488096b757377b4f86109253e3b275ea54254087
   1/*
   2 * Copyright (C) 2005 Junio C Hamano
   3 */
   4#include "cache.h"
   5#include "config.h"
   6#include "tempfile.h"
   7#include "quote.h"
   8#include "diff.h"
   9#include "diffcore.h"
  10#include "delta.h"
  11#include "xdiff-interface.h"
  12#include "color.h"
  13#include "attr.h"
  14#include "run-command.h"
  15#include "utf8.h"
  16#include "userdiff.h"
  17#include "submodule-config.h"
  18#include "submodule.h"
  19#include "ll-merge.h"
  20#include "string-list.h"
  21#include "argv-array.h"
  22#include "graph.h"
  23
  24#ifdef NO_FAST_WORKING_DIRECTORY
  25#define FAST_WORKING_DIRECTORY 0
  26#else
  27#define FAST_WORKING_DIRECTORY 1
  28#endif
  29
  30static int diff_detect_rename_default;
  31static int diff_indent_heuristic = 1;
  32static int diff_rename_limit_default = 400;
  33static int diff_suppress_blank_empty;
  34static int diff_use_color_default = -1;
  35static int diff_context_default = 3;
  36static int diff_interhunk_context_default;
  37static const char *diff_word_regex_cfg;
  38static const char *external_diff_cmd_cfg;
  39static const char *diff_order_file_cfg;
  40int diff_auto_refresh_index = 1;
  41static int diff_mnemonic_prefix;
  42static int diff_no_prefix;
  43static int diff_stat_graph_width;
  44static int diff_dirstat_permille_default = 30;
  45static struct diff_options default_diff_options;
  46static long diff_algorithm;
  47static unsigned ws_error_highlight_default = WSEH_NEW;
  48
  49static char diff_colors[][COLOR_MAXLEN] = {
  50        GIT_COLOR_RESET,
  51        GIT_COLOR_NORMAL,       /* CONTEXT */
  52        GIT_COLOR_BOLD,         /* METAINFO */
  53        GIT_COLOR_CYAN,         /* FRAGINFO */
  54        GIT_COLOR_RED,          /* OLD */
  55        GIT_COLOR_GREEN,        /* NEW */
  56        GIT_COLOR_YELLOW,       /* COMMIT */
  57        GIT_COLOR_BG_RED,       /* WHITESPACE */
  58        GIT_COLOR_NORMAL,       /* FUNCINFO */
  59};
  60
  61static NORETURN void die_want_option(const char *option_name)
  62{
  63        die(_("option '%s' requires a value"), option_name);
  64}
  65
  66static int parse_diff_color_slot(const char *var)
  67{
  68        if (!strcasecmp(var, "context") || !strcasecmp(var, "plain"))
  69                return DIFF_CONTEXT;
  70        if (!strcasecmp(var, "meta"))
  71                return DIFF_METAINFO;
  72        if (!strcasecmp(var, "frag"))
  73                return DIFF_FRAGINFO;
  74        if (!strcasecmp(var, "old"))
  75                return DIFF_FILE_OLD;
  76        if (!strcasecmp(var, "new"))
  77                return DIFF_FILE_NEW;
  78        if (!strcasecmp(var, "commit"))
  79                return DIFF_COMMIT;
  80        if (!strcasecmp(var, "whitespace"))
  81                return DIFF_WHITESPACE;
  82        if (!strcasecmp(var, "func"))
  83                return DIFF_FUNCINFO;
  84        return -1;
  85}
  86
  87static int parse_dirstat_params(struct diff_options *options, const char *params_string,
  88                                struct strbuf *errmsg)
  89{
  90        char *params_copy = xstrdup(params_string);
  91        struct string_list params = STRING_LIST_INIT_NODUP;
  92        int ret = 0;
  93        int i;
  94
  95        if (*params_copy)
  96                string_list_split_in_place(&params, params_copy, ',', -1);
  97        for (i = 0; i < params.nr; i++) {
  98                const char *p = params.items[i].string;
  99                if (!strcmp(p, "changes")) {
 100                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
 101                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
 102                } else if (!strcmp(p, "lines")) {
 103                        DIFF_OPT_SET(options, DIRSTAT_BY_LINE);
 104                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
 105                } else if (!strcmp(p, "files")) {
 106                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
 107                        DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
 108                } else if (!strcmp(p, "noncumulative")) {
 109                        DIFF_OPT_CLR(options, DIRSTAT_CUMULATIVE);
 110                } else if (!strcmp(p, "cumulative")) {
 111                        DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
 112                } else if (isdigit(*p)) {
 113                        char *end;
 114                        int permille = strtoul(p, &end, 10) * 10;
 115                        if (*end == '.' && isdigit(*++end)) {
 116                                /* only use first digit */
 117                                permille += *end - '0';
 118                                /* .. and ignore any further digits */
 119                                while (isdigit(*++end))
 120                                        ; /* nothing */
 121                        }
 122                        if (!*end)
 123                                options->dirstat_permille = permille;
 124                        else {
 125                                strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%s'\n"),
 126                                            p);
 127                                ret++;
 128                        }
 129                } else {
 130                        strbuf_addf(errmsg, _("  Unknown dirstat parameter '%s'\n"), p);
 131                        ret++;
 132                }
 133
 134        }
 135        string_list_clear(&params, 0);
 136        free(params_copy);
 137        return ret;
 138}
 139
 140static int parse_submodule_params(struct diff_options *options, const char *value)
 141{
 142        if (!strcmp(value, "log"))
 143                options->submodule_format = DIFF_SUBMODULE_LOG;
 144        else if (!strcmp(value, "short"))
 145                options->submodule_format = DIFF_SUBMODULE_SHORT;
 146        else if (!strcmp(value, "diff"))
 147                options->submodule_format = DIFF_SUBMODULE_INLINE_DIFF;
 148        else
 149                return -1;
 150        return 0;
 151}
 152
 153static int git_config_rename(const char *var, const char *value)
 154{
 155        if (!value)
 156                return DIFF_DETECT_RENAME;
 157        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 158                return  DIFF_DETECT_COPY;
 159        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 160}
 161
 162long parse_algorithm_value(const char *value)
 163{
 164        if (!value)
 165                return -1;
 166        else if (!strcasecmp(value, "myers") || !strcasecmp(value, "default"))
 167                return 0;
 168        else if (!strcasecmp(value, "minimal"))
 169                return XDF_NEED_MINIMAL;
 170        else if (!strcasecmp(value, "patience"))
 171                return XDF_PATIENCE_DIFF;
 172        else if (!strcasecmp(value, "histogram"))
 173                return XDF_HISTOGRAM_DIFF;
 174        return -1;
 175}
 176
 177static int parse_one_token(const char **arg, const char *token)
 178{
 179        const char *rest;
 180        if (skip_prefix(*arg, token, &rest) && (!*rest || *rest == ',')) {
 181                *arg = rest;
 182                return 1;
 183        }
 184        return 0;
 185}
 186
 187static int parse_ws_error_highlight(const char *arg)
 188{
 189        const char *orig_arg = arg;
 190        unsigned val = 0;
 191
 192        while (*arg) {
 193                if (parse_one_token(&arg, "none"))
 194                        val = 0;
 195                else if (parse_one_token(&arg, "default"))
 196                        val = WSEH_NEW;
 197                else if (parse_one_token(&arg, "all"))
 198                        val = WSEH_NEW | WSEH_OLD | WSEH_CONTEXT;
 199                else if (parse_one_token(&arg, "new"))
 200                        val |= WSEH_NEW;
 201                else if (parse_one_token(&arg, "old"))
 202                        val |= WSEH_OLD;
 203                else if (parse_one_token(&arg, "context"))
 204                        val |= WSEH_CONTEXT;
 205                else {
 206                        return -1 - (int)(arg - orig_arg);
 207                }
 208                if (*arg)
 209                        arg++;
 210        }
 211        return val;
 212}
 213
 214/*
 215 * These are to give UI layer defaults.
 216 * The core-level commands such as git-diff-files should
 217 * never be affected by the setting of diff.renames
 218 * the user happens to have in the configuration file.
 219 */
 220void init_diff_ui_defaults(void)
 221{
 222        diff_detect_rename_default = 1;
 223}
 224
 225int git_diff_heuristic_config(const char *var, const char *value, void *cb)
 226{
 227        if (!strcmp(var, "diff.indentheuristic"))
 228                diff_indent_heuristic = git_config_bool(var, value);
 229        return 0;
 230}
 231
 232int git_diff_ui_config(const char *var, const char *value, void *cb)
 233{
 234        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 235                diff_use_color_default = git_config_colorbool(var, value);
 236                return 0;
 237        }
 238        if (!strcmp(var, "diff.context")) {
 239                diff_context_default = git_config_int(var, value);
 240                if (diff_context_default < 0)
 241                        return -1;
 242                return 0;
 243        }
 244        if (!strcmp(var, "diff.interhunkcontext")) {
 245                diff_interhunk_context_default = git_config_int(var, value);
 246                if (diff_interhunk_context_default < 0)
 247                        return -1;
 248                return 0;
 249        }
 250        if (!strcmp(var, "diff.renames")) {
 251                diff_detect_rename_default = git_config_rename(var, value);
 252                return 0;
 253        }
 254        if (!strcmp(var, "diff.autorefreshindex")) {
 255                diff_auto_refresh_index = git_config_bool(var, value);
 256                return 0;
 257        }
 258        if (!strcmp(var, "diff.mnemonicprefix")) {
 259                diff_mnemonic_prefix = git_config_bool(var, value);
 260                return 0;
 261        }
 262        if (!strcmp(var, "diff.noprefix")) {
 263                diff_no_prefix = git_config_bool(var, value);
 264                return 0;
 265        }
 266        if (!strcmp(var, "diff.statgraphwidth")) {
 267                diff_stat_graph_width = git_config_int(var, value);
 268                return 0;
 269        }
 270        if (!strcmp(var, "diff.external"))
 271                return git_config_string(&external_diff_cmd_cfg, var, value);
 272        if (!strcmp(var, "diff.wordregex"))
 273                return git_config_string(&diff_word_regex_cfg, var, value);
 274        if (!strcmp(var, "diff.orderfile"))
 275                return git_config_pathname(&diff_order_file_cfg, var, value);
 276
 277        if (!strcmp(var, "diff.ignoresubmodules"))
 278                handle_ignore_submodules_arg(&default_diff_options, value);
 279
 280        if (!strcmp(var, "diff.submodule")) {
 281                if (parse_submodule_params(&default_diff_options, value))
 282                        warning(_("Unknown value for 'diff.submodule' config variable: '%s'"),
 283                                value);
 284                return 0;
 285        }
 286
 287        if (!strcmp(var, "diff.algorithm")) {
 288                diff_algorithm = parse_algorithm_value(value);
 289                if (diff_algorithm < 0)
 290                        return -1;
 291                return 0;
 292        }
 293
 294        if (!strcmp(var, "diff.wserrorhighlight")) {
 295                int val = parse_ws_error_highlight(value);
 296                if (val < 0)
 297                        return -1;
 298                ws_error_highlight_default = val;
 299                return 0;
 300        }
 301
 302        if (git_color_config(var, value, cb) < 0)
 303                return -1;
 304
 305        return git_diff_basic_config(var, value, cb);
 306}
 307
 308int git_diff_basic_config(const char *var, const char *value, void *cb)
 309{
 310        const char *name;
 311
 312        if (!strcmp(var, "diff.renamelimit")) {
 313                diff_rename_limit_default = git_config_int(var, value);
 314                return 0;
 315        }
 316
 317        if (userdiff_config(var, value) < 0)
 318                return -1;
 319
 320        if (skip_prefix(var, "diff.color.", &name) ||
 321            skip_prefix(var, "color.diff.", &name)) {
 322                int slot = parse_diff_color_slot(name);
 323                if (slot < 0)
 324                        return 0;
 325                if (!value)
 326                        return config_error_nonbool(var);
 327                return color_parse(value, diff_colors[slot]);
 328        }
 329
 330        /* like GNU diff's --suppress-blank-empty option  */
 331        if (!strcmp(var, "diff.suppressblankempty") ||
 332                        /* for backwards compatibility */
 333                        !strcmp(var, "diff.suppress-blank-empty")) {
 334                diff_suppress_blank_empty = git_config_bool(var, value);
 335                return 0;
 336        }
 337
 338        if (!strcmp(var, "diff.dirstat")) {
 339                struct strbuf errmsg = STRBUF_INIT;
 340                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 341                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 342                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 343                                errmsg.buf);
 344                strbuf_release(&errmsg);
 345                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 346                return 0;
 347        }
 348
 349        if (starts_with(var, "submodule."))
 350                return parse_submodule_config_option(var, value);
 351
 352        if (git_diff_heuristic_config(var, value, cb) < 0)
 353                return -1;
 354
 355        return git_default_config(var, value, cb);
 356}
 357
 358static char *quote_two(const char *one, const char *two)
 359{
 360        int need_one = quote_c_style(one, NULL, NULL, 1);
 361        int need_two = quote_c_style(two, NULL, NULL, 1);
 362        struct strbuf res = STRBUF_INIT;
 363
 364        if (need_one + need_two) {
 365                strbuf_addch(&res, '"');
 366                quote_c_style(one, &res, NULL, 1);
 367                quote_c_style(two, &res, NULL, 1);
 368                strbuf_addch(&res, '"');
 369        } else {
 370                strbuf_addstr(&res, one);
 371                strbuf_addstr(&res, two);
 372        }
 373        return strbuf_detach(&res, NULL);
 374}
 375
 376static const char *external_diff(void)
 377{
 378        static const char *external_diff_cmd = NULL;
 379        static int done_preparing = 0;
 380
 381        if (done_preparing)
 382                return external_diff_cmd;
 383        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 384        if (!external_diff_cmd)
 385                external_diff_cmd = external_diff_cmd_cfg;
 386        done_preparing = 1;
 387        return external_diff_cmd;
 388}
 389
 390/*
 391 * Keep track of files used for diffing. Sometimes such an entry
 392 * refers to a temporary file, sometimes to an existing file, and
 393 * sometimes to "/dev/null".
 394 */
 395static struct diff_tempfile {
 396        /*
 397         * filename external diff should read from, or NULL if this
 398         * entry is currently not in use:
 399         */
 400        const char *name;
 401
 402        char hex[GIT_MAX_HEXSZ + 1];
 403        char mode[10];
 404
 405        /*
 406         * If this diff_tempfile instance refers to a temporary file,
 407         * this tempfile object is used to manage its lifetime.
 408         */
 409        struct tempfile tempfile;
 410} diff_temp[2];
 411
 412typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 413
 414struct emit_callback {
 415        int color_diff;
 416        unsigned ws_rule;
 417        int blank_at_eof_in_preimage;
 418        int blank_at_eof_in_postimage;
 419        int lno_in_preimage;
 420        int lno_in_postimage;
 421        sane_truncate_fn truncate;
 422        const char **label_path;
 423        struct diff_words_data *diff_words;
 424        struct diff_options *opt;
 425        struct strbuf *header;
 426};
 427
 428static int count_lines(const char *data, int size)
 429{
 430        int count, ch, completely_empty = 1, nl_just_seen = 0;
 431        count = 0;
 432        while (0 < size--) {
 433                ch = *data++;
 434                if (ch == '\n') {
 435                        count++;
 436                        nl_just_seen = 1;
 437                        completely_empty = 0;
 438                }
 439                else {
 440                        nl_just_seen = 0;
 441                        completely_empty = 0;
 442                }
 443        }
 444        if (completely_empty)
 445                return 0;
 446        if (!nl_just_seen)
 447                count++; /* no trailing newline */
 448        return count;
 449}
 450
 451static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 452{
 453        if (!DIFF_FILE_VALID(one)) {
 454                mf->ptr = (char *)""; /* does not matter */
 455                mf->size = 0;
 456                return 0;
 457        }
 458        else if (diff_populate_filespec(one, 0))
 459                return -1;
 460
 461        mf->ptr = one->data;
 462        mf->size = one->size;
 463        return 0;
 464}
 465
 466/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 467static unsigned long diff_filespec_size(struct diff_filespec *one)
 468{
 469        if (!DIFF_FILE_VALID(one))
 470                return 0;
 471        diff_populate_filespec(one, CHECK_SIZE_ONLY);
 472        return one->size;
 473}
 474
 475static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 476{
 477        char *ptr = mf->ptr;
 478        long size = mf->size;
 479        int cnt = 0;
 480
 481        if (!size)
 482                return cnt;
 483        ptr += size - 1; /* pointing at the very end */
 484        if (*ptr != '\n')
 485                ; /* incomplete line */
 486        else
 487                ptr--; /* skip the last LF */
 488        while (mf->ptr < ptr) {
 489                char *prev_eol;
 490                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 491                        if (*prev_eol == '\n')
 492                                break;
 493                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 494                        break;
 495                cnt++;
 496                ptr = prev_eol - 1;
 497        }
 498        return cnt;
 499}
 500
 501static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 502                               struct emit_callback *ecbdata)
 503{
 504        int l1, l2, at;
 505        unsigned ws_rule = ecbdata->ws_rule;
 506        l1 = count_trailing_blank(mf1, ws_rule);
 507        l2 = count_trailing_blank(mf2, ws_rule);
 508        if (l2 <= l1) {
 509                ecbdata->blank_at_eof_in_preimage = 0;
 510                ecbdata->blank_at_eof_in_postimage = 0;
 511                return;
 512        }
 513        at = count_lines(mf1->ptr, mf1->size);
 514        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 515
 516        at = count_lines(mf2->ptr, mf2->size);
 517        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 518}
 519
 520static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 521                        int first, const char *line, int len)
 522{
 523        int has_trailing_newline, has_trailing_carriage_return;
 524        int nofirst;
 525        FILE *file = o->file;
 526
 527        fputs(diff_line_prefix(o), file);
 528
 529        if (len == 0) {
 530                has_trailing_newline = (first == '\n');
 531                has_trailing_carriage_return = (!has_trailing_newline &&
 532                                                (first == '\r'));
 533                nofirst = has_trailing_newline || has_trailing_carriage_return;
 534        } else {
 535                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 536                if (has_trailing_newline)
 537                        len--;
 538                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 539                if (has_trailing_carriage_return)
 540                        len--;
 541                nofirst = 0;
 542        }
 543
 544        if (len || !nofirst) {
 545                fputs(set, file);
 546                if (!nofirst)
 547                        fputc(first, file);
 548                fwrite(line, len, 1, file);
 549                fputs(reset, file);
 550        }
 551        if (has_trailing_carriage_return)
 552                fputc('\r', file);
 553        if (has_trailing_newline)
 554                fputc('\n', file);
 555}
 556
 557static void emit_line(struct diff_options *o, const char *set, const char *reset,
 558                      const char *line, int len)
 559{
 560        emit_line_0(o, set, reset, line[0], line+1, len-1);
 561}
 562
 563enum diff_symbol {
 564        DIFF_SYMBOL_NO_LF_EOF,
 565        DIFF_SYMBOL_CONTEXT_FRAGINFO,
 566        DIFF_SYMBOL_CONTEXT_MARKER,
 567        DIFF_SYMBOL_SEPARATOR
 568};
 569
 570static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
 571                             const char *line, int len)
 572{
 573        static const char *nneof = " No newline at end of file\n";
 574        const char *context, *reset;
 575        switch (s) {
 576        case DIFF_SYMBOL_NO_LF_EOF:
 577                context = diff_get_color_opt(o, DIFF_CONTEXT);
 578                reset = diff_get_color_opt(o, DIFF_RESET);
 579                putc('\n', o->file);
 580                emit_line_0(o, context, reset, '\\',
 581                            nneof, strlen(nneof));
 582                break;
 583        case DIFF_SYMBOL_CONTEXT_FRAGINFO:
 584                emit_line(o, "", "", line, len);
 585                break;
 586        case DIFF_SYMBOL_CONTEXT_MARKER:
 587                context = diff_get_color_opt(o, DIFF_CONTEXT);
 588                reset = diff_get_color_opt(o, DIFF_RESET);
 589                emit_line(o, context, reset, line, len);
 590                break;
 591        case DIFF_SYMBOL_SEPARATOR:
 592                fprintf(o->file, "%s%c",
 593                        diff_line_prefix(o),
 594                        o->line_termination);
 595                break;
 596        default:
 597                die("BUG: unknown diff symbol");
 598        }
 599}
 600
 601static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 602{
 603        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 604              ecbdata->blank_at_eof_in_preimage &&
 605              ecbdata->blank_at_eof_in_postimage &&
 606              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 607              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 608                return 0;
 609        return ws_blank_line(line, len, ecbdata->ws_rule);
 610}
 611
 612static void emit_line_checked(const char *reset,
 613                              struct emit_callback *ecbdata,
 614                              const char *line, int len,
 615                              enum color_diff color,
 616                              unsigned ws_error_highlight,
 617                              char sign)
 618{
 619        const char *set = diff_get_color(ecbdata->color_diff, color);
 620        const char *ws = NULL;
 621
 622        if (ecbdata->opt->ws_error_highlight & ws_error_highlight) {
 623                ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 624                if (!*ws)
 625                        ws = NULL;
 626        }
 627
 628        if (!ws)
 629                emit_line_0(ecbdata->opt, set, reset, sign, line, len);
 630        else if (sign == '+' && new_blank_line_at_eof(ecbdata, line, len))
 631                /* Blank line at EOF - paint '+' as well */
 632                emit_line_0(ecbdata->opt, ws, reset, sign, line, len);
 633        else {
 634                /* Emit just the prefix, then the rest. */
 635                emit_line_0(ecbdata->opt, set, reset, sign, "", 0);
 636                ws_check_emit(line, len, ecbdata->ws_rule,
 637                              ecbdata->opt->file, set, reset, ws);
 638        }
 639}
 640
 641static void emit_add_line(const char *reset,
 642                          struct emit_callback *ecbdata,
 643                          const char *line, int len)
 644{
 645        emit_line_checked(reset, ecbdata, line, len,
 646                          DIFF_FILE_NEW, WSEH_NEW, '+');
 647}
 648
 649static void emit_del_line(const char *reset,
 650                          struct emit_callback *ecbdata,
 651                          const char *line, int len)
 652{
 653        emit_line_checked(reset, ecbdata, line, len,
 654                          DIFF_FILE_OLD, WSEH_OLD, '-');
 655}
 656
 657static void emit_context_line(const char *reset,
 658                              struct emit_callback *ecbdata,
 659                              const char *line, int len)
 660{
 661        emit_line_checked(reset, ecbdata, line, len,
 662                          DIFF_CONTEXT, WSEH_CONTEXT, ' ');
 663}
 664
 665static void emit_hunk_header(struct emit_callback *ecbdata,
 666                             const char *line, int len)
 667{
 668        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
 669        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 670        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 671        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 672        static const char atat[2] = { '@', '@' };
 673        const char *cp, *ep;
 674        struct strbuf msgbuf = STRBUF_INIT;
 675        int org_len = len;
 676        int i = 1;
 677
 678        /*
 679         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 680         * it always is at least 10 bytes long.
 681         */
 682        if (len < 10 ||
 683            memcmp(line, atat, 2) ||
 684            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 685                emit_diff_symbol(ecbdata->opt,
 686                                 DIFF_SYMBOL_CONTEXT_MARKER, line, len);
 687                return;
 688        }
 689        ep += 2; /* skip over @@ */
 690
 691        /* The hunk header in fraginfo color */
 692        strbuf_addstr(&msgbuf, frag);
 693        strbuf_add(&msgbuf, line, ep - line);
 694        strbuf_addstr(&msgbuf, reset);
 695
 696        /*
 697         * trailing "\r\n"
 698         */
 699        for ( ; i < 3; i++)
 700                if (line[len - i] == '\r' || line[len - i] == '\n')
 701                        len--;
 702
 703        /* blank before the func header */
 704        for (cp = ep; ep - line < len; ep++)
 705                if (*ep != ' ' && *ep != '\t')
 706                        break;
 707        if (ep != cp) {
 708                strbuf_addstr(&msgbuf, context);
 709                strbuf_add(&msgbuf, cp, ep - cp);
 710                strbuf_addstr(&msgbuf, reset);
 711        }
 712
 713        if (ep < line + len) {
 714                strbuf_addstr(&msgbuf, func);
 715                strbuf_add(&msgbuf, ep, line + len - ep);
 716                strbuf_addstr(&msgbuf, reset);
 717        }
 718
 719        strbuf_add(&msgbuf, line + len, org_len - len);
 720        strbuf_complete_line(&msgbuf);
 721        emit_diff_symbol(ecbdata->opt,
 722                         DIFF_SYMBOL_CONTEXT_FRAGINFO, msgbuf.buf, msgbuf.len);
 723        strbuf_release(&msgbuf);
 724}
 725
 726static struct diff_tempfile *claim_diff_tempfile(void) {
 727        int i;
 728        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 729                if (!diff_temp[i].name)
 730                        return diff_temp + i;
 731        die("BUG: diff is failing to clean up its tempfiles");
 732}
 733
 734static void remove_tempfile(void)
 735{
 736        int i;
 737        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 738                if (is_tempfile_active(&diff_temp[i].tempfile))
 739                        delete_tempfile(&diff_temp[i].tempfile);
 740                diff_temp[i].name = NULL;
 741        }
 742}
 743
 744static void print_line_count(FILE *file, int count)
 745{
 746        switch (count) {
 747        case 0:
 748                fprintf(file, "0,0");
 749                break;
 750        case 1:
 751                fprintf(file, "1");
 752                break;
 753        default:
 754                fprintf(file, "1,%d", count);
 755                break;
 756        }
 757}
 758
 759static void emit_rewrite_lines(struct emit_callback *ecb,
 760                               int prefix, const char *data, int size)
 761{
 762        const char *endp = NULL;
 763        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 764
 765        while (0 < size) {
 766                int len;
 767
 768                endp = memchr(data, '\n', size);
 769                len = endp ? (endp - data + 1) : size;
 770                if (prefix != '+') {
 771                        ecb->lno_in_preimage++;
 772                        emit_del_line(reset, ecb, data, len);
 773                } else {
 774                        ecb->lno_in_postimage++;
 775                        emit_add_line(reset, ecb, data, len);
 776                }
 777                size -= len;
 778                data += len;
 779        }
 780        if (!endp)
 781                emit_diff_symbol(ecb->opt, DIFF_SYMBOL_NO_LF_EOF, NULL, 0);
 782}
 783
 784static void emit_rewrite_diff(const char *name_a,
 785                              const char *name_b,
 786                              struct diff_filespec *one,
 787                              struct diff_filespec *two,
 788                              struct userdiff_driver *textconv_one,
 789                              struct userdiff_driver *textconv_two,
 790                              struct diff_options *o)
 791{
 792        int lc_a, lc_b;
 793        const char *name_a_tab, *name_b_tab;
 794        const char *metainfo = diff_get_color(o->use_color, DIFF_METAINFO);
 795        const char *fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
 796        const char *reset = diff_get_color(o->use_color, DIFF_RESET);
 797        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 798        const char *a_prefix, *b_prefix;
 799        char *data_one, *data_two;
 800        size_t size_one, size_two;
 801        struct emit_callback ecbdata;
 802        const char *line_prefix = diff_line_prefix(o);
 803
 804        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 805                a_prefix = o->b_prefix;
 806                b_prefix = o->a_prefix;
 807        } else {
 808                a_prefix = o->a_prefix;
 809                b_prefix = o->b_prefix;
 810        }
 811
 812        name_a += (*name_a == '/');
 813        name_b += (*name_b == '/');
 814        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 815        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 816
 817        strbuf_reset(&a_name);
 818        strbuf_reset(&b_name);
 819        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 820        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 821
 822        size_one = fill_textconv(textconv_one, one, &data_one);
 823        size_two = fill_textconv(textconv_two, two, &data_two);
 824
 825        memset(&ecbdata, 0, sizeof(ecbdata));
 826        ecbdata.color_diff = want_color(o->use_color);
 827        ecbdata.ws_rule = whitespace_rule(name_b);
 828        ecbdata.opt = o;
 829        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 830                mmfile_t mf1, mf2;
 831                mf1.ptr = (char *)data_one;
 832                mf2.ptr = (char *)data_two;
 833                mf1.size = size_one;
 834                mf2.size = size_two;
 835                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 836        }
 837        ecbdata.lno_in_preimage = 1;
 838        ecbdata.lno_in_postimage = 1;
 839
 840        lc_a = count_lines(data_one, size_one);
 841        lc_b = count_lines(data_two, size_two);
 842        fprintf(o->file,
 843                "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
 844                line_prefix, metainfo, a_name.buf, name_a_tab, reset,
 845                line_prefix, metainfo, b_name.buf, name_b_tab, reset,
 846                line_prefix, fraginfo);
 847        if (!o->irreversible_delete)
 848                print_line_count(o->file, lc_a);
 849        else
 850                fprintf(o->file, "?,?");
 851        fprintf(o->file, " +");
 852        print_line_count(o->file, lc_b);
 853        fprintf(o->file, " @@%s\n", reset);
 854        if (lc_a && !o->irreversible_delete)
 855                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 856        if (lc_b)
 857                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 858        if (textconv_one)
 859                free((char *)data_one);
 860        if (textconv_two)
 861                free((char *)data_two);
 862}
 863
 864struct diff_words_buffer {
 865        mmfile_t text;
 866        long alloc;
 867        struct diff_words_orig {
 868                const char *begin, *end;
 869        } *orig;
 870        int orig_nr, orig_alloc;
 871};
 872
 873static void diff_words_append(char *line, unsigned long len,
 874                struct diff_words_buffer *buffer)
 875{
 876        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 877        line++;
 878        len--;
 879        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 880        buffer->text.size += len;
 881        buffer->text.ptr[buffer->text.size] = '\0';
 882}
 883
 884struct diff_words_style_elem {
 885        const char *prefix;
 886        const char *suffix;
 887        const char *color; /* NULL; filled in by the setup code if
 888                            * color is enabled */
 889};
 890
 891struct diff_words_style {
 892        enum diff_words_type type;
 893        struct diff_words_style_elem new, old, ctx;
 894        const char *newline;
 895};
 896
 897static struct diff_words_style diff_words_styles[] = {
 898        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 899        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 900        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 901};
 902
 903struct diff_words_data {
 904        struct diff_words_buffer minus, plus;
 905        const char *current_plus;
 906        int last_minus;
 907        struct diff_options *opt;
 908        regex_t *word_regex;
 909        enum diff_words_type type;
 910        struct diff_words_style *style;
 911};
 912
 913static int fn_out_diff_words_write_helper(FILE *fp,
 914                                          struct diff_words_style_elem *st_el,
 915                                          const char *newline,
 916                                          size_t count, const char *buf,
 917                                          const char *line_prefix)
 918{
 919        int print = 0;
 920
 921        while (count) {
 922                char *p = memchr(buf, '\n', count);
 923                if (print)
 924                        fputs(line_prefix, fp);
 925                if (p != buf) {
 926                        if (st_el->color && fputs(st_el->color, fp) < 0)
 927                                return -1;
 928                        if (fputs(st_el->prefix, fp) < 0 ||
 929                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 930                            fputs(st_el->suffix, fp) < 0)
 931                                return -1;
 932                        if (st_el->color && *st_el->color
 933                            && fputs(GIT_COLOR_RESET, fp) < 0)
 934                                return -1;
 935                }
 936                if (!p)
 937                        return 0;
 938                if (fputs(newline, fp) < 0)
 939                        return -1;
 940                count -= p + 1 - buf;
 941                buf = p + 1;
 942                print = 1;
 943        }
 944        return 0;
 945}
 946
 947/*
 948 * '--color-words' algorithm can be described as:
 949 *
 950 *   1. collect the minus/plus lines of a diff hunk, divided into
 951 *      minus-lines and plus-lines;
 952 *
 953 *   2. break both minus-lines and plus-lines into words and
 954 *      place them into two mmfile_t with one word for each line;
 955 *
 956 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
 957 *
 958 * And for the common parts of the both file, we output the plus side text.
 959 * diff_words->current_plus is used to trace the current position of the plus file
 960 * which printed. diff_words->last_minus is used to trace the last minus word
 961 * printed.
 962 *
 963 * For '--graph' to work with '--color-words', we need to output the graph prefix
 964 * on each line of color words output. Generally, there are two conditions on
 965 * which we should output the prefix.
 966 *
 967 *   1. diff_words->last_minus == 0 &&
 968 *      diff_words->current_plus == diff_words->plus.text.ptr
 969 *
 970 *      that is: the plus text must start as a new line, and if there is no minus
 971 *      word printed, a graph prefix must be printed.
 972 *
 973 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
 974 *      *(diff_words->current_plus - 1) == '\n'
 975 *
 976 *      that is: a graph prefix must be printed following a '\n'
 977 */
 978static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
 979{
 980        if ((diff_words->last_minus == 0 &&
 981                diff_words->current_plus == diff_words->plus.text.ptr) ||
 982                (diff_words->current_plus > diff_words->plus.text.ptr &&
 983                *(diff_words->current_plus - 1) == '\n')) {
 984                return 1;
 985        } else {
 986                return 0;
 987        }
 988}
 989
 990static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 991{
 992        struct diff_words_data *diff_words = priv;
 993        struct diff_words_style *style = diff_words->style;
 994        int minus_first, minus_len, plus_first, plus_len;
 995        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 996        struct diff_options *opt = diff_words->opt;
 997        const char *line_prefix;
 998
 999        if (line[0] != '@' || parse_hunk_header(line, len,
1000                        &minus_first, &minus_len, &plus_first, &plus_len))
1001                return;
1002
1003        assert(opt);
1004        line_prefix = diff_line_prefix(opt);
1005
1006        /* POSIX requires that first be decremented by one if len == 0... */
1007        if (minus_len) {
1008                minus_begin = diff_words->minus.orig[minus_first].begin;
1009                minus_end =
1010                        diff_words->minus.orig[minus_first + minus_len - 1].end;
1011        } else
1012                minus_begin = minus_end =
1013                        diff_words->minus.orig[minus_first].end;
1014
1015        if (plus_len) {
1016                plus_begin = diff_words->plus.orig[plus_first].begin;
1017                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
1018        } else
1019                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
1020
1021        if (color_words_output_graph_prefix(diff_words)) {
1022                fputs(line_prefix, diff_words->opt->file);
1023        }
1024        if (diff_words->current_plus != plus_begin) {
1025                fn_out_diff_words_write_helper(diff_words->opt->file,
1026                                &style->ctx, style->newline,
1027                                plus_begin - diff_words->current_plus,
1028                                diff_words->current_plus, line_prefix);
1029                if (*(plus_begin - 1) == '\n')
1030                        fputs(line_prefix, diff_words->opt->file);
1031        }
1032        if (minus_begin != minus_end) {
1033                fn_out_diff_words_write_helper(diff_words->opt->file,
1034                                &style->old, style->newline,
1035                                minus_end - minus_begin, minus_begin,
1036                                line_prefix);
1037        }
1038        if (plus_begin != plus_end) {
1039                fn_out_diff_words_write_helper(diff_words->opt->file,
1040                                &style->new, style->newline,
1041                                plus_end - plus_begin, plus_begin,
1042                                line_prefix);
1043        }
1044
1045        diff_words->current_plus = plus_end;
1046        diff_words->last_minus = minus_first;
1047}
1048
1049/* This function starts looking at *begin, and returns 0 iff a word was found. */
1050static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
1051                int *begin, int *end)
1052{
1053        if (word_regex && *begin < buffer->size) {
1054                regmatch_t match[1];
1055                if (!regexec_buf(word_regex, buffer->ptr + *begin,
1056                                 buffer->size - *begin, 1, match, 0)) {
1057                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
1058                                        '\n', match[0].rm_eo - match[0].rm_so);
1059                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
1060                        *begin += match[0].rm_so;
1061                        return *begin >= *end;
1062                }
1063                return -1;
1064        }
1065
1066        /* find the next word */
1067        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
1068                (*begin)++;
1069        if (*begin >= buffer->size)
1070                return -1;
1071
1072        /* find the end of the word */
1073        *end = *begin + 1;
1074        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
1075                (*end)++;
1076
1077        return 0;
1078}
1079
1080/*
1081 * This function splits the words in buffer->text, stores the list with
1082 * newline separator into out, and saves the offsets of the original words
1083 * in buffer->orig.
1084 */
1085static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
1086                regex_t *word_regex)
1087{
1088        int i, j;
1089        long alloc = 0;
1090
1091        out->size = 0;
1092        out->ptr = NULL;
1093
1094        /* fake an empty "0th" word */
1095        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
1096        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
1097        buffer->orig_nr = 1;
1098
1099        for (i = 0; i < buffer->text.size; i++) {
1100                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
1101                        return;
1102
1103                /* store original boundaries */
1104                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
1105                                buffer->orig_alloc);
1106                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
1107                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
1108                buffer->orig_nr++;
1109
1110                /* store one word */
1111                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
1112                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
1113                out->ptr[out->size + j - i] = '\n';
1114                out->size += j - i + 1;
1115
1116                i = j - 1;
1117        }
1118}
1119
1120/* this executes the word diff on the accumulated buffers */
1121static void diff_words_show(struct diff_words_data *diff_words)
1122{
1123        xpparam_t xpp;
1124        xdemitconf_t xecfg;
1125        mmfile_t minus, plus;
1126        struct diff_words_style *style = diff_words->style;
1127
1128        struct diff_options *opt = diff_words->opt;
1129        const char *line_prefix;
1130
1131        assert(opt);
1132        line_prefix = diff_line_prefix(opt);
1133
1134        /* special case: only removal */
1135        if (!diff_words->plus.text.size) {
1136                fputs(line_prefix, diff_words->opt->file);
1137                fn_out_diff_words_write_helper(diff_words->opt->file,
1138                        &style->old, style->newline,
1139                        diff_words->minus.text.size,
1140                        diff_words->minus.text.ptr, line_prefix);
1141                diff_words->minus.text.size = 0;
1142                return;
1143        }
1144
1145        diff_words->current_plus = diff_words->plus.text.ptr;
1146        diff_words->last_minus = 0;
1147
1148        memset(&xpp, 0, sizeof(xpp));
1149        memset(&xecfg, 0, sizeof(xecfg));
1150        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
1151        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
1152        xpp.flags = 0;
1153        /* as only the hunk header will be parsed, we need a 0-context */
1154        xecfg.ctxlen = 0;
1155        if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
1156                          &xpp, &xecfg))
1157                die("unable to generate word diff");
1158        free(minus.ptr);
1159        free(plus.ptr);
1160        if (diff_words->current_plus != diff_words->plus.text.ptr +
1161                        diff_words->plus.text.size) {
1162                if (color_words_output_graph_prefix(diff_words))
1163                        fputs(line_prefix, diff_words->opt->file);
1164                fn_out_diff_words_write_helper(diff_words->opt->file,
1165                        &style->ctx, style->newline,
1166                        diff_words->plus.text.ptr + diff_words->plus.text.size
1167                        - diff_words->current_plus, diff_words->current_plus,
1168                        line_prefix);
1169        }
1170        diff_words->minus.text.size = diff_words->plus.text.size = 0;
1171}
1172
1173/* In "color-words" mode, show word-diff of words accumulated in the buffer */
1174static void diff_words_flush(struct emit_callback *ecbdata)
1175{
1176        if (ecbdata->diff_words->minus.text.size ||
1177            ecbdata->diff_words->plus.text.size)
1178                diff_words_show(ecbdata->diff_words);
1179}
1180
1181static void diff_filespec_load_driver(struct diff_filespec *one)
1182{
1183        /* Use already-loaded driver */
1184        if (one->driver)
1185                return;
1186
1187        if (S_ISREG(one->mode))
1188                one->driver = userdiff_find_by_path(one->path);
1189
1190        /* Fallback to default settings */
1191        if (!one->driver)
1192                one->driver = userdiff_find_by_name("default");
1193}
1194
1195static const char *userdiff_word_regex(struct diff_filespec *one)
1196{
1197        diff_filespec_load_driver(one);
1198        return one->driver->word_regex;
1199}
1200
1201static void init_diff_words_data(struct emit_callback *ecbdata,
1202                                 struct diff_options *orig_opts,
1203                                 struct diff_filespec *one,
1204                                 struct diff_filespec *two)
1205{
1206        int i;
1207        struct diff_options *o = xmalloc(sizeof(struct diff_options));
1208        memcpy(o, orig_opts, sizeof(struct diff_options));
1209
1210        ecbdata->diff_words =
1211                xcalloc(1, sizeof(struct diff_words_data));
1212        ecbdata->diff_words->type = o->word_diff;
1213        ecbdata->diff_words->opt = o;
1214        if (!o->word_regex)
1215                o->word_regex = userdiff_word_regex(one);
1216        if (!o->word_regex)
1217                o->word_regex = userdiff_word_regex(two);
1218        if (!o->word_regex)
1219                o->word_regex = diff_word_regex_cfg;
1220        if (o->word_regex) {
1221                ecbdata->diff_words->word_regex = (regex_t *)
1222                        xmalloc(sizeof(regex_t));
1223                if (regcomp(ecbdata->diff_words->word_regex,
1224                            o->word_regex,
1225                            REG_EXTENDED | REG_NEWLINE))
1226                        die ("Invalid regular expression: %s",
1227                             o->word_regex);
1228        }
1229        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
1230                if (o->word_diff == diff_words_styles[i].type) {
1231                        ecbdata->diff_words->style =
1232                                &diff_words_styles[i];
1233                        break;
1234                }
1235        }
1236        if (want_color(o->use_color)) {
1237                struct diff_words_style *st = ecbdata->diff_words->style;
1238                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
1239                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
1240                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
1241        }
1242}
1243
1244static void free_diff_words_data(struct emit_callback *ecbdata)
1245{
1246        if (ecbdata->diff_words) {
1247                diff_words_flush(ecbdata);
1248                free (ecbdata->diff_words->opt);
1249                free (ecbdata->diff_words->minus.text.ptr);
1250                free (ecbdata->diff_words->minus.orig);
1251                free (ecbdata->diff_words->plus.text.ptr);
1252                free (ecbdata->diff_words->plus.orig);
1253                if (ecbdata->diff_words->word_regex) {
1254                        regfree(ecbdata->diff_words->word_regex);
1255                        free(ecbdata->diff_words->word_regex);
1256                }
1257                FREE_AND_NULL(ecbdata->diff_words);
1258        }
1259}
1260
1261const char *diff_get_color(int diff_use_color, enum color_diff ix)
1262{
1263        if (want_color(diff_use_color))
1264                return diff_colors[ix];
1265        return "";
1266}
1267
1268const char *diff_line_prefix(struct diff_options *opt)
1269{
1270        struct strbuf *msgbuf;
1271        if (!opt->output_prefix)
1272                return "";
1273
1274        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
1275        return msgbuf->buf;
1276}
1277
1278static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
1279{
1280        const char *cp;
1281        unsigned long allot;
1282        size_t l = len;
1283
1284        if (ecb->truncate)
1285                return ecb->truncate(line, len);
1286        cp = line;
1287        allot = l;
1288        while (0 < l) {
1289                (void) utf8_width(&cp, &l);
1290                if (!cp)
1291                        break; /* truncated in the middle? */
1292        }
1293        return allot - l;
1294}
1295
1296static void find_lno(const char *line, struct emit_callback *ecbdata)
1297{
1298        const char *p;
1299        ecbdata->lno_in_preimage = 0;
1300        ecbdata->lno_in_postimage = 0;
1301        p = strchr(line, '-');
1302        if (!p)
1303                return; /* cannot happen */
1304        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1305        p = strchr(p, '+');
1306        if (!p)
1307                return; /* cannot happen */
1308        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
1309}
1310
1311static void fn_out_consume(void *priv, char *line, unsigned long len)
1312{
1313        struct emit_callback *ecbdata = priv;
1314        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
1315        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
1316        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1317        struct diff_options *o = ecbdata->opt;
1318        const char *line_prefix = diff_line_prefix(o);
1319
1320        o->found_changes = 1;
1321
1322        if (ecbdata->header) {
1323                fprintf(o->file, "%s", ecbdata->header->buf);
1324                strbuf_reset(ecbdata->header);
1325                ecbdata->header = NULL;
1326        }
1327
1328        if (ecbdata->label_path[0]) {
1329                const char *name_a_tab, *name_b_tab;
1330
1331                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
1332                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
1333
1334                fprintf(o->file, "%s%s--- %s%s%s\n",
1335                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
1336                fprintf(o->file, "%s%s+++ %s%s%s\n",
1337                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1338                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1339        }
1340
1341        if (diff_suppress_blank_empty
1342            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1343                line[0] = '\n';
1344                len = 1;
1345        }
1346
1347        if (line[0] == '@') {
1348                if (ecbdata->diff_words)
1349                        diff_words_flush(ecbdata);
1350                len = sane_truncate_line(ecbdata, line, len);
1351                find_lno(line, ecbdata);
1352                emit_hunk_header(ecbdata, line, len);
1353                return;
1354        }
1355
1356        if (ecbdata->diff_words) {
1357                if (line[0] == '-') {
1358                        diff_words_append(line, len,
1359                                          &ecbdata->diff_words->minus);
1360                        return;
1361                } else if (line[0] == '+') {
1362                        diff_words_append(line, len,
1363                                          &ecbdata->diff_words->plus);
1364                        return;
1365                } else if (starts_with(line, "\\ ")) {
1366                        /*
1367                         * Eat the "no newline at eof" marker as if we
1368                         * saw a "+" or "-" line with nothing on it,
1369                         * and return without diff_words_flush() to
1370                         * defer processing. If this is the end of
1371                         * preimage, more "+" lines may come after it.
1372                         */
1373                        return;
1374                }
1375                diff_words_flush(ecbdata);
1376                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1377                        emit_line(o, context, reset, line, len);
1378                        fputs("~\n", o->file);
1379                } else {
1380                        /*
1381                         * Skip the prefix character, if any.  With
1382                         * diff_suppress_blank_empty, there may be
1383                         * none.
1384                         */
1385                        if (line[0] != '\n') {
1386                              line++;
1387                              len--;
1388                        }
1389                        emit_line(o, context, reset, line, len);
1390                }
1391                return;
1392        }
1393
1394        switch (line[0]) {
1395        case '+':
1396                ecbdata->lno_in_postimage++;
1397                emit_add_line(reset, ecbdata, line + 1, len - 1);
1398                break;
1399        case '-':
1400                ecbdata->lno_in_preimage++;
1401                emit_del_line(reset, ecbdata, line + 1, len - 1);
1402                break;
1403        case ' ':
1404                ecbdata->lno_in_postimage++;
1405                ecbdata->lno_in_preimage++;
1406                emit_context_line(reset, ecbdata, line + 1, len - 1);
1407                break;
1408        default:
1409                /* incomplete line at the end */
1410                ecbdata->lno_in_preimage++;
1411                emit_line(o, diff_get_color(ecbdata->color_diff, DIFF_CONTEXT),
1412                          reset, line, len);
1413                break;
1414        }
1415}
1416
1417static char *pprint_rename(const char *a, const char *b)
1418{
1419        const char *old = a;
1420        const char *new = b;
1421        struct strbuf name = STRBUF_INIT;
1422        int pfx_length, sfx_length;
1423        int pfx_adjust_for_slash;
1424        int len_a = strlen(a);
1425        int len_b = strlen(b);
1426        int a_midlen, b_midlen;
1427        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1428        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1429
1430        if (qlen_a || qlen_b) {
1431                quote_c_style(a, &name, NULL, 0);
1432                strbuf_addstr(&name, " => ");
1433                quote_c_style(b, &name, NULL, 0);
1434                return strbuf_detach(&name, NULL);
1435        }
1436
1437        /* Find common prefix */
1438        pfx_length = 0;
1439        while (*old && *new && *old == *new) {
1440                if (*old == '/')
1441                        pfx_length = old - a + 1;
1442                old++;
1443                new++;
1444        }
1445
1446        /* Find common suffix */
1447        old = a + len_a;
1448        new = b + len_b;
1449        sfx_length = 0;
1450        /*
1451         * If there is a common prefix, it must end in a slash.  In
1452         * that case we let this loop run 1 into the prefix to see the
1453         * same slash.
1454         *
1455         * If there is no common prefix, we cannot do this as it would
1456         * underrun the input strings.
1457         */
1458        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
1459        while (a + pfx_length - pfx_adjust_for_slash <= old &&
1460               b + pfx_length - pfx_adjust_for_slash <= new &&
1461               *old == *new) {
1462                if (*old == '/')
1463                        sfx_length = len_a - (old - a);
1464                old--;
1465                new--;
1466        }
1467
1468        /*
1469         * pfx{mid-a => mid-b}sfx
1470         * {pfx-a => pfx-b}sfx
1471         * pfx{sfx-a => sfx-b}
1472         * name-a => name-b
1473         */
1474        a_midlen = len_a - pfx_length - sfx_length;
1475        b_midlen = len_b - pfx_length - sfx_length;
1476        if (a_midlen < 0)
1477                a_midlen = 0;
1478        if (b_midlen < 0)
1479                b_midlen = 0;
1480
1481        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1482        if (pfx_length + sfx_length) {
1483                strbuf_add(&name, a, pfx_length);
1484                strbuf_addch(&name, '{');
1485        }
1486        strbuf_add(&name, a + pfx_length, a_midlen);
1487        strbuf_addstr(&name, " => ");
1488        strbuf_add(&name, b + pfx_length, b_midlen);
1489        if (pfx_length + sfx_length) {
1490                strbuf_addch(&name, '}');
1491                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1492        }
1493        return strbuf_detach(&name, NULL);
1494}
1495
1496struct diffstat_t {
1497        int nr;
1498        int alloc;
1499        struct diffstat_file {
1500                char *from_name;
1501                char *name;
1502                char *print_name;
1503                unsigned is_unmerged:1;
1504                unsigned is_binary:1;
1505                unsigned is_renamed:1;
1506                unsigned is_interesting:1;
1507                uintmax_t added, deleted;
1508        } **files;
1509};
1510
1511static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1512                                          const char *name_a,
1513                                          const char *name_b)
1514{
1515        struct diffstat_file *x;
1516        x = xcalloc(1, sizeof(*x));
1517        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
1518        diffstat->files[diffstat->nr++] = x;
1519        if (name_b) {
1520                x->from_name = xstrdup(name_a);
1521                x->name = xstrdup(name_b);
1522                x->is_renamed = 1;
1523        }
1524        else {
1525                x->from_name = NULL;
1526                x->name = xstrdup(name_a);
1527        }
1528        return x;
1529}
1530
1531static void diffstat_consume(void *priv, char *line, unsigned long len)
1532{
1533        struct diffstat_t *diffstat = priv;
1534        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1535
1536        if (line[0] == '+')
1537                x->added++;
1538        else if (line[0] == '-')
1539                x->deleted++;
1540}
1541
1542const char mime_boundary_leader[] = "------------";
1543
1544static int scale_linear(int it, int width, int max_change)
1545{
1546        if (!it)
1547                return 0;
1548        /*
1549         * make sure that at least one '-' or '+' is printed if
1550         * there is any change to this path. The easiest way is to
1551         * scale linearly as if the alloted width is one column shorter
1552         * than it is, and then add 1 to the result.
1553         */
1554        return 1 + (it * (width - 1) / max_change);
1555}
1556
1557static void show_name(FILE *file,
1558                      const char *prefix, const char *name, int len)
1559{
1560        fprintf(file, " %s%-*s |", prefix, len, name);
1561}
1562
1563static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1564{
1565        if (cnt <= 0)
1566                return;
1567        fprintf(file, "%s", set);
1568        while (cnt--)
1569                putc(ch, file);
1570        fprintf(file, "%s", reset);
1571}
1572
1573static void fill_print_name(struct diffstat_file *file)
1574{
1575        char *pname;
1576
1577        if (file->print_name)
1578                return;
1579
1580        if (!file->is_renamed) {
1581                struct strbuf buf = STRBUF_INIT;
1582                if (quote_c_style(file->name, &buf, NULL, 0)) {
1583                        pname = strbuf_detach(&buf, NULL);
1584                } else {
1585                        pname = file->name;
1586                        strbuf_release(&buf);
1587                }
1588        } else {
1589                pname = pprint_rename(file->from_name, file->name);
1590        }
1591        file->print_name = pname;
1592}
1593
1594int print_stat_summary(FILE *fp, int files, int insertions, int deletions)
1595{
1596        struct strbuf sb = STRBUF_INIT;
1597        int ret;
1598
1599        if (!files) {
1600                assert(insertions == 0 && deletions == 0);
1601                return fprintf(fp, "%s\n", " 0 files changed");
1602        }
1603
1604        strbuf_addf(&sb,
1605                    (files == 1) ? " %d file changed" : " %d files changed",
1606                    files);
1607
1608        /*
1609         * For binary diff, the caller may want to print "x files
1610         * changed" with insertions == 0 && deletions == 0.
1611         *
1612         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
1613         * is probably less confusing (i.e skip over "2 files changed
1614         * but nothing about added/removed lines? Is this a bug in Git?").
1615         */
1616        if (insertions || deletions == 0) {
1617                strbuf_addf(&sb,
1618                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
1619                            insertions);
1620        }
1621
1622        if (deletions || insertions == 0) {
1623                strbuf_addf(&sb,
1624                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
1625                            deletions);
1626        }
1627        strbuf_addch(&sb, '\n');
1628        ret = fputs(sb.buf, fp);
1629        strbuf_release(&sb);
1630        return ret;
1631}
1632
1633static void show_stats(struct diffstat_t *data, struct diff_options *options)
1634{
1635        int i, len, add, del, adds = 0, dels = 0;
1636        uintmax_t max_change = 0, max_len = 0;
1637        int total_files = data->nr, count;
1638        int width, name_width, graph_width, number_width = 0, bin_width = 0;
1639        const char *reset, *add_c, *del_c;
1640        const char *line_prefix = "";
1641        int extra_shown = 0;
1642
1643        if (data->nr == 0)
1644                return;
1645
1646        line_prefix = diff_line_prefix(options);
1647        count = options->stat_count ? options->stat_count : data->nr;
1648
1649        reset = diff_get_color_opt(options, DIFF_RESET);
1650        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1651        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1652
1653        /*
1654         * Find the longest filename and max number of changes
1655         */
1656        for (i = 0; (i < count) && (i < data->nr); i++) {
1657                struct diffstat_file *file = data->files[i];
1658                uintmax_t change = file->added + file->deleted;
1659
1660                if (!file->is_interesting && (change == 0)) {
1661                        count++; /* not shown == room for one more */
1662                        continue;
1663                }
1664                fill_print_name(file);
1665                len = strlen(file->print_name);
1666                if (max_len < len)
1667                        max_len = len;
1668
1669                if (file->is_unmerged) {
1670                        /* "Unmerged" is 8 characters */
1671                        bin_width = bin_width < 8 ? 8 : bin_width;
1672                        continue;
1673                }
1674                if (file->is_binary) {
1675                        /* "Bin XXX -> YYY bytes" */
1676                        int w = 14 + decimal_width(file->added)
1677                                + decimal_width(file->deleted);
1678                        bin_width = bin_width < w ? w : bin_width;
1679                        /* Display change counts aligned with "Bin" */
1680                        number_width = 3;
1681                        continue;
1682                }
1683
1684                if (max_change < change)
1685                        max_change = change;
1686        }
1687        count = i; /* where we can stop scanning in data->files[] */
1688
1689        /*
1690         * We have width = stat_width or term_columns() columns total.
1691         * We want a maximum of min(max_len, stat_name_width) for the name part.
1692         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
1693         * We also need 1 for " " and 4 + decimal_width(max_change)
1694         * for " | NNNN " and one the empty column at the end, altogether
1695         * 6 + decimal_width(max_change).
1696         *
1697         * If there's not enough space, we will use the smaller of
1698         * stat_name_width (if set) and 5/8*width for the filename,
1699         * and the rest for constant elements + graph part, but no more
1700         * than stat_graph_width for the graph part.
1701         * (5/8 gives 50 for filename and 30 for the constant parts + graph
1702         * for the standard terminal size).
1703         *
1704         * In other words: stat_width limits the maximum width, and
1705         * stat_name_width fixes the maximum width of the filename,
1706         * and is also used to divide available columns if there
1707         * aren't enough.
1708         *
1709         * Binary files are displayed with "Bin XXX -> YYY bytes"
1710         * instead of the change count and graph. This part is treated
1711         * similarly to the graph part, except that it is not
1712         * "scaled". If total width is too small to accommodate the
1713         * guaranteed minimum width of the filename part and the
1714         * separators and this message, this message will "overflow"
1715         * making the line longer than the maximum width.
1716         */
1717
1718        if (options->stat_width == -1)
1719                width = term_columns() - strlen(line_prefix);
1720        else
1721                width = options->stat_width ? options->stat_width : 80;
1722        number_width = decimal_width(max_change) > number_width ?
1723                decimal_width(max_change) : number_width;
1724
1725        if (options->stat_graph_width == -1)
1726                options->stat_graph_width = diff_stat_graph_width;
1727
1728        /*
1729         * Guarantee 3/8*16==6 for the graph part
1730         * and 5/8*16==10 for the filename part
1731         */
1732        if (width < 16 + 6 + number_width)
1733                width = 16 + 6 + number_width;
1734
1735        /*
1736         * First assign sizes that are wanted, ignoring available width.
1737         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
1738         * starting from "XXX" should fit in graph_width.
1739         */
1740        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
1741        if (options->stat_graph_width &&
1742            options->stat_graph_width < graph_width)
1743                graph_width = options->stat_graph_width;
1744
1745        name_width = (options->stat_name_width > 0 &&
1746                      options->stat_name_width < max_len) ?
1747                options->stat_name_width : max_len;
1748
1749        /*
1750         * Adjust adjustable widths not to exceed maximum width
1751         */
1752        if (name_width + number_width + 6 + graph_width > width) {
1753                if (graph_width > width * 3/8 - number_width - 6) {
1754                        graph_width = width * 3/8 - number_width - 6;
1755                        if (graph_width < 6)
1756                                graph_width = 6;
1757                }
1758
1759                if (options->stat_graph_width &&
1760                    graph_width > options->stat_graph_width)
1761                        graph_width = options->stat_graph_width;
1762                if (name_width > width - number_width - 6 - graph_width)
1763                        name_width = width - number_width - 6 - graph_width;
1764                else
1765                        graph_width = width - number_width - 6 - name_width;
1766        }
1767
1768        /*
1769         * From here name_width is the width of the name area,
1770         * and graph_width is the width of the graph area.
1771         * max_change is used to scale graph properly.
1772         */
1773        for (i = 0; i < count; i++) {
1774                const char *prefix = "";
1775                struct diffstat_file *file = data->files[i];
1776                char *name = file->print_name;
1777                uintmax_t added = file->added;
1778                uintmax_t deleted = file->deleted;
1779                int name_len;
1780
1781                if (!file->is_interesting && (added + deleted == 0))
1782                        continue;
1783
1784                /*
1785                 * "scale" the filename
1786                 */
1787                len = name_width;
1788                name_len = strlen(name);
1789                if (name_width < name_len) {
1790                        char *slash;
1791                        prefix = "...";
1792                        len -= 3;
1793                        name += name_len - len;
1794                        slash = strchr(name, '/');
1795                        if (slash)
1796                                name = slash;
1797                }
1798
1799                if (file->is_binary) {
1800                        fprintf(options->file, "%s", line_prefix);
1801                        show_name(options->file, prefix, name, len);
1802                        fprintf(options->file, " %*s", number_width, "Bin");
1803                        if (!added && !deleted) {
1804                                putc('\n', options->file);
1805                                continue;
1806                        }
1807                        fprintf(options->file, " %s%"PRIuMAX"%s",
1808                                del_c, deleted, reset);
1809                        fprintf(options->file, " -> ");
1810                        fprintf(options->file, "%s%"PRIuMAX"%s",
1811                                add_c, added, reset);
1812                        fprintf(options->file, " bytes");
1813                        fprintf(options->file, "\n");
1814                        continue;
1815                }
1816                else if (file->is_unmerged) {
1817                        fprintf(options->file, "%s", line_prefix);
1818                        show_name(options->file, prefix, name, len);
1819                        fprintf(options->file, " Unmerged\n");
1820                        continue;
1821                }
1822
1823                /*
1824                 * scale the add/delete
1825                 */
1826                add = added;
1827                del = deleted;
1828
1829                if (graph_width <= max_change) {
1830                        int total = scale_linear(add + del, graph_width, max_change);
1831                        if (total < 2 && add && del)
1832                                /* width >= 2 due to the sanity check */
1833                                total = 2;
1834                        if (add < del) {
1835                                add = scale_linear(add, graph_width, max_change);
1836                                del = total - add;
1837                        } else {
1838                                del = scale_linear(del, graph_width, max_change);
1839                                add = total - del;
1840                        }
1841                }
1842                fprintf(options->file, "%s", line_prefix);
1843                show_name(options->file, prefix, name, len);
1844                fprintf(options->file, " %*"PRIuMAX"%s",
1845                        number_width, added + deleted,
1846                        added + deleted ? " " : "");
1847                show_graph(options->file, '+', add, add_c, reset);
1848                show_graph(options->file, '-', del, del_c, reset);
1849                fprintf(options->file, "\n");
1850        }
1851
1852        for (i = 0; i < data->nr; i++) {
1853                struct diffstat_file *file = data->files[i];
1854                uintmax_t added = file->added;
1855                uintmax_t deleted = file->deleted;
1856
1857                if (file->is_unmerged ||
1858                    (!file->is_interesting && (added + deleted == 0))) {
1859                        total_files--;
1860                        continue;
1861                }
1862
1863                if (!file->is_binary) {
1864                        adds += added;
1865                        dels += deleted;
1866                }
1867                if (i < count)
1868                        continue;
1869                if (!extra_shown)
1870                        fprintf(options->file, "%s ...\n", line_prefix);
1871                extra_shown = 1;
1872        }
1873        fprintf(options->file, "%s", line_prefix);
1874        print_stat_summary(options->file, total_files, adds, dels);
1875}
1876
1877static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1878{
1879        int i, adds = 0, dels = 0, total_files = data->nr;
1880
1881        if (data->nr == 0)
1882                return;
1883
1884        for (i = 0; i < data->nr; i++) {
1885                int added = data->files[i]->added;
1886                int deleted= data->files[i]->deleted;
1887
1888                if (data->files[i]->is_unmerged ||
1889                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
1890                        total_files--;
1891                } else if (!data->files[i]->is_binary) { /* don't count bytes */
1892                        adds += added;
1893                        dels += deleted;
1894                }
1895        }
1896        fprintf(options->file, "%s", diff_line_prefix(options));
1897        print_stat_summary(options->file, total_files, adds, dels);
1898}
1899
1900static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1901{
1902        int i;
1903
1904        if (data->nr == 0)
1905                return;
1906
1907        for (i = 0; i < data->nr; i++) {
1908                struct diffstat_file *file = data->files[i];
1909
1910                fprintf(options->file, "%s", diff_line_prefix(options));
1911
1912                if (file->is_binary)
1913                        fprintf(options->file, "-\t-\t");
1914                else
1915                        fprintf(options->file,
1916                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1917                                file->added, file->deleted);
1918                if (options->line_termination) {
1919                        fill_print_name(file);
1920                        if (!file->is_renamed)
1921                                write_name_quoted(file->name, options->file,
1922                                                  options->line_termination);
1923                        else {
1924                                fputs(file->print_name, options->file);
1925                                putc(options->line_termination, options->file);
1926                        }
1927                } else {
1928                        if (file->is_renamed) {
1929                                putc('\0', options->file);
1930                                write_name_quoted(file->from_name, options->file, '\0');
1931                        }
1932                        write_name_quoted(file->name, options->file, '\0');
1933                }
1934        }
1935}
1936
1937struct dirstat_file {
1938        const char *name;
1939        unsigned long changed;
1940};
1941
1942struct dirstat_dir {
1943        struct dirstat_file *files;
1944        int alloc, nr, permille, cumulative;
1945};
1946
1947static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1948                unsigned long changed, const char *base, int baselen)
1949{
1950        unsigned long this_dir = 0;
1951        unsigned int sources = 0;
1952        const char *line_prefix = diff_line_prefix(opt);
1953
1954        while (dir->nr) {
1955                struct dirstat_file *f = dir->files;
1956                int namelen = strlen(f->name);
1957                unsigned long this;
1958                char *slash;
1959
1960                if (namelen < baselen)
1961                        break;
1962                if (memcmp(f->name, base, baselen))
1963                        break;
1964                slash = strchr(f->name + baselen, '/');
1965                if (slash) {
1966                        int newbaselen = slash + 1 - f->name;
1967                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1968                        sources++;
1969                } else {
1970                        this = f->changed;
1971                        dir->files++;
1972                        dir->nr--;
1973                        sources += 2;
1974                }
1975                this_dir += this;
1976        }
1977
1978        /*
1979         * We don't report dirstat's for
1980         *  - the top level
1981         *  - or cases where everything came from a single directory
1982         *    under this directory (sources == 1).
1983         */
1984        if (baselen && sources != 1) {
1985                if (this_dir) {
1986                        int permille = this_dir * 1000 / changed;
1987                        if (permille >= dir->permille) {
1988                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1989                                        permille / 10, permille % 10, baselen, base);
1990                                if (!dir->cumulative)
1991                                        return 0;
1992                        }
1993                }
1994        }
1995        return this_dir;
1996}
1997
1998static int dirstat_compare(const void *_a, const void *_b)
1999{
2000        const struct dirstat_file *a = _a;
2001        const struct dirstat_file *b = _b;
2002        return strcmp(a->name, b->name);
2003}
2004
2005static void show_dirstat(struct diff_options *options)
2006{
2007        int i;
2008        unsigned long changed;
2009        struct dirstat_dir dir;
2010        struct diff_queue_struct *q = &diff_queued_diff;
2011
2012        dir.files = NULL;
2013        dir.alloc = 0;
2014        dir.nr = 0;
2015        dir.permille = options->dirstat_permille;
2016        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
2017
2018        changed = 0;
2019        for (i = 0; i < q->nr; i++) {
2020                struct diff_filepair *p = q->queue[i];
2021                const char *name;
2022                unsigned long copied, added, damage;
2023                int content_changed;
2024
2025                name = p->two->path ? p->two->path : p->one->path;
2026
2027                if (p->one->oid_valid && p->two->oid_valid)
2028                        content_changed = oidcmp(&p->one->oid, &p->two->oid);
2029                else
2030                        content_changed = 1;
2031
2032                if (!content_changed) {
2033                        /*
2034                         * The SHA1 has not changed, so pre-/post-content is
2035                         * identical. We can therefore skip looking at the
2036                         * file contents altogether.
2037                         */
2038                        damage = 0;
2039                        goto found_damage;
2040                }
2041
2042                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
2043                        /*
2044                         * In --dirstat-by-file mode, we don't really need to
2045                         * look at the actual file contents at all.
2046                         * The fact that the SHA1 changed is enough for us to
2047                         * add this file to the list of results
2048                         * (with each file contributing equal damage).
2049                         */
2050                        damage = 1;
2051                        goto found_damage;
2052                }
2053
2054                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
2055                        diff_populate_filespec(p->one, 0);
2056                        diff_populate_filespec(p->two, 0);
2057                        diffcore_count_changes(p->one, p->two, NULL, NULL,
2058                                               &copied, &added);
2059                        diff_free_filespec_data(p->one);
2060                        diff_free_filespec_data(p->two);
2061                } else if (DIFF_FILE_VALID(p->one)) {
2062                        diff_populate_filespec(p->one, CHECK_SIZE_ONLY);
2063                        copied = added = 0;
2064                        diff_free_filespec_data(p->one);
2065                } else if (DIFF_FILE_VALID(p->two)) {
2066                        diff_populate_filespec(p->two, CHECK_SIZE_ONLY);
2067                        copied = 0;
2068                        added = p->two->size;
2069                        diff_free_filespec_data(p->two);
2070                } else
2071                        continue;
2072
2073                /*
2074                 * Original minus copied is the removed material,
2075                 * added is the new material.  They are both damages
2076                 * made to the preimage.
2077                 * If the resulting damage is zero, we know that
2078                 * diffcore_count_changes() considers the two entries to
2079                 * be identical, but since content_changed is true, we
2080                 * know that there must have been _some_ kind of change,
2081                 * so we force all entries to have damage > 0.
2082                 */
2083                damage = (p->one->size - copied) + added;
2084                if (!damage)
2085                        damage = 1;
2086
2087found_damage:
2088                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
2089                dir.files[dir.nr].name = name;
2090                dir.files[dir.nr].changed = damage;
2091                changed += damage;
2092                dir.nr++;
2093        }
2094
2095        /* This can happen even with many files, if everything was renames */
2096        if (!changed)
2097                return;
2098
2099        /* Show all directories with more than x% of the changes */
2100        QSORT(dir.files, dir.nr, dirstat_compare);
2101        gather_dirstat(options, &dir, changed, "", 0);
2102}
2103
2104static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
2105{
2106        int i;
2107        unsigned long changed;
2108        struct dirstat_dir dir;
2109
2110        if (data->nr == 0)
2111                return;
2112
2113        dir.files = NULL;
2114        dir.alloc = 0;
2115        dir.nr = 0;
2116        dir.permille = options->dirstat_permille;
2117        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
2118
2119        changed = 0;
2120        for (i = 0; i < data->nr; i++) {
2121                struct diffstat_file *file = data->files[i];
2122                unsigned long damage = file->added + file->deleted;
2123                if (file->is_binary)
2124                        /*
2125                         * binary files counts bytes, not lines. Must find some
2126                         * way to normalize binary bytes vs. textual lines.
2127                         * The following heuristic assumes that there are 64
2128                         * bytes per "line".
2129                         * This is stupid and ugly, but very cheap...
2130                         */
2131                        damage = (damage + 63) / 64;
2132                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
2133                dir.files[dir.nr].name = file->name;
2134                dir.files[dir.nr].changed = damage;
2135                changed += damage;
2136                dir.nr++;
2137        }
2138
2139        /* This can happen even with many files, if everything was renames */
2140        if (!changed)
2141                return;
2142
2143        /* Show all directories with more than x% of the changes */
2144        QSORT(dir.files, dir.nr, dirstat_compare);
2145        gather_dirstat(options, &dir, changed, "", 0);
2146}
2147
2148static void free_diffstat_info(struct diffstat_t *diffstat)
2149{
2150        int i;
2151        for (i = 0; i < diffstat->nr; i++) {
2152                struct diffstat_file *f = diffstat->files[i];
2153                if (f->name != f->print_name)
2154                        free(f->print_name);
2155                free(f->name);
2156                free(f->from_name);
2157                free(f);
2158        }
2159        free(diffstat->files);
2160}
2161
2162struct checkdiff_t {
2163        const char *filename;
2164        int lineno;
2165        int conflict_marker_size;
2166        struct diff_options *o;
2167        unsigned ws_rule;
2168        unsigned status;
2169};
2170
2171static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
2172{
2173        char firstchar;
2174        int cnt;
2175
2176        if (len < marker_size + 1)
2177                return 0;
2178        firstchar = line[0];
2179        switch (firstchar) {
2180        case '=': case '>': case '<': case '|':
2181                break;
2182        default:
2183                return 0;
2184        }
2185        for (cnt = 1; cnt < marker_size; cnt++)
2186                if (line[cnt] != firstchar)
2187                        return 0;
2188        /* line[1] thru line[marker_size-1] are same as firstchar */
2189        if (len < marker_size + 1 || !isspace(line[marker_size]))
2190                return 0;
2191        return 1;
2192}
2193
2194static void checkdiff_consume(void *priv, char *line, unsigned long len)
2195{
2196        struct checkdiff_t *data = priv;
2197        int marker_size = data->conflict_marker_size;
2198        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
2199        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
2200        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
2201        char *err;
2202        const char *line_prefix;
2203
2204        assert(data->o);
2205        line_prefix = diff_line_prefix(data->o);
2206
2207        if (line[0] == '+') {
2208                unsigned bad;
2209                data->lineno++;
2210                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
2211                        data->status |= 1;
2212                        fprintf(data->o->file,
2213                                "%s%s:%d: leftover conflict marker\n",
2214                                line_prefix, data->filename, data->lineno);
2215                }
2216                bad = ws_check(line + 1, len - 1, data->ws_rule);
2217                if (!bad)
2218                        return;
2219                data->status |= bad;
2220                err = whitespace_error_string(bad);
2221                fprintf(data->o->file, "%s%s:%d: %s.\n",
2222                        line_prefix, data->filename, data->lineno, err);
2223                free(err);
2224                emit_line(data->o, set, reset, line, 1);
2225                ws_check_emit(line + 1, len - 1, data->ws_rule,
2226                              data->o->file, set, reset, ws);
2227        } else if (line[0] == ' ') {
2228                data->lineno++;
2229        } else if (line[0] == '@') {
2230                char *plus = strchr(line, '+');
2231                if (plus)
2232                        data->lineno = strtol(plus, NULL, 10) - 1;
2233                else
2234                        die("invalid diff");
2235        }
2236}
2237
2238static unsigned char *deflate_it(char *data,
2239                                 unsigned long size,
2240                                 unsigned long *result_size)
2241{
2242        int bound;
2243        unsigned char *deflated;
2244        git_zstream stream;
2245
2246        git_deflate_init(&stream, zlib_compression_level);
2247        bound = git_deflate_bound(&stream, size);
2248        deflated = xmalloc(bound);
2249        stream.next_out = deflated;
2250        stream.avail_out = bound;
2251
2252        stream.next_in = (unsigned char *)data;
2253        stream.avail_in = size;
2254        while (git_deflate(&stream, Z_FINISH) == Z_OK)
2255                ; /* nothing */
2256        git_deflate_end(&stream);
2257        *result_size = stream.total_out;
2258        return deflated;
2259}
2260
2261static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two,
2262                                  const char *prefix)
2263{
2264        void *cp;
2265        void *delta;
2266        void *deflated;
2267        void *data;
2268        unsigned long orig_size;
2269        unsigned long delta_size;
2270        unsigned long deflate_size;
2271        unsigned long data_size;
2272
2273        /* We could do deflated delta, or we could do just deflated two,
2274         * whichever is smaller.
2275         */
2276        delta = NULL;
2277        deflated = deflate_it(two->ptr, two->size, &deflate_size);
2278        if (one->size && two->size) {
2279                delta = diff_delta(one->ptr, one->size,
2280                                   two->ptr, two->size,
2281                                   &delta_size, deflate_size);
2282                if (delta) {
2283                        void *to_free = delta;
2284                        orig_size = delta_size;
2285                        delta = deflate_it(delta, delta_size, &delta_size);
2286                        free(to_free);
2287                }
2288        }
2289
2290        if (delta && delta_size < deflate_size) {
2291                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
2292                free(deflated);
2293                data = delta;
2294                data_size = delta_size;
2295        }
2296        else {
2297                fprintf(file, "%sliteral %lu\n", prefix, two->size);
2298                free(delta);
2299                data = deflated;
2300                data_size = deflate_size;
2301        }
2302
2303        /* emit data encoded in base85 */
2304        cp = data;
2305        while (data_size) {
2306                int bytes = (52 < data_size) ? 52 : data_size;
2307                char line[70];
2308                data_size -= bytes;
2309                if (bytes <= 26)
2310                        line[0] = bytes + 'A' - 1;
2311                else
2312                        line[0] = bytes - 26 + 'a' - 1;
2313                encode_85(line + 1, cp, bytes);
2314                cp = (char *) cp + bytes;
2315                fprintf(file, "%s", prefix);
2316                fputs(line, file);
2317                fputc('\n', file);
2318        }
2319        fprintf(file, "%s\n", prefix);
2320        free(data);
2321}
2322
2323static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two,
2324                             const char *prefix)
2325{
2326        fprintf(file, "%sGIT binary patch\n", prefix);
2327        emit_binary_diff_body(file, one, two, prefix);
2328        emit_binary_diff_body(file, two, one, prefix);
2329}
2330
2331int diff_filespec_is_binary(struct diff_filespec *one)
2332{
2333        if (one->is_binary == -1) {
2334                diff_filespec_load_driver(one);
2335                if (one->driver->binary != -1)
2336                        one->is_binary = one->driver->binary;
2337                else {
2338                        if (!one->data && DIFF_FILE_VALID(one))
2339                                diff_populate_filespec(one, CHECK_BINARY);
2340                        if (one->is_binary == -1 && one->data)
2341                                one->is_binary = buffer_is_binary(one->data,
2342                                                one->size);
2343                        if (one->is_binary == -1)
2344                                one->is_binary = 0;
2345                }
2346        }
2347        return one->is_binary;
2348}
2349
2350static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
2351{
2352        diff_filespec_load_driver(one);
2353        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
2354}
2355
2356void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
2357{
2358        if (!options->a_prefix)
2359                options->a_prefix = a;
2360        if (!options->b_prefix)
2361                options->b_prefix = b;
2362}
2363
2364struct userdiff_driver *get_textconv(struct diff_filespec *one)
2365{
2366        if (!DIFF_FILE_VALID(one))
2367                return NULL;
2368
2369        diff_filespec_load_driver(one);
2370        return userdiff_get_textconv(one->driver);
2371}
2372
2373static void builtin_diff(const char *name_a,
2374                         const char *name_b,
2375                         struct diff_filespec *one,
2376                         struct diff_filespec *two,
2377                         const char *xfrm_msg,
2378                         int must_show_header,
2379                         struct diff_options *o,
2380                         int complete_rewrite)
2381{
2382        mmfile_t mf1, mf2;
2383        const char *lbl[2];
2384        char *a_one, *b_two;
2385        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
2386        const char *reset = diff_get_color_opt(o, DIFF_RESET);
2387        const char *a_prefix, *b_prefix;
2388        struct userdiff_driver *textconv_one = NULL;
2389        struct userdiff_driver *textconv_two = NULL;
2390        struct strbuf header = STRBUF_INIT;
2391        const char *line_prefix = diff_line_prefix(o);
2392
2393        diff_set_mnemonic_prefix(o, "a/", "b/");
2394        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
2395                a_prefix = o->b_prefix;
2396                b_prefix = o->a_prefix;
2397        } else {
2398                a_prefix = o->a_prefix;
2399                b_prefix = o->b_prefix;
2400        }
2401
2402        if (o->submodule_format == DIFF_SUBMODULE_LOG &&
2403            (!one->mode || S_ISGITLINK(one->mode)) &&
2404            (!two->mode || S_ISGITLINK(two->mode))) {
2405                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2406                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2407                show_submodule_summary(o->file, one->path ? one->path : two->path,
2408                                line_prefix,
2409                                &one->oid, &two->oid,
2410                                two->dirty_submodule,
2411                                meta, del, add, reset);
2412                return;
2413        } else if (o->submodule_format == DIFF_SUBMODULE_INLINE_DIFF &&
2414                   (!one->mode || S_ISGITLINK(one->mode)) &&
2415                   (!two->mode || S_ISGITLINK(two->mode))) {
2416                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2417                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2418                show_submodule_inline_diff(o->file, one->path ? one->path : two->path,
2419                                line_prefix,
2420                                &one->oid, &two->oid,
2421                                two->dirty_submodule,
2422                                meta, del, add, reset, o);
2423                return;
2424        }
2425
2426        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
2427                textconv_one = get_textconv(one);
2428                textconv_two = get_textconv(two);
2429        }
2430
2431        /* Never use a non-valid filename anywhere if at all possible */
2432        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
2433        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
2434
2435        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
2436        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
2437        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
2438        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
2439        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
2440        if (lbl[0][0] == '/') {
2441                /* /dev/null */
2442                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
2443                if (xfrm_msg)
2444                        strbuf_addstr(&header, xfrm_msg);
2445                must_show_header = 1;
2446        }
2447        else if (lbl[1][0] == '/') {
2448                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
2449                if (xfrm_msg)
2450                        strbuf_addstr(&header, xfrm_msg);
2451                must_show_header = 1;
2452        }
2453        else {
2454                if (one->mode != two->mode) {
2455                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
2456                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
2457                        must_show_header = 1;
2458                }
2459                if (xfrm_msg)
2460                        strbuf_addstr(&header, xfrm_msg);
2461
2462                /*
2463                 * we do not run diff between different kind
2464                 * of objects.
2465                 */
2466                if ((one->mode ^ two->mode) & S_IFMT)
2467                        goto free_ab_and_return;
2468                if (complete_rewrite &&
2469                    (textconv_one || !diff_filespec_is_binary(one)) &&
2470                    (textconv_two || !diff_filespec_is_binary(two))) {
2471                        fprintf(o->file, "%s", header.buf);
2472                        strbuf_reset(&header);
2473                        emit_rewrite_diff(name_a, name_b, one, two,
2474                                                textconv_one, textconv_two, o);
2475                        o->found_changes = 1;
2476                        goto free_ab_and_return;
2477                }
2478        }
2479
2480        if (o->irreversible_delete && lbl[1][0] == '/') {
2481                fprintf(o->file, "%s", header.buf);
2482                strbuf_reset(&header);
2483                goto free_ab_and_return;
2484        } else if (!DIFF_OPT_TST(o, TEXT) &&
2485            ( (!textconv_one && diff_filespec_is_binary(one)) ||
2486              (!textconv_two && diff_filespec_is_binary(two)) )) {
2487                if (!one->data && !two->data &&
2488                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
2489                    !DIFF_OPT_TST(o, BINARY)) {
2490                        if (!oidcmp(&one->oid, &two->oid)) {
2491                                if (must_show_header)
2492                                        fprintf(o->file, "%s", header.buf);
2493                                goto free_ab_and_return;
2494                        }
2495                        fprintf(o->file, "%s", header.buf);
2496                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2497                                line_prefix, lbl[0], lbl[1]);
2498                        goto free_ab_and_return;
2499                }
2500                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2501                        die("unable to read files to diff");
2502                /* Quite common confusing case */
2503                if (mf1.size == mf2.size &&
2504                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2505                        if (must_show_header)
2506                                fprintf(o->file, "%s", header.buf);
2507                        goto free_ab_and_return;
2508                }
2509                fprintf(o->file, "%s", header.buf);
2510                strbuf_reset(&header);
2511                if (DIFF_OPT_TST(o, BINARY))
2512                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2513                else
2514                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2515                                line_prefix, lbl[0], lbl[1]);
2516                o->found_changes = 1;
2517        } else {
2518                /* Crazy xdl interfaces.. */
2519                const char *diffopts = getenv("GIT_DIFF_OPTS");
2520                const char *v;
2521                xpparam_t xpp;
2522                xdemitconf_t xecfg;
2523                struct emit_callback ecbdata;
2524                const struct userdiff_funcname *pe;
2525
2526                if (must_show_header) {
2527                        fprintf(o->file, "%s", header.buf);
2528                        strbuf_reset(&header);
2529                }
2530
2531                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2532                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2533
2534                pe = diff_funcname_pattern(one);
2535                if (!pe)
2536                        pe = diff_funcname_pattern(two);
2537
2538                memset(&xpp, 0, sizeof(xpp));
2539                memset(&xecfg, 0, sizeof(xecfg));
2540                memset(&ecbdata, 0, sizeof(ecbdata));
2541                ecbdata.label_path = lbl;
2542                ecbdata.color_diff = want_color(o->use_color);
2543                ecbdata.ws_rule = whitespace_rule(name_b);
2544                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2545                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2546                ecbdata.opt = o;
2547                ecbdata.header = header.len ? &header : NULL;
2548                xpp.flags = o->xdl_opts;
2549                xecfg.ctxlen = o->context;
2550                xecfg.interhunkctxlen = o->interhunkcontext;
2551                xecfg.flags = XDL_EMIT_FUNCNAMES;
2552                if (DIFF_OPT_TST(o, FUNCCONTEXT))
2553                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
2554                if (pe)
2555                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2556                if (!diffopts)
2557                        ;
2558                else if (skip_prefix(diffopts, "--unified=", &v))
2559                        xecfg.ctxlen = strtoul(v, NULL, 10);
2560                else if (skip_prefix(diffopts, "-u", &v))
2561                        xecfg.ctxlen = strtoul(v, NULL, 10);
2562                if (o->word_diff)
2563                        init_diff_words_data(&ecbdata, o, one, two);
2564                if (xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2565                                  &xpp, &xecfg))
2566                        die("unable to generate diff for %s", one->path);
2567                if (o->word_diff)
2568                        free_diff_words_data(&ecbdata);
2569                if (textconv_one)
2570                        free(mf1.ptr);
2571                if (textconv_two)
2572                        free(mf2.ptr);
2573                xdiff_clear_find_func(&xecfg);
2574        }
2575
2576 free_ab_and_return:
2577        strbuf_release(&header);
2578        diff_free_filespec_data(one);
2579        diff_free_filespec_data(two);
2580        free(a_one);
2581        free(b_two);
2582        return;
2583}
2584
2585static void builtin_diffstat(const char *name_a, const char *name_b,
2586                             struct diff_filespec *one,
2587                             struct diff_filespec *two,
2588                             struct diffstat_t *diffstat,
2589                             struct diff_options *o,
2590                             struct diff_filepair *p)
2591{
2592        mmfile_t mf1, mf2;
2593        struct diffstat_file *data;
2594        int same_contents;
2595        int complete_rewrite = 0;
2596
2597        if (!DIFF_PAIR_UNMERGED(p)) {
2598                if (p->status == DIFF_STATUS_MODIFIED && p->score)
2599                        complete_rewrite = 1;
2600        }
2601
2602        data = diffstat_add(diffstat, name_a, name_b);
2603        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
2604
2605        if (!one || !two) {
2606                data->is_unmerged = 1;
2607                return;
2608        }
2609
2610        same_contents = !oidcmp(&one->oid, &two->oid);
2611
2612        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2613                data->is_binary = 1;
2614                if (same_contents) {
2615                        data->added = 0;
2616                        data->deleted = 0;
2617                } else {
2618                        data->added = diff_filespec_size(two);
2619                        data->deleted = diff_filespec_size(one);
2620                }
2621        }
2622
2623        else if (complete_rewrite) {
2624                diff_populate_filespec(one, 0);
2625                diff_populate_filespec(two, 0);
2626                data->deleted = count_lines(one->data, one->size);
2627                data->added = count_lines(two->data, two->size);
2628        }
2629
2630        else if (!same_contents) {
2631                /* Crazy xdl interfaces.. */
2632                xpparam_t xpp;
2633                xdemitconf_t xecfg;
2634
2635                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2636                        die("unable to read files to diff");
2637
2638                memset(&xpp, 0, sizeof(xpp));
2639                memset(&xecfg, 0, sizeof(xecfg));
2640                xpp.flags = o->xdl_opts;
2641                xecfg.ctxlen = o->context;
2642                xecfg.interhunkctxlen = o->interhunkcontext;
2643                if (xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2644                                  &xpp, &xecfg))
2645                        die("unable to generate diffstat for %s", one->path);
2646        }
2647
2648        diff_free_filespec_data(one);
2649        diff_free_filespec_data(two);
2650}
2651
2652static void builtin_checkdiff(const char *name_a, const char *name_b,
2653                              const char *attr_path,
2654                              struct diff_filespec *one,
2655                              struct diff_filespec *two,
2656                              struct diff_options *o)
2657{
2658        mmfile_t mf1, mf2;
2659        struct checkdiff_t data;
2660
2661        if (!two)
2662                return;
2663
2664        memset(&data, 0, sizeof(data));
2665        data.filename = name_b ? name_b : name_a;
2666        data.lineno = 0;
2667        data.o = o;
2668        data.ws_rule = whitespace_rule(attr_path);
2669        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2670
2671        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2672                die("unable to read files to diff");
2673
2674        /*
2675         * All the other codepaths check both sides, but not checking
2676         * the "old" side here is deliberate.  We are checking the newly
2677         * introduced changes, and as long as the "new" side is text, we
2678         * can and should check what it introduces.
2679         */
2680        if (diff_filespec_is_binary(two))
2681                goto free_and_return;
2682        else {
2683                /* Crazy xdl interfaces.. */
2684                xpparam_t xpp;
2685                xdemitconf_t xecfg;
2686
2687                memset(&xpp, 0, sizeof(xpp));
2688                memset(&xecfg, 0, sizeof(xecfg));
2689                xecfg.ctxlen = 1; /* at least one context line */
2690                xpp.flags = 0;
2691                if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2692                                  &xpp, &xecfg))
2693                        die("unable to generate checkdiff for %s", one->path);
2694
2695                if (data.ws_rule & WS_BLANK_AT_EOF) {
2696                        struct emit_callback ecbdata;
2697                        int blank_at_eof;
2698
2699                        ecbdata.ws_rule = data.ws_rule;
2700                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2701                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2702
2703                        if (blank_at_eof) {
2704                                static char *err;
2705                                if (!err)
2706                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2707                                fprintf(o->file, "%s:%d: %s.\n",
2708                                        data.filename, blank_at_eof, err);
2709                                data.status = 1; /* report errors */
2710                        }
2711                }
2712        }
2713 free_and_return:
2714        diff_free_filespec_data(one);
2715        diff_free_filespec_data(two);
2716        if (data.status)
2717                DIFF_OPT_SET(o, CHECK_FAILED);
2718}
2719
2720struct diff_filespec *alloc_filespec(const char *path)
2721{
2722        struct diff_filespec *spec;
2723
2724        FLEXPTR_ALLOC_STR(spec, path, path);
2725        spec->count = 1;
2726        spec->is_binary = -1;
2727        return spec;
2728}
2729
2730void free_filespec(struct diff_filespec *spec)
2731{
2732        if (!--spec->count) {
2733                diff_free_filespec_data(spec);
2734                free(spec);
2735        }
2736}
2737
2738void fill_filespec(struct diff_filespec *spec, const struct object_id *oid,
2739                   int oid_valid, unsigned short mode)
2740{
2741        if (mode) {
2742                spec->mode = canon_mode(mode);
2743                oidcpy(&spec->oid, oid);
2744                spec->oid_valid = oid_valid;
2745        }
2746}
2747
2748/*
2749 * Given a name and sha1 pair, if the index tells us the file in
2750 * the work tree has that object contents, return true, so that
2751 * prepare_temp_file() does not have to inflate and extract.
2752 */
2753static int reuse_worktree_file(const char *name, const struct object_id *oid, int want_file)
2754{
2755        const struct cache_entry *ce;
2756        struct stat st;
2757        int pos, len;
2758
2759        /*
2760         * We do not read the cache ourselves here, because the
2761         * benchmark with my previous version that always reads cache
2762         * shows that it makes things worse for diff-tree comparing
2763         * two linux-2.6 kernel trees in an already checked out work
2764         * tree.  This is because most diff-tree comparisons deal with
2765         * only a small number of files, while reading the cache is
2766         * expensive for a large project, and its cost outweighs the
2767         * savings we get by not inflating the object to a temporary
2768         * file.  Practically, this code only helps when we are used
2769         * by diff-cache --cached, which does read the cache before
2770         * calling us.
2771         */
2772        if (!active_cache)
2773                return 0;
2774
2775        /* We want to avoid the working directory if our caller
2776         * doesn't need the data in a normal file, this system
2777         * is rather slow with its stat/open/mmap/close syscalls,
2778         * and the object is contained in a pack file.  The pack
2779         * is probably already open and will be faster to obtain
2780         * the data through than the working directory.  Loose
2781         * objects however would tend to be slower as they need
2782         * to be individually opened and inflated.
2783         */
2784        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(oid->hash))
2785                return 0;
2786
2787        /*
2788         * Similarly, if we'd have to convert the file contents anyway, that
2789         * makes the optimization not worthwhile.
2790         */
2791        if (!want_file && would_convert_to_git(&the_index, name))
2792                return 0;
2793
2794        len = strlen(name);
2795        pos = cache_name_pos(name, len);
2796        if (pos < 0)
2797                return 0;
2798        ce = active_cache[pos];
2799
2800        /*
2801         * This is not the sha1 we are looking for, or
2802         * unreusable because it is not a regular file.
2803         */
2804        if (oidcmp(oid, &ce->oid) || !S_ISREG(ce->ce_mode))
2805                return 0;
2806
2807        /*
2808         * If ce is marked as "assume unchanged", there is no
2809         * guarantee that work tree matches what we are looking for.
2810         */
2811        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2812                return 0;
2813
2814        /*
2815         * If ce matches the file in the work tree, we can reuse it.
2816         */
2817        if (ce_uptodate(ce) ||
2818            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2819                return 1;
2820
2821        return 0;
2822}
2823
2824static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2825{
2826        struct strbuf buf = STRBUF_INIT;
2827        char *dirty = "";
2828
2829        /* Are we looking at the work tree? */
2830        if (s->dirty_submodule)
2831                dirty = "-dirty";
2832
2833        strbuf_addf(&buf, "Subproject commit %s%s\n",
2834                    oid_to_hex(&s->oid), dirty);
2835        s->size = buf.len;
2836        if (size_only) {
2837                s->data = NULL;
2838                strbuf_release(&buf);
2839        } else {
2840                s->data = strbuf_detach(&buf, NULL);
2841                s->should_free = 1;
2842        }
2843        return 0;
2844}
2845
2846/*
2847 * While doing rename detection and pickaxe operation, we may need to
2848 * grab the data for the blob (or file) for our own in-core comparison.
2849 * diff_filespec has data and size fields for this purpose.
2850 */
2851int diff_populate_filespec(struct diff_filespec *s, unsigned int flags)
2852{
2853        int size_only = flags & CHECK_SIZE_ONLY;
2854        int err = 0;
2855        /*
2856         * demote FAIL to WARN to allow inspecting the situation
2857         * instead of refusing.
2858         */
2859        enum safe_crlf crlf_warn = (safe_crlf == SAFE_CRLF_FAIL
2860                                    ? SAFE_CRLF_WARN
2861                                    : safe_crlf);
2862
2863        if (!DIFF_FILE_VALID(s))
2864                die("internal error: asking to populate invalid file.");
2865        if (S_ISDIR(s->mode))
2866                return -1;
2867
2868        if (s->data)
2869                return 0;
2870
2871        if (size_only && 0 < s->size)
2872                return 0;
2873
2874        if (S_ISGITLINK(s->mode))
2875                return diff_populate_gitlink(s, size_only);
2876
2877        if (!s->oid_valid ||
2878            reuse_worktree_file(s->path, &s->oid, 0)) {
2879                struct strbuf buf = STRBUF_INIT;
2880                struct stat st;
2881                int fd;
2882
2883                if (lstat(s->path, &st) < 0) {
2884                        if (errno == ENOENT) {
2885                        err_empty:
2886                                err = -1;
2887                        empty:
2888                                s->data = (char *)"";
2889                                s->size = 0;
2890                                return err;
2891                        }
2892                }
2893                s->size = xsize_t(st.st_size);
2894                if (!s->size)
2895                        goto empty;
2896                if (S_ISLNK(st.st_mode)) {
2897                        struct strbuf sb = STRBUF_INIT;
2898
2899                        if (strbuf_readlink(&sb, s->path, s->size))
2900                                goto err_empty;
2901                        s->size = sb.len;
2902                        s->data = strbuf_detach(&sb, NULL);
2903                        s->should_free = 1;
2904                        return 0;
2905                }
2906
2907                /*
2908                 * Even if the caller would be happy with getting
2909                 * only the size, we cannot return early at this
2910                 * point if the path requires us to run the content
2911                 * conversion.
2912                 */
2913                if (size_only && !would_convert_to_git(&the_index, s->path))
2914                        return 0;
2915
2916                /*
2917                 * Note: this check uses xsize_t(st.st_size) that may
2918                 * not be the true size of the blob after it goes
2919                 * through convert_to_git().  This may not strictly be
2920                 * correct, but the whole point of big_file_threshold
2921                 * and is_binary check being that we want to avoid
2922                 * opening the file and inspecting the contents, this
2923                 * is probably fine.
2924                 */
2925                if ((flags & CHECK_BINARY) &&
2926                    s->size > big_file_threshold && s->is_binary == -1) {
2927                        s->is_binary = 1;
2928                        return 0;
2929                }
2930                fd = open(s->path, O_RDONLY);
2931                if (fd < 0)
2932                        goto err_empty;
2933                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2934                close(fd);
2935                s->should_munmap = 1;
2936
2937                /*
2938                 * Convert from working tree format to canonical git format
2939                 */
2940                if (convert_to_git(&the_index, s->path, s->data, s->size, &buf, crlf_warn)) {
2941                        size_t size = 0;
2942                        munmap(s->data, s->size);
2943                        s->should_munmap = 0;
2944                        s->data = strbuf_detach(&buf, &size);
2945                        s->size = size;
2946                        s->should_free = 1;
2947                }
2948        }
2949        else {
2950                enum object_type type;
2951                if (size_only || (flags & CHECK_BINARY)) {
2952                        type = sha1_object_info(s->oid.hash, &s->size);
2953                        if (type < 0)
2954                                die("unable to read %s",
2955                                    oid_to_hex(&s->oid));
2956                        if (size_only)
2957                                return 0;
2958                        if (s->size > big_file_threshold && s->is_binary == -1) {
2959                                s->is_binary = 1;
2960                                return 0;
2961                        }
2962                }
2963                s->data = read_sha1_file(s->oid.hash, &type, &s->size);
2964                if (!s->data)
2965                        die("unable to read %s", oid_to_hex(&s->oid));
2966                s->should_free = 1;
2967        }
2968        return 0;
2969}
2970
2971void diff_free_filespec_blob(struct diff_filespec *s)
2972{
2973        if (s->should_free)
2974                free(s->data);
2975        else if (s->should_munmap)
2976                munmap(s->data, s->size);
2977
2978        if (s->should_free || s->should_munmap) {
2979                s->should_free = s->should_munmap = 0;
2980                s->data = NULL;
2981        }
2982}
2983
2984void diff_free_filespec_data(struct diff_filespec *s)
2985{
2986        diff_free_filespec_blob(s);
2987        FREE_AND_NULL(s->cnt_data);
2988}
2989
2990static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2991                           void *blob,
2992                           unsigned long size,
2993                           const struct object_id *oid,
2994                           int mode)
2995{
2996        int fd;
2997        struct strbuf buf = STRBUF_INIT;
2998        struct strbuf template = STRBUF_INIT;
2999        char *path_dup = xstrdup(path);
3000        const char *base = basename(path_dup);
3001
3002        /* Generate "XXXXXX_basename.ext" */
3003        strbuf_addstr(&template, "XXXXXX_");
3004        strbuf_addstr(&template, base);
3005
3006        fd = mks_tempfile_ts(&temp->tempfile, template.buf, strlen(base) + 1);
3007        if (fd < 0)
3008                die_errno("unable to create temp-file");
3009        if (convert_to_working_tree(path,
3010                        (const char *)blob, (size_t)size, &buf)) {
3011                blob = buf.buf;
3012                size = buf.len;
3013        }
3014        if (write_in_full(fd, blob, size) != size)
3015                die_errno("unable to write temp-file");
3016        close_tempfile(&temp->tempfile);
3017        temp->name = get_tempfile_path(&temp->tempfile);
3018        oid_to_hex_r(temp->hex, oid);
3019        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
3020        strbuf_release(&buf);
3021        strbuf_release(&template);
3022        free(path_dup);
3023}
3024
3025static struct diff_tempfile *prepare_temp_file(const char *name,
3026                struct diff_filespec *one)
3027{
3028        struct diff_tempfile *temp = claim_diff_tempfile();
3029
3030        if (!DIFF_FILE_VALID(one)) {
3031        not_a_valid_file:
3032                /* A '-' entry produces this for file-2, and
3033                 * a '+' entry produces this for file-1.
3034                 */
3035                temp->name = "/dev/null";
3036                xsnprintf(temp->hex, sizeof(temp->hex), ".");
3037                xsnprintf(temp->mode, sizeof(temp->mode), ".");
3038                return temp;
3039        }
3040
3041        if (!S_ISGITLINK(one->mode) &&
3042            (!one->oid_valid ||
3043             reuse_worktree_file(name, &one->oid, 1))) {
3044                struct stat st;
3045                if (lstat(name, &st) < 0) {
3046                        if (errno == ENOENT)
3047                                goto not_a_valid_file;
3048                        die_errno("stat(%s)", name);
3049                }
3050                if (S_ISLNK(st.st_mode)) {
3051                        struct strbuf sb = STRBUF_INIT;
3052                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
3053                                die_errno("readlink(%s)", name);
3054                        prep_temp_blob(name, temp, sb.buf, sb.len,
3055                                       (one->oid_valid ?
3056                                        &one->oid : &null_oid),
3057                                       (one->oid_valid ?
3058                                        one->mode : S_IFLNK));
3059                        strbuf_release(&sb);
3060                }
3061                else {
3062                        /* we can borrow from the file in the work tree */
3063                        temp->name = name;
3064                        if (!one->oid_valid)
3065                                oid_to_hex_r(temp->hex, &null_oid);
3066                        else
3067                                oid_to_hex_r(temp->hex, &one->oid);
3068                        /* Even though we may sometimes borrow the
3069                         * contents from the work tree, we always want
3070                         * one->mode.  mode is trustworthy even when
3071                         * !(one->oid_valid), as long as
3072                         * DIFF_FILE_VALID(one).
3073                         */
3074                        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
3075                }
3076                return temp;
3077        }
3078        else {
3079                if (diff_populate_filespec(one, 0))
3080                        die("cannot read data blob for %s", one->path);
3081                prep_temp_blob(name, temp, one->data, one->size,
3082                               &one->oid, one->mode);
3083        }
3084        return temp;
3085}
3086
3087static void add_external_diff_name(struct argv_array *argv,
3088                                   const char *name,
3089                                   struct diff_filespec *df)
3090{
3091        struct diff_tempfile *temp = prepare_temp_file(name, df);
3092        argv_array_push(argv, temp->name);
3093        argv_array_push(argv, temp->hex);
3094        argv_array_push(argv, temp->mode);
3095}
3096
3097/* An external diff command takes:
3098 *
3099 * diff-cmd name infile1 infile1-sha1 infile1-mode \
3100 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
3101 *
3102 */
3103static void run_external_diff(const char *pgm,
3104                              const char *name,
3105                              const char *other,
3106                              struct diff_filespec *one,
3107                              struct diff_filespec *two,
3108                              const char *xfrm_msg,
3109                              int complete_rewrite,
3110                              struct diff_options *o)
3111{
3112        struct argv_array argv = ARGV_ARRAY_INIT;
3113        struct argv_array env = ARGV_ARRAY_INIT;
3114        struct diff_queue_struct *q = &diff_queued_diff;
3115
3116        argv_array_push(&argv, pgm);
3117        argv_array_push(&argv, name);
3118
3119        if (one && two) {
3120                add_external_diff_name(&argv, name, one);
3121                if (!other)
3122                        add_external_diff_name(&argv, name, two);
3123                else {
3124                        add_external_diff_name(&argv, other, two);
3125                        argv_array_push(&argv, other);
3126                        argv_array_push(&argv, xfrm_msg);
3127                }
3128        }
3129
3130        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
3131        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
3132
3133        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
3134                die(_("external diff died, stopping at %s"), name);
3135
3136        remove_tempfile();
3137        argv_array_clear(&argv);
3138        argv_array_clear(&env);
3139}
3140
3141static int similarity_index(struct diff_filepair *p)
3142{
3143        return p->score * 100 / MAX_SCORE;
3144}
3145
3146static const char *diff_abbrev_oid(const struct object_id *oid, int abbrev)
3147{
3148        if (startup_info->have_repository)
3149                return find_unique_abbrev(oid->hash, abbrev);
3150        else {
3151                char *hex = oid_to_hex(oid);
3152                if (abbrev < 0)
3153                        abbrev = FALLBACK_DEFAULT_ABBREV;
3154                if (abbrev > GIT_SHA1_HEXSZ)
3155                        die("BUG: oid abbreviation out of range: %d", abbrev);
3156                if (abbrev)
3157                        hex[abbrev] = '\0';
3158                return hex;
3159        }
3160}
3161
3162static void fill_metainfo(struct strbuf *msg,
3163                          const char *name,
3164                          const char *other,
3165                          struct diff_filespec *one,
3166                          struct diff_filespec *two,
3167                          struct diff_options *o,
3168                          struct diff_filepair *p,
3169                          int *must_show_header,
3170                          int use_color)
3171{
3172        const char *set = diff_get_color(use_color, DIFF_METAINFO);
3173        const char *reset = diff_get_color(use_color, DIFF_RESET);
3174        const char *line_prefix = diff_line_prefix(o);
3175
3176        *must_show_header = 1;
3177        strbuf_init(msg, PATH_MAX * 2 + 300);
3178        switch (p->status) {
3179        case DIFF_STATUS_COPIED:
3180                strbuf_addf(msg, "%s%ssimilarity index %d%%",
3181                            line_prefix, set, similarity_index(p));
3182                strbuf_addf(msg, "%s\n%s%scopy from ",
3183                            reset,  line_prefix, set);
3184                quote_c_style(name, msg, NULL, 0);
3185                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
3186                quote_c_style(other, msg, NULL, 0);
3187                strbuf_addf(msg, "%s\n", reset);
3188                break;
3189        case DIFF_STATUS_RENAMED:
3190                strbuf_addf(msg, "%s%ssimilarity index %d%%",
3191                            line_prefix, set, similarity_index(p));
3192                strbuf_addf(msg, "%s\n%s%srename from ",
3193                            reset, line_prefix, set);
3194                quote_c_style(name, msg, NULL, 0);
3195                strbuf_addf(msg, "%s\n%s%srename to ",
3196                            reset, line_prefix, set);
3197                quote_c_style(other, msg, NULL, 0);
3198                strbuf_addf(msg, "%s\n", reset);
3199                break;
3200        case DIFF_STATUS_MODIFIED:
3201                if (p->score) {
3202                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
3203                                    line_prefix,
3204                                    set, similarity_index(p), reset);
3205                        break;
3206                }
3207                /* fallthru */
3208        default:
3209                *must_show_header = 0;
3210        }
3211        if (one && two && oidcmp(&one->oid, &two->oid)) {
3212                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
3213
3214                if (DIFF_OPT_TST(o, BINARY)) {
3215                        mmfile_t mf;
3216                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
3217                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
3218                                abbrev = 40;
3219                }
3220                strbuf_addf(msg, "%s%sindex %s..%s", line_prefix, set,
3221                            diff_abbrev_oid(&one->oid, abbrev),
3222                            diff_abbrev_oid(&two->oid, abbrev));
3223                if (one->mode == two->mode)
3224                        strbuf_addf(msg, " %06o", one->mode);
3225                strbuf_addf(msg, "%s\n", reset);
3226        }
3227}
3228
3229static void run_diff_cmd(const char *pgm,
3230                         const char *name,
3231                         const char *other,
3232                         const char *attr_path,
3233                         struct diff_filespec *one,
3234                         struct diff_filespec *two,
3235                         struct strbuf *msg,
3236                         struct diff_options *o,
3237                         struct diff_filepair *p)
3238{
3239        const char *xfrm_msg = NULL;
3240        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
3241        int must_show_header = 0;
3242
3243
3244        if (DIFF_OPT_TST(o, ALLOW_EXTERNAL)) {
3245                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
3246                if (drv && drv->external)
3247                        pgm = drv->external;
3248        }
3249
3250        if (msg) {
3251                /*
3252                 * don't use colors when the header is intended for an
3253                 * external diff driver
3254                 */
3255                fill_metainfo(msg, name, other, one, two, o, p,
3256                              &must_show_header,
3257                              want_color(o->use_color) && !pgm);
3258                xfrm_msg = msg->len ? msg->buf : NULL;
3259        }
3260
3261        if (pgm) {
3262                run_external_diff(pgm, name, other, one, two, xfrm_msg,
3263                                  complete_rewrite, o);
3264                return;
3265        }
3266        if (one && two)
3267                builtin_diff(name, other ? other : name,
3268                             one, two, xfrm_msg, must_show_header,
3269                             o, complete_rewrite);
3270        else
3271                fprintf(o->file, "* Unmerged path %s\n", name);
3272}
3273
3274static void diff_fill_oid_info(struct diff_filespec *one)
3275{
3276        if (DIFF_FILE_VALID(one)) {
3277                if (!one->oid_valid) {
3278                        struct stat st;
3279                        if (one->is_stdin) {
3280                                oidclr(&one->oid);
3281                                return;
3282                        }
3283                        if (lstat(one->path, &st) < 0)
3284                                die_errno("stat '%s'", one->path);
3285                        if (index_path(one->oid.hash, one->path, &st, 0))
3286                                die("cannot hash %s", one->path);
3287                }
3288        }
3289        else
3290                oidclr(&one->oid);
3291}
3292
3293static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
3294{
3295        /* Strip the prefix but do not molest /dev/null and absolute paths */
3296        if (*namep && **namep != '/') {
3297                *namep += prefix_length;
3298                if (**namep == '/')
3299                        ++*namep;
3300        }
3301        if (*otherp && **otherp != '/') {
3302                *otherp += prefix_length;
3303                if (**otherp == '/')
3304                        ++*otherp;
3305        }
3306}
3307
3308static void run_diff(struct diff_filepair *p, struct diff_options *o)
3309{
3310        const char *pgm = external_diff();
3311        struct strbuf msg;
3312        struct diff_filespec *one = p->one;
3313        struct diff_filespec *two = p->two;
3314        const char *name;
3315        const char *other;
3316        const char *attr_path;
3317
3318        name  = one->path;
3319        other = (strcmp(name, two->path) ? two->path : NULL);
3320        attr_path = name;
3321        if (o->prefix_length)
3322                strip_prefix(o->prefix_length, &name, &other);
3323
3324        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
3325                pgm = NULL;
3326
3327        if (DIFF_PAIR_UNMERGED(p)) {
3328                run_diff_cmd(pgm, name, NULL, attr_path,
3329                             NULL, NULL, NULL, o, p);
3330                return;
3331        }
3332
3333        diff_fill_oid_info(one);
3334        diff_fill_oid_info(two);
3335
3336        if (!pgm &&
3337            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
3338            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
3339                /*
3340                 * a filepair that changes between file and symlink
3341                 * needs to be split into deletion and creation.
3342                 */
3343                struct diff_filespec *null = alloc_filespec(two->path);
3344                run_diff_cmd(NULL, name, other, attr_path,
3345                             one, null, &msg, o, p);
3346                free(null);
3347                strbuf_release(&msg);
3348
3349                null = alloc_filespec(one->path);
3350                run_diff_cmd(NULL, name, other, attr_path,
3351                             null, two, &msg, o, p);
3352                free(null);
3353        }
3354        else
3355                run_diff_cmd(pgm, name, other, attr_path,
3356                             one, two, &msg, o, p);
3357
3358        strbuf_release(&msg);
3359}
3360
3361static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
3362                         struct diffstat_t *diffstat)
3363{
3364        const char *name;
3365        const char *other;
3366
3367        if (DIFF_PAIR_UNMERGED(p)) {
3368                /* unmerged */
3369                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, p);
3370                return;
3371        }
3372
3373        name = p->one->path;
3374        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3375
3376        if (o->prefix_length)
3377                strip_prefix(o->prefix_length, &name, &other);
3378
3379        diff_fill_oid_info(p->one);
3380        diff_fill_oid_info(p->two);
3381
3382        builtin_diffstat(name, other, p->one, p->two, diffstat, o, p);
3383}
3384
3385static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
3386{
3387        const char *name;
3388        const char *other;
3389        const char *attr_path;
3390
3391        if (DIFF_PAIR_UNMERGED(p)) {
3392                /* unmerged */
3393                return;
3394        }
3395
3396        name = p->one->path;
3397        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3398        attr_path = other ? other : name;
3399
3400        if (o->prefix_length)
3401                strip_prefix(o->prefix_length, &name, &other);
3402
3403        diff_fill_oid_info(p->one);
3404        diff_fill_oid_info(p->two);
3405
3406        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
3407}
3408
3409void diff_setup(struct diff_options *options)
3410{
3411        memcpy(options, &default_diff_options, sizeof(*options));
3412
3413        options->file = stdout;
3414
3415        options->abbrev = DEFAULT_ABBREV;
3416        options->line_termination = '\n';
3417        options->break_opt = -1;
3418        options->rename_limit = -1;
3419        options->dirstat_permille = diff_dirstat_permille_default;
3420        options->context = diff_context_default;
3421        options->interhunkcontext = diff_interhunk_context_default;
3422        options->ws_error_highlight = ws_error_highlight_default;
3423        DIFF_OPT_SET(options, RENAME_EMPTY);
3424
3425        /* pathchange left =NULL by default */
3426        options->change = diff_change;
3427        options->add_remove = diff_addremove;
3428        options->use_color = diff_use_color_default;
3429        options->detect_rename = diff_detect_rename_default;
3430        options->xdl_opts |= diff_algorithm;
3431        if (diff_indent_heuristic)
3432                DIFF_XDL_SET(options, INDENT_HEURISTIC);
3433
3434        options->orderfile = diff_order_file_cfg;
3435
3436        if (diff_no_prefix) {
3437                options->a_prefix = options->b_prefix = "";
3438        } else if (!diff_mnemonic_prefix) {
3439                options->a_prefix = "a/";
3440                options->b_prefix = "b/";
3441        }
3442}
3443
3444void diff_setup_done(struct diff_options *options)
3445{
3446        int count = 0;
3447
3448        if (options->set_default)
3449                options->set_default(options);
3450
3451        if (options->output_format & DIFF_FORMAT_NAME)
3452                count++;
3453        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
3454                count++;
3455        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
3456                count++;
3457        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
3458                count++;
3459        if (count > 1)
3460                die(_("--name-only, --name-status, --check and -s are mutually exclusive"));
3461
3462        /*
3463         * Most of the time we can say "there are changes"
3464         * only by checking if there are changed paths, but
3465         * --ignore-whitespace* options force us to look
3466         * inside contents.
3467         */
3468
3469        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
3470            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
3471            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
3472                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
3473        else
3474                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
3475
3476        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3477                options->detect_rename = DIFF_DETECT_COPY;
3478
3479        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
3480                options->prefix = NULL;
3481        if (options->prefix)
3482                options->prefix_length = strlen(options->prefix);
3483        else
3484                options->prefix_length = 0;
3485
3486        if (options->output_format & (DIFF_FORMAT_NAME |
3487                                      DIFF_FORMAT_NAME_STATUS |
3488                                      DIFF_FORMAT_CHECKDIFF |
3489                                      DIFF_FORMAT_NO_OUTPUT))
3490                options->output_format &= ~(DIFF_FORMAT_RAW |
3491                                            DIFF_FORMAT_NUMSTAT |
3492                                            DIFF_FORMAT_DIFFSTAT |
3493                                            DIFF_FORMAT_SHORTSTAT |
3494                                            DIFF_FORMAT_DIRSTAT |
3495                                            DIFF_FORMAT_SUMMARY |
3496                                            DIFF_FORMAT_PATCH);
3497
3498        /*
3499         * These cases always need recursive; we do not drop caller-supplied
3500         * recursive bits for other formats here.
3501         */
3502        if (options->output_format & (DIFF_FORMAT_PATCH |
3503                                      DIFF_FORMAT_NUMSTAT |
3504                                      DIFF_FORMAT_DIFFSTAT |
3505                                      DIFF_FORMAT_SHORTSTAT |
3506                                      DIFF_FORMAT_DIRSTAT |
3507                                      DIFF_FORMAT_SUMMARY |
3508                                      DIFF_FORMAT_CHECKDIFF))
3509                DIFF_OPT_SET(options, RECURSIVE);
3510        /*
3511         * Also pickaxe would not work very well if you do not say recursive
3512         */
3513        if (options->pickaxe)
3514                DIFF_OPT_SET(options, RECURSIVE);
3515        /*
3516         * When patches are generated, submodules diffed against the work tree
3517         * must be checked for dirtiness too so it can be shown in the output
3518         */
3519        if (options->output_format & DIFF_FORMAT_PATCH)
3520                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3521
3522        if (options->detect_rename && options->rename_limit < 0)
3523                options->rename_limit = diff_rename_limit_default;
3524        if (options->setup & DIFF_SETUP_USE_CACHE) {
3525                if (!active_cache)
3526                        /* read-cache does not die even when it fails
3527                         * so it is safe for us to do this here.  Also
3528                         * it does not smudge active_cache or active_nr
3529                         * when it fails, so we do not have to worry about
3530                         * cleaning it up ourselves either.
3531                         */
3532                        read_cache();
3533        }
3534        if (40 < options->abbrev)
3535                options->abbrev = 40; /* full */
3536
3537        /*
3538         * It does not make sense to show the first hit we happened
3539         * to have found.  It does not make sense not to return with
3540         * exit code in such a case either.
3541         */
3542        if (DIFF_OPT_TST(options, QUICK)) {
3543                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3544                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3545        }
3546
3547        options->diff_path_counter = 0;
3548
3549        if (DIFF_OPT_TST(options, FOLLOW_RENAMES) && options->pathspec.nr != 1)
3550                die(_("--follow requires exactly one pathspec"));
3551}
3552
3553static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3554{
3555        char c, *eq;
3556        int len;
3557
3558        if (*arg != '-')
3559                return 0;
3560        c = *++arg;
3561        if (!c)
3562                return 0;
3563        if (c == arg_short) {
3564                c = *++arg;
3565                if (!c)
3566                        return 1;
3567                if (val && isdigit(c)) {
3568                        char *end;
3569                        int n = strtoul(arg, &end, 10);
3570                        if (*end)
3571                                return 0;
3572                        *val = n;
3573                        return 1;
3574                }
3575                return 0;
3576        }
3577        if (c != '-')
3578                return 0;
3579        arg++;
3580        eq = strchrnul(arg, '=');
3581        len = eq - arg;
3582        if (!len || strncmp(arg, arg_long, len))
3583                return 0;
3584        if (*eq) {
3585                int n;
3586                char *end;
3587                if (!isdigit(*++eq))
3588                        return 0;
3589                n = strtoul(eq, &end, 10);
3590                if (*end)
3591                        return 0;
3592                *val = n;
3593        }
3594        return 1;
3595}
3596
3597static int diff_scoreopt_parse(const char *opt);
3598
3599static inline int short_opt(char opt, const char **argv,
3600                            const char **optarg)
3601{
3602        const char *arg = argv[0];
3603        if (arg[0] != '-' || arg[1] != opt)
3604                return 0;
3605        if (arg[2] != '\0') {
3606                *optarg = arg + 2;
3607                return 1;
3608        }
3609        if (!argv[1])
3610                die("Option '%c' requires a value", opt);
3611        *optarg = argv[1];
3612        return 2;
3613}
3614
3615int parse_long_opt(const char *opt, const char **argv,
3616                   const char **optarg)
3617{
3618        const char *arg = argv[0];
3619        if (!skip_prefix(arg, "--", &arg))
3620                return 0;
3621        if (!skip_prefix(arg, opt, &arg))
3622                return 0;
3623        if (*arg == '=') { /* stuck form: --option=value */
3624                *optarg = arg + 1;
3625                return 1;
3626        }
3627        if (*arg != '\0')
3628                return 0;
3629        /* separate form: --option value */
3630        if (!argv[1])
3631                die("Option '--%s' requires a value", opt);
3632        *optarg = argv[1];
3633        return 2;
3634}
3635
3636static int stat_opt(struct diff_options *options, const char **av)
3637{
3638        const char *arg = av[0];
3639        char *end;
3640        int width = options->stat_width;
3641        int name_width = options->stat_name_width;
3642        int graph_width = options->stat_graph_width;
3643        int count = options->stat_count;
3644        int argcount = 1;
3645
3646        if (!skip_prefix(arg, "--stat", &arg))
3647                die("BUG: stat option does not begin with --stat: %s", arg);
3648        end = (char *)arg;
3649
3650        switch (*arg) {
3651        case '-':
3652                if (skip_prefix(arg, "-width", &arg)) {
3653                        if (*arg == '=')
3654                                width = strtoul(arg + 1, &end, 10);
3655                        else if (!*arg && !av[1])
3656                                die_want_option("--stat-width");
3657                        else if (!*arg) {
3658                                width = strtoul(av[1], &end, 10);
3659                                argcount = 2;
3660                        }
3661                } else if (skip_prefix(arg, "-name-width", &arg)) {
3662                        if (*arg == '=')
3663                                name_width = strtoul(arg + 1, &end, 10);
3664                        else if (!*arg && !av[1])
3665                                die_want_option("--stat-name-width");
3666                        else if (!*arg) {
3667                                name_width = strtoul(av[1], &end, 10);
3668                                argcount = 2;
3669                        }
3670                } else if (skip_prefix(arg, "-graph-width", &arg)) {
3671                        if (*arg == '=')
3672                                graph_width = strtoul(arg + 1, &end, 10);
3673                        else if (!*arg && !av[1])
3674                                die_want_option("--stat-graph-width");
3675                        else if (!*arg) {
3676                                graph_width = strtoul(av[1], &end, 10);
3677                                argcount = 2;
3678                        }
3679                } else if (skip_prefix(arg, "-count", &arg)) {
3680                        if (*arg == '=')
3681                                count = strtoul(arg + 1, &end, 10);
3682                        else if (!*arg && !av[1])
3683                                die_want_option("--stat-count");
3684                        else if (!*arg) {
3685                                count = strtoul(av[1], &end, 10);
3686                                argcount = 2;
3687                        }
3688                }
3689                break;
3690        case '=':
3691                width = strtoul(arg+1, &end, 10);
3692                if (*end == ',')
3693                        name_width = strtoul(end+1, &end, 10);
3694                if (*end == ',')
3695                        count = strtoul(end+1, &end, 10);
3696        }
3697
3698        /* Important! This checks all the error cases! */
3699        if (*end)
3700                return 0;
3701        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3702        options->stat_name_width = name_width;
3703        options->stat_graph_width = graph_width;
3704        options->stat_width = width;
3705        options->stat_count = count;
3706        return argcount;
3707}
3708
3709static int parse_dirstat_opt(struct diff_options *options, const char *params)
3710{
3711        struct strbuf errmsg = STRBUF_INIT;
3712        if (parse_dirstat_params(options, params, &errmsg))
3713                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
3714                    errmsg.buf);
3715        strbuf_release(&errmsg);
3716        /*
3717         * The caller knows a dirstat-related option is given from the command
3718         * line; allow it to say "return this_function();"
3719         */
3720        options->output_format |= DIFF_FORMAT_DIRSTAT;
3721        return 1;
3722}
3723
3724static int parse_submodule_opt(struct diff_options *options, const char *value)
3725{
3726        if (parse_submodule_params(options, value))
3727                die(_("Failed to parse --submodule option parameter: '%s'"),
3728                        value);
3729        return 1;
3730}
3731
3732static const char diff_status_letters[] = {
3733        DIFF_STATUS_ADDED,
3734        DIFF_STATUS_COPIED,
3735        DIFF_STATUS_DELETED,
3736        DIFF_STATUS_MODIFIED,
3737        DIFF_STATUS_RENAMED,
3738        DIFF_STATUS_TYPE_CHANGED,
3739        DIFF_STATUS_UNKNOWN,
3740        DIFF_STATUS_UNMERGED,
3741        DIFF_STATUS_FILTER_AON,
3742        DIFF_STATUS_FILTER_BROKEN,
3743        '\0',
3744};
3745
3746static unsigned int filter_bit['Z' + 1];
3747
3748static void prepare_filter_bits(void)
3749{
3750        int i;
3751
3752        if (!filter_bit[DIFF_STATUS_ADDED]) {
3753                for (i = 0; diff_status_letters[i]; i++)
3754                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
3755        }
3756}
3757
3758static unsigned filter_bit_tst(char status, const struct diff_options *opt)
3759{
3760        return opt->filter & filter_bit[(int) status];
3761}
3762
3763static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
3764{
3765        int i, optch;
3766
3767        prepare_filter_bits();
3768
3769        /*
3770         * If there is a negation e.g. 'd' in the input, and we haven't
3771         * initialized the filter field with another --diff-filter, start
3772         * from full set of bits, except for AON.
3773         */
3774        if (!opt->filter) {
3775                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
3776                        if (optch < 'a' || 'z' < optch)
3777                                continue;
3778                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
3779                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
3780                        break;
3781                }
3782        }
3783
3784        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
3785                unsigned int bit;
3786                int negate;
3787
3788                if ('a' <= optch && optch <= 'z') {
3789                        negate = 1;
3790                        optch = toupper(optch);
3791                } else {
3792                        negate = 0;
3793                }
3794
3795                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
3796                if (!bit)
3797                        return optarg[i];
3798                if (negate)
3799                        opt->filter &= ~bit;
3800                else
3801                        opt->filter |= bit;
3802        }
3803        return 0;
3804}
3805
3806static void enable_patch_output(int *fmt) {
3807        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
3808        *fmt |= DIFF_FORMAT_PATCH;
3809}
3810
3811static int parse_ws_error_highlight_opt(struct diff_options *opt, const char *arg)
3812{
3813        int val = parse_ws_error_highlight(arg);
3814
3815        if (val < 0) {
3816                error("unknown value after ws-error-highlight=%.*s",
3817                      -1 - val, arg);
3818                return 0;
3819        }
3820        opt->ws_error_highlight = val;
3821        return 1;
3822}
3823
3824int diff_opt_parse(struct diff_options *options,
3825                   const char **av, int ac, const char *prefix)
3826{
3827        const char *arg = av[0];
3828        const char *optarg;
3829        int argcount;
3830
3831        if (!prefix)
3832                prefix = "";
3833
3834        /* Output format options */
3835        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
3836            || opt_arg(arg, 'U', "unified", &options->context))
3837                enable_patch_output(&options->output_format);
3838        else if (!strcmp(arg, "--raw"))
3839                options->output_format |= DIFF_FORMAT_RAW;
3840        else if (!strcmp(arg, "--patch-with-raw")) {
3841                enable_patch_output(&options->output_format);
3842                options->output_format |= DIFF_FORMAT_RAW;
3843        } else if (!strcmp(arg, "--numstat"))
3844                options->output_format |= DIFF_FORMAT_NUMSTAT;
3845        else if (!strcmp(arg, "--shortstat"))
3846                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3847        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
3848                return parse_dirstat_opt(options, "");
3849        else if (skip_prefix(arg, "-X", &arg))
3850                return parse_dirstat_opt(options, arg);
3851        else if (skip_prefix(arg, "--dirstat=", &arg))
3852                return parse_dirstat_opt(options, arg);
3853        else if (!strcmp(arg, "--cumulative"))
3854                return parse_dirstat_opt(options, "cumulative");
3855        else if (!strcmp(arg, "--dirstat-by-file"))
3856                return parse_dirstat_opt(options, "files");
3857        else if (skip_prefix(arg, "--dirstat-by-file=", &arg)) {
3858                parse_dirstat_opt(options, "files");
3859                return parse_dirstat_opt(options, arg);
3860        }
3861        else if (!strcmp(arg, "--check"))
3862                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3863        else if (!strcmp(arg, "--summary"))
3864                options->output_format |= DIFF_FORMAT_SUMMARY;
3865        else if (!strcmp(arg, "--patch-with-stat")) {
3866                enable_patch_output(&options->output_format);
3867                options->output_format |= DIFF_FORMAT_DIFFSTAT;
3868        } else if (!strcmp(arg, "--name-only"))
3869                options->output_format |= DIFF_FORMAT_NAME;
3870        else if (!strcmp(arg, "--name-status"))
3871                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3872        else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
3873                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3874        else if (starts_with(arg, "--stat"))
3875                /* --stat, --stat-width, --stat-name-width, or --stat-count */
3876                return stat_opt(options, av);
3877
3878        /* renames options */
3879        else if (starts_with(arg, "-B") || starts_with(arg, "--break-rewrites=") ||
3880                 !strcmp(arg, "--break-rewrites")) {
3881                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3882                        return error("invalid argument to -B: %s", arg+2);
3883        }
3884        else if (starts_with(arg, "-M") || starts_with(arg, "--find-renames=") ||
3885                 !strcmp(arg, "--find-renames")) {
3886                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3887                        return error("invalid argument to -M: %s", arg+2);
3888                options->detect_rename = DIFF_DETECT_RENAME;
3889        }
3890        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3891                options->irreversible_delete = 1;
3892        }
3893        else if (starts_with(arg, "-C") || starts_with(arg, "--find-copies=") ||
3894                 !strcmp(arg, "--find-copies")) {
3895                if (options->detect_rename == DIFF_DETECT_COPY)
3896                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3897                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3898                        return error("invalid argument to -C: %s", arg+2);
3899                options->detect_rename = DIFF_DETECT_COPY;
3900        }
3901        else if (!strcmp(arg, "--no-renames"))
3902                options->detect_rename = 0;
3903        else if (!strcmp(arg, "--rename-empty"))
3904                DIFF_OPT_SET(options, RENAME_EMPTY);
3905        else if (!strcmp(arg, "--no-rename-empty"))
3906                DIFF_OPT_CLR(options, RENAME_EMPTY);
3907        else if (!strcmp(arg, "--relative"))
3908                DIFF_OPT_SET(options, RELATIVE_NAME);
3909        else if (skip_prefix(arg, "--relative=", &arg)) {
3910                DIFF_OPT_SET(options, RELATIVE_NAME);
3911                options->prefix = arg;
3912        }
3913
3914        /* xdiff options */
3915        else if (!strcmp(arg, "--minimal"))
3916                DIFF_XDL_SET(options, NEED_MINIMAL);
3917        else if (!strcmp(arg, "--no-minimal"))
3918                DIFF_XDL_CLR(options, NEED_MINIMAL);
3919        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3920                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3921        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3922                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3923        else if (!strcmp(arg, "--ignore-space-at-eol"))
3924                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3925        else if (!strcmp(arg, "--ignore-blank-lines"))
3926                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
3927        else if (!strcmp(arg, "--indent-heuristic"))
3928                DIFF_XDL_SET(options, INDENT_HEURISTIC);
3929        else if (!strcmp(arg, "--no-indent-heuristic"))
3930                DIFF_XDL_CLR(options, INDENT_HEURISTIC);
3931        else if (!strcmp(arg, "--patience"))
3932                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
3933        else if (!strcmp(arg, "--histogram"))
3934                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
3935        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
3936                long value = parse_algorithm_value(optarg);
3937                if (value < 0)
3938                        return error("option diff-algorithm accepts \"myers\", "
3939                                     "\"minimal\", \"patience\" and \"histogram\"");
3940                /* clear out previous settings */
3941                DIFF_XDL_CLR(options, NEED_MINIMAL);
3942                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
3943                options->xdl_opts |= value;
3944                return argcount;
3945        }
3946
3947        /* flags options */
3948        else if (!strcmp(arg, "--binary")) {
3949                enable_patch_output(&options->output_format);
3950                DIFF_OPT_SET(options, BINARY);
3951        }
3952        else if (!strcmp(arg, "--full-index"))
3953                DIFF_OPT_SET(options, FULL_INDEX);
3954        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3955                DIFF_OPT_SET(options, TEXT);
3956        else if (!strcmp(arg, "-R"))
3957                DIFF_OPT_SET(options, REVERSE_DIFF);
3958        else if (!strcmp(arg, "--find-copies-harder"))
3959                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3960        else if (!strcmp(arg, "--follow"))
3961                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3962        else if (!strcmp(arg, "--no-follow")) {
3963                DIFF_OPT_CLR(options, FOLLOW_RENAMES);
3964                DIFF_OPT_CLR(options, DEFAULT_FOLLOW_RENAMES);
3965        } else if (!strcmp(arg, "--color"))
3966                options->use_color = 1;
3967        else if (skip_prefix(arg, "--color=", &arg)) {
3968                int value = git_config_colorbool(NULL, arg);
3969                if (value < 0)
3970                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3971                options->use_color = value;
3972        }
3973        else if (!strcmp(arg, "--no-color"))
3974                options->use_color = 0;
3975        else if (!strcmp(arg, "--color-words")) {
3976                options->use_color = 1;
3977                options->word_diff = DIFF_WORDS_COLOR;
3978        }
3979        else if (skip_prefix(arg, "--color-words=", &arg)) {
3980                options->use_color = 1;
3981                options->word_diff = DIFF_WORDS_COLOR;
3982                options->word_regex = arg;
3983        }
3984        else if (!strcmp(arg, "--word-diff")) {
3985                if (options->word_diff == DIFF_WORDS_NONE)
3986                        options->word_diff = DIFF_WORDS_PLAIN;
3987        }
3988        else if (skip_prefix(arg, "--word-diff=", &arg)) {
3989                if (!strcmp(arg, "plain"))
3990                        options->word_diff = DIFF_WORDS_PLAIN;
3991                else if (!strcmp(arg, "color")) {
3992                        options->use_color = 1;
3993                        options->word_diff = DIFF_WORDS_COLOR;
3994                }
3995                else if (!strcmp(arg, "porcelain"))
3996                        options->word_diff = DIFF_WORDS_PORCELAIN;
3997                else if (!strcmp(arg, "none"))
3998                        options->word_diff = DIFF_WORDS_NONE;
3999                else
4000                        die("bad --word-diff argument: %s", arg);
4001        }
4002        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
4003                if (options->word_diff == DIFF_WORDS_NONE)
4004                        options->word_diff = DIFF_WORDS_PLAIN;
4005                options->word_regex = optarg;
4006                return argcount;
4007        }
4008        else if (!strcmp(arg, "--exit-code"))
4009                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
4010        else if (!strcmp(arg, "--quiet"))
4011                DIFF_OPT_SET(options, QUICK);
4012        else if (!strcmp(arg, "--ext-diff"))
4013                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
4014        else if (!strcmp(arg, "--no-ext-diff"))
4015                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
4016        else if (!strcmp(arg, "--textconv"))
4017                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
4018        else if (!strcmp(arg, "--no-textconv"))
4019                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
4020        else if (!strcmp(arg, "--ignore-submodules")) {
4021                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
4022                handle_ignore_submodules_arg(options, "all");
4023        } else if (skip_prefix(arg, "--ignore-submodules=", &arg)) {
4024                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
4025                handle_ignore_submodules_arg(options, arg);
4026        } else if (!strcmp(arg, "--submodule"))
4027                options->submodule_format = DIFF_SUBMODULE_LOG;
4028        else if (skip_prefix(arg, "--submodule=", &arg))
4029                return parse_submodule_opt(options, arg);
4030        else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
4031                return parse_ws_error_highlight_opt(options, arg);
4032        else if (!strcmp(arg, "--ita-invisible-in-index"))
4033                options->ita_invisible_in_index = 1;
4034        else if (!strcmp(arg, "--ita-visible-in-index"))
4035                options->ita_invisible_in_index = 0;
4036
4037        /* misc options */
4038        else if (!strcmp(arg, "-z"))
4039                options->line_termination = 0;
4040        else if ((argcount = short_opt('l', av, &optarg))) {
4041                options->rename_limit = strtoul(optarg, NULL, 10);
4042                return argcount;
4043        }
4044        else if ((argcount = short_opt('S', av, &optarg))) {
4045                options->pickaxe = optarg;
4046                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
4047                return argcount;
4048        } else if ((argcount = short_opt('G', av, &optarg))) {
4049                options->pickaxe = optarg;
4050                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
4051                return argcount;
4052        }
4053        else if (!strcmp(arg, "--pickaxe-all"))
4054                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
4055        else if (!strcmp(arg, "--pickaxe-regex"))
4056                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
4057        else if ((argcount = short_opt('O', av, &optarg))) {
4058                options->orderfile = prefix_filename(prefix, optarg);
4059                return argcount;
4060        }
4061        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
4062                int offending = parse_diff_filter_opt(optarg, options);
4063                if (offending)
4064                        die("unknown change class '%c' in --diff-filter=%s",
4065                            offending, optarg);
4066                return argcount;
4067        }
4068        else if (!strcmp(arg, "--no-abbrev"))
4069                options->abbrev = 0;
4070        else if (!strcmp(arg, "--abbrev"))
4071                options->abbrev = DEFAULT_ABBREV;
4072        else if (skip_prefix(arg, "--abbrev=", &arg)) {
4073                options->abbrev = strtoul(arg, NULL, 10);
4074                if (options->abbrev < MINIMUM_ABBREV)
4075                        options->abbrev = MINIMUM_ABBREV;
4076                else if (40 < options->abbrev)
4077                        options->abbrev = 40;
4078        }
4079        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
4080                options->a_prefix = optarg;
4081                return argcount;
4082        }
4083        else if ((argcount = parse_long_opt("line-prefix", av, &optarg))) {
4084                options->line_prefix = optarg;
4085                options->line_prefix_length = strlen(options->line_prefix);
4086                graph_setup_line_prefix(options);
4087                return argcount;
4088        }
4089        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
4090                options->b_prefix = optarg;
4091                return argcount;
4092        }
4093        else if (!strcmp(arg, "--no-prefix"))
4094                options->a_prefix = options->b_prefix = "";
4095        else if (opt_arg(arg, '\0', "inter-hunk-context",
4096                         &options->interhunkcontext))
4097                ;
4098        else if (!strcmp(arg, "-W"))
4099                DIFF_OPT_SET(options, FUNCCONTEXT);
4100        else if (!strcmp(arg, "--function-context"))
4101                DIFF_OPT_SET(options, FUNCCONTEXT);
4102        else if (!strcmp(arg, "--no-function-context"))
4103                DIFF_OPT_CLR(options, FUNCCONTEXT);
4104        else if ((argcount = parse_long_opt("output", av, &optarg))) {
4105                char *path = prefix_filename(prefix, optarg);
4106                options->file = xfopen(path, "w");
4107                options->close_file = 1;
4108                if (options->use_color != GIT_COLOR_ALWAYS)
4109                        options->use_color = GIT_COLOR_NEVER;
4110                free(path);
4111                return argcount;
4112        } else
4113                return 0;
4114        return 1;
4115}
4116
4117int parse_rename_score(const char **cp_p)
4118{
4119        unsigned long num, scale;
4120        int ch, dot;
4121        const char *cp = *cp_p;
4122
4123        num = 0;
4124        scale = 1;
4125        dot = 0;
4126        for (;;) {
4127                ch = *cp;
4128                if ( !dot && ch == '.' ) {
4129                        scale = 1;
4130                        dot = 1;
4131                } else if ( ch == '%' ) {
4132                        scale = dot ? scale*100 : 100;
4133                        cp++;   /* % is always at the end */
4134                        break;
4135                } else if ( ch >= '0' && ch <= '9' ) {
4136                        if ( scale < 100000 ) {
4137                                scale *= 10;
4138                                num = (num*10) + (ch-'0');
4139                        }
4140                } else {
4141                        break;
4142                }
4143                cp++;
4144        }
4145        *cp_p = cp;
4146
4147        /* user says num divided by scale and we say internally that
4148         * is MAX_SCORE * num / scale.
4149         */
4150        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
4151}
4152
4153static int diff_scoreopt_parse(const char *opt)
4154{
4155        int opt1, opt2, cmd;
4156
4157        if (*opt++ != '-')
4158                return -1;
4159        cmd = *opt++;
4160        if (cmd == '-') {
4161                /* convert the long-form arguments into short-form versions */
4162                if (skip_prefix(opt, "break-rewrites", &opt)) {
4163                        if (*opt == 0 || *opt++ == '=')
4164                                cmd = 'B';
4165                } else if (skip_prefix(opt, "find-copies", &opt)) {
4166                        if (*opt == 0 || *opt++ == '=')
4167                                cmd = 'C';
4168                } else if (skip_prefix(opt, "find-renames", &opt)) {
4169                        if (*opt == 0 || *opt++ == '=')
4170                                cmd = 'M';
4171                }
4172        }
4173        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
4174                return -1; /* that is not a -M, -C, or -B option */
4175
4176        opt1 = parse_rename_score(&opt);
4177        if (cmd != 'B')
4178                opt2 = 0;
4179        else {
4180                if (*opt == 0)
4181                        opt2 = 0;
4182                else if (*opt != '/')
4183                        return -1; /* we expect -B80/99 or -B80 */
4184                else {
4185                        opt++;
4186                        opt2 = parse_rename_score(&opt);
4187                }
4188        }
4189        if (*opt != 0)
4190                return -1;
4191        return opt1 | (opt2 << 16);
4192}
4193
4194struct diff_queue_struct diff_queued_diff;
4195
4196void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
4197{
4198        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
4199        queue->queue[queue->nr++] = dp;
4200}
4201
4202struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
4203                                 struct diff_filespec *one,
4204                                 struct diff_filespec *two)
4205{
4206        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
4207        dp->one = one;
4208        dp->two = two;
4209        if (queue)
4210                diff_q(queue, dp);
4211        return dp;
4212}
4213
4214void diff_free_filepair(struct diff_filepair *p)
4215{
4216        free_filespec(p->one);
4217        free_filespec(p->two);
4218        free(p);
4219}
4220
4221const char *diff_aligned_abbrev(const struct object_id *oid, int len)
4222{
4223        int abblen;
4224        const char *abbrev;
4225
4226        if (len == GIT_SHA1_HEXSZ)
4227                return oid_to_hex(oid);
4228
4229        abbrev = diff_abbrev_oid(oid, len);
4230        abblen = strlen(abbrev);
4231
4232        /*
4233         * In well-behaved cases, where the abbbreviated result is the
4234         * same as the requested length, append three dots after the
4235         * abbreviation (hence the whole logic is limited to the case
4236         * where abblen < 37); when the actual abbreviated result is a
4237         * bit longer than the requested length, we reduce the number
4238         * of dots so that they match the well-behaved ones.  However,
4239         * if the actual abbreviation is longer than the requested
4240         * length by more than three, we give up on aligning, and add
4241         * three dots anyway, to indicate that the output is not the
4242         * full object name.  Yes, this may be suboptimal, but this
4243         * appears only in "diff --raw --abbrev" output and it is not
4244         * worth the effort to change it now.  Note that this would
4245         * likely to work fine when the automatic sizing of default
4246         * abbreviation length is used--we would be fed -1 in "len" in
4247         * that case, and will end up always appending three-dots, but
4248         * the automatic sizing is supposed to give abblen that ensures
4249         * uniqueness across all objects (statistically speaking).
4250         */
4251        if (abblen < GIT_SHA1_HEXSZ - 3) {
4252                static char hex[GIT_MAX_HEXSZ + 1];
4253                if (len < abblen && abblen <= len + 2)
4254                        xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
4255                else
4256                        xsnprintf(hex, sizeof(hex), "%s...", abbrev);
4257                return hex;
4258        }
4259
4260        return oid_to_hex(oid);
4261}
4262
4263static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
4264{
4265        int line_termination = opt->line_termination;
4266        int inter_name_termination = line_termination ? '\t' : '\0';
4267
4268        fprintf(opt->file, "%s", diff_line_prefix(opt));
4269        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
4270                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
4271                        diff_aligned_abbrev(&p->one->oid, opt->abbrev));
4272                fprintf(opt->file, "%s ",
4273                        diff_aligned_abbrev(&p->two->oid, opt->abbrev));
4274        }
4275        if (p->score) {
4276                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
4277                        inter_name_termination);
4278        } else {
4279                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
4280        }
4281
4282        if (p->status == DIFF_STATUS_COPIED ||
4283            p->status == DIFF_STATUS_RENAMED) {
4284                const char *name_a, *name_b;
4285                name_a = p->one->path;
4286                name_b = p->two->path;
4287                strip_prefix(opt->prefix_length, &name_a, &name_b);
4288                write_name_quoted(name_a, opt->file, inter_name_termination);
4289                write_name_quoted(name_b, opt->file, line_termination);
4290        } else {
4291                const char *name_a, *name_b;
4292                name_a = p->one->mode ? p->one->path : p->two->path;
4293                name_b = NULL;
4294                strip_prefix(opt->prefix_length, &name_a, &name_b);
4295                write_name_quoted(name_a, opt->file, line_termination);
4296        }
4297}
4298
4299int diff_unmodified_pair(struct diff_filepair *p)
4300{
4301        /* This function is written stricter than necessary to support
4302         * the currently implemented transformers, but the idea is to
4303         * let transformers to produce diff_filepairs any way they want,
4304         * and filter and clean them up here before producing the output.
4305         */
4306        struct diff_filespec *one = p->one, *two = p->two;
4307
4308        if (DIFF_PAIR_UNMERGED(p))
4309                return 0; /* unmerged is interesting */
4310
4311        /* deletion, addition, mode or type change
4312         * and rename are all interesting.
4313         */
4314        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
4315            DIFF_PAIR_MODE_CHANGED(p) ||
4316            strcmp(one->path, two->path))
4317                return 0;
4318
4319        /* both are valid and point at the same path.  that is, we are
4320         * dealing with a change.
4321         */
4322        if (one->oid_valid && two->oid_valid &&
4323            !oidcmp(&one->oid, &two->oid) &&
4324            !one->dirty_submodule && !two->dirty_submodule)
4325                return 1; /* no change */
4326        if (!one->oid_valid && !two->oid_valid)
4327                return 1; /* both look at the same file on the filesystem. */
4328        return 0;
4329}
4330
4331static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
4332{
4333        if (diff_unmodified_pair(p))
4334                return;
4335
4336        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4337            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4338                return; /* no tree diffs in patch format */
4339
4340        run_diff(p, o);
4341}
4342
4343static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
4344                            struct diffstat_t *diffstat)
4345{
4346        if (diff_unmodified_pair(p))
4347                return;
4348
4349        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4350            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4351                return; /* no useful stat for tree diffs */
4352
4353        run_diffstat(p, o, diffstat);
4354}
4355
4356static void diff_flush_checkdiff(struct diff_filepair *p,
4357                struct diff_options *o)
4358{
4359        if (diff_unmodified_pair(p))
4360                return;
4361
4362        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4363            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4364                return; /* nothing to check in tree diffs */
4365
4366        run_checkdiff(p, o);
4367}
4368
4369int diff_queue_is_empty(void)
4370{
4371        struct diff_queue_struct *q = &diff_queued_diff;
4372        int i;
4373        for (i = 0; i < q->nr; i++)
4374                if (!diff_unmodified_pair(q->queue[i]))
4375                        return 0;
4376        return 1;
4377}
4378
4379#if DIFF_DEBUG
4380void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
4381{
4382        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
4383                x, one ? one : "",
4384                s->path,
4385                DIFF_FILE_VALID(s) ? "valid" : "invalid",
4386                s->mode,
4387                s->oid_valid ? oid_to_hex(&s->oid) : "");
4388        fprintf(stderr, "queue[%d] %s size %lu\n",
4389                x, one ? one : "",
4390                s->size);
4391}
4392
4393void diff_debug_filepair(const struct diff_filepair *p, int i)
4394{
4395        diff_debug_filespec(p->one, i, "one");
4396        diff_debug_filespec(p->two, i, "two");
4397        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
4398                p->score, p->status ? p->status : '?',
4399                p->one->rename_used, p->broken_pair);
4400}
4401
4402void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
4403{
4404        int i;
4405        if (msg)
4406                fprintf(stderr, "%s\n", msg);
4407        fprintf(stderr, "q->nr = %d\n", q->nr);
4408        for (i = 0; i < q->nr; i++) {
4409                struct diff_filepair *p = q->queue[i];
4410                diff_debug_filepair(p, i);
4411        }
4412}
4413#endif
4414
4415static void diff_resolve_rename_copy(void)
4416{
4417        int i;
4418        struct diff_filepair *p;
4419        struct diff_queue_struct *q = &diff_queued_diff;
4420
4421        diff_debug_queue("resolve-rename-copy", q);
4422
4423        for (i = 0; i < q->nr; i++) {
4424                p = q->queue[i];
4425                p->status = 0; /* undecided */
4426                if (DIFF_PAIR_UNMERGED(p))
4427                        p->status = DIFF_STATUS_UNMERGED;
4428                else if (!DIFF_FILE_VALID(p->one))
4429                        p->status = DIFF_STATUS_ADDED;
4430                else if (!DIFF_FILE_VALID(p->two))
4431                        p->status = DIFF_STATUS_DELETED;
4432                else if (DIFF_PAIR_TYPE_CHANGED(p))
4433                        p->status = DIFF_STATUS_TYPE_CHANGED;
4434
4435                /* from this point on, we are dealing with a pair
4436                 * whose both sides are valid and of the same type, i.e.
4437                 * either in-place edit or rename/copy edit.
4438                 */
4439                else if (DIFF_PAIR_RENAME(p)) {
4440                        /*
4441                         * A rename might have re-connected a broken
4442                         * pair up, causing the pathnames to be the
4443                         * same again. If so, that's not a rename at
4444                         * all, just a modification..
4445                         *
4446                         * Otherwise, see if this source was used for
4447                         * multiple renames, in which case we decrement
4448                         * the count, and call it a copy.
4449                         */
4450                        if (!strcmp(p->one->path, p->two->path))
4451                                p->status = DIFF_STATUS_MODIFIED;
4452                        else if (--p->one->rename_used > 0)
4453                                p->status = DIFF_STATUS_COPIED;
4454                        else
4455                                p->status = DIFF_STATUS_RENAMED;
4456                }
4457                else if (oidcmp(&p->one->oid, &p->two->oid) ||
4458                         p->one->mode != p->two->mode ||
4459                         p->one->dirty_submodule ||
4460                         p->two->dirty_submodule ||
4461                         is_null_oid(&p->one->oid))
4462                        p->status = DIFF_STATUS_MODIFIED;
4463                else {
4464                        /* This is a "no-change" entry and should not
4465                         * happen anymore, but prepare for broken callers.
4466                         */
4467                        error("feeding unmodified %s to diffcore",
4468                              p->one->path);
4469                        p->status = DIFF_STATUS_UNKNOWN;
4470                }
4471        }
4472        diff_debug_queue("resolve-rename-copy done", q);
4473}
4474
4475static int check_pair_status(struct diff_filepair *p)
4476{
4477        switch (p->status) {
4478        case DIFF_STATUS_UNKNOWN:
4479                return 0;
4480        case 0:
4481                die("internal error in diff-resolve-rename-copy");
4482        default:
4483                return 1;
4484        }
4485}
4486
4487static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
4488{
4489        int fmt = opt->output_format;
4490
4491        if (fmt & DIFF_FORMAT_CHECKDIFF)
4492                diff_flush_checkdiff(p, opt);
4493        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
4494                diff_flush_raw(p, opt);
4495        else if (fmt & DIFF_FORMAT_NAME) {
4496                const char *name_a, *name_b;
4497                name_a = p->two->path;
4498                name_b = NULL;
4499                strip_prefix(opt->prefix_length, &name_a, &name_b);
4500                fprintf(opt->file, "%s", diff_line_prefix(opt));
4501                write_name_quoted(name_a, opt->file, opt->line_termination);
4502        }
4503}
4504
4505static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
4506{
4507        if (fs->mode)
4508                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
4509        else
4510                fprintf(file, " %s ", newdelete);
4511        write_name_quoted(fs->path, file, '\n');
4512}
4513
4514
4515static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
4516                const char *line_prefix)
4517{
4518        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
4519                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
4520                        p->two->mode, show_name ? ' ' : '\n');
4521                if (show_name) {
4522                        write_name_quoted(p->two->path, file, '\n');
4523                }
4524        }
4525}
4526
4527static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
4528                        const char *line_prefix)
4529{
4530        char *names = pprint_rename(p->one->path, p->two->path);
4531
4532        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
4533        free(names);
4534        show_mode_change(file, p, 0, line_prefix);
4535}
4536
4537static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
4538{
4539        FILE *file = opt->file;
4540        const char *line_prefix = diff_line_prefix(opt);
4541
4542        switch(p->status) {
4543        case DIFF_STATUS_DELETED:
4544                fputs(line_prefix, file);
4545                show_file_mode_name(file, "delete", p->one);
4546                break;
4547        case DIFF_STATUS_ADDED:
4548                fputs(line_prefix, file);
4549                show_file_mode_name(file, "create", p->two);
4550                break;
4551        case DIFF_STATUS_COPIED:
4552                fputs(line_prefix, file);
4553                show_rename_copy(file, "copy", p, line_prefix);
4554                break;
4555        case DIFF_STATUS_RENAMED:
4556                fputs(line_prefix, file);
4557                show_rename_copy(file, "rename", p, line_prefix);
4558                break;
4559        default:
4560                if (p->score) {
4561                        fprintf(file, "%s rewrite ", line_prefix);
4562                        write_name_quoted(p->two->path, file, ' ');
4563                        fprintf(file, "(%d%%)\n", similarity_index(p));
4564                }
4565                show_mode_change(file, p, !p->score, line_prefix);
4566                break;
4567        }
4568}
4569
4570struct patch_id_t {
4571        git_SHA_CTX *ctx;
4572        int patchlen;
4573};
4574
4575static int remove_space(char *line, int len)
4576{
4577        int i;
4578        char *dst = line;
4579        unsigned char c;
4580
4581        for (i = 0; i < len; i++)
4582                if (!isspace((c = line[i])))
4583                        *dst++ = c;
4584
4585        return dst - line;
4586}
4587
4588static void patch_id_consume(void *priv, char *line, unsigned long len)
4589{
4590        struct patch_id_t *data = priv;
4591        int new_len;
4592
4593        /* Ignore line numbers when computing the SHA1 of the patch */
4594        if (starts_with(line, "@@ -"))
4595                return;
4596
4597        new_len = remove_space(line, len);
4598
4599        git_SHA1_Update(data->ctx, line, new_len);
4600        data->patchlen += new_len;
4601}
4602
4603static void patch_id_add_string(git_SHA_CTX *ctx, const char *str)
4604{
4605        git_SHA1_Update(ctx, str, strlen(str));
4606}
4607
4608static void patch_id_add_mode(git_SHA_CTX *ctx, unsigned mode)
4609{
4610        /* large enough for 2^32 in octal */
4611        char buf[12];
4612        int len = xsnprintf(buf, sizeof(buf), "%06o", mode);
4613        git_SHA1_Update(ctx, buf, len);
4614}
4615
4616/* returns 0 upon success, and writes result into sha1 */
4617static int diff_get_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
4618{
4619        struct diff_queue_struct *q = &diff_queued_diff;
4620        int i;
4621        git_SHA_CTX ctx;
4622        struct patch_id_t data;
4623
4624        git_SHA1_Init(&ctx);
4625        memset(&data, 0, sizeof(struct patch_id_t));
4626        data.ctx = &ctx;
4627
4628        for (i = 0; i < q->nr; i++) {
4629                xpparam_t xpp;
4630                xdemitconf_t xecfg;
4631                mmfile_t mf1, mf2;
4632                struct diff_filepair *p = q->queue[i];
4633                int len1, len2;
4634
4635                memset(&xpp, 0, sizeof(xpp));
4636                memset(&xecfg, 0, sizeof(xecfg));
4637                if (p->status == 0)
4638                        return error("internal diff status error");
4639                if (p->status == DIFF_STATUS_UNKNOWN)
4640                        continue;
4641                if (diff_unmodified_pair(p))
4642                        continue;
4643                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4644                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4645                        continue;
4646                if (DIFF_PAIR_UNMERGED(p))
4647                        continue;
4648
4649                diff_fill_oid_info(p->one);
4650                diff_fill_oid_info(p->two);
4651
4652                len1 = remove_space(p->one->path, strlen(p->one->path));
4653                len2 = remove_space(p->two->path, strlen(p->two->path));
4654                patch_id_add_string(&ctx, "diff--git");
4655                patch_id_add_string(&ctx, "a/");
4656                git_SHA1_Update(&ctx, p->one->path, len1);
4657                patch_id_add_string(&ctx, "b/");
4658                git_SHA1_Update(&ctx, p->two->path, len2);
4659
4660                if (p->one->mode == 0) {
4661                        patch_id_add_string(&ctx, "newfilemode");
4662                        patch_id_add_mode(&ctx, p->two->mode);
4663                        patch_id_add_string(&ctx, "---/dev/null");
4664                        patch_id_add_string(&ctx, "+++b/");
4665                        git_SHA1_Update(&ctx, p->two->path, len2);
4666                } else if (p->two->mode == 0) {
4667                        patch_id_add_string(&ctx, "deletedfilemode");
4668                        patch_id_add_mode(&ctx, p->one->mode);
4669                        patch_id_add_string(&ctx, "---a/");
4670                        git_SHA1_Update(&ctx, p->one->path, len1);
4671                        patch_id_add_string(&ctx, "+++/dev/null");
4672                } else {
4673                        patch_id_add_string(&ctx, "---a/");
4674                        git_SHA1_Update(&ctx, p->one->path, len1);
4675                        patch_id_add_string(&ctx, "+++b/");
4676                        git_SHA1_Update(&ctx, p->two->path, len2);
4677                }
4678
4679                if (diff_header_only)
4680                        continue;
4681
4682                if (fill_mmfile(&mf1, p->one) < 0 ||
4683                    fill_mmfile(&mf2, p->two) < 0)
4684                        return error("unable to read files to diff");
4685
4686                if (diff_filespec_is_binary(p->one) ||
4687                    diff_filespec_is_binary(p->two)) {
4688                        git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
4689                                        GIT_SHA1_HEXSZ);
4690                        git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
4691                                        GIT_SHA1_HEXSZ);
4692                        continue;
4693                }
4694
4695                xpp.flags = 0;
4696                xecfg.ctxlen = 3;
4697                xecfg.flags = 0;
4698                if (xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4699                                  &xpp, &xecfg))
4700                        return error("unable to generate patch-id diff for %s",
4701                                     p->one->path);
4702        }
4703
4704        git_SHA1_Final(oid->hash, &ctx);
4705        return 0;
4706}
4707
4708int diff_flush_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
4709{
4710        struct diff_queue_struct *q = &diff_queued_diff;
4711        int i;
4712        int result = diff_get_patch_id(options, oid, diff_header_only);
4713
4714        for (i = 0; i < q->nr; i++)
4715                diff_free_filepair(q->queue[i]);
4716
4717        free(q->queue);
4718        DIFF_QUEUE_CLEAR(q);
4719
4720        return result;
4721}
4722
4723static int is_summary_empty(const struct diff_queue_struct *q)
4724{
4725        int i;
4726
4727        for (i = 0; i < q->nr; i++) {
4728                const struct diff_filepair *p = q->queue[i];
4729
4730                switch (p->status) {
4731                case DIFF_STATUS_DELETED:
4732                case DIFF_STATUS_ADDED:
4733                case DIFF_STATUS_COPIED:
4734                case DIFF_STATUS_RENAMED:
4735                        return 0;
4736                default:
4737                        if (p->score)
4738                                return 0;
4739                        if (p->one->mode && p->two->mode &&
4740                            p->one->mode != p->two->mode)
4741                                return 0;
4742                        break;
4743                }
4744        }
4745        return 1;
4746}
4747
4748static const char rename_limit_warning[] =
4749N_("inexact rename detection was skipped due to too many files.");
4750
4751static const char degrade_cc_to_c_warning[] =
4752N_("only found copies from modified paths due to too many files.");
4753
4754static const char rename_limit_advice[] =
4755N_("you may want to set your %s variable to at least "
4756   "%d and retry the command.");
4757
4758void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4759{
4760        if (degraded_cc)
4761                warning(_(degrade_cc_to_c_warning));
4762        else if (needed)
4763                warning(_(rename_limit_warning));
4764        else
4765                return;
4766        if (0 < needed && needed < 32767)
4767                warning(_(rename_limit_advice), varname, needed);
4768}
4769
4770static void diff_flush_patch_all_file_pairs(struct diff_options *o)
4771{
4772        int i;
4773        struct diff_queue_struct *q = &diff_queued_diff;
4774        for (i = 0; i < q->nr; i++) {
4775                struct diff_filepair *p = q->queue[i];
4776                if (check_pair_status(p))
4777                        diff_flush_patch(p, o);
4778        }
4779}
4780
4781void diff_flush(struct diff_options *options)
4782{
4783        struct diff_queue_struct *q = &diff_queued_diff;
4784        int i, output_format = options->output_format;
4785        int separator = 0;
4786        int dirstat_by_line = 0;
4787
4788        /*
4789         * Order: raw, stat, summary, patch
4790         * or:    name/name-status/checkdiff (other bits clear)
4791         */
4792        if (!q->nr)
4793                goto free_queue;
4794
4795        if (output_format & (DIFF_FORMAT_RAW |
4796                             DIFF_FORMAT_NAME |
4797                             DIFF_FORMAT_NAME_STATUS |
4798                             DIFF_FORMAT_CHECKDIFF)) {
4799                for (i = 0; i < q->nr; i++) {
4800                        struct diff_filepair *p = q->queue[i];
4801                        if (check_pair_status(p))
4802                                flush_one_pair(p, options);
4803                }
4804                separator++;
4805        }
4806
4807        if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
4808                dirstat_by_line = 1;
4809
4810        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
4811            dirstat_by_line) {
4812                struct diffstat_t diffstat;
4813
4814                memset(&diffstat, 0, sizeof(struct diffstat_t));
4815                for (i = 0; i < q->nr; i++) {
4816                        struct diff_filepair *p = q->queue[i];
4817                        if (check_pair_status(p))
4818                                diff_flush_stat(p, options, &diffstat);
4819                }
4820                if (output_format & DIFF_FORMAT_NUMSTAT)
4821                        show_numstat(&diffstat, options);
4822                if (output_format & DIFF_FORMAT_DIFFSTAT)
4823                        show_stats(&diffstat, options);
4824                if (output_format & DIFF_FORMAT_SHORTSTAT)
4825                        show_shortstats(&diffstat, options);
4826                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
4827                        show_dirstat_by_line(&diffstat, options);
4828                free_diffstat_info(&diffstat);
4829                separator++;
4830        }
4831        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
4832                show_dirstat(options);
4833
4834        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4835                for (i = 0; i < q->nr; i++) {
4836                        diff_summary(options, q->queue[i]);
4837                }
4838                separator++;
4839        }
4840
4841        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4842            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4843            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4844                /*
4845                 * run diff_flush_patch for the exit status. setting
4846                 * options->file to /dev/null should be safe, because we
4847                 * aren't supposed to produce any output anyway.
4848                 */
4849                if (options->close_file)
4850                        fclose(options->file);
4851                options->file = xfopen("/dev/null", "w");
4852                options->close_file = 1;
4853                for (i = 0; i < q->nr; i++) {
4854                        struct diff_filepair *p = q->queue[i];
4855                        if (check_pair_status(p))
4856                                diff_flush_patch(p, options);
4857                        if (options->found_changes)
4858                                break;
4859                }
4860        }
4861
4862        if (output_format & DIFF_FORMAT_PATCH) {
4863                if (separator) {
4864                        emit_diff_symbol(options, DIFF_SYMBOL_SEPARATOR, NULL, 0);
4865                        if (options->stat_sep) {
4866                                /* attach patch instead of inline */
4867                                fputs(options->stat_sep, options->file);
4868                        }
4869                }
4870
4871                diff_flush_patch_all_file_pairs(options);
4872        }
4873
4874        if (output_format & DIFF_FORMAT_CALLBACK)
4875                options->format_callback(q, options, options->format_callback_data);
4876
4877        for (i = 0; i < q->nr; i++)
4878                diff_free_filepair(q->queue[i]);
4879free_queue:
4880        free(q->queue);
4881        DIFF_QUEUE_CLEAR(q);
4882        if (options->close_file)
4883                fclose(options->file);
4884
4885        /*
4886         * Report the content-level differences with HAS_CHANGES;
4887         * diff_addremove/diff_change does not set the bit when
4888         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4889         */
4890        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4891                if (options->found_changes)
4892                        DIFF_OPT_SET(options, HAS_CHANGES);
4893                else
4894                        DIFF_OPT_CLR(options, HAS_CHANGES);
4895        }
4896}
4897
4898static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
4899{
4900        return (((p->status == DIFF_STATUS_MODIFIED) &&
4901                 ((p->score &&
4902                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
4903                  (!p->score &&
4904                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
4905                ((p->status != DIFF_STATUS_MODIFIED) &&
4906                 filter_bit_tst(p->status, options)));
4907}
4908
4909static void diffcore_apply_filter(struct diff_options *options)
4910{
4911        int i;
4912        struct diff_queue_struct *q = &diff_queued_diff;
4913        struct diff_queue_struct outq;
4914
4915        DIFF_QUEUE_CLEAR(&outq);
4916
4917        if (!options->filter)
4918                return;
4919
4920        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
4921                int found;
4922                for (i = found = 0; !found && i < q->nr; i++) {
4923                        if (match_filter(options, q->queue[i]))
4924                                found++;
4925                }
4926                if (found)
4927                        return;
4928
4929                /* otherwise we will clear the whole queue
4930                 * by copying the empty outq at the end of this
4931                 * function, but first clear the current entries
4932                 * in the queue.
4933                 */
4934                for (i = 0; i < q->nr; i++)
4935                        diff_free_filepair(q->queue[i]);
4936        }
4937        else {
4938                /* Only the matching ones */
4939                for (i = 0; i < q->nr; i++) {
4940                        struct diff_filepair *p = q->queue[i];
4941                        if (match_filter(options, p))
4942                                diff_q(&outq, p);
4943                        else
4944                                diff_free_filepair(p);
4945                }
4946        }
4947        free(q->queue);
4948        *q = outq;
4949}
4950
4951/* Check whether two filespecs with the same mode and size are identical */
4952static int diff_filespec_is_identical(struct diff_filespec *one,
4953                                      struct diff_filespec *two)
4954{
4955        if (S_ISGITLINK(one->mode))
4956                return 0;
4957        if (diff_populate_filespec(one, 0))
4958                return 0;
4959        if (diff_populate_filespec(two, 0))
4960                return 0;
4961        return !memcmp(one->data, two->data, one->size);
4962}
4963
4964static int diff_filespec_check_stat_unmatch(struct diff_filepair *p)
4965{
4966        if (p->done_skip_stat_unmatch)
4967                return p->skip_stat_unmatch_result;
4968
4969        p->done_skip_stat_unmatch = 1;
4970        p->skip_stat_unmatch_result = 0;
4971        /*
4972         * 1. Entries that come from stat info dirtiness
4973         *    always have both sides (iow, not create/delete),
4974         *    one side of the object name is unknown, with
4975         *    the same mode and size.  Keep the ones that
4976         *    do not match these criteria.  They have real
4977         *    differences.
4978         *
4979         * 2. At this point, the file is known to be modified,
4980         *    with the same mode and size, and the object
4981         *    name of one side is unknown.  Need to inspect
4982         *    the identical contents.
4983         */
4984        if (!DIFF_FILE_VALID(p->one) || /* (1) */
4985            !DIFF_FILE_VALID(p->two) ||
4986            (p->one->oid_valid && p->two->oid_valid) ||
4987            (p->one->mode != p->two->mode) ||
4988            diff_populate_filespec(p->one, CHECK_SIZE_ONLY) ||
4989            diff_populate_filespec(p->two, CHECK_SIZE_ONLY) ||
4990            (p->one->size != p->two->size) ||
4991            !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4992                p->skip_stat_unmatch_result = 1;
4993        return p->skip_stat_unmatch_result;
4994}
4995
4996static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4997{
4998        int i;
4999        struct diff_queue_struct *q = &diff_queued_diff;
5000        struct diff_queue_struct outq;
5001        DIFF_QUEUE_CLEAR(&outq);
5002
5003        for (i = 0; i < q->nr; i++) {
5004                struct diff_filepair *p = q->queue[i];
5005
5006                if (diff_filespec_check_stat_unmatch(p))
5007                        diff_q(&outq, p);
5008                else {
5009                        /*
5010                         * The caller can subtract 1 from skip_stat_unmatch
5011                         * to determine how many paths were dirty only
5012                         * due to stat info mismatch.
5013                         */
5014                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
5015                                diffopt->skip_stat_unmatch++;
5016                        diff_free_filepair(p);
5017                }
5018        }
5019        free(q->queue);
5020        *q = outq;
5021}
5022
5023static int diffnamecmp(const void *a_, const void *b_)
5024{
5025        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
5026        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
5027        const char *name_a, *name_b;
5028
5029        name_a = a->one ? a->one->path : a->two->path;
5030        name_b = b->one ? b->one->path : b->two->path;
5031        return strcmp(name_a, name_b);
5032}
5033
5034void diffcore_fix_diff_index(struct diff_options *options)
5035{
5036        struct diff_queue_struct *q = &diff_queued_diff;
5037        QSORT(q->queue, q->nr, diffnamecmp);
5038}
5039
5040void diffcore_std(struct diff_options *options)
5041{
5042        /* NOTE please keep the following in sync with diff_tree_combined() */
5043        if (options->skip_stat_unmatch)
5044                diffcore_skip_stat_unmatch(options);
5045        if (!options->found_follow) {
5046                /* See try_to_follow_renames() in tree-diff.c */
5047                if (options->break_opt != -1)
5048                        diffcore_break(options->break_opt);
5049                if (options->detect_rename)
5050                        diffcore_rename(options);
5051                if (options->break_opt != -1)
5052                        diffcore_merge_broken();
5053        }
5054        if (options->pickaxe)
5055                diffcore_pickaxe(options);
5056        if (options->orderfile)
5057                diffcore_order(options->orderfile);
5058        if (!options->found_follow)
5059                /* See try_to_follow_renames() in tree-diff.c */
5060                diff_resolve_rename_copy();
5061        diffcore_apply_filter(options);
5062
5063        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
5064                DIFF_OPT_SET(options, HAS_CHANGES);
5065        else
5066                DIFF_OPT_CLR(options, HAS_CHANGES);
5067
5068        options->found_follow = 0;
5069}
5070
5071int diff_result_code(struct diff_options *opt, int status)
5072{
5073        int result = 0;
5074
5075        diff_warn_rename_limit("diff.renameLimit",
5076                               opt->needed_rename_limit,
5077                               opt->degraded_cc_to_c);
5078        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
5079            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
5080                return status;
5081        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
5082            DIFF_OPT_TST(opt, HAS_CHANGES))
5083                result |= 01;
5084        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
5085            DIFF_OPT_TST(opt, CHECK_FAILED))
5086                result |= 02;
5087        return result;
5088}
5089
5090int diff_can_quit_early(struct diff_options *opt)
5091{
5092        return (DIFF_OPT_TST(opt, QUICK) &&
5093                !opt->filter &&
5094                DIFF_OPT_TST(opt, HAS_CHANGES));
5095}
5096
5097/*
5098 * Shall changes to this submodule be ignored?
5099 *
5100 * Submodule changes can be configured to be ignored separately for each path,
5101 * but that configuration can be overridden from the command line.
5102 */
5103static int is_submodule_ignored(const char *path, struct diff_options *options)
5104{
5105        int ignored = 0;
5106        unsigned orig_flags = options->flags;
5107        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
5108                set_diffopt_flags_from_submodule_config(options, path);
5109        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
5110                ignored = 1;
5111        options->flags = orig_flags;
5112        return ignored;
5113}
5114
5115void diff_addremove(struct diff_options *options,
5116                    int addremove, unsigned mode,
5117                    const struct object_id *oid,
5118                    int oid_valid,
5119                    const char *concatpath, unsigned dirty_submodule)
5120{
5121        struct diff_filespec *one, *two;
5122
5123        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
5124                return;
5125
5126        /* This may look odd, but it is a preparation for
5127         * feeding "there are unchanged files which should
5128         * not produce diffs, but when you are doing copy
5129         * detection you would need them, so here they are"
5130         * entries to the diff-core.  They will be prefixed
5131         * with something like '=' or '*' (I haven't decided
5132         * which but should not make any difference).
5133         * Feeding the same new and old to diff_change()
5134         * also has the same effect.
5135         * Before the final output happens, they are pruned after
5136         * merged into rename/copy pairs as appropriate.
5137         */
5138        if (DIFF_OPT_TST(options, REVERSE_DIFF))
5139                addremove = (addremove == '+' ? '-' :
5140                             addremove == '-' ? '+' : addremove);
5141
5142        if (options->prefix &&
5143            strncmp(concatpath, options->prefix, options->prefix_length))
5144                return;
5145
5146        one = alloc_filespec(concatpath);
5147        two = alloc_filespec(concatpath);
5148
5149        if (addremove != '+')
5150                fill_filespec(one, oid, oid_valid, mode);
5151        if (addremove != '-') {
5152                fill_filespec(two, oid, oid_valid, mode);
5153                two->dirty_submodule = dirty_submodule;
5154        }
5155
5156        diff_queue(&diff_queued_diff, one, two);
5157        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
5158                DIFF_OPT_SET(options, HAS_CHANGES);
5159}
5160
5161void diff_change(struct diff_options *options,
5162                 unsigned old_mode, unsigned new_mode,
5163                 const struct object_id *old_oid,
5164                 const struct object_id *new_oid,
5165                 int old_oid_valid, int new_oid_valid,
5166                 const char *concatpath,
5167                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
5168{
5169        struct diff_filespec *one, *two;
5170        struct diff_filepair *p;
5171
5172        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
5173            is_submodule_ignored(concatpath, options))
5174                return;
5175
5176        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
5177                SWAP(old_mode, new_mode);
5178                SWAP(old_oid, new_oid);
5179                SWAP(old_oid_valid, new_oid_valid);
5180                SWAP(old_dirty_submodule, new_dirty_submodule);
5181        }
5182
5183        if (options->prefix &&
5184            strncmp(concatpath, options->prefix, options->prefix_length))
5185                return;
5186
5187        one = alloc_filespec(concatpath);
5188        two = alloc_filespec(concatpath);
5189        fill_filespec(one, old_oid, old_oid_valid, old_mode);
5190        fill_filespec(two, new_oid, new_oid_valid, new_mode);
5191        one->dirty_submodule = old_dirty_submodule;
5192        two->dirty_submodule = new_dirty_submodule;
5193        p = diff_queue(&diff_queued_diff, one, two);
5194
5195        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
5196                return;
5197
5198        if (DIFF_OPT_TST(options, QUICK) && options->skip_stat_unmatch &&
5199            !diff_filespec_check_stat_unmatch(p))
5200                return;
5201
5202        DIFF_OPT_SET(options, HAS_CHANGES);
5203}
5204
5205struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
5206{
5207        struct diff_filepair *pair;
5208        struct diff_filespec *one, *two;
5209
5210        if (options->prefix &&
5211            strncmp(path, options->prefix, options->prefix_length))
5212                return NULL;
5213
5214        one = alloc_filespec(path);
5215        two = alloc_filespec(path);
5216        pair = diff_queue(&diff_queued_diff, one, two);
5217        pair->is_unmerged = 1;
5218        return pair;
5219}
5220
5221static char *run_textconv(const char *pgm, struct diff_filespec *spec,
5222                size_t *outsize)
5223{
5224        struct diff_tempfile *temp;
5225        const char *argv[3];
5226        const char **arg = argv;
5227        struct child_process child = CHILD_PROCESS_INIT;
5228        struct strbuf buf = STRBUF_INIT;
5229        int err = 0;
5230
5231        temp = prepare_temp_file(spec->path, spec);
5232        *arg++ = pgm;
5233        *arg++ = temp->name;
5234        *arg = NULL;
5235
5236        child.use_shell = 1;
5237        child.argv = argv;
5238        child.out = -1;
5239        if (start_command(&child)) {
5240                remove_tempfile();
5241                return NULL;
5242        }
5243
5244        if (strbuf_read(&buf, child.out, 0) < 0)
5245                err = error("error reading from textconv command '%s'", pgm);
5246        close(child.out);
5247
5248        if (finish_command(&child) || err) {
5249                strbuf_release(&buf);
5250                remove_tempfile();
5251                return NULL;
5252        }
5253        remove_tempfile();
5254
5255        return strbuf_detach(&buf, outsize);
5256}
5257
5258size_t fill_textconv(struct userdiff_driver *driver,
5259                     struct diff_filespec *df,
5260                     char **outbuf)
5261{
5262        size_t size;
5263
5264        if (!driver) {
5265                if (!DIFF_FILE_VALID(df)) {
5266                        *outbuf = "";
5267                        return 0;
5268                }
5269                if (diff_populate_filespec(df, 0))
5270                        die("unable to read files to diff");
5271                *outbuf = df->data;
5272                return df->size;
5273        }
5274
5275        if (!driver->textconv)
5276                die("BUG: fill_textconv called with non-textconv driver");
5277
5278        if (driver->textconv_cache && df->oid_valid) {
5279                *outbuf = notes_cache_get(driver->textconv_cache,
5280                                          &df->oid,
5281                                          &size);
5282                if (*outbuf)
5283                        return size;
5284        }
5285
5286        *outbuf = run_textconv(driver->textconv, df, &size);
5287        if (!*outbuf)
5288                die("unable to read files to diff");
5289
5290        if (driver->textconv_cache && df->oid_valid) {
5291                /* ignore errors, as we might be in a readonly repository */
5292                notes_cache_put(driver->textconv_cache, &df->oid, *outbuf,
5293                                size);
5294                /*
5295                 * we could save up changes and flush them all at the end,
5296                 * but we would need an extra call after all diffing is done.
5297                 * Since generating a cache entry is the slow path anyway,
5298                 * this extra overhead probably isn't a big deal.
5299                 */
5300                notes_cache_write(driver->textconv_cache);
5301        }
5302
5303        return size;
5304}
5305
5306int textconv_object(const char *path,
5307                    unsigned mode,
5308                    const struct object_id *oid,
5309                    int oid_valid,
5310                    char **buf,
5311                    unsigned long *buf_size)
5312{
5313        struct diff_filespec *df;
5314        struct userdiff_driver *textconv;
5315
5316        df = alloc_filespec(path);
5317        fill_filespec(df, oid, oid_valid, mode);
5318        textconv = get_textconv(df);
5319        if (!textconv) {
5320                free_filespec(df);
5321                return 0;
5322        }
5323
5324        *buf_size = fill_textconv(textconv, df, buf);
5325        free_filespec(df);
5326        return 1;
5327}
5328
5329void setup_diff_pager(struct diff_options *opt)
5330{
5331        /*
5332         * If the user asked for our exit code, then either they want --quiet
5333         * or --exit-code. We should definitely not bother with a pager in the
5334         * former case, as we will generate no output. Since we still properly
5335         * report our exit code even when a pager is run, we _could_ run a
5336         * pager with --exit-code. But since we have not done so historically,
5337         * and because it is easy to find people oneline advising "git diff
5338         * --exit-code" in hooks and other scripts, we do not do so.
5339         */
5340        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
5341            check_pager_config("diff") != 0)
5342                setup_pager();
5343}