diff.con commit diff.c: emit_diff_symbol learns DIFF_SYMBOL_FILEPAIR_{PLUS, MINUS} (3ee8b7b)
   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_FILEPAIR_PLUS,
 565        DIFF_SYMBOL_FILEPAIR_MINUS,
 566        DIFF_SYMBOL_WORDS_PORCELAIN,
 567        DIFF_SYMBOL_WORDS,
 568        DIFF_SYMBOL_CONTEXT,
 569        DIFF_SYMBOL_CONTEXT_INCOMPLETE,
 570        DIFF_SYMBOL_PLUS,
 571        DIFF_SYMBOL_MINUS,
 572        DIFF_SYMBOL_NO_LF_EOF,
 573        DIFF_SYMBOL_CONTEXT_FRAGINFO,
 574        DIFF_SYMBOL_CONTEXT_MARKER,
 575        DIFF_SYMBOL_SEPARATOR
 576};
 577/*
 578 * Flags for content lines:
 579 * 0..12 are whitespace rules
 580 * 13-15 are WSEH_NEW | WSEH_OLD | WSEH_CONTEXT
 581 * 16 is marking if the line is blank at EOF
 582 */
 583#define DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF (1<<16)
 584#define DIFF_SYMBOL_CONTENT_WS_MASK (WSEH_NEW | WSEH_OLD | WSEH_CONTEXT | WS_RULE_MASK)
 585
 586static void emit_line_ws_markup(struct diff_options *o,
 587                                const char *set, const char *reset,
 588                                const char *line, int len, char sign,
 589                                unsigned ws_rule, int blank_at_eof)
 590{
 591        const char *ws = NULL;
 592
 593        if (o->ws_error_highlight & ws_rule) {
 594                ws = diff_get_color_opt(o, DIFF_WHITESPACE);
 595                if (!*ws)
 596                        ws = NULL;
 597        }
 598
 599        if (!ws)
 600                emit_line_0(o, set, reset, sign, line, len);
 601        else if (blank_at_eof)
 602                /* Blank line at EOF - paint '+' as well */
 603                emit_line_0(o, ws, reset, sign, line, len);
 604        else {
 605                /* Emit just the prefix, then the rest. */
 606                emit_line_0(o, set, reset, sign, "", 0);
 607                ws_check_emit(line, len, ws_rule,
 608                              o->file, set, reset, ws);
 609        }
 610}
 611
 612static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
 613                             const char *line, int len, unsigned flags)
 614{
 615        static const char *nneof = " No newline at end of file\n";
 616        const char *context, *reset, *set, *meta;
 617        switch (s) {
 618        case DIFF_SYMBOL_NO_LF_EOF:
 619                context = diff_get_color_opt(o, DIFF_CONTEXT);
 620                reset = diff_get_color_opt(o, DIFF_RESET);
 621                putc('\n', o->file);
 622                emit_line_0(o, context, reset, '\\',
 623                            nneof, strlen(nneof));
 624                break;
 625        case DIFF_SYMBOL_CONTEXT_FRAGINFO:
 626                emit_line(o, "", "", line, len);
 627                break;
 628        case DIFF_SYMBOL_CONTEXT_INCOMPLETE:
 629        case DIFF_SYMBOL_CONTEXT_MARKER:
 630                context = diff_get_color_opt(o, DIFF_CONTEXT);
 631                reset = diff_get_color_opt(o, DIFF_RESET);
 632                emit_line(o, context, reset, line, len);
 633                break;
 634        case DIFF_SYMBOL_SEPARATOR:
 635                fprintf(o->file, "%s%c",
 636                        diff_line_prefix(o),
 637                        o->line_termination);
 638                break;
 639        case DIFF_SYMBOL_CONTEXT:
 640                set = diff_get_color_opt(o, DIFF_CONTEXT);
 641                reset = diff_get_color_opt(o, DIFF_RESET);
 642                emit_line_ws_markup(o, set, reset, line, len, ' ',
 643                                    flags & (DIFF_SYMBOL_CONTENT_WS_MASK), 0);
 644                break;
 645        case DIFF_SYMBOL_PLUS:
 646                set = diff_get_color_opt(o, DIFF_FILE_NEW);
 647                reset = diff_get_color_opt(o, DIFF_RESET);
 648                emit_line_ws_markup(o, set, reset, line, len, '+',
 649                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK,
 650                                    flags & DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF);
 651                break;
 652        case DIFF_SYMBOL_MINUS:
 653                set = diff_get_color_opt(o, DIFF_FILE_OLD);
 654                reset = diff_get_color_opt(o, DIFF_RESET);
 655                emit_line_ws_markup(o, set, reset, line, len, '-',
 656                                    flags & DIFF_SYMBOL_CONTENT_WS_MASK, 0);
 657                break;
 658        case DIFF_SYMBOL_WORDS_PORCELAIN:
 659                context = diff_get_color_opt(o, DIFF_CONTEXT);
 660                reset = diff_get_color_opt(o, DIFF_RESET);
 661                emit_line(o, context, reset, line, len);
 662                fputs("~\n", o->file);
 663                break;
 664        case DIFF_SYMBOL_WORDS:
 665                context = diff_get_color_opt(o, DIFF_CONTEXT);
 666                reset = diff_get_color_opt(o, DIFF_RESET);
 667                /*
 668                 * Skip the prefix character, if any.  With
 669                 * diff_suppress_blank_empty, there may be
 670                 * none.
 671                 */
 672                if (line[0] != '\n') {
 673                        line++;
 674                        len--;
 675                }
 676                emit_line(o, context, reset, line, len);
 677                break;
 678        case DIFF_SYMBOL_FILEPAIR_PLUS:
 679                meta = diff_get_color_opt(o, DIFF_METAINFO);
 680                reset = diff_get_color_opt(o, DIFF_RESET);
 681                fprintf(o->file, "%s%s+++ %s%s%s\n", diff_line_prefix(o), meta,
 682                        line, reset,
 683                        strchr(line, ' ') ? "\t" : "");
 684                break;
 685        case DIFF_SYMBOL_FILEPAIR_MINUS:
 686                meta = diff_get_color_opt(o, DIFF_METAINFO);
 687                reset = diff_get_color_opt(o, DIFF_RESET);
 688                fprintf(o->file, "%s%s--- %s%s%s\n", diff_line_prefix(o), meta,
 689                        line, reset,
 690                        strchr(line, ' ') ? "\t" : "");
 691                break;
 692        default:
 693                die("BUG: unknown diff symbol");
 694        }
 695}
 696
 697static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 698{
 699        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 700              ecbdata->blank_at_eof_in_preimage &&
 701              ecbdata->blank_at_eof_in_postimage &&
 702              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 703              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 704                return 0;
 705        return ws_blank_line(line, len, ecbdata->ws_rule);
 706}
 707
 708static void emit_add_line(const char *reset,
 709                          struct emit_callback *ecbdata,
 710                          const char *line, int len)
 711{
 712        unsigned flags = WSEH_NEW | ecbdata->ws_rule;
 713        if (new_blank_line_at_eof(ecbdata, line, len))
 714                flags |= DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF;
 715
 716        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_PLUS, line, len, flags);
 717}
 718
 719static void emit_del_line(const char *reset,
 720                          struct emit_callback *ecbdata,
 721                          const char *line, int len)
 722{
 723        unsigned flags = WSEH_OLD | ecbdata->ws_rule;
 724        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_MINUS, line, len, flags);
 725}
 726
 727static void emit_context_line(const char *reset,
 728                              struct emit_callback *ecbdata,
 729                              const char *line, int len)
 730{
 731        unsigned flags = WSEH_CONTEXT | ecbdata->ws_rule;
 732        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_CONTEXT, line, len, flags);
 733}
 734
 735static void emit_hunk_header(struct emit_callback *ecbdata,
 736                             const char *line, int len)
 737{
 738        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
 739        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 740        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 741        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 742        static const char atat[2] = { '@', '@' };
 743        const char *cp, *ep;
 744        struct strbuf msgbuf = STRBUF_INIT;
 745        int org_len = len;
 746        int i = 1;
 747
 748        /*
 749         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 750         * it always is at least 10 bytes long.
 751         */
 752        if (len < 10 ||
 753            memcmp(line, atat, 2) ||
 754            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 755                emit_diff_symbol(ecbdata->opt,
 756                                 DIFF_SYMBOL_CONTEXT_MARKER, line, len, 0);
 757                return;
 758        }
 759        ep += 2; /* skip over @@ */
 760
 761        /* The hunk header in fraginfo color */
 762        strbuf_addstr(&msgbuf, frag);
 763        strbuf_add(&msgbuf, line, ep - line);
 764        strbuf_addstr(&msgbuf, reset);
 765
 766        /*
 767         * trailing "\r\n"
 768         */
 769        for ( ; i < 3; i++)
 770                if (line[len - i] == '\r' || line[len - i] == '\n')
 771                        len--;
 772
 773        /* blank before the func header */
 774        for (cp = ep; ep - line < len; ep++)
 775                if (*ep != ' ' && *ep != '\t')
 776                        break;
 777        if (ep != cp) {
 778                strbuf_addstr(&msgbuf, context);
 779                strbuf_add(&msgbuf, cp, ep - cp);
 780                strbuf_addstr(&msgbuf, reset);
 781        }
 782
 783        if (ep < line + len) {
 784                strbuf_addstr(&msgbuf, func);
 785                strbuf_add(&msgbuf, ep, line + len - ep);
 786                strbuf_addstr(&msgbuf, reset);
 787        }
 788
 789        strbuf_add(&msgbuf, line + len, org_len - len);
 790        strbuf_complete_line(&msgbuf);
 791        emit_diff_symbol(ecbdata->opt,
 792                         DIFF_SYMBOL_CONTEXT_FRAGINFO, msgbuf.buf, msgbuf.len, 0);
 793        strbuf_release(&msgbuf);
 794}
 795
 796static struct diff_tempfile *claim_diff_tempfile(void) {
 797        int i;
 798        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 799                if (!diff_temp[i].name)
 800                        return diff_temp + i;
 801        die("BUG: diff is failing to clean up its tempfiles");
 802}
 803
 804static void remove_tempfile(void)
 805{
 806        int i;
 807        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 808                if (is_tempfile_active(&diff_temp[i].tempfile))
 809                        delete_tempfile(&diff_temp[i].tempfile);
 810                diff_temp[i].name = NULL;
 811        }
 812}
 813
 814static void print_line_count(FILE *file, int count)
 815{
 816        switch (count) {
 817        case 0:
 818                fprintf(file, "0,0");
 819                break;
 820        case 1:
 821                fprintf(file, "1");
 822                break;
 823        default:
 824                fprintf(file, "1,%d", count);
 825                break;
 826        }
 827}
 828
 829static void emit_rewrite_lines(struct emit_callback *ecb,
 830                               int prefix, const char *data, int size)
 831{
 832        const char *endp = NULL;
 833        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 834
 835        while (0 < size) {
 836                int len;
 837
 838                endp = memchr(data, '\n', size);
 839                len = endp ? (endp - data + 1) : size;
 840                if (prefix != '+') {
 841                        ecb->lno_in_preimage++;
 842                        emit_del_line(reset, ecb, data, len);
 843                } else {
 844                        ecb->lno_in_postimage++;
 845                        emit_add_line(reset, ecb, data, len);
 846                }
 847                size -= len;
 848                data += len;
 849        }
 850        if (!endp)
 851                emit_diff_symbol(ecb->opt, DIFF_SYMBOL_NO_LF_EOF, NULL, 0, 0);
 852}
 853
 854static void emit_rewrite_diff(const char *name_a,
 855                              const char *name_b,
 856                              struct diff_filespec *one,
 857                              struct diff_filespec *two,
 858                              struct userdiff_driver *textconv_one,
 859                              struct userdiff_driver *textconv_two,
 860                              struct diff_options *o)
 861{
 862        int lc_a, lc_b;
 863        const char *fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
 864        const char *reset = diff_get_color(o->use_color, DIFF_RESET);
 865        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 866        const char *a_prefix, *b_prefix;
 867        char *data_one, *data_two;
 868        size_t size_one, size_two;
 869        struct emit_callback ecbdata;
 870        const char *line_prefix = diff_line_prefix(o);
 871
 872        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 873                a_prefix = o->b_prefix;
 874                b_prefix = o->a_prefix;
 875        } else {
 876                a_prefix = o->a_prefix;
 877                b_prefix = o->b_prefix;
 878        }
 879
 880        name_a += (*name_a == '/');
 881        name_b += (*name_b == '/');
 882
 883        strbuf_reset(&a_name);
 884        strbuf_reset(&b_name);
 885        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 886        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 887
 888        size_one = fill_textconv(textconv_one, one, &data_one);
 889        size_two = fill_textconv(textconv_two, two, &data_two);
 890
 891        memset(&ecbdata, 0, sizeof(ecbdata));
 892        ecbdata.color_diff = want_color(o->use_color);
 893        ecbdata.ws_rule = whitespace_rule(name_b);
 894        ecbdata.opt = o;
 895        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 896                mmfile_t mf1, mf2;
 897                mf1.ptr = (char *)data_one;
 898                mf2.ptr = (char *)data_two;
 899                mf1.size = size_one;
 900                mf2.size = size_two;
 901                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 902        }
 903        ecbdata.lno_in_preimage = 1;
 904        ecbdata.lno_in_postimage = 1;
 905
 906        lc_a = count_lines(data_one, size_one);
 907        lc_b = count_lines(data_two, size_two);
 908
 909        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
 910                         a_name.buf, a_name.len, 0);
 911        emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
 912                         b_name.buf, b_name.len, 0);
 913
 914        fprintf(o->file, "%s%s@@ -", line_prefix, fraginfo);
 915        if (!o->irreversible_delete)
 916                print_line_count(o->file, lc_a);
 917        else
 918                fprintf(o->file, "?,?");
 919        fprintf(o->file, " +");
 920        print_line_count(o->file, lc_b);
 921        fprintf(o->file, " @@%s\n", reset);
 922        if (lc_a && !o->irreversible_delete)
 923                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 924        if (lc_b)
 925                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 926        if (textconv_one)
 927                free((char *)data_one);
 928        if (textconv_two)
 929                free((char *)data_two);
 930}
 931
 932struct diff_words_buffer {
 933        mmfile_t text;
 934        long alloc;
 935        struct diff_words_orig {
 936                const char *begin, *end;
 937        } *orig;
 938        int orig_nr, orig_alloc;
 939};
 940
 941static void diff_words_append(char *line, unsigned long len,
 942                struct diff_words_buffer *buffer)
 943{
 944        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 945        line++;
 946        len--;
 947        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 948        buffer->text.size += len;
 949        buffer->text.ptr[buffer->text.size] = '\0';
 950}
 951
 952struct diff_words_style_elem {
 953        const char *prefix;
 954        const char *suffix;
 955        const char *color; /* NULL; filled in by the setup code if
 956                            * color is enabled */
 957};
 958
 959struct diff_words_style {
 960        enum diff_words_type type;
 961        struct diff_words_style_elem new, old, ctx;
 962        const char *newline;
 963};
 964
 965static struct diff_words_style diff_words_styles[] = {
 966        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 967        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 968        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 969};
 970
 971struct diff_words_data {
 972        struct diff_words_buffer minus, plus;
 973        const char *current_plus;
 974        int last_minus;
 975        struct diff_options *opt;
 976        regex_t *word_regex;
 977        enum diff_words_type type;
 978        struct diff_words_style *style;
 979};
 980
 981static int fn_out_diff_words_write_helper(FILE *fp,
 982                                          struct diff_words_style_elem *st_el,
 983                                          const char *newline,
 984                                          size_t count, const char *buf,
 985                                          const char *line_prefix)
 986{
 987        int print = 0;
 988
 989        while (count) {
 990                char *p = memchr(buf, '\n', count);
 991                if (print)
 992                        fputs(line_prefix, fp);
 993                if (p != buf) {
 994                        if (st_el->color && fputs(st_el->color, fp) < 0)
 995                                return -1;
 996                        if (fputs(st_el->prefix, fp) < 0 ||
 997                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 998                            fputs(st_el->suffix, fp) < 0)
 999                                return -1;
1000                        if (st_el->color && *st_el->color
1001                            && fputs(GIT_COLOR_RESET, fp) < 0)
1002                                return -1;
1003                }
1004                if (!p)
1005                        return 0;
1006                if (fputs(newline, fp) < 0)
1007                        return -1;
1008                count -= p + 1 - buf;
1009                buf = p + 1;
1010                print = 1;
1011        }
1012        return 0;
1013}
1014
1015/*
1016 * '--color-words' algorithm can be described as:
1017 *
1018 *   1. collect the minus/plus lines of a diff hunk, divided into
1019 *      minus-lines and plus-lines;
1020 *
1021 *   2. break both minus-lines and plus-lines into words and
1022 *      place them into two mmfile_t with one word for each line;
1023 *
1024 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
1025 *
1026 * And for the common parts of the both file, we output the plus side text.
1027 * diff_words->current_plus is used to trace the current position of the plus file
1028 * which printed. diff_words->last_minus is used to trace the last minus word
1029 * printed.
1030 *
1031 * For '--graph' to work with '--color-words', we need to output the graph prefix
1032 * on each line of color words output. Generally, there are two conditions on
1033 * which we should output the prefix.
1034 *
1035 *   1. diff_words->last_minus == 0 &&
1036 *      diff_words->current_plus == diff_words->plus.text.ptr
1037 *
1038 *      that is: the plus text must start as a new line, and if there is no minus
1039 *      word printed, a graph prefix must be printed.
1040 *
1041 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
1042 *      *(diff_words->current_plus - 1) == '\n'
1043 *
1044 *      that is: a graph prefix must be printed following a '\n'
1045 */
1046static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
1047{
1048        if ((diff_words->last_minus == 0 &&
1049                diff_words->current_plus == diff_words->plus.text.ptr) ||
1050                (diff_words->current_plus > diff_words->plus.text.ptr &&
1051                *(diff_words->current_plus - 1) == '\n')) {
1052                return 1;
1053        } else {
1054                return 0;
1055        }
1056}
1057
1058static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
1059{
1060        struct diff_words_data *diff_words = priv;
1061        struct diff_words_style *style = diff_words->style;
1062        int minus_first, minus_len, plus_first, plus_len;
1063        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
1064        struct diff_options *opt = diff_words->opt;
1065        const char *line_prefix;
1066
1067        if (line[0] != '@' || parse_hunk_header(line, len,
1068                        &minus_first, &minus_len, &plus_first, &plus_len))
1069                return;
1070
1071        assert(opt);
1072        line_prefix = diff_line_prefix(opt);
1073
1074        /* POSIX requires that first be decremented by one if len == 0... */
1075        if (minus_len) {
1076                minus_begin = diff_words->minus.orig[minus_first].begin;
1077                minus_end =
1078                        diff_words->minus.orig[minus_first + minus_len - 1].end;
1079        } else
1080                minus_begin = minus_end =
1081                        diff_words->minus.orig[minus_first].end;
1082
1083        if (plus_len) {
1084                plus_begin = diff_words->plus.orig[plus_first].begin;
1085                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
1086        } else
1087                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
1088
1089        if (color_words_output_graph_prefix(diff_words)) {
1090                fputs(line_prefix, diff_words->opt->file);
1091        }
1092        if (diff_words->current_plus != plus_begin) {
1093                fn_out_diff_words_write_helper(diff_words->opt->file,
1094                                &style->ctx, style->newline,
1095                                plus_begin - diff_words->current_plus,
1096                                diff_words->current_plus, line_prefix);
1097                if (*(plus_begin - 1) == '\n')
1098                        fputs(line_prefix, diff_words->opt->file);
1099        }
1100        if (minus_begin != minus_end) {
1101                fn_out_diff_words_write_helper(diff_words->opt->file,
1102                                &style->old, style->newline,
1103                                minus_end - minus_begin, minus_begin,
1104                                line_prefix);
1105        }
1106        if (plus_begin != plus_end) {
1107                fn_out_diff_words_write_helper(diff_words->opt->file,
1108                                &style->new, style->newline,
1109                                plus_end - plus_begin, plus_begin,
1110                                line_prefix);
1111        }
1112
1113        diff_words->current_plus = plus_end;
1114        diff_words->last_minus = minus_first;
1115}
1116
1117/* This function starts looking at *begin, and returns 0 iff a word was found. */
1118static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
1119                int *begin, int *end)
1120{
1121        if (word_regex && *begin < buffer->size) {
1122                regmatch_t match[1];
1123                if (!regexec_buf(word_regex, buffer->ptr + *begin,
1124                                 buffer->size - *begin, 1, match, 0)) {
1125                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
1126                                        '\n', match[0].rm_eo - match[0].rm_so);
1127                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
1128                        *begin += match[0].rm_so;
1129                        return *begin >= *end;
1130                }
1131                return -1;
1132        }
1133
1134        /* find the next word */
1135        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
1136                (*begin)++;
1137        if (*begin >= buffer->size)
1138                return -1;
1139
1140        /* find the end of the word */
1141        *end = *begin + 1;
1142        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
1143                (*end)++;
1144
1145        return 0;
1146}
1147
1148/*
1149 * This function splits the words in buffer->text, stores the list with
1150 * newline separator into out, and saves the offsets of the original words
1151 * in buffer->orig.
1152 */
1153static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
1154                regex_t *word_regex)
1155{
1156        int i, j;
1157        long alloc = 0;
1158
1159        out->size = 0;
1160        out->ptr = NULL;
1161
1162        /* fake an empty "0th" word */
1163        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
1164        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
1165        buffer->orig_nr = 1;
1166
1167        for (i = 0; i < buffer->text.size; i++) {
1168                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
1169                        return;
1170
1171                /* store original boundaries */
1172                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
1173                                buffer->orig_alloc);
1174                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
1175                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
1176                buffer->orig_nr++;
1177
1178                /* store one word */
1179                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
1180                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
1181                out->ptr[out->size + j - i] = '\n';
1182                out->size += j - i + 1;
1183
1184                i = j - 1;
1185        }
1186}
1187
1188/* this executes the word diff on the accumulated buffers */
1189static void diff_words_show(struct diff_words_data *diff_words)
1190{
1191        xpparam_t xpp;
1192        xdemitconf_t xecfg;
1193        mmfile_t minus, plus;
1194        struct diff_words_style *style = diff_words->style;
1195
1196        struct diff_options *opt = diff_words->opt;
1197        const char *line_prefix;
1198
1199        assert(opt);
1200        line_prefix = diff_line_prefix(opt);
1201
1202        /* special case: only removal */
1203        if (!diff_words->plus.text.size) {
1204                fputs(line_prefix, diff_words->opt->file);
1205                fn_out_diff_words_write_helper(diff_words->opt->file,
1206                        &style->old, style->newline,
1207                        diff_words->minus.text.size,
1208                        diff_words->minus.text.ptr, line_prefix);
1209                diff_words->minus.text.size = 0;
1210                return;
1211        }
1212
1213        diff_words->current_plus = diff_words->plus.text.ptr;
1214        diff_words->last_minus = 0;
1215
1216        memset(&xpp, 0, sizeof(xpp));
1217        memset(&xecfg, 0, sizeof(xecfg));
1218        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
1219        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
1220        xpp.flags = 0;
1221        /* as only the hunk header will be parsed, we need a 0-context */
1222        xecfg.ctxlen = 0;
1223        if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
1224                          &xpp, &xecfg))
1225                die("unable to generate word diff");
1226        free(minus.ptr);
1227        free(plus.ptr);
1228        if (diff_words->current_plus != diff_words->plus.text.ptr +
1229                        diff_words->plus.text.size) {
1230                if (color_words_output_graph_prefix(diff_words))
1231                        fputs(line_prefix, diff_words->opt->file);
1232                fn_out_diff_words_write_helper(diff_words->opt->file,
1233                        &style->ctx, style->newline,
1234                        diff_words->plus.text.ptr + diff_words->plus.text.size
1235                        - diff_words->current_plus, diff_words->current_plus,
1236                        line_prefix);
1237        }
1238        diff_words->minus.text.size = diff_words->plus.text.size = 0;
1239}
1240
1241/* In "color-words" mode, show word-diff of words accumulated in the buffer */
1242static void diff_words_flush(struct emit_callback *ecbdata)
1243{
1244        if (ecbdata->diff_words->minus.text.size ||
1245            ecbdata->diff_words->plus.text.size)
1246                diff_words_show(ecbdata->diff_words);
1247}
1248
1249static void diff_filespec_load_driver(struct diff_filespec *one)
1250{
1251        /* Use already-loaded driver */
1252        if (one->driver)
1253                return;
1254
1255        if (S_ISREG(one->mode))
1256                one->driver = userdiff_find_by_path(one->path);
1257
1258        /* Fallback to default settings */
1259        if (!one->driver)
1260                one->driver = userdiff_find_by_name("default");
1261}
1262
1263static const char *userdiff_word_regex(struct diff_filespec *one)
1264{
1265        diff_filespec_load_driver(one);
1266        return one->driver->word_regex;
1267}
1268
1269static void init_diff_words_data(struct emit_callback *ecbdata,
1270                                 struct diff_options *orig_opts,
1271                                 struct diff_filespec *one,
1272                                 struct diff_filespec *two)
1273{
1274        int i;
1275        struct diff_options *o = xmalloc(sizeof(struct diff_options));
1276        memcpy(o, orig_opts, sizeof(struct diff_options));
1277
1278        ecbdata->diff_words =
1279                xcalloc(1, sizeof(struct diff_words_data));
1280        ecbdata->diff_words->type = o->word_diff;
1281        ecbdata->diff_words->opt = o;
1282        if (!o->word_regex)
1283                o->word_regex = userdiff_word_regex(one);
1284        if (!o->word_regex)
1285                o->word_regex = userdiff_word_regex(two);
1286        if (!o->word_regex)
1287                o->word_regex = diff_word_regex_cfg;
1288        if (o->word_regex) {
1289                ecbdata->diff_words->word_regex = (regex_t *)
1290                        xmalloc(sizeof(regex_t));
1291                if (regcomp(ecbdata->diff_words->word_regex,
1292                            o->word_regex,
1293                            REG_EXTENDED | REG_NEWLINE))
1294                        die ("Invalid regular expression: %s",
1295                             o->word_regex);
1296        }
1297        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
1298                if (o->word_diff == diff_words_styles[i].type) {
1299                        ecbdata->diff_words->style =
1300                                &diff_words_styles[i];
1301                        break;
1302                }
1303        }
1304        if (want_color(o->use_color)) {
1305                struct diff_words_style *st = ecbdata->diff_words->style;
1306                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
1307                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
1308                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
1309        }
1310}
1311
1312static void free_diff_words_data(struct emit_callback *ecbdata)
1313{
1314        if (ecbdata->diff_words) {
1315                diff_words_flush(ecbdata);
1316                free (ecbdata->diff_words->opt);
1317                free (ecbdata->diff_words->minus.text.ptr);
1318                free (ecbdata->diff_words->minus.orig);
1319                free (ecbdata->diff_words->plus.text.ptr);
1320                free (ecbdata->diff_words->plus.orig);
1321                if (ecbdata->diff_words->word_regex) {
1322                        regfree(ecbdata->diff_words->word_regex);
1323                        free(ecbdata->diff_words->word_regex);
1324                }
1325                FREE_AND_NULL(ecbdata->diff_words);
1326        }
1327}
1328
1329const char *diff_get_color(int diff_use_color, enum color_diff ix)
1330{
1331        if (want_color(diff_use_color))
1332                return diff_colors[ix];
1333        return "";
1334}
1335
1336const char *diff_line_prefix(struct diff_options *opt)
1337{
1338        struct strbuf *msgbuf;
1339        if (!opt->output_prefix)
1340                return "";
1341
1342        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
1343        return msgbuf->buf;
1344}
1345
1346static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
1347{
1348        const char *cp;
1349        unsigned long allot;
1350        size_t l = len;
1351
1352        if (ecb->truncate)
1353                return ecb->truncate(line, len);
1354        cp = line;
1355        allot = l;
1356        while (0 < l) {
1357                (void) utf8_width(&cp, &l);
1358                if (!cp)
1359                        break; /* truncated in the middle? */
1360        }
1361        return allot - l;
1362}
1363
1364static void find_lno(const char *line, struct emit_callback *ecbdata)
1365{
1366        const char *p;
1367        ecbdata->lno_in_preimage = 0;
1368        ecbdata->lno_in_postimage = 0;
1369        p = strchr(line, '-');
1370        if (!p)
1371                return; /* cannot happen */
1372        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1373        p = strchr(p, '+');
1374        if (!p)
1375                return; /* cannot happen */
1376        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
1377}
1378
1379static void fn_out_consume(void *priv, char *line, unsigned long len)
1380{
1381        struct emit_callback *ecbdata = priv;
1382        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1383        struct diff_options *o = ecbdata->opt;
1384
1385        o->found_changes = 1;
1386
1387        if (ecbdata->header) {
1388                fprintf(o->file, "%s", ecbdata->header->buf);
1389                strbuf_reset(ecbdata->header);
1390                ecbdata->header = NULL;
1391        }
1392
1393        if (ecbdata->label_path[0]) {
1394                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
1395                                 ecbdata->label_path[0],
1396                                 strlen(ecbdata->label_path[0]), 0);
1397                emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
1398                                 ecbdata->label_path[1],
1399                                 strlen(ecbdata->label_path[1]), 0);
1400                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1401        }
1402
1403        if (diff_suppress_blank_empty
1404            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1405                line[0] = '\n';
1406                len = 1;
1407        }
1408
1409        if (line[0] == '@') {
1410                if (ecbdata->diff_words)
1411                        diff_words_flush(ecbdata);
1412                len = sane_truncate_line(ecbdata, line, len);
1413                find_lno(line, ecbdata);
1414                emit_hunk_header(ecbdata, line, len);
1415                return;
1416        }
1417
1418        if (ecbdata->diff_words) {
1419                enum diff_symbol s =
1420                        ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN ?
1421                        DIFF_SYMBOL_WORDS_PORCELAIN : DIFF_SYMBOL_WORDS;
1422                if (line[0] == '-') {
1423                        diff_words_append(line, len,
1424                                          &ecbdata->diff_words->minus);
1425                        return;
1426                } else if (line[0] == '+') {
1427                        diff_words_append(line, len,
1428                                          &ecbdata->diff_words->plus);
1429                        return;
1430                } else if (starts_with(line, "\\ ")) {
1431                        /*
1432                         * Eat the "no newline at eof" marker as if we
1433                         * saw a "+" or "-" line with nothing on it,
1434                         * and return without diff_words_flush() to
1435                         * defer processing. If this is the end of
1436                         * preimage, more "+" lines may come after it.
1437                         */
1438                        return;
1439                }
1440                diff_words_flush(ecbdata);
1441                emit_diff_symbol(o, s, line, len, 0);
1442                return;
1443        }
1444
1445        switch (line[0]) {
1446        case '+':
1447                ecbdata->lno_in_postimage++;
1448                emit_add_line(reset, ecbdata, line + 1, len - 1);
1449                break;
1450        case '-':
1451                ecbdata->lno_in_preimage++;
1452                emit_del_line(reset, ecbdata, line + 1, len - 1);
1453                break;
1454        case ' ':
1455                ecbdata->lno_in_postimage++;
1456                ecbdata->lno_in_preimage++;
1457                emit_context_line(reset, ecbdata, line + 1, len - 1);
1458                break;
1459        default:
1460                /* incomplete line at the end */
1461                ecbdata->lno_in_preimage++;
1462                emit_diff_symbol(o, DIFF_SYMBOL_CONTEXT_INCOMPLETE,
1463                                 line, len, 0);
1464                break;
1465        }
1466}
1467
1468static char *pprint_rename(const char *a, const char *b)
1469{
1470        const char *old = a;
1471        const char *new = b;
1472        struct strbuf name = STRBUF_INIT;
1473        int pfx_length, sfx_length;
1474        int pfx_adjust_for_slash;
1475        int len_a = strlen(a);
1476        int len_b = strlen(b);
1477        int a_midlen, b_midlen;
1478        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1479        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1480
1481        if (qlen_a || qlen_b) {
1482                quote_c_style(a, &name, NULL, 0);
1483                strbuf_addstr(&name, " => ");
1484                quote_c_style(b, &name, NULL, 0);
1485                return strbuf_detach(&name, NULL);
1486        }
1487
1488        /* Find common prefix */
1489        pfx_length = 0;
1490        while (*old && *new && *old == *new) {
1491                if (*old == '/')
1492                        pfx_length = old - a + 1;
1493                old++;
1494                new++;
1495        }
1496
1497        /* Find common suffix */
1498        old = a + len_a;
1499        new = b + len_b;
1500        sfx_length = 0;
1501        /*
1502         * If there is a common prefix, it must end in a slash.  In
1503         * that case we let this loop run 1 into the prefix to see the
1504         * same slash.
1505         *
1506         * If there is no common prefix, we cannot do this as it would
1507         * underrun the input strings.
1508         */
1509        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
1510        while (a + pfx_length - pfx_adjust_for_slash <= old &&
1511               b + pfx_length - pfx_adjust_for_slash <= new &&
1512               *old == *new) {
1513                if (*old == '/')
1514                        sfx_length = len_a - (old - a);
1515                old--;
1516                new--;
1517        }
1518
1519        /*
1520         * pfx{mid-a => mid-b}sfx
1521         * {pfx-a => pfx-b}sfx
1522         * pfx{sfx-a => sfx-b}
1523         * name-a => name-b
1524         */
1525        a_midlen = len_a - pfx_length - sfx_length;
1526        b_midlen = len_b - pfx_length - sfx_length;
1527        if (a_midlen < 0)
1528                a_midlen = 0;
1529        if (b_midlen < 0)
1530                b_midlen = 0;
1531
1532        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1533        if (pfx_length + sfx_length) {
1534                strbuf_add(&name, a, pfx_length);
1535                strbuf_addch(&name, '{');
1536        }
1537        strbuf_add(&name, a + pfx_length, a_midlen);
1538        strbuf_addstr(&name, " => ");
1539        strbuf_add(&name, b + pfx_length, b_midlen);
1540        if (pfx_length + sfx_length) {
1541                strbuf_addch(&name, '}');
1542                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1543        }
1544        return strbuf_detach(&name, NULL);
1545}
1546
1547struct diffstat_t {
1548        int nr;
1549        int alloc;
1550        struct diffstat_file {
1551                char *from_name;
1552                char *name;
1553                char *print_name;
1554                unsigned is_unmerged:1;
1555                unsigned is_binary:1;
1556                unsigned is_renamed:1;
1557                unsigned is_interesting:1;
1558                uintmax_t added, deleted;
1559        } **files;
1560};
1561
1562static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1563                                          const char *name_a,
1564                                          const char *name_b)
1565{
1566        struct diffstat_file *x;
1567        x = xcalloc(1, sizeof(*x));
1568        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
1569        diffstat->files[diffstat->nr++] = x;
1570        if (name_b) {
1571                x->from_name = xstrdup(name_a);
1572                x->name = xstrdup(name_b);
1573                x->is_renamed = 1;
1574        }
1575        else {
1576                x->from_name = NULL;
1577                x->name = xstrdup(name_a);
1578        }
1579        return x;
1580}
1581
1582static void diffstat_consume(void *priv, char *line, unsigned long len)
1583{
1584        struct diffstat_t *diffstat = priv;
1585        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1586
1587        if (line[0] == '+')
1588                x->added++;
1589        else if (line[0] == '-')
1590                x->deleted++;
1591}
1592
1593const char mime_boundary_leader[] = "------------";
1594
1595static int scale_linear(int it, int width, int max_change)
1596{
1597        if (!it)
1598                return 0;
1599        /*
1600         * make sure that at least one '-' or '+' is printed if
1601         * there is any change to this path. The easiest way is to
1602         * scale linearly as if the alloted width is one column shorter
1603         * than it is, and then add 1 to the result.
1604         */
1605        return 1 + (it * (width - 1) / max_change);
1606}
1607
1608static void show_name(FILE *file,
1609                      const char *prefix, const char *name, int len)
1610{
1611        fprintf(file, " %s%-*s |", prefix, len, name);
1612}
1613
1614static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1615{
1616        if (cnt <= 0)
1617                return;
1618        fprintf(file, "%s", set);
1619        while (cnt--)
1620                putc(ch, file);
1621        fprintf(file, "%s", reset);
1622}
1623
1624static void fill_print_name(struct diffstat_file *file)
1625{
1626        char *pname;
1627
1628        if (file->print_name)
1629                return;
1630
1631        if (!file->is_renamed) {
1632                struct strbuf buf = STRBUF_INIT;
1633                if (quote_c_style(file->name, &buf, NULL, 0)) {
1634                        pname = strbuf_detach(&buf, NULL);
1635                } else {
1636                        pname = file->name;
1637                        strbuf_release(&buf);
1638                }
1639        } else {
1640                pname = pprint_rename(file->from_name, file->name);
1641        }
1642        file->print_name = pname;
1643}
1644
1645int print_stat_summary(FILE *fp, int files, int insertions, int deletions)
1646{
1647        struct strbuf sb = STRBUF_INIT;
1648        int ret;
1649
1650        if (!files) {
1651                assert(insertions == 0 && deletions == 0);
1652                return fprintf(fp, "%s\n", " 0 files changed");
1653        }
1654
1655        strbuf_addf(&sb,
1656                    (files == 1) ? " %d file changed" : " %d files changed",
1657                    files);
1658
1659        /*
1660         * For binary diff, the caller may want to print "x files
1661         * changed" with insertions == 0 && deletions == 0.
1662         *
1663         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
1664         * is probably less confusing (i.e skip over "2 files changed
1665         * but nothing about added/removed lines? Is this a bug in Git?").
1666         */
1667        if (insertions || deletions == 0) {
1668                strbuf_addf(&sb,
1669                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
1670                            insertions);
1671        }
1672
1673        if (deletions || insertions == 0) {
1674                strbuf_addf(&sb,
1675                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
1676                            deletions);
1677        }
1678        strbuf_addch(&sb, '\n');
1679        ret = fputs(sb.buf, fp);
1680        strbuf_release(&sb);
1681        return ret;
1682}
1683
1684static void show_stats(struct diffstat_t *data, struct diff_options *options)
1685{
1686        int i, len, add, del, adds = 0, dels = 0;
1687        uintmax_t max_change = 0, max_len = 0;
1688        int total_files = data->nr, count;
1689        int width, name_width, graph_width, number_width = 0, bin_width = 0;
1690        const char *reset, *add_c, *del_c;
1691        const char *line_prefix = "";
1692        int extra_shown = 0;
1693
1694        if (data->nr == 0)
1695                return;
1696
1697        line_prefix = diff_line_prefix(options);
1698        count = options->stat_count ? options->stat_count : data->nr;
1699
1700        reset = diff_get_color_opt(options, DIFF_RESET);
1701        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1702        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1703
1704        /*
1705         * Find the longest filename and max number of changes
1706         */
1707        for (i = 0; (i < count) && (i < data->nr); i++) {
1708                struct diffstat_file *file = data->files[i];
1709                uintmax_t change = file->added + file->deleted;
1710
1711                if (!file->is_interesting && (change == 0)) {
1712                        count++; /* not shown == room for one more */
1713                        continue;
1714                }
1715                fill_print_name(file);
1716                len = strlen(file->print_name);
1717                if (max_len < len)
1718                        max_len = len;
1719
1720                if (file->is_unmerged) {
1721                        /* "Unmerged" is 8 characters */
1722                        bin_width = bin_width < 8 ? 8 : bin_width;
1723                        continue;
1724                }
1725                if (file->is_binary) {
1726                        /* "Bin XXX -> YYY bytes" */
1727                        int w = 14 + decimal_width(file->added)
1728                                + decimal_width(file->deleted);
1729                        bin_width = bin_width < w ? w : bin_width;
1730                        /* Display change counts aligned with "Bin" */
1731                        number_width = 3;
1732                        continue;
1733                }
1734
1735                if (max_change < change)
1736                        max_change = change;
1737        }
1738        count = i; /* where we can stop scanning in data->files[] */
1739
1740        /*
1741         * We have width = stat_width or term_columns() columns total.
1742         * We want a maximum of min(max_len, stat_name_width) for the name part.
1743         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
1744         * We also need 1 for " " and 4 + decimal_width(max_change)
1745         * for " | NNNN " and one the empty column at the end, altogether
1746         * 6 + decimal_width(max_change).
1747         *
1748         * If there's not enough space, we will use the smaller of
1749         * stat_name_width (if set) and 5/8*width for the filename,
1750         * and the rest for constant elements + graph part, but no more
1751         * than stat_graph_width for the graph part.
1752         * (5/8 gives 50 for filename and 30 for the constant parts + graph
1753         * for the standard terminal size).
1754         *
1755         * In other words: stat_width limits the maximum width, and
1756         * stat_name_width fixes the maximum width of the filename,
1757         * and is also used to divide available columns if there
1758         * aren't enough.
1759         *
1760         * Binary files are displayed with "Bin XXX -> YYY bytes"
1761         * instead of the change count and graph. This part is treated
1762         * similarly to the graph part, except that it is not
1763         * "scaled". If total width is too small to accommodate the
1764         * guaranteed minimum width of the filename part and the
1765         * separators and this message, this message will "overflow"
1766         * making the line longer than the maximum width.
1767         */
1768
1769        if (options->stat_width == -1)
1770                width = term_columns() - strlen(line_prefix);
1771        else
1772                width = options->stat_width ? options->stat_width : 80;
1773        number_width = decimal_width(max_change) > number_width ?
1774                decimal_width(max_change) : number_width;
1775
1776        if (options->stat_graph_width == -1)
1777                options->stat_graph_width = diff_stat_graph_width;
1778
1779        /*
1780         * Guarantee 3/8*16==6 for the graph part
1781         * and 5/8*16==10 for the filename part
1782         */
1783        if (width < 16 + 6 + number_width)
1784                width = 16 + 6 + number_width;
1785
1786        /*
1787         * First assign sizes that are wanted, ignoring available width.
1788         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
1789         * starting from "XXX" should fit in graph_width.
1790         */
1791        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
1792        if (options->stat_graph_width &&
1793            options->stat_graph_width < graph_width)
1794                graph_width = options->stat_graph_width;
1795
1796        name_width = (options->stat_name_width > 0 &&
1797                      options->stat_name_width < max_len) ?
1798                options->stat_name_width : max_len;
1799
1800        /*
1801         * Adjust adjustable widths not to exceed maximum width
1802         */
1803        if (name_width + number_width + 6 + graph_width > width) {
1804                if (graph_width > width * 3/8 - number_width - 6) {
1805                        graph_width = width * 3/8 - number_width - 6;
1806                        if (graph_width < 6)
1807                                graph_width = 6;
1808                }
1809
1810                if (options->stat_graph_width &&
1811                    graph_width > options->stat_graph_width)
1812                        graph_width = options->stat_graph_width;
1813                if (name_width > width - number_width - 6 - graph_width)
1814                        name_width = width - number_width - 6 - graph_width;
1815                else
1816                        graph_width = width - number_width - 6 - name_width;
1817        }
1818
1819        /*
1820         * From here name_width is the width of the name area,
1821         * and graph_width is the width of the graph area.
1822         * max_change is used to scale graph properly.
1823         */
1824        for (i = 0; i < count; i++) {
1825                const char *prefix = "";
1826                struct diffstat_file *file = data->files[i];
1827                char *name = file->print_name;
1828                uintmax_t added = file->added;
1829                uintmax_t deleted = file->deleted;
1830                int name_len;
1831
1832                if (!file->is_interesting && (added + deleted == 0))
1833                        continue;
1834
1835                /*
1836                 * "scale" the filename
1837                 */
1838                len = name_width;
1839                name_len = strlen(name);
1840                if (name_width < name_len) {
1841                        char *slash;
1842                        prefix = "...";
1843                        len -= 3;
1844                        name += name_len - len;
1845                        slash = strchr(name, '/');
1846                        if (slash)
1847                                name = slash;
1848                }
1849
1850                if (file->is_binary) {
1851                        fprintf(options->file, "%s", line_prefix);
1852                        show_name(options->file, prefix, name, len);
1853                        fprintf(options->file, " %*s", number_width, "Bin");
1854                        if (!added && !deleted) {
1855                                putc('\n', options->file);
1856                                continue;
1857                        }
1858                        fprintf(options->file, " %s%"PRIuMAX"%s",
1859                                del_c, deleted, reset);
1860                        fprintf(options->file, " -> ");
1861                        fprintf(options->file, "%s%"PRIuMAX"%s",
1862                                add_c, added, reset);
1863                        fprintf(options->file, " bytes");
1864                        fprintf(options->file, "\n");
1865                        continue;
1866                }
1867                else if (file->is_unmerged) {
1868                        fprintf(options->file, "%s", line_prefix);
1869                        show_name(options->file, prefix, name, len);
1870                        fprintf(options->file, " Unmerged\n");
1871                        continue;
1872                }
1873
1874                /*
1875                 * scale the add/delete
1876                 */
1877                add = added;
1878                del = deleted;
1879
1880                if (graph_width <= max_change) {
1881                        int total = scale_linear(add + del, graph_width, max_change);
1882                        if (total < 2 && add && del)
1883                                /* width >= 2 due to the sanity check */
1884                                total = 2;
1885                        if (add < del) {
1886                                add = scale_linear(add, graph_width, max_change);
1887                                del = total - add;
1888                        } else {
1889                                del = scale_linear(del, graph_width, max_change);
1890                                add = total - del;
1891                        }
1892                }
1893                fprintf(options->file, "%s", line_prefix);
1894                show_name(options->file, prefix, name, len);
1895                fprintf(options->file, " %*"PRIuMAX"%s",
1896                        number_width, added + deleted,
1897                        added + deleted ? " " : "");
1898                show_graph(options->file, '+', add, add_c, reset);
1899                show_graph(options->file, '-', del, del_c, reset);
1900                fprintf(options->file, "\n");
1901        }
1902
1903        for (i = 0; i < data->nr; i++) {
1904                struct diffstat_file *file = data->files[i];
1905                uintmax_t added = file->added;
1906                uintmax_t deleted = file->deleted;
1907
1908                if (file->is_unmerged ||
1909                    (!file->is_interesting && (added + deleted == 0))) {
1910                        total_files--;
1911                        continue;
1912                }
1913
1914                if (!file->is_binary) {
1915                        adds += added;
1916                        dels += deleted;
1917                }
1918                if (i < count)
1919                        continue;
1920                if (!extra_shown)
1921                        fprintf(options->file, "%s ...\n", line_prefix);
1922                extra_shown = 1;
1923        }
1924        fprintf(options->file, "%s", line_prefix);
1925        print_stat_summary(options->file, total_files, adds, dels);
1926}
1927
1928static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1929{
1930        int i, adds = 0, dels = 0, total_files = data->nr;
1931
1932        if (data->nr == 0)
1933                return;
1934
1935        for (i = 0; i < data->nr; i++) {
1936                int added = data->files[i]->added;
1937                int deleted= data->files[i]->deleted;
1938
1939                if (data->files[i]->is_unmerged ||
1940                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
1941                        total_files--;
1942                } else if (!data->files[i]->is_binary) { /* don't count bytes */
1943                        adds += added;
1944                        dels += deleted;
1945                }
1946        }
1947        fprintf(options->file, "%s", diff_line_prefix(options));
1948        print_stat_summary(options->file, total_files, adds, dels);
1949}
1950
1951static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1952{
1953        int i;
1954
1955        if (data->nr == 0)
1956                return;
1957
1958        for (i = 0; i < data->nr; i++) {
1959                struct diffstat_file *file = data->files[i];
1960
1961                fprintf(options->file, "%s", diff_line_prefix(options));
1962
1963                if (file->is_binary)
1964                        fprintf(options->file, "-\t-\t");
1965                else
1966                        fprintf(options->file,
1967                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1968                                file->added, file->deleted);
1969                if (options->line_termination) {
1970                        fill_print_name(file);
1971                        if (!file->is_renamed)
1972                                write_name_quoted(file->name, options->file,
1973                                                  options->line_termination);
1974                        else {
1975                                fputs(file->print_name, options->file);
1976                                putc(options->line_termination, options->file);
1977                        }
1978                } else {
1979                        if (file->is_renamed) {
1980                                putc('\0', options->file);
1981                                write_name_quoted(file->from_name, options->file, '\0');
1982                        }
1983                        write_name_quoted(file->name, options->file, '\0');
1984                }
1985        }
1986}
1987
1988struct dirstat_file {
1989        const char *name;
1990        unsigned long changed;
1991};
1992
1993struct dirstat_dir {
1994        struct dirstat_file *files;
1995        int alloc, nr, permille, cumulative;
1996};
1997
1998static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1999                unsigned long changed, const char *base, int baselen)
2000{
2001        unsigned long this_dir = 0;
2002        unsigned int sources = 0;
2003        const char *line_prefix = diff_line_prefix(opt);
2004
2005        while (dir->nr) {
2006                struct dirstat_file *f = dir->files;
2007                int namelen = strlen(f->name);
2008                unsigned long this;
2009                char *slash;
2010
2011                if (namelen < baselen)
2012                        break;
2013                if (memcmp(f->name, base, baselen))
2014                        break;
2015                slash = strchr(f->name + baselen, '/');
2016                if (slash) {
2017                        int newbaselen = slash + 1 - f->name;
2018                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
2019                        sources++;
2020                } else {
2021                        this = f->changed;
2022                        dir->files++;
2023                        dir->nr--;
2024                        sources += 2;
2025                }
2026                this_dir += this;
2027        }
2028
2029        /*
2030         * We don't report dirstat's for
2031         *  - the top level
2032         *  - or cases where everything came from a single directory
2033         *    under this directory (sources == 1).
2034         */
2035        if (baselen && sources != 1) {
2036                if (this_dir) {
2037                        int permille = this_dir * 1000 / changed;
2038                        if (permille >= dir->permille) {
2039                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
2040                                        permille / 10, permille % 10, baselen, base);
2041                                if (!dir->cumulative)
2042                                        return 0;
2043                        }
2044                }
2045        }
2046        return this_dir;
2047}
2048
2049static int dirstat_compare(const void *_a, const void *_b)
2050{
2051        const struct dirstat_file *a = _a;
2052        const struct dirstat_file *b = _b;
2053        return strcmp(a->name, b->name);
2054}
2055
2056static void show_dirstat(struct diff_options *options)
2057{
2058        int i;
2059        unsigned long changed;
2060        struct dirstat_dir dir;
2061        struct diff_queue_struct *q = &diff_queued_diff;
2062
2063        dir.files = NULL;
2064        dir.alloc = 0;
2065        dir.nr = 0;
2066        dir.permille = options->dirstat_permille;
2067        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
2068
2069        changed = 0;
2070        for (i = 0; i < q->nr; i++) {
2071                struct diff_filepair *p = q->queue[i];
2072                const char *name;
2073                unsigned long copied, added, damage;
2074                int content_changed;
2075
2076                name = p->two->path ? p->two->path : p->one->path;
2077
2078                if (p->one->oid_valid && p->two->oid_valid)
2079                        content_changed = oidcmp(&p->one->oid, &p->two->oid);
2080                else
2081                        content_changed = 1;
2082
2083                if (!content_changed) {
2084                        /*
2085                         * The SHA1 has not changed, so pre-/post-content is
2086                         * identical. We can therefore skip looking at the
2087                         * file contents altogether.
2088                         */
2089                        damage = 0;
2090                        goto found_damage;
2091                }
2092
2093                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
2094                        /*
2095                         * In --dirstat-by-file mode, we don't really need to
2096                         * look at the actual file contents at all.
2097                         * The fact that the SHA1 changed is enough for us to
2098                         * add this file to the list of results
2099                         * (with each file contributing equal damage).
2100                         */
2101                        damage = 1;
2102                        goto found_damage;
2103                }
2104
2105                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
2106                        diff_populate_filespec(p->one, 0);
2107                        diff_populate_filespec(p->two, 0);
2108                        diffcore_count_changes(p->one, p->two, NULL, NULL,
2109                                               &copied, &added);
2110                        diff_free_filespec_data(p->one);
2111                        diff_free_filespec_data(p->two);
2112                } else if (DIFF_FILE_VALID(p->one)) {
2113                        diff_populate_filespec(p->one, CHECK_SIZE_ONLY);
2114                        copied = added = 0;
2115                        diff_free_filespec_data(p->one);
2116                } else if (DIFF_FILE_VALID(p->two)) {
2117                        diff_populate_filespec(p->two, CHECK_SIZE_ONLY);
2118                        copied = 0;
2119                        added = p->two->size;
2120                        diff_free_filespec_data(p->two);
2121                } else
2122                        continue;
2123
2124                /*
2125                 * Original minus copied is the removed material,
2126                 * added is the new material.  They are both damages
2127                 * made to the preimage.
2128                 * If the resulting damage is zero, we know that
2129                 * diffcore_count_changes() considers the two entries to
2130                 * be identical, but since content_changed is true, we
2131                 * know that there must have been _some_ kind of change,
2132                 * so we force all entries to have damage > 0.
2133                 */
2134                damage = (p->one->size - copied) + added;
2135                if (!damage)
2136                        damage = 1;
2137
2138found_damage:
2139                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
2140                dir.files[dir.nr].name = name;
2141                dir.files[dir.nr].changed = damage;
2142                changed += damage;
2143                dir.nr++;
2144        }
2145
2146        /* This can happen even with many files, if everything was renames */
2147        if (!changed)
2148                return;
2149
2150        /* Show all directories with more than x% of the changes */
2151        QSORT(dir.files, dir.nr, dirstat_compare);
2152        gather_dirstat(options, &dir, changed, "", 0);
2153}
2154
2155static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
2156{
2157        int i;
2158        unsigned long changed;
2159        struct dirstat_dir dir;
2160
2161        if (data->nr == 0)
2162                return;
2163
2164        dir.files = NULL;
2165        dir.alloc = 0;
2166        dir.nr = 0;
2167        dir.permille = options->dirstat_permille;
2168        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
2169
2170        changed = 0;
2171        for (i = 0; i < data->nr; i++) {
2172                struct diffstat_file *file = data->files[i];
2173                unsigned long damage = file->added + file->deleted;
2174                if (file->is_binary)
2175                        /*
2176                         * binary files counts bytes, not lines. Must find some
2177                         * way to normalize binary bytes vs. textual lines.
2178                         * The following heuristic assumes that there are 64
2179                         * bytes per "line".
2180                         * This is stupid and ugly, but very cheap...
2181                         */
2182                        damage = (damage + 63) / 64;
2183                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
2184                dir.files[dir.nr].name = file->name;
2185                dir.files[dir.nr].changed = damage;
2186                changed += damage;
2187                dir.nr++;
2188        }
2189
2190        /* This can happen even with many files, if everything was renames */
2191        if (!changed)
2192                return;
2193
2194        /* Show all directories with more than x% of the changes */
2195        QSORT(dir.files, dir.nr, dirstat_compare);
2196        gather_dirstat(options, &dir, changed, "", 0);
2197}
2198
2199static void free_diffstat_info(struct diffstat_t *diffstat)
2200{
2201        int i;
2202        for (i = 0; i < diffstat->nr; i++) {
2203                struct diffstat_file *f = diffstat->files[i];
2204                if (f->name != f->print_name)
2205                        free(f->print_name);
2206                free(f->name);
2207                free(f->from_name);
2208                free(f);
2209        }
2210        free(diffstat->files);
2211}
2212
2213struct checkdiff_t {
2214        const char *filename;
2215        int lineno;
2216        int conflict_marker_size;
2217        struct diff_options *o;
2218        unsigned ws_rule;
2219        unsigned status;
2220};
2221
2222static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
2223{
2224        char firstchar;
2225        int cnt;
2226
2227        if (len < marker_size + 1)
2228                return 0;
2229        firstchar = line[0];
2230        switch (firstchar) {
2231        case '=': case '>': case '<': case '|':
2232                break;
2233        default:
2234                return 0;
2235        }
2236        for (cnt = 1; cnt < marker_size; cnt++)
2237                if (line[cnt] != firstchar)
2238                        return 0;
2239        /* line[1] thru line[marker_size-1] are same as firstchar */
2240        if (len < marker_size + 1 || !isspace(line[marker_size]))
2241                return 0;
2242        return 1;
2243}
2244
2245static void checkdiff_consume(void *priv, char *line, unsigned long len)
2246{
2247        struct checkdiff_t *data = priv;
2248        int marker_size = data->conflict_marker_size;
2249        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
2250        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
2251        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
2252        char *err;
2253        const char *line_prefix;
2254
2255        assert(data->o);
2256        line_prefix = diff_line_prefix(data->o);
2257
2258        if (line[0] == '+') {
2259                unsigned bad;
2260                data->lineno++;
2261                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
2262                        data->status |= 1;
2263                        fprintf(data->o->file,
2264                                "%s%s:%d: leftover conflict marker\n",
2265                                line_prefix, data->filename, data->lineno);
2266                }
2267                bad = ws_check(line + 1, len - 1, data->ws_rule);
2268                if (!bad)
2269                        return;
2270                data->status |= bad;
2271                err = whitespace_error_string(bad);
2272                fprintf(data->o->file, "%s%s:%d: %s.\n",
2273                        line_prefix, data->filename, data->lineno, err);
2274                free(err);
2275                emit_line(data->o, set, reset, line, 1);
2276                ws_check_emit(line + 1, len - 1, data->ws_rule,
2277                              data->o->file, set, reset, ws);
2278        } else if (line[0] == ' ') {
2279                data->lineno++;
2280        } else if (line[0] == '@') {
2281                char *plus = strchr(line, '+');
2282                if (plus)
2283                        data->lineno = strtol(plus, NULL, 10) - 1;
2284                else
2285                        die("invalid diff");
2286        }
2287}
2288
2289static unsigned char *deflate_it(char *data,
2290                                 unsigned long size,
2291                                 unsigned long *result_size)
2292{
2293        int bound;
2294        unsigned char *deflated;
2295        git_zstream stream;
2296
2297        git_deflate_init(&stream, zlib_compression_level);
2298        bound = git_deflate_bound(&stream, size);
2299        deflated = xmalloc(bound);
2300        stream.next_out = deflated;
2301        stream.avail_out = bound;
2302
2303        stream.next_in = (unsigned char *)data;
2304        stream.avail_in = size;
2305        while (git_deflate(&stream, Z_FINISH) == Z_OK)
2306                ; /* nothing */
2307        git_deflate_end(&stream);
2308        *result_size = stream.total_out;
2309        return deflated;
2310}
2311
2312static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two,
2313                                  const char *prefix)
2314{
2315        void *cp;
2316        void *delta;
2317        void *deflated;
2318        void *data;
2319        unsigned long orig_size;
2320        unsigned long delta_size;
2321        unsigned long deflate_size;
2322        unsigned long data_size;
2323
2324        /* We could do deflated delta, or we could do just deflated two,
2325         * whichever is smaller.
2326         */
2327        delta = NULL;
2328        deflated = deflate_it(two->ptr, two->size, &deflate_size);
2329        if (one->size && two->size) {
2330                delta = diff_delta(one->ptr, one->size,
2331                                   two->ptr, two->size,
2332                                   &delta_size, deflate_size);
2333                if (delta) {
2334                        void *to_free = delta;
2335                        orig_size = delta_size;
2336                        delta = deflate_it(delta, delta_size, &delta_size);
2337                        free(to_free);
2338                }
2339        }
2340
2341        if (delta && delta_size < deflate_size) {
2342                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
2343                free(deflated);
2344                data = delta;
2345                data_size = delta_size;
2346        }
2347        else {
2348                fprintf(file, "%sliteral %lu\n", prefix, two->size);
2349                free(delta);
2350                data = deflated;
2351                data_size = deflate_size;
2352        }
2353
2354        /* emit data encoded in base85 */
2355        cp = data;
2356        while (data_size) {
2357                int bytes = (52 < data_size) ? 52 : data_size;
2358                char line[70];
2359                data_size -= bytes;
2360                if (bytes <= 26)
2361                        line[0] = bytes + 'A' - 1;
2362                else
2363                        line[0] = bytes - 26 + 'a' - 1;
2364                encode_85(line + 1, cp, bytes);
2365                cp = (char *) cp + bytes;
2366                fprintf(file, "%s", prefix);
2367                fputs(line, file);
2368                fputc('\n', file);
2369        }
2370        fprintf(file, "%s\n", prefix);
2371        free(data);
2372}
2373
2374static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two,
2375                             const char *prefix)
2376{
2377        fprintf(file, "%sGIT binary patch\n", prefix);
2378        emit_binary_diff_body(file, one, two, prefix);
2379        emit_binary_diff_body(file, two, one, prefix);
2380}
2381
2382int diff_filespec_is_binary(struct diff_filespec *one)
2383{
2384        if (one->is_binary == -1) {
2385                diff_filespec_load_driver(one);
2386                if (one->driver->binary != -1)
2387                        one->is_binary = one->driver->binary;
2388                else {
2389                        if (!one->data && DIFF_FILE_VALID(one))
2390                                diff_populate_filespec(one, CHECK_BINARY);
2391                        if (one->is_binary == -1 && one->data)
2392                                one->is_binary = buffer_is_binary(one->data,
2393                                                one->size);
2394                        if (one->is_binary == -1)
2395                                one->is_binary = 0;
2396                }
2397        }
2398        return one->is_binary;
2399}
2400
2401static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
2402{
2403        diff_filespec_load_driver(one);
2404        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
2405}
2406
2407void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
2408{
2409        if (!options->a_prefix)
2410                options->a_prefix = a;
2411        if (!options->b_prefix)
2412                options->b_prefix = b;
2413}
2414
2415struct userdiff_driver *get_textconv(struct diff_filespec *one)
2416{
2417        if (!DIFF_FILE_VALID(one))
2418                return NULL;
2419
2420        diff_filespec_load_driver(one);
2421        return userdiff_get_textconv(one->driver);
2422}
2423
2424static void builtin_diff(const char *name_a,
2425                         const char *name_b,
2426                         struct diff_filespec *one,
2427                         struct diff_filespec *two,
2428                         const char *xfrm_msg,
2429                         int must_show_header,
2430                         struct diff_options *o,
2431                         int complete_rewrite)
2432{
2433        mmfile_t mf1, mf2;
2434        const char *lbl[2];
2435        char *a_one, *b_two;
2436        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
2437        const char *reset = diff_get_color_opt(o, DIFF_RESET);
2438        const char *a_prefix, *b_prefix;
2439        struct userdiff_driver *textconv_one = NULL;
2440        struct userdiff_driver *textconv_two = NULL;
2441        struct strbuf header = STRBUF_INIT;
2442        const char *line_prefix = diff_line_prefix(o);
2443
2444        diff_set_mnemonic_prefix(o, "a/", "b/");
2445        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
2446                a_prefix = o->b_prefix;
2447                b_prefix = o->a_prefix;
2448        } else {
2449                a_prefix = o->a_prefix;
2450                b_prefix = o->b_prefix;
2451        }
2452
2453        if (o->submodule_format == DIFF_SUBMODULE_LOG &&
2454            (!one->mode || S_ISGITLINK(one->mode)) &&
2455            (!two->mode || S_ISGITLINK(two->mode))) {
2456                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2457                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2458                show_submodule_summary(o->file, one->path ? one->path : two->path,
2459                                line_prefix,
2460                                &one->oid, &two->oid,
2461                                two->dirty_submodule,
2462                                meta, del, add, reset);
2463                return;
2464        } else if (o->submodule_format == DIFF_SUBMODULE_INLINE_DIFF &&
2465                   (!one->mode || S_ISGITLINK(one->mode)) &&
2466                   (!two->mode || S_ISGITLINK(two->mode))) {
2467                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2468                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2469                show_submodule_inline_diff(o->file, one->path ? one->path : two->path,
2470                                line_prefix,
2471                                &one->oid, &two->oid,
2472                                two->dirty_submodule,
2473                                meta, del, add, reset, o);
2474                return;
2475        }
2476
2477        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
2478                textconv_one = get_textconv(one);
2479                textconv_two = get_textconv(two);
2480        }
2481
2482        /* Never use a non-valid filename anywhere if at all possible */
2483        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
2484        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
2485
2486        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
2487        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
2488        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
2489        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
2490        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
2491        if (lbl[0][0] == '/') {
2492                /* /dev/null */
2493                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
2494                if (xfrm_msg)
2495                        strbuf_addstr(&header, xfrm_msg);
2496                must_show_header = 1;
2497        }
2498        else if (lbl[1][0] == '/') {
2499                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
2500                if (xfrm_msg)
2501                        strbuf_addstr(&header, xfrm_msg);
2502                must_show_header = 1;
2503        }
2504        else {
2505                if (one->mode != two->mode) {
2506                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
2507                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
2508                        must_show_header = 1;
2509                }
2510                if (xfrm_msg)
2511                        strbuf_addstr(&header, xfrm_msg);
2512
2513                /*
2514                 * we do not run diff between different kind
2515                 * of objects.
2516                 */
2517                if ((one->mode ^ two->mode) & S_IFMT)
2518                        goto free_ab_and_return;
2519                if (complete_rewrite &&
2520                    (textconv_one || !diff_filespec_is_binary(one)) &&
2521                    (textconv_two || !diff_filespec_is_binary(two))) {
2522                        fprintf(o->file, "%s", header.buf);
2523                        strbuf_reset(&header);
2524                        emit_rewrite_diff(name_a, name_b, one, two,
2525                                                textconv_one, textconv_two, o);
2526                        o->found_changes = 1;
2527                        goto free_ab_and_return;
2528                }
2529        }
2530
2531        if (o->irreversible_delete && lbl[1][0] == '/') {
2532                fprintf(o->file, "%s", header.buf);
2533                strbuf_reset(&header);
2534                goto free_ab_and_return;
2535        } else if (!DIFF_OPT_TST(o, TEXT) &&
2536            ( (!textconv_one && diff_filespec_is_binary(one)) ||
2537              (!textconv_two && diff_filespec_is_binary(two)) )) {
2538                if (!one->data && !two->data &&
2539                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
2540                    !DIFF_OPT_TST(o, BINARY)) {
2541                        if (!oidcmp(&one->oid, &two->oid)) {
2542                                if (must_show_header)
2543                                        fprintf(o->file, "%s", header.buf);
2544                                goto free_ab_and_return;
2545                        }
2546                        fprintf(o->file, "%s", header.buf);
2547                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2548                                line_prefix, lbl[0], lbl[1]);
2549                        goto free_ab_and_return;
2550                }
2551                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2552                        die("unable to read files to diff");
2553                /* Quite common confusing case */
2554                if (mf1.size == mf2.size &&
2555                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2556                        if (must_show_header)
2557                                fprintf(o->file, "%s", header.buf);
2558                        goto free_ab_and_return;
2559                }
2560                fprintf(o->file, "%s", header.buf);
2561                strbuf_reset(&header);
2562                if (DIFF_OPT_TST(o, BINARY))
2563                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2564                else
2565                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2566                                line_prefix, lbl[0], lbl[1]);
2567                o->found_changes = 1;
2568        } else {
2569                /* Crazy xdl interfaces.. */
2570                const char *diffopts = getenv("GIT_DIFF_OPTS");
2571                const char *v;
2572                xpparam_t xpp;
2573                xdemitconf_t xecfg;
2574                struct emit_callback ecbdata;
2575                const struct userdiff_funcname *pe;
2576
2577                if (must_show_header) {
2578                        fprintf(o->file, "%s", header.buf);
2579                        strbuf_reset(&header);
2580                }
2581
2582                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2583                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2584
2585                pe = diff_funcname_pattern(one);
2586                if (!pe)
2587                        pe = diff_funcname_pattern(two);
2588
2589                memset(&xpp, 0, sizeof(xpp));
2590                memset(&xecfg, 0, sizeof(xecfg));
2591                memset(&ecbdata, 0, sizeof(ecbdata));
2592                ecbdata.label_path = lbl;
2593                ecbdata.color_diff = want_color(o->use_color);
2594                ecbdata.ws_rule = whitespace_rule(name_b);
2595                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2596                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2597                ecbdata.opt = o;
2598                ecbdata.header = header.len ? &header : NULL;
2599                xpp.flags = o->xdl_opts;
2600                xecfg.ctxlen = o->context;
2601                xecfg.interhunkctxlen = o->interhunkcontext;
2602                xecfg.flags = XDL_EMIT_FUNCNAMES;
2603                if (DIFF_OPT_TST(o, FUNCCONTEXT))
2604                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
2605                if (pe)
2606                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2607                if (!diffopts)
2608                        ;
2609                else if (skip_prefix(diffopts, "--unified=", &v))
2610                        xecfg.ctxlen = strtoul(v, NULL, 10);
2611                else if (skip_prefix(diffopts, "-u", &v))
2612                        xecfg.ctxlen = strtoul(v, NULL, 10);
2613                if (o->word_diff)
2614                        init_diff_words_data(&ecbdata, o, one, two);
2615                if (xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2616                                  &xpp, &xecfg))
2617                        die("unable to generate diff for %s", one->path);
2618                if (o->word_diff)
2619                        free_diff_words_data(&ecbdata);
2620                if (textconv_one)
2621                        free(mf1.ptr);
2622                if (textconv_two)
2623                        free(mf2.ptr);
2624                xdiff_clear_find_func(&xecfg);
2625        }
2626
2627 free_ab_and_return:
2628        strbuf_release(&header);
2629        diff_free_filespec_data(one);
2630        diff_free_filespec_data(two);
2631        free(a_one);
2632        free(b_two);
2633        return;
2634}
2635
2636static void builtin_diffstat(const char *name_a, const char *name_b,
2637                             struct diff_filespec *one,
2638                             struct diff_filespec *two,
2639                             struct diffstat_t *diffstat,
2640                             struct diff_options *o,
2641                             struct diff_filepair *p)
2642{
2643        mmfile_t mf1, mf2;
2644        struct diffstat_file *data;
2645        int same_contents;
2646        int complete_rewrite = 0;
2647
2648        if (!DIFF_PAIR_UNMERGED(p)) {
2649                if (p->status == DIFF_STATUS_MODIFIED && p->score)
2650                        complete_rewrite = 1;
2651        }
2652
2653        data = diffstat_add(diffstat, name_a, name_b);
2654        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
2655
2656        if (!one || !two) {
2657                data->is_unmerged = 1;
2658                return;
2659        }
2660
2661        same_contents = !oidcmp(&one->oid, &two->oid);
2662
2663        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2664                data->is_binary = 1;
2665                if (same_contents) {
2666                        data->added = 0;
2667                        data->deleted = 0;
2668                } else {
2669                        data->added = diff_filespec_size(two);
2670                        data->deleted = diff_filespec_size(one);
2671                }
2672        }
2673
2674        else if (complete_rewrite) {
2675                diff_populate_filespec(one, 0);
2676                diff_populate_filespec(two, 0);
2677                data->deleted = count_lines(one->data, one->size);
2678                data->added = count_lines(two->data, two->size);
2679        }
2680
2681        else if (!same_contents) {
2682                /* Crazy xdl interfaces.. */
2683                xpparam_t xpp;
2684                xdemitconf_t xecfg;
2685
2686                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2687                        die("unable to read files to diff");
2688
2689                memset(&xpp, 0, sizeof(xpp));
2690                memset(&xecfg, 0, sizeof(xecfg));
2691                xpp.flags = o->xdl_opts;
2692                xecfg.ctxlen = o->context;
2693                xecfg.interhunkctxlen = o->interhunkcontext;
2694                if (xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2695                                  &xpp, &xecfg))
2696                        die("unable to generate diffstat for %s", one->path);
2697        }
2698
2699        diff_free_filespec_data(one);
2700        diff_free_filespec_data(two);
2701}
2702
2703static void builtin_checkdiff(const char *name_a, const char *name_b,
2704                              const char *attr_path,
2705                              struct diff_filespec *one,
2706                              struct diff_filespec *two,
2707                              struct diff_options *o)
2708{
2709        mmfile_t mf1, mf2;
2710        struct checkdiff_t data;
2711
2712        if (!two)
2713                return;
2714
2715        memset(&data, 0, sizeof(data));
2716        data.filename = name_b ? name_b : name_a;
2717        data.lineno = 0;
2718        data.o = o;
2719        data.ws_rule = whitespace_rule(attr_path);
2720        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2721
2722        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2723                die("unable to read files to diff");
2724
2725        /*
2726         * All the other codepaths check both sides, but not checking
2727         * the "old" side here is deliberate.  We are checking the newly
2728         * introduced changes, and as long as the "new" side is text, we
2729         * can and should check what it introduces.
2730         */
2731        if (diff_filespec_is_binary(two))
2732                goto free_and_return;
2733        else {
2734                /* Crazy xdl interfaces.. */
2735                xpparam_t xpp;
2736                xdemitconf_t xecfg;
2737
2738                memset(&xpp, 0, sizeof(xpp));
2739                memset(&xecfg, 0, sizeof(xecfg));
2740                xecfg.ctxlen = 1; /* at least one context line */
2741                xpp.flags = 0;
2742                if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2743                                  &xpp, &xecfg))
2744                        die("unable to generate checkdiff for %s", one->path);
2745
2746                if (data.ws_rule & WS_BLANK_AT_EOF) {
2747                        struct emit_callback ecbdata;
2748                        int blank_at_eof;
2749
2750                        ecbdata.ws_rule = data.ws_rule;
2751                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2752                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2753
2754                        if (blank_at_eof) {
2755                                static char *err;
2756                                if (!err)
2757                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2758                                fprintf(o->file, "%s:%d: %s.\n",
2759                                        data.filename, blank_at_eof, err);
2760                                data.status = 1; /* report errors */
2761                        }
2762                }
2763        }
2764 free_and_return:
2765        diff_free_filespec_data(one);
2766        diff_free_filespec_data(two);
2767        if (data.status)
2768                DIFF_OPT_SET(o, CHECK_FAILED);
2769}
2770
2771struct diff_filespec *alloc_filespec(const char *path)
2772{
2773        struct diff_filespec *spec;
2774
2775        FLEXPTR_ALLOC_STR(spec, path, path);
2776        spec->count = 1;
2777        spec->is_binary = -1;
2778        return spec;
2779}
2780
2781void free_filespec(struct diff_filespec *spec)
2782{
2783        if (!--spec->count) {
2784                diff_free_filespec_data(spec);
2785                free(spec);
2786        }
2787}
2788
2789void fill_filespec(struct diff_filespec *spec, const struct object_id *oid,
2790                   int oid_valid, unsigned short mode)
2791{
2792        if (mode) {
2793                spec->mode = canon_mode(mode);
2794                oidcpy(&spec->oid, oid);
2795                spec->oid_valid = oid_valid;
2796        }
2797}
2798
2799/*
2800 * Given a name and sha1 pair, if the index tells us the file in
2801 * the work tree has that object contents, return true, so that
2802 * prepare_temp_file() does not have to inflate and extract.
2803 */
2804static int reuse_worktree_file(const char *name, const struct object_id *oid, int want_file)
2805{
2806        const struct cache_entry *ce;
2807        struct stat st;
2808        int pos, len;
2809
2810        /*
2811         * We do not read the cache ourselves here, because the
2812         * benchmark with my previous version that always reads cache
2813         * shows that it makes things worse for diff-tree comparing
2814         * two linux-2.6 kernel trees in an already checked out work
2815         * tree.  This is because most diff-tree comparisons deal with
2816         * only a small number of files, while reading the cache is
2817         * expensive for a large project, and its cost outweighs the
2818         * savings we get by not inflating the object to a temporary
2819         * file.  Practically, this code only helps when we are used
2820         * by diff-cache --cached, which does read the cache before
2821         * calling us.
2822         */
2823        if (!active_cache)
2824                return 0;
2825
2826        /* We want to avoid the working directory if our caller
2827         * doesn't need the data in a normal file, this system
2828         * is rather slow with its stat/open/mmap/close syscalls,
2829         * and the object is contained in a pack file.  The pack
2830         * is probably already open and will be faster to obtain
2831         * the data through than the working directory.  Loose
2832         * objects however would tend to be slower as they need
2833         * to be individually opened and inflated.
2834         */
2835        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(oid->hash))
2836                return 0;
2837
2838        /*
2839         * Similarly, if we'd have to convert the file contents anyway, that
2840         * makes the optimization not worthwhile.
2841         */
2842        if (!want_file && would_convert_to_git(&the_index, name))
2843                return 0;
2844
2845        len = strlen(name);
2846        pos = cache_name_pos(name, len);
2847        if (pos < 0)
2848                return 0;
2849        ce = active_cache[pos];
2850
2851        /*
2852         * This is not the sha1 we are looking for, or
2853         * unreusable because it is not a regular file.
2854         */
2855        if (oidcmp(oid, &ce->oid) || !S_ISREG(ce->ce_mode))
2856                return 0;
2857
2858        /*
2859         * If ce is marked as "assume unchanged", there is no
2860         * guarantee that work tree matches what we are looking for.
2861         */
2862        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2863                return 0;
2864
2865        /*
2866         * If ce matches the file in the work tree, we can reuse it.
2867         */
2868        if (ce_uptodate(ce) ||
2869            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2870                return 1;
2871
2872        return 0;
2873}
2874
2875static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2876{
2877        struct strbuf buf = STRBUF_INIT;
2878        char *dirty = "";
2879
2880        /* Are we looking at the work tree? */
2881        if (s->dirty_submodule)
2882                dirty = "-dirty";
2883
2884        strbuf_addf(&buf, "Subproject commit %s%s\n",
2885                    oid_to_hex(&s->oid), dirty);
2886        s->size = buf.len;
2887        if (size_only) {
2888                s->data = NULL;
2889                strbuf_release(&buf);
2890        } else {
2891                s->data = strbuf_detach(&buf, NULL);
2892                s->should_free = 1;
2893        }
2894        return 0;
2895}
2896
2897/*
2898 * While doing rename detection and pickaxe operation, we may need to
2899 * grab the data for the blob (or file) for our own in-core comparison.
2900 * diff_filespec has data and size fields for this purpose.
2901 */
2902int diff_populate_filespec(struct diff_filespec *s, unsigned int flags)
2903{
2904        int size_only = flags & CHECK_SIZE_ONLY;
2905        int err = 0;
2906        /*
2907         * demote FAIL to WARN to allow inspecting the situation
2908         * instead of refusing.
2909         */
2910        enum safe_crlf crlf_warn = (safe_crlf == SAFE_CRLF_FAIL
2911                                    ? SAFE_CRLF_WARN
2912                                    : safe_crlf);
2913
2914        if (!DIFF_FILE_VALID(s))
2915                die("internal error: asking to populate invalid file.");
2916        if (S_ISDIR(s->mode))
2917                return -1;
2918
2919        if (s->data)
2920                return 0;
2921
2922        if (size_only && 0 < s->size)
2923                return 0;
2924
2925        if (S_ISGITLINK(s->mode))
2926                return diff_populate_gitlink(s, size_only);
2927
2928        if (!s->oid_valid ||
2929            reuse_worktree_file(s->path, &s->oid, 0)) {
2930                struct strbuf buf = STRBUF_INIT;
2931                struct stat st;
2932                int fd;
2933
2934                if (lstat(s->path, &st) < 0) {
2935                        if (errno == ENOENT) {
2936                        err_empty:
2937                                err = -1;
2938                        empty:
2939                                s->data = (char *)"";
2940                                s->size = 0;
2941                                return err;
2942                        }
2943                }
2944                s->size = xsize_t(st.st_size);
2945                if (!s->size)
2946                        goto empty;
2947                if (S_ISLNK(st.st_mode)) {
2948                        struct strbuf sb = STRBUF_INIT;
2949
2950                        if (strbuf_readlink(&sb, s->path, s->size))
2951                                goto err_empty;
2952                        s->size = sb.len;
2953                        s->data = strbuf_detach(&sb, NULL);
2954                        s->should_free = 1;
2955                        return 0;
2956                }
2957
2958                /*
2959                 * Even if the caller would be happy with getting
2960                 * only the size, we cannot return early at this
2961                 * point if the path requires us to run the content
2962                 * conversion.
2963                 */
2964                if (size_only && !would_convert_to_git(&the_index, s->path))
2965                        return 0;
2966
2967                /*
2968                 * Note: this check uses xsize_t(st.st_size) that may
2969                 * not be the true size of the blob after it goes
2970                 * through convert_to_git().  This may not strictly be
2971                 * correct, but the whole point of big_file_threshold
2972                 * and is_binary check being that we want to avoid
2973                 * opening the file and inspecting the contents, this
2974                 * is probably fine.
2975                 */
2976                if ((flags & CHECK_BINARY) &&
2977                    s->size > big_file_threshold && s->is_binary == -1) {
2978                        s->is_binary = 1;
2979                        return 0;
2980                }
2981                fd = open(s->path, O_RDONLY);
2982                if (fd < 0)
2983                        goto err_empty;
2984                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2985                close(fd);
2986                s->should_munmap = 1;
2987
2988                /*
2989                 * Convert from working tree format to canonical git format
2990                 */
2991                if (convert_to_git(&the_index, s->path, s->data, s->size, &buf, crlf_warn)) {
2992                        size_t size = 0;
2993                        munmap(s->data, s->size);
2994                        s->should_munmap = 0;
2995                        s->data = strbuf_detach(&buf, &size);
2996                        s->size = size;
2997                        s->should_free = 1;
2998                }
2999        }
3000        else {
3001                enum object_type type;
3002                if (size_only || (flags & CHECK_BINARY)) {
3003                        type = sha1_object_info(s->oid.hash, &s->size);
3004                        if (type < 0)
3005                                die("unable to read %s",
3006                                    oid_to_hex(&s->oid));
3007                        if (size_only)
3008                                return 0;
3009                        if (s->size > big_file_threshold && s->is_binary == -1) {
3010                                s->is_binary = 1;
3011                                return 0;
3012                        }
3013                }
3014                s->data = read_sha1_file(s->oid.hash, &type, &s->size);
3015                if (!s->data)
3016                        die("unable to read %s", oid_to_hex(&s->oid));
3017                s->should_free = 1;
3018        }
3019        return 0;
3020}
3021
3022void diff_free_filespec_blob(struct diff_filespec *s)
3023{
3024        if (s->should_free)
3025                free(s->data);
3026        else if (s->should_munmap)
3027                munmap(s->data, s->size);
3028
3029        if (s->should_free || s->should_munmap) {
3030                s->should_free = s->should_munmap = 0;
3031                s->data = NULL;
3032        }
3033}
3034
3035void diff_free_filespec_data(struct diff_filespec *s)
3036{
3037        diff_free_filespec_blob(s);
3038        FREE_AND_NULL(s->cnt_data);
3039}
3040
3041static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
3042                           void *blob,
3043                           unsigned long size,
3044                           const struct object_id *oid,
3045                           int mode)
3046{
3047        int fd;
3048        struct strbuf buf = STRBUF_INIT;
3049        struct strbuf template = STRBUF_INIT;
3050        char *path_dup = xstrdup(path);
3051        const char *base = basename(path_dup);
3052
3053        /* Generate "XXXXXX_basename.ext" */
3054        strbuf_addstr(&template, "XXXXXX_");
3055        strbuf_addstr(&template, base);
3056
3057        fd = mks_tempfile_ts(&temp->tempfile, template.buf, strlen(base) + 1);
3058        if (fd < 0)
3059                die_errno("unable to create temp-file");
3060        if (convert_to_working_tree(path,
3061                        (const char *)blob, (size_t)size, &buf)) {
3062                blob = buf.buf;
3063                size = buf.len;
3064        }
3065        if (write_in_full(fd, blob, size) != size)
3066                die_errno("unable to write temp-file");
3067        close_tempfile(&temp->tempfile);
3068        temp->name = get_tempfile_path(&temp->tempfile);
3069        oid_to_hex_r(temp->hex, oid);
3070        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
3071        strbuf_release(&buf);
3072        strbuf_release(&template);
3073        free(path_dup);
3074}
3075
3076static struct diff_tempfile *prepare_temp_file(const char *name,
3077                struct diff_filespec *one)
3078{
3079        struct diff_tempfile *temp = claim_diff_tempfile();
3080
3081        if (!DIFF_FILE_VALID(one)) {
3082        not_a_valid_file:
3083                /* A '-' entry produces this for file-2, and
3084                 * a '+' entry produces this for file-1.
3085                 */
3086                temp->name = "/dev/null";
3087                xsnprintf(temp->hex, sizeof(temp->hex), ".");
3088                xsnprintf(temp->mode, sizeof(temp->mode), ".");
3089                return temp;
3090        }
3091
3092        if (!S_ISGITLINK(one->mode) &&
3093            (!one->oid_valid ||
3094             reuse_worktree_file(name, &one->oid, 1))) {
3095                struct stat st;
3096                if (lstat(name, &st) < 0) {
3097                        if (errno == ENOENT)
3098                                goto not_a_valid_file;
3099                        die_errno("stat(%s)", name);
3100                }
3101                if (S_ISLNK(st.st_mode)) {
3102                        struct strbuf sb = STRBUF_INIT;
3103                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
3104                                die_errno("readlink(%s)", name);
3105                        prep_temp_blob(name, temp, sb.buf, sb.len,
3106                                       (one->oid_valid ?
3107                                        &one->oid : &null_oid),
3108                                       (one->oid_valid ?
3109                                        one->mode : S_IFLNK));
3110                        strbuf_release(&sb);
3111                }
3112                else {
3113                        /* we can borrow from the file in the work tree */
3114                        temp->name = name;
3115                        if (!one->oid_valid)
3116                                oid_to_hex_r(temp->hex, &null_oid);
3117                        else
3118                                oid_to_hex_r(temp->hex, &one->oid);
3119                        /* Even though we may sometimes borrow the
3120                         * contents from the work tree, we always want
3121                         * one->mode.  mode is trustworthy even when
3122                         * !(one->oid_valid), as long as
3123                         * DIFF_FILE_VALID(one).
3124                         */
3125                        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
3126                }
3127                return temp;
3128        }
3129        else {
3130                if (diff_populate_filespec(one, 0))
3131                        die("cannot read data blob for %s", one->path);
3132                prep_temp_blob(name, temp, one->data, one->size,
3133                               &one->oid, one->mode);
3134        }
3135        return temp;
3136}
3137
3138static void add_external_diff_name(struct argv_array *argv,
3139                                   const char *name,
3140                                   struct diff_filespec *df)
3141{
3142        struct diff_tempfile *temp = prepare_temp_file(name, df);
3143        argv_array_push(argv, temp->name);
3144        argv_array_push(argv, temp->hex);
3145        argv_array_push(argv, temp->mode);
3146}
3147
3148/* An external diff command takes:
3149 *
3150 * diff-cmd name infile1 infile1-sha1 infile1-mode \
3151 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
3152 *
3153 */
3154static void run_external_diff(const char *pgm,
3155                              const char *name,
3156                              const char *other,
3157                              struct diff_filespec *one,
3158                              struct diff_filespec *two,
3159                              const char *xfrm_msg,
3160                              int complete_rewrite,
3161                              struct diff_options *o)
3162{
3163        struct argv_array argv = ARGV_ARRAY_INIT;
3164        struct argv_array env = ARGV_ARRAY_INIT;
3165        struct diff_queue_struct *q = &diff_queued_diff;
3166
3167        argv_array_push(&argv, pgm);
3168        argv_array_push(&argv, name);
3169
3170        if (one && two) {
3171                add_external_diff_name(&argv, name, one);
3172                if (!other)
3173                        add_external_diff_name(&argv, name, two);
3174                else {
3175                        add_external_diff_name(&argv, other, two);
3176                        argv_array_push(&argv, other);
3177                        argv_array_push(&argv, xfrm_msg);
3178                }
3179        }
3180
3181        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
3182        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
3183
3184        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
3185                die(_("external diff died, stopping at %s"), name);
3186
3187        remove_tempfile();
3188        argv_array_clear(&argv);
3189        argv_array_clear(&env);
3190}
3191
3192static int similarity_index(struct diff_filepair *p)
3193{
3194        return p->score * 100 / MAX_SCORE;
3195}
3196
3197static const char *diff_abbrev_oid(const struct object_id *oid, int abbrev)
3198{
3199        if (startup_info->have_repository)
3200                return find_unique_abbrev(oid->hash, abbrev);
3201        else {
3202                char *hex = oid_to_hex(oid);
3203                if (abbrev < 0)
3204                        abbrev = FALLBACK_DEFAULT_ABBREV;
3205                if (abbrev > GIT_SHA1_HEXSZ)
3206                        die("BUG: oid abbreviation out of range: %d", abbrev);
3207                if (abbrev)
3208                        hex[abbrev] = '\0';
3209                return hex;
3210        }
3211}
3212
3213static void fill_metainfo(struct strbuf *msg,
3214                          const char *name,
3215                          const char *other,
3216                          struct diff_filespec *one,
3217                          struct diff_filespec *two,
3218                          struct diff_options *o,
3219                          struct diff_filepair *p,
3220                          int *must_show_header,
3221                          int use_color)
3222{
3223        const char *set = diff_get_color(use_color, DIFF_METAINFO);
3224        const char *reset = diff_get_color(use_color, DIFF_RESET);
3225        const char *line_prefix = diff_line_prefix(o);
3226
3227        *must_show_header = 1;
3228        strbuf_init(msg, PATH_MAX * 2 + 300);
3229        switch (p->status) {
3230        case DIFF_STATUS_COPIED:
3231                strbuf_addf(msg, "%s%ssimilarity index %d%%",
3232                            line_prefix, set, similarity_index(p));
3233                strbuf_addf(msg, "%s\n%s%scopy from ",
3234                            reset,  line_prefix, set);
3235                quote_c_style(name, msg, NULL, 0);
3236                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
3237                quote_c_style(other, msg, NULL, 0);
3238                strbuf_addf(msg, "%s\n", reset);
3239                break;
3240        case DIFF_STATUS_RENAMED:
3241                strbuf_addf(msg, "%s%ssimilarity index %d%%",
3242                            line_prefix, set, similarity_index(p));
3243                strbuf_addf(msg, "%s\n%s%srename from ",
3244                            reset, line_prefix, set);
3245                quote_c_style(name, msg, NULL, 0);
3246                strbuf_addf(msg, "%s\n%s%srename to ",
3247                            reset, line_prefix, set);
3248                quote_c_style(other, msg, NULL, 0);
3249                strbuf_addf(msg, "%s\n", reset);
3250                break;
3251        case DIFF_STATUS_MODIFIED:
3252                if (p->score) {
3253                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
3254                                    line_prefix,
3255                                    set, similarity_index(p), reset);
3256                        break;
3257                }
3258                /* fallthru */
3259        default:
3260                *must_show_header = 0;
3261        }
3262        if (one && two && oidcmp(&one->oid, &two->oid)) {
3263                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
3264
3265                if (DIFF_OPT_TST(o, BINARY)) {
3266                        mmfile_t mf;
3267                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
3268                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
3269                                abbrev = 40;
3270                }
3271                strbuf_addf(msg, "%s%sindex %s..%s", line_prefix, set,
3272                            diff_abbrev_oid(&one->oid, abbrev),
3273                            diff_abbrev_oid(&two->oid, abbrev));
3274                if (one->mode == two->mode)
3275                        strbuf_addf(msg, " %06o", one->mode);
3276                strbuf_addf(msg, "%s\n", reset);
3277        }
3278}
3279
3280static void run_diff_cmd(const char *pgm,
3281                         const char *name,
3282                         const char *other,
3283                         const char *attr_path,
3284                         struct diff_filespec *one,
3285                         struct diff_filespec *two,
3286                         struct strbuf *msg,
3287                         struct diff_options *o,
3288                         struct diff_filepair *p)
3289{
3290        const char *xfrm_msg = NULL;
3291        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
3292        int must_show_header = 0;
3293
3294
3295        if (DIFF_OPT_TST(o, ALLOW_EXTERNAL)) {
3296                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
3297                if (drv && drv->external)
3298                        pgm = drv->external;
3299        }
3300
3301        if (msg) {
3302                /*
3303                 * don't use colors when the header is intended for an
3304                 * external diff driver
3305                 */
3306                fill_metainfo(msg, name, other, one, two, o, p,
3307                              &must_show_header,
3308                              want_color(o->use_color) && !pgm);
3309                xfrm_msg = msg->len ? msg->buf : NULL;
3310        }
3311
3312        if (pgm) {
3313                run_external_diff(pgm, name, other, one, two, xfrm_msg,
3314                                  complete_rewrite, o);
3315                return;
3316        }
3317        if (one && two)
3318                builtin_diff(name, other ? other : name,
3319                             one, two, xfrm_msg, must_show_header,
3320                             o, complete_rewrite);
3321        else
3322                fprintf(o->file, "* Unmerged path %s\n", name);
3323}
3324
3325static void diff_fill_oid_info(struct diff_filespec *one)
3326{
3327        if (DIFF_FILE_VALID(one)) {
3328                if (!one->oid_valid) {
3329                        struct stat st;
3330                        if (one->is_stdin) {
3331                                oidclr(&one->oid);
3332                                return;
3333                        }
3334                        if (lstat(one->path, &st) < 0)
3335                                die_errno("stat '%s'", one->path);
3336                        if (index_path(one->oid.hash, one->path, &st, 0))
3337                                die("cannot hash %s", one->path);
3338                }
3339        }
3340        else
3341                oidclr(&one->oid);
3342}
3343
3344static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
3345{
3346        /* Strip the prefix but do not molest /dev/null and absolute paths */
3347        if (*namep && **namep != '/') {
3348                *namep += prefix_length;
3349                if (**namep == '/')
3350                        ++*namep;
3351        }
3352        if (*otherp && **otherp != '/') {
3353                *otherp += prefix_length;
3354                if (**otherp == '/')
3355                        ++*otherp;
3356        }
3357}
3358
3359static void run_diff(struct diff_filepair *p, struct diff_options *o)
3360{
3361        const char *pgm = external_diff();
3362        struct strbuf msg;
3363        struct diff_filespec *one = p->one;
3364        struct diff_filespec *two = p->two;
3365        const char *name;
3366        const char *other;
3367        const char *attr_path;
3368
3369        name  = one->path;
3370        other = (strcmp(name, two->path) ? two->path : NULL);
3371        attr_path = name;
3372        if (o->prefix_length)
3373                strip_prefix(o->prefix_length, &name, &other);
3374
3375        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
3376                pgm = NULL;
3377
3378        if (DIFF_PAIR_UNMERGED(p)) {
3379                run_diff_cmd(pgm, name, NULL, attr_path,
3380                             NULL, NULL, NULL, o, p);
3381                return;
3382        }
3383
3384        diff_fill_oid_info(one);
3385        diff_fill_oid_info(two);
3386
3387        if (!pgm &&
3388            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
3389            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
3390                /*
3391                 * a filepair that changes between file and symlink
3392                 * needs to be split into deletion and creation.
3393                 */
3394                struct diff_filespec *null = alloc_filespec(two->path);
3395                run_diff_cmd(NULL, name, other, attr_path,
3396                             one, null, &msg, o, p);
3397                free(null);
3398                strbuf_release(&msg);
3399
3400                null = alloc_filespec(one->path);
3401                run_diff_cmd(NULL, name, other, attr_path,
3402                             null, two, &msg, o, p);
3403                free(null);
3404        }
3405        else
3406                run_diff_cmd(pgm, name, other, attr_path,
3407                             one, two, &msg, o, p);
3408
3409        strbuf_release(&msg);
3410}
3411
3412static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
3413                         struct diffstat_t *diffstat)
3414{
3415        const char *name;
3416        const char *other;
3417
3418        if (DIFF_PAIR_UNMERGED(p)) {
3419                /* unmerged */
3420                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, p);
3421                return;
3422        }
3423
3424        name = p->one->path;
3425        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3426
3427        if (o->prefix_length)
3428                strip_prefix(o->prefix_length, &name, &other);
3429
3430        diff_fill_oid_info(p->one);
3431        diff_fill_oid_info(p->two);
3432
3433        builtin_diffstat(name, other, p->one, p->two, diffstat, o, p);
3434}
3435
3436static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
3437{
3438        const char *name;
3439        const char *other;
3440        const char *attr_path;
3441
3442        if (DIFF_PAIR_UNMERGED(p)) {
3443                /* unmerged */
3444                return;
3445        }
3446
3447        name = p->one->path;
3448        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3449        attr_path = other ? other : name;
3450
3451        if (o->prefix_length)
3452                strip_prefix(o->prefix_length, &name, &other);
3453
3454        diff_fill_oid_info(p->one);
3455        diff_fill_oid_info(p->two);
3456
3457        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
3458}
3459
3460void diff_setup(struct diff_options *options)
3461{
3462        memcpy(options, &default_diff_options, sizeof(*options));
3463
3464        options->file = stdout;
3465
3466        options->abbrev = DEFAULT_ABBREV;
3467        options->line_termination = '\n';
3468        options->break_opt = -1;
3469        options->rename_limit = -1;
3470        options->dirstat_permille = diff_dirstat_permille_default;
3471        options->context = diff_context_default;
3472        options->interhunkcontext = diff_interhunk_context_default;
3473        options->ws_error_highlight = ws_error_highlight_default;
3474        DIFF_OPT_SET(options, RENAME_EMPTY);
3475
3476        /* pathchange left =NULL by default */
3477        options->change = diff_change;
3478        options->add_remove = diff_addremove;
3479        options->use_color = diff_use_color_default;
3480        options->detect_rename = diff_detect_rename_default;
3481        options->xdl_opts |= diff_algorithm;
3482        if (diff_indent_heuristic)
3483                DIFF_XDL_SET(options, INDENT_HEURISTIC);
3484
3485        options->orderfile = diff_order_file_cfg;
3486
3487        if (diff_no_prefix) {
3488                options->a_prefix = options->b_prefix = "";
3489        } else if (!diff_mnemonic_prefix) {
3490                options->a_prefix = "a/";
3491                options->b_prefix = "b/";
3492        }
3493}
3494
3495void diff_setup_done(struct diff_options *options)
3496{
3497        int count = 0;
3498
3499        if (options->set_default)
3500                options->set_default(options);
3501
3502        if (options->output_format & DIFF_FORMAT_NAME)
3503                count++;
3504        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
3505                count++;
3506        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
3507                count++;
3508        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
3509                count++;
3510        if (count > 1)
3511                die(_("--name-only, --name-status, --check and -s are mutually exclusive"));
3512
3513        /*
3514         * Most of the time we can say "there are changes"
3515         * only by checking if there are changed paths, but
3516         * --ignore-whitespace* options force us to look
3517         * inside contents.
3518         */
3519
3520        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
3521            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
3522            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
3523                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
3524        else
3525                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
3526
3527        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3528                options->detect_rename = DIFF_DETECT_COPY;
3529
3530        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
3531                options->prefix = NULL;
3532        if (options->prefix)
3533                options->prefix_length = strlen(options->prefix);
3534        else
3535                options->prefix_length = 0;
3536
3537        if (options->output_format & (DIFF_FORMAT_NAME |
3538                                      DIFF_FORMAT_NAME_STATUS |
3539                                      DIFF_FORMAT_CHECKDIFF |
3540                                      DIFF_FORMAT_NO_OUTPUT))
3541                options->output_format &= ~(DIFF_FORMAT_RAW |
3542                                            DIFF_FORMAT_NUMSTAT |
3543                                            DIFF_FORMAT_DIFFSTAT |
3544                                            DIFF_FORMAT_SHORTSTAT |
3545                                            DIFF_FORMAT_DIRSTAT |
3546                                            DIFF_FORMAT_SUMMARY |
3547                                            DIFF_FORMAT_PATCH);
3548
3549        /*
3550         * These cases always need recursive; we do not drop caller-supplied
3551         * recursive bits for other formats here.
3552         */
3553        if (options->output_format & (DIFF_FORMAT_PATCH |
3554                                      DIFF_FORMAT_NUMSTAT |
3555                                      DIFF_FORMAT_DIFFSTAT |
3556                                      DIFF_FORMAT_SHORTSTAT |
3557                                      DIFF_FORMAT_DIRSTAT |
3558                                      DIFF_FORMAT_SUMMARY |
3559                                      DIFF_FORMAT_CHECKDIFF))
3560                DIFF_OPT_SET(options, RECURSIVE);
3561        /*
3562         * Also pickaxe would not work very well if you do not say recursive
3563         */
3564        if (options->pickaxe)
3565                DIFF_OPT_SET(options, RECURSIVE);
3566        /*
3567         * When patches are generated, submodules diffed against the work tree
3568         * must be checked for dirtiness too so it can be shown in the output
3569         */
3570        if (options->output_format & DIFF_FORMAT_PATCH)
3571                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3572
3573        if (options->detect_rename && options->rename_limit < 0)
3574                options->rename_limit = diff_rename_limit_default;
3575        if (options->setup & DIFF_SETUP_USE_CACHE) {
3576                if (!active_cache)
3577                        /* read-cache does not die even when it fails
3578                         * so it is safe for us to do this here.  Also
3579                         * it does not smudge active_cache or active_nr
3580                         * when it fails, so we do not have to worry about
3581                         * cleaning it up ourselves either.
3582                         */
3583                        read_cache();
3584        }
3585        if (40 < options->abbrev)
3586                options->abbrev = 40; /* full */
3587
3588        /*
3589         * It does not make sense to show the first hit we happened
3590         * to have found.  It does not make sense not to return with
3591         * exit code in such a case either.
3592         */
3593        if (DIFF_OPT_TST(options, QUICK)) {
3594                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3595                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3596        }
3597
3598        options->diff_path_counter = 0;
3599
3600        if (DIFF_OPT_TST(options, FOLLOW_RENAMES) && options->pathspec.nr != 1)
3601                die(_("--follow requires exactly one pathspec"));
3602}
3603
3604static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3605{
3606        char c, *eq;
3607        int len;
3608
3609        if (*arg != '-')
3610                return 0;
3611        c = *++arg;
3612        if (!c)
3613                return 0;
3614        if (c == arg_short) {
3615                c = *++arg;
3616                if (!c)
3617                        return 1;
3618                if (val && isdigit(c)) {
3619                        char *end;
3620                        int n = strtoul(arg, &end, 10);
3621                        if (*end)
3622                                return 0;
3623                        *val = n;
3624                        return 1;
3625                }
3626                return 0;
3627        }
3628        if (c != '-')
3629                return 0;
3630        arg++;
3631        eq = strchrnul(arg, '=');
3632        len = eq - arg;
3633        if (!len || strncmp(arg, arg_long, len))
3634                return 0;
3635        if (*eq) {
3636                int n;
3637                char *end;
3638                if (!isdigit(*++eq))
3639                        return 0;
3640                n = strtoul(eq, &end, 10);
3641                if (*end)
3642                        return 0;
3643                *val = n;
3644        }
3645        return 1;
3646}
3647
3648static int diff_scoreopt_parse(const char *opt);
3649
3650static inline int short_opt(char opt, const char **argv,
3651                            const char **optarg)
3652{
3653        const char *arg = argv[0];
3654        if (arg[0] != '-' || arg[1] != opt)
3655                return 0;
3656        if (arg[2] != '\0') {
3657                *optarg = arg + 2;
3658                return 1;
3659        }
3660        if (!argv[1])
3661                die("Option '%c' requires a value", opt);
3662        *optarg = argv[1];
3663        return 2;
3664}
3665
3666int parse_long_opt(const char *opt, const char **argv,
3667                   const char **optarg)
3668{
3669        const char *arg = argv[0];
3670        if (!skip_prefix(arg, "--", &arg))
3671                return 0;
3672        if (!skip_prefix(arg, opt, &arg))
3673                return 0;
3674        if (*arg == '=') { /* stuck form: --option=value */
3675                *optarg = arg + 1;
3676                return 1;
3677        }
3678        if (*arg != '\0')
3679                return 0;
3680        /* separate form: --option value */
3681        if (!argv[1])
3682                die("Option '--%s' requires a value", opt);
3683        *optarg = argv[1];
3684        return 2;
3685}
3686
3687static int stat_opt(struct diff_options *options, const char **av)
3688{
3689        const char *arg = av[0];
3690        char *end;
3691        int width = options->stat_width;
3692        int name_width = options->stat_name_width;
3693        int graph_width = options->stat_graph_width;
3694        int count = options->stat_count;
3695        int argcount = 1;
3696
3697        if (!skip_prefix(arg, "--stat", &arg))
3698                die("BUG: stat option does not begin with --stat: %s", arg);
3699        end = (char *)arg;
3700
3701        switch (*arg) {
3702        case '-':
3703                if (skip_prefix(arg, "-width", &arg)) {
3704                        if (*arg == '=')
3705                                width = strtoul(arg + 1, &end, 10);
3706                        else if (!*arg && !av[1])
3707                                die_want_option("--stat-width");
3708                        else if (!*arg) {
3709                                width = strtoul(av[1], &end, 10);
3710                                argcount = 2;
3711                        }
3712                } else if (skip_prefix(arg, "-name-width", &arg)) {
3713                        if (*arg == '=')
3714                                name_width = strtoul(arg + 1, &end, 10);
3715                        else if (!*arg && !av[1])
3716                                die_want_option("--stat-name-width");
3717                        else if (!*arg) {
3718                                name_width = strtoul(av[1], &end, 10);
3719                                argcount = 2;
3720                        }
3721                } else if (skip_prefix(arg, "-graph-width", &arg)) {
3722                        if (*arg == '=')
3723                                graph_width = strtoul(arg + 1, &end, 10);
3724                        else if (!*arg && !av[1])
3725                                die_want_option("--stat-graph-width");
3726                        else if (!*arg) {
3727                                graph_width = strtoul(av[1], &end, 10);
3728                                argcount = 2;
3729                        }
3730                } else if (skip_prefix(arg, "-count", &arg)) {
3731                        if (*arg == '=')
3732                                count = strtoul(arg + 1, &end, 10);
3733                        else if (!*arg && !av[1])
3734                                die_want_option("--stat-count");
3735                        else if (!*arg) {
3736                                count = strtoul(av[1], &end, 10);
3737                                argcount = 2;
3738                        }
3739                }
3740                break;
3741        case '=':
3742                width = strtoul(arg+1, &end, 10);
3743                if (*end == ',')
3744                        name_width = strtoul(end+1, &end, 10);
3745                if (*end == ',')
3746                        count = strtoul(end+1, &end, 10);
3747        }
3748
3749        /* Important! This checks all the error cases! */
3750        if (*end)
3751                return 0;
3752        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3753        options->stat_name_width = name_width;
3754        options->stat_graph_width = graph_width;
3755        options->stat_width = width;
3756        options->stat_count = count;
3757        return argcount;
3758}
3759
3760static int parse_dirstat_opt(struct diff_options *options, const char *params)
3761{
3762        struct strbuf errmsg = STRBUF_INIT;
3763        if (parse_dirstat_params(options, params, &errmsg))
3764                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
3765                    errmsg.buf);
3766        strbuf_release(&errmsg);
3767        /*
3768         * The caller knows a dirstat-related option is given from the command
3769         * line; allow it to say "return this_function();"
3770         */
3771        options->output_format |= DIFF_FORMAT_DIRSTAT;
3772        return 1;
3773}
3774
3775static int parse_submodule_opt(struct diff_options *options, const char *value)
3776{
3777        if (parse_submodule_params(options, value))
3778                die(_("Failed to parse --submodule option parameter: '%s'"),
3779                        value);
3780        return 1;
3781}
3782
3783static const char diff_status_letters[] = {
3784        DIFF_STATUS_ADDED,
3785        DIFF_STATUS_COPIED,
3786        DIFF_STATUS_DELETED,
3787        DIFF_STATUS_MODIFIED,
3788        DIFF_STATUS_RENAMED,
3789        DIFF_STATUS_TYPE_CHANGED,
3790        DIFF_STATUS_UNKNOWN,
3791        DIFF_STATUS_UNMERGED,
3792        DIFF_STATUS_FILTER_AON,
3793        DIFF_STATUS_FILTER_BROKEN,
3794        '\0',
3795};
3796
3797static unsigned int filter_bit['Z' + 1];
3798
3799static void prepare_filter_bits(void)
3800{
3801        int i;
3802
3803        if (!filter_bit[DIFF_STATUS_ADDED]) {
3804                for (i = 0; diff_status_letters[i]; i++)
3805                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
3806        }
3807}
3808
3809static unsigned filter_bit_tst(char status, const struct diff_options *opt)
3810{
3811        return opt->filter & filter_bit[(int) status];
3812}
3813
3814static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
3815{
3816        int i, optch;
3817
3818        prepare_filter_bits();
3819
3820        /*
3821         * If there is a negation e.g. 'd' in the input, and we haven't
3822         * initialized the filter field with another --diff-filter, start
3823         * from full set of bits, except for AON.
3824         */
3825        if (!opt->filter) {
3826                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
3827                        if (optch < 'a' || 'z' < optch)
3828                                continue;
3829                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
3830                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
3831                        break;
3832                }
3833        }
3834
3835        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
3836                unsigned int bit;
3837                int negate;
3838
3839                if ('a' <= optch && optch <= 'z') {
3840                        negate = 1;
3841                        optch = toupper(optch);
3842                } else {
3843                        negate = 0;
3844                }
3845
3846                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
3847                if (!bit)
3848                        return optarg[i];
3849                if (negate)
3850                        opt->filter &= ~bit;
3851                else
3852                        opt->filter |= bit;
3853        }
3854        return 0;
3855}
3856
3857static void enable_patch_output(int *fmt) {
3858        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
3859        *fmt |= DIFF_FORMAT_PATCH;
3860}
3861
3862static int parse_ws_error_highlight_opt(struct diff_options *opt, const char *arg)
3863{
3864        int val = parse_ws_error_highlight(arg);
3865
3866        if (val < 0) {
3867                error("unknown value after ws-error-highlight=%.*s",
3868                      -1 - val, arg);
3869                return 0;
3870        }
3871        opt->ws_error_highlight = val;
3872        return 1;
3873}
3874
3875int diff_opt_parse(struct diff_options *options,
3876                   const char **av, int ac, const char *prefix)
3877{
3878        const char *arg = av[0];
3879        const char *optarg;
3880        int argcount;
3881
3882        if (!prefix)
3883                prefix = "";
3884
3885        /* Output format options */
3886        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
3887            || opt_arg(arg, 'U', "unified", &options->context))
3888                enable_patch_output(&options->output_format);
3889        else if (!strcmp(arg, "--raw"))
3890                options->output_format |= DIFF_FORMAT_RAW;
3891        else if (!strcmp(arg, "--patch-with-raw")) {
3892                enable_patch_output(&options->output_format);
3893                options->output_format |= DIFF_FORMAT_RAW;
3894        } else if (!strcmp(arg, "--numstat"))
3895                options->output_format |= DIFF_FORMAT_NUMSTAT;
3896        else if (!strcmp(arg, "--shortstat"))
3897                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3898        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
3899                return parse_dirstat_opt(options, "");
3900        else if (skip_prefix(arg, "-X", &arg))
3901                return parse_dirstat_opt(options, arg);
3902        else if (skip_prefix(arg, "--dirstat=", &arg))
3903                return parse_dirstat_opt(options, arg);
3904        else if (!strcmp(arg, "--cumulative"))
3905                return parse_dirstat_opt(options, "cumulative");
3906        else if (!strcmp(arg, "--dirstat-by-file"))
3907                return parse_dirstat_opt(options, "files");
3908        else if (skip_prefix(arg, "--dirstat-by-file=", &arg)) {
3909                parse_dirstat_opt(options, "files");
3910                return parse_dirstat_opt(options, arg);
3911        }
3912        else if (!strcmp(arg, "--check"))
3913                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3914        else if (!strcmp(arg, "--summary"))
3915                options->output_format |= DIFF_FORMAT_SUMMARY;
3916        else if (!strcmp(arg, "--patch-with-stat")) {
3917                enable_patch_output(&options->output_format);
3918                options->output_format |= DIFF_FORMAT_DIFFSTAT;
3919        } else if (!strcmp(arg, "--name-only"))
3920                options->output_format |= DIFF_FORMAT_NAME;
3921        else if (!strcmp(arg, "--name-status"))
3922                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3923        else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
3924                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3925        else if (starts_with(arg, "--stat"))
3926                /* --stat, --stat-width, --stat-name-width, or --stat-count */
3927                return stat_opt(options, av);
3928
3929        /* renames options */
3930        else if (starts_with(arg, "-B") || starts_with(arg, "--break-rewrites=") ||
3931                 !strcmp(arg, "--break-rewrites")) {
3932                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3933                        return error("invalid argument to -B: %s", arg+2);
3934        }
3935        else if (starts_with(arg, "-M") || starts_with(arg, "--find-renames=") ||
3936                 !strcmp(arg, "--find-renames")) {
3937                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3938                        return error("invalid argument to -M: %s", arg+2);
3939                options->detect_rename = DIFF_DETECT_RENAME;
3940        }
3941        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3942                options->irreversible_delete = 1;
3943        }
3944        else if (starts_with(arg, "-C") || starts_with(arg, "--find-copies=") ||
3945                 !strcmp(arg, "--find-copies")) {
3946                if (options->detect_rename == DIFF_DETECT_COPY)
3947                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3948                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3949                        return error("invalid argument to -C: %s", arg+2);
3950                options->detect_rename = DIFF_DETECT_COPY;
3951        }
3952        else if (!strcmp(arg, "--no-renames"))
3953                options->detect_rename = 0;
3954        else if (!strcmp(arg, "--rename-empty"))
3955                DIFF_OPT_SET(options, RENAME_EMPTY);
3956        else if (!strcmp(arg, "--no-rename-empty"))
3957                DIFF_OPT_CLR(options, RENAME_EMPTY);
3958        else if (!strcmp(arg, "--relative"))
3959                DIFF_OPT_SET(options, RELATIVE_NAME);
3960        else if (skip_prefix(arg, "--relative=", &arg)) {
3961                DIFF_OPT_SET(options, RELATIVE_NAME);
3962                options->prefix = arg;
3963        }
3964
3965        /* xdiff options */
3966        else if (!strcmp(arg, "--minimal"))
3967                DIFF_XDL_SET(options, NEED_MINIMAL);
3968        else if (!strcmp(arg, "--no-minimal"))
3969                DIFF_XDL_CLR(options, NEED_MINIMAL);
3970        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3971                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3972        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3973                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3974        else if (!strcmp(arg, "--ignore-space-at-eol"))
3975                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3976        else if (!strcmp(arg, "--ignore-blank-lines"))
3977                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
3978        else if (!strcmp(arg, "--indent-heuristic"))
3979                DIFF_XDL_SET(options, INDENT_HEURISTIC);
3980        else if (!strcmp(arg, "--no-indent-heuristic"))
3981                DIFF_XDL_CLR(options, INDENT_HEURISTIC);
3982        else if (!strcmp(arg, "--patience"))
3983                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
3984        else if (!strcmp(arg, "--histogram"))
3985                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
3986        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
3987                long value = parse_algorithm_value(optarg);
3988                if (value < 0)
3989                        return error("option diff-algorithm accepts \"myers\", "
3990                                     "\"minimal\", \"patience\" and \"histogram\"");
3991                /* clear out previous settings */
3992                DIFF_XDL_CLR(options, NEED_MINIMAL);
3993                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
3994                options->xdl_opts |= value;
3995                return argcount;
3996        }
3997
3998        /* flags options */
3999        else if (!strcmp(arg, "--binary")) {
4000                enable_patch_output(&options->output_format);
4001                DIFF_OPT_SET(options, BINARY);
4002        }
4003        else if (!strcmp(arg, "--full-index"))
4004                DIFF_OPT_SET(options, FULL_INDEX);
4005        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
4006                DIFF_OPT_SET(options, TEXT);
4007        else if (!strcmp(arg, "-R"))
4008                DIFF_OPT_SET(options, REVERSE_DIFF);
4009        else if (!strcmp(arg, "--find-copies-harder"))
4010                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
4011        else if (!strcmp(arg, "--follow"))
4012                DIFF_OPT_SET(options, FOLLOW_RENAMES);
4013        else if (!strcmp(arg, "--no-follow")) {
4014                DIFF_OPT_CLR(options, FOLLOW_RENAMES);
4015                DIFF_OPT_CLR(options, DEFAULT_FOLLOW_RENAMES);
4016        } else if (!strcmp(arg, "--color"))
4017                options->use_color = 1;
4018        else if (skip_prefix(arg, "--color=", &arg)) {
4019                int value = git_config_colorbool(NULL, arg);
4020                if (value < 0)
4021                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
4022                options->use_color = value;
4023        }
4024        else if (!strcmp(arg, "--no-color"))
4025                options->use_color = 0;
4026        else if (!strcmp(arg, "--color-words")) {
4027                options->use_color = 1;
4028                options->word_diff = DIFF_WORDS_COLOR;
4029        }
4030        else if (skip_prefix(arg, "--color-words=", &arg)) {
4031                options->use_color = 1;
4032                options->word_diff = DIFF_WORDS_COLOR;
4033                options->word_regex = arg;
4034        }
4035        else if (!strcmp(arg, "--word-diff")) {
4036                if (options->word_diff == DIFF_WORDS_NONE)
4037                        options->word_diff = DIFF_WORDS_PLAIN;
4038        }
4039        else if (skip_prefix(arg, "--word-diff=", &arg)) {
4040                if (!strcmp(arg, "plain"))
4041                        options->word_diff = DIFF_WORDS_PLAIN;
4042                else if (!strcmp(arg, "color")) {
4043                        options->use_color = 1;
4044                        options->word_diff = DIFF_WORDS_COLOR;
4045                }
4046                else if (!strcmp(arg, "porcelain"))
4047                        options->word_diff = DIFF_WORDS_PORCELAIN;
4048                else if (!strcmp(arg, "none"))
4049                        options->word_diff = DIFF_WORDS_NONE;
4050                else
4051                        die("bad --word-diff argument: %s", arg);
4052        }
4053        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
4054                if (options->word_diff == DIFF_WORDS_NONE)
4055                        options->word_diff = DIFF_WORDS_PLAIN;
4056                options->word_regex = optarg;
4057                return argcount;
4058        }
4059        else if (!strcmp(arg, "--exit-code"))
4060                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
4061        else if (!strcmp(arg, "--quiet"))
4062                DIFF_OPT_SET(options, QUICK);
4063        else if (!strcmp(arg, "--ext-diff"))
4064                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
4065        else if (!strcmp(arg, "--no-ext-diff"))
4066                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
4067        else if (!strcmp(arg, "--textconv"))
4068                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
4069        else if (!strcmp(arg, "--no-textconv"))
4070                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
4071        else if (!strcmp(arg, "--ignore-submodules")) {
4072                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
4073                handle_ignore_submodules_arg(options, "all");
4074        } else if (skip_prefix(arg, "--ignore-submodules=", &arg)) {
4075                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
4076                handle_ignore_submodules_arg(options, arg);
4077        } else if (!strcmp(arg, "--submodule"))
4078                options->submodule_format = DIFF_SUBMODULE_LOG;
4079        else if (skip_prefix(arg, "--submodule=", &arg))
4080                return parse_submodule_opt(options, arg);
4081        else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
4082                return parse_ws_error_highlight_opt(options, arg);
4083        else if (!strcmp(arg, "--ita-invisible-in-index"))
4084                options->ita_invisible_in_index = 1;
4085        else if (!strcmp(arg, "--ita-visible-in-index"))
4086                options->ita_invisible_in_index = 0;
4087
4088        /* misc options */
4089        else if (!strcmp(arg, "-z"))
4090                options->line_termination = 0;
4091        else if ((argcount = short_opt('l', av, &optarg))) {
4092                options->rename_limit = strtoul(optarg, NULL, 10);
4093                return argcount;
4094        }
4095        else if ((argcount = short_opt('S', av, &optarg))) {
4096                options->pickaxe = optarg;
4097                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
4098                return argcount;
4099        } else if ((argcount = short_opt('G', av, &optarg))) {
4100                options->pickaxe = optarg;
4101                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
4102                return argcount;
4103        }
4104        else if (!strcmp(arg, "--pickaxe-all"))
4105                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
4106        else if (!strcmp(arg, "--pickaxe-regex"))
4107                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
4108        else if ((argcount = short_opt('O', av, &optarg))) {
4109                options->orderfile = prefix_filename(prefix, optarg);
4110                return argcount;
4111        }
4112        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
4113                int offending = parse_diff_filter_opt(optarg, options);
4114                if (offending)
4115                        die("unknown change class '%c' in --diff-filter=%s",
4116                            offending, optarg);
4117                return argcount;
4118        }
4119        else if (!strcmp(arg, "--no-abbrev"))
4120                options->abbrev = 0;
4121        else if (!strcmp(arg, "--abbrev"))
4122                options->abbrev = DEFAULT_ABBREV;
4123        else if (skip_prefix(arg, "--abbrev=", &arg)) {
4124                options->abbrev = strtoul(arg, NULL, 10);
4125                if (options->abbrev < MINIMUM_ABBREV)
4126                        options->abbrev = MINIMUM_ABBREV;
4127                else if (40 < options->abbrev)
4128                        options->abbrev = 40;
4129        }
4130        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
4131                options->a_prefix = optarg;
4132                return argcount;
4133        }
4134        else if ((argcount = parse_long_opt("line-prefix", av, &optarg))) {
4135                options->line_prefix = optarg;
4136                options->line_prefix_length = strlen(options->line_prefix);
4137                graph_setup_line_prefix(options);
4138                return argcount;
4139        }
4140        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
4141                options->b_prefix = optarg;
4142                return argcount;
4143        }
4144        else if (!strcmp(arg, "--no-prefix"))
4145                options->a_prefix = options->b_prefix = "";
4146        else if (opt_arg(arg, '\0', "inter-hunk-context",
4147                         &options->interhunkcontext))
4148                ;
4149        else if (!strcmp(arg, "-W"))
4150                DIFF_OPT_SET(options, FUNCCONTEXT);
4151        else if (!strcmp(arg, "--function-context"))
4152                DIFF_OPT_SET(options, FUNCCONTEXT);
4153        else if (!strcmp(arg, "--no-function-context"))
4154                DIFF_OPT_CLR(options, FUNCCONTEXT);
4155        else if ((argcount = parse_long_opt("output", av, &optarg))) {
4156                char *path = prefix_filename(prefix, optarg);
4157                options->file = xfopen(path, "w");
4158                options->close_file = 1;
4159                if (options->use_color != GIT_COLOR_ALWAYS)
4160                        options->use_color = GIT_COLOR_NEVER;
4161                free(path);
4162                return argcount;
4163        } else
4164                return 0;
4165        return 1;
4166}
4167
4168int parse_rename_score(const char **cp_p)
4169{
4170        unsigned long num, scale;
4171        int ch, dot;
4172        const char *cp = *cp_p;
4173
4174        num = 0;
4175        scale = 1;
4176        dot = 0;
4177        for (;;) {
4178                ch = *cp;
4179                if ( !dot && ch == '.' ) {
4180                        scale = 1;
4181                        dot = 1;
4182                } else if ( ch == '%' ) {
4183                        scale = dot ? scale*100 : 100;
4184                        cp++;   /* % is always at the end */
4185                        break;
4186                } else if ( ch >= '0' && ch <= '9' ) {
4187                        if ( scale < 100000 ) {
4188                                scale *= 10;
4189                                num = (num*10) + (ch-'0');
4190                        }
4191                } else {
4192                        break;
4193                }
4194                cp++;
4195        }
4196        *cp_p = cp;
4197
4198        /* user says num divided by scale and we say internally that
4199         * is MAX_SCORE * num / scale.
4200         */
4201        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
4202}
4203
4204static int diff_scoreopt_parse(const char *opt)
4205{
4206        int opt1, opt2, cmd;
4207
4208        if (*opt++ != '-')
4209                return -1;
4210        cmd = *opt++;
4211        if (cmd == '-') {
4212                /* convert the long-form arguments into short-form versions */
4213                if (skip_prefix(opt, "break-rewrites", &opt)) {
4214                        if (*opt == 0 || *opt++ == '=')
4215                                cmd = 'B';
4216                } else if (skip_prefix(opt, "find-copies", &opt)) {
4217                        if (*opt == 0 || *opt++ == '=')
4218                                cmd = 'C';
4219                } else if (skip_prefix(opt, "find-renames", &opt)) {
4220                        if (*opt == 0 || *opt++ == '=')
4221                                cmd = 'M';
4222                }
4223        }
4224        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
4225                return -1; /* that is not a -M, -C, or -B option */
4226
4227        opt1 = parse_rename_score(&opt);
4228        if (cmd != 'B')
4229                opt2 = 0;
4230        else {
4231                if (*opt == 0)
4232                        opt2 = 0;
4233                else if (*opt != '/')
4234                        return -1; /* we expect -B80/99 or -B80 */
4235                else {
4236                        opt++;
4237                        opt2 = parse_rename_score(&opt);
4238                }
4239        }
4240        if (*opt != 0)
4241                return -1;
4242        return opt1 | (opt2 << 16);
4243}
4244
4245struct diff_queue_struct diff_queued_diff;
4246
4247void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
4248{
4249        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
4250        queue->queue[queue->nr++] = dp;
4251}
4252
4253struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
4254                                 struct diff_filespec *one,
4255                                 struct diff_filespec *two)
4256{
4257        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
4258        dp->one = one;
4259        dp->two = two;
4260        if (queue)
4261                diff_q(queue, dp);
4262        return dp;
4263}
4264
4265void diff_free_filepair(struct diff_filepair *p)
4266{
4267        free_filespec(p->one);
4268        free_filespec(p->two);
4269        free(p);
4270}
4271
4272const char *diff_aligned_abbrev(const struct object_id *oid, int len)
4273{
4274        int abblen;
4275        const char *abbrev;
4276
4277        if (len == GIT_SHA1_HEXSZ)
4278                return oid_to_hex(oid);
4279
4280        abbrev = diff_abbrev_oid(oid, len);
4281        abblen = strlen(abbrev);
4282
4283        /*
4284         * In well-behaved cases, where the abbbreviated result is the
4285         * same as the requested length, append three dots after the
4286         * abbreviation (hence the whole logic is limited to the case
4287         * where abblen < 37); when the actual abbreviated result is a
4288         * bit longer than the requested length, we reduce the number
4289         * of dots so that they match the well-behaved ones.  However,
4290         * if the actual abbreviation is longer than the requested
4291         * length by more than three, we give up on aligning, and add
4292         * three dots anyway, to indicate that the output is not the
4293         * full object name.  Yes, this may be suboptimal, but this
4294         * appears only in "diff --raw --abbrev" output and it is not
4295         * worth the effort to change it now.  Note that this would
4296         * likely to work fine when the automatic sizing of default
4297         * abbreviation length is used--we would be fed -1 in "len" in
4298         * that case, and will end up always appending three-dots, but
4299         * the automatic sizing is supposed to give abblen that ensures
4300         * uniqueness across all objects (statistically speaking).
4301         */
4302        if (abblen < GIT_SHA1_HEXSZ - 3) {
4303                static char hex[GIT_MAX_HEXSZ + 1];
4304                if (len < abblen && abblen <= len + 2)
4305                        xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
4306                else
4307                        xsnprintf(hex, sizeof(hex), "%s...", abbrev);
4308                return hex;
4309        }
4310
4311        return oid_to_hex(oid);
4312}
4313
4314static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
4315{
4316        int line_termination = opt->line_termination;
4317        int inter_name_termination = line_termination ? '\t' : '\0';
4318
4319        fprintf(opt->file, "%s", diff_line_prefix(opt));
4320        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
4321                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
4322                        diff_aligned_abbrev(&p->one->oid, opt->abbrev));
4323                fprintf(opt->file, "%s ",
4324                        diff_aligned_abbrev(&p->two->oid, opt->abbrev));
4325        }
4326        if (p->score) {
4327                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
4328                        inter_name_termination);
4329        } else {
4330                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
4331        }
4332
4333        if (p->status == DIFF_STATUS_COPIED ||
4334            p->status == DIFF_STATUS_RENAMED) {
4335                const char *name_a, *name_b;
4336                name_a = p->one->path;
4337                name_b = p->two->path;
4338                strip_prefix(opt->prefix_length, &name_a, &name_b);
4339                write_name_quoted(name_a, opt->file, inter_name_termination);
4340                write_name_quoted(name_b, opt->file, line_termination);
4341        } else {
4342                const char *name_a, *name_b;
4343                name_a = p->one->mode ? p->one->path : p->two->path;
4344                name_b = NULL;
4345                strip_prefix(opt->prefix_length, &name_a, &name_b);
4346                write_name_quoted(name_a, opt->file, line_termination);
4347        }
4348}
4349
4350int diff_unmodified_pair(struct diff_filepair *p)
4351{
4352        /* This function is written stricter than necessary to support
4353         * the currently implemented transformers, but the idea is to
4354         * let transformers to produce diff_filepairs any way they want,
4355         * and filter and clean them up here before producing the output.
4356         */
4357        struct diff_filespec *one = p->one, *two = p->two;
4358
4359        if (DIFF_PAIR_UNMERGED(p))
4360                return 0; /* unmerged is interesting */
4361
4362        /* deletion, addition, mode or type change
4363         * and rename are all interesting.
4364         */
4365        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
4366            DIFF_PAIR_MODE_CHANGED(p) ||
4367            strcmp(one->path, two->path))
4368                return 0;
4369
4370        /* both are valid and point at the same path.  that is, we are
4371         * dealing with a change.
4372         */
4373        if (one->oid_valid && two->oid_valid &&
4374            !oidcmp(&one->oid, &two->oid) &&
4375            !one->dirty_submodule && !two->dirty_submodule)
4376                return 1; /* no change */
4377        if (!one->oid_valid && !two->oid_valid)
4378                return 1; /* both look at the same file on the filesystem. */
4379        return 0;
4380}
4381
4382static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
4383{
4384        if (diff_unmodified_pair(p))
4385                return;
4386
4387        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4388            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4389                return; /* no tree diffs in patch format */
4390
4391        run_diff(p, o);
4392}
4393
4394static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
4395                            struct diffstat_t *diffstat)
4396{
4397        if (diff_unmodified_pair(p))
4398                return;
4399
4400        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4401            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4402                return; /* no useful stat for tree diffs */
4403
4404        run_diffstat(p, o, diffstat);
4405}
4406
4407static void diff_flush_checkdiff(struct diff_filepair *p,
4408                struct diff_options *o)
4409{
4410        if (diff_unmodified_pair(p))
4411                return;
4412
4413        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4414            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4415                return; /* nothing to check in tree diffs */
4416
4417        run_checkdiff(p, o);
4418}
4419
4420int diff_queue_is_empty(void)
4421{
4422        struct diff_queue_struct *q = &diff_queued_diff;
4423        int i;
4424        for (i = 0; i < q->nr; i++)
4425                if (!diff_unmodified_pair(q->queue[i]))
4426                        return 0;
4427        return 1;
4428}
4429
4430#if DIFF_DEBUG
4431void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
4432{
4433        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
4434                x, one ? one : "",
4435                s->path,
4436                DIFF_FILE_VALID(s) ? "valid" : "invalid",
4437                s->mode,
4438                s->oid_valid ? oid_to_hex(&s->oid) : "");
4439        fprintf(stderr, "queue[%d] %s size %lu\n",
4440                x, one ? one : "",
4441                s->size);
4442}
4443
4444void diff_debug_filepair(const struct diff_filepair *p, int i)
4445{
4446        diff_debug_filespec(p->one, i, "one");
4447        diff_debug_filespec(p->two, i, "two");
4448        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
4449                p->score, p->status ? p->status : '?',
4450                p->one->rename_used, p->broken_pair);
4451}
4452
4453void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
4454{
4455        int i;
4456        if (msg)
4457                fprintf(stderr, "%s\n", msg);
4458        fprintf(stderr, "q->nr = %d\n", q->nr);
4459        for (i = 0; i < q->nr; i++) {
4460                struct diff_filepair *p = q->queue[i];
4461                diff_debug_filepair(p, i);
4462        }
4463}
4464#endif
4465
4466static void diff_resolve_rename_copy(void)
4467{
4468        int i;
4469        struct diff_filepair *p;
4470        struct diff_queue_struct *q = &diff_queued_diff;
4471
4472        diff_debug_queue("resolve-rename-copy", q);
4473
4474        for (i = 0; i < q->nr; i++) {
4475                p = q->queue[i];
4476                p->status = 0; /* undecided */
4477                if (DIFF_PAIR_UNMERGED(p))
4478                        p->status = DIFF_STATUS_UNMERGED;
4479                else if (!DIFF_FILE_VALID(p->one))
4480                        p->status = DIFF_STATUS_ADDED;
4481                else if (!DIFF_FILE_VALID(p->two))
4482                        p->status = DIFF_STATUS_DELETED;
4483                else if (DIFF_PAIR_TYPE_CHANGED(p))
4484                        p->status = DIFF_STATUS_TYPE_CHANGED;
4485
4486                /* from this point on, we are dealing with a pair
4487                 * whose both sides are valid and of the same type, i.e.
4488                 * either in-place edit or rename/copy edit.
4489                 */
4490                else if (DIFF_PAIR_RENAME(p)) {
4491                        /*
4492                         * A rename might have re-connected a broken
4493                         * pair up, causing the pathnames to be the
4494                         * same again. If so, that's not a rename at
4495                         * all, just a modification..
4496                         *
4497                         * Otherwise, see if this source was used for
4498                         * multiple renames, in which case we decrement
4499                         * the count, and call it a copy.
4500                         */
4501                        if (!strcmp(p->one->path, p->two->path))
4502                                p->status = DIFF_STATUS_MODIFIED;
4503                        else if (--p->one->rename_used > 0)
4504                                p->status = DIFF_STATUS_COPIED;
4505                        else
4506                                p->status = DIFF_STATUS_RENAMED;
4507                }
4508                else if (oidcmp(&p->one->oid, &p->two->oid) ||
4509                         p->one->mode != p->two->mode ||
4510                         p->one->dirty_submodule ||
4511                         p->two->dirty_submodule ||
4512                         is_null_oid(&p->one->oid))
4513                        p->status = DIFF_STATUS_MODIFIED;
4514                else {
4515                        /* This is a "no-change" entry and should not
4516                         * happen anymore, but prepare for broken callers.
4517                         */
4518                        error("feeding unmodified %s to diffcore",
4519                              p->one->path);
4520                        p->status = DIFF_STATUS_UNKNOWN;
4521                }
4522        }
4523        diff_debug_queue("resolve-rename-copy done", q);
4524}
4525
4526static int check_pair_status(struct diff_filepair *p)
4527{
4528        switch (p->status) {
4529        case DIFF_STATUS_UNKNOWN:
4530                return 0;
4531        case 0:
4532                die("internal error in diff-resolve-rename-copy");
4533        default:
4534                return 1;
4535        }
4536}
4537
4538static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
4539{
4540        int fmt = opt->output_format;
4541
4542        if (fmt & DIFF_FORMAT_CHECKDIFF)
4543                diff_flush_checkdiff(p, opt);
4544        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
4545                diff_flush_raw(p, opt);
4546        else if (fmt & DIFF_FORMAT_NAME) {
4547                const char *name_a, *name_b;
4548                name_a = p->two->path;
4549                name_b = NULL;
4550                strip_prefix(opt->prefix_length, &name_a, &name_b);
4551                fprintf(opt->file, "%s", diff_line_prefix(opt));
4552                write_name_quoted(name_a, opt->file, opt->line_termination);
4553        }
4554}
4555
4556static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
4557{
4558        if (fs->mode)
4559                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
4560        else
4561                fprintf(file, " %s ", newdelete);
4562        write_name_quoted(fs->path, file, '\n');
4563}
4564
4565
4566static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
4567                const char *line_prefix)
4568{
4569        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
4570                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
4571                        p->two->mode, show_name ? ' ' : '\n');
4572                if (show_name) {
4573                        write_name_quoted(p->two->path, file, '\n');
4574                }
4575        }
4576}
4577
4578static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
4579                        const char *line_prefix)
4580{
4581        char *names = pprint_rename(p->one->path, p->two->path);
4582
4583        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
4584        free(names);
4585        show_mode_change(file, p, 0, line_prefix);
4586}
4587
4588static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
4589{
4590        FILE *file = opt->file;
4591        const char *line_prefix = diff_line_prefix(opt);
4592
4593        switch(p->status) {
4594        case DIFF_STATUS_DELETED:
4595                fputs(line_prefix, file);
4596                show_file_mode_name(file, "delete", p->one);
4597                break;
4598        case DIFF_STATUS_ADDED:
4599                fputs(line_prefix, file);
4600                show_file_mode_name(file, "create", p->two);
4601                break;
4602        case DIFF_STATUS_COPIED:
4603                fputs(line_prefix, file);
4604                show_rename_copy(file, "copy", p, line_prefix);
4605                break;
4606        case DIFF_STATUS_RENAMED:
4607                fputs(line_prefix, file);
4608                show_rename_copy(file, "rename", p, line_prefix);
4609                break;
4610        default:
4611                if (p->score) {
4612                        fprintf(file, "%s rewrite ", line_prefix);
4613                        write_name_quoted(p->two->path, file, ' ');
4614                        fprintf(file, "(%d%%)\n", similarity_index(p));
4615                }
4616                show_mode_change(file, p, !p->score, line_prefix);
4617                break;
4618        }
4619}
4620
4621struct patch_id_t {
4622        git_SHA_CTX *ctx;
4623        int patchlen;
4624};
4625
4626static int remove_space(char *line, int len)
4627{
4628        int i;
4629        char *dst = line;
4630        unsigned char c;
4631
4632        for (i = 0; i < len; i++)
4633                if (!isspace((c = line[i])))
4634                        *dst++ = c;
4635
4636        return dst - line;
4637}
4638
4639static void patch_id_consume(void *priv, char *line, unsigned long len)
4640{
4641        struct patch_id_t *data = priv;
4642        int new_len;
4643
4644        /* Ignore line numbers when computing the SHA1 of the patch */
4645        if (starts_with(line, "@@ -"))
4646                return;
4647
4648        new_len = remove_space(line, len);
4649
4650        git_SHA1_Update(data->ctx, line, new_len);
4651        data->patchlen += new_len;
4652}
4653
4654static void patch_id_add_string(git_SHA_CTX *ctx, const char *str)
4655{
4656        git_SHA1_Update(ctx, str, strlen(str));
4657}
4658
4659static void patch_id_add_mode(git_SHA_CTX *ctx, unsigned mode)
4660{
4661        /* large enough for 2^32 in octal */
4662        char buf[12];
4663        int len = xsnprintf(buf, sizeof(buf), "%06o", mode);
4664        git_SHA1_Update(ctx, buf, len);
4665}
4666
4667/* returns 0 upon success, and writes result into sha1 */
4668static int diff_get_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
4669{
4670        struct diff_queue_struct *q = &diff_queued_diff;
4671        int i;
4672        git_SHA_CTX ctx;
4673        struct patch_id_t data;
4674
4675        git_SHA1_Init(&ctx);
4676        memset(&data, 0, sizeof(struct patch_id_t));
4677        data.ctx = &ctx;
4678
4679        for (i = 0; i < q->nr; i++) {
4680                xpparam_t xpp;
4681                xdemitconf_t xecfg;
4682                mmfile_t mf1, mf2;
4683                struct diff_filepair *p = q->queue[i];
4684                int len1, len2;
4685
4686                memset(&xpp, 0, sizeof(xpp));
4687                memset(&xecfg, 0, sizeof(xecfg));
4688                if (p->status == 0)
4689                        return error("internal diff status error");
4690                if (p->status == DIFF_STATUS_UNKNOWN)
4691                        continue;
4692                if (diff_unmodified_pair(p))
4693                        continue;
4694                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4695                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4696                        continue;
4697                if (DIFF_PAIR_UNMERGED(p))
4698                        continue;
4699
4700                diff_fill_oid_info(p->one);
4701                diff_fill_oid_info(p->two);
4702
4703                len1 = remove_space(p->one->path, strlen(p->one->path));
4704                len2 = remove_space(p->two->path, strlen(p->two->path));
4705                patch_id_add_string(&ctx, "diff--git");
4706                patch_id_add_string(&ctx, "a/");
4707                git_SHA1_Update(&ctx, p->one->path, len1);
4708                patch_id_add_string(&ctx, "b/");
4709                git_SHA1_Update(&ctx, p->two->path, len2);
4710
4711                if (p->one->mode == 0) {
4712                        patch_id_add_string(&ctx, "newfilemode");
4713                        patch_id_add_mode(&ctx, p->two->mode);
4714                        patch_id_add_string(&ctx, "---/dev/null");
4715                        patch_id_add_string(&ctx, "+++b/");
4716                        git_SHA1_Update(&ctx, p->two->path, len2);
4717                } else if (p->two->mode == 0) {
4718                        patch_id_add_string(&ctx, "deletedfilemode");
4719                        patch_id_add_mode(&ctx, p->one->mode);
4720                        patch_id_add_string(&ctx, "---a/");
4721                        git_SHA1_Update(&ctx, p->one->path, len1);
4722                        patch_id_add_string(&ctx, "+++/dev/null");
4723                } else {
4724                        patch_id_add_string(&ctx, "---a/");
4725                        git_SHA1_Update(&ctx, p->one->path, len1);
4726                        patch_id_add_string(&ctx, "+++b/");
4727                        git_SHA1_Update(&ctx, p->two->path, len2);
4728                }
4729
4730                if (diff_header_only)
4731                        continue;
4732
4733                if (fill_mmfile(&mf1, p->one) < 0 ||
4734                    fill_mmfile(&mf2, p->two) < 0)
4735                        return error("unable to read files to diff");
4736
4737                if (diff_filespec_is_binary(p->one) ||
4738                    diff_filespec_is_binary(p->two)) {
4739                        git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
4740                                        GIT_SHA1_HEXSZ);
4741                        git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
4742                                        GIT_SHA1_HEXSZ);
4743                        continue;
4744                }
4745
4746                xpp.flags = 0;
4747                xecfg.ctxlen = 3;
4748                xecfg.flags = 0;
4749                if (xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4750                                  &xpp, &xecfg))
4751                        return error("unable to generate patch-id diff for %s",
4752                                     p->one->path);
4753        }
4754
4755        git_SHA1_Final(oid->hash, &ctx);
4756        return 0;
4757}
4758
4759int diff_flush_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
4760{
4761        struct diff_queue_struct *q = &diff_queued_diff;
4762        int i;
4763        int result = diff_get_patch_id(options, oid, diff_header_only);
4764
4765        for (i = 0; i < q->nr; i++)
4766                diff_free_filepair(q->queue[i]);
4767
4768        free(q->queue);
4769        DIFF_QUEUE_CLEAR(q);
4770
4771        return result;
4772}
4773
4774static int is_summary_empty(const struct diff_queue_struct *q)
4775{
4776        int i;
4777
4778        for (i = 0; i < q->nr; i++) {
4779                const struct diff_filepair *p = q->queue[i];
4780
4781                switch (p->status) {
4782                case DIFF_STATUS_DELETED:
4783                case DIFF_STATUS_ADDED:
4784                case DIFF_STATUS_COPIED:
4785                case DIFF_STATUS_RENAMED:
4786                        return 0;
4787                default:
4788                        if (p->score)
4789                                return 0;
4790                        if (p->one->mode && p->two->mode &&
4791                            p->one->mode != p->two->mode)
4792                                return 0;
4793                        break;
4794                }
4795        }
4796        return 1;
4797}
4798
4799static const char rename_limit_warning[] =
4800N_("inexact rename detection was skipped due to too many files.");
4801
4802static const char degrade_cc_to_c_warning[] =
4803N_("only found copies from modified paths due to too many files.");
4804
4805static const char rename_limit_advice[] =
4806N_("you may want to set your %s variable to at least "
4807   "%d and retry the command.");
4808
4809void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4810{
4811        if (degraded_cc)
4812                warning(_(degrade_cc_to_c_warning));
4813        else if (needed)
4814                warning(_(rename_limit_warning));
4815        else
4816                return;
4817        if (0 < needed && needed < 32767)
4818                warning(_(rename_limit_advice), varname, needed);
4819}
4820
4821static void diff_flush_patch_all_file_pairs(struct diff_options *o)
4822{
4823        int i;
4824        struct diff_queue_struct *q = &diff_queued_diff;
4825
4826        if (WSEH_NEW & WS_RULE_MASK)
4827                die("BUG: WS rules bit mask overlaps with diff symbol flags");
4828
4829        for (i = 0; i < q->nr; i++) {
4830                struct diff_filepair *p = q->queue[i];
4831                if (check_pair_status(p))
4832                        diff_flush_patch(p, o);
4833        }
4834}
4835
4836void diff_flush(struct diff_options *options)
4837{
4838        struct diff_queue_struct *q = &diff_queued_diff;
4839        int i, output_format = options->output_format;
4840        int separator = 0;
4841        int dirstat_by_line = 0;
4842
4843        /*
4844         * Order: raw, stat, summary, patch
4845         * or:    name/name-status/checkdiff (other bits clear)
4846         */
4847        if (!q->nr)
4848                goto free_queue;
4849
4850        if (output_format & (DIFF_FORMAT_RAW |
4851                             DIFF_FORMAT_NAME |
4852                             DIFF_FORMAT_NAME_STATUS |
4853                             DIFF_FORMAT_CHECKDIFF)) {
4854                for (i = 0; i < q->nr; i++) {
4855                        struct diff_filepair *p = q->queue[i];
4856                        if (check_pair_status(p))
4857                                flush_one_pair(p, options);
4858                }
4859                separator++;
4860        }
4861
4862        if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
4863                dirstat_by_line = 1;
4864
4865        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
4866            dirstat_by_line) {
4867                struct diffstat_t diffstat;
4868
4869                memset(&diffstat, 0, sizeof(struct diffstat_t));
4870                for (i = 0; i < q->nr; i++) {
4871                        struct diff_filepair *p = q->queue[i];
4872                        if (check_pair_status(p))
4873                                diff_flush_stat(p, options, &diffstat);
4874                }
4875                if (output_format & DIFF_FORMAT_NUMSTAT)
4876                        show_numstat(&diffstat, options);
4877                if (output_format & DIFF_FORMAT_DIFFSTAT)
4878                        show_stats(&diffstat, options);
4879                if (output_format & DIFF_FORMAT_SHORTSTAT)
4880                        show_shortstats(&diffstat, options);
4881                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
4882                        show_dirstat_by_line(&diffstat, options);
4883                free_diffstat_info(&diffstat);
4884                separator++;
4885        }
4886        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
4887                show_dirstat(options);
4888
4889        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4890                for (i = 0; i < q->nr; i++) {
4891                        diff_summary(options, q->queue[i]);
4892                }
4893                separator++;
4894        }
4895
4896        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4897            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4898            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4899                /*
4900                 * run diff_flush_patch for the exit status. setting
4901                 * options->file to /dev/null should be safe, because we
4902                 * aren't supposed to produce any output anyway.
4903                 */
4904                if (options->close_file)
4905                        fclose(options->file);
4906                options->file = xfopen("/dev/null", "w");
4907                options->close_file = 1;
4908                for (i = 0; i < q->nr; i++) {
4909                        struct diff_filepair *p = q->queue[i];
4910                        if (check_pair_status(p))
4911                                diff_flush_patch(p, options);
4912                        if (options->found_changes)
4913                                break;
4914                }
4915        }
4916
4917        if (output_format & DIFF_FORMAT_PATCH) {
4918                if (separator) {
4919                        emit_diff_symbol(options, DIFF_SYMBOL_SEPARATOR, NULL, 0, 0);
4920                        if (options->stat_sep) {
4921                                /* attach patch instead of inline */
4922                                fputs(options->stat_sep, options->file);
4923                        }
4924                }
4925
4926                diff_flush_patch_all_file_pairs(options);
4927        }
4928
4929        if (output_format & DIFF_FORMAT_CALLBACK)
4930                options->format_callback(q, options, options->format_callback_data);
4931
4932        for (i = 0; i < q->nr; i++)
4933                diff_free_filepair(q->queue[i]);
4934free_queue:
4935        free(q->queue);
4936        DIFF_QUEUE_CLEAR(q);
4937        if (options->close_file)
4938                fclose(options->file);
4939
4940        /*
4941         * Report the content-level differences with HAS_CHANGES;
4942         * diff_addremove/diff_change does not set the bit when
4943         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4944         */
4945        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4946                if (options->found_changes)
4947                        DIFF_OPT_SET(options, HAS_CHANGES);
4948                else
4949                        DIFF_OPT_CLR(options, HAS_CHANGES);
4950        }
4951}
4952
4953static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
4954{
4955        return (((p->status == DIFF_STATUS_MODIFIED) &&
4956                 ((p->score &&
4957                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
4958                  (!p->score &&
4959                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
4960                ((p->status != DIFF_STATUS_MODIFIED) &&
4961                 filter_bit_tst(p->status, options)));
4962}
4963
4964static void diffcore_apply_filter(struct diff_options *options)
4965{
4966        int i;
4967        struct diff_queue_struct *q = &diff_queued_diff;
4968        struct diff_queue_struct outq;
4969
4970        DIFF_QUEUE_CLEAR(&outq);
4971
4972        if (!options->filter)
4973                return;
4974
4975        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
4976                int found;
4977                for (i = found = 0; !found && i < q->nr; i++) {
4978                        if (match_filter(options, q->queue[i]))
4979                                found++;
4980                }
4981                if (found)
4982                        return;
4983
4984                /* otherwise we will clear the whole queue
4985                 * by copying the empty outq at the end of this
4986                 * function, but first clear the current entries
4987                 * in the queue.
4988                 */
4989                for (i = 0; i < q->nr; i++)
4990                        diff_free_filepair(q->queue[i]);
4991        }
4992        else {
4993                /* Only the matching ones */
4994                for (i = 0; i < q->nr; i++) {
4995                        struct diff_filepair *p = q->queue[i];
4996                        if (match_filter(options, p))
4997                                diff_q(&outq, p);
4998                        else
4999                                diff_free_filepair(p);
5000                }
5001        }
5002        free(q->queue);
5003        *q = outq;
5004}
5005
5006/* Check whether two filespecs with the same mode and size are identical */
5007static int diff_filespec_is_identical(struct diff_filespec *one,
5008                                      struct diff_filespec *two)
5009{
5010        if (S_ISGITLINK(one->mode))
5011                return 0;
5012        if (diff_populate_filespec(one, 0))
5013                return 0;
5014        if (diff_populate_filespec(two, 0))
5015                return 0;
5016        return !memcmp(one->data, two->data, one->size);
5017}
5018
5019static int diff_filespec_check_stat_unmatch(struct diff_filepair *p)
5020{
5021        if (p->done_skip_stat_unmatch)
5022                return p->skip_stat_unmatch_result;
5023
5024        p->done_skip_stat_unmatch = 1;
5025        p->skip_stat_unmatch_result = 0;
5026        /*
5027         * 1. Entries that come from stat info dirtiness
5028         *    always have both sides (iow, not create/delete),
5029         *    one side of the object name is unknown, with
5030         *    the same mode and size.  Keep the ones that
5031         *    do not match these criteria.  They have real
5032         *    differences.
5033         *
5034         * 2. At this point, the file is known to be modified,
5035         *    with the same mode and size, and the object
5036         *    name of one side is unknown.  Need to inspect
5037         *    the identical contents.
5038         */
5039        if (!DIFF_FILE_VALID(p->one) || /* (1) */
5040            !DIFF_FILE_VALID(p->two) ||
5041            (p->one->oid_valid && p->two->oid_valid) ||
5042            (p->one->mode != p->two->mode) ||
5043            diff_populate_filespec(p->one, CHECK_SIZE_ONLY) ||
5044            diff_populate_filespec(p->two, CHECK_SIZE_ONLY) ||
5045            (p->one->size != p->two->size) ||
5046            !diff_filespec_is_identical(p->one, p->two)) /* (2) */
5047                p->skip_stat_unmatch_result = 1;
5048        return p->skip_stat_unmatch_result;
5049}
5050
5051static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
5052{
5053        int i;
5054        struct diff_queue_struct *q = &diff_queued_diff;
5055        struct diff_queue_struct outq;
5056        DIFF_QUEUE_CLEAR(&outq);
5057
5058        for (i = 0; i < q->nr; i++) {
5059                struct diff_filepair *p = q->queue[i];
5060
5061                if (diff_filespec_check_stat_unmatch(p))
5062                        diff_q(&outq, p);
5063                else {
5064                        /*
5065                         * The caller can subtract 1 from skip_stat_unmatch
5066                         * to determine how many paths were dirty only
5067                         * due to stat info mismatch.
5068                         */
5069                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
5070                                diffopt->skip_stat_unmatch++;
5071                        diff_free_filepair(p);
5072                }
5073        }
5074        free(q->queue);
5075        *q = outq;
5076}
5077
5078static int diffnamecmp(const void *a_, const void *b_)
5079{
5080        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
5081        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
5082        const char *name_a, *name_b;
5083
5084        name_a = a->one ? a->one->path : a->two->path;
5085        name_b = b->one ? b->one->path : b->two->path;
5086        return strcmp(name_a, name_b);
5087}
5088
5089void diffcore_fix_diff_index(struct diff_options *options)
5090{
5091        struct diff_queue_struct *q = &diff_queued_diff;
5092        QSORT(q->queue, q->nr, diffnamecmp);
5093}
5094
5095void diffcore_std(struct diff_options *options)
5096{
5097        /* NOTE please keep the following in sync with diff_tree_combined() */
5098        if (options->skip_stat_unmatch)
5099                diffcore_skip_stat_unmatch(options);
5100        if (!options->found_follow) {
5101                /* See try_to_follow_renames() in tree-diff.c */
5102                if (options->break_opt != -1)
5103                        diffcore_break(options->break_opt);
5104                if (options->detect_rename)
5105                        diffcore_rename(options);
5106                if (options->break_opt != -1)
5107                        diffcore_merge_broken();
5108        }
5109        if (options->pickaxe)
5110                diffcore_pickaxe(options);
5111        if (options->orderfile)
5112                diffcore_order(options->orderfile);
5113        if (!options->found_follow)
5114                /* See try_to_follow_renames() in tree-diff.c */
5115                diff_resolve_rename_copy();
5116        diffcore_apply_filter(options);
5117
5118        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
5119                DIFF_OPT_SET(options, HAS_CHANGES);
5120        else
5121                DIFF_OPT_CLR(options, HAS_CHANGES);
5122
5123        options->found_follow = 0;
5124}
5125
5126int diff_result_code(struct diff_options *opt, int status)
5127{
5128        int result = 0;
5129
5130        diff_warn_rename_limit("diff.renameLimit",
5131                               opt->needed_rename_limit,
5132                               opt->degraded_cc_to_c);
5133        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
5134            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
5135                return status;
5136        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
5137            DIFF_OPT_TST(opt, HAS_CHANGES))
5138                result |= 01;
5139        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
5140            DIFF_OPT_TST(opt, CHECK_FAILED))
5141                result |= 02;
5142        return result;
5143}
5144
5145int diff_can_quit_early(struct diff_options *opt)
5146{
5147        return (DIFF_OPT_TST(opt, QUICK) &&
5148                !opt->filter &&
5149                DIFF_OPT_TST(opt, HAS_CHANGES));
5150}
5151
5152/*
5153 * Shall changes to this submodule be ignored?
5154 *
5155 * Submodule changes can be configured to be ignored separately for each path,
5156 * but that configuration can be overridden from the command line.
5157 */
5158static int is_submodule_ignored(const char *path, struct diff_options *options)
5159{
5160        int ignored = 0;
5161        unsigned orig_flags = options->flags;
5162        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
5163                set_diffopt_flags_from_submodule_config(options, path);
5164        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
5165                ignored = 1;
5166        options->flags = orig_flags;
5167        return ignored;
5168}
5169
5170void diff_addremove(struct diff_options *options,
5171                    int addremove, unsigned mode,
5172                    const struct object_id *oid,
5173                    int oid_valid,
5174                    const char *concatpath, unsigned dirty_submodule)
5175{
5176        struct diff_filespec *one, *two;
5177
5178        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
5179                return;
5180
5181        /* This may look odd, but it is a preparation for
5182         * feeding "there are unchanged files which should
5183         * not produce diffs, but when you are doing copy
5184         * detection you would need them, so here they are"
5185         * entries to the diff-core.  They will be prefixed
5186         * with something like '=' or '*' (I haven't decided
5187         * which but should not make any difference).
5188         * Feeding the same new and old to diff_change()
5189         * also has the same effect.
5190         * Before the final output happens, they are pruned after
5191         * merged into rename/copy pairs as appropriate.
5192         */
5193        if (DIFF_OPT_TST(options, REVERSE_DIFF))
5194                addremove = (addremove == '+' ? '-' :
5195                             addremove == '-' ? '+' : addremove);
5196
5197        if (options->prefix &&
5198            strncmp(concatpath, options->prefix, options->prefix_length))
5199                return;
5200
5201        one = alloc_filespec(concatpath);
5202        two = alloc_filespec(concatpath);
5203
5204        if (addremove != '+')
5205                fill_filespec(one, oid, oid_valid, mode);
5206        if (addremove != '-') {
5207                fill_filespec(two, oid, oid_valid, mode);
5208                two->dirty_submodule = dirty_submodule;
5209        }
5210
5211        diff_queue(&diff_queued_diff, one, two);
5212        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
5213                DIFF_OPT_SET(options, HAS_CHANGES);
5214}
5215
5216void diff_change(struct diff_options *options,
5217                 unsigned old_mode, unsigned new_mode,
5218                 const struct object_id *old_oid,
5219                 const struct object_id *new_oid,
5220                 int old_oid_valid, int new_oid_valid,
5221                 const char *concatpath,
5222                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
5223{
5224        struct diff_filespec *one, *two;
5225        struct diff_filepair *p;
5226
5227        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
5228            is_submodule_ignored(concatpath, options))
5229                return;
5230
5231        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
5232                SWAP(old_mode, new_mode);
5233                SWAP(old_oid, new_oid);
5234                SWAP(old_oid_valid, new_oid_valid);
5235                SWAP(old_dirty_submodule, new_dirty_submodule);
5236        }
5237
5238        if (options->prefix &&
5239            strncmp(concatpath, options->prefix, options->prefix_length))
5240                return;
5241
5242        one = alloc_filespec(concatpath);
5243        two = alloc_filespec(concatpath);
5244        fill_filespec(one, old_oid, old_oid_valid, old_mode);
5245        fill_filespec(two, new_oid, new_oid_valid, new_mode);
5246        one->dirty_submodule = old_dirty_submodule;
5247        two->dirty_submodule = new_dirty_submodule;
5248        p = diff_queue(&diff_queued_diff, one, two);
5249
5250        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
5251                return;
5252
5253        if (DIFF_OPT_TST(options, QUICK) && options->skip_stat_unmatch &&
5254            !diff_filespec_check_stat_unmatch(p))
5255                return;
5256
5257        DIFF_OPT_SET(options, HAS_CHANGES);
5258}
5259
5260struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
5261{
5262        struct diff_filepair *pair;
5263        struct diff_filespec *one, *two;
5264
5265        if (options->prefix &&
5266            strncmp(path, options->prefix, options->prefix_length))
5267                return NULL;
5268
5269        one = alloc_filespec(path);
5270        two = alloc_filespec(path);
5271        pair = diff_queue(&diff_queued_diff, one, two);
5272        pair->is_unmerged = 1;
5273        return pair;
5274}
5275
5276static char *run_textconv(const char *pgm, struct diff_filespec *spec,
5277                size_t *outsize)
5278{
5279        struct diff_tempfile *temp;
5280        const char *argv[3];
5281        const char **arg = argv;
5282        struct child_process child = CHILD_PROCESS_INIT;
5283        struct strbuf buf = STRBUF_INIT;
5284        int err = 0;
5285
5286        temp = prepare_temp_file(spec->path, spec);
5287        *arg++ = pgm;
5288        *arg++ = temp->name;
5289        *arg = NULL;
5290
5291        child.use_shell = 1;
5292        child.argv = argv;
5293        child.out = -1;
5294        if (start_command(&child)) {
5295                remove_tempfile();
5296                return NULL;
5297        }
5298
5299        if (strbuf_read(&buf, child.out, 0) < 0)
5300                err = error("error reading from textconv command '%s'", pgm);
5301        close(child.out);
5302
5303        if (finish_command(&child) || err) {
5304                strbuf_release(&buf);
5305                remove_tempfile();
5306                return NULL;
5307        }
5308        remove_tempfile();
5309
5310        return strbuf_detach(&buf, outsize);
5311}
5312
5313size_t fill_textconv(struct userdiff_driver *driver,
5314                     struct diff_filespec *df,
5315                     char **outbuf)
5316{
5317        size_t size;
5318
5319        if (!driver) {
5320                if (!DIFF_FILE_VALID(df)) {
5321                        *outbuf = "";
5322                        return 0;
5323                }
5324                if (diff_populate_filespec(df, 0))
5325                        die("unable to read files to diff");
5326                *outbuf = df->data;
5327                return df->size;
5328        }
5329
5330        if (!driver->textconv)
5331                die("BUG: fill_textconv called with non-textconv driver");
5332
5333        if (driver->textconv_cache && df->oid_valid) {
5334                *outbuf = notes_cache_get(driver->textconv_cache,
5335                                          &df->oid,
5336                                          &size);
5337                if (*outbuf)
5338                        return size;
5339        }
5340
5341        *outbuf = run_textconv(driver->textconv, df, &size);
5342        if (!*outbuf)
5343                die("unable to read files to diff");
5344
5345        if (driver->textconv_cache && df->oid_valid) {
5346                /* ignore errors, as we might be in a readonly repository */
5347                notes_cache_put(driver->textconv_cache, &df->oid, *outbuf,
5348                                size);
5349                /*
5350                 * we could save up changes and flush them all at the end,
5351                 * but we would need an extra call after all diffing is done.
5352                 * Since generating a cache entry is the slow path anyway,
5353                 * this extra overhead probably isn't a big deal.
5354                 */
5355                notes_cache_write(driver->textconv_cache);
5356        }
5357
5358        return size;
5359}
5360
5361int textconv_object(const char *path,
5362                    unsigned mode,
5363                    const struct object_id *oid,
5364                    int oid_valid,
5365                    char **buf,
5366                    unsigned long *buf_size)
5367{
5368        struct diff_filespec *df;
5369        struct userdiff_driver *textconv;
5370
5371        df = alloc_filespec(path);
5372        fill_filespec(df, oid, oid_valid, mode);
5373        textconv = get_textconv(df);
5374        if (!textconv) {
5375                free_filespec(df);
5376                return 0;
5377        }
5378
5379        *buf_size = fill_textconv(textconv, df, buf);
5380        free_filespec(df);
5381        return 1;
5382}
5383
5384void setup_diff_pager(struct diff_options *opt)
5385{
5386        /*
5387         * If the user asked for our exit code, then either they want --quiet
5388         * or --exit-code. We should definitely not bother with a pager in the
5389         * former case, as we will generate no output. Since we still properly
5390         * report our exit code even when a pager is run, we _could_ run a
5391         * pager with --exit-code. But since we have not done so historically,
5392         * and because it is easy to find people oneline advising "git diff
5393         * --exit-code" in hooks and other scripts, we do not do so.
5394         */
5395        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
5396            check_pager_config("diff") != 0)
5397                setup_pager();
5398}