diff.con commit Remove inadvertently added outgoing/packfile.h (97e64b0)
   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#include "packfile.h"
  24
  25#ifdef NO_FAST_WORKING_DIRECTORY
  26#define FAST_WORKING_DIRECTORY 0
  27#else
  28#define FAST_WORKING_DIRECTORY 1
  29#endif
  30
  31static int diff_detect_rename_default;
  32static int diff_indent_heuristic = 1;
  33static int diff_rename_limit_default = 400;
  34static int diff_suppress_blank_empty;
  35static int diff_use_color_default = -1;
  36static int diff_context_default = 3;
  37static int diff_interhunk_context_default;
  38static const char *diff_word_regex_cfg;
  39static const char *external_diff_cmd_cfg;
  40static const char *diff_order_file_cfg;
  41int diff_auto_refresh_index = 1;
  42static int diff_mnemonic_prefix;
  43static int diff_no_prefix;
  44static int diff_stat_graph_width;
  45static int diff_dirstat_permille_default = 30;
  46static struct diff_options default_diff_options;
  47static long diff_algorithm;
  48static unsigned ws_error_highlight_default = WSEH_NEW;
  49
  50static char diff_colors[][COLOR_MAXLEN] = {
  51        GIT_COLOR_RESET,
  52        GIT_COLOR_NORMAL,       /* CONTEXT */
  53        GIT_COLOR_BOLD,         /* METAINFO */
  54        GIT_COLOR_CYAN,         /* FRAGINFO */
  55        GIT_COLOR_RED,          /* OLD */
  56        GIT_COLOR_GREEN,        /* NEW */
  57        GIT_COLOR_YELLOW,       /* COMMIT */
  58        GIT_COLOR_BG_RED,       /* WHITESPACE */
  59        GIT_COLOR_NORMAL,       /* FUNCINFO */
  60};
  61
  62static NORETURN void die_want_option(const char *option_name)
  63{
  64        die(_("option '%s' requires a value"), option_name);
  65}
  66
  67static int parse_diff_color_slot(const char *var)
  68{
  69        if (!strcasecmp(var, "context") || !strcasecmp(var, "plain"))
  70                return DIFF_CONTEXT;
  71        if (!strcasecmp(var, "meta"))
  72                return DIFF_METAINFO;
  73        if (!strcasecmp(var, "frag"))
  74                return DIFF_FRAGINFO;
  75        if (!strcasecmp(var, "old"))
  76                return DIFF_FILE_OLD;
  77        if (!strcasecmp(var, "new"))
  78                return DIFF_FILE_NEW;
  79        if (!strcasecmp(var, "commit"))
  80                return DIFF_COMMIT;
  81        if (!strcasecmp(var, "whitespace"))
  82                return DIFF_WHITESPACE;
  83        if (!strcasecmp(var, "func"))
  84                return DIFF_FUNCINFO;
  85        return -1;
  86}
  87
  88static int parse_dirstat_params(struct diff_options *options, const char *params_string,
  89                                struct strbuf *errmsg)
  90{
  91        char *params_copy = xstrdup(params_string);
  92        struct string_list params = STRING_LIST_INIT_NODUP;
  93        int ret = 0;
  94        int i;
  95
  96        if (*params_copy)
  97                string_list_split_in_place(&params, params_copy, ',', -1);
  98        for (i = 0; i < params.nr; i++) {
  99                const char *p = params.items[i].string;
 100                if (!strcmp(p, "changes")) {
 101                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
 102                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
 103                } else if (!strcmp(p, "lines")) {
 104                        DIFF_OPT_SET(options, DIRSTAT_BY_LINE);
 105                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
 106                } else if (!strcmp(p, "files")) {
 107                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
 108                        DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
 109                } else if (!strcmp(p, "noncumulative")) {
 110                        DIFF_OPT_CLR(options, DIRSTAT_CUMULATIVE);
 111                } else if (!strcmp(p, "cumulative")) {
 112                        DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
 113                } else if (isdigit(*p)) {
 114                        char *end;
 115                        int permille = strtoul(p, &end, 10) * 10;
 116                        if (*end == '.' && isdigit(*++end)) {
 117                                /* only use first digit */
 118                                permille += *end - '0';
 119                                /* .. and ignore any further digits */
 120                                while (isdigit(*++end))
 121                                        ; /* nothing */
 122                        }
 123                        if (!*end)
 124                                options->dirstat_permille = permille;
 125                        else {
 126                                strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%s'\n"),
 127                                            p);
 128                                ret++;
 129                        }
 130                } else {
 131                        strbuf_addf(errmsg, _("  Unknown dirstat parameter '%s'\n"), p);
 132                        ret++;
 133                }
 134
 135        }
 136        string_list_clear(&params, 0);
 137        free(params_copy);
 138        return ret;
 139}
 140
 141static int parse_submodule_params(struct diff_options *options, const char *value)
 142{
 143        if (!strcmp(value, "log"))
 144                options->submodule_format = DIFF_SUBMODULE_LOG;
 145        else if (!strcmp(value, "short"))
 146                options->submodule_format = DIFF_SUBMODULE_SHORT;
 147        else if (!strcmp(value, "diff"))
 148                options->submodule_format = DIFF_SUBMODULE_INLINE_DIFF;
 149        else
 150                return -1;
 151        return 0;
 152}
 153
 154static int git_config_rename(const char *var, const char *value)
 155{
 156        if (!value)
 157                return DIFF_DETECT_RENAME;
 158        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 159                return  DIFF_DETECT_COPY;
 160        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 161}
 162
 163long parse_algorithm_value(const char *value)
 164{
 165        if (!value)
 166                return -1;
 167        else if (!strcasecmp(value, "myers") || !strcasecmp(value, "default"))
 168                return 0;
 169        else if (!strcasecmp(value, "minimal"))
 170                return XDF_NEED_MINIMAL;
 171        else if (!strcasecmp(value, "patience"))
 172                return XDF_PATIENCE_DIFF;
 173        else if (!strcasecmp(value, "histogram"))
 174                return XDF_HISTOGRAM_DIFF;
 175        return -1;
 176}
 177
 178static int parse_one_token(const char **arg, const char *token)
 179{
 180        const char *rest;
 181        if (skip_prefix(*arg, token, &rest) && (!*rest || *rest == ',')) {
 182                *arg = rest;
 183                return 1;
 184        }
 185        return 0;
 186}
 187
 188static int parse_ws_error_highlight(const char *arg)
 189{
 190        const char *orig_arg = arg;
 191        unsigned val = 0;
 192
 193        while (*arg) {
 194                if (parse_one_token(&arg, "none"))
 195                        val = 0;
 196                else if (parse_one_token(&arg, "default"))
 197                        val = WSEH_NEW;
 198                else if (parse_one_token(&arg, "all"))
 199                        val = WSEH_NEW | WSEH_OLD | WSEH_CONTEXT;
 200                else if (parse_one_token(&arg, "new"))
 201                        val |= WSEH_NEW;
 202                else if (parse_one_token(&arg, "old"))
 203                        val |= WSEH_OLD;
 204                else if (parse_one_token(&arg, "context"))
 205                        val |= WSEH_CONTEXT;
 206                else {
 207                        return -1 - (int)(arg - orig_arg);
 208                }
 209                if (*arg)
 210                        arg++;
 211        }
 212        return val;
 213}
 214
 215/*
 216 * These are to give UI layer defaults.
 217 * The core-level commands such as git-diff-files should
 218 * never be affected by the setting of diff.renames
 219 * the user happens to have in the configuration file.
 220 */
 221void init_diff_ui_defaults(void)
 222{
 223        diff_detect_rename_default = 1;
 224}
 225
 226int git_diff_heuristic_config(const char *var, const char *value, void *cb)
 227{
 228        if (!strcmp(var, "diff.indentheuristic"))
 229                diff_indent_heuristic = git_config_bool(var, value);
 230        return 0;
 231}
 232
 233int git_diff_ui_config(const char *var, const char *value, void *cb)
 234{
 235        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 236                diff_use_color_default = git_config_colorbool(var, value);
 237                return 0;
 238        }
 239        if (!strcmp(var, "diff.context")) {
 240                diff_context_default = git_config_int(var, value);
 241                if (diff_context_default < 0)
 242                        return -1;
 243                return 0;
 244        }
 245        if (!strcmp(var, "diff.interhunkcontext")) {
 246                diff_interhunk_context_default = git_config_int(var, value);
 247                if (diff_interhunk_context_default < 0)
 248                        return -1;
 249                return 0;
 250        }
 251        if (!strcmp(var, "diff.renames")) {
 252                diff_detect_rename_default = git_config_rename(var, value);
 253                return 0;
 254        }
 255        if (!strcmp(var, "diff.autorefreshindex")) {
 256                diff_auto_refresh_index = git_config_bool(var, value);
 257                return 0;
 258        }
 259        if (!strcmp(var, "diff.mnemonicprefix")) {
 260                diff_mnemonic_prefix = git_config_bool(var, value);
 261                return 0;
 262        }
 263        if (!strcmp(var, "diff.noprefix")) {
 264                diff_no_prefix = git_config_bool(var, value);
 265                return 0;
 266        }
 267        if (!strcmp(var, "diff.statgraphwidth")) {
 268                diff_stat_graph_width = git_config_int(var, value);
 269                return 0;
 270        }
 271        if (!strcmp(var, "diff.external"))
 272                return git_config_string(&external_diff_cmd_cfg, var, value);
 273        if (!strcmp(var, "diff.wordregex"))
 274                return git_config_string(&diff_word_regex_cfg, var, value);
 275        if (!strcmp(var, "diff.orderfile"))
 276                return git_config_pathname(&diff_order_file_cfg, var, value);
 277
 278        if (!strcmp(var, "diff.ignoresubmodules"))
 279                handle_ignore_submodules_arg(&default_diff_options, value);
 280
 281        if (!strcmp(var, "diff.submodule")) {
 282                if (parse_submodule_params(&default_diff_options, value))
 283                        warning(_("Unknown value for 'diff.submodule' config variable: '%s'"),
 284                                value);
 285                return 0;
 286        }
 287
 288        if (!strcmp(var, "diff.algorithm")) {
 289                diff_algorithm = parse_algorithm_value(value);
 290                if (diff_algorithm < 0)
 291                        return -1;
 292                return 0;
 293        }
 294
 295        if (!strcmp(var, "diff.wserrorhighlight")) {
 296                int val = parse_ws_error_highlight(value);
 297                if (val < 0)
 298                        return -1;
 299                ws_error_highlight_default = val;
 300                return 0;
 301        }
 302
 303        return git_diff_basic_config(var, value, cb);
 304}
 305
 306int git_diff_basic_config(const char *var, const char *value, void *cb)
 307{
 308        const char *name;
 309
 310        if (!strcmp(var, "diff.renamelimit")) {
 311                diff_rename_limit_default = git_config_int(var, value);
 312                return 0;
 313        }
 314
 315        if (userdiff_config(var, value) < 0)
 316                return -1;
 317
 318        if (skip_prefix(var, "diff.color.", &name) ||
 319            skip_prefix(var, "color.diff.", &name)) {
 320                int slot = parse_diff_color_slot(name);
 321                if (slot < 0)
 322                        return 0;
 323                if (!value)
 324                        return config_error_nonbool(var);
 325                return color_parse(value, diff_colors[slot]);
 326        }
 327
 328        /* like GNU diff's --suppress-blank-empty option  */
 329        if (!strcmp(var, "diff.suppressblankempty") ||
 330                        /* for backwards compatibility */
 331                        !strcmp(var, "diff.suppress-blank-empty")) {
 332                diff_suppress_blank_empty = git_config_bool(var, value);
 333                return 0;
 334        }
 335
 336        if (!strcmp(var, "diff.dirstat")) {
 337                struct strbuf errmsg = STRBUF_INIT;
 338                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 339                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 340                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 341                                errmsg.buf);
 342                strbuf_release(&errmsg);
 343                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 344                return 0;
 345        }
 346
 347        if (starts_with(var, "submodule."))
 348                return parse_submodule_config_option(var, value);
 349
 350        if (git_diff_heuristic_config(var, value, cb) < 0)
 351                return -1;
 352
 353        return git_default_config(var, value, cb);
 354}
 355
 356static char *quote_two(const char *one, const char *two)
 357{
 358        int need_one = quote_c_style(one, NULL, NULL, 1);
 359        int need_two = quote_c_style(two, NULL, NULL, 1);
 360        struct strbuf res = STRBUF_INIT;
 361
 362        if (need_one + need_two) {
 363                strbuf_addch(&res, '"');
 364                quote_c_style(one, &res, NULL, 1);
 365                quote_c_style(two, &res, NULL, 1);
 366                strbuf_addch(&res, '"');
 367        } else {
 368                strbuf_addstr(&res, one);
 369                strbuf_addstr(&res, two);
 370        }
 371        return strbuf_detach(&res, NULL);
 372}
 373
 374static const char *external_diff(void)
 375{
 376        static const char *external_diff_cmd = NULL;
 377        static int done_preparing = 0;
 378
 379        if (done_preparing)
 380                return external_diff_cmd;
 381        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 382        if (!external_diff_cmd)
 383                external_diff_cmd = external_diff_cmd_cfg;
 384        done_preparing = 1;
 385        return external_diff_cmd;
 386}
 387
 388/*
 389 * Keep track of files used for diffing. Sometimes such an entry
 390 * refers to a temporary file, sometimes to an existing file, and
 391 * sometimes to "/dev/null".
 392 */
 393static struct diff_tempfile {
 394        /*
 395         * filename external diff should read from, or NULL if this
 396         * entry is currently not in use:
 397         */
 398        const char *name;
 399
 400        char hex[GIT_MAX_HEXSZ + 1];
 401        char mode[10];
 402
 403        /*
 404         * If this diff_tempfile instance refers to a temporary file,
 405         * this tempfile object is used to manage its lifetime.
 406         */
 407        struct tempfile tempfile;
 408} diff_temp[2];
 409
 410struct emit_callback {
 411        int color_diff;
 412        unsigned ws_rule;
 413        int blank_at_eof_in_preimage;
 414        int blank_at_eof_in_postimage;
 415        int lno_in_preimage;
 416        int lno_in_postimage;
 417        const char **label_path;
 418        struct diff_words_data *diff_words;
 419        struct diff_options *opt;
 420        struct strbuf *header;
 421};
 422
 423static int count_lines(const char *data, int size)
 424{
 425        int count, ch, completely_empty = 1, nl_just_seen = 0;
 426        count = 0;
 427        while (0 < size--) {
 428                ch = *data++;
 429                if (ch == '\n') {
 430                        count++;
 431                        nl_just_seen = 1;
 432                        completely_empty = 0;
 433                }
 434                else {
 435                        nl_just_seen = 0;
 436                        completely_empty = 0;
 437                }
 438        }
 439        if (completely_empty)
 440                return 0;
 441        if (!nl_just_seen)
 442                count++; /* no trailing newline */
 443        return count;
 444}
 445
 446static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 447{
 448        if (!DIFF_FILE_VALID(one)) {
 449                mf->ptr = (char *)""; /* does not matter */
 450                mf->size = 0;
 451                return 0;
 452        }
 453        else if (diff_populate_filespec(one, 0))
 454                return -1;
 455
 456        mf->ptr = one->data;
 457        mf->size = one->size;
 458        return 0;
 459}
 460
 461/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 462static unsigned long diff_filespec_size(struct diff_filespec *one)
 463{
 464        if (!DIFF_FILE_VALID(one))
 465                return 0;
 466        diff_populate_filespec(one, CHECK_SIZE_ONLY);
 467        return one->size;
 468}
 469
 470static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 471{
 472        char *ptr = mf->ptr;
 473        long size = mf->size;
 474        int cnt = 0;
 475
 476        if (!size)
 477                return cnt;
 478        ptr += size - 1; /* pointing at the very end */
 479        if (*ptr != '\n')
 480                ; /* incomplete line */
 481        else
 482                ptr--; /* skip the last LF */
 483        while (mf->ptr < ptr) {
 484                char *prev_eol;
 485                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 486                        if (*prev_eol == '\n')
 487                                break;
 488                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 489                        break;
 490                cnt++;
 491                ptr = prev_eol - 1;
 492        }
 493        return cnt;
 494}
 495
 496static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 497                               struct emit_callback *ecbdata)
 498{
 499        int l1, l2, at;
 500        unsigned ws_rule = ecbdata->ws_rule;
 501        l1 = count_trailing_blank(mf1, ws_rule);
 502        l2 = count_trailing_blank(mf2, ws_rule);
 503        if (l2 <= l1) {
 504                ecbdata->blank_at_eof_in_preimage = 0;
 505                ecbdata->blank_at_eof_in_postimage = 0;
 506                return;
 507        }
 508        at = count_lines(mf1->ptr, mf1->size);
 509        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 510
 511        at = count_lines(mf2->ptr, mf2->size);
 512        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 513}
 514
 515static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 516                        int first, const char *line, int len)
 517{
 518        int has_trailing_newline, has_trailing_carriage_return;
 519        int nofirst;
 520        FILE *file = o->file;
 521
 522        fputs(diff_line_prefix(o), file);
 523
 524        if (len == 0) {
 525                has_trailing_newline = (first == '\n');
 526                has_trailing_carriage_return = (!has_trailing_newline &&
 527                                                (first == '\r'));
 528                nofirst = has_trailing_newline || has_trailing_carriage_return;
 529        } else {
 530                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 531                if (has_trailing_newline)
 532                        len--;
 533                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 534                if (has_trailing_carriage_return)
 535                        len--;
 536                nofirst = 0;
 537        }
 538
 539        if (len || !nofirst) {
 540                fputs(set, file);
 541                if (!nofirst)
 542                        fputc(first, file);
 543                fwrite(line, len, 1, file);
 544                fputs(reset, file);
 545        }
 546        if (has_trailing_carriage_return)
 547                fputc('\r', file);
 548        if (has_trailing_newline)
 549                fputc('\n', file);
 550}
 551
 552static void emit_line(struct diff_options *o, const char *set, const char *reset,
 553                      const char *line, int len)
 554{
 555        emit_line_0(o, set, reset, line[0], line+1, len-1);
 556}
 557
 558static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 559{
 560        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 561              ecbdata->blank_at_eof_in_preimage &&
 562              ecbdata->blank_at_eof_in_postimage &&
 563              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 564              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 565                return 0;
 566        return ws_blank_line(line, len, ecbdata->ws_rule);
 567}
 568
 569static void emit_line_checked(const char *reset,
 570                              struct emit_callback *ecbdata,
 571                              const char *line, int len,
 572                              enum color_diff color,
 573                              unsigned ws_error_highlight,
 574                              char sign)
 575{
 576        const char *set = diff_get_color(ecbdata->color_diff, color);
 577        const char *ws = NULL;
 578
 579        if (ecbdata->opt->ws_error_highlight & ws_error_highlight) {
 580                ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 581                if (!*ws)
 582                        ws = NULL;
 583        }
 584
 585        if (!ws)
 586                emit_line_0(ecbdata->opt, set, reset, sign, line, len);
 587        else if (sign == '+' && new_blank_line_at_eof(ecbdata, line, len))
 588                /* Blank line at EOF - paint '+' as well */
 589                emit_line_0(ecbdata->opt, ws, reset, sign, line, len);
 590        else {
 591                /* Emit just the prefix, then the rest. */
 592                emit_line_0(ecbdata->opt, set, reset, sign, "", 0);
 593                ws_check_emit(line, len, ecbdata->ws_rule,
 594                              ecbdata->opt->file, set, reset, ws);
 595        }
 596}
 597
 598static void emit_add_line(const char *reset,
 599                          struct emit_callback *ecbdata,
 600                          const char *line, int len)
 601{
 602        emit_line_checked(reset, ecbdata, line, len,
 603                          DIFF_FILE_NEW, WSEH_NEW, '+');
 604}
 605
 606static void emit_del_line(const char *reset,
 607                          struct emit_callback *ecbdata,
 608                          const char *line, int len)
 609{
 610        emit_line_checked(reset, ecbdata, line, len,
 611                          DIFF_FILE_OLD, WSEH_OLD, '-');
 612}
 613
 614static void emit_context_line(const char *reset,
 615                              struct emit_callback *ecbdata,
 616                              const char *line, int len)
 617{
 618        emit_line_checked(reset, ecbdata, line, len,
 619                          DIFF_CONTEXT, WSEH_CONTEXT, ' ');
 620}
 621
 622static void emit_hunk_header(struct emit_callback *ecbdata,
 623                             const char *line, int len)
 624{
 625        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
 626        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 627        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 628        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 629        static const char atat[2] = { '@', '@' };
 630        const char *cp, *ep;
 631        struct strbuf msgbuf = STRBUF_INIT;
 632        int org_len = len;
 633        int i = 1;
 634
 635        /*
 636         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 637         * it always is at least 10 bytes long.
 638         */
 639        if (len < 10 ||
 640            memcmp(line, atat, 2) ||
 641            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 642                emit_line(ecbdata->opt, context, reset, line, len);
 643                return;
 644        }
 645        ep += 2; /* skip over @@ */
 646
 647        /* The hunk header in fraginfo color */
 648        strbuf_addstr(&msgbuf, frag);
 649        strbuf_add(&msgbuf, line, ep - line);
 650        strbuf_addstr(&msgbuf, reset);
 651
 652        /*
 653         * trailing "\r\n"
 654         */
 655        for ( ; i < 3; i++)
 656                if (line[len - i] == '\r' || line[len - i] == '\n')
 657                        len--;
 658
 659        /* blank before the func header */
 660        for (cp = ep; ep - line < len; ep++)
 661                if (*ep != ' ' && *ep != '\t')
 662                        break;
 663        if (ep != cp) {
 664                strbuf_addstr(&msgbuf, context);
 665                strbuf_add(&msgbuf, cp, ep - cp);
 666                strbuf_addstr(&msgbuf, reset);
 667        }
 668
 669        if (ep < line + len) {
 670                strbuf_addstr(&msgbuf, func);
 671                strbuf_add(&msgbuf, ep, line + len - ep);
 672                strbuf_addstr(&msgbuf, reset);
 673        }
 674
 675        strbuf_add(&msgbuf, line + len, org_len - len);
 676        emit_line(ecbdata->opt, "", "", msgbuf.buf, msgbuf.len);
 677        strbuf_release(&msgbuf);
 678}
 679
 680static struct diff_tempfile *claim_diff_tempfile(void) {
 681        int i;
 682        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 683                if (!diff_temp[i].name)
 684                        return diff_temp + i;
 685        die("BUG: diff is failing to clean up its tempfiles");
 686}
 687
 688static void remove_tempfile(void)
 689{
 690        int i;
 691        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 692                if (is_tempfile_active(&diff_temp[i].tempfile))
 693                        delete_tempfile(&diff_temp[i].tempfile);
 694                diff_temp[i].name = NULL;
 695        }
 696}
 697
 698static void print_line_count(FILE *file, int count)
 699{
 700        switch (count) {
 701        case 0:
 702                fprintf(file, "0,0");
 703                break;
 704        case 1:
 705                fprintf(file, "1");
 706                break;
 707        default:
 708                fprintf(file, "1,%d", count);
 709                break;
 710        }
 711}
 712
 713static void emit_rewrite_lines(struct emit_callback *ecb,
 714                               int prefix, const char *data, int size)
 715{
 716        const char *endp = NULL;
 717        static const char *nneof = " No newline at end of file\n";
 718        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 719
 720        while (0 < size) {
 721                int len;
 722
 723                endp = memchr(data, '\n', size);
 724                len = endp ? (endp - data + 1) : size;
 725                if (prefix != '+') {
 726                        ecb->lno_in_preimage++;
 727                        emit_del_line(reset, ecb, data, len);
 728                } else {
 729                        ecb->lno_in_postimage++;
 730                        emit_add_line(reset, ecb, data, len);
 731                }
 732                size -= len;
 733                data += len;
 734        }
 735        if (!endp) {
 736                const char *context = diff_get_color(ecb->color_diff,
 737                                                     DIFF_CONTEXT);
 738                putc('\n', ecb->opt->file);
 739                emit_line_0(ecb->opt, context, reset, '\\',
 740                            nneof, strlen(nneof));
 741        }
 742}
 743
 744static void emit_rewrite_diff(const char *name_a,
 745                              const char *name_b,
 746                              struct diff_filespec *one,
 747                              struct diff_filespec *two,
 748                              struct userdiff_driver *textconv_one,
 749                              struct userdiff_driver *textconv_two,
 750                              struct diff_options *o)
 751{
 752        int lc_a, lc_b;
 753        const char *name_a_tab, *name_b_tab;
 754        const char *metainfo = diff_get_color(o->use_color, DIFF_METAINFO);
 755        const char *fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
 756        const char *reset = diff_get_color(o->use_color, DIFF_RESET);
 757        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 758        const char *a_prefix, *b_prefix;
 759        char *data_one, *data_two;
 760        size_t size_one, size_two;
 761        struct emit_callback ecbdata;
 762        const char *line_prefix = diff_line_prefix(o);
 763
 764        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 765                a_prefix = o->b_prefix;
 766                b_prefix = o->a_prefix;
 767        } else {
 768                a_prefix = o->a_prefix;
 769                b_prefix = o->b_prefix;
 770        }
 771
 772        name_a += (*name_a == '/');
 773        name_b += (*name_b == '/');
 774        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 775        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 776
 777        strbuf_reset(&a_name);
 778        strbuf_reset(&b_name);
 779        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 780        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 781
 782        size_one = fill_textconv(textconv_one, one, &data_one);
 783        size_two = fill_textconv(textconv_two, two, &data_two);
 784
 785        memset(&ecbdata, 0, sizeof(ecbdata));
 786        ecbdata.color_diff = want_color(o->use_color);
 787        ecbdata.ws_rule = whitespace_rule(name_b);
 788        ecbdata.opt = o;
 789        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 790                mmfile_t mf1, mf2;
 791                mf1.ptr = (char *)data_one;
 792                mf2.ptr = (char *)data_two;
 793                mf1.size = size_one;
 794                mf2.size = size_two;
 795                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 796        }
 797        ecbdata.lno_in_preimage = 1;
 798        ecbdata.lno_in_postimage = 1;
 799
 800        lc_a = count_lines(data_one, size_one);
 801        lc_b = count_lines(data_two, size_two);
 802        fprintf(o->file,
 803                "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
 804                line_prefix, metainfo, a_name.buf, name_a_tab, reset,
 805                line_prefix, metainfo, b_name.buf, name_b_tab, reset,
 806                line_prefix, fraginfo);
 807        if (!o->irreversible_delete)
 808                print_line_count(o->file, lc_a);
 809        else
 810                fprintf(o->file, "?,?");
 811        fprintf(o->file, " +");
 812        print_line_count(o->file, lc_b);
 813        fprintf(o->file, " @@%s\n", reset);
 814        if (lc_a && !o->irreversible_delete)
 815                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 816        if (lc_b)
 817                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 818        if (textconv_one)
 819                free((char *)data_one);
 820        if (textconv_two)
 821                free((char *)data_two);
 822}
 823
 824struct diff_words_buffer {
 825        mmfile_t text;
 826        long alloc;
 827        struct diff_words_orig {
 828                const char *begin, *end;
 829        } *orig;
 830        int orig_nr, orig_alloc;
 831};
 832
 833static void diff_words_append(char *line, unsigned long len,
 834                struct diff_words_buffer *buffer)
 835{
 836        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 837        line++;
 838        len--;
 839        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 840        buffer->text.size += len;
 841        buffer->text.ptr[buffer->text.size] = '\0';
 842}
 843
 844struct diff_words_style_elem {
 845        const char *prefix;
 846        const char *suffix;
 847        const char *color; /* NULL; filled in by the setup code if
 848                            * color is enabled */
 849};
 850
 851struct diff_words_style {
 852        enum diff_words_type type;
 853        struct diff_words_style_elem new, old, ctx;
 854        const char *newline;
 855};
 856
 857static struct diff_words_style diff_words_styles[] = {
 858        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 859        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 860        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 861};
 862
 863struct diff_words_data {
 864        struct diff_words_buffer minus, plus;
 865        const char *current_plus;
 866        int last_minus;
 867        struct diff_options *opt;
 868        regex_t *word_regex;
 869        enum diff_words_type type;
 870        struct diff_words_style *style;
 871};
 872
 873static int fn_out_diff_words_write_helper(FILE *fp,
 874                                          struct diff_words_style_elem *st_el,
 875                                          const char *newline,
 876                                          size_t count, const char *buf,
 877                                          const char *line_prefix)
 878{
 879        int print = 0;
 880
 881        while (count) {
 882                char *p = memchr(buf, '\n', count);
 883                if (print)
 884                        fputs(line_prefix, fp);
 885                if (p != buf) {
 886                        if (st_el->color && fputs(st_el->color, fp) < 0)
 887                                return -1;
 888                        if (fputs(st_el->prefix, fp) < 0 ||
 889                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 890                            fputs(st_el->suffix, fp) < 0)
 891                                return -1;
 892                        if (st_el->color && *st_el->color
 893                            && fputs(GIT_COLOR_RESET, fp) < 0)
 894                                return -1;
 895                }
 896                if (!p)
 897                        return 0;
 898                if (fputs(newline, fp) < 0)
 899                        return -1;
 900                count -= p + 1 - buf;
 901                buf = p + 1;
 902                print = 1;
 903        }
 904        return 0;
 905}
 906
 907/*
 908 * '--color-words' algorithm can be described as:
 909 *
 910 *   1. collect the minus/plus lines of a diff hunk, divided into
 911 *      minus-lines and plus-lines;
 912 *
 913 *   2. break both minus-lines and plus-lines into words and
 914 *      place them into two mmfile_t with one word for each line;
 915 *
 916 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
 917 *
 918 * And for the common parts of the both file, we output the plus side text.
 919 * diff_words->current_plus is used to trace the current position of the plus file
 920 * which printed. diff_words->last_minus is used to trace the last minus word
 921 * printed.
 922 *
 923 * For '--graph' to work with '--color-words', we need to output the graph prefix
 924 * on each line of color words output. Generally, there are two conditions on
 925 * which we should output the prefix.
 926 *
 927 *   1. diff_words->last_minus == 0 &&
 928 *      diff_words->current_plus == diff_words->plus.text.ptr
 929 *
 930 *      that is: the plus text must start as a new line, and if there is no minus
 931 *      word printed, a graph prefix must be printed.
 932 *
 933 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
 934 *      *(diff_words->current_plus - 1) == '\n'
 935 *
 936 *      that is: a graph prefix must be printed following a '\n'
 937 */
 938static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
 939{
 940        if ((diff_words->last_minus == 0 &&
 941                diff_words->current_plus == diff_words->plus.text.ptr) ||
 942                (diff_words->current_plus > diff_words->plus.text.ptr &&
 943                *(diff_words->current_plus - 1) == '\n')) {
 944                return 1;
 945        } else {
 946                return 0;
 947        }
 948}
 949
 950static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 951{
 952        struct diff_words_data *diff_words = priv;
 953        struct diff_words_style *style = diff_words->style;
 954        int minus_first, minus_len, plus_first, plus_len;
 955        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 956        struct diff_options *opt = diff_words->opt;
 957        const char *line_prefix;
 958
 959        if (line[0] != '@' || parse_hunk_header(line, len,
 960                        &minus_first, &minus_len, &plus_first, &plus_len))
 961                return;
 962
 963        assert(opt);
 964        line_prefix = diff_line_prefix(opt);
 965
 966        /* POSIX requires that first be decremented by one if len == 0... */
 967        if (minus_len) {
 968                minus_begin = diff_words->minus.orig[minus_first].begin;
 969                minus_end =
 970                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 971        } else
 972                minus_begin = minus_end =
 973                        diff_words->minus.orig[minus_first].end;
 974
 975        if (plus_len) {
 976                plus_begin = diff_words->plus.orig[plus_first].begin;
 977                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 978        } else
 979                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 980
 981        if (color_words_output_graph_prefix(diff_words)) {
 982                fputs(line_prefix, diff_words->opt->file);
 983        }
 984        if (diff_words->current_plus != plus_begin) {
 985                fn_out_diff_words_write_helper(diff_words->opt->file,
 986                                &style->ctx, style->newline,
 987                                plus_begin - diff_words->current_plus,
 988                                diff_words->current_plus, line_prefix);
 989                if (*(plus_begin - 1) == '\n')
 990                        fputs(line_prefix, diff_words->opt->file);
 991        }
 992        if (minus_begin != minus_end) {
 993                fn_out_diff_words_write_helper(diff_words->opt->file,
 994                                &style->old, style->newline,
 995                                minus_end - minus_begin, minus_begin,
 996                                line_prefix);
 997        }
 998        if (plus_begin != plus_end) {
 999                fn_out_diff_words_write_helper(diff_words->opt->file,
1000                                &style->new, style->newline,
1001                                plus_end - plus_begin, plus_begin,
1002                                line_prefix);
1003        }
1004
1005        diff_words->current_plus = plus_end;
1006        diff_words->last_minus = minus_first;
1007}
1008
1009/* This function starts looking at *begin, and returns 0 iff a word was found. */
1010static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
1011                int *begin, int *end)
1012{
1013        if (word_regex && *begin < buffer->size) {
1014                regmatch_t match[1];
1015                if (!regexec_buf(word_regex, buffer->ptr + *begin,
1016                                 buffer->size - *begin, 1, match, 0)) {
1017                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
1018                                        '\n', match[0].rm_eo - match[0].rm_so);
1019                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
1020                        *begin += match[0].rm_so;
1021                        return *begin >= *end;
1022                }
1023                return -1;
1024        }
1025
1026        /* find the next word */
1027        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
1028                (*begin)++;
1029        if (*begin >= buffer->size)
1030                return -1;
1031
1032        /* find the end of the word */
1033        *end = *begin + 1;
1034        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
1035                (*end)++;
1036
1037        return 0;
1038}
1039
1040/*
1041 * This function splits the words in buffer->text, stores the list with
1042 * newline separator into out, and saves the offsets of the original words
1043 * in buffer->orig.
1044 */
1045static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
1046                regex_t *word_regex)
1047{
1048        int i, j;
1049        long alloc = 0;
1050
1051        out->size = 0;
1052        out->ptr = NULL;
1053
1054        /* fake an empty "0th" word */
1055        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
1056        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
1057        buffer->orig_nr = 1;
1058
1059        for (i = 0; i < buffer->text.size; i++) {
1060                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
1061                        return;
1062
1063                /* store original boundaries */
1064                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
1065                                buffer->orig_alloc);
1066                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
1067                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
1068                buffer->orig_nr++;
1069
1070                /* store one word */
1071                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
1072                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
1073                out->ptr[out->size + j - i] = '\n';
1074                out->size += j - i + 1;
1075
1076                i = j - 1;
1077        }
1078}
1079
1080/* this executes the word diff on the accumulated buffers */
1081static void diff_words_show(struct diff_words_data *diff_words)
1082{
1083        xpparam_t xpp;
1084        xdemitconf_t xecfg;
1085        mmfile_t minus, plus;
1086        struct diff_words_style *style = diff_words->style;
1087
1088        struct diff_options *opt = diff_words->opt;
1089        const char *line_prefix;
1090
1091        assert(opt);
1092        line_prefix = diff_line_prefix(opt);
1093
1094        /* special case: only removal */
1095        if (!diff_words->plus.text.size) {
1096                fputs(line_prefix, diff_words->opt->file);
1097                fn_out_diff_words_write_helper(diff_words->opt->file,
1098                        &style->old, style->newline,
1099                        diff_words->minus.text.size,
1100                        diff_words->minus.text.ptr, line_prefix);
1101                diff_words->minus.text.size = 0;
1102                return;
1103        }
1104
1105        diff_words->current_plus = diff_words->plus.text.ptr;
1106        diff_words->last_minus = 0;
1107
1108        memset(&xpp, 0, sizeof(xpp));
1109        memset(&xecfg, 0, sizeof(xecfg));
1110        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
1111        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
1112        xpp.flags = 0;
1113        /* as only the hunk header will be parsed, we need a 0-context */
1114        xecfg.ctxlen = 0;
1115        if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
1116                          &xpp, &xecfg))
1117                die("unable to generate word diff");
1118        free(minus.ptr);
1119        free(plus.ptr);
1120        if (diff_words->current_plus != diff_words->plus.text.ptr +
1121                        diff_words->plus.text.size) {
1122                if (color_words_output_graph_prefix(diff_words))
1123                        fputs(line_prefix, diff_words->opt->file);
1124                fn_out_diff_words_write_helper(diff_words->opt->file,
1125                        &style->ctx, style->newline,
1126                        diff_words->plus.text.ptr + diff_words->plus.text.size
1127                        - diff_words->current_plus, diff_words->current_plus,
1128                        line_prefix);
1129        }
1130        diff_words->minus.text.size = diff_words->plus.text.size = 0;
1131}
1132
1133/* In "color-words" mode, show word-diff of words accumulated in the buffer */
1134static void diff_words_flush(struct emit_callback *ecbdata)
1135{
1136        if (ecbdata->diff_words->minus.text.size ||
1137            ecbdata->diff_words->plus.text.size)
1138                diff_words_show(ecbdata->diff_words);
1139}
1140
1141static void diff_filespec_load_driver(struct diff_filespec *one)
1142{
1143        /* Use already-loaded driver */
1144        if (one->driver)
1145                return;
1146
1147        if (S_ISREG(one->mode))
1148                one->driver = userdiff_find_by_path(one->path);
1149
1150        /* Fallback to default settings */
1151        if (!one->driver)
1152                one->driver = userdiff_find_by_name("default");
1153}
1154
1155static const char *userdiff_word_regex(struct diff_filespec *one)
1156{
1157        diff_filespec_load_driver(one);
1158        return one->driver->word_regex;
1159}
1160
1161static void init_diff_words_data(struct emit_callback *ecbdata,
1162                                 struct diff_options *orig_opts,
1163                                 struct diff_filespec *one,
1164                                 struct diff_filespec *two)
1165{
1166        int i;
1167        struct diff_options *o = xmalloc(sizeof(struct diff_options));
1168        memcpy(o, orig_opts, sizeof(struct diff_options));
1169
1170        ecbdata->diff_words =
1171                xcalloc(1, sizeof(struct diff_words_data));
1172        ecbdata->diff_words->type = o->word_diff;
1173        ecbdata->diff_words->opt = o;
1174        if (!o->word_regex)
1175                o->word_regex = userdiff_word_regex(one);
1176        if (!o->word_regex)
1177                o->word_regex = userdiff_word_regex(two);
1178        if (!o->word_regex)
1179                o->word_regex = diff_word_regex_cfg;
1180        if (o->word_regex) {
1181                ecbdata->diff_words->word_regex = (regex_t *)
1182                        xmalloc(sizeof(regex_t));
1183                if (regcomp(ecbdata->diff_words->word_regex,
1184                            o->word_regex,
1185                            REG_EXTENDED | REG_NEWLINE))
1186                        die ("Invalid regular expression: %s",
1187                             o->word_regex);
1188        }
1189        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
1190                if (o->word_diff == diff_words_styles[i].type) {
1191                        ecbdata->diff_words->style =
1192                                &diff_words_styles[i];
1193                        break;
1194                }
1195        }
1196        if (want_color(o->use_color)) {
1197                struct diff_words_style *st = ecbdata->diff_words->style;
1198                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
1199                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
1200                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
1201        }
1202}
1203
1204static void free_diff_words_data(struct emit_callback *ecbdata)
1205{
1206        if (ecbdata->diff_words) {
1207                diff_words_flush(ecbdata);
1208                free (ecbdata->diff_words->opt);
1209                free (ecbdata->diff_words->minus.text.ptr);
1210                free (ecbdata->diff_words->minus.orig);
1211                free (ecbdata->diff_words->plus.text.ptr);
1212                free (ecbdata->diff_words->plus.orig);
1213                if (ecbdata->diff_words->word_regex) {
1214                        regfree(ecbdata->diff_words->word_regex);
1215                        free(ecbdata->diff_words->word_regex);
1216                }
1217                FREE_AND_NULL(ecbdata->diff_words);
1218        }
1219}
1220
1221const char *diff_get_color(int diff_use_color, enum color_diff ix)
1222{
1223        if (want_color(diff_use_color))
1224                return diff_colors[ix];
1225        return "";
1226}
1227
1228const char *diff_line_prefix(struct diff_options *opt)
1229{
1230        struct strbuf *msgbuf;
1231        if (!opt->output_prefix)
1232                return "";
1233
1234        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
1235        return msgbuf->buf;
1236}
1237
1238static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
1239{
1240        const char *cp;
1241        unsigned long allot;
1242        size_t l = len;
1243
1244        cp = line;
1245        allot = l;
1246        while (0 < l) {
1247                (void) utf8_width(&cp, &l);
1248                if (!cp)
1249                        break; /* truncated in the middle? */
1250        }
1251        return allot - l;
1252}
1253
1254static void find_lno(const char *line, struct emit_callback *ecbdata)
1255{
1256        const char *p;
1257        ecbdata->lno_in_preimage = 0;
1258        ecbdata->lno_in_postimage = 0;
1259        p = strchr(line, '-');
1260        if (!p)
1261                return; /* cannot happen */
1262        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1263        p = strchr(p, '+');
1264        if (!p)
1265                return; /* cannot happen */
1266        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
1267}
1268
1269static void fn_out_consume(void *priv, char *line, unsigned long len)
1270{
1271        struct emit_callback *ecbdata = priv;
1272        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
1273        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
1274        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1275        struct diff_options *o = ecbdata->opt;
1276        const char *line_prefix = diff_line_prefix(o);
1277
1278        o->found_changes = 1;
1279
1280        if (ecbdata->header) {
1281                fprintf(o->file, "%s", ecbdata->header->buf);
1282                strbuf_reset(ecbdata->header);
1283                ecbdata->header = NULL;
1284        }
1285
1286        if (ecbdata->label_path[0]) {
1287                const char *name_a_tab, *name_b_tab;
1288
1289                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
1290                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
1291
1292                fprintf(o->file, "%s%s--- %s%s%s\n",
1293                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
1294                fprintf(o->file, "%s%s+++ %s%s%s\n",
1295                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1296                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1297        }
1298
1299        if (diff_suppress_blank_empty
1300            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1301                line[0] = '\n';
1302                len = 1;
1303        }
1304
1305        if (line[0] == '@') {
1306                if (ecbdata->diff_words)
1307                        diff_words_flush(ecbdata);
1308                len = sane_truncate_line(ecbdata, line, len);
1309                find_lno(line, ecbdata);
1310                emit_hunk_header(ecbdata, line, len);
1311                if (line[len-1] != '\n')
1312                        putc('\n', o->file);
1313                return;
1314        }
1315
1316        if (ecbdata->diff_words) {
1317                if (line[0] == '-') {
1318                        diff_words_append(line, len,
1319                                          &ecbdata->diff_words->minus);
1320                        return;
1321                } else if (line[0] == '+') {
1322                        diff_words_append(line, len,
1323                                          &ecbdata->diff_words->plus);
1324                        return;
1325                } else if (starts_with(line, "\\ ")) {
1326                        /*
1327                         * Eat the "no newline at eof" marker as if we
1328                         * saw a "+" or "-" line with nothing on it,
1329                         * and return without diff_words_flush() to
1330                         * defer processing. If this is the end of
1331                         * preimage, more "+" lines may come after it.
1332                         */
1333                        return;
1334                }
1335                diff_words_flush(ecbdata);
1336                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1337                        emit_line(o, context, reset, line, len);
1338                        fputs("~\n", o->file);
1339                } else {
1340                        /*
1341                         * Skip the prefix character, if any.  With
1342                         * diff_suppress_blank_empty, there may be
1343                         * none.
1344                         */
1345                        if (line[0] != '\n') {
1346                              line++;
1347                              len--;
1348                        }
1349                        emit_line(o, context, reset, line, len);
1350                }
1351                return;
1352        }
1353
1354        switch (line[0]) {
1355        case '+':
1356                ecbdata->lno_in_postimage++;
1357                emit_add_line(reset, ecbdata, line + 1, len - 1);
1358                break;
1359        case '-':
1360                ecbdata->lno_in_preimage++;
1361                emit_del_line(reset, ecbdata, line + 1, len - 1);
1362                break;
1363        case ' ':
1364                ecbdata->lno_in_postimage++;
1365                ecbdata->lno_in_preimage++;
1366                emit_context_line(reset, ecbdata, line + 1, len - 1);
1367                break;
1368        default:
1369                /* incomplete line at the end */
1370                ecbdata->lno_in_preimage++;
1371                emit_line(o, diff_get_color(ecbdata->color_diff, DIFF_CONTEXT),
1372                          reset, line, len);
1373                break;
1374        }
1375}
1376
1377static char *pprint_rename(const char *a, const char *b)
1378{
1379        const char *old = a;
1380        const char *new = b;
1381        struct strbuf name = STRBUF_INIT;
1382        int pfx_length, sfx_length;
1383        int pfx_adjust_for_slash;
1384        int len_a = strlen(a);
1385        int len_b = strlen(b);
1386        int a_midlen, b_midlen;
1387        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1388        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1389
1390        if (qlen_a || qlen_b) {
1391                quote_c_style(a, &name, NULL, 0);
1392                strbuf_addstr(&name, " => ");
1393                quote_c_style(b, &name, NULL, 0);
1394                return strbuf_detach(&name, NULL);
1395        }
1396
1397        /* Find common prefix */
1398        pfx_length = 0;
1399        while (*old && *new && *old == *new) {
1400                if (*old == '/')
1401                        pfx_length = old - a + 1;
1402                old++;
1403                new++;
1404        }
1405
1406        /* Find common suffix */
1407        old = a + len_a;
1408        new = b + len_b;
1409        sfx_length = 0;
1410        /*
1411         * If there is a common prefix, it must end in a slash.  In
1412         * that case we let this loop run 1 into the prefix to see the
1413         * same slash.
1414         *
1415         * If there is no common prefix, we cannot do this as it would
1416         * underrun the input strings.
1417         */
1418        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
1419        while (a + pfx_length - pfx_adjust_for_slash <= old &&
1420               b + pfx_length - pfx_adjust_for_slash <= new &&
1421               *old == *new) {
1422                if (*old == '/')
1423                        sfx_length = len_a - (old - a);
1424                old--;
1425                new--;
1426        }
1427
1428        /*
1429         * pfx{mid-a => mid-b}sfx
1430         * {pfx-a => pfx-b}sfx
1431         * pfx{sfx-a => sfx-b}
1432         * name-a => name-b
1433         */
1434        a_midlen = len_a - pfx_length - sfx_length;
1435        b_midlen = len_b - pfx_length - sfx_length;
1436        if (a_midlen < 0)
1437                a_midlen = 0;
1438        if (b_midlen < 0)
1439                b_midlen = 0;
1440
1441        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1442        if (pfx_length + sfx_length) {
1443                strbuf_add(&name, a, pfx_length);
1444                strbuf_addch(&name, '{');
1445        }
1446        strbuf_add(&name, a + pfx_length, a_midlen);
1447        strbuf_addstr(&name, " => ");
1448        strbuf_add(&name, b + pfx_length, b_midlen);
1449        if (pfx_length + sfx_length) {
1450                strbuf_addch(&name, '}');
1451                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1452        }
1453        return strbuf_detach(&name, NULL);
1454}
1455
1456struct diffstat_t {
1457        int nr;
1458        int alloc;
1459        struct diffstat_file {
1460                char *from_name;
1461                char *name;
1462                char *print_name;
1463                unsigned is_unmerged:1;
1464                unsigned is_binary:1;
1465                unsigned is_renamed:1;
1466                unsigned is_interesting:1;
1467                uintmax_t added, deleted;
1468        } **files;
1469};
1470
1471static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1472                                          const char *name_a,
1473                                          const char *name_b)
1474{
1475        struct diffstat_file *x;
1476        x = xcalloc(1, sizeof(*x));
1477        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
1478        diffstat->files[diffstat->nr++] = x;
1479        if (name_b) {
1480                x->from_name = xstrdup(name_a);
1481                x->name = xstrdup(name_b);
1482                x->is_renamed = 1;
1483        }
1484        else {
1485                x->from_name = NULL;
1486                x->name = xstrdup(name_a);
1487        }
1488        return x;
1489}
1490
1491static void diffstat_consume(void *priv, char *line, unsigned long len)
1492{
1493        struct diffstat_t *diffstat = priv;
1494        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1495
1496        if (line[0] == '+')
1497                x->added++;
1498        else if (line[0] == '-')
1499                x->deleted++;
1500}
1501
1502const char mime_boundary_leader[] = "------------";
1503
1504static int scale_linear(int it, int width, int max_change)
1505{
1506        if (!it)
1507                return 0;
1508        /*
1509         * make sure that at least one '-' or '+' is printed if
1510         * there is any change to this path. The easiest way is to
1511         * scale linearly as if the alloted width is one column shorter
1512         * than it is, and then add 1 to the result.
1513         */
1514        return 1 + (it * (width - 1) / max_change);
1515}
1516
1517static void show_name(FILE *file,
1518                      const char *prefix, const char *name, int len)
1519{
1520        fprintf(file, " %s%-*s |", prefix, len, name);
1521}
1522
1523static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1524{
1525        if (cnt <= 0)
1526                return;
1527        fprintf(file, "%s", set);
1528        while (cnt--)
1529                putc(ch, file);
1530        fprintf(file, "%s", reset);
1531}
1532
1533static void fill_print_name(struct diffstat_file *file)
1534{
1535        char *pname;
1536
1537        if (file->print_name)
1538                return;
1539
1540        if (!file->is_renamed) {
1541                struct strbuf buf = STRBUF_INIT;
1542                if (quote_c_style(file->name, &buf, NULL, 0)) {
1543                        pname = strbuf_detach(&buf, NULL);
1544                } else {
1545                        pname = file->name;
1546                        strbuf_release(&buf);
1547                }
1548        } else {
1549                pname = pprint_rename(file->from_name, file->name);
1550        }
1551        file->print_name = pname;
1552}
1553
1554int print_stat_summary(FILE *fp, int files, int insertions, int deletions)
1555{
1556        struct strbuf sb = STRBUF_INIT;
1557        int ret;
1558
1559        if (!files) {
1560                assert(insertions == 0 && deletions == 0);
1561                return fprintf(fp, "%s\n", " 0 files changed");
1562        }
1563
1564        strbuf_addf(&sb,
1565                    (files == 1) ? " %d file changed" : " %d files changed",
1566                    files);
1567
1568        /*
1569         * For binary diff, the caller may want to print "x files
1570         * changed" with insertions == 0 && deletions == 0.
1571         *
1572         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
1573         * is probably less confusing (i.e skip over "2 files changed
1574         * but nothing about added/removed lines? Is this a bug in Git?").
1575         */
1576        if (insertions || deletions == 0) {
1577                strbuf_addf(&sb,
1578                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
1579                            insertions);
1580        }
1581
1582        if (deletions || insertions == 0) {
1583                strbuf_addf(&sb,
1584                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
1585                            deletions);
1586        }
1587        strbuf_addch(&sb, '\n');
1588        ret = fputs(sb.buf, fp);
1589        strbuf_release(&sb);
1590        return ret;
1591}
1592
1593static void show_stats(struct diffstat_t *data, struct diff_options *options)
1594{
1595        int i, len, add, del, adds = 0, dels = 0;
1596        uintmax_t max_change = 0, max_len = 0;
1597        int total_files = data->nr, count;
1598        int width, name_width, graph_width, number_width = 0, bin_width = 0;
1599        const char *reset, *add_c, *del_c;
1600        const char *line_prefix = "";
1601        int extra_shown = 0;
1602
1603        if (data->nr == 0)
1604                return;
1605
1606        line_prefix = diff_line_prefix(options);
1607        count = options->stat_count ? options->stat_count : data->nr;
1608
1609        reset = diff_get_color_opt(options, DIFF_RESET);
1610        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1611        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1612
1613        /*
1614         * Find the longest filename and max number of changes
1615         */
1616        for (i = 0; (i < count) && (i < data->nr); i++) {
1617                struct diffstat_file *file = data->files[i];
1618                uintmax_t change = file->added + file->deleted;
1619
1620                if (!file->is_interesting && (change == 0)) {
1621                        count++; /* not shown == room for one more */
1622                        continue;
1623                }
1624                fill_print_name(file);
1625                len = strlen(file->print_name);
1626                if (max_len < len)
1627                        max_len = len;
1628
1629                if (file->is_unmerged) {
1630                        /* "Unmerged" is 8 characters */
1631                        bin_width = bin_width < 8 ? 8 : bin_width;
1632                        continue;
1633                }
1634                if (file->is_binary) {
1635                        /* "Bin XXX -> YYY bytes" */
1636                        int w = 14 + decimal_width(file->added)
1637                                + decimal_width(file->deleted);
1638                        bin_width = bin_width < w ? w : bin_width;
1639                        /* Display change counts aligned with "Bin" */
1640                        number_width = 3;
1641                        continue;
1642                }
1643
1644                if (max_change < change)
1645                        max_change = change;
1646        }
1647        count = i; /* where we can stop scanning in data->files[] */
1648
1649        /*
1650         * We have width = stat_width or term_columns() columns total.
1651         * We want a maximum of min(max_len, stat_name_width) for the name part.
1652         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
1653         * We also need 1 for " " and 4 + decimal_width(max_change)
1654         * for " | NNNN " and one the empty column at the end, altogether
1655         * 6 + decimal_width(max_change).
1656         *
1657         * If there's not enough space, we will use the smaller of
1658         * stat_name_width (if set) and 5/8*width for the filename,
1659         * and the rest for constant elements + graph part, but no more
1660         * than stat_graph_width for the graph part.
1661         * (5/8 gives 50 for filename and 30 for the constant parts + graph
1662         * for the standard terminal size).
1663         *
1664         * In other words: stat_width limits the maximum width, and
1665         * stat_name_width fixes the maximum width of the filename,
1666         * and is also used to divide available columns if there
1667         * aren't enough.
1668         *
1669         * Binary files are displayed with "Bin XXX -> YYY bytes"
1670         * instead of the change count and graph. This part is treated
1671         * similarly to the graph part, except that it is not
1672         * "scaled". If total width is too small to accommodate the
1673         * guaranteed minimum width of the filename part and the
1674         * separators and this message, this message will "overflow"
1675         * making the line longer than the maximum width.
1676         */
1677
1678        if (options->stat_width == -1)
1679                width = term_columns() - strlen(line_prefix);
1680        else
1681                width = options->stat_width ? options->stat_width : 80;
1682        number_width = decimal_width(max_change) > number_width ?
1683                decimal_width(max_change) : number_width;
1684
1685        if (options->stat_graph_width == -1)
1686                options->stat_graph_width = diff_stat_graph_width;
1687
1688        /*
1689         * Guarantee 3/8*16==6 for the graph part
1690         * and 5/8*16==10 for the filename part
1691         */
1692        if (width < 16 + 6 + number_width)
1693                width = 16 + 6 + number_width;
1694
1695        /*
1696         * First assign sizes that are wanted, ignoring available width.
1697         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
1698         * starting from "XXX" should fit in graph_width.
1699         */
1700        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
1701        if (options->stat_graph_width &&
1702            options->stat_graph_width < graph_width)
1703                graph_width = options->stat_graph_width;
1704
1705        name_width = (options->stat_name_width > 0 &&
1706                      options->stat_name_width < max_len) ?
1707                options->stat_name_width : max_len;
1708
1709        /*
1710         * Adjust adjustable widths not to exceed maximum width
1711         */
1712        if (name_width + number_width + 6 + graph_width > width) {
1713                if (graph_width > width * 3/8 - number_width - 6) {
1714                        graph_width = width * 3/8 - number_width - 6;
1715                        if (graph_width < 6)
1716                                graph_width = 6;
1717                }
1718
1719                if (options->stat_graph_width &&
1720                    graph_width > options->stat_graph_width)
1721                        graph_width = options->stat_graph_width;
1722                if (name_width > width - number_width - 6 - graph_width)
1723                        name_width = width - number_width - 6 - graph_width;
1724                else
1725                        graph_width = width - number_width - 6 - name_width;
1726        }
1727
1728        /*
1729         * From here name_width is the width of the name area,
1730         * and graph_width is the width of the graph area.
1731         * max_change is used to scale graph properly.
1732         */
1733        for (i = 0; i < count; i++) {
1734                const char *prefix = "";
1735                struct diffstat_file *file = data->files[i];
1736                char *name = file->print_name;
1737                uintmax_t added = file->added;
1738                uintmax_t deleted = file->deleted;
1739                int name_len;
1740
1741                if (!file->is_interesting && (added + deleted == 0))
1742                        continue;
1743
1744                /*
1745                 * "scale" the filename
1746                 */
1747                len = name_width;
1748                name_len = strlen(name);
1749                if (name_width < name_len) {
1750                        char *slash;
1751                        prefix = "...";
1752                        len -= 3;
1753                        name += name_len - len;
1754                        slash = strchr(name, '/');
1755                        if (slash)
1756                                name = slash;
1757                }
1758
1759                if (file->is_binary) {
1760                        fprintf(options->file, "%s", line_prefix);
1761                        show_name(options->file, prefix, name, len);
1762                        fprintf(options->file, " %*s", number_width, "Bin");
1763                        if (!added && !deleted) {
1764                                putc('\n', options->file);
1765                                continue;
1766                        }
1767                        fprintf(options->file, " %s%"PRIuMAX"%s",
1768                                del_c, deleted, reset);
1769                        fprintf(options->file, " -> ");
1770                        fprintf(options->file, "%s%"PRIuMAX"%s",
1771                                add_c, added, reset);
1772                        fprintf(options->file, " bytes");
1773                        fprintf(options->file, "\n");
1774                        continue;
1775                }
1776                else if (file->is_unmerged) {
1777                        fprintf(options->file, "%s", line_prefix);
1778                        show_name(options->file, prefix, name, len);
1779                        fprintf(options->file, " Unmerged\n");
1780                        continue;
1781                }
1782
1783                /*
1784                 * scale the add/delete
1785                 */
1786                add = added;
1787                del = deleted;
1788
1789                if (graph_width <= max_change) {
1790                        int total = scale_linear(add + del, graph_width, max_change);
1791                        if (total < 2 && add && del)
1792                                /* width >= 2 due to the sanity check */
1793                                total = 2;
1794                        if (add < del) {
1795                                add = scale_linear(add, graph_width, max_change);
1796                                del = total - add;
1797                        } else {
1798                                del = scale_linear(del, graph_width, max_change);
1799                                add = total - del;
1800                        }
1801                }
1802                fprintf(options->file, "%s", line_prefix);
1803                show_name(options->file, prefix, name, len);
1804                fprintf(options->file, " %*"PRIuMAX"%s",
1805                        number_width, added + deleted,
1806                        added + deleted ? " " : "");
1807                show_graph(options->file, '+', add, add_c, reset);
1808                show_graph(options->file, '-', del, del_c, reset);
1809                fprintf(options->file, "\n");
1810        }
1811
1812        for (i = 0; i < data->nr; i++) {
1813                struct diffstat_file *file = data->files[i];
1814                uintmax_t added = file->added;
1815                uintmax_t deleted = file->deleted;
1816
1817                if (file->is_unmerged ||
1818                    (!file->is_interesting && (added + deleted == 0))) {
1819                        total_files--;
1820                        continue;
1821                }
1822
1823                if (!file->is_binary) {
1824                        adds += added;
1825                        dels += deleted;
1826                }
1827                if (i < count)
1828                        continue;
1829                if (!extra_shown)
1830                        fprintf(options->file, "%s ...\n", line_prefix);
1831                extra_shown = 1;
1832        }
1833        fprintf(options->file, "%s", line_prefix);
1834        print_stat_summary(options->file, total_files, adds, dels);
1835}
1836
1837static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1838{
1839        int i, adds = 0, dels = 0, total_files = data->nr;
1840
1841        if (data->nr == 0)
1842                return;
1843
1844        for (i = 0; i < data->nr; i++) {
1845                int added = data->files[i]->added;
1846                int deleted= data->files[i]->deleted;
1847
1848                if (data->files[i]->is_unmerged ||
1849                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
1850                        total_files--;
1851                } else if (!data->files[i]->is_binary) { /* don't count bytes */
1852                        adds += added;
1853                        dels += deleted;
1854                }
1855        }
1856        fprintf(options->file, "%s", diff_line_prefix(options));
1857        print_stat_summary(options->file, total_files, adds, dels);
1858}
1859
1860static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1861{
1862        int i;
1863
1864        if (data->nr == 0)
1865                return;
1866
1867        for (i = 0; i < data->nr; i++) {
1868                struct diffstat_file *file = data->files[i];
1869
1870                fprintf(options->file, "%s", diff_line_prefix(options));
1871
1872                if (file->is_binary)
1873                        fprintf(options->file, "-\t-\t");
1874                else
1875                        fprintf(options->file,
1876                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1877                                file->added, file->deleted);
1878                if (options->line_termination) {
1879                        fill_print_name(file);
1880                        if (!file->is_renamed)
1881                                write_name_quoted(file->name, options->file,
1882                                                  options->line_termination);
1883                        else {
1884                                fputs(file->print_name, options->file);
1885                                putc(options->line_termination, options->file);
1886                        }
1887                } else {
1888                        if (file->is_renamed) {
1889                                putc('\0', options->file);
1890                                write_name_quoted(file->from_name, options->file, '\0');
1891                        }
1892                        write_name_quoted(file->name, options->file, '\0');
1893                }
1894        }
1895}
1896
1897struct dirstat_file {
1898        const char *name;
1899        unsigned long changed;
1900};
1901
1902struct dirstat_dir {
1903        struct dirstat_file *files;
1904        int alloc, nr, permille, cumulative;
1905};
1906
1907static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1908                unsigned long changed, const char *base, int baselen)
1909{
1910        unsigned long this_dir = 0;
1911        unsigned int sources = 0;
1912        const char *line_prefix = diff_line_prefix(opt);
1913
1914        while (dir->nr) {
1915                struct dirstat_file *f = dir->files;
1916                int namelen = strlen(f->name);
1917                unsigned long this;
1918                char *slash;
1919
1920                if (namelen < baselen)
1921                        break;
1922                if (memcmp(f->name, base, baselen))
1923                        break;
1924                slash = strchr(f->name + baselen, '/');
1925                if (slash) {
1926                        int newbaselen = slash + 1 - f->name;
1927                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1928                        sources++;
1929                } else {
1930                        this = f->changed;
1931                        dir->files++;
1932                        dir->nr--;
1933                        sources += 2;
1934                }
1935                this_dir += this;
1936        }
1937
1938        /*
1939         * We don't report dirstat's for
1940         *  - the top level
1941         *  - or cases where everything came from a single directory
1942         *    under this directory (sources == 1).
1943         */
1944        if (baselen && sources != 1) {
1945                if (this_dir) {
1946                        int permille = this_dir * 1000 / changed;
1947                        if (permille >= dir->permille) {
1948                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1949                                        permille / 10, permille % 10, baselen, base);
1950                                if (!dir->cumulative)
1951                                        return 0;
1952                        }
1953                }
1954        }
1955        return this_dir;
1956}
1957
1958static int dirstat_compare(const void *_a, const void *_b)
1959{
1960        const struct dirstat_file *a = _a;
1961        const struct dirstat_file *b = _b;
1962        return strcmp(a->name, b->name);
1963}
1964
1965static void show_dirstat(struct diff_options *options)
1966{
1967        int i;
1968        unsigned long changed;
1969        struct dirstat_dir dir;
1970        struct diff_queue_struct *q = &diff_queued_diff;
1971
1972        dir.files = NULL;
1973        dir.alloc = 0;
1974        dir.nr = 0;
1975        dir.permille = options->dirstat_permille;
1976        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1977
1978        changed = 0;
1979        for (i = 0; i < q->nr; i++) {
1980                struct diff_filepair *p = q->queue[i];
1981                const char *name;
1982                unsigned long copied, added, damage;
1983                int content_changed;
1984
1985                name = p->two->path ? p->two->path : p->one->path;
1986
1987                if (p->one->oid_valid && p->two->oid_valid)
1988                        content_changed = oidcmp(&p->one->oid, &p->two->oid);
1989                else
1990                        content_changed = 1;
1991
1992                if (!content_changed) {
1993                        /*
1994                         * The SHA1 has not changed, so pre-/post-content is
1995                         * identical. We can therefore skip looking at the
1996                         * file contents altogether.
1997                         */
1998                        damage = 0;
1999                        goto found_damage;
2000                }
2001
2002                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
2003                        /*
2004                         * In --dirstat-by-file mode, we don't really need to
2005                         * look at the actual file contents at all.
2006                         * The fact that the SHA1 changed is enough for us to
2007                         * add this file to the list of results
2008                         * (with each file contributing equal damage).
2009                         */
2010                        damage = 1;
2011                        goto found_damage;
2012                }
2013
2014                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
2015                        diff_populate_filespec(p->one, 0);
2016                        diff_populate_filespec(p->two, 0);
2017                        diffcore_count_changes(p->one, p->two, NULL, NULL,
2018                                               &copied, &added);
2019                        diff_free_filespec_data(p->one);
2020                        diff_free_filespec_data(p->two);
2021                } else if (DIFF_FILE_VALID(p->one)) {
2022                        diff_populate_filespec(p->one, CHECK_SIZE_ONLY);
2023                        copied = added = 0;
2024                        diff_free_filespec_data(p->one);
2025                } else if (DIFF_FILE_VALID(p->two)) {
2026                        diff_populate_filespec(p->two, CHECK_SIZE_ONLY);
2027                        copied = 0;
2028                        added = p->two->size;
2029                        diff_free_filespec_data(p->two);
2030                } else
2031                        continue;
2032
2033                /*
2034                 * Original minus copied is the removed material,
2035                 * added is the new material.  They are both damages
2036                 * made to the preimage.
2037                 * If the resulting damage is zero, we know that
2038                 * diffcore_count_changes() considers the two entries to
2039                 * be identical, but since content_changed is true, we
2040                 * know that there must have been _some_ kind of change,
2041                 * so we force all entries to have damage > 0.
2042                 */
2043                damage = (p->one->size - copied) + added;
2044                if (!damage)
2045                        damage = 1;
2046
2047found_damage:
2048                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
2049                dir.files[dir.nr].name = name;
2050                dir.files[dir.nr].changed = damage;
2051                changed += damage;
2052                dir.nr++;
2053        }
2054
2055        /* This can happen even with many files, if everything was renames */
2056        if (!changed)
2057                return;
2058
2059        /* Show all directories with more than x% of the changes */
2060        QSORT(dir.files, dir.nr, dirstat_compare);
2061        gather_dirstat(options, &dir, changed, "", 0);
2062}
2063
2064static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
2065{
2066        int i;
2067        unsigned long changed;
2068        struct dirstat_dir dir;
2069
2070        if (data->nr == 0)
2071                return;
2072
2073        dir.files = NULL;
2074        dir.alloc = 0;
2075        dir.nr = 0;
2076        dir.permille = options->dirstat_permille;
2077        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
2078
2079        changed = 0;
2080        for (i = 0; i < data->nr; i++) {
2081                struct diffstat_file *file = data->files[i];
2082                unsigned long damage = file->added + file->deleted;
2083                if (file->is_binary)
2084                        /*
2085                         * binary files counts bytes, not lines. Must find some
2086                         * way to normalize binary bytes vs. textual lines.
2087                         * The following heuristic assumes that there are 64
2088                         * bytes per "line".
2089                         * This is stupid and ugly, but very cheap...
2090                         */
2091                        damage = DIV_ROUND_UP(damage, 64);
2092                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
2093                dir.files[dir.nr].name = file->name;
2094                dir.files[dir.nr].changed = damage;
2095                changed += damage;
2096                dir.nr++;
2097        }
2098
2099        /* This can happen even with many files, if everything was renames */
2100        if (!changed)
2101                return;
2102
2103        /* Show all directories with more than x% of the changes */
2104        QSORT(dir.files, dir.nr, dirstat_compare);
2105        gather_dirstat(options, &dir, changed, "", 0);
2106}
2107
2108static void free_diffstat_info(struct diffstat_t *diffstat)
2109{
2110        int i;
2111        for (i = 0; i < diffstat->nr; i++) {
2112                struct diffstat_file *f = diffstat->files[i];
2113                if (f->name != f->print_name)
2114                        free(f->print_name);
2115                free(f->name);
2116                free(f->from_name);
2117                free(f);
2118        }
2119        free(diffstat->files);
2120}
2121
2122struct checkdiff_t {
2123        const char *filename;
2124        int lineno;
2125        int conflict_marker_size;
2126        struct diff_options *o;
2127        unsigned ws_rule;
2128        unsigned status;
2129};
2130
2131static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
2132{
2133        char firstchar;
2134        int cnt;
2135
2136        if (len < marker_size + 1)
2137                return 0;
2138        firstchar = line[0];
2139        switch (firstchar) {
2140        case '=': case '>': case '<': case '|':
2141                break;
2142        default:
2143                return 0;
2144        }
2145        for (cnt = 1; cnt < marker_size; cnt++)
2146                if (line[cnt] != firstchar)
2147                        return 0;
2148        /* line[1] thru line[marker_size-1] are same as firstchar */
2149        if (len < marker_size + 1 || !isspace(line[marker_size]))
2150                return 0;
2151        return 1;
2152}
2153
2154static void checkdiff_consume(void *priv, char *line, unsigned long len)
2155{
2156        struct checkdiff_t *data = priv;
2157        int marker_size = data->conflict_marker_size;
2158        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
2159        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
2160        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
2161        char *err;
2162        const char *line_prefix;
2163
2164        assert(data->o);
2165        line_prefix = diff_line_prefix(data->o);
2166
2167        if (line[0] == '+') {
2168                unsigned bad;
2169                data->lineno++;
2170                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
2171                        data->status |= 1;
2172                        fprintf(data->o->file,
2173                                "%s%s:%d: leftover conflict marker\n",
2174                                line_prefix, data->filename, data->lineno);
2175                }
2176                bad = ws_check(line + 1, len - 1, data->ws_rule);
2177                if (!bad)
2178                        return;
2179                data->status |= bad;
2180                err = whitespace_error_string(bad);
2181                fprintf(data->o->file, "%s%s:%d: %s.\n",
2182                        line_prefix, data->filename, data->lineno, err);
2183                free(err);
2184                emit_line(data->o, set, reset, line, 1);
2185                ws_check_emit(line + 1, len - 1, data->ws_rule,
2186                              data->o->file, set, reset, ws);
2187        } else if (line[0] == ' ') {
2188                data->lineno++;
2189        } else if (line[0] == '@') {
2190                char *plus = strchr(line, '+');
2191                if (plus)
2192                        data->lineno = strtol(plus, NULL, 10) - 1;
2193                else
2194                        die("invalid diff");
2195        }
2196}
2197
2198static unsigned char *deflate_it(char *data,
2199                                 unsigned long size,
2200                                 unsigned long *result_size)
2201{
2202        int bound;
2203        unsigned char *deflated;
2204        git_zstream stream;
2205
2206        git_deflate_init(&stream, zlib_compression_level);
2207        bound = git_deflate_bound(&stream, size);
2208        deflated = xmalloc(bound);
2209        stream.next_out = deflated;
2210        stream.avail_out = bound;
2211
2212        stream.next_in = (unsigned char *)data;
2213        stream.avail_in = size;
2214        while (git_deflate(&stream, Z_FINISH) == Z_OK)
2215                ; /* nothing */
2216        git_deflate_end(&stream);
2217        *result_size = stream.total_out;
2218        return deflated;
2219}
2220
2221static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two,
2222                                  const char *prefix)
2223{
2224        void *cp;
2225        void *delta;
2226        void *deflated;
2227        void *data;
2228        unsigned long orig_size;
2229        unsigned long delta_size;
2230        unsigned long deflate_size;
2231        unsigned long data_size;
2232
2233        /* We could do deflated delta, or we could do just deflated two,
2234         * whichever is smaller.
2235         */
2236        delta = NULL;
2237        deflated = deflate_it(two->ptr, two->size, &deflate_size);
2238        if (one->size && two->size) {
2239                delta = diff_delta(one->ptr, one->size,
2240                                   two->ptr, two->size,
2241                                   &delta_size, deflate_size);
2242                if (delta) {
2243                        void *to_free = delta;
2244                        orig_size = delta_size;
2245                        delta = deflate_it(delta, delta_size, &delta_size);
2246                        free(to_free);
2247                }
2248        }
2249
2250        if (delta && delta_size < deflate_size) {
2251                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
2252                free(deflated);
2253                data = delta;
2254                data_size = delta_size;
2255        }
2256        else {
2257                fprintf(file, "%sliteral %lu\n", prefix, two->size);
2258                free(delta);
2259                data = deflated;
2260                data_size = deflate_size;
2261        }
2262
2263        /* emit data encoded in base85 */
2264        cp = data;
2265        while (data_size) {
2266                int bytes = (52 < data_size) ? 52 : data_size;
2267                char line[70];
2268                data_size -= bytes;
2269                if (bytes <= 26)
2270                        line[0] = bytes + 'A' - 1;
2271                else
2272                        line[0] = bytes - 26 + 'a' - 1;
2273                encode_85(line + 1, cp, bytes);
2274                cp = (char *) cp + bytes;
2275                fprintf(file, "%s", prefix);
2276                fputs(line, file);
2277                fputc('\n', file);
2278        }
2279        fprintf(file, "%s\n", prefix);
2280        free(data);
2281}
2282
2283static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two,
2284                             const char *prefix)
2285{
2286        fprintf(file, "%sGIT binary patch\n", prefix);
2287        emit_binary_diff_body(file, one, two, prefix);
2288        emit_binary_diff_body(file, two, one, prefix);
2289}
2290
2291int diff_filespec_is_binary(struct diff_filespec *one)
2292{
2293        if (one->is_binary == -1) {
2294                diff_filespec_load_driver(one);
2295                if (one->driver->binary != -1)
2296                        one->is_binary = one->driver->binary;
2297                else {
2298                        if (!one->data && DIFF_FILE_VALID(one))
2299                                diff_populate_filespec(one, CHECK_BINARY);
2300                        if (one->is_binary == -1 && one->data)
2301                                one->is_binary = buffer_is_binary(one->data,
2302                                                one->size);
2303                        if (one->is_binary == -1)
2304                                one->is_binary = 0;
2305                }
2306        }
2307        return one->is_binary;
2308}
2309
2310static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
2311{
2312        diff_filespec_load_driver(one);
2313        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
2314}
2315
2316void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
2317{
2318        if (!options->a_prefix)
2319                options->a_prefix = a;
2320        if (!options->b_prefix)
2321                options->b_prefix = b;
2322}
2323
2324struct userdiff_driver *get_textconv(struct diff_filespec *one)
2325{
2326        if (!DIFF_FILE_VALID(one))
2327                return NULL;
2328
2329        diff_filespec_load_driver(one);
2330        return userdiff_get_textconv(one->driver);
2331}
2332
2333static void builtin_diff(const char *name_a,
2334                         const char *name_b,
2335                         struct diff_filespec *one,
2336                         struct diff_filespec *two,
2337                         const char *xfrm_msg,
2338                         int must_show_header,
2339                         struct diff_options *o,
2340                         int complete_rewrite)
2341{
2342        mmfile_t mf1, mf2;
2343        const char *lbl[2];
2344        char *a_one, *b_two;
2345        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
2346        const char *reset = diff_get_color_opt(o, DIFF_RESET);
2347        const char *a_prefix, *b_prefix;
2348        struct userdiff_driver *textconv_one = NULL;
2349        struct userdiff_driver *textconv_two = NULL;
2350        struct strbuf header = STRBUF_INIT;
2351        const char *line_prefix = diff_line_prefix(o);
2352
2353        diff_set_mnemonic_prefix(o, "a/", "b/");
2354        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
2355                a_prefix = o->b_prefix;
2356                b_prefix = o->a_prefix;
2357        } else {
2358                a_prefix = o->a_prefix;
2359                b_prefix = o->b_prefix;
2360        }
2361
2362        if (o->submodule_format == DIFF_SUBMODULE_LOG &&
2363            (!one->mode || S_ISGITLINK(one->mode)) &&
2364            (!two->mode || S_ISGITLINK(two->mode))) {
2365                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2366                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2367                show_submodule_summary(o->file, one->path ? one->path : two->path,
2368                                line_prefix,
2369                                &one->oid, &two->oid,
2370                                two->dirty_submodule,
2371                                meta, del, add, reset);
2372                return;
2373        } else if (o->submodule_format == DIFF_SUBMODULE_INLINE_DIFF &&
2374                   (!one->mode || S_ISGITLINK(one->mode)) &&
2375                   (!two->mode || S_ISGITLINK(two->mode))) {
2376                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2377                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2378                show_submodule_inline_diff(o->file, one->path ? one->path : two->path,
2379                                line_prefix,
2380                                &one->oid, &two->oid,
2381                                two->dirty_submodule,
2382                                meta, del, add, reset, o);
2383                return;
2384        }
2385
2386        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
2387                textconv_one = get_textconv(one);
2388                textconv_two = get_textconv(two);
2389        }
2390
2391        /* Never use a non-valid filename anywhere if at all possible */
2392        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
2393        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
2394
2395        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
2396        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
2397        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
2398        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
2399        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
2400        if (lbl[0][0] == '/') {
2401                /* /dev/null */
2402                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
2403                if (xfrm_msg)
2404                        strbuf_addstr(&header, xfrm_msg);
2405                must_show_header = 1;
2406        }
2407        else if (lbl[1][0] == '/') {
2408                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
2409                if (xfrm_msg)
2410                        strbuf_addstr(&header, xfrm_msg);
2411                must_show_header = 1;
2412        }
2413        else {
2414                if (one->mode != two->mode) {
2415                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
2416                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
2417                        must_show_header = 1;
2418                }
2419                if (xfrm_msg)
2420                        strbuf_addstr(&header, xfrm_msg);
2421
2422                /*
2423                 * we do not run diff between different kind
2424                 * of objects.
2425                 */
2426                if ((one->mode ^ two->mode) & S_IFMT)
2427                        goto free_ab_and_return;
2428                if (complete_rewrite &&
2429                    (textconv_one || !diff_filespec_is_binary(one)) &&
2430                    (textconv_two || !diff_filespec_is_binary(two))) {
2431                        fprintf(o->file, "%s", header.buf);
2432                        strbuf_reset(&header);
2433                        emit_rewrite_diff(name_a, name_b, one, two,
2434                                                textconv_one, textconv_two, o);
2435                        o->found_changes = 1;
2436                        goto free_ab_and_return;
2437                }
2438        }
2439
2440        if (o->irreversible_delete && lbl[1][0] == '/') {
2441                fprintf(o->file, "%s", header.buf);
2442                strbuf_reset(&header);
2443                goto free_ab_and_return;
2444        } else if (!DIFF_OPT_TST(o, TEXT) &&
2445            ( (!textconv_one && diff_filespec_is_binary(one)) ||
2446              (!textconv_two && diff_filespec_is_binary(two)) )) {
2447                if (!one->data && !two->data &&
2448                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
2449                    !DIFF_OPT_TST(o, BINARY)) {
2450                        if (!oidcmp(&one->oid, &two->oid)) {
2451                                if (must_show_header)
2452                                        fprintf(o->file, "%s", header.buf);
2453                                goto free_ab_and_return;
2454                        }
2455                        fprintf(o->file, "%s", header.buf);
2456                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2457                                line_prefix, lbl[0], lbl[1]);
2458                        goto free_ab_and_return;
2459                }
2460                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2461                        die("unable to read files to diff");
2462                /* Quite common confusing case */
2463                if (mf1.size == mf2.size &&
2464                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2465                        if (must_show_header)
2466                                fprintf(o->file, "%s", header.buf);
2467                        goto free_ab_and_return;
2468                }
2469                fprintf(o->file, "%s", header.buf);
2470                strbuf_reset(&header);
2471                if (DIFF_OPT_TST(o, BINARY))
2472                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2473                else
2474                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2475                                line_prefix, lbl[0], lbl[1]);
2476                o->found_changes = 1;
2477        } else {
2478                /* Crazy xdl interfaces.. */
2479                const char *diffopts = getenv("GIT_DIFF_OPTS");
2480                const char *v;
2481                xpparam_t xpp;
2482                xdemitconf_t xecfg;
2483                struct emit_callback ecbdata;
2484                const struct userdiff_funcname *pe;
2485
2486                if (must_show_header) {
2487                        fprintf(o->file, "%s", header.buf);
2488                        strbuf_reset(&header);
2489                }
2490
2491                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2492                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2493
2494                pe = diff_funcname_pattern(one);
2495                if (!pe)
2496                        pe = diff_funcname_pattern(two);
2497
2498                memset(&xpp, 0, sizeof(xpp));
2499                memset(&xecfg, 0, sizeof(xecfg));
2500                memset(&ecbdata, 0, sizeof(ecbdata));
2501                ecbdata.label_path = lbl;
2502                ecbdata.color_diff = want_color(o->use_color);
2503                ecbdata.ws_rule = whitespace_rule(name_b);
2504                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2505                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2506                ecbdata.opt = o;
2507                ecbdata.header = header.len ? &header : NULL;
2508                xpp.flags = o->xdl_opts;
2509                xecfg.ctxlen = o->context;
2510                xecfg.interhunkctxlen = o->interhunkcontext;
2511                xecfg.flags = XDL_EMIT_FUNCNAMES;
2512                if (DIFF_OPT_TST(o, FUNCCONTEXT))
2513                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
2514                if (pe)
2515                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2516                if (!diffopts)
2517                        ;
2518                else if (skip_prefix(diffopts, "--unified=", &v))
2519                        xecfg.ctxlen = strtoul(v, NULL, 10);
2520                else if (skip_prefix(diffopts, "-u", &v))
2521                        xecfg.ctxlen = strtoul(v, NULL, 10);
2522                if (o->word_diff)
2523                        init_diff_words_data(&ecbdata, o, one, two);
2524                if (xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2525                                  &xpp, &xecfg))
2526                        die("unable to generate diff for %s", one->path);
2527                if (o->word_diff)
2528                        free_diff_words_data(&ecbdata);
2529                if (textconv_one)
2530                        free(mf1.ptr);
2531                if (textconv_two)
2532                        free(mf2.ptr);
2533                xdiff_clear_find_func(&xecfg);
2534        }
2535
2536 free_ab_and_return:
2537        strbuf_release(&header);
2538        diff_free_filespec_data(one);
2539        diff_free_filespec_data(two);
2540        free(a_one);
2541        free(b_two);
2542        return;
2543}
2544
2545static void builtin_diffstat(const char *name_a, const char *name_b,
2546                             struct diff_filespec *one,
2547                             struct diff_filespec *two,
2548                             struct diffstat_t *diffstat,
2549                             struct diff_options *o,
2550                             struct diff_filepair *p)
2551{
2552        mmfile_t mf1, mf2;
2553        struct diffstat_file *data;
2554        int same_contents;
2555        int complete_rewrite = 0;
2556
2557        if (!DIFF_PAIR_UNMERGED(p)) {
2558                if (p->status == DIFF_STATUS_MODIFIED && p->score)
2559                        complete_rewrite = 1;
2560        }
2561
2562        data = diffstat_add(diffstat, name_a, name_b);
2563        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
2564
2565        if (!one || !two) {
2566                data->is_unmerged = 1;
2567                return;
2568        }
2569
2570        same_contents = !oidcmp(&one->oid, &two->oid);
2571
2572        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2573                data->is_binary = 1;
2574                if (same_contents) {
2575                        data->added = 0;
2576                        data->deleted = 0;
2577                } else {
2578                        data->added = diff_filespec_size(two);
2579                        data->deleted = diff_filespec_size(one);
2580                }
2581        }
2582
2583        else if (complete_rewrite) {
2584                diff_populate_filespec(one, 0);
2585                diff_populate_filespec(two, 0);
2586                data->deleted = count_lines(one->data, one->size);
2587                data->added = count_lines(two->data, two->size);
2588        }
2589
2590        else if (!same_contents) {
2591                /* Crazy xdl interfaces.. */
2592                xpparam_t xpp;
2593                xdemitconf_t xecfg;
2594
2595                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2596                        die("unable to read files to diff");
2597
2598                memset(&xpp, 0, sizeof(xpp));
2599                memset(&xecfg, 0, sizeof(xecfg));
2600                xpp.flags = o->xdl_opts;
2601                xecfg.ctxlen = o->context;
2602                xecfg.interhunkctxlen = o->interhunkcontext;
2603                if (xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2604                                  &xpp, &xecfg))
2605                        die("unable to generate diffstat for %s", one->path);
2606        }
2607
2608        diff_free_filespec_data(one);
2609        diff_free_filespec_data(two);
2610}
2611
2612static void builtin_checkdiff(const char *name_a, const char *name_b,
2613                              const char *attr_path,
2614                              struct diff_filespec *one,
2615                              struct diff_filespec *two,
2616                              struct diff_options *o)
2617{
2618        mmfile_t mf1, mf2;
2619        struct checkdiff_t data;
2620
2621        if (!two)
2622                return;
2623
2624        memset(&data, 0, sizeof(data));
2625        data.filename = name_b ? name_b : name_a;
2626        data.lineno = 0;
2627        data.o = o;
2628        data.ws_rule = whitespace_rule(attr_path);
2629        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2630
2631        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2632                die("unable to read files to diff");
2633
2634        /*
2635         * All the other codepaths check both sides, but not checking
2636         * the "old" side here is deliberate.  We are checking the newly
2637         * introduced changes, and as long as the "new" side is text, we
2638         * can and should check what it introduces.
2639         */
2640        if (diff_filespec_is_binary(two))
2641                goto free_and_return;
2642        else {
2643                /* Crazy xdl interfaces.. */
2644                xpparam_t xpp;
2645                xdemitconf_t xecfg;
2646
2647                memset(&xpp, 0, sizeof(xpp));
2648                memset(&xecfg, 0, sizeof(xecfg));
2649                xecfg.ctxlen = 1; /* at least one context line */
2650                xpp.flags = 0;
2651                if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2652                                  &xpp, &xecfg))
2653                        die("unable to generate checkdiff for %s", one->path);
2654
2655                if (data.ws_rule & WS_BLANK_AT_EOF) {
2656                        struct emit_callback ecbdata;
2657                        int blank_at_eof;
2658
2659                        ecbdata.ws_rule = data.ws_rule;
2660                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2661                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2662
2663                        if (blank_at_eof) {
2664                                static char *err;
2665                                if (!err)
2666                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2667                                fprintf(o->file, "%s:%d: %s.\n",
2668                                        data.filename, blank_at_eof, err);
2669                                data.status = 1; /* report errors */
2670                        }
2671                }
2672        }
2673 free_and_return:
2674        diff_free_filespec_data(one);
2675        diff_free_filespec_data(two);
2676        if (data.status)
2677                DIFF_OPT_SET(o, CHECK_FAILED);
2678}
2679
2680struct diff_filespec *alloc_filespec(const char *path)
2681{
2682        struct diff_filespec *spec;
2683
2684        FLEXPTR_ALLOC_STR(spec, path, path);
2685        spec->count = 1;
2686        spec->is_binary = -1;
2687        return spec;
2688}
2689
2690void free_filespec(struct diff_filespec *spec)
2691{
2692        if (!--spec->count) {
2693                diff_free_filespec_data(spec);
2694                free(spec);
2695        }
2696}
2697
2698void fill_filespec(struct diff_filespec *spec, const struct object_id *oid,
2699                   int oid_valid, unsigned short mode)
2700{
2701        if (mode) {
2702                spec->mode = canon_mode(mode);
2703                oidcpy(&spec->oid, oid);
2704                spec->oid_valid = oid_valid;
2705        }
2706}
2707
2708/*
2709 * Given a name and sha1 pair, if the index tells us the file in
2710 * the work tree has that object contents, return true, so that
2711 * prepare_temp_file() does not have to inflate and extract.
2712 */
2713static int reuse_worktree_file(const char *name, const struct object_id *oid, int want_file)
2714{
2715        const struct cache_entry *ce;
2716        struct stat st;
2717        int pos, len;
2718
2719        /*
2720         * We do not read the cache ourselves here, because the
2721         * benchmark with my previous version that always reads cache
2722         * shows that it makes things worse for diff-tree comparing
2723         * two linux-2.6 kernel trees in an already checked out work
2724         * tree.  This is because most diff-tree comparisons deal with
2725         * only a small number of files, while reading the cache is
2726         * expensive for a large project, and its cost outweighs the
2727         * savings we get by not inflating the object to a temporary
2728         * file.  Practically, this code only helps when we are used
2729         * by diff-cache --cached, which does read the cache before
2730         * calling us.
2731         */
2732        if (!active_cache)
2733                return 0;
2734
2735        /* We want to avoid the working directory if our caller
2736         * doesn't need the data in a normal file, this system
2737         * is rather slow with its stat/open/mmap/close syscalls,
2738         * and the object is contained in a pack file.  The pack
2739         * is probably already open and will be faster to obtain
2740         * the data through than the working directory.  Loose
2741         * objects however would tend to be slower as they need
2742         * to be individually opened and inflated.
2743         */
2744        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(oid->hash))
2745                return 0;
2746
2747        /*
2748         * Similarly, if we'd have to convert the file contents anyway, that
2749         * makes the optimization not worthwhile.
2750         */
2751        if (!want_file && would_convert_to_git(&the_index, name))
2752                return 0;
2753
2754        len = strlen(name);
2755        pos = cache_name_pos(name, len);
2756        if (pos < 0)
2757                return 0;
2758        ce = active_cache[pos];
2759
2760        /*
2761         * This is not the sha1 we are looking for, or
2762         * unreusable because it is not a regular file.
2763         */
2764        if (oidcmp(oid, &ce->oid) || !S_ISREG(ce->ce_mode))
2765                return 0;
2766
2767        /*
2768         * If ce is marked as "assume unchanged", there is no
2769         * guarantee that work tree matches what we are looking for.
2770         */
2771        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2772                return 0;
2773
2774        /*
2775         * If ce matches the file in the work tree, we can reuse it.
2776         */
2777        if (ce_uptodate(ce) ||
2778            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2779                return 1;
2780
2781        return 0;
2782}
2783
2784static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2785{
2786        struct strbuf buf = STRBUF_INIT;
2787        char *dirty = "";
2788
2789        /* Are we looking at the work tree? */
2790        if (s->dirty_submodule)
2791                dirty = "-dirty";
2792
2793        strbuf_addf(&buf, "Subproject commit %s%s\n",
2794                    oid_to_hex(&s->oid), dirty);
2795        s->size = buf.len;
2796        if (size_only) {
2797                s->data = NULL;
2798                strbuf_release(&buf);
2799        } else {
2800                s->data = strbuf_detach(&buf, NULL);
2801                s->should_free = 1;
2802        }
2803        return 0;
2804}
2805
2806/*
2807 * While doing rename detection and pickaxe operation, we may need to
2808 * grab the data for the blob (or file) for our own in-core comparison.
2809 * diff_filespec has data and size fields for this purpose.
2810 */
2811int diff_populate_filespec(struct diff_filespec *s, unsigned int flags)
2812{
2813        int size_only = flags & CHECK_SIZE_ONLY;
2814        int err = 0;
2815        /*
2816         * demote FAIL to WARN to allow inspecting the situation
2817         * instead of refusing.
2818         */
2819        enum safe_crlf crlf_warn = (safe_crlf == SAFE_CRLF_FAIL
2820                                    ? SAFE_CRLF_WARN
2821                                    : safe_crlf);
2822
2823        if (!DIFF_FILE_VALID(s))
2824                die("internal error: asking to populate invalid file.");
2825        if (S_ISDIR(s->mode))
2826                return -1;
2827
2828        if (s->data)
2829                return 0;
2830
2831        if (size_only && 0 < s->size)
2832                return 0;
2833
2834        if (S_ISGITLINK(s->mode))
2835                return diff_populate_gitlink(s, size_only);
2836
2837        if (!s->oid_valid ||
2838            reuse_worktree_file(s->path, &s->oid, 0)) {
2839                struct strbuf buf = STRBUF_INIT;
2840                struct stat st;
2841                int fd;
2842
2843                if (lstat(s->path, &st) < 0) {
2844                        if (errno == ENOENT) {
2845                        err_empty:
2846                                err = -1;
2847                        empty:
2848                                s->data = (char *)"";
2849                                s->size = 0;
2850                                return err;
2851                        }
2852                }
2853                s->size = xsize_t(st.st_size);
2854                if (!s->size)
2855                        goto empty;
2856                if (S_ISLNK(st.st_mode)) {
2857                        struct strbuf sb = STRBUF_INIT;
2858
2859                        if (strbuf_readlink(&sb, s->path, s->size))
2860                                goto err_empty;
2861                        s->size = sb.len;
2862                        s->data = strbuf_detach(&sb, NULL);
2863                        s->should_free = 1;
2864                        return 0;
2865                }
2866
2867                /*
2868                 * Even if the caller would be happy with getting
2869                 * only the size, we cannot return early at this
2870                 * point if the path requires us to run the content
2871                 * conversion.
2872                 */
2873                if (size_only && !would_convert_to_git(&the_index, s->path))
2874                        return 0;
2875
2876                /*
2877                 * Note: this check uses xsize_t(st.st_size) that may
2878                 * not be the true size of the blob after it goes
2879                 * through convert_to_git().  This may not strictly be
2880                 * correct, but the whole point of big_file_threshold
2881                 * and is_binary check being that we want to avoid
2882                 * opening the file and inspecting the contents, this
2883                 * is probably fine.
2884                 */
2885                if ((flags & CHECK_BINARY) &&
2886                    s->size > big_file_threshold && s->is_binary == -1) {
2887                        s->is_binary = 1;
2888                        return 0;
2889                }
2890                fd = open(s->path, O_RDONLY);
2891                if (fd < 0)
2892                        goto err_empty;
2893                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2894                close(fd);
2895                s->should_munmap = 1;
2896
2897                /*
2898                 * Convert from working tree format to canonical git format
2899                 */
2900                if (convert_to_git(&the_index, s->path, s->data, s->size, &buf, crlf_warn)) {
2901                        size_t size = 0;
2902                        munmap(s->data, s->size);
2903                        s->should_munmap = 0;
2904                        s->data = strbuf_detach(&buf, &size);
2905                        s->size = size;
2906                        s->should_free = 1;
2907                }
2908        }
2909        else {
2910                enum object_type type;
2911                if (size_only || (flags & CHECK_BINARY)) {
2912                        type = sha1_object_info(s->oid.hash, &s->size);
2913                        if (type < 0)
2914                                die("unable to read %s",
2915                                    oid_to_hex(&s->oid));
2916                        if (size_only)
2917                                return 0;
2918                        if (s->size > big_file_threshold && s->is_binary == -1) {
2919                                s->is_binary = 1;
2920                                return 0;
2921                        }
2922                }
2923                s->data = read_sha1_file(s->oid.hash, &type, &s->size);
2924                if (!s->data)
2925                        die("unable to read %s", oid_to_hex(&s->oid));
2926                s->should_free = 1;
2927        }
2928        return 0;
2929}
2930
2931void diff_free_filespec_blob(struct diff_filespec *s)
2932{
2933        if (s->should_free)
2934                free(s->data);
2935        else if (s->should_munmap)
2936                munmap(s->data, s->size);
2937
2938        if (s->should_free || s->should_munmap) {
2939                s->should_free = s->should_munmap = 0;
2940                s->data = NULL;
2941        }
2942}
2943
2944void diff_free_filespec_data(struct diff_filespec *s)
2945{
2946        diff_free_filespec_blob(s);
2947        FREE_AND_NULL(s->cnt_data);
2948}
2949
2950static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2951                           void *blob,
2952                           unsigned long size,
2953                           const struct object_id *oid,
2954                           int mode)
2955{
2956        int fd;
2957        struct strbuf buf = STRBUF_INIT;
2958        struct strbuf template = STRBUF_INIT;
2959        char *path_dup = xstrdup(path);
2960        const char *base = basename(path_dup);
2961
2962        /* Generate "XXXXXX_basename.ext" */
2963        strbuf_addstr(&template, "XXXXXX_");
2964        strbuf_addstr(&template, base);
2965
2966        fd = mks_tempfile_ts(&temp->tempfile, template.buf, strlen(base) + 1);
2967        if (fd < 0)
2968                die_errno("unable to create temp-file");
2969        if (convert_to_working_tree(path,
2970                        (const char *)blob, (size_t)size, &buf)) {
2971                blob = buf.buf;
2972                size = buf.len;
2973        }
2974        if (write_in_full(fd, blob, size) != size)
2975                die_errno("unable to write temp-file");
2976        close_tempfile(&temp->tempfile);
2977        temp->name = get_tempfile_path(&temp->tempfile);
2978        oid_to_hex_r(temp->hex, oid);
2979        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
2980        strbuf_release(&buf);
2981        strbuf_release(&template);
2982        free(path_dup);
2983}
2984
2985static struct diff_tempfile *prepare_temp_file(const char *name,
2986                struct diff_filespec *one)
2987{
2988        struct diff_tempfile *temp = claim_diff_tempfile();
2989
2990        if (!DIFF_FILE_VALID(one)) {
2991        not_a_valid_file:
2992                /* A '-' entry produces this for file-2, and
2993                 * a '+' entry produces this for file-1.
2994                 */
2995                temp->name = "/dev/null";
2996                xsnprintf(temp->hex, sizeof(temp->hex), ".");
2997                xsnprintf(temp->mode, sizeof(temp->mode), ".");
2998                return temp;
2999        }
3000
3001        if (!S_ISGITLINK(one->mode) &&
3002            (!one->oid_valid ||
3003             reuse_worktree_file(name, &one->oid, 1))) {
3004                struct stat st;
3005                if (lstat(name, &st) < 0) {
3006                        if (errno == ENOENT)
3007                                goto not_a_valid_file;
3008                        die_errno("stat(%s)", name);
3009                }
3010                if (S_ISLNK(st.st_mode)) {
3011                        struct strbuf sb = STRBUF_INIT;
3012                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
3013                                die_errno("readlink(%s)", name);
3014                        prep_temp_blob(name, temp, sb.buf, sb.len,
3015                                       (one->oid_valid ?
3016                                        &one->oid : &null_oid),
3017                                       (one->oid_valid ?
3018                                        one->mode : S_IFLNK));
3019                        strbuf_release(&sb);
3020                }
3021                else {
3022                        /* we can borrow from the file in the work tree */
3023                        temp->name = name;
3024                        if (!one->oid_valid)
3025                                oid_to_hex_r(temp->hex, &null_oid);
3026                        else
3027                                oid_to_hex_r(temp->hex, &one->oid);
3028                        /* Even though we may sometimes borrow the
3029                         * contents from the work tree, we always want
3030                         * one->mode.  mode is trustworthy even when
3031                         * !(one->oid_valid), as long as
3032                         * DIFF_FILE_VALID(one).
3033                         */
3034                        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
3035                }
3036                return temp;
3037        }
3038        else {
3039                if (diff_populate_filespec(one, 0))
3040                        die("cannot read data blob for %s", one->path);
3041                prep_temp_blob(name, temp, one->data, one->size,
3042                               &one->oid, one->mode);
3043        }
3044        return temp;
3045}
3046
3047static void add_external_diff_name(struct argv_array *argv,
3048                                   const char *name,
3049                                   struct diff_filespec *df)
3050{
3051        struct diff_tempfile *temp = prepare_temp_file(name, df);
3052        argv_array_push(argv, temp->name);
3053        argv_array_push(argv, temp->hex);
3054        argv_array_push(argv, temp->mode);
3055}
3056
3057/* An external diff command takes:
3058 *
3059 * diff-cmd name infile1 infile1-sha1 infile1-mode \
3060 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
3061 *
3062 */
3063static void run_external_diff(const char *pgm,
3064                              const char *name,
3065                              const char *other,
3066                              struct diff_filespec *one,
3067                              struct diff_filespec *two,
3068                              const char *xfrm_msg,
3069                              int complete_rewrite,
3070                              struct diff_options *o)
3071{
3072        struct argv_array argv = ARGV_ARRAY_INIT;
3073        struct argv_array env = ARGV_ARRAY_INIT;
3074        struct diff_queue_struct *q = &diff_queued_diff;
3075
3076        argv_array_push(&argv, pgm);
3077        argv_array_push(&argv, name);
3078
3079        if (one && two) {
3080                add_external_diff_name(&argv, name, one);
3081                if (!other)
3082                        add_external_diff_name(&argv, name, two);
3083                else {
3084                        add_external_diff_name(&argv, other, two);
3085                        argv_array_push(&argv, other);
3086                        argv_array_push(&argv, xfrm_msg);
3087                }
3088        }
3089
3090        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
3091        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
3092
3093        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
3094                die(_("external diff died, stopping at %s"), name);
3095
3096        remove_tempfile();
3097        argv_array_clear(&argv);
3098        argv_array_clear(&env);
3099}
3100
3101static int similarity_index(struct diff_filepair *p)
3102{
3103        return p->score * 100 / MAX_SCORE;
3104}
3105
3106static const char *diff_abbrev_oid(const struct object_id *oid, int abbrev)
3107{
3108        if (startup_info->have_repository)
3109                return find_unique_abbrev(oid->hash, abbrev);
3110        else {
3111                char *hex = oid_to_hex(oid);
3112                if (abbrev < 0)
3113                        abbrev = FALLBACK_DEFAULT_ABBREV;
3114                if (abbrev > GIT_SHA1_HEXSZ)
3115                        die("BUG: oid abbreviation out of range: %d", abbrev);
3116                if (abbrev)
3117                        hex[abbrev] = '\0';
3118                return hex;
3119        }
3120}
3121
3122static void fill_metainfo(struct strbuf *msg,
3123                          const char *name,
3124                          const char *other,
3125                          struct diff_filespec *one,
3126                          struct diff_filespec *two,
3127                          struct diff_options *o,
3128                          struct diff_filepair *p,
3129                          int *must_show_header,
3130                          int use_color)
3131{
3132        const char *set = diff_get_color(use_color, DIFF_METAINFO);
3133        const char *reset = diff_get_color(use_color, DIFF_RESET);
3134        const char *line_prefix = diff_line_prefix(o);
3135
3136        *must_show_header = 1;
3137        strbuf_init(msg, PATH_MAX * 2 + 300);
3138        switch (p->status) {
3139        case DIFF_STATUS_COPIED:
3140                strbuf_addf(msg, "%s%ssimilarity index %d%%",
3141                            line_prefix, set, similarity_index(p));
3142                strbuf_addf(msg, "%s\n%s%scopy from ",
3143                            reset,  line_prefix, set);
3144                quote_c_style(name, msg, NULL, 0);
3145                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
3146                quote_c_style(other, msg, NULL, 0);
3147                strbuf_addf(msg, "%s\n", reset);
3148                break;
3149        case DIFF_STATUS_RENAMED:
3150                strbuf_addf(msg, "%s%ssimilarity index %d%%",
3151                            line_prefix, set, similarity_index(p));
3152                strbuf_addf(msg, "%s\n%s%srename from ",
3153                            reset, line_prefix, set);
3154                quote_c_style(name, msg, NULL, 0);
3155                strbuf_addf(msg, "%s\n%s%srename to ",
3156                            reset, line_prefix, set);
3157                quote_c_style(other, msg, NULL, 0);
3158                strbuf_addf(msg, "%s\n", reset);
3159                break;
3160        case DIFF_STATUS_MODIFIED:
3161                if (p->score) {
3162                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
3163                                    line_prefix,
3164                                    set, similarity_index(p), reset);
3165                        break;
3166                }
3167                /* fallthru */
3168        default:
3169                *must_show_header = 0;
3170        }
3171        if (one && two && oidcmp(&one->oid, &two->oid)) {
3172                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
3173
3174                if (DIFF_OPT_TST(o, BINARY)) {
3175                        mmfile_t mf;
3176                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
3177                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
3178                                abbrev = 40;
3179                }
3180                strbuf_addf(msg, "%s%sindex %s..%s", line_prefix, set,
3181                            diff_abbrev_oid(&one->oid, abbrev),
3182                            diff_abbrev_oid(&two->oid, abbrev));
3183                if (one->mode == two->mode)
3184                        strbuf_addf(msg, " %06o", one->mode);
3185                strbuf_addf(msg, "%s\n", reset);
3186        }
3187}
3188
3189static void run_diff_cmd(const char *pgm,
3190                         const char *name,
3191                         const char *other,
3192                         const char *attr_path,
3193                         struct diff_filespec *one,
3194                         struct diff_filespec *two,
3195                         struct strbuf *msg,
3196                         struct diff_options *o,
3197                         struct diff_filepair *p)
3198{
3199        const char *xfrm_msg = NULL;
3200        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
3201        int must_show_header = 0;
3202
3203
3204        if (DIFF_OPT_TST(o, ALLOW_EXTERNAL)) {
3205                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
3206                if (drv && drv->external)
3207                        pgm = drv->external;
3208        }
3209
3210        if (msg) {
3211                /*
3212                 * don't use colors when the header is intended for an
3213                 * external diff driver
3214                 */
3215                fill_metainfo(msg, name, other, one, two, o, p,
3216                              &must_show_header,
3217                              want_color(o->use_color) && !pgm);
3218                xfrm_msg = msg->len ? msg->buf : NULL;
3219        }
3220
3221        if (pgm) {
3222                run_external_diff(pgm, name, other, one, two, xfrm_msg,
3223                                  complete_rewrite, o);
3224                return;
3225        }
3226        if (one && two)
3227                builtin_diff(name, other ? other : name,
3228                             one, two, xfrm_msg, must_show_header,
3229                             o, complete_rewrite);
3230        else
3231                fprintf(o->file, "* Unmerged path %s\n", name);
3232}
3233
3234static void diff_fill_oid_info(struct diff_filespec *one)
3235{
3236        if (DIFF_FILE_VALID(one)) {
3237                if (!one->oid_valid) {
3238                        struct stat st;
3239                        if (one->is_stdin) {
3240                                oidclr(&one->oid);
3241                                return;
3242                        }
3243                        if (lstat(one->path, &st) < 0)
3244                                die_errno("stat '%s'", one->path);
3245                        if (index_path(one->oid.hash, one->path, &st, 0))
3246                                die("cannot hash %s", one->path);
3247                }
3248        }
3249        else
3250                oidclr(&one->oid);
3251}
3252
3253static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
3254{
3255        /* Strip the prefix but do not molest /dev/null and absolute paths */
3256        if (*namep && **namep != '/') {
3257                *namep += prefix_length;
3258                if (**namep == '/')
3259                        ++*namep;
3260        }
3261        if (*otherp && **otherp != '/') {
3262                *otherp += prefix_length;
3263                if (**otherp == '/')
3264                        ++*otherp;
3265        }
3266}
3267
3268static void run_diff(struct diff_filepair *p, struct diff_options *o)
3269{
3270        const char *pgm = external_diff();
3271        struct strbuf msg;
3272        struct diff_filespec *one = p->one;
3273        struct diff_filespec *two = p->two;
3274        const char *name;
3275        const char *other;
3276        const char *attr_path;
3277
3278        name  = p->one->path;
3279        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3280        attr_path = name;
3281        if (o->prefix_length)
3282                strip_prefix(o->prefix_length, &name, &other);
3283
3284        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
3285                pgm = NULL;
3286
3287        if (DIFF_PAIR_UNMERGED(p)) {
3288                run_diff_cmd(pgm, name, NULL, attr_path,
3289                             NULL, NULL, NULL, o, p);
3290                return;
3291        }
3292
3293        diff_fill_oid_info(one);
3294        diff_fill_oid_info(two);
3295
3296        if (!pgm &&
3297            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
3298            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
3299                /*
3300                 * a filepair that changes between file and symlink
3301                 * needs to be split into deletion and creation.
3302                 */
3303                struct diff_filespec *null = alloc_filespec(two->path);
3304                run_diff_cmd(NULL, name, other, attr_path,
3305                             one, null, &msg, o, p);
3306                free(null);
3307                strbuf_release(&msg);
3308
3309                null = alloc_filespec(one->path);
3310                run_diff_cmd(NULL, name, other, attr_path,
3311                             null, two, &msg, o, p);
3312                free(null);
3313        }
3314        else
3315                run_diff_cmd(pgm, name, other, attr_path,
3316                             one, two, &msg, o, p);
3317
3318        strbuf_release(&msg);
3319}
3320
3321static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
3322                         struct diffstat_t *diffstat)
3323{
3324        const char *name;
3325        const char *other;
3326
3327        if (DIFF_PAIR_UNMERGED(p)) {
3328                /* unmerged */
3329                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, p);
3330                return;
3331        }
3332
3333        name = p->one->path;
3334        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3335
3336        if (o->prefix_length)
3337                strip_prefix(o->prefix_length, &name, &other);
3338
3339        diff_fill_oid_info(p->one);
3340        diff_fill_oid_info(p->two);
3341
3342        builtin_diffstat(name, other, p->one, p->two, diffstat, o, p);
3343}
3344
3345static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
3346{
3347        const char *name;
3348        const char *other;
3349        const char *attr_path;
3350
3351        if (DIFF_PAIR_UNMERGED(p)) {
3352                /* unmerged */
3353                return;
3354        }
3355
3356        name = p->one->path;
3357        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3358        attr_path = other ? other : name;
3359
3360        if (o->prefix_length)
3361                strip_prefix(o->prefix_length, &name, &other);
3362
3363        diff_fill_oid_info(p->one);
3364        diff_fill_oid_info(p->two);
3365
3366        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
3367}
3368
3369void diff_setup(struct diff_options *options)
3370{
3371        memcpy(options, &default_diff_options, sizeof(*options));
3372
3373        options->file = stdout;
3374
3375        options->abbrev = DEFAULT_ABBREV;
3376        options->line_termination = '\n';
3377        options->break_opt = -1;
3378        options->rename_limit = -1;
3379        options->dirstat_permille = diff_dirstat_permille_default;
3380        options->context = diff_context_default;
3381        options->interhunkcontext = diff_interhunk_context_default;
3382        options->ws_error_highlight = ws_error_highlight_default;
3383        DIFF_OPT_SET(options, RENAME_EMPTY);
3384
3385        /* pathchange left =NULL by default */
3386        options->change = diff_change;
3387        options->add_remove = diff_addremove;
3388        options->use_color = diff_use_color_default;
3389        options->detect_rename = diff_detect_rename_default;
3390        options->xdl_opts |= diff_algorithm;
3391        if (diff_indent_heuristic)
3392                DIFF_XDL_SET(options, INDENT_HEURISTIC);
3393
3394        options->orderfile = diff_order_file_cfg;
3395
3396        if (diff_no_prefix) {
3397                options->a_prefix = options->b_prefix = "";
3398        } else if (!diff_mnemonic_prefix) {
3399                options->a_prefix = "a/";
3400                options->b_prefix = "b/";
3401        }
3402}
3403
3404void diff_setup_done(struct diff_options *options)
3405{
3406        int count = 0;
3407
3408        if (options->set_default)
3409                options->set_default(options);
3410
3411        if (options->output_format & DIFF_FORMAT_NAME)
3412                count++;
3413        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
3414                count++;
3415        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
3416                count++;
3417        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
3418                count++;
3419        if (count > 1)
3420                die(_("--name-only, --name-status, --check and -s are mutually exclusive"));
3421
3422        /*
3423         * Most of the time we can say "there are changes"
3424         * only by checking if there are changed paths, but
3425         * --ignore-whitespace* options force us to look
3426         * inside contents.
3427         */
3428
3429        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
3430            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
3431            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
3432                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
3433        else
3434                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
3435
3436        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3437                options->detect_rename = DIFF_DETECT_COPY;
3438
3439        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
3440                options->prefix = NULL;
3441        if (options->prefix)
3442                options->prefix_length = strlen(options->prefix);
3443        else
3444                options->prefix_length = 0;
3445
3446        if (options->output_format & (DIFF_FORMAT_NAME |
3447                                      DIFF_FORMAT_NAME_STATUS |
3448                                      DIFF_FORMAT_CHECKDIFF |
3449                                      DIFF_FORMAT_NO_OUTPUT))
3450                options->output_format &= ~(DIFF_FORMAT_RAW |
3451                                            DIFF_FORMAT_NUMSTAT |
3452                                            DIFF_FORMAT_DIFFSTAT |
3453                                            DIFF_FORMAT_SHORTSTAT |
3454                                            DIFF_FORMAT_DIRSTAT |
3455                                            DIFF_FORMAT_SUMMARY |
3456                                            DIFF_FORMAT_PATCH);
3457
3458        /*
3459         * These cases always need recursive; we do not drop caller-supplied
3460         * recursive bits for other formats here.
3461         */
3462        if (options->output_format & (DIFF_FORMAT_PATCH |
3463                                      DIFF_FORMAT_NUMSTAT |
3464                                      DIFF_FORMAT_DIFFSTAT |
3465                                      DIFF_FORMAT_SHORTSTAT |
3466                                      DIFF_FORMAT_DIRSTAT |
3467                                      DIFF_FORMAT_SUMMARY |
3468                                      DIFF_FORMAT_CHECKDIFF))
3469                DIFF_OPT_SET(options, RECURSIVE);
3470        /*
3471         * Also pickaxe would not work very well if you do not say recursive
3472         */
3473        if (options->pickaxe)
3474                DIFF_OPT_SET(options, RECURSIVE);
3475        /*
3476         * When patches are generated, submodules diffed against the work tree
3477         * must be checked for dirtiness too so it can be shown in the output
3478         */
3479        if (options->output_format & DIFF_FORMAT_PATCH)
3480                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3481
3482        if (options->detect_rename && options->rename_limit < 0)
3483                options->rename_limit = diff_rename_limit_default;
3484        if (options->setup & DIFF_SETUP_USE_CACHE) {
3485                if (!active_cache)
3486                        /* read-cache does not die even when it fails
3487                         * so it is safe for us to do this here.  Also
3488                         * it does not smudge active_cache or active_nr
3489                         * when it fails, so we do not have to worry about
3490                         * cleaning it up ourselves either.
3491                         */
3492                        read_cache();
3493        }
3494        if (40 < options->abbrev)
3495                options->abbrev = 40; /* full */
3496
3497        /*
3498         * It does not make sense to show the first hit we happened
3499         * to have found.  It does not make sense not to return with
3500         * exit code in such a case either.
3501         */
3502        if (DIFF_OPT_TST(options, QUICK)) {
3503                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3504                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3505        }
3506
3507        options->diff_path_counter = 0;
3508
3509        if (DIFF_OPT_TST(options, FOLLOW_RENAMES) && options->pathspec.nr != 1)
3510                die(_("--follow requires exactly one pathspec"));
3511}
3512
3513static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3514{
3515        char c, *eq;
3516        int len;
3517
3518        if (*arg != '-')
3519                return 0;
3520        c = *++arg;
3521        if (!c)
3522                return 0;
3523        if (c == arg_short) {
3524                c = *++arg;
3525                if (!c)
3526                        return 1;
3527                if (val && isdigit(c)) {
3528                        char *end;
3529                        int n = strtoul(arg, &end, 10);
3530                        if (*end)
3531                                return 0;
3532                        *val = n;
3533                        return 1;
3534                }
3535                return 0;
3536        }
3537        if (c != '-')
3538                return 0;
3539        arg++;
3540        eq = strchrnul(arg, '=');
3541        len = eq - arg;
3542        if (!len || strncmp(arg, arg_long, len))
3543                return 0;
3544        if (*eq) {
3545                int n;
3546                char *end;
3547                if (!isdigit(*++eq))
3548                        return 0;
3549                n = strtoul(eq, &end, 10);
3550                if (*end)
3551                        return 0;
3552                *val = n;
3553        }
3554        return 1;
3555}
3556
3557static int diff_scoreopt_parse(const char *opt);
3558
3559static inline int short_opt(char opt, const char **argv,
3560                            const char **optarg)
3561{
3562        const char *arg = argv[0];
3563        if (arg[0] != '-' || arg[1] != opt)
3564                return 0;
3565        if (arg[2] != '\0') {
3566                *optarg = arg + 2;
3567                return 1;
3568        }
3569        if (!argv[1])
3570                die("Option '%c' requires a value", opt);
3571        *optarg = argv[1];
3572        return 2;
3573}
3574
3575int parse_long_opt(const char *opt, const char **argv,
3576                   const char **optarg)
3577{
3578        const char *arg = argv[0];
3579        if (!skip_prefix(arg, "--", &arg))
3580                return 0;
3581        if (!skip_prefix(arg, opt, &arg))
3582                return 0;
3583        if (*arg == '=') { /* stuck form: --option=value */
3584                *optarg = arg + 1;
3585                return 1;
3586        }
3587        if (*arg != '\0')
3588                return 0;
3589        /* separate form: --option value */
3590        if (!argv[1])
3591                die("Option '--%s' requires a value", opt);
3592        *optarg = argv[1];
3593        return 2;
3594}
3595
3596static int stat_opt(struct diff_options *options, const char **av)
3597{
3598        const char *arg = av[0];
3599        char *end;
3600        int width = options->stat_width;
3601        int name_width = options->stat_name_width;
3602        int graph_width = options->stat_graph_width;
3603        int count = options->stat_count;
3604        int argcount = 1;
3605
3606        if (!skip_prefix(arg, "--stat", &arg))
3607                die("BUG: stat option does not begin with --stat: %s", arg);
3608        end = (char *)arg;
3609
3610        switch (*arg) {
3611        case '-':
3612                if (skip_prefix(arg, "-width", &arg)) {
3613                        if (*arg == '=')
3614                                width = strtoul(arg + 1, &end, 10);
3615                        else if (!*arg && !av[1])
3616                                die_want_option("--stat-width");
3617                        else if (!*arg) {
3618                                width = strtoul(av[1], &end, 10);
3619                                argcount = 2;
3620                        }
3621                } else if (skip_prefix(arg, "-name-width", &arg)) {
3622                        if (*arg == '=')
3623                                name_width = strtoul(arg + 1, &end, 10);
3624                        else if (!*arg && !av[1])
3625                                die_want_option("--stat-name-width");
3626                        else if (!*arg) {
3627                                name_width = strtoul(av[1], &end, 10);
3628                                argcount = 2;
3629                        }
3630                } else if (skip_prefix(arg, "-graph-width", &arg)) {
3631                        if (*arg == '=')
3632                                graph_width = strtoul(arg + 1, &end, 10);
3633                        else if (!*arg && !av[1])
3634                                die_want_option("--stat-graph-width");
3635                        else if (!*arg) {
3636                                graph_width = strtoul(av[1], &end, 10);
3637                                argcount = 2;
3638                        }
3639                } else if (skip_prefix(arg, "-count", &arg)) {
3640                        if (*arg == '=')
3641                                count = strtoul(arg + 1, &end, 10);
3642                        else if (!*arg && !av[1])
3643                                die_want_option("--stat-count");
3644                        else if (!*arg) {
3645                                count = strtoul(av[1], &end, 10);
3646                                argcount = 2;
3647                        }
3648                }
3649                break;
3650        case '=':
3651                width = strtoul(arg+1, &end, 10);
3652                if (*end == ',')
3653                        name_width = strtoul(end+1, &end, 10);
3654                if (*end == ',')
3655                        count = strtoul(end+1, &end, 10);
3656        }
3657
3658        /* Important! This checks all the error cases! */
3659        if (*end)
3660                return 0;
3661        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3662        options->stat_name_width = name_width;
3663        options->stat_graph_width = graph_width;
3664        options->stat_width = width;
3665        options->stat_count = count;
3666        return argcount;
3667}
3668
3669static int parse_dirstat_opt(struct diff_options *options, const char *params)
3670{
3671        struct strbuf errmsg = STRBUF_INIT;
3672        if (parse_dirstat_params(options, params, &errmsg))
3673                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
3674                    errmsg.buf);
3675        strbuf_release(&errmsg);
3676        /*
3677         * The caller knows a dirstat-related option is given from the command
3678         * line; allow it to say "return this_function();"
3679         */
3680        options->output_format |= DIFF_FORMAT_DIRSTAT;
3681        return 1;
3682}
3683
3684static int parse_submodule_opt(struct diff_options *options, const char *value)
3685{
3686        if (parse_submodule_params(options, value))
3687                die(_("Failed to parse --submodule option parameter: '%s'"),
3688                        value);
3689        return 1;
3690}
3691
3692static const char diff_status_letters[] = {
3693        DIFF_STATUS_ADDED,
3694        DIFF_STATUS_COPIED,
3695        DIFF_STATUS_DELETED,
3696        DIFF_STATUS_MODIFIED,
3697        DIFF_STATUS_RENAMED,
3698        DIFF_STATUS_TYPE_CHANGED,
3699        DIFF_STATUS_UNKNOWN,
3700        DIFF_STATUS_UNMERGED,
3701        DIFF_STATUS_FILTER_AON,
3702        DIFF_STATUS_FILTER_BROKEN,
3703        '\0',
3704};
3705
3706static unsigned int filter_bit['Z' + 1];
3707
3708static void prepare_filter_bits(void)
3709{
3710        int i;
3711
3712        if (!filter_bit[DIFF_STATUS_ADDED]) {
3713                for (i = 0; diff_status_letters[i]; i++)
3714                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
3715        }
3716}
3717
3718static unsigned filter_bit_tst(char status, const struct diff_options *opt)
3719{
3720        return opt->filter & filter_bit[(int) status];
3721}
3722
3723static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
3724{
3725        int i, optch;
3726
3727        prepare_filter_bits();
3728
3729        /*
3730         * If there is a negation e.g. 'd' in the input, and we haven't
3731         * initialized the filter field with another --diff-filter, start
3732         * from full set of bits, except for AON.
3733         */
3734        if (!opt->filter) {
3735                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
3736                        if (optch < 'a' || 'z' < optch)
3737                                continue;
3738                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
3739                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
3740                        break;
3741                }
3742        }
3743
3744        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
3745                unsigned int bit;
3746                int negate;
3747
3748                if ('a' <= optch && optch <= 'z') {
3749                        negate = 1;
3750                        optch = toupper(optch);
3751                } else {
3752                        negate = 0;
3753                }
3754
3755                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
3756                if (!bit)
3757                        return optarg[i];
3758                if (negate)
3759                        opt->filter &= ~bit;
3760                else
3761                        opt->filter |= bit;
3762        }
3763        return 0;
3764}
3765
3766static void enable_patch_output(int *fmt) {
3767        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
3768        *fmt |= DIFF_FORMAT_PATCH;
3769}
3770
3771static int parse_ws_error_highlight_opt(struct diff_options *opt, const char *arg)
3772{
3773        int val = parse_ws_error_highlight(arg);
3774
3775        if (val < 0) {
3776                error("unknown value after ws-error-highlight=%.*s",
3777                      -1 - val, arg);
3778                return 0;
3779        }
3780        opt->ws_error_highlight = val;
3781        return 1;
3782}
3783
3784int diff_opt_parse(struct diff_options *options,
3785                   const char **av, int ac, const char *prefix)
3786{
3787        const char *arg = av[0];
3788        const char *optarg;
3789        int argcount;
3790
3791        if (!prefix)
3792                prefix = "";
3793
3794        /* Output format options */
3795        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
3796            || opt_arg(arg, 'U', "unified", &options->context))
3797                enable_patch_output(&options->output_format);
3798        else if (!strcmp(arg, "--raw"))
3799                options->output_format |= DIFF_FORMAT_RAW;
3800        else if (!strcmp(arg, "--patch-with-raw")) {
3801                enable_patch_output(&options->output_format);
3802                options->output_format |= DIFF_FORMAT_RAW;
3803        } else if (!strcmp(arg, "--numstat"))
3804                options->output_format |= DIFF_FORMAT_NUMSTAT;
3805        else if (!strcmp(arg, "--shortstat"))
3806                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3807        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
3808                return parse_dirstat_opt(options, "");
3809        else if (skip_prefix(arg, "-X", &arg))
3810                return parse_dirstat_opt(options, arg);
3811        else if (skip_prefix(arg, "--dirstat=", &arg))
3812                return parse_dirstat_opt(options, arg);
3813        else if (!strcmp(arg, "--cumulative"))
3814                return parse_dirstat_opt(options, "cumulative");
3815        else if (!strcmp(arg, "--dirstat-by-file"))
3816                return parse_dirstat_opt(options, "files");
3817        else if (skip_prefix(arg, "--dirstat-by-file=", &arg)) {
3818                parse_dirstat_opt(options, "files");
3819                return parse_dirstat_opt(options, arg);
3820        }
3821        else if (!strcmp(arg, "--check"))
3822                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3823        else if (!strcmp(arg, "--summary"))
3824                options->output_format |= DIFF_FORMAT_SUMMARY;
3825        else if (!strcmp(arg, "--patch-with-stat")) {
3826                enable_patch_output(&options->output_format);
3827                options->output_format |= DIFF_FORMAT_DIFFSTAT;
3828        } else if (!strcmp(arg, "--name-only"))
3829                options->output_format |= DIFF_FORMAT_NAME;
3830        else if (!strcmp(arg, "--name-status"))
3831                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3832        else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
3833                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3834        else if (starts_with(arg, "--stat"))
3835                /* --stat, --stat-width, --stat-name-width, or --stat-count */
3836                return stat_opt(options, av);
3837
3838        /* renames options */
3839        else if (starts_with(arg, "-B") || starts_with(arg, "--break-rewrites=") ||
3840                 !strcmp(arg, "--break-rewrites")) {
3841                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3842                        return error("invalid argument to -B: %s", arg+2);
3843        }
3844        else if (starts_with(arg, "-M") || starts_with(arg, "--find-renames=") ||
3845                 !strcmp(arg, "--find-renames")) {
3846                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3847                        return error("invalid argument to -M: %s", arg+2);
3848                options->detect_rename = DIFF_DETECT_RENAME;
3849        }
3850        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3851                options->irreversible_delete = 1;
3852        }
3853        else if (starts_with(arg, "-C") || starts_with(arg, "--find-copies=") ||
3854                 !strcmp(arg, "--find-copies")) {
3855                if (options->detect_rename == DIFF_DETECT_COPY)
3856                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3857                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3858                        return error("invalid argument to -C: %s", arg+2);
3859                options->detect_rename = DIFF_DETECT_COPY;
3860        }
3861        else if (!strcmp(arg, "--no-renames"))
3862                options->detect_rename = 0;
3863        else if (!strcmp(arg, "--rename-empty"))
3864                DIFF_OPT_SET(options, RENAME_EMPTY);
3865        else if (!strcmp(arg, "--no-rename-empty"))
3866                DIFF_OPT_CLR(options, RENAME_EMPTY);
3867        else if (!strcmp(arg, "--relative"))
3868                DIFF_OPT_SET(options, RELATIVE_NAME);
3869        else if (skip_prefix(arg, "--relative=", &arg)) {
3870                DIFF_OPT_SET(options, RELATIVE_NAME);
3871                options->prefix = arg;
3872        }
3873
3874        /* xdiff options */
3875        else if (!strcmp(arg, "--minimal"))
3876                DIFF_XDL_SET(options, NEED_MINIMAL);
3877        else if (!strcmp(arg, "--no-minimal"))
3878                DIFF_XDL_CLR(options, NEED_MINIMAL);
3879        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3880                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3881        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3882                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3883        else if (!strcmp(arg, "--ignore-space-at-eol"))
3884                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3885        else if (!strcmp(arg, "--ignore-blank-lines"))
3886                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
3887        else if (!strcmp(arg, "--indent-heuristic"))
3888                DIFF_XDL_SET(options, INDENT_HEURISTIC);
3889        else if (!strcmp(arg, "--no-indent-heuristic"))
3890                DIFF_XDL_CLR(options, INDENT_HEURISTIC);
3891        else if (!strcmp(arg, "--patience"))
3892                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
3893        else if (!strcmp(arg, "--histogram"))
3894                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
3895        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
3896                long value = parse_algorithm_value(optarg);
3897                if (value < 0)
3898                        return error("option diff-algorithm accepts \"myers\", "
3899                                     "\"minimal\", \"patience\" and \"histogram\"");
3900                /* clear out previous settings */
3901                DIFF_XDL_CLR(options, NEED_MINIMAL);
3902                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
3903                options->xdl_opts |= value;
3904                return argcount;
3905        }
3906
3907        /* flags options */
3908        else if (!strcmp(arg, "--binary")) {
3909                enable_patch_output(&options->output_format);
3910                DIFF_OPT_SET(options, BINARY);
3911        }
3912        else if (!strcmp(arg, "--full-index"))
3913                DIFF_OPT_SET(options, FULL_INDEX);
3914        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3915                DIFF_OPT_SET(options, TEXT);
3916        else if (!strcmp(arg, "-R"))
3917                DIFF_OPT_SET(options, REVERSE_DIFF);
3918        else if (!strcmp(arg, "--find-copies-harder"))
3919                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3920        else if (!strcmp(arg, "--follow"))
3921                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3922        else if (!strcmp(arg, "--no-follow")) {
3923                DIFF_OPT_CLR(options, FOLLOW_RENAMES);
3924                DIFF_OPT_CLR(options, DEFAULT_FOLLOW_RENAMES);
3925        } else if (!strcmp(arg, "--color"))
3926                options->use_color = 1;
3927        else if (skip_prefix(arg, "--color=", &arg)) {
3928                int value = git_config_colorbool(NULL, arg);
3929                if (value < 0)
3930                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3931                options->use_color = value;
3932        }
3933        else if (!strcmp(arg, "--no-color"))
3934                options->use_color = 0;
3935        else if (!strcmp(arg, "--color-words")) {
3936                options->use_color = 1;
3937                options->word_diff = DIFF_WORDS_COLOR;
3938        }
3939        else if (skip_prefix(arg, "--color-words=", &arg)) {
3940                options->use_color = 1;
3941                options->word_diff = DIFF_WORDS_COLOR;
3942                options->word_regex = arg;
3943        }
3944        else if (!strcmp(arg, "--word-diff")) {
3945                if (options->word_diff == DIFF_WORDS_NONE)
3946                        options->word_diff = DIFF_WORDS_PLAIN;
3947        }
3948        else if (skip_prefix(arg, "--word-diff=", &arg)) {
3949                if (!strcmp(arg, "plain"))
3950                        options->word_diff = DIFF_WORDS_PLAIN;
3951                else if (!strcmp(arg, "color")) {
3952                        options->use_color = 1;
3953                        options->word_diff = DIFF_WORDS_COLOR;
3954                }
3955                else if (!strcmp(arg, "porcelain"))
3956                        options->word_diff = DIFF_WORDS_PORCELAIN;
3957                else if (!strcmp(arg, "none"))
3958                        options->word_diff = DIFF_WORDS_NONE;
3959                else
3960                        die("bad --word-diff argument: %s", arg);
3961        }
3962        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3963                if (options->word_diff == DIFF_WORDS_NONE)
3964                        options->word_diff = DIFF_WORDS_PLAIN;
3965                options->word_regex = optarg;
3966                return argcount;
3967        }
3968        else if (!strcmp(arg, "--exit-code"))
3969                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3970        else if (!strcmp(arg, "--quiet"))
3971                DIFF_OPT_SET(options, QUICK);
3972        else if (!strcmp(arg, "--ext-diff"))
3973                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3974        else if (!strcmp(arg, "--no-ext-diff"))
3975                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3976        else if (!strcmp(arg, "--textconv"))
3977                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3978        else if (!strcmp(arg, "--no-textconv"))
3979                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3980        else if (!strcmp(arg, "--ignore-submodules")) {
3981                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3982                handle_ignore_submodules_arg(options, "all");
3983        } else if (skip_prefix(arg, "--ignore-submodules=", &arg)) {
3984                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3985                handle_ignore_submodules_arg(options, arg);
3986        } else if (!strcmp(arg, "--submodule"))
3987                options->submodule_format = DIFF_SUBMODULE_LOG;
3988        else if (skip_prefix(arg, "--submodule=", &arg))
3989                return parse_submodule_opt(options, arg);
3990        else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
3991                return parse_ws_error_highlight_opt(options, arg);
3992        else if (!strcmp(arg, "--ita-invisible-in-index"))
3993                options->ita_invisible_in_index = 1;
3994        else if (!strcmp(arg, "--ita-visible-in-index"))
3995                options->ita_invisible_in_index = 0;
3996
3997        /* misc options */
3998        else if (!strcmp(arg, "-z"))
3999                options->line_termination = 0;
4000        else if ((argcount = short_opt('l', av, &optarg))) {
4001                options->rename_limit = strtoul(optarg, NULL, 10);
4002                return argcount;
4003        }
4004        else if ((argcount = short_opt('S', av, &optarg))) {
4005                options->pickaxe = optarg;
4006                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
4007                return argcount;
4008        } else if ((argcount = short_opt('G', av, &optarg))) {
4009                options->pickaxe = optarg;
4010                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
4011                return argcount;
4012        }
4013        else if (!strcmp(arg, "--pickaxe-all"))
4014                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
4015        else if (!strcmp(arg, "--pickaxe-regex"))
4016                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
4017        else if ((argcount = short_opt('O', av, &optarg))) {
4018                options->orderfile = prefix_filename(prefix, optarg);
4019                return argcount;
4020        }
4021        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
4022                int offending = parse_diff_filter_opt(optarg, options);
4023                if (offending)
4024                        die("unknown change class '%c' in --diff-filter=%s",
4025                            offending, optarg);
4026                return argcount;
4027        }
4028        else if (!strcmp(arg, "--no-abbrev"))
4029                options->abbrev = 0;
4030        else if (!strcmp(arg, "--abbrev"))
4031                options->abbrev = DEFAULT_ABBREV;
4032        else if (skip_prefix(arg, "--abbrev=", &arg)) {
4033                options->abbrev = strtoul(arg, NULL, 10);
4034                if (options->abbrev < MINIMUM_ABBREV)
4035                        options->abbrev = MINIMUM_ABBREV;
4036                else if (40 < options->abbrev)
4037                        options->abbrev = 40;
4038        }
4039        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
4040                options->a_prefix = optarg;
4041                return argcount;
4042        }
4043        else if ((argcount = parse_long_opt("line-prefix", av, &optarg))) {
4044                options->line_prefix = optarg;
4045                options->line_prefix_length = strlen(options->line_prefix);
4046                graph_setup_line_prefix(options);
4047                return argcount;
4048        }
4049        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
4050                options->b_prefix = optarg;
4051                return argcount;
4052        }
4053        else if (!strcmp(arg, "--no-prefix"))
4054                options->a_prefix = options->b_prefix = "";
4055        else if (opt_arg(arg, '\0', "inter-hunk-context",
4056                         &options->interhunkcontext))
4057                ;
4058        else if (!strcmp(arg, "-W"))
4059                DIFF_OPT_SET(options, FUNCCONTEXT);
4060        else if (!strcmp(arg, "--function-context"))
4061                DIFF_OPT_SET(options, FUNCCONTEXT);
4062        else if (!strcmp(arg, "--no-function-context"))
4063                DIFF_OPT_CLR(options, FUNCCONTEXT);
4064        else if ((argcount = parse_long_opt("output", av, &optarg))) {
4065                char *path = prefix_filename(prefix, optarg);
4066                options->file = xfopen(path, "w");
4067                options->close_file = 1;
4068                if (options->use_color != GIT_COLOR_ALWAYS)
4069                        options->use_color = GIT_COLOR_NEVER;
4070                free(path);
4071                return argcount;
4072        } else
4073                return 0;
4074        return 1;
4075}
4076
4077int parse_rename_score(const char **cp_p)
4078{
4079        unsigned long num, scale;
4080        int ch, dot;
4081        const char *cp = *cp_p;
4082
4083        num = 0;
4084        scale = 1;
4085        dot = 0;
4086        for (;;) {
4087                ch = *cp;
4088                if ( !dot && ch == '.' ) {
4089                        scale = 1;
4090                        dot = 1;
4091                } else if ( ch == '%' ) {
4092                        scale = dot ? scale*100 : 100;
4093                        cp++;   /* % is always at the end */
4094                        break;
4095                } else if ( ch >= '0' && ch <= '9' ) {
4096                        if ( scale < 100000 ) {
4097                                scale *= 10;
4098                                num = (num*10) + (ch-'0');
4099                        }
4100                } else {
4101                        break;
4102                }
4103                cp++;
4104        }
4105        *cp_p = cp;
4106
4107        /* user says num divided by scale and we say internally that
4108         * is MAX_SCORE * num / scale.
4109         */
4110        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
4111}
4112
4113static int diff_scoreopt_parse(const char *opt)
4114{
4115        int opt1, opt2, cmd;
4116
4117        if (*opt++ != '-')
4118                return -1;
4119        cmd = *opt++;
4120        if (cmd == '-') {
4121                /* convert the long-form arguments into short-form versions */
4122                if (skip_prefix(opt, "break-rewrites", &opt)) {
4123                        if (*opt == 0 || *opt++ == '=')
4124                                cmd = 'B';
4125                } else if (skip_prefix(opt, "find-copies", &opt)) {
4126                        if (*opt == 0 || *opt++ == '=')
4127                                cmd = 'C';
4128                } else if (skip_prefix(opt, "find-renames", &opt)) {
4129                        if (*opt == 0 || *opt++ == '=')
4130                                cmd = 'M';
4131                }
4132        }
4133        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
4134                return -1; /* that is not a -M, -C, or -B option */
4135
4136        opt1 = parse_rename_score(&opt);
4137        if (cmd != 'B')
4138                opt2 = 0;
4139        else {
4140                if (*opt == 0)
4141                        opt2 = 0;
4142                else if (*opt != '/')
4143                        return -1; /* we expect -B80/99 or -B80 */
4144                else {
4145                        opt++;
4146                        opt2 = parse_rename_score(&opt);
4147                }
4148        }
4149        if (*opt != 0)
4150                return -1;
4151        return opt1 | (opt2 << 16);
4152}
4153
4154struct diff_queue_struct diff_queued_diff;
4155
4156void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
4157{
4158        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
4159        queue->queue[queue->nr++] = dp;
4160}
4161
4162struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
4163                                 struct diff_filespec *one,
4164                                 struct diff_filespec *two)
4165{
4166        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
4167        dp->one = one;
4168        dp->two = two;
4169        if (queue)
4170                diff_q(queue, dp);
4171        return dp;
4172}
4173
4174void diff_free_filepair(struct diff_filepair *p)
4175{
4176        free_filespec(p->one);
4177        free_filespec(p->two);
4178        free(p);
4179}
4180
4181const char *diff_aligned_abbrev(const struct object_id *oid, int len)
4182{
4183        int abblen;
4184        const char *abbrev;
4185
4186        if (len == GIT_SHA1_HEXSZ)
4187                return oid_to_hex(oid);
4188
4189        abbrev = diff_abbrev_oid(oid, len);
4190        abblen = strlen(abbrev);
4191
4192        /*
4193         * In well-behaved cases, where the abbbreviated result is the
4194         * same as the requested length, append three dots after the
4195         * abbreviation (hence the whole logic is limited to the case
4196         * where abblen < 37); when the actual abbreviated result is a
4197         * bit longer than the requested length, we reduce the number
4198         * of dots so that they match the well-behaved ones.  However,
4199         * if the actual abbreviation is longer than the requested
4200         * length by more than three, we give up on aligning, and add
4201         * three dots anyway, to indicate that the output is not the
4202         * full object name.  Yes, this may be suboptimal, but this
4203         * appears only in "diff --raw --abbrev" output and it is not
4204         * worth the effort to change it now.  Note that this would
4205         * likely to work fine when the automatic sizing of default
4206         * abbreviation length is used--we would be fed -1 in "len" in
4207         * that case, and will end up always appending three-dots, but
4208         * the automatic sizing is supposed to give abblen that ensures
4209         * uniqueness across all objects (statistically speaking).
4210         */
4211        if (abblen < GIT_SHA1_HEXSZ - 3) {
4212                static char hex[GIT_MAX_HEXSZ + 1];
4213                if (len < abblen && abblen <= len + 2)
4214                        xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
4215                else
4216                        xsnprintf(hex, sizeof(hex), "%s...", abbrev);
4217                return hex;
4218        }
4219
4220        return oid_to_hex(oid);
4221}
4222
4223static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
4224{
4225        int line_termination = opt->line_termination;
4226        int inter_name_termination = line_termination ? '\t' : '\0';
4227
4228        fprintf(opt->file, "%s", diff_line_prefix(opt));
4229        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
4230                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
4231                        diff_aligned_abbrev(&p->one->oid, opt->abbrev));
4232                fprintf(opt->file, "%s ",
4233                        diff_aligned_abbrev(&p->two->oid, opt->abbrev));
4234        }
4235        if (p->score) {
4236                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
4237                        inter_name_termination);
4238        } else {
4239                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
4240        }
4241
4242        if (p->status == DIFF_STATUS_COPIED ||
4243            p->status == DIFF_STATUS_RENAMED) {
4244                const char *name_a, *name_b;
4245                name_a = p->one->path;
4246                name_b = p->two->path;
4247                strip_prefix(opt->prefix_length, &name_a, &name_b);
4248                write_name_quoted(name_a, opt->file, inter_name_termination);
4249                write_name_quoted(name_b, opt->file, line_termination);
4250        } else {
4251                const char *name_a, *name_b;
4252                name_a = p->one->mode ? p->one->path : p->two->path;
4253                name_b = NULL;
4254                strip_prefix(opt->prefix_length, &name_a, &name_b);
4255                write_name_quoted(name_a, opt->file, line_termination);
4256        }
4257}
4258
4259int diff_unmodified_pair(struct diff_filepair *p)
4260{
4261        /* This function is written stricter than necessary to support
4262         * the currently implemented transformers, but the idea is to
4263         * let transformers to produce diff_filepairs any way they want,
4264         * and filter and clean them up here before producing the output.
4265         */
4266        struct diff_filespec *one = p->one, *two = p->two;
4267
4268        if (DIFF_PAIR_UNMERGED(p))
4269                return 0; /* unmerged is interesting */
4270
4271        /* deletion, addition, mode or type change
4272         * and rename are all interesting.
4273         */
4274        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
4275            DIFF_PAIR_MODE_CHANGED(p) ||
4276            strcmp(one->path, two->path))
4277                return 0;
4278
4279        /* both are valid and point at the same path.  that is, we are
4280         * dealing with a change.
4281         */
4282        if (one->oid_valid && two->oid_valid &&
4283            !oidcmp(&one->oid, &two->oid) &&
4284            !one->dirty_submodule && !two->dirty_submodule)
4285                return 1; /* no change */
4286        if (!one->oid_valid && !two->oid_valid)
4287                return 1; /* both look at the same file on the filesystem. */
4288        return 0;
4289}
4290
4291static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
4292{
4293        if (diff_unmodified_pair(p))
4294                return;
4295
4296        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4297            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4298                return; /* no tree diffs in patch format */
4299
4300        run_diff(p, o);
4301}
4302
4303static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
4304                            struct diffstat_t *diffstat)
4305{
4306        if (diff_unmodified_pair(p))
4307                return;
4308
4309        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4310            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4311                return; /* no useful stat for tree diffs */
4312
4313        run_diffstat(p, o, diffstat);
4314}
4315
4316static void diff_flush_checkdiff(struct diff_filepair *p,
4317                struct diff_options *o)
4318{
4319        if (diff_unmodified_pair(p))
4320                return;
4321
4322        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4323            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4324                return; /* nothing to check in tree diffs */
4325
4326        run_checkdiff(p, o);
4327}
4328
4329int diff_queue_is_empty(void)
4330{
4331        struct diff_queue_struct *q = &diff_queued_diff;
4332        int i;
4333        for (i = 0; i < q->nr; i++)
4334                if (!diff_unmodified_pair(q->queue[i]))
4335                        return 0;
4336        return 1;
4337}
4338
4339#if DIFF_DEBUG
4340void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
4341{
4342        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
4343                x, one ? one : "",
4344                s->path,
4345                DIFF_FILE_VALID(s) ? "valid" : "invalid",
4346                s->mode,
4347                s->oid_valid ? oid_to_hex(&s->oid) : "");
4348        fprintf(stderr, "queue[%d] %s size %lu\n",
4349                x, one ? one : "",
4350                s->size);
4351}
4352
4353void diff_debug_filepair(const struct diff_filepair *p, int i)
4354{
4355        diff_debug_filespec(p->one, i, "one");
4356        diff_debug_filespec(p->two, i, "two");
4357        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
4358                p->score, p->status ? p->status : '?',
4359                p->one->rename_used, p->broken_pair);
4360}
4361
4362void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
4363{
4364        int i;
4365        if (msg)
4366                fprintf(stderr, "%s\n", msg);
4367        fprintf(stderr, "q->nr = %d\n", q->nr);
4368        for (i = 0; i < q->nr; i++) {
4369                struct diff_filepair *p = q->queue[i];
4370                diff_debug_filepair(p, i);
4371        }
4372}
4373#endif
4374
4375static void diff_resolve_rename_copy(void)
4376{
4377        int i;
4378        struct diff_filepair *p;
4379        struct diff_queue_struct *q = &diff_queued_diff;
4380
4381        diff_debug_queue("resolve-rename-copy", q);
4382
4383        for (i = 0; i < q->nr; i++) {
4384                p = q->queue[i];
4385                p->status = 0; /* undecided */
4386                if (DIFF_PAIR_UNMERGED(p))
4387                        p->status = DIFF_STATUS_UNMERGED;
4388                else if (!DIFF_FILE_VALID(p->one))
4389                        p->status = DIFF_STATUS_ADDED;
4390                else if (!DIFF_FILE_VALID(p->two))
4391                        p->status = DIFF_STATUS_DELETED;
4392                else if (DIFF_PAIR_TYPE_CHANGED(p))
4393                        p->status = DIFF_STATUS_TYPE_CHANGED;
4394
4395                /* from this point on, we are dealing with a pair
4396                 * whose both sides are valid and of the same type, i.e.
4397                 * either in-place edit or rename/copy edit.
4398                 */
4399                else if (DIFF_PAIR_RENAME(p)) {
4400                        /*
4401                         * A rename might have re-connected a broken
4402                         * pair up, causing the pathnames to be the
4403                         * same again. If so, that's not a rename at
4404                         * all, just a modification..
4405                         *
4406                         * Otherwise, see if this source was used for
4407                         * multiple renames, in which case we decrement
4408                         * the count, and call it a copy.
4409                         */
4410                        if (!strcmp(p->one->path, p->two->path))
4411                                p->status = DIFF_STATUS_MODIFIED;
4412                        else if (--p->one->rename_used > 0)
4413                                p->status = DIFF_STATUS_COPIED;
4414                        else
4415                                p->status = DIFF_STATUS_RENAMED;
4416                }
4417                else if (oidcmp(&p->one->oid, &p->two->oid) ||
4418                         p->one->mode != p->two->mode ||
4419                         p->one->dirty_submodule ||
4420                         p->two->dirty_submodule ||
4421                         is_null_oid(&p->one->oid))
4422                        p->status = DIFF_STATUS_MODIFIED;
4423                else {
4424                        /* This is a "no-change" entry and should not
4425                         * happen anymore, but prepare for broken callers.
4426                         */
4427                        error("feeding unmodified %s to diffcore",
4428                              p->one->path);
4429                        p->status = DIFF_STATUS_UNKNOWN;
4430                }
4431        }
4432        diff_debug_queue("resolve-rename-copy done", q);
4433}
4434
4435static int check_pair_status(struct diff_filepair *p)
4436{
4437        switch (p->status) {
4438        case DIFF_STATUS_UNKNOWN:
4439                return 0;
4440        case 0:
4441                die("internal error in diff-resolve-rename-copy");
4442        default:
4443                return 1;
4444        }
4445}
4446
4447static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
4448{
4449        int fmt = opt->output_format;
4450
4451        if (fmt & DIFF_FORMAT_CHECKDIFF)
4452                diff_flush_checkdiff(p, opt);
4453        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
4454                diff_flush_raw(p, opt);
4455        else if (fmt & DIFF_FORMAT_NAME) {
4456                const char *name_a, *name_b;
4457                name_a = p->two->path;
4458                name_b = NULL;
4459                strip_prefix(opt->prefix_length, &name_a, &name_b);
4460                fprintf(opt->file, "%s", diff_line_prefix(opt));
4461                write_name_quoted(name_a, opt->file, opt->line_termination);
4462        }
4463}
4464
4465static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
4466{
4467        if (fs->mode)
4468                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
4469        else
4470                fprintf(file, " %s ", newdelete);
4471        write_name_quoted(fs->path, file, '\n');
4472}
4473
4474
4475static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
4476                const char *line_prefix)
4477{
4478        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
4479                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
4480                        p->two->mode, show_name ? ' ' : '\n');
4481                if (show_name) {
4482                        write_name_quoted(p->two->path, file, '\n');
4483                }
4484        }
4485}
4486
4487static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
4488                        const char *line_prefix)
4489{
4490        char *names = pprint_rename(p->one->path, p->two->path);
4491
4492        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
4493        free(names);
4494        show_mode_change(file, p, 0, line_prefix);
4495}
4496
4497static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
4498{
4499        FILE *file = opt->file;
4500        const char *line_prefix = diff_line_prefix(opt);
4501
4502        switch(p->status) {
4503        case DIFF_STATUS_DELETED:
4504                fputs(line_prefix, file);
4505                show_file_mode_name(file, "delete", p->one);
4506                break;
4507        case DIFF_STATUS_ADDED:
4508                fputs(line_prefix, file);
4509                show_file_mode_name(file, "create", p->two);
4510                break;
4511        case DIFF_STATUS_COPIED:
4512                fputs(line_prefix, file);
4513                show_rename_copy(file, "copy", p, line_prefix);
4514                break;
4515        case DIFF_STATUS_RENAMED:
4516                fputs(line_prefix, file);
4517                show_rename_copy(file, "rename", p, line_prefix);
4518                break;
4519        default:
4520                if (p->score) {
4521                        fprintf(file, "%s rewrite ", line_prefix);
4522                        write_name_quoted(p->two->path, file, ' ');
4523                        fprintf(file, "(%d%%)\n", similarity_index(p));
4524                }
4525                show_mode_change(file, p, !p->score, line_prefix);
4526                break;
4527        }
4528}
4529
4530struct patch_id_t {
4531        git_SHA_CTX *ctx;
4532        int patchlen;
4533};
4534
4535static int remove_space(char *line, int len)
4536{
4537        int i;
4538        char *dst = line;
4539        unsigned char c;
4540
4541        for (i = 0; i < len; i++)
4542                if (!isspace((c = line[i])))
4543                        *dst++ = c;
4544
4545        return dst - line;
4546}
4547
4548static void patch_id_consume(void *priv, char *line, unsigned long len)
4549{
4550        struct patch_id_t *data = priv;
4551        int new_len;
4552
4553        /* Ignore line numbers when computing the SHA1 of the patch */
4554        if (starts_with(line, "@@ -"))
4555                return;
4556
4557        new_len = remove_space(line, len);
4558
4559        git_SHA1_Update(data->ctx, line, new_len);
4560        data->patchlen += new_len;
4561}
4562
4563static void patch_id_add_string(git_SHA_CTX *ctx, const char *str)
4564{
4565        git_SHA1_Update(ctx, str, strlen(str));
4566}
4567
4568static void patch_id_add_mode(git_SHA_CTX *ctx, unsigned mode)
4569{
4570        /* large enough for 2^32 in octal */
4571        char buf[12];
4572        int len = xsnprintf(buf, sizeof(buf), "%06o", mode);
4573        git_SHA1_Update(ctx, buf, len);
4574}
4575
4576/* returns 0 upon success, and writes result into sha1 */
4577static int diff_get_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
4578{
4579        struct diff_queue_struct *q = &diff_queued_diff;
4580        int i;
4581        git_SHA_CTX ctx;
4582        struct patch_id_t data;
4583
4584        git_SHA1_Init(&ctx);
4585        memset(&data, 0, sizeof(struct patch_id_t));
4586        data.ctx = &ctx;
4587
4588        for (i = 0; i < q->nr; i++) {
4589                xpparam_t xpp;
4590                xdemitconf_t xecfg;
4591                mmfile_t mf1, mf2;
4592                struct diff_filepair *p = q->queue[i];
4593                int len1, len2;
4594
4595                memset(&xpp, 0, sizeof(xpp));
4596                memset(&xecfg, 0, sizeof(xecfg));
4597                if (p->status == 0)
4598                        return error("internal diff status error");
4599                if (p->status == DIFF_STATUS_UNKNOWN)
4600                        continue;
4601                if (diff_unmodified_pair(p))
4602                        continue;
4603                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4604                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4605                        continue;
4606                if (DIFF_PAIR_UNMERGED(p))
4607                        continue;
4608
4609                diff_fill_oid_info(p->one);
4610                diff_fill_oid_info(p->two);
4611
4612                len1 = remove_space(p->one->path, strlen(p->one->path));
4613                len2 = remove_space(p->two->path, strlen(p->two->path));
4614                patch_id_add_string(&ctx, "diff--git");
4615                patch_id_add_string(&ctx, "a/");
4616                git_SHA1_Update(&ctx, p->one->path, len1);
4617                patch_id_add_string(&ctx, "b/");
4618                git_SHA1_Update(&ctx, p->two->path, len2);
4619
4620                if (p->one->mode == 0) {
4621                        patch_id_add_string(&ctx, "newfilemode");
4622                        patch_id_add_mode(&ctx, p->two->mode);
4623                        patch_id_add_string(&ctx, "---/dev/null");
4624                        patch_id_add_string(&ctx, "+++b/");
4625                        git_SHA1_Update(&ctx, p->two->path, len2);
4626                } else if (p->two->mode == 0) {
4627                        patch_id_add_string(&ctx, "deletedfilemode");
4628                        patch_id_add_mode(&ctx, p->one->mode);
4629                        patch_id_add_string(&ctx, "---a/");
4630                        git_SHA1_Update(&ctx, p->one->path, len1);
4631                        patch_id_add_string(&ctx, "+++/dev/null");
4632                } else {
4633                        patch_id_add_string(&ctx, "---a/");
4634                        git_SHA1_Update(&ctx, p->one->path, len1);
4635                        patch_id_add_string(&ctx, "+++b/");
4636                        git_SHA1_Update(&ctx, p->two->path, len2);
4637                }
4638
4639                if (diff_header_only)
4640                        continue;
4641
4642                if (fill_mmfile(&mf1, p->one) < 0 ||
4643                    fill_mmfile(&mf2, p->two) < 0)
4644                        return error("unable to read files to diff");
4645
4646                if (diff_filespec_is_binary(p->one) ||
4647                    diff_filespec_is_binary(p->two)) {
4648                        git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
4649                                        GIT_SHA1_HEXSZ);
4650                        git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
4651                                        GIT_SHA1_HEXSZ);
4652                        continue;
4653                }
4654
4655                xpp.flags = 0;
4656                xecfg.ctxlen = 3;
4657                xecfg.flags = 0;
4658                if (xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4659                                  &xpp, &xecfg))
4660                        return error("unable to generate patch-id diff for %s",
4661                                     p->one->path);
4662        }
4663
4664        git_SHA1_Final(oid->hash, &ctx);
4665        return 0;
4666}
4667
4668int diff_flush_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        int result = diff_get_patch_id(options, oid, diff_header_only);
4673
4674        for (i = 0; i < q->nr; i++)
4675                diff_free_filepair(q->queue[i]);
4676
4677        free(q->queue);
4678        DIFF_QUEUE_CLEAR(q);
4679
4680        return result;
4681}
4682
4683static int is_summary_empty(const struct diff_queue_struct *q)
4684{
4685        int i;
4686
4687        for (i = 0; i < q->nr; i++) {
4688                const struct diff_filepair *p = q->queue[i];
4689
4690                switch (p->status) {
4691                case DIFF_STATUS_DELETED:
4692                case DIFF_STATUS_ADDED:
4693                case DIFF_STATUS_COPIED:
4694                case DIFF_STATUS_RENAMED:
4695                        return 0;
4696                default:
4697                        if (p->score)
4698                                return 0;
4699                        if (p->one->mode && p->two->mode &&
4700                            p->one->mode != p->two->mode)
4701                                return 0;
4702                        break;
4703                }
4704        }
4705        return 1;
4706}
4707
4708static const char rename_limit_warning[] =
4709N_("inexact rename detection was skipped due to too many files.");
4710
4711static const char degrade_cc_to_c_warning[] =
4712N_("only found copies from modified paths due to too many files.");
4713
4714static const char rename_limit_advice[] =
4715N_("you may want to set your %s variable to at least "
4716   "%d and retry the command.");
4717
4718void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4719{
4720        if (degraded_cc)
4721                warning(_(degrade_cc_to_c_warning));
4722        else if (needed)
4723                warning(_(rename_limit_warning));
4724        else
4725                return;
4726        if (0 < needed && needed < 32767)
4727                warning(_(rename_limit_advice), varname, needed);
4728}
4729
4730void diff_flush(struct diff_options *options)
4731{
4732        struct diff_queue_struct *q = &diff_queued_diff;
4733        int i, output_format = options->output_format;
4734        int separator = 0;
4735        int dirstat_by_line = 0;
4736
4737        /*
4738         * Order: raw, stat, summary, patch
4739         * or:    name/name-status/checkdiff (other bits clear)
4740         */
4741        if (!q->nr)
4742                goto free_queue;
4743
4744        if (output_format & (DIFF_FORMAT_RAW |
4745                             DIFF_FORMAT_NAME |
4746                             DIFF_FORMAT_NAME_STATUS |
4747                             DIFF_FORMAT_CHECKDIFF)) {
4748                for (i = 0; i < q->nr; i++) {
4749                        struct diff_filepair *p = q->queue[i];
4750                        if (check_pair_status(p))
4751                                flush_one_pair(p, options);
4752                }
4753                separator++;
4754        }
4755
4756        if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
4757                dirstat_by_line = 1;
4758
4759        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
4760            dirstat_by_line) {
4761                struct diffstat_t diffstat;
4762
4763                memset(&diffstat, 0, sizeof(struct diffstat_t));
4764                for (i = 0; i < q->nr; i++) {
4765                        struct diff_filepair *p = q->queue[i];
4766                        if (check_pair_status(p))
4767                                diff_flush_stat(p, options, &diffstat);
4768                }
4769                if (output_format & DIFF_FORMAT_NUMSTAT)
4770                        show_numstat(&diffstat, options);
4771                if (output_format & DIFF_FORMAT_DIFFSTAT)
4772                        show_stats(&diffstat, options);
4773                if (output_format & DIFF_FORMAT_SHORTSTAT)
4774                        show_shortstats(&diffstat, options);
4775                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
4776                        show_dirstat_by_line(&diffstat, options);
4777                free_diffstat_info(&diffstat);
4778                separator++;
4779        }
4780        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
4781                show_dirstat(options);
4782
4783        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4784                for (i = 0; i < q->nr; i++) {
4785                        diff_summary(options, q->queue[i]);
4786                }
4787                separator++;
4788        }
4789
4790        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4791            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4792            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4793                /*
4794                 * run diff_flush_patch for the exit status. setting
4795                 * options->file to /dev/null should be safe, because we
4796                 * aren't supposed to produce any output anyway.
4797                 */
4798                if (options->close_file)
4799                        fclose(options->file);
4800                options->file = xfopen("/dev/null", "w");
4801                options->close_file = 1;
4802                for (i = 0; i < q->nr; i++) {
4803                        struct diff_filepair *p = q->queue[i];
4804                        if (check_pair_status(p))
4805                                diff_flush_patch(p, options);
4806                        if (options->found_changes)
4807                                break;
4808                }
4809        }
4810
4811        if (output_format & DIFF_FORMAT_PATCH) {
4812                if (separator) {
4813                        fprintf(options->file, "%s%c",
4814                                diff_line_prefix(options),
4815                                options->line_termination);
4816                        if (options->stat_sep) {
4817                                /* attach patch instead of inline */
4818                                fputs(options->stat_sep, options->file);
4819                        }
4820                }
4821
4822                for (i = 0; i < q->nr; i++) {
4823                        struct diff_filepair *p = q->queue[i];
4824                        if (check_pair_status(p))
4825                                diff_flush_patch(p, options);
4826                }
4827        }
4828
4829        if (output_format & DIFF_FORMAT_CALLBACK)
4830                options->format_callback(q, options, options->format_callback_data);
4831
4832        for (i = 0; i < q->nr; i++)
4833                diff_free_filepair(q->queue[i]);
4834free_queue:
4835        free(q->queue);
4836        DIFF_QUEUE_CLEAR(q);
4837        if (options->close_file)
4838                fclose(options->file);
4839
4840        /*
4841         * Report the content-level differences with HAS_CHANGES;
4842         * diff_addremove/diff_change does not set the bit when
4843         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4844         */
4845        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4846                if (options->found_changes)
4847                        DIFF_OPT_SET(options, HAS_CHANGES);
4848                else
4849                        DIFF_OPT_CLR(options, HAS_CHANGES);
4850        }
4851}
4852
4853static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
4854{
4855        return (((p->status == DIFF_STATUS_MODIFIED) &&
4856                 ((p->score &&
4857                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
4858                  (!p->score &&
4859                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
4860                ((p->status != DIFF_STATUS_MODIFIED) &&
4861                 filter_bit_tst(p->status, options)));
4862}
4863
4864static void diffcore_apply_filter(struct diff_options *options)
4865{
4866        int i;
4867        struct diff_queue_struct *q = &diff_queued_diff;
4868        struct diff_queue_struct outq;
4869
4870        DIFF_QUEUE_CLEAR(&outq);
4871
4872        if (!options->filter)
4873                return;
4874
4875        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
4876                int found;
4877                for (i = found = 0; !found && i < q->nr; i++) {
4878                        if (match_filter(options, q->queue[i]))
4879                                found++;
4880                }
4881                if (found)
4882                        return;
4883
4884                /* otherwise we will clear the whole queue
4885                 * by copying the empty outq at the end of this
4886                 * function, but first clear the current entries
4887                 * in the queue.
4888                 */
4889                for (i = 0; i < q->nr; i++)
4890                        diff_free_filepair(q->queue[i]);
4891        }
4892        else {
4893                /* Only the matching ones */
4894                for (i = 0; i < q->nr; i++) {
4895                        struct diff_filepair *p = q->queue[i];
4896                        if (match_filter(options, p))
4897                                diff_q(&outq, p);
4898                        else
4899                                diff_free_filepair(p);
4900                }
4901        }
4902        free(q->queue);
4903        *q = outq;
4904}
4905
4906/* Check whether two filespecs with the same mode and size are identical */
4907static int diff_filespec_is_identical(struct diff_filespec *one,
4908                                      struct diff_filespec *two)
4909{
4910        if (S_ISGITLINK(one->mode))
4911                return 0;
4912        if (diff_populate_filespec(one, 0))
4913                return 0;
4914        if (diff_populate_filespec(two, 0))
4915                return 0;
4916        return !memcmp(one->data, two->data, one->size);
4917}
4918
4919static int diff_filespec_check_stat_unmatch(struct diff_filepair *p)
4920{
4921        if (p->done_skip_stat_unmatch)
4922                return p->skip_stat_unmatch_result;
4923
4924        p->done_skip_stat_unmatch = 1;
4925        p->skip_stat_unmatch_result = 0;
4926        /*
4927         * 1. Entries that come from stat info dirtiness
4928         *    always have both sides (iow, not create/delete),
4929         *    one side of the object name is unknown, with
4930         *    the same mode and size.  Keep the ones that
4931         *    do not match these criteria.  They have real
4932         *    differences.
4933         *
4934         * 2. At this point, the file is known to be modified,
4935         *    with the same mode and size, and the object
4936         *    name of one side is unknown.  Need to inspect
4937         *    the identical contents.
4938         */
4939        if (!DIFF_FILE_VALID(p->one) || /* (1) */
4940            !DIFF_FILE_VALID(p->two) ||
4941            (p->one->oid_valid && p->two->oid_valid) ||
4942            (p->one->mode != p->two->mode) ||
4943            diff_populate_filespec(p->one, CHECK_SIZE_ONLY) ||
4944            diff_populate_filespec(p->two, CHECK_SIZE_ONLY) ||
4945            (p->one->size != p->two->size) ||
4946            !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4947                p->skip_stat_unmatch_result = 1;
4948        return p->skip_stat_unmatch_result;
4949}
4950
4951static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4952{
4953        int i;
4954        struct diff_queue_struct *q = &diff_queued_diff;
4955        struct diff_queue_struct outq;
4956        DIFF_QUEUE_CLEAR(&outq);
4957
4958        for (i = 0; i < q->nr; i++) {
4959                struct diff_filepair *p = q->queue[i];
4960
4961                if (diff_filespec_check_stat_unmatch(p))
4962                        diff_q(&outq, p);
4963                else {
4964                        /*
4965                         * The caller can subtract 1 from skip_stat_unmatch
4966                         * to determine how many paths were dirty only
4967                         * due to stat info mismatch.
4968                         */
4969                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4970                                diffopt->skip_stat_unmatch++;
4971                        diff_free_filepair(p);
4972                }
4973        }
4974        free(q->queue);
4975        *q = outq;
4976}
4977
4978static int diffnamecmp(const void *a_, const void *b_)
4979{
4980        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4981        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4982        const char *name_a, *name_b;
4983
4984        name_a = a->one ? a->one->path : a->two->path;
4985        name_b = b->one ? b->one->path : b->two->path;
4986        return strcmp(name_a, name_b);
4987}
4988
4989void diffcore_fix_diff_index(struct diff_options *options)
4990{
4991        struct diff_queue_struct *q = &diff_queued_diff;
4992        QSORT(q->queue, q->nr, diffnamecmp);
4993}
4994
4995void diffcore_std(struct diff_options *options)
4996{
4997        /* NOTE please keep the following in sync with diff_tree_combined() */
4998        if (options->skip_stat_unmatch)
4999                diffcore_skip_stat_unmatch(options);
5000        if (!options->found_follow) {
5001                /* See try_to_follow_renames() in tree-diff.c */
5002                if (options->break_opt != -1)
5003                        diffcore_break(options->break_opt);
5004                if (options->detect_rename)
5005                        diffcore_rename(options);
5006                if (options->break_opt != -1)
5007                        diffcore_merge_broken();
5008        }
5009        if (options->pickaxe)
5010                diffcore_pickaxe(options);
5011        if (options->orderfile)
5012                diffcore_order(options->orderfile);
5013        if (!options->found_follow)
5014                /* See try_to_follow_renames() in tree-diff.c */
5015                diff_resolve_rename_copy();
5016        diffcore_apply_filter(options);
5017
5018        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
5019                DIFF_OPT_SET(options, HAS_CHANGES);
5020        else
5021                DIFF_OPT_CLR(options, HAS_CHANGES);
5022
5023        options->found_follow = 0;
5024}
5025
5026int diff_result_code(struct diff_options *opt, int status)
5027{
5028        int result = 0;
5029
5030        diff_warn_rename_limit("diff.renameLimit",
5031                               opt->needed_rename_limit,
5032                               opt->degraded_cc_to_c);
5033        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
5034            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
5035                return status;
5036        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
5037            DIFF_OPT_TST(opt, HAS_CHANGES))
5038                result |= 01;
5039        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
5040            DIFF_OPT_TST(opt, CHECK_FAILED))
5041                result |= 02;
5042        return result;
5043}
5044
5045int diff_can_quit_early(struct diff_options *opt)
5046{
5047        return (DIFF_OPT_TST(opt, QUICK) &&
5048                !opt->filter &&
5049                DIFF_OPT_TST(opt, HAS_CHANGES));
5050}
5051
5052/*
5053 * Shall changes to this submodule be ignored?
5054 *
5055 * Submodule changes can be configured to be ignored separately for each path,
5056 * but that configuration can be overridden from the command line.
5057 */
5058static int is_submodule_ignored(const char *path, struct diff_options *options)
5059{
5060        int ignored = 0;
5061        unsigned orig_flags = options->flags;
5062        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
5063                set_diffopt_flags_from_submodule_config(options, path);
5064        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
5065                ignored = 1;
5066        options->flags = orig_flags;
5067        return ignored;
5068}
5069
5070void diff_addremove(struct diff_options *options,
5071                    int addremove, unsigned mode,
5072                    const struct object_id *oid,
5073                    int oid_valid,
5074                    const char *concatpath, unsigned dirty_submodule)
5075{
5076        struct diff_filespec *one, *two;
5077
5078        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
5079                return;
5080
5081        /* This may look odd, but it is a preparation for
5082         * feeding "there are unchanged files which should
5083         * not produce diffs, but when you are doing copy
5084         * detection you would need them, so here they are"
5085         * entries to the diff-core.  They will be prefixed
5086         * with something like '=' or '*' (I haven't decided
5087         * which but should not make any difference).
5088         * Feeding the same new and old to diff_change()
5089         * also has the same effect.
5090         * Before the final output happens, they are pruned after
5091         * merged into rename/copy pairs as appropriate.
5092         */
5093        if (DIFF_OPT_TST(options, REVERSE_DIFF))
5094                addremove = (addremove == '+' ? '-' :
5095                             addremove == '-' ? '+' : addremove);
5096
5097        if (options->prefix &&
5098            strncmp(concatpath, options->prefix, options->prefix_length))
5099                return;
5100
5101        one = alloc_filespec(concatpath);
5102        two = alloc_filespec(concatpath);
5103
5104        if (addremove != '+')
5105                fill_filespec(one, oid, oid_valid, mode);
5106        if (addremove != '-') {
5107                fill_filespec(two, oid, oid_valid, mode);
5108                two->dirty_submodule = dirty_submodule;
5109        }
5110
5111        diff_queue(&diff_queued_diff, one, two);
5112        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
5113                DIFF_OPT_SET(options, HAS_CHANGES);
5114}
5115
5116void diff_change(struct diff_options *options,
5117                 unsigned old_mode, unsigned new_mode,
5118                 const struct object_id *old_oid,
5119                 const struct object_id *new_oid,
5120                 int old_oid_valid, int new_oid_valid,
5121                 const char *concatpath,
5122                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
5123{
5124        struct diff_filespec *one, *two;
5125        struct diff_filepair *p;
5126
5127        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
5128            is_submodule_ignored(concatpath, options))
5129                return;
5130
5131        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
5132                SWAP(old_mode, new_mode);
5133                SWAP(old_oid, new_oid);
5134                SWAP(old_oid_valid, new_oid_valid);
5135                SWAP(old_dirty_submodule, new_dirty_submodule);
5136        }
5137
5138        if (options->prefix &&
5139            strncmp(concatpath, options->prefix, options->prefix_length))
5140                return;
5141
5142        one = alloc_filespec(concatpath);
5143        two = alloc_filespec(concatpath);
5144        fill_filespec(one, old_oid, old_oid_valid, old_mode);
5145        fill_filespec(two, new_oid, new_oid_valid, new_mode);
5146        one->dirty_submodule = old_dirty_submodule;
5147        two->dirty_submodule = new_dirty_submodule;
5148        p = diff_queue(&diff_queued_diff, one, two);
5149
5150        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
5151                return;
5152
5153        if (DIFF_OPT_TST(options, QUICK) && options->skip_stat_unmatch &&
5154            !diff_filespec_check_stat_unmatch(p))
5155                return;
5156
5157        DIFF_OPT_SET(options, HAS_CHANGES);
5158}
5159
5160struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
5161{
5162        struct diff_filepair *pair;
5163        struct diff_filespec *one, *two;
5164
5165        if (options->prefix &&
5166            strncmp(path, options->prefix, options->prefix_length))
5167                return NULL;
5168
5169        one = alloc_filespec(path);
5170        two = alloc_filespec(path);
5171        pair = diff_queue(&diff_queued_diff, one, two);
5172        pair->is_unmerged = 1;
5173        return pair;
5174}
5175
5176static char *run_textconv(const char *pgm, struct diff_filespec *spec,
5177                size_t *outsize)
5178{
5179        struct diff_tempfile *temp;
5180        const char *argv[3];
5181        const char **arg = argv;
5182        struct child_process child = CHILD_PROCESS_INIT;
5183        struct strbuf buf = STRBUF_INIT;
5184        int err = 0;
5185
5186        temp = prepare_temp_file(spec->path, spec);
5187        *arg++ = pgm;
5188        *arg++ = temp->name;
5189        *arg = NULL;
5190
5191        child.use_shell = 1;
5192        child.argv = argv;
5193        child.out = -1;
5194        if (start_command(&child)) {
5195                remove_tempfile();
5196                return NULL;
5197        }
5198
5199        if (strbuf_read(&buf, child.out, 0) < 0)
5200                err = error("error reading from textconv command '%s'", pgm);
5201        close(child.out);
5202
5203        if (finish_command(&child) || err) {
5204                strbuf_release(&buf);
5205                remove_tempfile();
5206                return NULL;
5207        }
5208        remove_tempfile();
5209
5210        return strbuf_detach(&buf, outsize);
5211}
5212
5213size_t fill_textconv(struct userdiff_driver *driver,
5214                     struct diff_filespec *df,
5215                     char **outbuf)
5216{
5217        size_t size;
5218
5219        if (!driver) {
5220                if (!DIFF_FILE_VALID(df)) {
5221                        *outbuf = "";
5222                        return 0;
5223                }
5224                if (diff_populate_filespec(df, 0))
5225                        die("unable to read files to diff");
5226                *outbuf = df->data;
5227                return df->size;
5228        }
5229
5230        if (!driver->textconv)
5231                die("BUG: fill_textconv called with non-textconv driver");
5232
5233        if (driver->textconv_cache && df->oid_valid) {
5234                *outbuf = notes_cache_get(driver->textconv_cache,
5235                                          &df->oid,
5236                                          &size);
5237                if (*outbuf)
5238                        return size;
5239        }
5240
5241        *outbuf = run_textconv(driver->textconv, df, &size);
5242        if (!*outbuf)
5243                die("unable to read files to diff");
5244
5245        if (driver->textconv_cache && df->oid_valid) {
5246                /* ignore errors, as we might be in a readonly repository */
5247                notes_cache_put(driver->textconv_cache, &df->oid, *outbuf,
5248                                size);
5249                /*
5250                 * we could save up changes and flush them all at the end,
5251                 * but we would need an extra call after all diffing is done.
5252                 * Since generating a cache entry is the slow path anyway,
5253                 * this extra overhead probably isn't a big deal.
5254                 */
5255                notes_cache_write(driver->textconv_cache);
5256        }
5257
5258        return size;
5259}
5260
5261int textconv_object(const char *path,
5262                    unsigned mode,
5263                    const struct object_id *oid,
5264                    int oid_valid,
5265                    char **buf,
5266                    unsigned long *buf_size)
5267{
5268        struct diff_filespec *df;
5269        struct userdiff_driver *textconv;
5270
5271        df = alloc_filespec(path);
5272        fill_filespec(df, oid, oid_valid, mode);
5273        textconv = get_textconv(df);
5274        if (!textconv) {
5275                free_filespec(df);
5276                return 0;
5277        }
5278
5279        *buf_size = fill_textconv(textconv, df, buf);
5280        free_filespec(df);
5281        return 1;
5282}
5283
5284void setup_diff_pager(struct diff_options *opt)
5285{
5286        /*
5287         * If the user asked for our exit code, then either they want --quiet
5288         * or --exit-code. We should definitely not bother with a pager in the
5289         * former case, as we will generate no output. Since we still properly
5290         * report our exit code even when a pager is run, we _could_ run a
5291         * pager with --exit-code. But since we have not done so historically,
5292         * and because it is easy to find people oneline advising "git diff
5293         * --exit-code" in hooks and other scripts, we do not do so.
5294         */
5295        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
5296            check_pager_config("diff") != 0)
5297                setup_pager();
5298}