER;
5033                free(path);
5034                return argcount;
5035        } else
5036                return 0;
5037        return 1;
5038}
5039
5040int parse_rename_score(const char **cp_p)
5041{
5042        unsigned long num, scale;
5043        int ch, dot;
5044        const char *cp = *cp_p;
5045
5046        num = 0;
5047        scale = 1;
5048        dot = 0;
5049        for (;;) {
5050                ch = *cp;
5051                if ( !dot && ch == '.' ) {
5052                        scale = 1;
5053                        dot = 1;
5054                } else if ( ch == '%' ) {
5055                        scale = dot ? scale*100 : 100;
5056                        cp++;   /* % is always at the end */
5057                        break;
5058                } else if ( ch >= '0' && ch <= '9' ) {
5059                        if ( scale < 100000 ) {
5060                                scale *= 10;
5061                                num = (num*10) + (ch-'0');
5062                        }
5063                } else {
5064                        break;
5065                }
5066                cp++;
5067        }
5068        *cp_p = cp;
5069
5070        /* user says num divided by scale and we say internally that
5071         * is MAX_SCORE * num / scale.
5072         */
5073        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
5074}
5075
5076static int diff_scoreopt_parse(const char *opt)
5077{
5078        int opt1, opt2, cmd;
5079
5080        if (*opt++ != '-')
5081                return -1;
5082        cmd = *opt++;
5083        if (cmd == '-') {
5084                /* convert the long-form arguments into short-form versions */
5085                if (skip_prefix(opt, "break-rewrites", &opt)) {
5086                        if (*opt == 0 || *opt++ == '=')
5087                                cmd = 'B';
5088                } else if (skip_prefix(opt, "find-copies", &opt)) {
5089                        if (*opt == 0 || *opt++ == '=')
5090                                cmd = 'C';
5091                } else if (skip_prefix(opt, "find-renames", &opt)) {
5092                        if (*opt == 0 || *opt++ == '=')
5093                                cmd = 'M';
5094                }
5095        }
5096        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
5097                return -1; /* that is not a -M, -C, or -B option */
5098
5099        opt1 = parse_rename_score(&opt);
5100        if (cmd != 'B')
5101                opt2 = 0;
5102        else {
5103                if (*opt == 0)
5104                        opt2 = 0;
5105                else if (*opt != '/')
5106                        return -1; /* we expect -B80/99 or -B80 */
5107                else {
5108                        opt++;
5109                        opt2 = parse_rename_score(&opt);
5110                }
5111        }
5112        if (*opt != 0)
5113                return -1;
5114        return opt1 | (opt2 << 16);
5115}
5116
5117struct diff_queue_struct diff_queued_diff;
5118
5119void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
5120{
5121        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
5122        queue->queue[queue->nr++] = dp;
5123}
5124
5125struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
5126                                 struct diff_filespec *one,
5127                                 struct diff_filespec *two)
5128{
5129        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
5130        dp->one = one;
5131        dp->two = two;
5132        if (queue)
5133                diff_q(queue, dp);
5134        return dp;
5135}
5136
5137void diff_free_filepair(struct diff_filepair *p)
5138{
5139        free_filespec(p->one);
5140        free_filespec(p->two);
5141        free(p);
5142}
5143
5144const char *diff_aligned_abbrev(const struct object_id *oid, int len)
5145{
5146        int abblen;
5147        const char *abbrev;
5148
5149        /* Do we want all 40 hex characters? */
5150        if (len == GIT_SHA1_HEXSZ)
5151                return oid_to_hex(oid);
5152
5153        /* An abbreviated value is fine, possibly followed by an ellipsis. */
5154        abbrev = diff_abbrev_oid(oid, len);
5155
5156        if (!print_sha1_ellipsis())
5157                return abbrev;
5158
5159        abblen = strlen(abbrev);
5160
5161        /*
5162         * In well-behaved cases, where the abbreviated result is the
5163         * same as the requested length, append three dots after the
5164         * abbreviation (hence the whole logic is limited to the case
5165         * where abblen < 37); when the actual abbreviated result is a
5166         * bit longer than the requested length, we reduce the number
5167         * of dots so that they match the well-behaved ones.  However,
5168         * if the actual abbreviation is longer than the requested
5169         * length by more than three, we give up on aligning, and add
5170         * three dots anyway, to indicate that the output is not the
5171         * full object name.  Yes, this may be suboptimal, but this
5172         * appears only in "diff --raw --abbrev" output and it is not
5173         * worth the effort to change it now.  Note that this would
5174         * likely to work fine when the automatic sizing of default
5175         * abbreviation length is used--we would be fed -1 in "len" in
5176         * that case, and will end up always appending three-dots, but
5177         * the automatic sizing is supposed to give abblen that ensures
5178         * uniqueness across all objects (statistically speaking).
5179         */
5180        if (abblen < GIT_SHA1_HEXSZ - 3) {
5181                static char hex[GIT_MAX_HEXSZ + 1];
5182                if (len < abblen && abblen <= len + 2)
5183                        xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
5184                else
5185                        xsnprintf(hex, sizeof(hex), "%s...", abbrev);
5186                return hex;
5187        }
5188
5189        return oid_to_hex(oid);
5190}
5191
5192static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
5193{
5194        int line_termination = opt->line_termination;
5195        int inter_name_termination = line_termination ? '\t' : '\0';
5196
5197        fprintf(opt->file, "%s", diff_line_prefix(opt));
5198        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
5199                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
5200                        diff_aligned_abbrev(&p->one->oid, opt->abbrev));
5201                fprintf(opt->file, "%s ",
5202                        diff_aligned_abbrev(&p->two->oid, opt->abbrev));
5203        }
5204        if (p->score) {
5205                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
5206                        inter_name_termination);
5207        } else {
5208                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
5209        }
5210
5211        if (p->status == DIFF_STATUS_COPIED ||
5212            p->status == DIFF_STATUS_RENAMED) {
5213                const char *name_a, *name_b;
5214                name_a = p->one->path;
5215                name_b = p->two->path;
5216                strip_prefix(opt->prefix_length, &name_a, &name_b);
5217                write_name_quoted(name_a, opt->file, inter_name_termination);
5218                write_name_quoted(name_b, opt->file, line_termination);
5219        } else {
5220                const char *name_a, *name_b;
5221                name_a = p->one->mode ? p->one->path : p->two->path;
5222                name_b = NULL;
5223                strip_prefix(opt->prefix_length, &name_a, &name_b);
5224                write_name_quoted(name_a, opt->file, line_termination);
5225        }
5226}
5227
5228int diff_unmodified_pair(struct diff_filepair *p)
5229{
5230        /* This function is written stricter than necessary to support
5231         * the currently implemented transformers, but the idea is to
5232         * let transformers to produce diff_filepairs any way they want,
5233         * and filter and clean them up here before producing the output.
5234         */
5235        struct diff_filespec *one = p->one, *two = p->two;
5236
5237        if (DIFF_PAIR_UNMERGED(p))
5238                return 0; /* unmerged is interesting */
5239
5240        /* deletion, addition, mode or type change
5241         * and rename are all interesting.
5242         */
5243        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
5244            DIFF_PAIR_MODE_CHANGED(p) ||
5245            strcmp(one->path, two->path))
5246                return 0;
5247
5248        /* both are valid and point at the same path.  that is, we are
5249         * dealing with a change.
5250         */
5251        if (one->oid_valid && two->oid_valid &&
5252            !oidcmp(&one->oid, &two->oid) &&
5253            !one->dirty_submodule && !two->dirty_submodule)
5254                return 1; /* no change */
5255        if (!one->oid_valid && !two->oid_valid)
5256                return 1; /* both look at the same file on the filesystem. */
5257        return 0;
5258}
5259
5260static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
5261{
5262        if (diff_unmodified_pair(p))
5263                return;
5264
5265        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5266            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5267                return; /* no tree diffs in patch format */
5268
5269        run_diff(p, o);
5270}
5271
5272static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
5273                            struct diffstat_t *diffstat)
5274{
5275        if (diff_unmodified_pair(p))
5276                return;
5277
5278        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5279            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5280                return; /* no useful stat for tree diffs */
5281
5282        run_diffstat(p, o, diffstat);
5283}
5284
5285static void diff_flush_checkdiff(struct diff_filepair *p,
5286                struct diff_options *o)
5287{
5288        if (diff_unmodified_pair(p))
5289                return;
5290
5291        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5292            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5293                return; /* nothing to check in tree diffs */
5294
5295        run_checkdiff(p, o);
5296}
5297
5298int diff_queue_is_empty(void)
5299{
5300        struct diff_queue_struct *q = &diff_queued_diff;
5301        int i;
5302        for (i = 0; i < q->nr; i++)
5303                if (!diff_unmodified_pair(q->queue[i]))
5304                        return 0;
5305        return 1;
5306}
5307
5308#if DIFF_DEBUG
5309void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
5310{
5311        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
5312                x, one ? one : "",
5313                s->path,
5314                DIFF_FILE_VALID(s) ? "valid" : "invalid",
5315                s->mode,
5316                s->oid_valid ? oid_to_hex(&s->oid) : "");
5317        fprintf(stderr, "queue[%d] %s size %lu\n",
5318                x, one ? one : "",
5319                s->size);
5320}
5321
5322void diff_debug_filepair(const struct diff_filepair *p, int i)
5323{
5324        diff_debug_filespec(p->one, i, "one");
5325        diff_debug_filespec(p->two, i, "two");
5326        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
5327                p->score, p->status ? p->status : '?',
5328                p->one->rename_used, p->broken_pair);
5329}
5330
5331void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
5332{
5333        int i;
5334        if (msg)
5335                fprintf(stderr, "%s\n", msg);
5336        fprintf(stderr, "q->nr = %d\n", q->nr);
5337        for (i = 0; i < q->nr; i++) {
5338                struct diff_filepair *p = q->queue[i];
5339                diff_debug_filepair(p, i);
5340        }
5341}
5342#endif
5343
5344static void diff_resolve_rename_copy(void)
5345{
5346        int i;
5347        struct diff_filepair *p;
5348        struct diff_queue_struct *q = &diff_queued_diff;
5349
5350        diff_debug_queue("resolve-rename-copy", q);
5351
5352        for (i = 0; i < q->nr; i++) {
5353                p = q->queue[i];
5354                p->status = 0; /* undecided */
5355                if (DIFF_PAIR_UNMERGED(p))
5356                        p->status = DIFF_STATUS_UNMERGED;
5357                else if (!DIFF_FILE_VALID(p->one))
5358                        p->status = DIFF_STATUS_ADDED;
5359                else if (!DIFF_FILE_VALID(p->two))
5360                        p->status = DIFF_STATUS_DELETED;
5361                else if (DIFF_PAIR_TYPE_CHANGED(p))
5362                        p->status = DIFF_STATUS_TYPE_CHANGED;
5363
5364                /* from this point on, we are dealing with a pair
5365                 * whose both sides are valid and of the same type, i.e.
5366                 * either in-place edit or rename/copy edit.
5367                 */
5368                else if (DIFF_PAIR_RENAME(p)) {
5369                        /*
5370                         * A rename might have re-connected a broken
5371                         * pair up, causing the pathnames to be the
5372                         * same again. If so, that's not a rename at
5373                         * all, just a modification..
5374                         *
5375                         * Otherwise, see if this source was used for
5376                         * multiple renames, in which case we decrement
5377                         * the count, and call it a copy.
5378                         */
5379                        if (!strcmp(p->one->path, p->two->path))
5380                                p->status = DIFF_STATUS_MODIFIED;
5381                        else if (--p->one->rename_used > 0)
5382                                p->status = DIFF_STATUS_COPIED;
5383                        else
5384                                p->status = DIFF_STATUS_RENAMED;
5385                }
5386                else if (oidcmp(&p->one->oid, &p->two->oid) ||
5387                         p->one->mode != p->two->mode ||
5388                         p->one->dirty_submodule ||
5389                         p->two->dirty_submodule ||
5390                         is_null_oid(&p->one->oid))
5391                        p->status = DIFF_STATUS_MODIFIED;
5392                else {
5393                        /* This is a "no-change" entry and should not
5394                         * happen anymore, but prepare for broken callers.
5395                         */
5396                        error("feeding unmodified %s to diffcore",
5397                              p->one->path);
5398                        p->status = DIFF_STATUS_UNKNOWN;
5399                }
5400        }
5401        diff_debug_queue("resolve-rename-copy done", q);
5402}
5403
5404static int check_pair_status(struct diff_filepair *p)
5405{
5406        switch (p->status) {
5407        case DIFF_STATUS_UNKNOWN:
5408                return 0;
5409        case 0:
5410                die("internal error in diff-resolve-rename-copy");
5411        default:
5412                return 1;
5413        }
5414}
5415
5416static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
5417{
5418        int fmt = opt->output_format;
5419
5420        if (fmt & DIFF_FORMAT_CHECKDIFF)
5421                diff_flush_checkdiff(p, opt);
5422        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
5423                diff_flush_raw(p, opt);
5424        else if (fmt & DIFF_FORMAT_NAME) {
5425                const char *name_a, *name_b;
5426                name_a = p->two->path;
5427                name_b = NULL;
5428                strip_prefix(opt->prefix_length, &name_a, &name_b);
5429                fprintf(opt->file, "%s", diff_line_prefix(opt));
5430                write_name_quoted(name_a, opt->file, opt->line_termination);
5431        }
5432}
5433
5434static void show_file_mode_name(struct diff_options *opt, const char *newdelete, struct diff_filespec *fs)
5435{
5436        struct strbuf sb = STRBUF_INIT;
5437        if (fs->mode)
5438                strbuf_addf(&sb, " %s mode %06o ", newdelete, fs->mode);
5439        else
5440                strbuf_addf(&sb, " %s ", newdelete);
5441
5442        quote_c_style(fs->path, &sb, NULL, 0);
5443        strbuf_addch(&sb, '\n');
5444        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5445                         sb.buf, sb.len, 0);
5446        strbuf_release(&sb);
5447}
5448
5449static void show_mode_change(struct diff_options *opt, struct diff_filepair *p,
5450                int show_name)
5451{
5452        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
5453                struct strbuf sb = STRBUF_INIT;
5454                strbuf_addf(&sb, " mode change %06o => %06o",
5455                            p->one->mode, p->two->mode);
5456                if (show_name) {
5457                        strbuf_addch(&sb, ' ');
5458                        quote_c_style(p->two->path, &sb, NULL, 0);
5459                }
5460                strbuf_addch(&sb, '\n');
5461                emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5462                                 sb.buf, sb.len, 0);
5463                strbuf_release(&sb);
5464        }
5465}
5466
5467static void show_rename_copy(struct diff_options *opt, const char *renamecopy,
5468                struct diff_filepair *p)
5469{
5470        struct strbuf sb = STRBUF_INIT;
5471        struct strbuf names = STRBUF_INIT;
5472
5473        pprint_rename(&names, p->one->path, p->two->path);
5474        strbuf_addf(&sb, " %s %s (%d%%)\n",
5475                    renamecopy, names.buf, similarity_index(p));
5476        strbuf_release(&names);
5477        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5478                                 sb.buf, sb.len, 0);
5479        show_mode_change(opt, p, 0);
5480        strbuf_release(&sb);
5481}
5482
5483static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
5484{
5485        switch(p->status) {
5486        case DIFF_STATUS_DELETED:
5487                show_file_mode_name(opt, "delete", p->one);
5488                break;
5489        case DIFF_STATUS_ADDED:
5490                show_file_mode_name(opt, "create", p->two);
5491                break;
5492        case DIFF_STATUS_COPIED:
5493                show_rename_copy(opt, "copy", p);
5494                break;
5495        case DIFF_STATUS_RENAMED:
5496                show_rename_copy(opt, "rename", p);
5497                break;
5498        default:
5499                if (p->score) {
5500                        struct strbuf sb = STRBUF_INIT;
5501                        strbuf_addstr(&sb, " rewrite ");
5502                        quote_c_style(p->two->path, &sb, NULL, 0);
5503                        strbuf_addf(&sb, " (%d%%)\n", similarity_index(p));
5504                        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5505                                         sb.buf, sb.len, 0);
5506                        strbuf_release(&sb);
5507                }
5508                show_mode_change(opt, p, !p->score);
5509                break;
5510        }
5511}
5512
5513struct patch_id_t {
5514        git_SHA_CTX *ctx;
5515        int patchlen;
5516};
5517
5518static int remove_space(char *line, int len)
5519{
5520        int i;
5521        char *dst = line;
5522        unsigned char c;
5523
5524        for (i = 0; i < len; i++)
5525                if (!isspace((c = line[i])))
5526                        *dst++ = c;
5527
5528        return dst - line;
5529}
5530
5531static void patch_id_consume(void *priv, char *line, unsigned long len)
5532{
5533        struct patch_id_t *data = priv;
5534        int new_len;
5535
5536        /* Ignore line numbers when computing the SHA1 of the patch */
5537        if (starts_with(line, "@@ -"))
5538                return;
5539
5540        new_len = remove_space(line, len);
5541
5542        git_SHA1_Update(data->ctx, line, new_len);
5543        data->patchlen += new_len;
5544}
5545
5546static void patch_id_add_string(git_SHA_CTX *ctx, const char *str)
5547{
5548        git_SHA1_Update(ctx, str, strlen(str));
5549}
5550
5551static void patch_id_add_mode(git_SHA_CTX *ctx, unsigned mode)
5552{
5553        /* large enough for 2^32 in octal */
5554        char buf[12];
5555        int len = xsnprintf(buf, sizeof(buf), "%06o", mode);
5556        git_SHA1_Update(ctx, buf, len);
5557}
5558
5559/* returns 0 upon success, and writes result into sha1 */
5560static int diff_get_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5561{
5562        struct diff_queue_struct *q = &diff_queued_diff;
5563        int i;
5564        git_SHA_CTX ctx;
5565        struct patch_id_t data;
5566
5567        git_SHA1_Init(&ctx);
5568        memset(&data, 0, sizeof(struct patch_id_t));
5569        data.ctx = &ctx;
5570
5571        for (i = 0; i < q->nr; i++) {
5572                xpparam_t xpp;
5573                xdemitconf_t xecfg;
5574                mmfile_t mf1, mf2;
5575                struct diff_filepair *p = q->queue[i];
5576                int len1, len2;
5577
5578                memset(&xpp, 0, sizeof(xpp));
5579                memset(&xecfg, 0, sizeof(xecfg));
5580                if (p->status == 0)
5581                        return error("internal diff status error");
5582                if (p->status == DIFF_STATUS_UNKNOWN)
5583                        continue;
5584                if (diff_unmodified_pair(p))
5585                        continue;
5586                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5587                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5588                        continue;
5589                if (DIFF_PAIR_UNMERGED(p))
5590                        continue;
5591
5592                diff_fill_oid_info(p->one);
5593                diff_fill_oid_info(p->two);
5594
5595                len1 = remove_space(p->one->path, strlen(p->one->path));
5596                len2 = remove_space(p->two->path, strlen(p->two->path));
5597                patch_id_add_string(&ctx, "diff--git");
5598                patch_id_add_string(&ctx, "a/");
5599                git_SHA1_Update(&ctx, p->one->path, len1);
5600                patch_id_add_string(&ctx, "b/");
5601                git_SHA1_Update(&ctx, p->two->path, len2);
5602
5603                if (p->one->mode == 0) {
5604                        patch_id_add_string(&ctx, "newfilemode");
5605                        patch_id_add_mode(&ctx, p->two->mode);
5606                        patch_id_add_string(&ctx, "---/dev/null");
5607                        patch_id_add_string(&ctx, "+++b/");
5608                        git_SHA1_Update(&ctx, p->two->path, len2);
5609                } else if (p->two->mode == 0) {
5610                        patch_id_add_string(&ctx, "deletedfilemode");
5611                        patch_id_add_mode(&ctx, p->one->mode);
5612                        patch_id_add_string(&ctx, "---a/");
5613                        git_SHA1_Update(&ctx, p->one->path, len1);
5614                        patch_id_add_string(&ctx, "+++/dev/null");
5615                } else {
5616                        patch_id_add_string(&ctx, "---a/");
5617                        git_SHA1_Update(&ctx, p->one->path, len1);
5618                        patch_id_add_string(&ctx, "+++b/");
5619                        git_SHA1_Update(&ctx, p->two->path, len2);
5620                }
5621
5622                if (diff_header_only)
5623                        continue;
5624
5625                if (fill_mmfile(&mf1, p->one) < 0 ||
5626                    fill_mmfile(&mf2, p->two) < 0)
5627                        return error("unable to read files to diff");
5628
5629                if (diff_filespec_is_binary(p->one) ||
5630                    diff_filespec_is_binary(p->two)) {
5631                        git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
5632                                        GIT_SHA1_HEXSZ);
5633                        git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
5634                                        GIT_SHA1_HEXSZ);
5635                        continue;
5636                }
5637
5638                xpp.flags = 0;
5639                xecfg.ctxlen = 3;
5640                xecfg.flags = 0;
5641                if (xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
5642                                  &xpp, &xecfg))
5643                        return error("unable to generate patch-id diff for %s",
5644                                     p->one->path);
5645        }
5646
5647        git_SHA1_Final(oid->hash, &ctx);
5648        return 0;
5649}
5650
5651int diff_flush_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5652{
5653        struct diff_queue_struct *q = &diff_queued_diff;
5654        int i;
5655        int result = diff_get_patch_id(options, oid, diff_header_only);
5656
5657        for (i = 0; i < q->nr; i++)
5658                diff_free_filepair(q->queue[i]);
5659
5660        free(q->queue);
5661        DIFF_QUEUE_CLEAR(q);
5662
5663        return result;
5664}
5665
5666static int is_summary_empty(const struct diff_queue_struct *q)
5667{
5668        int i;
5669
5670        for (i = 0; i < q->nr; i++) {
5671                const struct diff_filepair *p = q->queue[i];
5672
5673                switch (p->status) {
5674                case DIFF_STATUS_DELETED:
5675                case DIFF_STATUS_ADDED:
5676                case DIFF_STATUS_COPIED:
5677                case DIFF_STATUS_RENAMED:
5678                        return 0;
5679                default:
5680                        if (p->score)
5681                                return 0;
5682                        if (p->one->mode && p->two->mode &&
5683                            p->one->mode != p->two->mode)
5684                                return 0;
5685                        break;
5686                }
5687        }
5688        return 1;
5689}
5690
5691static const char rename_limit_warning[] =
5692N_("inexact rename detection was skipped due to too many files.");
5693
5694static const char degrade_cc_to_c_warning[] =
5695N_("only found copies from modified paths due to too many files.");
5696
5697static const char rename_limit_advice[] =
5698N_("you may want to set your %s variable to at least "
5699   "%d and retry the command.");
5700
5701void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
5702{
5703        fflush(stdout);
5704        if (degraded_cc)
5705                warning(_(degrade_cc_to_c_warning));
5706        else if (needed)
5707                warning(_(rename_limit_warning));
5708        else
5709                return;
5710        if (0 < needed)
5711                warning(_(rename_limit_advice), varname, needed);
5712}
5713
5714static void diff_flush_patch_all_file_pairs(struct diff_options *o)
5715{
5716        int i;
5717        static struct emitted_diff_symbols esm = EMITTED_DIFF_SYMBOLS_INIT;
5718        struct diff_queue_struct *q = &diff_queued_diff;
5719
5720        if (WSEH_NEW & WS_RULE_MASK)
5721                die("BUG: WS rules bit mask overlaps with diff symbol flags");
5722
5723        if (o->color_moved)
5724                o->emitted_symbols = &esm;
5725
5726        for (i = 0; i < q->nr; i++) {
5727                struct diff_filepair *p = q->queue[i];
5728                if (check_pair_status(p))
5729                        diff_flush_patch(p, o);
5730        }
5731
5732        if (o->emitted_symbols) {
5733                if (o->color_moved) {
5734                        struct hashmap add_lines, del_lines;
5735
5736                        if (o->color_moved_ws_handling &
5737                            COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
5738                                o->color_moved_ws_handling |= XDF_IGNORE_WHITESPACE;
5739
5740                        hashmap_init(&del_lines, moved_entry_cmp, o, 0);
5741                        hashmap_init(&add_lines, moved_entry_cmp, o, 0);
5742
5743                        add_lines_to_move_detection(o, &add_lines, &del_lines);
5744                        mark_color_as_moved(o, &add_lines, &del_lines);
5745                        if (o->color_moved == COLOR_MOVED_ZEBRA_DIM)
5746                                dim_moved_lines(o);
5747
5748                        hashmap_free(&add_lines, 0);
5749                        hashmap_free(&del_lines, 0);
5750                }
5751
5752                for (i = 0; i < esm.nr; i++)
5753                        emit_diff_symbol_from_struct(o, &esm.buf[i]);
5754
5755                for (i = 0; i < esm.nr; i++)
5756                        free((void *)esm.buf[i].line);
5757        }
5758        esm.nr = 0;
5759}
5760
5761void diff_flush(struct diff_options *options)
5762{
5763        struct diff_queue_struct *q = &diff_queued_diff;
5764        int i, output_format = options->output_format;
5765        int separator = 0;
5766        int dirstat_by_line = 0;
5767
5768        /*
5769         * Order: raw, stat, summary, patch
5770         * or:    name/name-status/checkdiff (other bits clear)
5771         */
5772        if (!q->nr)
5773                goto free_queue;
5774
5775        if (output_format & (DIFF_FORMAT_RAW |
5776                             DIFF_FORMAT_NAME |
5777                             DIFF_FORMAT_NAME_STATUS |
5778                             DIFF_FORMAT_CHECKDIFF)) {
5779                for (i = 0; i < q->nr; i++) {
5780                        struct diff_filepair *p = q->queue[i];
5781                        if (check_pair_status(p))
5782                                flush_one_pair(p, options);
5783                }
5784                separator++;
5785        }
5786
5787        if (output_format & DIFF_FORMAT_DIRSTAT && options->flags.dirstat_by_line)
5788                dirstat_by_line = 1;
5789
5790        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
5791            dirstat_by_line) {
5792                struct diffstat_t diffstat;
5793
5794                memset(&diffstat, 0, sizeof(struct diffstat_t));
5795                for (i = 0; i < q->nr; i++) {
5796                        struct diff_filepair *p = q->queue[i];
5797                        if (check_pair_status(p))
5798                                diff_flush_stat(p, options, &diffstat);
5799                }
5800                if (output_format & DIFF_FORMAT_NUMSTAT)
5801                        show_numstat(&diffstat, options);
5802                if (output_format & DIFF_FORMAT_DIFFSTAT)
5803                        show_stats(&diffstat, options);
5804                if (output_format & DIFF_FORMAT_SHORTSTAT)
5805                        show_shortstats(&diffstat, options);
5806                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
5807                        show_dirstat_by_line(&diffstat, options);
5808                free_diffstat_info(&diffstat);
5809                separator++;
5810        }
5811        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
5812                show_dirstat(options);
5813
5814        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
5815                for (i = 0; i < q->nr; i++) {
5816                        diff_summary(options, q->queue[i]);
5817                }
5818                separator++;
5819        }
5820
5821        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
5822            options->flags.exit_with_status &&
5823            options->flags.diff_from_contents) {
5824                /*
5825                 * run diff_flush_patch for the exit status. setting
5826                 * options->file to /dev/null should be safe, because we
5827                 * aren't supposed to produce any output anyway.
5828                 */
5829                if (options->close_file)
5830                        fclose(options->file);
5831                options->file = xfopen("/dev/null", "w");
5832                options->close_file = 1;
5833                options->color_moved = 0;
5834                for (i = 0; i < q->nr; i++) {
5835                        struct diff_filepair *p = q->queue[i];
5836                        if (check_pair_status(p))
5837                                diff_flush_patch(p, options);
5838                        if (options->found_changes)
5839                                break;
5840                }
5841        }
5842
5843        if (output_format & DIFF_FORMAT_PATCH) {
5844                if (separator) {
5845                        emit_diff_symbol(options, DIFF_SYMBOL_SEPARATOR, NULL, 0, 0);
5846                        if (options->stat_sep)
5847                                /* attach patch instead of inline */
5848                                emit_diff_symbol(options, DIFF_SYMBOL_STAT_SEP,
5849                                                 NULL, 0, 0);
5850                }
5851
5852                diff_flush_patch_all_file_pairs(options);
5853        }
5854
5855        if (output_format & DIFF_FORMAT_CALLBACK)
5856                options->format_callback(q, options, options->format_callback_data);
5857
5858        for (i = 0; i < q->nr; i++)
5859                diff_free_filepair(q->queue[i]);
5860free_queue:
5861        free(q->queue);
5862        DIFF_QUEUE_CLEAR(q);
5863        if (options->close_file)
5864                fclose(options->file);
5865
5866        /*
5867         * Report the content-level differences with HAS_CHANGES;
5868         * diff_addremove/diff_change does not set the bit when
5869         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
5870         */
5871        if (options->flags.diff_from_contents) {
5872                if (options->found_changes)
5873                        options->flags.has_changes = 1;
5874                else
5875                        options->flags.has_changes = 0;
5876        }
5877}
5878
5879static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
5880{
5881        return (((p->status == DIFF_STATUS_MODIFIED) &&
5882                 ((p->score &&
5883                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
5884                  (!p->score &&
5885                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
5886                ((p->status != DIFF_STATUS_MODIFIED) &&
5887                 filter_bit_tst(p->status, options)));
5888}
5889
5890static void diffcore_apply_filter(struct diff_options *options)
5891{
5892        int i;
5893        struct diff_queue_struct *q = &diff_queued_diff;
5894        struct diff_queue_struct outq;
5895
5896        DIFF_QUEUE_CLEAR(&outq);
5897
5898        if (!options->filter)
5899                return;
5900
5901        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
5902                int found;
5903                for (i = found = 0; !found && i < q->nr; i++) {
5904                        if (match_filter(options, q->queue[i]))
5905                                found++;
5906                }
5907                if (found)
5908                        return;
5909
5910                /* otherwise we will clear the whole queue
5911                 * by copying the empty outq at the end of this
5912                 * function, but first clear the current entries
5913                 * in the queue.
5914                 */
5915                for (i = 0; i < q->nr; i++)
5916                        diff_free_filepair(q->queue[i]);
5917        }
5918        else {
5919                /* Only the matching ones */
5920                for (i = 0; i < q->nr; i++) {
5921                        struct diff_filepair *p = q->queue[i];
5922                        if (match_filter(options, p))
5923                                diff_q(&outq, p);
5924                        else
5925                                diff_free_filepair(p);
5926                }
5927        }
5928        free(q->queue);
5929        *q = outq;
5930}
5931
5932/* Check whether two filespecs with the same mode and size are identical */
5933static int diff_filespec_is_identical(struct diff_filespec *one,
5934                                      struct diff_filespec *two)
5935{
5936        if (S_ISGITLINK(one->mode))
5937                return 0;
5938        if (diff_populate_filespec(one, 0))
5939                return 0;
5940        if (diff_populate_filespec(two, 0))
5941                return 0;
5942        return !memcmp(one->data, two->data, one->size);
5943}
5944
5945static int diff_filespec_check_stat_unmatch(struct diff_filepair *p)
5946{
5947        if (p->done_skip_stat_unmatch)
5948                return p->skip_stat_unmatch_result;
5949
5950        p->done_skip_stat_unmatch = 1;
5951        p->skip_stat_unmatch_result = 0;
5952        /*
5953         * 1. Entries that come from stat info dirtiness
5954         *    always have both sides (iow, not create/delete),
5955         *    one side of the object name is unknown, with
5956         *    the same mode and size.  Keep the ones that
5957         *    do not match these criteria.  They have real
5958         *    differences.
5959         *
5960         * 2. At this point, the file is known to be modified,
5961         *    with the same mode and size, and the object
5962         *    name of one side is unknown.  Need to inspect
5963         *    the identical contents.
5964         */
5965        if (!DIFF_FILE_VALID(p->one) || /* (1) */
5966            !DIFF_FILE_VALID(p->two) ||
5967            (p->one->oid_valid && p->two->oid_valid) ||
5968            (p->one->mode != p->two->mode) ||
5969            diff_populate_filespec(p->one, CHECK_SIZE_ONLY) ||
5970            diff_populate_filespec(p->two, CHECK_SIZE_ONLY) ||
5971            (p->one->size != p->two->size) ||
5972            !diff_filespec_is_identical(p->one, p->two)) /* (2) */
5973                p->skip_stat_unmatch_result = 1;
5974        return p->skip_stat_unmatch_result;
5975}
5976
5977static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
5978{
5979        int i;
5980        struct diff_queue_struct *q = &diff_queued_diff;
5981        struct diff_queue_struct outq;
5982        DIFF_QUEUE_CLEAR(&outq);
5983
5984        for (i = 0; i < q->nr; i++) {
5985                struct diff_filepair *p = q->queue[i];
5986
5987                if (diff_filespec_check_stat_unmatch(p))
5988                        diff_q(&outq, p);
5989                else {
5990                        /*
5991                         * The caller can subtract 1 from skip_stat_unmatch
5992                         * to determine how many paths were dirty only
5993                         * due to stat info mismatch.
5994                         */
5995                        if (!diffopt->flags.no_index)
5996                                diffopt->skip_stat_unmatch++;
5997                        diff_free_filepair(p);
5998                }
5999        }
6000        free(q->queue);
6001        *q = outq;
6002}
6003
6004static int diffnamecmp(const void *a_, const void *b_)
6005{
6006        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
6007        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
6008        const char *name_a, *name_b;
6009
6010        name_a = a->one ? a->one->path : a->two->path;
6011        name_b = b->one ? b->one->path : b->two->path;
6012        return strcmp(name_a, name_b);
6013}
6014
6015void diffcore_fix_diff_index(struct diff_options *options)
6016{
6017        struct diff_queue_struct *q = &diff_queued_diff;
6018        QSORT(q->queue, q->nr, diffnamecmp);
6019}
6020
6021void diffcore_std(struct diff_options *options)
6022{
6023        /* NOTE please keep the following in sync with diff_tree_combined() */
6024        if (options->skip_stat_unmatch)
6025                diffcore_skip_stat_unmatch(options);
6026        if (!options->found_follow) {
6027                /* See try_to_follow_renames() in tree-diff.c */
6028                if (options->break_opt != -1)
6029                        diffcore_break(options->break_opt);
6030                if (options->detect_rename)
6031                        diffcore_rename(options);
6032                if (options->break_opt != -1)
6033                        diffcore_merge_broken();
6034        }
6035        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
6036                diffcore_pickaxe(options);
6037        if (options->orderfile)
6038                diffcore_order(options->orderfile);
6039        if (!options->found_follow)
6040                /* See try_to_follow_renames() in tree-diff.c */
6041                diff_resolve_rename_copy();
6042        diffcore_apply_filter(options);
6043
6044        if (diff_queued_diff.nr && !options->flags.diff_from_contents)
6045                options->flags.has_changes = 1;
6046        else
6047                options->flags.has_changes = 0;
6048
6049        options->found_follow = 0;
6050}
6051
6052int diff_result_code(struct diff_options *opt, int status)
6053{
6054        int result = 0;
6055
6056        diff_warn_rename_limit("diff.renameLimit",
6057                               opt->needed_rename_limit,
6058                               opt->degraded_cc_to_c);
6059        if (!opt->flags.exit_with_status &&
6060            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
6061                return status;
6062        if (opt->flags.exit_with_status &&
6063            opt->flags.has_changes)
6064                result |= 01;
6065        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
6066            opt->flags.check_failed)
6067                result |= 02;
6068        return result;
6069}
6070
6071int diff_can_quit_early(struct diff_options *opt)
6072{
6073        return (opt->flags.quick &&
6074                !opt->filter &&
6075                opt->flags.has_changes);
6076}
6077
6078/*
6079 * Shall changes to this submodule be ignored?
6080 *
6081 * Submodule changes can be configured to be ignored separately for each path,
6082 * but that configuration can be overridden from the command line.
6083 */
6084static int is_submodule_ignored(const char *path, struct diff_options *options)
6085{
6086        int ignored = 0;
6087        struct diff_flags orig_flags = options->flags;
6088        if (!options->flags.override_submodule_config)
6089                set_diffopt_flags_from_submodule_config(options, path);
6090        if (options->flags.ignore_submodules)
6091                ignored = 1;
6092        options->flags = orig_flags;
6093        return ignored;
6094}
6095
6096void diff_addremove(struct diff_options *options,
6097                    int addremove, unsigned mode,
6098                    const struct object_id *oid,
6099                    int oid_valid,
6100                    const char *concatpath, unsigned dirty_submodule)
6101{
6102        struct diff_filespec *one, *two;
6103
6104        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
6105                return;
6106
6107        /* This may look odd, but it is a preparation for
6108         * feeding "there are unchanged files which should
6109         * not produce diffs, but when you are doing copy
6110         * detection you would need them, so here they are"
6111         * entries to the diff-core.  They will be prefixed
6112         * with something like '=' or '*' (I haven't decided
6113         * which but should not make any difference).
6114         * Feeding the same new and old to diff_change()
6115         * also has the same effect.
6116         * Before the final output happens, they are pruned after
6117         * merged into rename/copy pairs as appropriate.
6118         */
6119        if (options->flags.reverse_diff)
6120                addremove = (addremove == '+' ? '-' :
6121                             addremove == '-' ? '+' : addremove);
6122
6123        if (options->prefix &&
6124            strncmp(concatpath, options->prefix, options->prefix_length))
6125                return;
6126
6127        one = alloc_filespec(concatpath);
6128        two = alloc_filespec(concatpath);
6129
6130        if (addremove != '+')
6131                fill_filespec(one, oid, oid_valid, mode);
6132        if (addremove != '-') {
6133                fill_filespec(two, oid, oid_valid, mode);
6134                two->dirty_submodule = dirty_submodule;
6135        }
6136
6137        diff_queue(&diff_queued_diff, one, two);
6138        if (!options->flags.diff_from_contents)
6139                options->flags.has_changes = 1;
6140}
6141
6142void diff_change(struct diff_options *options,
6143                 unsigned old_mode, unsigned new_mode,
6144                 const struct object_id *old_oid,
6145                 const struct object_id *new_oid,
6146                 int old_oid_valid, int new_oid_valid,
6147                 const char *concatpath,
6148                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
6149{
6150        struct diff_filespec *one, *two;
6151        struct diff_filepair *p;
6152
6153        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
6154            is_submodule_ignored(concatpath, options))
6155                return;
6156
6157        if (options->flags.reverse_diff) {
6158                SWAP(old_mode, new_mode);
6159                SWAP(old_oid, new_oid);
6160                SWAP(old_oid_valid, new_oid_valid);
6161                SWAP(old_dirty_submodule, new_dirty_submodule);
6162        }
6163
6164        if (options->prefix &&
6165            strncmp(concatpath, options->prefix, options->prefix_length))
6166                return;
6167
6168        one = alloc_filespec(concatpath);
6169        two = alloc_filespec(concatpath);
6170        fill_filespec(one, old_oid, old_oid_valid, old_mode);
6171        fill_filespec(two, new_oid, new_oid_valid, new_mode);
6172        one->dirty_submodule = old_dirty_submodule;
6173        two->dirty_submodule = new_dirty_submodule;
6174        p = diff_queue(&diff_queued_diff, one, two);
6175
6176        if (options->flags.diff_from_contents)
6177                return;
6178
6179        if (options->flags.quick && options->skip_stat_unmatch &&
6180            !diff_filespec_check_stat_unmatch(p))
6181                return;
6182
6183        options->flags.has_changes = 1;
6184}
6185
6186struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
6187{
6188        struct diff_filepair *pair;
6189        struct diff_filespec *one, *two;
6190
6191        if (options->prefix &&
6192            strncmp(path, options->prefix, options->prefix_length))
6193                return NULL;
6194
6195        one = alloc_filespec(path);
6196        two = alloc_filespec(path);
6197        pair = diff_queue(&diff_queued_diff, one, two);
6198        pair->is_unmerged = 1;
6199        return pair;
6200}
6201
6202static char *run_textconv(const char *pgm, struct diff_filespec *spec,
6203                size_t *outsize)
6204{
6205        struct diff_tempfile *temp;
6206        const char *argv[3];
6207        const char **arg = argv;
6208        struct child_process child = CHILD_PROCESS_INIT;
6209        struct strbuf buf = STRBUF_INIT;
6210        int err = 0;
6211
6212        temp = prepare_temp_file(spec->path, spec);
6213        *arg++ = pgm;
6214        *arg++ = temp->name;
6215        *arg = NULL;
6216
6217        child.use_shell = 1;
6218        child.argv = argv;
6219        child.out = -1;
6220        if (start_command(&child)) {
6221                remove_tempfile();
6222                return NULL;
6223        }
6224
6225        if (strbuf_read(&buf, child.out, 0) < 0)
6226                err = error("error reading from textconv command '%s'", pgm);
6227        close(child.out);
6228
6229        if (finish_command(&child) || err) {
6230                strbuf_release(&buf);
6231                remove_tempfile();
6232                return NULL;
6233        }
6234        remove_tempfile();
6235
6236        return strbuf_detach(&buf, outsize);
6237}
6238
6239size_t fill_textconv(struct userdiff_driver *driver,
6240                     struct diff_filespec *df,
6241                     char **outbuf)
6242{
6243        size_t size;
6244
6245        if (!driver) {
6246                if (!DIFF_FILE_VALID(df)) {
6247                        *outbuf = "";
6248                        return 0;
6249                }
6250                if (diff_populate_filespec(df, 0))
6251                        die("unable to read files to diff");
6252                *outbuf = df->data;
6253                return df->size;
6254        }
6255
6256        if (!driver->textconv)
6257                die("BUG: fill_textconv called with non-textconv driver");
6258
6259        if (driver->textconv_cache && df->oid_valid) {
6260                *outbuf = notes_cache_get(driver->textconv_cache,
6261                                          &df->oid,
6262                                          &size);
6263                if (*outbuf)
6264                        return size;
6265        }
6266
6267        *outbuf = run_textconv(driver->textconv, df, &size);
6268        if (!*outbuf)
6269                die("unable to read files to diff");
6270
6271        if (driver->textconv_cache && df->oid_valid) {
6272                /* ignore errors, as we might be in a readonly repository */
6273                notes_cache_put(driver->textconv_cache, &df->oid, *outbuf,
6274                                size);
6275                /*
6276                 * we could save up changes and flush them all at the end,
6277                 * but we would need an extra call after all diffing is done.
6278                 * Since generating a cache entry is the slow path anyway,
6279                 * this extra overhead probably isn't a big deal.
6280                 */
6281                notes_cache_write(driver->textconv_cache);
6282        }
6283
6284        return size;
6285}
6286
6287int textconv_object(const char *path,
6288                    unsigned mode,
6289                    const struct object_id *oid,
6290                    int oid_valid,
6291                    char **buf,
6292                    unsigned long *buf_size)
6293{
6294        struct diff_filespec *df;
6295        struct userdiff_driver *textconv;
6296
6297        df = alloc_filespec(path);
6298        fill_filespec(df, oid, oid_valid, mode);
6299        textconv = get_textconv(df);
6300        if (!textconv) {
6301                free_filespec(df);
6302                return 0;
6303        }
6304
6305        *buf_size = fill_textconv(textconv, df, buf);
6306        free_filespec(df);
6307        return 1;
6308}
6309
6310void setup_diff_pager(struct diff_options *opt)
6311{
6312        /*
6313         * If the user asked for our exit code, then either they want --quiet
6314         * or --exit-code. We should definitely not bother with a pager in the
6315         * former case, as we will generate no output. Since we still properly
6316         * report our exit code even when a pager is run, we _could_ run a
6317         * pager with --exit-code. But since we have not done so historically,
6318         * and because it is easy to find people oneline advising "git diff
6319         * --exit-code" in hooks and other scripts, we do not do so.
6320         */
6321        if (!opt->flags.exit_with_status &&
6322            check_pager_config("diff") != 0)
6323                setup_pager();
6324}