diff.con commit diff: retire sane_truncate_fn (08a8509)
   1/*
   2 * Copyright (C) 2005 Junio C Hamano
   3 */
   4#include "cache.h"
   5#include "config.h"
   6#include "tempfile.h"
   7#include "quote.h"
   8#include "diff.h"
   9#include "diffcore.h"
  10#include "delta.h"
  11#include "xdiff-interface.h"
  12#include "color.h"
  13#include "attr.h"
  14#include "run-command.h"
  15#include "utf8.h"
  16#include "userdiff.h"
  17#include "submodule-config.h"
  18#include "submodule.h"
  19#include "ll-merge.h"
  20#include "string-list.h"
  21#include "argv-array.h"
  22#include "graph.h"
  23
  24#ifdef NO_FAST_WORKING_DIRECTORY
  25#define FAST_WORKING_DIRECTORY 0
  26#else
  27#define FAST_WORKING_DIRECTORY 1
  28#endif
  29
  30static int diff_detect_rename_default;
  31static int diff_indent_heuristic = 1;
  32static int diff_rename_limit_default = 400;
  33static int diff_suppress_blank_empty;
  34static int diff_use_color_default = -1;
  35static int diff_context_default = 3;
  36static int diff_interhunk_context_default;
  37static const char *diff_word_regex_cfg;
  38static const char *external_diff_cmd_cfg;
  39static const char *diff_order_file_cfg;
  40int diff_auto_refresh_index = 1;
  41static int diff_mnemonic_prefix;
  42static int diff_no_prefix;
  43static int diff_stat_graph_width;
  44static int diff_dirstat_permille_default = 30;
  45static struct diff_options default_diff_options;
  46static long diff_algorithm;
  47static unsigned ws_error_highlight_default = WSEH_NEW;
  48
  49static char diff_colors[][COLOR_MAXLEN] = {
  50        GIT_COLOR_RESET,
  51        GIT_COLOR_NORMAL,       /* CONTEXT */
  52        GIT_COLOR_BOLD,         /* METAINFO */
  53        GIT_COLOR_CYAN,         /* FRAGINFO */
  54        GIT_COLOR_RED,          /* OLD */
  55        GIT_COLOR_GREEN,        /* NEW */
  56        GIT_COLOR_YELLOW,       /* COMMIT */
  57        GIT_COLOR_BG_RED,       /* WHITESPACE */
  58        GIT_COLOR_NORMAL,       /* FUNCINFO */
  59};
  60
  61static NORETURN void die_want_option(const char *option_name)
  62{
  63        die(_("option '%s' requires a value"), option_name);
  64}
  65
  66static int parse_diff_color_slot(const char *var)
  67{
  68        if (!strcasecmp(var, "context") || !strcasecmp(var, "plain"))
  69                return DIFF_CONTEXT;
  70        if (!strcasecmp(var, "meta"))
  71                return DIFF_METAINFO;
  72        if (!strcasecmp(var, "frag"))
  73                return DIFF_FRAGINFO;
  74        if (!strcasecmp(var, "old"))
  75                return DIFF_FILE_OLD;
  76        if (!strcasecmp(var, "new"))
  77                return DIFF_FILE_NEW;
  78        if (!strcasecmp(var, "commit"))
  79                return DIFF_COMMIT;
  80        if (!strcasecmp(var, "whitespace"))
  81                return DIFF_WHITESPACE;
  82        if (!strcasecmp(var, "func"))
  83                return DIFF_FUNCINFO;
  84        return -1;
  85}
  86
  87static int parse_dirstat_params(struct diff_options *options, const char *params_string,
  88                                struct strbuf *errmsg)
  89{
  90        char *params_copy = xstrdup(params_string);
  91        struct string_list params = STRING_LIST_INIT_NODUP;
  92        int ret = 0;
  93        int i;
  94
  95        if (*params_copy)
  96                string_list_split_in_place(&params, params_copy, ',', -1);
  97        for (i = 0; i < params.nr; i++) {
  98                const char *p = params.items[i].string;
  99                if (!strcmp(p, "changes")) {
 100                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
 101                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
 102                } else if (!strcmp(p, "lines")) {
 103                        DIFF_OPT_SET(options, DIRSTAT_BY_LINE);
 104                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
 105                } else if (!strcmp(p, "files")) {
 106                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
 107                        DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
 108                } else if (!strcmp(p, "noncumulative")) {
 109                        DIFF_OPT_CLR(options, DIRSTAT_CUMULATIVE);
 110                } else if (!strcmp(p, "cumulative")) {
 111                        DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
 112                } else if (isdigit(*p)) {
 113                        char *end;
 114                        int permille = strtoul(p, &end, 10) * 10;
 115                        if (*end == '.' && isdigit(*++end)) {
 116                                /* only use first digit */
 117                                permille += *end - '0';
 118                                /* .. and ignore any further digits */
 119                                while (isdigit(*++end))
 120                                        ; /* nothing */
 121                        }
 122                        if (!*end)
 123                                options->dirstat_permille = permille;
 124                        else {
 125                                strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%s'\n"),
 126                                            p);
 127                                ret++;
 128                        }
 129                } else {
 130                        strbuf_addf(errmsg, _("  Unknown dirstat parameter '%s'\n"), p);
 131                        ret++;
 132                }
 133
 134        }
 135        string_list_clear(&params, 0);
 136        free(params_copy);
 137        return ret;
 138}
 139
 140static int parse_submodule_params(struct diff_options *options, const char *value)
 141{
 142        if (!strcmp(value, "log"))
 143                options->submodule_format = DIFF_SUBMODULE_LOG;
 144        else if (!strcmp(value, "short"))
 145                options->submodule_format = DIFF_SUBMODULE_SHORT;
 146        else if (!strcmp(value, "diff"))
 147                options->submodule_format = DIFF_SUBMODULE_INLINE_DIFF;
 148        else
 149                return -1;
 150        return 0;
 151}
 152
 153static int git_config_rename(const char *var, const char *value)
 154{
 155        if (!value)
 156                return DIFF_DETECT_RENAME;
 157        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 158                return  DIFF_DETECT_COPY;
 159        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 160}
 161
 162long parse_algorithm_value(const char *value)
 163{
 164        if (!value)
 165                return -1;
 166        else if (!strcasecmp(value, "myers") || !strcasecmp(value, "default"))
 167                return 0;
 168        else if (!strcasecmp(value, "minimal"))
 169                return XDF_NEED_MINIMAL;
 170        else if (!strcasecmp(value, "patience"))
 171                return XDF_PATIENCE_DIFF;
 172        else if (!strcasecmp(value, "histogram"))
 173                return XDF_HISTOGRAM_DIFF;
 174        return -1;
 175}
 176
 177static int parse_one_token(const char **arg, const char *token)
 178{
 179        const char *rest;
 180        if (skip_prefix(*arg, token, &rest) && (!*rest || *rest == ',')) {
 181                *arg = rest;
 182                return 1;
 183        }
 184        return 0;
 185}
 186
 187static int parse_ws_error_highlight(const char *arg)
 188{
 189        const char *orig_arg = arg;
 190        unsigned val = 0;
 191
 192        while (*arg) {
 193                if (parse_one_token(&arg, "none"))
 194                        val = 0;
 195                else if (parse_one_token(&arg, "default"))
 196                        val = WSEH_NEW;
 197                else if (parse_one_token(&arg, "all"))
 198                        val = WSEH_NEW | WSEH_OLD | WSEH_CONTEXT;
 199                else if (parse_one_token(&arg, "new"))
 200                        val |= WSEH_NEW;
 201                else if (parse_one_token(&arg, "old"))
 202                        val |= WSEH_OLD;
 203                else if (parse_one_token(&arg, "context"))
 204                        val |= WSEH_CONTEXT;
 205                else {
 206                        return -1 - (int)(arg - orig_arg);
 207                }
 208                if (*arg)
 209                        arg++;
 210        }
 211        return val;
 212}
 213
 214/*
 215 * These are to give UI layer defaults.
 216 * The core-level commands such as git-diff-files should
 217 * never be affected by the setting of diff.renames
 218 * the user happens to have in the configuration file.
 219 */
 220void init_diff_ui_defaults(void)
 221{
 222        diff_detect_rename_default = 1;
 223}
 224
 225int git_diff_heuristic_config(const char *var, const char *value, void *cb)
 226{
 227        if (!strcmp(var, "diff.indentheuristic"))
 228                diff_indent_heuristic = git_config_bool(var, value);
 229        return 0;
 230}
 231
 232int git_diff_ui_config(const char *var, const char *value, void *cb)
 233{
 234        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 235                diff_use_color_default = git_config_colorbool(var, value);
 236                return 0;
 237        }
 238        if (!strcmp(var, "diff.context")) {
 239                diff_context_default = git_config_int(var, value);
 240                if (diff_context_default < 0)
 241                        return -1;
 242                return 0;
 243        }
 244        if (!strcmp(var, "diff.interhunkcontext")) {
 245                diff_interhunk_context_default = git_config_int(var, value);
 246                if (diff_interhunk_context_default < 0)
 247                        return -1;
 248                return 0;
 249        }
 250        if (!strcmp(var, "diff.renames")) {
 251                diff_detect_rename_default = git_config_rename(var, value);
 252                return 0;
 253        }
 254        if (!strcmp(var, "diff.autorefreshindex")) {
 255                diff_auto_refresh_index = git_config_bool(var, value);
 256                return 0;
 257        }
 258        if (!strcmp(var, "diff.mnemonicprefix")) {
 259                diff_mnemonic_prefix = git_config_bool(var, value);
 260                return 0;
 261        }
 262        if (!strcmp(var, "diff.noprefix")) {
 263                diff_no_prefix = git_config_bool(var, value);
 264                return 0;
 265        }
 266        if (!strcmp(var, "diff.statgraphwidth")) {
 267                diff_stat_graph_width = git_config_int(var, value);
 268                return 0;
 269        }
 270        if (!strcmp(var, "diff.external"))
 271                return git_config_string(&external_diff_cmd_cfg, var, value);
 272        if (!strcmp(var, "diff.wordregex"))
 273                return git_config_string(&diff_word_regex_cfg, var, value);
 274        if (!strcmp(var, "diff.orderfile"))
 275                return git_config_pathname(&diff_order_file_cfg, var, value);
 276
 277        if (!strcmp(var, "diff.ignoresubmodules"))
 278                handle_ignore_submodules_arg(&default_diff_options, value);
 279
 280        if (!strcmp(var, "diff.submodule")) {
 281                if (parse_submodule_params(&default_diff_options, value))
 282                        warning(_("Unknown value for 'diff.submodule' config variable: '%s'"),
 283                                value);
 284                return 0;
 285        }
 286
 287        if (!strcmp(var, "diff.algorithm")) {
 288                diff_algorithm = parse_algorithm_value(value);
 289                if (diff_algorithm < 0)
 290                        return -1;
 291                return 0;
 292        }
 293
 294        if (!strcmp(var, "diff.wserrorhighlight")) {
 295                int val = parse_ws_error_highlight(value);
 296                if (val < 0)
 297                        return -1;
 298                ws_error_highlight_default = val;
 299                return 0;
 300        }
 301
 302        return git_diff_basic_config(var, value, cb);
 303}
 304
 305int git_diff_basic_config(const char *var, const char *value, void *cb)
 306{
 307        const char *name;
 308
 309        if (!strcmp(var, "diff.renamelimit")) {
 310                diff_rename_limit_default = git_config_int(var, value);
 311                return 0;
 312        }
 313
 314        if (userdiff_config(var, value) < 0)
 315                return -1;
 316
 317        if (skip_prefix(var, "diff.color.", &name) ||
 318            skip_prefix(var, "color.diff.", &name)) {
 319                int slot = parse_diff_color_slot(name);
 320                if (slot < 0)
 321                        return 0;
 322                if (!value)
 323                        return config_error_nonbool(var);
 324                return color_parse(value, diff_colors[slot]);
 325        }
 326
 327        /* like GNU diff's --suppress-blank-empty option  */
 328        if (!strcmp(var, "diff.suppressblankempty") ||
 329                        /* for backwards compatibility */
 330                        !strcmp(var, "diff.suppress-blank-empty")) {
 331                diff_suppress_blank_empty = git_config_bool(var, value);
 332                return 0;
 333        }
 334
 335        if (!strcmp(var, "diff.dirstat")) {
 336                struct strbuf errmsg = STRBUF_INIT;
 337                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 338                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 339                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 340                                errmsg.buf);
 341                strbuf_release(&errmsg);
 342                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 343                return 0;
 344        }
 345
 346        if (starts_with(var, "submodule."))
 347                return parse_submodule_config_option(var, value);
 348
 349        if (git_diff_heuristic_config(var, value, cb) < 0)
 350                return -1;
 351
 352        return git_default_config(var, value, cb);
 353}
 354
 355static char *quote_two(const char *one, const char *two)
 356{
 357        int need_one = quote_c_style(one, NULL, NULL, 1);
 358        int need_two = quote_c_style(two, NULL, NULL, 1);
 359        struct strbuf res = STRBUF_INIT;
 360
 361        if (need_one + need_two) {
 362                strbuf_addch(&res, '"');
 363                quote_c_style(one, &res, NULL, 1);
 364                quote_c_style(two, &res, NULL, 1);
 365                strbuf_addch(&res, '"');
 366        } else {
 367                strbuf_addstr(&res, one);
 368                strbuf_addstr(&res, two);
 369        }
 370        return strbuf_detach(&res, NULL);
 371}
 372
 373static const char *external_diff(void)
 374{
 375        static const char *external_diff_cmd = NULL;
 376        static int done_preparing = 0;
 377
 378        if (done_preparing)
 379                return external_diff_cmd;
 380        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 381        if (!external_diff_cmd)
 382                external_diff_cmd = external_diff_cmd_cfg;
 383        done_preparing = 1;
 384        return external_diff_cmd;
 385}
 386
 387/*
 388 * Keep track of files used for diffing. Sometimes such an entry
 389 * refers to a temporary file, sometimes to an existing file, and
 390 * sometimes to "/dev/null".
 391 */
 392static struct diff_tempfile {
 393        /*
 394         * filename external diff should read from, or NULL if this
 395         * entry is currently not in use:
 396         */
 397        const char *name;
 398
 399        char hex[GIT_MAX_HEXSZ + 1];
 400        char mode[10];
 401
 402        /*
 403         * If this diff_tempfile instance refers to a temporary file,
 404         * this tempfile object is used to manage its lifetime.
 405         */
 406        struct tempfile tempfile;
 407} diff_temp[2];
 408
 409struct emit_callback {
 410        int color_diff;
 411        unsigned ws_rule;
 412        int blank_at_eof_in_preimage;
 413        int blank_at_eof_in_postimage;
 414        int lno_in_preimage;
 415        int lno_in_postimage;
 416        const char **label_path;
 417        struct diff_words_data *diff_words;
 418        struct diff_options *opt;
 419        struct strbuf *header;
 420};
 421
 422static int count_lines(const char *data, int size)
 423{
 424        int count, ch, completely_empty = 1, nl_just_seen = 0;
 425        count = 0;
 426        while (0 < size--) {
 427                ch = *data++;
 428                if (ch == '\n') {
 429                        count++;
 430                        nl_just_seen = 1;
 431                        completely_empty = 0;
 432                }
 433                else {
 434                        nl_just_seen = 0;
 435                        completely_empty = 0;
 436                }
 437        }
 438        if (completely_empty)
 439                return 0;
 440        if (!nl_just_seen)
 441                count++; /* no trailing newline */
 442        return count;
 443}
 444
 445static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 446{
 447        if (!DIFF_FILE_VALID(one)) {
 448                mf->ptr = (char *)""; /* does not matter */
 449                mf->size = 0;
 450                return 0;
 451        }
 452        else if (diff_populate_filespec(one, 0))
 453                return -1;
 454
 455        mf->ptr = one->data;
 456        mf->size = one->size;
 457        return 0;
 458}
 459
 460/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 461static unsigned long diff_filespec_size(struct diff_filespec *one)
 462{
 463        if (!DIFF_FILE_VALID(one))
 464                return 0;
 465        diff_populate_filespec(one, CHECK_SIZE_ONLY);
 466        return one->size;
 467}
 468
 469static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 470{
 471        char *ptr = mf->ptr;
 472        long size = mf->size;
 473        int cnt = 0;
 474
 475        if (!size)
 476                return cnt;
 477        ptr += size - 1; /* pointing at the very end */
 478        if (*ptr != '\n')
 479                ; /* incomplete line */
 480        else
 481                ptr--; /* skip the last LF */
 482        while (mf->ptr < ptr) {
 483                char *prev_eol;
 484                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 485                        if (*prev_eol == '\n')
 486                                break;
 487                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 488                        break;
 489                cnt++;
 490                ptr = prev_eol - 1;
 491        }
 492        return cnt;
 493}
 494
 495static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 496                               struct emit_callback *ecbdata)
 497{
 498        int l1, l2, at;
 499        unsigned ws_rule = ecbdata->ws_rule;
 500        l1 = count_trailing_blank(mf1, ws_rule);
 501        l2 = count_trailing_blank(mf2, ws_rule);
 502        if (l2 <= l1) {
 503                ecbdata->blank_at_eof_in_preimage = 0;
 504                ecbdata->blank_at_eof_in_postimage = 0;
 505                return;
 506        }
 507        at = count_lines(mf1->ptr, mf1->size);
 508        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 509
 510        at = count_lines(mf2->ptr, mf2->size);
 511        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 512}
 513
 514static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 515                        int first, const char *line, int len)
 516{
 517        int has_trailing_newline, has_trailing_carriage_return;
 518        int nofirst;
 519        FILE *file = o->file;
 520
 521        fputs(diff_line_prefix(o), file);
 522
 523        if (len == 0) {
 524                has_trailing_newline = (first == '\n');
 525                has_trailing_carriage_return = (!has_trailing_newline &&
 526                                                (first == '\r'));
 527                nofirst = has_trailing_newline || has_trailing_carriage_return;
 528        } else {
 529                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 530                if (has_trailing_newline)
 531                        len--;
 532                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 533                if (has_trailing_carriage_return)
 534                        len--;
 535                nofirst = 0;
 536        }
 537
 538        if (len || !nofirst) {
 539                fputs(set, file);
 540                if (!nofirst)
 541                        fputc(first, file);
 542                fwrite(line, len, 1, file);
 543                fputs(reset, file);
 544        }
 545        if (has_trailing_carriage_return)
 546                fputc('\r', file);
 547        if (has_trailing_newline)
 548                fputc('\n', file);
 549}
 550
 551static void emit_line(struct diff_options *o, const char *set, const char *reset,
 552                      const char *line, int len)
 553{
 554        emit_line_0(o, set, reset, line[0], line+1, len-1);
 555}
 556
 557static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 558{
 559        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 560              ecbdata->blank_at_eof_in_preimage &&
 561              ecbdata->blank_at_eof_in_postimage &&
 562              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 563              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 564                return 0;
 565        return ws_blank_line(line, len, ecbdata->ws_rule);
 566}
 567
 568static void emit_line_checked(const char *reset,
 569                              struct emit_callback *ecbdata,
 570                              const char *line, int len,
 571                              enum color_diff color,
 572                              unsigned ws_error_highlight,
 573                              char sign)
 574{
 575        const char *set = diff_get_color(ecbdata->color_diff, color);
 576        const char *ws = NULL;
 577
 578        if (ecbdata->opt->ws_error_highlight & ws_error_highlight) {
 579                ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 580                if (!*ws)
 581                        ws = NULL;
 582        }
 583
 584        if (!ws)
 585                emit_line_0(ecbdata->opt, set, reset, sign, line, len);
 586        else if (sign == '+' && new_blank_line_at_eof(ecbdata, line, len))
 587                /* Blank line at EOF - paint '+' as well */
 588                emit_line_0(ecbdata->opt, ws, reset, sign, line, len);
 589        else {
 590                /* Emit just the prefix, then the rest. */
 591                emit_line_0(ecbdata->opt, set, reset, sign, "", 0);
 592                ws_check_emit(line, len, ecbdata->ws_rule,
 593                              ecbdata->opt->file, set, reset, ws);
 594        }
 595}
 596
 597static void emit_add_line(const char *reset,
 598                          struct emit_callback *ecbdata,
 599                          const char *line, int len)
 600{
 601        emit_line_checked(reset, ecbdata, line, len,
 602                          DIFF_FILE_NEW, WSEH_NEW, '+');
 603}
 604
 605static void emit_del_line(const char *reset,
 606                          struct emit_callback *ecbdata,
 607                          const char *line, int len)
 608{
 609        emit_line_checked(reset, ecbdata, line, len,
 610                          DIFF_FILE_OLD, WSEH_OLD, '-');
 611}
 612
 613static void emit_context_line(const char *reset,
 614                              struct emit_callback *ecbdata,
 615                              const char *line, int len)
 616{
 617        emit_line_checked(reset, ecbdata, line, len,
 618                          DIFF_CONTEXT, WSEH_CONTEXT, ' ');
 619}
 620
 621static void emit_hunk_header(struct emit_callback *ecbdata,
 622                             const char *line, int len)
 623{
 624        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
 625        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 626        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 627        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 628        static const char atat[2] = { '@', '@' };
 629        const char *cp, *ep;
 630        struct strbuf msgbuf = STRBUF_INIT;
 631        int org_len = len;
 632        int i = 1;
 633
 634        /*
 635         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 636         * it always is at least 10 bytes long.
 637         */
 638        if (len < 10 ||
 639            memcmp(line, atat, 2) ||
 640            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 641                emit_line(ecbdata->opt, context, reset, line, len);
 642                return;
 643        }
 644        ep += 2; /* skip over @@ */
 645
 646        /* The hunk header in fraginfo color */
 647        strbuf_addstr(&msgbuf, frag);
 648        strbuf_add(&msgbuf, line, ep - line);
 649        strbuf_addstr(&msgbuf, reset);
 650
 651        /*
 652         * trailing "\r\n"
 653         */
 654        for ( ; i < 3; i++)
 655                if (line[len - i] == '\r' || line[len - i] == '\n')
 656                        len--;
 657
 658        /* blank before the func header */
 659        for (cp = ep; ep - line < len; ep++)
 660                if (*ep != ' ' && *ep != '\t')
 661                        break;
 662        if (ep != cp) {
 663                strbuf_addstr(&msgbuf, context);
 664                strbuf_add(&msgbuf, cp, ep - cp);
 665                strbuf_addstr(&msgbuf, reset);
 666        }
 667
 668        if (ep < line + len) {
 669                strbuf_addstr(&msgbuf, func);
 670                strbuf_add(&msgbuf, ep, line + len - ep);
 671                strbuf_addstr(&msgbuf, reset);
 672        }
 673
 674        strbuf_add(&msgbuf, line + len, org_len - len);
 675        emit_line(ecbdata->opt, "", "", msgbuf.buf, msgbuf.len);
 676        strbuf_release(&msgbuf);
 677}
 678
 679static struct diff_tempfile *claim_diff_tempfile(void) {
 680        int i;
 681        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 682                if (!diff_temp[i].name)
 683                        return diff_temp + i;
 684        die("BUG: diff is failing to clean up its tempfiles");
 685}
 686
 687static void remove_tempfile(void)
 688{
 689        int i;
 690        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 691                if (is_tempfile_active(&diff_temp[i].tempfile))
 692                        delete_tempfile(&diff_temp[i].tempfile);
 693                diff_temp[i].name = NULL;
 694        }
 695}
 696
 697static void print_line_count(FILE *file, int count)
 698{
 699        switch (count) {
 700        case 0:
 701                fprintf(file, "0,0");
 702                break;
 703        case 1:
 704                fprintf(file, "1");
 705                break;
 706        default:
 707                fprintf(file, "1,%d", count);
 708                break;
 709        }
 710}
 711
 712static void emit_rewrite_lines(struct emit_callback *ecb,
 713                               int prefix, const char *data, int size)
 714{
 715        const char *endp = NULL;
 716        static const char *nneof = " No newline at end of file\n";
 717        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 718
 719        while (0 < size) {
 720                int len;
 721
 722                endp = memchr(data, '\n', size);
 723                len = endp ? (endp - data + 1) : size;
 724                if (prefix != '+') {
 725                        ecb->lno_in_preimage++;
 726                        emit_del_line(reset, ecb, data, len);
 727                } else {
 728                        ecb->lno_in_postimage++;
 729                        emit_add_line(reset, ecb, data, len);
 730                }
 731                size -= len;
 732                data += len;
 733        }
 734        if (!endp) {
 735                const char *context = diff_get_color(ecb->color_diff,
 736                                                     DIFF_CONTEXT);
 737                putc('\n', ecb->opt->file);
 738                emit_line_0(ecb->opt, context, reset, '\\',
 739                            nneof, strlen(nneof));
 740        }
 741}
 742
 743static void emit_rewrite_diff(const char *name_a,
 744                              const char *name_b,
 745                              struct diff_filespec *one,
 746                              struct diff_filespec *two,
 747                              struct userdiff_driver *textconv_one,
 748                              struct userdiff_driver *textconv_two,
 749                              struct diff_options *o)
 750{
 751        int lc_a, lc_b;
 752        const char *name_a_tab, *name_b_tab;
 753        const char *metainfo = diff_get_color(o->use_color, DIFF_METAINFO);
 754        const char *fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
 755        const char *reset = diff_get_color(o->use_color, DIFF_RESET);
 756        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 757        const char *a_prefix, *b_prefix;
 758        char *data_one, *data_two;
 759        size_t size_one, size_two;
 760        struct emit_callback ecbdata;
 761        const char *line_prefix = diff_line_prefix(o);
 762
 763        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 764                a_prefix = o->b_prefix;
 765                b_prefix = o->a_prefix;
 766        } else {
 767                a_prefix = o->a_prefix;
 768                b_prefix = o->b_prefix;
 769        }
 770
 771        name_a += (*name_a == '/');
 772        name_b += (*name_b == '/');
 773        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 774        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 775
 776        strbuf_reset(&a_name);
 777        strbuf_reset(&b_name);
 778        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 779        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 780
 781        size_one = fill_textconv(textconv_one, one, &data_one);
 782        size_two = fill_textconv(textconv_two, two, &data_two);
 783
 784        memset(&ecbdata, 0, sizeof(ecbdata));
 785        ecbdata.color_diff = want_color(o->use_color);
 786        ecbdata.ws_rule = whitespace_rule(name_b);
 787        ecbdata.opt = o;
 788        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 789                mmfile_t mf1, mf2;
 790                mf1.ptr = (char *)data_one;
 791                mf2.ptr = (char *)data_two;
 792                mf1.size = size_one;
 793                mf2.size = size_two;
 794                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 795        }
 796        ecbdata.lno_in_preimage = 1;
 797        ecbdata.lno_in_postimage = 1;
 798
 799        lc_a = count_lines(data_one, size_one);
 800        lc_b = count_lines(data_two, size_two);
 801        fprintf(o->file,
 802                "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
 803                line_prefix, metainfo, a_name.buf, name_a_tab, reset,
 804                line_prefix, metainfo, b_name.buf, name_b_tab, reset,
 805                line_prefix, fraginfo);
 806        if (!o->irreversible_delete)
 807                print_line_count(o->file, lc_a);
 808        else
 809                fprintf(o->file, "?,?");
 810        fprintf(o->file, " +");
 811        print_line_count(o->file, lc_b);
 812        fprintf(o->file, " @@%s\n", reset);
 813        if (lc_a && !o->irreversible_delete)
 814                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 815        if (lc_b)
 816                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 817        if (textconv_one)
 818                free((char *)data_one);
 819        if (textconv_two)
 820                free((char *)data_two);
 821}
 822
 823struct diff_words_buffer {
 824        mmfile_t text;
 825        long alloc;
 826        struct diff_words_orig {
 827                const char *begin, *end;
 828        } *orig;
 829        int orig_nr, orig_alloc;
 830};
 831
 832static void diff_words_append(char *line, unsigned long len,
 833                struct diff_words_buffer *buffer)
 834{
 835        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 836        line++;
 837        len--;
 838        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 839        buffer->text.size += len;
 840        buffer->text.ptr[buffer->text.size] = '\0';
 841}
 842
 843struct diff_words_style_elem {
 844        const char *prefix;
 845        const char *suffix;
 846        const char *color; /* NULL; filled in by the setup code if
 847                            * color is enabled */
 848};
 849
 850struct diff_words_style {
 851        enum diff_words_type type;
 852        struct diff_words_style_elem new, old, ctx;
 853        const char *newline;
 854};
 855
 856static struct diff_words_style diff_words_styles[] = {
 857        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 858        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 859        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 860};
 861
 862struct diff_words_data {
 863        struct diff_words_buffer minus, plus;
 864        const char *current_plus;
 865        int last_minus;
 866        struct diff_options *opt;
 867        regex_t *word_regex;
 868        enum diff_words_type type;
 869        struct diff_words_style *style;
 870};
 871
 872static int fn_out_diff_words_write_helper(FILE *fp,
 873                                          struct diff_words_style_elem *st_el,
 874                                          const char *newline,
 875                                          size_t count, const char *buf,
 876                                          const char *line_prefix)
 877{
 878        int print = 0;
 879
 880        while (count) {
 881                char *p = memchr(buf, '\n', count);
 882                if (print)
 883                        fputs(line_prefix, fp);
 884                if (p != buf) {
 885                        if (st_el->color && fputs(st_el->color, fp) < 0)
 886                                return -1;
 887                        if (fputs(st_el->prefix, fp) < 0 ||
 888                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 889                            fputs(st_el->suffix, fp) < 0)
 890                                return -1;
 891                        if (st_el->color && *st_el->color
 892                            && fputs(GIT_COLOR_RESET, fp) < 0)
 893                                return -1;
 894                }
 895                if (!p)
 896                        return 0;
 897                if (fputs(newline, fp) < 0)
 898                        return -1;
 899                count -= p + 1 - buf;
 900                buf = p + 1;
 901                print = 1;
 902        }
 903        return 0;
 904}
 905
 906/*
 907 * '--color-words' algorithm can be described as:
 908 *
 909 *   1. collect the minus/plus lines of a diff hunk, divided into
 910 *      minus-lines and plus-lines;
 911 *
 912 *   2. break both minus-lines and plus-lines into words and
 913 *      place them into two mmfile_t with one word for each line;
 914 *
 915 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
 916 *
 917 * And for the common parts of the both file, we output the plus side text.
 918 * diff_words->current_plus is used to trace the current position of the plus file
 919 * which printed. diff_words->last_minus is used to trace the last minus word
 920 * printed.
 921 *
 922 * For '--graph' to work with '--color-words', we need to output the graph prefix
 923 * on each line of color words output. Generally, there are two conditions on
 924 * which we should output the prefix.
 925 *
 926 *   1. diff_words->last_minus == 0 &&
 927 *      diff_words->current_plus == diff_words->plus.text.ptr
 928 *
 929 *      that is: the plus text must start as a new line, and if there is no minus
 930 *      word printed, a graph prefix must be printed.
 931 *
 932 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
 933 *      *(diff_words->current_plus - 1) == '\n'
 934 *
 935 *      that is: a graph prefix must be printed following a '\n'
 936 */
 937static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
 938{
 939        if ((diff_words->last_minus == 0 &&
 940                diff_words->current_plus == diff_words->plus.text.ptr) ||
 941                (diff_words->current_plus > diff_words->plus.text.ptr &&
 942                *(diff_words->current_plus - 1) == '\n')) {
 943                return 1;
 944        } else {
 945                return 0;
 946        }
 947}
 948
 949static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 950{
 951        struct diff_words_data *diff_words = priv;
 952        struct diff_words_style *style = diff_words->style;
 953        int minus_first, minus_len, plus_first, plus_len;
 954        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 955        struct diff_options *opt = diff_words->opt;
 956        const char *line_prefix;
 957
 958        if (line[0] != '@' || parse_hunk_header(line, len,
 959                        &minus_first, &minus_len, &plus_first, &plus_len))
 960                return;
 961
 962        assert(opt);
 963        line_prefix = diff_line_prefix(opt);
 964
 965        /* POSIX requires that first be decremented by one if len == 0... */
 966        if (minus_len) {
 967                minus_begin = diff_words->minus.orig[minus_first].begin;
 968                minus_end =
 969                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 970        } else
 971                minus_begin = minus_end =
 972                        diff_words->minus.orig[minus_first].end;
 973
 974        if (plus_len) {
 975                plus_begin = diff_words->plus.orig[plus_first].begin;
 976                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 977        } else
 978                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 979
 980        if (color_words_output_graph_prefix(diff_words)) {
 981                fputs(line_prefix, diff_words->opt->file);
 982        }
 983        if (diff_words->current_plus != plus_begin) {
 984                fn_out_diff_words_write_helper(diff_words->opt->file,
 985                                &style->ctx, style->newline,
 986                                plus_begin - diff_words->current_plus,
 987                                diff_words->current_plus, line_prefix);
 988                if (*(plus_begin - 1) == '\n')
 989                        fputs(line_prefix, diff_words->opt->file);
 990        }
 991        if (minus_begin != minus_end) {
 992                fn_out_diff_words_write_helper(diff_words->opt->file,
 993                                &style->old, style->newline,
 994                                minus_end - minus_begin, minus_begin,
 995                                line_prefix);
 996        }
 997        if (plus_begin != plus_end) {
 998                fn_out_diff_words_write_helper(diff_words->opt->file,
 999                                &style->new, style->newline,
1000                                plus_end - plus_begin, plus_begin,
1001                                line_prefix);
1002        }
1003
1004        diff_words->current_plus = plus_end;
1005        diff_words->last_minus = minus_first;
1006}
1007
1008/* This function starts looking at *begin, and returns 0 iff a word was found. */
1009static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
1010                int *begin, int *end)
1011{
1012        if (word_regex && *begin < buffer->size) {
1013                regmatch_t match[1];
1014                if (!regexec_buf(word_regex, buffer->ptr + *begin,
1015                                 buffer->size - *begin, 1, match, 0)) {
1016                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
1017                                        '\n', match[0].rm_eo - match[0].rm_so);
1018                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
1019                        *begin += match[0].rm_so;
1020                        return *begin >= *end;
1021                }
1022                return -1;
1023        }
1024
1025        /* find the next word */
1026        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
1027                (*begin)++;
1028        if (*begin >= buffer->size)
1029                return -1;
1030
1031        /* find the end of the word */
1032        *end = *begin + 1;
1033        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
1034                (*end)++;
1035
1036        return 0;
1037}
1038
1039/*
1040 * This function splits the words in buffer->text, stores the list with
1041 * newline separator into out, and saves the offsets of the original words
1042 * in buffer->orig.
1043 */
1044static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
1045                regex_t *word_regex)
1046{
1047        int i, j;
1048        long alloc = 0;
1049
1050        out->size = 0;
1051        out->ptr = NULL;
1052
1053        /* fake an empty "0th" word */
1054        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
1055        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
1056        buffer->orig_nr = 1;
1057
1058        for (i = 0; i < buffer->text.size; i++) {
1059                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
1060                        return;
1061
1062                /* store original boundaries */
1063                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
1064                                buffer->orig_alloc);
1065                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
1066                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
1067                buffer->orig_nr++;
1068
1069                /* store one word */
1070                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
1071                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
1072                out->ptr[out->size + j - i] = '\n';
1073                out->size += j - i + 1;
1074
1075                i = j - 1;
1076        }
1077}
1078
1079/* this executes the word diff on the accumulated buffers */
1080static void diff_words_show(struct diff_words_data *diff_words)
1081{
1082        xpparam_t xpp;
1083        xdemitconf_t xecfg;
1084        mmfile_t minus, plus;
1085        struct diff_words_style *style = diff_words->style;
1086
1087        struct diff_options *opt = diff_words->opt;
1088        const char *line_prefix;
1089
1090        assert(opt);
1091        line_prefix = diff_line_prefix(opt);
1092
1093        /* special case: only removal */
1094        if (!diff_words->plus.text.size) {
1095                fputs(line_prefix, diff_words->opt->file);
1096                fn_out_diff_words_write_helper(diff_words->opt->file,
1097                        &style->old, style->newline,
1098                        diff_words->minus.text.size,
1099                        diff_words->minus.text.ptr, line_prefix);
1100                diff_words->minus.text.size = 0;
1101                return;
1102        }
1103
1104        diff_words->current_plus = diff_words->plus.text.ptr;
1105        diff_words->last_minus = 0;
1106
1107        memset(&xpp, 0, sizeof(xpp));
1108        memset(&xecfg, 0, sizeof(xecfg));
1109        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
1110        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
1111        xpp.flags = 0;
1112        /* as only the hunk header will be parsed, we need a 0-context */
1113        xecfg.ctxlen = 0;
1114        if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
1115                          &xpp, &xecfg))
1116                die("unable to generate word diff");
1117        free(minus.ptr);
1118        free(plus.ptr);
1119        if (diff_words->current_plus != diff_words->plus.text.ptr +
1120                        diff_words->plus.text.size) {
1121                if (color_words_output_graph_prefix(diff_words))
1122                        fputs(line_prefix, diff_words->opt->file);
1123                fn_out_diff_words_write_helper(diff_words->opt->file,
1124                        &style->ctx, style->newline,
1125                        diff_words->plus.text.ptr + diff_words->plus.text.size
1126                        - diff_words->current_plus, diff_words->current_plus,
1127                        line_prefix);
1128        }
1129        diff_words->minus.text.size = diff_words->plus.text.size = 0;
1130}
1131
1132/* In "color-words" mode, show word-diff of words accumulated in the buffer */
1133static void diff_words_flush(struct emit_callback *ecbdata)
1134{
1135        if (ecbdata->diff_words->minus.text.size ||
1136            ecbdata->diff_words->plus.text.size)
1137                diff_words_show(ecbdata->diff_words);
1138}
1139
1140static void diff_filespec_load_driver(struct diff_filespec *one)
1141{
1142        /* Use already-loaded driver */
1143        if (one->driver)
1144                return;
1145
1146        if (S_ISREG(one->mode))
1147                one->driver = userdiff_find_by_path(one->path);
1148
1149        /* Fallback to default settings */
1150        if (!one->driver)
1151                one->driver = userdiff_find_by_name("default");
1152}
1153
1154static const char *userdiff_word_regex(struct diff_filespec *one)
1155{
1156        diff_filespec_load_driver(one);
1157        return one->driver->word_regex;
1158}
1159
1160static void init_diff_words_data(struct emit_callback *ecbdata,
1161                                 struct diff_options *orig_opts,
1162                                 struct diff_filespec *one,
1163                                 struct diff_filespec *two)
1164{
1165        int i;
1166        struct diff_options *o = xmalloc(sizeof(struct diff_options));
1167        memcpy(o, orig_opts, sizeof(struct diff_options));
1168
1169        ecbdata->diff_words =
1170                xcalloc(1, sizeof(struct diff_words_data));
1171        ecbdata->diff_words->type = o->word_diff;
1172        ecbdata->diff_words->opt = o;
1173        if (!o->word_regex)
1174                o->word_regex = userdiff_word_regex(one);
1175        if (!o->word_regex)
1176                o->word_regex = userdiff_word_regex(two);
1177        if (!o->word_regex)
1178                o->word_regex = diff_word_regex_cfg;
1179        if (o->word_regex) {
1180                ecbdata->diff_words->word_regex = (regex_t *)
1181                        xmalloc(sizeof(regex_t));
1182                if (regcomp(ecbdata->diff_words->word_regex,
1183                            o->word_regex,
1184                            REG_EXTENDED | REG_NEWLINE))
1185                        die ("Invalid regular expression: %s",
1186                             o->word_regex);
1187        }
1188        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
1189                if (o->word_diff == diff_words_styles[i].type) {
1190                        ecbdata->diff_words->style =
1191                                &diff_words_styles[i];
1192                        break;
1193                }
1194        }
1195        if (want_color(o->use_color)) {
1196                struct diff_words_style *st = ecbdata->diff_words->style;
1197                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
1198                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
1199                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
1200        }
1201}
1202
1203static void free_diff_words_data(struct emit_callback *ecbdata)
1204{
1205        if (ecbdata->diff_words) {
1206                diff_words_flush(ecbdata);
1207                free (ecbdata->diff_words->opt);
1208                free (ecbdata->diff_words->minus.text.ptr);
1209                free (ecbdata->diff_words->minus.orig);
1210                free (ecbdata->diff_words->plus.text.ptr);
1211                free (ecbdata->diff_words->plus.orig);
1212                if (ecbdata->diff_words->word_regex) {
1213                        regfree(ecbdata->diff_words->word_regex);
1214                        free(ecbdata->diff_words->word_regex);
1215                }
1216                FREE_AND_NULL(ecbdata->diff_words);
1217        }
1218}
1219
1220const char *diff_get_color(int diff_use_color, enum color_diff ix)
1221{
1222        if (want_color(diff_use_color))
1223                return diff_colors[ix];
1224        return "";
1225}
1226
1227const char *diff_line_prefix(struct diff_options *opt)
1228{
1229        struct strbuf *msgbuf;
1230        if (!opt->output_prefix)
1231                return "";
1232
1233        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
1234        return msgbuf->buf;
1235}
1236
1237static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
1238{
1239        const char *cp;
1240        unsigned long allot;
1241        size_t l = len;
1242
1243        cp = line;
1244        allot = l;
1245        while (0 < l) {
1246                (void) utf8_width(&cp, &l);
1247                if (!cp)
1248                        break; /* truncated in the middle? */
1249        }
1250        return allot - l;
1251}
1252
1253static void find_lno(const char *line, struct emit_callback *ecbdata)
1254{
1255        const char *p;
1256        ecbdata->lno_in_preimage = 0;
1257        ecbdata->lno_in_postimage = 0;
1258        p = strchr(line, '-');
1259        if (!p)
1260                return; /* cannot happen */
1261        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1262        p = strchr(p, '+');
1263        if (!p)
1264                return; /* cannot happen */
1265        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
1266}
1267
1268static void fn_out_consume(void *priv, char *line, unsigned long len)
1269{
1270        struct emit_callback *ecbdata = priv;
1271        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
1272        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
1273        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1274        struct diff_options *o = ecbdata->opt;
1275        const char *line_prefix = diff_line_prefix(o);
1276
1277        o->found_changes = 1;
1278
1279        if (ecbdata->header) {
1280                fprintf(o->file, "%s", ecbdata->header->buf);
1281                strbuf_reset(ecbdata->header);
1282                ecbdata->header = NULL;
1283        }
1284
1285        if (ecbdata->label_path[0]) {
1286                const char *name_a_tab, *name_b_tab;
1287
1288                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
1289                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
1290
1291                fprintf(o->file, "%s%s--- %s%s%s\n",
1292                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
1293                fprintf(o->file, "%s%s+++ %s%s%s\n",
1294                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1295                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1296        }
1297
1298        if (diff_suppress_blank_empty
1299            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1300                line[0] = '\n';
1301                len = 1;
1302        }
1303
1304        if (line[0] == '@') {
1305                if (ecbdata->diff_words)
1306                        diff_words_flush(ecbdata);
1307                len = sane_truncate_line(ecbdata, line, len);
1308                find_lno(line, ecbdata);
1309                emit_hunk_header(ecbdata, line, len);
1310                if (line[len-1] != '\n')
1311                        putc('\n', o->file);
1312                return;
1313        }
1314
1315        if (ecbdata->diff_words) {
1316                if (line[0] == '-') {
1317                        diff_words_append(line, len,
1318                                          &ecbdata->diff_words->minus);
1319                        return;
1320                } else if (line[0] == '+') {
1321                        diff_words_append(line, len,
1322                                          &ecbdata->diff_words->plus);
1323                        return;
1324                } else if (starts_with(line, "\\ ")) {
1325                        /*
1326                         * Eat the "no newline at eof" marker as if we
1327                         * saw a "+" or "-" line with nothing on it,
1328                         * and return without diff_words_flush() to
1329                         * defer processing. If this is the end of
1330                         * preimage, more "+" lines may come after it.
1331                         */
1332                        return;
1333                }
1334                diff_words_flush(ecbdata);
1335                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1336                        emit_line(o, context, reset, line, len);
1337                        fputs("~\n", o->file);
1338                } else {
1339                        /*
1340                         * Skip the prefix character, if any.  With
1341                         * diff_suppress_blank_empty, there may be
1342                         * none.
1343                         */
1344                        if (line[0] != '\n') {
1345                              line++;
1346                              len--;
1347                        }
1348                        emit_line(o, context, reset, line, len);
1349                }
1350                return;
1351        }
1352
1353        switch (line[0]) {
1354        case '+':
1355                ecbdata->lno_in_postimage++;
1356                emit_add_line(reset, ecbdata, line + 1, len - 1);
1357                break;
1358        case '-':
1359                ecbdata->lno_in_preimage++;
1360                emit_del_line(reset, ecbdata, line + 1, len - 1);
1361                break;
1362        case ' ':
1363                ecbdata->lno_in_postimage++;
1364                ecbdata->lno_in_preimage++;
1365                emit_context_line(reset, ecbdata, line + 1, len - 1);
1366                break;
1367        default:
1368                /* incomplete line at the end */
1369                ecbdata->lno_in_preimage++;
1370                emit_line(o, diff_get_color(ecbdata->color_diff, DIFF_CONTEXT),
1371                          reset, line, len);
1372                break;
1373        }
1374}
1375
1376static char *pprint_rename(const char *a, const char *b)
1377{
1378        const char *old = a;
1379        const char *new = b;
1380        struct strbuf name = STRBUF_INIT;
1381        int pfx_length, sfx_length;
1382        int pfx_adjust_for_slash;
1383        int len_a = strlen(a);
1384        int len_b = strlen(b);
1385        int a_midlen, b_midlen;
1386        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1387        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1388
1389        if (qlen_a || qlen_b) {
1390                quote_c_style(a, &name, NULL, 0);
1391                strbuf_addstr(&name, " => ");
1392                quote_c_style(b, &name, NULL, 0);
1393                return strbuf_detach(&name, NULL);
1394        }
1395
1396        /* Find common prefix */
1397        pfx_length = 0;
1398        while (*old && *new && *old == *new) {
1399                if (*old == '/')
1400                        pfx_length = old - a + 1;
1401                old++;
1402                new++;
1403        }
1404
1405        /* Find common suffix */
1406        old = a + len_a;
1407        new = b + len_b;
1408        sfx_length = 0;
1409        /*
1410         * If there is a common prefix, it must end in a slash.  In
1411         * that case we let this loop run 1 into the prefix to see the
1412         * same slash.
1413         *
1414         * If there is no common prefix, we cannot do this as it would
1415         * underrun the input strings.
1416         */
1417        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
1418        while (a + pfx_length - pfx_adjust_for_slash <= old &&
1419               b + pfx_length - pfx_adjust_for_slash <= new &&
1420               *old == *new) {
1421                if (*old == '/')
1422                        sfx_length = len_a - (old - a);
1423                old--;
1424                new--;
1425        }
1426
1427        /*
1428         * pfx{mid-a => mid-b}sfx
1429         * {pfx-a => pfx-b}sfx
1430         * pfx{sfx-a => sfx-b}
1431         * name-a => name-b
1432         */
1433        a_midlen = len_a - pfx_length - sfx_length;
1434        b_midlen = len_b - pfx_length - sfx_length;
1435        if (a_midlen < 0)
1436                a_midlen = 0;
1437        if (b_midlen < 0)
1438                b_midlen = 0;
1439
1440        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1441        if (pfx_length + sfx_length) {
1442                strbuf_add(&name, a, pfx_length);
1443                strbuf_addch(&name, '{');
1444        }
1445        strbuf_add(&name, a + pfx_length, a_midlen);
1446        strbuf_addstr(&name, " => ");
1447        strbuf_add(&name, b + pfx_length, b_midlen);
1448        if (pfx_length + sfx_length) {
1449                strbuf_addch(&name, '}');
1450                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1451        }
1452        return strbuf_detach(&name, NULL);
1453}
1454
1455struct diffstat_t {
1456        int nr;
1457        int alloc;
1458        struct diffstat_file {
1459                char *from_name;
1460                char *name;
1461                char *print_name;
1462                unsigned is_unmerged:1;
1463                unsigned is_binary:1;
1464                unsigned is_renamed:1;
1465                unsigned is_interesting:1;
1466                uintmax_t added, deleted;
1467        } **files;
1468};
1469
1470static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1471                                          const char *name_a,
1472                                          const char *name_b)
1473{
1474        struct diffstat_file *x;
1475        x = xcalloc(1, sizeof(*x));
1476        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
1477        diffstat->files[diffstat->nr++] = x;
1478        if (name_b) {
1479                x->from_name = xstrdup(name_a);
1480                x->name = xstrdup(name_b);
1481                x->is_renamed = 1;
1482        }
1483        else {
1484                x->from_name = NULL;
1485                x->name = xstrdup(name_a);
1486        }
1487        return x;
1488}
1489
1490static void diffstat_consume(void *priv, char *line, unsigned long len)
1491{
1492        struct diffstat_t *diffstat = priv;
1493        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1494
1495        if (line[0] == '+')
1496                x->added++;
1497        else if (line[0] == '-')
1498                x->deleted++;
1499}
1500
1501const char mime_boundary_leader[] = "------------";
1502
1503static int scale_linear(int it, int width, int max_change)
1504{
1505        if (!it)
1506                return 0;
1507        /*
1508         * make sure that at least one '-' or '+' is printed if
1509         * there is any change to this path. The easiest way is to
1510         * scale linearly as if the alloted width is one column shorter
1511         * than it is, and then add 1 to the result.
1512         */
1513        return 1 + (it * (width - 1) / max_change);
1514}
1515
1516static void show_name(FILE *file,
1517                      const char *prefix, const char *name, int len)
1518{
1519        fprintf(file, " %s%-*s |", prefix, len, name);
1520}
1521
1522static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1523{
1524        if (cnt <= 0)
1525                return;
1526        fprintf(file, "%s", set);
1527        while (cnt--)
1528                putc(ch, file);
1529        fprintf(file, "%s", reset);
1530}
1531
1532static void fill_print_name(struct diffstat_file *file)
1533{
1534        char *pname;
1535
1536        if (file->print_name)
1537                return;
1538
1539        if (!file->is_renamed) {
1540                struct strbuf buf = STRBUF_INIT;
1541                if (quote_c_style(file->name, &buf, NULL, 0)) {
1542                        pname = strbuf_detach(&buf, NULL);
1543                } else {
1544                        pname = file->name;
1545                        strbuf_release(&buf);
1546                }
1547        } else {
1548                pname = pprint_rename(file->from_name, file->name);
1549        }
1550        file->print_name = pname;
1551}
1552
1553int print_stat_summary(FILE *fp, int files, int insertions, int deletions)
1554{
1555        struct strbuf sb = STRBUF_INIT;
1556        int ret;
1557
1558        if (!files) {
1559                assert(insertions == 0 && deletions == 0);
1560                return fprintf(fp, "%s\n", " 0 files changed");
1561        }
1562
1563        strbuf_addf(&sb,
1564                    (files == 1) ? " %d file changed" : " %d files changed",
1565                    files);
1566
1567        /*
1568         * For binary diff, the caller may want to print "x files
1569         * changed" with insertions == 0 && deletions == 0.
1570         *
1571         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
1572         * is probably less confusing (i.e skip over "2 files changed
1573         * but nothing about added/removed lines? Is this a bug in Git?").
1574         */
1575        if (insertions || deletions == 0) {
1576                strbuf_addf(&sb,
1577                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
1578                            insertions);
1579        }
1580
1581        if (deletions || insertions == 0) {
1582                strbuf_addf(&sb,
1583                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
1584                            deletions);
1585        }
1586        strbuf_addch(&sb, '\n');
1587        ret = fputs(sb.buf, fp);
1588        strbuf_release(&sb);
1589        return ret;
1590}
1591
1592static void show_stats(struct diffstat_t *data, struct diff_options *options)
1593{
1594        int i, len, add, del, adds = 0, dels = 0;
1595        uintmax_t max_change = 0, max_len = 0;
1596        int total_files = data->nr, count;
1597        int width, name_width, graph_width, number_width = 0, bin_width = 0;
1598        const char *reset, *add_c, *del_c;
1599        const char *line_prefix = "";
1600        int extra_shown = 0;
1601
1602        if (data->nr == 0)
1603                return;
1604
1605        line_prefix = diff_line_prefix(options);
1606        count = options->stat_count ? options->stat_count : data->nr;
1607
1608        reset = diff_get_color_opt(options, DIFF_RESET);
1609        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1610        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1611
1612        /*
1613         * Find the longest filename and max number of changes
1614         */
1615        for (i = 0; (i < count) && (i < data->nr); i++) {
1616                struct diffstat_file *file = data->files[i];
1617                uintmax_t change = file->added + file->deleted;
1618
1619                if (!file->is_interesting && (change == 0)) {
1620                        count++; /* not shown == room for one more */
1621                        continue;
1622                }
1623                fill_print_name(file);
1624                len = strlen(file->print_name);
1625                if (max_len < len)
1626                        max_len = len;
1627
1628                if (file->is_unmerged) {
1629                        /* "Unmerged" is 8 characters */
1630                        bin_width = bin_width < 8 ? 8 : bin_width;
1631                        continue;
1632                }
1633                if (file->is_binary) {
1634                        /* "Bin XXX -> YYY bytes" */
1635                        int w = 14 + decimal_width(file->added)
1636                                + decimal_width(file->deleted);
1637                        bin_width = bin_width < w ? w : bin_width;
1638                        /* Display change counts aligned with "Bin" */
1639                        number_width = 3;
1640                        continue;
1641                }
1642
1643                if (max_change < change)
1644                        max_change = change;
1645        }
1646        count = i; /* where we can stop scanning in data->files[] */
1647
1648        /*
1649         * We have width = stat_width or term_columns() columns total.
1650         * We want a maximum of min(max_len, stat_name_width) for the name part.
1651         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
1652         * We also need 1 for " " and 4 + decimal_width(max_change)
1653         * for " | NNNN " and one the empty column at the end, altogether
1654         * 6 + decimal_width(max_change).
1655         *
1656         * If there's not enough space, we will use the smaller of
1657         * stat_name_width (if set) and 5/8*width for the filename,
1658         * and the rest for constant elements + graph part, but no more
1659         * than stat_graph_width for the graph part.
1660         * (5/8 gives 50 for filename and 30 for the constant parts + graph
1661         * for the standard terminal size).
1662         *
1663         * In other words: stat_width limits the maximum width, and
1664         * stat_name_width fixes the maximum width of the filename,
1665         * and is also used to divide available columns if there
1666         * aren't enough.
1667         *
1668         * Binary files are displayed with "Bin XXX -> YYY bytes"
1669         * instead of the change count and graph. This part is treated
1670         * similarly to the graph part, except that it is not
1671         * "scaled". If total width is too small to accommodate the
1672         * guaranteed minimum width of the filename part and the
1673         * separators and this message, this message will "overflow"
1674         * making the line longer than the maximum width.
1675         */
1676
1677        if (options->stat_width == -1)
1678                width = term_columns() - strlen(line_prefix);
1679        else
1680                width = options->stat_width ? options->stat_width : 80;
1681        number_width = decimal_width(max_change) > number_width ?
1682                decimal_width(max_change) : number_width;
1683
1684        if (options->stat_graph_width == -1)
1685                options->stat_graph_width = diff_stat_graph_width;
1686
1687        /*
1688         * Guarantee 3/8*16==6 for the graph part
1689         * and 5/8*16==10 for the filename part
1690         */
1691        if (width < 16 + 6 + number_width)
1692                width = 16 + 6 + number_width;
1693
1694        /*
1695         * First assign sizes that are wanted, ignoring available width.
1696         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
1697         * starting from "XXX" should fit in graph_width.
1698         */
1699        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
1700        if (options->stat_graph_width &&
1701            options->stat_graph_width < graph_width)
1702                graph_width = options->stat_graph_width;
1703
1704        name_width = (options->stat_name_width > 0 &&
1705                      options->stat_name_width < max_len) ?
1706                options->stat_name_width : max_len;
1707
1708        /*
1709         * Adjust adjustable widths not to exceed maximum width
1710         */
1711        if (name_width + number_width + 6 + graph_width > width) {
1712                if (graph_width > width * 3/8 - number_width - 6) {
1713                        graph_width = width * 3/8 - number_width - 6;
1714                        if (graph_width < 6)
1715                                graph_width = 6;
1716                }
1717
1718                if (options->stat_graph_width &&
1719                    graph_width > options->stat_graph_width)
1720                        graph_width = options->stat_graph_width;
1721                if (name_width > width - number_width - 6 - graph_width)
1722                        name_width = width - number_width - 6 - graph_width;
1723                else
1724                        graph_width = width - number_width - 6 - name_width;
1725        }
1726
1727        /*
1728         * From here name_width is the width of the name area,
1729         * and graph_width is the width of the graph area.
1730         * max_change is used to scale graph properly.
1731         */
1732        for (i = 0; i < count; i++) {
1733                const char *prefix = "";
1734                struct diffstat_file *file = data->files[i];
1735                char *name = file->print_name;
1736                uintmax_t added = file->added;
1737                uintmax_t deleted = file->deleted;
1738                int name_len;
1739
1740                if (!file->is_interesting && (added + deleted == 0))
1741                        continue;
1742
1743                /*
1744                 * "scale" the filename
1745                 */
1746                len = name_width;
1747                name_len = strlen(name);
1748                if (name_width < name_len) {
1749                        char *slash;
1750                        prefix = "...";
1751                        len -= 3;
1752                        name += name_len - len;
1753                        slash = strchr(name, '/');
1754                        if (slash)
1755                                name = slash;
1756                }
1757
1758                if (file->is_binary) {
1759                        fprintf(options->file, "%s", line_prefix);
1760                        show_name(options->file, prefix, name, len);
1761                        fprintf(options->file, " %*s", number_width, "Bin");
1762                        if (!added && !deleted) {
1763                                putc('\n', options->file);
1764                                continue;
1765                        }
1766                        fprintf(options->file, " %s%"PRIuMAX"%s",
1767                                del_c, deleted, reset);
1768                        fprintf(options->file, " -> ");
1769                        fprintf(options->file, "%s%"PRIuMAX"%s",
1770                                add_c, added, reset);
1771                        fprintf(options->file, " bytes");
1772                        fprintf(options->file, "\n");
1773                        continue;
1774                }
1775                else if (file->is_unmerged) {
1776                        fprintf(options->file, "%s", line_prefix);
1777                        show_name(options->file, prefix, name, len);
1778                        fprintf(options->file, " Unmerged\n");
1779                        continue;
1780                }
1781
1782                /*
1783                 * scale the add/delete
1784                 */
1785                add = added;
1786                del = deleted;
1787
1788                if (graph_width <= max_change) {
1789                        int total = scale_linear(add + del, graph_width, max_change);
1790                        if (total < 2 && add && del)
1791                                /* width >= 2 due to the sanity check */
1792                                total = 2;
1793                        if (add < del) {
1794                                add = scale_linear(add, graph_width, max_change);
1795                                del = total - add;
1796                        } else {
1797                                del = scale_linear(del, graph_width, max_change);
1798                                add = total - del;
1799                        }
1800                }
1801                fprintf(options->file, "%s", line_prefix);
1802                show_name(options->file, prefix, name, len);
1803                fprintf(options->file, " %*"PRIuMAX"%s",
1804                        number_width, added + deleted,
1805                        added + deleted ? " " : "");
1806                show_graph(options->file, '+', add, add_c, reset);
1807                show_graph(options->file, '-', del, del_c, reset);
1808                fprintf(options->file, "\n");
1809        }
1810
1811        for (i = 0; i < data->nr; i++) {
1812                struct diffstat_file *file = data->files[i];
1813                uintmax_t added = file->added;
1814                uintmax_t deleted = file->deleted;
1815
1816                if (file->is_unmerged ||
1817                    (!file->is_interesting && (added + deleted == 0))) {
1818                        total_files--;
1819                        continue;
1820                }
1821
1822                if (!file->is_binary) {
1823                        adds += added;
1824                        dels += deleted;
1825                }
1826                if (i < count)
1827                        continue;
1828                if (!extra_shown)
1829                        fprintf(options->file, "%s ...\n", line_prefix);
1830                extra_shown = 1;
1831        }
1832        fprintf(options->file, "%s", line_prefix);
1833        print_stat_summary(options->file, total_files, adds, dels);
1834}
1835
1836static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1837{
1838        int i, adds = 0, dels = 0, total_files = data->nr;
1839
1840        if (data->nr == 0)
1841                return;
1842
1843        for (i = 0; i < data->nr; i++) {
1844                int added = data->files[i]->added;
1845                int deleted= data->files[i]->deleted;
1846
1847                if (data->files[i]->is_unmerged ||
1848                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
1849                        total_files--;
1850                } else if (!data->files[i]->is_binary) { /* don't count bytes */
1851                        adds += added;
1852                        dels += deleted;
1853                }
1854        }
1855        fprintf(options->file, "%s", diff_line_prefix(options));
1856        print_stat_summary(options->file, total_files, adds, dels);
1857}
1858
1859static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1860{
1861        int i;
1862
1863        if (data->nr == 0)
1864                return;
1865
1866        for (i = 0; i < data->nr; i++) {
1867                struct diffstat_file *file = data->files[i];
1868
1869                fprintf(options->file, "%s", diff_line_prefix(options));
1870
1871                if (file->is_binary)
1872                        fprintf(options->file, "-\t-\t");
1873                else
1874                        fprintf(options->file,
1875                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1876                                file->added, file->deleted);
1877                if (options->line_termination) {
1878                        fill_print_name(file);
1879                        if (!file->is_renamed)
1880                                write_name_quoted(file->name, options->file,
1881                                                  options->line_termination);
1882                        else {
1883                                fputs(file->print_name, options->file);
1884                                putc(options->line_termination, options->file);
1885                        }
1886                } else {
1887                        if (file->is_renamed) {
1888                                putc('\0', options->file);
1889                                write_name_quoted(file->from_name, options->file, '\0');
1890                        }
1891                        write_name_quoted(file->name, options->file, '\0');
1892                }
1893        }
1894}
1895
1896struct dirstat_file {
1897        const char *name;
1898        unsigned long changed;
1899};
1900
1901struct dirstat_dir {
1902        struct dirstat_file *files;
1903        int alloc, nr, permille, cumulative;
1904};
1905
1906static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1907                unsigned long changed, const char *base, int baselen)
1908{
1909        unsigned long this_dir = 0;
1910        unsigned int sources = 0;
1911        const char *line_prefix = diff_line_prefix(opt);
1912
1913        while (dir->nr) {
1914                struct dirstat_file *f = dir->files;
1915                int namelen = strlen(f->name);
1916                unsigned long this;
1917                char *slash;
1918
1919                if (namelen < baselen)
1920                        break;
1921                if (memcmp(f->name, base, baselen))
1922                        break;
1923                slash = strchr(f->name + baselen, '/');
1924                if (slash) {
1925                        int newbaselen = slash + 1 - f->name;
1926                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1927                        sources++;
1928                } else {
1929                        this = f->changed;
1930                        dir->files++;
1931                        dir->nr--;
1932                        sources += 2;
1933                }
1934                this_dir += this;
1935        }
1936
1937        /*
1938         * We don't report dirstat's for
1939         *  - the top level
1940         *  - or cases where everything came from a single directory
1941         *    under this directory (sources == 1).
1942         */
1943        if (baselen && sources != 1) {
1944                if (this_dir) {
1945                        int permille = this_dir * 1000 / changed;
1946                        if (permille >= dir->permille) {
1947                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1948                                        permille / 10, permille % 10, baselen, base);
1949                                if (!dir->cumulative)
1950                                        return 0;
1951                        }
1952                }
1953        }
1954        return this_dir;
1955}
1956
1957static int dirstat_compare(const void *_a, const void *_b)
1958{
1959        const struct dirstat_file *a = _a;
1960        const struct dirstat_file *b = _b;
1961        return strcmp(a->name, b->name);
1962}
1963
1964static void show_dirstat(struct diff_options *options)
1965{
1966        int i;
1967        unsigned long changed;
1968        struct dirstat_dir dir;
1969        struct diff_queue_struct *q = &diff_queued_diff;
1970
1971        dir.files = NULL;
1972        dir.alloc = 0;
1973        dir.nr = 0;
1974        dir.permille = options->dirstat_permille;
1975        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1976
1977        changed = 0;
1978        for (i = 0; i < q->nr; i++) {
1979                struct diff_filepair *p = q->queue[i];
1980                const char *name;
1981                unsigned long copied, added, damage;
1982                int content_changed;
1983
1984                name = p->two->path ? p->two->path : p->one->path;
1985
1986                if (p->one->oid_valid && p->two->oid_valid)
1987                        content_changed = oidcmp(&p->one->oid, &p->two->oid);
1988                else
1989                        content_changed = 1;
1990
1991                if (!content_changed) {
1992                        /*
1993                         * The SHA1 has not changed, so pre-/post-content is
1994                         * identical. We can therefore skip looking at the
1995                         * file contents altogether.
1996                         */
1997                        damage = 0;
1998                        goto found_damage;
1999                }
2000
2001                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
2002                        /*
2003                         * In --dirstat-by-file mode, we don't really need to
2004                         * look at the actual file contents at all.
2005                         * The fact that the SHA1 changed is enough for us to
2006                         * add this file to the list of results
2007                         * (with each file contributing equal damage).
2008                         */
2009                        damage = 1;
2010                        goto found_damage;
2011                }
2012
2013                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
2014                        diff_populate_filespec(p->one, 0);
2015                        diff_populate_filespec(p->two, 0);
2016                        diffcore_count_changes(p->one, p->two, NULL, NULL,
2017                                               &copied, &added);
2018                        diff_free_filespec_data(p->one);
2019                        diff_free_filespec_data(p->two);
2020                } else if (DIFF_FILE_VALID(p->one)) {
2021                        diff_populate_filespec(p->one, CHECK_SIZE_ONLY);
2022                        copied = added = 0;
2023                        diff_free_filespec_data(p->one);
2024                } else if (DIFF_FILE_VALID(p->two)) {
2025                        diff_populate_filespec(p->two, CHECK_SIZE_ONLY);
2026                        copied = 0;
2027                        added = p->two->size;
2028                        diff_free_filespec_data(p->two);
2029                } else
2030                        continue;
2031
2032                /*
2033                 * Original minus copied is the removed material,
2034                 * added is the new material.  They are both damages
2035                 * made to the preimage.
2036                 * If the resulting damage is zero, we know that
2037                 * diffcore_count_changes() considers the two entries to
2038                 * be identical, but since content_changed is true, we
2039                 * know that there must have been _some_ kind of change,
2040                 * so we force all entries to have damage > 0.
2041                 */
2042                damage = (p->one->size - copied) + added;
2043                if (!damage)
2044                        damage = 1;
2045
2046found_damage:
2047                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
2048                dir.files[dir.nr].name = name;
2049                dir.files[dir.nr].changed = damage;
2050                changed += damage;
2051                dir.nr++;
2052        }
2053
2054        /* This can happen even with many files, if everything was renames */
2055        if (!changed)
2056                return;
2057
2058        /* Show all directories with more than x% of the changes */
2059        QSORT(dir.files, dir.nr, dirstat_compare);
2060        gather_dirstat(options, &dir, changed, "", 0);
2061}
2062
2063static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
2064{
2065        int i;
2066        unsigned long changed;
2067        struct dirstat_dir dir;
2068
2069        if (data->nr == 0)
2070                return;
2071
2072        dir.files = NULL;
2073        dir.alloc = 0;
2074        dir.nr = 0;
2075        dir.permille = options->dirstat_permille;
2076        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
2077
2078        changed = 0;
2079        for (i = 0; i < data->nr; i++) {
2080                struct diffstat_file *file = data->files[i];
2081                unsigned long damage = file->added + file->deleted;
2082                if (file->is_binary)
2083                        /*
2084                         * binary files counts bytes, not lines. Must find some
2085                         * way to normalize binary bytes vs. textual lines.
2086                         * The following heuristic assumes that there are 64
2087                         * bytes per "line".
2088                         * This is stupid and ugly, but very cheap...
2089                         */
2090                        damage = DIV_ROUND_UP(damage, 64);
2091                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
2092                dir.files[dir.nr].name = file->name;
2093                dir.files[dir.nr].changed = damage;
2094                changed += damage;
2095                dir.nr++;
2096        }
2097
2098        /* This can happen even with many files, if everything was renames */
2099        if (!changed)
2100                return;
2101
2102        /* Show all directories with more than x% of the changes */
2103        QSORT(dir.files, dir.nr, dirstat_compare);
2104        gather_dirstat(options, &dir, changed, "", 0);
2105}
2106
2107static void free_diffstat_info(struct diffstat_t *diffstat)
2108{
2109        int i;
2110        for (i = 0; i < diffstat->nr; i++) {
2111                struct diffstat_file *f = diffstat->files[i];
2112                if (f->name != f->print_name)
2113                        free(f->print_name);
2114                free(f->name);
2115                free(f->from_name);
2116                free(f);
2117        }
2118        free(diffstat->files);
2119}
2120
2121struct checkdiff_t {
2122        const char *filename;
2123        int lineno;
2124        int conflict_marker_size;
2125        struct diff_options *o;
2126        unsigned ws_rule;
2127        unsigned status;
2128};
2129
2130static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
2131{
2132        char firstchar;
2133        int cnt;
2134
2135        if (len < marker_size + 1)
2136                return 0;
2137        firstchar = line[0];
2138        switch (firstchar) {
2139        case '=': case '>': case '<': case '|':
2140                break;
2141        default:
2142                return 0;
2143        }
2144        for (cnt = 1; cnt < marker_size; cnt++)
2145                if (line[cnt] != firstchar)
2146                        return 0;
2147        /* line[1] thru line[marker_size-1] are same as firstchar */
2148        if (len < marker_size + 1 || !isspace(line[marker_size]))
2149                return 0;
2150        return 1;
2151}
2152
2153static void checkdiff_consume(void *priv, char *line, unsigned long len)
2154{
2155        struct checkdiff_t *data = priv;
2156        int marker_size = data->conflict_marker_size;
2157        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
2158        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
2159        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
2160        char *err;
2161        const char *line_prefix;
2162
2163        assert(data->o);
2164        line_prefix = diff_line_prefix(data->o);
2165
2166        if (line[0] == '+') {
2167                unsigned bad;
2168                data->lineno++;
2169                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
2170                        data->status |= 1;
2171                        fprintf(data->o->file,
2172                                "%s%s:%d: leftover conflict marker\n",
2173                                line_prefix, data->filename, data->lineno);
2174                }
2175                bad = ws_check(line + 1, len - 1, data->ws_rule);
2176                if (!bad)
2177                        return;
2178                data->status |= bad;
2179                err = whitespace_error_string(bad);
2180                fprintf(data->o->file, "%s%s:%d: %s.\n",
2181                        line_prefix, data->filename, data->lineno, err);
2182                free(err);
2183                emit_line(data->o, set, reset, line, 1);
2184                ws_check_emit(line + 1, len - 1, data->ws_rule,
2185                              data->o->file, set, reset, ws);
2186        } else if (line[0] == ' ') {
2187                data->lineno++;
2188        } else if (line[0] == '@') {
2189                char *plus = strchr(line, '+');
2190                if (plus)
2191                        data->lineno = strtol(plus, NULL, 10) - 1;
2192                else
2193                        die("invalid diff");
2194        }
2195}
2196
2197static unsigned char *deflate_it(char *data,
2198                                 unsigned long size,
2199                                 unsigned long *result_size)
2200{
2201        int bound;
2202        unsigned char *deflated;
2203        git_zstream stream;
2204
2205        git_deflate_init(&stream, zlib_compression_level);
2206        bound = git_deflate_bound(&stream, size);
2207        deflated = xmalloc(bound);
2208        stream.next_out = deflated;
2209        stream.avail_out = bound;
2210
2211        stream.next_in = (unsigned char *)data;
2212        stream.avail_in = size;
2213        while (git_deflate(&stream, Z_FINISH) == Z_OK)
2214                ; /* nothing */
2215        git_deflate_end(&stream);
2216        *result_size = stream.total_out;
2217        return deflated;
2218}
2219
2220static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two,
2221                                  const char *prefix)
2222{
2223        void *cp;
2224        void *delta;
2225        void *deflated;
2226        void *data;
2227        unsigned long orig_size;
2228        unsigned long delta_size;
2229        unsigned long deflate_size;
2230        unsigned long data_size;
2231
2232        /* We could do deflated delta, or we could do just deflated two,
2233         * whichever is smaller.
2234         */
2235        delta = NULL;
2236        deflated = deflate_it(two->ptr, two->size, &deflate_size);
2237        if (one->size && two->size) {
2238                delta = diff_delta(one->ptr, one->size,
2239                                   two->ptr, two->size,
2240                                   &delta_size, deflate_size);
2241                if (delta) {
2242                        void *to_free = delta;
2243                        orig_size = delta_size;
2244                        delta = deflate_it(delta, delta_size, &delta_size);
2245                        free(to_free);
2246                }
2247        }
2248
2249        if (delta && delta_size < deflate_size) {
2250                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
2251                free(deflated);
2252                data = delta;
2253                data_size = delta_size;
2254        }
2255        else {
2256                fprintf(file, "%sliteral %lu\n", prefix, two->size);
2257                free(delta);
2258                data = deflated;
2259                data_size = deflate_size;
2260        }
2261
2262        /* emit data encoded in base85 */
2263        cp = data;
2264        while (data_size) {
2265                int bytes = (52 < data_size) ? 52 : data_size;
2266                char line[70];
2267                data_size -= bytes;
2268                if (bytes <= 26)
2269                        line[0] = bytes + 'A' - 1;
2270                else
2271                        line[0] = bytes - 26 + 'a' - 1;
2272                encode_85(line + 1, cp, bytes);
2273                cp = (char *) cp + bytes;
2274                fprintf(file, "%s", prefix);
2275                fputs(line, file);
2276                fputc('\n', file);
2277        }
2278        fprintf(file, "%s\n", prefix);
2279        free(data);
2280}
2281
2282static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two,
2283                             const char *prefix)
2284{
2285        fprintf(file, "%sGIT binary patch\n", prefix);
2286        emit_binary_diff_body(file, one, two, prefix);
2287        emit_binary_diff_body(file, two, one, prefix);
2288}
2289
2290int diff_filespec_is_binary(struct diff_filespec *one)
2291{
2292        if (one->is_binary == -1) {
2293                diff_filespec_load_driver(one);
2294                if (one->driver->binary != -1)
2295                        one->is_binary = one->driver->binary;
2296                else {
2297                        if (!one->data && DIFF_FILE_VALID(one))
2298                                diff_populate_filespec(one, CHECK_BINARY);
2299                        if (one->is_binary == -1 && one->data)
2300                                one->is_binary = buffer_is_binary(one->data,
2301                                                one->size);
2302                        if (one->is_binary == -1)
2303                                one->is_binary = 0;
2304                }
2305        }
2306        return one->is_binary;
2307}
2308
2309static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
2310{
2311        diff_filespec_load_driver(one);
2312        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
2313}
2314
2315void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
2316{
2317        if (!options->a_prefix)
2318                options->a_prefix = a;
2319        if (!options->b_prefix)
2320                options->b_prefix = b;
2321}
2322
2323struct userdiff_driver *get_textconv(struct diff_filespec *one)
2324{
2325        if (!DIFF_FILE_VALID(one))
2326                return NULL;
2327
2328        diff_filespec_load_driver(one);
2329        return userdiff_get_textconv(one->driver);
2330}
2331
2332static void builtin_diff(const char *name_a,
2333                         const char *name_b,
2334                         struct diff_filespec *one,
2335                         struct diff_filespec *two,
2336                         const char *xfrm_msg,
2337                         int must_show_header,
2338                         struct diff_options *o,
2339                         int complete_rewrite)
2340{
2341        mmfile_t mf1, mf2;
2342        const char *lbl[2];
2343        char *a_one, *b_two;
2344        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
2345        const char *reset = diff_get_color_opt(o, DIFF_RESET);
2346        const char *a_prefix, *b_prefix;
2347        struct userdiff_driver *textconv_one = NULL;
2348        struct userdiff_driver *textconv_two = NULL;
2349        struct strbuf header = STRBUF_INIT;
2350        const char *line_prefix = diff_line_prefix(o);
2351
2352        diff_set_mnemonic_prefix(o, "a/", "b/");
2353        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
2354                a_prefix = o->b_prefix;
2355                b_prefix = o->a_prefix;
2356        } else {
2357                a_prefix = o->a_prefix;
2358                b_prefix = o->b_prefix;
2359        }
2360
2361        if (o->submodule_format == DIFF_SUBMODULE_LOG &&
2362            (!one->mode || S_ISGITLINK(one->mode)) &&
2363            (!two->mode || S_ISGITLINK(two->mode))) {
2364                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2365                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2366                show_submodule_summary(o->file, one->path ? one->path : two->path,
2367                                line_prefix,
2368                                &one->oid, &two->oid,
2369                                two->dirty_submodule,
2370                                meta, del, add, reset);
2371                return;
2372        } else if (o->submodule_format == DIFF_SUBMODULE_INLINE_DIFF &&
2373                   (!one->mode || S_ISGITLINK(one->mode)) &&
2374                   (!two->mode || S_ISGITLINK(two->mode))) {
2375                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2376                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2377                show_submodule_inline_diff(o->file, one->path ? one->path : two->path,
2378                                line_prefix,
2379                                &one->oid, &two->oid,
2380                                two->dirty_submodule,
2381                                meta, del, add, reset, o);
2382                return;
2383        }
2384
2385        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
2386                textconv_one = get_textconv(one);
2387                textconv_two = get_textconv(two);
2388        }
2389
2390        /* Never use a non-valid filename anywhere if at all possible */
2391        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
2392        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
2393
2394        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
2395        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
2396        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
2397        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
2398        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
2399        if (lbl[0][0] == '/') {
2400                /* /dev/null */
2401                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
2402                if (xfrm_msg)
2403                        strbuf_addstr(&header, xfrm_msg);
2404                must_show_header = 1;
2405        }
2406        else if (lbl[1][0] == '/') {
2407                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
2408                if (xfrm_msg)
2409                        strbuf_addstr(&header, xfrm_msg);
2410                must_show_header = 1;
2411        }
2412        else {
2413                if (one->mode != two->mode) {
2414                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
2415                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
2416                        must_show_header = 1;
2417                }
2418                if (xfrm_msg)
2419                        strbuf_addstr(&header, xfrm_msg);
2420
2421                /*
2422                 * we do not run diff between different kind
2423                 * of objects.
2424                 */
2425                if ((one->mode ^ two->mode) & S_IFMT)
2426                        goto free_ab_and_return;
2427                if (complete_rewrite &&
2428                    (textconv_one || !diff_filespec_is_binary(one)) &&
2429                    (textconv_two || !diff_filespec_is_binary(two))) {
2430                        fprintf(o->file, "%s", header.buf);
2431                        strbuf_reset(&header);
2432                        emit_rewrite_diff(name_a, name_b, one, two,
2433                                                textconv_one, textconv_two, o);
2434                        o->found_changes = 1;
2435                        goto free_ab_and_return;
2436                }
2437        }
2438
2439        if (o->irreversible_delete && lbl[1][0] == '/') {
2440                fprintf(o->file, "%s", header.buf);
2441                strbuf_reset(&header);
2442                goto free_ab_and_return;
2443        } else if (!DIFF_OPT_TST(o, TEXT) &&
2444            ( (!textconv_one && diff_filespec_is_binary(one)) ||
2445              (!textconv_two && diff_filespec_is_binary(two)) )) {
2446                if (!one->data && !two->data &&
2447                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
2448                    !DIFF_OPT_TST(o, BINARY)) {
2449                        if (!oidcmp(&one->oid, &two->oid)) {
2450                                if (must_show_header)
2451                                        fprintf(o->file, "%s", header.buf);
2452                                goto free_ab_and_return;
2453                        }
2454                        fprintf(o->file, "%s", header.buf);
2455                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2456                                line_prefix, lbl[0], lbl[1]);
2457                        goto free_ab_and_return;
2458                }
2459                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2460                        die("unable to read files to diff");
2461                /* Quite common confusing case */
2462                if (mf1.size == mf2.size &&
2463                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2464                        if (must_show_header)
2465                                fprintf(o->file, "%s", header.buf);
2466                        goto free_ab_and_return;
2467                }
2468                fprintf(o->file, "%s", header.buf);
2469                strbuf_reset(&header);
2470                if (DIFF_OPT_TST(o, BINARY))
2471                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2472                else
2473                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2474                                line_prefix, lbl[0], lbl[1]);
2475                o->found_changes = 1;
2476        } else {
2477                /* Crazy xdl interfaces.. */
2478                const char *diffopts = getenv("GIT_DIFF_OPTS");
2479                const char *v;
2480                xpparam_t xpp;
2481                xdemitconf_t xecfg;
2482                struct emit_callback ecbdata;
2483                const struct userdiff_funcname *pe;
2484
2485                if (must_show_header) {
2486                        fprintf(o->file, "%s", header.buf);
2487                        strbuf_reset(&header);
2488                }
2489
2490                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2491                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2492
2493                pe = diff_funcname_pattern(one);
2494                if (!pe)
2495                        pe = diff_funcname_pattern(two);
2496
2497                memset(&xpp, 0, sizeof(xpp));
2498                memset(&xecfg, 0, sizeof(xecfg));
2499                memset(&ecbdata, 0, sizeof(ecbdata));
2500                ecbdata.label_path = lbl;
2501                ecbdata.color_diff = want_color(o->use_color);
2502                ecbdata.ws_rule = whitespace_rule(name_b);
2503                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2504                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2505                ecbdata.opt = o;
2506                ecbdata.header = header.len ? &header : NULL;
2507                xpp.flags = o->xdl_opts;
2508                xecfg.ctxlen = o->context;
2509                xecfg.interhunkctxlen = o->interhunkcontext;
2510                xecfg.flags = XDL_EMIT_FUNCNAMES;
2511                if (DIFF_OPT_TST(o, FUNCCONTEXT))
2512                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
2513                if (pe)
2514                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2515                if (!diffopts)
2516                        ;
2517                else if (skip_prefix(diffopts, "--unified=", &v))
2518                        xecfg.ctxlen = strtoul(v, NULL, 10);
2519                else if (skip_prefix(diffopts, "-u", &v))
2520                        xecfg.ctxlen = strtoul(v, NULL, 10);
2521                if (o->word_diff)
2522                        init_diff_words_data(&ecbdata, o, one, two);
2523                if (xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2524                                  &xpp, &xecfg))
2525                        die("unable to generate diff for %s", one->path);
2526                if (o->word_diff)
2527                        free_diff_words_data(&ecbdata);
2528                if (textconv_one)
2529                        free(mf1.ptr);
2530                if (textconv_two)
2531                        free(mf2.ptr);
2532                xdiff_clear_find_func(&xecfg);
2533        }
2534
2535 free_ab_and_return:
2536        strbuf_release(&header);
2537        diff_free_filespec_data(one);
2538        diff_free_filespec_data(two);
2539        free(a_one);
2540        free(b_two);
2541        return;
2542}
2543
2544static void builtin_diffstat(const char *name_a, const char *name_b,
2545                             struct diff_filespec *one,
2546                             struct diff_filespec *two,
2547                             struct diffstat_t *diffstat,
2548                             struct diff_options *o,
2549                             struct diff_filepair *p)
2550{
2551        mmfile_t mf1, mf2;
2552        struct diffstat_file *data;
2553        int same_contents;
2554        int complete_rewrite = 0;
2555
2556        if (!DIFF_PAIR_UNMERGED(p)) {
2557                if (p->status == DIFF_STATUS_MODIFIED && p->score)
2558                        complete_rewrite = 1;
2559        }
2560
2561        data = diffstat_add(diffstat, name_a, name_b);
2562        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
2563
2564        if (!one || !two) {
2565                data->is_unmerged = 1;
2566                return;
2567        }
2568
2569        same_contents = !oidcmp(&one->oid, &two->oid);
2570
2571        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2572                data->is_binary = 1;
2573                if (same_contents) {
2574                        data->added = 0;
2575                        data->deleted = 0;
2576                } else {
2577                        data->added = diff_filespec_size(two);
2578                        data->deleted = diff_filespec_size(one);
2579                }
2580        }
2581
2582        else if (complete_rewrite) {
2583                diff_populate_filespec(one, 0);
2584                diff_populate_filespec(two, 0);
2585                data->deleted = count_lines(one->data, one->size);
2586                data->added = count_lines(two->data, two->size);
2587        }
2588
2589        else if (!same_contents) {
2590                /* Crazy xdl interfaces.. */
2591                xpparam_t xpp;
2592                xdemitconf_t xecfg;
2593
2594                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2595                        die("unable to read files to diff");
2596
2597                memset(&xpp, 0, sizeof(xpp));
2598                memset(&xecfg, 0, sizeof(xecfg));
2599                xpp.flags = o->xdl_opts;
2600                xecfg.ctxlen = o->context;
2601                xecfg.interhunkctxlen = o->interhunkcontext;
2602                if (xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2603                                  &xpp, &xecfg))
2604                        die("unable to generate diffstat for %s", one->path);
2605        }
2606
2607        diff_free_filespec_data(one);
2608        diff_free_filespec_data(two);
2609}
2610
2611static void builtin_checkdiff(const char *name_a, const char *name_b,
2612                              const char *attr_path,
2613                              struct diff_filespec *one,
2614                              struct diff_filespec *two,
2615                              struct diff_options *o)
2616{
2617        mmfile_t mf1, mf2;
2618        struct checkdiff_t data;
2619
2620        if (!two)
2621                return;
2622
2623        memset(&data, 0, sizeof(data));
2624        data.filename = name_b ? name_b : name_a;
2625        data.lineno = 0;
2626        data.o = o;
2627        data.ws_rule = whitespace_rule(attr_path);
2628        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2629
2630        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2631                die("unable to read files to diff");
2632
2633        /*
2634         * All the other codepaths check both sides, but not checking
2635         * the "old" side here is deliberate.  We are checking the newly
2636         * introduced changes, and as long as the "new" side is text, we
2637         * can and should check what it introduces.
2638         */
2639        if (diff_filespec_is_binary(two))
2640                goto free_and_return;
2641        else {
2642                /* Crazy xdl interfaces.. */
2643                xpparam_t xpp;
2644                xdemitconf_t xecfg;
2645
2646                memset(&xpp, 0, sizeof(xpp));
2647                memset(&xecfg, 0, sizeof(xecfg));
2648                xecfg.ctxlen = 1; /* at least one context line */
2649                xpp.flags = 0;
2650                if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2651                                  &xpp, &xecfg))
2652                        die("unable to generate checkdiff for %s", one->path);
2653
2654                if (data.ws_rule & WS_BLANK_AT_EOF) {
2655                        struct emit_callback ecbdata;
2656                        int blank_at_eof;
2657
2658                        ecbdata.ws_rule = data.ws_rule;
2659                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2660                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2661
2662                        if (blank_at_eof) {
2663                                static char *err;
2664                                if (!err)
2665                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2666                                fprintf(o->file, "%s:%d: %s.\n",
2667                                        data.filename, blank_at_eof, err);
2668                                data.status = 1; /* report errors */
2669                        }
2670                }
2671        }
2672 free_and_return:
2673        diff_free_filespec_data(one);
2674        diff_free_filespec_data(two);
2675        if (data.status)
2676                DIFF_OPT_SET(o, CHECK_FAILED);
2677}
2678
2679struct diff_filespec *alloc_filespec(const char *path)
2680{
2681        struct diff_filespec *spec;
2682
2683        FLEXPTR_ALLOC_STR(spec, path, path);
2684        spec->count = 1;
2685        spec->is_binary = -1;
2686        return spec;
2687}
2688
2689void free_filespec(struct diff_filespec *spec)
2690{
2691        if (!--spec->count) {
2692                diff_free_filespec_data(spec);
2693                free(spec);
2694        }
2695}
2696
2697void fill_filespec(struct diff_filespec *spec, const struct object_id *oid,
2698                   int oid_valid, unsigned short mode)
2699{
2700        if (mode) {
2701                spec->mode = canon_mode(mode);
2702                oidcpy(&spec->oid, oid);
2703                spec->oid_valid = oid_valid;
2704        }
2705}
2706
2707/*
2708 * Given a name and sha1 pair, if the index tells us the file in
2709 * the work tree has that object contents, return true, so that
2710 * prepare_temp_file() does not have to inflate and extract.
2711 */
2712static int reuse_worktree_file(const char *name, const struct object_id *oid, int want_file)
2713{
2714        const struct cache_entry *ce;
2715        struct stat st;
2716        int pos, len;
2717
2718        /*
2719         * We do not read the cache ourselves here, because the
2720         * benchmark with my previous version that always reads cache
2721         * shows that it makes things worse for diff-tree comparing
2722         * two linux-2.6 kernel trees in an already checked out work
2723         * tree.  This is because most diff-tree comparisons deal with
2724         * only a small number of files, while reading the cache is
2725         * expensive for a large project, and its cost outweighs the
2726         * savings we get by not inflating the object to a temporary
2727         * file.  Practically, this code only helps when we are used
2728         * by diff-cache --cached, which does read the cache before
2729         * calling us.
2730         */
2731        if (!active_cache)
2732                return 0;
2733
2734        /* We want to avoid the working directory if our caller
2735         * doesn't need the data in a normal file, this system
2736         * is rather slow with its stat/open/mmap/close syscalls,
2737         * and the object is contained in a pack file.  The pack
2738         * is probably already open and will be faster to obtain
2739         * the data through than the working directory.  Loose
2740         * objects however would tend to be slower as they need
2741         * to be individually opened and inflated.
2742         */
2743        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(oid->hash))
2744                return 0;
2745
2746        /*
2747         * Similarly, if we'd have to convert the file contents anyway, that
2748         * makes the optimization not worthwhile.
2749         */
2750        if (!want_file && would_convert_to_git(&the_index, name))
2751                return 0;
2752
2753        len = strlen(name);
2754        pos = cache_name_pos(name, len);
2755        if (pos < 0)
2756                return 0;
2757        ce = active_cache[pos];
2758
2759        /*
2760         * This is not the sha1 we are looking for, or
2761         * unreusable because it is not a regular file.
2762         */
2763        if (oidcmp(oid, &ce->oid) || !S_ISREG(ce->ce_mode))
2764                return 0;
2765
2766        /*
2767         * If ce is marked as "assume unchanged", there is no
2768         * guarantee that work tree matches what we are looking for.
2769         */
2770        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2771                return 0;
2772
2773        /*
2774         * If ce matches the file in the work tree, we can reuse it.
2775         */
2776        if (ce_uptodate(ce) ||
2777            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2778                return 1;
2779
2780        return 0;
2781}
2782
2783static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2784{
2785        struct strbuf buf = STRBUF_INIT;
2786        char *dirty = "";
2787
2788        /* Are we looking at the work tree? */
2789        if (s->dirty_submodule)
2790                dirty = "-dirty";
2791
2792        strbuf_addf(&buf, "Subproject commit %s%s\n",
2793                    oid_to_hex(&s->oid), dirty);
2794        s->size = buf.len;
2795        if (size_only) {
2796                s->data = NULL;
2797                strbuf_release(&buf);
2798        } else {
2799                s->data = strbuf_detach(&buf, NULL);
2800                s->should_free = 1;
2801        }
2802        return 0;
2803}
2804
2805/*
2806 * While doing rename detection and pickaxe operation, we may need to
2807 * grab the data for the blob (or file) for our own in-core comparison.
2808 * diff_filespec has data and size fields for this purpose.
2809 */
2810int diff_populate_filespec(struct diff_filespec *s, unsigned int flags)
2811{
2812        int size_only = flags & CHECK_SIZE_ONLY;
2813        int err = 0;
2814        /*
2815         * demote FAIL to WARN to allow inspecting the situation
2816         * instead of refusing.
2817         */
2818        enum safe_crlf crlf_warn = (safe_crlf == SAFE_CRLF_FAIL
2819                                    ? SAFE_CRLF_WARN
2820                                    : safe_crlf);
2821
2822        if (!DIFF_FILE_VALID(s))
2823                die("internal error: asking to populate invalid file.");
2824        if (S_ISDIR(s->mode))
2825                return -1;
2826
2827        if (s->data)
2828                return 0;
2829
2830        if (size_only && 0 < s->size)
2831                return 0;
2832
2833        if (S_ISGITLINK(s->mode))
2834                return diff_populate_gitlink(s, size_only);
2835
2836        if (!s->oid_valid ||
2837            reuse_worktree_file(s->path, &s->oid, 0)) {
2838                struct strbuf buf = STRBUF_INIT;
2839                struct stat st;
2840                int fd;
2841
2842                if (lstat(s->path, &st) < 0) {
2843                        if (errno == ENOENT) {
2844                        err_empty:
2845                                err = -1;
2846                        empty:
2847                                s->data = (char *)"";
2848                                s->size = 0;
2849                                return err;
2850                        }
2851                }
2852                s->size = xsize_t(st.st_size);
2853                if (!s->size)
2854                        goto empty;
2855                if (S_ISLNK(st.st_mode)) {
2856                        struct strbuf sb = STRBUF_INIT;
2857
2858                        if (strbuf_readlink(&sb, s->path, s->size))
2859                                goto err_empty;
2860                        s->size = sb.len;
2861                        s->data = strbuf_detach(&sb, NULL);
2862                        s->should_free = 1;
2863                        return 0;
2864                }
2865
2866                /*
2867                 * Even if the caller would be happy with getting
2868                 * only the size, we cannot return early at this
2869                 * point if the path requires us to run the content
2870                 * conversion.
2871                 */
2872                if (size_only && !would_convert_to_git(&the_index, s->path))
2873                        return 0;
2874
2875                /*
2876                 * Note: this check uses xsize_t(st.st_size) that may
2877                 * not be the true size of the blob after it goes
2878                 * through convert_to_git().  This may not strictly be
2879                 * correct, but the whole point of big_file_threshold
2880                 * and is_binary check being that we want to avoid
2881                 * opening the file and inspecting the contents, this
2882                 * is probably fine.
2883                 */
2884                if ((flags & CHECK_BINARY) &&
2885                    s->size > big_file_threshold && s->is_binary == -1) {
2886                        s->is_binary = 1;
2887                        return 0;
2888                }
2889                fd = open(s->path, O_RDONLY);
2890                if (fd < 0)
2891                        goto err_empty;
2892                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2893                close(fd);
2894                s->should_munmap = 1;
2895
2896                /*
2897                 * Convert from working tree format to canonical git format
2898                 */
2899                if (convert_to_git(&the_index, s->path, s->data, s->size, &buf, crlf_warn)) {
2900                        size_t size = 0;
2901                        munmap(s->data, s->size);
2902                        s->should_munmap = 0;
2903                        s->data = strbuf_detach(&buf, &size);
2904                        s->size = size;
2905                        s->should_free = 1;
2906                }
2907        }
2908        else {
2909                enum object_type type;
2910                if (size_only || (flags & CHECK_BINARY)) {
2911                        type = sha1_object_info(s->oid.hash, &s->size);
2912                        if (type < 0)
2913                                die("unable to read %s",
2914                                    oid_to_hex(&s->oid));
2915                        if (size_only)
2916                                return 0;
2917                        if (s->size > big_file_threshold && s->is_binary == -1) {
2918                                s->is_binary = 1;
2919                                return 0;
2920                        }
2921                }
2922                s->data = read_sha1_file(s->oid.hash, &type, &s->size);
2923                if (!s->data)
2924                        die("unable to read %s", oid_to_hex(&s->oid));
2925                s->should_free = 1;
2926        }
2927        return 0;
2928}
2929
2930void diff_free_filespec_blob(struct diff_filespec *s)
2931{
2932        if (s->should_free)
2933                free(s->data);
2934        else if (s->should_munmap)
2935                munmap(s->data, s->size);
2936
2937        if (s->should_free || s->should_munmap) {
2938                s->should_free = s->should_munmap = 0;
2939                s->data = NULL;
2940        }
2941}
2942
2943void diff_free_filespec_data(struct diff_filespec *s)
2944{
2945        diff_free_filespec_blob(s);
2946        FREE_AND_NULL(s->cnt_data);
2947}
2948
2949static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2950                           void *blob,
2951                           unsigned long size,
2952                           const struct object_id *oid,
2953                           int mode)
2954{
2955        int fd;
2956        struct strbuf buf = STRBUF_INIT;
2957        struct strbuf template = STRBUF_INIT;
2958        char *path_dup = xstrdup(path);
2959        const char *base = basename(path_dup);
2960
2961        /* Generate "XXXXXX_basename.ext" */
2962        strbuf_addstr(&template, "XXXXXX_");
2963        strbuf_addstr(&template, base);
2964
2965        fd = mks_tempfile_ts(&temp->tempfile, template.buf, strlen(base) + 1);
2966        if (fd < 0)
2967                die_errno("unable to create temp-file");
2968        if (convert_to_working_tree(path,
2969                        (const char *)blob, (size_t)size, &buf)) {
2970                blob = buf.buf;
2971                size = buf.len;
2972        }
2973        if (write_in_full(fd, blob, size) != size)
2974                die_errno("unable to write temp-file");
2975        close_tempfile(&temp->tempfile);
2976        temp->name = get_tempfile_path(&temp->tempfile);
2977        oid_to_hex_r(temp->hex, oid);
2978        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
2979        strbuf_release(&buf);
2980        strbuf_release(&template);
2981        free(path_dup);
2982}
2983
2984static struct diff_tempfile *prepare_temp_file(const char *name,
2985                struct diff_filespec *one)
2986{
2987        struct diff_tempfile *temp = claim_diff_tempfile();
2988
2989        if (!DIFF_FILE_VALID(one)) {
2990        not_a_valid_file:
2991                /* A '-' entry produces this for file-2, and
2992                 * a '+' entry produces this for file-1.
2993                 */
2994                temp->name = "/dev/null";
2995                xsnprintf(temp->hex, sizeof(temp->hex), ".");
2996                xsnprintf(temp->mode, sizeof(temp->mode), ".");
2997                return temp;
2998        }
2999
3000        if (!S_ISGITLINK(one->mode) &&
3001            (!one->oid_valid ||
3002             reuse_worktree_file(name, &one->oid, 1))) {
3003                struct stat st;
3004                if (lstat(name, &st) < 0) {
3005                        if (errno == ENOENT)
3006                                goto not_a_valid_file;
3007                        die_errno("stat(%s)", name);
3008                }
3009                if (S_ISLNK(st.st_mode)) {
3010                        struct strbuf sb = STRBUF_INIT;
3011                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
3012                                die_errno("readlink(%s)", name);
3013                        prep_temp_blob(name, temp, sb.buf, sb.len,
3014                                       (one->oid_valid ?
3015                                        &one->oid : &null_oid),
3016                                       (one->oid_valid ?
3017                                        one->mode : S_IFLNK));
3018                        strbuf_release(&sb);
3019                }
3020                else {
3021                        /* we can borrow from the file in the work tree */
3022                        temp->name = name;
3023                        if (!one->oid_valid)
3024                                oid_to_hex_r(temp->hex, &null_oid);
3025                        else
3026                                oid_to_hex_r(temp->hex, &one->oid);
3027                        /* Even though we may sometimes borrow the
3028                         * contents from the work tree, we always want
3029                         * one->mode.  mode is trustworthy even when
3030                         * !(one->oid_valid), as long as
3031                         * DIFF_FILE_VALID(one).
3032                         */
3033                        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
3034                }
3035                return temp;
3036        }
3037        else {
3038                if (diff_populate_filespec(one, 0))
3039                        die("cannot read data blob for %s", one->path);
3040                prep_temp_blob(name, temp, one->data, one->size,
3041                               &one->oid, one->mode);
3042        }
3043        return temp;
3044}
3045
3046static void add_external_diff_name(struct argv_array *argv,
3047                                   const char *name,
3048                                   struct diff_filespec *df)
3049{
3050        struct diff_tempfile *temp = prepare_temp_file(name, df);
3051        argv_array_push(argv, temp->name);
3052        argv_array_push(argv, temp->hex);
3053        argv_array_push(argv, temp->mode);
3054}
3055
3056/* An external diff command takes:
3057 *
3058 * diff-cmd name infile1 infile1-sha1 infile1-mode \
3059 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
3060 *
3061 */
3062static void run_external_diff(const char *pgm,
3063                              const char *name,
3064                              const char *other,
3065                              struct diff_filespec *one,
3066                              struct diff_filespec *two,
3067                              const char *xfrm_msg,
3068                              int complete_rewrite,
3069                              struct diff_options *o)
3070{
3071        struct argv_array argv = ARGV_ARRAY_INIT;
3072        struct argv_array env = ARGV_ARRAY_INIT;
3073        struct diff_queue_struct *q = &diff_queued_diff;
3074
3075        argv_array_push(&argv, pgm);
3076        argv_array_push(&argv, name);
3077
3078        if (one && two) {
3079                add_external_diff_name(&argv, name, one);
3080                if (!other)
3081                        add_external_diff_name(&argv, name, two);
3082                else {
3083                        add_external_diff_name(&argv, other, two);
3084                        argv_array_push(&argv, other);
3085                        argv_array_push(&argv, xfrm_msg);
3086                }
3087        }
3088
3089        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
3090        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
3091
3092        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
3093                die(_("external diff died, stopping at %s"), name);
3094
3095        remove_tempfile();
3096        argv_array_clear(&argv);
3097        argv_array_clear(&env);
3098}
3099
3100static int similarity_index(struct diff_filepair *p)
3101{
3102        return p->score * 100 / MAX_SCORE;
3103}
3104
3105static const char *diff_abbrev_oid(const struct object_id *oid, int abbrev)
3106{
3107        if (startup_info->have_repository)
3108                return find_unique_abbrev(oid->hash, abbrev);
3109        else {
3110                char *hex = oid_to_hex(oid);
3111                if (abbrev < 0)
3112                        abbrev = FALLBACK_DEFAULT_ABBREV;
3113                if (abbrev > GIT_SHA1_HEXSZ)
3114                        die("BUG: oid abbreviation out of range: %d", abbrev);
3115                if (abbrev)
3116                        hex[abbrev] = '\0';
3117                return hex;
3118        }
3119}
3120
3121static void fill_metainfo(struct strbuf *msg,
3122                          const char *name,
3123                          const char *other,
3124                          struct diff_filespec *one,
3125                          struct diff_filespec *two,
3126                          struct diff_options *o,
3127                          struct diff_filepair *p,
3128                          int *must_show_header,
3129                          int use_color)
3130{
3131        const char *set = diff_get_color(use_color, DIFF_METAINFO);
3132        const char *reset = diff_get_color(use_color, DIFF_RESET);
3133        const char *line_prefix = diff_line_prefix(o);
3134
3135        *must_show_header = 1;
3136        strbuf_init(msg, PATH_MAX * 2 + 300);
3137        switch (p->status) {
3138        case DIFF_STATUS_COPIED:
3139                strbuf_addf(msg, "%s%ssimilarity index %d%%",
3140                            line_prefix, set, similarity_index(p));
3141                strbuf_addf(msg, "%s\n%s%scopy from ",
3142                            reset,  line_prefix, set);
3143                quote_c_style(name, msg, NULL, 0);
3144                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
3145                quote_c_style(other, msg, NULL, 0);
3146                strbuf_addf(msg, "%s\n", reset);
3147                break;
3148        case DIFF_STATUS_RENAMED:
3149                strbuf_addf(msg, "%s%ssimilarity index %d%%",
3150                            line_prefix, set, similarity_index(p));
3151                strbuf_addf(msg, "%s\n%s%srename from ",
3152                            reset, line_prefix, set);
3153                quote_c_style(name, msg, NULL, 0);
3154                strbuf_addf(msg, "%s\n%s%srename to ",
3155                            reset, line_prefix, set);
3156                quote_c_style(other, msg, NULL, 0);
3157                strbuf_addf(msg, "%s\n", reset);
3158                break;
3159        case DIFF_STATUS_MODIFIED:
3160                if (p->score) {
3161                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
3162                                    line_prefix,
3163                                    set, similarity_index(p), reset);
3164                        break;
3165                }
3166                /* fallthru */
3167        default:
3168                *must_show_header = 0;
3169        }
3170        if (one && two && oidcmp(&one->oid, &two->oid)) {
3171                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
3172
3173                if (DIFF_OPT_TST(o, BINARY)) {
3174                        mmfile_t mf;
3175                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
3176                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
3177                                abbrev = 40;
3178                }
3179                strbuf_addf(msg, "%s%sindex %s..%s", line_prefix, set,
3180                            diff_abbrev_oid(&one->oid, abbrev),
3181                            diff_abbrev_oid(&two->oid, abbrev));
3182                if (one->mode == two->mode)
3183                        strbuf_addf(msg, " %06o", one->mode);
3184                strbuf_addf(msg, "%s\n", reset);
3185        }
3186}
3187
3188static void run_diff_cmd(const char *pgm,
3189                         const char *name,
3190                         const char *other,
3191                         const char *attr_path,
3192                         struct diff_filespec *one,
3193                         struct diff_filespec *two,
3194                         struct strbuf *msg,
3195                         struct diff_options *o,
3196                         struct diff_filepair *p)
3197{
3198        const char *xfrm_msg = NULL;
3199        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
3200        int must_show_header = 0;
3201
3202
3203        if (DIFF_OPT_TST(o, ALLOW_EXTERNAL)) {
3204                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
3205                if (drv && drv->external)
3206                        pgm = drv->external;
3207        }
3208
3209        if (msg) {
3210                /*
3211                 * don't use colors when the header is intended for an
3212                 * external diff driver
3213                 */
3214                fill_metainfo(msg, name, other, one, two, o, p,
3215                              &must_show_header,
3216                              want_color(o->use_color) && !pgm);
3217                xfrm_msg = msg->len ? msg->buf : NULL;
3218        }
3219
3220        if (pgm) {
3221                run_external_diff(pgm, name, other, one, two, xfrm_msg,
3222                                  complete_rewrite, o);
3223                return;
3224        }
3225        if (one && two)
3226                builtin_diff(name, other ? other : name,
3227                             one, two, xfrm_msg, must_show_header,
3228                             o, complete_rewrite);
3229        else
3230                fprintf(o->file, "* Unmerged path %s\n", name);
3231}
3232
3233static void diff_fill_oid_info(struct diff_filespec *one)
3234{
3235        if (DIFF_FILE_VALID(one)) {
3236                if (!one->oid_valid) {
3237                        struct stat st;
3238                        if (one->is_stdin) {
3239                                oidclr(&one->oid);
3240                                return;
3241                        }
3242                        if (lstat(one->path, &st) < 0)
3243                                die_errno("stat '%s'", one->path);
3244                        if (index_path(one->oid.hash, one->path, &st, 0))
3245                                die("cannot hash %s", one->path);
3246                }
3247        }
3248        else
3249                oidclr(&one->oid);
3250}
3251
3252static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
3253{
3254        /* Strip the prefix but do not molest /dev/null and absolute paths */
3255        if (*namep && **namep != '/') {
3256                *namep += prefix_length;
3257                if (**namep == '/')
3258                        ++*namep;
3259        }
3260        if (*otherp && **otherp != '/') {
3261                *otherp += prefix_length;
3262                if (**otherp == '/')
3263                        ++*otherp;
3264        }
3265}
3266
3267static void run_diff(struct diff_filepair *p, struct diff_options *o)
3268{
3269        const char *pgm = external_diff();
3270        struct strbuf msg;
3271        struct diff_filespec *one = p->one;
3272        struct diff_filespec *two = p->two;
3273        const char *name;
3274        const char *other;
3275        const char *attr_path;
3276
3277        name  = p->one->path;
3278        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3279        attr_path = name;
3280        if (o->prefix_length)
3281                strip_prefix(o->prefix_length, &name, &other);
3282
3283        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
3284                pgm = NULL;
3285
3286        if (DIFF_PAIR_UNMERGED(p)) {
3287                run_diff_cmd(pgm, name, NULL, attr_path,
3288                             NULL, NULL, NULL, o, p);
3289                return;
3290        }
3291
3292        diff_fill_oid_info(one);
3293        diff_fill_oid_info(two);
3294
3295        if (!pgm &&
3296            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
3297            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
3298                /*
3299                 * a filepair that changes between file and symlink
3300                 * needs to be split into deletion and creation.
3301                 */
3302                struct diff_filespec *null = alloc_filespec(two->path);
3303                run_diff_cmd(NULL, name, other, attr_path,
3304                             one, null, &msg, o, p);
3305                free(null);
3306                strbuf_release(&msg);
3307
3308                null = alloc_filespec(one->path);
3309                run_diff_cmd(NULL, name, other, attr_path,
3310                             null, two, &msg, o, p);
3311                free(null);
3312        }
3313        else
3314                run_diff_cmd(pgm, name, other, attr_path,
3315                             one, two, &msg, o, p);
3316
3317        strbuf_release(&msg);
3318}
3319
3320static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
3321                         struct diffstat_t *diffstat)
3322{
3323        const char *name;
3324        const char *other;
3325
3326        if (DIFF_PAIR_UNMERGED(p)) {
3327                /* unmerged */
3328                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, p);
3329                return;
3330        }
3331
3332        name = p->one->path;
3333        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3334
3335        if (o->prefix_length)
3336                strip_prefix(o->prefix_length, &name, &other);
3337
3338        diff_fill_oid_info(p->one);
3339        diff_fill_oid_info(p->two);
3340
3341        builtin_diffstat(name, other, p->one, p->two, diffstat, o, p);
3342}
3343
3344static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
3345{
3346        const char *name;
3347        const char *other;
3348        const char *attr_path;
3349
3350        if (DIFF_PAIR_UNMERGED(p)) {
3351                /* unmerged */
3352                return;
3353        }
3354
3355        name = p->one->path;
3356        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3357        attr_path = other ? other : name;
3358
3359        if (o->prefix_length)
3360                strip_prefix(o->prefix_length, &name, &other);
3361
3362        diff_fill_oid_info(p->one);
3363        diff_fill_oid_info(p->two);
3364
3365        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
3366}
3367
3368void diff_setup(struct diff_options *options)
3369{
3370        memcpy(options, &default_diff_options, sizeof(*options));
3371
3372        options->file = stdout;
3373
3374        options->abbrev = DEFAULT_ABBREV;
3375        options->line_termination = '\n';
3376        options->break_opt = -1;
3377        options->rename_limit = -1;
3378        options->dirstat_permille = diff_dirstat_permille_default;
3379        options->context = diff_context_default;
3380        options->interhunkcontext = diff_interhunk_context_default;
3381        options->ws_error_highlight = ws_error_highlight_default;
3382        DIFF_OPT_SET(options, RENAME_EMPTY);
3383
3384        /* pathchange left =NULL by default */
3385        options->change = diff_change;
3386        options->add_remove = diff_addremove;
3387        options->use_color = diff_use_color_default;
3388        options->detect_rename = diff_detect_rename_default;
3389        options->xdl_opts |= diff_algorithm;
3390        if (diff_indent_heuristic)
3391                DIFF_XDL_SET(options, INDENT_HEURISTIC);
3392
3393        options->orderfile = diff_order_file_cfg;
3394
3395        if (diff_no_prefix) {
3396                options->a_prefix = options->b_prefix = "";
3397        } else if (!diff_mnemonic_prefix) {
3398                options->a_prefix = "a/";
3399                options->b_prefix = "b/";
3400        }
3401}
3402
3403void diff_setup_done(struct diff_options *options)
3404{
3405        int count = 0;
3406
3407        if (options->set_default)
3408                options->set_default(options);
3409
3410        if (options->output_format & DIFF_FORMAT_NAME)
3411                count++;
3412        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
3413                count++;
3414        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
3415                count++;
3416        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
3417                count++;
3418        if (count > 1)
3419                die(_("--name-only, --name-status, --check and -s are mutually exclusive"));
3420
3421        /*
3422         * Most of the time we can say "there are changes"
3423         * only by checking if there are changed paths, but
3424         * --ignore-whitespace* options force us to look
3425         * inside contents.
3426         */
3427
3428        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
3429            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
3430            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
3431                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
3432        else
3433                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
3434
3435        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3436                options->detect_rename = DIFF_DETECT_COPY;
3437
3438        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
3439                options->prefix = NULL;
3440        if (options->prefix)
3441                options->prefix_length = strlen(options->prefix);
3442        else
3443                options->prefix_length = 0;
3444
3445        if (options->output_format & (DIFF_FORMAT_NAME |
3446                                      DIFF_FORMAT_NAME_STATUS |
3447                                      DIFF_FORMAT_CHECKDIFF |
3448                                      DIFF_FORMAT_NO_OUTPUT))
3449                options->output_format &= ~(DIFF_FORMAT_RAW |
3450                                            DIFF_FORMAT_NUMSTAT |
3451                                            DIFF_FORMAT_DIFFSTAT |
3452                                            DIFF_FORMAT_SHORTSTAT |
3453                                            DIFF_FORMAT_DIRSTAT |
3454                                            DIFF_FORMAT_SUMMARY |
3455                                            DIFF_FORMAT_PATCH);
3456
3457        /*
3458         * These cases always need recursive; we do not drop caller-supplied
3459         * recursive bits for other formats here.
3460         */
3461        if (options->output_format & (DIFF_FORMAT_PATCH |
3462                                      DIFF_FORMAT_NUMSTAT |
3463                                      DIFF_FORMAT_DIFFSTAT |
3464                                      DIFF_FORMAT_SHORTSTAT |
3465                                      DIFF_FORMAT_DIRSTAT |
3466                                      DIFF_FORMAT_SUMMARY |
3467                                      DIFF_FORMAT_CHECKDIFF))
3468                DIFF_OPT_SET(options, RECURSIVE);
3469        /*
3470         * Also pickaxe would not work very well if you do not say recursive
3471         */
3472        if (options->pickaxe)
3473                DIFF_OPT_SET(options, RECURSIVE);
3474        /*
3475         * When patches are generated, submodules diffed against the work tree
3476         * must be checked for dirtiness too so it can be shown in the output
3477         */
3478        if (options->output_format & DIFF_FORMAT_PATCH)
3479                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3480
3481        if (options->detect_rename && options->rename_limit < 0)
3482                options->rename_limit = diff_rename_limit_default;
3483        if (options->setup & DIFF_SETUP_USE_CACHE) {
3484                if (!active_cache)
3485                        /* read-cache does not die even when it fails
3486                         * so it is safe for us to do this here.  Also
3487                         * it does not smudge active_cache or active_nr
3488                         * when it fails, so we do not have to worry about
3489                         * cleaning it up ourselves either.
3490                         */
3491                        read_cache();
3492        }
3493        if (40 < options->abbrev)
3494                options->abbrev = 40; /* full */
3495
3496        /*
3497         * It does not make sense to show the first hit we happened
3498         * to have found.  It does not make sense not to return with
3499         * exit code in such a case either.
3500         */
3501        if (DIFF_OPT_TST(options, QUICK)) {
3502                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3503                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3504        }
3505
3506        options->diff_path_counter = 0;
3507
3508        if (DIFF_OPT_TST(options, FOLLOW_RENAMES) && options->pathspec.nr != 1)
3509                die(_("--follow requires exactly one pathspec"));
3510}
3511
3512static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3513{
3514        char c, *eq;
3515        int len;
3516
3517        if (*arg != '-')
3518                return 0;
3519        c = *++arg;
3520        if (!c)
3521                return 0;
3522        if (c == arg_short) {
3523                c = *++arg;
3524                if (!c)
3525                        return 1;
3526                if (val && isdigit(c)) {
3527                        char *end;
3528                        int n = strtoul(arg, &end, 10);
3529                        if (*end)
3530                                return 0;
3531                        *val = n;
3532                        return 1;
3533                }
3534                return 0;
3535        }
3536        if (c != '-')
3537                return 0;
3538        arg++;
3539        eq = strchrnul(arg, '=');
3540        len = eq - arg;
3541        if (!len || strncmp(arg, arg_long, len))
3542                return 0;
3543        if (*eq) {
3544                int n;
3545                char *end;
3546                if (!isdigit(*++eq))
3547                        return 0;
3548                n = strtoul(eq, &end, 10);
3549                if (*end)
3550                        return 0;
3551                *val = n;
3552        }
3553        return 1;
3554}
3555
3556static int diff_scoreopt_parse(const char *opt);
3557
3558static inline int short_opt(char opt, const char **argv,
3559                            const char **optarg)
3560{
3561        const char *arg = argv[0];
3562        if (arg[0] != '-' || arg[1] != opt)
3563                return 0;
3564        if (arg[2] != '\0') {
3565                *optarg = arg + 2;
3566                return 1;
3567        }
3568        if (!argv[1])
3569                die("Option '%c' requires a value", opt);
3570        *optarg = argv[1];
3571        return 2;
3572}
3573
3574int parse_long_opt(const char *opt, const char **argv,
3575                   const char **optarg)
3576{
3577        const char *arg = argv[0];
3578        if (!skip_prefix(arg, "--", &arg))
3579                return 0;
3580        if (!skip_prefix(arg, opt, &arg))
3581                return 0;
3582        if (*arg == '=') { /* stuck form: --option=value */
3583                *optarg = arg + 1;
3584                return 1;
3585        }
3586        if (*arg != '\0')
3587                return 0;
3588        /* separate form: --option value */
3589        if (!argv[1])
3590                die("Option '--%s' requires a value", opt);
3591        *optarg = argv[1];
3592        return 2;
3593}
3594
3595static int stat_opt(struct diff_options *options, const char **av)
3596{
3597        const char *arg = av[0];
3598        char *end;
3599        int width = options->stat_width;
3600        int name_width = options->stat_name_width;
3601        int graph_width = options->stat_graph_width;
3602        int count = options->stat_count;
3603        int argcount = 1;
3604
3605        if (!skip_prefix(arg, "--stat", &arg))
3606                die("BUG: stat option does not begin with --stat: %s", arg);
3607        end = (char *)arg;
3608
3609        switch (*arg) {
3610        case '-':
3611                if (skip_prefix(arg, "-width", &arg)) {
3612                        if (*arg == '=')
3613                                width = strtoul(arg + 1, &end, 10);
3614                        else if (!*arg && !av[1])
3615                                die_want_option("--stat-width");
3616                        else if (!*arg) {
3617                                width = strtoul(av[1], &end, 10);
3618                                argcount = 2;
3619                        }
3620                } else if (skip_prefix(arg, "-name-width", &arg)) {
3621                        if (*arg == '=')
3622                                name_width = strtoul(arg + 1, &end, 10);
3623                        else if (!*arg && !av[1])
3624                                die_want_option("--stat-name-width");
3625                        else if (!*arg) {
3626                                name_width = strtoul(av[1], &end, 10);
3627                                argcount = 2;
3628                        }
3629                } else if (skip_prefix(arg, "-graph-width", &arg)) {
3630                        if (*arg == '=')
3631                                graph_width = strtoul(arg + 1, &end, 10);
3632                        else if (!*arg && !av[1])
3633                                die_want_option("--stat-graph-width");
3634                        else if (!*arg) {
3635                                graph_width = strtoul(av[1], &end, 10);
3636                                argcount = 2;
3637                        }
3638                } else if (skip_prefix(arg, "-count", &arg)) {
3639                        if (*arg == '=')
3640                                count = strtoul(arg + 1, &end, 10);
3641                        else if (!*arg && !av[1])
3642                                die_want_option("--stat-count");
3643                        else if (!*arg) {
3644                                count = strtoul(av[1], &end, 10);
3645                                argcount = 2;
3646                        }
3647                }
3648                break;
3649        case '=':
3650                width = strtoul(arg+1, &end, 10);
3651                if (*end == ',')
3652                        name_width = strtoul(end+1, &end, 10);
3653                if (*end == ',')
3654                        count = strtoul(end+1, &end, 10);
3655        }
3656
3657        /* Important! This checks all the error cases! */
3658        if (*end)
3659                return 0;
3660        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3661        options->stat_name_width = name_width;
3662        options->stat_graph_width = graph_width;
3663        options->stat_width = width;
3664        options->stat_count = count;
3665        return argcount;
3666}
3667
3668static int parse_dirstat_opt(struct diff_options *options, const char *params)
3669{
3670        struct strbuf errmsg = STRBUF_INIT;
3671        if (parse_dirstat_params(options, params, &errmsg))
3672                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
3673                    errmsg.buf);
3674        strbuf_release(&errmsg);
3675        /*
3676         * The caller knows a dirstat-related option is given from the command
3677         * line; allow it to say "return this_function();"
3678         */
3679        options->output_format |= DIFF_FORMAT_DIRSTAT;
3680        return 1;
3681}
3682
3683static int parse_submodule_opt(struct diff_options *options, const char *value)
3684{
3685        if (parse_submodule_params(options, value))
3686                die(_("Failed to parse --submodule option parameter: '%s'"),
3687                        value);
3688        return 1;
3689}
3690
3691static const char diff_status_letters[] = {
3692        DIFF_STATUS_ADDED,
3693        DIFF_STATUS_COPIED,
3694        DIFF_STATUS_DELETED,
3695        DIFF_STATUS_MODIFIED,
3696        DIFF_STATUS_RENAMED,
3697        DIFF_STATUS_TYPE_CHANGED,
3698        DIFF_STATUS_UNKNOWN,
3699        DIFF_STATUS_UNMERGED,
3700        DIFF_STATUS_FILTER_AON,
3701        DIFF_STATUS_FILTER_BROKEN,
3702        '\0',
3703};
3704
3705static unsigned int filter_bit['Z' + 1];
3706
3707static void prepare_filter_bits(void)
3708{
3709        int i;
3710
3711        if (!filter_bit[DIFF_STATUS_ADDED]) {
3712                for (i = 0; diff_status_letters[i]; i++)
3713                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
3714        }
3715}
3716
3717static unsigned filter_bit_tst(char status, const struct diff_options *opt)
3718{
3719        return opt->filter & filter_bit[(int) status];
3720}
3721
3722static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
3723{
3724        int i, optch;
3725
3726        prepare_filter_bits();
3727
3728        /*
3729         * If there is a negation e.g. 'd' in the input, and we haven't
3730         * initialized the filter field with another --diff-filter, start
3731         * from full set of bits, except for AON.
3732         */
3733        if (!opt->filter) {
3734                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
3735                        if (optch < 'a' || 'z' < optch)
3736                                continue;
3737                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
3738                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
3739                        break;
3740                }
3741        }
3742
3743        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
3744                unsigned int bit;
3745                int negate;
3746
3747                if ('a' <= optch && optch <= 'z') {
3748                        negate = 1;
3749                        optch = toupper(optch);
3750                } else {
3751                        negate = 0;
3752                }
3753
3754                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
3755                if (!bit)
3756                        return optarg[i];
3757                if (negate)
3758                        opt->filter &= ~bit;
3759                else
3760                        opt->filter |= bit;
3761        }
3762        return 0;
3763}
3764
3765static void enable_patch_output(int *fmt) {
3766        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
3767        *fmt |= DIFF_FORMAT_PATCH;
3768}
3769
3770static int parse_ws_error_highlight_opt(struct diff_options *opt, const char *arg)
3771{
3772        int val = parse_ws_error_highlight(arg);
3773
3774        if (val < 0) {
3775                error("unknown value after ws-error-highlight=%.*s",
3776                      -1 - val, arg);
3777                return 0;
3778        }
3779        opt->ws_error_highlight = val;
3780        return 1;
3781}
3782
3783int diff_opt_parse(struct diff_options *options,
3784                   const char **av, int ac, const char *prefix)
3785{
3786        const char *arg = av[0];
3787        const char *optarg;
3788        int argcount;
3789
3790        if (!prefix)
3791                prefix = "";
3792
3793        /* Output format options */
3794        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
3795            || opt_arg(arg, 'U', "unified", &options->context))
3796                enable_patch_output(&options->output_format);
3797        else if (!strcmp(arg, "--raw"))
3798                options->output_format |= DIFF_FORMAT_RAW;
3799        else if (!strcmp(arg, "--patch-with-raw")) {
3800                enable_patch_output(&options->output_format);
3801                options->output_format |= DIFF_FORMAT_RAW;
3802        } else if (!strcmp(arg, "--numstat"))
3803                options->output_format |= DIFF_FORMAT_NUMSTAT;
3804        else if (!strcmp(arg, "--shortstat"))
3805                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3806        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
3807                return parse_dirstat_opt(options, "");
3808        else if (skip_prefix(arg, "-X", &arg))
3809                return parse_dirstat_opt(options, arg);
3810        else if (skip_prefix(arg, "--dirstat=", &arg))
3811                return parse_dirstat_opt(options, arg);
3812        else if (!strcmp(arg, "--cumulative"))
3813                return parse_dirstat_opt(options, "cumulative");
3814        else if (!strcmp(arg, "--dirstat-by-file"))
3815                return parse_dirstat_opt(options, "files");
3816        else if (skip_prefix(arg, "--dirstat-by-file=", &arg)) {
3817                parse_dirstat_opt(options, "files");
3818                return parse_dirstat_opt(options, arg);
3819        }
3820        else if (!strcmp(arg, "--check"))
3821                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3822        else if (!strcmp(arg, "--summary"))
3823                options->output_format |= DIFF_FORMAT_SUMMARY;
3824        else if (!strcmp(arg, "--patch-with-stat")) {
3825                enable_patch_output(&options->output_format);
3826                options->output_format |= DIFF_FORMAT_DIFFSTAT;
3827        } else if (!strcmp(arg, "--name-only"))
3828                options->output_format |= DIFF_FORMAT_NAME;
3829        else if (!strcmp(arg, "--name-status"))
3830                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3831        else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
3832                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3833        else if (starts_with(arg, "--stat"))
3834                /* --stat, --stat-width, --stat-name-width, or --stat-count */
3835                return stat_opt(options, av);
3836
3837        /* renames options */
3838        else if (starts_with(arg, "-B") || starts_with(arg, "--break-rewrites=") ||
3839                 !strcmp(arg, "--break-rewrites")) {
3840                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3841                        return error("invalid argument to -B: %s", arg+2);
3842        }
3843        else if (starts_with(arg, "-M") || starts_with(arg, "--find-renames=") ||
3844                 !strcmp(arg, "--find-renames")) {
3845                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3846                        return error("invalid argument to -M: %s", arg+2);
3847                options->detect_rename = DIFF_DETECT_RENAME;
3848        }
3849        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3850                options->irreversible_delete = 1;
3851        }
3852        else if (starts_with(arg, "-C") || starts_with(arg, "--find-copies=") ||
3853                 !strcmp(arg, "--find-copies")) {
3854                if (options->detect_rename == DIFF_DETECT_COPY)
3855                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3856                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3857                        return error("invalid argument to -C: %s", arg+2);
3858                options->detect_rename = DIFF_DETECT_COPY;
3859        }
3860        else if (!strcmp(arg, "--no-renames"))
3861                options->detect_rename = 0;
3862        else if (!strcmp(arg, "--rename-empty"))
3863                DIFF_OPT_SET(options, RENAME_EMPTY);
3864        else if (!strcmp(arg, "--no-rename-empty"))
3865                DIFF_OPT_CLR(options, RENAME_EMPTY);
3866        else if (!strcmp(arg, "--relative"))
3867                DIFF_OPT_SET(options, RELATIVE_NAME);
3868        else if (skip_prefix(arg, "--relative=", &arg)) {
3869                DIFF_OPT_SET(options, RELATIVE_NAME);
3870                options->prefix = arg;
3871        }
3872
3873        /* xdiff options */
3874        else if (!strcmp(arg, "--minimal"))
3875                DIFF_XDL_SET(options, NEED_MINIMAL);
3876        else if (!strcmp(arg, "--no-minimal"))
3877                DIFF_XDL_CLR(options, NEED_MINIMAL);
3878        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3879                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3880        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3881                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3882        else if (!strcmp(arg, "--ignore-space-at-eol"))
3883                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3884        else if (!strcmp(arg, "--ignore-blank-lines"))
3885                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
3886        else if (!strcmp(arg, "--indent-heuristic"))
3887                DIFF_XDL_SET(options, INDENT_HEURISTIC);
3888        else if (!strcmp(arg, "--no-indent-heuristic"))
3889                DIFF_XDL_CLR(options, INDENT_HEURISTIC);
3890        else if (!strcmp(arg, "--patience"))
3891                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
3892        else if (!strcmp(arg, "--histogram"))
3893                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
3894        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
3895                long value = parse_algorithm_value(optarg);
3896                if (value < 0)
3897                        return error("option diff-algorithm accepts \"myers\", "
3898                                     "\"minimal\", \"patience\" and \"histogram\"");
3899                /* clear out previous settings */
3900                DIFF_XDL_CLR(options, NEED_MINIMAL);
3901                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
3902                options->xdl_opts |= value;
3903                return argcount;
3904        }
3905
3906        /* flags options */
3907        else if (!strcmp(arg, "--binary")) {
3908                enable_patch_output(&options->output_format);
3909                DIFF_OPT_SET(options, BINARY);
3910        }
3911        else if (!strcmp(arg, "--full-index"))
3912                DIFF_OPT_SET(options, FULL_INDEX);
3913        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3914                DIFF_OPT_SET(options, TEXT);
3915        else if (!strcmp(arg, "-R"))
3916                DIFF_OPT_SET(options, REVERSE_DIFF);
3917        else if (!strcmp(arg, "--find-copies-harder"))
3918                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3919        else if (!strcmp(arg, "--follow"))
3920                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3921        else if (!strcmp(arg, "--no-follow")) {
3922                DIFF_OPT_CLR(options, FOLLOW_RENAMES);
3923                DIFF_OPT_CLR(options, DEFAULT_FOLLOW_RENAMES);
3924        } else if (!strcmp(arg, "--color"))
3925                options->use_color = 1;
3926        else if (skip_prefix(arg, "--color=", &arg)) {
3927                int value = git_config_colorbool(NULL, arg);
3928                if (value < 0)
3929                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3930                options->use_color = value;
3931        }
3932        else if (!strcmp(arg, "--no-color"))
3933                options->use_color = 0;
3934        else if (!strcmp(arg, "--color-words")) {
3935                options->use_color = 1;
3936                options->word_diff = DIFF_WORDS_COLOR;
3937        }
3938        else if (skip_prefix(arg, "--color-words=", &arg)) {
3939                options->use_color = 1;
3940                options->word_diff = DIFF_WORDS_COLOR;
3941                options->word_regex = arg;
3942        }
3943        else if (!strcmp(arg, "--word-diff")) {
3944                if (options->word_diff == DIFF_WORDS_NONE)
3945                        options->word_diff = DIFF_WORDS_PLAIN;
3946        }
3947        else if (skip_prefix(arg, "--word-diff=", &arg)) {
3948                if (!strcmp(arg, "plain"))
3949                        options->word_diff = DIFF_WORDS_PLAIN;
3950                else if (!strcmp(arg, "color")) {
3951                        options->use_color = 1;
3952                        options->word_diff = DIFF_WORDS_COLOR;
3953                }
3954                else if (!strcmp(arg, "porcelain"))
3955                        options->word_diff = DIFF_WORDS_PORCELAIN;
3956                else if (!strcmp(arg, "none"))
3957                        options->word_diff = DIFF_WORDS_NONE;
3958                else
3959                        die("bad --word-diff argument: %s", arg);
3960        }
3961        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3962                if (options->word_diff == DIFF_WORDS_NONE)
3963                        options->word_diff = DIFF_WORDS_PLAIN;
3964                options->word_regex = optarg;
3965                return argcount;
3966        }
3967        else if (!strcmp(arg, "--exit-code"))
3968                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3969        else if (!strcmp(arg, "--quiet"))
3970                DIFF_OPT_SET(options, QUICK);
3971        else if (!strcmp(arg, "--ext-diff"))
3972                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3973        else if (!strcmp(arg, "--no-ext-diff"))
3974                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3975        else if (!strcmp(arg, "--textconv"))
3976                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3977        else if (!strcmp(arg, "--no-textconv"))
3978                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3979        else if (!strcmp(arg, "--ignore-submodules")) {
3980                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3981                handle_ignore_submodules_arg(options, "all");
3982        } else if (skip_prefix(arg, "--ignore-submodules=", &arg)) {
3983                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3984                handle_ignore_submodules_arg(options, arg);
3985        } else if (!strcmp(arg, "--submodule"))
3986                options->submodule_format = DIFF_SUBMODULE_LOG;
3987        else if (skip_prefix(arg, "--submodule=", &arg))
3988                return parse_submodule_opt(options, arg);
3989        else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
3990                return parse_ws_error_highlight_opt(options, arg);
3991        else if (!strcmp(arg, "--ita-invisible-in-index"))
3992                options->ita_invisible_in_index = 1;
3993        else if (!strcmp(arg, "--ita-visible-in-index"))
3994                options->ita_invisible_in_index = 0;
3995
3996        /* misc options */
3997        else if (!strcmp(arg, "-z"))
3998                options->line_termination = 0;
3999        else if ((argcount = short_opt('l', av, &optarg))) {
4000                options->rename_limit = strtoul(optarg, NULL, 10);
4001                return argcount;
4002        }
4003        else if ((argcount = short_opt('S', av, &optarg))) {
4004                options->pickaxe = optarg;
4005                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
4006                return argcount;
4007        } else if ((argcount = short_opt('G', av, &optarg))) {
4008                options->pickaxe = optarg;
4009                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
4010                return argcount;
4011        }
4012        else if (!strcmp(arg, "--pickaxe-all"))
4013                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
4014        else if (!strcmp(arg, "--pickaxe-regex"))
4015                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
4016        else if ((argcount = short_opt('O', av, &optarg))) {
4017                options->orderfile = prefix_filename(prefix, optarg);
4018                return argcount;
4019        }
4020        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
4021                int offending = parse_diff_filter_opt(optarg, options);
4022                if (offending)
4023                        die("unknown change class '%c' in --diff-filter=%s",
4024                            offending, optarg);
4025                return argcount;
4026        }
4027        else if (!strcmp(arg, "--no-abbrev"))
4028                options->abbrev = 0;
4029        else if (!strcmp(arg, "--abbrev"))
4030                options->abbrev = DEFAULT_ABBREV;
4031        else if (skip_prefix(arg, "--abbrev=", &arg)) {
4032                options->abbrev = strtoul(arg, NULL, 10);
4033                if (options->abbrev < MINIMUM_ABBREV)
4034                        options->abbrev = MINIMUM_ABBREV;
4035                else if (40 < options->abbrev)
4036                        options->abbrev = 40;
4037        }
4038        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
4039                options->a_prefix = optarg;
4040                return argcount;
4041        }
4042        else if ((argcount = parse_long_opt("line-prefix", av, &optarg))) {
4043                options->line_prefix = optarg;
4044                options->line_prefix_length = strlen(options->line_prefix);
4045                graph_setup_line_prefix(options);
4046                return argcount;
4047        }
4048        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
4049                options->b_prefix = optarg;
4050                return argcount;
4051        }
4052        else if (!strcmp(arg, "--no-prefix"))
4053                options->a_prefix = options->b_prefix = "";
4054        else if (opt_arg(arg, '\0', "inter-hunk-context",
4055                         &options->interhunkcontext))
4056                ;
4057        else if (!strcmp(arg, "-W"))
4058                DIFF_OPT_SET(options, FUNCCONTEXT);
4059        else if (!strcmp(arg, "--function-context"))
4060                DIFF_OPT_SET(options, FUNCCONTEXT);
4061        else if (!strcmp(arg, "--no-function-context"))
4062                DIFF_OPT_CLR(options, FUNCCONTEXT);
4063        else if ((argcount = parse_long_opt("output", av, &optarg))) {
4064                char *path = prefix_filename(prefix, optarg);
4065                options->file = xfopen(path, "w");
4066                options->close_file = 1;
4067                if (options->use_color != GIT_COLOR_ALWAYS)
4068                        options->use_color = GIT_COLOR_NEVER;
4069                free(path);
4070                return argcount;
4071        } else
4072                return 0;
4073        return 1;
4074}
4075
4076int parse_rename_score(const char **cp_p)
4077{
4078        unsigned long num, scale;
4079        int ch, dot;
4080        const char *cp = *cp_p;
4081
4082        num = 0;
4083        scale = 1;
4084        dot = 0;
4085        for (;;) {
4086                ch = *cp;
4087                if ( !dot && ch == '.' ) {
4088                        scale = 1;
4089                        dot = 1;
4090                } else if ( ch == '%' ) {
4091                        scale = dot ? scale*100 : 100;
4092                        cp++;   /* % is always at the end */
4093                        break;
4094                } else if ( ch >= '0' && ch <= '9' ) {
4095                        if ( scale < 100000 ) {
4096                                scale *= 10;
4097                                num = (num*10) + (ch-'0');
4098                        }
4099                } else {
4100                        break;
4101                }
4102                cp++;
4103        }
4104        *cp_p = cp;
4105
4106        /* user says num divided by scale and we say internally that
4107         * is MAX_SCORE * num / scale.
4108         */
4109        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
4110}
4111
4112static int diff_scoreopt_parse(const char *opt)
4113{
4114        int opt1, opt2, cmd;
4115
4116        if (*opt++ != '-')
4117                return -1;
4118        cmd = *opt++;
4119        if (cmd == '-') {
4120                /* convert the long-form arguments into short-form versions */
4121                if (skip_prefix(opt, "break-rewrites", &opt)) {
4122                        if (*opt == 0 || *opt++ == '=')
4123                                cmd = 'B';
4124                } else if (skip_prefix(opt, "find-copies", &opt)) {
4125                        if (*opt == 0 || *opt++ == '=')
4126                                cmd = 'C';
4127                } else if (skip_prefix(opt, "find-renames", &opt)) {
4128                        if (*opt == 0 || *opt++ == '=')
4129                                cmd = 'M';
4130                }
4131        }
4132        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
4133                return -1; /* that is not a -M, -C, or -B option */
4134
4135        opt1 = parse_rename_score(&opt);
4136        if (cmd != 'B')
4137                opt2 = 0;
4138        else {
4139                if (*opt == 0)
4140                        opt2 = 0;
4141                else if (*opt != '/')
4142                        return -1; /* we expect -B80/99 or -B80 */
4143                else {
4144                        opt++;
4145                        opt2 = parse_rename_score(&opt);
4146                }
4147        }
4148        if (*opt != 0)
4149                return -1;
4150        return opt1 | (opt2 << 16);
4151}
4152
4153struct diff_queue_struct diff_queued_diff;
4154
4155void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
4156{
4157        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
4158        queue->queue[queue->nr++] = dp;
4159}
4160
4161struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
4162                                 struct diff_filespec *one,
4163                                 struct diff_filespec *two)
4164{
4165        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
4166        dp->one = one;
4167        dp->two = two;
4168        if (queue)
4169                diff_q(queue, dp);
4170        return dp;
4171}
4172
4173void diff_free_filepair(struct diff_filepair *p)
4174{
4175        free_filespec(p->one);
4176        free_filespec(p->two);
4177        free(p);
4178}
4179
4180const char *diff_aligned_abbrev(const struct object_id *oid, int len)
4181{
4182        int abblen;
4183        const char *abbrev;
4184
4185        if (len == GIT_SHA1_HEXSZ)
4186                return oid_to_hex(oid);
4187
4188        abbrev = diff_abbrev_oid(oid, len);
4189        abblen = strlen(abbrev);
4190
4191        /*
4192         * In well-behaved cases, where the abbbreviated result is the
4193         * same as the requested length, append three dots after the
4194         * abbreviation (hence the whole logic is limited to the case
4195         * where abblen < 37); when the actual abbreviated result is a
4196         * bit longer than the requested length, we reduce the number
4197         * of dots so that they match the well-behaved ones.  However,
4198         * if the actual abbreviation is longer than the requested
4199         * length by more than three, we give up on aligning, and add
4200         * three dots anyway, to indicate that the output is not the
4201         * full object name.  Yes, this may be suboptimal, but this
4202         * appears only in "diff --raw --abbrev" output and it is not
4203         * worth the effort to change it now.  Note that this would
4204         * likely to work fine when the automatic sizing of default
4205         * abbreviation length is used--we would be fed -1 in "len" in
4206         * that case, and will end up always appending three-dots, but
4207         * the automatic sizing is supposed to give abblen that ensures
4208         * uniqueness across all objects (statistically speaking).
4209         */
4210        if (abblen < GIT_SHA1_HEXSZ - 3) {
4211                static char hex[GIT_MAX_HEXSZ + 1];
4212                if (len < abblen && abblen <= len + 2)
4213                        xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
4214                else
4215                        xsnprintf(hex, sizeof(hex), "%s...", abbrev);
4216                return hex;
4217        }
4218
4219        return oid_to_hex(oid);
4220}
4221
4222static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
4223{
4224        int line_termination = opt->line_termination;
4225        int inter_name_termination = line_termination ? '\t' : '\0';
4226
4227        fprintf(opt->file, "%s", diff_line_prefix(opt));
4228        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
4229                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
4230                        diff_aligned_abbrev(&p->one->oid, opt->abbrev));
4231                fprintf(opt->file, "%s ",
4232                        diff_aligned_abbrev(&p->two->oid, opt->abbrev));
4233        }
4234        if (p->score) {
4235                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
4236                        inter_name_termination);
4237        } else {
4238                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
4239        }
4240
4241        if (p->status == DIFF_STATUS_COPIED ||
4242            p->status == DIFF_STATUS_RENAMED) {
4243                const char *name_a, *name_b;
4244                name_a = p->one->path;
4245                name_b = p->two->path;
4246                strip_prefix(opt->prefix_length, &name_a, &name_b);
4247                write_name_quoted(name_a, opt->file, inter_name_termination);
4248                write_name_quoted(name_b, opt->file, line_termination);
4249        } else {
4250                const char *name_a, *name_b;
4251                name_a = p->one->mode ? p->one->path : p->two->path;
4252                name_b = NULL;
4253                strip_prefix(opt->prefix_length, &name_a, &name_b);
4254                write_name_quoted(name_a, opt->file, line_termination);
4255        }
4256}
4257
4258int diff_unmodified_pair(struct diff_filepair *p)
4259{
4260        /* This function is written stricter than necessary to support
4261         * the currently implemented transformers, but the idea is to
4262         * let transformers to produce diff_filepairs any way they want,
4263         * and filter and clean them up here before producing the output.
4264         */
4265        struct diff_filespec *one = p->one, *two = p->two;
4266
4267        if (DIFF_PAIR_UNMERGED(p))
4268                return 0; /* unmerged is interesting */
4269
4270        /* deletion, addition, mode or type change
4271         * and rename are all interesting.
4272         */
4273        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
4274            DIFF_PAIR_MODE_CHANGED(p) ||
4275            strcmp(one->path, two->path))
4276                return 0;
4277
4278        /* both are valid and point at the same path.  that is, we are
4279         * dealing with a change.
4280         */
4281        if (one->oid_valid && two->oid_valid &&
4282            !oidcmp(&one->oid, &two->oid) &&
4283            !one->dirty_submodule && !two->dirty_submodule)
4284                return 1; /* no change */
4285        if (!one->oid_valid && !two->oid_valid)
4286                return 1; /* both look at the same file on the filesystem. */
4287        return 0;
4288}
4289
4290static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
4291{
4292        if (diff_unmodified_pair(p))
4293                return;
4294
4295        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4296            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4297                return; /* no tree diffs in patch format */
4298
4299        run_diff(p, o);
4300}
4301
4302static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
4303                            struct diffstat_t *diffstat)
4304{
4305        if (diff_unmodified_pair(p))
4306                return;
4307
4308        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4309            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4310                return; /* no useful stat for tree diffs */
4311
4312        run_diffstat(p, o, diffstat);
4313}
4314
4315static void diff_flush_checkdiff(struct diff_filepair *p,
4316                struct diff_options *o)
4317{
4318        if (diff_unmodified_pair(p))
4319                return;
4320
4321        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4322            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4323                return; /* nothing to check in tree diffs */
4324
4325        run_checkdiff(p, o);
4326}
4327
4328int diff_queue_is_empty(void)
4329{
4330        struct diff_queue_struct *q = &diff_queued_diff;
4331        int i;
4332        for (i = 0; i < q->nr; i++)
4333                if (!diff_unmodified_pair(q->queue[i]))
4334                        return 0;
4335        return 1;
4336}
4337
4338#if DIFF_DEBUG
4339void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
4340{
4341        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
4342                x, one ? one : "",
4343                s->path,
4344                DIFF_FILE_VALID(s) ? "valid" : "invalid",
4345                s->mode,
4346                s->oid_valid ? oid_to_hex(&s->oid) : "");
4347        fprintf(stderr, "queue[%d] %s size %lu\n",
4348                x, one ? one : "",
4349                s->size);
4350}
4351
4352void diff_debug_filepair(const struct diff_filepair *p, int i)
4353{
4354        diff_debug_filespec(p->one, i, "one");
4355        diff_debug_filespec(p->two, i, "two");
4356        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
4357                p->score, p->status ? p->status : '?',
4358                p->one->rename_used, p->broken_pair);
4359}
4360
4361void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
4362{
4363        int i;
4364        if (msg)
4365                fprintf(stderr, "%s\n", msg);
4366        fprintf(stderr, "q->nr = %d\n", q->nr);
4367        for (i = 0; i < q->nr; i++) {
4368                struct diff_filepair *p = q->queue[i];
4369                diff_debug_filepair(p, i);
4370        }
4371}
4372#endif
4373
4374static void diff_resolve_rename_copy(void)
4375{
4376        int i;
4377        struct diff_filepair *p;
4378        struct diff_queue_struct *q = &diff_queued_diff;
4379
4380        diff_debug_queue("resolve-rename-copy", q);
4381
4382        for (i = 0; i < q->nr; i++) {
4383                p = q->queue[i];
4384                p->status = 0; /* undecided */
4385                if (DIFF_PAIR_UNMERGED(p))
4386                        p->status = DIFF_STATUS_UNMERGED;
4387                else if (!DIFF_FILE_VALID(p->one))
4388                        p->status = DIFF_STATUS_ADDED;
4389                else if (!DIFF_FILE_VALID(p->two))
4390                        p->status = DIFF_STATUS_DELETED;
4391                else if (DIFF_PAIR_TYPE_CHANGED(p))
4392                        p->status = DIFF_STATUS_TYPE_CHANGED;
4393
4394                /* from this point on, we are dealing with a pair
4395                 * whose both sides are valid and of the same type, i.e.
4396                 * either in-place edit or rename/copy edit.
4397                 */
4398                else if (DIFF_PAIR_RENAME(p)) {
4399                        /*
4400                         * A rename might have re-connected a broken
4401                         * pair up, causing the pathnames to be the
4402                         * same again. If so, that's not a rename at
4403                         * all, just a modification..
4404                         *
4405                         * Otherwise, see if this source was used for
4406                         * multiple renames, in which case we decrement
4407                         * the count, and call it a copy.
4408                         */
4409                        if (!strcmp(p->one->path, p->two->path))
4410                                p->status = DIFF_STATUS_MODIFIED;
4411                        else if (--p->one->rename_used > 0)
4412                                p->status = DIFF_STATUS_COPIED;
4413                        else
4414                                p->status = DIFF_STATUS_RENAMED;
4415                }
4416                else if (oidcmp(&p->one->oid, &p->two->oid) ||
4417                         p->one->mode != p->two->mode ||
4418                         p->one->dirty_submodule ||
4419                         p->two->dirty_submodule ||
4420                         is_null_oid(&p->one->oid))
4421                        p->status = DIFF_STATUS_MODIFIED;
4422                else {
4423                        /* This is a "no-change" entry and should not
4424                         * happen anymore, but prepare for broken callers.
4425                         */
4426                        error("feeding unmodified %s to diffcore",
4427                              p->one->path);
4428                        p->status = DIFF_STATUS_UNKNOWN;
4429                }
4430        }
4431        diff_debug_queue("resolve-rename-copy done", q);
4432}
4433
4434static int check_pair_status(struct diff_filepair *p)
4435{
4436        switch (p->status) {
4437        case DIFF_STATUS_UNKNOWN:
4438                return 0;
4439        case 0:
4440                die("internal error in diff-resolve-rename-copy");
4441        default:
4442                return 1;
4443        }
4444}
4445
4446static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
4447{
4448        int fmt = opt->output_format;
4449
4450        if (fmt & DIFF_FORMAT_CHECKDIFF)
4451                diff_flush_checkdiff(p, opt);
4452        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
4453                diff_flush_raw(p, opt);
4454        else if (fmt & DIFF_FORMAT_NAME) {
4455                const char *name_a, *name_b;
4456                name_a = p->two->path;
4457                name_b = NULL;
4458                strip_prefix(opt->prefix_length, &name_a, &name_b);
4459                fprintf(opt->file, "%s", diff_line_prefix(opt));
4460                write_name_quoted(name_a, opt->file, opt->line_termination);
4461        }
4462}
4463
4464static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
4465{
4466        if (fs->mode)
4467                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
4468        else
4469                fprintf(file, " %s ", newdelete);
4470        write_name_quoted(fs->path, file, '\n');
4471}
4472
4473
4474static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
4475                const char *line_prefix)
4476{
4477        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
4478                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
4479                        p->two->mode, show_name ? ' ' : '\n');
4480                if (show_name) {
4481                        write_name_quoted(p->two->path, file, '\n');
4482                }
4483        }
4484}
4485
4486static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
4487                        const char *line_prefix)
4488{
4489        char *names = pprint_rename(p->one->path, p->two->path);
4490
4491        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
4492        free(names);
4493        show_mode_change(file, p, 0, line_prefix);
4494}
4495
4496static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
4497{
4498        FILE *file = opt->file;
4499        const char *line_prefix = diff_line_prefix(opt);
4500
4501        switch(p->status) {
4502        case DIFF_STATUS_DELETED:
4503                fputs(line_prefix, file);
4504                show_file_mode_name(file, "delete", p->one);
4505                break;
4506        case DIFF_STATUS_ADDED:
4507                fputs(line_prefix, file);
4508                show_file_mode_name(file, "create", p->two);
4509                break;
4510        case DIFF_STATUS_COPIED:
4511                fputs(line_prefix, file);
4512                show_rename_copy(file, "copy", p, line_prefix);
4513                break;
4514        case DIFF_STATUS_RENAMED:
4515                fputs(line_prefix, file);
4516                show_rename_copy(file, "rename", p, line_prefix);
4517                break;
4518        default:
4519                if (p->score) {
4520                        fprintf(file, "%s rewrite ", line_prefix);
4521                        write_name_quoted(p->two->path, file, ' ');
4522                        fprintf(file, "(%d%%)\n", similarity_index(p));
4523                }
4524                show_mode_change(file, p, !p->score, line_prefix);
4525                break;
4526        }
4527}
4528
4529struct patch_id_t {
4530        git_SHA_CTX *ctx;
4531        int patchlen;
4532};
4533
4534static int remove_space(char *line, int len)
4535{
4536        int i;
4537        char *dst = line;
4538        unsigned char c;
4539
4540        for (i = 0; i < len; i++)
4541                if (!isspace((c = line[i])))
4542                        *dst++ = c;
4543
4544        return dst - line;
4545}
4546
4547static void patch_id_consume(void *priv, char *line, unsigned long len)
4548{
4549        struct patch_id_t *data = priv;
4550        int new_len;
4551
4552        /* Ignore line numbers when computing the SHA1 of the patch */
4553        if (starts_with(line, "@@ -"))
4554                return;
4555
4556        new_len = remove_space(line, len);
4557
4558        git_SHA1_Update(data->ctx, line, new_len);
4559        data->patchlen += new_len;
4560}
4561
4562static void patch_id_add_string(git_SHA_CTX *ctx, const char *str)
4563{
4564        git_SHA1_Update(ctx, str, strlen(str));
4565}
4566
4567static void patch_id_add_mode(git_SHA_CTX *ctx, unsigned mode)
4568{
4569        /* large enough for 2^32 in octal */
4570        char buf[12];
4571        int len = xsnprintf(buf, sizeof(buf), "%06o", mode);
4572        git_SHA1_Update(ctx, buf, len);
4573}
4574
4575/* returns 0 upon success, and writes result into sha1 */
4576static int diff_get_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
4577{
4578        struct diff_queue_struct *q = &diff_queued_diff;
4579        int i;
4580        git_SHA_CTX ctx;
4581        struct patch_id_t data;
4582
4583        git_SHA1_Init(&ctx);
4584        memset(&data, 0, sizeof(struct patch_id_t));
4585        data.ctx = &ctx;
4586
4587        for (i = 0; i < q->nr; i++) {
4588                xpparam_t xpp;
4589                xdemitconf_t xecfg;
4590                mmfile_t mf1, mf2;
4591                struct diff_filepair *p = q->queue[i];
4592                int len1, len2;
4593
4594                memset(&xpp, 0, sizeof(xpp));
4595                memset(&xecfg, 0, sizeof(xecfg));
4596                if (p->status == 0)
4597                        return error("internal diff status error");
4598                if (p->status == DIFF_STATUS_UNKNOWN)
4599                        continue;
4600                if (diff_unmodified_pair(p))
4601                        continue;
4602                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4603                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4604                        continue;
4605                if (DIFF_PAIR_UNMERGED(p))
4606                        continue;
4607
4608                diff_fill_oid_info(p->one);
4609                diff_fill_oid_info(p->two);
4610
4611                len1 = remove_space(p->one->path, strlen(p->one->path));
4612                len2 = remove_space(p->two->path, strlen(p->two->path));
4613                patch_id_add_string(&ctx, "diff--git");
4614                patch_id_add_string(&ctx, "a/");
4615                git_SHA1_Update(&ctx, p->one->path, len1);
4616                patch_id_add_string(&ctx, "b/");
4617                git_SHA1_Update(&ctx, p->two->path, len2);
4618
4619                if (p->one->mode == 0) {
4620                        patch_id_add_string(&ctx, "newfilemode");
4621                        patch_id_add_mode(&ctx, p->two->mode);
4622                        patch_id_add_string(&ctx, "---/dev/null");
4623                        patch_id_add_string(&ctx, "+++b/");
4624                        git_SHA1_Update(&ctx, p->two->path, len2);
4625                } else if (p->two->mode == 0) {
4626                        patch_id_add_string(&ctx, "deletedfilemode");
4627                        patch_id_add_mode(&ctx, p->one->mode);
4628                        patch_id_add_string(&ctx, "---a/");
4629                        git_SHA1_Update(&ctx, p->one->path, len1);
4630                        patch_id_add_string(&ctx, "+++/dev/null");
4631                } else {
4632                        patch_id_add_string(&ctx, "---a/");
4633                        git_SHA1_Update(&ctx, p->one->path, len1);
4634                        patch_id_add_string(&ctx, "+++b/");
4635                        git_SHA1_Update(&ctx, p->two->path, len2);
4636                }
4637
4638                if (diff_header_only)
4639                        continue;
4640
4641                if (fill_mmfile(&mf1, p->one) < 0 ||
4642                    fill_mmfile(&mf2, p->two) < 0)
4643                        return error("unable to read files to diff");
4644
4645                if (diff_filespec_is_binary(p->one) ||
4646                    diff_filespec_is_binary(p->two)) {
4647                        git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
4648                                        GIT_SHA1_HEXSZ);
4649                        git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
4650                                        GIT_SHA1_HEXSZ);
4651                        continue;
4652                }
4653
4654                xpp.flags = 0;
4655                xecfg.ctxlen = 3;
4656                xecfg.flags = 0;
4657                if (xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4658                                  &xpp, &xecfg))
4659                        return error("unable to generate patch-id diff for %s",
4660                                     p->one->path);
4661        }
4662
4663        git_SHA1_Final(oid->hash, &ctx);
4664        return 0;
4665}
4666
4667int diff_flush_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
4668{
4669        struct diff_queue_struct *q = &diff_queued_diff;
4670        int i;
4671        int result = diff_get_patch_id(options, oid, diff_header_only);
4672
4673        for (i = 0; i < q->nr; i++)
4674                diff_free_filepair(q->queue[i]);
4675
4676        free(q->queue);
4677        DIFF_QUEUE_CLEAR(q);
4678
4679        return result;
4680}
4681
4682static int is_summary_empty(const struct diff_queue_struct *q)
4683{
4684        int i;
4685
4686        for (i = 0; i < q->nr; i++) {
4687                const struct diff_filepair *p = q->queue[i];
4688
4689                switch (p->status) {
4690                case DIFF_STATUS_DELETED:
4691                case DIFF_STATUS_ADDED:
4692                case DIFF_STATUS_COPIED:
4693                case DIFF_STATUS_RENAMED:
4694                        return 0;
4695                default:
4696                        if (p->score)
4697                                return 0;
4698                        if (p->one->mode && p->two->mode &&
4699                            p->one->mode != p->two->mode)
4700                                return 0;
4701                        break;
4702                }
4703        }
4704        return 1;
4705}
4706
4707static const char rename_limit_warning[] =
4708N_("inexact rename detection was skipped due to too many files.");
4709
4710static const char degrade_cc_to_c_warning[] =
4711N_("only found copies from modified paths due to too many files.");
4712
4713static const char rename_limit_advice[] =
4714N_("you may want to set your %s variable to at least "
4715   "%d and retry the command.");
4716
4717void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4718{
4719        if (degraded_cc)
4720                warning(_(degrade_cc_to_c_warning));
4721        else if (needed)
4722                warning(_(rename_limit_warning));
4723        else
4724                return;
4725        if (0 < needed && needed < 32767)
4726                warning(_(rename_limit_advice), varname, needed);
4727}
4728
4729void diff_flush(struct diff_options *options)
4730{
4731        struct diff_queue_struct *q = &diff_queued_diff;
4732        int i, output_format = options->output_format;
4733        int separator = 0;
4734        int dirstat_by_line = 0;
4735
4736        /*
4737         * Order: raw, stat, summary, patch
4738         * or:    name/name-status/checkdiff (other bits clear)
4739         */
4740        if (!q->nr)
4741                goto free_queue;
4742
4743        if (output_format & (DIFF_FORMAT_RAW |
4744                             DIFF_FORMAT_NAME |
4745                             DIFF_FORMAT_NAME_STATUS |
4746                             DIFF_FORMAT_CHECKDIFF)) {
4747                for (i = 0; i < q->nr; i++) {
4748                        struct diff_filepair *p = q->queue[i];
4749                        if (check_pair_status(p))
4750                                flush_one_pair(p, options);
4751                }
4752                separator++;
4753        }
4754
4755        if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
4756                dirstat_by_line = 1;
4757
4758        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
4759            dirstat_by_line) {
4760                struct diffstat_t diffstat;
4761
4762                memset(&diffstat, 0, sizeof(struct diffstat_t));
4763                for (i = 0; i < q->nr; i++) {
4764                        struct diff_filepair *p = q->queue[i];
4765                        if (check_pair_status(p))
4766                                diff_flush_stat(p, options, &diffstat);
4767                }
4768                if (output_format & DIFF_FORMAT_NUMSTAT)
4769                        show_numstat(&diffstat, options);
4770                if (output_format & DIFF_FORMAT_DIFFSTAT)
4771                        show_stats(&diffstat, options);
4772                if (output_format & DIFF_FORMAT_SHORTSTAT)
4773                        show_shortstats(&diffstat, options);
4774                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
4775                        show_dirstat_by_line(&diffstat, options);
4776                free_diffstat_info(&diffstat);
4777                separator++;
4778        }
4779        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
4780                show_dirstat(options);
4781
4782        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4783                for (i = 0; i < q->nr; i++) {
4784                        diff_summary(options, q->queue[i]);
4785                }
4786                separator++;
4787        }
4788
4789        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4790            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4791            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4792                /*
4793                 * run diff_flush_patch for the exit status. setting
4794                 * options->file to /dev/null should be safe, because we
4795                 * aren't supposed to produce any output anyway.
4796                 */
4797                if (options->close_file)
4798                        fclose(options->file);
4799                options->file = xfopen("/dev/null", "w");
4800                options->close_file = 1;
4801                for (i = 0; i < q->nr; i++) {
4802                        struct diff_filepair *p = q->queue[i];
4803                        if (check_pair_status(p))
4804                                diff_flush_patch(p, options);
4805                        if (options->found_changes)
4806                                break;
4807                }
4808        }
4809
4810        if (output_format & DIFF_FORMAT_PATCH) {
4811                if (separator) {
4812                        fprintf(options->file, "%s%c",
4813                                diff_line_prefix(options),
4814                                options->line_termination);
4815                        if (options->stat_sep) {
4816                                /* attach patch instead of inline */
4817                                fputs(options->stat_sep, options->file);
4818                        }
4819                }
4820
4821                for (i = 0; i < q->nr; i++) {
4822                        struct diff_filepair *p = q->queue[i];
4823                        if (check_pair_status(p))
4824                                diff_flush_patch(p, options);
4825                }
4826        }
4827
4828        if (output_format & DIFF_FORMAT_CALLBACK)
4829                options->format_callback(q, options, options->format_callback_data);
4830
4831        for (i = 0; i < q->nr; i++)
4832                diff_free_filepair(q->queue[i]);
4833free_queue:
4834        free(q->queue);
4835        DIFF_QUEUE_CLEAR(q);
4836        if (options->close_file)
4837                fclose(options->file);
4838
4839        /*
4840         * Report the content-level differences with HAS_CHANGES;
4841         * diff_addremove/diff_change does not set the bit when
4842         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4843         */
4844        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4845                if (options->found_changes)
4846                        DIFF_OPT_SET(options, HAS_CHANGES);
4847                else
4848                        DIFF_OPT_CLR(options, HAS_CHANGES);
4849        }
4850}
4851
4852static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
4853{
4854        return (((p->status == DIFF_STATUS_MODIFIED) &&
4855                 ((p->score &&
4856                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
4857                  (!p->score &&
4858                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
4859                ((p->status != DIFF_STATUS_MODIFIED) &&
4860                 filter_bit_tst(p->status, options)));
4861}
4862
4863static void diffcore_apply_filter(struct diff_options *options)
4864{
4865        int i;
4866        struct diff_queue_struct *q = &diff_queued_diff;
4867        struct diff_queue_struct outq;
4868
4869        DIFF_QUEUE_CLEAR(&outq);
4870
4871        if (!options->filter)
4872                return;
4873
4874        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
4875                int found;
4876                for (i = found = 0; !found && i < q->nr; i++) {
4877                        if (match_filter(options, q->queue[i]))
4878                                found++;
4879                }
4880                if (found)
4881                        return;
4882
4883                /* otherwise we will clear the whole queue
4884                 * by copying the empty outq at the end of this
4885                 * function, but first clear the current entries
4886                 * in the queue.
4887                 */
4888                for (i = 0; i < q->nr; i++)
4889                        diff_free_filepair(q->queue[i]);
4890        }
4891        else {
4892                /* Only the matching ones */
4893                for (i = 0; i < q->nr; i++) {
4894                        struct diff_filepair *p = q->queue[i];
4895                        if (match_filter(options, p))
4896                                diff_q(&outq, p);
4897                        else
4898                                diff_free_filepair(p);
4899                }
4900        }
4901        free(q->queue);
4902        *q = outq;
4903}
4904
4905/* Check whether two filespecs with the same mode and size are identical */
4906static int diff_filespec_is_identical(struct diff_filespec *one,
4907                                      struct diff_filespec *two)
4908{
4909        if (S_ISGITLINK(one->mode))
4910                return 0;
4911        if (diff_populate_filespec(one, 0))
4912                return 0;
4913        if (diff_populate_filespec(two, 0))
4914                return 0;
4915        return !memcmp(one->data, two->data, one->size);
4916}
4917
4918static int diff_filespec_check_stat_unmatch(struct diff_filepair *p)
4919{
4920        if (p->done_skip_stat_unmatch)
4921                return p->skip_stat_unmatch_result;
4922
4923        p->done_skip_stat_unmatch = 1;
4924        p->skip_stat_unmatch_result = 0;
4925        /*
4926         * 1. Entries that come from stat info dirtiness
4927         *    always have both sides (iow, not create/delete),
4928         *    one side of the object name is unknown, with
4929         *    the same mode and size.  Keep the ones that
4930         *    do not match these criteria.  They have real
4931         *    differences.
4932         *
4933         * 2. At this point, the file is known to be modified,
4934         *    with the same mode and size, and the object
4935         *    name of one side is unknown.  Need to inspect
4936         *    the identical contents.
4937         */
4938        if (!DIFF_FILE_VALID(p->one) || /* (1) */
4939            !DIFF_FILE_VALID(p->two) ||
4940            (p->one->oid_valid && p->two->oid_valid) ||
4941            (p->one->mode != p->two->mode) ||
4942            diff_populate_filespec(p->one, CHECK_SIZE_ONLY) ||
4943            diff_populate_filespec(p->two, CHECK_SIZE_ONLY) ||
4944            (p->one->size != p->two->size) ||
4945            !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4946                p->skip_stat_unmatch_result = 1;
4947        return p->skip_stat_unmatch_result;
4948}
4949
4950static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4951{
4952        int i;
4953        struct diff_queue_struct *q = &diff_queued_diff;
4954        struct diff_queue_struct outq;
4955        DIFF_QUEUE_CLEAR(&outq);
4956
4957        for (i = 0; i < q->nr; i++) {
4958                struct diff_filepair *p = q->queue[i];
4959
4960                if (diff_filespec_check_stat_unmatch(p))
4961                        diff_q(&outq, p);
4962                else {
4963                        /*
4964                         * The caller can subtract 1 from skip_stat_unmatch
4965                         * to determine how many paths were dirty only
4966                         * due to stat info mismatch.
4967                         */
4968                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4969                                diffopt->skip_stat_unmatch++;
4970                        diff_free_filepair(p);
4971                }
4972        }
4973        free(q->queue);
4974        *q = outq;
4975}
4976
4977static int diffnamecmp(const void *a_, const void *b_)
4978{
4979        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4980        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4981        const char *name_a, *name_b;
4982
4983        name_a = a->one ? a->one->path : a->two->path;
4984        name_b = b->one ? b->one->path : b->two->path;
4985        return strcmp(name_a, name_b);
4986}
4987
4988void diffcore_fix_diff_index(struct diff_options *options)
4989{
4990        struct diff_queue_struct *q = &diff_queued_diff;
4991        QSORT(q->queue, q->nr, diffnamecmp);
4992}
4993
4994void diffcore_std(struct diff_options *options)
4995{
4996        /* NOTE please keep the following in sync with diff_tree_combined() */
4997        if (options->skip_stat_unmatch)
4998                diffcore_skip_stat_unmatch(options);
4999        if (!options->found_follow) {
5000                /* See try_to_follow_renames() in tree-diff.c */
5001                if (options->break_opt != -1)
5002                        diffcore_break(options->break_opt);
5003                if (options->detect_rename)
5004                        diffcore_rename(options);
5005                if (options->break_opt != -1)
5006                        diffcore_merge_broken();
5007        }
5008        if (options->pickaxe)
5009                diffcore_pickaxe(options);
5010        if (options->orderfile)
5011                diffcore_order(options->orderfile);
5012        if (!options->found_follow)
5013                /* See try_to_follow_renames() in tree-diff.c */
5014                diff_resolve_rename_copy();
5015        diffcore_apply_filter(options);
5016
5017        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
5018                DIFF_OPT_SET(options, HAS_CHANGES);
5019        else
5020                DIFF_OPT_CLR(options, HAS_CHANGES);
5021
5022        options->found_follow = 0;
5023}
5024
5025int diff_result_code(struct diff_options *opt, int status)
5026{
5027        int result = 0;
5028
5029        diff_warn_rename_limit("diff.renameLimit",
5030                               opt->needed_rename_limit,
5031                               opt->degraded_cc_to_c);
5032        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
5033            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
5034                return status;
5035        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
5036            DIFF_OPT_TST(opt, HAS_CHANGES))
5037                result |= 01;
5038        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
5039            DIFF_OPT_TST(opt, CHECK_FAILED))
5040                result |= 02;
5041        return result;
5042}
5043
5044int diff_can_quit_early(struct diff_options *opt)
5045{
5046        return (DIFF_OPT_TST(opt, QUICK) &&
5047                !opt->filter &&
5048                DIFF_OPT_TST(opt, HAS_CHANGES));
5049}
5050
5051/*
5052 * Shall changes to this submodule be ignored?
5053 *
5054 * Submodule changes can be configured to be ignored separately for each path,
5055 * but that configuration can be overridden from the command line.
5056 */
5057static int is_submodule_ignored(const char *path, struct diff_options *options)
5058{
5059        int ignored = 0;
5060        unsigned orig_flags = options->flags;
5061        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
5062                set_diffopt_flags_from_submodule_config(options, path);
5063        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
5064                ignored = 1;
5065        options->flags = orig_flags;
5066        return ignored;
5067}
5068
5069void diff_addremove(struct diff_options *options,
5070                    int addremove, unsigned mode,
5071                    const struct object_id *oid,
5072                    int oid_valid,
5073                    const char *concatpath, unsigned dirty_submodule)
5074{
5075        struct diff_filespec *one, *two;
5076
5077        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
5078                return;
5079
5080        /* This may look odd, but it is a preparation for
5081         * feeding "there are unchanged files which should
5082         * not produce diffs, but when you are doing copy
5083         * detection you would need them, so here they are"
5084         * entries to the diff-core.  They will be prefixed
5085         * with something like '=' or '*' (I haven't decided
5086         * which but should not make any difference).
5087         * Feeding the same new and old to diff_change()
5088         * also has the same effect.
5089         * Before the final output happens, they are pruned after
5090         * merged into rename/copy pairs as appropriate.
5091         */
5092        if (DIFF_OPT_TST(options, REVERSE_DIFF))
5093                addremove = (addremove == '+' ? '-' :
5094                             addremove == '-' ? '+' : addremove);
5095
5096        if (options->prefix &&
5097            strncmp(concatpath, options->prefix, options->prefix_length))
5098                return;
5099
5100        one = alloc_filespec(concatpath);
5101        two = alloc_filespec(concatpath);
5102
5103        if (addremove != '+')
5104                fill_filespec(one, oid, oid_valid, mode);
5105        if (addremove != '-') {
5106                fill_filespec(two, oid, oid_valid, mode);
5107                two->dirty_submodule = dirty_submodule;
5108        }
5109
5110        diff_queue(&diff_queued_diff, one, two);
5111        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
5112                DIFF_OPT_SET(options, HAS_CHANGES);
5113}
5114
5115void diff_change(struct diff_options *options,
5116                 unsigned old_mode, unsigned new_mode,
5117                 const struct object_id *old_oid,
5118                 const struct object_id *new_oid,
5119                 int old_oid_valid, int new_oid_valid,
5120                 const char *concatpath,
5121                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
5122{
5123        struct diff_filespec *one, *two;
5124        struct diff_filepair *p;
5125
5126        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
5127            is_submodule_ignored(concatpath, options))
5128                return;
5129
5130        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
5131                SWAP(old_mode, new_mode);
5132                SWAP(old_oid, new_oid);
5133                SWAP(old_oid_valid, new_oid_valid);
5134                SWAP(old_dirty_submodule, new_dirty_submodule);
5135        }
5136
5137        if (options->prefix &&
5138            strncmp(concatpath, options->prefix, options->prefix_length))
5139                return;
5140
5141        one = alloc_filespec(concatpath);
5142        two = alloc_filespec(concatpath);
5143        fill_filespec(one, old_oid, old_oid_valid, old_mode);
5144        fill_filespec(two, new_oid, new_oid_valid, new_mode);
5145        one->dirty_submodule = old_dirty_submodule;
5146        two->dirty_submodule = new_dirty_submodule;
5147        p = diff_queue(&diff_queued_diff, one, two);
5148
5149        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
5150                return;
5151
5152        if (DIFF_OPT_TST(options, QUICK) && options->skip_stat_unmatch &&
5153            !diff_filespec_check_stat_unmatch(p))
5154                return;
5155
5156        DIFF_OPT_SET(options, HAS_CHANGES);
5157}
5158
5159struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
5160{
5161        struct diff_filepair *pair;
5162        struct diff_filespec *one, *two;
5163
5164        if (options->prefix &&
5165            strncmp(path, options->prefix, options->prefix_length))
5166                return NULL;
5167
5168        one = alloc_filespec(path);
5169        two = alloc_filespec(path);
5170        pair = diff_queue(&diff_queued_diff, one, two);
5171        pair->is_unmerged = 1;
5172        return pair;
5173}
5174
5175static char *run_textconv(const char *pgm, struct diff_filespec *spec,
5176                size_t *outsize)
5177{
5178        struct diff_tempfile *temp;
5179        const char *argv[3];
5180        const char **arg = argv;
5181        struct child_process child = CHILD_PROCESS_INIT;
5182        struct strbuf buf = STRBUF_INIT;
5183        int err = 0;
5184
5185        temp = prepare_temp_file(spec->path, spec);
5186        *arg++ = pgm;
5187        *arg++ = temp->name;
5188        *arg = NULL;
5189
5190        child.use_shell = 1;
5191        child.argv = argv;
5192        child.out = -1;
5193        if (start_command(&child)) {
5194                remove_tempfile();
5195                return NULL;
5196        }
5197
5198        if (strbuf_read(&buf, child.out, 0) < 0)
5199                err = error("error reading from textconv command '%s'", pgm);
5200        close(child.out);
5201
5202        if (finish_command(&child) || err) {
5203                strbuf_release(&buf);
5204                remove_tempfile();
5205                return NULL;
5206        }
5207        remove_tempfile();
5208
5209        return strbuf_detach(&buf, outsize);
5210}
5211
5212size_t fill_textconv(struct userdiff_driver *driver,
5213                     struct diff_filespec *df,
5214                     char **outbuf)
5215{
5216        size_t size;
5217
5218        if (!driver) {
5219                if (!DIFF_FILE_VALID(df)) {
5220                        *outbuf = "";
5221                        return 0;
5222                }
5223                if (diff_populate_filespec(df, 0))
5224                        die("unable to read files to diff");
5225                *outbuf = df->data;
5226                return df->size;
5227        }
5228
5229        if (!driver->textconv)
5230                die("BUG: fill_textconv called with non-textconv driver");
5231
5232        if (driver->textconv_cache && df->oid_valid) {
5233                *outbuf = notes_cache_get(driver->textconv_cache,
5234                                          &df->oid,
5235                                          &size);
5236                if (*outbuf)
5237                        return size;
5238        }
5239
5240        *outbuf = run_textconv(driver->textconv, df, &size);
5241        if (!*outbuf)
5242                die("unable to read files to diff");
5243
5244        if (driver->textconv_cache && df->oid_valid) {
5245                /* ignore errors, as we might be in a readonly repository */
5246                notes_cache_put(driver->textconv_cache, &df->oid, *outbuf,
5247                                size);
5248                /*
5249                 * we could save up changes and flush them all at the end,
5250                 * but we would need an extra call after all diffing is done.
5251                 * Since generating a cache entry is the slow path anyway,
5252                 * this extra overhead probably isn't a big deal.
5253                 */
5254                notes_cache_write(driver->textconv_cache);
5255        }
5256
5257        return size;
5258}
5259
5260int textconv_object(const char *path,
5261                    unsigned mode,
5262                    const struct object_id *oid,
5263                    int oid_valid,
5264                    char **buf,
5265                    unsigned long *buf_size)
5266{
5267        struct diff_filespec *df;
5268        struct userdiff_driver *textconv;
5269
5270        df = alloc_filespec(path);
5271        fill_filespec(df, oid, oid_valid, mode);
5272        textconv = get_textconv(df);
5273        if (!textconv) {
5274                free_filespec(df);
5275                return 0;
5276        }
5277
5278        *buf_size = fill_textconv(textconv, df, buf);
5279        free_filespec(df);
5280        return 1;
5281}
5282
5283void setup_diff_pager(struct diff_options *opt)
5284{
5285        /*
5286         * If the user asked for our exit code, then either they want --quiet
5287         * or --exit-code. We should definitely not bother with a pager in the
5288         * former case, as we will generate no output. Since we still properly
5289         * report our exit code even when a pager is run, we _could_ run a
5290         * pager with --exit-code. But since we have not done so historically,
5291         * and because it is easy to find people oneline advising "git diff
5292         * --exit-code" in hooks and other scripts, we do not do so.
5293         */
5294        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
5295            check_pager_config("diff") != 0)
5296                setup_pager();
5297}