diff.con commit cache: convert get_graft_file to handle arbitrary repositories (0437a2e)
   1/*
   2 * Copyright (C) 2005 Junio C Hamano
   3 */
   4#include "cache.h"
   5#include "config.h"
   6#include "tempfile.h"
   7#include "quote.h"
   8#include "diff.h"
   9#include "diffcore.h"
  10#include "delta.h"
  11#include "xdiff-interface.h"
  12#include "color.h"
  13#include "attr.h"
  14#include "run-command.h"
  15#include "utf8.h"
  16#include "object-store.h"
  17#include "userdiff.h"
  18#include "submodule-config.h"
  19#include "submodule.h"
  20#include "hashmap.h"
  21#include "ll-merge.h"
  22#include "string-list.h"
  23#include "argv-array.h"
  24#include "graph.h"
  25#include "packfile.h"
  26
  27#ifdef NO_FAST_WORKING_DIRECTORY
  28#define FAST_WORKING_DIRECTORY 0
  29#else
  30#define FAST_WORKING_DIRECTORY 1
  31#endif
  32
  33static int diff_detect_rename_default;
  34static int diff_indent_heuristic = 1;
  35static int diff_rename_limit_default = 400;
  36static int diff_suppress_blank_empty;
  37static int diff_use_color_default = -1;
  38static int diff_color_moved_default;
  39static int diff_context_default = 3;
  40static int diff_interhunk_context_default;
  41static const char *diff_word_regex_cfg;
  42static const char *external_diff_cmd_cfg;
  43static const char *diff_order_file_cfg;
  44int diff_auto_refresh_index = 1;
  45static int diff_mnemonic_prefix;
  46static int diff_no_prefix;
  47static int diff_stat_graph_width;
  48static int diff_dirstat_permille_default = 30;
  49static struct diff_options default_diff_options;
  50static long diff_algorithm;
  51static unsigned ws_error_highlight_default = WSEH_NEW;
  52
  53static char diff_colors[][COLOR_MAXLEN] = {
  54        GIT_COLOR_RESET,
  55        GIT_COLOR_NORMAL,       /* CONTEXT */
  56        GIT_COLOR_BOLD,         /* METAINFO */
  57        GIT_COLOR_CYAN,         /* FRAGINFO */
  58        GIT_COLOR_RED,          /* OLD */
  59        GIT_COLOR_GREEN,        /* NEW */
  60        GIT_COLOR_YELLOW,       /* COMMIT */
  61        GIT_COLOR_BG_RED,       /* WHITESPACE */
  62        GIT_COLOR_NORMAL,       /* FUNCINFO */
  63        GIT_COLOR_BOLD_MAGENTA, /* OLD_MOVED */
  64        GIT_COLOR_BOLD_BLUE,    /* OLD_MOVED ALTERNATIVE */
  65        GIT_COLOR_FAINT,        /* OLD_MOVED_DIM */
  66        GIT_COLOR_FAINT_ITALIC, /* OLD_MOVED_ALTERNATIVE_DIM */
  67        GIT_COLOR_BOLD_CYAN,    /* NEW_MOVED */
  68        GIT_COLOR_BOLD_YELLOW,  /* NEW_MOVED ALTERNATIVE */
  69        GIT_COLOR_FAINT,        /* NEW_MOVED_DIM */
  70        GIT_COLOR_FAINT_ITALIC, /* NEW_MOVED_ALTERNATIVE_DIM */
  71};
  72
  73static NORETURN void die_want_option(const char *option_name)
  74{
  75        die(_("option '%s' requires a value"), option_name);
  76}
  77
  78static int parse_diff_color_slot(const char *var)
  79{
  80        if (!strcasecmp(var, "context") || !strcasecmp(var, "plain"))
  81                return DIFF_CONTEXT;
  82        if (!strcasecmp(var, "meta"))
  83                return DIFF_METAINFO;
  84        if (!strcasecmp(var, "frag"))
  85                return DIFF_FRAGINFO;
  86        if (!strcasecmp(var, "old"))
  87                return DIFF_FILE_OLD;
  88        if (!strcasecmp(var, "new"))
  89                return DIFF_FILE_NEW;
  90        if (!strcasecmp(var, "commit"))
  91                return DIFF_COMMIT;
  92        if (!strcasecmp(var, "whitespace"))
  93                return DIFF_WHITESPACE;
  94        if (!strcasecmp(var, "func"))
  95                return DIFF_FUNCINFO;
  96        if (!strcasecmp(var, "oldmoved"))
  97                return DIFF_FILE_OLD_MOVED;
  98        if (!strcasecmp(var, "oldmovedalternative"))
  99                return DIFF_FILE_OLD_MOVED_ALT;
 100        if (!strcasecmp(var, "oldmoveddimmed"))
 101                return DIFF_FILE_OLD_MOVED_DIM;
 102        if (!strcasecmp(var, "oldmovedalternativedimmed"))
 103                return DIFF_FILE_OLD_MOVED_ALT_DIM;
 104        if (!strcasecmp(var, "newmoved"))
 105                return DIFF_FILE_NEW_MOVED;
 106        if (!strcasecmp(var, "newmovedalternative"))
 107                return DIFF_FILE_NEW_MOVED_ALT;
 108        if (!strcasecmp(var, "newmoveddimmed"))
 109                return DIFF_FILE_NEW_MOVED_DIM;
 110        if (!strcasecmp(var, "newmovedalternativedimmed"))
 111                return DIFF_FILE_NEW_MOVED_ALT_DIM;
 112        return -1;
 113}
 114
 115static int parse_dirstat_params(struct diff_options *options, const char *params_string,
 116                                struct strbuf *errmsg)
 117{
 118        char *params_copy = xstrdup(params_string);
 119        struct string_list params = STRING_LIST_INIT_NODUP;
 120        int ret = 0;
 121        int i;
 122
 123        if (*params_copy)
 124                string_list_split_in_place(&params, params_copy, ',', -1);
 125        for (i = 0; i < params.nr; i++) {
 126                const char *p = params.items[i].string;
 127                if (!strcmp(p, "changes")) {
 128                        options->flags.dirstat_by_line = 0;
 129                        options->flags.dirstat_by_file = 0;
 130                } else if (!strcmp(p, "lines")) {
 131                        options->flags.dirstat_by_line = 1;
 132                        options->flags.dirstat_by_file = 0;
 133                } else if (!strcmp(p, "files")) {
 134                        options->flags.dirstat_by_line = 0;
 135                        options->flags.dirstat_by_file = 1;
 136                } else if (!strcmp(p, "noncumulative")) {
 137                        options->flags.dirstat_cumulative = 0;
 138                } else if (!strcmp(p, "cumulative")) {
 139                        options->flags.dirstat_cumulative = 1;
 140                } else if (isdigit(*p)) {
 141                        char *end;
 142                        int permille = strtoul(p, &end, 10) * 10;
 143                        if (*end == '.' && isdigit(*++end)) {
 144                                /* only use first digit */
 145                                permille += *end - '0';
 146                                /* .. and ignore any further digits */
 147                                while (isdigit(*++end))
 148                                        ; /* nothing */
 149                        }
 150                        if (!*end)
 151                                options->dirstat_permille = permille;
 152                        else {
 153                                strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%s'\n"),
 154                                            p);
 155                                ret++;
 156                        }
 157                } else {
 158                        strbuf_addf(errmsg, _("  Unknown dirstat parameter '%s'\n"), p);
 159                        ret++;
 160                }
 161
 162        }
 163        string_list_clear(&params, 0);
 164        free(params_copy);
 165        return ret;
 166}
 167
 168static int parse_submodule_params(struct diff_options *options, const char *value)
 169{
 170        if (!strcmp(value, "log"))
 171                options->submodule_format = DIFF_SUBMODULE_LOG;
 172        else if (!strcmp(value, "short"))
 173                options->submodule_format = DIFF_SUBMODULE_SHORT;
 174        else if (!strcmp(value, "diff"))
 175                options->submodule_format = DIFF_SUBMODULE_INLINE_DIFF;
 176        else
 177                return -1;
 178        return 0;
 179}
 180
 181static int git_config_rename(const char *var, const char *value)
 182{
 183        if (!value)
 184                return DIFF_DETECT_RENAME;
 185        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 186                return  DIFF_DETECT_COPY;
 187        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 188}
 189
 190long parse_algorithm_value(const char *value)
 191{
 192        if (!value)
 193                return -1;
 194        else if (!strcasecmp(value, "myers") || !strcasecmp(value, "default"))
 195                return 0;
 196        else if (!strcasecmp(value, "minimal"))
 197                return XDF_NEED_MINIMAL;
 198        else if (!strcasecmp(value, "patience"))
 199                return XDF_PATIENCE_DIFF;
 200        else if (!strcasecmp(value, "histogram"))
 201                return XDF_HISTOGRAM_DIFF;
 202        return -1;
 203}
 204
 205static int parse_one_token(const char **arg, const char *token)
 206{
 207        const char *rest;
 208        if (skip_prefix(*arg, token, &rest) && (!*rest || *rest == ',')) {
 209                *arg = rest;
 210                return 1;
 211        }
 212        return 0;
 213}
 214
 215static int parse_ws_error_highlight(const char *arg)
 216{
 217        const char *orig_arg = arg;
 218        unsigned val = 0;
 219
 220        while (*arg) {
 221                if (parse_one_token(&arg, "none"))
 222                        val = 0;
 223                else if (parse_one_token(&arg, "default"))
 224                        val = WSEH_NEW;
 225                else if (parse_one_token(&arg, "all"))
 226                        val = WSEH_NEW | WSEH_OLD | WSEH_CONTEXT;
 227                else if (parse_one_token(&arg, "new"))
 228                        val |= WSEH_NEW;
 229                else if (parse_one_token(&arg, "old"))
 230                        val |= WSEH_OLD;
 231                else if (parse_one_token(&arg, "context"))
 232                        val |= WSEH_CONTEXT;
 233                else {
 234                        return -1 - (int)(arg - orig_arg);
 235                }
 236                if (*arg)
 237                        arg++;
 238        }
 239        return val;
 240}
 241
 242/*
 243 * These are to give UI layer defaults.
 244 * The core-level commands such as git-diff-files should
 245 * never be affected by the setting of diff.renames
 246 * the user happens to have in the configuration file.
 247 */
 248void init_diff_ui_defaults(void)
 249{
 250        diff_detect_rename_default = DIFF_DETECT_RENAME;
 251}
 252
 253int git_diff_heuristic_config(const char *var, const char *value, void *cb)
 254{
 255        if (!strcmp(var, "diff.indentheuristic"))
 256                diff_indent_heuristic = git_config_bool(var, value);
 257        return 0;
 258}
 259
 260static int parse_color_moved(const char *arg)
 261{
 262        switch (git_parse_maybe_bool(arg)) {
 263        case 0:
 264                return COLOR_MOVED_NO;
 265        case 1:
 266                return COLOR_MOVED_DEFAULT;
 267        default:
 268                break;
 269        }
 270
 271        if (!strcmp(arg, "no"))
 272                return COLOR_MOVED_NO;
 273        else if (!strcmp(arg, "plain"))
 274                return COLOR_MOVED_PLAIN;
 275        else if (!strcmp(arg, "zebra"))
 276                return COLOR_MOVED_ZEBRA;
 277        else if (!strcmp(arg, "default"))
 278                return COLOR_MOVED_DEFAULT;
 279        else if (!strcmp(arg, "dimmed_zebra"))
 280                return COLOR_MOVED_ZEBRA_DIM;
 281        else
 282                return error(_("color moved setting must be one of 'no', 'default', 'zebra', 'dimmed_zebra', 'plain'"));
 283}
 284
 285int git_diff_ui_config(const char *var, const char *value, void *cb)
 286{
 287        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 288                diff_use_color_default = git_config_colorbool(var, value);
 289                return 0;
 290        }
 291        if (!strcmp(var, "diff.colormoved")) {
 292                int cm = parse_color_moved(value);
 293                if (cm < 0)
 294                        return -1;
 295                diff_color_moved_default = cm;
 296                return 0;
 297        }
 298        if (!strcmp(var, "diff.context")) {
 299                diff_context_default = git_config_int(var, value);
 300                if (diff_context_default < 0)
 301                        return -1;
 302                return 0;
 303        }
 304        if (!strcmp(var, "diff.interhunkcontext")) {
 305                diff_interhunk_context_default = git_config_int(var, value);
 306                if (diff_interhunk_context_default < 0)
 307                        return -1;
 308                return 0;
 309        }
 310        if (!strcmp(var, "diff.renames")) {
 311                diff_detect_rename_default = git_config_rename(var, value);
 312                return 0;
 313        }
 314        if (!strcmp(var, "diff.autorefreshindex")) {
 315                diff_auto_refresh_index = git_config_bool(var, value);
 316                return 0;
 317        }
 318        if (!strcmp(var, "diff.mnemonicprefix")) {
 319                diff_mnemonic_prefix = git_config_bool(var, value);
 320                return 0;
 321        }
 322        if (!strcmp(var, "diff.noprefix")) {
 323                diff_no_prefix = git_config_bool(var, value);
 324                return 0;
 325        }
 326        if (!strcmp(var, "diff.statgraphwidth")) {
 327                diff_stat_graph_width = git_config_int(var, value);
 328                return 0;
 329        }
 330        if (!strcmp(var, "diff.external"))
 331                return git_config_string(&external_diff_cmd_cfg, var, value);
 332        if (!strcmp(var, "diff.wordregex"))
 333                return git_config_string(&diff_word_regex_cfg, var, value);
 334        if (!strcmp(var, "diff.orderfile"))
 335                return git_config_pathname(&diff_order_file_cfg, var, value);
 336
 337        if (!strcmp(var, "diff.ignoresubmodules"))
 338                handle_ignore_submodules_arg(&default_diff_options, value);
 339
 340        if (!strcmp(var, "diff.submodule")) {
 341                if (parse_submodule_params(&default_diff_options, value))
 342                        warning(_("Unknown value for 'diff.submodule' config variable: '%s'"),
 343                                value);
 344                return 0;
 345        }
 346
 347        if (!strcmp(var, "diff.algorithm")) {
 348                diff_algorithm = parse_algorithm_value(value);
 349                if (diff_algorithm < 0)
 350                        return -1;
 351                return 0;
 352        }
 353
 354        if (!strcmp(var, "diff.wserrorhighlight")) {
 355                int val = parse_ws_error_highlight(value);
 356                if (val < 0)
 357                        return -1;
 358                ws_error_highlight_default = val;
 359                return 0;
 360        }
 361
 362        if (git_color_config(var, value, cb) < 0)
 363                return -1;
 364
 365        return git_diff_basic_config(var, value, cb);
 366}
 367
 368int git_diff_basic_config(const char *var, const char *value, void *cb)
 369{
 370        const char *name;
 371
 372        if (!strcmp(var, "diff.renamelimit")) {
 373                diff_rename_limit_default = git_config_int(var, value);
 374                return 0;
 375        }
 376
 377        if (userdiff_config(var, value) < 0)
 378                return -1;
 379
 380        if (skip_prefix(var, "diff.color.", &name) ||
 381            skip_prefix(var, "color.diff.", &name)) {
 382                int slot = parse_diff_color_slot(name);
 383                if (slot < 0)
 384                        return 0;
 385                if (!value)
 386                        return config_error_nonbool(var);
 387                return color_parse(value, diff_colors[slot]);
 388        }
 389
 390        /* like GNU diff's --suppress-blank-empty option  */
 391        if (!strcmp(var, "diff.suppressblankempty") ||
 392                        /* for backwards compatibility */
 393                        !strcmp(var, "diff.suppress-blank-empty")) {
 394                diff_suppress_blank_empty = git_config_bool(var, value);
 395                return 0;
 396        }
 397
 398        if (!strcmp(var, "diff.dirstat")) {
 399                struct strbuf errmsg = STRBUF_INIT;
 400                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 401                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 402                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 403                                errmsg.buf);
 404                strbuf_release(&errmsg);
 405                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 406                return 0;
 407        }
 408
 409        if (git_diff_heuristic_config(var, value, cb) < 0)
 410                return -1;
 411
 412        return git_default_config(var, value, cb);
 413}
 414
 415static char *quote_two(const char *one, const char *two)
 416{
 417        int need_one = quote_c_style(one, NULL, NULL, 1);
 418        int need_two = quote_c_style(two, NULL, NULL, 1);
 419        struct strbuf res = STRBUF_INIT;
 420
 421        if (need_one + need_two) {
 422                strbuf_addch(&res, '"');
 423                quote_c_style(one, &res, NULL, 1);
 424                quote_c_style(two, &res, NULL, 1);
 425                strbuf_addch(&res, '"');
 426        } else {
 427                strbuf_addstr(&res, one);
 428                strbuf_addstr(&res, two);
 429        }
 430        return strbuf_detach(&res, NULL);
 431}
 432
 433static const char *external_diff(void)
 434{
 435        static const char *external_diff_cmd = NULL;
 436        static int done_preparing = 0;
 437
 438        if (done_preparing)
 439                return external_diff_cmd;
 440        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 441        if (!external_diff_cmd)
 442                external_diff_cmd = external_diff_cmd_cfg;
 443        done_preparing = 1;
 444        return external_diff_cmd;
 445}
 446
 447/*
 448 * Keep track of files used for diffing. Sometimes such an entry
 449 * refers to a temporary file, sometimes to an existing file, and
 450 * sometimes to "/dev/null".
 451 */
 452static struct diff_tempfile {
 453        /*
 454         * filename external diff should read from, or NULL if this
 455         * entry is currently not in use:
 456         */
 457        const char *name;
 458
 459        char hex[GIT_MAX_HEXSZ + 1];
 460        char mode[10];
 461
 462        /*
 463         * If this diff_tempfile instance refers to a temporary file,
 464         * this tempfile object is used to manage its lifetime.
 465         */
 466        struct tempfile *tempfile;
 467} diff_temp[2];
 468
 469struct emit_callback {
 470        int color_diff;
 471        unsigned ws_rule;
 472        int blank_at_eof_in_preimage;
 473        int blank_at_eof_in_postimage;
 474        int lno_in_preimage;
 475        int lno_in_postimage;
 476        const char **label_path;
 477        struct diff_words_data *diff_words;
 478        struct diff_options *opt;
 479        struct strbuf *header;
 480};
 481
 482static int count_lines(const char *data, int size)
 483{
 484        int count, ch, completely_empty = 1, nl_just_seen = 0;
 485        count = 0;
 486        while (0 < size--) {
 487                ch = *data++;
 488                if (ch == '\n') {
 489                        count++;
 490                        nl_just_seen = 1;
 491                        completely_empty = 0;
 492                }
 493                else {
 494                        nl_just_seen = 0;
 495                        completely_empty = 0;
 496                }
 497        }
 498        if (completely_empty)
 499                return 0;
 500        if (!nl_just_seen)
 501                count++; /* no trailing newline */
 502        return count;
 503}
 504
 505static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 506{
 507        if (!DIFF_FILE_VALID(one)) {
 508                mf->ptr = (char *)""; /* does not matter */
 509                mf->size = 0;
 510                return 0;
 511        }
 512        else if (diff_populate_filespec(one, 0))
 513                return -1;
 514
 515        mf->ptr = one->data;
 516        mf->size = one->size;
 517        return 0;
 518}
 519
 520/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 521static unsigned long diff_filespec_size(struct diff_filespec *one)
 522{
 523        if (!DIFF_FILE_VALID(one))
 524                return 0;
 525        diff_populate_filespec(one, CHECK_SIZE_ONLY);
 526        return one->size;
 527}
 528
 529static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 530{
 531        char *ptr = mf->ptr;
 532        long size = mf->size;
 533        int cnt = 0;
 534
 535        if (!size)
 536                return cnt;
 537        ptr += size - 1; /* pointing at the very end */
 538        if (*ptr != '\n')
 539                ; /* incomplete line */
 540        else
 541                ptr--; /* skip the last LF */
 542        while (mf->ptr < ptr) {
 543                char *prev_eol;
 544                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 545                        if (*prev_eol == '\n')
 546                                break;
 547                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 548                        break;
 549                cnt++;
 550                ptr = prev_eol - 1;
 551        }
 552        return cnt;
 553}
 554
 555static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 556                               struct emit_callback *ecbdata)
 557{
 558        int l1, l2, at;
 559        unsigned ws_rule = ecbdata->ws_rule;
 560        l1 = count_trailing_blank(mf1, ws_rule);
 561        l2 = count_trailing_blank(mf2, ws_rule);
 562        if (l2 <= l1) {
 563                ecbdata->blank_at_eof_in_preimage = 0;
 564                ecbdata->blank_at_eof_in_postimage = 0;
 565                return;
 566        }
 567        at = count_lines(mf1->ptr, mf1->size);
 568        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 569
 570        at = count_lines(mf2->ptr, mf2->size);
 571        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 572}
 573
 574static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 575                        int first, const char *line, int len)
 576{
 577        int has_trailing_newline, has_trailing_carriage_return;
 578        int nofirst;
 579        FILE *file = o->file;
 580
 581        fputs(diff_line_prefix(o), file);
 582
 583        if (len == 0) {
 584                has_trailing_newline = (first == '\n');
 585                has_trailing_carriage_return = (!has_trailing_newline &&
 586                                                (first == '\r'));
 587                nofirst = has_trailing_newline || has_trailing_carriage_return;
 588        } else {
 589                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 590                if (has_trailing_newline)
 591                        len--;
 592                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 593                if (has_trailing_carriage_return)
 594                        len--;
 595                nofirst = 0;
 596        }
 597
 598        if (len || !nofirst) {
 599                fputs(set, file);
 600                if (!nofirst)
 601                        fputc(first, file);
 602                fwrite(line, len, 1, file);
 603                fputs(reset, file);
 604        }
 605        if (has_trailing_carriage_return)
 606                fputc('\r', file);
 607        if (has_trailing_newline)
 608                fputc('\n', file);
 609}
 610
 611static void emit_line(struct diff_options *o, const char *set, const char *reset,
 612                      const char *line, int len)
 613{
 614        emit_line_0(o, set, reset, line[0], line+1, len-1);
 615}
 616
 617enum diff_symbol {
 618        DIFF_SYMBOL_BINARY_DIFF_HEADER,
 619        DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
 620        DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
 621        DIFF_SYMBOL_BINARY_DIFF_BODY,
 622        DIFF_SYMBOL_BINARY_DIFF_FOOTER,
 623        DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
 624        DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
 625        DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
 626        DIFF_SYMBOL_STATS_LINE,
 627        DIFF_SYMBOL_WORD_DIFF,
 628        DIFF_SYMBOL_STAT_SEP,
 629        DIFF_SYMBOL_SUMMARY,
 630        DIFF_SYMBOL_SUBMODULE_ADD,
 631        DIFF_SYMBOL_SUBMODULE_DEL,
 632        DIFF_SYMBOL_SUBMODULE_UNTRACKED,
 633        DIFF_SYMBOL_SUBMODULE_MODIFIED,
 634        DIFF_SYMBOL_SUBMODULE_HEADER,
 635        DIFF_SYMBOL_SUBMODULE_ERROR,
 636        DIFF_SYMBOL_SUBMODULE_PIPETHROUGH,
 637        DIFF_SYMBOL_REWRITE_DIFF,
 638        DIFF_SYMBOL_BINARY_FILES,
 639        DIFF_SYMBOL_HEADER,
 640        DIFF_SYMBOL_FILEPAIR_PLUS,
 641        DIFF_SYMBOL_FILEPAIR_MINUS,
 642        DIFF_SYMBOL_WORDS_PORCELAIN,
 643        DIFF_SYMBOL_WORDS,
 644        DIFF_SYMBOL_CONTEXT,
 645        DIFF_SYMBOL_CONTEXT_INCOMPLETE,
 646        DIFF_SYMBOL_PLUS,
 647        DIFF_SYMBOL_MINUS,
 648        DIFF_SYMBOL_NO_LF_EOF,
 649        DIFF_SYMBOL_CONTEXT_FRAGINFO,
 650        DIFF_SYMBOL_CONTEXT_MARKER,
 651        DIFF_SYMBOL_SEPARATOR
 652};
 653/*
 654 * Flags for content lines:
 655 * 0..12 are whitespace rules
 656 * 13-15 are WSEH_NEW | WSEH_OLD | WSEH_CONTEXT
 657 * 16 is marking if the line is blank at EOF
 658 */
 659#define DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF      (1<<16)
 660#define DIFF_SYMBOL_MOVED_LINE                  (1<<17)
 661#define DIFF_SYMBOL_MOVED_LINE_ALT              (1<<18)
 662#define DIFF_SYMBOL_MOVED_LINE_UNINTERESTING    (1<<19)
 663#define DIFF_SYMBOL_CONTENT_WS_MASK (WSEH_NEW | WSEH_OLD | WSEH_CONTEXT | WS_RULE_MASK)
 664
 665/*
 666 * This struct is used when we need to buffer the output of the diff output.
 667 *
 668 * NEEDSWORK: Instead of storing a copy of the line, add an offset pointer
 669 * into the pre/post image file. This pointer could be a union with the
 670 * line pointer. By storing an offset into the file instead of the literal line,
 671 * we can decrease the memory footprint for the buffered output. At first we
 672 * may want to only have indirection for the content lines, but we could also
 673 * enhance the state for emitting prefabricated lines, e.g. the similarity
 674 * score line or hunk/file headers would only need to store a number or path
 675 * and then the output can be constructed later on depending on state.
 676 */
 677struct emitted_diff_symbol {
 678        const char *line;
 679        int len;
 680        int flags;
 681        enum diff_symbol s;
 682};
 683#define EMITTED_DIFF_SYMBOL_INIT {NULL}
 684
 685struct emitted_diff_symbols {
 686        struct emitted_diff_symbol *buf;
 687        int nr, alloc;
 688};
 689#define EMITTED_DIFF_SYMBOLS_INIT {NULL, 0, 0}
 690
 691static void append_emitted_diff_symbol(struct diff_options *o,
 692                                       struct emitted_diff_symbol *e)
 693{
 694        struct emitted_diff_symbol *f;
 695
 696        ALLOC_GROW(o->emitted_symbols->buf,
 697                   o->emitted_symbols->nr + 1,
 698                   o->emitted_symbols->alloc);
 699        f = &o->emitted_symbols->buf[o->emitted_symbols->nr++];
 700
 701        memcpy(f, e, sizeof(struct emitted_diff_symbol));
 702        f->line = e->line ? xmemdupz(e->line, e->len) : NULL;
 703}
 704
 705struct moved_entry {
 706        struct hashmap_entry ent;
 707        const struct emitted_diff_symbol *es;
 708        struct moved_entry *next_line;
 709};
 710
 711static int moved_entry_cmp(const struct diff_options *diffopt,
 712                           const struct moved_entry *a,
 713                           const struct moved_entry *b,
 714                           const void *keydata)
 715{
 716        return !xdiff_compare_lines(a->es->line, a->es->len,
 717                                    b->es->line, b->es->len,
 718                                    diffopt->xdl_opts);
 719}
 720
 721static struct moved_entry *prepare_entry(struct diff_options *o,
 722                                         int line_no)
 723{
 724        struct moved_entry *ret = xmalloc(sizeof(*ret));
 725        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[line_no];
 726
 727        ret->ent.hash = xdiff_hash_string(l->line, l->len, o->xdl_opts);
 728        ret->es = l;
 729        ret->next_line = NULL;
 730
 731        return ret;
 732}
 733
 734static void add_lines_to_move_detection(struct diff_options *o,
 735                                        struct hashmap *add_lines,
 736                                        struct hashmap *del_lines)
 737{
 738        struct moved_entry *prev_line = NULL;
 739
 740        int n;
 741        for (n = 0; n < o->emitted_symbols->nr; n++) {
 742                struct hashmap *hm;
 743                struct moved_entry *key;
 744
 745                switch (o->emitted_symbols->buf[n].s) {
 746                case DIFF_SYMBOL_PLUS:
 747                        hm = add_lines;
 748                        break;
 749                case DIFF_SYMBOL_MINUS:
 750                        hm = del_lines;
 751                        break;
 752                default:
 753                        prev_line = NULL;
 754                        continue;
 755                }
 756
 757                key = prepare_entry(o, n);
 758                if (prev_line && prev_line->es->s == o->emitted_symbols->buf[n].s)
 759                        prev_line->next_line = key;
 760
 761                hashmap_add(hm, key);
 762                prev_line = key;
 763        }
 764}
 765
 766static int shrink_potential_moved_blocks(struct moved_entry **pmb,
 767                                         int pmb_nr)
 768{
 769        int lp, rp;
 770
 771        /* Shrink the set of potential block to the remaining running */
 772        for (lp = 0, rp = pmb_nr - 1; lp <= rp;) {
 773                while (lp < pmb_nr && pmb[lp])
 774                        lp++;
 775                /* lp points at the first NULL now */
 776
 777                while (rp > -1 && !pmb[rp])
 778                        rp--;
 779                /* rp points at the last non-NULL */
 780
 781                if (lp < pmb_nr && rp > -1 && lp < rp) {
 782                        pmb[lp] = pmb[rp];
 783                        pmb[rp] = NULL;
 784                        rp--;
 785                        lp++;
 786                }
 787        }
 788
 789        /* Remember the number of running sets */
 790        return rp + 1;
 791}
 792
 793/*
 794 * If o->color_moved is COLOR_MOVED_PLAIN, this function does nothing.
 795 *
 796 * Otherwise, if the last block has fewer alphanumeric characters than
 797 * COLOR_MOVED_MIN_ALNUM_COUNT, unset DIFF_SYMBOL_MOVED_LINE on all lines in
 798 * that block.
 799 *
 800 * The last block consists of the (n - block_length)'th line up to but not
 801 * including the nth line.
 802 *
 803 * NEEDSWORK: This uses the same heuristic as blame_entry_score() in blame.c.
 804 * Think of a way to unify them.
 805 */
 806static void adjust_last_block(struct diff_options *o, int n, int block_length)
 807{
 808        int i, alnum_count = 0;
 809        if (o->color_moved == COLOR_MOVED_PLAIN)
 810                return;
 811        for (i = 1; i < block_length + 1; i++) {
 812                const char *c = o->emitted_symbols->buf[n - i].line;
 813                for (; *c; c++) {
 814                        if (!isalnum(*c))
 815                                continue;
 816                        alnum_count++;
 817                        if (alnum_count >= COLOR_MOVED_MIN_ALNUM_COUNT)
 818                                return;
 819                }
 820        }
 821        for (i = 1; i < block_length + 1; i++)
 822                o->emitted_symbols->buf[n - i].flags &= ~DIFF_SYMBOL_MOVED_LINE;
 823}
 824
 825/* Find blocks of moved code, delegate actual coloring decision to helper */
 826static void mark_color_as_moved(struct diff_options *o,
 827                                struct hashmap *add_lines,
 828                                struct hashmap *del_lines)
 829{
 830        struct moved_entry **pmb = NULL; /* potentially moved blocks */
 831        int pmb_nr = 0, pmb_alloc = 0;
 832        int n, flipped_block = 1, block_length = 0;
 833
 834
 835        for (n = 0; n < o->emitted_symbols->nr; n++) {
 836                struct hashmap *hm = NULL;
 837                struct moved_entry *key;
 838                struct moved_entry *match = NULL;
 839                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
 840                int i;
 841
 842                switch (l->s) {
 843                case DIFF_SYMBOL_PLUS:
 844                        hm = del_lines;
 845                        key = prepare_entry(o, n);
 846                        match = hashmap_get(hm, key, o);
 847                        free(key);
 848                        break;
 849                case DIFF_SYMBOL_MINUS:
 850                        hm = add_lines;
 851                        key = prepare_entry(o, n);
 852                        match = hashmap_get(hm, key, o);
 853                        free(key);
 854                        break;
 855                default:
 856                        flipped_block = 1;
 857                }
 858
 859                if (!match) {
 860                        adjust_last_block(o, n, block_length);
 861                        pmb_nr = 0;
 862                        block_length = 0;
 863                        continue;
 864                }
 865
 866                l->flags |= DIFF_SYMBOL_MOVED_LINE;
 867
 868                if (o->color_moved == COLOR_MOVED_PLAIN)
 869                        continue;
 870
 871                /* Check any potential block runs, advance each or nullify */
 872                for (i = 0; i < pmb_nr; i++) {
 873                        struct moved_entry *p = pmb[i];
 874                        struct moved_entry *pnext = (p && p->next_line) ?
 875                                        p->next_line : NULL;
 876                        if (pnext && !hm->cmpfn(o, pnext, match, NULL)) {
 877                                pmb[i] = p->next_line;
 878                        } else {
 879                                pmb[i] = NULL;
 880                        }
 881                }
 882
 883                pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
 884
 885                if (pmb_nr == 0) {
 886                        /*
 887                         * The current line is the start of a new block.
 888                         * Setup the set of potential blocks.
 889                         */
 890                        for (; match; match = hashmap_get_next(hm, match)) {
 891                                ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
 892                                pmb[pmb_nr++] = match;
 893                        }
 894
 895                        flipped_block = (flipped_block + 1) % 2;
 896
 897                        adjust_last_block(o, n, block_length);
 898                        block_length = 0;
 899                }
 900
 901                block_length++;
 902
 903                if (flipped_block)
 904                        l->flags |= DIFF_SYMBOL_MOVED_LINE_ALT;
 905        }
 906        adjust_last_block(o, n, block_length);
 907
 908        free(pmb);
 909}
 910
 911#define DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK \
 912  (DIFF_SYMBOL_MOVED_LINE | DIFF_SYMBOL_MOVED_LINE_ALT)
 913static void dim_moved_lines(struct diff_options *o)
 914{
 915        int n;
 916        for (n = 0; n < o->emitted_symbols->nr; n++) {
 917                struct emitted_diff_symbol *prev = (n != 0) ?
 918                                &o->emitted_symbols->buf[n - 1] : NULL;
 919                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
 920                struct emitted_diff_symbol *next =
 921                                (n < o->emitted_symbols->nr - 1) ?
 922                                &o->emitted_symbols->buf[n + 1] : NULL;
 923
 924                /* Not a plus or minus line? */
 925                if (l->s != DIFF_SYMBOL_PLUS && l->s != DIFF_SYMBOL_MINUS)
 926                        continue;
 927
 928                /* Not a moved line? */
 929                if (!(l->flags & DIFF_SYMBOL_MOVED_LINE))
 930                        continue;
 931
 932                /*
 933                 * If prev or next are not a plus or minus line,
 934                 * pretend they don't exist
 935                 */
 936                if (prev && prev->s != DIFF_SYMBOL_PLUS &&
 937                            prev->s != DIFF_SYMBOL_MINUS)
 938                        prev = NULL;
 939                if (next && next->s != DIFF_SYMBOL_PLUS &&
 940                            next->s != DIFF_SYMBOL_MINUS)
 941                        next = NULL;
 942
 943                /* Inside a block? */
 944                if ((prev &&
 945                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
 946                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK)) &&
 947                    (next &&
 948                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
 949                    (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK))) {
 950                        l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
 951                        continue;
 952                }
 953
 954                /* Check if we are at an interesting bound: */
 955                if (prev && (prev->flags & DIFF_SYMBOL_MOVED_LINE) &&
 956                    (prev->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
 957                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
 958                        continue;
 959                if (next && (next->flags & DIFF_SYMBOL_MOVED_LINE) &&
 960                    (next->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
 961                       (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
 962                        continue;
 963
 964                /*
 965                 * The boundary to prev and next are not interesting,
 966                 * so this line is not interesting as a whole
 967                 */
 968                l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
 969        }
 970}
 971
 972static void emit_line_ws_markup(struct diff_options *o,
 973                                const char *set, const char *reset,
 974                                const char *line, int len, char sign,
 975                                unsigned ws_rule, int blank_at_eof)
 976{
 977        const char *ws = NULL;
 978
 979        if (o->ws_error_highlight & ws_rule) {
 980                ws = diff_get_color_opt(o, DIFF_WHITESPACE);
 981                if (!*ws)
 982                        ws = NULL;
 983        }
 984
 985        if (!ws)
 986                emit_line_0(o, set, reset, sign, line, len);
 987        else if (blank_at_eof)
 988                /* Blank line at EOF - paint '+' as well */
 989                emit_line_0(o, ws, reset, sign, line, len);
 990        else {
 991                /* Emit just the prefix, then the rest. */
 992                emit_line_0(o, set, reset, sign, "", 0);
 993                ws_check_emit(line, len, ws_rule,
 994                              o->file, set, reset, ws);
 995        }
 996}
 997
 998static void emit_diff_symbol_from_struct(struct diff_options *o,
 999                                         struct emitted_diff_symbol *eds)
1000{
1001        static const char *nneof = " No newline at end of file\n";
1002        const char *context, *reset, *set, *meta, *fraginfo;
1003        struct strbuf sb = STRBUF_INIT;
1004
1005        enum diff_symbol s = eds->s;
1006        const char *line = eds->line;
1007        int len = eds->len;
1008        unsigned flags = eds->flags;
1009
1010        switch (s) {
1011        case DIFF_SYMBOL_NO_LF_EOF:
1012                context = diff_get_color_opt(o, DIFF_CONTEXT);
1013                reset = diff_get_color_opt(o, DIFF_RESET);
1014                putc('\n', o->file);
1015                emit_line_0(o, context, reset, '\\',
1016                            nneof, strlen(nneof));
1017                break;
1018        case DIFF_SYMBOL_SUBMODULE_HEADER:
1019        case DIFF_SYMBOL_SUBMODULE_ERROR:
1020        case DIFF_SYMBOL_SUBMODULE_PIPETHROUGH:
1021        case DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES:
1022        case DIFF_SYMBOL_SUMMARY:
1023        case DIFF_SYMBOL_STATS_LINE:
1024        case DIFF_SYMBOL_BINARY_DIFF_BODY:
1025        case DIFF_SYMBOL_CONTEXT_FRAGINFO:
1026                emit_line(o, "", "", line, len);
1027                break;
1028        case DIFF_SYMBOL_CONTEXT_INCOMPLETE:
1029        case DIFF_SYMBOL_CONTEXT_MARKER:
1030                context = diff_get_color_opt(o, DIFF_CONTEXT);
1031                reset = diff_get_color_opt(o, DIFF_RESET);
1032                emit_line(o, context, reset, line, len);
1033                break;
1034        case DIFF_SYMBOL_SEPARATOR:
1035                fprintf(o->file, "%s%c",
1036                        diff_line_prefix(o),
1037                        o->line_termination);
1038                break;
1039        case DIFF_SYMBOL_CONTEXT:
1040                set = diff_get_color_opt(o, DIFF_CONTEXT);
1041                reset = diff_get_color_opt(o, DIFF_RESET);
1042                emit_line_ws_markup(o, set, reset, line, len, ' ',
1043                                    flags & (DIFF_SYMBOL_CONTENT_WS_MASK), 0);
1044                break;
1045        case DIFF_SYMBOL_PLUS:
1046                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1047                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1048                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1049                case DIFF_SYMBOL_MOVED_LINE |
1050                     DIFF_SYMBOL_MOVED_LINE_ALT |
1051                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1052                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT_DIM);
1053                        break;
1054                case DIFF_SYMBOL_MOVED_LINE |
1055                     DIFF_SYMBOL_MOVED_LINE_ALT:
1056                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT);
1057                        break;
1058                case DIFF_SYMBOL_MOVED_LINE |
1059                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1060                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_DIM);
1061                        break;
1062                case DIFF_SYMBOL_MOVED_LINE:
1063                        set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED);
1064                        break;
1065                default:
1066                        set = diff_get_color_opt(o, DIFF_FILE_NEW);
1067                }
1068                reset = diff_get_color_opt(o, DIFF_RESET);
1069                emit_line_ws_markup(o, set, reset, line, len, '+',
1070                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK,
1071                                    flags & DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF);
1072                break;
1073        case DIFF_SYMBOL_MINUS:
1074                switch (flags & (DIFF_SYMBOL_MOVED_LINE |
1075                                 DIFF_SYMBOL_MOVED_LINE_ALT |
1076                                 DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
1077                case DIFF_SYMBOL_MOVED_LINE |
1078                     DIFF_SYMBOL_MOVED_LINE_ALT |
1079                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1080                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT_DIM);
1081                        break;
1082                case DIFF_SYMBOL_MOVED_LINE |
1083                     DIFF_SYMBOL_MOVED_LINE_ALT:
1084                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT);
1085                        break;
1086                case DIFF_SYMBOL_MOVED_LINE |
1087                     DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
1088                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_DIM);
1089                        break;
1090                case DIFF_SYMBOL_MOVED_LINE:
1091                        set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED);
1092                        break;
1093                default:
1094                        set = diff_get_color_opt(o, DIFF_FILE_OLD);
1095                }
1096                reset = diff_get_color_opt(o, DIFF_RESET);
1097                emit_line_ws_markup(o, set, reset, line, len, '-',
1098                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK, 0);
1099                break;
1100        case DIFF_SYMBOL_WORDS_PORCELAIN:
1101                context = diff_get_color_opt(o, DIFF_CONTEXT);
1102                reset = diff_get_color_opt(o, DIFF_RESET);
1103                emit_line(o, context, reset, line, len);
1104                fputs("~\n", o->file);
1105                break;
1106        case DIFF_SYMBOL_WORDS:
1107                context = diff_get_color_opt(o, DIFF_CONTEXT);
1108                reset = diff_get_color_opt(o, DIFF_RESET);
1109                /*
1110                 * Skip the prefix character, if any.  With
1111                 * diff_suppress_blank_empty, there may be
1112                 * none.
1113                 */
1114                if (line[0] != '\n') {
1115                        line++;
1116                        len--;
1117                }
1118                emit_line(o, context, reset, line, len);
1119                break;
1120        case DIFF_SYMBOL_FILEPAIR_PLUS:
1121                meta = diff_get_color_opt(o, DIFF_METAINFO);
1122                reset = diff_get_color_opt(o, DIFF_RESET);
1123                fprintf(o->file, "%s%s+++ %s%s%s\n", diff_line_prefix(o), meta,
1124                        line, reset,
1125                        strchr(line, ' ') ? "\t" : "");
1126                break;
1127        case DIFF_SYMBOL_FILEPAIR_MINUS:
1128                meta = diff_get_color_opt(o, DIFF_METAINFO);
1129                reset = diff_get_color_opt(o, DIFF_RESET);
1130                fprintf(o->file, "%s%s--- %s%s%s\n", diff_line_prefix(o), meta,
1131                        line, reset,
1132                        strchr(line, ' ') ? "\t" : "");
1133                break;
1134        case DIFF_SYMBOL_BINARY_FILES:
1135        case DIFF_SYMBOL_HEADER:
1136                fprintf(o->file, "%s", line);
1137                break;
1138        case DIFF_SYMBOL_BINARY_DIFF_HEADER:
1139                fprintf(o->file, "%sGIT binary patch\n", diff_line_prefix(o));
1140                break;
1141        case DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA:
1142                fprintf(o->file, "%sdelta %s\n", diff_line_prefix(o), line);
1143                break;
1144        case DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL:
1145                fprintf(o->file, "%sliteral %s\n", diff_line_prefix(o), line);
1146                break;
1147        case DIFF_SYMBOL_BINARY_DIFF_FOOTER:
1148                fputs(diff_line_prefix(o), o->file);
1149                fputc('\n', o->file);
1150                break;
1151        case DIFF_SYMBOL_REWRITE_DIFF:
1152                fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
1153                reset = diff_get_color_opt(o, DIFF_RESET);
1154                emit_line(o, fraginfo, reset, line, len);
1155                break;
1156        case DIFF_SYMBOL_SUBMODULE_ADD:
1157                set = diff_get_color_opt(o, DIFF_FILE_NEW);
1158                reset = diff_get_color_opt(o, DIFF_RESET);
1159                emit_line(o, set, reset, line, len);
1160                break;
1161        case DIFF_SYMBOL_SUBMODULE_DEL:
1162                set = diff_get_color_opt(o, DIFF_FILE_OLD);
1163                reset = diff_get_color_opt(o, DIFF_RESET);
1164                emit_line(o, set, reset, line, len);
1165                break;
1166        case DIFF_SYMBOL_SUBMODULE_UNTRACKED:
1167                fprintf(o->file, "%sSubmodule %s contains untracked content\n",
1168                        diff_line_prefix(o), line);
1169                break;
1170        case DIFF_SYMBOL_SUBMODULE_MODIFIED:
1171                fprintf(o->file, "%sSubmodule %s contains modified content\n",
1172                        diff_line_prefix(o), line);
1173                break;
1174        case DIFF_SYMBOL_STATS_SUMMARY_NO_FILES:
1175                emit_line(o, "", "", " 0 files changed\n",
1176                          strlen(" 0 files changed\n"));
1177                break;
1178        case DIFF_SYMBOL_STATS_SUMMARY_ABBREV:
1179                emit_line(o, "", "", " ...\n", strlen(" ...\n"));
1180                break;
1181        case DIFF_SYMBOL_WORD_DIFF:
1182                fprintf(o->file, "%.*s", len, line);
1183                break;
1184        case DIFF_SYMBOL_STAT_SEP:
1185                fputs(o->stat_sep, o->file);
1186                break;
1187        default:
1188                die("BUG: unknown diff symbol");
1189        }
1190        strbuf_release(&sb);
1191}
1192
1193static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
1194                             const char *line, int len, unsigned flags)
1195{
1196        struct emitted_diff_symbol e = {line, len, flags, s};
1197
1198        if (o->emitted_symbols)
1199                append_emitted_diff_symbol(o, &e);
1200        else
1201                emit_diff_symbol_from_struct(o, &e);
1202}
1203
1204void diff_emit_submodule_del(struct diff_options *o, const char *line)
1205{
1206        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_DEL, line, strlen(line), 0);
1207}
1208
1209void diff_emit_submodule_add(struct diff_options *o, const char *line)
1210{
1211        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ADD, line, strlen(line), 0);
1212}
1213
1214void diff_emit_submodule_untracked(struct diff_options *o, const char *path)
1215{
1216        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_UNTRACKED,
1217                         path, strlen(path), 0);
1218}
1219
1220void diff_emit_submodule_modified(struct diff_options *o, const char *path)
1221{
1222        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_MODIFIED,
1223                         path, strlen(path), 0);
1224}
1225
1226void diff_emit_submodule_header(struct diff_options *o, const char *header)
1227{
1228        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_HEADER,
1229                         header, strlen(header), 0);
1230}
1231
1232void diff_emit_submodule_error(struct diff_options *o, const char *err)
1233{
1234        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ERROR, err, strlen(err), 0);
1235}
1236
1237void diff_emit_submodule_pipethrough(struct diff_options *o,
1238                                     const char *line, int len)
1239{
1240        emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_PIPETHROUGH, line, len, 0);
1241}
1242
1243static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
1244{
1245        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
1246              ecbdata->blank_at_eof_in_preimage &&
1247              ecbdata->blank_at_eof_in_postimage &&
1248              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
1249              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
1250                return 0;
1251        return ws_blank_line(line, len, ecbdata->ws_rule);
1252}
1253
1254static void emit_add_line(const char *reset,
1255                          struct emit_callback *ecbdata,
1256                          const char *line, int len)
1257{
1258        unsigned flags = WSEH_NEW | ecbdata->ws_rule;
1259        if (new_blank_line_at_eof(ecbdata, line, len))
1260                flags |= DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF;
1261
1262        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_PLUS, line, len, flags);
1263}
1264
1265static void emit_del_line(const char *reset,
1266                          struct emit_callback *ecbdata,
1267                          const char *line, int len)
1268{
1269        unsigned flags = WSEH_OLD | ecbdata->ws_rule;
1270        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_MINUS, line, len, flags);
1271}
1272
1273static void emit_context_line(const char *reset,
1274                              struct emit_callback *ecbdata,
1275                              const char *line, int len)
1276{
1277        unsigned flags = WSEH_CONTEXT | ecbdata->ws_rule;
1278        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_CONTEXT, line, len, flags);
1279}
1280
1281static void emit_hunk_header(struct emit_callback *ecbdata,
1282                             const char *line, int len)
1283{
1284        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
1285        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
1286        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
1287        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1288        static const char atat[2] = { '@', '@' };
1289        const char *cp, *ep;
1290        struct strbuf msgbuf = STRBUF_INIT;
1291        int org_len = len;
1292        int i = 1;
1293
1294        /*
1295         * As a hunk header must begin with "@@ -<old>, +<new> @@",
1296         * it always is at least 10 bytes long.
1297         */
1298        if (len < 10 ||
1299            memcmp(line, atat, 2) ||
1300            !(ep = memmem(line + 2, len - 2, atat, 2))) {
1301                emit_diff_symbol(ecbdata->opt,
1302                                 DIFF_SYMBOL_CONTEXT_MARKER, line, len, 0);
1303                return;
1304        }
1305        ep += 2; /* skip over @@ */
1306
1307        /* The hunk header in fraginfo color */
1308        strbuf_addstr(&msgbuf, frag);
1309        strbuf_add(&msgbuf, line, ep - line);
1310        strbuf_addstr(&msgbuf, reset);
1311
1312        /*
1313         * trailing "\r\n"
1314         */
1315        for ( ; i < 3; i++)
1316                if (line[len - i] == '\r' || line[len - i] == '\n')
1317                        len--;
1318
1319        /* blank before the func header */
1320        for (cp = ep; ep - line < len; ep++)
1321                if (*ep != ' ' && *ep != '\t')
1322                        break;
1323        if (ep != cp) {
1324                strbuf_addstr(&msgbuf, context);
1325                strbuf_add(&msgbuf, cp, ep - cp);
1326                strbuf_addstr(&msgbuf, reset);
1327        }
1328
1329        if (ep < line + len) {
1330                strbuf_addstr(&msgbuf, func);
1331                strbuf_add(&msgbuf, ep, line + len - ep);
1332                strbuf_addstr(&msgbuf, reset);
1333        }
1334
1335        strbuf_add(&msgbuf, line + len, org_len - len);
1336        strbuf_complete_line(&msgbuf);
1337        emit_diff_symbol(ecbdata->opt,
1338                         DIFF_SYMBOL_CONTEXT_FRAGINFO, msgbuf.buf, msgbuf.len, 0);
1339        strbuf_release(&msgbuf);
1340}
1341
1342static struct diff_tempfile *claim_diff_tempfile(void) {
1343        int i;
1344        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
1345                if (!diff_temp[i].name)
1346                        return diff_temp + i;
1347        die("BUG: diff is failing to clean up its tempfiles");
1348}
1349
1350static void remove_tempfile(void)
1351{
1352        int i;
1353        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
1354                if (is_tempfile_active(diff_temp[i].tempfile))
1355                        delete_tempfile(&diff_temp[i].tempfile);
1356                diff_temp[i].name = NULL;
1357        }
1358}
1359
1360static void add_line_count(struct strbuf *out, int count)
1361{
1362        switch (count) {
1363        case 0:
1364                strbuf_addstr(out, "0,0");
1365                break;
1366        case 1:
1367                strbuf_addstr(out, "1");
1368                break;
1369        default:
1370                strbuf_addf(out, "1,%d", count);
1371                break;
1372        }
1373}
1374
1375static void emit_rewrite_lines(struct emit_callback *ecb,
1376                               int prefix, const char *data, int size)
1377{
1378        const char *endp = NULL;
1379        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
1380
1381        while (0 < size) {
1382                int len;
1383
1384                endp = memchr(data, '\n', size);
1385                len = endp ? (endp - data + 1) : size;
1386                if (prefix != '+') {
1387                        ecb->lno_in_preimage++;
1388                        emit_del_line(reset, ecb, data, len);
1389                } else {
1390                        ecb->lno_in_postimage++;
1391                        emit_add_line(reset, ecb, data, len);
1392                }
1393                size -= len;
1394                data += len;
1395        }
1396        if (!endp)
1397                emit_diff_symbol(ecb->opt, DIFF_SYMBOL_NO_LF_EOF, NULL, 0, 0);
1398}
1399
1400static void emit_rewrite_diff(const char *name_a,
1401                              const char *name_b,
1402                              struct diff_filespec *one,
1403                              struct diff_filespec *two,
1404                              struct userdiff_driver *textconv_one,
1405                              struct userdiff_driver *textconv_two,
1406                              struct diff_options *o)
1407{
1408        int lc_a, lc_b;
1409        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
1410        const char *a_prefix, *b_prefix;
1411        char *data_one, *data_two;
1412        size_t size_one, size_two;
1413        struct emit_callback ecbdata;
1414        struct strbuf out = STRBUF_INIT;
1415
1416        if (diff_mnemonic_prefix && o->flags.reverse_diff) {
1417                a_prefix = o->b_prefix;
1418                b_prefix = o->a_prefix;
1419        } else {
1420                a_prefix = o->a_prefix;
1421                b_prefix = o->b_prefix;
1422        }
1423
1424        name_a += (*name_a == '/');
1425        name_b += (*name_b == '/');
1426
1427        strbuf_reset(&a_name);
1428        strbuf_reset(&b_name);
1429        quote_two_c_style(&a_name, a_prefix, name_a, 0);
1430        quote_two_c_style(&b_name, b_prefix, name_b, 0);
1431
1432        size_one = fill_textconv(textconv_one, one, &data_one);
1433        size_two = fill_textconv(textconv_two, two, &data_two);
1434
1435        memset(&ecbdata, 0, sizeof(ecbdata));
1436        ecbdata.color_diff = want_color(o->use_color);
1437        ecbdata.ws_rule = whitespace_rule(name_b);
1438        ecbdata.opt = o;
1439        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
1440                mmfile_t mf1, mf2;
1441                mf1.ptr = (char *)data_one;
1442                mf2.ptr = (char *)data_two;
1443                mf1.size = size_one;
1444                mf2.size = size_two;
1445                check_blank_at_eof(&mf1, &mf2, &ecbdata);
1446        }
1447        ecbdata.lno_in_preimage = 1;
1448        ecbdata.lno_in_postimage = 1;
1449
1450        lc_a = count_lines(data_one, size_one);
1451        lc_b = count_lines(data_two, size_two);
1452
1453        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
1454                         a_name.buf, a_name.len, 0);
1455        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
1456                         b_name.buf, b_name.len, 0);
1457
1458        strbuf_addstr(&out, "@@ -");
1459        if (!o->irreversible_delete)
1460                add_line_count(&out, lc_a);
1461        else
1462                strbuf_addstr(&out, "?,?");
1463        strbuf_addstr(&out, " +");
1464        add_line_count(&out, lc_b);
1465        strbuf_addstr(&out, " @@\n");
1466        emit_diff_symbol(o, DIFF_SYMBOL_REWRITE_DIFF, out.buf, out.len, 0);
1467        strbuf_release(&out);
1468
1469        if (lc_a && !o->irreversible_delete)
1470                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
1471        if (lc_b)
1472                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
1473        if (textconv_one)
1474                free((char *)data_one);
1475        if (textconv_two)
1476                free((char *)data_two);
1477}
1478
1479struct diff_words_buffer {
1480        mmfile_t text;
1481        unsigned long alloc;
1482        struct diff_words_orig {
1483                const char *begin, *end;
1484        } *orig;
1485        int orig_nr, orig_alloc;
1486};
1487
1488static void diff_words_append(char *line, unsigned long len,
1489                struct diff_words_buffer *buffer)
1490{
1491        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
1492        line++;
1493        len--;
1494        memcpy(buffer->text.ptr + buffer->text.size, line, len);
1495        buffer->text.size += len;
1496        buffer->text.ptr[buffer->text.size] = '\0';
1497}
1498
1499struct diff_words_style_elem {
1500        const char *prefix;
1501        const char *suffix;
1502        const char *color; /* NULL; filled in by the setup code if
1503                            * color is enabled */
1504};
1505
1506struct diff_words_style {
1507        enum diff_words_type type;
1508        struct diff_words_style_elem new_word, old_word, ctx;
1509        const char *newline;
1510};
1511
1512static struct diff_words_style diff_words_styles[] = {
1513        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
1514        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
1515        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
1516};
1517
1518struct diff_words_data {
1519        struct diff_words_buffer minus, plus;
1520        const char *current_plus;
1521        int last_minus;
1522        struct diff_options *opt;
1523        regex_t *word_regex;
1524        enum diff_words_type type;
1525        struct diff_words_style *style;
1526};
1527
1528static int fn_out_diff_words_write_helper(struct diff_options *o,
1529                                          struct diff_words_style_elem *st_el,
1530                                          const char *newline,
1531                                          size_t count, const char *buf)
1532{
1533        int print = 0;
1534        struct strbuf sb = STRBUF_INIT;
1535
1536        while (count) {
1537                char *p = memchr(buf, '\n', count);
1538                if (print)
1539                        strbuf_addstr(&sb, diff_line_prefix(o));
1540
1541                if (p != buf) {
1542                        const char *reset = st_el->color && *st_el->color ?
1543                                            GIT_COLOR_RESET : NULL;
1544                        if (st_el->color && *st_el->color)
1545                                strbuf_addstr(&sb, st_el->color);
1546                        strbuf_addstr(&sb, st_el->prefix);
1547                        strbuf_add(&sb, buf, p ? p - buf : count);
1548                        strbuf_addstr(&sb, st_el->suffix);
1549                        if (reset)
1550                                strbuf_addstr(&sb, reset);
1551                }
1552                if (!p)
1553                        goto out;
1554
1555                strbuf_addstr(&sb, newline);
1556                count -= p + 1 - buf;
1557                buf = p + 1;
1558                print = 1;
1559                if (count) {
1560                        emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1561                                         sb.buf, sb.len, 0);
1562                        strbuf_reset(&sb);
1563                }
1564        }
1565
1566out:
1567        if (sb.len)
1568                emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
1569                                 sb.buf, sb.len, 0);
1570        strbuf_release(&sb);
1571        return 0;
1572}
1573
1574/*
1575 * '--color-words' algorithm can be described as:
1576 *
1577 *   1. collect the minus/plus lines of a diff hunk, divided into
1578 *      minus-lines and plus-lines;
1579 *
1580 *   2. break both minus-lines and plus-lines into words and
1581 *      place them into two mmfile_t with one word for each line;
1582 *
1583 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
1584 *
1585 * And for the common parts of the both file, we output the plus side text.
1586 * diff_words->current_plus is used to trace the current position of the plus file
1587 * which printed. diff_words->last_minus is used to trace the last minus word
1588 * printed.
1589 *
1590 * For '--graph' to work with '--color-words', we need to output the graph prefix
1591 * on each line of color words output. Generally, there are two conditions on
1592 * which we should output the prefix.
1593 *
1594 *   1. diff_words->last_minus == 0 &&
1595 *      diff_words->current_plus == diff_words->plus.text.ptr
1596 *
1597 *      that is: the plus text must start as a new line, and if there is no minus
1598 *      word printed, a graph prefix must be printed.
1599 *
1600 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
1601 *      *(diff_words->current_plus - 1) == '\n'
1602 *
1603 *      that is: a graph prefix must be printed following a '\n'
1604 */
1605static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
1606{
1607        if ((diff_words->last_minus == 0 &&
1608                diff_words->current_plus == diff_words->plus.text.ptr) ||
1609                (diff_words->current_plus > diff_words->plus.text.ptr &&
1610                *(diff_words->current_plus - 1) == '\n')) {
1611                return 1;
1612        } else {
1613                return 0;
1614        }
1615}
1616
1617static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
1618{
1619        struct diff_words_data *diff_words = priv;
1620        struct diff_words_style *style = diff_words->style;
1621        int minus_first, minus_len, plus_first, plus_len;
1622        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
1623        struct diff_options *opt = diff_words->opt;
1624        const char *line_prefix;
1625
1626        if (line[0] != '@' || parse_hunk_header(line, len,
1627                        &minus_first, &minus_len, &plus_first, &plus_len))
1628                return;
1629
1630        assert(opt);
1631        line_prefix = diff_line_prefix(opt);
1632
1633        /* POSIX requires that first be decremented by one if len == 0... */
1634        if (minus_len) {
1635                minus_begin = diff_words->minus.orig[minus_first].begin;
1636                minus_end =
1637                        diff_words->minus.orig[minus_first + minus_len - 1].end;
1638        } else
1639                minus_begin = minus_end =
1640                        diff_words->minus.orig[minus_first].end;
1641
1642        if (plus_len) {
1643                plus_begin = diff_words->plus.orig[plus_first].begin;
1644                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
1645        } else
1646                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
1647
1648        if (color_words_output_graph_prefix(diff_words)) {
1649                fputs(line_prefix, diff_words->opt->file);
1650        }
1651        if (diff_words->current_plus != plus_begin) {
1652                fn_out_diff_words_write_helper(diff_words->opt,
1653                                &style->ctx, style->newline,
1654                                plus_begin - diff_words->current_plus,
1655                                diff_words->current_plus);
1656        }
1657        if (minus_begin != minus_end) {
1658                fn_out_diff_words_write_helper(diff_words->opt,
1659                                &style->old_word, style->newline,
1660                                minus_end - minus_begin, minus_begin);
1661        }
1662        if (plus_begin != plus_end) {
1663                fn_out_diff_words_write_helper(diff_words->opt,
1664                                &style->new_word, style->newline,
1665                                plus_end - plus_begin, plus_begin);
1666        }
1667
1668        diff_words->current_plus = plus_end;
1669        diff_words->last_minus = minus_first;
1670}
1671
1672/* This function starts looking at *begin, and returns 0 iff a word was found. */
1673static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
1674                int *begin, int *end)
1675{
1676        if (word_regex && *begin < buffer->size) {
1677                regmatch_t match[1];
1678                if (!regexec_buf(word_regex, buffer->ptr + *begin,
1679                                 buffer->size - *begin, 1, match, 0)) {
1680                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
1681                                        '\n', match[0].rm_eo - match[0].rm_so);
1682                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
1683                        *begin += match[0].rm_so;
1684                        return *begin >= *end;
1685                }
1686                return -1;
1687        }
1688
1689        /* find the next word */
1690        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
1691                (*begin)++;
1692        if (*begin >= buffer->size)
1693                return -1;
1694
1695        /* find the end of the word */
1696        *end = *begin + 1;
1697        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
1698                (*end)++;
1699
1700        return 0;
1701}
1702
1703/*
1704 * This function splits the words in buffer->text, stores the list with
1705 * newline separator into out, and saves the offsets of the original words
1706 * in buffer->orig.
1707 */
1708static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
1709                regex_t *word_regex)
1710{
1711        int i, j;
1712        long alloc = 0;
1713
1714        out->size = 0;
1715        out->ptr = NULL;
1716
1717        /* fake an empty "0th" word */
1718        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
1719        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
1720        buffer->orig_nr = 1;
1721
1722        for (i = 0; i < buffer->text.size; i++) {
1723                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
1724                        return;
1725
1726                /* store original boundaries */
1727                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
1728                                buffer->orig_alloc);
1729                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
1730                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
1731                buffer->orig_nr++;
1732
1733                /* store one word */
1734                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
1735                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
1736                out->ptr[out->size + j - i] = '\n';
1737                out->size += j - i + 1;
1738
1739                i = j - 1;
1740        }
1741}
1742
1743/* this executes the word diff on the accumulated buffers */
1744static void diff_words_show(struct diff_words_data *diff_words)
1745{
1746        xpparam_t xpp;
1747        xdemitconf_t xecfg;
1748        mmfile_t minus, plus;
1749        struct diff_words_style *style = diff_words->style;
1750
1751        struct diff_options *opt = diff_words->opt;
1752        const char *line_prefix;
1753
1754        assert(opt);
1755        line_prefix = diff_line_prefix(opt);
1756
1757        /* special case: only removal */
1758        if (!diff_words->plus.text.size) {
1759                emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
1760                                 line_prefix, strlen(line_prefix), 0);
1761                fn_out_diff_words_write_helper(diff_words->opt,
1762                        &style->old_word, style->newline,
1763                        diff_words->minus.text.size,
1764                        diff_words->minus.text.ptr);
1765                diff_words->minus.text.size = 0;
1766                return;
1767        }
1768
1769        diff_words->current_plus = diff_words->plus.text.ptr;
1770        diff_words->last_minus = 0;
1771
1772        memset(&xpp, 0, sizeof(xpp));
1773        memset(&xecfg, 0, sizeof(xecfg));
1774        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
1775        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
1776        xpp.flags = 0;
1777        /* as only the hunk header will be parsed, we need a 0-context */
1778        xecfg.ctxlen = 0;
1779        if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
1780                          &xpp, &xecfg))
1781                die("unable to generate word diff");
1782        free(minus.ptr);
1783        free(plus.ptr);
1784        if (diff_words->current_plus != diff_words->plus.text.ptr +
1785                        diff_words->plus.text.size) {
1786                if (color_words_output_graph_prefix(diff_words))
1787                        emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
1788                                         line_prefix, strlen(line_prefix), 0);
1789                fn_out_diff_words_write_helper(diff_words->opt,
1790                        &style->ctx, style->newline,
1791                        diff_words->plus.text.ptr + diff_words->plus.text.size
1792                        - diff_words->current_plus, diff_words->current_plus);
1793        }
1794        diff_words->minus.text.size = diff_words->plus.text.size = 0;
1795}
1796
1797/* In "color-words" mode, show word-diff of words accumulated in the buffer */
1798static void diff_words_flush(struct emit_callback *ecbdata)
1799{
1800        struct diff_options *wo = ecbdata->diff_words->opt;
1801
1802        if (ecbdata->diff_words->minus.text.size ||
1803            ecbdata->diff_words->plus.text.size)
1804                diff_words_show(ecbdata->diff_words);
1805
1806        if (wo->emitted_symbols) {
1807                struct diff_options *o = ecbdata->opt;
1808                struct emitted_diff_symbols *wol = wo->emitted_symbols;
1809                int i;
1810
1811                /*
1812                 * NEEDSWORK:
1813                 * Instead of appending each, concat all words to a line?
1814                 */
1815                for (i = 0; i < wol->nr; i++)
1816                        append_emitted_diff_symbol(o, &wol->buf[i]);
1817
1818                for (i = 0; i < wol->nr; i++)
1819                        free((void *)wol->buf[i].line);
1820
1821                wol->nr = 0;
1822        }
1823}
1824
1825static void diff_filespec_load_driver(struct diff_filespec *one)
1826{
1827        /* Use already-loaded driver */
1828        if (one->driver)
1829                return;
1830
1831        if (S_ISREG(one->mode))
1832                one->driver = userdiff_find_by_path(one->path);
1833
1834        /* Fallback to default settings */
1835        if (!one->driver)
1836                one->driver = userdiff_find_by_name("default");
1837}
1838
1839static const char *userdiff_word_regex(struct diff_filespec *one)
1840{
1841        diff_filespec_load_driver(one);
1842        return one->driver->word_regex;
1843}
1844
1845static void init_diff_words_data(struct emit_callback *ecbdata,
1846                                 struct diff_options *orig_opts,
1847                                 struct diff_filespec *one,
1848                                 struct diff_filespec *two)
1849{
1850        int i;
1851        struct diff_options *o = xmalloc(sizeof(struct diff_options));
1852        memcpy(o, orig_opts, sizeof(struct diff_options));
1853
1854        ecbdata->diff_words =
1855                xcalloc(1, sizeof(struct diff_words_data));
1856        ecbdata->diff_words->type = o->word_diff;
1857        ecbdata->diff_words->opt = o;
1858
1859        if (orig_opts->emitted_symbols)
1860                o->emitted_symbols =
1861                        xcalloc(1, sizeof(struct emitted_diff_symbols));
1862
1863        if (!o->word_regex)
1864                o->word_regex = userdiff_word_regex(one);
1865        if (!o->word_regex)
1866                o->word_regex = userdiff_word_regex(two);
1867        if (!o->word_regex)
1868                o->word_regex = diff_word_regex_cfg;
1869        if (o->word_regex) {
1870                ecbdata->diff_words->word_regex = (regex_t *)
1871                        xmalloc(sizeof(regex_t));
1872                if (regcomp(ecbdata->diff_words->word_regex,
1873                            o->word_regex,
1874                            REG_EXTENDED | REG_NEWLINE))
1875                        die ("Invalid regular expression: %s",
1876                             o->word_regex);
1877        }
1878        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
1879                if (o->word_diff == diff_words_styles[i].type) {
1880                        ecbdata->diff_words->style =
1881                                &diff_words_styles[i];
1882                        break;
1883                }
1884        }
1885        if (want_color(o->use_color)) {
1886                struct diff_words_style *st = ecbdata->diff_words->style;
1887                st->old_word.color = diff_get_color_opt(o, DIFF_FILE_OLD);
1888                st->new_word.color = diff_get_color_opt(o, DIFF_FILE_NEW);
1889                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
1890        }
1891}
1892
1893static void free_diff_words_data(struct emit_callback *ecbdata)
1894{
1895        if (ecbdata->diff_words) {
1896                diff_words_flush(ecbdata);
1897                free (ecbdata->diff_words->opt->emitted_symbols);
1898                free (ecbdata->diff_words->opt);
1899                free (ecbdata->diff_words->minus.text.ptr);
1900                free (ecbdata->diff_words->minus.orig);
1901                free (ecbdata->diff_words->plus.text.ptr);
1902                free (ecbdata->diff_words->plus.orig);
1903                if (ecbdata->diff_words->word_regex) {
1904                        regfree(ecbdata->diff_words->word_regex);
1905                        free(ecbdata->diff_words->word_regex);
1906                }
1907                FREE_AND_NULL(ecbdata->diff_words);
1908        }
1909}
1910
1911const char *diff_get_color(int diff_use_color, enum color_diff ix)
1912{
1913        if (want_color(diff_use_color))
1914                return diff_colors[ix];
1915        return "";
1916}
1917
1918const char *diff_line_prefix(struct diff_options *opt)
1919{
1920        struct strbuf *msgbuf;
1921        if (!opt->output_prefix)
1922                return "";
1923
1924        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
1925        return msgbuf->buf;
1926}
1927
1928static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
1929{
1930        const char *cp;
1931        unsigned long allot;
1932        size_t l = len;
1933
1934        cp = line;
1935        allot = l;
1936        while (0 < l) {
1937                (void) utf8_width(&cp, &l);
1938                if (!cp)
1939                        break; /* truncated in the middle? */
1940        }
1941        return allot - l;
1942}
1943
1944static void find_lno(const char *line, struct emit_callback *ecbdata)
1945{
1946        const char *p;
1947        ecbdata->lno_in_preimage = 0;
1948        ecbdata->lno_in_postimage = 0;
1949        p = strchr(line, '-');
1950        if (!p)
1951                return; /* cannot happen */
1952        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1953        p = strchr(p, '+');
1954        if (!p)
1955                return; /* cannot happen */
1956        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
1957}
1958
1959static void fn_out_consume(void *priv, char *line, unsigned long len)
1960{
1961        struct emit_callback *ecbdata = priv;
1962        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1963        struct diff_options *o = ecbdata->opt;
1964
1965        o->found_changes = 1;
1966
1967        if (ecbdata->header) {
1968                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
1969                                 ecbdata->header->buf, ecbdata->header->len, 0);
1970                strbuf_reset(ecbdata->header);
1971                ecbdata->header = NULL;
1972        }
1973
1974        if (ecbdata->label_path[0]) {
1975                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
1976                                 ecbdata->label_path[0],
1977                                 strlen(ecbdata->label_path[0]), 0);
1978                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
1979                                 ecbdata->label_path[1],
1980                                 strlen(ecbdata->label_path[1]), 0);
1981                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1982        }
1983
1984        if (diff_suppress_blank_empty
1985            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1986                line[0] = '\n';
1987                len = 1;
1988        }
1989
1990        if (line[0] == '@') {
1991                if (ecbdata->diff_words)
1992                        diff_words_flush(ecbdata);
1993                len = sane_truncate_line(ecbdata, line, len);
1994                find_lno(line, ecbdata);
1995                emit_hunk_header(ecbdata, line, len);
1996                return;
1997        }
1998
1999        if (ecbdata->diff_words) {
2000                enum diff_symbol s =
2001                        ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN ?
2002                        DIFF_SYMBOL_WORDS_PORCELAIN : DIFF_SYMBOL_WORDS;
2003                if (line[0] == '-') {
2004                        diff_words_append(line, len,
2005                                          &ecbdata->diff_words->minus);
2006                        return;
2007                } else if (line[0] == '+') {
2008                        diff_words_append(line, len,
2009                                          &ecbdata->diff_words->plus);
2010                        return;
2011                } else if (starts_with(line, "\\ ")) {
2012                        /*
2013                         * Eat the "no newline at eof" marker as if we
2014                         * saw a "+" or "-" line with nothing on it,
2015                         * and return without diff_words_flush() to
2016                         * defer processing. If this is the end of
2017                         * preimage, more "+" lines may come after it.
2018                         */
2019                        return;
2020                }
2021                diff_words_flush(ecbdata);
2022                emit_diff_symbol(o, s, line, len, 0);
2023                return;
2024        }
2025
2026        switch (line[0]) {
2027        case '+':
2028                ecbdata->lno_in_postimage++;
2029                emit_add_line(reset, ecbdata, line + 1, len - 1);
2030                break;
2031        case '-':
2032                ecbdata->lno_in_preimage++;
2033                emit_del_line(reset, ecbdata, line + 1, len - 1);
2034                break;
2035        case ' ':
2036                ecbdata->lno_in_postimage++;
2037                ecbdata->lno_in_preimage++;
2038                emit_context_line(reset, ecbdata, line + 1, len - 1);
2039                break;
2040        default:
2041                /* incomplete line at the end */
2042                ecbdata->lno_in_preimage++;
2043                emit_diff_symbol(o, DIFF_SYMBOL_CONTEXT_INCOMPLETE,
2044                                 line, len, 0);
2045                break;
2046        }
2047}
2048
2049static void pprint_rename(struct strbuf *name, const char *a, const char *b)
2050{
2051        const char *old_name = a;
2052        const char *new_name = b;
2053        int pfx_length, sfx_length;
2054        int pfx_adjust_for_slash;
2055        int len_a = strlen(a);
2056        int len_b = strlen(b);
2057        int a_midlen, b_midlen;
2058        int qlen_a = quote_c_style(a, NULL, NULL, 0);
2059        int qlen_b = quote_c_style(b, NULL, NULL, 0);
2060
2061        if (qlen_a || qlen_b) {
2062                quote_c_style(a, name, NULL, 0);
2063                strbuf_addstr(name, " => ");
2064                quote_c_style(b, name, NULL, 0);
2065                return;
2066        }
2067
2068        /* Find common prefix */
2069        pfx_length = 0;
2070        while (*old_name && *new_name && *old_name == *new_name) {
2071                if (*old_name == '/')
2072                        pfx_length = old_name - a + 1;
2073                old_name++;
2074                new_name++;
2075        }
2076
2077        /* Find common suffix */
2078        old_name = a + len_a;
2079        new_name = b + len_b;
2080        sfx_length = 0;
2081        /*
2082         * If there is a common prefix, it must end in a slash.  In
2083         * that case we let this loop run 1 into the prefix to see the
2084         * same slash.
2085         *
2086         * If there is no common prefix, we cannot do this as it would
2087         * underrun the input strings.
2088         */
2089        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
2090        while (a + pfx_length - pfx_adjust_for_slash <= old_name &&
2091               b + pfx_length - pfx_adjust_for_slash <= new_name &&
2092               *old_name == *new_name) {
2093                if (*old_name == '/')
2094                        sfx_length = len_a - (old_name - a);
2095                old_name--;
2096                new_name--;
2097        }
2098
2099        /*
2100         * pfx{mid-a => mid-b}sfx
2101         * {pfx-a => pfx-b}sfx
2102         * pfx{sfx-a => sfx-b}
2103         * name-a => name-b
2104         */
2105        a_midlen = len_a - pfx_length - sfx_length;
2106        b_midlen = len_b - pfx_length - sfx_length;
2107        if (a_midlen < 0)
2108                a_midlen = 0;
2109        if (b_midlen < 0)
2110                b_midlen = 0;
2111
2112        strbuf_grow(name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
2113        if (pfx_length + sfx_length) {
2114                strbuf_add(name, a, pfx_length);
2115                strbuf_addch(name, '{');
2116        }
2117        strbuf_add(name, a + pfx_length, a_midlen);
2118        strbuf_addstr(name, " => ");
2119        strbuf_add(name, b + pfx_length, b_midlen);
2120        if (pfx_length + sfx_length) {
2121                strbuf_addch(name, '}');
2122                strbuf_add(name, a + len_a - sfx_length, sfx_length);
2123        }
2124}
2125
2126struct diffstat_t {
2127        int nr;
2128        int alloc;
2129        struct diffstat_file {
2130                char *from_name;
2131                char *name;
2132                char *print_name;
2133                const char *comments;
2134                unsigned is_unmerged:1;
2135                unsigned is_binary:1;
2136                unsigned is_renamed:1;
2137                unsigned is_interesting:1;
2138                uintmax_t added, deleted;
2139        } **files;
2140};
2141
2142static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
2143                                          const char *name_a,
2144                                          const char *name_b)
2145{
2146        struct diffstat_file *x;
2147        x = xcalloc(1, sizeof(*x));
2148        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
2149        diffstat->files[diffstat->nr++] = x;
2150        if (name_b) {
2151                x->from_name = xstrdup(name_a);
2152                x->name = xstrdup(name_b);
2153                x->is_renamed = 1;
2154        }
2155        else {
2156                x->from_name = NULL;
2157                x->name = xstrdup(name_a);
2158        }
2159        return x;
2160}
2161
2162static void diffstat_consume(void *priv, char *line, unsigned long len)
2163{
2164        struct diffstat_t *diffstat = priv;
2165        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
2166
2167        if (line[0] == '+')
2168                x->added++;
2169        else if (line[0] == '-')
2170                x->deleted++;
2171}
2172
2173const char mime_boundary_leader[] = "------------";
2174
2175static int scale_linear(int it, int width, int max_change)
2176{
2177        if (!it)
2178                return 0;
2179        /*
2180         * make sure that at least one '-' or '+' is printed if
2181         * there is any change to this path. The easiest way is to
2182         * scale linearly as if the alloted width is one column shorter
2183         * than it is, and then add 1 to the result.
2184         */
2185        return 1 + (it * (width - 1) / max_change);
2186}
2187
2188static void show_graph(struct strbuf *out, char ch, int cnt,
2189                       const char *set, const char *reset)
2190{
2191        if (cnt <= 0)
2192                return;
2193        strbuf_addstr(out, set);
2194        strbuf_addchars(out, ch, cnt);
2195        strbuf_addstr(out, reset);
2196}
2197
2198static void fill_print_name(struct diffstat_file *file)
2199{
2200        struct strbuf pname = STRBUF_INIT;
2201
2202        if (file->print_name)
2203                return;
2204
2205        if (file->is_renamed)
2206                pprint_rename(&pname, file->from_name, file->name);
2207        else
2208                quote_c_style(file->name, &pname, NULL, 0);
2209
2210        if (file->comments)
2211                strbuf_addf(&pname, " (%s)", file->comments);
2212
2213        file->print_name = strbuf_detach(&pname, NULL);
2214}
2215
2216static void print_stat_summary_inserts_deletes(struct diff_options *options,
2217                int files, int insertions, int deletions)
2218{
2219        struct strbuf sb = STRBUF_INIT;
2220
2221        if (!files) {
2222                assert(insertions == 0 && deletions == 0);
2223                emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
2224                                 NULL, 0, 0);
2225                return;
2226        }
2227
2228        strbuf_addf(&sb,
2229                    (files == 1) ? " %d file changed" : " %d files changed",
2230                    files);
2231
2232        /*
2233         * For binary diff, the caller may want to print "x files
2234         * changed" with insertions == 0 && deletions == 0.
2235         *
2236         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
2237         * is probably less confusing (i.e skip over "2 files changed
2238         * but nothing about added/removed lines? Is this a bug in Git?").
2239         */
2240        if (insertions || deletions == 0) {
2241                strbuf_addf(&sb,
2242                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
2243                            insertions);
2244        }
2245
2246        if (deletions || insertions == 0) {
2247                strbuf_addf(&sb,
2248                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
2249                            deletions);
2250        }
2251        strbuf_addch(&sb, '\n');
2252        emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
2253                         sb.buf, sb.len, 0);
2254        strbuf_release(&sb);
2255}
2256
2257void print_stat_summary(FILE *fp, int files,
2258                        int insertions, int deletions)
2259{
2260        struct diff_options o;
2261        memset(&o, 0, sizeof(o));
2262        o.file = fp;
2263
2264        print_stat_summary_inserts_deletes(&o, files, insertions, deletions);
2265}
2266
2267static void show_stats(struct diffstat_t *data, struct diff_options *options)
2268{
2269        int i, len, add, del, adds = 0, dels = 0;
2270        uintmax_t max_change = 0, max_len = 0;
2271        int total_files = data->nr, count;
2272        int width, name_width, graph_width, number_width = 0, bin_width = 0;
2273        const char *reset, *add_c, *del_c;
2274        int extra_shown = 0;
2275        const char *line_prefix = diff_line_prefix(options);
2276        struct strbuf out = STRBUF_INIT;
2277
2278        if (data->nr == 0)
2279                return;
2280
2281        count = options->stat_count ? options->stat_count : data->nr;
2282
2283        reset = diff_get_color_opt(options, DIFF_RESET);
2284        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
2285        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
2286
2287        /*
2288         * Find the longest filename and max number of changes
2289         */
2290        for (i = 0; (i < count) && (i < data->nr); i++) {
2291                struct diffstat_file *file = data->files[i];
2292                uintmax_t change = file->added + file->deleted;
2293
2294                if (!file->is_interesting && (change == 0)) {
2295                        count++; /* not shown == room for one more */
2296                        continue;
2297                }
2298                fill_print_name(file);
2299                len = strlen(file->print_name);
2300                if (max_len < len)
2301                        max_len = len;
2302
2303                if (file->is_unmerged) {
2304                        /* "Unmerged" is 8 characters */
2305                        bin_width = bin_width < 8 ? 8 : bin_width;
2306                        continue;
2307                }
2308                if (file->is_binary) {
2309                        /* "Bin XXX -> YYY bytes" */
2310                        int w = 14 + decimal_width(file->added)
2311                                + decimal_width(file->deleted);
2312                        bin_width = bin_width < w ? w : bin_width;
2313                        /* Display change counts aligned with "Bin" */
2314                        number_width = 3;
2315                        continue;
2316                }
2317
2318                if (max_change < change)
2319                        max_change = change;
2320        }
2321        count = i; /* where we can stop scanning in data->files[] */
2322
2323        /*
2324         * We have width = stat_width or term_columns() columns total.
2325         * We want a maximum of min(max_len, stat_name_width) for the name part.
2326         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
2327         * We also need 1 for " " and 4 + decimal_width(max_change)
2328         * for " | NNNN " and one the empty column at the end, altogether
2329         * 6 + decimal_width(max_change).
2330         *
2331         * If there's not enough space, we will use the smaller of
2332         * stat_name_width (if set) and 5/8*width for the filename,
2333         * and the rest for constant elements + graph part, but no more
2334         * than stat_graph_width for the graph part.
2335         * (5/8 gives 50 for filename and 30 for the constant parts + graph
2336         * for the standard terminal size).
2337         *
2338         * In other words: stat_width limits the maximum width, and
2339         * stat_name_width fixes the maximum width of the filename,
2340         * and is also used to divide available columns if there
2341         * aren't enough.
2342         *
2343         * Binary files are displayed with "Bin XXX -> YYY bytes"
2344         * instead of the change count and graph. This part is treated
2345         * similarly to the graph part, except that it is not
2346         * "scaled". If total width is too small to accommodate the
2347         * guaranteed minimum width of the filename part and the
2348         * separators and this message, this message will "overflow"
2349         * making the line longer than the maximum width.
2350         */
2351
2352        if (options->stat_width == -1)
2353                width = term_columns() - strlen(line_prefix);
2354        else
2355                width = options->stat_width ? options->stat_width : 80;
2356        number_width = decimal_width(max_change) > number_width ?
2357                decimal_width(max_change) : number_width;
2358
2359        if (options->stat_graph_width == -1)
2360                options->stat_graph_width = diff_stat_graph_width;
2361
2362        /*
2363         * Guarantee 3/8*16==6 for the graph part
2364         * and 5/8*16==10 for the filename part
2365         */
2366        if (width < 16 + 6 + number_width)
2367                width = 16 + 6 + number_width;
2368
2369        /*
2370         * First assign sizes that are wanted, ignoring available width.
2371         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
2372         * starting from "XXX" should fit in graph_width.
2373         */
2374        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
2375        if (options->stat_graph_width &&
2376            options->stat_graph_width < graph_width)
2377                graph_width = options->stat_graph_width;
2378
2379        name_width = (options->stat_name_width > 0 &&
2380                      options->stat_name_width < max_len) ?
2381                options->stat_name_width : max_len;
2382
2383        /*
2384         * Adjust adjustable widths not to exceed maximum width
2385         */
2386        if (name_width + number_width + 6 + graph_width > width) {
2387                if (graph_width > width * 3/8 - number_width - 6) {
2388                        graph_width = width * 3/8 - number_width - 6;
2389                        if (graph_width < 6)
2390                                graph_width = 6;
2391                }
2392
2393                if (options->stat_graph_width &&
2394                    graph_width > options->stat_graph_width)
2395                        graph_width = options->stat_graph_width;
2396                if (name_width > width - number_width - 6 - graph_width)
2397                        name_width = width - number_width - 6 - graph_width;
2398                else
2399                        graph_width = width - number_width - 6 - name_width;
2400        }
2401
2402        /*
2403         * From here name_width is the width of the name area,
2404         * and graph_width is the width of the graph area.
2405         * max_change is used to scale graph properly.
2406         */
2407        for (i = 0; i < count; i++) {
2408                const char *prefix = "";
2409                struct diffstat_file *file = data->files[i];
2410                char *name = file->print_name;
2411                uintmax_t added = file->added;
2412                uintmax_t deleted = file->deleted;
2413                int name_len;
2414
2415                if (!file->is_interesting && (added + deleted == 0))
2416                        continue;
2417
2418                /*
2419                 * "scale" the filename
2420                 */
2421                len = name_width;
2422                name_len = strlen(name);
2423                if (name_width < name_len) {
2424                        char *slash;
2425                        prefix = "...";
2426                        len -= 3;
2427                        name += name_len - len;
2428                        slash = strchr(name, '/');
2429                        if (slash)
2430                                name = slash;
2431                }
2432
2433                if (file->is_binary) {
2434                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2435                        strbuf_addf(&out, " %*s", number_width, "Bin");
2436                        if (!added && !deleted) {
2437                                strbuf_addch(&out, '\n');
2438                                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2439                                                 out.buf, out.len, 0);
2440                                strbuf_reset(&out);
2441                                continue;
2442                        }
2443                        strbuf_addf(&out, " %s%"PRIuMAX"%s",
2444                                del_c, deleted, reset);
2445                        strbuf_addstr(&out, " -> ");
2446                        strbuf_addf(&out, "%s%"PRIuMAX"%s",
2447                                add_c, added, reset);
2448                        strbuf_addstr(&out, " bytes\n");
2449                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2450                                         out.buf, out.len, 0);
2451                        strbuf_reset(&out);
2452                        continue;
2453                }
2454                else if (file->is_unmerged) {
2455                        strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2456                        strbuf_addstr(&out, " Unmerged\n");
2457                        emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2458                                         out.buf, out.len, 0);
2459                        strbuf_reset(&out);
2460                        continue;
2461                }
2462
2463                /*
2464                 * scale the add/delete
2465                 */
2466                add = added;
2467                del = deleted;
2468
2469                if (graph_width <= max_change) {
2470                        int total = scale_linear(add + del, graph_width, max_change);
2471                        if (total < 2 && add && del)
2472                                /* width >= 2 due to the sanity check */
2473                                total = 2;
2474                        if (add < del) {
2475                                add = scale_linear(add, graph_width, max_change);
2476                                del = total - add;
2477                        } else {
2478                                del = scale_linear(del, graph_width, max_change);
2479                                add = total - del;
2480                        }
2481                }
2482                strbuf_addf(&out, " %s%-*s |", prefix, len, name);
2483                strbuf_addf(&out, " %*"PRIuMAX"%s",
2484                        number_width, added + deleted,
2485                        added + deleted ? " " : "");
2486                show_graph(&out, '+', add, add_c, reset);
2487                show_graph(&out, '-', del, del_c, reset);
2488                strbuf_addch(&out, '\n');
2489                emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
2490                                 out.buf, out.len, 0);
2491                strbuf_reset(&out);
2492        }
2493
2494        for (i = 0; i < data->nr; i++) {
2495                struct diffstat_file *file = data->files[i];
2496                uintmax_t added = file->added;
2497                uintmax_t deleted = file->deleted;
2498
2499                if (file->is_unmerged ||
2500                    (!file->is_interesting && (added + deleted == 0))) {
2501                        total_files--;
2502                        continue;
2503                }
2504
2505                if (!file->is_binary) {
2506                        adds += added;
2507                        dels += deleted;
2508                }
2509                if (i < count)
2510                        continue;
2511                if (!extra_shown)
2512                        emit_diff_symbol(options,
2513                                         DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
2514                                         NULL, 0, 0);
2515                extra_shown = 1;
2516        }
2517
2518        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2519        strbuf_release(&out);
2520}
2521
2522static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
2523{
2524        int i, adds = 0, dels = 0, total_files = data->nr;
2525
2526        if (data->nr == 0)
2527                return;
2528
2529        for (i = 0; i < data->nr; i++) {
2530                int added = data->files[i]->added;
2531                int deleted = data->files[i]->deleted;
2532
2533                if (data->files[i]->is_unmerged ||
2534                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
2535                        total_files--;
2536                } else if (!data->files[i]->is_binary) { /* don't count bytes */
2537                        adds += added;
2538                        dels += deleted;
2539                }
2540        }
2541        print_stat_summary_inserts_deletes(options, total_files, adds, dels);
2542}
2543
2544static void show_numstat(struct diffstat_t *data, struct diff_options *options)
2545{
2546        int i;
2547
2548        if (data->nr == 0)
2549                return;
2550
2551        for (i = 0; i < data->nr; i++) {
2552                struct diffstat_file *file = data->files[i];
2553
2554                fprintf(options->file, "%s", diff_line_prefix(options));
2555
2556                if (file->is_binary)
2557                        fprintf(options->file, "-\t-\t");
2558                else
2559                        fprintf(options->file,
2560                                "%"PRIuMAX"\t%"PRIuMAX"\t",
2561                                file->added, file->deleted);
2562                if (options->line_termination) {
2563                        fill_print_name(file);
2564                        if (!file->is_renamed)
2565                                write_name_quoted(file->name, options->file,
2566                                                  options->line_termination);
2567                        else {
2568                                fputs(file->print_name, options->file);
2569                                putc(options->line_termination, options->file);
2570                        }
2571                } else {
2572                        if (file->is_renamed) {
2573                                putc('\0', options->file);
2574                                write_name_quoted(file->from_name, options->file, '\0');
2575                        }
2576                        write_name_quoted(file->name, options->file, '\0');
2577                }
2578        }
2579}
2580
2581struct dirstat_file {
2582        const char *name;
2583        unsigned long changed;
2584};
2585
2586struct dirstat_dir {
2587        struct dirstat_file *files;
2588        int alloc, nr, permille, cumulative;
2589};
2590
2591static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
2592                unsigned long changed, const char *base, int baselen)
2593{
2594        unsigned long sum_changes = 0;
2595        unsigned int sources = 0;
2596        const char *line_prefix = diff_line_prefix(opt);
2597
2598        while (dir->nr) {
2599                struct dirstat_file *f = dir->files;
2600                int namelen = strlen(f->name);
2601                unsigned long changes;
2602                char *slash;
2603
2604                if (namelen < baselen)
2605                        break;
2606                if (memcmp(f->name, base, baselen))
2607                        break;
2608                slash = strchr(f->name + baselen, '/');
2609                if (slash) {
2610                        int newbaselen = slash + 1 - f->name;
2611                        changes = gather_dirstat(opt, dir, changed, f->name, newbaselen);
2612                        sources++;
2613                } else {
2614                        changes = f->changed;
2615                        dir->files++;
2616                        dir->nr--;
2617                        sources += 2;
2618                }
2619                sum_changes += changes;
2620        }
2621
2622        /*
2623         * We don't report dirstat's for
2624         *  - the top level
2625         *  - or cases where everything came from a single directory
2626         *    under this directory (sources == 1).
2627         */
2628        if (baselen && sources != 1) {
2629                if (sum_changes) {
2630                        int permille = sum_changes * 1000 / changed;
2631                        if (permille >= dir->permille) {
2632                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
2633                                        permille / 10, permille % 10, baselen, base);
2634                                if (!dir->cumulative)
2635                                        return 0;
2636                        }
2637                }
2638        }
2639        return sum_changes;
2640}
2641
2642static int dirstat_compare(const void *_a, const void *_b)
2643{
2644        const struct dirstat_file *a = _a;
2645        const struct dirstat_file *b = _b;
2646        return strcmp(a->name, b->name);
2647}
2648
2649static void show_dirstat(struct diff_options *options)
2650{
2651        int i;
2652        unsigned long changed;
2653        struct dirstat_dir dir;
2654        struct diff_queue_struct *q = &diff_queued_diff;
2655
2656        dir.files = NULL;
2657        dir.alloc = 0;
2658        dir.nr = 0;
2659        dir.permille = options->dirstat_permille;
2660        dir.cumulative = options->flags.dirstat_cumulative;
2661
2662        changed = 0;
2663        for (i = 0; i < q->nr; i++) {
2664                struct diff_filepair *p = q->queue[i];
2665                const char *name;
2666                unsigned long copied, added, damage;
2667                int content_changed;
2668
2669                name = p->two->path ? p->two->path : p->one->path;
2670
2671                if (p->one->oid_valid && p->two->oid_valid)
2672                        content_changed = oidcmp(&p->one->oid, &p->two->oid);
2673                else
2674                        content_changed = 1;
2675
2676                if (!content_changed) {
2677                        /*
2678                         * The SHA1 has not changed, so pre-/post-content is
2679                         * identical. We can therefore skip looking at the
2680                         * file contents altogether.
2681                         */
2682                        damage = 0;
2683                        goto found_damage;
2684                }
2685
2686                if (options->flags.dirstat_by_file) {
2687                        /*
2688                         * In --dirstat-by-file mode, we don't really need to
2689                         * look at the actual file contents at all.
2690                         * The fact that the SHA1 changed is enough for us to
2691                         * add this file to the list of results
2692                         * (with each file contributing equal damage).
2693                         */
2694                        damage = 1;
2695                        goto found_damage;
2696                }
2697
2698                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
2699                        diff_populate_filespec(p->one, 0);
2700                        diff_populate_filespec(p->two, 0);
2701                        diffcore_count_changes(p->one, p->two, NULL, NULL,
2702                                               &copied, &added);
2703                        diff_free_filespec_data(p->one);
2704                        diff_free_filespec_data(p->two);
2705                } else if (DIFF_FILE_VALID(p->one)) {
2706                        diff_populate_filespec(p->one, CHECK_SIZE_ONLY);
2707                        copied = added = 0;
2708                        diff_free_filespec_data(p->one);
2709                } else if (DIFF_FILE_VALID(p->two)) {
2710                        diff_populate_filespec(p->two, CHECK_SIZE_ONLY);
2711                        copied = 0;
2712                        added = p->two->size;
2713                        diff_free_filespec_data(p->two);
2714                } else
2715                        continue;
2716
2717                /*
2718                 * Original minus copied is the removed material,
2719                 * added is the new material.  They are both damages
2720                 * made to the preimage.
2721                 * If the resulting damage is zero, we know that
2722                 * diffcore_count_changes() considers the two entries to
2723                 * be identical, but since content_changed is true, we
2724                 * know that there must have been _some_ kind of change,
2725                 * so we force all entries to have damage > 0.
2726                 */
2727                damage = (p->one->size - copied) + added;
2728                if (!damage)
2729                        damage = 1;
2730
2731found_damage:
2732                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
2733                dir.files[dir.nr].name = name;
2734                dir.files[dir.nr].changed = damage;
2735                changed += damage;
2736                dir.nr++;
2737        }
2738
2739        /* This can happen even with many files, if everything was renames */
2740        if (!changed)
2741                return;
2742
2743        /* Show all directories with more than x% of the changes */
2744        QSORT(dir.files, dir.nr, dirstat_compare);
2745        gather_dirstat(options, &dir, changed, "", 0);
2746}
2747
2748static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
2749{
2750        int i;
2751        unsigned long changed;
2752        struct dirstat_dir dir;
2753
2754        if (data->nr == 0)
2755                return;
2756
2757        dir.files = NULL;
2758        dir.alloc = 0;
2759        dir.nr = 0;
2760        dir.permille = options->dirstat_permille;
2761        dir.cumulative = options->flags.dirstat_cumulative;
2762
2763        changed = 0;
2764        for (i = 0; i < data->nr; i++) {
2765                struct diffstat_file *file = data->files[i];
2766                unsigned long damage = file->added + file->deleted;
2767                if (file->is_binary)
2768                        /*
2769                         * binary files counts bytes, not lines. Must find some
2770                         * way to normalize binary bytes vs. textual lines.
2771                         * The following heuristic assumes that there are 64
2772                         * bytes per "line".
2773                         * This is stupid and ugly, but very cheap...
2774                         */
2775                        damage = DIV_ROUND_UP(damage, 64);
2776                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
2777                dir.files[dir.nr].name = file->name;
2778                dir.files[dir.nr].changed = damage;
2779                changed += damage;
2780                dir.nr++;
2781        }
2782
2783        /* This can happen even with many files, if everything was renames */
2784        if (!changed)
2785                return;
2786
2787        /* Show all directories with more than x% of the changes */
2788        QSORT(dir.files, dir.nr, dirstat_compare);
2789        gather_dirstat(options, &dir, changed, "", 0);
2790}
2791
2792static void free_diffstat_info(struct diffstat_t *diffstat)
2793{
2794        int i;
2795        for (i = 0; i < diffstat->nr; i++) {
2796                struct diffstat_file *f = diffstat->files[i];
2797                free(f->print_name);
2798                free(f->name);
2799                free(f->from_name);
2800                free(f);
2801        }
2802        free(diffstat->files);
2803}
2804
2805struct checkdiff_t {
2806        const char *filename;
2807        int lineno;
2808        int conflict_marker_size;
2809        struct diff_options *o;
2810        unsigned ws_rule;
2811        unsigned status;
2812};
2813
2814static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
2815{
2816        char firstchar;
2817        int cnt;
2818
2819        if (len < marker_size + 1)
2820                return 0;
2821        firstchar = line[0];
2822        switch (firstchar) {
2823        case '=': case '>': case '<': case '|':
2824                break;
2825        default:
2826                return 0;
2827        }
2828        for (cnt = 1; cnt < marker_size; cnt++)
2829                if (line[cnt] != firstchar)
2830                        return 0;
2831        /* line[1] thru line[marker_size-1] are same as firstchar */
2832        if (len < marker_size + 1 || !isspace(line[marker_size]))
2833                return 0;
2834        return 1;
2835}
2836
2837static void checkdiff_consume(void *priv, char *line, unsigned long len)
2838{
2839        struct checkdiff_t *data = priv;
2840        int marker_size = data->conflict_marker_size;
2841        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
2842        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
2843        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
2844        char *err;
2845        const char *line_prefix;
2846
2847        assert(data->o);
2848        line_prefix = diff_line_prefix(data->o);
2849
2850        if (line[0] == '+') {
2851                unsigned bad;
2852                data->lineno++;
2853                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
2854                        data->status |= 1;
2855                        fprintf(data->o->file,
2856                                "%s%s:%d: leftover conflict marker\n",
2857                                line_prefix, data->filename, data->lineno);
2858                }
2859                bad = ws_check(line + 1, len - 1, data->ws_rule);
2860                if (!bad)
2861                        return;
2862                data->status |= bad;
2863                err = whitespace_error_string(bad);
2864                fprintf(data->o->file, "%s%s:%d: %s.\n",
2865                        line_prefix, data->filename, data->lineno, err);
2866                free(err);
2867                emit_line(data->o, set, reset, line, 1);
2868                ws_check_emit(line + 1, len - 1, data->ws_rule,
2869                              data->o->file, set, reset, ws);
2870        } else if (line[0] == ' ') {
2871                data->lineno++;
2872        } else if (line[0] == '@') {
2873                char *plus = strchr(line, '+');
2874                if (plus)
2875                        data->lineno = strtol(plus, NULL, 10) - 1;
2876                else
2877                        die("invalid diff");
2878        }
2879}
2880
2881static unsigned char *deflate_it(char *data,
2882                                 unsigned long size,
2883                                 unsigned long *result_size)
2884{
2885        int bound;
2886        unsigned char *deflated;
2887        git_zstream stream;
2888
2889        git_deflate_init(&stream, zlib_compression_level);
2890        bound = git_deflate_bound(&stream, size);
2891        deflated = xmalloc(bound);
2892        stream.next_out = deflated;
2893        stream.avail_out = bound;
2894
2895        stream.next_in = (unsigned char *)data;
2896        stream.avail_in = size;
2897        while (git_deflate(&stream, Z_FINISH) == Z_OK)
2898                ; /* nothing */
2899        git_deflate_end(&stream);
2900        *result_size = stream.total_out;
2901        return deflated;
2902}
2903
2904static void emit_binary_diff_body(struct diff_options *o,
2905                                  mmfile_t *one, mmfile_t *two)
2906{
2907        void *cp;
2908        void *delta;
2909        void *deflated;
2910        void *data;
2911        unsigned long orig_size;
2912        unsigned long delta_size;
2913        unsigned long deflate_size;
2914        unsigned long data_size;
2915
2916        /* We could do deflated delta, or we could do just deflated two,
2917         * whichever is smaller.
2918         */
2919        delta = NULL;
2920        deflated = deflate_it(two->ptr, two->size, &deflate_size);
2921        if (one->size && two->size) {
2922                delta = diff_delta(one->ptr, one->size,
2923                                   two->ptr, two->size,
2924                                   &delta_size, deflate_size);
2925                if (delta) {
2926                        void *to_free = delta;
2927                        orig_size = delta_size;
2928                        delta = deflate_it(delta, delta_size, &delta_size);
2929                        free(to_free);
2930                }
2931        }
2932
2933        if (delta && delta_size < deflate_size) {
2934                char *s = xstrfmt("%lu", orig_size);
2935                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
2936                                 s, strlen(s), 0);
2937                free(s);
2938                free(deflated);
2939                data = delta;
2940                data_size = delta_size;
2941        } else {
2942                char *s = xstrfmt("%lu", two->size);
2943                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
2944                                 s, strlen(s), 0);
2945                free(s);
2946                free(delta);
2947                data = deflated;
2948                data_size = deflate_size;
2949        }
2950
2951        /* emit data encoded in base85 */
2952        cp = data;
2953        while (data_size) {
2954                int len;
2955                int bytes = (52 < data_size) ? 52 : data_size;
2956                char line[71];
2957                data_size -= bytes;
2958                if (bytes <= 26)
2959                        line[0] = bytes + 'A' - 1;
2960                else
2961                        line[0] = bytes - 26 + 'a' - 1;
2962                encode_85(line + 1, cp, bytes);
2963                cp = (char *) cp + bytes;
2964
2965                len = strlen(line);
2966                line[len++] = '\n';
2967                line[len] = '\0';
2968
2969                emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_BODY,
2970                                 line, len, 0);
2971        }
2972        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_FOOTER, NULL, 0, 0);
2973        free(data);
2974}
2975
2976static void emit_binary_diff(struct diff_options *o,
2977                             mmfile_t *one, mmfile_t *two)
2978{
2979        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER, NULL, 0, 0);
2980        emit_binary_diff_body(o, one, two);
2981        emit_binary_diff_body(o, two, one);
2982}
2983
2984int diff_filespec_is_binary(struct diff_filespec *one)
2985{
2986        if (one->is_binary == -1) {
2987                diff_filespec_load_driver(one);
2988                if (one->driver->binary != -1)
2989                        one->is_binary = one->driver->binary;
2990                else {
2991                        if (!one->data && DIFF_FILE_VALID(one))
2992                                diff_populate_filespec(one, CHECK_BINARY);
2993                        if (one->is_binary == -1 && one->data)
2994                                one->is_binary = buffer_is_binary(one->data,
2995                                                one->size);
2996                        if (one->is_binary == -1)
2997                                one->is_binary = 0;
2998                }
2999        }
3000        return one->is_binary;
3001}
3002
3003static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
3004{
3005        diff_filespec_load_driver(one);
3006        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
3007}
3008
3009void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
3010{
3011        if (!options->a_prefix)
3012                options->a_prefix = a;
3013        if (!options->b_prefix)
3014                options->b_prefix = b;
3015}
3016
3017struct userdiff_driver *get_textconv(struct diff_filespec *one)
3018{
3019        if (!DIFF_FILE_VALID(one))
3020                return NULL;
3021
3022        diff_filespec_load_driver(one);
3023        return userdiff_get_textconv(one->driver);
3024}
3025
3026static void builtin_diff(const char *name_a,
3027                         const char *name_b,
3028                         struct diff_filespec *one,
3029                         struct diff_filespec *two,
3030                         const char *xfrm_msg,
3031                         int must_show_header,
3032                         struct diff_options *o,
3033                         int complete_rewrite)
3034{
3035        mmfile_t mf1, mf2;
3036        const char *lbl[2];
3037        char *a_one, *b_two;
3038        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
3039        const char *reset = diff_get_color_opt(o, DIFF_RESET);
3040        const char *a_prefix, *b_prefix;
3041        struct userdiff_driver *textconv_one = NULL;
3042        struct userdiff_driver *textconv_two = NULL;
3043        struct strbuf header = STRBUF_INIT;
3044        const char *line_prefix = diff_line_prefix(o);
3045
3046        diff_set_mnemonic_prefix(o, "a/", "b/");
3047        if (o->flags.reverse_diff) {
3048                a_prefix = o->b_prefix;
3049                b_prefix = o->a_prefix;
3050        } else {
3051                a_prefix = o->a_prefix;
3052                b_prefix = o->b_prefix;
3053        }
3054
3055        if (o->submodule_format == DIFF_SUBMODULE_LOG &&
3056            (!one->mode || S_ISGITLINK(one->mode)) &&
3057            (!two->mode || S_ISGITLINK(two->mode))) {
3058                show_submodule_summary(o, one->path ? one->path : two->path,
3059                                &one->oid, &two->oid,
3060                                two->dirty_submodule);
3061                return;
3062        } else if (o->submodule_format == DIFF_SUBMODULE_INLINE_DIFF &&
3063                   (!one->mode || S_ISGITLINK(one->mode)) &&
3064                   (!two->mode || S_ISGITLINK(two->mode))) {
3065                show_submodule_inline_diff(o, one->path ? one->path : two->path,
3066                                &one->oid, &two->oid,
3067                                two->dirty_submodule);
3068                return;
3069        }
3070
3071        if (o->flags.allow_textconv) {
3072                textconv_one = get_textconv(one);
3073                textconv_two = get_textconv(two);
3074        }
3075
3076        /* Never use a non-valid filename anywhere if at all possible */
3077        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
3078        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
3079
3080        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
3081        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
3082        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
3083        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
3084        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
3085        if (lbl[0][0] == '/') {
3086                /* /dev/null */
3087                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
3088                if (xfrm_msg)
3089                        strbuf_addstr(&header, xfrm_msg);
3090                must_show_header = 1;
3091        }
3092        else if (lbl[1][0] == '/') {
3093                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
3094                if (xfrm_msg)
3095                        strbuf_addstr(&header, xfrm_msg);
3096                must_show_header = 1;
3097        }
3098        else {
3099                if (one->mode != two->mode) {
3100                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
3101                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
3102                        must_show_header = 1;
3103                }
3104                if (xfrm_msg)
3105                        strbuf_addstr(&header, xfrm_msg);
3106
3107                /*
3108                 * we do not run diff between different kind
3109                 * of objects.
3110                 */
3111                if ((one->mode ^ two->mode) & S_IFMT)
3112                        goto free_ab_and_return;
3113                if (complete_rewrite &&
3114                    (textconv_one || !diff_filespec_is_binary(one)) &&
3115                    (textconv_two || !diff_filespec_is_binary(two))) {
3116                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3117                                         header.buf, header.len, 0);
3118                        strbuf_reset(&header);
3119                        emit_rewrite_diff(name_a, name_b, one, two,
3120                                                textconv_one, textconv_two, o);
3121                        o->found_changes = 1;
3122                        goto free_ab_and_return;
3123                }
3124        }
3125
3126        if (o->irreversible_delete && lbl[1][0] == '/') {
3127                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf,
3128                                 header.len, 0);
3129                strbuf_reset(&header);
3130                goto free_ab_and_return;
3131        } else if (!o->flags.text &&
3132            ( (!textconv_one && diff_filespec_is_binary(one)) ||
3133              (!textconv_two && diff_filespec_is_binary(two)) )) {
3134                struct strbuf sb = STRBUF_INIT;
3135                if (!one->data && !two->data &&
3136                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
3137                    !o->flags.binary) {
3138                        if (!oidcmp(&one->oid, &two->oid)) {
3139                                if (must_show_header)
3140                                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3141                                                         header.buf, header.len,
3142                                                         0);
3143                                goto free_ab_and_return;
3144                        }
3145                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3146                                         header.buf, header.len, 0);
3147                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3148                                    diff_line_prefix(o), lbl[0], lbl[1]);
3149                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3150                                         sb.buf, sb.len, 0);
3151                        strbuf_release(&sb);
3152                        goto free_ab_and_return;
3153                }
3154                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3155                        die("unable to read files to diff");
3156                /* Quite common confusing case */
3157                if (mf1.size == mf2.size &&
3158                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
3159                        if (must_show_header)
3160                                emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3161                                                 header.buf, header.len, 0);
3162                        goto free_ab_and_return;
3163                }
3164                emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf, header.len, 0);
3165                strbuf_reset(&header);
3166                if (o->flags.binary)
3167                        emit_binary_diff(o, &mf1, &mf2);
3168                else {
3169                        strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
3170                                    diff_line_prefix(o), lbl[0], lbl[1]);
3171                        emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
3172                                         sb.buf, sb.len, 0);
3173                        strbuf_release(&sb);
3174                }
3175                o->found_changes = 1;
3176        } else {
3177                /* Crazy xdl interfaces.. */
3178                const char *diffopts = getenv("GIT_DIFF_OPTS");
3179                const char *v;
3180                xpparam_t xpp;
3181                xdemitconf_t xecfg;
3182                struct emit_callback ecbdata;
3183                const struct userdiff_funcname *pe;
3184
3185                if (must_show_header) {
3186                        emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
3187                                         header.buf, header.len, 0);
3188                        strbuf_reset(&header);
3189                }
3190
3191                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
3192                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
3193
3194                pe = diff_funcname_pattern(one);
3195                if (!pe)
3196                        pe = diff_funcname_pattern(two);
3197
3198                memset(&xpp, 0, sizeof(xpp));
3199                memset(&xecfg, 0, sizeof(xecfg));
3200                memset(&ecbdata, 0, sizeof(ecbdata));
3201                ecbdata.label_path = lbl;
3202                ecbdata.color_diff = want_color(o->use_color);
3203                ecbdata.ws_rule = whitespace_rule(name_b);
3204                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
3205                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3206                ecbdata.opt = o;
3207                ecbdata.header = header.len ? &header : NULL;
3208                xpp.flags = o->xdl_opts;
3209                xpp.anchors = o->anchors;
3210                xpp.anchors_nr = o->anchors_nr;
3211                xecfg.ctxlen = o->context;
3212                xecfg.interhunkctxlen = o->interhunkcontext;
3213                xecfg.flags = XDL_EMIT_FUNCNAMES;
3214                if (o->flags.funccontext)
3215                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
3216                if (pe)
3217                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
3218                if (!diffopts)
3219                        ;
3220                else if (skip_prefix(diffopts, "--unified=", &v))
3221                        xecfg.ctxlen = strtoul(v, NULL, 10);
3222                else if (skip_prefix(diffopts, "-u", &v))
3223                        xecfg.ctxlen = strtoul(v, NULL, 10);
3224                if (o->word_diff)
3225                        init_diff_words_data(&ecbdata, o, one, two);
3226                if (xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
3227                                  &xpp, &xecfg))
3228                        die("unable to generate diff for %s", one->path);
3229                if (o->word_diff)
3230                        free_diff_words_data(&ecbdata);
3231                if (textconv_one)
3232                        free(mf1.ptr);
3233                if (textconv_two)
3234                        free(mf2.ptr);
3235                xdiff_clear_find_func(&xecfg);
3236        }
3237
3238 free_ab_and_return:
3239        strbuf_release(&header);
3240        diff_free_filespec_data(one);
3241        diff_free_filespec_data(two);
3242        free(a_one);
3243        free(b_two);
3244        return;
3245}
3246
3247static char *get_compact_summary(const struct diff_filepair *p, int is_renamed)
3248{
3249        if (!is_renamed) {
3250                if (p->status == DIFF_STATUS_ADDED) {
3251                        if (S_ISLNK(p->two->mode))
3252                                return "new +l";
3253                        else if ((p->two->mode & 0777) == 0755)
3254                                return "new +x";
3255                        else
3256                                return "new";
3257                } else if (p->status == DIFF_STATUS_DELETED)
3258                        return "gone";
3259        }
3260        if (S_ISLNK(p->one->mode) && !S_ISLNK(p->two->mode))
3261                return "mode -l";
3262        else if (!S_ISLNK(p->one->mode) && S_ISLNK(p->two->mode))
3263                return "mode +l";
3264        else if ((p->one->mode & 0777) == 0644 &&
3265                 (p->two->mode & 0777) == 0755)
3266                return "mode +x";
3267        else if ((p->one->mode & 0777) == 0755 &&
3268                 (p->two->mode & 0777) == 0644)
3269                return "mode -x";
3270        return NULL;
3271}
3272
3273static void builtin_diffstat(const char *name_a, const char *name_b,
3274                             struct diff_filespec *one,
3275                             struct diff_filespec *two,
3276                             struct diffstat_t *diffstat,
3277                             struct diff_options *o,
3278                             struct diff_filepair *p)
3279{
3280        mmfile_t mf1, mf2;
3281        struct diffstat_file *data;
3282        int same_contents;
3283        int complete_rewrite = 0;
3284
3285        if (!DIFF_PAIR_UNMERGED(p)) {
3286                if (p->status == DIFF_STATUS_MODIFIED && p->score)
3287                        complete_rewrite = 1;
3288        }
3289
3290        data = diffstat_add(diffstat, name_a, name_b);
3291        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
3292        if (o->flags.stat_with_summary)
3293                data->comments = get_compact_summary(p, data->is_renamed);
3294
3295        if (!one || !two) {
3296                data->is_unmerged = 1;
3297                return;
3298        }
3299
3300        same_contents = !oidcmp(&one->oid, &two->oid);
3301
3302        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
3303                data->is_binary = 1;
3304                if (same_contents) {
3305                        data->added = 0;
3306                        data->deleted = 0;
3307                } else {
3308                        data->added = diff_filespec_size(two);
3309                        data->deleted = diff_filespec_size(one);
3310                }
3311        }
3312
3313        else if (complete_rewrite) {
3314                diff_populate_filespec(one, 0);
3315                diff_populate_filespec(two, 0);
3316                data->deleted = count_lines(one->data, one->size);
3317                data->added = count_lines(two->data, two->size);
3318        }
3319
3320        else if (!same_contents) {
3321                /* Crazy xdl interfaces.. */
3322                xpparam_t xpp;
3323                xdemitconf_t xecfg;
3324
3325                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3326                        die("unable to read files to diff");
3327
3328                memset(&xpp, 0, sizeof(xpp));
3329                memset(&xecfg, 0, sizeof(xecfg));
3330                xpp.flags = o->xdl_opts;
3331                xpp.anchors = o->anchors;
3332                xpp.anchors_nr = o->anchors_nr;
3333                xecfg.ctxlen = o->context;
3334                xecfg.interhunkctxlen = o->interhunkcontext;
3335                if (xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
3336                                  &xpp, &xecfg))
3337                        die("unable to generate diffstat for %s", one->path);
3338        }
3339
3340        diff_free_filespec_data(one);
3341        diff_free_filespec_data(two);
3342}
3343
3344static void builtin_checkdiff(const char *name_a, const char *name_b,
3345                              const char *attr_path,
3346                              struct diff_filespec *one,
3347                              struct diff_filespec *two,
3348                              struct diff_options *o)
3349{
3350        mmfile_t mf1, mf2;
3351        struct checkdiff_t data;
3352
3353        if (!two)
3354                return;
3355
3356        memset(&data, 0, sizeof(data));
3357        data.filename = name_b ? name_b : name_a;
3358        data.lineno = 0;
3359        data.o = o;
3360        data.ws_rule = whitespace_rule(attr_path);
3361        data.conflict_marker_size = ll_merge_marker_size(attr_path);
3362
3363        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
3364                die("unable to read files to diff");
3365
3366        /*
3367         * All the other codepaths check both sides, but not checking
3368         * the "old" side here is deliberate.  We are checking the newly
3369         * introduced changes, and as long as the "new" side is text, we
3370         * can and should check what it introduces.
3371         */
3372        if (diff_filespec_is_binary(two))
3373                goto free_and_return;
3374        else {
3375                /* Crazy xdl interfaces.. */
3376                xpparam_t xpp;
3377                xdemitconf_t xecfg;
3378
3379                memset(&xpp, 0, sizeof(xpp));
3380                memset(&xecfg, 0, sizeof(xecfg));
3381                xecfg.ctxlen = 1; /* at least one context line */
3382                xpp.flags = 0;
3383                if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
3384                                  &xpp, &xecfg))
3385                        die("unable to generate checkdiff for %s", one->path);
3386
3387                if (data.ws_rule & WS_BLANK_AT_EOF) {
3388                        struct emit_callback ecbdata;
3389                        int blank_at_eof;
3390
3391                        ecbdata.ws_rule = data.ws_rule;
3392                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
3393                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
3394
3395                        if (blank_at_eof) {
3396                                static char *err;
3397                                if (!err)
3398                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
3399                                fprintf(o->file, "%s:%d: %s.\n",
3400                                        data.filename, blank_at_eof, err);
3401                                data.status = 1; /* report errors */
3402                        }
3403                }
3404        }
3405 free_and_return:
3406        diff_free_filespec_data(one);
3407        diff_free_filespec_data(two);
3408        if (data.status)
3409                o->flags.check_failed = 1;
3410}
3411
3412struct diff_filespec *alloc_filespec(const char *path)
3413{
3414        struct diff_filespec *spec;
3415
3416        FLEXPTR_ALLOC_STR(spec, path, path);
3417        spec->count = 1;
3418        spec->is_binary = -1;
3419        return spec;
3420}
3421
3422void free_filespec(struct diff_filespec *spec)
3423{
3424        if (!--spec->count) {
3425                diff_free_filespec_data(spec);
3426                free(spec);
3427        }
3428}
3429
3430void fill_filespec(struct diff_filespec *spec, const struct object_id *oid,
3431                   int oid_valid, unsigned short mode)
3432{
3433        if (mode) {
3434                spec->mode = canon_mode(mode);
3435                oidcpy(&spec->oid, oid);
3436                spec->oid_valid = oid_valid;
3437        }
3438}
3439
3440/*
3441 * Given a name and sha1 pair, if the index tells us the file in
3442 * the work tree has that object contents, return true, so that
3443 * prepare_temp_file() does not have to inflate and extract.
3444 */
3445static int reuse_worktree_file(const char *name, const struct object_id *oid, int want_file)
3446{
3447        const struct cache_entry *ce;
3448        struct stat st;
3449        int pos, len;
3450
3451        /*
3452         * We do not read the cache ourselves here, because the
3453         * benchmark with my previous version that always reads cache
3454         * shows that it makes things worse for diff-tree comparing
3455         * two linux-2.6 kernel trees in an already checked out work
3456         * tree.  This is because most diff-tree comparisons deal with
3457         * only a small number of files, while reading the cache is
3458         * expensive for a large project, and its cost outweighs the
3459         * savings we get by not inflating the object to a temporary
3460         * file.  Practically, this code only helps when we are used
3461         * by diff-cache --cached, which does read the cache before
3462         * calling us.
3463         */
3464        if (!active_cache)
3465                return 0;
3466
3467        /* We want to avoid the working directory if our caller
3468         * doesn't need the data in a normal file, this system
3469         * is rather slow with its stat/open/mmap/close syscalls,
3470         * and the object is contained in a pack file.  The pack
3471         * is probably already open and will be faster to obtain
3472         * the data through than the working directory.  Loose
3473         * objects however would tend to be slower as they need
3474         * to be individually opened and inflated.
3475         */
3476        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(oid->hash))
3477                return 0;
3478
3479        /*
3480         * Similarly, if we'd have to convert the file contents anyway, that
3481         * makes the optimization not worthwhile.
3482         */
3483        if (!want_file && would_convert_to_git(&the_index, name))
3484                return 0;
3485
3486        len = strlen(name);
3487        pos = cache_name_pos(name, len);
3488        if (pos < 0)
3489                return 0;
3490        ce = active_cache[pos];
3491
3492        /*
3493         * This is not the sha1 we are looking for, or
3494         * unreusable because it is not a regular file.
3495         */
3496        if (oidcmp(oid, &ce->oid) || !S_ISREG(ce->ce_mode))
3497                return 0;
3498
3499        /*
3500         * If ce is marked as "assume unchanged", there is no
3501         * guarantee that work tree matches what we are looking for.
3502         */
3503        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
3504                return 0;
3505
3506        /*
3507         * If ce matches the file in the work tree, we can reuse it.
3508         */
3509        if (ce_uptodate(ce) ||
3510            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
3511                return 1;
3512
3513        return 0;
3514}
3515
3516static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
3517{
3518        struct strbuf buf = STRBUF_INIT;
3519        char *dirty = "";
3520
3521        /* Are we looking at the work tree? */
3522        if (s->dirty_submodule)
3523                dirty = "-dirty";
3524
3525        strbuf_addf(&buf, "Subproject commit %s%s\n",
3526                    oid_to_hex(&s->oid), dirty);
3527        s->size = buf.len;
3528        if (size_only) {
3529                s->data = NULL;
3530                strbuf_release(&buf);
3531        } else {
3532                s->data = strbuf_detach(&buf, NULL);
3533                s->should_free = 1;
3534        }
3535        return 0;
3536}
3537
3538/*
3539 * While doing rename detection and pickaxe operation, we may need to
3540 * grab the data for the blob (or file) for our own in-core comparison.
3541 * diff_filespec has data and size fields for this purpose.
3542 */
3543int diff_populate_filespec(struct diff_filespec *s, unsigned int flags)
3544{
3545        int size_only = flags & CHECK_SIZE_ONLY;
3546        int err = 0;
3547        int conv_flags = global_conv_flags_eol;
3548        /*
3549         * demote FAIL to WARN to allow inspecting the situation
3550         * instead of refusing.
3551         */
3552        if (conv_flags & CONV_EOL_RNDTRP_DIE)
3553                conv_flags = CONV_EOL_RNDTRP_WARN;
3554
3555        if (!DIFF_FILE_VALID(s))
3556                die("internal error: asking to populate invalid file.");
3557        if (S_ISDIR(s->mode))
3558                return -1;
3559
3560        if (s->data)
3561                return 0;
3562
3563        if (size_only && 0 < s->size)
3564                return 0;
3565
3566        if (S_ISGITLINK(s->mode))
3567                return diff_populate_gitlink(s, size_only);
3568
3569        if (!s->oid_valid ||
3570            reuse_worktree_file(s->path, &s->oid, 0)) {
3571                struct strbuf buf = STRBUF_INIT;
3572                struct stat st;
3573                int fd;
3574
3575                if (lstat(s->path, &st) < 0) {
3576                err_empty:
3577                        err = -1;
3578                empty:
3579                        s->data = (char *)"";
3580                        s->size = 0;
3581                        return err;
3582                }
3583                s->size = xsize_t(st.st_size);
3584                if (!s->size)
3585                        goto empty;
3586                if (S_ISLNK(st.st_mode)) {
3587                        struct strbuf sb = STRBUF_INIT;
3588
3589                        if (strbuf_readlink(&sb, s->path, s->size))
3590                                goto err_empty;
3591                        s->size = sb.len;
3592                        s->data = strbuf_detach(&sb, NULL);
3593                        s->should_free = 1;
3594                        return 0;
3595                }
3596
3597                /*
3598                 * Even if the caller would be happy with getting
3599                 * only the size, we cannot return early at this
3600                 * point if the path requires us to run the content
3601                 * conversion.
3602                 */
3603                if (size_only && !would_convert_to_git(&the_index, s->path))
3604                        return 0;
3605
3606                /*
3607                 * Note: this check uses xsize_t(st.st_size) that may
3608                 * not be the true size of the blob after it goes
3609                 * through convert_to_git().  This may not strictly be
3610                 * correct, but the whole point of big_file_threshold
3611                 * and is_binary check being that we want to avoid
3612                 * opening the file and inspecting the contents, this
3613                 * is probably fine.
3614                 */
3615                if ((flags & CHECK_BINARY) &&
3616                    s->size > big_file_threshold && s->is_binary == -1) {
3617                        s->is_binary = 1;
3618                        return 0;
3619                }
3620                fd = open(s->path, O_RDONLY);
3621                if (fd < 0)
3622                        goto err_empty;
3623                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
3624                close(fd);
3625                s->should_munmap = 1;
3626
3627                /*
3628                 * Convert from working tree format to canonical git format
3629                 */
3630                if (convert_to_git(&the_index, s->path, s->data, s->size, &buf, conv_flags)) {
3631                        size_t size = 0;
3632                        munmap(s->data, s->size);
3633                        s->should_munmap = 0;
3634                        s->data = strbuf_detach(&buf, &size);
3635                        s->size = size;
3636                        s->should_free = 1;
3637                }
3638        }
3639        else {
3640                enum object_type type;
3641                if (size_only || (flags & CHECK_BINARY)) {
3642                        type = oid_object_info(the_repository, &s->oid,
3643                                               &s->size);
3644                        if (type < 0)
3645                                die("unable to read %s",
3646                                    oid_to_hex(&s->oid));
3647                        if (size_only)
3648                                return 0;
3649                        if (s->size > big_file_threshold && s->is_binary == -1) {
3650                                s->is_binary = 1;
3651                                return 0;
3652                        }
3653                }
3654                s->data = read_object_file(&s->oid, &type, &s->size);
3655                if (!s->data)
3656                        die("unable to read %s", oid_to_hex(&s->oid));
3657                s->should_free = 1;
3658        }
3659        return 0;
3660}
3661
3662void diff_free_filespec_blob(struct diff_filespec *s)
3663{
3664        if (s->should_free)
3665                free(s->data);
3666        else if (s->should_munmap)
3667                munmap(s->data, s->size);
3668
3669        if (s->should_free || s->should_munmap) {
3670                s->should_free = s->should_munmap = 0;
3671                s->data = NULL;
3672        }
3673}
3674
3675void diff_free_filespec_data(struct diff_filespec *s)
3676{
3677        diff_free_filespec_blob(s);
3678        FREE_AND_NULL(s->cnt_data);
3679}
3680
3681static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
3682                           void *blob,
3683                           unsigned long size,
3684                           const struct object_id *oid,
3685                           int mode)
3686{
3687        struct strbuf buf = STRBUF_INIT;
3688        struct strbuf tempfile = STRBUF_INIT;
3689        char *path_dup = xstrdup(path);
3690        const char *base = basename(path_dup);
3691
3692        /* Generate "XXXXXX_basename.ext" */
3693        strbuf_addstr(&tempfile, "XXXXXX_");
3694        strbuf_addstr(&tempfile, base);
3695
3696        temp->tempfile = mks_tempfile_ts(tempfile.buf, strlen(base) + 1);
3697        if (!temp->tempfile)
3698                die_errno("unable to create temp-file");
3699        if (convert_to_working_tree(path,
3700                        (const char *)blob, (size_t)size, &buf)) {
3701                blob = buf.buf;
3702                size = buf.len;
3703        }
3704        if (write_in_full(temp->tempfile->fd, blob, size) < 0 ||
3705            close_tempfile_gently(temp->tempfile))
3706                die_errno("unable to write temp-file");
3707        temp->name = get_tempfile_path(temp->tempfile);
3708        oid_to_hex_r(temp->hex, oid);
3709        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
3710        strbuf_release(&buf);
3711        strbuf_release(&tempfile);
3712        free(path_dup);
3713}
3714
3715static struct diff_tempfile *prepare_temp_file(const char *name,
3716                struct diff_filespec *one)
3717{
3718        struct diff_tempfile *temp = claim_diff_tempfile();
3719
3720        if (!DIFF_FILE_VALID(one)) {
3721        not_a_valid_file:
3722                /* A '-' entry produces this for file-2, and
3723                 * a '+' entry produces this for file-1.
3724                 */
3725                temp->name = "/dev/null";
3726                xsnprintf(temp->hex, sizeof(temp->hex), ".");
3727                xsnprintf(temp->mode, sizeof(temp->mode), ".");
3728                return temp;
3729        }
3730
3731        if (!S_ISGITLINK(one->mode) &&
3732            (!one->oid_valid ||
3733             reuse_worktree_file(name, &one->oid, 1))) {
3734                struct stat st;
3735                if (lstat(name, &st) < 0) {
3736                        if (errno == ENOENT)
3737                                goto not_a_valid_file;
3738                        die_errno("stat(%s)", name);
3739                }
3740                if (S_ISLNK(st.st_mode)) {
3741                        struct strbuf sb = STRBUF_INIT;
3742                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
3743                                die_errno("readlink(%s)", name);
3744                        prep_temp_blob(name, temp, sb.buf, sb.len,
3745                                       (one->oid_valid ?
3746                                        &one->oid : &null_oid),
3747                                       (one->oid_valid ?
3748                                        one->mode : S_IFLNK));
3749                        strbuf_release(&sb);
3750                }
3751                else {
3752                        /* we can borrow from the file in the work tree */
3753                        temp->name = name;
3754                        if (!one->oid_valid)
3755                                oid_to_hex_r(temp->hex, &null_oid);
3756                        else
3757                                oid_to_hex_r(temp->hex, &one->oid);
3758                        /* Even though we may sometimes borrow the
3759                         * contents from the work tree, we always want
3760                         * one->mode.  mode is trustworthy even when
3761                         * !(one->oid_valid), as long as
3762                         * DIFF_FILE_VALID(one).
3763                         */
3764                        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
3765                }
3766                return temp;
3767        }
3768        else {
3769                if (diff_populate_filespec(one, 0))
3770                        die("cannot read data blob for %s", one->path);
3771                prep_temp_blob(name, temp, one->data, one->size,
3772                               &one->oid, one->mode);
3773        }
3774        return temp;
3775}
3776
3777static void add_external_diff_name(struct argv_array *argv,
3778                                   const char *name,
3779                                   struct diff_filespec *df)
3780{
3781        struct diff_tempfile *temp = prepare_temp_file(name, df);
3782        argv_array_push(argv, temp->name);
3783        argv_array_push(argv, temp->hex);
3784        argv_array_push(argv, temp->mode);
3785}
3786
3787/* An external diff command takes:
3788 *
3789 * diff-cmd name infile1 infile1-sha1 infile1-mode \
3790 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
3791 *
3792 */
3793static void run_external_diff(const char *pgm,
3794                              const char *name,
3795                              const char *other,
3796                              struct diff_filespec *one,
3797                              struct diff_filespec *two,
3798                              const char *xfrm_msg,
3799                              int complete_rewrite,
3800                              struct diff_options *o)
3801{
3802        struct argv_array argv = ARGV_ARRAY_INIT;
3803        struct argv_array env = ARGV_ARRAY_INIT;
3804        struct diff_queue_struct *q = &diff_queued_diff;
3805
3806        argv_array_push(&argv, pgm);
3807        argv_array_push(&argv, name);
3808
3809        if (one && two) {
3810                add_external_diff_name(&argv, name, one);
3811                if (!other)
3812                        add_external_diff_name(&argv, name, two);
3813                else {
3814                        add_external_diff_name(&argv, other, two);
3815                        argv_array_push(&argv, other);
3816                        argv_array_push(&argv, xfrm_msg);
3817                }
3818        }
3819
3820        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
3821        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
3822
3823        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
3824                die(_("external diff died, stopping at %s"), name);
3825
3826        remove_tempfile();
3827        argv_array_clear(&argv);
3828        argv_array_clear(&env);
3829}
3830
3831static int similarity_index(struct diff_filepair *p)
3832{
3833        return p->score * 100 / MAX_SCORE;
3834}
3835
3836static const char *diff_abbrev_oid(const struct object_id *oid, int abbrev)
3837{
3838        if (startup_info->have_repository)
3839                return find_unique_abbrev(oid, abbrev);
3840        else {
3841                char *hex = oid_to_hex(oid);
3842                if (abbrev < 0)
3843                        abbrev = FALLBACK_DEFAULT_ABBREV;
3844                if (abbrev > GIT_SHA1_HEXSZ)
3845                        die("BUG: oid abbreviation out of range: %d", abbrev);
3846                if (abbrev)
3847                        hex[abbrev] = '\0';
3848                return hex;
3849        }
3850}
3851
3852static void fill_metainfo(struct strbuf *msg,
3853                          const char *name,
3854                          const char *other,
3855                          struct diff_filespec *one,
3856                          struct diff_filespec *two,
3857                          struct diff_options *o,
3858                          struct diff_filepair *p,
3859                          int *must_show_header,
3860                          int use_color)
3861{
3862        const char *set = diff_get_color(use_color, DIFF_METAINFO);
3863        const char *reset = diff_get_color(use_color, DIFF_RESET);
3864        const char *line_prefix = diff_line_prefix(o);
3865
3866        *must_show_header = 1;
3867        strbuf_init(msg, PATH_MAX * 2 + 300);
3868        switch (p->status) {
3869        case DIFF_STATUS_COPIED:
3870                strbuf_addf(msg, "%s%ssimilarity index %d%%",
3871                            line_prefix, set, similarity_index(p));
3872                strbuf_addf(msg, "%s\n%s%scopy from ",
3873                            reset,  line_prefix, set);
3874                quote_c_style(name, msg, NULL, 0);
3875                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
3876                quote_c_style(other, msg, NULL, 0);
3877                strbuf_addf(msg, "%s\n", reset);
3878                break;
3879        case DIFF_STATUS_RENAMED:
3880                strbuf_addf(msg, "%s%ssimilarity index %d%%",
3881                            line_prefix, set, similarity_index(p));
3882                strbuf_addf(msg, "%s\n%s%srename from ",
3883                            reset, line_prefix, set);
3884                quote_c_style(name, msg, NULL, 0);
3885                strbuf_addf(msg, "%s\n%s%srename to ",
3886                            reset, line_prefix, set);
3887                quote_c_style(other, msg, NULL, 0);
3888                strbuf_addf(msg, "%s\n", reset);
3889                break;
3890        case DIFF_STATUS_MODIFIED:
3891                if (p->score) {
3892                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
3893                                    line_prefix,
3894                                    set, similarity_index(p), reset);
3895                        break;
3896                }
3897                /* fallthru */
3898        default:
3899                *must_show_header = 0;
3900        }
3901        if (one && two && oidcmp(&one->oid, &two->oid)) {
3902                int abbrev = o->flags.full_index ? 40 : DEFAULT_ABBREV;
3903
3904                if (o->flags.binary) {
3905                        mmfile_t mf;
3906                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
3907                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
3908                                abbrev = 40;
3909                }
3910                strbuf_addf(msg, "%s%sindex %s..%s", line_prefix, set,
3911                            diff_abbrev_oid(&one->oid, abbrev),
3912                            diff_abbrev_oid(&two->oid, abbrev));
3913                if (one->mode == two->mode)
3914                        strbuf_addf(msg, " %06o", one->mode);
3915                strbuf_addf(msg, "%s\n", reset);
3916        }
3917}
3918
3919static void run_diff_cmd(const char *pgm,
3920                         const char *name,
3921                         const char *other,
3922                         const char *attr_path,
3923                         struct diff_filespec *one,
3924                         struct diff_filespec *two,
3925                         struct strbuf *msg,
3926                         struct diff_options *o,
3927                         struct diff_filepair *p)
3928{
3929        const char *xfrm_msg = NULL;
3930        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
3931        int must_show_header = 0;
3932
3933
3934        if (o->flags.allow_external) {
3935                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
3936                if (drv && drv->external)
3937                        pgm = drv->external;
3938        }
3939
3940        if (msg) {
3941                /*
3942                 * don't use colors when the header is intended for an
3943                 * external diff driver
3944                 */
3945                fill_metainfo(msg, name, other, one, two, o, p,
3946                              &must_show_header,
3947                              want_color(o->use_color) && !pgm);
3948                xfrm_msg = msg->len ? msg->buf : NULL;
3949        }
3950
3951        if (pgm) {
3952                run_external_diff(pgm, name, other, one, two, xfrm_msg,
3953                                  complete_rewrite, o);
3954                return;
3955        }
3956        if (one && two)
3957                builtin_diff(name, other ? other : name,
3958                             one, two, xfrm_msg, must_show_header,
3959                             o, complete_rewrite);
3960        else
3961                fprintf(o->file, "* Unmerged path %s\n", name);
3962}
3963
3964static void diff_fill_oid_info(struct diff_filespec *one)
3965{
3966        if (DIFF_FILE_VALID(one)) {
3967                if (!one->oid_valid) {
3968                        struct stat st;
3969                        if (one->is_stdin) {
3970                                oidclr(&one->oid);
3971                                return;
3972                        }
3973                        if (lstat(one->path, &st) < 0)
3974                                die_errno("stat '%s'", one->path);
3975                        if (index_path(&one->oid, one->path, &st, 0))
3976                                die("cannot hash %s", one->path);
3977                }
3978        }
3979        else
3980                oidclr(&one->oid);
3981}
3982
3983static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
3984{
3985        /* Strip the prefix but do not molest /dev/null and absolute paths */
3986        if (*namep && **namep != '/') {
3987                *namep += prefix_length;
3988                if (**namep == '/')
3989                        ++*namep;
3990        }
3991        if (*otherp && **otherp != '/') {
3992                *otherp += prefix_length;
3993                if (**otherp == '/')
3994                        ++*otherp;
3995        }
3996}
3997
3998static void run_diff(struct diff_filepair *p, struct diff_options *o)
3999{
4000        const char *pgm = external_diff();
4001        struct strbuf msg;
4002        struct diff_filespec *one = p->one;
4003        struct diff_filespec *two = p->two;
4004        const char *name;
4005        const char *other;
4006        const char *attr_path;
4007
4008        name  = one->path;
4009        other = (strcmp(name, two->path) ? two->path : NULL);
4010        attr_path = name;
4011        if (o->prefix_length)
4012                strip_prefix(o->prefix_length, &name, &other);
4013
4014        if (!o->flags.allow_external)
4015                pgm = NULL;
4016
4017        if (DIFF_PAIR_UNMERGED(p)) {
4018                run_diff_cmd(pgm, name, NULL, attr_path,
4019                             NULL, NULL, NULL, o, p);
4020                return;
4021        }
4022
4023        diff_fill_oid_info(one);
4024        diff_fill_oid_info(two);
4025
4026        if (!pgm &&
4027            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
4028            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
4029                /*
4030                 * a filepair that changes between file and symlink
4031                 * needs to be split into deletion and creation.
4032                 */
4033                struct diff_filespec *null = alloc_filespec(two->path);
4034                run_diff_cmd(NULL, name, other, attr_path,
4035                             one, null, &msg, o, p);
4036                free(null);
4037                strbuf_release(&msg);
4038
4039                null = alloc_filespec(one->path);
4040                run_diff_cmd(NULL, name, other, attr_path,
4041                             null, two, &msg, o, p);
4042                free(null);
4043        }
4044        else
4045                run_diff_cmd(pgm, name, other, attr_path,
4046                             one, two, &msg, o, p);
4047
4048        strbuf_release(&msg);
4049}
4050
4051static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
4052                         struct diffstat_t *diffstat)
4053{
4054        const char *name;
4055        const char *other;
4056
4057        if (DIFF_PAIR_UNMERGED(p)) {
4058                /* unmerged */
4059                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, p);
4060                return;
4061        }
4062
4063        name = p->one->path;
4064        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4065
4066        if (o->prefix_length)
4067                strip_prefix(o->prefix_length, &name, &other);
4068
4069        diff_fill_oid_info(p->one);
4070        diff_fill_oid_info(p->two);
4071
4072        builtin_diffstat(name, other, p->one, p->two, diffstat, o, p);
4073}
4074
4075static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
4076{
4077        const char *name;
4078        const char *other;
4079        const char *attr_path;
4080
4081        if (DIFF_PAIR_UNMERGED(p)) {
4082                /* unmerged */
4083                return;
4084        }
4085
4086        name = p->one->path;
4087        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
4088        attr_path = other ? other : name;
4089
4090        if (o->prefix_length)
4091                strip_prefix(o->prefix_length, &name, &other);
4092
4093        diff_fill_oid_info(p->one);
4094        diff_fill_oid_info(p->two);
4095
4096        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
4097}
4098
4099void diff_setup(struct diff_options *options)
4100{
4101        memcpy(options, &default_diff_options, sizeof(*options));
4102
4103        options->file = stdout;
4104
4105        options->abbrev = DEFAULT_ABBREV;
4106        options->line_termination = '\n';
4107        options->break_opt = -1;
4108        options->rename_limit = -1;
4109        options->dirstat_permille = diff_dirstat_permille_default;
4110        options->context = diff_context_default;
4111        options->interhunkcontext = diff_interhunk_context_default;
4112        options->ws_error_highlight = ws_error_highlight_default;
4113        options->flags.rename_empty = 1;
4114        options->objfind = NULL;
4115
4116        /* pathchange left =NULL by default */
4117        options->change = diff_change;
4118        options->add_remove = diff_addremove;
4119        options->use_color = diff_use_color_default;
4120        options->detect_rename = diff_detect_rename_default;
4121        options->xdl_opts |= diff_algorithm;
4122        if (diff_indent_heuristic)
4123                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4124
4125        options->orderfile = diff_order_file_cfg;
4126
4127        if (diff_no_prefix) {
4128                options->a_prefix = options->b_prefix = "";
4129        } else if (!diff_mnemonic_prefix) {
4130                options->a_prefix = "a/";
4131                options->b_prefix = "b/";
4132        }
4133
4134        options->color_moved = diff_color_moved_default;
4135}
4136
4137void diff_setup_done(struct diff_options *options)
4138{
4139        unsigned check_mask = DIFF_FORMAT_NAME |
4140                              DIFF_FORMAT_NAME_STATUS |
4141                              DIFF_FORMAT_CHECKDIFF |
4142                              DIFF_FORMAT_NO_OUTPUT;
4143
4144        if (options->set_default)
4145                options->set_default(options);
4146
4147        if (HAS_MULTI_BITS(options->output_format & check_mask))
4148                die(_("--name-only, --name-status, --check and -s are mutually exclusive"));
4149
4150        if (HAS_MULTI_BITS(options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK))
4151                die(_("-G, -S and --find-object are mutually exclusive"));
4152
4153        /*
4154         * Most of the time we can say "there are changes"
4155         * only by checking if there are changed paths, but
4156         * --ignore-whitespace* options force us to look
4157         * inside contents.
4158         */
4159
4160        if ((options->xdl_opts & XDF_WHITESPACE_FLAGS))
4161                options->flags.diff_from_contents = 1;
4162        else
4163                options->flags.diff_from_contents = 0;
4164
4165        if (options->flags.find_copies_harder)
4166                options->detect_rename = DIFF_DETECT_COPY;
4167
4168        if (!options->flags.relative_name)
4169                options->prefix = NULL;
4170        if (options->prefix)
4171                options->prefix_length = strlen(options->prefix);
4172        else
4173                options->prefix_length = 0;
4174
4175        if (options->output_format & (DIFF_FORMAT_NAME |
4176                                      DIFF_FORMAT_NAME_STATUS |
4177                                      DIFF_FORMAT_CHECKDIFF |
4178                                      DIFF_FORMAT_NO_OUTPUT))
4179                options->output_format &= ~(DIFF_FORMAT_RAW |
4180                                            DIFF_FORMAT_NUMSTAT |
4181                                            DIFF_FORMAT_DIFFSTAT |
4182                                            DIFF_FORMAT_SHORTSTAT |
4183                                            DIFF_FORMAT_DIRSTAT |
4184                                            DIFF_FORMAT_SUMMARY |
4185                                            DIFF_FORMAT_PATCH);
4186
4187        /*
4188         * These cases always need recursive; we do not drop caller-supplied
4189         * recursive bits for other formats here.
4190         */
4191        if (options->output_format & (DIFF_FORMAT_PATCH |
4192                                      DIFF_FORMAT_NUMSTAT |
4193                                      DIFF_FORMAT_DIFFSTAT |
4194                                      DIFF_FORMAT_SHORTSTAT |
4195                                      DIFF_FORMAT_DIRSTAT |
4196                                      DIFF_FORMAT_SUMMARY |
4197                                      DIFF_FORMAT_CHECKDIFF))
4198                options->flags.recursive = 1;
4199        /*
4200         * Also pickaxe would not work very well if you do not say recursive
4201         */
4202        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
4203                options->flags.recursive = 1;
4204        /*
4205         * When patches are generated, submodules diffed against the work tree
4206         * must be checked for dirtiness too so it can be shown in the output
4207         */
4208        if (options->output_format & DIFF_FORMAT_PATCH)
4209                options->flags.dirty_submodules = 1;
4210
4211        if (options->detect_rename && options->rename_limit < 0)
4212                options->rename_limit = diff_rename_limit_default;
4213        if (options->setup & DIFF_SETUP_USE_CACHE) {
4214                if (!active_cache)
4215                        /* read-cache does not die even when it fails
4216                         * so it is safe for us to do this here.  Also
4217                         * it does not smudge active_cache or active_nr
4218                         * when it fails, so we do not have to worry about
4219                         * cleaning it up ourselves either.
4220                         */
4221                        read_cache();
4222        }
4223        if (40 < options->abbrev)
4224                options->abbrev = 40; /* full */
4225
4226        /*
4227         * It does not make sense to show the first hit we happened
4228         * to have found.  It does not make sense not to return with
4229         * exit code in such a case either.
4230         */
4231        if (options->flags.quick) {
4232                options->output_format = DIFF_FORMAT_NO_OUTPUT;
4233                options->flags.exit_with_status = 1;
4234        }
4235
4236        options->diff_path_counter = 0;
4237
4238        if (options->flags.follow_renames && options->pathspec.nr != 1)
4239                die(_("--follow requires exactly one pathspec"));
4240
4241        if (!options->use_color || external_diff())
4242                options->color_moved = 0;
4243}
4244
4245static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
4246{
4247        char c, *eq;
4248        int len;
4249
4250        if (*arg != '-')
4251                return 0;
4252        c = *++arg;
4253        if (!c)
4254                return 0;
4255        if (c == arg_short) {
4256                c = *++arg;
4257                if (!c)
4258                        return 1;
4259                if (val && isdigit(c)) {
4260                        char *end;
4261                        int n = strtoul(arg, &end, 10);
4262                        if (*end)
4263                                return 0;
4264                        *val = n;
4265                        return 1;
4266                }
4267                return 0;
4268        }
4269        if (c != '-')
4270                return 0;
4271        arg++;
4272        eq = strchrnul(arg, '=');
4273        len = eq - arg;
4274        if (!len || strncmp(arg, arg_long, len))
4275                return 0;
4276        if (*eq) {
4277                int n;
4278                char *end;
4279                if (!isdigit(*++eq))
4280                        return 0;
4281                n = strtoul(eq, &end, 10);
4282                if (*end)
4283                        return 0;
4284                *val = n;
4285        }
4286        return 1;
4287}
4288
4289static int diff_scoreopt_parse(const char *opt);
4290
4291static inline int short_opt(char opt, const char **argv,
4292                            const char **optarg)
4293{
4294        const char *arg = argv[0];
4295        if (arg[0] != '-' || arg[1] != opt)
4296                return 0;
4297        if (arg[2] != '\0') {
4298                *optarg = arg + 2;
4299                return 1;
4300        }
4301        if (!argv[1])
4302                die("Option '%c' requires a value", opt);
4303        *optarg = argv[1];
4304        return 2;
4305}
4306
4307int parse_long_opt(const char *opt, const char **argv,
4308                   const char **optarg)
4309{
4310        const char *arg = argv[0];
4311        if (!skip_prefix(arg, "--", &arg))
4312                return 0;
4313        if (!skip_prefix(arg, opt, &arg))
4314                return 0;
4315        if (*arg == '=') { /* stuck form: --option=value */
4316                *optarg = arg + 1;
4317                return 1;
4318        }
4319        if (*arg != '\0')
4320                return 0;
4321        /* separate form: --option value */
4322        if (!argv[1])
4323                die("Option '--%s' requires a value", opt);
4324        *optarg = argv[1];
4325        return 2;
4326}
4327
4328static int stat_opt(struct diff_options *options, const char **av)
4329{
4330        const char *arg = av[0];
4331        char *end;
4332        int width = options->stat_width;
4333        int name_width = options->stat_name_width;
4334        int graph_width = options->stat_graph_width;
4335        int count = options->stat_count;
4336        int argcount = 1;
4337
4338        if (!skip_prefix(arg, "--stat", &arg))
4339                die("BUG: stat option does not begin with --stat: %s", arg);
4340        end = (char *)arg;
4341
4342        switch (*arg) {
4343        case '-':
4344                if (skip_prefix(arg, "-width", &arg)) {
4345                        if (*arg == '=')
4346                                width = strtoul(arg + 1, &end, 10);
4347                        else if (!*arg && !av[1])
4348                                die_want_option("--stat-width");
4349                        else if (!*arg) {
4350                                width = strtoul(av[1], &end, 10);
4351                                argcount = 2;
4352                        }
4353                } else if (skip_prefix(arg, "-name-width", &arg)) {
4354                        if (*arg == '=')
4355                                name_width = strtoul(arg + 1, &end, 10);
4356                        else if (!*arg && !av[1])
4357                                die_want_option("--stat-name-width");
4358                        else if (!*arg) {
4359                                name_width = strtoul(av[1], &end, 10);
4360                                argcount = 2;
4361                        }
4362                } else if (skip_prefix(arg, "-graph-width", &arg)) {
4363                        if (*arg == '=')
4364                                graph_width = strtoul(arg + 1, &end, 10);
4365                        else if (!*arg && !av[1])
4366                                die_want_option("--stat-graph-width");
4367                        else if (!*arg) {
4368                                graph_width = strtoul(av[1], &end, 10);
4369                                argcount = 2;
4370                        }
4371                } else if (skip_prefix(arg, "-count", &arg)) {
4372                        if (*arg == '=')
4373                                count = strtoul(arg + 1, &end, 10);
4374                        else if (!*arg && !av[1])
4375                                die_want_option("--stat-count");
4376                        else if (!*arg) {
4377                                count = strtoul(av[1], &end, 10);
4378                                argcount = 2;
4379                        }
4380                }
4381                break;
4382        case '=':
4383                width = strtoul(arg+1, &end, 10);
4384                if (*end == ',')
4385                        name_width = strtoul(end+1, &end, 10);
4386                if (*end == ',')
4387                        count = strtoul(end+1, &end, 10);
4388        }
4389
4390        /* Important! This checks all the error cases! */
4391        if (*end)
4392                return 0;
4393        options->output_format |= DIFF_FORMAT_DIFFSTAT;
4394        options->stat_name_width = name_width;
4395        options->stat_graph_width = graph_width;
4396        options->stat_width = width;
4397        options->stat_count = count;
4398        return argcount;
4399}
4400
4401static int parse_dirstat_opt(struct diff_options *options, const char *params)
4402{
4403        struct strbuf errmsg = STRBUF_INIT;
4404        if (parse_dirstat_params(options, params, &errmsg))
4405                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
4406                    errmsg.buf);
4407        strbuf_release(&errmsg);
4408        /*
4409         * The caller knows a dirstat-related option is given from the command
4410         * line; allow it to say "return this_function();"
4411         */
4412        options->output_format |= DIFF_FORMAT_DIRSTAT;
4413        return 1;
4414}
4415
4416static int parse_submodule_opt(struct diff_options *options, const char *value)
4417{
4418        if (parse_submodule_params(options, value))
4419                die(_("Failed to parse --submodule option parameter: '%s'"),
4420                        value);
4421        return 1;
4422}
4423
4424static const char diff_status_letters[] = {
4425        DIFF_STATUS_ADDED,
4426        DIFF_STATUS_COPIED,
4427        DIFF_STATUS_DELETED,
4428        DIFF_STATUS_MODIFIED,
4429        DIFF_STATUS_RENAMED,
4430        DIFF_STATUS_TYPE_CHANGED,
4431        DIFF_STATUS_UNKNOWN,
4432        DIFF_STATUS_UNMERGED,
4433        DIFF_STATUS_FILTER_AON,
4434        DIFF_STATUS_FILTER_BROKEN,
4435        '\0',
4436};
4437
4438static unsigned int filter_bit['Z' + 1];
4439
4440static void prepare_filter_bits(void)
4441{
4442        int i;
4443
4444        if (!filter_bit[DIFF_STATUS_ADDED]) {
4445                for (i = 0; diff_status_letters[i]; i++)
4446                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
4447        }
4448}
4449
4450static unsigned filter_bit_tst(char status, const struct diff_options *opt)
4451{
4452        return opt->filter & filter_bit[(int) status];
4453}
4454
4455static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
4456{
4457        int i, optch;
4458
4459        prepare_filter_bits();
4460
4461        /*
4462         * If there is a negation e.g. 'd' in the input, and we haven't
4463         * initialized the filter field with another --diff-filter, start
4464         * from full set of bits, except for AON.
4465         */
4466        if (!opt->filter) {
4467                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4468                        if (optch < 'a' || 'z' < optch)
4469                                continue;
4470                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
4471                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
4472                        break;
4473                }
4474        }
4475
4476        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
4477                unsigned int bit;
4478                int negate;
4479
4480                if ('a' <= optch && optch <= 'z') {
4481                        negate = 1;
4482                        optch = toupper(optch);
4483                } else {
4484                        negate = 0;
4485                }
4486
4487                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
4488                if (!bit)
4489                        return optarg[i];
4490                if (negate)
4491                        opt->filter &= ~bit;
4492                else
4493                        opt->filter |= bit;
4494        }
4495        return 0;
4496}
4497
4498static void enable_patch_output(int *fmt) {
4499        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
4500        *fmt |= DIFF_FORMAT_PATCH;
4501}
4502
4503static int parse_ws_error_highlight_opt(struct diff_options *opt, const char *arg)
4504{
4505        int val = parse_ws_error_highlight(arg);
4506
4507        if (val < 0) {
4508                error("unknown value after ws-error-highlight=%.*s",
4509                      -1 - val, arg);
4510                return 0;
4511        }
4512        opt->ws_error_highlight = val;
4513        return 1;
4514}
4515
4516static int parse_objfind_opt(struct diff_options *opt, const char *arg)
4517{
4518        struct object_id oid;
4519
4520        if (get_oid(arg, &oid))
4521                return error("unable to resolve '%s'", arg);
4522
4523        if (!opt->objfind)
4524                opt->objfind = xcalloc(1, sizeof(*opt->objfind));
4525
4526        opt->pickaxe_opts |= DIFF_PICKAXE_KIND_OBJFIND;
4527        opt->flags.recursive = 1;
4528        opt->flags.tree_in_recursive = 1;
4529        oidset_insert(opt->objfind, &oid);
4530        return 1;
4531}
4532
4533int diff_opt_parse(struct diff_options *options,
4534                   const char **av, int ac, const char *prefix)
4535{
4536        const char *arg = av[0];
4537        const char *optarg;
4538        int argcount;
4539
4540        if (!prefix)
4541                prefix = "";
4542
4543        /* Output format options */
4544        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
4545            || opt_arg(arg, 'U', "unified", &options->context))
4546                enable_patch_output(&options->output_format);
4547        else if (!strcmp(arg, "--raw"))
4548                options->output_format |= DIFF_FORMAT_RAW;
4549        else if (!strcmp(arg, "--patch-with-raw")) {
4550                enable_patch_output(&options->output_format);
4551                options->output_format |= DIFF_FORMAT_RAW;
4552        } else if (!strcmp(arg, "--numstat"))
4553                options->output_format |= DIFF_FORMAT_NUMSTAT;
4554        else if (!strcmp(arg, "--shortstat"))
4555                options->output_format |= DIFF_FORMAT_SHORTSTAT;
4556        else if (skip_prefix(arg, "-X", &arg) ||
4557                 skip_to_optional_arg(arg, "--dirstat", &arg))
4558                return parse_dirstat_opt(options, arg);
4559        else if (!strcmp(arg, "--cumulative"))
4560                return parse_dirstat_opt(options, "cumulative");
4561        else if (skip_to_optional_arg(arg, "--dirstat-by-file", &arg)) {
4562                parse_dirstat_opt(options, "files");
4563                return parse_dirstat_opt(options, arg);
4564        }
4565        else if (!strcmp(arg, "--check"))
4566                options->output_format |= DIFF_FORMAT_CHECKDIFF;
4567        else if (!strcmp(arg, "--summary"))
4568                options->output_format |= DIFF_FORMAT_SUMMARY;
4569        else if (!strcmp(arg, "--patch-with-stat")) {
4570                enable_patch_output(&options->output_format);
4571                options->output_format |= DIFF_FORMAT_DIFFSTAT;
4572        } else if (!strcmp(arg, "--name-only"))
4573                options->output_format |= DIFF_FORMAT_NAME;
4574        else if (!strcmp(arg, "--name-status"))
4575                options->output_format |= DIFF_FORMAT_NAME_STATUS;
4576        else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
4577                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
4578        else if (starts_with(arg, "--stat"))
4579                /* --stat, --stat-width, --stat-name-width, or --stat-count */
4580                return stat_opt(options, av);
4581        else if (!strcmp(arg, "--compact-summary")) {
4582                 options->flags.stat_with_summary = 1;
4583                 options->output_format |= DIFF_FORMAT_DIFFSTAT;
4584        } else if (!strcmp(arg, "--no-compact-summary"))
4585                 options->flags.stat_with_summary = 0;
4586
4587        /* renames options */
4588        else if (starts_with(arg, "-B") ||
4589                 skip_to_optional_arg(arg, "--break-rewrites", NULL)) {
4590                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
4591                        return error("invalid argument to -B: %s", arg+2);
4592        }
4593        else if (starts_with(arg, "-M") ||
4594                 skip_to_optional_arg(arg, "--find-renames", NULL)) {
4595                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4596                        return error("invalid argument to -M: %s", arg+2);
4597                options->detect_rename = DIFF_DETECT_RENAME;
4598        }
4599        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
4600                options->irreversible_delete = 1;
4601        }
4602        else if (starts_with(arg, "-C") ||
4603                 skip_to_optional_arg(arg, "--find-copies", NULL)) {
4604                if (options->detect_rename == DIFF_DETECT_COPY)
4605                        options->flags.find_copies_harder = 1;
4606                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
4607                        return error("invalid argument to -C: %s", arg+2);
4608                options->detect_rename = DIFF_DETECT_COPY;
4609        }
4610        else if (!strcmp(arg, "--no-renames"))
4611                options->detect_rename = 0;
4612        else if (!strcmp(arg, "--rename-empty"))
4613                options->flags.rename_empty = 1;
4614        else if (!strcmp(arg, "--no-rename-empty"))
4615                options->flags.rename_empty = 0;
4616        else if (skip_to_optional_arg_default(arg, "--relative", &arg, NULL)) {
4617                options->flags.relative_name = 1;
4618                if (arg)
4619                        options->prefix = arg;
4620        }
4621
4622        /* xdiff options */
4623        else if (!strcmp(arg, "--minimal"))
4624                DIFF_XDL_SET(options, NEED_MINIMAL);
4625        else if (!strcmp(arg, "--no-minimal"))
4626                DIFF_XDL_CLR(options, NEED_MINIMAL);
4627        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
4628                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
4629        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
4630                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
4631        else if (!strcmp(arg, "--ignore-space-at-eol"))
4632                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
4633        else if (!strcmp(arg, "--ignore-cr-at-eol"))
4634                DIFF_XDL_SET(options, IGNORE_CR_AT_EOL);
4635        else if (!strcmp(arg, "--ignore-blank-lines"))
4636                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
4637        else if (!strcmp(arg, "--indent-heuristic"))
4638                DIFF_XDL_SET(options, INDENT_HEURISTIC);
4639        else if (!strcmp(arg, "--no-indent-heuristic"))
4640                DIFF_XDL_CLR(options, INDENT_HEURISTIC);
4641        else if (!strcmp(arg, "--patience")) {
4642                int i;
4643                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4644                /*
4645                 * Both --patience and --anchored use PATIENCE_DIFF
4646                 * internally, so remove any anchors previously
4647                 * specified.
4648                 */
4649                for (i = 0; i < options->anchors_nr; i++)
4650                        free(options->anchors[i]);
4651                options->anchors_nr = 0;
4652        } else if (!strcmp(arg, "--histogram"))
4653                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
4654        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
4655                long value = parse_algorithm_value(optarg);
4656                if (value < 0)
4657                        return error("option diff-algorithm accepts \"myers\", "
4658                                     "\"minimal\", \"patience\" and \"histogram\"");
4659                /* clear out previous settings */
4660                DIFF_XDL_CLR(options, NEED_MINIMAL);
4661                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
4662                options->xdl_opts |= value;
4663                return argcount;
4664        } else if (skip_prefix(arg, "--anchored=", &arg)) {
4665                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
4666                ALLOC_GROW(options->anchors, options->anchors_nr + 1,
4667                           options->anchors_alloc);
4668                options->anchors[options->anchors_nr++] = xstrdup(arg);
4669        }
4670
4671        /* flags options */
4672        else if (!strcmp(arg, "--binary")) {
4673                enable_patch_output(&options->output_format);
4674                options->flags.binary = 1;
4675        }
4676        else if (!strcmp(arg, "--full-index"))
4677                options->flags.full_index = 1;
4678        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
4679                options->flags.text = 1;
4680        else if (!strcmp(arg, "-R"))
4681                options->flags.reverse_diff = 1;
4682        else if (!strcmp(arg, "--find-copies-harder"))
4683                options->flags.find_copies_harder = 1;
4684        else if (!strcmp(arg, "--follow"))
4685                options->flags.follow_renames = 1;
4686        else if (!strcmp(arg, "--no-follow")) {
4687                options->flags.follow_renames = 0;
4688                options->flags.default_follow_renames = 0;
4689        } else if (skip_to_optional_arg_default(arg, "--color", &arg, "always")) {
4690                int value = git_config_colorbool(NULL, arg);
4691                if (value < 0)
4692                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
4693                options->use_color = value;
4694        }
4695        else if (!strcmp(arg, "--no-color"))
4696                options->use_color = 0;
4697        else if (!strcmp(arg, "--color-moved")) {
4698                if (diff_color_moved_default)
4699                        options->color_moved = diff_color_moved_default;
4700                if (options->color_moved == COLOR_MOVED_NO)
4701                        options->color_moved = COLOR_MOVED_DEFAULT;
4702        } else if (!strcmp(arg, "--no-color-moved"))
4703                options->color_moved = COLOR_MOVED_NO;
4704        else if (skip_prefix(arg, "--color-moved=", &arg)) {
4705                int cm = parse_color_moved(arg);
4706                if (cm < 0)
4707                        die("bad --color-moved argument: %s", arg);
4708                options->color_moved = cm;
4709        } else if (skip_to_optional_arg_default(arg, "--color-words", &options->word_regex, NULL)) {
4710                options->use_color = 1;
4711                options->word_diff = DIFF_WORDS_COLOR;
4712        }
4713        else if (!strcmp(arg, "--word-diff")) {
4714                if (options->word_diff == DIFF_WORDS_NONE)
4715                        options->word_diff = DIFF_WORDS_PLAIN;
4716        }
4717        else if (skip_prefix(arg, "--word-diff=", &arg)) {
4718                if (!strcmp(arg, "plain"))
4719                        options->word_diff = DIFF_WORDS_PLAIN;
4720                else if (!strcmp(arg, "color")) {
4721                        options->use_color = 1;
4722                        options->word_diff = DIFF_WORDS_COLOR;
4723                }
4724                else if (!strcmp(arg, "porcelain"))
4725                        options->word_diff = DIFF_WORDS_PORCELAIN;
4726                else if (!strcmp(arg, "none"))
4727                        options->word_diff = DIFF_WORDS_NONE;
4728                else
4729                        die("bad --word-diff argument: %s", arg);
4730        }
4731        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
4732                if (options->word_diff == DIFF_WORDS_NONE)
4733                        options->word_diff = DIFF_WORDS_PLAIN;
4734                options->word_regex = optarg;
4735                return argcount;
4736        }
4737        else if (!strcmp(arg, "--exit-code"))
4738                options->flags.exit_with_status = 1;
4739        else if (!strcmp(arg, "--quiet"))
4740                options->flags.quick = 1;
4741        else if (!strcmp(arg, "--ext-diff"))
4742                options->flags.allow_external = 1;
4743        else if (!strcmp(arg, "--no-ext-diff"))
4744                options->flags.allow_external = 0;
4745        else if (!strcmp(arg, "--textconv")) {
4746                options->flags.allow_textconv = 1;
4747                options->flags.textconv_set_via_cmdline = 1;
4748        } else if (!strcmp(arg, "--no-textconv"))
4749                options->flags.allow_textconv = 0;
4750        else if (skip_to_optional_arg_default(arg, "--ignore-submodules", &arg, "all")) {
4751                options->flags.override_submodule_config = 1;
4752                handle_ignore_submodules_arg(options, arg);
4753        } else if (skip_to_optional_arg_default(arg, "--submodule", &arg, "log"))
4754                return parse_submodule_opt(options, arg);
4755        else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
4756                return parse_ws_error_highlight_opt(options, arg);
4757        else if (!strcmp(arg, "--ita-invisible-in-index"))
4758                options->ita_invisible_in_index = 1;
4759        else if (!strcmp(arg, "--ita-visible-in-index"))
4760                options->ita_invisible_in_index = 0;
4761
4762        /* misc options */
4763        else if (!strcmp(arg, "-z"))
4764                options->line_termination = 0;
4765        else if ((argcount = short_opt('l', av, &optarg))) {
4766                options->rename_limit = strtoul(optarg, NULL, 10);
4767                return argcount;
4768        }
4769        else if ((argcount = short_opt('S', av, &optarg))) {
4770                options->pickaxe = optarg;
4771                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
4772                return argcount;
4773        } else if ((argcount = short_opt('G', av, &optarg))) {
4774                options->pickaxe = optarg;
4775                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
4776                return argcount;
4777        }
4778        else if (!strcmp(arg, "--pickaxe-all"))
4779                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
4780        else if (!strcmp(arg, "--pickaxe-regex"))
4781                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
4782        else if ((argcount = short_opt('O', av, &optarg))) {
4783                options->orderfile = prefix_filename(prefix, optarg);
4784                return argcount;
4785        } else if (skip_prefix(arg, "--find-object=", &arg))
4786                return parse_objfind_opt(options, arg);
4787        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
4788                int offending = parse_diff_filter_opt(optarg, options);
4789                if (offending)
4790                        die("unknown change class '%c' in --diff-filter=%s",
4791                            offending, optarg);
4792                return argcount;
4793        }
4794        else if (!strcmp(arg, "--no-abbrev"))
4795                options->abbrev = 0;
4796        else if (!strcmp(arg, "--abbrev"))
4797                options->abbrev = DEFAULT_ABBREV;
4798        else if (skip_prefix(arg, "--abbrev=", &arg)) {
4799                options->abbrev = strtoul(arg, NULL, 10);
4800                if (options->abbrev < MINIMUM_ABBREV)
4801                        options->abbrev = MINIMUM_ABBREV;
4802                else if (40 < options->abbrev)
4803                        options->abbrev = 40;
4804        }
4805        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
4806                options->a_prefix = optarg;
4807                return argcount;
4808        }
4809        else if ((argcount = parse_long_opt("line-prefix", av, &optarg))) {
4810                options->line_prefix = optarg;
4811                options->line_prefix_length = strlen(options->line_prefix);
4812                graph_setup_line_prefix(options);
4813                return argcount;
4814        }
4815        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
4816                options->b_prefix = optarg;
4817                return argcount;
4818        }
4819        else if (!strcmp(arg, "--no-prefix"))
4820                options->a_prefix = options->b_prefix = "";
4821        else if (opt_arg(arg, '\0', "inter-hunk-context",
4822                         &options->interhunkcontext))
4823                ;
4824        else if (!strcmp(arg, "-W"))
4825                options->flags.funccontext = 1;
4826        else if (!strcmp(arg, "--function-context"))
4827                options->flags.funccontext = 1;
4828        else if (!strcmp(arg, "--no-function-context"))
4829                options->flags.funccontext = 0;
4830        else if ((argcount = parse_long_opt("output", av, &optarg))) {
4831                char *path = prefix_filename(prefix, optarg);
4832                options->file = xfopen(path, "w");
4833                options->close_file = 1;
4834                if (options->use_color != GIT_COLOR_ALWAYS)
4835                        options->use_color = GIT_COLOR_NEVER;
4836                free(path);
4837                return argcount;
4838        } else
4839                return 0;
4840        return 1;
4841}
4842
4843int parse_rename_score(const char **cp_p)
4844{
4845        unsigned long num, scale;
4846        int ch, dot;
4847        const char *cp = *cp_p;
4848
4849        num = 0;
4850        scale = 1;
4851        dot = 0;
4852        for (;;) {
4853                ch = *cp;
4854                if ( !dot && ch == '.' ) {
4855                        scale = 1;
4856                        dot = 1;
4857                } else if ( ch == '%' ) {
4858                        scale = dot ? scale*100 : 100;
4859                        cp++;   /* % is always at the end */
4860                        break;
4861                } else if ( ch >= '0' && ch <= '9' ) {
4862                        if ( scale < 100000 ) {
4863                                scale *= 10;
4864                                num = (num*10) + (ch-'0');
4865                        }
4866                } else {
4867                        break;
4868                }
4869                cp++;
4870        }
4871        *cp_p = cp;
4872
4873        /* user says num divided by scale and we say internally that
4874         * is MAX_SCORE * num / scale.
4875         */
4876        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
4877}
4878
4879static int diff_scoreopt_parse(const char *opt)
4880{
4881        int opt1, opt2, cmd;
4882
4883        if (*opt++ != '-')
4884                return -1;
4885        cmd = *opt++;
4886        if (cmd == '-') {
4887                /* convert the long-form arguments into short-form versions */
4888                if (skip_prefix(opt, "break-rewrites", &opt)) {
4889                        if (*opt == 0 || *opt++ == '=')
4890                                cmd = 'B';
4891                } else if (skip_prefix(opt, "find-copies", &opt)) {
4892                        if (*opt == 0 || *opt++ == '=')
4893                                cmd = 'C';
4894                } else if (skip_prefix(opt, "find-renames", &opt)) {
4895                        if (*opt == 0 || *opt++ == '=')
4896                                cmd = 'M';
4897                }
4898        }
4899        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
4900                return -1; /* that is not a -M, -C, or -B option */
4901
4902        opt1 = parse_rename_score(&opt);
4903        if (cmd != 'B')
4904                opt2 = 0;
4905        else {
4906                if (*opt == 0)
4907                        opt2 = 0;
4908                else if (*opt != '/')
4909                        return -1; /* we expect -B80/99 or -B80 */
4910                else {
4911                        opt++;
4912                        opt2 = parse_rename_score(&opt);
4913                }
4914        }
4915        if (*opt != 0)
4916                return -1;
4917        return opt1 | (opt2 << 16);
4918}
4919
4920struct diff_queue_struct diff_queued_diff;
4921
4922void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
4923{
4924        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
4925        queue->queue[queue->nr++] = dp;
4926}
4927
4928struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
4929                                 struct diff_filespec *one,
4930                                 struct diff_filespec *two)
4931{
4932        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
4933        dp->one = one;
4934        dp->two = two;
4935        if (queue)
4936                diff_q(queue, dp);
4937        return dp;
4938}
4939
4940void diff_free_filepair(struct diff_filepair *p)
4941{
4942        free_filespec(p->one);
4943        free_filespec(p->two);
4944        free(p);
4945}
4946
4947const char *diff_aligned_abbrev(const struct object_id *oid, int len)
4948{
4949        int abblen;
4950        const char *abbrev;
4951
4952        /* Do we want all 40 hex characters? */
4953        if (len == GIT_SHA1_HEXSZ)
4954                return oid_to_hex(oid);
4955
4956        /* An abbreviated value is fine, possibly followed by an ellipsis. */
4957        abbrev = diff_abbrev_oid(oid, len);
4958
4959        if (!print_sha1_ellipsis())
4960                return abbrev;
4961
4962        abblen = strlen(abbrev);
4963
4964        /*
4965         * In well-behaved cases, where the abbreviated result is the
4966         * same as the requested length, append three dots after the
4967         * abbreviation (hence the whole logic is limited to the case
4968         * where abblen < 37); when the actual abbreviated result is a
4969         * bit longer than the requested length, we reduce the number
4970         * of dots so that they match the well-behaved ones.  However,
4971         * if the actual abbreviation is longer than the requested
4972         * length by more than three, we give up on aligning, and add
4973         * three dots anyway, to indicate that the output is not the
4974         * full object name.  Yes, this may be suboptimal, but this
4975         * appears only in "diff --raw --abbrev" output and it is not
4976         * worth the effort to change it now.  Note that this would
4977         * likely to work fine when the automatic sizing of default
4978         * abbreviation length is used--we would be fed -1 in "len" in
4979         * that case, and will end up always appending three-dots, but
4980         * the automatic sizing is supposed to give abblen that ensures
4981         * uniqueness across all objects (statistically speaking).
4982         */
4983        if (abblen < GIT_SHA1_HEXSZ - 3) {
4984                static char hex[GIT_MAX_HEXSZ + 1];
4985                if (len < abblen && abblen <= len + 2)
4986                        xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
4987                else
4988                        xsnprintf(hex, sizeof(hex), "%s...", abbrev);
4989                return hex;
4990        }
4991
4992        return oid_to_hex(oid);
4993}
4994
4995static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
4996{
4997        int line_termination = opt->line_termination;
4998        int inter_name_termination = line_termination ? '\t' : '\0';
4999
5000        fprintf(opt->file, "%s", diff_line_prefix(opt));
5001        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
5002                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
5003                        diff_aligned_abbrev(&p->one->oid, opt->abbrev));
5004                fprintf(opt->file, "%s ",
5005                        diff_aligned_abbrev(&p->two->oid, opt->abbrev));
5006        }
5007        if (p->score) {
5008                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
5009                        inter_name_termination);
5010        } else {
5011                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
5012        }
5013
5014        if (p->status == DIFF_STATUS_COPIED ||
5015            p->status == DIFF_STATUS_RENAMED) {
5016                const char *name_a, *name_b;
5017                name_a = p->one->path;
5018                name_b = p->two->path;
5019                strip_prefix(opt->prefix_length, &name_a, &name_b);
5020                write_name_quoted(name_a, opt->file, inter_name_termination);
5021                write_name_quoted(name_b, opt->file, line_termination);
5022        } else {
5023                const char *name_a, *name_b;
5024                name_a = p->one->mode ? p->one->path : p->two->path;
5025                name_b = NULL;
5026                strip_prefix(opt->prefix_length, &name_a, &name_b);
5027                write_name_quoted(name_a, opt->file, line_termination);
5028        }
5029}
5030
5031int diff_unmodified_pair(struct diff_filepair *p)
5032{
5033        /* This function is written stricter than necessary to support
5034         * the currently implemented transformers, but the idea is to
5035         * let transformers to produce diff_filepairs any way they want,
5036         * and filter and clean them up here before producing the output.
5037         */
5038        struct diff_filespec *one = p->one, *two = p->two;
5039
5040        if (DIFF_PAIR_UNMERGED(p))
5041                return 0; /* unmerged is interesting */
5042
5043        /* deletion, addition, mode or type change
5044         * and rename are all interesting.
5045         */
5046        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
5047            DIFF_PAIR_MODE_CHANGED(p) ||
5048            strcmp(one->path, two->path))
5049                return 0;
5050
5051        /* both are valid and point at the same path.  that is, we are
5052         * dealing with a change.
5053         */
5054        if (one->oid_valid && two->oid_valid &&
5055            !oidcmp(&one->oid, &two->oid) &&
5056            !one->dirty_submodule && !two->dirty_submodule)
5057                return 1; /* no change */
5058        if (!one->oid_valid && !two->oid_valid)
5059                return 1; /* both look at the same file on the filesystem. */
5060        return 0;
5061}
5062
5063static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
5064{
5065        if (diff_unmodified_pair(p))
5066                return;
5067
5068        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5069            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5070                return; /* no tree diffs in patch format */
5071
5072        run_diff(p, o);
5073}
5074
5075static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
5076                            struct diffstat_t *diffstat)
5077{
5078        if (diff_unmodified_pair(p))
5079                return;
5080
5081        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5082            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5083                return; /* no useful stat for tree diffs */
5084
5085        run_diffstat(p, o, diffstat);
5086}
5087
5088static void diff_flush_checkdiff(struct diff_filepair *p,
5089                struct diff_options *o)
5090{
5091        if (diff_unmodified_pair(p))
5092                return;
5093
5094        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5095            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5096                return; /* nothing to check in tree diffs */
5097
5098        run_checkdiff(p, o);
5099}
5100
5101int diff_queue_is_empty(void)
5102{
5103        struct diff_queue_struct *q = &diff_queued_diff;
5104        int i;
5105        for (i = 0; i < q->nr; i++)
5106                if (!diff_unmodified_pair(q->queue[i]))
5107                        return 0;
5108        return 1;
5109}
5110
5111#if DIFF_DEBUG
5112void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
5113{
5114        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
5115                x, one ? one : "",
5116                s->path,
5117                DIFF_FILE_VALID(s) ? "valid" : "invalid",
5118                s->mode,
5119                s->oid_valid ? oid_to_hex(&s->oid) : "");
5120        fprintf(stderr, "queue[%d] %s size %lu\n",
5121                x, one ? one : "",
5122                s->size);
5123}
5124
5125void diff_debug_filepair(const struct diff_filepair *p, int i)
5126{
5127        diff_debug_filespec(p->one, i, "one");
5128        diff_debug_filespec(p->two, i, "two");
5129        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
5130                p->score, p->status ? p->status : '?',
5131                p->one->rename_used, p->broken_pair);
5132}
5133
5134void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
5135{
5136        int i;
5137        if (msg)
5138                fprintf(stderr, "%s\n", msg);
5139        fprintf(stderr, "q->nr = %d\n", q->nr);
5140        for (i = 0; i < q->nr; i++) {
5141                struct diff_filepair *p = q->queue[i];
5142                diff_debug_filepair(p, i);
5143        }
5144}
5145#endif
5146
5147static void diff_resolve_rename_copy(void)
5148{
5149        int i;
5150        struct diff_filepair *p;
5151        struct diff_queue_struct *q = &diff_queued_diff;
5152
5153        diff_debug_queue("resolve-rename-copy", q);
5154
5155        for (i = 0; i < q->nr; i++) {
5156                p = q->queue[i];
5157                p->status = 0; /* undecided */
5158                if (DIFF_PAIR_UNMERGED(p))
5159                        p->status = DIFF_STATUS_UNMERGED;
5160                else if (!DIFF_FILE_VALID(p->one))
5161                        p->status = DIFF_STATUS_ADDED;
5162                else if (!DIFF_FILE_VALID(p->two))
5163                        p->status = DIFF_STATUS_DELETED;
5164                else if (DIFF_PAIR_TYPE_CHANGED(p))
5165                        p->status = DIFF_STATUS_TYPE_CHANGED;
5166
5167                /* from this point on, we are dealing with a pair
5168                 * whose both sides are valid and of the same type, i.e.
5169                 * either in-place edit or rename/copy edit.
5170                 */
5171                else if (DIFF_PAIR_RENAME(p)) {
5172                        /*
5173                         * A rename might have re-connected a broken
5174                         * pair up, causing the pathnames to be the
5175                         * same again. If so, that's not a rename at
5176                         * all, just a modification..
5177                         *
5178                         * Otherwise, see if this source was used for
5179                         * multiple renames, in which case we decrement
5180                         * the count, and call it a copy.
5181                         */
5182                        if (!strcmp(p->one->path, p->two->path))
5183                                p->status = DIFF_STATUS_MODIFIED;
5184                        else if (--p->one->rename_used > 0)
5185                                p->status = DIFF_STATUS_COPIED;
5186                        else
5187                                p->status = DIFF_STATUS_RENAMED;
5188                }
5189                else if (oidcmp(&p->one->oid, &p->two->oid) ||
5190                         p->one->mode != p->two->mode ||
5191                         p->one->dirty_submodule ||
5192                         p->two->dirty_submodule ||
5193                         is_null_oid(&p->one->oid))
5194                        p->status = DIFF_STATUS_MODIFIED;
5195                else {
5196                        /* This is a "no-change" entry and should not
5197                         * happen anymore, but prepare for broken callers.
5198                         */
5199                        error("feeding unmodified %s to diffcore",
5200                              p->one->path);
5201                        p->status = DIFF_STATUS_UNKNOWN;
5202                }
5203        }
5204        diff_debug_queue("resolve-rename-copy done", q);
5205}
5206
5207static int check_pair_status(struct diff_filepair *p)
5208{
5209        switch (p->status) {
5210        case DIFF_STATUS_UNKNOWN:
5211                return 0;
5212        case 0:
5213                die("internal error in diff-resolve-rename-copy");
5214        default:
5215                return 1;
5216        }
5217}
5218
5219static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
5220{
5221        int fmt = opt->output_format;
5222
5223        if (fmt & DIFF_FORMAT_CHECKDIFF)
5224                diff_flush_checkdiff(p, opt);
5225        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
5226                diff_flush_raw(p, opt);
5227        else if (fmt & DIFF_FORMAT_NAME) {
5228                const char *name_a, *name_b;
5229                name_a = p->two->path;
5230                name_b = NULL;
5231                strip_prefix(opt->prefix_length, &name_a, &name_b);
5232                fprintf(opt->file, "%s", diff_line_prefix(opt));
5233                write_name_quoted(name_a, opt->file, opt->line_termination);
5234        }
5235}
5236
5237static void show_file_mode_name(struct diff_options *opt, const char *newdelete, struct diff_filespec *fs)
5238{
5239        struct strbuf sb = STRBUF_INIT;
5240        if (fs->mode)
5241                strbuf_addf(&sb, " %s mode %06o ", newdelete, fs->mode);
5242        else
5243                strbuf_addf(&sb, " %s ", newdelete);
5244
5245        quote_c_style(fs->path, &sb, NULL, 0);
5246        strbuf_addch(&sb, '\n');
5247        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5248                         sb.buf, sb.len, 0);
5249        strbuf_release(&sb);
5250}
5251
5252static void show_mode_change(struct diff_options *opt, struct diff_filepair *p,
5253                int show_name)
5254{
5255        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
5256                struct strbuf sb = STRBUF_INIT;
5257                strbuf_addf(&sb, " mode change %06o => %06o",
5258                            p->one->mode, p->two->mode);
5259                if (show_name) {
5260                        strbuf_addch(&sb, ' ');
5261                        quote_c_style(p->two->path, &sb, NULL, 0);
5262                }
5263                strbuf_addch(&sb, '\n');
5264                emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5265                                 sb.buf, sb.len, 0);
5266                strbuf_release(&sb);
5267        }
5268}
5269
5270static void show_rename_copy(struct diff_options *opt, const char *renamecopy,
5271                struct diff_filepair *p)
5272{
5273        struct strbuf sb = STRBUF_INIT;
5274        struct strbuf names = STRBUF_INIT;
5275
5276        pprint_rename(&names, p->one->path, p->two->path);
5277        strbuf_addf(&sb, " %s %s (%d%%)\n",
5278                    renamecopy, names.buf, similarity_index(p));
5279        strbuf_release(&names);
5280        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5281                                 sb.buf, sb.len, 0);
5282        show_mode_change(opt, p, 0);
5283        strbuf_release(&sb);
5284}
5285
5286static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
5287{
5288        switch(p->status) {
5289        case DIFF_STATUS_DELETED:
5290                show_file_mode_name(opt, "delete", p->one);
5291                break;
5292        case DIFF_STATUS_ADDED:
5293                show_file_mode_name(opt, "create", p->two);
5294                break;
5295        case DIFF_STATUS_COPIED:
5296                show_rename_copy(opt, "copy", p);
5297                break;
5298        case DIFF_STATUS_RENAMED:
5299                show_rename_copy(opt, "rename", p);
5300                break;
5301        default:
5302                if (p->score) {
5303                        struct strbuf sb = STRBUF_INIT;
5304                        strbuf_addstr(&sb, " rewrite ");
5305                        quote_c_style(p->two->path, &sb, NULL, 0);
5306                        strbuf_addf(&sb, " (%d%%)\n", similarity_index(p));
5307                        emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
5308                                         sb.buf, sb.len, 0);
5309                        strbuf_release(&sb);
5310                }
5311                show_mode_change(opt, p, !p->score);
5312                break;
5313        }
5314}
5315
5316struct patch_id_t {
5317        git_SHA_CTX *ctx;
5318        int patchlen;
5319};
5320
5321static int remove_space(char *line, int len)
5322{
5323        int i;
5324        char *dst = line;
5325        unsigned char c;
5326
5327        for (i = 0; i < len; i++)
5328                if (!isspace((c = line[i])))
5329                        *dst++ = c;
5330
5331        return dst - line;
5332}
5333
5334static void patch_id_consume(void *priv, char *line, unsigned long len)
5335{
5336        struct patch_id_t *data = priv;
5337        int new_len;
5338
5339        /* Ignore line numbers when computing the SHA1 of the patch */
5340        if (starts_with(line, "@@ -"))
5341                return;
5342
5343        new_len = remove_space(line, len);
5344
5345        git_SHA1_Update(data->ctx, line, new_len);
5346        data->patchlen += new_len;
5347}
5348
5349static void patch_id_add_string(git_SHA_CTX *ctx, const char *str)
5350{
5351        git_SHA1_Update(ctx, str, strlen(str));
5352}
5353
5354static void patch_id_add_mode(git_SHA_CTX *ctx, unsigned mode)
5355{
5356        /* large enough for 2^32 in octal */
5357        char buf[12];
5358        int len = xsnprintf(buf, sizeof(buf), "%06o", mode);
5359        git_SHA1_Update(ctx, buf, len);
5360}
5361
5362/* returns 0 upon success, and writes result into sha1 */
5363static int diff_get_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5364{
5365        struct diff_queue_struct *q = &diff_queued_diff;
5366        int i;
5367        git_SHA_CTX ctx;
5368        struct patch_id_t data;
5369
5370        git_SHA1_Init(&ctx);
5371        memset(&data, 0, sizeof(struct patch_id_t));
5372        data.ctx = &ctx;
5373
5374        for (i = 0; i < q->nr; i++) {
5375                xpparam_t xpp;
5376                xdemitconf_t xecfg;
5377                mmfile_t mf1, mf2;
5378                struct diff_filepair *p = q->queue[i];
5379                int len1, len2;
5380
5381                memset(&xpp, 0, sizeof(xpp));
5382                memset(&xecfg, 0, sizeof(xecfg));
5383                if (p->status == 0)
5384                        return error("internal diff status error");
5385                if (p->status == DIFF_STATUS_UNKNOWN)
5386                        continue;
5387                if (diff_unmodified_pair(p))
5388                        continue;
5389                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
5390                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
5391                        continue;
5392                if (DIFF_PAIR_UNMERGED(p))
5393                        continue;
5394
5395                diff_fill_oid_info(p->one);
5396                diff_fill_oid_info(p->two);
5397
5398                len1 = remove_space(p->one->path, strlen(p->one->path));
5399                len2 = remove_space(p->two->path, strlen(p->two->path));
5400                patch_id_add_string(&ctx, "diff--git");
5401                patch_id_add_string(&ctx, "a/");
5402                git_SHA1_Update(&ctx, p->one->path, len1);
5403                patch_id_add_string(&ctx, "b/");
5404                git_SHA1_Update(&ctx, p->two->path, len2);
5405
5406                if (p->one->mode == 0) {
5407                        patch_id_add_string(&ctx, "newfilemode");
5408                        patch_id_add_mode(&ctx, p->two->mode);
5409                        patch_id_add_string(&ctx, "---/dev/null");
5410                        patch_id_add_string(&ctx, "+++b/");
5411                        git_SHA1_Update(&ctx, p->two->path, len2);
5412                } else if (p->two->mode == 0) {
5413                        patch_id_add_string(&ctx, "deletedfilemode");
5414                        patch_id_add_mode(&ctx, p->one->mode);
5415                        patch_id_add_string(&ctx, "---a/");
5416                        git_SHA1_Update(&ctx, p->one->path, len1);
5417                        patch_id_add_string(&ctx, "+++/dev/null");
5418                } else {
5419                        patch_id_add_string(&ctx, "---a/");
5420                        git_SHA1_Update(&ctx, p->one->path, len1);
5421                        patch_id_add_string(&ctx, "+++b/");
5422                        git_SHA1_Update(&ctx, p->two->path, len2);
5423                }
5424
5425                if (diff_header_only)
5426                        continue;
5427
5428                if (fill_mmfile(&mf1, p->one) < 0 ||
5429                    fill_mmfile(&mf2, p->two) < 0)
5430                        return error("unable to read files to diff");
5431
5432                if (diff_filespec_is_binary(p->one) ||
5433                    diff_filespec_is_binary(p->two)) {
5434                        git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
5435                                        GIT_SHA1_HEXSZ);
5436                        git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
5437                                        GIT_SHA1_HEXSZ);
5438                        continue;
5439                }
5440
5441                xpp.flags = 0;
5442                xecfg.ctxlen = 3;
5443                xecfg.flags = 0;
5444                if (xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
5445                                  &xpp, &xecfg))
5446                        return error("unable to generate patch-id diff for %s",
5447                                     p->one->path);
5448        }
5449
5450        git_SHA1_Final(oid->hash, &ctx);
5451        return 0;
5452}
5453
5454int diff_flush_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
5455{
5456        struct diff_queue_struct *q = &diff_queued_diff;
5457        int i;
5458        int result = diff_get_patch_id(options, oid, diff_header_only);
5459
5460        for (i = 0; i < q->nr; i++)
5461                diff_free_filepair(q->queue[i]);
5462
5463        free(q->queue);
5464        DIFF_QUEUE_CLEAR(q);
5465
5466        return result;
5467}
5468
5469static int is_summary_empty(const struct diff_queue_struct *q)
5470{
5471        int i;
5472
5473        for (i = 0; i < q->nr; i++) {
5474                const struct diff_filepair *p = q->queue[i];
5475
5476                switch (p->status) {
5477                case DIFF_STATUS_DELETED:
5478                case DIFF_STATUS_ADDED:
5479                case DIFF_STATUS_COPIED:
5480                case DIFF_STATUS_RENAMED:
5481                        return 0;
5482                default:
5483                        if (p->score)
5484                                return 0;
5485                        if (p->one->mode && p->two->mode &&
5486                            p->one->mode != p->two->mode)
5487                                return 0;
5488                        break;
5489                }
5490        }
5491        return 1;
5492}
5493
5494static const char rename_limit_warning[] =
5495N_("inexact rename detection was skipped due to too many files.");
5496
5497static const char degrade_cc_to_c_warning[] =
5498N_("only found copies from modified paths due to too many files.");
5499
5500static const char rename_limit_advice[] =
5501N_("you may want to set your %s variable to at least "
5502   "%d and retry the command.");
5503
5504void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
5505{
5506        fflush(stdout);
5507        if (degraded_cc)
5508                warning(_(degrade_cc_to_c_warning));
5509        else if (needed)
5510                warning(_(rename_limit_warning));
5511        else
5512                return;
5513        if (0 < needed)
5514                warning(_(rename_limit_advice), varname, needed);
5515}
5516
5517static void diff_flush_patch_all_file_pairs(struct diff_options *o)
5518{
5519        int i;
5520        static struct emitted_diff_symbols esm = EMITTED_DIFF_SYMBOLS_INIT;
5521        struct diff_queue_struct *q = &diff_queued_diff;
5522
5523        if (WSEH_NEW & WS_RULE_MASK)
5524                die("BUG: WS rules bit mask overlaps with diff symbol flags");
5525
5526        if (o->color_moved)
5527                o->emitted_symbols = &esm;
5528
5529        for (i = 0; i < q->nr; i++) {
5530                struct diff_filepair *p = q->queue[i];
5531                if (check_pair_status(p))
5532                        diff_flush_patch(p, o);
5533        }
5534
5535        if (o->emitted_symbols) {
5536                if (o->color_moved) {
5537                        struct hashmap add_lines, del_lines;
5538
5539                        hashmap_init(&del_lines,
5540                                     (hashmap_cmp_fn)moved_entry_cmp, o, 0);
5541                        hashmap_init(&add_lines,
5542                                     (hashmap_cmp_fn)moved_entry_cmp, o, 0);
5543
5544                        add_lines_to_move_detection(o, &add_lines, &del_lines);
5545                        mark_color_as_moved(o, &add_lines, &del_lines);
5546                        if (o->color_moved == COLOR_MOVED_ZEBRA_DIM)
5547                                dim_moved_lines(o);
5548
5549                        hashmap_free(&add_lines, 0);
5550                        hashmap_free(&del_lines, 0);
5551                }
5552
5553                for (i = 0; i < esm.nr; i++)
5554                        emit_diff_symbol_from_struct(o, &esm.buf[i]);
5555
5556                for (i = 0; i < esm.nr; i++)
5557                        free((void *)esm.buf[i].line);
5558        }
5559        esm.nr = 0;
5560}
5561
5562void diff_flush(struct diff_options *options)
5563{
5564        struct diff_queue_struct *q = &diff_queued_diff;
5565        int i, output_format = options->output_format;
5566        int separator = 0;
5567        int dirstat_by_line = 0;
5568
5569        /*
5570         * Order: raw, stat, summary, patch
5571         * or:    name/name-status/checkdiff (other bits clear)
5572         */
5573        if (!q->nr)
5574                goto free_queue;
5575
5576        if (output_format & (DIFF_FORMAT_RAW |
5577                             DIFF_FORMAT_NAME |
5578                             DIFF_FORMAT_NAME_STATUS |
5579                             DIFF_FORMAT_CHECKDIFF)) {
5580                for (i = 0; i < q->nr; i++) {
5581                        struct diff_filepair *p = q->queue[i];
5582                        if (check_pair_status(p))
5583                                flush_one_pair(p, options);
5584                }
5585                separator++;
5586        }
5587
5588        if (output_format & DIFF_FORMAT_DIRSTAT && options->flags.dirstat_by_line)
5589                dirstat_by_line = 1;
5590
5591        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
5592            dirstat_by_line) {
5593                struct diffstat_t diffstat;
5594
5595                memset(&diffstat, 0, sizeof(struct diffstat_t));
5596                for (i = 0; i < q->nr; i++) {
5597                        struct diff_filepair *p = q->queue[i];
5598                        if (check_pair_status(p))
5599                                diff_flush_stat(p, options, &diffstat);
5600                }
5601                if (output_format & DIFF_FORMAT_NUMSTAT)
5602                        show_numstat(&diffstat, options);
5603                if (output_format & DIFF_FORMAT_DIFFSTAT)
5604                        show_stats(&diffstat, options);
5605                if (output_format & DIFF_FORMAT_SHORTSTAT)
5606                        show_shortstats(&diffstat, options);
5607                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
5608                        show_dirstat_by_line(&diffstat, options);
5609                free_diffstat_info(&diffstat);
5610                separator++;
5611        }
5612        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
5613                show_dirstat(options);
5614
5615        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
5616                for (i = 0; i < q->nr; i++) {
5617                        diff_summary(options, q->queue[i]);
5618                }
5619                separator++;
5620        }
5621
5622        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
5623            options->flags.exit_with_status &&
5624            options->flags.diff_from_contents) {
5625                /*
5626                 * run diff_flush_patch for the exit status. setting
5627                 * options->file to /dev/null should be safe, because we
5628                 * aren't supposed to produce any output anyway.
5629                 */
5630                if (options->close_file)
5631                        fclose(options->file);
5632                options->file = xfopen("/dev/null", "w");
5633                options->close_file = 1;
5634                options->color_moved = 0;
5635                for (i = 0; i < q->nr; i++) {
5636                        struct diff_filepair *p = q->queue[i];
5637                        if (check_pair_status(p))
5638                                diff_flush_patch(p, options);
5639                        if (options->found_changes)
5640                                break;
5641                }
5642        }
5643
5644        if (output_format & DIFF_FORMAT_PATCH) {
5645                if (separator) {
5646                        emit_diff_symbol(options, DIFF_SYMBOL_SEPARATOR, NULL, 0, 0);
5647                        if (options->stat_sep)
5648                                /* attach patch instead of inline */
5649                                emit_diff_symbol(options, DIFF_SYMBOL_STAT_SEP,
5650                                                 NULL, 0, 0);
5651                }
5652
5653                diff_flush_patch_all_file_pairs(options);
5654        }
5655
5656        if (output_format & DIFF_FORMAT_CALLBACK)
5657                options->format_callback(q, options, options->format_callback_data);
5658
5659        for (i = 0; i < q->nr; i++)
5660                diff_free_filepair(q->queue[i]);
5661free_queue:
5662        free(q->queue);
5663        DIFF_QUEUE_CLEAR(q);
5664        if (options->close_file)
5665                fclose(options->file);
5666
5667        /*
5668         * Report the content-level differences with HAS_CHANGES;
5669         * diff_addremove/diff_change does not set the bit when
5670         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
5671         */
5672        if (options->flags.diff_from_contents) {
5673                if (options->found_changes)
5674                        options->flags.has_changes = 1;
5675                else
5676                        options->flags.has_changes = 0;
5677        }
5678}
5679
5680static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
5681{
5682        return (((p->status == DIFF_STATUS_MODIFIED) &&
5683                 ((p->score &&
5684                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
5685                  (!p->score &&
5686                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
5687                ((p->status != DIFF_STATUS_MODIFIED) &&
5688                 filter_bit_tst(p->status, options)));
5689}
5690
5691static void diffcore_apply_filter(struct diff_options *options)
5692{
5693        int i;
5694        struct diff_queue_struct *q = &diff_queued_diff;
5695        struct diff_queue_struct outq;
5696
5697        DIFF_QUEUE_CLEAR(&outq);
5698
5699        if (!options->filter)
5700                return;
5701
5702        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
5703                int found;
5704                for (i = found = 0; !found && i < q->nr; i++) {
5705                        if (match_filter(options, q->queue[i]))
5706                                found++;
5707                }
5708                if (found)
5709                        return;
5710
5711                /* otherwise we will clear the whole queue
5712                 * by copying the empty outq at the end of this
5713                 * function, but first clear the current entries
5714                 * in the queue.
5715                 */
5716                for (i = 0; i < q->nr; i++)
5717                        diff_free_filepair(q->queue[i]);
5718        }
5719        else {
5720                /* Only the matching ones */
5721                for (i = 0; i < q->nr; i++) {
5722                        struct diff_filepair *p = q->queue[i];
5723                        if (match_filter(options, p))
5724                                diff_q(&outq, p);
5725                        else
5726                                diff_free_filepair(p);
5727                }
5728        }
5729        free(q->queue);
5730        *q = outq;
5731}
5732
5733/* Check whether two filespecs with the same mode and size are identical */
5734static int diff_filespec_is_identical(struct diff_filespec *one,
5735                                      struct diff_filespec *two)
5736{
5737        if (S_ISGITLINK(one->mode))
5738                return 0;
5739        if (diff_populate_filespec(one, 0))
5740                return 0;
5741        if (diff_populate_filespec(two, 0))
5742                return 0;
5743        return !memcmp(one->data, two->data, one->size);
5744}
5745
5746static int diff_filespec_check_stat_unmatch(struct diff_filepair *p)
5747{
5748        if (p->done_skip_stat_unmatch)
5749                return p->skip_stat_unmatch_result;
5750
5751        p->done_skip_stat_unmatch = 1;
5752        p->skip_stat_unmatch_result = 0;
5753        /*
5754         * 1. Entries that come from stat info dirtiness
5755         *    always have both sides (iow, not create/delete),
5756         *    one side of the object name is unknown, with
5757         *    the same mode and size.  Keep the ones that
5758         *    do not match these criteria.  They have real
5759         *    differences.
5760         *
5761         * 2. At this point, the file is known to be modified,
5762         *    with the same mode and size, and the object
5763         *    name of one side is unknown.  Need to inspect
5764         *    the identical contents.
5765         */
5766        if (!DIFF_FILE_VALID(p->one) || /* (1) */
5767            !DIFF_FILE_VALID(p->two) ||
5768            (p->one->oid_valid && p->two->oid_valid) ||
5769            (p->one->mode != p->two->mode) ||
5770            diff_populate_filespec(p->one, CHECK_SIZE_ONLY) ||
5771            diff_populate_filespec(p->two, CHECK_SIZE_ONLY) ||
5772            (p->one->size != p->two->size) ||
5773            !diff_filespec_is_identical(p->one, p->two)) /* (2) */
5774                p->skip_stat_unmatch_result = 1;
5775        return p->skip_stat_unmatch_result;
5776}
5777
5778static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
5779{
5780        int i;
5781        struct diff_queue_struct *q = &diff_queued_diff;
5782        struct diff_queue_struct outq;
5783        DIFF_QUEUE_CLEAR(&outq);
5784
5785        for (i = 0; i < q->nr; i++) {
5786                struct diff_filepair *p = q->queue[i];
5787
5788                if (diff_filespec_check_stat_unmatch(p))
5789                        diff_q(&outq, p);
5790                else {
5791                        /*
5792                         * The caller can subtract 1 from skip_stat_unmatch
5793                         * to determine how many paths were dirty only
5794                         * due to stat info mismatch.
5795                         */
5796                        if (!diffopt->flags.no_index)
5797                                diffopt->skip_stat_unmatch++;
5798                        diff_free_filepair(p);
5799                }
5800        }
5801        free(q->queue);
5802        *q = outq;
5803}
5804
5805static int diffnamecmp(const void *a_, const void *b_)
5806{
5807        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
5808        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
5809        const char *name_a, *name_b;
5810
5811        name_a = a->one ? a->one->path : a->two->path;
5812        name_b = b->one ? b->one->path : b->two->path;
5813        return strcmp(name_a, name_b);
5814}
5815
5816void diffcore_fix_diff_index(struct diff_options *options)
5817{
5818        struct diff_queue_struct *q = &diff_queued_diff;
5819        QSORT(q->queue, q->nr, diffnamecmp);
5820}
5821
5822void diffcore_std(struct diff_options *options)
5823{
5824        /* NOTE please keep the following in sync with diff_tree_combined() */
5825        if (options->skip_stat_unmatch)
5826                diffcore_skip_stat_unmatch(options);
5827        if (!options->found_follow) {
5828                /* See try_to_follow_renames() in tree-diff.c */
5829                if (options->break_opt != -1)
5830                        diffcore_break(options->break_opt);
5831                if (options->detect_rename)
5832                        diffcore_rename(options);
5833                if (options->break_opt != -1)
5834                        diffcore_merge_broken();
5835        }
5836        if (options->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)
5837                diffcore_pickaxe(options);
5838        if (options->orderfile)
5839                diffcore_order(options->orderfile);
5840        if (!options->found_follow)
5841                /* See try_to_follow_renames() in tree-diff.c */
5842                diff_resolve_rename_copy();
5843        diffcore_apply_filter(options);
5844
5845        if (diff_queued_diff.nr && !options->flags.diff_from_contents)
5846                options->flags.has_changes = 1;
5847        else
5848                options->flags.has_changes = 0;
5849
5850        options->found_follow = 0;
5851}
5852
5853int diff_result_code(struct diff_options *opt, int status)
5854{
5855        int result = 0;
5856
5857        diff_warn_rename_limit("diff.renameLimit",
5858                               opt->needed_rename_limit,
5859                               opt->degraded_cc_to_c);
5860        if (!opt->flags.exit_with_status &&
5861            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
5862                return status;
5863        if (opt->flags.exit_with_status &&
5864            opt->flags.has_changes)
5865                result |= 01;
5866        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
5867            opt->flags.check_failed)
5868                result |= 02;
5869        return result;
5870}
5871
5872int diff_can_quit_early(struct diff_options *opt)
5873{
5874        return (opt->flags.quick &&
5875                !opt->filter &&
5876                opt->flags.has_changes);
5877}
5878
5879/*
5880 * Shall changes to this submodule be ignored?
5881 *
5882 * Submodule changes can be configured to be ignored separately for each path,
5883 * but that configuration can be overridden from the command line.
5884 */
5885static int is_submodule_ignored(const char *path, struct diff_options *options)
5886{
5887        int ignored = 0;
5888        struct diff_flags orig_flags = options->flags;
5889        if (!options->flags.override_submodule_config)
5890                set_diffopt_flags_from_submodule_config(options, path);
5891        if (options->flags.ignore_submodules)
5892                ignored = 1;
5893        options->flags = orig_flags;
5894        return ignored;
5895}
5896
5897void diff_addremove(struct diff_options *options,
5898                    int addremove, unsigned mode,
5899                    const struct object_id *oid,
5900                    int oid_valid,
5901                    const char *concatpath, unsigned dirty_submodule)
5902{
5903        struct diff_filespec *one, *two;
5904
5905        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
5906                return;
5907
5908        /* This may look odd, but it is a preparation for
5909         * feeding "there are unchanged files which should
5910         * not produce diffs, but when you are doing copy
5911         * detection you would need them, so here they are"
5912         * entries to the diff-core.  They will be prefixed
5913         * with something like '=' or '*' (I haven't decided
5914         * which but should not make any difference).
5915         * Feeding the same new and old to diff_change()
5916         * also has the same effect.
5917         * Before the final output happens, they are pruned after
5918         * merged into rename/copy pairs as appropriate.
5919         */
5920        if (options->flags.reverse_diff)
5921                addremove = (addremove == '+' ? '-' :
5922                             addremove == '-' ? '+' : addremove);
5923
5924        if (options->prefix &&
5925            strncmp(concatpath, options->prefix, options->prefix_length))
5926                return;
5927
5928        one = alloc_filespec(concatpath);
5929        two = alloc_filespec(concatpath);
5930
5931        if (addremove != '+')
5932                fill_filespec(one, oid, oid_valid, mode);
5933        if (addremove != '-') {
5934                fill_filespec(two, oid, oid_valid, mode);
5935                two->dirty_submodule = dirty_submodule;
5936        }
5937
5938        diff_queue(&diff_queued_diff, one, two);
5939        if (!options->flags.diff_from_contents)
5940                options->flags.has_changes = 1;
5941}
5942
5943void diff_change(struct diff_options *options,
5944                 unsigned old_mode, unsigned new_mode,
5945                 const struct object_id *old_oid,
5946                 const struct object_id *new_oid,
5947                 int old_oid_valid, int new_oid_valid,
5948                 const char *concatpath,
5949                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
5950{
5951        struct diff_filespec *one, *two;
5952        struct diff_filepair *p;
5953
5954        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
5955            is_submodule_ignored(concatpath, options))
5956                return;
5957
5958        if (options->flags.reverse_diff) {
5959                SWAP(old_mode, new_mode);
5960                SWAP(old_oid, new_oid);
5961                SWAP(old_oid_valid, new_oid_valid);
5962                SWAP(old_dirty_submodule, new_dirty_submodule);
5963        }
5964
5965        if (options->prefix &&
5966            strncmp(concatpath, options->prefix, options->prefix_length))
5967                return;
5968
5969        one = alloc_filespec(concatpath);
5970        two = alloc_filespec(concatpath);
5971        fill_filespec(one, old_oid, old_oid_valid, old_mode);
5972        fill_filespec(two, new_oid, new_oid_valid, new_mode);
5973        one->dirty_submodule = old_dirty_submodule;
5974        two->dirty_submodule = new_dirty_submodule;
5975        p = diff_queue(&diff_queued_diff, one, two);
5976
5977        if (options->flags.diff_from_contents)
5978                return;
5979
5980        if (options->flags.quick && options->skip_stat_unmatch &&
5981            !diff_filespec_check_stat_unmatch(p))
5982                return;
5983
5984        options->flags.has_changes = 1;
5985}
5986
5987struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
5988{
5989        struct diff_filepair *pair;
5990        struct diff_filespec *one, *two;
5991
5992        if (options->prefix &&
5993            strncmp(path, options->prefix, options->prefix_length))
5994                return NULL;
5995
5996        one = alloc_filespec(path);
5997        two = alloc_filespec(path);
5998        pair = diff_queue(&diff_queued_diff, one, two);
5999        pair->is_unmerged = 1;
6000        return pair;
6001}
6002
6003static char *run_textconv(const char *pgm, struct diff_filespec *spec,
6004                size_t *outsize)
6005{
6006        struct diff_tempfile *temp;
6007        const char *argv[3];
6008        const char **arg = argv;
6009        struct child_process child = CHILD_PROCESS_INIT;
6010        struct strbuf buf = STRBUF_INIT;
6011        int err = 0;
6012
6013        temp = prepare_temp_file(spec->path, spec);
6014        *arg++ = pgm;
6015        *arg++ = temp->name;
6016        *arg = NULL;
6017
6018        child.use_shell = 1;
6019        child.argv = argv;
6020        child.out = -1;
6021        if (start_command(&child)) {
6022                remove_tempfile();
6023                return NULL;
6024        }
6025
6026        if (strbuf_read(&buf, child.out, 0) < 0)
6027                err = error("error reading from textconv command '%s'", pgm);
6028        close(child.out);
6029
6030        if (finish_command(&child) || err) {
6031                strbuf_release(&buf);
6032                remove_tempfile();
6033                return NULL;
6034        }
6035        remove_tempfile();
6036
6037        return strbuf_detach(&buf, outsize);
6038}
6039
6040size_t fill_textconv(struct userdiff_driver *driver,
6041                     struct diff_filespec *df,
6042                     char **outbuf)
6043{
6044        size_t size;
6045
6046        if (!driver) {
6047                if (!DIFF_FILE_VALID(df)) {
6048                        *outbuf = "";
6049                        return 0;
6050                }
6051                if (diff_populate_filespec(df, 0))
6052                        die("unable to read files to diff");
6053                *outbuf = df->data;
6054                return df->size;
6055        }
6056
6057        if (!driver->textconv)
6058                die("BUG: fill_textconv called with non-textconv driver");
6059
6060        if (driver->textconv_cache && df->oid_valid) {
6061                *outbuf = notes_cache_get(driver->textconv_cache,
6062                                          &df->oid,
6063                                          &size);
6064                if (*outbuf)
6065                        return size;
6066        }
6067
6068        *outbuf = run_textconv(driver->textconv, df, &size);
6069        if (!*outbuf)
6070                die("unable to read files to diff");
6071
6072        if (driver->textconv_cache && df->oid_valid) {
6073                /* ignore errors, as we might be in a readonly repository */
6074                notes_cache_put(driver->textconv_cache, &df->oid, *outbuf,
6075                                size);
6076                /*
6077                 * we could save up changes and flush them all at the end,
6078                 * but we would need an extra call after all diffing is done.
6079                 * Since generating a cache entry is the slow path anyway,
6080                 * this extra overhead probably isn't a big deal.
6081                 */
6082                notes_cache_write(driver->textconv_cache);
6083        }
6084
6085        return size;
6086}
6087
6088int textconv_object(const char *path,
6089                    unsigned mode,
6090                    const struct object_id *oid,
6091                    int oid_valid,
6092                    char **buf,
6093                    unsigned long *buf_size)
6094{
6095        struct diff_filespec *df;
6096        struct userdiff_driver *textconv;
6097
6098        df = alloc_filespec(path);
6099        fill_filespec(df, oid, oid_valid, mode);
6100        textconv = get_textconv(df);
6101        if (!textconv) {
6102                free_filespec(df);
6103                return 0;
6104        }
6105
6106        *buf_size = fill_textconv(textconv, df, buf);
6107        free_filespec(df);
6108        return 1;
6109}
6110
6111void setup_diff_pager(struct diff_options *opt)
6112{
6113        /*
6114         * If the user asked for our exit code, then either they want --quiet
6115         * or --exit-code. We should definitely not bother with a pager in the
6116         * former case, as we will generate no output. Since we still properly
6117         * report our exit code even when a pager is run, we _could_ run a
6118         * pager with --exit-code. But since we have not done so historically,
6119         * and because it is easy to find people oneline advising "git diff
6120         * --exit-code" in hooks and other scripts, we do not do so.
6121         */
6122        if (!opt->flags.exit_with_status &&
6123            check_pager_config("diff") != 0)
6124                setup_pager();
6125}