diff.con commit Merge branch 'jk/apply-p-doc' (ece4810)
   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, "zebra"))
 275                return COLOR_MOVED_ZEBRA;
 276        else if (!strcmp(arg, "default"))
 277                return COLOR_MOVED_DEFAULT;
 278        else if (!strcmp(arg, "dimmed_zebra"))
 279                return COLOR_MOVED_ZEBRA_DIM;
 280        else
 281                return error(_("color moved setting must be one of 'no', 'default', 'zebra', 'dimmed_zebra', 'plain'"));
 282}
 283
 284int git_diff_ui_config(const char *var, const char *value, void *cb)
 285{
 286        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 287                diff_use_color_default = git_config_colorbool(var, value);
 288                return 0;
 289        }
 290        if (!strcmp(var, "diff.colormoved")) {
 291                int cm = parse_color_moved(value);
 292                if (cm < 0)
 293                        return -1;
 294                diff_color_moved_default = cm;
 295                return 0;
 296        }
 297        if (!strcmp(var, "diff.context")) {
 298                diff_context_default = git_config_int(var, value);
 299                if (diff_context_default < 0)
 300                        return -1;
 301                return 0;
 302        }
 303        if (!strcmp(var, "diff.interhunkcontext")) {
 304                diff_interhunk_context_default = git_config_int(var, value);
 305                if (diff_interhunk_context_default < 0)
 306                        return -1;
 307                return 0;
 308        }
 309        if (!strcmp(var, "diff.renames")) {
 310                diff_detect_rename_default = git_config_rename(var, value);
 311                return 0;
 312        }
 313        if (!strcmp(var, "diff.autorefreshindex")) {
 314                diff_auto_refresh_index = git_config_bool(var, value);
 315                return 0;
 316        }
 317        if (!strcmp(var, "diff.mnemonicprefix")) {
 318                diff_mnemonic_prefix = git_config_bool(var, value);
 319                return 0;
 320        }
 321        if (!strcmp(var, "diff.noprefix")) {
 322                diff_no_prefix = git_config_bool(var, value);
 323                return 0;
 324        }
 325        if (!strcmp(var, "diff.statgraphwidth")) {
 326                diff_stat_graph_width = git_config_int(var, value);
 327                return 0;
 328        }
 329        if (!strcmp(var, "diff.external"))
 330                return git_config_string(&external_diff_cmd_cfg, var, value);
 331        if (!strcmp(var, "diff.wordregex"))
 332                return git_config_string(&diff_word_regex_cfg, var, value);
 333        if (!strcmp(var, "diff.orderfile"))
 334                return git_config_pathname(&diff_order_file_cfg, var, value);
 335
 336        if (!strcmp(var, "diff.ignoresubmodules"))
 337                handle_ignore_submodules_arg(&default_diff_options, value);
 338
 339        if (!strcmp(var, "diff.submodule")) {
 340                if (parse_submodule_params(&default_diff_options, value))
 341                        warning(_("Unknown value for 'diff.submodule' config variable: '%s'"),
 342                                value);
 343                return 0;
 344        }
 345
 346        if (!strcmp(var, "diff.algorithm")) {
 347                diff_algorithm = parse_algorithm_value(value);
 348                if (diff_algorithm < 0)
 349                        return -1;
 350                return 0;
 351        }
 352
 353        if (!strcmp(var, "diff.wserrorhighlight")) {
 354                int val = parse_ws_error_highlight(value);
 355                if (val < 0)
 356                        return -1;
 357                ws_error_highlight_default = val;
 358                return 0;
 359        }
 360
 361        if (git_color_config(var, value, cb) < 0)
 362                return -1;
 363
 364        return git_diff_basic_config(var, value, cb);
 365}
 366
 367int git_diff_basic_config(const char *var, const char *value, void *cb)
 368{
 369        const char *name;
 370
 371        if (!strcmp(var, "diff.renamelimit")) {
 372                diff_rename_limit_default = git_config_int(var, value);
 373                return 0;
 374        }
 375
 376        if (userdiff_config(var, value) < 0)
 377                return -1;
 378
 379        if (skip_prefix(var, "diff.color.", &name) ||
 380            skip_prefix(var, "color.diff.", &name)) {
 381                int slot = parse_diff_color_slot(name);
 382                if (slot < 0)
 383                        return 0;
 384                if (!value)
 385                        return config_error_nonbool(var);
 386                return color_parse(value, diff_colors[slot]);
 387        }
 388
 389        /* like GNU diff's --suppress-blank-empty option  */
 390        if (!strcmp(var, "diff.suppressblankempty") ||
 391                        /* for backwards compatibility */
 392                        !strcmp(var, "diff.suppress-blank-empty")) {
 393                diff_suppress_blank_empty = git_config_bool(var, value);
 394                return 0;
 395        }
 396
 397        if (!strcmp(var, "diff.dirstat")) {
 398                struct strbuf errmsg = STRBUF_INIT;
 399                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 400                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 401                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 402                                errmsg.buf);
 403                strbuf_release(&errmsg);
 404                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 405                return 0;
 406        }
 407
 408        if (git_diff_heuristic_config(var, value, cb) < 0)
 409                return -1;
 410
 411        return git_default_config(var, value, cb);
 412}
 413
 414static char *quote_two(const char *one, const char *two)
 415{
 416        int need_one = quote_c_style(one, NULL, NULL, 1);
 417        int need_two = quote_c_style(two, NULL, NULL, 1);
 418        struct strbuf res = STRBUF_INIT;
 419
 420        if (need_one + need_two) {
 421                strbuf_addch(&res, '"');
 422                quote_c_style(one, &res, NULL, 1);
 423                quote_c_style(two, &res, NULL, 1);
 424                strbuf_addch(&res, '"');
 425        } else {
 426                strbuf_addstr(&res, one);
 427                strbuf_addstr(&res, two);
 428        }
 429        return strbuf_detach(&res, NULL);
 430}
 431
 432static const char *external_diff(void)
 433{
 434        static const char *external_diff_cmd = NULL;
 435        static int done_preparing = 0;
 436
 437        if (done_preparing)
 438                return external_diff_cmd;
 439        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 440        if (!external_diff_cmd)
 441                external_diff_cmd = external_diff_cmd_cfg;
 442        done_preparing = 1;
 443        return external_diff_cmd;
 444}
 445
 446/*
 447 * Keep track of files used for diffing. Sometimes such an entry
 448 * refers to a temporary file, sometimes to an existing file, and
 449 * sometimes to "/dev/null".
 450 */
 451static struct diff_tempfile {
 452        /*
 453         * filename external diff should read from, or NULL if this
 454         * entry is currently not in use:
 455         */
 456        const char *name;
 457
 458        char hex[GIT_MAX_HEXSZ + 1];
 459        char mode[10];
 460
 461        /*
 462         * If this diff_tempfile instance refers to a temporary file,
 463         * this tempfile object is used to manage its lifetime.
 464         */
 465        struct tempfile *tempfile;
 466} diff_temp[2];
 467
 468struct emit_callback {
 469        int color_diff;
 470        unsigned ws_rule;
 471        int blank_at_eof_in_preimage;
 472        int blank_at_eof_in_postimage;
 473        int lno_in_preimage;
 474        int lno_in_postimage;
 475        const char **label_path;
 476        struct diff_words_data *diff_words;
 477        struct diff_options *opt;
 478        struct strbuf *header;
 479};
 480
 481static int count_lines(const char *data, int size)
 482{
 483        int count, ch, completely_empty = 1, nl_just_seen = 0;
 484        count = 0;
 485        while (0 < size--) {
 486                ch = *data++;
 487                if (ch == '\n') {
 488                        count++;
 489                        nl_just_seen = 1;
 490                        completely_empty = 0;
 491                }
 492                else {
 493                        nl_just_seen = 0;
 494                        completely_empty = 0;
 495                }
 496        }
 497        if (completely_empty)
 498                return 0;
 499        if (!nl_just_seen)
 500                count++; /* no trailing newline */
 501        return count;
 502}
 503
 504static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 505{
 506        if (!DIFF_FILE_VALID(one)) {
 507                mf->ptr = (char *)""; /* does not matter */
 508                mf->size = 0;
 509                return 0;
 510        }
 511        else if (diff_populate_filespec(one, 0))
 512                return -1;
 513
 514        mf->ptr = one->data;
 515        mf->size = one->size;
 516        return 0;
 517}
 518
 519/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 520static unsigned long diff_filespec_size(struct diff_filespec *one)
 521{
 522        if (!DIFF_FILE_VALID(one))
 523                return 0;
 524        diff_populate_filespec(one, CHECK_SIZE_ONLY);
 525        return one->size;
 526}
 527
 528static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 529{
 530        char *ptr = mf->ptr;
 531        long size = mf->size;
 532        int cnt = 0;
 533
 534        if (!size)
 535                return cnt;
 536        ptr += size - 1; /* pointing at the very end */
 537        if (*ptr != '\n')
 538                ; /* incomplete line */
 539        else
 540                ptr--; /* skip the last LF */
 541        while (mf->ptr < ptr) {
 542                char *prev_eol;
 543                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 544                        if (*prev_eol == '\n')
 545                                break;
 546                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 547                        break;
 548                cnt++;
 549                ptr = prev_eol - 1;
 550        }
 551        return cnt;
 552}
 553
 554static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 555                               struct emit_callback *ecbdata)
 556{
 557        int l1, l2, at;
 558        unsigned ws_rule = ecbdata->ws_rule;
 559        l1 = count_trailing_blank(mf1, ws_rule);
 560        l2 = count_trailing_blank(mf2, ws_rule);
 561        if (l2 <= l1) {
 562                ecbdata->blank_at_eof_in_preimage = 0;
 563                ecbdata->blank_at_eof_in_postimage = 0;
 564                return;
 565        }
 566        at = count_lines(mf1->ptr, mf1->size);
 567        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 568
 569        at = count_lines(mf2->ptr, mf2->size);
 570        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 571}
 572
 573static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 574                        int first, const char *line, int len)
 575{
 576        int has_trailing_newline, has_trailing_carriage_return;
 577        int nofirst;
 578        FILE *file = o->file;
 579
 580        fputs(diff_line_prefix(o), file);
 581
 582        if (len == 0) {
 583                has_trailing_newline = (first == '\n');
 584                has_trailing_carriage_return = (!has_trailing_newline &&
 585                                                (first == '\r'));
 586                nofirst = has_trailing_newline || has_trailing_carriage_return;
 587        } else {
 588                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 589                if (has_trailing_newline)
 590                        len--;
 591                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 592                if (has_trailing_carriage_return)
 593                        len--;
 594                nofirst = 0;
 595        }
 596
 597        if (len || !nofirst) {
 598                fputs(set, file);
 599                if (!nofirst)
 600                        fputc(first, file);
 601                fwrite(line, len, 1, file);
 602                fputs(reset, file);
 603        }
 604        if (has_trailing_carriage_return)
 605                fputc('\r', file);
 606        if (has_trailing_newline)
 607                fputc('\n', file);
 608}
 609
 610static void emit_line(struct diff_options *o, const char *set, const char *reset,
 611                      const char *line, int len)
 612{
 613        emit_line_0(o, set, reset, line[0], line+1, len-1);
 614}
 615
 616enum diff_symbol {
 617        DIFF_SYMBOL_BINARY_DIFF_HEADER,
 618        DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
 619        DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
 620        DIFF_SYMBOL_BINARY_DIFF_BODY,
 621        DIFF_SYMBOL_BINARY_DIFF_FOOTER,
 622        DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
 623        DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
 624        DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
 625        DIFF_SYMBOL_STATS_LINE,
 626        DIFF_SYMBOL_WORD_DIFF,
 627        DIFF_SYMBOL_STAT_SEP,
 628        DIFF_SYMBOL_SUMMARY,
 629        DIFF_SYMBOL_SUBMODULE_ADD,
 630        DIFF_SYMBOL_SUBMODULE_DEL,
 631        DIFF_SYMBOL_SUBMODULE_UNTRACKED,
 632        DIFF_SYMBOL_SUBMODULE_MODIFIED,
 633        DIFF_SYMBOL_SUBMODULE_HEADER,
 634        DIFF_SYMBOL_SUBMODULE_ERROR,
 635        DIFF_SYMBOL_SUBMODULE_PIPETHROUGH,
 636        DIFF_SYMBOL_REWRITE_DIFF,
 637        DIFF_SYMBOL_BINARY_FILES,
 638        DIFF_SYMBOL_HEADER,
 639        DIFF_SYMBOL_FILEPAIR_PLUS,
 640        DIFF_SYMBOL_FILEPAIR_MINUS,
 641        DIFF_SYMBOL_WORDS_PORCELAIN,
 642        DIFF_SYMBOL_WORDS,
 643        DIFF_SYMBOL_CONTEXT,
 644        DIFF_SYMBOL_CONTEXT_INCOMPLETE,
 645        DIFF_SYMBOL_PLUS,
 646        DIFF_SYMBOL_MINUS,
 647        DIFF_SYMBOL_NO_LF_EOF,
 648        DIFF_SYMBOL_CONTEXT_FRAGINFO,
 649        DIFF_SYMBOL_CONTEXT_MARKER,
 650        DIFF_SYMBOL_SEPARATOR
 651};
 652/*
 653 * Flags for content lines:
 654 * 0..12 are whitespace rules
 655 * 13-15 are WSEH_NEW | WSEH_OLD | WSEH_CONTEXT
 656 * 16 is marking if the line is blank at EOF
 657 */
 658#define DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF      (1<<16)
 659#define DIFF_SYMBOL_MOVED_LINE                  (1<<17)
 660#define DIFF_SYMBOL_MOVED_LINE_ALT              (1<<18)
 661#define DIFF_SYMBOL_MOVED_LINE_UNINTERESTING    (1<<19)
 662#define DIFF_SYMBOL_CONTENT_WS_MASK (WSEH_NEW | WSEH_OLD | WSEH_CONTEXT | WS_RULE_MASK)
 663
 664/*
 665 * This struct is used when we need to buffer the output of the diff output.
 666 *
 667 * NEEDSWORK: Instead of storing a copy of the line, add an offset pointer
 668 * into the pre/post image file. This pointer could be a union with the
 669 * line pointer. By storing an offset into the file instead of the literal line,
 670 * we can decrease the memory footprint for the buffered output. At first we
 671 * may want to only have indirection for the content lines, but we could also
 672 * enhance the state for emitting prefabricated lines, e.g. the similarity
 673 * score line or hunk/file headers would only need to store a number or path
 674 * and then the output can be constructed later on depending on state.
 675 */
 676struct emitted_diff_symbol {
 677        const char *line;
 678        int len;
 679        int flags;
 680        enum diff_symbol s;
 681};
 682#define EMITTED_DIFF_SYMBOL_INIT {NULL}
 683
 684struct emitted_diff_symbols {
 685        struct emitted_diff_symbol *buf;
 686        int nr, alloc;
 687};
 688#define EMITTED_DIFF_SYMBOLS_INIT {NULL, 0, 0}
 689
 690static void append_emitted_diff_symbol(struct diff_options *o,
 691                                       struct emitted_diff_symbol *e)
 692{
 693        struct emitted_diff_symbol *f;
 694
 695        ALLOC_GROW(o->emitted_symbols->buf,
 696                   o->emitted_symbols->nr + 1,
 697                   o->emitted_symbols->alloc);
 698        f = &o->emitted_symbols->buf[o->emitted_symbols->nr++];
 699
 700        memcpy(f, e, sizeof(struct emitted_diff_symbol));
 701        f->line = e->line ? xmemdupz(e->line, e->len) : NULL;
 702}
 703
 704struct moved_entry {
 705        struct hashmap_entry ent;
 706        const struct emitted_diff_symbol *es;
 707        struct moved_entry *next_line;
 708};
 709
 710static int moved_entry_cmp(const struct diff_options *diffopt,
 711                           const struct moved_entry *a,
 712                           const struct moved_entry *b,
 713                           const void *keydata)
 714{
 715        return !xdiff_compare_lines(a->es->line, a->es->len,
 716                                    b->es->line, b->es->len,
 717                                    diffopt->xdl_opts);
 718}
 719
 720static struct moved_entry *prepare_entry(struct diff_options *o,
 721                                         int line_no)
 722{
 723        struct moved_entry *ret = xmalloc(sizeof(*ret));
 724        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[line_no];
 725
 726        ret->ent.hash = xdiff_hash_string(l->line, l->len, o->xdl_opts);
 727        ret->es = l;
 728        ret->next_line = NULL;
 729
 730        return ret;
 731}
 732
 733static void add_lines_to_move_detection(struct diff_options *o,
 734                                        struct hashmap *add_lines,
 735                                        struct hashmap *del_lines)
 736{
 737        struct moved_entry *prev_line = NULL;
 738
 739        int n;
 740        for (n = 0; n < o->emitted_symbols->nr; n++) {
 741                struct hashmap *hm;
 742                struct moved_entry *key;
 743
 744                switch (o->emitted_symbols->buf[n].s) {
 745                case DIFF_SYMBOL_PLUS:
 746                        hm = add_lines;
 747                        break;
 748                case DIFF_SYMBOL_MINUS:
 749                        hm = del_lines;
 750                        break;
 751                default:
 752                        prev_line = NULL;
 753                        continue;
 754                }
 755
 756                key = prepare_entry(o, n);
 757                if (prev_line && prev_line->es->s == o->emitted_symbols->buf[n].s)
 758                        prev_line->next_line = key;
 759
 760                hashmap_add(hm, key);
 761                prev_line = key;
 762        }
 763}
 764
 765static int shrink_potential_moved_blocks(struct moved_entry **pmb,
 766                                         int pmb_nr)
 767{
 768        int lp, rp;
 769
 770        /* Shrink the set of potential block to the remaining running */
 771        for (lp = 0, rp = pmb_nr - 1; lp <= rp;) {
 772                while (lp < pmb_nr && pmb[lp])
 773                        lp++;
 774                /* lp points at the first NULL now */
 775
 776                while (rp > -1 && !pmb[rp])
 777                        rp--;
 778                /* rp points at the last non-NULL */
 779
 780                if (lp < pmb_nr && rp > -1 && lp < rp) {
 781                        pmb[lp] = pmb[rp];
 782                        pmb[rp] = NULL;
 783                        rp--;
 784                        lp++;
 785                }
 786        }
 787
 788        /* Remember the number of running sets */
 789        return rp + 1;
 790}
 791
 792/*
 793 * If o->color_moved is COLOR_MOVED_PLAIN, this function does nothing.
 794 *
 795 * Otherwise, if the last block has fewer alphanumeric characters than
 796 * COLOR_MOVED_MIN_ALNUM_COUNT, unset DIFF_SYMBOL_MOVED_LINE on all lines in
 797 * that block.
 798 *
 799 * The last block consists of the (n - block_length)'th line up to but not
 800 * including the nth line.
 801 *
 802 * NEEDSWORK: This uses the same heuristic as blame_entry_score() in blame.c.
 803 * Think of a way to unify them.
 804 */
 805static void adjust_last_block(struct diff_options *o, int n, int block_length)
 806{
 807        int i, alnum_count = 0;
 808        if (o->color_moved == COLOR_MOVED_PLAIN)
 809                return;
 810        for (i = 1; i < block_length + 1; i++) {
 811                const char *c = o->emitted_symbols->buf[n - i].line;
 812                for (; *c; c++) {
 813                        if (!isalnum(*c))
 814                                continue;
 815                        alnum_count++;
 816                        if (alnum_count >= COLOR_MOVED_MIN_ALNUM_COUNT)
 817                                return;
 818                }
 819        }
 820        for (i = 1; i < block_length + 1; i++)
 821                o->emitted_symbols->buf[n - i].flags &= ~DIFF_SYMBOL_MOVED_LINE;
 822}
 823
 824/* Find blocks of moved code, delegate actual coloring decision to helper */
 825static void mark_color_as_moved(struct diff_options *o,
 826                                struct hashmap *add_lines,
 827                                struct hashmap *del_lines)
 828{
 829        struct moved_entry **pmb = NULL; /* potentially moved blocks */
 830        int pmb_nr = 0, pmb_alloc = 0;
 831        int n, flipped_block = 1, block_length = 0;
 832
 833
 834        for (n = 0; n < o->emitted_symbols->nr; n++) {
 835                struct hashmap *hm = NULL;
 836                struct moved_entry *key;
 837                struct moved_entry *match = NULL;
 838                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
 839                int i;
 840
 841                switch (l->s) {
 842                case DIFF_SYMBOL_PLUS:
 843                        hm = del_lines;
 844                        key = prepare_entry(o, n);
 845                        match = hashmap_get(hm, key, o);
 846                        free(key);
 847                        break;
 848                case DIFF_SYMBOL_MINUS:
 849                        hm = add_lines;
 850                        key = prepare_entry(o, n);
 851                        match = hashmap_get(hm, key, o);
 852                        free(key);
 853                        break;
 854                default:
 855                        flipped_block = 1;
 856                }
 857
 858                if (!match) {
 859                        adjust_last_block(o, n, block_length);
 860                        pmb_nr = 0;
 861                        block_length = 0;
 862                        continue;
 863                }
 864
 865                l->flags |= DIFF_SYMBOL_MOVED_LINE;
 866
 867                if (o->color_moved == COLOR_MOVED_PLAIN)
 868                        continue;
 869
 870                /* Check any potential block runs, advance each or nullify */
 871                for (i = 0; i < pmb_nr; i++) {
 872                        struct moved_entry *p = pmb[i];
 873                        struct moved_entry *pnext = (p && p->next_line) ?
 874                                        p->next_line : NULL;
 875                        if (pnext && !hm->cmpfn(o, pnext, match, NULL)) {
 876                                pmb[i] = p->next_line;
 877                        } else {
 878                                pmb[i] = NULL;
 879                        }
 880                }
 881
 882                pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
 883
 884                if (pmb_nr == 0) {
 885                        /*
 886                         * The current line is the start of a new block.
 887                         * Setup the set of potential blocks.
 888                         */
 889                        for (; match; match = hashmap_get_next(hm, match)) {
 890                                ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
 891                                pmb[pmb_nr++] = match;
 892                        }
 893
 894                        flipped_block = (flipped_block + 1) % 2;
 895
 896                        adjust_last_block(o, n, block_length);
 897                        block_length = 0;
 898                }
 899
 900                block_length++;
 901
 902                if (flipped_block)
 903                        l->flags |= DIFF_SYMBOL_MOVED_LINE_ALT;
 904        }
 905        adjust_last_block(o, n, block_length);
 906
 907        free(pmb);
 908}
 909
 910#define DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK \
 911  (DIFF_SYMBOL_MOVED_LINE | DIFF_SYMBOL_MOVED_LINE_ALT)
 912static void dim_moved_lines(struct diff_options *o)
 913{
 914        int n;
 915        for (n = 0; n < o->emitted_symbols->nr; n++) {
 916                struct emitted_diff_symbol *prev = (n != 0) ?
 917                                &o->emitted_symbols->buf[n - 1] : NULL;
 918                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
 919                struct emitted_diff_symbol *next =
 920                                (n < o->emitted_symbols->nr - 1) ?
 921                                &o->emitted_symbols->buf[n + 1] : NULL;
 922
 923                /* Not a plus or minus line? */
 924                if (l->s != DIFF_SYMBOL_PLUS && l->s != DIFF_SYMBOL_MINUS)
 925                        continue;
 926
 927                /* Not a moved line? */
 928                if (!(l->flags & DIFF_SYMBOL_MOVED_LINE))
 929                        continue;
 930
 931                /*
 932                 * If prev or next are not a plus or minus line,
 933                 * pretend they don't exist
 934                 */
 935                if (prev && prev->s != DIFF_SYMBOL_PLUS &&
 936                            prev->s != DIFF_SYMBOL_MINUS)
 937                        prev = NULL;
 938                if (next && next->s != DIFF_SYMBOL_PLUS &&
 939                            next->s != DIFF_SYMBOL_MINUS)
 940                        next = NULL;
 941
 942                /* Inside a block? */
 943                if ((prev &&
 944                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
 945                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK)) &&
 946                    (next &&
 947                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
 948                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK))) {
 949                        l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
 950                        continue;
 951                }
 952
 953                /* Check if we are at an interesting bound: */
 954                if (prev && (prev->flags & DIFF_SYMBOL_MOVED_LINE) &&
 955                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
 956                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
 957                        continue;
 958                if (next && (next->flags & DIFF_SYMBOL_MOVED_LINE) &&
 959                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
 960                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
 961                        continue;
 962
 963                /*
 964                 * The boundary to prev and next are not interesting,
 965                 * so this line is not interesting as a whole
 966                 */
 967                l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
 968        }
 969}
 970
 971static void emit_line_ws_markup(struct diff_options *o,
 972                                const char *set, const char *reset,
 973                                const char *line, int len, char sign,
 974                                unsigned ws_rule, int blank_at_eof)
 975{
 976        const char *ws = NULL;
 977
 978        if (o->ws_error_highlight & ws_rule) {
 979                ws = diff_get_color_opt(o, DIFF_WHITESPACE);
 980                if (!*ws)
 981                        ws = NULL;
 982        }
 983
 984        if (!ws)
 985                emit_line_0(o, set, reset, sign, line, len);
 986        else if (blank_at_eof)
 987                /* Blank line at EOF - paint '+' as well */
 988                emit_line_0(o, ws, reset, sign, line, len);
 989        else {
 990                /* Emit just the prefix, then the rest. */
 991                emit_line_0(o, set, reset, sign, "", 0);
 992                ws_check_emit(line, len, ws_rule,
 993                              o->file, set, reset, ws);
 994        }
 995}
 996
 997static void emit_diff_symbol_from_struct(struct diff_options *o,
 998                                         struct emitted_diff_symbol *eds)
 999{
1000        static const char *nneof = " No newline at end of file\n";
1001        const char *context, *reset, *set, *meta, *fraginfo;
1002        struct strbuf sb = STRBUF_INIT;
1003
1004        enum diff_symbol s = eds->s;
1005        const char *line = eds->line;
1006        int len = eds->len;
1007        unsigned flags = eds->flags;
1008
1009        switch (s) {
1010        case DIFF_SYMBOL_NO_LF_EOF:
1011                context = diff_get_color_opt(o, DIFF_CONTEXT);
1012                reset = diff_get_color_opt(o, DIFF_RESET);
1013                putc('\n', o->file);
1014                emit_line_0(o, context, reset, '\\',
1015                            nneof, strlen(nneof));
1016                break;
1017        case DIFF_SYMBOL_SUBMODULE_HEADER:
1018        case DIFF_SYMBOL_SUBMODULE_ERROR:
1019        case DIFF_SYMBOL_SUBMODULE_PIPETHROUGH:
1020        case DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES:
1021        case DIFF_SYMBOL_SUMMARY:
1022        case DIFF_SYMBOL_STATS_LINE:
1023        case DIFF_SYMBOL_BINARY_DIFF_BODY:
1024        case DIFF_SYMBOL_CONTEXT_FRAGINFO:
1025                emit_line(o, "", "", line, len);
1026                break;
1027        case DIFF_SYMBOL_CONTEXT_INCOMPLETE:
1028        case DIFF_SYMBOL_CONTEXT_MARKER:
1029                context = diff_get_color_opt(o, DIFF_CONTEXT);
1030                reset = diff_get_color_opt(o, DIFF_RESET);
1031                emit_line(o, context, reset, line, len);
1032                break;
1033        case DIFF_SYMBOL_SEPARATOR:
1034                fprintf(o->file, "%s%c",
1035                        diff_line_prefix(o),
1036                        o->line_termination);
1037                break;
1038        case DIFF_SYMBOL_CONTEXT:
1039                set = diff_get_color_opt(o, DIFF_CONTEXT);
1040                reset = diff_get_color_opt(o, DIFF_RESET);
1041                emit_line_ws_markup(o, set, reset, line, len, ' ',
1042                                    flags & (DIFF_SYMBOL_CONTENT_WS_MASK), 0);
1043                break;
1044        case DIFF_SYMBOL_PLUS:
1045                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1046                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1047                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1048                case DIFF_SYMBOL_MOVED_LINE |
1049                     DIFF_SYMBOL_MOVED_LINE_ALT |
1050                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1051                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT_DIM);
1052                        break;
1053                case DIFF_SYMBOL_MOVED_LINE |
1054                     DIFF_SYMBOL_MOVED_LINE_ALT:
1055                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT);
1056                        break;
1057                case DIFF_SYMBOL_MOVED_LINE |
1058                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1059                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_DIM);
1060                        break;
1061                case DIFF_SYMBOL_MOVED_LINE:
1062                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED);
1063                        break;
1064                default:
1065                        set = diff_get_color_opt(o, DIFF_FILE_NEW);
1066                }
1067                reset = diff_get_color_opt(o, DIFF_RESET);
1068                emit_line_ws_markup(o, set, reset, line, len, '+',
1069                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK,
1070                                    flags & DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF);
1071                break;
1072        case DIFF_SYMBOL_MINUS:
1073                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1074                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1075                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1076                case DIFF_SYMBOL_MOVED_LINE |
1077                     DIFF_SYMBOL_MOVED_LINE_ALT |
1078                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1079                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT_DIM);
1080                        break;
1081                case DIFF_SYMBOL_MOVED_LINE |
1082                     DIFF_SYMBOL_MOVED_LINE_ALT:
1083                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT);
1084                        break;
1085                case DIFF_SYMBOL_MOVED_LINE |
1086                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1087                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_DIM);
1088                        break;
1089                case DIFF_SYMBOL_MOVED_LINE:
1090                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED);
1091                        break;
1092                default:
1093                        set = diff_get_color_opt(o, DIFF_FILE_OLD);
1094                }
1095                reset = diff_get_color_opt(o, DIFF_RESET);
1096                emit_line_ws_markup(o, set, reset, line, len, '-',
1097                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK, 0);
1098                break;
1099        case DIFF_SYMBOL_WORDS_PORCELAIN:
1100                context = diff_get_color_opt(o, DIFF_CONTEXT);
1101                reset = diff_get_color_opt(o, DIFF_RESET);
1102                emit_line(o, context, reset, line, len);
1103                fputs("~\n", o->file);
1104                break;
1105        case DIFF_SYMBOL_WORDS:
1106                context = diff_get_color_opt(o, DIFF_CONTEXT);
1107                reset = diff_get_color_opt(o, DIFF_RESET);
1108                /*
1109                 * Skip the prefix character, if any.  With
1110                 * diff_suppress_blank_empty, there may be
1111                 * none.
1112                 */
1113                if (line[0] != '\n') {
1114                        line++;
1115                        len--;
1116                }
1117                emit_line(o, context, reset, line, len);
1118                break;
1119        case DIFF_SYMBOL_FILEPAIR_PLUS:
1120                meta = diff_get_color_opt(o, DIFF_METAINFO);
1121                reset = diff_get_color_opt(o, DIFF_RESET);
1122                fprintf(o->file, "%s%s+++ %s%s%s\n", diff_line_prefix(o), meta,
1123                        line, reset,
1124                        strchr(line, ' ') ? "\t" : "");
1125                break;
1126        case DIFF_SYMBOL_FILEPAIR_MINUS:
1127                meta = diff_get_color_opt(o, DIFF_METAINFO);
1128                reset = diff_get_color_opt(o, DIFF_RESET);
1129                fprintf(o->file, "%s%s--- %s%s%s\n", diff_line_prefix(o), meta,
1130                        line, reset,
1131                        strchr(line, ' ') ? "\t" : "");
1132                break;
1133        case DIFF_SYMBOL_BINARY_FILES:
1134        case DIFF_SYMBOL_HEADER:
1135                fprintf(o->file, "%s", line);
1136                break;
1137        case DIFF_SYMBOL_BINARY_DIFF_HEADER:
1138                fprintf(o->file, "%sGIT binary patch\n", diff_line_prefix(o));
1139                break;
1140        case DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA:
1141                fprintf(o->file, "%sdelta %s\n", diff_line_prefix(o), line);
1142                break;
1143        case DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL:
1144                fprintf(o->file, "%sliteral %s\n", diff_line_prefix(o), line);
1145                break;
1146        case DIFF_SYMBOL_BINARY_DIFF_FOOTER:
1147                fputs(diff_line_prefix(o), o->file);
1148                fputc('\n', o->file);
1149                break;
1150        case DIFF_SYMBOL_REWRITE_DIFF:
1151                fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
1152                reset = diff_get_color_opt(o, DIFF_RESET);
1153                emit_line(o, fraginfo, reset, line, len);
1154                break;
1155        case DIFF_SYMBOL_SUBMODULE_ADD:
1156                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1157                reset = diff_get_color_opt(o, DIFF_RESET);
1158                emit_line(o, set, reset, line, len);
1159                break;
1160        case DIFF_SYMBOL_SUBMODULE_DEL:
1161                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1162                reset = diff_get_color_opt(o, DIFF_RESET);
1163                emit_line(o, set, reset, line, len);
1164                break;
1165        case DIFF_SYMBOL_SUBMODULE_UNTRACKED:
1166                fprintf(o->file, "%sSubmodule %s contains untracked content\n",
1167                        diff_line_prefix(o), line);
1168                break;
1169        case DIFF_SYMBOL_SUBMODULE_MODIFIED:
1170                fprintf(o->file, "%sSubmodule %s contains modified content\n",
1171                        diff_line_prefix(o), line);
1172                break;
1173        case DIFF_SYMBOL_STATS_SUMMARY_NO_FILES:
1174                emit_line(o, "", "", " 0 files changed\n",
1175                          strlen(" 0 files changed\n"));
1176                break;
1177        case DIFF_SYMBOL_STATS_SUMMARY_ABBREV:
1178                emit_line(o, "", "", " ...\n", strlen(" ...\n"));
1179                break;
1180        case DIFF_SYMBOL_WORD_DIFF:
1181                fprintf(o->file, "%.*s", len, line);
1182                break;
1183        case DIFF_SYMBOL_STAT_SEP:
1184                fputs(o->stat_sep, o->file);
1185                break;
1186        default:
1187                die("BUG: unknown diff symbol");
1188        }
1189        strbuf_release(&sb);
1190}
1191
1192static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
1193                             const char *line, int len, unsigned flags)
1194{
1195        struct emitted_diff_symbol e = {line, len, flags, s};
1196
1197        if (o->emitted_symbols)
1198                append_emitted_diff_symbol(o, &e);
1199        else
1200                emit_diff_symbol_from_struct(o, &e);
1201}
1202
1203void diff_emit_submodule_del(struct diff_options *o, const char *line)
1204{
1205        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_DEL, line, strlen(line), 0);
1206}
1207
1208void diff_emit_submodule_add(struct diff_options *o, const char *line)
1209{
1210        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ADD, line, strlen(line), 0);
1211}
1212
1213void diff_emit_submodule_untracked(struct diff_options *o, const char *path)
1214{
1215        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_UNTRACKED,
1216                         path, strlen(path), 0);
1217}
1218
1219void diff_emit_submodule_modified(struct diff_options *o, const char *path)
1220{
1221        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_MODIFIED,
1222                         path, strlen(path), 0);
1223}
1224
1225void diff_emit_submodule_header(struct diff_options *o, const char *header)
1226{
1227        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_HEADER,
1228                         header, strlen(header), 0);
1229}
1230
1231void diff_emit_submodule_error(struct diff_options *o, const char *err)
1232{
1233        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ERROR, err, strlen(err), 0);
1234}
1235
1236void diff_emit_submodule_pipethrough(struct diff_options *o,
1237                                     const char *line, int len)
1238{
1239        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_PIPETHROUGH, line, len, 0);
1240}
1241
1242static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
1243{
1244        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
1245              ecbdata->blank_at_eof_in_preimage &&
1246              ecbdata->blank_at_eof_in_postimage &&
1247              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
1248              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
1249                return 0;
1250        return ws_blank_line(line, len, ecbdata->ws_rule);
1251}
1252
1253static void emit_add_line(const char *reset,
1254                          struct emit_callback *ecbdata,
1255                          const char *line, int len)
1256{
1257        unsigned flags = WSEH_NEW | ecbdata->ws_rule;
1258        if (new_blank_line_at_eof(ecbdata, line, len))
1259                flags |= DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF;
1260
1261        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_PLUS, line, len, flags);
1262}
1263
1264static void emit_del_line(const char *reset,
1265                          struct emit_callback *ecbdata,
1266                          const char *line, int len)
1267{
1268        unsigned flags = WSEH_OLD | ecbdata->ws_rule;
1269        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_MINUS, line, len, flags);
1270}
1271
1272static void emit_context_line(const char *reset,
1273                              struct emit_callback *ecbdata,
1274                              const char *line, int len)
1275{
1276        unsigned flags = WSEH_CONTEXT | ecbdata->ws_rule;
1277        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_CONTEXT, line, len, flags);
1278}
1279
1280static void emit_hunk_header(struct emit_callback *ecbdata,
1281                             const char *line, int len)
1282{
1283        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
1284        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
1285        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
1286        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1287        static const char atat[2] = { '@', '@' };
1288        const char *cp, *ep;
1289        struct strbuf msgbuf = STRBUF_INIT;
1290        int org_len = len;
1291        int i = 1;
1292
1293        /*
1294         * As a hunk header must begin with "@@ -<old>, +<new> @@",
1295         * it always is at least 10 bytes long.
1296         */
1297        if (len < 10 ||
1298            memcmp(line, atat, 2) ||
1299            !(ep = memmem(line + 2, len - 2, atat, 2))) {
1300                emit_diff_symbol(ecbdata->opt,
1301                                 DIFF_SYMBOL_CONTEXT_MARKER, line, len, 0);
1302                return;
1303        }
1304        ep += 2; /* skip over @@ */
1305
1306        /* The hunk header in fraginfo color */
1307        strbuf_addstr(&msgbuf, frag);
1308        strbuf_add(&msgbuf, line, ep - line);
1309        strbuf_addstr(&msgbuf, reset);
1310
1311        /*
1312         * trailing "\r\n"
1313         */
1314        for ( ; i < 3; i++)
1315                if (line[len - i] == '\r' || line[len - i] == '\n')
1316                        len--;
1317
1318        /* blank before the func header */
1319        for (cp = ep; ep - line < len; ep++)
1320                if (*ep != ' ' && *ep != '\t')
1321                        break;
1322        if (ep != cp) {
1323                strbuf_addstr(&msgbuf, context);
1324                strbuf_add(&msgbuf, cp, ep - cp);
1325                strbuf_addstr(&msgbuf, reset);
1326        }
1327
1328        if (ep < line + len) {
1329                strbuf_addstr(&msgbuf, func);
1330                strbuf_add(&msgbuf, ep, line + len - ep);
1331                strbuf_addstr(&msgbuf, reset);
1332        }
1333
1334        strbuf_add(&msgbuf, line + len, org_len - len);
1335        strbuf_complete_line(&msgbuf);
1336        emit_diff_symbol(ecbdata->opt,
1337                         DIFF_SYMBOL_CONTEXT_FRAGINFO, msgbuf.buf, msgbuf.len, 0);
1338        strbuf_release(&msgbuf);
1339}
1340
1341static struct diff_tempfile *claim_diff_tempfile(void) {
1342        int i;
1343        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
1344                if (!diff_temp[i].name)
1345                        return diff_temp + i;
1346        die("BUG: diff is failing to clean up its tempfiles");
1347}
1348
1349static void remove_tempfile(void)
1350{
1351        int i;
1352        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
1353                if (is_tempfile_active(diff_temp[i].tempfile))
1354                        delete_tempfile(&diff_temp[i].tempfile);
1355                diff_temp[i].name = NULL;
1356        }
1357}
1358
1359static void add_line_count(struct strbuf *out, int count)
1360{
1361        switch (count) {
1362        case 0:
1363                strbuf_addstr(out, "0,0");
1364                break;
1365        case 1:
1366                strbuf_addstr(out, "1");
1367                break;
1368        default:
1369                strbuf_addf(out, "1,%d", count);
1370                break;
1371        }
1372}
1373
1374static void emit_rewrite_lines(struct emit_callback *ecb,
1375                               int prefix, const char *data, int size)
1376{
1377        const char *endp = NULL;
1378        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
1379
1380        while (0 < size) {
1381                int len;
1382
1383                endp = memchr(data, '\n', size);
1384                len = endp ? (endp - data + 1) : size;
1385                if (prefix != '+') {
1386                        ecb->lno_in_preimage++;
1387                        emit_del_line(reset, ecb, data, len);
1388                } else {
1389                        ecb->lno_in_postimage++;
1390                        emit_add_line(reset, ecb, data, len);
1391                }
1392                size -= len;
1393                data += len;
1394        }
1395        if (!endp)
1396                emit_diff_symbol(ecb->opt, DIFF_SYMBOL_NO_LF_EOF, NULL, 0, 0);
1397}
1398
1399static void emit_rewrite_diff(const char *name_a,
1400                              const char *name_b,
1401                              struct diff_filespec *one,
1402                              struct diff_filespec *two,
1403                              struct userdiff_driver *textconv_one,
1404                              struct userdiff_driver *textconv_two,
1405                              struct diff_options *o)
1406{
1407        int lc_a, lc_b;
1408        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
1409        const char *a_prefix, *b_prefix;
1410        char *data_one, *data_two;
1411        size_t size_one, size_two;
1412        struct emit_callback ecbdata;
1413        struct strbuf out = STRBUF_INIT;
1414
1415        if (diff_mnemonic_prefix && o->flags.reverse_diff) {
1416                a_prefix = o->b_prefix;
1417                b_prefix = o->a_prefix;
1418        } else {
1419                a_prefix = o->a_prefix;
1420                b_prefix = o->b_prefix;
1421        }
1422
1423        name_a += (*name_a == '/');
1424        name_b += (*name_b == '/');
1425
1426        strbuf_reset(&a_name);
1427        strbuf_reset(&b_name);
1428        quote_two_c_style(&a_name, a_prefix, name_a, 0);
1429        quote_two_c_style(&b_name, b_prefix, name_b, 0);
1430
1431        size_one = fill_textconv(textconv_one, one, &data_one);
1432        size_two = fill_textconv(textconv_two, two, &data_two);
1433
1434        memset(&ecbdata, 0, sizeof(ecbdata));
1435        ecbdata.color_diff = want_color(o->use_color);
1436        ecbdata.ws_rule = whitespace_rule(name_b);
1437        ecbdata.opt = o;
1438        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
1439                mmfile_t mf1, mf2;
1440                mf1.ptr = (char *)data_one;
1441                mf2.ptr = (char *)data_two;
1442                mf1.size = size_one;
1443                mf2.size = size_two;
1444                check_blank_at_eof(&mf1, &mf2, &ecbdata);
1445        }
1446        ecbdata.lno_in_preimage = 1;
1447        ecbdata.lno_in_postimage = 1;
1448
1449        lc_a = count_lines(data_one, size_one);
1450        lc_b = count_lines(data_two, size_two);
1451
1452        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
1453                         a_name.buf, a_name.len, 0);
1454        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
1455                         b_name.buf, b_name.len, 0);
1456
1457        strbuf_addstr(&out, "@@ -");
1458        if (!o->irreversible_delete)
1459                add_line_count(&out, lc_a);
1460        else
1461                strbuf_addstr(&out, "?,?");
1462        strbuf_addstr(&out, " +");
1463        add_line_count(&out, lc_b);
1464        strbuf_addstr(&out, " @@\n");
1465        emit_diff_symbol(o, DIFF_SYMBOL_REWRITE_DIFF, out.buf, out.len, 0);
1466        strbuf_release(&out);
1467
1468        if (lc_a && !o->irreversible_delete)
1469                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
1470        if (lc_b)
1471                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
1472        if (textconv_one)
1473                free((char *)data_one);
1474        if (textconv_two)
1475                free((char *)data_two);
1476}
1477
1478struct diff_words_buffer {
1479        mmfile_t text;
1480        unsigned long alloc;
1481        struct diff_words_orig {
1482                const char *begin, *end;
1483        } *orig;
1484        int orig_nr, orig_alloc;
1485};
1486
1487static void diff_words_append(char *line, unsigned long len,
1488                struct diff_words_buffer *buffer)
1489{
1490        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
1491        line++;
1492        len--;
1493        memcpy(buffer->text.ptr + buffer->text.size, line, len);
1494        buffer->text.size += len;
1495        buffer->text.ptr[buffer->text.size] = '\0';
1496}
1497
1498struct diff_words_style_elem {
1499        const char *prefix;
1500        const char *suffix;
1501        const char *color; /* NULL; filled in by the setup code if
1502                            * color is enabled */
1503};
1504
1505struct diff_words_style {
1506        enum diff_words_type type;
1507        struct diff_words_style_elem new_word, old_word, ctx;
1508        const char *newline;
1509};
1510
1511static struct diff_words_style diff_words_styles[] = {
1512        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
1513        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
1514        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
1515};
1516
1517struct diff_words_data {
1518        struct diff_words_buffer minus, plus;
1519        const char *current_plus;
1520        int last_minus;
1521        struct diff_options *opt;
1522        regex_t *word_regex;
1523        enum diff_words_type type;
1524        struct diff_words_style *style;
1525};
1526
1527static int fn_out_diff_words_write_helper(struct diff_options *o,
1528                                          struct diff_words_style_elem *st_el,
1529                                          const char *newline,
1530                                          size_t count, const char *buf)
1531{
1532        int print = 0;
1533        struct strbuf sb = STRBUF_INIT;
1534
1535        while (count) {
1536                char *p = memchr(buf, '\n', count);
1537                if (print)
1538                        strbuf_addstr(&sb, diff_line_prefix(o));
1539
1540                if (p != buf) {
1541                        const char *reset = st_el->color && *st_el->color ?
1542                                            GIT_COLOR_RESET : NULL;
1543                        if (st_el->color && *st_el->color)
1544                                strbuf_addstr(&sb, st_el->color);
1545                        strbuf_addstr(&sb, st_el->prefix);
1546                        strbuf_add(&sb, buf, p ? p - buf : count);
1547                        strbuf_addstr(&sb, st_el->suffix);
1548                        if (reset)
1549                                strbuf_addstr(&sb, reset);
1550                }
1551                if (!p)
1552                        goto out;
1553
1554                strbuf_addstr(&sb, newline);
1555                count -= p + 1 - buf;
1556                buf = p + 1;
1557                print = 1;
1558                if (count) {
1559                        emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1560                                         sb.buf, sb.len, 0);
1561                        strbuf_reset(&sb);
1562                }
1563        }
1564
1565out:
1566        if (sb.len)
1567                emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1568                                 sb.buf, sb.len, 0);
1569        strbuf_release(&sb);
1570        return 0;
1571}
1572
1573/*
1574 * '--color-words' algorithm can be described as:
1575 *
1576 *   1. collect the minus/plus lines of a diff hunk, divided into
1577 *      minus-lines and plus-lines;
1578 *
1579 *   2. break both minus-lines and plus-lines into words and
1580 *      place them into two mmfile_t with one word for each line;
1581 *
1582 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
1583 *
1584 * And for the common parts of the both file, we output the plus side text.
1585 * diff_words->current_plus is used to trace the current position of the plus file
1586 * which printed. diff_words->last_minus is used to trace the last minus word
1587 * printed.
1588 *
1589 * For '--graph' to work with '--color-words', we need to output the graph prefix
1590 * on each line of color words output. Generally, there are two conditions on
1591 * which we should output the prefix.
1592 *
1593 *   1. diff_words->last_minus == 0 &&
1594 *      diff_words->current_plus == diff_words->plus.text.ptr
1595 *
1596 *      that is: the plus text must start as a new line, and if there is no minus
1597 *      word printed, a graph prefix must be printed.
1598 *
1599 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
1600 *      *(diff_words->current_plus - 1) == '\n'
1601 *
1602 *      that is: a graph prefix must be printed following a '\n'
1603 */
1604static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
1605{
1606        if ((diff_words->last_minus == 0 &&
1607                diff_words->current_plus == diff_words->plus.text.ptr) ||
1608                (diff_words->current_plus > diff_words->plus.text.ptr &&
1609                *(diff_words->current_plus - 1) == '\n')) {
1610                return 1;
1611        } else {
1612                return 0;
1613        }
1614}
1615
1616static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
1617{
1618        struct diff_words_data *diff_words = priv;
1619        struct diff_words_style *style = diff_words->style;
1620        int minus_first, minus_len, plus_first, plus_len;
1621        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
1622        struct diff_options *opt = diff_words->opt;
1623        const char *line_prefix;
1624
1625        if (line[0] != '@' || parse_hunk_header(line, len,
1626                        &minus_first, &minus_len, &plus_first, &plus_len))
1627                return;
1628
1629        assert(opt);
1630        line_prefix = diff_line_prefix(opt);
1631
1632        /* POSIX requires that first be decremented by one if len == 0... */
1633        if (minus_len) {
1634                minus_begin = diff_words->minus.orig[minus_first].begin;
1635                minus_end =
1636                        diff_words->minus.orig[minus_first + minus_len - 1].end;
1637        } else
1638                minus_begin = minus_end =
1639                        diff_words->minus.orig[minus_first].end;
1640
1641        if (plus_len) {
1642                plus_begin = diff_words->plus.orig[plus_first].begin;
1643                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
1644        } else
1645                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
1646
1647        if (color_words_output_graph_prefix(diff_words)) {
1648                fputs(line_prefix, diff_words->opt->file);
1649        }
1650        if (diff_words->current_plus != plus_begin) {
1651                fn_out_diff_words_write_helper(diff_words->opt,
1652                                &style->ctx, style->newline,
1653                                plus_begin - diff_words->current_plus,
1654                                diff_words->current_plus);
1655        }
1656        if (minus_begin != minus_end) {
1657                fn_out_diff_words_write_helper(diff_words->opt,
1658                                &style->old_word, style->newline,
1659                                minus_end - minus_begin, minus_begin);
1660        }
1661        if (plus_begin != plus_end) {
1662                fn_out_diff_words_write_helper(diff_words->opt,
1663                                &style->new_word, style->newline,
1664                                plus_end - plus_begin, plus_begin);
1665        }
1666
1667        diff_words->current_plus = plus_end;
1668        diff_words->last_minus = minus_first;
1669}
1670
1671/* This function starts looking at *begin, and returns 0 iff a word was found. */
1672static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
1673                int *begin, int *end)
1674{
1675        if (word_regex && *begin < buffer->size) {
1676                regmatch_t match[1];
1677                if (!regexec_buf(word_regex, buffer->ptr + *begin,
1678                                 buffer->size - *begin, 1, match, 0)) {
1679                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
1680                                        '\n', match[0].rm_eo - match[0].rm_so);
1681                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
1682                        *begin += match[0].rm_so;
1683                        return *begin >= *end;
1684                }
1685                return -1;
1686        }
1687
1688        /* find the next word */
1689        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
1690                (*begin)++;
1691        if (*begin >= buffer->size)
1692                return -1;
1693
1694        /* find the end of the word */
1695        *end = *begin + 1;
1696        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
1697                (*end)++;
1698
1699        return 0;
1700}
1701
1702/*
1703 * This function splits the words in buffer->text, stores the list with
1704 * newline separator into out, and saves the offsets of the original words
1705 * in buffer->orig.
1706 */
1707static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
1708                regex_t *word_regex)
1709{
1710        int i, j;
1711        long alloc = 0;
1712
1713        out->size = 0;
1714        out->ptr = NULL;
1715
1716        /* fake an empty "0th" word */
1717        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
1718        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
1719        buffer->orig_nr = 1;
1720
1721        for (i = 0; i < buffer->text.size; i++) {
1722                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
1723                        return;
1724
1725                /* store original boundaries */
1726                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
1727                                buffer->orig_alloc);
1728                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
1729                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
1730                buffer->orig_nr++;
1731
1732                /* store one word */
1733                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
1734                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
1735                out->ptr[out->size + j - i] = '\n';
1736                out->size += j - i + 1;
1737
1738                i = j - 1;
1739        }
1740}
1741
1742/* this executes the word diff on the accumulated buffers */
1743static void diff_words_show(struct diff_words_data *diff_words)
1744{
1745        xpparam_t xpp;
1746        xdemitconf_t xecfg;
1747        mmfile_t minus, plus;
1748        struct diff_words_style *style = diff_words->style;
1749
1750        struct diff_options *opt = diff_words->opt;
1751        const char *line_prefix;
1752
1753        assert(opt);
1754        line_prefix = diff_line_prefix(opt);
1755
1756        /* special case: only removal */
1757        if (!diff_words->plus.text.size) {
1758                emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
1759                                 line_prefix, strlen(line_prefix), 0);
1760                fn_out_diff_words_write_helper(diff_words->opt,
1761                        &style->old_word, style->newline,
1762                        diff_words->minus.text.size,
1763                        diff_words->minus.text.ptr);
1764                diff_words->minus.text.size = 0;
1765                return;
1766        }
1767
1768        diff_words->current_plus = diff_words->plus.text.ptr;
1769        diff_words->last_minus = 0;
1770
1771        memset(&xpp, 0, sizeof(xpp));
1772        memset(&xecfg, 0, sizeof(xecfg));
1773        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
1774        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
1775        xpp.flags = 0;
1776        /* as only the hunk header will be parsed, we need a 0-context */
1777        xecfg.ctxlen = 0;
1778        if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
1779                          &xpp, &xecfg))
1780                die("unable to generate word diff");
1781        free(minus.ptr);
1782        free(plus.ptr);
1783        if (diff_words->current_plus != diff_words->plus.text.ptr +
1784                        diff_words->plus.text.size) {
1785                if (color_words_output_graph_prefix(diff_words))
1786                        emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
1787                                         line_prefix, strlen(line_prefix), 0);
1788                fn_out_diff_words_write_helper(diff_words->opt,
1789                        &style->ctx, style->newline,
1790                        diff_words->plus.text.ptr + diff_words->plus.text.size
1791                        - diff_words->current_plus, diff_words->current_plus);
1792        }
1793        diff_words->minus.text.size = diff_words->plus.text.size = 0;
1794}
1795
1796/* In "color-words" mode, show word-diff of words accumulated in the buffer */
1797static void diff_words_flush(struct emit_callback *ecbdata)
1798{
1799        struct diff_options *wo = ecbdata->diff_words->opt;
1800
1801        if (ecbdata->diff_words->minus.text.size ||
1802            ecbdata->diff_words->plus.text.size)
1803                diff_words_show(ecbdata->diff_words);
1804
1805        if (wo->emitted_symbols) {
1806                struct diff_options *o = ecbdata->opt;
1807                struct emitted_diff_symbols *wol = wo->emitted_symbols;
1808                int i;
1809
1810                /*
1811                 * NEEDSWORK:
1812                 * Instead of appending each, concat all words to a line?
1813                 */
1814                for (i = 0; i < wol->nr; i++)
1815                        append_emitted_diff_symbol(o, &wol->buf[i]);
1816
1817                for (i = 0; i < wol->nr; i++)
1818                        free((void *)wol->buf[i].line);
1819
1820                wol->nr = 0;
1821        }
1822}
1823
1824static void diff_filespec_load_driver(struct diff_filespec *one)
1825{
1826        /* Use already-loaded driver */
1827        if (one->driver)
1828                return;
1829
1830        if (S_ISREG(one->mode))
1831                one->driver = userdiff_find_by_path(one->path);
1832
1833        /* Fallback to default settings */
1834        if (!one->driver)
1835                one->driver = userdiff_find_by_name("default");
1836}
1837
1838static const char *userdiff_word_regex(struct diff_filespec *one)
1839{
1840        diff_filespec_load_driver(one);
1841        return one->driver->word_regex;
1842}
1843
1844static void init_diff_words_data(struct emit_callback *ecbdata,
1845                                 struct diff_options *orig_opts,
1846                                 struct diff_filespec *one,
1847                                 struct diff_filespec *two)
1848{
1849        int i;
1850        struct diff_options *o = xmalloc(sizeof(struct diff_options));
1851        memcpy(o, orig_opts, sizeof(struct diff_options));
1852
1853        ecbdata->diff_words =
1854                xcalloc(1, sizeof(struct diff_words_data));
1855        ecbdata->diff_words->type = o->word_diff;
1856        ecbdata->diff_words->opt = o;
1857
1858        if (orig_opts->emitted_symbols)
1859                o->emitted_symbols =
1860                        xcalloc(1, sizeof(struct emitted_diff_symbols));
1861
1862        if (!o->word_regex)
1863                o->word_regex = userdiff_word_regex(one);
1864        if (!o->word_regex)
1865                o->word_regex = userdiff_word_regex(two);
1866        if (!o->word_regex)
1867                o->word_regex = diff_word_regex_cfg;
1868        if (o->word_regex) {
1869                ecbdata->diff_words->word_regex = (regex_t *)
1870                        xmalloc(sizeof(regex_t));
1871                if (regcomp(ecbdata->diff_words->word_regex,
1872                            o->word_regex,
1873                            REG_EXTENDED | REG_NEWLINE))
1874                        die ("Invalid regular expression: %s",
1875                             o->word_regex);
1876        }
1877        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
1878                if (o->word_diff == diff_words_styles[i].type) {
1879                        ecbdata->diff_words->style =
1880                                &diff_words_styles[i];
1881                        break;
1882                }
1883        }
1884        if (want_color(o->use_color)) {
1885                struct diff_words_style *st = ecbdata->diff_words->style;
1886                st->old_word.color = diff_get_color_opt(o, DIFF_FILE_OLD);
1887                st->new_word.color = diff_get_color_opt(o, DIFF_FILE_NEW);
1888                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
1889        }
1890}
1891
1892static void free_diff_words_data(struct emit_callback *ecbdata)
1893{
1894        if (ecbdata->diff_words) {
1895                diff_words_flush(ecbdata);
1896                free (ecbdata->diff_words->opt->emitted_symbols);
1897                free (ecbdata->diff_words->opt);
1898                free (ecbdata->diff_words->minus.text.ptr);
1899                free (ecbdata->diff_words->minus.orig);
1900                free (ecbdata->diff_words->plus.text.ptr);
1901                free (ecbdata->diff_words->plus.orig);
1902                if (ecbdata->diff_words->word_regex) {
1903                        regfree(ecbdata->diff_words->word_regex);
1904                        free(ecbdata->diff_words->word_regex);
1905                }
1906                FREE_AND_NULL(ecbdata->diff_words);
1907        }
1908}
1909
1910const char *diff_get_color(int diff_use_color, enum color_diff ix)
1911{
1912        if (want_color(diff_use_color))
1913                return diff_colors[ix];
1914        return "";
1915}
1916
1917const char *diff_line_prefix(struct diff_options *opt)
1918{
1919        struct strbuf *msgbuf;
1920        if (!opt->output_prefix)
1921                return "";
1922
1923        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
1924        return msgbuf->buf;
1925}
1926
1927static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
1928{
1929        const char *cp;
1930        unsigned long allot;
1931        size_t l = len;
1932
1933        cp = line;
1934        allot = l;
1935        while (0 < l) {
1936                (void) utf8_width(&cp, &l);
1937                if (!cp)
1938                        break; /* truncated in the middle? */
1939        }
1940        return allot - l;
1941}
1942
1943static void find_lno(const char *line, struct emit_callback *ecbdata)
1944{
1945        const char *p;
1946        ecbdata->lno_in_preimage = 0;
1947        ecbdata->lno_in_postimage = 0;
1948        p = strchr(line, '-');
1949        if (!p)
1950                return; /* cannot happen */
1951        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1952        p = strchr(p, '+');
1953        if (!p)
1954                return; /* cannot happen */
1955        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
1956}
1957
1958static void fn_out_consume(void *priv, char *line, unsigned long len)
1959{
1960        struct emit_callback *ecbdata = priv;
1961        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1962        struct diff_options *o = ecbdata->opt;
1963
1964        o->found_changes = 1;
1965
1966        if (ecbdata->header) {
1967                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
1968                                 ecbdata->header->buf, ecbdata->header->len, 0);
1969                strbuf_reset(ecbdata->header);
1970                ecbdata->header = NULL;
1971        }
1972
1973        if (ecbdata->label_path[0]) {
1974                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
1975                                 ecbdata->label_path[0],
1976                                 strlen(ecbdata->label_path[0]), 0);
1977                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
1978                                 ecbdata->label_path[1],
1979                                 strlen(ecbdata->label_path[1]), 0);
1980                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1981        }
1982
1983        if (diff_suppress_blank_empty
1984            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1985                line[0] = '\n';
1986                len = 1;
1987        }
1988
1989        if (line[0] == '@') {
1990                if (ecbdata->diff_words)
1991                        diff_words_flush(ecbdata);
1992                len = sane_truncate_line(ecbdata, line, len);
1993                find_lno(line, ecbdata);
1994                emit_hunk_header(ecbdata, line, len);
1995                return;
1996        }
1997
1998        if (ecbdata->diff_words) {
1999                enum diff_symbol s =
2000                        ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN ?
2001                        DIFF_SYMBOL_WORDS_PORCELAIN : DIFF_SYMBOL_WORDS;
2002                if (line[0] == '-') {
2003                        diff_words_append(line, len,
2004                                          &ecbdata->diff_words->minus);
2005                        return;
2006                } else if (line[0] == '+') {
2007                        diff_words_append(line, len,
2008                                          &ecbdata->diff_words->plus);
2009                        return;
2010                } else if (starts_with(line, "\\ ")) {
2011                        /*
2012                         * Eat the "no newline at eof" marker as if we
2013                         * saw a "+" or "-" line with nothing on it,
2014                         * and return without diff_words_flush() to
2015                         * defer processing. If this is the end of
2016                         * preimage, more "+" lines may come after it.
2017                         */
2018                        return;
2019                }
2020                diff_words_flush(ecbdata);
2021                emit_diff_symbol(o, s, line, len, 0);
2022                return;
2023        }
2024
2025        switch (line[0]) {
2026        case '+':
2027                ecbdata->lno_in_postimage++;
2028                emit_add_line(reset, ecbdata, line + 1, len - 1);
2029                break;
2030        case '-':
2031                ecbdata->lno_in_preimage++;
2032                emit_del_line(reset, ecbdata, line + 1, len - 1);
2033                break;
2034        case ' ':
2035                ecbdata->lno_in_postimage++;
2036                ecbdata->lno_in_preimage++;
2037                emit_context_line(reset, ecbdata, line + 1, len - 1);
2038                break;
2039        default:
2040                /* incomplete line at the end */
2041                ecbdata->lno_in_preimage++;
2042                emit_diff_symbol(o, DIFF_SYMBOL_CONTEXT_INCOMPLETE,
2043                                 line, len, 0);
2044                break;
2045        }
2046}
2047
2048static void pprint_rename(struct strbuf *name, const char *a, const char *b)
2049{
2050        const char *old_name = a;
2051        const char *new_name = b;
2052        int pfx_length, sfx_length;
2053        int pfx_adjust_for_slash;
2054        int len_a = strlen(a);
2055        int len_b = strlen(b);
2056        int a_midlen, b_midlen;
2057        int qlen_a = quote_c_style(a, NULL, NULL, 0);
2058        int qlen_b = quote_c_style(b, NULL, NULL, 0);
2059
2060        if (qlen_a || qlen_b) {
2061                quote_c_style(a, name, NULL, 0);
2062                strbuf_addstr(name, " => ");
2063                quote_c_style(b, name, NULL, 0);
2064                return;
2065        }
2066
2067        /* Find common prefix */
2068        pfx_length = 0;
2069        while (*old_name && *new_name && *old_name == *new_name) {
2070                if (*old_name == '/')
2071                        pfx_length = old_name - a + 1;
2072                old_name++;
2073                new_name++;
2074        }
2075
2076        /* Find common suffix */
2077        old_name = a + len_a;
2078        new_name = b + len_b;
2079        sfx_length = 0;
2080        /*
2081         * If there is a common prefix, it must end in a slash.  In
2082         * that case we let this loop run 1 into the prefix to see the
2083         * same slash.
2084         *
2085         * If there is no common prefix, we cannot do this as it would
2086         * underrun the input strings.
2087         */
2088        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
2089        while (a + pfx_length - pfx_adjust_for_slash <= old_name &&
2090               b + pfx_length - pfx_adjust_for_slash <= new_name &&
2091               *old_name == *new_name) {
2092                if (*old_name == '/')
2093                        sfx_length = len_a - (old_name - a);
2094                old_name--;
2095                new_name--;
2096        }
2097
2098        /*
2099         * pfx{mid-a => mid-b}sfx
2100         * {pfx-a => pfx-b}sfx
2101         * pfx{sfx-a => sfx-b}
2102         * name-a => name-b
2103         */
2104        a_midlen = len_a - pfx_length - sfx_length;
2105        b_midlen = len_b - pfx_length - sfx_length;
2106        if (a_midlen < 0)
2107                a_midlen = 0;
2108        if (b_midlen < 0)
2109                b_midlen = 0;
2110
2111        strbuf_grow(name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
2112        if (pfx_length + sfx_length) {
2113                strbuf_add(name, a, pfx_length);
2114                strbuf_addch(name, '{');
2115        }
2116        strbuf_add(name, a + pfx_length, a_midlen);
2117        strbuf_addstr(name, " => ");
2118        strbuf_add(name, b + pfx_length, b_midlen);
2119        if (pfx_length + sfx_length) {
2120                strbuf_addch(name, '}');
2121                strbuf_add(name, a + len_a - sfx_length, sfx_length);
2122        }
2123}
2124
2125struct diffstat_t {
2126        int nr;
2127        int alloc;
2128        struct diffstat_file {
2129                char *from_name;
2130                char *name;
2131                char *print_name;
2132                const char *comments;
2133                unsigned is_unmerged:1;
2134                unsigned is_binary:1;
2135                unsigned is_renamed:1;
2136                unsigned is_interesting:1;
2137                uintmax_t added, deleted;
2138        } **files;
2139};
2140
2141static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
2142                                          const char *name_a,
2143                                          const char *name_b)
2144{
2145        struct diffstat_file *x;
2146        x = xcalloc(1, sizeof(*x));
2147        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
2148        diffstat->files[diffstat->nr++] = x;
2149        if (name_b) {
2150                x->from_name = xstrdup(name_a);
2151                x->name = xstrdup(name_b);
2152                x->is_renamed = 1;
2153        }
2154        else {
2155                x->from_name = NULL;
2156                x->name = xstrdup(name_a);
2157        }
2158        return x;
2159}
2160
2161static void diffstat_consume(void *priv, char *line, unsigned long len)
2162{
2163        struct diffstat_t *diffstat = priv;
2164        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
2165
2166        if (line[0] == '+')
2167                x->added++;
2168        else if (line[0] == '-')
2169                x->deleted++;
2170}
2171
2172const char mime_boundary_leader[] = "------------";
2173
2174static int scale_linear(int it, int width, int max_change)
2175{
2176        if (!it)
2177                return 0;
2178        /*
2179         * make sure that at least one '-' or '+' is printed if
2180         * there is any change to this path. The easiest way is to
2181         * scale linearly as if the alloted width is one column shorter
2182         * than it is, and then add 1 to the result.
2183         */
2184        return 1 + (it * (width - 1) / max_change);
2185}
2186
2187static void show_graph(struct strbuf *out, char ch, int cnt,
2188                       const char *set, const char *reset)
2189{
2190        if (cnt <= 0)
2191                return;
2192        strbuf_addstr(out, set);
2193        strbuf_addchars(out, ch, cnt);
2194        strbuf_addstr(out, reset);
2195}
2196
2197static void fill_print_name(struct diffstat_file *file)
2198{
2199        struct strbuf pname = STRBUF_INIT;
2200
2201        if (file->print_name)
2202                return;
2203
2204        if (file->is_renamed)
2205                pprint_rename(&pname, file->from_name, file->name);
2206        else
2207                quote_c_style(file->name, &pname, NULL, 0);
2208
2209        if (file->comments)
2210                strbuf_addf(&pname, " (%s)", file->comments);
2211
2212        file->print_name = strbuf_detach(&pname, NULL);
2213}
2214
2215static void print_stat_summary_inserts_deletes(struct diff_options *options,
2216                int files, int insertions, int deletions)
2217{
2218        struct strbuf sb = STRBUF_INIT;
2219
2220        if (!files) {
2221                assert(insertions == 0 && deletions == 0);
2222                emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
2223                                 NULL, 0, 0);
2224                return;
2225        }
2226
2227        strbuf_addf(&sb,
2228                    (files == 1) ? " %d file changed" : " %d files changed",
2229                    files);
2230
2231        /*
2232         * For binary diff, the caller may want to print "x files
2233         * changed" with insertions == 0 && deletions == 0.
2234         *
2235         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
2236         * is probably less confusing (i.e skip over "2 files changed
2237         * but nothing about added/removed lines? Is this a bug in Git?").
2238         */
2239        if (insertions || deletions == 0) {
2240                strbuf_addf(&sb,
2241                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
2242                            insertions);
2243        }
2244
2245        if (deletions || insertions == 0) {
2246                strbuf_addf(&sb,
2247                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
2248                            deletions);
2249        }
2250        strbuf_addch(&sb, '\n');
2251        emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
2252                         sb.buf, sb.len, 0);
2253        strbuf_release(&sb);
2254}
2255
2256void print_stat_summary(FILE *fp, int files,
2257                        int insertions, int deletions)
2258{
2259        struct diff_options o;
2260        memset(&o, 0, sizeof(o));
2261        o.file = fp;
2262
2263        print_stat_summary_inserts_deletes(&o, files, insertions, deletions);
2264}
2265
2266static void show_stats(struct diffstat_t *data, struct diff_options *options)
2267{
2268        int i, len, add, del, adds = 0, dels = 0;
2269        uintmax_t max_change = 0, max_len = 0;
2270        int total_files = data->nr, count;
2271        int width, name_width, graph_width, number_width = 0, bin_width = 0;
2272        const char *reset, *add_c, *del_c;
2273        int extra_shown = 0;
2274        const char *line_prefix = diff_line_prefix(options);
2275        struct strbuf out = STRBUF_INIT;
2276
2277        if (data->nr == 0)
2278                return;
2279
2280        count = options->stat_count ? options->stat_count : data->nr;
2281
2282        reset = diff_get_color_opt(options, DIFF_RESET);
2283        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
2284        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
2285
2286        /*
2287         * Find the longest filename and max number of changes
2288         */
2289        for (i = 0; (i < count) && (i < data->nr); i++) {
2290                struct diffstat_file *file = data->files[i];
2291                uintmax_t change = file->added + file->deleted;
2292
2293                if (!file->is_interesting && (change == 0)) {
2294                        count++; /* not shown == room for one more */
2295                        continue;
2296                }
2297                fill_print_name(file);
2298                len = strlen(file->print_name);
2299                if (max_len < len)
2300                        max_len = len;
2301
2302                if (file->is_unmerged) {
2303                        /* "Unmerged" is 8 characters */
2304                        bin_width = bin_width < 8 ? 8 : bin_width;
2305                        continue;
2306                }
2307                if (file->is_binary) {
2308                        /* "Bin XXX -> YYY bytes" */
2309                        int w = 14 + decimal_width(file->added)
2310                                + decimal_width(file->deleted);
2311                        bin_width = bin_width < w ? w : bin_width;
2312                        /* Display change counts aligned with "Bin" */
2313                        number_width = 3;
2314                        continue;
2315                }
2316
2317                if (max_change < change)
2318                        max_change = change;
2319        }
2320        count = i; /* where we can stop scanning in data->files[] */
2321
2322        /*
2323         * We have width = stat_width or term_columns() columns total.
2324         * We want a maximum of min(max_len, stat_name_width) for the name part.
2325         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
2326         * We also need 1 for " " and 4 + decimal_width(max_change)
2327         * for " | NNNN " and one the empty column at the end, altogether
2328         * 6 + decimal_width(max_change).
2329         *
2330         * If there's not enough space, we will use the smaller of
2331         * stat_name_width (if set) and 5/8*width for the filename,
2332         * and the rest for constant elements + graph part, but no more
2333         * than stat_graph_width for the graph part.
2334         * (5/8 gives 50 for filename and 30 for the constant parts + graph
2335         * for the standard terminal size).
2336         *
2337         * In other words: stat_width limits the maximum width, and
2338         * stat_name_width fixes the maximum width of the filename,
2339         * and is also used to divide available columns if there
2340         * aren't enough.
2341         *
2342         * Binary files are displayed with "Bin XXX -> YYY bytes"
2343         * instead of the change count and graph. This part is treated
2344         * similarly to the graph part, except that it is not
2345         * "scaled". If total width is too small to accommodate the
2346         * guaranteed minimum width of the filename part and the
2347         * separators and this message, this message will "overflow"
2348         * making the line longer than the maximum width.
2349         */
2350
2351        if (options->stat_width == -1)
2352                width = term_columns() - strlen(line_prefix);
2353        else
2354                width = options->stat_width ? options->stat_width : 80;
2355        number_width = decimal_width(max_change) > number_width ?
2356                decimal_width(max_change) : number_width;
2357
2358        if (options->stat_graph_width == -1)
2359                options->stat_graph_width = diff_stat_graph_width;
2360
2361        /*
2362         * Guarantee 3/8*16==6 for the graph part
2363         * and 5/8*16==10 for the filename part
2364         */
2365        if (width < 16 + 6 + number_width)
2366                width = 16 + 6 + number_width;
2367
2368        /*
2369         * First assign sizes that are wanted, ignoring available width.
2370         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
2371         * starting from "XXX" should fit in graph_width.
2372         */
2373        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
2374        if (options->stat_graph_width &&
2375            options->stat_graph_width < graph_width)
2376                graph_width = options->stat_graph_width;
2377
2378        name_width = (options->stat_name_width > 0 &&
2379                      options->stat_name_width < max_len) ?
2380                options->stat_name_width : max_len;
2381
2382        /*
2383         * Adjust adjustable widths not to exceed maximum width
2384         */
2385        if (name_width + number_width + 6 + graph_width > width) {
2386                if (graph_width > width * 3/8 - number_width - 6) {
2387                        graph_width = width * 3/8 - number_width - 6;
2388                        if (graph_width < 6)
2389                                graph_width = 6;
2390                }
2391
2392                if (options->stat_graph_width &&
2393                    graph_width > options->stat_graph_width)
2394                        graph_width = options->stat_graph_width;
2395                if (name_width > width - number_width - 6 - graph_width)
2396                        name_width = width - number_width - 6 - graph_width;
2397                else
2398                        graph_width = width - number_width - 6 - name_width;
2399        }
2400
2401        /*
2402         * From here name_width is the width of the name area,
2403         * and graph_width is the width of the graph area.
2404         * max_change is used to scale graph properly.
2405         */
2406        for (i = 0; i < count; i++) {
2407                const char *prefix = "";
2408                struct diffstat_file *file = data->files[i];
2409                char *name = file->print_name;
2410                uintmax_t added = file->added;
2411                uintmax_t deleted = file->deleted;
2412                int name_len;
2413
2414                if (!file->is_interesting && (added + deleted == 0))
2415                        continue;
2416
2417                /*
2418                 * "scale" the filename
2419                 */
2420                len = name_width;
2421                name_len = strlen(name);
2422                if (name_width < name_len) {
2423                        char *slash;
2424                        prefix = "...";
2425                        len -= 3;
2426                        name += name_len - len;
2427                        slash = strchr(name, '/');
2428                        if (slash)
2429                                name = slash;
2430                }
2431
2432                if (file->is_binary) {
2433                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2434                        strbuf_addf(&out, " %*s", number_width, "Bin");
2435                        if (!added && !deleted) {
2436                                strbuf_addch(&out, '\n');
2437                                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2438                                                 out.buf, out.len, 0);
2439                                strbuf_reset(&out);
2440                                continue;
2441                        }
2442                        strbuf_addf(&out, " %s%"PRIuMAX"%s",
2443                                del_c, deleted, reset);
2444                        strbuf_addstr(&out, " -> ");
2445                        strbuf_addf(&out, "%s%"PRIuMAX"%s",
2446                                add_c, added, reset);
2447                        strbuf_addstr(&out, " bytes\n");
2448                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2449                                         out.buf, out.len, 0);
2450                        strbuf_reset(&out);
2451                        continue;
2452                }
2453                else if (file->is_unmerged) {
2454                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2455                        strbuf_addstr(&out, " Unmerged\n");
2456                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2457                                         out.buf, out.len, 0);
2458                        strbuf_reset(&out);
2459                        continue;
2460                }
2461
2462                /*
2463                 * scale the add/delete
2464                 */
2465                add = added;
2466                del = deleted;
2467
2468                if (graph_width <= max_change) {
2469                        int total = scale_linear(add + del, graph_width, max_change);
2470                        if (total < 2 && add && del)
2471                                /* width >= 2 due to the sanity check */
2472                                total = 2;
2473                        if (add < del) {
2474                                add = scale_linear(add, graph_width, max_change);
2475                                del = total - add;
2476                        } else {
2477                                del = scale_linear(del, graph_width, max_change);
2478                                add = total - del;
2479                        }
2480                }
2481                strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2482                strbuf_addf(&out, " %*"PRIuMAX"%s",
2483                        number_width, added + deleted,
2484                        added + deleted ? " " : "");
2485                show_graph(&out, '+', add, add_c, reset);
2486                show_graph(&out, '-', del, del_c, reset);
2487                strbuf_addch(&out, '\n');
2488                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2489                                 out.buf, out.len, 0);
2490                strbuf_reset(&out);
2491        }
2492
2493        for (i = 0; i < data->nr; i++) {
2494                struct diffstat_file *file = data->files[i];
2495                uintmax_t added = file->added;
2496                uintmax_t deleted = file->deleted;
2497
2498                if (file->is_unmerged ||
2499                    (!file->is_interesting && (added + deleted == 0))) {
2500                        total_files--;
2501                        continue;
2502                }
2503
2504                if (!file->is_binary) {
2505                        adds += added;
2506                        dels += deleted;
2507                }
2508                if (i < count)
2509                        continue;
2510                if (!extra_shown)
2511                        emit_diff_symbol(options,
2512                                         DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
2513                                         NULL, 0, 0);
2514                extra_shown = 1;
2515        }
2516
2517        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2518        strbuf_release(&out);
2519}
2520
2521static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
2522{
2523        int i, adds = 0, dels = 0, total_files = data->nr;
2524
2525        if (data->nr == 0)
2526                return;
2527
2528        for (i = 0; i < data->nr; i++) {
2529                int added = data->files[i]->added;
2530                int deleted = data->files[i]->deleted;
2531
2532                if (data->files[i]->is_unmerged ||
2533                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
2534                        total_files--;
2535                } else if (!data->files[i]->is_binary) { /* don't count bytes */
2536                        adds += added;
2537                        dels += deleted;
2538                }
2539        }
2540        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2541}
2542
2543static void show_numstat(struct diffstat_t *data, struct diff_options *options)
2544{
2545        int i;
2546
2547        if (data->nr == 0)
2548                return;
2549
2550        for (i = 0; i < data->nr; i++) {
2551                struct diffstat_file *file = data->files[i];
2552
2553                fprintf(options->file, "%s", diff_line_prefix(options));
2554
2555                if (file->is_binary)
2556                        fprintf(options->file, "-\t-\t");
2557                else
2558                        fprintf(options->file,
2559                                "%"PRIuMAX"\t%"PRIuMAX"\t",
2560                                file->added, file->deleted);
2561                if (options->line_termination) {
2562                        fill_print_name(file);
2563                        if (!file->is_renamed)
2564                                write_name_quoted(file->name, options->file,
2565                                                  options->line_termination);
2566                        else {
2567                                fputs(file->print_name, options->file);
2568                                putc(options->line_termination, options->file);
2569                        }
2570                } else {
2571                        if (file->is_renamed) {
2572                                putc('\0', options->file);
2573                                write_name_quoted(file->from_name, options->file, '\0');
2574                        }
2575                        write_name_quoted(file->name, options->file, '\0');
2576                }
2577        }
2578}
2579
2580struct dirstat_file {
2581        const char *name;
2582        unsigned long changed;
2583};
2584
2585struct dirstat_dir {
2586        struct dirstat_file *files;
2587        int alloc, nr, permille, cumulative;
2588};
2589
2590static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
2591                unsigned long changed, const char *base, int baselen)
2592{
2593        unsigned long sum_changes = 0;
2594        unsigned int sources = 0;
2595        const char *line_prefix = diff_line_prefix(opt);
2596
2597        while (dir->nr) {
2598                struct dirstat_file *f = dir->files;
2599                int namelen = strlen(f->name);
2600                unsigned long changes;
2601                char *slash;
2602
2603                if (namelen < baselen)
2604                        break;
2605                if (memcmp(f->name, base, baselen))
2606                        break;
2607                slash = strchr(f->name + baselen, '/');
2608                if (slash) {
2609                        int newbaselen = slash + 1 - f->name;
2610                        changes = gather_dirstat(opt, dir, changed, f->name, newbaselen);
2611                        sources++;
2612                } else {
2613                        changes = f->changed;
2614                        dir->files++;
2615                        dir->nr--;
2616                        sources += 2;
2617                }
2618                sum_changes += changes;
2619        }
2620
2621        /*
2622         * We don't report dirstat's for
2623         *  - the top level
2624         *  - or cases where everything came from a single directory
2625         *    under this directory (sources == 1).
2626         */
2627        if (baselen && sources != 1) {
2628                if (sum_changes) {
2629                        int permille = sum_changes * 1000 / changed;
2630                        if (permille >= dir->permille) {
2631                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
2632                                        permille / 10, permille % 10, baselen, base);
2633                                if (!dir->cumulative)
2634                                        return 0;
2635                        }
2636                }
2637        }
2638        return sum_changes;
2639}
2640
2641static int dirstat_compare(const void *_a, const void *_b)
2642{
2643        const struct dirstat_file *a = _a;
2644        const struct dirstat_file *b = _b;
2645        return strcmp(a->name, b->name);
2646}
2647
2648static void show_dirstat(struct diff_options *options)
2649{
2650        int i;
2651        unsigned long changed;
2652        struct dirstat_dir dir;
2653        struct diff_queue_struct *q = &diff_queued_diff;
2654
2655        dir.files = NULL;
2656        dir.alloc = 0;
2657        dir.nr = 0;
2658        dir.permille = options->dirstat_permille;
2659        dir.cumulative = options->flags.dirstat_cumulative;
2660
2661        changed = 0;
2662        for (i = 0; i < q->nr; i++) {
2663                struct diff_filepair *p = q->queue[i];
2664                const char *name;
2665                unsigned long copied, added, damage;
2666                int content_changed;
2667
2668                name = p->two->path ? p->two->path : p->one->path;
2669
2670                if (p->one->oid_valid && p->two->oid_valid)
2671                        content_changed = oidcmp(&p->one->oid, &p->two->oid);
2672                else
2673                        content_changed = 1;
2674
2675                if (!content_changed) {
2676                        /*
2677                         * The SHA1 has not changed, so pre-/post-content is
2678                         * identical. We can therefore skip looking at the
2679                         * file contents altogether.
2680                         */
2681                        damage = 0;
2682                        goto found_damage;
2683                }
2684
2685                if (options->flags.dirstat_by_file) {
2686                        /*
2687                         * In --dirstat-by-file mode, we don't really need to
2688                         * look at the actual file contents at all.
2689                         * The fact that the SHA1 changed is enough for us to
2690                         * add this file to the list of results
2691                         * (with each file contributing equal damage).
2692                         */
2693                        damage = 1;
2694                        goto found_damage;
2695                }
2696
2697                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
2698                        diff_populate_filespec(p->one, 0);
2699                        diff_populate_filespec(p->two, 0);
2700                        diffcore_count_changes(p->one, p->two, NULL, NULL,
2701                                               &copied, &added);
2702                        diff_free_filespec_data(p->one);
2703                        diff_free_filespec_data(p->two);
2704                } else if (DIFF_FILE_VALID(p->one)) {
2705                        diff_populate_filespec(p->one, CHECK_SIZE_ONLY);
2706                        copied = added = 0;
2707                        diff_free_filespec_data(p->one);
2708                } else if (DIFF_FILE_VALID(p->two)) {
2709                        diff_populate_filespec(p->two, CHECK_SIZE_ONLY);
2710                        copied = 0;
2711                        added = p->two->size;
2712                        diff_free_filespec_data(p->two);
2713                } else
2714                        continue;
2715
2716                /*
2717                 * Original minus copied is the removed material,
2718                 * added is the new material.  They are both damages
2719                 * made to the preimage.
2720                 * If the resulting damage is zero, we know that
2721                 * diffcore_count_changes() considers the two entries to
2722                 * be identical, but since content_changed is true, we
2723                 * know that there must have been _some_ kind of change,
2724                 * so we force all entries to have damage > 0.
2725                 */
2726                damage = (p->one->size - copied) + added;
2727                if (!damage)
2728                        damage = 1;
2729
2730found_damage:
2731                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
2732                dir.files[dir.nr].name = name;
2733                dir.files[dir.nr].changed = damage;
2734                changed += damage;
2735                dir.nr++;
2736        }
2737
2738        /* This can happen even with many files, if everything was renames */
2739        if (!changed)
2740                return;
2741
2742        /* Show all directories with more than x% of the changes */
2743        QSORT(dir.files, dir.nr, dirstat_compare);
2744        gather_dirstat(options, &dir, changed, "", 0);
2745}
2746
2747static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
2748{
2749        int i;
2750        unsigned long changed;
2751        struct dirstat_dir dir;
2752
2753        if (data->nr == 0)
2754                return;
2755
2756        dir.files = NULL;
2757        dir.alloc = 0;
2758        dir.nr = 0;
2759        dir.permille = options->dirstat_permille;
2760        dir.cumulative = options->flags.dirstat_cumulative;
2761
2762        changed = 0;
2763        for (i = 0; i < data->nr; i++) {
2764                struct diffstat_file *file = data->files[i];
2765                unsigned long damage = file->added + file->deleted;
2766                if (file->is_binary)
2767                        /*
2768                         * binary files counts bytes, not lines. Must find some
2769                         * way to normalize binary bytes vs. textual lines.
2770                         * The following heuristic assumes that there are 64
2771                         * bytes per "line".
2772                         * This is stupid and ugly, but very cheap...
2773                         */
2774                        damage = DIV_ROUND_UP(damage, 64);
2775                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
2776                dir.files[dir.nr].name = file->name;
2777                dir.files[dir.nr].changed = damage;
2778                changed += damage;
2779                dir.nr++;
2780        }
2781
2782        /* This can happen even with many files, if everything was renames */
2783        if (!changed)
2784                return;
2785
2786        /* Show all directories with more than x% of the changes */
2787        QSORT(dir.files, dir.nr, dirstat_compare);
2788        gather_dirstat(options, &dir, changed, "", 0);
2789}
2790
2791static void free_diffstat_info(struct diffstat_t *diffstat)
2792{
2793        int i;
2794        for (i = 0; i < diffstat->nr; i++) {
2795                struct diffstat_file *f = diffstat->files[i];
2796                free(f->print_name);
2797                free(f->name);
2798                free(f->from_name);
2799                free(f);
2800        }
2801        free(diffstat->files);
2802}
2803
2804struct checkdiff_t {
2805        const char *filename;
2806        int lineno;
2807        int conflict_marker_size;
2808        struct diff_options *o;
2809        unsigned ws_rule;
2810        unsigned status;
2811};
2812
2813static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
2814{
2815        char firstchar;
2816        int cnt;
2817
2818        if (len < marker_size + 1)
2819                return 0;
2820        firstchar = line[0];
2821        switch (firstchar) {
2822        case '=': case '>': case '<': case '|':
2823                break;
2824        default:
2825                return 0;
2826        }
2827        for (cnt = 1; cnt < marker_size; cnt++)
2828                if (line[cnt] != firstchar)
2829                        return 0;
2830        /* line[1] thru line[marker_size-1] are same as firstchar */
2831        if (len < marker_size + 1 || !isspace(line[marker_size]))
2832                return 0;
2833        return 1;
2834}
2835
2836static void checkdiff_consume(void *priv, char *line, unsigned long len)
2837{
2838        struct checkdiff_t *data = priv;
2839        int marker_size = data->conflict_marker_size;
2840        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
2841        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
2842        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
2843        char *err;
2844        const char *line_prefix;
2845
2846        assert(data->o);
2847        line_prefix = diff_line_prefix(data->o);
2848
2849        if (line[0] == '+') {
2850                unsigned bad;
2851                data->lineno++;
2852                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
2853                        data->status |= 1;
2854                        fprintf(data->o->file,
2855                                "%s%s:%d: leftover conflict marker\n",
2856                                line_prefix, data->filename, data->lineno);
2857                }
2858                bad = ws_check(line + 1, len - 1, data->ws_rule);
2859                if (!bad)
2860                        return;
2861                data->status |= bad;
2862                err = whitespace_error_string(bad);
2863                fprintf(data->o->file, "%s%s:%d: %s.\n",
2864                        line_prefix, data->filename, data->lineno, err);
2865                free(err);
2866                emit_line(data->o, set, reset, line, 1);
2867                ws_check_emit(line + 1, len - 1, data->ws_rule,
2868                              data->o->file, set, reset, ws);
2869        } else if (line[0] == ' ') {
2870                data->lineno++;
2871        } else if (line[0] == '@') {
2872                char *plus = strchr(line, '+');
2873                if (plus)
2874                        data->lineno = strtol(plus, NULL, 10) - 1;
2875                else
2876                        die("invalid diff");
2877        }
2878}
2879
2880static unsigned char *deflate_it(char *data,
2881                                 unsigned long size,
2882                                 unsigned long *result_size)
2883{
2884        int bound;
2885        unsigned char *deflated;
2886        git_zstream stream;
2887
2888        git_deflate_init(&stream, zlib_compression_level);
2889        bound = git_deflate_bound(&stream, size);
2890        deflated = xmalloc(bound);
2891        stream.next_out = deflated;
2892        stream.avail_out = bound;
2893
2894        stream.next_in = (unsigned char *)data;
2895        stream.avail_in = size;
2896        while (git_deflate(&stream, Z_FINISH) == Z_OK)
2897                ; /* nothing */
2898        git_deflate_end(&stream);
2899        *result_size = stream.total_out;
2900        return deflated;
2901}
2902
2903static void emit_binary_diff_body(struct diff_options *o,
2904                                  mmfile_t *one, mmfile_t *two)
2905{
2906        void *cp;
2907        void *delta;
2908        void *deflated;
2909        void *data;
2910        unsigned long orig_size;
2911        unsigned long delta_size;
2912        unsigned long deflate_size;
2913        unsigned long data_size;
2914
2915        /* We could do deflated delta, or we could do just deflated two,
2916         * whichever is smaller.
2917         */
2918        delta = NULL;
2919        deflated = deflate_it(two->ptr, two->size, &deflate_size);
2920        if (one->size && two->size) {
2921                delta = diff_delta(one->ptr, one->size,
2922                                   two->ptr, two->size,
2923                                   &delta_size, deflate_size);
2924                if (delta) {
2925                        void *to_free = delta;
2926                        orig_size = delta_size;
2927                        delta = deflate_it(delta, delta_size, &delta_size);
2928                        free(to_free);
2929                }
2930        }
2931
2932        if (delta && delta_size < deflate_size) {
2933                char *s = xstrfmt("%lu", orig_size);
2934                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
2935                                 s, strlen(s), 0);
2936                free(s);
2937                free(deflated);
2938                data = delta;
2939                data_size = delta_size;
2940        } else {
2941                char *s = xstrfmt("%lu", two->size);
2942                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
2943                                 s, strlen(s), 0);
2944                free(s);
2945                free(delta);
2946                data = deflated;
2947                data_size = deflate_size;
2948        }
2949
2950        /* emit data encoded in base85 */
2951        cp = data;
2952        while (data_size) {
2953                int len;
2954                int bytes = (52 < data_size) ? 52 : data_size;
2955                char line[71];
2956                data_size -= bytes;
2957                if (bytes <= 26)
2958                        line[0] = bytes + 'A' - 1;
2959                else
2960                        line[0] = bytes - 26 + 'a' - 1;
2961                encode_85(line + 1, cp, bytes);
2962                cp = (char *) cp + bytes;
2963
2964                len = strlen(line);
2965                line[len++] = '\n';
2966                line[len] = '\0';
2967
2968                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_BODY,
2969                                 line, len, 0);
2970        }
2971        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_FOOTER, NULL, 0, 0);
2972        free(data);
2973}
2974
2975static void emit_binary_diff(struct diff_options *o,
2976                             mmfile_t *one, mmfile_t *two)
2977{
2978        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER, NULL, 0, 0);
2979        emit_binary_diff_body(o, one, two);
2980        emit_binary_diff_body(o, two, one);
2981}
2982
2983int diff_filespec_is_binary(struct diff_filespec *one)
2984{
2985        if (one->is_binary == -1) {
2986                diff_filespec_load_driver(one);
2987                if (one->driver->binary != -1)
2988                        one->is_binary = one->driver->binary;
2989                else {
2990                        if (!one->data && DIFF_FILE_VALID(one))
2991                                diff_populate_filespec(one, CHECK_BINARY);
2992                        if (one->is_binary == -1 && one->data)
2993                                one->is_binary = buffer_is_binary(one->data,
2994                                                one->size);
2995                        if (one->is_binary == -1)
2996                                one->is_binary = 0;
2997                }
2998        }
2999        return one->is_binary;
3000}
3001
3002static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
3003{
3004        diff_filespec_load_driver(one);
3005        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
3006}
3007
3008void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
3009{
3010        if (!options->a_prefix)
3011                options->a_prefix = a;
3012        if (!options->b_prefix)
3013                options->b_prefix = b;
3014}
3015
3016struct userdiff_driver *get_textconv(struct diff_filespec *one)
3017{
3018        if (!DIFF_FILE_VALID(one))
3019                return NULL;
3020
3021        diff_filespec_load_driver(one);
3022        return userdiff_get_textconv(one->driver);
3023}
3024
3025static void builtin_diff(const char *name_a,
3026                         const char *name_b,
3027                         struct diff_filespec *one,
3028                         struct diff_filespec *two,
3029                         const char *xfrm_msg,
3030                         int must_show_header,
3031                         struct diff_options *o,
3032                         int complete_rewrite)
3033{
3034        mmfile_t mf1, mf2;
3035        const char *lbl[2];
3036        char *a_one, *b_two;
3037        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
3038        const char *reset = diff_get_color_opt(o, DIFF_RESET);
3039        const char *a_prefix, *b_prefix;
3040        struct userdiff_driver *textconv_one = NULL;
3041        struct userdiff_driver *textconv_two = NULL;
3042        struct strbuf header = STRBUF_INIT;
3043        const char *line_prefix = diff_line_prefix(o);
3044
3045        diff_set_mnemonic_prefix(o, "a/", "b/");
3046        if (o->flags.reverse_diff) {
3047                a_prefix = o->b_prefix;
3048                b_prefix = o->a_prefix;
3049        } else {
3050                a_prefix = o->a_prefix;
3051                b_prefix = o->b_prefix;
3052        }
3053
3054        if (o->submodule_format == DIFF_SUBMODULE_LOG &&
3055            (!one->mode || S_ISGITLINK(one->mode)) &&
3056            (!two->mode || S_ISGITLINK(two->mode))) {
3057                show_submodule_summary(o, one->path ? one->path : two->path,
3058                                &one->oid, &two->oid,
3059                                two->dirty_submodule);
3060                return;
3061        } else if (o->submodule_format == DIFF_SUBMODULE_INLINE_DIFF &&
3062                   (!one->mode || S_ISGITLINK(one->mode)) &&
3063                   (!two->mode || S_ISGITLINK(two->mode))) {
3064                show_submodule_inline_diff(o, one->path ? one->path : two->path,
3065                                &one->oid, &two->oid,
3066                                two->dirty_submodule);
3067                return;
3068        }
3069
3070        if (o->flags.allow_textconv) {
3071                textconv_one = get_textconv(one);
3072                textconv_two = get_textconv(two);
3073        }
3074
3075        /* Never use a non-valid filename anywhere if at all possible */
3076        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
3077        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
3078
3079        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
3080        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
3081        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
3082        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
3083        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
3084        if (lbl[0][0] == '/') {
3085                /* /dev/null */
3086                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
3087                if (xfrm_msg)
3088                        strbuf_addstr(&header, xfrm_msg);
3089                must_show_header = 1;
3090        }
3091        else if (lbl[1][0] == '/') {
3092                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
3093                if (xfrm_msg)
3094                        strbuf_addstr(&header, xfrm_msg);
3095                must_show_header = 1;
3096        }
3097        else {
3098                if (one->mode != two->mode) {
3099                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
3100                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
3101                        must_show_header = 1;
3102                }
3103                if (xfrm_msg)
3104                        strbuf_addstr(&header, xfrm_msg);
3105
3106                /*
3107                 * we do not run diff between different kind
3108                 * of objects.
3109                 */
3110                if ((one->mode ^ two->mode) & S_IFMT)
3111                        goto free_ab_and_return;
3112                if (complete_rewrite &&
3113                    (textconv_one || !diff_filespec_is_binary(one)) &&
3114                    (textconv_two || !diff_filespec_is_binary(two))) {
3115                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3116                                         header.buf, header.len, 0);
3117                        strbuf_reset(&header);
3118                        emit_rewrite_diff(name_a, name_b, one, two,
3119                                                textconv_one, textconv_two, o);
3120                        o->found_changes = 1;
3121                        goto free_ab_and_return;
3122                }
3123        }
3124
3125        if (o->irreversible_delete && lbl[1][0] == '/') {
3126                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf,
3127                                 header.len, 0);
3128                strbuf_reset(&header);
3129                goto free_ab_and_return;
3130        } else if (!o->flags.text &&
3131            ( (!textconv_one && diff_filespec_is_binary(one)) ||
3132              (!textconv_two && diff_filespec_is_binary(two)) )) {
3133                struct strbuf sb = STRBUF_INIT;
3134                if (!one->data && !two->data &&
3135                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
3136                    !o->flags.binary) {
3137                        if (!oidcmp(&one->oid, &two->oid)) {
3138                                if (must_show_header)
3139                                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3140                                                         header.buf, header.len,
3141                                                         0);
3142                                goto free_ab_and_return;
3143                        }
3144                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3145                                         header.buf, header.len, 0);
3146                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3147                                    diff_line_prefix(o), lbl[0], lbl[1]);
3148                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3149                                         sb.buf, sb.len, 0);
3150                        strbuf_release(&sb);
3151                        goto free_ab_and_return;
3152                }
3153                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3154                        die("unable to read files to diff");
3155                /* Quite common confusing case */
3156                if (mf1.size == mf2.size &&
3157                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
3158                        if (must_show_header)
3159                                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3160                                                 header.buf, header.len, 0);
3161                        goto free_ab_and_return;
3162                }
3163                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf, header.len, 0);
3164                strbuf_reset(&header);
3165                if (o->flags.binary)
3166                        emit_binary_diff(o, &mf1, &mf2);
3167                else {
3168                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3169                                    diff_line_prefix(o), lbl[0], lbl[1]);
3170                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3171                                         sb.buf, sb.len, 0);
3172                        strbuf_release(&sb);
3173                }
3174                o->found_changes = 1;
3175        } else {
3176                /* Crazy xdl interfaces.. */
3177                const char *diffopts = getenv("GIT_DIFF_OPTS");
3178                const char *v;
3179                xpparam_t xpp;
3180                xdemitconf_t xecfg;
3181                struct emit_callback ecbdata;
3182                const struct userdiff_funcname *pe;
3183
3184                if (must_show_header) {
3185                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3186                                         header.buf, header.len, 0);
3187                        strbuf_reset(&header);
3188                }
3189
3190                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
3191                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
3192
3193                pe = diff_funcname_pattern(one);
3194                if (!pe)
3195                        pe = diff_funcname_pattern(two);
3196
3197                memset(&xpp, 0, sizeof(xpp));
3198                memset(&xecfg, 0, sizeof(xecfg));
3199                memset(&ecbdata, 0, sizeof(ecbdata));
3200                ecbdata.label_path = lbl;
3201                ecbdata.color_diff = want_color(o->use_color);
3202                ecbdata.ws_rule = whitespace_rule(name_b);
3203                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
3204                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3205                ecbdata.opt = o;
3206                ecbdata.header = header.len ? &header : NULL;
3207                xpp.flags = o->xdl_opts;
3208                xpp.anchors = o->anchors;
3209                xpp.anchors_nr = o->anchors_nr;
3210                xecfg.ctxlen = o->context;
3211                xecfg.interhunkctxlen = o->interhunkcontext;
3212                xecfg.flags = XDL_EMIT_FUNCNAMES;
3213                if (o->flags.funccontext)
3214                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
3215                if (pe)
3216                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
3217                if (!diffopts)
3218                        ;
3219                else if (skip_prefix(diffopts, "--unified=", &v))
3220                        xecfg.ctxlen = strtoul(v, NULL, 10);
3221                else if (skip_prefix(diffopts, "-u", &v))
3222                        xecfg.ctxlen = strtoul(v, NULL, 10);
3223                if (o->word_diff)
3224                        init_diff_words_data(&ecbdata, o, one, two);
3225                if (xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
3226                                  &xpp, &xecfg))
3227                        die("unable to generate diff for %s", one->path);
3228                if (o->word_diff)
3229                        free_diff_words_data(&ecbdata);
3230                if (textconv_one)
3231                        free(mf1.ptr);
3232                if (textconv_two)
3233                        free(mf2.ptr);
3234                xdiff_clear_find_func(&xecfg);
3235        }
3236
3237 free_ab_and_return:
3238        strbuf_release(&header);
3239        diff_free_filespec_data(one);
3240        diff_free_filespec_data(two);
3241        free(a_one);
3242        free(b_two);
3243        return;
3244}
3245
3246static char *get_compact_summary(const struct diff_filepair *p, int is_renamed)
3247{
3248        if (!is_renamed) {
3249                if (p->status == DIFF_STATUS_ADDED) {
3250                        if (S_ISLNK(p->two->mode))
3251                                return "new +l";
3252                        else if ((p->two->mode & 0777) == 0755)
3253                                return "new +x";
3254                        else
3255                                return "new";
3256                } else if (p->status == DIFF_STATUS_DELETED)
3257                        return "gone";
3258        }
3259        if (S_ISLNK(p->one->mode) && !S_ISLNK(p->two->mode))
3260                return "mode -l";
3261        else if (!S_ISLNK(p->one->mode) && S_ISLNK(p->two->mode))
3262                return "mode +l";
3263        else if ((p->one->mode & 0777) == 0644 &&
3264                 (p->two->mode & 0777) == 0755)
3265                return "mode +x";
3266        else if ((p->one->mode & 0777) == 0755 &&
3267                 (p->two->mode & 0777) == 0644)
3268                return "mode -x";
3269        return NULL;
3270}
3271
3272static void builtin_diffstat(const char *name_a, const char *name_b,
3273                             struct diff_filespec *one,
3274                             struct diff_filespec *two,
3275                             struct diffstat_t *diffstat,
3276                             struct diff_options *o,
3277                             struct diff_filepair *p)
3278{
3279        mmfile_t mf1, mf2;
3280        struct diffstat_file *data;
3281        int same_contents;
3282        int complete_rewrite = 0;
3283
3284        if (!DIFF_PAIR_UNMERGED(p)) {
3285                if (p->status == DIFF_STATUS_MODIFIED && p->score)
3286                        complete_rewrite = 1;
3287        }
3288
3289        data = diffstat_add(diffstat, name_a, name_b);
3290        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
3291        if (o->flags.stat_with_summary)
3292                data->comments = get_compact_summary(p, data->is_renamed);
3293
3294        if (!one || !two) {
3295                data->is_unmerged = 1;
3296                return;
3297        }
3298
3299        same_contents = !oidcmp(&one->oid, &two->oid);
3300
3301        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
3302                data->is_binary = 1;
3303                if (same_contents) {
3304                        data->added = 0;
3305                        data->deleted = 0;
3306                } else {
3307                        data->added = diff_filespec_size(two);
3308                        data->deleted = diff_filespec_size(one);
3309                }
3310        }
3311
3312        else if (complete_rewrite) {
3313                diff_populate_filespec(one, 0);
3314                diff_populate_filespec(two, 0);
3315                data->deleted = count_lines(one->data, one->size);
3316                data->added = count_lines(two->data, two->size);
3317        }
3318
3319        else if (!same_contents) {
3320                /* Crazy xdl interfaces.. */
3321                xpparam_t xpp;
3322                xdemitconf_t xecfg;
3323
3324                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3325                        die("unable to read files to diff");
3326
3327                memset(&xpp, 0, sizeof(xpp));
3328                memset(&xecfg, 0, sizeof(xecfg));
3329                xpp.flags = o->xdl_opts;
3330                xpp.anchors = o->anchors;
3331                xpp.anchors_nr = o->anchors_nr;
3332                xecfg.ctxlen = o->context;
3333                xecfg.interhunkctxlen = o->interhunkcontext;
3334                if (xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
3335                                  &xpp, &xecfg))
3336                        die("unable to generate diffstat for %s", one->path);
3337        }
3338
3339        diff_free_filespec_data(one);
3340        diff_free_filespec_data(two);
3341}
3342
3343static void builtin_checkdiff(const char *name_a, const char *name_b,
3344                              const char *attr_path,
3345                              struct diff_filespec *one,
3346                              struct diff_filespec *two,
3347                              struct diff_options *o)
3348{
3349        mmfile_t mf1, mf2;
3350        struct checkdiff_t data;
3351
3352        if (!two)
3353                return;
3354
3355        memset(&data, 0, sizeof(data));
3356        data.filename = name_b ? name_b : name_a;
3357        data.lineno = 0;
3358        data.o = o;
3359        data.ws_rule = whitespace_rule(attr_path);
3360        data.conflict_marker_size = ll_merge_marker_size(attr_path);
3361
3362        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3363                die("unable to read files to diff");
3364
3365        /*
3366         * All the other codepaths check both sides, but not checking
3367         * the "old" side here is deliberate.  We are checking the newly
3368         * introduced changes, and as long as the "new" side is text, we
3369         * can and should check what it introduces.
3370         */
3371        if (diff_filespec_is_binary(two))
3372                goto free_and_return;
3373        else {
3374                /* Crazy xdl interfaces.. */
3375                xpparam_t xpp;
3376                xdemitconf_t xecfg;
3377
3378                memset(&xpp, 0, sizeof(xpp));
3379                memset(&xecfg, 0, sizeof(xecfg));
3380                xecfg.ctxlen = 1; /* at least one context line */
3381                xpp.flags = 0;
3382                if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
3383                                  &xpp, &xecfg))
3384                        die("unable to generate checkdiff for %s", one->path);
3385
3386                if (data.ws_rule & WS_BLANK_AT_EOF) {
3387                        struct emit_callback ecbdata;
3388                        int blank_at_eof;
3389
3390                        ecbdata.ws_rule = data.ws_rule;
3391                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3392                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
3393
3394                        if (blank_at_eof) {
3395                                static char *err;
3396                                if (!err)
3397                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
3398                                fprintf(o->file, "%s:%d: %s.\n",
3399                                        data.filename, blank_at_eof, err);
3400                                data.status = 1; /* report errors */
3401                        }
3402                }
3403        }
3404 free_and_return:
3405        diff_free_filespec_data(one);
3406        diff_free_filespec_data(two);
3407        if (data.status)
3408                o->flags.check_failed = 1;
3409}
3410
3411struct diff_filespec *alloc_filespec(const char *path)
3412{
3413        struct diff_filespec *spec;
3414
3415        FLEXPTR_ALLOC_STR(spec, path, path);
3416        spec->count = 1;
3417        spec->is_binary = -1;
3418        return spec;
3419}
3420
3421void free_filespec(struct diff_filespec *spec)
3422{
3423        if (!--spec->count) {
3424                diff_free_filespec_data(spec);
3425                free(spec);
3426        }
3427}
3428
3429void fill_filespec(struct diff_filespec *spec, const struct object_id *oid,
3430                   int oid_valid, unsigned short mode)
3431{
3432        if (mode) {
3433                spec->mode = canon_mode(mode);
3434                oidcpy(&spec->oid, oid);
3435                spec->oid_valid = oid_valid;
3436        }
3437}
3438
3439/*
3440 * Given a name and sha1 pair, if the index tells us the file in
3441 * the work tree has that object contents, return true, so that
3442 * prepare_temp_file() does not have to inflate and extract.
3443 */
3444static int reuse_worktree_file(const char *name, const struct object_id *oid, int want_file)
3445{
3446        const struct cache_entry *ce;
3447        struct stat st;
3448        int pos, len;
3449
3450        /*
3451         * We do not read the cache ourselves here, because the
3452         * benchmark with my previous version that always reads cache
3453         * shows that it makes things worse for diff-tree comparing
3454         * two linux-2.6 kernel trees in an already checked out work
3455         * tree.  This is because most diff-tree comparisons deal with
3456         * only a small number of files, while reading the cache is
3457         * expensive for a large project, and its cost outweighs the
3458         * savings we get by not inflating the object to a temporary
3459         * file.  Practically, this code only helps when we are used
3460         * by diff-cache --cached, which does read the cache before
3461         * calling us.
3462         */
3463        if (!active_cache)
3464                return 0;
3465
3466        /* We want to avoid the working directory if our caller
3467         * doesn't need the data in a normal file, this system
3468         * is rather slow with its stat/open/mmap/close syscalls,
3469         * and the object is contained in a pack file.  The pack
3470         * is probably already open and will be faster to obtain
3471         * the data through than the working directory.  Loose
3472         * objects however would tend to be slower as they need
3473         * to be individually opened and inflated.
3474         */
3475        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(oid->hash))
3476                return 0;
3477
3478        /*
3479         * Similarly, if we'd have to convert the file contents anyway, that
3480         * makes the optimization not worthwhile.
3481         */
3482        if (!want_file && would_convert_to_git(&the_index, name))
3483                return 0;
3484
3485        len = strlen(name);
3486        pos = cache_name_pos(name, len);
3487        if (pos < 0)
3488                return 0;
3489        ce = active_cache[pos];
3490
3491        /*
3492         * This is not the sha1 we are looking for, or
3493         * unreusable because it is not a regular file.
3494         */
3495        if (oidcmp(oid, &ce->oid) || !S_ISREG(ce->ce_mode))
3496                return 0;
3497
3498        /*
3499         * If ce is marked as "assume unchanged", there is no
3500         * guarantee that work tree matches what we are looking for.
3501         */
3502        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
3503                return 0;
3504
3505        /*
3506         * If ce matches the file in the work tree, we can reuse it.
3507         */
3508        if (ce_uptodate(ce) ||
3509            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
3510                return 1;
3511
3512        return 0;
3513}
3514
3515static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
3516{
3517        struct strbuf buf = STRBUF_INIT;
3518        char *dirty = "";
3519
3520        /* Are we looking at the work tree? */
3521        if (s->dirty_submodule)
3522                dirty = "-dirty";
3523
3524        strbuf_addf(&buf, "Subproject commit %s%s\n",
3525                    oid_to_hex(&s->oid), dirty);
3526        s->size = buf.len;
3527        if (size_only) {
3528                s->data = NULL;
3529                strbuf_release(&buf);
3530        } else {
3531                s->data = strbuf_detach(&buf, NULL);
3532                s->should_free = 1;
3533        }
3534        return 0;
3535}
3536
3537/*
3538 * While doing rename detection and pickaxe operation, we may need to
3539 * grab the data for the blob (or file) for our own in-core comparison.
3540 * diff_filespec has data and size fields for this purpose.
3541 */
3542int diff_populate_filespec(struct diff_filespec *s, unsigned int flags)
3543{
3544        int size_only = flags & CHECK_SIZE_ONLY;
3545        int err = 0;
3546        int conv_flags = global_conv_flags_eol;
3547        /*
3548         * demote FAIL to WARN to allow inspecting the situation
3549         * instead of refusing.
3550         */
3551        if (conv_flags & CONV_EOL_RNDTRP_DIE)
3552                conv_flags = CONV_EOL_RNDTRP_WARN;
3553
3554        if (!DIFF_FILE_VALID(s))
3555                die("internal error: asking to populate invalid file.");
3556        if (S_ISDIR(s->mode))
3557                return -1;
3558
3559        if (s->data)
3560                return 0;
3561
3562        if (size_only && 0 < s->size)
3563                return 0;
3564
3565        if (S_ISGITLINK(s->mode))
3566                return diff_populate_gitlink(s, size_only);
3567
3568        if (!s->oid_valid ||
3569            reuse_worktree_file(s->path, &s->oid, 0)) {
3570                struct strbuf buf = STRBUF_INIT;
3571                struct stat st;
3572                int fd;
3573
3574                if (lstat(s->path, &st) < 0) {
3575                err_empty:
3576                        err = -1;
3577                empty:
3578                        s->data = (char *)"";
3579                        s->size = 0;
3580                        return err;
3581                }
3582                s->size = xsize_t(st.st_size);
3583                if (!s->size)
3584                        goto empty;
3585                if (S_ISLNK(st.st_mode)) {
3586                        struct strbuf sb = STRBUF_INIT;
3587
3588                        if (strbuf_readlink(&sb, s->path, s->size))
3589                                goto err_empty;
3590                        s->size = sb.len;
3591                        s->data = strbuf_detach(&sb, NULL);
3592                        s->should_free = 1;
3593                        return 0;
3594                }
3595
3596                /*
3597                 * Even if the caller would be happy with getting
3598                 * only the size, we cannot return early at this
3599                 * point if the path requires us to run the content
3600                 * conversion.
3601                 */
3602                if (size_only && !would_convert_to_git(&the_index, s->path))
3603                        return 0;
3604
3605                /*
3606                 * Note: this check uses xsize_t(st.st_size) that may
3607                 * not be the true size of the blob after it goes
3608                 * through convert_to_git().  This may not strictly be
3609                 * correct, but the whole point of big_file_threshold
3610                 * and is_binary check being that we want to avoid
3611                 * opening the file and inspecting the contents, this
3612                 * is probably fine.
3613                 */
3614                if ((flags & CHECK_BINARY) &&
3615                    s->size > big_file_threshold && s->is_binary == -1) {
3616                        s->is_binary = 1;
3617                        return 0;
3618                }
3619                fd = open(s->path, O_RDONLY);
3620                if (fd < 0)
3621                        goto err_empty;
3622                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
3623                close(fd);
3624                s->should_munmap = 1;
3625
3626                /*
3627                 * Convert from working tree format to canonical git format
3628                 */
3629                if (convert_to_git(&the_index, s->path, s->data, s->size, &buf, conv_flags)) {
3630                        size_t size = 0;
3631                        munmap(s->data, s->size);
3632                        s->should_munmap = 0;
3633                        s->data = strbuf_detach(&buf, &size);
3634                        s->size = size;
3635                        s->should_free = 1;
3636                }
3637        }
3638        else {
3639                enum object_type type;
3640                if (size_only || (flags & CHECK_BINARY)) {
3641                        type = oid_object_info(&s->oid, &s->size);
3642                        if (type < 0)
3643                                die("unable to read %s",
3644                                    oid_to_hex(&s->oid));
3645                        if (size_only)
3646                                return 0;
3647                        if (s->size > big_file_threshold && s->is_binary == -1) {
3648                                s->is_binary = 1;
3649                                return 0;
3650                        }
3651                }
3652                s->data = read_object_file(&s->oid, &type, &s->size);
3653                if (!s->data)
3654                        die("unable to read %s", oid_to_hex(&s->oid));
3655                s->should_free = 1;
3656        }
3657        return 0;
3658}
3659
3660void diff_free_filespec_blob(struct diff_filespec *s)
3661{
3662        if (s->should_free)
3663                free(s->data);
3664        else if (s->should_munmap)
3665                munmap(s->data, s->size);
3666
3667        if (s->should_free || s->should_munmap) {
3668                s->should_free = s->should_munmap = 0;
3669                s->data = NULL;
3670        }
3671}
3672
3673void diff_free_filespec_data(struct diff_filespec *s)
3674{
3675        diff_free_filespec_blob(s);
3676        FREE_AND_NULL(s->cnt_data);
3677}
3678
3679static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
3680                           void *blob,
3681                           unsigned long size,
3682                           const struct object_id *oid,
3683                           int mode)
3684{
3685        struct strbuf buf = STRBUF_INIT;
3686        struct strbuf tempfile = STRBUF_INIT;
3687        char *path_dup = xstrdup(path);
3688        const char *base = basename(path_dup);
3689
3690        /* Generate "XXXXXX_basename.ext" */
3691        strbuf_addstr(&tempfile, "XXXXXX_");
3692        strbuf_addstr(&tempfile, base);
3693
3694        temp->tempfile = mks_tempfile_ts(tempfile.buf, strlen(base) + 1);
3695        if (!temp->tempfile)
3696                die_errno("unable to create temp-file");
3697        if (convert_to_working_tree(path,
3698                        (const char *)blob, (size_t)size, &buf)) {
3699                blob = buf.buf;
3700                size = buf.len;
3701        }
3702        if (write_in_full(temp->tempfile->fd, blob, size) < 0 ||
3703            close_tempfile_gently(temp->tempfile))
3704                die_errno("unable to write temp-file");
3705        temp->name = get_tempfile_path(temp->tempfile);
3706        oid_to_hex_r(temp->hex, oid);
3707        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
3708        strbuf_release(&buf);
3709        strbuf_release(&tempfile);
3710        free(path_dup);
3711}
3712
3713static struct diff_tempfile *prepare_temp_file(const char *name,
3714                struct diff_filespec *one)
3715{
3716        struct diff_tempfile *temp = claim_diff_tempfile();
3717
3718        if (!DIFF_FILE_VALID(one)) {
3719        not_a_valid_file:
3720                /* A '-' entry produces this for file-2, and
3721                 * a '+' entry produces this for file-1.
3722                 */
3723                temp->name = "/dev/null";
3724                xsnprintf(temp->hex, sizeof(temp->hex), ".");
3725                xsnprintf(temp->mode, sizeof(temp->mode), ".");
3726                return temp;
3727        }
3728
3729        if (!S_ISGITLINK(one->mode) &&
3730            (!one->oid_valid ||
3731             reuse_worktree_file(name, &one->oid, 1))) {
3732                struct stat st;
3733                if (lstat(name, &st) < 0) {
3734                        if (errno == ENOENT)
3735                                goto not_a_valid_file;
3736                        die_errno("stat(%s)", name);
3737                }
3738                if (S_ISLNK(st.st_mode)) {
3739                        struct strbuf sb = STRBUF_INIT;
3740                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
3741                                die_errno("readlink(%s)", name);
3742                        prep_temp_blob(name, temp, sb.buf, sb.len,
3743                                       (one->oid_valid ?
3744                                        &one->oid : &null_oid),
3745                                       (one->oid_valid ?
3746                                        one->mode : S_IFLNK));
3747                        strbuf_release(&sb);
3748                }
3749                else {
3750                        /* we can borrow from the file in the work tree */
3751                        temp->name = name;
3752                        if (!one->oid_valid)
3753                                oid_to_hex_r(temp->hex, &null_oid);
3754                        else
3755                                oid_to_hex_r(temp->hex, &one->oid);
3756                        /* Even though we may sometimes borrow the
3757                         * contents from the work tree, we always want
3758                         * one->mode.  mode is trustworthy even when
3759                         * !(one->oid_valid), as long as
3760                         * DIFF_FILE_VALID(one).
3761                         */
3762                        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
3763                }
3764                return temp;
3765        }
3766        else {
3767                if (diff_populate_filespec(one, 0))
3768                        die("cannot read data blob for %s", one->path);
3769                prep_temp_blob(name, temp, one->data, one->size,
3770                               &one->oid, one->mode);
3771        }
3772        return temp;
3773}
3774
3775static void add_external_diff_name(struct argv_array *argv,
3776                                   const char *name,
3777                                   struct diff_filespec *df)
3778{
3779        struct diff_tempfile *temp = prepare_temp_file(name, df);
3780        argv_array_push(argv, temp->name);
3781        argv_array_push(argv, temp->hex);
3782        argv_array_push(argv, temp->mode);
3783}
3784
3785/* An external diff command takes:
3786 *
3787 * diff-cmd name infile1 infile1-sha1 infile1-mode \
3788 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
3789 *
3790 */
3791static void run_external_diff(const char *pgm,
3792                              const char *name,
3793                              const char *other,
3794                              struct diff_filespec *one,
3795                              struct diff_filespec *two,
3796                              const char *xfrm_msg,
3797                              int complete_rewrite,
3798                              struct diff_options *o)
3799{
3800        struct argv_array argv = ARGV_ARRAY_INIT;
3801        struct argv_array env = ARGV_ARRAY_INIT;
3802        struct diff_queue_struct *q = &diff_queued_diff;
3803
3804        argv_array_push(&argv, pgm);
3805        argv_array_push(&argv, name);
3806
3807        if (one && two) {
3808                add_external_diff_name(&argv, name, one);
3809                if (!other)
3810                        add_external_diff_name(&argv, name, two);
3811                else {
3812                        add_external_diff_name(&argv, other, two);
3813                        argv_array_push(&argv, other);
3814                        argv_array_push(&argv, xfrm_msg);
3815                }
3816        }
3817
3818        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
3819        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
3820
3821        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
3822                die(_("external diff died, stopping at %s"), name);
3823
3824        remove_tempfile();
3825        argv_array_clear(&argv);
3826        argv_array_clear(&env);
3827}
3828
3829static int similarity_index(struct diff_filepair *p)
3830{
3831        return p->score * 100 / MAX_SCORE;
3832}
3833
3834static const char *diff_abbrev_oid(const struct object_id *oid, int abbrev)
3835{
3836        if (startup_info->have_repository)
3837                return find_unique_abbrev(oid, abbrev);
3838        else {
3839                char *hex = oid_to_hex(oid);
3840                if (abbrev < 0)
3841                        abbrev = FALLBACK_DEFAULT_ABBREV;
3842                if (abbrev > GIT_SHA1_HEXSZ)
3843                        die("BUG: oid abbreviation out of range: %d", abbrev);
3844                if (abbrev)
3845                        hex[abbrev] = '\0';
3846                return hex;
3847        }
3848}
3849
3850static void fill_metainfo(struct strbuf *msg,
3851                          const char *name,
3852                          const char *other,
3853                          struct diff_filespec *one,
3854                          struct diff_filespec *two,
3855                          struct diff_options *o,
3856                          struct diff_filepair *p,
3857                          int *must_show_header,
3858                          int use_color)
3859{
3860        const char *set = diff_get_color(use_color, DIFF_METAINFO);
3861        const char *reset = diff_get_color(use_color, DIFF_RESET);
3862        const char *line_prefix = diff_line_prefix(o);
3863
3864        *must_show_header = 1;
3865        strbuf_init(msg, PATH_MAX * 2 + 300);
3866        switch (p->status) {
3867        case DIFF_STATUS_COPIED:
3868                strbuf_addf(msg, "%s%ssimilarity index %d%%",
3869                            line_prefix, set, similarity_index(p));
3870                strbuf_addf(msg, "%s\n%s%scopy from ",
3871                            reset,  line_prefix, set);
3872                quote_c_style(name, msg, NULL, 0);
3873                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
3874                quote_c_style(other, msg, NULL, 0);
3875                strbuf_addf(msg, "%s\n", reset);
3876                break;
3877        case DIFF_STATUS_RENAMED:
3878                strbuf_addf(msg, "%s%ssimilarity index %d%%",
3879                            line_prefix, set, similarity_index(p));
3880                strbuf_addf(msg, "%s\n%s%srename from ",
3881                            reset, line_prefix, set);
3882                quote_c_style(name, msg, NULL, 0);
3883                strbuf_addf(msg, "%s\n%s%srename to ",
3884                            reset, line_prefix, set);
3885                quote_c_style(other, msg, NULL, 0);
3886                strbuf_addf(msg, "%s\n", reset);
3887                break;
3888        case DIFF_STATUS_MODIFIED:
3889                if (p->score) {
3890                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
3891                                    line_prefix,
3892                                    set, similarity_index(p), reset);
3893                        break;
3894                }
3895                /* fallthru */
3896        default:
3897                *must_show_header = 0;
3898        }
3899        if (one && two && oidcmp(&one->oid, &two->oid)) {
3900                int abbrev = o->flags.full_index ? 40 : DEFAULT_ABBREV;
3901
3902                if (o->flags.binary) {
3903                        mmfile_t mf;
3904                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
3905                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
3906                                abbrev = 40;
3907                }
3908                strbuf_addf(msg, "%s%sindex %s..%s", line_prefix, set,
3909                            diff_abbrev_oid(&one->oid, abbrev),
3910                            diff_abbrev_oid(&two->oid, abbrev));
3911                if (one->mode == two->mode)
3912                        strbuf_addf(msg, " %06o", one->mode);
3913                strbuf_addf(msg, "%s\n", reset);
3914        }
3915}
3916
3917static void run_diff_cmd(const char *pgm,
3918                         const char *name,
3919                         const char *other,
3920                         const char *attr_path,
3921                         struct diff_filespec *one,
3922                         struct diff_filespec *two,
3923                         struct strbuf *msg,
3924                         struct diff_options *o,
3925                         struct diff_filepair *p)
3926{
3927        const char *xfrm_msg = NULL;
3928        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
3929        int must_show_header = 0;
3930
3931
3932        if (o->flags.allow_external) {
3933                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
3934                if (drv && drv->external)
3935                        pgm = drv->external;
3936        }
3937
3938        if (msg) {
3939                /*
3940                 * don't use colors when the header is intended for an
3941                 * external diff driver
3942                 */
3943                fill_metainfo(msg, name, other, one, two, o, p,
3944                              &must_show_header,
3945                              want_color(o->use_color) && !pgm);
3946                xfrm_msg = msg->len ? msg->buf : NULL;
3947        }
3948
3949        if (pgm) {
3950                run_external_diff(pgm, name, other, one, two, xfrm_msg,
3951                                  complete_rewrite, o);
3952                return;
3953        }
3954        if (one && two)
3955                builtin_diff(name, other ? other : name,
3956                             one, two, xfrm_msg, must_show_header,
3957                             o, complete_rewrite);
3958        else
3959                fprintf(o->file, "* Unmerged path %s\n", name);
3960}
3961
3962static void diff_fill_oid_info(struct diff_filespec *one)
3963{
3964        if (DIFF_FILE_VALID(one)) {
3965                if (!one->oid_valid) {
3966                        struct stat st;
3967                        if (one->is_stdin) {
3968                                oidclr(&one->oid);
3969                                return;
3970                        }
3971                        if (lstat(one->path, &st) < 0)
3972                                die_errno("stat '%s'", one->path);
3973                        if (index_path(&one->oid, one->path, &st, 0))
3974                                die("cannot hash %s", one->path);
3975                }
3976        }
3977        else
3978                oidclr(&one->oid);
3979}
3980
3981static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
3982{
3983        /* Strip the prefix but do not molest /dev/null and absolute paths */
3984        if (*namep && **namep != '/') {
3985                *namep += prefix_length;
3986                if (**namep == '/')
3987                        ++*namep;
3988        }
3989        if (*otherp && **otherp != '/') {
3990                *otherp += prefix_length;
3991                if (**otherp == '/')
3992                        ++*otherp;
3993        }
3994}
3995
3996static void run_diff(struct diff_filepair *p, struct diff_options *o)
3997{
3998        const char *pgm = external_diff();
3999        struct strbuf msg;
4000        struct diff_filespec *one = p->one;
4001        struct diff_filespec *two = p->two;
4002        const char *name;
4003        const char *other;
4004        const char *attr_path;
4005
4006        name  = one->path;
4007        other = (strcmp(name, two->path) ? two->path : NULL);
4008        attr_path = name;
4009        if (o->prefix_length)
4010                strip_prefix(o->prefix_length, &name, &other);
4011
4012        if (!o->flags.allow_external)
4013                pgm = NULL;
4014
4015        if (DIFF_PAIR_UNMERGED(p)) {
4016                run_diff_cmd(pgm, name, NULL, attr_path,
4017                             NULL, NULL, NULL, o, p);
4018                return;
4019        }
4020
4021        diff_fill_oid_info(one);
4022        diff_fill_oid_info(two);
4023
4024        if (!pgm &&
4025            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
4026            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
4027                /*
4028                 * a filepair that changes between file and symlink
4029                 * needs to be split into deletion and creation.
4030                 */
4031                struct diff_filespec *null = alloc_filespec(two->path);
4032                run_diff_cmd(NULL, name, other, attr_path,
4033                             one, null, &msg, o, p);
4034                free(null);
4035                strbuf_release(&msg);
4036
4037                null = alloc_filespec(one->path);
4038                run_diff_cmd(NULL, name, other, attr_path,
4039                             null, two, &msg, o, p);
4040                free(null);
4041        }
4042        else
4043                run_diff_cmd(pgm, name, other, attr_path,
4044                             one, two, &msg, o, p);
4045
4046        strbuf_release(&msg);
4047}
4048
4049static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
4050                         struct diffstat_t *diffstat)
4051{
4052        const char *name;
4053        const char *other;
4054
4055        if (DIFF_PAIR_UNMERGED(p)) {
4056                /* unmerged */
4057                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, p);
4058                return;
4059        }
4060
4061        name = p->one->path;
4062        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4063
4064        if (o->prefix_length)
4065                strip_prefix(o->prefix_length, &name, &other);
4066
4067        diff_fill_oid_info(p->one);
4068        diff_fill_oid_info(p->two);
4069
4070        builtin_diffstat(name, other, p->one, p->two, diffstat, o, p);
4071}
4072
4073static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
4074{
4075        const char *name;
4076        const char *other;
4077        const char *attr_path;
4078
4079        if (DIFF_PAIR_UNMERGED(p)) {
4080                /* unmerged */
4081                return;
4082        }
4083
4084        name = p->one->path;
4085        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4086        attr_path = other ? other : name;
4087
4088        if (o->prefix_length)
4089                strip_prefix(o->prefix_length, &name, &other);
4090
4091        diff_fill_oid_info(p->one);
4092        diff_fill_oid_info(p->two);
4093
4094        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
4095}
4096
4097void diff_setup(struct diff_options *options)
4098{
4099        memcpy(options, &default_diff_options, sizeof(*options));
4100
4101        options->file = stdout;
4102
4103        options->abbrev = DEFAULT_ABBREV;
4104        options->line_termination = '\n';
4105        options->break_opt = -1;
4106        options->rename_limit = -1;
4107        options->dirstat_permille = diff_dirstat_permille_default;
4108        options->context = diff_context_default;
4109        options->interhunkcontext = diff_interhunk_context_default;
4110        options->ws_error_highlight = ws_error_highlight_default;
4111        options->flags.rename_empty = 1;
4112        options->objfind = NULL;
4113
4114        /* pathchange left =NULL by default */
4115        options->change = diff_change;
4116        options->add_remove = diff_addremove;
4117        options->use_color = diff_use_color_default;
4118        options->detect_rename = diff_detect_rename_default;
4119        options->xdl_opts |= diff_algorithm;
4120        if (diff_indent_heuristic)
4121                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4122
4123        options->orderfile = diff_order_file_cfg;
4124
4125        if (diff_no_prefix) {
4126                options->a_prefix = options->b_prefix = "";
4127        } else if (!diff_mnemonic_prefix) {
4128                options->a_prefix = "a/";
4129                options->b_prefix = "b/";
4130        }
4131
4132        options->color_moved = diff_color_moved_default;
4133}
4134
4135void diff_setup_done(struct diff_options *options)
4136{
4137        unsigned check_mask = DIFF_FORMAT_NAME |
4138                              DIFF_FORMAT_NAME_STATUS |
4139                              DIFF_FORMAT_CHECKDIFF |
4140                              DIFF_FORMAT_NO_OUTPUT;
4141
4142        if (options->set_default)
4143                options->set_default(options);
4144
4145        if (HAS_MULTI_BITS(options->output_format & check_mask))
4146                die(_("--name-only, --name-status, --check and -s are mutually exclusive"));
4147
4148        if (HAS_MULTI_BITS(options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK))
4149                die(_("-G, -S and --find-object are mutually exclusive"));
4150
4151        /*
4152         * Most of the time we can say "there are changes"
4153         * only by checking if there are changed paths, but
4154         * --ignore-whitespace* options force us to look
4155         * inside contents.
4156         */
4157
4158        if ((options->xdl_opts & XDF_WHITESPACE_FLAGS))
4159                options->flags.diff_from_contents = 1;
4160        else
4161                options->flags.diff_from_contents = 0;
4162
4163        if (options->flags.find_copies_harder)
4164                options->detect_rename = DIFF_DETECT_COPY;
4165
4166        if (!options->flags.relative_name)
4167                options->prefix = NULL;
4168        if (options->prefix)
4169                options->prefix_length = strlen(options->prefix);
4170        else
4171                options->prefix_length = 0;
4172
4173        if (options->output_format & (DIFF_FORMAT_NAME |
4174                                      DIFF_FORMAT_NAME_STATUS |
4175                                      DIFF_FORMAT_CHECKDIFF |
4176                                      DIFF_FORMAT_NO_OUTPUT))
4177                options->output_format &= ~(DIFF_FORMAT_RAW |
4178                                            DIFF_FORMAT_NUMSTAT |
4179                                            DIFF_FORMAT_DIFFSTAT |
4180                                            DIFF_FORMAT_SHORTSTAT |
4181                                            DIFF_FORMAT_DIRSTAT |
4182                                            DIFF_FORMAT_SUMMARY |
4183                                            DIFF_FORMAT_PATCH);
4184
4185        /*
4186         * These cases always need recursive; we do not drop caller-supplied
4187         * recursive bits for other formats here.
4188         */
4189        if (options->output_format & (DIFF_FORMAT_PATCH |
4190                                      DIFF_FORMAT_NUMSTAT |
4191                                      DIFF_FORMAT_DIFFSTAT |
4192                                      DIFF_FORMAT_SHORTSTAT |
4193                                      DIFF_FORMAT_DIRSTAT |
4194                                      DIFF_FORMAT_SUMMARY |
4195                                      DIFF_FORMAT_CHECKDIFF))
4196                options->flags.recursive = 1;
4197        /*
4198         * Also pickaxe would not work very well if you do not say recursive
4199         */
4200        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
4201                options->flags.recursive = 1;
4202        /*
4203         * When patches are generated, submodules diffed against the work tree
4204         * must be checked for dirtiness too so it can be shown in the output
4205         */
4206        if (options->output_format & DIFF_FORMAT_PATCH)
4207                options->flags.dirty_submodules = 1;
4208
4209        if (options->detect_rename && options->rename_limit < 0)
4210                options->rename_limit = diff_rename_limit_default;
4211        if (options->setup & DIFF_SETUP_USE_CACHE) {
4212                if (!active_cache)
4213                        /* read-cache does not die even when it fails
4214                         * so it is safe for us to do this here.  Also
4215                         * it does not smudge active_cache or active_nr
4216                         * when it fails, so we do not have to worry about
4217                         * cleaning it up ourselves either.
4218                         */
4219                        read_cache();
4220        }
4221        if (40 < options->abbrev)
4222                options->abbrev = 40; /* full */
4223
4224        /*
4225         * It does not make sense to show the first hit we happened
4226         * to have found.  It does not make sense not to return with
4227         * exit code in such a case either.
4228         */
4229        if (options->flags.quick) {
4230                options->output_format = DIFF_FORMAT_NO_OUTPUT;
4231                options->flags.exit_with_status = 1;
4232        }
4233
4234        options->diff_path_counter = 0;
4235
4236        if (options->flags.follow_renames && options->pathspec.nr != 1)
4237                die(_("--follow requires exactly one pathspec"));
4238
4239        if (!options->use_color || external_diff())
4240                options->color_moved = 0;
4241}
4242
4243static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
4244{
4245        char c, *eq;
4246        int len;
4247
4248        if (*arg != '-')
4249                return 0;
4250        c = *++arg;
4251        if (!c)
4252                return 0;
4253        if (c == arg_short) {
4254                c = *++arg;
4255                if (!c)
4256                        return 1;
4257                if (val && isdigit(c)) {
4258                        char *end;
4259                        int n = strtoul(arg, &end, 10);
4260                        if (*end)
4261                                return 0;
4262                        *val = n;
4263                        return 1;
4264                }
4265                return 0;
4266        }
4267        if (c != '-')
4268                return 0;
4269        arg++;
4270        eq = strchrnul(arg, '=');
4271        len = eq - arg;
4272        if (!len || strncmp(arg, arg_long, len))
4273                return 0;
4274        if (*eq) {
4275                int n;
4276                char *end;
4277                if (!isdigit(*++eq))
4278                        return 0;
4279                n = strtoul(eq, &end, 10);
4280                if (*end)
4281                        return 0;
4282                *val = n;
4283        }
4284        return 1;
4285}
4286
4287static int diff_scoreopt_parse(const char *opt);
4288
4289static inline int short_opt(char opt, const char **argv,
4290                            const char **optarg)
4291{
4292        const char *arg = argv[0];
4293        if (arg[0] != '-' || arg[1] != opt)
4294                return 0;
4295        if (arg[2] != '\0') {
4296                *optarg = arg + 2;
4297                return 1;
4298        }
4299        if (!argv[1])
4300                die("Option '%c' requires a value", opt);
4301        *optarg = argv[1];
4302        return 2;
4303}
4304
4305int parse_long_opt(const char *opt, const char **argv,
4306                   const char **optarg)
4307{
4308        const char *arg = argv[0];
4309        if (!skip_prefix(arg, "--", &arg))
4310                return 0;
4311        if (!skip_prefix(arg, opt, &arg))
4312                return 0;
4313        if (*arg == '=') { /* stuck form: --option=value */
4314                *optarg = arg + 1;
4315                return 1;
4316        }
4317        if (*arg != '\0')
4318                return 0;
4319        /* separate form: --option value */
4320        if (!argv[1])
4321                die("Option '--%s' requires a value", opt);
4322        *optarg = argv[1];
4323        return 2;
4324}
4325
4326static int stat_opt(struct diff_options *options, const char **av)
4327{
4328        const char *arg = av[0];
4329        char *end;
4330        int width = options->stat_width;
4331        int name_width = options->stat_name_width;
4332        int graph_width = options->stat_graph_width;
4333        int count = options->stat_count;
4334        int argcount = 1;
4335
4336        if (!skip_prefix(arg, "--stat", &arg))
4337                die("BUG: stat option does not begin with --stat: %s", arg);
4338        end = (char *)arg;
4339
4340        switch (*arg) {
4341        case '-':
4342                if (skip_prefix(arg, "-width", &arg)) {
4343                        if (*arg == '=')
4344                                width = strtoul(arg + 1, &end, 10);
4345                        else if (!*arg && !av[1])
4346                                die_want_option("--stat-width");
4347                        else if (!*arg) {
4348                                width = strtoul(av[1], &end, 10);
4349                                argcount = 2;
4350                        }
4351                } else if (skip_prefix(arg, "-name-width", &arg)) {
4352                        if (*arg == '=')
4353                                name_width = strtoul(arg + 1, &end, 10);
4354                        else if (!*arg && !av[1])
4355                                die_want_option("--stat-name-width");
4356                        else if (!*arg) {
4357                                name_width = strtoul(av[1], &end, 10);
4358                                argcount = 2;
4359                        }
4360                } else if (skip_prefix(arg, "-graph-width", &arg)) {
4361                        if (*arg == '=')
4362                                graph_width = strtoul(arg + 1, &end, 10);
4363                        else if (!*arg && !av[1])
4364                                die_want_option("--stat-graph-width");
4365                        else if (!*arg) {
4366                                graph_width = strtoul(av[1], &end, 10);
4367                                argcount = 2;
4368                        }
4369                } else if (skip_prefix(arg, "-count", &arg)) {
4370                        if (*arg == '=')
4371                                count = strtoul(arg + 1, &end, 10);
4372                        else if (!*arg && !av[1])
4373                                die_want_option("--stat-count");
4374                        else if (!*arg) {
4375                                count = strtoul(av[1], &end, 10);
4376                                argcount = 2;
4377                        }
4378                }
4379                break;
4380        case '=':
4381                width = strtoul(arg+1, &end, 10);
4382                if (*end == ',')
4383                        name_width = strtoul(end+1, &end, 10);
4384                if (*end == ',')
4385                        count = strtoul(end+1, &end, 10);
4386        }
4387
4388        /* Important! This checks all the error cases! */
4389        if (*end)
4390                return 0;
4391        options->output_format |= DIFF_FORMAT_DIFFSTAT;
4392        options->stat_name_width = name_width;
4393        options->stat_graph_width = graph_width;
4394        options->stat_width = width;
4395        options->stat_count = count;
4396        return argcount;
4397}
4398
4399static int parse_dirstat_opt(struct diff_options *options, const char *params)
4400{
4401        struct strbuf errmsg = STRBUF_INIT;
4402        if (parse_dirstat_params(options, params, &errmsg))
4403                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
4404                    errmsg.buf);
4405        strbuf_release(&errmsg);
4406        /*
4407         * The caller knows a dirstat-related option is given from the command
4408         * line; allow it to say "return this_function();"
4409         */
4410        options->output_format |= DIFF_FORMAT_DIRSTAT;
4411        return 1;
4412}
4413
4414static int parse_submodule_opt(struct diff_options *options, const char *value)
4415{
4416        if (parse_submodule_params(options, value))
4417                die(_("Failed to parse --submodule option parameter: '%s'"),
4418                        value);
4419        return 1;
4420}
4421
4422static const char diff_status_letters[] = {
4423        DIFF_STATUS_ADDED,
4424        DIFF_STATUS_COPIED,
4425        DIFF_STATUS_DELETED,
4426        DIFF_STATUS_MODIFIED,
4427        DIFF_STATUS_RENAMED,
4428        DIFF_STATUS_TYPE_CHANGED,
4429        DIFF_STATUS_UNKNOWN,
4430        DIFF_STATUS_UNMERGED,
4431        DIFF_STATUS_FILTER_AON,
4432        DIFF_STATUS_FILTER_BROKEN,
4433        '\0',
4434};
4435
4436static unsigned int filter_bit['Z' + 1];
4437
4438static void prepare_filter_bits(void)
4439{
4440        int i;
4441
4442        if (!filter_bit[DIFF_STATUS_ADDED]) {
4443                for (i = 0; diff_status_letters[i]; i++)
4444                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
4445        }
4446}
4447
4448static unsigned filter_bit_tst(char status, const struct diff_options *opt)
4449{
4450        return opt->filter & filter_bit[(int) status];
4451}
4452
4453static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
4454{
4455        int i, optch;
4456
4457        prepare_filter_bits();
4458
4459        /*
4460         * If there is a negation e.g. 'd' in the input, and we haven't
4461         * initialized the filter field with another --diff-filter, start
4462         * from full set of bits, except for AON.
4463         */
4464        if (!opt->filter) {
4465                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4466                        if (optch < 'a' || 'z' < optch)
4467                                continue;
4468                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
4469                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
4470                        break;
4471                }
4472        }
4473
4474        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4475                unsigned int bit;
4476                int negate;
4477
4478                if ('a' <= optch && optch <= 'z') {
4479                        negate = 1;
4480                        optch = toupper(optch);
4481                } else {
4482                        negate = 0;
4483                }
4484
4485                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
4486                if (!bit)
4487                        return optarg[i];
4488                if (negate)
4489                        opt->filter &= ~bit;
4490                else
4491                        opt->filter |= bit;
4492        }
4493        return 0;
4494}
4495
4496static void enable_patch_output(int *fmt) {
4497        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
4498        *fmt |= DIFF_FORMAT_PATCH;
4499}
4500
4501static int parse_ws_error_highlight_opt(struct diff_options *opt, const char *arg)
4502{
4503        int val = parse_ws_error_highlight(arg);
4504
4505        if (val < 0) {
4506                error("unknown value after ws-error-highlight=%.*s",
4507                      -1 - val, arg);
4508                return 0;
4509        }
4510        opt->ws_error_highlight = val;
4511        return 1;
4512}
4513
4514static int parse_objfind_opt(struct diff_options *opt, const char *arg)
4515{
4516        struct object_id oid;
4517
4518        if (get_oid(arg, &oid))
4519                return error("unable to resolve '%s'", arg);
4520
4521        if (!opt->objfind)
4522                opt->objfind = xcalloc(1, sizeof(*opt->objfind));
4523
4524        opt->pickaxe_opts |= DIFF_PICKAXE_KIND_OBJFIND;
4525        opt->flags.recursive = 1;
4526        opt->flags.tree_in_recursive = 1;
4527        oidset_insert(opt->objfind, &oid);
4528        return 1;
4529}
4530
4531int diff_opt_parse(struct diff_options *options,
4532                   const char **av, int ac, const char *prefix)
4533{
4534        const char *arg = av[0];
4535        const char *optarg;
4536        int argcount;
4537
4538        if (!prefix)
4539                prefix = "";
4540
4541        /* Output format options */
4542        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
4543            || opt_arg(arg, 'U', "unified", &options->context))
4544                enable_patch_output(&options->output_format);
4545        else if (!strcmp(arg, "--raw"))
4546                options->output_format |= DIFF_FORMAT_RAW;
4547        else if (!strcmp(arg, "--patch-with-raw")) {
4548                enable_patch_output(&options->output_format);
4549                options->output_format |= DIFF_FORMAT_RAW;
4550        } else if (!strcmp(arg, "--numstat"))
4551                options->output_format |= DIFF_FORMAT_NUMSTAT;
4552        else if (!strcmp(arg, "--shortstat"))
4553                options->output_format |= DIFF_FORMAT_SHORTSTAT;
4554        else if (skip_prefix(arg, "-X", &arg) ||
4555                 skip_to_optional_arg(arg, "--dirstat", &arg))
4556                return parse_dirstat_opt(options, arg);
4557        else if (!strcmp(arg, "--cumulative"))
4558                return parse_dirstat_opt(options, "cumulative");
4559        else if (skip_to_optional_arg(arg, "--dirstat-by-file", &arg)) {
4560                parse_dirstat_opt(options, "files");
4561                return parse_dirstat_opt(options, arg);
4562        }
4563        else if (!strcmp(arg, "--check"))
4564                options->output_format |= DIFF_FORMAT_CHECKDIFF;
4565        else if (!strcmp(arg, "--summary"))
4566                options->output_format |= DIFF_FORMAT_SUMMARY;
4567        else if (!strcmp(arg, "--patch-with-stat")) {
4568                enable_patch_output(&options->output_format);
4569                options->output_format |= DIFF_FORMAT_DIFFSTAT;
4570        } else if (!strcmp(arg, "--name-only"))
4571                options->output_format |= DIFF_FORMAT_NAME;
4572        else if (!strcmp(arg, "--name-status"))
4573                options->output_format |= DIFF_FORMAT_NAME_STATUS;
4574        else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
4575                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
4576        else if (starts_with(arg, "--stat"))
4577                /* --stat, --stat-width, --stat-name-width, or --stat-count */
4578                return stat_opt(options, av);
4579        else if (!strcmp(arg, "--compact-summary")) {
4580                 options->flags.stat_with_summary = 1;
4581                 options->output_format |= DIFF_FORMAT_DIFFSTAT;
4582        } else if (!strcmp(arg, "--no-compact-summary"))
4583                 options->flags.stat_with_summary = 0;
4584
4585        /* renames options */
4586        else if (starts_with(arg, "-B") ||
4587                 skip_to_optional_arg(arg, "--break-rewrites", NULL)) {
4588                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
4589                        return error("invalid argument to -B: %s", arg+2);
4590        }
4591        else if (starts_with(arg, "-M") ||
4592                 skip_to_optional_arg(arg, "--find-renames", NULL)) {
4593                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4594                        return error("invalid argument to -M: %s", arg+2);
4595                options->detect_rename = DIFF_DETECT_RENAME;
4596        }
4597        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
4598                options->irreversible_delete = 1;
4599        }
4600        else if (starts_with(arg, "-C") ||
4601                 skip_to_optional_arg(arg, "--find-copies", NULL)) {
4602                if (options->detect_rename == DIFF_DETECT_COPY)
4603                        options->flags.find_copies_harder = 1;
4604                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4605                        return error("invalid argument to -C: %s", arg+2);
4606                options->detect_rename = DIFF_DETECT_COPY;
4607        }
4608        else if (!strcmp(arg, "--no-renames"))
4609                options->detect_rename = 0;
4610        else if (!strcmp(arg, "--rename-empty"))
4611                options->flags.rename_empty = 1;
4612        else if (!strcmp(arg, "--no-rename-empty"))
4613                options->flags.rename_empty = 0;
4614        else if (skip_to_optional_arg_default(arg, "--relative", &arg, NULL)) {
4615                options->flags.relative_name = 1;
4616                if (arg)
4617                        options->prefix = arg;
4618        }
4619
4620        /* xdiff options */
4621        else if (!strcmp(arg, "--minimal"))
4622                DIFF_XDL_SET(options, NEED_MINIMAL);
4623        else if (!strcmp(arg, "--no-minimal"))
4624                DIFF_XDL_CLR(options, NEED_MINIMAL);
4625        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
4626                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
4627        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
4628                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
4629        else if (!strcmp(arg, "--ignore-space-at-eol"))
4630                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
4631        else if (!strcmp(arg, "--ignore-cr-at-eol"))
4632                DIFF_XDL_SET(options, IGNORE_CR_AT_EOL);
4633        else if (!strcmp(arg, "--ignore-blank-lines"))
4634                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
4635        else if (!strcmp(arg, "--indent-heuristic"))
4636                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4637        else if (!strcmp(arg, "--no-indent-heuristic"))
4638                DIFF_XDL_CLR(options, INDENT_HEURISTIC);
4639        else if (!strcmp(arg, "--patience")) {
4640                int i;
4641                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4642                /*
4643                 * Both --patience and --anchored use PATIENCE_DIFF
4644                 * internally, so remove any anchors previously
4645                 * specified.
4646                 */
4647                for (i = 0; i < options->anchors_nr; i++)
4648                        free(options->anchors[i]);
4649                options->anchors_nr = 0;
4650        } else if (!strcmp(arg, "--histogram"))
4651                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
4652        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
4653                long value = parse_algorithm_value(optarg);
4654                if (value < 0)
4655                        return error("option diff-algorithm accepts \"myers\", "
4656                                     "\"minimal\", \"patience\" and \"histogram\"");
4657                /* clear out previous settings */
4658                DIFF_XDL_CLR(options, NEED_MINIMAL);
4659                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
4660                options->xdl_opts |= value;
4661                return argcount;
4662        } else if (skip_prefix(arg, "--anchored=", &arg)) {
4663                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4664                ALLOC_GROW(options->anchors, options->anchors_nr + 1,
4665                           options->anchors_alloc);
4666                options->anchors[options->anchors_nr++] = xstrdup(arg);
4667        }
4668
4669        /* flags options */
4670        else if (!strcmp(arg, "--binary")) {
4671                enable_patch_output(&options->output_format);
4672                options->flags.binary = 1;
4673        }
4674        else if (!strcmp(arg, "--full-index"))
4675                options->flags.full_index = 1;
4676        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
4677                options->flags.text = 1;
4678        else if (!strcmp(arg, "-R"))
4679                options->flags.reverse_diff = 1;
4680        else if (!strcmp(arg, "--find-copies-harder"))
4681                options->flags.find_copies_harder = 1;
4682        else if (!strcmp(arg, "--follow"))
4683                options->flags.follow_renames = 1;
4684        else if (!strcmp(arg, "--no-follow")) {
4685                options->flags.follow_renames = 0;
4686                options->flags.default_follow_renames = 0;
4687        } else if (skip_to_optional_arg_default(arg, "--color", &arg, "always")) {
4688                int value = git_config_colorbool(NULL, arg);
4689                if (value < 0)
4690                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
4691                options->use_color = value;
4692        }
4693        else if (!strcmp(arg, "--no-color"))
4694                options->use_color = 0;
4695        else if (!strcmp(arg, "--color-moved")) {
4696                if (diff_color_moved_default)
4697                        options->color_moved = diff_color_moved_default;
4698                if (options->color_moved == COLOR_MOVED_NO)
4699                        options->color_moved = COLOR_MOVED_DEFAULT;
4700        } else if (!strcmp(arg, "--no-color-moved"))
4701                options->color_moved = COLOR_MOVED_NO;
4702        else if (skip_prefix(arg, "--color-moved=", &arg)) {
4703                int cm = parse_color_moved(arg);
4704                if (cm < 0)
4705                        die("bad --color-moved argument: %s", arg);
4706                options->color_moved = cm;
4707        } else if (skip_to_optional_arg_default(arg, "--color-words", &options->word_regex, NULL)) {
4708                options->use_color = 1;
4709                options->word_diff = DIFF_WORDS_COLOR;
4710        }
4711        else if (!strcmp(arg, "--word-diff")) {
4712                if (options->word_diff == DIFF_WORDS_NONE)
4713                        options->word_diff = DIFF_WORDS_PLAIN;
4714        }
4715        else if (skip_prefix(arg, "--word-diff=", &arg)) {
4716                if (!strcmp(arg, "plain"))
4717                        options->word_diff = DIFF_WORDS_PLAIN;
4718                else if (!strcmp(arg, "color")) {
4719                        options->use_color = 1;
4720                        options->word_diff = DIFF_WORDS_COLOR;
4721                }
4722                else if (!strcmp(arg, "porcelain"))
4723                        options->word_diff = DIFF_WORDS_PORCELAIN;
4724                else if (!strcmp(arg, "none"))
4725                        options->word_diff = DIFF_WORDS_NONE;
4726                else
4727                        die("bad --word-diff argument: %s", arg);
4728        }
4729        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
4730                if (options->word_diff == DIFF_WORDS_NONE)
4731                        options->word_diff = DIFF_WORDS_PLAIN;
4732                options->word_regex = optarg;
4733                return argcount;
4734        }
4735        else if (!strcmp(arg, "--exit-code"))
4736                options->flags.exit_with_status = 1;
4737        else if (!strcmp(arg, "--quiet"))
4738                options->flags.quick = 1;
4739        else if (!strcmp(arg, "--ext-diff"))
4740                options->flags.allow_external = 1;
4741        else if (!strcmp(arg, "--no-ext-diff"))
4742                options->flags.allow_external = 0;
4743        else if (!strcmp(arg, "--textconv")) {
4744                options->flags.allow_textconv = 1;
4745                options->flags.textconv_set_via_cmdline = 1;
4746        } else if (!strcmp(arg, "--no-textconv"))
4747                options->flags.allow_textconv = 0;
4748        else if (skip_to_optional_arg_default(arg, "--ignore-submodules", &arg, "all")) {
4749                options->flags.override_submodule_config = 1;
4750                handle_ignore_submodules_arg(options, arg);
4751        } else if (skip_to_optional_arg_default(arg, "--submodule", &arg, "log"))
4752                return parse_submodule_opt(options, arg);
4753        else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
4754                return parse_ws_error_highlight_opt(options, arg);
4755        else if (!strcmp(arg, "--ita-invisible-in-index"))
4756                options->ita_invisible_in_index = 1;
4757        else if (!strcmp(arg, "--ita-visible-in-index"))
4758                options->ita_invisible_in_index = 0;
4759
4760        /* misc options */
4761        else if (!strcmp(arg, "-z"))
4762                options->line_termination = 0;
4763        else if ((argcount = short_opt('l', av, &optarg))) {
4764                options->rename_limit = strtoul(optarg, NULL, 10);
4765                return argcount;
4766        }
4767        else if ((argcount = short_opt('S', av, &optarg))) {
4768                options->pickaxe = optarg;
4769                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
4770                return argcount;
4771        } else if ((argcount = short_opt('G', av, &optarg))) {
4772                options->pickaxe = optarg;
4773                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
4774                return argcount;
4775        }
4776        else if (!strcmp(arg, "--pickaxe-all"))
4777                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
4778        else if (!strcmp(arg, "--pickaxe-regex"))
4779                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
4780        else if ((argcount = short_opt('O', av, &optarg))) {
4781                options->orderfile = prefix_filename(prefix, optarg);
4782                return argcount;
4783        } else if (skip_prefix(arg, "--find-object=", &arg))
4784                return parse_objfind_opt(options, arg);
4785        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
4786                int offending = parse_diff_filter_opt(optarg, options);
4787                if (offending)
4788                        die("unknown change class '%c' in --diff-filter=%s",
4789                            offending, optarg);
4790                return argcount;
4791        }
4792        else if (!strcmp(arg, "--no-abbrev"))
4793                options->abbrev = 0;
4794        else if (!strcmp(arg, "--abbrev"))
4795                options->abbrev = DEFAULT_ABBREV;
4796        else if (skip_prefix(arg, "--abbrev=", &arg)) {
4797                options->abbrev = strtoul(arg, NULL, 10);
4798                if (options->abbrev < MINIMUM_ABBREV)
4799                        options->abbrev = MINIMUM_ABBREV;
4800                else if (40 < options->abbrev)
4801                        options->abbrev = 40;
4802        }
4803        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
4804                options->a_prefix = optarg;
4805                return argcount;
4806        }
4807        else if ((argcount = parse_long_opt("line-prefix", av, &optarg))) {
4808                options->line_prefix = optarg;
4809                options->line_prefix_length = strlen(options->line_prefix);
4810                graph_setup_line_prefix(options);
4811                return argcount;
4812        }
4813        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
4814                options->b_prefix = optarg;
4815                return argcount;
4816        }
4817        else if (!strcmp(arg, "--no-prefix"))
4818                options->a_prefix = options->b_prefix = "";
4819        else if (opt_arg(arg, '\0', "inter-hunk-context",
4820                         &options->interhunkcontext))
4821                ;
4822        else if (!strcmp(arg, "-W"))
4823                options->flags.funccontext = 1;
4824        else if (!strcmp(arg, "--function-context"))
4825                options->flags.funccontext = 1;
4826        else if (!strcmp(arg, "--no-function-context"))
4827                options->flags.funccontext = 0;
4828        else if ((argcount = parse_long_opt("output", av, &optarg))) {
4829                char *path = prefix_filename(prefix, optarg);
4830                options->file = xfopen(path, "w");
4831                options->close_file = 1;
4832                if (options->use_color != GIT_COLOR_ALWAYS)
4833                        options->use_color = GIT_COLOR_NEVER;
4834                free(path);
4835                return argcount;
4836        } else
4837                return 0;
4838        return 1;
4839}
4840
4841int parse_rename_score(const char **cp_p)
4842{
4843        unsigned long num, scale;
4844        int ch, dot;
4845        const char *cp = *cp_p;
4846
4847        num = 0;
4848        scale = 1;
4849        dot = 0;
4850        for (;;) {
4851                ch = *cp;
4852                if ( !dot && ch == '.' ) {
4853                        scale = 1;
4854                        dot = 1;
4855                } else if ( ch == '%' ) {
4856                        scale = dot ? scale*100 : 100;
4857                        cp++;   /* % is always at the end */
4858                        break;
4859                } else if ( ch >= '0' && ch <= '9' ) {
4860                        if ( scale < 100000 ) {
4861                                scale *= 10;
4862                                num = (num*10) + (ch-'0');
4863                        }
4864                } else {
4865                        break;
4866                }
4867                cp++;
4868        }
4869        *cp_p = cp;
4870
4871        /* user says num divided by scale and we say internally that
4872         * is MAX_SCORE * num / scale.
4873         */
4874        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
4875}
4876
4877static int diff_scoreopt_parse(const char *opt)
4878{
4879        int opt1, opt2, cmd;
4880
4881        if (*opt++ != '-')
4882                return -1;
4883        cmd = *opt++;
4884        if (cmd == '-') {
4885                /* convert the long-form arguments into short-form versions */
4886                if (skip_prefix(opt, "break-rewrites", &opt)) {
4887                        if (*opt == 0 || *opt++ == '=')
4888                                cmd = 'B';
4889                } else if (skip_prefix(opt, "find-copies", &opt)) {
4890                        if (*opt == 0 || *opt++ == '=')
4891                                cmd = 'C';
4892                } else if (skip_prefix(opt, "find-renames", &opt)) {
4893                        if (*opt == 0 || *opt++ == '=')
4894                                cmd = 'M';
4895                }
4896        }
4897        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
4898                return -1; /* that is not a -M, -C, or -B option */
4899
4900        opt1 = parse_rename_score(&opt);
4901        if (cmd != 'B')
4902                opt2 = 0;
4903        else {
4904                if (*opt == 0)
4905                        opt2 = 0;
4906                else if (*opt != '/')
4907                        return -1; /* we expect -B80/99 or -B80 */
4908                else {
4909                        opt++;
4910                        opt2 = parse_rename_score(&opt);
4911                }
4912        }
4913        if (*opt != 0)
4914                return -1;
4915        return opt1 | (opt2 << 16);
4916}
4917
4918struct diff_queue_struct diff_queued_diff;
4919
4920void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
4921{
4922        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
4923        queue->queue[queue->nr++] = dp;
4924}
4925
4926struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
4927                                 struct diff_filespec *one,
4928                                 struct diff_filespec *two)
4929{
4930        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
4931        dp->one = one;
4932        dp->two = two;
4933        if (queue)
4934                diff_q(queue, dp);
4935        return dp;
4936}
4937
4938void diff_free_filepair(struct diff_filepair *p)
4939{
4940        free_filespec(p->one);
4941        free_filespec(p->two);
4942        free(p);
4943}
4944
4945const char *diff_aligned_abbrev(const struct object_id *oid, int len)
4946{
4947        int abblen;
4948        const char *abbrev;
4949
4950        /* Do we want all 40 hex characters? */
4951        if (len == GIT_SHA1_HEXSZ)
4952                return oid_to_hex(oid);
4953
4954        /* An abbreviated value is fine, possibly followed by an ellipsis. */
4955        abbrev = diff_abbrev_oid(oid, len);
4956
4957        if (!print_sha1_ellipsis())
4958                return abbrev;
4959
4960        abblen = strlen(abbrev);
4961
4962        /*
4963         * In well-behaved cases, where the abbreviated result is the
4964         * same as the requested length, append three dots after the
4965         * abbreviation (hence the whole logic is limited to the case
4966         * where abblen < 37); when the actual abbreviated result is a
4967         * bit longer than the requested length, we reduce the number
4968         * of dots so that they match the well-behaved ones.  However,
4969         * if the actual abbreviation is longer than the requested
4970         * length by more than three, we give up on aligning, and add
4971         * three dots anyway, to indicate that the output is not the
4972         * full object name.  Yes, this may be suboptimal, but this
4973         * appears only in "diff --raw --abbrev" output and it is not
4974         * worth the effort to change it now.  Note that this would
4975         * likely to work fine when the automatic sizing of default
4976         * abbreviation length is used--we would be fed -1 in "len" in
4977         * that case, and will end up always appending three-dots, but
4978         * the automatic sizing is supposed to give abblen that ensures
4979         * uniqueness across all objects (statistically speaking).
4980         */
4981        if (abblen < GIT_SHA1_HEXSZ - 3) {
4982                static char hex[GIT_MAX_HEXSZ + 1];
4983                if (len < abblen && abblen <= len + 2)
4984                        xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
4985                else
4986                        xsnprintf(hex, sizeof(hex), "%s...", abbrev);
4987                return hex;
4988        }
4989
4990        return oid_to_hex(oid);
4991}
4992
4993static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
4994{
4995        int line_termination = opt->line_termination;
4996        int inter_name_termination = line_termination ? '\t' : '\0';
4997
4998        fprintf(opt->file, "%s", diff_line_prefix(opt));
4999        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
5000                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
5001                        diff_aligned_abbrev(&p->one->oid, opt->abbrev));
5002                fprintf(opt->file, "%s ",
5003                        diff_aligned_abbrev(&p->two->oid, opt->abbrev));
5004        }
5005        if (p->score) {
5006                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
5007                        inter_name_termination);
5008        } else {
5009                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
5010        }
5011
5012        if (p->status == DIFF_STATUS_COPIED ||
5013            p->status == DIFF_STATUS_RENAMED) {
5014                const char *name_a, *name_b;
5015                name_a = p->one->path;
5016                name_b = p->two->path;
5017                strip_prefix(opt->prefix_length, &name_a, &name_b);
5018                write_name_quoted(name_a, opt->file, inter_name_termination);
5019                write_name_quoted(name_b, opt->file, line_termination);
5020        } else {
5021                const char *name_a, *name_b;
5022                name_a = p->one->mode ? p->one->path : p->two->path;
5023                name_b = NULL;
5024                strip_prefix(opt->prefix_length, &name_a, &name_b);
5025                write_name_quoted(name_a, opt->file, line_termination);
5026        }
5027}
5028
5029int diff_unmodified_pair(struct diff_filepair *p)
5030{
5031        /* This function is written stricter than necessary to support
5032         * the currently implemented transformers, but the idea is to
5033         * let transformers to produce diff_filepairs any way they want,
5034         * and filter and clean them up here before producing the output.
5035         */
5036        struct diff_filespec *one = p->one, *two = p->two;
5037
5038        if (DIFF_PAIR_UNMERGED(p))
5039                return 0; /* unmerged is interesting */
5040
5041        /* deletion, addition, mode or type change
5042         * and rename are all interesting.
5043         */
5044        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
5045            DIFF_PAIR_MODE_CHANGED(p) ||
5046            strcmp(one->path, two->path))
5047                return 0;
5048
5049        /* both are valid and point at the same path.  that is, we are
5050         * dealing with a change.
5051         */
5052        if (one->oid_valid && two->oid_valid &&
5053            !oidcmp(&one->oid, &two->oid) &&
5054            !one->dirty_submodule && !two->dirty_submodule)
5055                return 1; /* no change */
5056        if (!one->oid_valid && !two->oid_valid)
5057                return 1; /* both look at the same file on the filesystem. */
5058        return 0;
5059}
5060
5061static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
5062{
5063        if (diff_unmodified_pair(p))
5064                return;
5065
5066        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5067            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5068                return; /* no tree diffs in patch format */
5069
5070        run_diff(p, o);
5071}
5072
5073static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
5074                            struct diffstat_t *diffstat)
5075{
5076        if (diff_unmodified_pair(p))
5077                return;
5078
5079        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5080            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5081                return; /* no useful stat for tree diffs */
5082
5083        run_diffstat(p, o, diffstat);
5084}
5085
5086static void diff_flush_checkdiff(struct diff_filepair *p,
5087                struct diff_options *o)
5088{
5089        if (diff_unmodified_pair(p))
5090                return;
5091
5092        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5093            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5094                return; /* nothing to check in tree diffs */
5095
5096        run_checkdiff(p, o);
5097}
5098
5099int diff_queue_is_empty(void)
5100{
5101        struct diff_queue_struct *q = &diff_queued_diff;
5102        int i;
5103        for (i = 0; i < q->nr; i++)
5104                if (!diff_unmodified_pair(q->queue[i]))
5105                        return 0;
5106        return 1;
5107}
5108
5109#if DIFF_DEBUG
5110void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
5111{
5112        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
5113                x, one ? one : "",
5114                s->path,
5115                DIFF_FILE_VALID(s) ? "valid" : "invalid",
5116                s->mode,
5117                s->oid_valid ? oid_to_hex(&s->oid) : "");
5118        fprintf(stderr, "queue[%d] %s size %lu\n",
5119                x, one ? one : "",
5120                s->size);
5121}
5122
5123void diff_debug_filepair(const struct diff_filepair *p, int i)
5124{
5125        diff_debug_filespec(p->one, i, "one");
5126        diff_debug_filespec(p->two, i, "two");
5127        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
5128                p->score, p->status ? p->status : '?',
5129                p->one->rename_used, p->broken_pair);
5130}
5131
5132void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
5133{
5134        int i;
5135        if (msg)
5136                fprintf(stderr, "%s\n", msg);
5137        fprintf(stderr, "q->nr = %d\n", q->nr);
5138        for (i = 0; i < q->nr; i++) {
5139                struct diff_filepair *p = q->queue[i];
5140                diff_debug_filepair(p, i);
5141        }
5142}
5143#endif
5144
5145static void diff_resolve_rename_copy(void)
5146{
5147        int i;
5148        struct diff_filepair *p;
5149        struct diff_queue_struct *q = &diff_queued_diff;
5150
5151        diff_debug_queue("resolve-rename-copy", q);
5152
5153        for (i = 0; i < q->nr; i++) {
5154                p = q->queue[i];
5155                p->status = 0; /* undecided */
5156                if (DIFF_PAIR_UNMERGED(p))
5157                        p->status = DIFF_STATUS_UNMERGED;
5158                else if (!DIFF_FILE_VALID(p->one))
5159                        p->status = DIFF_STATUS_ADDED;
5160                else if (!DIFF_FILE_VALID(p->two))
5161                        p->status = DIFF_STATUS_DELETED;
5162                else if (DIFF_PAIR_TYPE_CHANGED(p))
5163                        p->status = DIFF_STATUS_TYPE_CHANGED;
5164
5165                /* from this point on, we are dealing with a pair
5166                 * whose both sides are valid and of the same type, i.e.
5167                 * either in-place edit or rename/copy edit.
5168                 */
5169                else if (DIFF_PAIR_RENAME(p)) {
5170                        /*
5171                         * A rename might have re-connected a broken
5172                         * pair up, causing the pathnames to be the
5173                         * same again. If so, that's not a rename at
5174                         * all, just a modification..
5175                         *
5176                         * Otherwise, see if this source was used for
5177                         * multiple renames, in which case we decrement
5178                         * the count, and call it a copy.
5179                         */
5180                        if (!strcmp(p->one->path, p->two->path))
5181                                p->status = DIFF_STATUS_MODIFIED;
5182                        else if (--p->one->rename_used > 0)
5183                                p->status = DIFF_STATUS_COPIED;
5184                        else
5185                                p->status = DIFF_STATUS_RENAMED;
5186                }
5187                else if (oidcmp(&p->one->oid, &p->two->oid) ||
5188                         p->one->mode != p->two->mode ||
5189                         p->one->dirty_submodule ||
5190                         p->two->dirty_submodule ||
5191                         is_null_oid(&p->one->oid))
5192                        p->status = DIFF_STATUS_MODIFIED;
5193                else {
5194                        /* This is a "no-change" entry and should not
5195                         * happen anymore, but prepare for broken callers.
5196                         */
5197                        error("feeding unmodified %s to diffcore",
5198                              p->one->path);
5199                        p->status = DIFF_STATUS_UNKNOWN;
5200                }
5201        }
5202        diff_debug_queue("resolve-rename-copy done", q);
5203}
5204
5205static int check_pair_status(struct diff_filepair *p)
5206{
5207        switch (p->status) {
5208        case DIFF_STATUS_UNKNOWN:
5209                return 0;
5210        case 0:
5211                die("internal error in diff-resolve-rename-copy");
5212        default:
5213                return 1;
5214        }
5215}
5216
5217static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
5218{
5219        int fmt = opt->output_format;
5220
5221        if (fmt & DIFF_FORMAT_CHECKDIFF)
5222                diff_flush_checkdiff(p, opt);
5223        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
5224                diff_flush_raw(p, opt);
5225        else if (fmt & DIFF_FORMAT_NAME) {
5226                const char *name_a, *name_b;
5227                name_a = p->two->path;
5228                name_b = NULL;
5229                strip_prefix(opt->prefix_length, &name_a, &name_b);
5230                fprintf(opt->file, "%s", diff_line_prefix(opt));
5231                write_name_quoted(name_a, opt->file, opt->line_termination);
5232        }
5233}
5234
5235static void show_file_mode_name(struct diff_options *opt, const char *newdelete, struct diff_filespec *fs)
5236{
5237        struct strbuf sb = STRBUF_INIT;
5238        if (fs->mode)
5239                strbuf_addf(&sb, " %s mode %06o ", newdelete, fs->mode);
5240        else
5241                strbuf_addf(&sb, " %s ", newdelete);
5242
5243        quote_c_style(fs->path, &sb, NULL, 0);
5244        strbuf_addch(&sb, '\n');
5245        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5246                         sb.buf, sb.len, 0);
5247        strbuf_release(&sb);
5248}
5249
5250static void show_mode_change(struct diff_options *opt, struct diff_filepair *p,
5251                int show_name)
5252{
5253        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
5254                struct strbuf sb = STRBUF_INIT;
5255                strbuf_addf(&sb, " mode change %06o => %06o",
5256                            p->one->mode, p->two->mode);
5257                if (show_name) {
5258                        strbuf_addch(&sb, ' ');
5259                        quote_c_style(p->two->path, &sb, NULL, 0);
5260                }
5261                strbuf_addch(&sb, '\n');
5262                emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5263                                 sb.buf, sb.len, 0);
5264                strbuf_release(&sb);
5265        }
5266}
5267
5268static void show_rename_copy(struct diff_options *opt, const char *renamecopy,
5269                struct diff_filepair *p)
5270{
5271        struct strbuf sb = STRBUF_INIT;
5272        struct strbuf names = STRBUF_INIT;
5273
5274        pprint_rename(&names, p->one->path, p->two->path);
5275        strbuf_addf(&sb, " %s %s (%d%%)\n",
5276                    renamecopy, names.buf, similarity_index(p));
5277        strbuf_release(&names);
5278        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5279                                 sb.buf, sb.len, 0);
5280        show_mode_change(opt, p, 0);
5281        strbuf_release(&sb);
5282}
5283
5284static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
5285{
5286        switch(p->status) {
5287        case DIFF_STATUS_DELETED:
5288                show_file_mode_name(opt, "delete", p->one);
5289                break;
5290        case DIFF_STATUS_ADDED:
5291                show_file_mode_name(opt, "create", p->two);
5292                break;
5293        case DIFF_STATUS_COPIED:
5294                show_rename_copy(opt, "copy", p);
5295                break;
5296        case DIFF_STATUS_RENAMED:
5297                show_rename_copy(opt, "rename", p);
5298                break;
5299        default:
5300                if (p->score) {
5301                        struct strbuf sb = STRBUF_INIT;
5302                        strbuf_addstr(&sb, " rewrite ");
5303                        quote_c_style(p->two->path, &sb, NULL, 0);
5304                        strbuf_addf(&sb, " (%d%%)\n", similarity_index(p));
5305                        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5306                                         sb.buf, sb.len, 0);
5307                        strbuf_release(&sb);
5308                }
5309                show_mode_change(opt, p, !p->score);
5310                break;
5311        }
5312}
5313
5314struct patch_id_t {
5315        git_SHA_CTX *ctx;
5316        int patchlen;
5317};
5318
5319static int remove_space(char *line, int len)
5320{
5321        int i;
5322        char *dst = line;
5323        unsigned char c;
5324
5325        for (i = 0; i < len; i++)
5326                if (!isspace((c = line[i])))
5327                        *dst++ = c;
5328
5329        return dst - line;
5330}
5331
5332static void patch_id_consume(void *priv, char *line, unsigned long len)
5333{
5334        struct patch_id_t *data = priv;
5335        int new_len;
5336
5337        /* Ignore line numbers when computing the SHA1 of the patch */
5338        if (starts_with(line, "@@ -"))
5339                return;
5340
5341        new_len = remove_space(line, len);
5342
5343        git_SHA1_Update(data->ctx, line, new_len);
5344        data->patchlen += new_len;
5345}
5346
5347static void patch_id_add_string(git_SHA_CTX *ctx, const char *str)
5348{
5349        git_SHA1_Update(ctx, str, strlen(str));
5350}
5351
5352static void patch_id_add_mode(git_SHA_CTX *ctx, unsigned mode)
5353{
5354        /* large enough for 2^32 in octal */
5355        char buf[12];
5356        int len = xsnprintf(buf, sizeof(buf), "%06o", mode);
5357        git_SHA1_Update(ctx, buf, len);
5358}
5359
5360/* returns 0 upon success, and writes result into sha1 */
5361static int diff_get_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5362{
5363        struct diff_queue_struct *q = &diff_queued_diff;
5364        int i;
5365        git_SHA_CTX ctx;
5366        struct patch_id_t data;
5367
5368        git_SHA1_Init(&ctx);
5369        memset(&data, 0, sizeof(struct patch_id_t));
5370        data.ctx = &ctx;
5371
5372        for (i = 0; i < q->nr; i++) {
5373                xpparam_t xpp;
5374                xdemitconf_t xecfg;
5375                mmfile_t mf1, mf2;
5376                struct diff_filepair *p = q->queue[i];
5377                int len1, len2;
5378
5379                memset(&xpp, 0, sizeof(xpp));
5380                memset(&xecfg, 0, sizeof(xecfg));
5381                if (p->status == 0)
5382                        return error("internal diff status error");
5383                if (p->status == DIFF_STATUS_UNKNOWN)
5384                        continue;
5385                if (diff_unmodified_pair(p))
5386                        continue;
5387                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5388                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5389                        continue;
5390                if (DIFF_PAIR_UNMERGED(p))
5391                        continue;
5392
5393                diff_fill_oid_info(p->one);
5394                diff_fill_oid_info(p->two);
5395
5396                len1 = remove_space(p->one->path, strlen(p->one->path));
5397                len2 = remove_space(p->two->path, strlen(p->two->path));
5398                patch_id_add_string(&ctx, "diff--git");
5399                patch_id_add_string(&ctx, "a/");
5400                git_SHA1_Update(&ctx, p->one->path, len1);
5401                patch_id_add_string(&ctx, "b/");
5402                git_SHA1_Update(&ctx, p->two->path, len2);
5403
5404                if (p->one->mode == 0) {
5405                        patch_id_add_string(&ctx, "newfilemode");
5406                        patch_id_add_mode(&ctx, p->two->mode);
5407                        patch_id_add_string(&ctx, "---/dev/null");
5408                        patch_id_add_string(&ctx, "+++b/");
5409                        git_SHA1_Update(&ctx, p->two->path, len2);
5410                } else if (p->two->mode == 0) {
5411                        patch_id_add_string(&ctx, "deletedfilemode");
5412                        patch_id_add_mode(&ctx, p->one->mode);
5413                        patch_id_add_string(&ctx, "---a/");
5414                        git_SHA1_Update(&ctx, p->one->path, len1);
5415                        patch_id_add_string(&ctx, "+++/dev/null");
5416                } else {
5417                        patch_id_add_string(&ctx, "---a/");
5418                        git_SHA1_Update(&ctx, p->one->path, len1);
5419                        patch_id_add_string(&ctx, "+++b/");
5420                        git_SHA1_Update(&ctx, p->two->path, len2);
5421                }
5422
5423                if (diff_header_only)
5424                        continue;
5425
5426                if (fill_mmfile(&mf1, p->one) < 0 ||
5427                    fill_mmfile(&mf2, p->two) < 0)
5428                        return error("unable to read files to diff");
5429
5430                if (diff_filespec_is_binary(p->one) ||
5431                    diff_filespec_is_binary(p->two)) {
5432                        git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
5433                                        GIT_SHA1_HEXSZ);
5434                        git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
5435                                        GIT_SHA1_HEXSZ);
5436                        continue;
5437                }
5438
5439                xpp.flags = 0;
5440                xecfg.ctxlen = 3;
5441                xecfg.flags = 0;
5442                if (xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
5443                                  &xpp, &xecfg))
5444                        return error("unable to generate patch-id diff for %s",
5445                                     p->one->path);
5446        }
5447
5448        git_SHA1_Final(oid->hash, &ctx);
5449        return 0;
5450}
5451
5452int diff_flush_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5453{
5454        struct diff_queue_struct *q = &diff_queued_diff;
5455        int i;
5456        int result = diff_get_patch_id(options, oid, diff_header_only);
5457
5458        for (i = 0; i < q->nr; i++)
5459                diff_free_filepair(q->queue[i]);
5460
5461        free(q->queue);
5462        DIFF_QUEUE_CLEAR(q);
5463
5464        return result;
5465}
5466
5467static int is_summary_empty(const struct diff_queue_struct *q)
5468{
5469        int i;
5470
5471        for (i = 0; i < q->nr; i++) {
5472                const struct diff_filepair *p = q->queue[i];
5473
5474                switch (p->status) {
5475                case DIFF_STATUS_DELETED:
5476                case DIFF_STATUS_ADDED:
5477                case DIFF_STATUS_COPIED:
5478                case DIFF_STATUS_RENAMED:
5479                        return 0;
5480                default:
5481                        if (p->score)
5482                                return 0;
5483                        if (p->one->mode && p->two->mode &&
5484                            p->one->mode != p->two->mode)
5485                                return 0;
5486                        break;
5487                }
5488        }
5489        return 1;
5490}
5491
5492static const char rename_limit_warning[] =
5493N_("inexact rename detection was skipped due to too many files.");
5494
5495static const char degrade_cc_to_c_warning[] =
5496N_("only found copies from modified paths due to too many files.");
5497
5498static const char rename_limit_advice[] =
5499N_("you may want to set your %s variable to at least "
5500   "%d and retry the command.");
5501
5502void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
5503{
5504        fflush(stdout);
5505        if (degraded_cc)
5506                warning(_(degrade_cc_to_c_warning));
5507        else if (needed)
5508                warning(_(rename_limit_warning));
5509        else
5510                return;
5511        if (0 < needed)
5512                warning(_(rename_limit_advice), varname, needed);
5513}
5514
5515static void diff_flush_patch_all_file_pairs(struct diff_options *o)
5516{
5517        int i;
5518        static struct emitted_diff_symbols esm = EMITTED_DIFF_SYMBOLS_INIT;
5519        struct diff_queue_struct *q = &diff_queued_diff;
5520
5521        if (WSEH_NEW & WS_RULE_MASK)
5522                die("BUG: WS rules bit mask overlaps with diff symbol flags");
5523
5524        if (o->color_moved)
5525                o->emitted_symbols = &esm;
5526
5527        for (i = 0; i < q->nr; i++) {
5528                struct diff_filepair *p = q->queue[i];
5529                if (check_pair_status(p))
5530                        diff_flush_patch(p, o);
5531        }
5532
5533        if (o->emitted_symbols) {
5534                if (o->color_moved) {
5535                        struct hashmap add_lines, del_lines;
5536
5537                        hashmap_init(&del_lines,
5538                                     (hashmap_cmp_fn)moved_entry_cmp, o, 0);
5539                        hashmap_init(&add_lines,
5540                                     (hashmap_cmp_fn)moved_entry_cmp, o, 0);
5541
5542                        add_lines_to_move_detection(o, &add_lines, &del_lines);
5543                        mark_color_as_moved(o, &add_lines, &del_lines);
5544                        if (o->color_moved == COLOR_MOVED_ZEBRA_DIM)
5545                                dim_moved_lines(o);
5546
5547                        hashmap_free(&add_lines, 0);
5548                        hashmap_free(&del_lines, 0);
5549                }
5550
5551                for (i = 0; i < esm.nr; i++)
5552                        emit_diff_symbol_from_struct(o, &esm.buf[i]);
5553
5554                for (i = 0; i < esm.nr; i++)
5555                        free((void *)esm.buf[i].line);
5556        }
5557        esm.nr = 0;
5558}
5559
5560void diff_flush(struct diff_options *options)
5561{
5562        struct diff_queue_struct *q = &diff_queued_diff;
5563        int i, output_format = options->output_format;
5564        int separator = 0;
5565        int dirstat_by_line = 0;
5566
5567        /*
5568         * Order: raw, stat, summary, patch
5569         * or:    name/name-status/checkdiff (other bits clear)
5570         */
5571        if (!q->nr)
5572                goto free_queue;
5573
5574        if (output_format & (DIFF_FORMAT_RAW |
5575                             DIFF_FORMAT_NAME |
5576                             DIFF_FORMAT_NAME_STATUS |
5577                             DIFF_FORMAT_CHECKDIFF)) {
5578                for (i = 0; i < q->nr; i++) {
5579                        struct diff_filepair *p = q->queue[i];
5580                        if (check_pair_status(p))
5581                                flush_one_pair(p, options);
5582                }
5583                separator++;
5584        }
5585
5586        if (output_format & DIFF_FORMAT_DIRSTAT && options->flags.dirstat_by_line)
5587                dirstat_by_line = 1;
5588
5589        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
5590            dirstat_by_line) {
5591                struct diffstat_t diffstat;
5592
5593                memset(&diffstat, 0, sizeof(struct diffstat_t));
5594                for (i = 0; i < q->nr; i++) {
5595                        struct diff_filepair *p = q->queue[i];
5596                        if (check_pair_status(p))
5597                                diff_flush_stat(p, options, &diffstat);
5598                }
5599                if (output_format & DIFF_FORMAT_NUMSTAT)
5600                        show_numstat(&diffstat, options);
5601                if (output_format & DIFF_FORMAT_DIFFSTAT)
5602                        show_stats(&diffstat, options);
5603                if (output_format & DIFF_FORMAT_SHORTSTAT)
5604                        show_shortstats(&diffstat, options);
5605                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
5606                        show_dirstat_by_line(&diffstat, options);
5607                free_diffstat_info(&diffstat);
5608                separator++;
5609        }
5610        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
5611                show_dirstat(options);
5612
5613        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
5614                for (i = 0; i < q->nr; i++) {
5615                        diff_summary(options, q->queue[i]);
5616                }
5617                separator++;
5618        }
5619
5620        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
5621            options->flags.exit_with_status &&
5622            options->flags.diff_from_contents) {
5623                /*
5624                 * run diff_flush_patch for the exit status. setting
5625                 * options->file to /dev/null should be safe, because we
5626                 * aren't supposed to produce any output anyway.
5627                 */
5628                if (options->close_file)
5629                        fclose(options->file);
5630                options->file = xfopen("/dev/null", "w");
5631                options->close_file = 1;
5632                options->color_moved = 0;
5633                for (i = 0; i < q->nr; i++) {
5634                        struct diff_filepair *p = q->queue[i];
5635                        if (check_pair_status(p))
5636                                diff_flush_patch(p, options);
5637                        if (options->found_changes)
5638                                break;
5639                }
5640        }
5641
5642        if (output_format & DIFF_FORMAT_PATCH) {
5643                if (separator) {
5644                        emit_diff_symbol(options, DIFF_SYMBOL_SEPARATOR, NULL, 0, 0);
5645                        if (options->stat_sep)
5646                                /* attach patch instead of inline */
5647                                emit_diff_symbol(options, DIFF_SYMBOL_STAT_SEP,
5648                                                 NULL, 0, 0);
5649                }
5650
5651                diff_flush_patch_all_file_pairs(options);
5652        }
5653
5654        if (output_format & DIFF_FORMAT_CALLBACK)
5655                options->format_callback(q, options, options->format_callback_data);
5656
5657        for (i = 0; i < q->nr; i++)
5658                diff_free_filepair(q->queue[i]);
5659free_queue:
5660        free(q->queue);
5661        DIFF_QUEUE_CLEAR(q);
5662        if (options->close_file)
5663                fclose(options->file);
5664
5665        /*
5666         * Report the content-level differences with HAS_CHANGES;
5667         * diff_addremove/diff_change does not set the bit when
5668         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
5669         */
5670        if (options->flags.diff_from_contents) {
5671                if (options->found_changes)
5672                        options->flags.has_changes = 1;
5673                else
5674                        options->flags.has_changes = 0;
5675        }
5676}
5677
5678static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
5679{
5680        return (((p->status == DIFF_STATUS_MODIFIED) &&
5681                 ((p->score &&
5682                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
5683                  (!p->score &&
5684                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
5685                ((p->status != DIFF_STATUS_MODIFIED) &&
5686                 filter_bit_tst(p->status, options)));
5687}
5688
5689static void diffcore_apply_filter(struct diff_options *options)
5690{
5691        int i;
5692        struct diff_queue_struct *q = &diff_queued_diff;
5693        struct diff_queue_struct outq;
5694
5695        DIFF_QUEUE_CLEAR(&outq);
5696
5697        if (!options->filter)
5698                return;
5699
5700        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
5701                int found;
5702                for (i = found = 0; !found && i < q->nr; i++) {
5703                        if (match_filter(options, q->queue[i]))
5704                                found++;
5705                }
5706                if (found)
5707                        return;
5708
5709                /* otherwise we will clear the whole queue
5710                 * by copying the empty outq at the end of this
5711                 * function, but first clear the current entries
5712                 * in the queue.
5713                 */
5714                for (i = 0; i < q->nr; i++)
5715                        diff_free_filepair(q->queue[i]);
5716        }
5717        else {
5718                /* Only the matching ones */
5719                for (i = 0; i < q->nr; i++) {
5720                        struct diff_filepair *p = q->queue[i];
5721                        if (match_filter(options, p))
5722                                diff_q(&outq, p);
5723                        else
5724                                diff_free_filepair(p);
5725                }
5726        }
5727        free(q->queue);
5728        *q = outq;
5729}
5730
5731/* Check whether two filespecs with the same mode and size are identical */
5732static int diff_filespec_is_identical(struct diff_filespec *one,
5733                                      struct diff_filespec *two)
5734{
5735        if (S_ISGITLINK(one->mode))
5736                return 0;
5737        if (diff_populate_filespec(one, 0))
5738                return 0;
5739        if (diff_populate_filespec(two, 0))
5740                return 0;
5741        return !memcmp(one->data, two->data, one->size);
5742}
5743
5744static int diff_filespec_check_stat_unmatch(struct diff_filepair *p)
5745{
5746        if (p->done_skip_stat_unmatch)
5747                return p->skip_stat_unmatch_result;
5748
5749        p->done_skip_stat_unmatch = 1;
5750        p->skip_stat_unmatch_result = 0;
5751        /*
5752         * 1. Entries that come from stat info dirtiness
5753         *    always have both sides (iow, not create/delete),
5754         *    one side of the object name is unknown, with
5755         *    the same mode and size.  Keep the ones that
5756         *    do not match these criteria.  They have real
5757         *    differences.
5758         *
5759         * 2. At this point, the file is known to be modified,
5760         *    with the same mode and size, and the object
5761         *    name of one side is unknown.  Need to inspect
5762         *    the identical contents.
5763         */
5764        if (!DIFF_FILE_VALID(p->one) || /* (1) */
5765            !DIFF_FILE_VALID(p->two) ||
5766            (p->one->oid_valid && p->two->oid_valid) ||
5767            (p->one->mode != p->two->mode) ||
5768            diff_populate_filespec(p->one, CHECK_SIZE_ONLY) ||
5769            diff_populate_filespec(p->two, CHECK_SIZE_ONLY) ||
5770            (p->one->size != p->two->size) ||
5771            !diff_filespec_is_identical(p->one, p->two)) /* (2) */
5772                p->skip_stat_unmatch_result = 1;
5773        return p->skip_stat_unmatch_result;
5774}
5775
5776static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
5777{
5778        int i;
5779        struct diff_queue_struct *q = &diff_queued_diff;
5780        struct diff_queue_struct outq;
5781        DIFF_QUEUE_CLEAR(&outq);
5782
5783        for (i = 0; i < q->nr; i++) {
5784                struct diff_filepair *p = q->queue[i];
5785
5786                if (diff_filespec_check_stat_unmatch(p))
5787                        diff_q(&outq, p);
5788                else {
5789                        /*
5790                         * The caller can subtract 1 from skip_stat_unmatch
5791                         * to determine how many paths were dirty only
5792                         * due to stat info mismatch.
5793                         */
5794                        if (!diffopt->flags.no_index)
5795                                diffopt->skip_stat_unmatch++;
5796                        diff_free_filepair(p);
5797                }
5798        }
5799        free(q->queue);
5800        *q = outq;
5801}
5802
5803static int diffnamecmp(const void *a_, const void *b_)
5804{
5805        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
5806        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
5807        const char *name_a, *name_b;
5808
5809        name_a = a->one ? a->one->path : a->two->path;
5810        name_b = b->one ? b->one->path : b->two->path;
5811        return strcmp(name_a, name_b);
5812}
5813
5814void diffcore_fix_diff_index(struct diff_options *options)
5815{
5816        struct diff_queue_struct *q = &diff_queued_diff;
5817        QSORT(q->queue, q->nr, diffnamecmp);
5818}
5819
5820void diffcore_std(struct diff_options *options)
5821{
5822        /* NOTE please keep the following in sync with diff_tree_combined() */
5823        if (options->skip_stat_unmatch)
5824                diffcore_skip_stat_unmatch(options);
5825        if (!options->found_follow) {
5826                /* See try_to_follow_renames() in tree-diff.c */
5827                if (options->break_opt != -1)
5828                        diffcore_break(options->break_opt);
5829                if (options->detect_rename)
5830                        diffcore_rename(options);
5831                if (options->break_opt != -1)
5832                        diffcore_merge_broken();
5833        }
5834        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
5835                diffcore_pickaxe(options);
5836        if (options->orderfile)
5837                diffcore_order(options->orderfile);
5838        if (!options->found_follow)
5839                /* See try_to_follow_renames() in tree-diff.c */
5840                diff_resolve_rename_copy();
5841        diffcore_apply_filter(options);
5842
5843        if (diff_queued_diff.nr && !options->flags.diff_from_contents)
5844                options->flags.has_changes = 1;
5845        else
5846                options->flags.has_changes = 0;
5847
5848        options->found_follow = 0;
5849}
5850
5851int diff_result_code(struct diff_options *opt, int status)
5852{
5853        int result = 0;
5854
5855        diff_warn_rename_limit("diff.renameLimit",
5856                               opt->needed_rename_limit,
5857                               opt->degraded_cc_to_c);
5858        if (!opt->flags.exit_with_status &&
5859            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
5860                return status;
5861        if (opt->flags.exit_with_status &&
5862            opt->flags.has_changes)
5863                result |= 01;
5864        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
5865            opt->flags.check_failed)
5866                result |= 02;
5867        return result;
5868}
5869
5870int diff_can_quit_early(struct diff_options *opt)
5871{
5872        return (opt->flags.quick &&
5873                !opt->filter &&
5874                opt->flags.has_changes);
5875}
5876
5877/*
5878 * Shall changes to this submodule be ignored?
5879 *
5880 * Submodule changes can be configured to be ignored separately for each path,
5881 * but that configuration can be overridden from the command line.
5882 */
5883static int is_submodule_ignored(const char *path, struct diff_options *options)
5884{
5885        int ignored = 0;
5886        struct diff_flags orig_flags = options->flags;
5887        if (!options->flags.override_submodule_config)
5888                set_diffopt_flags_from_submodule_config(options, path);
5889        if (options->flags.ignore_submodules)
5890                ignored = 1;
5891        options->flags = orig_flags;
5892        return ignored;
5893}
5894
5895void diff_addremove(struct diff_options *options,
5896                    int addremove, unsigned mode,
5897                    const struct object_id *oid,
5898                    int oid_valid,
5899                    const char *concatpath, unsigned dirty_submodule)
5900{
5901        struct diff_filespec *one, *two;
5902
5903        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
5904                return;
5905
5906        /* This may look odd, but it is a preparation for
5907         * feeding "there are unchanged files which should
5908         * not produce diffs, but when you are doing copy
5909         * detection you would need them, so here they are"
5910         * entries to the diff-core.  They will be prefixed
5911         * with something like '=' or '*' (I haven't decided
5912         * which but should not make any difference).
5913         * Feeding the same new and old to diff_change()
5914         * also has the same effect.
5915         * Before the final output happens, they are pruned after
5916         * merged into rename/copy pairs as appropriate.
5917         */
5918        if (options->flags.reverse_diff)
5919                addremove = (addremove == '+' ? '-' :
5920                             addremove == '-' ? '+' : addremove);
5921
5922        if (options->prefix &&
5923            strncmp(concatpath, options->prefix, options->prefix_length))
5924                return;
5925
5926        one = alloc_filespec(concatpath);
5927        two = alloc_filespec(concatpath);
5928
5929        if (addremove != '+')
5930                fill_filespec(one, oid, oid_valid, mode);
5931        if (addremove != '-') {
5932                fill_filespec(two, oid, oid_valid, mode);
5933                two->dirty_submodule = dirty_submodule;
5934        }
5935
5936        diff_queue(&diff_queued_diff, one, two);
5937        if (!options->flags.diff_from_contents)
5938                options->flags.has_changes = 1;
5939}
5940
5941void diff_change(struct diff_options *options,
5942                 unsigned old_mode, unsigned new_mode,
5943                 const struct object_id *old_oid,
5944                 const struct object_id *new_oid,
5945                 int old_oid_valid, int new_oid_valid,
5946                 const char *concatpath,
5947                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
5948{
5949        struct diff_filespec *one, *two;
5950        struct diff_filepair *p;
5951
5952        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
5953            is_submodule_ignored(concatpath, options))
5954                return;
5955
5956        if (options->flags.reverse_diff) {
5957                SWAP(old_mode, new_mode);
5958                SWAP(old_oid, new_oid);
5959                SWAP(old_oid_valid, new_oid_valid);
5960                SWAP(old_dirty_submodule, new_dirty_submodule);
5961        }
5962
5963        if (options->prefix &&
5964            strncmp(concatpath, options->prefix, options->prefix_length))
5965                return;
5966
5967        one = alloc_filespec(concatpath);
5968        two = alloc_filespec(concatpath);
5969        fill_filespec(one, old_oid, old_oid_valid, old_mode);
5970        fill_filespec(two, new_oid, new_oid_valid, new_mode);
5971        one->dirty_submodule = old_dirty_submodule;
5972        two->dirty_submodule = new_dirty_submodule;
5973        p = diff_queue(&diff_queued_diff, one, two);
5974
5975        if (options->flags.diff_from_contents)
5976                return;
5977
5978        if (options->flags.quick && options->skip_stat_unmatch &&
5979            !diff_filespec_check_stat_unmatch(p))
5980                return;
5981
5982        options->flags.has_changes = 1;
5983}
5984
5985struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
5986{
5987        struct diff_filepair *pair;
5988        struct diff_filespec *one, *two;
5989
5990        if (options->prefix &&
5991            strncmp(path, options->prefix, options->prefix_length))
5992                return NULL;
5993
5994        one = alloc_filespec(path);
5995        two = alloc_filespec(path);
5996        pair = diff_queue(&diff_queued_diff, one, two);
5997        pair->is_unmerged = 1;
5998        return pair;
5999}
6000
6001static char *run_textconv(const char *pgm, struct diff_filespec *spec,
6002                size_t *outsize)
6003{
6004        struct diff_tempfile *temp;
6005        const char *argv[3];
6006        const char **arg = argv;
6007        struct child_process child = CHILD_PROCESS_INIT;
6008        struct strbuf buf = STRBUF_INIT;
6009        int err = 0;
6010
6011        temp = prepare_temp_file(spec->path, spec);
6012        *arg++ = pgm;
6013        *arg++ = temp->name;
6014        *arg = NULL;
6015
6016        child.use_shell = 1;
6017        child.argv = argv;
6018        child.out = -1;
6019        if (start_command(&child)) {
6020                remove_tempfile();
6021                return NULL;
6022        }
6023
6024        if (strbuf_read(&buf, child.out, 0) < 0)
6025                err = error("error reading from textconv command '%s'", pgm);
6026        close(child.out);
6027
6028        if (finish_command(&child) || err) {
6029                strbuf_release(&buf);
6030                remove_tempfile();
6031                return NULL;
6032        }
6033        remove_tempfile();
6034
6035        return strbuf_detach(&buf, outsize);
6036}
6037
6038size_t fill_textconv(struct userdiff_driver *driver,
6039                     struct diff_filespec *df,
6040                     char **outbuf)
6041{
6042        size_t size;
6043
6044        if (!driver) {
6045                if (!DIFF_FILE_VALID(df)) {
6046                        *outbuf = "";
6047                        return 0;
6048                }
6049                if (diff_populate_filespec(df, 0))
6050                        die("unable to read files to diff");
6051                *outbuf = df->data;
6052                return df->size;
6053        }
6054
6055        if (!driver->textconv)
6056                die("BUG: fill_textconv called with non-textconv driver");
6057
6058        if (driver->textconv_cache && df->oid_valid) {
6059                *outbuf = notes_cache_get(driver->textconv_cache,
6060                                          &df->oid,
6061                                          &size);
6062                if (*outbuf)
6063                        return size;
6064        }
6065
6066        *outbuf = run_textconv(driver->textconv, df, &size);
6067        if (!*outbuf)
6068                die("unable to read files to diff");
6069
6070        if (driver->textconv_cache && df->oid_valid) {
6071                /* ignore errors, as we might be in a readonly repository */
6072                notes_cache_put(driver->textconv_cache, &df->oid, *outbuf,
6073                                size);
6074                /*
6075                 * we could save up changes and flush them all at the end,
6076                 * but we would need an extra call after all diffing is done.
6077                 * Since generating a cache entry is the slow path anyway,
6078                 * this extra overhead probably isn't a big deal.
6079                 */
6080                notes_cache_write(driver->textconv_cache);
6081        }
6082
6083        return size;
6084}
6085
6086int textconv_object(const char *path,
6087                    unsigned mode,
6088                    const struct object_id *oid,
6089                    int oid_valid,
6090                    char **buf,
6091                    unsigned long *buf_size)
6092{
6093        struct diff_filespec *df;
6094        struct userdiff_driver *textconv;
6095
6096        df = alloc_filespec(path);
6097        fill_filespec(df, oid, oid_valid, mode);
6098        textconv = get_textconv(df);
6099        if (!textconv) {
6100                free_filespec(df);
6101                return 0;
6102        }
6103
6104        *buf_size = fill_textconv(textconv, df, buf);
6105        free_filespec(df);
6106        return 1;
6107}
6108
6109void setup_diff_pager(struct diff_options *opt)
6110{
6111        /*
6112         * If the user asked for our exit code, then either they want --quiet
6113         * or --exit-code. We should definitely not bother with a pager in the
6114         * former case, as we will generate no output. Since we still properly
6115         * report our exit code even when a pager is run, we _could_ run a
6116         * pager with --exit-code. But since we have not done so historically,
6117         * and because it is easy to find people oneline advising "git diff
6118         * --exit-code" in hooks and other scripts, we do not do so.
6119         */
6120        if (!opt->flags.exit_with_status &&
6121            check_pager_config("diff") != 0)
6122                setup_pager();
6123}