diff.con commit setup.c: re-fix d95138e (setup: set env $GIT_WORK_TREE when .. (86d26f2)
   1/*
   2 * Copyright (C) 2005 Junio C Hamano
   3 */
   4#include "cache.h"
   5#include "quote.h"
   6#include "diff.h"
   7#include "diffcore.h"
   8#include "delta.h"
   9#include "xdiff-interface.h"
  10#include "color.h"
  11#include "attr.h"
  12#include "run-command.h"
  13#include "utf8.h"
  14#include "userdiff.h"
  15#include "sigchain.h"
  16#include "submodule.h"
  17#include "ll-merge.h"
  18#include "string-list.h"
  19#include "argv-array.h"
  20
  21#ifdef NO_FAST_WORKING_DIRECTORY
  22#define FAST_WORKING_DIRECTORY 0
  23#else
  24#define FAST_WORKING_DIRECTORY 1
  25#endif
  26
  27static int diff_detect_rename_default;
  28static int diff_rename_limit_default = 400;
  29static int diff_suppress_blank_empty;
  30static int diff_use_color_default = -1;
  31static int diff_context_default = 3;
  32static const char *diff_word_regex_cfg;
  33static const char *external_diff_cmd_cfg;
  34static const char *diff_order_file_cfg;
  35int diff_auto_refresh_index = 1;
  36static int diff_mnemonic_prefix;
  37static int diff_no_prefix;
  38static int diff_stat_graph_width;
  39static int diff_dirstat_permille_default = 30;
  40static struct diff_options default_diff_options;
  41static long diff_algorithm;
  42
  43static char diff_colors[][COLOR_MAXLEN] = {
  44        GIT_COLOR_RESET,
  45        GIT_COLOR_NORMAL,       /* CONTEXT */
  46        GIT_COLOR_BOLD,         /* METAINFO */
  47        GIT_COLOR_CYAN,         /* FRAGINFO */
  48        GIT_COLOR_RED,          /* OLD */
  49        GIT_COLOR_GREEN,        /* NEW */
  50        GIT_COLOR_YELLOW,       /* COMMIT */
  51        GIT_COLOR_BG_RED,       /* WHITESPACE */
  52        GIT_COLOR_NORMAL,       /* FUNCINFO */
  53};
  54
  55static int parse_diff_color_slot(const char *var)
  56{
  57        if (!strcasecmp(var, "context") || !strcasecmp(var, "plain"))
  58                return DIFF_CONTEXT;
  59        if (!strcasecmp(var, "meta"))
  60                return DIFF_METAINFO;
  61        if (!strcasecmp(var, "frag"))
  62                return DIFF_FRAGINFO;
  63        if (!strcasecmp(var, "old"))
  64                return DIFF_FILE_OLD;
  65        if (!strcasecmp(var, "new"))
  66                return DIFF_FILE_NEW;
  67        if (!strcasecmp(var, "commit"))
  68                return DIFF_COMMIT;
  69        if (!strcasecmp(var, "whitespace"))
  70                return DIFF_WHITESPACE;
  71        if (!strcasecmp(var, "func"))
  72                return DIFF_FUNCINFO;
  73        return -1;
  74}
  75
  76static int parse_dirstat_params(struct diff_options *options, const char *params_string,
  77                                struct strbuf *errmsg)
  78{
  79        char *params_copy = xstrdup(params_string);
  80        struct string_list params = STRING_LIST_INIT_NODUP;
  81        int ret = 0;
  82        int i;
  83
  84        if (*params_copy)
  85                string_list_split_in_place(&params, params_copy, ',', -1);
  86        for (i = 0; i < params.nr; i++) {
  87                const char *p = params.items[i].string;
  88                if (!strcmp(p, "changes")) {
  89                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
  90                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
  91                } else if (!strcmp(p, "lines")) {
  92                        DIFF_OPT_SET(options, DIRSTAT_BY_LINE);
  93                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
  94                } else if (!strcmp(p, "files")) {
  95                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
  96                        DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
  97                } else if (!strcmp(p, "noncumulative")) {
  98                        DIFF_OPT_CLR(options, DIRSTAT_CUMULATIVE);
  99                } else if (!strcmp(p, "cumulative")) {
 100                        DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
 101                } else if (isdigit(*p)) {
 102                        char *end;
 103                        int permille = strtoul(p, &end, 10) * 10;
 104                        if (*end == '.' && isdigit(*++end)) {
 105                                /* only use first digit */
 106                                permille += *end - '0';
 107                                /* .. and ignore any further digits */
 108                                while (isdigit(*++end))
 109                                        ; /* nothing */
 110                        }
 111                        if (!*end)
 112                                options->dirstat_permille = permille;
 113                        else {
 114                                strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%s'\n"),
 115                                            p);
 116                                ret++;
 117                        }
 118                } else {
 119                        strbuf_addf(errmsg, _("  Unknown dirstat parameter '%s'\n"), p);
 120                        ret++;
 121                }
 122
 123        }
 124        string_list_clear(&params, 0);
 125        free(params_copy);
 126        return ret;
 127}
 128
 129static int parse_submodule_params(struct diff_options *options, const char *value)
 130{
 131        if (!strcmp(value, "log"))
 132                DIFF_OPT_SET(options, SUBMODULE_LOG);
 133        else if (!strcmp(value, "short"))
 134                DIFF_OPT_CLR(options, SUBMODULE_LOG);
 135        else
 136                return -1;
 137        return 0;
 138}
 139
 140static int git_config_rename(const char *var, const char *value)
 141{
 142        if (!value)
 143                return DIFF_DETECT_RENAME;
 144        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 145                return  DIFF_DETECT_COPY;
 146        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 147}
 148
 149long parse_algorithm_value(const char *value)
 150{
 151        if (!value)
 152                return -1;
 153        else if (!strcasecmp(value, "myers") || !strcasecmp(value, "default"))
 154                return 0;
 155        else if (!strcasecmp(value, "minimal"))
 156                return XDF_NEED_MINIMAL;
 157        else if (!strcasecmp(value, "patience"))
 158                return XDF_PATIENCE_DIFF;
 159        else if (!strcasecmp(value, "histogram"))
 160                return XDF_HISTOGRAM_DIFF;
 161        return -1;
 162}
 163
 164/*
 165 * These are to give UI layer defaults.
 166 * The core-level commands such as git-diff-files should
 167 * never be affected by the setting of diff.renames
 168 * the user happens to have in the configuration file.
 169 */
 170int git_diff_ui_config(const char *var, const char *value, void *cb)
 171{
 172        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 173                diff_use_color_default = git_config_colorbool(var, value);
 174                return 0;
 175        }
 176        if (!strcmp(var, "diff.context")) {
 177                diff_context_default = git_config_int(var, value);
 178                if (diff_context_default < 0)
 179                        return -1;
 180                return 0;
 181        }
 182        if (!strcmp(var, "diff.renames")) {
 183                diff_detect_rename_default = git_config_rename(var, value);
 184                return 0;
 185        }
 186        if (!strcmp(var, "diff.autorefreshindex")) {
 187                diff_auto_refresh_index = git_config_bool(var, value);
 188                return 0;
 189        }
 190        if (!strcmp(var, "diff.mnemonicprefix")) {
 191                diff_mnemonic_prefix = git_config_bool(var, value);
 192                return 0;
 193        }
 194        if (!strcmp(var, "diff.noprefix")) {
 195                diff_no_prefix = git_config_bool(var, value);
 196                return 0;
 197        }
 198        if (!strcmp(var, "diff.statgraphwidth")) {
 199                diff_stat_graph_width = git_config_int(var, value);
 200                return 0;
 201        }
 202        if (!strcmp(var, "diff.external"))
 203                return git_config_string(&external_diff_cmd_cfg, var, value);
 204        if (!strcmp(var, "diff.wordregex"))
 205                return git_config_string(&diff_word_regex_cfg, var, value);
 206        if (!strcmp(var, "diff.orderfile"))
 207                return git_config_pathname(&diff_order_file_cfg, var, value);
 208
 209        if (!strcmp(var, "diff.ignoresubmodules"))
 210                handle_ignore_submodules_arg(&default_diff_options, value);
 211
 212        if (!strcmp(var, "diff.submodule")) {
 213                if (parse_submodule_params(&default_diff_options, value))
 214                        warning(_("Unknown value for 'diff.submodule' config variable: '%s'"),
 215                                value);
 216                return 0;
 217        }
 218
 219        if (!strcmp(var, "diff.algorithm")) {
 220                diff_algorithm = parse_algorithm_value(value);
 221                if (diff_algorithm < 0)
 222                        return -1;
 223                return 0;
 224        }
 225
 226        if (git_color_config(var, value, cb) < 0)
 227                return -1;
 228
 229        return git_diff_basic_config(var, value, cb);
 230}
 231
 232int git_diff_basic_config(const char *var, const char *value, void *cb)
 233{
 234        const char *name;
 235
 236        if (!strcmp(var, "diff.renamelimit")) {
 237                diff_rename_limit_default = git_config_int(var, value);
 238                return 0;
 239        }
 240
 241        if (userdiff_config(var, value) < 0)
 242                return -1;
 243
 244        if (skip_prefix(var, "diff.color.", &name) ||
 245            skip_prefix(var, "color.diff.", &name)) {
 246                int slot = parse_diff_color_slot(name);
 247                if (slot < 0)
 248                        return 0;
 249                if (!value)
 250                        return config_error_nonbool(var);
 251                return color_parse(value, diff_colors[slot]);
 252        }
 253
 254        /* like GNU diff's --suppress-blank-empty option  */
 255        if (!strcmp(var, "diff.suppressblankempty") ||
 256                        /* for backwards compatibility */
 257                        !strcmp(var, "diff.suppress-blank-empty")) {
 258                diff_suppress_blank_empty = git_config_bool(var, value);
 259                return 0;
 260        }
 261
 262        if (!strcmp(var, "diff.dirstat")) {
 263                struct strbuf errmsg = STRBUF_INIT;
 264                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 265                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 266                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 267                                errmsg.buf);
 268                strbuf_release(&errmsg);
 269                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 270                return 0;
 271        }
 272
 273        if (starts_with(var, "submodule."))
 274                return parse_submodule_config_option(var, value);
 275
 276        return git_default_config(var, value, cb);
 277}
 278
 279static char *quote_two(const char *one, const char *two)
 280{
 281        int need_one = quote_c_style(one, NULL, NULL, 1);
 282        int need_two = quote_c_style(two, NULL, NULL, 1);
 283        struct strbuf res = STRBUF_INIT;
 284
 285        if (need_one + need_two) {
 286                strbuf_addch(&res, '"');
 287                quote_c_style(one, &res, NULL, 1);
 288                quote_c_style(two, &res, NULL, 1);
 289                strbuf_addch(&res, '"');
 290        } else {
 291                strbuf_addstr(&res, one);
 292                strbuf_addstr(&res, two);
 293        }
 294        return strbuf_detach(&res, NULL);
 295}
 296
 297static const char *external_diff(void)
 298{
 299        static const char *external_diff_cmd = NULL;
 300        static int done_preparing = 0;
 301
 302        if (done_preparing)
 303                return external_diff_cmd;
 304        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 305        if (!external_diff_cmd)
 306                external_diff_cmd = external_diff_cmd_cfg;
 307        done_preparing = 1;
 308        return external_diff_cmd;
 309}
 310
 311static struct diff_tempfile {
 312        const char *name; /* filename external diff should read from */
 313        char hex[41];
 314        char mode[10];
 315        char tmp_path[PATH_MAX];
 316} diff_temp[2];
 317
 318typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 319
 320struct emit_callback {
 321        int color_diff;
 322        unsigned ws_rule;
 323        int blank_at_eof_in_preimage;
 324        int blank_at_eof_in_postimage;
 325        int lno_in_preimage;
 326        int lno_in_postimage;
 327        sane_truncate_fn truncate;
 328        const char **label_path;
 329        struct diff_words_data *diff_words;
 330        struct diff_options *opt;
 331        int *found_changesp;
 332        struct strbuf *header;
 333};
 334
 335static int count_lines(const char *data, int size)
 336{
 337        int count, ch, completely_empty = 1, nl_just_seen = 0;
 338        count = 0;
 339        while (0 < size--) {
 340                ch = *data++;
 341                if (ch == '\n') {
 342                        count++;
 343                        nl_just_seen = 1;
 344                        completely_empty = 0;
 345                }
 346                else {
 347                        nl_just_seen = 0;
 348                        completely_empty = 0;
 349                }
 350        }
 351        if (completely_empty)
 352                return 0;
 353        if (!nl_just_seen)
 354                count++; /* no trailing newline */
 355        return count;
 356}
 357
 358static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 359{
 360        if (!DIFF_FILE_VALID(one)) {
 361                mf->ptr = (char *)""; /* does not matter */
 362                mf->size = 0;
 363                return 0;
 364        }
 365        else if (diff_populate_filespec(one, 0))
 366                return -1;
 367
 368        mf->ptr = one->data;
 369        mf->size = one->size;
 370        return 0;
 371}
 372
 373/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 374static unsigned long diff_filespec_size(struct diff_filespec *one)
 375{
 376        if (!DIFF_FILE_VALID(one))
 377                return 0;
 378        diff_populate_filespec(one, CHECK_SIZE_ONLY);
 379        return one->size;
 380}
 381
 382static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 383{
 384        char *ptr = mf->ptr;
 385        long size = mf->size;
 386        int cnt = 0;
 387
 388        if (!size)
 389                return cnt;
 390        ptr += size - 1; /* pointing at the very end */
 391        if (*ptr != '\n')
 392                ; /* incomplete line */
 393        else
 394                ptr--; /* skip the last LF */
 395        while (mf->ptr < ptr) {
 396                char *prev_eol;
 397                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 398                        if (*prev_eol == '\n')
 399                                break;
 400                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 401                        break;
 402                cnt++;
 403                ptr = prev_eol - 1;
 404        }
 405        return cnt;
 406}
 407
 408static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 409                               struct emit_callback *ecbdata)
 410{
 411        int l1, l2, at;
 412        unsigned ws_rule = ecbdata->ws_rule;
 413        l1 = count_trailing_blank(mf1, ws_rule);
 414        l2 = count_trailing_blank(mf2, ws_rule);
 415        if (l2 <= l1) {
 416                ecbdata->blank_at_eof_in_preimage = 0;
 417                ecbdata->blank_at_eof_in_postimage = 0;
 418                return;
 419        }
 420        at = count_lines(mf1->ptr, mf1->size);
 421        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 422
 423        at = count_lines(mf2->ptr, mf2->size);
 424        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 425}
 426
 427static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 428                        int first, const char *line, int len)
 429{
 430        int has_trailing_newline, has_trailing_carriage_return;
 431        int nofirst;
 432        FILE *file = o->file;
 433
 434        fputs(diff_line_prefix(o), file);
 435
 436        if (len == 0) {
 437                has_trailing_newline = (first == '\n');
 438                has_trailing_carriage_return = (!has_trailing_newline &&
 439                                                (first == '\r'));
 440                nofirst = has_trailing_newline || has_trailing_carriage_return;
 441        } else {
 442                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 443                if (has_trailing_newline)
 444                        len--;
 445                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 446                if (has_trailing_carriage_return)
 447                        len--;
 448                nofirst = 0;
 449        }
 450
 451        if (len || !nofirst) {
 452                fputs(set, file);
 453                if (!nofirst)
 454                        fputc(first, file);
 455                fwrite(line, len, 1, file);
 456                fputs(reset, file);
 457        }
 458        if (has_trailing_carriage_return)
 459                fputc('\r', file);
 460        if (has_trailing_newline)
 461                fputc('\n', file);
 462}
 463
 464static void emit_line(struct diff_options *o, const char *set, const char *reset,
 465                      const char *line, int len)
 466{
 467        emit_line_0(o, set, reset, line[0], line+1, len-1);
 468}
 469
 470static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 471{
 472        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 473              ecbdata->blank_at_eof_in_preimage &&
 474              ecbdata->blank_at_eof_in_postimage &&
 475              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 476              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 477                return 0;
 478        return ws_blank_line(line, len, ecbdata->ws_rule);
 479}
 480
 481static void emit_line_checked(const char *reset,
 482                              struct emit_callback *ecbdata,
 483                              const char *line, int len,
 484                              enum color_diff color,
 485                              unsigned ws_error_highlight,
 486                              char sign)
 487{
 488        const char *set = diff_get_color(ecbdata->color_diff, color);
 489        const char *ws = NULL;
 490
 491        if (ecbdata->opt->ws_error_highlight & ws_error_highlight) {
 492                ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 493                if (!*ws)
 494                        ws = NULL;
 495        }
 496
 497        if (!ws)
 498                emit_line_0(ecbdata->opt, set, reset, sign, line, len);
 499        else if (sign == '+' && new_blank_line_at_eof(ecbdata, line, len))
 500                /* Blank line at EOF - paint '+' as well */
 501                emit_line_0(ecbdata->opt, ws, reset, sign, line, len);
 502        else {
 503                /* Emit just the prefix, then the rest. */
 504                emit_line_0(ecbdata->opt, set, reset, sign, "", 0);
 505                ws_check_emit(line, len, ecbdata->ws_rule,
 506                              ecbdata->opt->file, set, reset, ws);
 507        }
 508}
 509
 510static void emit_add_line(const char *reset,
 511                          struct emit_callback *ecbdata,
 512                          const char *line, int len)
 513{
 514        emit_line_checked(reset, ecbdata, line, len,
 515                          DIFF_FILE_NEW, WSEH_NEW, '+');
 516}
 517
 518static void emit_del_line(const char *reset,
 519                          struct emit_callback *ecbdata,
 520                          const char *line, int len)
 521{
 522        emit_line_checked(reset, ecbdata, line, len,
 523                          DIFF_FILE_OLD, WSEH_OLD, '-');
 524}
 525
 526static void emit_context_line(const char *reset,
 527                              struct emit_callback *ecbdata,
 528                              const char *line, int len)
 529{
 530        emit_line_checked(reset, ecbdata, line, len,
 531                          DIFF_CONTEXT, WSEH_CONTEXT, ' ');
 532}
 533
 534static void emit_hunk_header(struct emit_callback *ecbdata,
 535                             const char *line, int len)
 536{
 537        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
 538        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 539        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 540        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 541        static const char atat[2] = { '@', '@' };
 542        const char *cp, *ep;
 543        struct strbuf msgbuf = STRBUF_INIT;
 544        int org_len = len;
 545        int i = 1;
 546
 547        /*
 548         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 549         * it always is at least 10 bytes long.
 550         */
 551        if (len < 10 ||
 552            memcmp(line, atat, 2) ||
 553            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 554                emit_line(ecbdata->opt, context, reset, line, len);
 555                return;
 556        }
 557        ep += 2; /* skip over @@ */
 558
 559        /* The hunk header in fraginfo color */
 560        strbuf_addstr(&msgbuf, frag);
 561        strbuf_add(&msgbuf, line, ep - line);
 562        strbuf_addstr(&msgbuf, reset);
 563
 564        /*
 565         * trailing "\r\n"
 566         */
 567        for ( ; i < 3; i++)
 568                if (line[len - i] == '\r' || line[len - i] == '\n')
 569                        len--;
 570
 571        /* blank before the func header */
 572        for (cp = ep; ep - line < len; ep++)
 573                if (*ep != ' ' && *ep != '\t')
 574                        break;
 575        if (ep != cp) {
 576                strbuf_addstr(&msgbuf, context);
 577                strbuf_add(&msgbuf, cp, ep - cp);
 578                strbuf_addstr(&msgbuf, reset);
 579        }
 580
 581        if (ep < line + len) {
 582                strbuf_addstr(&msgbuf, func);
 583                strbuf_add(&msgbuf, ep, line + len - ep);
 584                strbuf_addstr(&msgbuf, reset);
 585        }
 586
 587        strbuf_add(&msgbuf, line + len, org_len - len);
 588        emit_line(ecbdata->opt, "", "", msgbuf.buf, msgbuf.len);
 589        strbuf_release(&msgbuf);
 590}
 591
 592static struct diff_tempfile *claim_diff_tempfile(void) {
 593        int i;
 594        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 595                if (!diff_temp[i].name)
 596                        return diff_temp + i;
 597        die("BUG: diff is failing to clean up its tempfiles");
 598}
 599
 600static int remove_tempfile_installed;
 601
 602static void remove_tempfile(void)
 603{
 604        int i;
 605        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 606                if (diff_temp[i].name == diff_temp[i].tmp_path)
 607                        unlink_or_warn(diff_temp[i].name);
 608                diff_temp[i].name = NULL;
 609        }
 610}
 611
 612static void remove_tempfile_on_signal(int signo)
 613{
 614        remove_tempfile();
 615        sigchain_pop(signo);
 616        raise(signo);
 617}
 618
 619static void print_line_count(FILE *file, int count)
 620{
 621        switch (count) {
 622        case 0:
 623                fprintf(file, "0,0");
 624                break;
 625        case 1:
 626                fprintf(file, "1");
 627                break;
 628        default:
 629                fprintf(file, "1,%d", count);
 630                break;
 631        }
 632}
 633
 634static void emit_rewrite_lines(struct emit_callback *ecb,
 635                               int prefix, const char *data, int size)
 636{
 637        const char *endp = NULL;
 638        static const char *nneof = " No newline at end of file\n";
 639        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 640
 641        while (0 < size) {
 642                int len;
 643
 644                endp = memchr(data, '\n', size);
 645                len = endp ? (endp - data + 1) : size;
 646                if (prefix != '+') {
 647                        ecb->lno_in_preimage++;
 648                        emit_del_line(reset, ecb, data, len);
 649                } else {
 650                        ecb->lno_in_postimage++;
 651                        emit_add_line(reset, ecb, data, len);
 652                }
 653                size -= len;
 654                data += len;
 655        }
 656        if (!endp) {
 657                const char *context = diff_get_color(ecb->color_diff,
 658                                                     DIFF_CONTEXT);
 659                putc('\n', ecb->opt->file);
 660                emit_line_0(ecb->opt, context, reset, '\\',
 661                            nneof, strlen(nneof));
 662        }
 663}
 664
 665static void emit_rewrite_diff(const char *name_a,
 666                              const char *name_b,
 667                              struct diff_filespec *one,
 668                              struct diff_filespec *two,
 669                              struct userdiff_driver *textconv_one,
 670                              struct userdiff_driver *textconv_two,
 671                              struct diff_options *o)
 672{
 673        int lc_a, lc_b;
 674        const char *name_a_tab, *name_b_tab;
 675        const char *metainfo = diff_get_color(o->use_color, DIFF_METAINFO);
 676        const char *fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
 677        const char *reset = diff_get_color(o->use_color, DIFF_RESET);
 678        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 679        const char *a_prefix, *b_prefix;
 680        char *data_one, *data_two;
 681        size_t size_one, size_two;
 682        struct emit_callback ecbdata;
 683        const char *line_prefix = diff_line_prefix(o);
 684
 685        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 686                a_prefix = o->b_prefix;
 687                b_prefix = o->a_prefix;
 688        } else {
 689                a_prefix = o->a_prefix;
 690                b_prefix = o->b_prefix;
 691        }
 692
 693        name_a += (*name_a == '/');
 694        name_b += (*name_b == '/');
 695        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 696        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 697
 698        strbuf_reset(&a_name);
 699        strbuf_reset(&b_name);
 700        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 701        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 702
 703        size_one = fill_textconv(textconv_one, one, &data_one);
 704        size_two = fill_textconv(textconv_two, two, &data_two);
 705
 706        memset(&ecbdata, 0, sizeof(ecbdata));
 707        ecbdata.color_diff = want_color(o->use_color);
 708        ecbdata.found_changesp = &o->found_changes;
 709        ecbdata.ws_rule = whitespace_rule(name_b);
 710        ecbdata.opt = o;
 711        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 712                mmfile_t mf1, mf2;
 713                mf1.ptr = (char *)data_one;
 714                mf2.ptr = (char *)data_two;
 715                mf1.size = size_one;
 716                mf2.size = size_two;
 717                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 718        }
 719        ecbdata.lno_in_preimage = 1;
 720        ecbdata.lno_in_postimage = 1;
 721
 722        lc_a = count_lines(data_one, size_one);
 723        lc_b = count_lines(data_two, size_two);
 724        fprintf(o->file,
 725                "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
 726                line_prefix, metainfo, a_name.buf, name_a_tab, reset,
 727                line_prefix, metainfo, b_name.buf, name_b_tab, reset,
 728                line_prefix, fraginfo);
 729        if (!o->irreversible_delete)
 730                print_line_count(o->file, lc_a);
 731        else
 732                fprintf(o->file, "?,?");
 733        fprintf(o->file, " +");
 734        print_line_count(o->file, lc_b);
 735        fprintf(o->file, " @@%s\n", reset);
 736        if (lc_a && !o->irreversible_delete)
 737                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 738        if (lc_b)
 739                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 740        if (textconv_one)
 741                free((char *)data_one);
 742        if (textconv_two)
 743                free((char *)data_two);
 744}
 745
 746struct diff_words_buffer {
 747        mmfile_t text;
 748        long alloc;
 749        struct diff_words_orig {
 750                const char *begin, *end;
 751        } *orig;
 752        int orig_nr, orig_alloc;
 753};
 754
 755static void diff_words_append(char *line, unsigned long len,
 756                struct diff_words_buffer *buffer)
 757{
 758        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 759        line++;
 760        len--;
 761        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 762        buffer->text.size += len;
 763        buffer->text.ptr[buffer->text.size] = '\0';
 764}
 765
 766struct diff_words_style_elem {
 767        const char *prefix;
 768        const char *suffix;
 769        const char *color; /* NULL; filled in by the setup code if
 770                            * color is enabled */
 771};
 772
 773struct diff_words_style {
 774        enum diff_words_type type;
 775        struct diff_words_style_elem new, old, ctx;
 776        const char *newline;
 777};
 778
 779static struct diff_words_style diff_words_styles[] = {
 780        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 781        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 782        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 783};
 784
 785struct diff_words_data {
 786        struct diff_words_buffer minus, plus;
 787        const char *current_plus;
 788        int last_minus;
 789        struct diff_options *opt;
 790        regex_t *word_regex;
 791        enum diff_words_type type;
 792        struct diff_words_style *style;
 793};
 794
 795static int fn_out_diff_words_write_helper(FILE *fp,
 796                                          struct diff_words_style_elem *st_el,
 797                                          const char *newline,
 798                                          size_t count, const char *buf,
 799                                          const char *line_prefix)
 800{
 801        int print = 0;
 802
 803        while (count) {
 804                char *p = memchr(buf, '\n', count);
 805                if (print)
 806                        fputs(line_prefix, fp);
 807                if (p != buf) {
 808                        if (st_el->color && fputs(st_el->color, fp) < 0)
 809                                return -1;
 810                        if (fputs(st_el->prefix, fp) < 0 ||
 811                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 812                            fputs(st_el->suffix, fp) < 0)
 813                                return -1;
 814                        if (st_el->color && *st_el->color
 815                            && fputs(GIT_COLOR_RESET, fp) < 0)
 816                                return -1;
 817                }
 818                if (!p)
 819                        return 0;
 820                if (fputs(newline, fp) < 0)
 821                        return -1;
 822                count -= p + 1 - buf;
 823                buf = p + 1;
 824                print = 1;
 825        }
 826        return 0;
 827}
 828
 829/*
 830 * '--color-words' algorithm can be described as:
 831 *
 832 *   1. collect a the minus/plus lines of a diff hunk, divided into
 833 *      minus-lines and plus-lines;
 834 *
 835 *   2. break both minus-lines and plus-lines into words and
 836 *      place them into two mmfile_t with one word for each line;
 837 *
 838 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
 839 *
 840 * And for the common parts of the both file, we output the plus side text.
 841 * diff_words->current_plus is used to trace the current position of the plus file
 842 * which printed. diff_words->last_minus is used to trace the last minus word
 843 * printed.
 844 *
 845 * For '--graph' to work with '--color-words', we need to output the graph prefix
 846 * on each line of color words output. Generally, there are two conditions on
 847 * which we should output the prefix.
 848 *
 849 *   1. diff_words->last_minus == 0 &&
 850 *      diff_words->current_plus == diff_words->plus.text.ptr
 851 *
 852 *      that is: the plus text must start as a new line, and if there is no minus
 853 *      word printed, a graph prefix must be printed.
 854 *
 855 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
 856 *      *(diff_words->current_plus - 1) == '\n'
 857 *
 858 *      that is: a graph prefix must be printed following a '\n'
 859 */
 860static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
 861{
 862        if ((diff_words->last_minus == 0 &&
 863                diff_words->current_plus == diff_words->plus.text.ptr) ||
 864                (diff_words->current_plus > diff_words->plus.text.ptr &&
 865                *(diff_words->current_plus - 1) == '\n')) {
 866                return 1;
 867        } else {
 868                return 0;
 869        }
 870}
 871
 872static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 873{
 874        struct diff_words_data *diff_words = priv;
 875        struct diff_words_style *style = diff_words->style;
 876        int minus_first, minus_len, plus_first, plus_len;
 877        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 878        struct diff_options *opt = diff_words->opt;
 879        const char *line_prefix;
 880
 881        if (line[0] != '@' || parse_hunk_header(line, len,
 882                        &minus_first, &minus_len, &plus_first, &plus_len))
 883                return;
 884
 885        assert(opt);
 886        line_prefix = diff_line_prefix(opt);
 887
 888        /* POSIX requires that first be decremented by one if len == 0... */
 889        if (minus_len) {
 890                minus_begin = diff_words->minus.orig[minus_first].begin;
 891                minus_end =
 892                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 893        } else
 894                minus_begin = minus_end =
 895                        diff_words->minus.orig[minus_first].end;
 896
 897        if (plus_len) {
 898                plus_begin = diff_words->plus.orig[plus_first].begin;
 899                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 900        } else
 901                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 902
 903        if (color_words_output_graph_prefix(diff_words)) {
 904                fputs(line_prefix, diff_words->opt->file);
 905        }
 906        if (diff_words->current_plus != plus_begin) {
 907                fn_out_diff_words_write_helper(diff_words->opt->file,
 908                                &style->ctx, style->newline,
 909                                plus_begin - diff_words->current_plus,
 910                                diff_words->current_plus, line_prefix);
 911                if (*(plus_begin - 1) == '\n')
 912                        fputs(line_prefix, diff_words->opt->file);
 913        }
 914        if (minus_begin != minus_end) {
 915                fn_out_diff_words_write_helper(diff_words->opt->file,
 916                                &style->old, style->newline,
 917                                minus_end - minus_begin, minus_begin,
 918                                line_prefix);
 919        }
 920        if (plus_begin != plus_end) {
 921                fn_out_diff_words_write_helper(diff_words->opt->file,
 922                                &style->new, style->newline,
 923                                plus_end - plus_begin, plus_begin,
 924                                line_prefix);
 925        }
 926
 927        diff_words->current_plus = plus_end;
 928        diff_words->last_minus = minus_first;
 929}
 930
 931/* This function starts looking at *begin, and returns 0 iff a word was found. */
 932static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 933                int *begin, int *end)
 934{
 935        if (word_regex && *begin < buffer->size) {
 936                regmatch_t match[1];
 937                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 938                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 939                                        '\n', match[0].rm_eo - match[0].rm_so);
 940                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 941                        *begin += match[0].rm_so;
 942                        return *begin >= *end;
 943                }
 944                return -1;
 945        }
 946
 947        /* find the next word */
 948        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 949                (*begin)++;
 950        if (*begin >= buffer->size)
 951                return -1;
 952
 953        /* find the end of the word */
 954        *end = *begin + 1;
 955        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 956                (*end)++;
 957
 958        return 0;
 959}
 960
 961/*
 962 * This function splits the words in buffer->text, stores the list with
 963 * newline separator into out, and saves the offsets of the original words
 964 * in buffer->orig.
 965 */
 966static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 967                regex_t *word_regex)
 968{
 969        int i, j;
 970        long alloc = 0;
 971
 972        out->size = 0;
 973        out->ptr = NULL;
 974
 975        /* fake an empty "0th" word */
 976        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 977        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 978        buffer->orig_nr = 1;
 979
 980        for (i = 0; i < buffer->text.size; i++) {
 981                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 982                        return;
 983
 984                /* store original boundaries */
 985                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 986                                buffer->orig_alloc);
 987                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 988                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 989                buffer->orig_nr++;
 990
 991                /* store one word */
 992                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 993                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 994                out->ptr[out->size + j - i] = '\n';
 995                out->size += j - i + 1;
 996
 997                i = j - 1;
 998        }
 999}
1000
1001/* this executes the word diff on the accumulated buffers */
1002static void diff_words_show(struct diff_words_data *diff_words)
1003{
1004        xpparam_t xpp;
1005        xdemitconf_t xecfg;
1006        mmfile_t minus, plus;
1007        struct diff_words_style *style = diff_words->style;
1008
1009        struct diff_options *opt = diff_words->opt;
1010        const char *line_prefix;
1011
1012        assert(opt);
1013        line_prefix = diff_line_prefix(opt);
1014
1015        /* special case: only removal */
1016        if (!diff_words->plus.text.size) {
1017                fputs(line_prefix, diff_words->opt->file);
1018                fn_out_diff_words_write_helper(diff_words->opt->file,
1019                        &style->old, style->newline,
1020                        diff_words->minus.text.size,
1021                        diff_words->minus.text.ptr, line_prefix);
1022                diff_words->minus.text.size = 0;
1023                return;
1024        }
1025
1026        diff_words->current_plus = diff_words->plus.text.ptr;
1027        diff_words->last_minus = 0;
1028
1029        memset(&xpp, 0, sizeof(xpp));
1030        memset(&xecfg, 0, sizeof(xecfg));
1031        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
1032        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
1033        xpp.flags = 0;
1034        /* as only the hunk header will be parsed, we need a 0-context */
1035        xecfg.ctxlen = 0;
1036        if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
1037                          &xpp, &xecfg))
1038                die("unable to generate word diff");
1039        free(minus.ptr);
1040        free(plus.ptr);
1041        if (diff_words->current_plus != diff_words->plus.text.ptr +
1042                        diff_words->plus.text.size) {
1043                if (color_words_output_graph_prefix(diff_words))
1044                        fputs(line_prefix, diff_words->opt->file);
1045                fn_out_diff_words_write_helper(diff_words->opt->file,
1046                        &style->ctx, style->newline,
1047                        diff_words->plus.text.ptr + diff_words->plus.text.size
1048                        - diff_words->current_plus, diff_words->current_plus,
1049                        line_prefix);
1050        }
1051        diff_words->minus.text.size = diff_words->plus.text.size = 0;
1052}
1053
1054/* In "color-words" mode, show word-diff of words accumulated in the buffer */
1055static void diff_words_flush(struct emit_callback *ecbdata)
1056{
1057        if (ecbdata->diff_words->minus.text.size ||
1058            ecbdata->diff_words->plus.text.size)
1059                diff_words_show(ecbdata->diff_words);
1060}
1061
1062static void diff_filespec_load_driver(struct diff_filespec *one)
1063{
1064        /* Use already-loaded driver */
1065        if (one->driver)
1066                return;
1067
1068        if (S_ISREG(one->mode))
1069                one->driver = userdiff_find_by_path(one->path);
1070
1071        /* Fallback to default settings */
1072        if (!one->driver)
1073                one->driver = userdiff_find_by_name("default");
1074}
1075
1076static const char *userdiff_word_regex(struct diff_filespec *one)
1077{
1078        diff_filespec_load_driver(one);
1079        return one->driver->word_regex;
1080}
1081
1082static void init_diff_words_data(struct emit_callback *ecbdata,
1083                                 struct diff_options *orig_opts,
1084                                 struct diff_filespec *one,
1085                                 struct diff_filespec *two)
1086{
1087        int i;
1088        struct diff_options *o = xmalloc(sizeof(struct diff_options));
1089        memcpy(o, orig_opts, sizeof(struct diff_options));
1090
1091        ecbdata->diff_words =
1092                xcalloc(1, sizeof(struct diff_words_data));
1093        ecbdata->diff_words->type = o->word_diff;
1094        ecbdata->diff_words->opt = o;
1095        if (!o->word_regex)
1096                o->word_regex = userdiff_word_regex(one);
1097        if (!o->word_regex)
1098                o->word_regex = userdiff_word_regex(two);
1099        if (!o->word_regex)
1100                o->word_regex = diff_word_regex_cfg;
1101        if (o->word_regex) {
1102                ecbdata->diff_words->word_regex = (regex_t *)
1103                        xmalloc(sizeof(regex_t));
1104                if (regcomp(ecbdata->diff_words->word_regex,
1105                            o->word_regex,
1106                            REG_EXTENDED | REG_NEWLINE))
1107                        die ("Invalid regular expression: %s",
1108                             o->word_regex);
1109        }
1110        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
1111                if (o->word_diff == diff_words_styles[i].type) {
1112                        ecbdata->diff_words->style =
1113                                &diff_words_styles[i];
1114                        break;
1115                }
1116        }
1117        if (want_color(o->use_color)) {
1118                struct diff_words_style *st = ecbdata->diff_words->style;
1119                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
1120                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
1121                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
1122        }
1123}
1124
1125static void free_diff_words_data(struct emit_callback *ecbdata)
1126{
1127        if (ecbdata->diff_words) {
1128                diff_words_flush(ecbdata);
1129                free (ecbdata->diff_words->opt);
1130                free (ecbdata->diff_words->minus.text.ptr);
1131                free (ecbdata->diff_words->minus.orig);
1132                free (ecbdata->diff_words->plus.text.ptr);
1133                free (ecbdata->diff_words->plus.orig);
1134                if (ecbdata->diff_words->word_regex) {
1135                        regfree(ecbdata->diff_words->word_regex);
1136                        free(ecbdata->diff_words->word_regex);
1137                }
1138                free(ecbdata->diff_words);
1139                ecbdata->diff_words = NULL;
1140        }
1141}
1142
1143const char *diff_get_color(int diff_use_color, enum color_diff ix)
1144{
1145        if (want_color(diff_use_color))
1146                return diff_colors[ix];
1147        return "";
1148}
1149
1150const char *diff_line_prefix(struct diff_options *opt)
1151{
1152        struct strbuf *msgbuf;
1153        if (!opt->output_prefix)
1154                return "";
1155
1156        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
1157        return msgbuf->buf;
1158}
1159
1160static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
1161{
1162        const char *cp;
1163        unsigned long allot;
1164        size_t l = len;
1165
1166        if (ecb->truncate)
1167                return ecb->truncate(line, len);
1168        cp = line;
1169        allot = l;
1170        while (0 < l) {
1171                (void) utf8_width(&cp, &l);
1172                if (!cp)
1173                        break; /* truncated in the middle? */
1174        }
1175        return allot - l;
1176}
1177
1178static void find_lno(const char *line, struct emit_callback *ecbdata)
1179{
1180        const char *p;
1181        ecbdata->lno_in_preimage = 0;
1182        ecbdata->lno_in_postimage = 0;
1183        p = strchr(line, '-');
1184        if (!p)
1185                return; /* cannot happen */
1186        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1187        p = strchr(p, '+');
1188        if (!p)
1189                return; /* cannot happen */
1190        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
1191}
1192
1193static void fn_out_consume(void *priv, char *line, unsigned long len)
1194{
1195        struct emit_callback *ecbdata = priv;
1196        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
1197        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
1198        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1199        struct diff_options *o = ecbdata->opt;
1200        const char *line_prefix = diff_line_prefix(o);
1201
1202        if (ecbdata->header) {
1203                fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
1204                strbuf_reset(ecbdata->header);
1205                ecbdata->header = NULL;
1206        }
1207        *(ecbdata->found_changesp) = 1;
1208
1209        if (ecbdata->label_path[0]) {
1210                const char *name_a_tab, *name_b_tab;
1211
1212                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
1213                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
1214
1215                fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
1216                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
1217                fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
1218                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1219                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1220        }
1221
1222        if (diff_suppress_blank_empty
1223            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1224                line[0] = '\n';
1225                len = 1;
1226        }
1227
1228        if (line[0] == '@') {
1229                if (ecbdata->diff_words)
1230                        diff_words_flush(ecbdata);
1231                len = sane_truncate_line(ecbdata, line, len);
1232                find_lno(line, ecbdata);
1233                emit_hunk_header(ecbdata, line, len);
1234                if (line[len-1] != '\n')
1235                        putc('\n', ecbdata->opt->file);
1236                return;
1237        }
1238
1239        if (len < 1) {
1240                emit_line(ecbdata->opt, reset, reset, line, len);
1241                if (ecbdata->diff_words
1242                    && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
1243                        fputs("~\n", ecbdata->opt->file);
1244                return;
1245        }
1246
1247        if (ecbdata->diff_words) {
1248                if (line[0] == '-') {
1249                        diff_words_append(line, len,
1250                                          &ecbdata->diff_words->minus);
1251                        return;
1252                } else if (line[0] == '+') {
1253                        diff_words_append(line, len,
1254                                          &ecbdata->diff_words->plus);
1255                        return;
1256                } else if (starts_with(line, "\\ ")) {
1257                        /*
1258                         * Eat the "no newline at eof" marker as if we
1259                         * saw a "+" or "-" line with nothing on it,
1260                         * and return without diff_words_flush() to
1261                         * defer processing. If this is the end of
1262                         * preimage, more "+" lines may come after it.
1263                         */
1264                        return;
1265                }
1266                diff_words_flush(ecbdata);
1267                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1268                        emit_line(ecbdata->opt, context, reset, line, len);
1269                        fputs("~\n", ecbdata->opt->file);
1270                } else {
1271                        /*
1272                         * Skip the prefix character, if any.  With
1273                         * diff_suppress_blank_empty, there may be
1274                         * none.
1275                         */
1276                        if (line[0] != '\n') {
1277                              line++;
1278                              len--;
1279                        }
1280                        emit_line(ecbdata->opt, context, reset, line, len);
1281                }
1282                return;
1283        }
1284
1285        switch (line[0]) {
1286        case '+':
1287                ecbdata->lno_in_postimage++;
1288                emit_add_line(reset, ecbdata, line + 1, len - 1);
1289                break;
1290        case '-':
1291                ecbdata->lno_in_preimage++;
1292                emit_del_line(reset, ecbdata, line + 1, len - 1);
1293                break;
1294        case ' ':
1295                ecbdata->lno_in_postimage++;
1296                ecbdata->lno_in_preimage++;
1297                emit_context_line(reset, ecbdata, line + 1, len - 1);
1298                break;
1299        default:
1300                /* incomplete line at the end */
1301                ecbdata->lno_in_preimage++;
1302                emit_line(ecbdata->opt,
1303                          diff_get_color(ecbdata->color_diff, DIFF_CONTEXT),
1304                          reset, line, len);
1305                break;
1306        }
1307}
1308
1309static char *pprint_rename(const char *a, const char *b)
1310{
1311        const char *old = a;
1312        const char *new = b;
1313        struct strbuf name = STRBUF_INIT;
1314        int pfx_length, sfx_length;
1315        int pfx_adjust_for_slash;
1316        int len_a = strlen(a);
1317        int len_b = strlen(b);
1318        int a_midlen, b_midlen;
1319        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1320        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1321
1322        if (qlen_a || qlen_b) {
1323                quote_c_style(a, &name, NULL, 0);
1324                strbuf_addstr(&name, " => ");
1325                quote_c_style(b, &name, NULL, 0);
1326                return strbuf_detach(&name, NULL);
1327        }
1328
1329        /* Find common prefix */
1330        pfx_length = 0;
1331        while (*old && *new && *old == *new) {
1332                if (*old == '/')
1333                        pfx_length = old - a + 1;
1334                old++;
1335                new++;
1336        }
1337
1338        /* Find common suffix */
1339        old = a + len_a;
1340        new = b + len_b;
1341        sfx_length = 0;
1342        /*
1343         * If there is a common prefix, it must end in a slash.  In
1344         * that case we let this loop run 1 into the prefix to see the
1345         * same slash.
1346         *
1347         * If there is no common prefix, we cannot do this as it would
1348         * underrun the input strings.
1349         */
1350        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
1351        while (a + pfx_length - pfx_adjust_for_slash <= old &&
1352               b + pfx_length - pfx_adjust_for_slash <= new &&
1353               *old == *new) {
1354                if (*old == '/')
1355                        sfx_length = len_a - (old - a);
1356                old--;
1357                new--;
1358        }
1359
1360        /*
1361         * pfx{mid-a => mid-b}sfx
1362         * {pfx-a => pfx-b}sfx
1363         * pfx{sfx-a => sfx-b}
1364         * name-a => name-b
1365         */
1366        a_midlen = len_a - pfx_length - sfx_length;
1367        b_midlen = len_b - pfx_length - sfx_length;
1368        if (a_midlen < 0)
1369                a_midlen = 0;
1370        if (b_midlen < 0)
1371                b_midlen = 0;
1372
1373        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1374        if (pfx_length + sfx_length) {
1375                strbuf_add(&name, a, pfx_length);
1376                strbuf_addch(&name, '{');
1377        }
1378        strbuf_add(&name, a + pfx_length, a_midlen);
1379        strbuf_addstr(&name, " => ");
1380        strbuf_add(&name, b + pfx_length, b_midlen);
1381        if (pfx_length + sfx_length) {
1382                strbuf_addch(&name, '}');
1383                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1384        }
1385        return strbuf_detach(&name, NULL);
1386}
1387
1388struct diffstat_t {
1389        int nr;
1390        int alloc;
1391        struct diffstat_file {
1392                char *from_name;
1393                char *name;
1394                char *print_name;
1395                unsigned is_unmerged:1;
1396                unsigned is_binary:1;
1397                unsigned is_renamed:1;
1398                unsigned is_interesting:1;
1399                uintmax_t added, deleted;
1400        } **files;
1401};
1402
1403static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1404                                          const char *name_a,
1405                                          const char *name_b)
1406{
1407        struct diffstat_file *x;
1408        x = xcalloc(1, sizeof(*x));
1409        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
1410        diffstat->files[diffstat->nr++] = x;
1411        if (name_b) {
1412                x->from_name = xstrdup(name_a);
1413                x->name = xstrdup(name_b);
1414                x->is_renamed = 1;
1415        }
1416        else {
1417                x->from_name = NULL;
1418                x->name = xstrdup(name_a);
1419        }
1420        return x;
1421}
1422
1423static void diffstat_consume(void *priv, char *line, unsigned long len)
1424{
1425        struct diffstat_t *diffstat = priv;
1426        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1427
1428        if (line[0] == '+')
1429                x->added++;
1430        else if (line[0] == '-')
1431                x->deleted++;
1432}
1433
1434const char mime_boundary_leader[] = "------------";
1435
1436static int scale_linear(int it, int width, int max_change)
1437{
1438        if (!it)
1439                return 0;
1440        /*
1441         * make sure that at least one '-' or '+' is printed if
1442         * there is any change to this path. The easiest way is to
1443         * scale linearly as if the alloted width is one column shorter
1444         * than it is, and then add 1 to the result.
1445         */
1446        return 1 + (it * (width - 1) / max_change);
1447}
1448
1449static void show_name(FILE *file,
1450                      const char *prefix, const char *name, int len)
1451{
1452        fprintf(file, " %s%-*s |", prefix, len, name);
1453}
1454
1455static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1456{
1457        if (cnt <= 0)
1458                return;
1459        fprintf(file, "%s", set);
1460        while (cnt--)
1461                putc(ch, file);
1462        fprintf(file, "%s", reset);
1463}
1464
1465static void fill_print_name(struct diffstat_file *file)
1466{
1467        char *pname;
1468
1469        if (file->print_name)
1470                return;
1471
1472        if (!file->is_renamed) {
1473                struct strbuf buf = STRBUF_INIT;
1474                if (quote_c_style(file->name, &buf, NULL, 0)) {
1475                        pname = strbuf_detach(&buf, NULL);
1476                } else {
1477                        pname = file->name;
1478                        strbuf_release(&buf);
1479                }
1480        } else {
1481                pname = pprint_rename(file->from_name, file->name);
1482        }
1483        file->print_name = pname;
1484}
1485
1486int print_stat_summary(FILE *fp, int files, int insertions, int deletions)
1487{
1488        struct strbuf sb = STRBUF_INIT;
1489        int ret;
1490
1491        if (!files) {
1492                assert(insertions == 0 && deletions == 0);
1493                return fprintf(fp, "%s\n", " 0 files changed");
1494        }
1495
1496        strbuf_addf(&sb,
1497                    (files == 1) ? " %d file changed" : " %d files changed",
1498                    files);
1499
1500        /*
1501         * For binary diff, the caller may want to print "x files
1502         * changed" with insertions == 0 && deletions == 0.
1503         *
1504         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
1505         * is probably less confusing (i.e skip over "2 files changed
1506         * but nothing about added/removed lines? Is this a bug in Git?").
1507         */
1508        if (insertions || deletions == 0) {
1509                strbuf_addf(&sb,
1510                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
1511                            insertions);
1512        }
1513
1514        if (deletions || insertions == 0) {
1515                strbuf_addf(&sb,
1516                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
1517                            deletions);
1518        }
1519        strbuf_addch(&sb, '\n');
1520        ret = fputs(sb.buf, fp);
1521        strbuf_release(&sb);
1522        return ret;
1523}
1524
1525static void show_stats(struct diffstat_t *data, struct diff_options *options)
1526{
1527        int i, len, add, del, adds = 0, dels = 0;
1528        uintmax_t max_change = 0, max_len = 0;
1529        int total_files = data->nr, count;
1530        int width, name_width, graph_width, number_width = 0, bin_width = 0;
1531        const char *reset, *add_c, *del_c;
1532        const char *line_prefix = "";
1533        int extra_shown = 0;
1534
1535        if (data->nr == 0)
1536                return;
1537
1538        line_prefix = diff_line_prefix(options);
1539        count = options->stat_count ? options->stat_count : data->nr;
1540
1541        reset = diff_get_color_opt(options, DIFF_RESET);
1542        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1543        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1544
1545        /*
1546         * Find the longest filename and max number of changes
1547         */
1548        for (i = 0; (i < count) && (i < data->nr); i++) {
1549                struct diffstat_file *file = data->files[i];
1550                uintmax_t change = file->added + file->deleted;
1551
1552                if (!file->is_interesting && (change == 0)) {
1553                        count++; /* not shown == room for one more */
1554                        continue;
1555                }
1556                fill_print_name(file);
1557                len = strlen(file->print_name);
1558                if (max_len < len)
1559                        max_len = len;
1560
1561                if (file->is_unmerged) {
1562                        /* "Unmerged" is 8 characters */
1563                        bin_width = bin_width < 8 ? 8 : bin_width;
1564                        continue;
1565                }
1566                if (file->is_binary) {
1567                        /* "Bin XXX -> YYY bytes" */
1568                        int w = 14 + decimal_width(file->added)
1569                                + decimal_width(file->deleted);
1570                        bin_width = bin_width < w ? w : bin_width;
1571                        /* Display change counts aligned with "Bin" */
1572                        number_width = 3;
1573                        continue;
1574                }
1575
1576                if (max_change < change)
1577                        max_change = change;
1578        }
1579        count = i; /* where we can stop scanning in data->files[] */
1580
1581        /*
1582         * We have width = stat_width or term_columns() columns total.
1583         * We want a maximum of min(max_len, stat_name_width) for the name part.
1584         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
1585         * We also need 1 for " " and 4 + decimal_width(max_change)
1586         * for " | NNNN " and one the empty column at the end, altogether
1587         * 6 + decimal_width(max_change).
1588         *
1589         * If there's not enough space, we will use the smaller of
1590         * stat_name_width (if set) and 5/8*width for the filename,
1591         * and the rest for constant elements + graph part, but no more
1592         * than stat_graph_width for the graph part.
1593         * (5/8 gives 50 for filename and 30 for the constant parts + graph
1594         * for the standard terminal size).
1595         *
1596         * In other words: stat_width limits the maximum width, and
1597         * stat_name_width fixes the maximum width of the filename,
1598         * and is also used to divide available columns if there
1599         * aren't enough.
1600         *
1601         * Binary files are displayed with "Bin XXX -> YYY bytes"
1602         * instead of the change count and graph. This part is treated
1603         * similarly to the graph part, except that it is not
1604         * "scaled". If total width is too small to accommodate the
1605         * guaranteed minimum width of the filename part and the
1606         * separators and this message, this message will "overflow"
1607         * making the line longer than the maximum width.
1608         */
1609
1610        if (options->stat_width == -1)
1611                width = term_columns() - options->output_prefix_length;
1612        else
1613                width = options->stat_width ? options->stat_width : 80;
1614        number_width = decimal_width(max_change) > number_width ?
1615                decimal_width(max_change) : number_width;
1616
1617        if (options->stat_graph_width == -1)
1618                options->stat_graph_width = diff_stat_graph_width;
1619
1620        /*
1621         * Guarantee 3/8*16==6 for the graph part
1622         * and 5/8*16==10 for the filename part
1623         */
1624        if (width < 16 + 6 + number_width)
1625                width = 16 + 6 + number_width;
1626
1627        /*
1628         * First assign sizes that are wanted, ignoring available width.
1629         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
1630         * starting from "XXX" should fit in graph_width.
1631         */
1632        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
1633        if (options->stat_graph_width &&
1634            options->stat_graph_width < graph_width)
1635                graph_width = options->stat_graph_width;
1636
1637        name_width = (options->stat_name_width > 0 &&
1638                      options->stat_name_width < max_len) ?
1639                options->stat_name_width : max_len;
1640
1641        /*
1642         * Adjust adjustable widths not to exceed maximum width
1643         */
1644        if (name_width + number_width + 6 + graph_width > width) {
1645                if (graph_width > width * 3/8 - number_width - 6) {
1646                        graph_width = width * 3/8 - number_width - 6;
1647                        if (graph_width < 6)
1648                                graph_width = 6;
1649                }
1650
1651                if (options->stat_graph_width &&
1652                    graph_width > options->stat_graph_width)
1653                        graph_width = options->stat_graph_width;
1654                if (name_width > width - number_width - 6 - graph_width)
1655                        name_width = width - number_width - 6 - graph_width;
1656                else
1657                        graph_width = width - number_width - 6 - name_width;
1658        }
1659
1660        /*
1661         * From here name_width is the width of the name area,
1662         * and graph_width is the width of the graph area.
1663         * max_change is used to scale graph properly.
1664         */
1665        for (i = 0; i < count; i++) {
1666                const char *prefix = "";
1667                struct diffstat_file *file = data->files[i];
1668                char *name = file->print_name;
1669                uintmax_t added = file->added;
1670                uintmax_t deleted = file->deleted;
1671                int name_len;
1672
1673                if (!file->is_interesting && (added + deleted == 0))
1674                        continue;
1675
1676                /*
1677                 * "scale" the filename
1678                 */
1679                len = name_width;
1680                name_len = strlen(name);
1681                if (name_width < name_len) {
1682                        char *slash;
1683                        prefix = "...";
1684                        len -= 3;
1685                        name += name_len - len;
1686                        slash = strchr(name, '/');
1687                        if (slash)
1688                                name = slash;
1689                }
1690
1691                if (file->is_binary) {
1692                        fprintf(options->file, "%s", line_prefix);
1693                        show_name(options->file, prefix, name, len);
1694                        fprintf(options->file, " %*s", number_width, "Bin");
1695                        if (!added && !deleted) {
1696                                putc('\n', options->file);
1697                                continue;
1698                        }
1699                        fprintf(options->file, " %s%"PRIuMAX"%s",
1700                                del_c, deleted, reset);
1701                        fprintf(options->file, " -> ");
1702                        fprintf(options->file, "%s%"PRIuMAX"%s",
1703                                add_c, added, reset);
1704                        fprintf(options->file, " bytes");
1705                        fprintf(options->file, "\n");
1706                        continue;
1707                }
1708                else if (file->is_unmerged) {
1709                        fprintf(options->file, "%s", line_prefix);
1710                        show_name(options->file, prefix, name, len);
1711                        fprintf(options->file, " Unmerged\n");
1712                        continue;
1713                }
1714
1715                /*
1716                 * scale the add/delete
1717                 */
1718                add = added;
1719                del = deleted;
1720
1721                if (graph_width <= max_change) {
1722                        int total = scale_linear(add + del, graph_width, max_change);
1723                        if (total < 2 && add && del)
1724                                /* width >= 2 due to the sanity check */
1725                                total = 2;
1726                        if (add < del) {
1727                                add = scale_linear(add, graph_width, max_change);
1728                                del = total - add;
1729                        } else {
1730                                del = scale_linear(del, graph_width, max_change);
1731                                add = total - del;
1732                        }
1733                }
1734                fprintf(options->file, "%s", line_prefix);
1735                show_name(options->file, prefix, name, len);
1736                fprintf(options->file, " %*"PRIuMAX"%s",
1737                        number_width, added + deleted,
1738                        added + deleted ? " " : "");
1739                show_graph(options->file, '+', add, add_c, reset);
1740                show_graph(options->file, '-', del, del_c, reset);
1741                fprintf(options->file, "\n");
1742        }
1743
1744        for (i = 0; i < data->nr; i++) {
1745                struct diffstat_file *file = data->files[i];
1746                uintmax_t added = file->added;
1747                uintmax_t deleted = file->deleted;
1748
1749                if (file->is_unmerged ||
1750                    (!file->is_interesting && (added + deleted == 0))) {
1751                        total_files--;
1752                        continue;
1753                }
1754
1755                if (!file->is_binary) {
1756                        adds += added;
1757                        dels += deleted;
1758                }
1759                if (i < count)
1760                        continue;
1761                if (!extra_shown)
1762                        fprintf(options->file, "%s ...\n", line_prefix);
1763                extra_shown = 1;
1764        }
1765        fprintf(options->file, "%s", line_prefix);
1766        print_stat_summary(options->file, total_files, adds, dels);
1767}
1768
1769static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1770{
1771        int i, adds = 0, dels = 0, total_files = data->nr;
1772
1773        if (data->nr == 0)
1774                return;
1775
1776        for (i = 0; i < data->nr; i++) {
1777                int added = data->files[i]->added;
1778                int deleted= data->files[i]->deleted;
1779
1780                if (data->files[i]->is_unmerged ||
1781                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
1782                        total_files--;
1783                } else if (!data->files[i]->is_binary) { /* don't count bytes */
1784                        adds += added;
1785                        dels += deleted;
1786                }
1787        }
1788        fprintf(options->file, "%s", diff_line_prefix(options));
1789        print_stat_summary(options->file, total_files, adds, dels);
1790}
1791
1792static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1793{
1794        int i;
1795
1796        if (data->nr == 0)
1797                return;
1798
1799        for (i = 0; i < data->nr; i++) {
1800                struct diffstat_file *file = data->files[i];
1801
1802                fprintf(options->file, "%s", diff_line_prefix(options));
1803
1804                if (file->is_binary)
1805                        fprintf(options->file, "-\t-\t");
1806                else
1807                        fprintf(options->file,
1808                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1809                                file->added, file->deleted);
1810                if (options->line_termination) {
1811                        fill_print_name(file);
1812                        if (!file->is_renamed)
1813                                write_name_quoted(file->name, options->file,
1814                                                  options->line_termination);
1815                        else {
1816                                fputs(file->print_name, options->file);
1817                                putc(options->line_termination, options->file);
1818                        }
1819                } else {
1820                        if (file->is_renamed) {
1821                                putc('\0', options->file);
1822                                write_name_quoted(file->from_name, options->file, '\0');
1823                        }
1824                        write_name_quoted(file->name, options->file, '\0');
1825                }
1826        }
1827}
1828
1829struct dirstat_file {
1830        const char *name;
1831        unsigned long changed;
1832};
1833
1834struct dirstat_dir {
1835        struct dirstat_file *files;
1836        int alloc, nr, permille, cumulative;
1837};
1838
1839static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1840                unsigned long changed, const char *base, int baselen)
1841{
1842        unsigned long this_dir = 0;
1843        unsigned int sources = 0;
1844        const char *line_prefix = diff_line_prefix(opt);
1845
1846        while (dir->nr) {
1847                struct dirstat_file *f = dir->files;
1848                int namelen = strlen(f->name);
1849                unsigned long this;
1850                char *slash;
1851
1852                if (namelen < baselen)
1853                        break;
1854                if (memcmp(f->name, base, baselen))
1855                        break;
1856                slash = strchr(f->name + baselen, '/');
1857                if (slash) {
1858                        int newbaselen = slash + 1 - f->name;
1859                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1860                        sources++;
1861                } else {
1862                        this = f->changed;
1863                        dir->files++;
1864                        dir->nr--;
1865                        sources += 2;
1866                }
1867                this_dir += this;
1868        }
1869
1870        /*
1871         * We don't report dirstat's for
1872         *  - the top level
1873         *  - or cases where everything came from a single directory
1874         *    under this directory (sources == 1).
1875         */
1876        if (baselen && sources != 1) {
1877                if (this_dir) {
1878                        int permille = this_dir * 1000 / changed;
1879                        if (permille >= dir->permille) {
1880                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1881                                        permille / 10, permille % 10, baselen, base);
1882                                if (!dir->cumulative)
1883                                        return 0;
1884                        }
1885                }
1886        }
1887        return this_dir;
1888}
1889
1890static int dirstat_compare(const void *_a, const void *_b)
1891{
1892        const struct dirstat_file *a = _a;
1893        const struct dirstat_file *b = _b;
1894        return strcmp(a->name, b->name);
1895}
1896
1897static void show_dirstat(struct diff_options *options)
1898{
1899        int i;
1900        unsigned long changed;
1901        struct dirstat_dir dir;
1902        struct diff_queue_struct *q = &diff_queued_diff;
1903
1904        dir.files = NULL;
1905        dir.alloc = 0;
1906        dir.nr = 0;
1907        dir.permille = options->dirstat_permille;
1908        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1909
1910        changed = 0;
1911        for (i = 0; i < q->nr; i++) {
1912                struct diff_filepair *p = q->queue[i];
1913                const char *name;
1914                unsigned long copied, added, damage;
1915                int content_changed;
1916
1917                name = p->two->path ? p->two->path : p->one->path;
1918
1919                if (p->one->sha1_valid && p->two->sha1_valid)
1920                        content_changed = hashcmp(p->one->sha1, p->two->sha1);
1921                else
1922                        content_changed = 1;
1923
1924                if (!content_changed) {
1925                        /*
1926                         * The SHA1 has not changed, so pre-/post-content is
1927                         * identical. We can therefore skip looking at the
1928                         * file contents altogether.
1929                         */
1930                        damage = 0;
1931                        goto found_damage;
1932                }
1933
1934                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1935                        /*
1936                         * In --dirstat-by-file mode, we don't really need to
1937                         * look at the actual file contents at all.
1938                         * The fact that the SHA1 changed is enough for us to
1939                         * add this file to the list of results
1940                         * (with each file contributing equal damage).
1941                         */
1942                        damage = 1;
1943                        goto found_damage;
1944                }
1945
1946                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1947                        diff_populate_filespec(p->one, 0);
1948                        diff_populate_filespec(p->two, 0);
1949                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1950                                               &copied, &added);
1951                        diff_free_filespec_data(p->one);
1952                        diff_free_filespec_data(p->two);
1953                } else if (DIFF_FILE_VALID(p->one)) {
1954                        diff_populate_filespec(p->one, CHECK_SIZE_ONLY);
1955                        copied = added = 0;
1956                        diff_free_filespec_data(p->one);
1957                } else if (DIFF_FILE_VALID(p->two)) {
1958                        diff_populate_filespec(p->two, CHECK_SIZE_ONLY);
1959                        copied = 0;
1960                        added = p->two->size;
1961                        diff_free_filespec_data(p->two);
1962                } else
1963                        continue;
1964
1965                /*
1966                 * Original minus copied is the removed material,
1967                 * added is the new material.  They are both damages
1968                 * made to the preimage.
1969                 * If the resulting damage is zero, we know that
1970                 * diffcore_count_changes() considers the two entries to
1971                 * be identical, but since content_changed is true, we
1972                 * know that there must have been _some_ kind of change,
1973                 * so we force all entries to have damage > 0.
1974                 */
1975                damage = (p->one->size - copied) + added;
1976                if (!damage)
1977                        damage = 1;
1978
1979found_damage:
1980                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1981                dir.files[dir.nr].name = name;
1982                dir.files[dir.nr].changed = damage;
1983                changed += damage;
1984                dir.nr++;
1985        }
1986
1987        /* This can happen even with many files, if everything was renames */
1988        if (!changed)
1989                return;
1990
1991        /* Show all directories with more than x% of the changes */
1992        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1993        gather_dirstat(options, &dir, changed, "", 0);
1994}
1995
1996static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
1997{
1998        int i;
1999        unsigned long changed;
2000        struct dirstat_dir dir;
2001
2002        if (data->nr == 0)
2003                return;
2004
2005        dir.files = NULL;
2006        dir.alloc = 0;
2007        dir.nr = 0;
2008        dir.permille = options->dirstat_permille;
2009        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
2010
2011        changed = 0;
2012        for (i = 0; i < data->nr; i++) {
2013                struct diffstat_file *file = data->files[i];
2014                unsigned long damage = file->added + file->deleted;
2015                if (file->is_binary)
2016                        /*
2017                         * binary files counts bytes, not lines. Must find some
2018                         * way to normalize binary bytes vs. textual lines.
2019                         * The following heuristic assumes that there are 64
2020                         * bytes per "line".
2021                         * This is stupid and ugly, but very cheap...
2022                         */
2023                        damage = (damage + 63) / 64;
2024                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
2025                dir.files[dir.nr].name = file->name;
2026                dir.files[dir.nr].changed = damage;
2027                changed += damage;
2028                dir.nr++;
2029        }
2030
2031        /* This can happen even with many files, if everything was renames */
2032        if (!changed)
2033                return;
2034
2035        /* Show all directories with more than x% of the changes */
2036        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
2037        gather_dirstat(options, &dir, changed, "", 0);
2038}
2039
2040static void free_diffstat_info(struct diffstat_t *diffstat)
2041{
2042        int i;
2043        for (i = 0; i < diffstat->nr; i++) {
2044                struct diffstat_file *f = diffstat->files[i];
2045                if (f->name != f->print_name)
2046                        free(f->print_name);
2047                free(f->name);
2048                free(f->from_name);
2049                free(f);
2050        }
2051        free(diffstat->files);
2052}
2053
2054struct checkdiff_t {
2055        const char *filename;
2056        int lineno;
2057        int conflict_marker_size;
2058        struct diff_options *o;
2059        unsigned ws_rule;
2060        unsigned status;
2061};
2062
2063static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
2064{
2065        char firstchar;
2066        int cnt;
2067
2068        if (len < marker_size + 1)
2069                return 0;
2070        firstchar = line[0];
2071        switch (firstchar) {
2072        case '=': case '>': case '<': case '|':
2073                break;
2074        default:
2075                return 0;
2076        }
2077        for (cnt = 1; cnt < marker_size; cnt++)
2078                if (line[cnt] != firstchar)
2079                        return 0;
2080        /* line[1] thru line[marker_size-1] are same as firstchar */
2081        if (len < marker_size + 1 || !isspace(line[marker_size]))
2082                return 0;
2083        return 1;
2084}
2085
2086static void checkdiff_consume(void *priv, char *line, unsigned long len)
2087{
2088        struct checkdiff_t *data = priv;
2089        int marker_size = data->conflict_marker_size;
2090        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
2091        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
2092        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
2093        char *err;
2094        const char *line_prefix;
2095
2096        assert(data->o);
2097        line_prefix = diff_line_prefix(data->o);
2098
2099        if (line[0] == '+') {
2100                unsigned bad;
2101                data->lineno++;
2102                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
2103                        data->status |= 1;
2104                        fprintf(data->o->file,
2105                                "%s%s:%d: leftover conflict marker\n",
2106                                line_prefix, data->filename, data->lineno);
2107                }
2108                bad = ws_check(line + 1, len - 1, data->ws_rule);
2109                if (!bad)
2110                        return;
2111                data->status |= bad;
2112                err = whitespace_error_string(bad);
2113                fprintf(data->o->file, "%s%s:%d: %s.\n",
2114                        line_prefix, data->filename, data->lineno, err);
2115                free(err);
2116                emit_line(data->o, set, reset, line, 1);
2117                ws_check_emit(line + 1, len - 1, data->ws_rule,
2118                              data->o->file, set, reset, ws);
2119        } else if (line[0] == ' ') {
2120                data->lineno++;
2121        } else if (line[0] == '@') {
2122                char *plus = strchr(line, '+');
2123                if (plus)
2124                        data->lineno = strtol(plus, NULL, 10) - 1;
2125                else
2126                        die("invalid diff");
2127        }
2128}
2129
2130static unsigned char *deflate_it(char *data,
2131                                 unsigned long size,
2132                                 unsigned long *result_size)
2133{
2134        int bound;
2135        unsigned char *deflated;
2136        git_zstream stream;
2137
2138        git_deflate_init(&stream, zlib_compression_level);
2139        bound = git_deflate_bound(&stream, size);
2140        deflated = xmalloc(bound);
2141        stream.next_out = deflated;
2142        stream.avail_out = bound;
2143
2144        stream.next_in = (unsigned char *)data;
2145        stream.avail_in = size;
2146        while (git_deflate(&stream, Z_FINISH) == Z_OK)
2147                ; /* nothing */
2148        git_deflate_end(&stream);
2149        *result_size = stream.total_out;
2150        return deflated;
2151}
2152
2153static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two,
2154                                  const char *prefix)
2155{
2156        void *cp;
2157        void *delta;
2158        void *deflated;
2159        void *data;
2160        unsigned long orig_size;
2161        unsigned long delta_size;
2162        unsigned long deflate_size;
2163        unsigned long data_size;
2164
2165        /* We could do deflated delta, or we could do just deflated two,
2166         * whichever is smaller.
2167         */
2168        delta = NULL;
2169        deflated = deflate_it(two->ptr, two->size, &deflate_size);
2170        if (one->size && two->size) {
2171                delta = diff_delta(one->ptr, one->size,
2172                                   two->ptr, two->size,
2173                                   &delta_size, deflate_size);
2174                if (delta) {
2175                        void *to_free = delta;
2176                        orig_size = delta_size;
2177                        delta = deflate_it(delta, delta_size, &delta_size);
2178                        free(to_free);
2179                }
2180        }
2181
2182        if (delta && delta_size < deflate_size) {
2183                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
2184                free(deflated);
2185                data = delta;
2186                data_size = delta_size;
2187        }
2188        else {
2189                fprintf(file, "%sliteral %lu\n", prefix, two->size);
2190                free(delta);
2191                data = deflated;
2192                data_size = deflate_size;
2193        }
2194
2195        /* emit data encoded in base85 */
2196        cp = data;
2197        while (data_size) {
2198                int bytes = (52 < data_size) ? 52 : data_size;
2199                char line[70];
2200                data_size -= bytes;
2201                if (bytes <= 26)
2202                        line[0] = bytes + 'A' - 1;
2203                else
2204                        line[0] = bytes - 26 + 'a' - 1;
2205                encode_85(line + 1, cp, bytes);
2206                cp = (char *) cp + bytes;
2207                fprintf(file, "%s", prefix);
2208                fputs(line, file);
2209                fputc('\n', file);
2210        }
2211        fprintf(file, "%s\n", prefix);
2212        free(data);
2213}
2214
2215static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two,
2216                             const char *prefix)
2217{
2218        fprintf(file, "%sGIT binary patch\n", prefix);
2219        emit_binary_diff_body(file, one, two, prefix);
2220        emit_binary_diff_body(file, two, one, prefix);
2221}
2222
2223int diff_filespec_is_binary(struct diff_filespec *one)
2224{
2225        if (one->is_binary == -1) {
2226                diff_filespec_load_driver(one);
2227                if (one->driver->binary != -1)
2228                        one->is_binary = one->driver->binary;
2229                else {
2230                        if (!one->data && DIFF_FILE_VALID(one))
2231                                diff_populate_filespec(one, CHECK_BINARY);
2232                        if (one->is_binary == -1 && one->data)
2233                                one->is_binary = buffer_is_binary(one->data,
2234                                                one->size);
2235                        if (one->is_binary == -1)
2236                                one->is_binary = 0;
2237                }
2238        }
2239        return one->is_binary;
2240}
2241
2242static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
2243{
2244        diff_filespec_load_driver(one);
2245        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
2246}
2247
2248void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
2249{
2250        if (!options->a_prefix)
2251                options->a_prefix = a;
2252        if (!options->b_prefix)
2253                options->b_prefix = b;
2254}
2255
2256struct userdiff_driver *get_textconv(struct diff_filespec *one)
2257{
2258        if (!DIFF_FILE_VALID(one))
2259                return NULL;
2260
2261        diff_filespec_load_driver(one);
2262        return userdiff_get_textconv(one->driver);
2263}
2264
2265static void builtin_diff(const char *name_a,
2266                         const char *name_b,
2267                         struct diff_filespec *one,
2268                         struct diff_filespec *two,
2269                         const char *xfrm_msg,
2270                         int must_show_header,
2271                         struct diff_options *o,
2272                         int complete_rewrite)
2273{
2274        mmfile_t mf1, mf2;
2275        const char *lbl[2];
2276        char *a_one, *b_two;
2277        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
2278        const char *reset = diff_get_color_opt(o, DIFF_RESET);
2279        const char *a_prefix, *b_prefix;
2280        struct userdiff_driver *textconv_one = NULL;
2281        struct userdiff_driver *textconv_two = NULL;
2282        struct strbuf header = STRBUF_INIT;
2283        const char *line_prefix = diff_line_prefix(o);
2284
2285        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
2286                        (!one->mode || S_ISGITLINK(one->mode)) &&
2287                        (!two->mode || S_ISGITLINK(two->mode))) {
2288                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2289                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2290                show_submodule_summary(o->file, one->path ? one->path : two->path,
2291                                line_prefix,
2292                                one->sha1, two->sha1, two->dirty_submodule,
2293                                meta, del, add, reset);
2294                return;
2295        }
2296
2297        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
2298                textconv_one = get_textconv(one);
2299                textconv_two = get_textconv(two);
2300        }
2301
2302        diff_set_mnemonic_prefix(o, "a/", "b/");
2303        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
2304                a_prefix = o->b_prefix;
2305                b_prefix = o->a_prefix;
2306        } else {
2307                a_prefix = o->a_prefix;
2308                b_prefix = o->b_prefix;
2309        }
2310
2311        /* Never use a non-valid filename anywhere if at all possible */
2312        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
2313        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
2314
2315        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
2316        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
2317        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
2318        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
2319        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
2320        if (lbl[0][0] == '/') {
2321                /* /dev/null */
2322                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
2323                if (xfrm_msg)
2324                        strbuf_addstr(&header, xfrm_msg);
2325                must_show_header = 1;
2326        }
2327        else if (lbl[1][0] == '/') {
2328                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
2329                if (xfrm_msg)
2330                        strbuf_addstr(&header, xfrm_msg);
2331                must_show_header = 1;
2332        }
2333        else {
2334                if (one->mode != two->mode) {
2335                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
2336                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
2337                        must_show_header = 1;
2338                }
2339                if (xfrm_msg)
2340                        strbuf_addstr(&header, xfrm_msg);
2341
2342                /*
2343                 * we do not run diff between different kind
2344                 * of objects.
2345                 */
2346                if ((one->mode ^ two->mode) & S_IFMT)
2347                        goto free_ab_and_return;
2348                if (complete_rewrite &&
2349                    (textconv_one || !diff_filespec_is_binary(one)) &&
2350                    (textconv_two || !diff_filespec_is_binary(two))) {
2351                        fprintf(o->file, "%s", header.buf);
2352                        strbuf_reset(&header);
2353                        emit_rewrite_diff(name_a, name_b, one, two,
2354                                                textconv_one, textconv_two, o);
2355                        o->found_changes = 1;
2356                        goto free_ab_and_return;
2357                }
2358        }
2359
2360        if (o->irreversible_delete && lbl[1][0] == '/') {
2361                fprintf(o->file, "%s", header.buf);
2362                strbuf_reset(&header);
2363                goto free_ab_and_return;
2364        } else if (!DIFF_OPT_TST(o, TEXT) &&
2365            ( (!textconv_one && diff_filespec_is_binary(one)) ||
2366              (!textconv_two && diff_filespec_is_binary(two)) )) {
2367                if (!one->data && !two->data &&
2368                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
2369                    !DIFF_OPT_TST(o, BINARY)) {
2370                        if (!hashcmp(one->sha1, two->sha1)) {
2371                                if (must_show_header)
2372                                        fprintf(o->file, "%s", header.buf);
2373                                goto free_ab_and_return;
2374                        }
2375                        fprintf(o->file, "%s", header.buf);
2376                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2377                                line_prefix, lbl[0], lbl[1]);
2378                        goto free_ab_and_return;
2379                }
2380                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2381                        die("unable to read files to diff");
2382                /* Quite common confusing case */
2383                if (mf1.size == mf2.size &&
2384                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2385                        if (must_show_header)
2386                                fprintf(o->file, "%s", header.buf);
2387                        goto free_ab_and_return;
2388                }
2389                fprintf(o->file, "%s", header.buf);
2390                strbuf_reset(&header);
2391                if (DIFF_OPT_TST(o, BINARY))
2392                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2393                else
2394                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2395                                line_prefix, lbl[0], lbl[1]);
2396                o->found_changes = 1;
2397        } else {
2398                /* Crazy xdl interfaces.. */
2399                const char *diffopts = getenv("GIT_DIFF_OPTS");
2400                const char *v;
2401                xpparam_t xpp;
2402                xdemitconf_t xecfg;
2403                struct emit_callback ecbdata;
2404                const struct userdiff_funcname *pe;
2405
2406                if (must_show_header) {
2407                        fprintf(o->file, "%s", header.buf);
2408                        strbuf_reset(&header);
2409                }
2410
2411                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2412                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2413
2414                pe = diff_funcname_pattern(one);
2415                if (!pe)
2416                        pe = diff_funcname_pattern(two);
2417
2418                memset(&xpp, 0, sizeof(xpp));
2419                memset(&xecfg, 0, sizeof(xecfg));
2420                memset(&ecbdata, 0, sizeof(ecbdata));
2421                ecbdata.label_path = lbl;
2422                ecbdata.color_diff = want_color(o->use_color);
2423                ecbdata.found_changesp = &o->found_changes;
2424                ecbdata.ws_rule = whitespace_rule(name_b);
2425                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2426                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2427                ecbdata.opt = o;
2428                ecbdata.header = header.len ? &header : NULL;
2429                xpp.flags = o->xdl_opts;
2430                xecfg.ctxlen = o->context;
2431                xecfg.interhunkctxlen = o->interhunkcontext;
2432                xecfg.flags = XDL_EMIT_FUNCNAMES;
2433                if (DIFF_OPT_TST(o, FUNCCONTEXT))
2434                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
2435                if (pe)
2436                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2437                if (!diffopts)
2438                        ;
2439                else if (skip_prefix(diffopts, "--unified=", &v))
2440                        xecfg.ctxlen = strtoul(v, NULL, 10);
2441                else if (skip_prefix(diffopts, "-u", &v))
2442                        xecfg.ctxlen = strtoul(v, NULL, 10);
2443                if (o->word_diff)
2444                        init_diff_words_data(&ecbdata, o, one, two);
2445                if (xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2446                                  &xpp, &xecfg))
2447                        die("unable to generate diff for %s", one->path);
2448                if (o->word_diff)
2449                        free_diff_words_data(&ecbdata);
2450                if (textconv_one)
2451                        free(mf1.ptr);
2452                if (textconv_two)
2453                        free(mf2.ptr);
2454                xdiff_clear_find_func(&xecfg);
2455        }
2456
2457 free_ab_and_return:
2458        strbuf_release(&header);
2459        diff_free_filespec_data(one);
2460        diff_free_filespec_data(two);
2461        free(a_one);
2462        free(b_two);
2463        return;
2464}
2465
2466static void builtin_diffstat(const char *name_a, const char *name_b,
2467                             struct diff_filespec *one,
2468                             struct diff_filespec *two,
2469                             struct diffstat_t *diffstat,
2470                             struct diff_options *o,
2471                             struct diff_filepair *p)
2472{
2473        mmfile_t mf1, mf2;
2474        struct diffstat_file *data;
2475        int same_contents;
2476        int complete_rewrite = 0;
2477
2478        if (!DIFF_PAIR_UNMERGED(p)) {
2479                if (p->status == DIFF_STATUS_MODIFIED && p->score)
2480                        complete_rewrite = 1;
2481        }
2482
2483        data = diffstat_add(diffstat, name_a, name_b);
2484        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
2485
2486        if (!one || !two) {
2487                data->is_unmerged = 1;
2488                return;
2489        }
2490
2491        same_contents = !hashcmp(one->sha1, two->sha1);
2492
2493        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2494                data->is_binary = 1;
2495                if (same_contents) {
2496                        data->added = 0;
2497                        data->deleted = 0;
2498                } else {
2499                        data->added = diff_filespec_size(two);
2500                        data->deleted = diff_filespec_size(one);
2501                }
2502        }
2503
2504        else if (complete_rewrite) {
2505                diff_populate_filespec(one, 0);
2506                diff_populate_filespec(two, 0);
2507                data->deleted = count_lines(one->data, one->size);
2508                data->added = count_lines(two->data, two->size);
2509        }
2510
2511        else if (!same_contents) {
2512                /* Crazy xdl interfaces.. */
2513                xpparam_t xpp;
2514                xdemitconf_t xecfg;
2515
2516                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2517                        die("unable to read files to diff");
2518
2519                memset(&xpp, 0, sizeof(xpp));
2520                memset(&xecfg, 0, sizeof(xecfg));
2521                xpp.flags = o->xdl_opts;
2522                xecfg.ctxlen = o->context;
2523                xecfg.interhunkctxlen = o->interhunkcontext;
2524                if (xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2525                                  &xpp, &xecfg))
2526                        die("unable to generate diffstat for %s", one->path);
2527        }
2528
2529        diff_free_filespec_data(one);
2530        diff_free_filespec_data(two);
2531}
2532
2533static void builtin_checkdiff(const char *name_a, const char *name_b,
2534                              const char *attr_path,
2535                              struct diff_filespec *one,
2536                              struct diff_filespec *two,
2537                              struct diff_options *o)
2538{
2539        mmfile_t mf1, mf2;
2540        struct checkdiff_t data;
2541
2542        if (!two)
2543                return;
2544
2545        memset(&data, 0, sizeof(data));
2546        data.filename = name_b ? name_b : name_a;
2547        data.lineno = 0;
2548        data.o = o;
2549        data.ws_rule = whitespace_rule(attr_path);
2550        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2551
2552        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2553                die("unable to read files to diff");
2554
2555        /*
2556         * All the other codepaths check both sides, but not checking
2557         * the "old" side here is deliberate.  We are checking the newly
2558         * introduced changes, and as long as the "new" side is text, we
2559         * can and should check what it introduces.
2560         */
2561        if (diff_filespec_is_binary(two))
2562                goto free_and_return;
2563        else {
2564                /* Crazy xdl interfaces.. */
2565                xpparam_t xpp;
2566                xdemitconf_t xecfg;
2567
2568                memset(&xpp, 0, sizeof(xpp));
2569                memset(&xecfg, 0, sizeof(xecfg));
2570                xecfg.ctxlen = 1; /* at least one context line */
2571                xpp.flags = 0;
2572                if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2573                                  &xpp, &xecfg))
2574                        die("unable to generate checkdiff for %s", one->path);
2575
2576                if (data.ws_rule & WS_BLANK_AT_EOF) {
2577                        struct emit_callback ecbdata;
2578                        int blank_at_eof;
2579
2580                        ecbdata.ws_rule = data.ws_rule;
2581                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2582                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2583
2584                        if (blank_at_eof) {
2585                                static char *err;
2586                                if (!err)
2587                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2588                                fprintf(o->file, "%s:%d: %s.\n",
2589                                        data.filename, blank_at_eof, err);
2590                                data.status = 1; /* report errors */
2591                        }
2592                }
2593        }
2594 free_and_return:
2595        diff_free_filespec_data(one);
2596        diff_free_filespec_data(two);
2597        if (data.status)
2598                DIFF_OPT_SET(o, CHECK_FAILED);
2599}
2600
2601struct diff_filespec *alloc_filespec(const char *path)
2602{
2603        int namelen = strlen(path);
2604        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2605
2606        memset(spec, 0, sizeof(*spec));
2607        spec->path = (char *)(spec + 1);
2608        memcpy(spec->path, path, namelen+1);
2609        spec->count = 1;
2610        spec->is_binary = -1;
2611        return spec;
2612}
2613
2614void free_filespec(struct diff_filespec *spec)
2615{
2616        if (!--spec->count) {
2617                diff_free_filespec_data(spec);
2618                free(spec);
2619        }
2620}
2621
2622void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2623                   int sha1_valid, unsigned short mode)
2624{
2625        if (mode) {
2626                spec->mode = canon_mode(mode);
2627                hashcpy(spec->sha1, sha1);
2628                spec->sha1_valid = sha1_valid;
2629        }
2630}
2631
2632/*
2633 * Given a name and sha1 pair, if the index tells us the file in
2634 * the work tree has that object contents, return true, so that
2635 * prepare_temp_file() does not have to inflate and extract.
2636 */
2637static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2638{
2639        const struct cache_entry *ce;
2640        struct stat st;
2641        int pos, len;
2642
2643        /*
2644         * We do not read the cache ourselves here, because the
2645         * benchmark with my previous version that always reads cache
2646         * shows that it makes things worse for diff-tree comparing
2647         * two linux-2.6 kernel trees in an already checked out work
2648         * tree.  This is because most diff-tree comparisons deal with
2649         * only a small number of files, while reading the cache is
2650         * expensive for a large project, and its cost outweighs the
2651         * savings we get by not inflating the object to a temporary
2652         * file.  Practically, this code only helps when we are used
2653         * by diff-cache --cached, which does read the cache before
2654         * calling us.
2655         */
2656        if (!active_cache)
2657                return 0;
2658
2659        /* We want to avoid the working directory if our caller
2660         * doesn't need the data in a normal file, this system
2661         * is rather slow with its stat/open/mmap/close syscalls,
2662         * and the object is contained in a pack file.  The pack
2663         * is probably already open and will be faster to obtain
2664         * the data through than the working directory.  Loose
2665         * objects however would tend to be slower as they need
2666         * to be individually opened and inflated.
2667         */
2668        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2669                return 0;
2670
2671        len = strlen(name);
2672        pos = cache_name_pos(name, len);
2673        if (pos < 0)
2674                return 0;
2675        ce = active_cache[pos];
2676
2677        /*
2678         * This is not the sha1 we are looking for, or
2679         * unreusable because it is not a regular file.
2680         */
2681        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2682                return 0;
2683
2684        /*
2685         * If ce is marked as "assume unchanged", there is no
2686         * guarantee that work tree matches what we are looking for.
2687         */
2688        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2689                return 0;
2690
2691        /*
2692         * If ce matches the file in the work tree, we can reuse it.
2693         */
2694        if (ce_uptodate(ce) ||
2695            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2696                return 1;
2697
2698        return 0;
2699}
2700
2701static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2702{
2703        int len;
2704        char *data = xmalloc(100), *dirty = "";
2705
2706        /* Are we looking at the work tree? */
2707        if (s->dirty_submodule)
2708                dirty = "-dirty";
2709
2710        len = snprintf(data, 100,
2711                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2712        s->data = data;
2713        s->size = len;
2714        s->should_free = 1;
2715        if (size_only) {
2716                s->data = NULL;
2717                free(data);
2718        }
2719        return 0;
2720}
2721
2722/*
2723 * While doing rename detection and pickaxe operation, we may need to
2724 * grab the data for the blob (or file) for our own in-core comparison.
2725 * diff_filespec has data and size fields for this purpose.
2726 */
2727int diff_populate_filespec(struct diff_filespec *s, unsigned int flags)
2728{
2729        int size_only = flags & CHECK_SIZE_ONLY;
2730        int err = 0;
2731        /*
2732         * demote FAIL to WARN to allow inspecting the situation
2733         * instead of refusing.
2734         */
2735        enum safe_crlf crlf_warn = (safe_crlf == SAFE_CRLF_FAIL
2736                                    ? SAFE_CRLF_WARN
2737                                    : safe_crlf);
2738
2739        if (!DIFF_FILE_VALID(s))
2740                die("internal error: asking to populate invalid file.");
2741        if (S_ISDIR(s->mode))
2742                return -1;
2743
2744        if (s->data)
2745                return 0;
2746
2747        if (size_only && 0 < s->size)
2748                return 0;
2749
2750        if (S_ISGITLINK(s->mode))
2751                return diff_populate_gitlink(s, size_only);
2752
2753        if (!s->sha1_valid ||
2754            reuse_worktree_file(s->path, s->sha1, 0)) {
2755                struct strbuf buf = STRBUF_INIT;
2756                struct stat st;
2757                int fd;
2758
2759                if (lstat(s->path, &st) < 0) {
2760                        if (errno == ENOENT) {
2761                        err_empty:
2762                                err = -1;
2763                        empty:
2764                                s->data = (char *)"";
2765                                s->size = 0;
2766                                return err;
2767                        }
2768                }
2769                s->size = xsize_t(st.st_size);
2770                if (!s->size)
2771                        goto empty;
2772                if (S_ISLNK(st.st_mode)) {
2773                        struct strbuf sb = STRBUF_INIT;
2774
2775                        if (strbuf_readlink(&sb, s->path, s->size))
2776                                goto err_empty;
2777                        s->size = sb.len;
2778                        s->data = strbuf_detach(&sb, NULL);
2779                        s->should_free = 1;
2780                        return 0;
2781                }
2782                if (size_only)
2783                        return 0;
2784                if ((flags & CHECK_BINARY) &&
2785                    s->size > big_file_threshold && s->is_binary == -1) {
2786                        s->is_binary = 1;
2787                        return 0;
2788                }
2789                fd = open(s->path, O_RDONLY);
2790                if (fd < 0)
2791                        goto err_empty;
2792                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2793                close(fd);
2794                s->should_munmap = 1;
2795
2796                /*
2797                 * Convert from working tree format to canonical git format
2798                 */
2799                if (convert_to_git(s->path, s->data, s->size, &buf, crlf_warn)) {
2800                        size_t size = 0;
2801                        munmap(s->data, s->size);
2802                        s->should_munmap = 0;
2803                        s->data = strbuf_detach(&buf, &size);
2804                        s->size = size;
2805                        s->should_free = 1;
2806                }
2807        }
2808        else {
2809                enum object_type type;
2810                if (size_only || (flags & CHECK_BINARY)) {
2811                        type = sha1_object_info(s->sha1, &s->size);
2812                        if (type < 0)
2813                                die("unable to read %s", sha1_to_hex(s->sha1));
2814                        if (size_only)
2815                                return 0;
2816                        if (s->size > big_file_threshold && s->is_binary == -1) {
2817                                s->is_binary = 1;
2818                                return 0;
2819                        }
2820                }
2821                s->data = read_sha1_file(s->sha1, &type, &s->size);
2822                if (!s->data)
2823                        die("unable to read %s", sha1_to_hex(s->sha1));
2824                s->should_free = 1;
2825        }
2826        return 0;
2827}
2828
2829void diff_free_filespec_blob(struct diff_filespec *s)
2830{
2831        if (s->should_free)
2832                free(s->data);
2833        else if (s->should_munmap)
2834                munmap(s->data, s->size);
2835
2836        if (s->should_free || s->should_munmap) {
2837                s->should_free = s->should_munmap = 0;
2838                s->data = NULL;
2839        }
2840}
2841
2842void diff_free_filespec_data(struct diff_filespec *s)
2843{
2844        diff_free_filespec_blob(s);
2845        free(s->cnt_data);
2846        s->cnt_data = NULL;
2847}
2848
2849static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2850                           void *blob,
2851                           unsigned long size,
2852                           const unsigned char *sha1,
2853                           int mode)
2854{
2855        int fd;
2856        struct strbuf buf = STRBUF_INIT;
2857        struct strbuf template = STRBUF_INIT;
2858        char *path_dup = xstrdup(path);
2859        const char *base = basename(path_dup);
2860
2861        /* Generate "XXXXXX_basename.ext" */
2862        strbuf_addstr(&template, "XXXXXX_");
2863        strbuf_addstr(&template, base);
2864
2865        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2866                        strlen(base) + 1);
2867        if (fd < 0)
2868                die_errno("unable to create temp-file");
2869        if (convert_to_working_tree(path,
2870                        (const char *)blob, (size_t)size, &buf)) {
2871                blob = buf.buf;
2872                size = buf.len;
2873        }
2874        if (write_in_full(fd, blob, size) != size)
2875                die_errno("unable to write temp-file");
2876        close(fd);
2877        temp->name = temp->tmp_path;
2878        strcpy(temp->hex, sha1_to_hex(sha1));
2879        temp->hex[40] = 0;
2880        sprintf(temp->mode, "%06o", mode);
2881        strbuf_release(&buf);
2882        strbuf_release(&template);
2883        free(path_dup);
2884}
2885
2886static struct diff_tempfile *prepare_temp_file(const char *name,
2887                struct diff_filespec *one)
2888{
2889        struct diff_tempfile *temp = claim_diff_tempfile();
2890
2891        if (!DIFF_FILE_VALID(one)) {
2892        not_a_valid_file:
2893                /* A '-' entry produces this for file-2, and
2894                 * a '+' entry produces this for file-1.
2895                 */
2896                temp->name = "/dev/null";
2897                strcpy(temp->hex, ".");
2898                strcpy(temp->mode, ".");
2899                return temp;
2900        }
2901
2902        if (!remove_tempfile_installed) {
2903                atexit(remove_tempfile);
2904                sigchain_push_common(remove_tempfile_on_signal);
2905                remove_tempfile_installed = 1;
2906        }
2907
2908        if (!S_ISGITLINK(one->mode) &&
2909            (!one->sha1_valid ||
2910             reuse_worktree_file(name, one->sha1, 1))) {
2911                struct stat st;
2912                if (lstat(name, &st) < 0) {
2913                        if (errno == ENOENT)
2914                                goto not_a_valid_file;
2915                        die_errno("stat(%s)", name);
2916                }
2917                if (S_ISLNK(st.st_mode)) {
2918                        struct strbuf sb = STRBUF_INIT;
2919                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2920                                die_errno("readlink(%s)", name);
2921                        prep_temp_blob(name, temp, sb.buf, sb.len,
2922                                       (one->sha1_valid ?
2923                                        one->sha1 : null_sha1),
2924                                       (one->sha1_valid ?
2925                                        one->mode : S_IFLNK));
2926                        strbuf_release(&sb);
2927                }
2928                else {
2929                        /* we can borrow from the file in the work tree */
2930                        temp->name = name;
2931                        if (!one->sha1_valid)
2932                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2933                        else
2934                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2935                        /* Even though we may sometimes borrow the
2936                         * contents from the work tree, we always want
2937                         * one->mode.  mode is trustworthy even when
2938                         * !(one->sha1_valid), as long as
2939                         * DIFF_FILE_VALID(one).
2940                         */
2941                        sprintf(temp->mode, "%06o", one->mode);
2942                }
2943                return temp;
2944        }
2945        else {
2946                if (diff_populate_filespec(one, 0))
2947                        die("cannot read data blob for %s", one->path);
2948                prep_temp_blob(name, temp, one->data, one->size,
2949                               one->sha1, one->mode);
2950        }
2951        return temp;
2952}
2953
2954static void add_external_diff_name(struct argv_array *argv,
2955                                   const char *name,
2956                                   struct diff_filespec *df)
2957{
2958        struct diff_tempfile *temp = prepare_temp_file(name, df);
2959        argv_array_push(argv, temp->name);
2960        argv_array_push(argv, temp->hex);
2961        argv_array_push(argv, temp->mode);
2962}
2963
2964/* An external diff command takes:
2965 *
2966 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2967 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2968 *
2969 */
2970static void run_external_diff(const char *pgm,
2971                              const char *name,
2972                              const char *other,
2973                              struct diff_filespec *one,
2974                              struct diff_filespec *two,
2975                              const char *xfrm_msg,
2976                              int complete_rewrite,
2977                              struct diff_options *o)
2978{
2979        struct argv_array argv = ARGV_ARRAY_INIT;
2980        struct argv_array env = ARGV_ARRAY_INIT;
2981        struct diff_queue_struct *q = &diff_queued_diff;
2982
2983        argv_array_push(&argv, pgm);
2984        argv_array_push(&argv, name);
2985
2986        if (one && two) {
2987                add_external_diff_name(&argv, name, one);
2988                if (!other)
2989                        add_external_diff_name(&argv, name, two);
2990                else {
2991                        add_external_diff_name(&argv, other, two);
2992                        argv_array_push(&argv, other);
2993                        argv_array_push(&argv, xfrm_msg);
2994                }
2995        }
2996
2997        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
2998        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
2999
3000        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
3001                die(_("external diff died, stopping at %s"), name);
3002
3003        remove_tempfile();
3004        argv_array_clear(&argv);
3005        argv_array_clear(&env);
3006}
3007
3008static int similarity_index(struct diff_filepair *p)
3009{
3010        return p->score * 100 / MAX_SCORE;
3011}
3012
3013static void fill_metainfo(struct strbuf *msg,
3014                          const char *name,
3015                          const char *other,
3016                          struct diff_filespec *one,
3017                          struct diff_filespec *two,
3018                          struct diff_options *o,
3019                          struct diff_filepair *p,
3020                          int *must_show_header,
3021                          int use_color)
3022{
3023        const char *set = diff_get_color(use_color, DIFF_METAINFO);
3024        const char *reset = diff_get_color(use_color, DIFF_RESET);
3025        const char *line_prefix = diff_line_prefix(o);
3026
3027        *must_show_header = 1;
3028        strbuf_init(msg, PATH_MAX * 2 + 300);
3029        switch (p->status) {
3030        case DIFF_STATUS_COPIED:
3031                strbuf_addf(msg, "%s%ssimilarity index %d%%",
3032                            line_prefix, set, similarity_index(p));
3033                strbuf_addf(msg, "%s\n%s%scopy from ",
3034                            reset,  line_prefix, set);
3035                quote_c_style(name, msg, NULL, 0);
3036                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
3037                quote_c_style(other, msg, NULL, 0);
3038                strbuf_addf(msg, "%s\n", reset);
3039                break;
3040        case DIFF_STATUS_RENAMED:
3041                strbuf_addf(msg, "%s%ssimilarity index %d%%",
3042                            line_prefix, set, similarity_index(p));
3043                strbuf_addf(msg, "%s\n%s%srename from ",
3044                            reset, line_prefix, set);
3045                quote_c_style(name, msg, NULL, 0);
3046                strbuf_addf(msg, "%s\n%s%srename to ",
3047                            reset, line_prefix, set);
3048                quote_c_style(other, msg, NULL, 0);
3049                strbuf_addf(msg, "%s\n", reset);
3050                break;
3051        case DIFF_STATUS_MODIFIED:
3052                if (p->score) {
3053                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
3054                                    line_prefix,
3055                                    set, similarity_index(p), reset);
3056                        break;
3057                }
3058                /* fallthru */
3059        default:
3060                *must_show_header = 0;
3061        }
3062        if (one && two && hashcmp(one->sha1, two->sha1)) {
3063                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
3064
3065                if (DIFF_OPT_TST(o, BINARY)) {
3066                        mmfile_t mf;
3067                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
3068                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
3069                                abbrev = 40;
3070                }
3071                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
3072                            find_unique_abbrev(one->sha1, abbrev));
3073                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
3074                if (one->mode == two->mode)
3075                        strbuf_addf(msg, " %06o", one->mode);
3076                strbuf_addf(msg, "%s\n", reset);
3077        }
3078}
3079
3080static void run_diff_cmd(const char *pgm,
3081                         const char *name,
3082                         const char *other,
3083                         const char *attr_path,
3084                         struct diff_filespec *one,
3085                         struct diff_filespec *two,
3086                         struct strbuf *msg,
3087                         struct diff_options *o,
3088                         struct diff_filepair *p)
3089{
3090        const char *xfrm_msg = NULL;
3091        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
3092        int must_show_header = 0;
3093
3094
3095        if (DIFF_OPT_TST(o, ALLOW_EXTERNAL)) {
3096                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
3097                if (drv && drv->external)
3098                        pgm = drv->external;
3099        }
3100
3101        if (msg) {
3102                /*
3103                 * don't use colors when the header is intended for an
3104                 * external diff driver
3105                 */
3106                fill_metainfo(msg, name, other, one, two, o, p,
3107                              &must_show_header,
3108                              want_color(o->use_color) && !pgm);
3109                xfrm_msg = msg->len ? msg->buf : NULL;
3110        }
3111
3112        if (pgm) {
3113                run_external_diff(pgm, name, other, one, two, xfrm_msg,
3114                                  complete_rewrite, o);
3115                return;
3116        }
3117        if (one && two)
3118                builtin_diff(name, other ? other : name,
3119                             one, two, xfrm_msg, must_show_header,
3120                             o, complete_rewrite);
3121        else
3122                fprintf(o->file, "* Unmerged path %s\n", name);
3123}
3124
3125static void diff_fill_sha1_info(struct diff_filespec *one)
3126{
3127        if (DIFF_FILE_VALID(one)) {
3128                if (!one->sha1_valid) {
3129                        struct stat st;
3130                        if (one->is_stdin) {
3131                                hashcpy(one->sha1, null_sha1);
3132                                return;
3133                        }
3134                        if (lstat(one->path, &st) < 0)
3135                                die_errno("stat '%s'", one->path);
3136                        if (index_path(one->sha1, one->path, &st, 0))
3137                                die("cannot hash %s", one->path);
3138                }
3139        }
3140        else
3141                hashclr(one->sha1);
3142}
3143
3144static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
3145{
3146        /* Strip the prefix but do not molest /dev/null and absolute paths */
3147        if (*namep && **namep != '/') {
3148                *namep += prefix_length;
3149                if (**namep == '/')
3150                        ++*namep;
3151        }
3152        if (*otherp && **otherp != '/') {
3153                *otherp += prefix_length;
3154                if (**otherp == '/')
3155                        ++*otherp;
3156        }
3157}
3158
3159static void run_diff(struct diff_filepair *p, struct diff_options *o)
3160{
3161        const char *pgm = external_diff();
3162        struct strbuf msg;
3163        struct diff_filespec *one = p->one;
3164        struct diff_filespec *two = p->two;
3165        const char *name;
3166        const char *other;
3167        const char *attr_path;
3168
3169        name  = p->one->path;
3170        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3171        attr_path = name;
3172        if (o->prefix_length)
3173                strip_prefix(o->prefix_length, &name, &other);
3174
3175        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
3176                pgm = NULL;
3177
3178        if (DIFF_PAIR_UNMERGED(p)) {
3179                run_diff_cmd(pgm, name, NULL, attr_path,
3180                             NULL, NULL, NULL, o, p);
3181                return;
3182        }
3183
3184        diff_fill_sha1_info(one);
3185        diff_fill_sha1_info(two);
3186
3187        if (!pgm &&
3188            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
3189            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
3190                /*
3191                 * a filepair that changes between file and symlink
3192                 * needs to be split into deletion and creation.
3193                 */
3194                struct diff_filespec *null = alloc_filespec(two->path);
3195                run_diff_cmd(NULL, name, other, attr_path,
3196                             one, null, &msg, o, p);
3197                free(null);
3198                strbuf_release(&msg);
3199
3200                null = alloc_filespec(one->path);
3201                run_diff_cmd(NULL, name, other, attr_path,
3202                             null, two, &msg, o, p);
3203                free(null);
3204        }
3205        else
3206                run_diff_cmd(pgm, name, other, attr_path,
3207                             one, two, &msg, o, p);
3208
3209        strbuf_release(&msg);
3210}
3211
3212static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
3213                         struct diffstat_t *diffstat)
3214{
3215        const char *name;
3216        const char *other;
3217
3218        if (DIFF_PAIR_UNMERGED(p)) {
3219                /* unmerged */
3220                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, p);
3221                return;
3222        }
3223
3224        name = p->one->path;
3225        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3226
3227        if (o->prefix_length)
3228                strip_prefix(o->prefix_length, &name, &other);
3229
3230        diff_fill_sha1_info(p->one);
3231        diff_fill_sha1_info(p->two);
3232
3233        builtin_diffstat(name, other, p->one, p->two, diffstat, o, p);
3234}
3235
3236static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
3237{
3238        const char *name;
3239        const char *other;
3240        const char *attr_path;
3241
3242        if (DIFF_PAIR_UNMERGED(p)) {
3243                /* unmerged */
3244                return;
3245        }
3246
3247        name = p->one->path;
3248        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3249        attr_path = other ? other : name;
3250
3251        if (o->prefix_length)
3252                strip_prefix(o->prefix_length, &name, &other);
3253
3254        diff_fill_sha1_info(p->one);
3255        diff_fill_sha1_info(p->two);
3256
3257        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
3258}
3259
3260void diff_setup(struct diff_options *options)
3261{
3262        memcpy(options, &default_diff_options, sizeof(*options));
3263
3264        options->file = stdout;
3265
3266        options->line_termination = '\n';
3267        options->break_opt = -1;
3268        options->rename_limit = -1;
3269        options->dirstat_permille = diff_dirstat_permille_default;
3270        options->context = diff_context_default;
3271        options->ws_error_highlight = WSEH_NEW;
3272        DIFF_OPT_SET(options, RENAME_EMPTY);
3273
3274        /* pathchange left =NULL by default */
3275        options->change = diff_change;
3276        options->add_remove = diff_addremove;
3277        options->use_color = diff_use_color_default;
3278        options->detect_rename = diff_detect_rename_default;
3279        options->xdl_opts |= diff_algorithm;
3280
3281        options->orderfile = diff_order_file_cfg;
3282
3283        if (diff_no_prefix) {
3284                options->a_prefix = options->b_prefix = "";
3285        } else if (!diff_mnemonic_prefix) {
3286                options->a_prefix = "a/";
3287                options->b_prefix = "b/";
3288        }
3289}
3290
3291void diff_setup_done(struct diff_options *options)
3292{
3293        int count = 0;
3294
3295        if (options->set_default)
3296                options->set_default(options);
3297
3298        if (options->output_format & DIFF_FORMAT_NAME)
3299                count++;
3300        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
3301                count++;
3302        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
3303                count++;
3304        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
3305                count++;
3306        if (count > 1)
3307                die("--name-only, --name-status, --check and -s are mutually exclusive");
3308
3309        /*
3310         * Most of the time we can say "there are changes"
3311         * only by checking if there are changed paths, but
3312         * --ignore-whitespace* options force us to look
3313         * inside contents.
3314         */
3315
3316        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
3317            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
3318            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
3319                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
3320        else
3321                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
3322
3323        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3324                options->detect_rename = DIFF_DETECT_COPY;
3325
3326        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
3327                options->prefix = NULL;
3328        if (options->prefix)
3329                options->prefix_length = strlen(options->prefix);
3330        else
3331                options->prefix_length = 0;
3332
3333        if (options->output_format & (DIFF_FORMAT_NAME |
3334                                      DIFF_FORMAT_NAME_STATUS |
3335                                      DIFF_FORMAT_CHECKDIFF |
3336                                      DIFF_FORMAT_NO_OUTPUT))
3337                options->output_format &= ~(DIFF_FORMAT_RAW |
3338                                            DIFF_FORMAT_NUMSTAT |
3339                                            DIFF_FORMAT_DIFFSTAT |
3340                                            DIFF_FORMAT_SHORTSTAT |
3341                                            DIFF_FORMAT_DIRSTAT |
3342                                            DIFF_FORMAT_SUMMARY |
3343                                            DIFF_FORMAT_PATCH);
3344
3345        /*
3346         * These cases always need recursive; we do not drop caller-supplied
3347         * recursive bits for other formats here.
3348         */
3349        if (options->output_format & (DIFF_FORMAT_PATCH |
3350                                      DIFF_FORMAT_NUMSTAT |
3351                                      DIFF_FORMAT_DIFFSTAT |
3352                                      DIFF_FORMAT_SHORTSTAT |
3353                                      DIFF_FORMAT_DIRSTAT |
3354                                      DIFF_FORMAT_SUMMARY |
3355                                      DIFF_FORMAT_CHECKDIFF))
3356                DIFF_OPT_SET(options, RECURSIVE);
3357        /*
3358         * Also pickaxe would not work very well if you do not say recursive
3359         */
3360        if (options->pickaxe)
3361                DIFF_OPT_SET(options, RECURSIVE);
3362        /*
3363         * When patches are generated, submodules diffed against the work tree
3364         * must be checked for dirtiness too so it can be shown in the output
3365         */
3366        if (options->output_format & DIFF_FORMAT_PATCH)
3367                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3368
3369        if (options->detect_rename && options->rename_limit < 0)
3370                options->rename_limit = diff_rename_limit_default;
3371        if (options->setup & DIFF_SETUP_USE_CACHE) {
3372                if (!active_cache)
3373                        /* read-cache does not die even when it fails
3374                         * so it is safe for us to do this here.  Also
3375                         * it does not smudge active_cache or active_nr
3376                         * when it fails, so we do not have to worry about
3377                         * cleaning it up ourselves either.
3378                         */
3379                        read_cache();
3380        }
3381        if (options->abbrev <= 0 || 40 < options->abbrev)
3382                options->abbrev = 40; /* full */
3383
3384        /*
3385         * It does not make sense to show the first hit we happened
3386         * to have found.  It does not make sense not to return with
3387         * exit code in such a case either.
3388         */
3389        if (DIFF_OPT_TST(options, QUICK)) {
3390                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3391                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3392        }
3393
3394        options->diff_path_counter = 0;
3395
3396        if (DIFF_OPT_TST(options, FOLLOW_RENAMES) && options->pathspec.nr != 1)
3397                die(_("--follow requires exactly one pathspec"));
3398}
3399
3400static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3401{
3402        char c, *eq;
3403        int len;
3404
3405        if (*arg != '-')
3406                return 0;
3407        c = *++arg;
3408        if (!c)
3409                return 0;
3410        if (c == arg_short) {
3411                c = *++arg;
3412                if (!c)
3413                        return 1;
3414                if (val && isdigit(c)) {
3415                        char *end;
3416                        int n = strtoul(arg, &end, 10);
3417                        if (*end)
3418                                return 0;
3419                        *val = n;
3420                        return 1;
3421                }
3422                return 0;
3423        }
3424        if (c != '-')
3425                return 0;
3426        arg++;
3427        eq = strchrnul(arg, '=');
3428        len = eq - arg;
3429        if (!len || strncmp(arg, arg_long, len))
3430                return 0;
3431        if (*eq) {
3432                int n;
3433                char *end;
3434                if (!isdigit(*++eq))
3435                        return 0;
3436                n = strtoul(eq, &end, 10);
3437                if (*end)
3438                        return 0;
3439                *val = n;
3440        }
3441        return 1;
3442}
3443
3444static int diff_scoreopt_parse(const char *opt);
3445
3446static inline int short_opt(char opt, const char **argv,
3447                            const char **optarg)
3448{
3449        const char *arg = argv[0];
3450        if (arg[0] != '-' || arg[1] != opt)
3451                return 0;
3452        if (arg[2] != '\0') {
3453                *optarg = arg + 2;
3454                return 1;
3455        }
3456        if (!argv[1])
3457                die("Option '%c' requires a value", opt);
3458        *optarg = argv[1];
3459        return 2;
3460}
3461
3462int parse_long_opt(const char *opt, const char **argv,
3463                   const char **optarg)
3464{
3465        const char *arg = argv[0];
3466        if (!skip_prefix(arg, "--", &arg))
3467                return 0;
3468        if (!skip_prefix(arg, opt, &arg))
3469                return 0;
3470        if (*arg == '=') { /* stuck form: --option=value */
3471                *optarg = arg + 1;
3472                return 1;
3473        }
3474        if (*arg != '\0')
3475                return 0;
3476        /* separate form: --option value */
3477        if (!argv[1])
3478                die("Option '--%s' requires a value", opt);
3479        *optarg = argv[1];
3480        return 2;
3481}
3482
3483static int stat_opt(struct diff_options *options, const char **av)
3484{
3485        const char *arg = av[0];
3486        char *end;
3487        int width = options->stat_width;
3488        int name_width = options->stat_name_width;
3489        int graph_width = options->stat_graph_width;
3490        int count = options->stat_count;
3491        int argcount = 1;
3492
3493        if (!skip_prefix(arg, "--stat", &arg))
3494                die("BUG: stat option does not begin with --stat: %s", arg);
3495        end = (char *)arg;
3496
3497        switch (*arg) {
3498        case '-':
3499                if (skip_prefix(arg, "-width", &arg)) {
3500                        if (*arg == '=')
3501                                width = strtoul(arg + 1, &end, 10);
3502                        else if (!*arg && !av[1])
3503                                die("Option '--stat-width' requires a value");
3504                        else if (!*arg) {
3505                                width = strtoul(av[1], &end, 10);
3506                                argcount = 2;
3507                        }
3508                } else if (skip_prefix(arg, "-name-width", &arg)) {
3509                        if (*arg == '=')
3510                                name_width = strtoul(arg + 1, &end, 10);
3511                        else if (!*arg && !av[1])
3512                                die("Option '--stat-name-width' requires a value");
3513                        else if (!*arg) {
3514                                name_width = strtoul(av[1], &end, 10);
3515                                argcount = 2;
3516                        }
3517                } else if (skip_prefix(arg, "-graph-width", &arg)) {
3518                        if (*arg == '=')
3519                                graph_width = strtoul(arg + 1, &end, 10);
3520                        else if (!*arg && !av[1])
3521                                die("Option '--stat-graph-width' requires a value");
3522                        else if (!*arg) {
3523                                graph_width = strtoul(av[1], &end, 10);
3524                                argcount = 2;
3525                        }
3526                } else if (skip_prefix(arg, "-count", &arg)) {
3527                        if (*arg == '=')
3528                                count = strtoul(arg + 1, &end, 10);
3529                        else if (!*arg && !av[1])
3530                                die("Option '--stat-count' requires a value");
3531                        else if (!*arg) {
3532                                count = strtoul(av[1], &end, 10);
3533                                argcount = 2;
3534                        }
3535                }
3536                break;
3537        case '=':
3538                width = strtoul(arg+1, &end, 10);
3539                if (*end == ',')
3540                        name_width = strtoul(end+1, &end, 10);
3541                if (*end == ',')
3542                        count = strtoul(end+1, &end, 10);
3543        }
3544
3545        /* Important! This checks all the error cases! */
3546        if (*end)
3547                return 0;
3548        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3549        options->stat_name_width = name_width;
3550        options->stat_graph_width = graph_width;
3551        options->stat_width = width;
3552        options->stat_count = count;
3553        return argcount;
3554}
3555
3556static int parse_dirstat_opt(struct diff_options *options, const char *params)
3557{
3558        struct strbuf errmsg = STRBUF_INIT;
3559        if (parse_dirstat_params(options, params, &errmsg))
3560                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
3561                    errmsg.buf);
3562        strbuf_release(&errmsg);
3563        /*
3564         * The caller knows a dirstat-related option is given from the command
3565         * line; allow it to say "return this_function();"
3566         */
3567        options->output_format |= DIFF_FORMAT_DIRSTAT;
3568        return 1;
3569}
3570
3571static int parse_submodule_opt(struct diff_options *options, const char *value)
3572{
3573        if (parse_submodule_params(options, value))
3574                die(_("Failed to parse --submodule option parameter: '%s'"),
3575                        value);
3576        return 1;
3577}
3578
3579static const char diff_status_letters[] = {
3580        DIFF_STATUS_ADDED,
3581        DIFF_STATUS_COPIED,
3582        DIFF_STATUS_DELETED,
3583        DIFF_STATUS_MODIFIED,
3584        DIFF_STATUS_RENAMED,
3585        DIFF_STATUS_TYPE_CHANGED,
3586        DIFF_STATUS_UNKNOWN,
3587        DIFF_STATUS_UNMERGED,
3588        DIFF_STATUS_FILTER_AON,
3589        DIFF_STATUS_FILTER_BROKEN,
3590        '\0',
3591};
3592
3593static unsigned int filter_bit['Z' + 1];
3594
3595static void prepare_filter_bits(void)
3596{
3597        int i;
3598
3599        if (!filter_bit[DIFF_STATUS_ADDED]) {
3600                for (i = 0; diff_status_letters[i]; i++)
3601                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
3602        }
3603}
3604
3605static unsigned filter_bit_tst(char status, const struct diff_options *opt)
3606{
3607        return opt->filter & filter_bit[(int) status];
3608}
3609
3610static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
3611{
3612        int i, optch;
3613
3614        prepare_filter_bits();
3615
3616        /*
3617         * If there is a negation e.g. 'd' in the input, and we haven't
3618         * initialized the filter field with another --diff-filter, start
3619         * from full set of bits, except for AON.
3620         */
3621        if (!opt->filter) {
3622                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
3623                        if (optch < 'a' || 'z' < optch)
3624                                continue;
3625                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
3626                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
3627                        break;
3628                }
3629        }
3630
3631        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
3632                unsigned int bit;
3633                int negate;
3634
3635                if ('a' <= optch && optch <= 'z') {
3636                        negate = 1;
3637                        optch = toupper(optch);
3638                } else {
3639                        negate = 0;
3640                }
3641
3642                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
3643                if (!bit)
3644                        return optarg[i];
3645                if (negate)
3646                        opt->filter &= ~bit;
3647                else
3648                        opt->filter |= bit;
3649        }
3650        return 0;
3651}
3652
3653static void enable_patch_output(int *fmt) {
3654        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
3655        *fmt |= DIFF_FORMAT_PATCH;
3656}
3657
3658static int parse_one_token(const char **arg, const char *token)
3659{
3660        const char *rest;
3661        if (skip_prefix(*arg, token, &rest) && (!*rest || *rest == ',')) {
3662                *arg = rest;
3663                return 1;
3664        }
3665        return 0;
3666}
3667
3668static int parse_ws_error_highlight(struct diff_options *opt, const char *arg)
3669{
3670        const char *orig_arg = arg;
3671        unsigned val = 0;
3672        while (*arg) {
3673                if (parse_one_token(&arg, "none"))
3674                        val = 0;
3675                else if (parse_one_token(&arg, "default"))
3676                        val = WSEH_NEW;
3677                else if (parse_one_token(&arg, "all"))
3678                        val = WSEH_NEW | WSEH_OLD | WSEH_CONTEXT;
3679                else if (parse_one_token(&arg, "new"))
3680                        val |= WSEH_NEW;
3681                else if (parse_one_token(&arg, "old"))
3682                        val |= WSEH_OLD;
3683                else if (parse_one_token(&arg, "context"))
3684                        val |= WSEH_CONTEXT;
3685                else {
3686                        error("unknown value after ws-error-highlight=%.*s",
3687                              (int)(arg - orig_arg), orig_arg);
3688                        return 0;
3689                }
3690                if (*arg)
3691                        arg++;
3692        }
3693        opt->ws_error_highlight = val;
3694        return 1;
3695}
3696
3697int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3698{
3699        const char *arg = av[0];
3700        const char *optarg;
3701        int argcount;
3702
3703        /* Output format options */
3704        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
3705            || opt_arg(arg, 'U', "unified", &options->context))
3706                enable_patch_output(&options->output_format);
3707        else if (!strcmp(arg, "--raw"))
3708                options->output_format |= DIFF_FORMAT_RAW;
3709        else if (!strcmp(arg, "--patch-with-raw")) {
3710                enable_patch_output(&options->output_format);
3711                options->output_format |= DIFF_FORMAT_RAW;
3712        } else if (!strcmp(arg, "--numstat"))
3713                options->output_format |= DIFF_FORMAT_NUMSTAT;
3714        else if (!strcmp(arg, "--shortstat"))
3715                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3716        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
3717                return parse_dirstat_opt(options, "");
3718        else if (skip_prefix(arg, "-X", &arg))
3719                return parse_dirstat_opt(options, arg);
3720        else if (skip_prefix(arg, "--dirstat=", &arg))
3721                return parse_dirstat_opt(options, arg);
3722        else if (!strcmp(arg, "--cumulative"))
3723                return parse_dirstat_opt(options, "cumulative");
3724        else if (!strcmp(arg, "--dirstat-by-file"))
3725                return parse_dirstat_opt(options, "files");
3726        else if (skip_prefix(arg, "--dirstat-by-file=", &arg)) {
3727                parse_dirstat_opt(options, "files");
3728                return parse_dirstat_opt(options, arg);
3729        }
3730        else if (!strcmp(arg, "--check"))
3731                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3732        else if (!strcmp(arg, "--summary"))
3733                options->output_format |= DIFF_FORMAT_SUMMARY;
3734        else if (!strcmp(arg, "--patch-with-stat")) {
3735                enable_patch_output(&options->output_format);
3736                options->output_format |= DIFF_FORMAT_DIFFSTAT;
3737        } else if (!strcmp(arg, "--name-only"))
3738                options->output_format |= DIFF_FORMAT_NAME;
3739        else if (!strcmp(arg, "--name-status"))
3740                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3741        else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
3742                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3743        else if (starts_with(arg, "--stat"))
3744                /* --stat, --stat-width, --stat-name-width, or --stat-count */
3745                return stat_opt(options, av);
3746
3747        /* renames options */
3748        else if (starts_with(arg, "-B") || starts_with(arg, "--break-rewrites=") ||
3749                 !strcmp(arg, "--break-rewrites")) {
3750                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3751                        return error("invalid argument to -B: %s", arg+2);
3752        }
3753        else if (starts_with(arg, "-M") || starts_with(arg, "--find-renames=") ||
3754                 !strcmp(arg, "--find-renames")) {
3755                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3756                        return error("invalid argument to -M: %s", arg+2);
3757                options->detect_rename = DIFF_DETECT_RENAME;
3758        }
3759        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3760                options->irreversible_delete = 1;
3761        }
3762        else if (starts_with(arg, "-C") || starts_with(arg, "--find-copies=") ||
3763                 !strcmp(arg, "--find-copies")) {
3764                if (options->detect_rename == DIFF_DETECT_COPY)
3765                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3766                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3767                        return error("invalid argument to -C: %s", arg+2);
3768                options->detect_rename = DIFF_DETECT_COPY;
3769        }
3770        else if (!strcmp(arg, "--no-renames"))
3771                options->detect_rename = 0;
3772        else if (!strcmp(arg, "--rename-empty"))
3773                DIFF_OPT_SET(options, RENAME_EMPTY);
3774        else if (!strcmp(arg, "--no-rename-empty"))
3775                DIFF_OPT_CLR(options, RENAME_EMPTY);
3776        else if (!strcmp(arg, "--relative"))
3777                DIFF_OPT_SET(options, RELATIVE_NAME);
3778        else if (skip_prefix(arg, "--relative=", &arg)) {
3779                DIFF_OPT_SET(options, RELATIVE_NAME);
3780                options->prefix = arg;
3781        }
3782
3783        /* xdiff options */
3784        else if (!strcmp(arg, "--minimal"))
3785                DIFF_XDL_SET(options, NEED_MINIMAL);
3786        else if (!strcmp(arg, "--no-minimal"))
3787                DIFF_XDL_CLR(options, NEED_MINIMAL);
3788        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3789                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3790        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3791                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3792        else if (!strcmp(arg, "--ignore-space-at-eol"))
3793                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3794        else if (!strcmp(arg, "--ignore-blank-lines"))
3795                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
3796        else if (!strcmp(arg, "--patience"))
3797                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
3798        else if (!strcmp(arg, "--histogram"))
3799                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
3800        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
3801                long value = parse_algorithm_value(optarg);
3802                if (value < 0)
3803                        return error("option diff-algorithm accepts \"myers\", "
3804                                     "\"minimal\", \"patience\" and \"histogram\"");
3805                /* clear out previous settings */
3806                DIFF_XDL_CLR(options, NEED_MINIMAL);
3807                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
3808                options->xdl_opts |= value;
3809                return argcount;
3810        }
3811
3812        /* flags options */
3813        else if (!strcmp(arg, "--binary")) {
3814                enable_patch_output(&options->output_format);
3815                DIFF_OPT_SET(options, BINARY);
3816        }
3817        else if (!strcmp(arg, "--full-index"))
3818                DIFF_OPT_SET(options, FULL_INDEX);
3819        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3820                DIFF_OPT_SET(options, TEXT);
3821        else if (!strcmp(arg, "-R"))
3822                DIFF_OPT_SET(options, REVERSE_DIFF);
3823        else if (!strcmp(arg, "--find-copies-harder"))
3824                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3825        else if (!strcmp(arg, "--follow"))
3826                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3827        else if (!strcmp(arg, "--no-follow"))
3828                DIFF_OPT_CLR(options, FOLLOW_RENAMES);
3829        else if (!strcmp(arg, "--color"))
3830                options->use_color = 1;
3831        else if (skip_prefix(arg, "--color=", &arg)) {
3832                int value = git_config_colorbool(NULL, arg);
3833                if (value < 0)
3834                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3835                options->use_color = value;
3836        }
3837        else if (!strcmp(arg, "--no-color"))
3838                options->use_color = 0;
3839        else if (!strcmp(arg, "--color-words")) {
3840                options->use_color = 1;
3841                options->word_diff = DIFF_WORDS_COLOR;
3842        }
3843        else if (skip_prefix(arg, "--color-words=", &arg)) {
3844                options->use_color = 1;
3845                options->word_diff = DIFF_WORDS_COLOR;
3846                options->word_regex = arg;
3847        }
3848        else if (!strcmp(arg, "--word-diff")) {
3849                if (options->word_diff == DIFF_WORDS_NONE)
3850                        options->word_diff = DIFF_WORDS_PLAIN;
3851        }
3852        else if (skip_prefix(arg, "--word-diff=", &arg)) {
3853                if (!strcmp(arg, "plain"))
3854                        options->word_diff = DIFF_WORDS_PLAIN;
3855                else if (!strcmp(arg, "color")) {
3856                        options->use_color = 1;
3857                        options->word_diff = DIFF_WORDS_COLOR;
3858                }
3859                else if (!strcmp(arg, "porcelain"))
3860                        options->word_diff = DIFF_WORDS_PORCELAIN;
3861                else if (!strcmp(arg, "none"))
3862                        options->word_diff = DIFF_WORDS_NONE;
3863                else
3864                        die("bad --word-diff argument: %s", arg);
3865        }
3866        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3867                if (options->word_diff == DIFF_WORDS_NONE)
3868                        options->word_diff = DIFF_WORDS_PLAIN;
3869                options->word_regex = optarg;
3870                return argcount;
3871        }
3872        else if (!strcmp(arg, "--exit-code"))
3873                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3874        else if (!strcmp(arg, "--quiet"))
3875                DIFF_OPT_SET(options, QUICK);
3876        else if (!strcmp(arg, "--ext-diff"))
3877                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3878        else if (!strcmp(arg, "--no-ext-diff"))
3879                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3880        else if (!strcmp(arg, "--textconv"))
3881                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3882        else if (!strcmp(arg, "--no-textconv"))
3883                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3884        else if (!strcmp(arg, "--ignore-submodules")) {
3885                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3886                handle_ignore_submodules_arg(options, "all");
3887        } else if (skip_prefix(arg, "--ignore-submodules=", &arg)) {
3888                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3889                handle_ignore_submodules_arg(options, arg);
3890        } else if (!strcmp(arg, "--submodule"))
3891                DIFF_OPT_SET(options, SUBMODULE_LOG);
3892        else if (skip_prefix(arg, "--submodule=", &arg))
3893                return parse_submodule_opt(options, arg);
3894        else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
3895                return parse_ws_error_highlight(options, arg);
3896
3897        /* misc options */
3898        else if (!strcmp(arg, "-z"))
3899                options->line_termination = 0;
3900        else if ((argcount = short_opt('l', av, &optarg))) {
3901                options->rename_limit = strtoul(optarg, NULL, 10);
3902                return argcount;
3903        }
3904        else if ((argcount = short_opt('S', av, &optarg))) {
3905                options->pickaxe = optarg;
3906                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3907                return argcount;
3908        } else if ((argcount = short_opt('G', av, &optarg))) {
3909                options->pickaxe = optarg;
3910                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3911                return argcount;
3912        }
3913        else if (!strcmp(arg, "--pickaxe-all"))
3914                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3915        else if (!strcmp(arg, "--pickaxe-regex"))
3916                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3917        else if ((argcount = short_opt('O', av, &optarg))) {
3918                options->orderfile = optarg;
3919                return argcount;
3920        }
3921        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3922                int offending = parse_diff_filter_opt(optarg, options);
3923                if (offending)
3924                        die("unknown change class '%c' in --diff-filter=%s",
3925                            offending, optarg);
3926                return argcount;
3927        }
3928        else if (!strcmp(arg, "--abbrev"))
3929                options->abbrev = DEFAULT_ABBREV;
3930        else if (skip_prefix(arg, "--abbrev=", &arg)) {
3931                options->abbrev = strtoul(arg, NULL, 10);
3932                if (options->abbrev < MINIMUM_ABBREV)
3933                        options->abbrev = MINIMUM_ABBREV;
3934                else if (40 < options->abbrev)
3935                        options->abbrev = 40;
3936        }
3937        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3938                options->a_prefix = optarg;
3939                return argcount;
3940        }
3941        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3942                options->b_prefix = optarg;
3943                return argcount;
3944        }
3945        else if (!strcmp(arg, "--no-prefix"))
3946                options->a_prefix = options->b_prefix = "";
3947        else if (opt_arg(arg, '\0', "inter-hunk-context",
3948                         &options->interhunkcontext))
3949                ;
3950        else if (!strcmp(arg, "-W"))
3951                DIFF_OPT_SET(options, FUNCCONTEXT);
3952        else if (!strcmp(arg, "--function-context"))
3953                DIFF_OPT_SET(options, FUNCCONTEXT);
3954        else if (!strcmp(arg, "--no-function-context"))
3955                DIFF_OPT_CLR(options, FUNCCONTEXT);
3956        else if ((argcount = parse_long_opt("output", av, &optarg))) {
3957                options->file = fopen(optarg, "w");
3958                if (!options->file)
3959                        die_errno("Could not open '%s'", optarg);
3960                options->close_file = 1;
3961                return argcount;
3962        } else
3963                return 0;
3964        return 1;
3965}
3966
3967int parse_rename_score(const char **cp_p)
3968{
3969        unsigned long num, scale;
3970        int ch, dot;
3971        const char *cp = *cp_p;
3972
3973        num = 0;
3974        scale = 1;
3975        dot = 0;
3976        for (;;) {
3977                ch = *cp;
3978                if ( !dot && ch == '.' ) {
3979                        scale = 1;
3980                        dot = 1;
3981                } else if ( ch == '%' ) {
3982                        scale = dot ? scale*100 : 100;
3983                        cp++;   /* % is always at the end */
3984                        break;
3985                } else if ( ch >= '0' && ch <= '9' ) {
3986                        if ( scale < 100000 ) {
3987                                scale *= 10;
3988                                num = (num*10) + (ch-'0');
3989                        }
3990                } else {
3991                        break;
3992                }
3993                cp++;
3994        }
3995        *cp_p = cp;
3996
3997        /* user says num divided by scale and we say internally that
3998         * is MAX_SCORE * num / scale.
3999         */
4000        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
4001}
4002
4003static int diff_scoreopt_parse(const char *opt)
4004{
4005        int opt1, opt2, cmd;
4006
4007        if (*opt++ != '-')
4008                return -1;
4009        cmd = *opt++;
4010        if (cmd == '-') {
4011                /* convert the long-form arguments into short-form versions */
4012                if (skip_prefix(opt, "break-rewrites", &opt)) {
4013                        if (*opt == 0 || *opt++ == '=')
4014                                cmd = 'B';
4015                } else if (skip_prefix(opt, "find-copies", &opt)) {
4016                        if (*opt == 0 || *opt++ == '=')
4017                                cmd = 'C';
4018                } else if (skip_prefix(opt, "find-renames", &opt)) {
4019                        if (*opt == 0 || *opt++ == '=')
4020                                cmd = 'M';
4021                }
4022        }
4023        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
4024                return -1; /* that is not a -M, -C, or -B option */
4025
4026        opt1 = parse_rename_score(&opt);
4027        if (cmd != 'B')
4028                opt2 = 0;
4029        else {
4030                if (*opt == 0)
4031                        opt2 = 0;
4032                else if (*opt != '/')
4033                        return -1; /* we expect -B80/99 or -B80 */
4034                else {
4035                        opt++;
4036                        opt2 = parse_rename_score(&opt);
4037                }
4038        }
4039        if (*opt != 0)
4040                return -1;
4041        return opt1 | (opt2 << 16);
4042}
4043
4044struct diff_queue_struct diff_queued_diff;
4045
4046void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
4047{
4048        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
4049        queue->queue[queue->nr++] = dp;
4050}
4051
4052struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
4053                                 struct diff_filespec *one,
4054                                 struct diff_filespec *two)
4055{
4056        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
4057        dp->one = one;
4058        dp->two = two;
4059        if (queue)
4060                diff_q(queue, dp);
4061        return dp;
4062}
4063
4064void diff_free_filepair(struct diff_filepair *p)
4065{
4066        free_filespec(p->one);
4067        free_filespec(p->two);
4068        free(p);
4069}
4070
4071/* This is different from find_unique_abbrev() in that
4072 * it stuffs the result with dots for alignment.
4073 */
4074const char *diff_unique_abbrev(const unsigned char *sha1, int len)
4075{
4076        int abblen;
4077        const char *abbrev;
4078        if (len == 40)
4079                return sha1_to_hex(sha1);
4080
4081        abbrev = find_unique_abbrev(sha1, len);
4082        abblen = strlen(abbrev);
4083        if (abblen < 37) {
4084                static char hex[41];
4085                if (len < abblen && abblen <= len + 2)
4086                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
4087                else
4088                        sprintf(hex, "%s...", abbrev);
4089                return hex;
4090        }
4091        return sha1_to_hex(sha1);
4092}
4093
4094static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
4095{
4096        int line_termination = opt->line_termination;
4097        int inter_name_termination = line_termination ? '\t' : '\0';
4098
4099        fprintf(opt->file, "%s", diff_line_prefix(opt));
4100        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
4101                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
4102                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
4103                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
4104        }
4105        if (p->score) {
4106                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
4107                        inter_name_termination);
4108        } else {
4109                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
4110        }
4111
4112        if (p->status == DIFF_STATUS_COPIED ||
4113            p->status == DIFF_STATUS_RENAMED) {
4114                const char *name_a, *name_b;
4115                name_a = p->one->path;
4116                name_b = p->two->path;
4117                strip_prefix(opt->prefix_length, &name_a, &name_b);
4118                write_name_quoted(name_a, opt->file, inter_name_termination);
4119                write_name_quoted(name_b, opt->file, line_termination);
4120        } else {
4121                const char *name_a, *name_b;
4122                name_a = p->one->mode ? p->one->path : p->two->path;
4123                name_b = NULL;
4124                strip_prefix(opt->prefix_length, &name_a, &name_b);
4125                write_name_quoted(name_a, opt->file, line_termination);
4126        }
4127}
4128
4129int diff_unmodified_pair(struct diff_filepair *p)
4130{
4131        /* This function is written stricter than necessary to support
4132         * the currently implemented transformers, but the idea is to
4133         * let transformers to produce diff_filepairs any way they want,
4134         * and filter and clean them up here before producing the output.
4135         */
4136        struct diff_filespec *one = p->one, *two = p->two;
4137
4138        if (DIFF_PAIR_UNMERGED(p))
4139                return 0; /* unmerged is interesting */
4140
4141        /* deletion, addition, mode or type change
4142         * and rename are all interesting.
4143         */
4144        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
4145            DIFF_PAIR_MODE_CHANGED(p) ||
4146            strcmp(one->path, two->path))
4147                return 0;
4148
4149        /* both are valid and point at the same path.  that is, we are
4150         * dealing with a change.
4151         */
4152        if (one->sha1_valid && two->sha1_valid &&
4153            !hashcmp(one->sha1, two->sha1) &&
4154            !one->dirty_submodule && !two->dirty_submodule)
4155                return 1; /* no change */
4156        if (!one->sha1_valid && !two->sha1_valid)
4157                return 1; /* both look at the same file on the filesystem. */
4158        return 0;
4159}
4160
4161static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
4162{
4163        if (diff_unmodified_pair(p))
4164                return;
4165
4166        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4167            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4168                return; /* no tree diffs in patch format */
4169
4170        run_diff(p, o);
4171}
4172
4173static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
4174                            struct diffstat_t *diffstat)
4175{
4176        if (diff_unmodified_pair(p))
4177                return;
4178
4179        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4180            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4181                return; /* no useful stat for tree diffs */
4182
4183        run_diffstat(p, o, diffstat);
4184}
4185
4186static void diff_flush_checkdiff(struct diff_filepair *p,
4187                struct diff_options *o)
4188{
4189        if (diff_unmodified_pair(p))
4190                return;
4191
4192        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4193            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4194                return; /* nothing to check in tree diffs */
4195
4196        run_checkdiff(p, o);
4197}
4198
4199int diff_queue_is_empty(void)
4200{
4201        struct diff_queue_struct *q = &diff_queued_diff;
4202        int i;
4203        for (i = 0; i < q->nr; i++)
4204                if (!diff_unmodified_pair(q->queue[i]))
4205                        return 0;
4206        return 1;
4207}
4208
4209#if DIFF_DEBUG
4210void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
4211{
4212        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
4213                x, one ? one : "",
4214                s->path,
4215                DIFF_FILE_VALID(s) ? "valid" : "invalid",
4216                s->mode,
4217                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
4218        fprintf(stderr, "queue[%d] %s size %lu\n",
4219                x, one ? one : "",
4220                s->size);
4221}
4222
4223void diff_debug_filepair(const struct diff_filepair *p, int i)
4224{
4225        diff_debug_filespec(p->one, i, "one");
4226        diff_debug_filespec(p->two, i, "two");
4227        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
4228                p->score, p->status ? p->status : '?',
4229                p->one->rename_used, p->broken_pair);
4230}
4231
4232void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
4233{
4234        int i;
4235        if (msg)
4236                fprintf(stderr, "%s\n", msg);
4237        fprintf(stderr, "q->nr = %d\n", q->nr);
4238        for (i = 0; i < q->nr; i++) {
4239                struct diff_filepair *p = q->queue[i];
4240                diff_debug_filepair(p, i);
4241        }
4242}
4243#endif
4244
4245static void diff_resolve_rename_copy(void)
4246{
4247        int i;
4248        struct diff_filepair *p;
4249        struct diff_queue_struct *q = &diff_queued_diff;
4250
4251        diff_debug_queue("resolve-rename-copy", q);
4252
4253        for (i = 0; i < q->nr; i++) {
4254                p = q->queue[i];
4255                p->status = 0; /* undecided */
4256                if (DIFF_PAIR_UNMERGED(p))
4257                        p->status = DIFF_STATUS_UNMERGED;
4258                else if (!DIFF_FILE_VALID(p->one))
4259                        p->status = DIFF_STATUS_ADDED;
4260                else if (!DIFF_FILE_VALID(p->two))
4261                        p->status = DIFF_STATUS_DELETED;
4262                else if (DIFF_PAIR_TYPE_CHANGED(p))
4263                        p->status = DIFF_STATUS_TYPE_CHANGED;
4264
4265                /* from this point on, we are dealing with a pair
4266                 * whose both sides are valid and of the same type, i.e.
4267                 * either in-place edit or rename/copy edit.
4268                 */
4269                else if (DIFF_PAIR_RENAME(p)) {
4270                        /*
4271                         * A rename might have re-connected a broken
4272                         * pair up, causing the pathnames to be the
4273                         * same again. If so, that's not a rename at
4274                         * all, just a modification..
4275                         *
4276                         * Otherwise, see if this source was used for
4277                         * multiple renames, in which case we decrement
4278                         * the count, and call it a copy.
4279                         */
4280                        if (!strcmp(p->one->path, p->two->path))
4281                                p->status = DIFF_STATUS_MODIFIED;
4282                        else if (--p->one->rename_used > 0)
4283                                p->status = DIFF_STATUS_COPIED;
4284                        else
4285                                p->status = DIFF_STATUS_RENAMED;
4286                }
4287                else if (hashcmp(p->one->sha1, p->two->sha1) ||
4288                         p->one->mode != p->two->mode ||
4289                         p->one->dirty_submodule ||
4290                         p->two->dirty_submodule ||
4291                         is_null_sha1(p->one->sha1))
4292                        p->status = DIFF_STATUS_MODIFIED;
4293                else {
4294                        /* This is a "no-change" entry and should not
4295                         * happen anymore, but prepare for broken callers.
4296                         */
4297                        error("feeding unmodified %s to diffcore",
4298                              p->one->path);
4299                        p->status = DIFF_STATUS_UNKNOWN;
4300                }
4301        }
4302        diff_debug_queue("resolve-rename-copy done", q);
4303}
4304
4305static int check_pair_status(struct diff_filepair *p)
4306{
4307        switch (p->status) {
4308        case DIFF_STATUS_UNKNOWN:
4309                return 0;
4310        case 0:
4311                die("internal error in diff-resolve-rename-copy");
4312        default:
4313                return 1;
4314        }
4315}
4316
4317static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
4318{
4319        int fmt = opt->output_format;
4320
4321        if (fmt & DIFF_FORMAT_CHECKDIFF)
4322                diff_flush_checkdiff(p, opt);
4323        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
4324                diff_flush_raw(p, opt);
4325        else if (fmt & DIFF_FORMAT_NAME) {
4326                const char *name_a, *name_b;
4327                name_a = p->two->path;
4328                name_b = NULL;
4329                strip_prefix(opt->prefix_length, &name_a, &name_b);
4330                write_name_quoted(name_a, opt->file, opt->line_termination);
4331        }
4332}
4333
4334static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
4335{
4336        if (fs->mode)
4337                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
4338        else
4339                fprintf(file, " %s ", newdelete);
4340        write_name_quoted(fs->path, file, '\n');
4341}
4342
4343
4344static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
4345                const char *line_prefix)
4346{
4347        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
4348                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
4349                        p->two->mode, show_name ? ' ' : '\n');
4350                if (show_name) {
4351                        write_name_quoted(p->two->path, file, '\n');
4352                }
4353        }
4354}
4355
4356static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
4357                        const char *line_prefix)
4358{
4359        char *names = pprint_rename(p->one->path, p->two->path);
4360
4361        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
4362        free(names);
4363        show_mode_change(file, p, 0, line_prefix);
4364}
4365
4366static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
4367{
4368        FILE *file = opt->file;
4369        const char *line_prefix = diff_line_prefix(opt);
4370
4371        switch(p->status) {
4372        case DIFF_STATUS_DELETED:
4373                fputs(line_prefix, file);
4374                show_file_mode_name(file, "delete", p->one);
4375                break;
4376        case DIFF_STATUS_ADDED:
4377                fputs(line_prefix, file);
4378                show_file_mode_name(file, "create", p->two);
4379                break;
4380        case DIFF_STATUS_COPIED:
4381                fputs(line_prefix, file);
4382                show_rename_copy(file, "copy", p, line_prefix);
4383                break;
4384        case DIFF_STATUS_RENAMED:
4385                fputs(line_prefix, file);
4386                show_rename_copy(file, "rename", p, line_prefix);
4387                break;
4388        default:
4389                if (p->score) {
4390                        fprintf(file, "%s rewrite ", line_prefix);
4391                        write_name_quoted(p->two->path, file, ' ');
4392                        fprintf(file, "(%d%%)\n", similarity_index(p));
4393                }
4394                show_mode_change(file, p, !p->score, line_prefix);
4395                break;
4396        }
4397}
4398
4399struct patch_id_t {
4400        git_SHA_CTX *ctx;
4401        int patchlen;
4402};
4403
4404static int remove_space(char *line, int len)
4405{
4406        int i;
4407        char *dst = line;
4408        unsigned char c;
4409
4410        for (i = 0; i < len; i++)
4411                if (!isspace((c = line[i])))
4412                        *dst++ = c;
4413
4414        return dst - line;
4415}
4416
4417static void patch_id_consume(void *priv, char *line, unsigned long len)
4418{
4419        struct patch_id_t *data = priv;
4420        int new_len;
4421
4422        /* Ignore line numbers when computing the SHA1 of the patch */
4423        if (starts_with(line, "@@ -"))
4424                return;
4425
4426        new_len = remove_space(line, len);
4427
4428        git_SHA1_Update(data->ctx, line, new_len);
4429        data->patchlen += new_len;
4430}
4431
4432/* returns 0 upon success, and writes result into sha1 */
4433static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
4434{
4435        struct diff_queue_struct *q = &diff_queued_diff;
4436        int i;
4437        git_SHA_CTX ctx;
4438        struct patch_id_t data;
4439        char buffer[PATH_MAX * 4 + 20];
4440
4441        git_SHA1_Init(&ctx);
4442        memset(&data, 0, sizeof(struct patch_id_t));
4443        data.ctx = &ctx;
4444
4445        for (i = 0; i < q->nr; i++) {
4446                xpparam_t xpp;
4447                xdemitconf_t xecfg;
4448                mmfile_t mf1, mf2;
4449                struct diff_filepair *p = q->queue[i];
4450                int len1, len2;
4451
4452                memset(&xpp, 0, sizeof(xpp));
4453                memset(&xecfg, 0, sizeof(xecfg));
4454                if (p->status == 0)
4455                        return error("internal diff status error");
4456                if (p->status == DIFF_STATUS_UNKNOWN)
4457                        continue;
4458                if (diff_unmodified_pair(p))
4459                        continue;
4460                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4461                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4462                        continue;
4463                if (DIFF_PAIR_UNMERGED(p))
4464                        continue;
4465
4466                diff_fill_sha1_info(p->one);
4467                diff_fill_sha1_info(p->two);
4468                if (fill_mmfile(&mf1, p->one) < 0 ||
4469                                fill_mmfile(&mf2, p->two) < 0)
4470                        return error("unable to read files to diff");
4471
4472                len1 = remove_space(p->one->path, strlen(p->one->path));
4473                len2 = remove_space(p->two->path, strlen(p->two->path));
4474                if (p->one->mode == 0)
4475                        len1 = snprintf(buffer, sizeof(buffer),
4476                                        "diff--gita/%.*sb/%.*s"
4477                                        "newfilemode%06o"
4478                                        "---/dev/null"
4479                                        "+++b/%.*s",
4480                                        len1, p->one->path,
4481                                        len2, p->two->path,
4482                                        p->two->mode,
4483                                        len2, p->two->path);
4484                else if (p->two->mode == 0)
4485                        len1 = snprintf(buffer, sizeof(buffer),
4486                                        "diff--gita/%.*sb/%.*s"
4487                                        "deletedfilemode%06o"
4488                                        "---a/%.*s"
4489                                        "+++/dev/null",
4490                                        len1, p->one->path,
4491                                        len2, p->two->path,
4492                                        p->one->mode,
4493                                        len1, p->one->path);
4494                else
4495                        len1 = snprintf(buffer, sizeof(buffer),
4496                                        "diff--gita/%.*sb/%.*s"
4497                                        "---a/%.*s"
4498                                        "+++b/%.*s",
4499                                        len1, p->one->path,
4500                                        len2, p->two->path,
4501                                        len1, p->one->path,
4502                                        len2, p->two->path);
4503                git_SHA1_Update(&ctx, buffer, len1);
4504
4505                if (diff_filespec_is_binary(p->one) ||
4506                    diff_filespec_is_binary(p->two)) {
4507                        git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
4508                        git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
4509                        continue;
4510                }
4511
4512                xpp.flags = 0;
4513                xecfg.ctxlen = 3;
4514                xecfg.flags = 0;
4515                if (xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4516                                  &xpp, &xecfg))
4517                        return error("unable to generate patch-id diff for %s",
4518                                     p->one->path);
4519        }
4520
4521        git_SHA1_Final(sha1, &ctx);
4522        return 0;
4523}
4524
4525int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
4526{
4527        struct diff_queue_struct *q = &diff_queued_diff;
4528        int i;
4529        int result = diff_get_patch_id(options, sha1);
4530
4531        for (i = 0; i < q->nr; i++)
4532                diff_free_filepair(q->queue[i]);
4533
4534        free(q->queue);
4535        DIFF_QUEUE_CLEAR(q);
4536
4537        return result;
4538}
4539
4540static int is_summary_empty(const struct diff_queue_struct *q)
4541{
4542        int i;
4543
4544        for (i = 0; i < q->nr; i++) {
4545                const struct diff_filepair *p = q->queue[i];
4546
4547                switch (p->status) {
4548                case DIFF_STATUS_DELETED:
4549                case DIFF_STATUS_ADDED:
4550                case DIFF_STATUS_COPIED:
4551                case DIFF_STATUS_RENAMED:
4552                        return 0;
4553                default:
4554                        if (p->score)
4555                                return 0;
4556                        if (p->one->mode && p->two->mode &&
4557                            p->one->mode != p->two->mode)
4558                                return 0;
4559                        break;
4560                }
4561        }
4562        return 1;
4563}
4564
4565static const char rename_limit_warning[] =
4566"inexact rename detection was skipped due to too many files.";
4567
4568static const char degrade_cc_to_c_warning[] =
4569"only found copies from modified paths due to too many files.";
4570
4571static const char rename_limit_advice[] =
4572"you may want to set your %s variable to at least "
4573"%d and retry the command.";
4574
4575void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4576{
4577        if (degraded_cc)
4578                warning(degrade_cc_to_c_warning);
4579        else if (needed)
4580                warning(rename_limit_warning);
4581        else
4582                return;
4583        if (0 < needed && needed < 32767)
4584                warning(rename_limit_advice, varname, needed);
4585}
4586
4587void diff_flush(struct diff_options *options)
4588{
4589        struct diff_queue_struct *q = &diff_queued_diff;
4590        int i, output_format = options->output_format;
4591        int separator = 0;
4592        int dirstat_by_line = 0;
4593
4594        /*
4595         * Order: raw, stat, summary, patch
4596         * or:    name/name-status/checkdiff (other bits clear)
4597         */
4598        if (!q->nr)
4599                goto free_queue;
4600
4601        if (output_format & (DIFF_FORMAT_RAW |
4602                             DIFF_FORMAT_NAME |
4603                             DIFF_FORMAT_NAME_STATUS |
4604                             DIFF_FORMAT_CHECKDIFF)) {
4605                for (i = 0; i < q->nr; i++) {
4606                        struct diff_filepair *p = q->queue[i];
4607                        if (check_pair_status(p))
4608                                flush_one_pair(p, options);
4609                }
4610                separator++;
4611        }
4612
4613        if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
4614                dirstat_by_line = 1;
4615
4616        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
4617            dirstat_by_line) {
4618                struct diffstat_t diffstat;
4619
4620                memset(&diffstat, 0, sizeof(struct diffstat_t));
4621                for (i = 0; i < q->nr; i++) {
4622                        struct diff_filepair *p = q->queue[i];
4623                        if (check_pair_status(p))
4624                                diff_flush_stat(p, options, &diffstat);
4625                }
4626                if (output_format & DIFF_FORMAT_NUMSTAT)
4627                        show_numstat(&diffstat, options);
4628                if (output_format & DIFF_FORMAT_DIFFSTAT)
4629                        show_stats(&diffstat, options);
4630                if (output_format & DIFF_FORMAT_SHORTSTAT)
4631                        show_shortstats(&diffstat, options);
4632                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
4633                        show_dirstat_by_line(&diffstat, options);
4634                free_diffstat_info(&diffstat);
4635                separator++;
4636        }
4637        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
4638                show_dirstat(options);
4639
4640        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4641                for (i = 0; i < q->nr; i++) {
4642                        diff_summary(options, q->queue[i]);
4643                }
4644                separator++;
4645        }
4646
4647        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4648            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4649            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4650                /*
4651                 * run diff_flush_patch for the exit status. setting
4652                 * options->file to /dev/null should be safe, because we
4653                 * aren't supposed to produce any output anyway.
4654                 */
4655                if (options->close_file)
4656                        fclose(options->file);
4657                options->file = fopen("/dev/null", "w");
4658                if (!options->file)
4659                        die_errno("Could not open /dev/null");
4660                options->close_file = 1;
4661                for (i = 0; i < q->nr; i++) {
4662                        struct diff_filepair *p = q->queue[i];
4663                        if (check_pair_status(p))
4664                                diff_flush_patch(p, options);
4665                        if (options->found_changes)
4666                                break;
4667                }
4668        }
4669
4670        if (output_format & DIFF_FORMAT_PATCH) {
4671                if (separator) {
4672                        fprintf(options->file, "%s%c",
4673                                diff_line_prefix(options),
4674                                options->line_termination);
4675                        if (options->stat_sep) {
4676                                /* attach patch instead of inline */
4677                                fputs(options->stat_sep, options->file);
4678                        }
4679                }
4680
4681                for (i = 0; i < q->nr; i++) {
4682                        struct diff_filepair *p = q->queue[i];
4683                        if (check_pair_status(p))
4684                                diff_flush_patch(p, options);
4685                }
4686        }
4687
4688        if (output_format & DIFF_FORMAT_CALLBACK)
4689                options->format_callback(q, options, options->format_callback_data);
4690
4691        for (i = 0; i < q->nr; i++)
4692                diff_free_filepair(q->queue[i]);
4693free_queue:
4694        free(q->queue);
4695        DIFF_QUEUE_CLEAR(q);
4696        if (options->close_file)
4697                fclose(options->file);
4698
4699        /*
4700         * Report the content-level differences with HAS_CHANGES;
4701         * diff_addremove/diff_change does not set the bit when
4702         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4703         */
4704        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4705                if (options->found_changes)
4706                        DIFF_OPT_SET(options, HAS_CHANGES);
4707                else
4708                        DIFF_OPT_CLR(options, HAS_CHANGES);
4709        }
4710}
4711
4712static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
4713{
4714        return (((p->status == DIFF_STATUS_MODIFIED) &&
4715                 ((p->score &&
4716                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
4717                  (!p->score &&
4718                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
4719                ((p->status != DIFF_STATUS_MODIFIED) &&
4720                 filter_bit_tst(p->status, options)));
4721}
4722
4723static void diffcore_apply_filter(struct diff_options *options)
4724{
4725        int i;
4726        struct diff_queue_struct *q = &diff_queued_diff;
4727        struct diff_queue_struct outq;
4728
4729        DIFF_QUEUE_CLEAR(&outq);
4730
4731        if (!options->filter)
4732                return;
4733
4734        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
4735                int found;
4736                for (i = found = 0; !found && i < q->nr; i++) {
4737                        if (match_filter(options, q->queue[i]))
4738                                found++;
4739                }
4740                if (found)
4741                        return;
4742
4743                /* otherwise we will clear the whole queue
4744                 * by copying the empty outq at the end of this
4745                 * function, but first clear the current entries
4746                 * in the queue.
4747                 */
4748                for (i = 0; i < q->nr; i++)
4749                        diff_free_filepair(q->queue[i]);
4750        }
4751        else {
4752                /* Only the matching ones */
4753                for (i = 0; i < q->nr; i++) {
4754                        struct diff_filepair *p = q->queue[i];
4755                        if (match_filter(options, p))
4756                                diff_q(&outq, p);
4757                        else
4758                                diff_free_filepair(p);
4759                }
4760        }
4761        free(q->queue);
4762        *q = outq;
4763}
4764
4765/* Check whether two filespecs with the same mode and size are identical */
4766static int diff_filespec_is_identical(struct diff_filespec *one,
4767                                      struct diff_filespec *two)
4768{
4769        if (S_ISGITLINK(one->mode))
4770                return 0;
4771        if (diff_populate_filespec(one, 0))
4772                return 0;
4773        if (diff_populate_filespec(two, 0))
4774                return 0;
4775        return !memcmp(one->data, two->data, one->size);
4776}
4777
4778static int diff_filespec_check_stat_unmatch(struct diff_filepair *p)
4779{
4780        if (p->done_skip_stat_unmatch)
4781                return p->skip_stat_unmatch_result;
4782
4783        p->done_skip_stat_unmatch = 1;
4784        p->skip_stat_unmatch_result = 0;
4785        /*
4786         * 1. Entries that come from stat info dirtiness
4787         *    always have both sides (iow, not create/delete),
4788         *    one side of the object name is unknown, with
4789         *    the same mode and size.  Keep the ones that
4790         *    do not match these criteria.  They have real
4791         *    differences.
4792         *
4793         * 2. At this point, the file is known to be modified,
4794         *    with the same mode and size, and the object
4795         *    name of one side is unknown.  Need to inspect
4796         *    the identical contents.
4797         */
4798        if (!DIFF_FILE_VALID(p->one) || /* (1) */
4799            !DIFF_FILE_VALID(p->two) ||
4800            (p->one->sha1_valid && p->two->sha1_valid) ||
4801            (p->one->mode != p->two->mode) ||
4802            diff_populate_filespec(p->one, CHECK_SIZE_ONLY) ||
4803            diff_populate_filespec(p->two, CHECK_SIZE_ONLY) ||
4804            (p->one->size != p->two->size) ||
4805            !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4806                p->skip_stat_unmatch_result = 1;
4807        return p->skip_stat_unmatch_result;
4808}
4809
4810static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4811{
4812        int i;
4813        struct diff_queue_struct *q = &diff_queued_diff;
4814        struct diff_queue_struct outq;
4815        DIFF_QUEUE_CLEAR(&outq);
4816
4817        for (i = 0; i < q->nr; i++) {
4818                struct diff_filepair *p = q->queue[i];
4819
4820                if (diff_filespec_check_stat_unmatch(p))
4821                        diff_q(&outq, p);
4822                else {
4823                        /*
4824                         * The caller can subtract 1 from skip_stat_unmatch
4825                         * to determine how many paths were dirty only
4826                         * due to stat info mismatch.
4827                         */
4828                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4829                                diffopt->skip_stat_unmatch++;
4830                        diff_free_filepair(p);
4831                }
4832        }
4833        free(q->queue);
4834        *q = outq;
4835}
4836
4837static int diffnamecmp(const void *a_, const void *b_)
4838{
4839        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4840        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4841        const char *name_a, *name_b;
4842
4843        name_a = a->one ? a->one->path : a->two->path;
4844        name_b = b->one ? b->one->path : b->two->path;
4845        return strcmp(name_a, name_b);
4846}
4847
4848void diffcore_fix_diff_index(struct diff_options *options)
4849{
4850        struct diff_queue_struct *q = &diff_queued_diff;
4851        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4852}
4853
4854void diffcore_std(struct diff_options *options)
4855{
4856        /* NOTE please keep the following in sync with diff_tree_combined() */
4857        if (options->skip_stat_unmatch)
4858                diffcore_skip_stat_unmatch(options);
4859        if (!options->found_follow) {
4860                /* See try_to_follow_renames() in tree-diff.c */
4861                if (options->break_opt != -1)
4862                        diffcore_break(options->break_opt);
4863                if (options->detect_rename)
4864                        diffcore_rename(options);
4865                if (options->break_opt != -1)
4866                        diffcore_merge_broken();
4867        }
4868        if (options->pickaxe)
4869                diffcore_pickaxe(options);
4870        if (options->orderfile)
4871                diffcore_order(options->orderfile);
4872        if (!options->found_follow)
4873                /* See try_to_follow_renames() in tree-diff.c */
4874                diff_resolve_rename_copy();
4875        diffcore_apply_filter(options);
4876
4877        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4878                DIFF_OPT_SET(options, HAS_CHANGES);
4879        else
4880                DIFF_OPT_CLR(options, HAS_CHANGES);
4881
4882        options->found_follow = 0;
4883}
4884
4885int diff_result_code(struct diff_options *opt, int status)
4886{
4887        int result = 0;
4888
4889        diff_warn_rename_limit("diff.renameLimit",
4890                               opt->needed_rename_limit,
4891                               opt->degraded_cc_to_c);
4892        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4893            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4894                return status;
4895        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4896            DIFF_OPT_TST(opt, HAS_CHANGES))
4897                result |= 01;
4898        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4899            DIFF_OPT_TST(opt, CHECK_FAILED))
4900                result |= 02;
4901        return result;
4902}
4903
4904int diff_can_quit_early(struct diff_options *opt)
4905{
4906        return (DIFF_OPT_TST(opt, QUICK) &&
4907                !opt->filter &&
4908                DIFF_OPT_TST(opt, HAS_CHANGES));
4909}
4910
4911/*
4912 * Shall changes to this submodule be ignored?
4913 *
4914 * Submodule changes can be configured to be ignored separately for each path,
4915 * but that configuration can be overridden from the command line.
4916 */
4917static int is_submodule_ignored(const char *path, struct diff_options *options)
4918{
4919        int ignored = 0;
4920        unsigned orig_flags = options->flags;
4921        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4922                set_diffopt_flags_from_submodule_config(options, path);
4923        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4924                ignored = 1;
4925        options->flags = orig_flags;
4926        return ignored;
4927}
4928
4929void diff_addremove(struct diff_options *options,
4930                    int addremove, unsigned mode,
4931                    const unsigned char *sha1,
4932                    int sha1_valid,
4933                    const char *concatpath, unsigned dirty_submodule)
4934{
4935        struct diff_filespec *one, *two;
4936
4937        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4938                return;
4939
4940        /* This may look odd, but it is a preparation for
4941         * feeding "there are unchanged files which should
4942         * not produce diffs, but when you are doing copy
4943         * detection you would need them, so here they are"
4944         * entries to the diff-core.  They will be prefixed
4945         * with something like '=' or '*' (I haven't decided
4946         * which but should not make any difference).
4947         * Feeding the same new and old to diff_change()
4948         * also has the same effect.
4949         * Before the final output happens, they are pruned after
4950         * merged into rename/copy pairs as appropriate.
4951         */
4952        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4953                addremove = (addremove == '+' ? '-' :
4954                             addremove == '-' ? '+' : addremove);
4955
4956        if (options->prefix &&
4957            strncmp(concatpath, options->prefix, options->prefix_length))
4958                return;
4959
4960        one = alloc_filespec(concatpath);
4961        two = alloc_filespec(concatpath);
4962
4963        if (addremove != '+')
4964                fill_filespec(one, sha1, sha1_valid, mode);
4965        if (addremove != '-') {
4966                fill_filespec(two, sha1, sha1_valid, mode);
4967                two->dirty_submodule = dirty_submodule;
4968        }
4969
4970        diff_queue(&diff_queued_diff, one, two);
4971        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4972                DIFF_OPT_SET(options, HAS_CHANGES);
4973}
4974
4975void diff_change(struct diff_options *options,
4976                 unsigned old_mode, unsigned new_mode,
4977                 const unsigned char *old_sha1,
4978                 const unsigned char *new_sha1,
4979                 int old_sha1_valid, int new_sha1_valid,
4980                 const char *concatpath,
4981                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4982{
4983        struct diff_filespec *one, *two;
4984        struct diff_filepair *p;
4985
4986        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4987            is_submodule_ignored(concatpath, options))
4988                return;
4989
4990        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4991                unsigned tmp;
4992                const unsigned char *tmp_c;
4993                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4994                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4995                tmp = old_sha1_valid; old_sha1_valid = new_sha1_valid;
4996                        new_sha1_valid = tmp;
4997                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4998                        new_dirty_submodule = tmp;
4999        }
5000
5001        if (options->prefix &&
5002            strncmp(concatpath, options->prefix, options->prefix_length))
5003                return;
5004
5005        one = alloc_filespec(concatpath);
5006        two = alloc_filespec(concatpath);
5007        fill_filespec(one, old_sha1, old_sha1_valid, old_mode);
5008        fill_filespec(two, new_sha1, new_sha1_valid, new_mode);
5009        one->dirty_submodule = old_dirty_submodule;
5010        two->dirty_submodule = new_dirty_submodule;
5011        p = diff_queue(&diff_queued_diff, one, two);
5012
5013        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
5014                return;
5015
5016        if (DIFF_OPT_TST(options, QUICK) && options->skip_stat_unmatch &&
5017            !diff_filespec_check_stat_unmatch(p))
5018                return;
5019
5020        DIFF_OPT_SET(options, HAS_CHANGES);
5021}
5022
5023struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
5024{
5025        struct diff_filepair *pair;
5026        struct diff_filespec *one, *two;
5027
5028        if (options->prefix &&
5029            strncmp(path, options->prefix, options->prefix_length))
5030                return NULL;
5031
5032        one = alloc_filespec(path);
5033        two = alloc_filespec(path);
5034        pair = diff_queue(&diff_queued_diff, one, two);
5035        pair->is_unmerged = 1;
5036        return pair;
5037}
5038
5039static char *run_textconv(const char *pgm, struct diff_filespec *spec,
5040                size_t *outsize)
5041{
5042        struct diff_tempfile *temp;
5043        const char *argv[3];
5044        const char **arg = argv;
5045        struct child_process child = CHILD_PROCESS_INIT;
5046        struct strbuf buf = STRBUF_INIT;
5047        int err = 0;
5048
5049        temp = prepare_temp_file(spec->path, spec);
5050        *arg++ = pgm;
5051        *arg++ = temp->name;
5052        *arg = NULL;
5053
5054        child.use_shell = 1;
5055        child.argv = argv;
5056        child.out = -1;
5057        if (start_command(&child)) {
5058                remove_tempfile();
5059                return NULL;
5060        }
5061
5062        if (strbuf_read(&buf, child.out, 0) < 0)
5063                err = error("error reading from textconv command '%s'", pgm);
5064        close(child.out);
5065
5066        if (finish_command(&child) || err) {
5067                strbuf_release(&buf);
5068                remove_tempfile();
5069                return NULL;
5070        }
5071        remove_tempfile();
5072
5073        return strbuf_detach(&buf, outsize);
5074}
5075
5076size_t fill_textconv(struct userdiff_driver *driver,
5077                     struct diff_filespec *df,
5078                     char **outbuf)
5079{
5080        size_t size;
5081
5082        if (!driver || !driver->textconv) {
5083                if (!DIFF_FILE_VALID(df)) {
5084                        *outbuf = "";
5085                        return 0;
5086                }
5087                if (diff_populate_filespec(df, 0))
5088                        die("unable to read files to diff");
5089                *outbuf = df->data;
5090                return df->size;
5091        }
5092
5093        if (driver->textconv_cache && df->sha1_valid) {
5094                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
5095                                          &size);
5096                if (*outbuf)
5097                        return size;
5098        }
5099
5100        *outbuf = run_textconv(driver->textconv, df, &size);
5101        if (!*outbuf)
5102                die("unable to read files to diff");
5103
5104        if (driver->textconv_cache && df->sha1_valid) {
5105                /* ignore errors, as we might be in a readonly repository */
5106                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
5107                                size);
5108                /*
5109                 * we could save up changes and flush them all at the end,
5110                 * but we would need an extra call after all diffing is done.
5111                 * Since generating a cache entry is the slow path anyway,
5112                 * this extra overhead probably isn't a big deal.
5113                 */
5114                notes_cache_write(driver->textconv_cache);
5115        }
5116
5117        return size;
5118}
5119
5120void setup_diff_pager(struct diff_options *opt)
5121{
5122        /*
5123         * If the user asked for our exit code, then either they want --quiet
5124         * or --exit-code. We should definitely not bother with a pager in the
5125         * former case, as we will generate no output. Since we still properly
5126         * report our exit code even when a pager is run, we _could_ run a
5127         * pager with --exit-code. But since we have not done so historically,
5128         * and because it is easy to find people oneline advising "git diff
5129         * --exit-code" in hooks and other scripts, we do not do so.
5130         */
5131        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
5132            check_pager_config("diff") != 0)
5133                setup_pager();
5134}