diff.con commit Merge branch 'master' of git://github.com/git-l10n/git-po (e7551a8)
   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
  20#ifdef NO_FAST_WORKING_DIRECTORY
  21#define FAST_WORKING_DIRECTORY 0
  22#else
  23#define FAST_WORKING_DIRECTORY 1
  24#endif
  25
  26static int diff_detect_rename_default;
  27static int diff_rename_limit_default = 400;
  28static int diff_suppress_blank_empty;
  29static int diff_use_color_default = -1;
  30static int diff_context_default = 3;
  31static const char *diff_word_regex_cfg;
  32static const char *external_diff_cmd_cfg;
  33int diff_auto_refresh_index = 1;
  34static int diff_mnemonic_prefix;
  35static int diff_no_prefix;
  36static int diff_stat_graph_width;
  37static int diff_dirstat_permille_default = 30;
  38static struct diff_options default_diff_options;
  39
  40static char diff_colors[][COLOR_MAXLEN] = {
  41        GIT_COLOR_RESET,
  42        GIT_COLOR_NORMAL,       /* PLAIN */
  43        GIT_COLOR_BOLD,         /* METAINFO */
  44        GIT_COLOR_CYAN,         /* FRAGINFO */
  45        GIT_COLOR_RED,          /* OLD */
  46        GIT_COLOR_GREEN,        /* NEW */
  47        GIT_COLOR_YELLOW,       /* COMMIT */
  48        GIT_COLOR_BG_RED,       /* WHITESPACE */
  49        GIT_COLOR_NORMAL,       /* FUNCINFO */
  50};
  51
  52static int parse_diff_color_slot(const char *var, int ofs)
  53{
  54        if (!strcasecmp(var+ofs, "plain"))
  55                return DIFF_PLAIN;
  56        if (!strcasecmp(var+ofs, "meta"))
  57                return DIFF_METAINFO;
  58        if (!strcasecmp(var+ofs, "frag"))
  59                return DIFF_FRAGINFO;
  60        if (!strcasecmp(var+ofs, "old"))
  61                return DIFF_FILE_OLD;
  62        if (!strcasecmp(var+ofs, "new"))
  63                return DIFF_FILE_NEW;
  64        if (!strcasecmp(var+ofs, "commit"))
  65                return DIFF_COMMIT;
  66        if (!strcasecmp(var+ofs, "whitespace"))
  67                return DIFF_WHITESPACE;
  68        if (!strcasecmp(var+ofs, "func"))
  69                return DIFF_FUNCINFO;
  70        return -1;
  71}
  72
  73static int parse_dirstat_params(struct diff_options *options, const char *params_string,
  74                                struct strbuf *errmsg)
  75{
  76        char *params_copy = xstrdup(params_string);
  77        struct string_list params = STRING_LIST_INIT_NODUP;
  78        int ret = 0;
  79        int i;
  80
  81        if (*params_copy)
  82                string_list_split_in_place(&params, params_copy, ',', -1);
  83        for (i = 0; i < params.nr; i++) {
  84                const char *p = params.items[i].string;
  85                if (!strcmp(p, "changes")) {
  86                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
  87                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
  88                } else if (!strcmp(p, "lines")) {
  89                        DIFF_OPT_SET(options, DIRSTAT_BY_LINE);
  90                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
  91                } else if (!strcmp(p, "files")) {
  92                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
  93                        DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
  94                } else if (!strcmp(p, "noncumulative")) {
  95                        DIFF_OPT_CLR(options, DIRSTAT_CUMULATIVE);
  96                } else if (!strcmp(p, "cumulative")) {
  97                        DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
  98                } else if (isdigit(*p)) {
  99                        char *end;
 100                        int permille = strtoul(p, &end, 10) * 10;
 101                        if (*end == '.' && isdigit(*++end)) {
 102                                /* only use first digit */
 103                                permille += *end - '0';
 104                                /* .. and ignore any further digits */
 105                                while (isdigit(*++end))
 106                                        ; /* nothing */
 107                        }
 108                        if (!*end)
 109                                options->dirstat_permille = permille;
 110                        else {
 111                                strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%s'\n"),
 112                                            p);
 113                                ret++;
 114                        }
 115                } else {
 116                        strbuf_addf(errmsg, _("  Unknown dirstat parameter '%s'\n"), p);
 117                        ret++;
 118                }
 119
 120        }
 121        string_list_clear(&params, 0);
 122        free(params_copy);
 123        return ret;
 124}
 125
 126static int parse_submodule_params(struct diff_options *options, const char *value)
 127{
 128        if (!strcmp(value, "log"))
 129                DIFF_OPT_SET(options, SUBMODULE_LOG);
 130        else if (!strcmp(value, "short"))
 131                DIFF_OPT_CLR(options, SUBMODULE_LOG);
 132        else
 133                return -1;
 134        return 0;
 135}
 136
 137static int git_config_rename(const char *var, const char *value)
 138{
 139        if (!value)
 140                return DIFF_DETECT_RENAME;
 141        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 142                return  DIFF_DETECT_COPY;
 143        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 144}
 145
 146/*
 147 * These are to give UI layer defaults.
 148 * The core-level commands such as git-diff-files should
 149 * never be affected by the setting of diff.renames
 150 * the user happens to have in the configuration file.
 151 */
 152int git_diff_ui_config(const char *var, const char *value, void *cb)
 153{
 154        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 155                diff_use_color_default = git_config_colorbool(var, value);
 156                return 0;
 157        }
 158        if (!strcmp(var, "diff.context")) {
 159                diff_context_default = git_config_int(var, value);
 160                if (diff_context_default < 0)
 161                        return -1;
 162                return 0;
 163        }
 164        if (!strcmp(var, "diff.renames")) {
 165                diff_detect_rename_default = git_config_rename(var, value);
 166                return 0;
 167        }
 168        if (!strcmp(var, "diff.autorefreshindex")) {
 169                diff_auto_refresh_index = git_config_bool(var, value);
 170                return 0;
 171        }
 172        if (!strcmp(var, "diff.mnemonicprefix")) {
 173                diff_mnemonic_prefix = git_config_bool(var, value);
 174                return 0;
 175        }
 176        if (!strcmp(var, "diff.noprefix")) {
 177                diff_no_prefix = git_config_bool(var, value);
 178                return 0;
 179        }
 180        if (!strcmp(var, "diff.statgraphwidth")) {
 181                diff_stat_graph_width = git_config_int(var, value);
 182                return 0;
 183        }
 184        if (!strcmp(var, "diff.external"))
 185                return git_config_string(&external_diff_cmd_cfg, var, value);
 186        if (!strcmp(var, "diff.wordregex"))
 187                return git_config_string(&diff_word_regex_cfg, var, value);
 188
 189        if (!strcmp(var, "diff.ignoresubmodules"))
 190                handle_ignore_submodules_arg(&default_diff_options, value);
 191
 192        if (!strcmp(var, "diff.submodule")) {
 193                if (parse_submodule_params(&default_diff_options, value))
 194                        warning(_("Unknown value for 'diff.submodule' config variable: '%s'"),
 195                                value);
 196                return 0;
 197        }
 198
 199        if (git_color_config(var, value, cb) < 0)
 200                return -1;
 201
 202        return git_diff_basic_config(var, value, cb);
 203}
 204
 205int git_diff_basic_config(const char *var, const char *value, void *cb)
 206{
 207        if (!strcmp(var, "diff.renamelimit")) {
 208                diff_rename_limit_default = git_config_int(var, value);
 209                return 0;
 210        }
 211
 212        if (userdiff_config(var, value) < 0)
 213                return -1;
 214
 215        if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
 216                int slot = parse_diff_color_slot(var, 11);
 217                if (slot < 0)
 218                        return 0;
 219                if (!value)
 220                        return config_error_nonbool(var);
 221                color_parse(value, var, diff_colors[slot]);
 222                return 0;
 223        }
 224
 225        /* like GNU diff's --suppress-blank-empty option  */
 226        if (!strcmp(var, "diff.suppressblankempty") ||
 227                        /* for backwards compatibility */
 228                        !strcmp(var, "diff.suppress-blank-empty")) {
 229                diff_suppress_blank_empty = git_config_bool(var, value);
 230                return 0;
 231        }
 232
 233        if (!strcmp(var, "diff.dirstat")) {
 234                struct strbuf errmsg = STRBUF_INIT;
 235                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 236                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 237                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 238                                errmsg.buf);
 239                strbuf_release(&errmsg);
 240                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 241                return 0;
 242        }
 243
 244        if (!prefixcmp(var, "submodule."))
 245                return parse_submodule_config_option(var, value);
 246
 247        return git_default_config(var, value, cb);
 248}
 249
 250static char *quote_two(const char *one, const char *two)
 251{
 252        int need_one = quote_c_style(one, NULL, NULL, 1);
 253        int need_two = quote_c_style(two, NULL, NULL, 1);
 254        struct strbuf res = STRBUF_INIT;
 255
 256        if (need_one + need_two) {
 257                strbuf_addch(&res, '"');
 258                quote_c_style(one, &res, NULL, 1);
 259                quote_c_style(two, &res, NULL, 1);
 260                strbuf_addch(&res, '"');
 261        } else {
 262                strbuf_addstr(&res, one);
 263                strbuf_addstr(&res, two);
 264        }
 265        return strbuf_detach(&res, NULL);
 266}
 267
 268static const char *external_diff(void)
 269{
 270        static const char *external_diff_cmd = NULL;
 271        static int done_preparing = 0;
 272
 273        if (done_preparing)
 274                return external_diff_cmd;
 275        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 276        if (!external_diff_cmd)
 277                external_diff_cmd = external_diff_cmd_cfg;
 278        done_preparing = 1;
 279        return external_diff_cmd;
 280}
 281
 282static struct diff_tempfile {
 283        const char *name; /* filename external diff should read from */
 284        char hex[41];
 285        char mode[10];
 286        char tmp_path[PATH_MAX];
 287} diff_temp[2];
 288
 289typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 290
 291struct emit_callback {
 292        int color_diff;
 293        unsigned ws_rule;
 294        int blank_at_eof_in_preimage;
 295        int blank_at_eof_in_postimage;
 296        int lno_in_preimage;
 297        int lno_in_postimage;
 298        sane_truncate_fn truncate;
 299        const char **label_path;
 300        struct diff_words_data *diff_words;
 301        struct diff_options *opt;
 302        int *found_changesp;
 303        struct strbuf *header;
 304};
 305
 306static int count_lines(const char *data, int size)
 307{
 308        int count, ch, completely_empty = 1, nl_just_seen = 0;
 309        count = 0;
 310        while (0 < size--) {
 311                ch = *data++;
 312                if (ch == '\n') {
 313                        count++;
 314                        nl_just_seen = 1;
 315                        completely_empty = 0;
 316                }
 317                else {
 318                        nl_just_seen = 0;
 319                        completely_empty = 0;
 320                }
 321        }
 322        if (completely_empty)
 323                return 0;
 324        if (!nl_just_seen)
 325                count++; /* no trailing newline */
 326        return count;
 327}
 328
 329static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 330{
 331        if (!DIFF_FILE_VALID(one)) {
 332                mf->ptr = (char *)""; /* does not matter */
 333                mf->size = 0;
 334                return 0;
 335        }
 336        else if (diff_populate_filespec(one, 0))
 337                return -1;
 338
 339        mf->ptr = one->data;
 340        mf->size = one->size;
 341        return 0;
 342}
 343
 344/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 345static unsigned long diff_filespec_size(struct diff_filespec *one)
 346{
 347        if (!DIFF_FILE_VALID(one))
 348                return 0;
 349        diff_populate_filespec(one, 1);
 350        return one->size;
 351}
 352
 353static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 354{
 355        char *ptr = mf->ptr;
 356        long size = mf->size;
 357        int cnt = 0;
 358
 359        if (!size)
 360                return cnt;
 361        ptr += size - 1; /* pointing at the very end */
 362        if (*ptr != '\n')
 363                ; /* incomplete line */
 364        else
 365                ptr--; /* skip the last LF */
 366        while (mf->ptr < ptr) {
 367                char *prev_eol;
 368                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 369                        if (*prev_eol == '\n')
 370                                break;
 371                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 372                        break;
 373                cnt++;
 374                ptr = prev_eol - 1;
 375        }
 376        return cnt;
 377}
 378
 379static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 380                               struct emit_callback *ecbdata)
 381{
 382        int l1, l2, at;
 383        unsigned ws_rule = ecbdata->ws_rule;
 384        l1 = count_trailing_blank(mf1, ws_rule);
 385        l2 = count_trailing_blank(mf2, ws_rule);
 386        if (l2 <= l1) {
 387                ecbdata->blank_at_eof_in_preimage = 0;
 388                ecbdata->blank_at_eof_in_postimage = 0;
 389                return;
 390        }
 391        at = count_lines(mf1->ptr, mf1->size);
 392        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 393
 394        at = count_lines(mf2->ptr, mf2->size);
 395        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 396}
 397
 398static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 399                        int first, const char *line, int len)
 400{
 401        int has_trailing_newline, has_trailing_carriage_return;
 402        int nofirst;
 403        FILE *file = o->file;
 404
 405        if (o->output_prefix) {
 406                struct strbuf *msg = NULL;
 407                msg = o->output_prefix(o, o->output_prefix_data);
 408                assert(msg);
 409                fwrite(msg->buf, msg->len, 1, file);
 410        }
 411
 412        if (len == 0) {
 413                has_trailing_newline = (first == '\n');
 414                has_trailing_carriage_return = (!has_trailing_newline &&
 415                                                (first == '\r'));
 416                nofirst = has_trailing_newline || has_trailing_carriage_return;
 417        } else {
 418                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 419                if (has_trailing_newline)
 420                        len--;
 421                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 422                if (has_trailing_carriage_return)
 423                        len--;
 424                nofirst = 0;
 425        }
 426
 427        if (len || !nofirst) {
 428                fputs(set, file);
 429                if (!nofirst)
 430                        fputc(first, file);
 431                fwrite(line, len, 1, file);
 432                fputs(reset, file);
 433        }
 434        if (has_trailing_carriage_return)
 435                fputc('\r', file);
 436        if (has_trailing_newline)
 437                fputc('\n', file);
 438}
 439
 440static void emit_line(struct diff_options *o, const char *set, const char *reset,
 441                      const char *line, int len)
 442{
 443        emit_line_0(o, set, reset, line[0], line+1, len-1);
 444}
 445
 446static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 447{
 448        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 449              ecbdata->blank_at_eof_in_preimage &&
 450              ecbdata->blank_at_eof_in_postimage &&
 451              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 452              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 453                return 0;
 454        return ws_blank_line(line, len, ecbdata->ws_rule);
 455}
 456
 457static void emit_add_line(const char *reset,
 458                          struct emit_callback *ecbdata,
 459                          const char *line, int len)
 460{
 461        const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 462        const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 463
 464        if (!*ws)
 465                emit_line_0(ecbdata->opt, set, reset, '+', line, len);
 466        else if (new_blank_line_at_eof(ecbdata, line, len))
 467                /* Blank line at EOF - paint '+' as well */
 468                emit_line_0(ecbdata->opt, ws, reset, '+', line, len);
 469        else {
 470                /* Emit just the prefix, then the rest. */
 471                emit_line_0(ecbdata->opt, set, reset, '+', "", 0);
 472                ws_check_emit(line, len, ecbdata->ws_rule,
 473                              ecbdata->opt->file, set, reset, ws);
 474        }
 475}
 476
 477static void emit_hunk_header(struct emit_callback *ecbdata,
 478                             const char *line, int len)
 479{
 480        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 481        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 482        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 483        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 484        static const char atat[2] = { '@', '@' };
 485        const char *cp, *ep;
 486        struct strbuf msgbuf = STRBUF_INIT;
 487        int org_len = len;
 488        int i = 1;
 489
 490        /*
 491         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 492         * it always is at least 10 bytes long.
 493         */
 494        if (len < 10 ||
 495            memcmp(line, atat, 2) ||
 496            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 497                emit_line(ecbdata->opt, plain, reset, line, len);
 498                return;
 499        }
 500        ep += 2; /* skip over @@ */
 501
 502        /* The hunk header in fraginfo color */
 503        strbuf_add(&msgbuf, frag, strlen(frag));
 504        strbuf_add(&msgbuf, line, ep - line);
 505        strbuf_add(&msgbuf, reset, strlen(reset));
 506
 507        /*
 508         * trailing "\r\n"
 509         */
 510        for ( ; i < 3; i++)
 511                if (line[len - i] == '\r' || line[len - i] == '\n')
 512                        len--;
 513
 514        /* blank before the func header */
 515        for (cp = ep; ep - line < len; ep++)
 516                if (*ep != ' ' && *ep != '\t')
 517                        break;
 518        if (ep != cp) {
 519                strbuf_add(&msgbuf, plain, strlen(plain));
 520                strbuf_add(&msgbuf, cp, ep - cp);
 521                strbuf_add(&msgbuf, reset, strlen(reset));
 522        }
 523
 524        if (ep < line + len) {
 525                strbuf_add(&msgbuf, func, strlen(func));
 526                strbuf_add(&msgbuf, ep, line + len - ep);
 527                strbuf_add(&msgbuf, reset, strlen(reset));
 528        }
 529
 530        strbuf_add(&msgbuf, line + len, org_len - len);
 531        emit_line(ecbdata->opt, "", "", msgbuf.buf, msgbuf.len);
 532        strbuf_release(&msgbuf);
 533}
 534
 535static struct diff_tempfile *claim_diff_tempfile(void) {
 536        int i;
 537        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 538                if (!diff_temp[i].name)
 539                        return diff_temp + i;
 540        die("BUG: diff is failing to clean up its tempfiles");
 541}
 542
 543static int remove_tempfile_installed;
 544
 545static void remove_tempfile(void)
 546{
 547        int i;
 548        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 549                if (diff_temp[i].name == diff_temp[i].tmp_path)
 550                        unlink_or_warn(diff_temp[i].name);
 551                diff_temp[i].name = NULL;
 552        }
 553}
 554
 555static void remove_tempfile_on_signal(int signo)
 556{
 557        remove_tempfile();
 558        sigchain_pop(signo);
 559        raise(signo);
 560}
 561
 562static void print_line_count(FILE *file, int count)
 563{
 564        switch (count) {
 565        case 0:
 566                fprintf(file, "0,0");
 567                break;
 568        case 1:
 569                fprintf(file, "1");
 570                break;
 571        default:
 572                fprintf(file, "1,%d", count);
 573                break;
 574        }
 575}
 576
 577static void emit_rewrite_lines(struct emit_callback *ecb,
 578                               int prefix, const char *data, int size)
 579{
 580        const char *endp = NULL;
 581        static const char *nneof = " No newline at end of file\n";
 582        const char *old = diff_get_color(ecb->color_diff, DIFF_FILE_OLD);
 583        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 584
 585        while (0 < size) {
 586                int len;
 587
 588                endp = memchr(data, '\n', size);
 589                len = endp ? (endp - data + 1) : size;
 590                if (prefix != '+') {
 591                        ecb->lno_in_preimage++;
 592                        emit_line_0(ecb->opt, old, reset, '-',
 593                                    data, len);
 594                } else {
 595                        ecb->lno_in_postimage++;
 596                        emit_add_line(reset, ecb, data, len);
 597                }
 598                size -= len;
 599                data += len;
 600        }
 601        if (!endp) {
 602                const char *plain = diff_get_color(ecb->color_diff,
 603                                                   DIFF_PLAIN);
 604                putc('\n', ecb->opt->file);
 605                emit_line_0(ecb->opt, plain, reset, '\\',
 606                            nneof, strlen(nneof));
 607        }
 608}
 609
 610static void emit_rewrite_diff(const char *name_a,
 611                              const char *name_b,
 612                              struct diff_filespec *one,
 613                              struct diff_filespec *two,
 614                              struct userdiff_driver *textconv_one,
 615                              struct userdiff_driver *textconv_two,
 616                              struct diff_options *o)
 617{
 618        int lc_a, lc_b;
 619        const char *name_a_tab, *name_b_tab;
 620        const char *metainfo = diff_get_color(o->use_color, DIFF_METAINFO);
 621        const char *fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
 622        const char *reset = diff_get_color(o->use_color, DIFF_RESET);
 623        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 624        const char *a_prefix, *b_prefix;
 625        char *data_one, *data_two;
 626        size_t size_one, size_two;
 627        struct emit_callback ecbdata;
 628        char *line_prefix = "";
 629        struct strbuf *msgbuf;
 630
 631        if (o && o->output_prefix) {
 632                msgbuf = o->output_prefix(o, o->output_prefix_data);
 633                line_prefix = msgbuf->buf;
 634        }
 635
 636        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 637                a_prefix = o->b_prefix;
 638                b_prefix = o->a_prefix;
 639        } else {
 640                a_prefix = o->a_prefix;
 641                b_prefix = o->b_prefix;
 642        }
 643
 644        name_a += (*name_a == '/');
 645        name_b += (*name_b == '/');
 646        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 647        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 648
 649        strbuf_reset(&a_name);
 650        strbuf_reset(&b_name);
 651        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 652        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 653
 654        size_one = fill_textconv(textconv_one, one, &data_one);
 655        size_two = fill_textconv(textconv_two, two, &data_two);
 656
 657        memset(&ecbdata, 0, sizeof(ecbdata));
 658        ecbdata.color_diff = want_color(o->use_color);
 659        ecbdata.found_changesp = &o->found_changes;
 660        ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
 661        ecbdata.opt = o;
 662        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 663                mmfile_t mf1, mf2;
 664                mf1.ptr = (char *)data_one;
 665                mf2.ptr = (char *)data_two;
 666                mf1.size = size_one;
 667                mf2.size = size_two;
 668                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 669        }
 670        ecbdata.lno_in_preimage = 1;
 671        ecbdata.lno_in_postimage = 1;
 672
 673        lc_a = count_lines(data_one, size_one);
 674        lc_b = count_lines(data_two, size_two);
 675        fprintf(o->file,
 676                "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
 677                line_prefix, metainfo, a_name.buf, name_a_tab, reset,
 678                line_prefix, metainfo, b_name.buf, name_b_tab, reset,
 679                line_prefix, fraginfo);
 680        if (!o->irreversible_delete)
 681                print_line_count(o->file, lc_a);
 682        else
 683                fprintf(o->file, "?,?");
 684        fprintf(o->file, " +");
 685        print_line_count(o->file, lc_b);
 686        fprintf(o->file, " @@%s\n", reset);
 687        if (lc_a && !o->irreversible_delete)
 688                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 689        if (lc_b)
 690                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 691        if (textconv_one)
 692                free((char *)data_one);
 693        if (textconv_two)
 694                free((char *)data_two);
 695}
 696
 697struct diff_words_buffer {
 698        mmfile_t text;
 699        long alloc;
 700        struct diff_words_orig {
 701                const char *begin, *end;
 702        } *orig;
 703        int orig_nr, orig_alloc;
 704};
 705
 706static void diff_words_append(char *line, unsigned long len,
 707                struct diff_words_buffer *buffer)
 708{
 709        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 710        line++;
 711        len--;
 712        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 713        buffer->text.size += len;
 714        buffer->text.ptr[buffer->text.size] = '\0';
 715}
 716
 717struct diff_words_style_elem {
 718        const char *prefix;
 719        const char *suffix;
 720        const char *color; /* NULL; filled in by the setup code if
 721                            * color is enabled */
 722};
 723
 724struct diff_words_style {
 725        enum diff_words_type type;
 726        struct diff_words_style_elem new, old, ctx;
 727        const char *newline;
 728};
 729
 730static struct diff_words_style diff_words_styles[] = {
 731        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 732        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 733        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 734};
 735
 736struct diff_words_data {
 737        struct diff_words_buffer minus, plus;
 738        const char *current_plus;
 739        int last_minus;
 740        struct diff_options *opt;
 741        regex_t *word_regex;
 742        enum diff_words_type type;
 743        struct diff_words_style *style;
 744};
 745
 746static int fn_out_diff_words_write_helper(FILE *fp,
 747                                          struct diff_words_style_elem *st_el,
 748                                          const char *newline,
 749                                          size_t count, const char *buf,
 750                                          const char *line_prefix)
 751{
 752        int print = 0;
 753
 754        while (count) {
 755                char *p = memchr(buf, '\n', count);
 756                if (print)
 757                        fputs(line_prefix, fp);
 758                if (p != buf) {
 759                        if (st_el->color && fputs(st_el->color, fp) < 0)
 760                                return -1;
 761                        if (fputs(st_el->prefix, fp) < 0 ||
 762                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 763                            fputs(st_el->suffix, fp) < 0)
 764                                return -1;
 765                        if (st_el->color && *st_el->color
 766                            && fputs(GIT_COLOR_RESET, fp) < 0)
 767                                return -1;
 768                }
 769                if (!p)
 770                        return 0;
 771                if (fputs(newline, fp) < 0)
 772                        return -1;
 773                count -= p + 1 - buf;
 774                buf = p + 1;
 775                print = 1;
 776        }
 777        return 0;
 778}
 779
 780/*
 781 * '--color-words' algorithm can be described as:
 782 *
 783 *   1. collect a the minus/plus lines of a diff hunk, divided into
 784 *      minus-lines and plus-lines;
 785 *
 786 *   2. break both minus-lines and plus-lines into words and
 787 *      place them into two mmfile_t with one word for each line;
 788 *
 789 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
 790 *
 791 * And for the common parts of the both file, we output the plus side text.
 792 * diff_words->current_plus is used to trace the current position of the plus file
 793 * which printed. diff_words->last_minus is used to trace the last minus word
 794 * printed.
 795 *
 796 * For '--graph' to work with '--color-words', we need to output the graph prefix
 797 * on each line of color words output. Generally, there are two conditions on
 798 * which we should output the prefix.
 799 *
 800 *   1. diff_words->last_minus == 0 &&
 801 *      diff_words->current_plus == diff_words->plus.text.ptr
 802 *
 803 *      that is: the plus text must start as a new line, and if there is no minus
 804 *      word printed, a graph prefix must be printed.
 805 *
 806 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
 807 *      *(diff_words->current_plus - 1) == '\n'
 808 *
 809 *      that is: a graph prefix must be printed following a '\n'
 810 */
 811static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
 812{
 813        if ((diff_words->last_minus == 0 &&
 814                diff_words->current_plus == diff_words->plus.text.ptr) ||
 815                (diff_words->current_plus > diff_words->plus.text.ptr &&
 816                *(diff_words->current_plus - 1) == '\n')) {
 817                return 1;
 818        } else {
 819                return 0;
 820        }
 821}
 822
 823static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 824{
 825        struct diff_words_data *diff_words = priv;
 826        struct diff_words_style *style = diff_words->style;
 827        int minus_first, minus_len, plus_first, plus_len;
 828        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 829        struct diff_options *opt = diff_words->opt;
 830        struct strbuf *msgbuf;
 831        char *line_prefix = "";
 832
 833        if (line[0] != '@' || parse_hunk_header(line, len,
 834                        &minus_first, &minus_len, &plus_first, &plus_len))
 835                return;
 836
 837        assert(opt);
 838        if (opt->output_prefix) {
 839                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 840                line_prefix = msgbuf->buf;
 841        }
 842
 843        /* POSIX requires that first be decremented by one if len == 0... */
 844        if (minus_len) {
 845                minus_begin = diff_words->minus.orig[minus_first].begin;
 846                minus_end =
 847                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 848        } else
 849                minus_begin = minus_end =
 850                        diff_words->minus.orig[minus_first].end;
 851
 852        if (plus_len) {
 853                plus_begin = diff_words->plus.orig[plus_first].begin;
 854                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 855        } else
 856                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 857
 858        if (color_words_output_graph_prefix(diff_words)) {
 859                fputs(line_prefix, diff_words->opt->file);
 860        }
 861        if (diff_words->current_plus != plus_begin) {
 862                fn_out_diff_words_write_helper(diff_words->opt->file,
 863                                &style->ctx, style->newline,
 864                                plus_begin - diff_words->current_plus,
 865                                diff_words->current_plus, line_prefix);
 866                if (*(plus_begin - 1) == '\n')
 867                        fputs(line_prefix, diff_words->opt->file);
 868        }
 869        if (minus_begin != minus_end) {
 870                fn_out_diff_words_write_helper(diff_words->opt->file,
 871                                &style->old, style->newline,
 872                                minus_end - minus_begin, minus_begin,
 873                                line_prefix);
 874        }
 875        if (plus_begin != plus_end) {
 876                fn_out_diff_words_write_helper(diff_words->opt->file,
 877                                &style->new, style->newline,
 878                                plus_end - plus_begin, plus_begin,
 879                                line_prefix);
 880        }
 881
 882        diff_words->current_plus = plus_end;
 883        diff_words->last_minus = minus_first;
 884}
 885
 886/* This function starts looking at *begin, and returns 0 iff a word was found. */
 887static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 888                int *begin, int *end)
 889{
 890        if (word_regex && *begin < buffer->size) {
 891                regmatch_t match[1];
 892                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 893                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 894                                        '\n', match[0].rm_eo - match[0].rm_so);
 895                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 896                        *begin += match[0].rm_so;
 897                        return *begin >= *end;
 898                }
 899                return -1;
 900        }
 901
 902        /* find the next word */
 903        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 904                (*begin)++;
 905        if (*begin >= buffer->size)
 906                return -1;
 907
 908        /* find the end of the word */
 909        *end = *begin + 1;
 910        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 911                (*end)++;
 912
 913        return 0;
 914}
 915
 916/*
 917 * This function splits the words in buffer->text, stores the list with
 918 * newline separator into out, and saves the offsets of the original words
 919 * in buffer->orig.
 920 */
 921static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 922                regex_t *word_regex)
 923{
 924        int i, j;
 925        long alloc = 0;
 926
 927        out->size = 0;
 928        out->ptr = NULL;
 929
 930        /* fake an empty "0th" word */
 931        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 932        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 933        buffer->orig_nr = 1;
 934
 935        for (i = 0; i < buffer->text.size; i++) {
 936                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 937                        return;
 938
 939                /* store original boundaries */
 940                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 941                                buffer->orig_alloc);
 942                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 943                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 944                buffer->orig_nr++;
 945
 946                /* store one word */
 947                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 948                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 949                out->ptr[out->size + j - i] = '\n';
 950                out->size += j - i + 1;
 951
 952                i = j - 1;
 953        }
 954}
 955
 956/* this executes the word diff on the accumulated buffers */
 957static void diff_words_show(struct diff_words_data *diff_words)
 958{
 959        xpparam_t xpp;
 960        xdemitconf_t xecfg;
 961        mmfile_t minus, plus;
 962        struct diff_words_style *style = diff_words->style;
 963
 964        struct diff_options *opt = diff_words->opt;
 965        struct strbuf *msgbuf;
 966        char *line_prefix = "";
 967
 968        assert(opt);
 969        if (opt->output_prefix) {
 970                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 971                line_prefix = msgbuf->buf;
 972        }
 973
 974        /* special case: only removal */
 975        if (!diff_words->plus.text.size) {
 976                fputs(line_prefix, diff_words->opt->file);
 977                fn_out_diff_words_write_helper(diff_words->opt->file,
 978                        &style->old, style->newline,
 979                        diff_words->minus.text.size,
 980                        diff_words->minus.text.ptr, line_prefix);
 981                diff_words->minus.text.size = 0;
 982                return;
 983        }
 984
 985        diff_words->current_plus = diff_words->plus.text.ptr;
 986        diff_words->last_minus = 0;
 987
 988        memset(&xpp, 0, sizeof(xpp));
 989        memset(&xecfg, 0, sizeof(xecfg));
 990        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
 991        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
 992        xpp.flags = 0;
 993        /* as only the hunk header will be parsed, we need a 0-context */
 994        xecfg.ctxlen = 0;
 995        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 996                      &xpp, &xecfg);
 997        free(minus.ptr);
 998        free(plus.ptr);
 999        if (diff_words->current_plus != diff_words->plus.text.ptr +
1000                        diff_words->plus.text.size) {
1001                if (color_words_output_graph_prefix(diff_words))
1002                        fputs(line_prefix, diff_words->opt->file);
1003                fn_out_diff_words_write_helper(diff_words->opt->file,
1004                        &style->ctx, style->newline,
1005                        diff_words->plus.text.ptr + diff_words->plus.text.size
1006                        - diff_words->current_plus, diff_words->current_plus,
1007                        line_prefix);
1008        }
1009        diff_words->minus.text.size = diff_words->plus.text.size = 0;
1010}
1011
1012/* In "color-words" mode, show word-diff of words accumulated in the buffer */
1013static void diff_words_flush(struct emit_callback *ecbdata)
1014{
1015        if (ecbdata->diff_words->minus.text.size ||
1016            ecbdata->diff_words->plus.text.size)
1017                diff_words_show(ecbdata->diff_words);
1018}
1019
1020static void diff_filespec_load_driver(struct diff_filespec *one)
1021{
1022        /* Use already-loaded driver */
1023        if (one->driver)
1024                return;
1025
1026        if (S_ISREG(one->mode))
1027                one->driver = userdiff_find_by_path(one->path);
1028
1029        /* Fallback to default settings */
1030        if (!one->driver)
1031                one->driver = userdiff_find_by_name("default");
1032}
1033
1034static const char *userdiff_word_regex(struct diff_filespec *one)
1035{
1036        diff_filespec_load_driver(one);
1037        return one->driver->word_regex;
1038}
1039
1040static void init_diff_words_data(struct emit_callback *ecbdata,
1041                                 struct diff_options *orig_opts,
1042                                 struct diff_filespec *one,
1043                                 struct diff_filespec *two)
1044{
1045        int i;
1046        struct diff_options *o = xmalloc(sizeof(struct diff_options));
1047        memcpy(o, orig_opts, sizeof(struct diff_options));
1048
1049        ecbdata->diff_words =
1050                xcalloc(1, sizeof(struct diff_words_data));
1051        ecbdata->diff_words->type = o->word_diff;
1052        ecbdata->diff_words->opt = o;
1053        if (!o->word_regex)
1054                o->word_regex = userdiff_word_regex(one);
1055        if (!o->word_regex)
1056                o->word_regex = userdiff_word_regex(two);
1057        if (!o->word_regex)
1058                o->word_regex = diff_word_regex_cfg;
1059        if (o->word_regex) {
1060                ecbdata->diff_words->word_regex = (regex_t *)
1061                        xmalloc(sizeof(regex_t));
1062                if (regcomp(ecbdata->diff_words->word_regex,
1063                            o->word_regex,
1064                            REG_EXTENDED | REG_NEWLINE))
1065                        die ("Invalid regular expression: %s",
1066                             o->word_regex);
1067        }
1068        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
1069                if (o->word_diff == diff_words_styles[i].type) {
1070                        ecbdata->diff_words->style =
1071                                &diff_words_styles[i];
1072                        break;
1073                }
1074        }
1075        if (want_color(o->use_color)) {
1076                struct diff_words_style *st = ecbdata->diff_words->style;
1077                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
1078                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
1079                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
1080        }
1081}
1082
1083static void free_diff_words_data(struct emit_callback *ecbdata)
1084{
1085        if (ecbdata->diff_words) {
1086                diff_words_flush(ecbdata);
1087                free (ecbdata->diff_words->opt);
1088                free (ecbdata->diff_words->minus.text.ptr);
1089                free (ecbdata->diff_words->minus.orig);
1090                free (ecbdata->diff_words->plus.text.ptr);
1091                free (ecbdata->diff_words->plus.orig);
1092                if (ecbdata->diff_words->word_regex) {
1093                        regfree(ecbdata->diff_words->word_regex);
1094                        free(ecbdata->diff_words->word_regex);
1095                }
1096                free(ecbdata->diff_words);
1097                ecbdata->diff_words = NULL;
1098        }
1099}
1100
1101const char *diff_get_color(int diff_use_color, enum color_diff ix)
1102{
1103        if (want_color(diff_use_color))
1104                return diff_colors[ix];
1105        return "";
1106}
1107
1108static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
1109{
1110        const char *cp;
1111        unsigned long allot;
1112        size_t l = len;
1113
1114        if (ecb->truncate)
1115                return ecb->truncate(line, len);
1116        cp = line;
1117        allot = l;
1118        while (0 < l) {
1119                (void) utf8_width(&cp, &l);
1120                if (!cp)
1121                        break; /* truncated in the middle? */
1122        }
1123        return allot - l;
1124}
1125
1126static void find_lno(const char *line, struct emit_callback *ecbdata)
1127{
1128        const char *p;
1129        ecbdata->lno_in_preimage = 0;
1130        ecbdata->lno_in_postimage = 0;
1131        p = strchr(line, '-');
1132        if (!p)
1133                return; /* cannot happen */
1134        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1135        p = strchr(p, '+');
1136        if (!p)
1137                return; /* cannot happen */
1138        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
1139}
1140
1141static void fn_out_consume(void *priv, char *line, unsigned long len)
1142{
1143        struct emit_callback *ecbdata = priv;
1144        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
1145        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
1146        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1147        struct diff_options *o = ecbdata->opt;
1148        char *line_prefix = "";
1149        struct strbuf *msgbuf;
1150
1151        if (o && o->output_prefix) {
1152                msgbuf = o->output_prefix(o, o->output_prefix_data);
1153                line_prefix = msgbuf->buf;
1154        }
1155
1156        if (ecbdata->header) {
1157                fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
1158                strbuf_reset(ecbdata->header);
1159                ecbdata->header = NULL;
1160        }
1161        *(ecbdata->found_changesp) = 1;
1162
1163        if (ecbdata->label_path[0]) {
1164                const char *name_a_tab, *name_b_tab;
1165
1166                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
1167                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
1168
1169                fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
1170                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
1171                fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
1172                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1173                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1174        }
1175
1176        if (diff_suppress_blank_empty
1177            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1178                line[0] = '\n';
1179                len = 1;
1180        }
1181
1182        if (line[0] == '@') {
1183                if (ecbdata->diff_words)
1184                        diff_words_flush(ecbdata);
1185                len = sane_truncate_line(ecbdata, line, len);
1186                find_lno(line, ecbdata);
1187                emit_hunk_header(ecbdata, line, len);
1188                if (line[len-1] != '\n')
1189                        putc('\n', ecbdata->opt->file);
1190                return;
1191        }
1192
1193        if (len < 1) {
1194                emit_line(ecbdata->opt, reset, reset, line, len);
1195                if (ecbdata->diff_words
1196                    && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
1197                        fputs("~\n", ecbdata->opt->file);
1198                return;
1199        }
1200
1201        if (ecbdata->diff_words) {
1202                if (line[0] == '-') {
1203                        diff_words_append(line, len,
1204                                          &ecbdata->diff_words->minus);
1205                        return;
1206                } else if (line[0] == '+') {
1207                        diff_words_append(line, len,
1208                                          &ecbdata->diff_words->plus);
1209                        return;
1210                } else if (!prefixcmp(line, "\\ ")) {
1211                        /*
1212                         * Eat the "no newline at eof" marker as if we
1213                         * saw a "+" or "-" line with nothing on it,
1214                         * and return without diff_words_flush() to
1215                         * defer processing. If this is the end of
1216                         * preimage, more "+" lines may come after it.
1217                         */
1218                        return;
1219                }
1220                diff_words_flush(ecbdata);
1221                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1222                        emit_line(ecbdata->opt, plain, reset, line, len);
1223                        fputs("~\n", ecbdata->opt->file);
1224                } else {
1225                        /*
1226                         * Skip the prefix character, if any.  With
1227                         * diff_suppress_blank_empty, there may be
1228                         * none.
1229                         */
1230                        if (line[0] != '\n') {
1231                              line++;
1232                              len--;
1233                        }
1234                        emit_line(ecbdata->opt, plain, reset, line, len);
1235                }
1236                return;
1237        }
1238
1239        if (line[0] != '+') {
1240                const char *color =
1241                        diff_get_color(ecbdata->color_diff,
1242                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
1243                ecbdata->lno_in_preimage++;
1244                if (line[0] == ' ')
1245                        ecbdata->lno_in_postimage++;
1246                emit_line(ecbdata->opt, color, reset, line, len);
1247        } else {
1248                ecbdata->lno_in_postimage++;
1249                emit_add_line(reset, ecbdata, line + 1, len - 1);
1250        }
1251}
1252
1253static char *pprint_rename(const char *a, const char *b)
1254{
1255        const char *old = a;
1256        const char *new = b;
1257        struct strbuf name = STRBUF_INIT;
1258        int pfx_length, sfx_length;
1259        int len_a = strlen(a);
1260        int len_b = strlen(b);
1261        int a_midlen, b_midlen;
1262        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1263        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1264
1265        if (qlen_a || qlen_b) {
1266                quote_c_style(a, &name, NULL, 0);
1267                strbuf_addstr(&name, " => ");
1268                quote_c_style(b, &name, NULL, 0);
1269                return strbuf_detach(&name, NULL);
1270        }
1271
1272        /* Find common prefix */
1273        pfx_length = 0;
1274        while (*old && *new && *old == *new) {
1275                if (*old == '/')
1276                        pfx_length = old - a + 1;
1277                old++;
1278                new++;
1279        }
1280
1281        /* Find common suffix */
1282        old = a + len_a;
1283        new = b + len_b;
1284        sfx_length = 0;
1285        while (a <= old && b <= new && *old == *new) {
1286                if (*old == '/')
1287                        sfx_length = len_a - (old - a);
1288                old--;
1289                new--;
1290        }
1291
1292        /*
1293         * pfx{mid-a => mid-b}sfx
1294         * {pfx-a => pfx-b}sfx
1295         * pfx{sfx-a => sfx-b}
1296         * name-a => name-b
1297         */
1298        a_midlen = len_a - pfx_length - sfx_length;
1299        b_midlen = len_b - pfx_length - sfx_length;
1300        if (a_midlen < 0)
1301                a_midlen = 0;
1302        if (b_midlen < 0)
1303                b_midlen = 0;
1304
1305        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1306        if (pfx_length + sfx_length) {
1307                strbuf_add(&name, a, pfx_length);
1308                strbuf_addch(&name, '{');
1309        }
1310        strbuf_add(&name, a + pfx_length, a_midlen);
1311        strbuf_addstr(&name, " => ");
1312        strbuf_add(&name, b + pfx_length, b_midlen);
1313        if (pfx_length + sfx_length) {
1314                strbuf_addch(&name, '}');
1315                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1316        }
1317        return strbuf_detach(&name, NULL);
1318}
1319
1320struct diffstat_t {
1321        int nr;
1322        int alloc;
1323        struct diffstat_file {
1324                char *from_name;
1325                char *name;
1326                char *print_name;
1327                unsigned is_unmerged:1;
1328                unsigned is_binary:1;
1329                unsigned is_renamed:1;
1330                unsigned is_interesting:1;
1331                uintmax_t added, deleted;
1332        } **files;
1333};
1334
1335static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1336                                          const char *name_a,
1337                                          const char *name_b)
1338{
1339        struct diffstat_file *x;
1340        x = xcalloc(sizeof (*x), 1);
1341        if (diffstat->nr == diffstat->alloc) {
1342                diffstat->alloc = alloc_nr(diffstat->alloc);
1343                diffstat->files = xrealloc(diffstat->files,
1344                                diffstat->alloc * sizeof(x));
1345        }
1346        diffstat->files[diffstat->nr++] = x;
1347        if (name_b) {
1348                x->from_name = xstrdup(name_a);
1349                x->name = xstrdup(name_b);
1350                x->is_renamed = 1;
1351        }
1352        else {
1353                x->from_name = NULL;
1354                x->name = xstrdup(name_a);
1355        }
1356        return x;
1357}
1358
1359static void diffstat_consume(void *priv, char *line, unsigned long len)
1360{
1361        struct diffstat_t *diffstat = priv;
1362        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1363
1364        if (line[0] == '+')
1365                x->added++;
1366        else if (line[0] == '-')
1367                x->deleted++;
1368}
1369
1370const char mime_boundary_leader[] = "------------";
1371
1372static int scale_linear(int it, int width, int max_change)
1373{
1374        if (!it)
1375                return 0;
1376        /*
1377         * make sure that at least one '-' or '+' is printed if
1378         * there is any change to this path. The easiest way is to
1379         * scale linearly as if the alloted width is one column shorter
1380         * than it is, and then add 1 to the result.
1381         */
1382        return 1 + (it * (width - 1) / max_change);
1383}
1384
1385static void show_name(FILE *file,
1386                      const char *prefix, const char *name, int len)
1387{
1388        fprintf(file, " %s%-*s |", prefix, len, name);
1389}
1390
1391static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1392{
1393        if (cnt <= 0)
1394                return;
1395        fprintf(file, "%s", set);
1396        while (cnt--)
1397                putc(ch, file);
1398        fprintf(file, "%s", reset);
1399}
1400
1401static void fill_print_name(struct diffstat_file *file)
1402{
1403        char *pname;
1404
1405        if (file->print_name)
1406                return;
1407
1408        if (!file->is_renamed) {
1409                struct strbuf buf = STRBUF_INIT;
1410                if (quote_c_style(file->name, &buf, NULL, 0)) {
1411                        pname = strbuf_detach(&buf, NULL);
1412                } else {
1413                        pname = file->name;
1414                        strbuf_release(&buf);
1415                }
1416        } else {
1417                pname = pprint_rename(file->from_name, file->name);
1418        }
1419        file->print_name = pname;
1420}
1421
1422int print_stat_summary(FILE *fp, int files, int insertions, int deletions)
1423{
1424        struct strbuf sb = STRBUF_INIT;
1425        int ret;
1426
1427        if (!files) {
1428                assert(insertions == 0 && deletions == 0);
1429                return fprintf(fp, "%s\n", " 0 files changed");
1430        }
1431
1432        strbuf_addf(&sb,
1433                    (files == 1) ? " %d file changed" : " %d files changed",
1434                    files);
1435
1436        /*
1437         * For binary diff, the caller may want to print "x files
1438         * changed" with insertions == 0 && deletions == 0.
1439         *
1440         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
1441         * is probably less confusing (i.e skip over "2 files changed
1442         * but nothing about added/removed lines? Is this a bug in Git?").
1443         */
1444        if (insertions || deletions == 0) {
1445                /*
1446                 * TRANSLATORS: "+" in (+) is a line addition marker;
1447                 * do not translate it.
1448                 */
1449                strbuf_addf(&sb,
1450                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
1451                            insertions);
1452        }
1453
1454        if (deletions || insertions == 0) {
1455                /*
1456                 * TRANSLATORS: "-" in (-) is a line removal marker;
1457                 * do not translate it.
1458                 */
1459                strbuf_addf(&sb,
1460                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
1461                            deletions);
1462        }
1463        strbuf_addch(&sb, '\n');
1464        ret = fputs(sb.buf, fp);
1465        strbuf_release(&sb);
1466        return ret;
1467}
1468
1469static void show_stats(struct diffstat_t *data, struct diff_options *options)
1470{
1471        int i, len, add, del, adds = 0, dels = 0;
1472        uintmax_t max_change = 0, max_len = 0;
1473        int total_files = data->nr, count;
1474        int width, name_width, graph_width, number_width = 0, bin_width = 0;
1475        const char *reset, *add_c, *del_c;
1476        const char *line_prefix = "";
1477        int extra_shown = 0;
1478        struct strbuf *msg = NULL;
1479
1480        if (data->nr == 0)
1481                return;
1482
1483        if (options->output_prefix) {
1484                msg = options->output_prefix(options, options->output_prefix_data);
1485                line_prefix = msg->buf;
1486        }
1487
1488        count = options->stat_count ? options->stat_count : data->nr;
1489
1490        reset = diff_get_color_opt(options, DIFF_RESET);
1491        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1492        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1493
1494        /*
1495         * Find the longest filename and max number of changes
1496         */
1497        for (i = 0; (i < count) && (i < data->nr); i++) {
1498                struct diffstat_file *file = data->files[i];
1499                uintmax_t change = file->added + file->deleted;
1500                if (!data->files[i]->is_interesting &&
1501                         (change == 0)) {
1502                        count++; /* not shown == room for one more */
1503                        continue;
1504                }
1505                fill_print_name(file);
1506                len = strlen(file->print_name);
1507                if (max_len < len)
1508                        max_len = len;
1509
1510                if (file->is_unmerged) {
1511                        /* "Unmerged" is 8 characters */
1512                        bin_width = bin_width < 8 ? 8 : bin_width;
1513                        continue;
1514                }
1515                if (file->is_binary) {
1516                        /* "Bin XXX -> YYY bytes" */
1517                        int w = 14 + decimal_width(file->added)
1518                                + decimal_width(file->deleted);
1519                        bin_width = bin_width < w ? w : bin_width;
1520                        /* Display change counts aligned with "Bin" */
1521                        number_width = 3;
1522                        continue;
1523                }
1524
1525                if (max_change < change)
1526                        max_change = change;
1527        }
1528        count = i; /* min(count, data->nr) */
1529
1530        /*
1531         * We have width = stat_width or term_columns() columns total.
1532         * We want a maximum of min(max_len, stat_name_width) for the name part.
1533         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
1534         * We also need 1 for " " and 4 + decimal_width(max_change)
1535         * for " | NNNN " and one the empty column at the end, altogether
1536         * 6 + decimal_width(max_change).
1537         *
1538         * If there's not enough space, we will use the smaller of
1539         * stat_name_width (if set) and 5/8*width for the filename,
1540         * and the rest for constant elements + graph part, but no more
1541         * than stat_graph_width for the graph part.
1542         * (5/8 gives 50 for filename and 30 for the constant parts + graph
1543         * for the standard terminal size).
1544         *
1545         * In other words: stat_width limits the maximum width, and
1546         * stat_name_width fixes the maximum width of the filename,
1547         * and is also used to divide available columns if there
1548         * aren't enough.
1549         *
1550         * Binary files are displayed with "Bin XXX -> YYY bytes"
1551         * instead of the change count and graph. This part is treated
1552         * similarly to the graph part, except that it is not
1553         * "scaled". If total width is too small to accomodate the
1554         * guaranteed minimum width of the filename part and the
1555         * separators and this message, this message will "overflow"
1556         * making the line longer than the maximum width.
1557         */
1558
1559        if (options->stat_width == -1)
1560                width = term_columns() - options->output_prefix_length;
1561        else
1562                width = options->stat_width ? options->stat_width : 80;
1563        number_width = decimal_width(max_change) > number_width ?
1564                decimal_width(max_change) : number_width;
1565
1566        if (options->stat_graph_width == -1)
1567                options->stat_graph_width = diff_stat_graph_width;
1568
1569        /*
1570         * Guarantee 3/8*16==6 for the graph part
1571         * and 5/8*16==10 for the filename part
1572         */
1573        if (width < 16 + 6 + number_width)
1574                width = 16 + 6 + number_width;
1575
1576        /*
1577         * First assign sizes that are wanted, ignoring available width.
1578         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
1579         * starting from "XXX" should fit in graph_width.
1580         */
1581        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
1582        if (options->stat_graph_width &&
1583            options->stat_graph_width < graph_width)
1584                graph_width = options->stat_graph_width;
1585
1586        name_width = (options->stat_name_width > 0 &&
1587                      options->stat_name_width < max_len) ?
1588                options->stat_name_width : max_len;
1589
1590        /*
1591         * Adjust adjustable widths not to exceed maximum width
1592         */
1593        if (name_width + number_width + 6 + graph_width > width) {
1594                if (graph_width > width * 3/8 - number_width - 6) {
1595                        graph_width = width * 3/8 - number_width - 6;
1596                        if (graph_width < 6)
1597                                graph_width = 6;
1598                }
1599
1600                if (options->stat_graph_width &&
1601                    graph_width > options->stat_graph_width)
1602                        graph_width = options->stat_graph_width;
1603                if (name_width > width - number_width - 6 - graph_width)
1604                        name_width = width - number_width - 6 - graph_width;
1605                else
1606                        graph_width = width - number_width - 6 - name_width;
1607        }
1608
1609        /*
1610         * From here name_width is the width of the name area,
1611         * and graph_width is the width of the graph area.
1612         * max_change is used to scale graph properly.
1613         */
1614        for (i = 0; i < count; i++) {
1615                const char *prefix = "";
1616                char *name = data->files[i]->print_name;
1617                uintmax_t added = data->files[i]->added;
1618                uintmax_t deleted = data->files[i]->deleted;
1619                int name_len;
1620
1621                if (!data->files[i]->is_interesting &&
1622                         (added + deleted == 0)) {
1623                        total_files--;
1624                        continue;
1625                }
1626                /*
1627                 * "scale" the filename
1628                 */
1629                len = name_width;
1630                name_len = strlen(name);
1631                if (name_width < name_len) {
1632                        char *slash;
1633                        prefix = "...";
1634                        len -= 3;
1635                        name += name_len - len;
1636                        slash = strchr(name, '/');
1637                        if (slash)
1638                                name = slash;
1639                }
1640
1641                if (data->files[i]->is_binary) {
1642                        fprintf(options->file, "%s", line_prefix);
1643                        show_name(options->file, prefix, name, len);
1644                        fprintf(options->file, " %*s", number_width, "Bin");
1645                        if (!added && !deleted) {
1646                                putc('\n', options->file);
1647                                continue;
1648                        }
1649                        fprintf(options->file, " %s%"PRIuMAX"%s",
1650                                del_c, deleted, reset);
1651                        fprintf(options->file, " -> ");
1652                        fprintf(options->file, "%s%"PRIuMAX"%s",
1653                                add_c, added, reset);
1654                        fprintf(options->file, " bytes");
1655                        fprintf(options->file, "\n");
1656                        continue;
1657                }
1658                else if (data->files[i]->is_unmerged) {
1659                        fprintf(options->file, "%s", line_prefix);
1660                        show_name(options->file, prefix, name, len);
1661                        fprintf(options->file, " Unmerged\n");
1662                        continue;
1663                }
1664
1665                /*
1666                 * scale the add/delete
1667                 */
1668                add = added;
1669                del = deleted;
1670                adds += add;
1671                dels += del;
1672
1673                if (graph_width <= max_change) {
1674                        int total = add + del;
1675
1676                        total = scale_linear(add + del, graph_width, max_change);
1677                        if (total < 2 && add && del)
1678                                /* width >= 2 due to the sanity check */
1679                                total = 2;
1680                        if (add < del) {
1681                                add = scale_linear(add, graph_width, max_change);
1682                                del = total - add;
1683                        } else {
1684                                del = scale_linear(del, graph_width, max_change);
1685                                add = total - del;
1686                        }
1687                }
1688                fprintf(options->file, "%s", line_prefix);
1689                show_name(options->file, prefix, name, len);
1690                fprintf(options->file, " %*"PRIuMAX"%s",
1691                        number_width, added + deleted,
1692                        added + deleted ? " " : "");
1693                show_graph(options->file, '+', add, add_c, reset);
1694                show_graph(options->file, '-', del, del_c, reset);
1695                fprintf(options->file, "\n");
1696        }
1697        for (i = count; i < data->nr; i++) {
1698                uintmax_t added = data->files[i]->added;
1699                uintmax_t deleted = data->files[i]->deleted;
1700                if (!data->files[i]->is_interesting &&
1701                         (added + deleted == 0)) {
1702                        total_files--;
1703                        continue;
1704                }
1705                adds += added;
1706                dels += deleted;
1707                if (!extra_shown)
1708                        fprintf(options->file, "%s ...\n", line_prefix);
1709                extra_shown = 1;
1710        }
1711        fprintf(options->file, "%s", line_prefix);
1712        print_stat_summary(options->file, total_files, adds, dels);
1713}
1714
1715static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1716{
1717        int i, adds = 0, dels = 0, total_files = data->nr;
1718
1719        if (data->nr == 0)
1720                return;
1721
1722        for (i = 0; i < data->nr; i++) {
1723                int added = data->files[i]->added;
1724                int deleted= data->files[i]->deleted;
1725
1726                if (data->files[i]->is_unmerged)
1727                        continue;
1728                if (!data->files[i]->is_interesting && (added + deleted == 0)) {
1729                        total_files--;
1730                } else if (!data->files[i]->is_binary) { /* don't count bytes */
1731                        adds += added;
1732                        dels += deleted;
1733                }
1734        }
1735        if (options->output_prefix) {
1736                struct strbuf *msg = NULL;
1737                msg = options->output_prefix(options,
1738                                options->output_prefix_data);
1739                fprintf(options->file, "%s", msg->buf);
1740        }
1741        print_stat_summary(options->file, total_files, adds, dels);
1742}
1743
1744static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1745{
1746        int i;
1747
1748        if (data->nr == 0)
1749                return;
1750
1751        for (i = 0; i < data->nr; i++) {
1752                struct diffstat_file *file = data->files[i];
1753
1754                if (options->output_prefix) {
1755                        struct strbuf *msg = NULL;
1756                        msg = options->output_prefix(options,
1757                                        options->output_prefix_data);
1758                        fprintf(options->file, "%s", msg->buf);
1759                }
1760
1761                if (file->is_binary)
1762                        fprintf(options->file, "-\t-\t");
1763                else
1764                        fprintf(options->file,
1765                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1766                                file->added, file->deleted);
1767                if (options->line_termination) {
1768                        fill_print_name(file);
1769                        if (!file->is_renamed)
1770                                write_name_quoted(file->name, options->file,
1771                                                  options->line_termination);
1772                        else {
1773                                fputs(file->print_name, options->file);
1774                                putc(options->line_termination, options->file);
1775                        }
1776                } else {
1777                        if (file->is_renamed) {
1778                                putc('\0', options->file);
1779                                write_name_quoted(file->from_name, options->file, '\0');
1780                        }
1781                        write_name_quoted(file->name, options->file, '\0');
1782                }
1783        }
1784}
1785
1786struct dirstat_file {
1787        const char *name;
1788        unsigned long changed;
1789};
1790
1791struct dirstat_dir {
1792        struct dirstat_file *files;
1793        int alloc, nr, permille, cumulative;
1794};
1795
1796static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1797                unsigned long changed, const char *base, int baselen)
1798{
1799        unsigned long this_dir = 0;
1800        unsigned int sources = 0;
1801        const char *line_prefix = "";
1802        struct strbuf *msg = NULL;
1803
1804        if (opt->output_prefix) {
1805                msg = opt->output_prefix(opt, opt->output_prefix_data);
1806                line_prefix = msg->buf;
1807        }
1808
1809        while (dir->nr) {
1810                struct dirstat_file *f = dir->files;
1811                int namelen = strlen(f->name);
1812                unsigned long this;
1813                char *slash;
1814
1815                if (namelen < baselen)
1816                        break;
1817                if (memcmp(f->name, base, baselen))
1818                        break;
1819                slash = strchr(f->name + baselen, '/');
1820                if (slash) {
1821                        int newbaselen = slash + 1 - f->name;
1822                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1823                        sources++;
1824                } else {
1825                        this = f->changed;
1826                        dir->files++;
1827                        dir->nr--;
1828                        sources += 2;
1829                }
1830                this_dir += this;
1831        }
1832
1833        /*
1834         * We don't report dirstat's for
1835         *  - the top level
1836         *  - or cases where everything came from a single directory
1837         *    under this directory (sources == 1).
1838         */
1839        if (baselen && sources != 1) {
1840                if (this_dir) {
1841                        int permille = this_dir * 1000 / changed;
1842                        if (permille >= dir->permille) {
1843                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1844                                        permille / 10, permille % 10, baselen, base);
1845                                if (!dir->cumulative)
1846                                        return 0;
1847                        }
1848                }
1849        }
1850        return this_dir;
1851}
1852
1853static int dirstat_compare(const void *_a, const void *_b)
1854{
1855        const struct dirstat_file *a = _a;
1856        const struct dirstat_file *b = _b;
1857        return strcmp(a->name, b->name);
1858}
1859
1860static void show_dirstat(struct diff_options *options)
1861{
1862        int i;
1863        unsigned long changed;
1864        struct dirstat_dir dir;
1865        struct diff_queue_struct *q = &diff_queued_diff;
1866
1867        dir.files = NULL;
1868        dir.alloc = 0;
1869        dir.nr = 0;
1870        dir.permille = options->dirstat_permille;
1871        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1872
1873        changed = 0;
1874        for (i = 0; i < q->nr; i++) {
1875                struct diff_filepair *p = q->queue[i];
1876                const char *name;
1877                unsigned long copied, added, damage;
1878                int content_changed;
1879
1880                name = p->two->path ? p->two->path : p->one->path;
1881
1882                if (p->one->sha1_valid && p->two->sha1_valid)
1883                        content_changed = hashcmp(p->one->sha1, p->two->sha1);
1884                else
1885                        content_changed = 1;
1886
1887                if (!content_changed) {
1888                        /*
1889                         * The SHA1 has not changed, so pre-/post-content is
1890                         * identical. We can therefore skip looking at the
1891                         * file contents altogether.
1892                         */
1893                        damage = 0;
1894                        goto found_damage;
1895                }
1896
1897                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1898                        /*
1899                         * In --dirstat-by-file mode, we don't really need to
1900                         * look at the actual file contents at all.
1901                         * The fact that the SHA1 changed is enough for us to
1902                         * add this file to the list of results
1903                         * (with each file contributing equal damage).
1904                         */
1905                        damage = 1;
1906                        goto found_damage;
1907                }
1908
1909                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1910                        diff_populate_filespec(p->one, 0);
1911                        diff_populate_filespec(p->two, 0);
1912                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1913                                               &copied, &added);
1914                        diff_free_filespec_data(p->one);
1915                        diff_free_filespec_data(p->two);
1916                } else if (DIFF_FILE_VALID(p->one)) {
1917                        diff_populate_filespec(p->one, 1);
1918                        copied = added = 0;
1919                        diff_free_filespec_data(p->one);
1920                } else if (DIFF_FILE_VALID(p->two)) {
1921                        diff_populate_filespec(p->two, 1);
1922                        copied = 0;
1923                        added = p->two->size;
1924                        diff_free_filespec_data(p->two);
1925                } else
1926                        continue;
1927
1928                /*
1929                 * Original minus copied is the removed material,
1930                 * added is the new material.  They are both damages
1931                 * made to the preimage.
1932                 * If the resulting damage is zero, we know that
1933                 * diffcore_count_changes() considers the two entries to
1934                 * be identical, but since content_changed is true, we
1935                 * know that there must have been _some_ kind of change,
1936                 * so we force all entries to have damage > 0.
1937                 */
1938                damage = (p->one->size - copied) + added;
1939                if (!damage)
1940                        damage = 1;
1941
1942found_damage:
1943                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1944                dir.files[dir.nr].name = name;
1945                dir.files[dir.nr].changed = damage;
1946                changed += damage;
1947                dir.nr++;
1948        }
1949
1950        /* This can happen even with many files, if everything was renames */
1951        if (!changed)
1952                return;
1953
1954        /* Show all directories with more than x% of the changes */
1955        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1956        gather_dirstat(options, &dir, changed, "", 0);
1957}
1958
1959static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
1960{
1961        int i;
1962        unsigned long changed;
1963        struct dirstat_dir dir;
1964
1965        if (data->nr == 0)
1966                return;
1967
1968        dir.files = NULL;
1969        dir.alloc = 0;
1970        dir.nr = 0;
1971        dir.permille = options->dirstat_permille;
1972        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1973
1974        changed = 0;
1975        for (i = 0; i < data->nr; i++) {
1976                struct diffstat_file *file = data->files[i];
1977                unsigned long damage = file->added + file->deleted;
1978                if (file->is_binary)
1979                        /*
1980                         * binary files counts bytes, not lines. Must find some
1981                         * way to normalize binary bytes vs. textual lines.
1982                         * The following heuristic assumes that there are 64
1983                         * bytes per "line".
1984                         * This is stupid and ugly, but very cheap...
1985                         */
1986                        damage = (damage + 63) / 64;
1987                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1988                dir.files[dir.nr].name = file->name;
1989                dir.files[dir.nr].changed = damage;
1990                changed += damage;
1991                dir.nr++;
1992        }
1993
1994        /* This can happen even with many files, if everything was renames */
1995        if (!changed)
1996                return;
1997
1998        /* Show all directories with more than x% of the changes */
1999        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
2000        gather_dirstat(options, &dir, changed, "", 0);
2001}
2002
2003static void free_diffstat_info(struct diffstat_t *diffstat)
2004{
2005        int i;
2006        for (i = 0; i < diffstat->nr; i++) {
2007                struct diffstat_file *f = diffstat->files[i];
2008                if (f->name != f->print_name)
2009                        free(f->print_name);
2010                free(f->name);
2011                free(f->from_name);
2012                free(f);
2013        }
2014        free(diffstat->files);
2015}
2016
2017struct checkdiff_t {
2018        const char *filename;
2019        int lineno;
2020        int conflict_marker_size;
2021        struct diff_options *o;
2022        unsigned ws_rule;
2023        unsigned status;
2024};
2025
2026static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
2027{
2028        char firstchar;
2029        int cnt;
2030
2031        if (len < marker_size + 1)
2032                return 0;
2033        firstchar = line[0];
2034        switch (firstchar) {
2035        case '=': case '>': case '<': case '|':
2036                break;
2037        default:
2038                return 0;
2039        }
2040        for (cnt = 1; cnt < marker_size; cnt++)
2041                if (line[cnt] != firstchar)
2042                        return 0;
2043        /* line[1] thru line[marker_size-1] are same as firstchar */
2044        if (len < marker_size + 1 || !isspace(line[marker_size]))
2045                return 0;
2046        return 1;
2047}
2048
2049static void checkdiff_consume(void *priv, char *line, unsigned long len)
2050{
2051        struct checkdiff_t *data = priv;
2052        int marker_size = data->conflict_marker_size;
2053        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
2054        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
2055        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
2056        char *err;
2057        char *line_prefix = "";
2058        struct strbuf *msgbuf;
2059
2060        assert(data->o);
2061        if (data->o->output_prefix) {
2062                msgbuf = data->o->output_prefix(data->o,
2063                        data->o->output_prefix_data);
2064                line_prefix = msgbuf->buf;
2065        }
2066
2067        if (line[0] == '+') {
2068                unsigned bad;
2069                data->lineno++;
2070                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
2071                        data->status |= 1;
2072                        fprintf(data->o->file,
2073                                "%s%s:%d: leftover conflict marker\n",
2074                                line_prefix, data->filename, data->lineno);
2075                }
2076                bad = ws_check(line + 1, len - 1, data->ws_rule);
2077                if (!bad)
2078                        return;
2079                data->status |= bad;
2080                err = whitespace_error_string(bad);
2081                fprintf(data->o->file, "%s%s:%d: %s.\n",
2082                        line_prefix, data->filename, data->lineno, err);
2083                free(err);
2084                emit_line(data->o, set, reset, line, 1);
2085                ws_check_emit(line + 1, len - 1, data->ws_rule,
2086                              data->o->file, set, reset, ws);
2087        } else if (line[0] == ' ') {
2088                data->lineno++;
2089        } else if (line[0] == '@') {
2090                char *plus = strchr(line, '+');
2091                if (plus)
2092                        data->lineno = strtol(plus, NULL, 10) - 1;
2093                else
2094                        die("invalid diff");
2095        }
2096}
2097
2098static unsigned char *deflate_it(char *data,
2099                                 unsigned long size,
2100                                 unsigned long *result_size)
2101{
2102        int bound;
2103        unsigned char *deflated;
2104        git_zstream stream;
2105
2106        memset(&stream, 0, sizeof(stream));
2107        git_deflate_init(&stream, zlib_compression_level);
2108        bound = git_deflate_bound(&stream, size);
2109        deflated = xmalloc(bound);
2110        stream.next_out = deflated;
2111        stream.avail_out = bound;
2112
2113        stream.next_in = (unsigned char *)data;
2114        stream.avail_in = size;
2115        while (git_deflate(&stream, Z_FINISH) == Z_OK)
2116                ; /* nothing */
2117        git_deflate_end(&stream);
2118        *result_size = stream.total_out;
2119        return deflated;
2120}
2121
2122static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
2123{
2124        void *cp;
2125        void *delta;
2126        void *deflated;
2127        void *data;
2128        unsigned long orig_size;
2129        unsigned long delta_size;
2130        unsigned long deflate_size;
2131        unsigned long data_size;
2132
2133        /* We could do deflated delta, or we could do just deflated two,
2134         * whichever is smaller.
2135         */
2136        delta = NULL;
2137        deflated = deflate_it(two->ptr, two->size, &deflate_size);
2138        if (one->size && two->size) {
2139                delta = diff_delta(one->ptr, one->size,
2140                                   two->ptr, two->size,
2141                                   &delta_size, deflate_size);
2142                if (delta) {
2143                        void *to_free = delta;
2144                        orig_size = delta_size;
2145                        delta = deflate_it(delta, delta_size, &delta_size);
2146                        free(to_free);
2147                }
2148        }
2149
2150        if (delta && delta_size < deflate_size) {
2151                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
2152                free(deflated);
2153                data = delta;
2154                data_size = delta_size;
2155        }
2156        else {
2157                fprintf(file, "%sliteral %lu\n", prefix, two->size);
2158                free(delta);
2159                data = deflated;
2160                data_size = deflate_size;
2161        }
2162
2163        /* emit data encoded in base85 */
2164        cp = data;
2165        while (data_size) {
2166                int bytes = (52 < data_size) ? 52 : data_size;
2167                char line[70];
2168                data_size -= bytes;
2169                if (bytes <= 26)
2170                        line[0] = bytes + 'A' - 1;
2171                else
2172                        line[0] = bytes - 26 + 'a' - 1;
2173                encode_85(line + 1, cp, bytes);
2174                cp = (char *) cp + bytes;
2175                fprintf(file, "%s", prefix);
2176                fputs(line, file);
2177                fputc('\n', file);
2178        }
2179        fprintf(file, "%s\n", prefix);
2180        free(data);
2181}
2182
2183static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
2184{
2185        fprintf(file, "%sGIT binary patch\n", prefix);
2186        emit_binary_diff_body(file, one, two, prefix);
2187        emit_binary_diff_body(file, two, one, prefix);
2188}
2189
2190int diff_filespec_is_binary(struct diff_filespec *one)
2191{
2192        if (one->is_binary == -1) {
2193                diff_filespec_load_driver(one);
2194                if (one->driver->binary != -1)
2195                        one->is_binary = one->driver->binary;
2196                else {
2197                        if (!one->data && DIFF_FILE_VALID(one))
2198                                diff_populate_filespec(one, 0);
2199                        if (one->data)
2200                                one->is_binary = buffer_is_binary(one->data,
2201                                                one->size);
2202                        if (one->is_binary == -1)
2203                                one->is_binary = 0;
2204                }
2205        }
2206        return one->is_binary;
2207}
2208
2209static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
2210{
2211        diff_filespec_load_driver(one);
2212        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
2213}
2214
2215void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
2216{
2217        if (!options->a_prefix)
2218                options->a_prefix = a;
2219        if (!options->b_prefix)
2220                options->b_prefix = b;
2221}
2222
2223struct userdiff_driver *get_textconv(struct diff_filespec *one)
2224{
2225        if (!DIFF_FILE_VALID(one))
2226                return NULL;
2227
2228        diff_filespec_load_driver(one);
2229        return userdiff_get_textconv(one->driver);
2230}
2231
2232static void builtin_diff(const char *name_a,
2233                         const char *name_b,
2234                         struct diff_filespec *one,
2235                         struct diff_filespec *two,
2236                         const char *xfrm_msg,
2237                         int must_show_header,
2238                         struct diff_options *o,
2239                         int complete_rewrite)
2240{
2241        mmfile_t mf1, mf2;
2242        const char *lbl[2];
2243        char *a_one, *b_two;
2244        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
2245        const char *reset = diff_get_color_opt(o, DIFF_RESET);
2246        const char *a_prefix, *b_prefix;
2247        struct userdiff_driver *textconv_one = NULL;
2248        struct userdiff_driver *textconv_two = NULL;
2249        struct strbuf header = STRBUF_INIT;
2250        struct strbuf *msgbuf;
2251        char *line_prefix = "";
2252
2253        if (o->output_prefix) {
2254                msgbuf = o->output_prefix(o, o->output_prefix_data);
2255                line_prefix = msgbuf->buf;
2256        }
2257
2258        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
2259                        (!one->mode || S_ISGITLINK(one->mode)) &&
2260                        (!two->mode || S_ISGITLINK(two->mode))) {
2261                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2262                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2263                show_submodule_summary(o->file, one ? one->path : two->path,
2264                                one->sha1, two->sha1, two->dirty_submodule,
2265                                meta, del, add, reset);
2266                return;
2267        }
2268
2269        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
2270                textconv_one = get_textconv(one);
2271                textconv_two = get_textconv(two);
2272        }
2273
2274        diff_set_mnemonic_prefix(o, "a/", "b/");
2275        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
2276                a_prefix = o->b_prefix;
2277                b_prefix = o->a_prefix;
2278        } else {
2279                a_prefix = o->a_prefix;
2280                b_prefix = o->b_prefix;
2281        }
2282
2283        /* Never use a non-valid filename anywhere if at all possible */
2284        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
2285        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
2286
2287        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
2288        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
2289        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
2290        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
2291        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
2292        if (lbl[0][0] == '/') {
2293                /* /dev/null */
2294                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
2295                if (xfrm_msg)
2296                        strbuf_addstr(&header, xfrm_msg);
2297                must_show_header = 1;
2298        }
2299        else if (lbl[1][0] == '/') {
2300                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
2301                if (xfrm_msg)
2302                        strbuf_addstr(&header, xfrm_msg);
2303                must_show_header = 1;
2304        }
2305        else {
2306                if (one->mode != two->mode) {
2307                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
2308                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
2309                        must_show_header = 1;
2310                }
2311                if (xfrm_msg)
2312                        strbuf_addstr(&header, xfrm_msg);
2313
2314                /*
2315                 * we do not run diff between different kind
2316                 * of objects.
2317                 */
2318                if ((one->mode ^ two->mode) & S_IFMT)
2319                        goto free_ab_and_return;
2320                if (complete_rewrite &&
2321                    (textconv_one || !diff_filespec_is_binary(one)) &&
2322                    (textconv_two || !diff_filespec_is_binary(two))) {
2323                        fprintf(o->file, "%s", header.buf);
2324                        strbuf_reset(&header);
2325                        emit_rewrite_diff(name_a, name_b, one, two,
2326                                                textconv_one, textconv_two, o);
2327                        o->found_changes = 1;
2328                        goto free_ab_and_return;
2329                }
2330        }
2331
2332        if (o->irreversible_delete && lbl[1][0] == '/') {
2333                fprintf(o->file, "%s", header.buf);
2334                strbuf_reset(&header);
2335                goto free_ab_and_return;
2336        } else if (!DIFF_OPT_TST(o, TEXT) &&
2337            ( (!textconv_one && diff_filespec_is_binary(one)) ||
2338              (!textconv_two && diff_filespec_is_binary(two)) )) {
2339                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2340                        die("unable to read files to diff");
2341                /* Quite common confusing case */
2342                if (mf1.size == mf2.size &&
2343                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2344                        if (must_show_header)
2345                                fprintf(o->file, "%s", header.buf);
2346                        goto free_ab_and_return;
2347                }
2348                fprintf(o->file, "%s", header.buf);
2349                strbuf_reset(&header);
2350                if (DIFF_OPT_TST(o, BINARY))
2351                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2352                else
2353                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2354                                line_prefix, lbl[0], lbl[1]);
2355                o->found_changes = 1;
2356        } else {
2357                /* Crazy xdl interfaces.. */
2358                const char *diffopts = getenv("GIT_DIFF_OPTS");
2359                xpparam_t xpp;
2360                xdemitconf_t xecfg;
2361                struct emit_callback ecbdata;
2362                const struct userdiff_funcname *pe;
2363
2364                if (must_show_header) {
2365                        fprintf(o->file, "%s", header.buf);
2366                        strbuf_reset(&header);
2367                }
2368
2369                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2370                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2371
2372                pe = diff_funcname_pattern(one);
2373                if (!pe)
2374                        pe = diff_funcname_pattern(two);
2375
2376                memset(&xpp, 0, sizeof(xpp));
2377                memset(&xecfg, 0, sizeof(xecfg));
2378                memset(&ecbdata, 0, sizeof(ecbdata));
2379                ecbdata.label_path = lbl;
2380                ecbdata.color_diff = want_color(o->use_color);
2381                ecbdata.found_changesp = &o->found_changes;
2382                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
2383                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2384                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2385                ecbdata.opt = o;
2386                ecbdata.header = header.len ? &header : NULL;
2387                xpp.flags = o->xdl_opts;
2388                xecfg.ctxlen = o->context;
2389                xecfg.interhunkctxlen = o->interhunkcontext;
2390                xecfg.flags = XDL_EMIT_FUNCNAMES;
2391                if (DIFF_OPT_TST(o, FUNCCONTEXT))
2392                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
2393                if (pe)
2394                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2395                if (!diffopts)
2396                        ;
2397                else if (!prefixcmp(diffopts, "--unified="))
2398                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2399                else if (!prefixcmp(diffopts, "-u"))
2400                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2401                if (o->word_diff)
2402                        init_diff_words_data(&ecbdata, o, one, two);
2403                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2404                              &xpp, &xecfg);
2405                if (o->word_diff)
2406                        free_diff_words_data(&ecbdata);
2407                if (textconv_one)
2408                        free(mf1.ptr);
2409                if (textconv_two)
2410                        free(mf2.ptr);
2411                xdiff_clear_find_func(&xecfg);
2412        }
2413
2414 free_ab_and_return:
2415        strbuf_release(&header);
2416        diff_free_filespec_data(one);
2417        diff_free_filespec_data(two);
2418        free(a_one);
2419        free(b_two);
2420        return;
2421}
2422
2423static void builtin_diffstat(const char *name_a, const char *name_b,
2424                             struct diff_filespec *one,
2425                             struct diff_filespec *two,
2426                             struct diffstat_t *diffstat,
2427                             struct diff_options *o,
2428                             struct diff_filepair *p)
2429{
2430        mmfile_t mf1, mf2;
2431        struct diffstat_file *data;
2432        int same_contents;
2433        int complete_rewrite = 0;
2434
2435        if (!DIFF_PAIR_UNMERGED(p)) {
2436                if (p->status == DIFF_STATUS_MODIFIED && p->score)
2437                        complete_rewrite = 1;
2438        }
2439
2440        data = diffstat_add(diffstat, name_a, name_b);
2441        data->is_interesting = p->status != 0;
2442
2443        if (!one || !two) {
2444                data->is_unmerged = 1;
2445                return;
2446        }
2447
2448        same_contents = !hashcmp(one->sha1, two->sha1);
2449
2450        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2451                data->is_binary = 1;
2452                if (same_contents) {
2453                        data->added = 0;
2454                        data->deleted = 0;
2455                } else {
2456                        data->added = diff_filespec_size(two);
2457                        data->deleted = diff_filespec_size(one);
2458                }
2459        }
2460
2461        else if (complete_rewrite) {
2462                diff_populate_filespec(one, 0);
2463                diff_populate_filespec(two, 0);
2464                data->deleted = count_lines(one->data, one->size);
2465                data->added = count_lines(two->data, two->size);
2466        }
2467
2468        else if (!same_contents) {
2469                /* Crazy xdl interfaces.. */
2470                xpparam_t xpp;
2471                xdemitconf_t xecfg;
2472
2473                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2474                        die("unable to read files to diff");
2475
2476                memset(&xpp, 0, sizeof(xpp));
2477                memset(&xecfg, 0, sizeof(xecfg));
2478                xpp.flags = o->xdl_opts;
2479                xecfg.ctxlen = o->context;
2480                xecfg.interhunkctxlen = o->interhunkcontext;
2481                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2482                              &xpp, &xecfg);
2483        }
2484
2485        diff_free_filespec_data(one);
2486        diff_free_filespec_data(two);
2487}
2488
2489static void builtin_checkdiff(const char *name_a, const char *name_b,
2490                              const char *attr_path,
2491                              struct diff_filespec *one,
2492                              struct diff_filespec *two,
2493                              struct diff_options *o)
2494{
2495        mmfile_t mf1, mf2;
2496        struct checkdiff_t data;
2497
2498        if (!two)
2499                return;
2500
2501        memset(&data, 0, sizeof(data));
2502        data.filename = name_b ? name_b : name_a;
2503        data.lineno = 0;
2504        data.o = o;
2505        data.ws_rule = whitespace_rule(attr_path);
2506        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2507
2508        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2509                die("unable to read files to diff");
2510
2511        /*
2512         * All the other codepaths check both sides, but not checking
2513         * the "old" side here is deliberate.  We are checking the newly
2514         * introduced changes, and as long as the "new" side is text, we
2515         * can and should check what it introduces.
2516         */
2517        if (diff_filespec_is_binary(two))
2518                goto free_and_return;
2519        else {
2520                /* Crazy xdl interfaces.. */
2521                xpparam_t xpp;
2522                xdemitconf_t xecfg;
2523
2524                memset(&xpp, 0, sizeof(xpp));
2525                memset(&xecfg, 0, sizeof(xecfg));
2526                xecfg.ctxlen = 1; /* at least one context line */
2527                xpp.flags = 0;
2528                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2529                              &xpp, &xecfg);
2530
2531                if (data.ws_rule & WS_BLANK_AT_EOF) {
2532                        struct emit_callback ecbdata;
2533                        int blank_at_eof;
2534
2535                        ecbdata.ws_rule = data.ws_rule;
2536                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2537                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2538
2539                        if (blank_at_eof) {
2540                                static char *err;
2541                                if (!err)
2542                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2543                                fprintf(o->file, "%s:%d: %s.\n",
2544                                        data.filename, blank_at_eof, err);
2545                                data.status = 1; /* report errors */
2546                        }
2547                }
2548        }
2549 free_and_return:
2550        diff_free_filespec_data(one);
2551        diff_free_filespec_data(two);
2552        if (data.status)
2553                DIFF_OPT_SET(o, CHECK_FAILED);
2554}
2555
2556struct diff_filespec *alloc_filespec(const char *path)
2557{
2558        int namelen = strlen(path);
2559        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2560
2561        memset(spec, 0, sizeof(*spec));
2562        spec->path = (char *)(spec + 1);
2563        memcpy(spec->path, path, namelen+1);
2564        spec->count = 1;
2565        spec->is_binary = -1;
2566        return spec;
2567}
2568
2569void free_filespec(struct diff_filespec *spec)
2570{
2571        if (!--spec->count) {
2572                diff_free_filespec_data(spec);
2573                free(spec);
2574        }
2575}
2576
2577void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2578                   int sha1_valid, unsigned short mode)
2579{
2580        if (mode) {
2581                spec->mode = canon_mode(mode);
2582                hashcpy(spec->sha1, sha1);
2583                spec->sha1_valid = sha1_valid;
2584        }
2585}
2586
2587/*
2588 * Given a name and sha1 pair, if the index tells us the file in
2589 * the work tree has that object contents, return true, so that
2590 * prepare_temp_file() does not have to inflate and extract.
2591 */
2592static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2593{
2594        struct cache_entry *ce;
2595        struct stat st;
2596        int pos, len;
2597
2598        /*
2599         * We do not read the cache ourselves here, because the
2600         * benchmark with my previous version that always reads cache
2601         * shows that it makes things worse for diff-tree comparing
2602         * two linux-2.6 kernel trees in an already checked out work
2603         * tree.  This is because most diff-tree comparisons deal with
2604         * only a small number of files, while reading the cache is
2605         * expensive for a large project, and its cost outweighs the
2606         * savings we get by not inflating the object to a temporary
2607         * file.  Practically, this code only helps when we are used
2608         * by diff-cache --cached, which does read the cache before
2609         * calling us.
2610         */
2611        if (!active_cache)
2612                return 0;
2613
2614        /* We want to avoid the working directory if our caller
2615         * doesn't need the data in a normal file, this system
2616         * is rather slow with its stat/open/mmap/close syscalls,
2617         * and the object is contained in a pack file.  The pack
2618         * is probably already open and will be faster to obtain
2619         * the data through than the working directory.  Loose
2620         * objects however would tend to be slower as they need
2621         * to be individually opened and inflated.
2622         */
2623        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2624                return 0;
2625
2626        len = strlen(name);
2627        pos = cache_name_pos(name, len);
2628        if (pos < 0)
2629                return 0;
2630        ce = active_cache[pos];
2631
2632        /*
2633         * This is not the sha1 we are looking for, or
2634         * unreusable because it is not a regular file.
2635         */
2636        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2637                return 0;
2638
2639        /*
2640         * If ce is marked as "assume unchanged", there is no
2641         * guarantee that work tree matches what we are looking for.
2642         */
2643        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2644                return 0;
2645
2646        /*
2647         * If ce matches the file in the work tree, we can reuse it.
2648         */
2649        if (ce_uptodate(ce) ||
2650            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2651                return 1;
2652
2653        return 0;
2654}
2655
2656static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2657{
2658        int len;
2659        char *data = xmalloc(100), *dirty = "";
2660
2661        /* Are we looking at the work tree? */
2662        if (s->dirty_submodule)
2663                dirty = "-dirty";
2664
2665        len = snprintf(data, 100,
2666                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2667        s->data = data;
2668        s->size = len;
2669        s->should_free = 1;
2670        if (size_only) {
2671                s->data = NULL;
2672                free(data);
2673        }
2674        return 0;
2675}
2676
2677/*
2678 * While doing rename detection and pickaxe operation, we may need to
2679 * grab the data for the blob (or file) for our own in-core comparison.
2680 * diff_filespec has data and size fields for this purpose.
2681 */
2682int diff_populate_filespec(struct diff_filespec *s, int size_only)
2683{
2684        int err = 0;
2685        if (!DIFF_FILE_VALID(s))
2686                die("internal error: asking to populate invalid file.");
2687        if (S_ISDIR(s->mode))
2688                return -1;
2689
2690        if (s->data)
2691                return 0;
2692
2693        if (size_only && 0 < s->size)
2694                return 0;
2695
2696        if (S_ISGITLINK(s->mode))
2697                return diff_populate_gitlink(s, size_only);
2698
2699        if (!s->sha1_valid ||
2700            reuse_worktree_file(s->path, s->sha1, 0)) {
2701                struct strbuf buf = STRBUF_INIT;
2702                struct stat st;
2703                int fd;
2704
2705                if (lstat(s->path, &st) < 0) {
2706                        if (errno == ENOENT) {
2707                        err_empty:
2708                                err = -1;
2709                        empty:
2710                                s->data = (char *)"";
2711                                s->size = 0;
2712                                return err;
2713                        }
2714                }
2715                s->size = xsize_t(st.st_size);
2716                if (!s->size)
2717                        goto empty;
2718                if (S_ISLNK(st.st_mode)) {
2719                        struct strbuf sb = STRBUF_INIT;
2720
2721                        if (strbuf_readlink(&sb, s->path, s->size))
2722                                goto err_empty;
2723                        s->size = sb.len;
2724                        s->data = strbuf_detach(&sb, NULL);
2725                        s->should_free = 1;
2726                        return 0;
2727                }
2728                if (size_only)
2729                        return 0;
2730                fd = open(s->path, O_RDONLY);
2731                if (fd < 0)
2732                        goto err_empty;
2733                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2734                close(fd);
2735                s->should_munmap = 1;
2736
2737                /*
2738                 * Convert from working tree format to canonical git format
2739                 */
2740                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2741                        size_t size = 0;
2742                        munmap(s->data, s->size);
2743                        s->should_munmap = 0;
2744                        s->data = strbuf_detach(&buf, &size);
2745                        s->size = size;
2746                        s->should_free = 1;
2747                }
2748        }
2749        else {
2750                enum object_type type;
2751                if (size_only) {
2752                        type = sha1_object_info(s->sha1, &s->size);
2753                        if (type < 0)
2754                                die("unable to read %s", sha1_to_hex(s->sha1));
2755                } else {
2756                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2757                        if (!s->data)
2758                                die("unable to read %s", sha1_to_hex(s->sha1));
2759                        s->should_free = 1;
2760                }
2761        }
2762        return 0;
2763}
2764
2765void diff_free_filespec_blob(struct diff_filespec *s)
2766{
2767        if (s->should_free)
2768                free(s->data);
2769        else if (s->should_munmap)
2770                munmap(s->data, s->size);
2771
2772        if (s->should_free || s->should_munmap) {
2773                s->should_free = s->should_munmap = 0;
2774                s->data = NULL;
2775        }
2776}
2777
2778void diff_free_filespec_data(struct diff_filespec *s)
2779{
2780        diff_free_filespec_blob(s);
2781        free(s->cnt_data);
2782        s->cnt_data = NULL;
2783}
2784
2785static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2786                           void *blob,
2787                           unsigned long size,
2788                           const unsigned char *sha1,
2789                           int mode)
2790{
2791        int fd;
2792        struct strbuf buf = STRBUF_INIT;
2793        struct strbuf template = STRBUF_INIT;
2794        char *path_dup = xstrdup(path);
2795        const char *base = basename(path_dup);
2796
2797        /* Generate "XXXXXX_basename.ext" */
2798        strbuf_addstr(&template, "XXXXXX_");
2799        strbuf_addstr(&template, base);
2800
2801        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2802                        strlen(base) + 1);
2803        if (fd < 0)
2804                die_errno("unable to create temp-file");
2805        if (convert_to_working_tree(path,
2806                        (const char *)blob, (size_t)size, &buf)) {
2807                blob = buf.buf;
2808                size = buf.len;
2809        }
2810        if (write_in_full(fd, blob, size) != size)
2811                die_errno("unable to write temp-file");
2812        close(fd);
2813        temp->name = temp->tmp_path;
2814        strcpy(temp->hex, sha1_to_hex(sha1));
2815        temp->hex[40] = 0;
2816        sprintf(temp->mode, "%06o", mode);
2817        strbuf_release(&buf);
2818        strbuf_release(&template);
2819        free(path_dup);
2820}
2821
2822static struct diff_tempfile *prepare_temp_file(const char *name,
2823                struct diff_filespec *one)
2824{
2825        struct diff_tempfile *temp = claim_diff_tempfile();
2826
2827        if (!DIFF_FILE_VALID(one)) {
2828        not_a_valid_file:
2829                /* A '-' entry produces this for file-2, and
2830                 * a '+' entry produces this for file-1.
2831                 */
2832                temp->name = "/dev/null";
2833                strcpy(temp->hex, ".");
2834                strcpy(temp->mode, ".");
2835                return temp;
2836        }
2837
2838        if (!remove_tempfile_installed) {
2839                atexit(remove_tempfile);
2840                sigchain_push_common(remove_tempfile_on_signal);
2841                remove_tempfile_installed = 1;
2842        }
2843
2844        if (!one->sha1_valid ||
2845            reuse_worktree_file(name, one->sha1, 1)) {
2846                struct stat st;
2847                if (lstat(name, &st) < 0) {
2848                        if (errno == ENOENT)
2849                                goto not_a_valid_file;
2850                        die_errno("stat(%s)", name);
2851                }
2852                if (S_ISLNK(st.st_mode)) {
2853                        struct strbuf sb = STRBUF_INIT;
2854                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2855                                die_errno("readlink(%s)", name);
2856                        prep_temp_blob(name, temp, sb.buf, sb.len,
2857                                       (one->sha1_valid ?
2858                                        one->sha1 : null_sha1),
2859                                       (one->sha1_valid ?
2860                                        one->mode : S_IFLNK));
2861                        strbuf_release(&sb);
2862                }
2863                else {
2864                        /* we can borrow from the file in the work tree */
2865                        temp->name = name;
2866                        if (!one->sha1_valid)
2867                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2868                        else
2869                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2870                        /* Even though we may sometimes borrow the
2871                         * contents from the work tree, we always want
2872                         * one->mode.  mode is trustworthy even when
2873                         * !(one->sha1_valid), as long as
2874                         * DIFF_FILE_VALID(one).
2875                         */
2876                        sprintf(temp->mode, "%06o", one->mode);
2877                }
2878                return temp;
2879        }
2880        else {
2881                if (diff_populate_filespec(one, 0))
2882                        die("cannot read data blob for %s", one->path);
2883                prep_temp_blob(name, temp, one->data, one->size,
2884                               one->sha1, one->mode);
2885        }
2886        return temp;
2887}
2888
2889/* An external diff command takes:
2890 *
2891 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2892 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2893 *
2894 */
2895static void run_external_diff(const char *pgm,
2896                              const char *name,
2897                              const char *other,
2898                              struct diff_filespec *one,
2899                              struct diff_filespec *two,
2900                              const char *xfrm_msg,
2901                              int complete_rewrite)
2902{
2903        const char *spawn_arg[10];
2904        int retval;
2905        const char **arg = &spawn_arg[0];
2906
2907        if (one && two) {
2908                struct diff_tempfile *temp_one, *temp_two;
2909                const char *othername = (other ? other : name);
2910                temp_one = prepare_temp_file(name, one);
2911                temp_two = prepare_temp_file(othername, two);
2912                *arg++ = pgm;
2913                *arg++ = name;
2914                *arg++ = temp_one->name;
2915                *arg++ = temp_one->hex;
2916                *arg++ = temp_one->mode;
2917                *arg++ = temp_two->name;
2918                *arg++ = temp_two->hex;
2919                *arg++ = temp_two->mode;
2920                if (other) {
2921                        *arg++ = other;
2922                        *arg++ = xfrm_msg;
2923                }
2924        } else {
2925                *arg++ = pgm;
2926                *arg++ = name;
2927        }
2928        *arg = NULL;
2929        fflush(NULL);
2930        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2931        remove_tempfile();
2932        if (retval) {
2933                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2934                exit(1);
2935        }
2936}
2937
2938static int similarity_index(struct diff_filepair *p)
2939{
2940        return p->score * 100 / MAX_SCORE;
2941}
2942
2943static void fill_metainfo(struct strbuf *msg,
2944                          const char *name,
2945                          const char *other,
2946                          struct diff_filespec *one,
2947                          struct diff_filespec *two,
2948                          struct diff_options *o,
2949                          struct diff_filepair *p,
2950                          int *must_show_header,
2951                          int use_color)
2952{
2953        const char *set = diff_get_color(use_color, DIFF_METAINFO);
2954        const char *reset = diff_get_color(use_color, DIFF_RESET);
2955        struct strbuf *msgbuf;
2956        char *line_prefix = "";
2957
2958        *must_show_header = 1;
2959        if (o->output_prefix) {
2960                msgbuf = o->output_prefix(o, o->output_prefix_data);
2961                line_prefix = msgbuf->buf;
2962        }
2963        strbuf_init(msg, PATH_MAX * 2 + 300);
2964        switch (p->status) {
2965        case DIFF_STATUS_COPIED:
2966                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2967                            line_prefix, set, similarity_index(p));
2968                strbuf_addf(msg, "%s\n%s%scopy from ",
2969                            reset,  line_prefix, set);
2970                quote_c_style(name, msg, NULL, 0);
2971                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2972                quote_c_style(other, msg, NULL, 0);
2973                strbuf_addf(msg, "%s\n", reset);
2974                break;
2975        case DIFF_STATUS_RENAMED:
2976                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2977                            line_prefix, set, similarity_index(p));
2978                strbuf_addf(msg, "%s\n%s%srename from ",
2979                            reset, line_prefix, set);
2980                quote_c_style(name, msg, NULL, 0);
2981                strbuf_addf(msg, "%s\n%s%srename to ",
2982                            reset, line_prefix, set);
2983                quote_c_style(other, msg, NULL, 0);
2984                strbuf_addf(msg, "%s\n", reset);
2985                break;
2986        case DIFF_STATUS_MODIFIED:
2987                if (p->score) {
2988                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2989                                    line_prefix,
2990                                    set, similarity_index(p), reset);
2991                        break;
2992                }
2993                /* fallthru */
2994        default:
2995                *must_show_header = 0;
2996        }
2997        if (one && two && hashcmp(one->sha1, two->sha1)) {
2998                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2999
3000                if (DIFF_OPT_TST(o, BINARY)) {
3001                        mmfile_t mf;
3002                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
3003                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
3004                                abbrev = 40;
3005                }
3006                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
3007                            find_unique_abbrev(one->sha1, abbrev));
3008                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
3009                if (one->mode == two->mode)
3010                        strbuf_addf(msg, " %06o", one->mode);
3011                strbuf_addf(msg, "%s\n", reset);
3012        }
3013}
3014
3015static void run_diff_cmd(const char *pgm,
3016                         const char *name,
3017                         const char *other,
3018                         const char *attr_path,
3019                         struct diff_filespec *one,
3020                         struct diff_filespec *two,
3021                         struct strbuf *msg,
3022                         struct diff_options *o,
3023                         struct diff_filepair *p)
3024{
3025        const char *xfrm_msg = NULL;
3026        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
3027        int must_show_header = 0;
3028
3029
3030        if (DIFF_OPT_TST(o, ALLOW_EXTERNAL)) {
3031                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
3032                if (drv && drv->external)
3033                        pgm = drv->external;
3034        }
3035
3036        if (msg) {
3037                /*
3038                 * don't use colors when the header is intended for an
3039                 * external diff driver
3040                 */
3041                fill_metainfo(msg, name, other, one, two, o, p,
3042                              &must_show_header,
3043                              want_color(o->use_color) && !pgm);
3044                xfrm_msg = msg->len ? msg->buf : NULL;
3045        }
3046
3047        if (pgm) {
3048                run_external_diff(pgm, name, other, one, two, xfrm_msg,
3049                                  complete_rewrite);
3050                return;
3051        }
3052        if (one && two)
3053                builtin_diff(name, other ? other : name,
3054                             one, two, xfrm_msg, must_show_header,
3055                             o, complete_rewrite);
3056        else
3057                fprintf(o->file, "* Unmerged path %s\n", name);
3058}
3059
3060static void diff_fill_sha1_info(struct diff_filespec *one)
3061{
3062        if (DIFF_FILE_VALID(one)) {
3063                if (!one->sha1_valid) {
3064                        struct stat st;
3065                        if (one->is_stdin) {
3066                                hashcpy(one->sha1, null_sha1);
3067                                return;
3068                        }
3069                        if (lstat(one->path, &st) < 0)
3070                                die_errno("stat '%s'", one->path);
3071                        if (index_path(one->sha1, one->path, &st, 0))
3072                                die("cannot hash %s", one->path);
3073                }
3074        }
3075        else
3076                hashclr(one->sha1);
3077}
3078
3079static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
3080{
3081        /* Strip the prefix but do not molest /dev/null and absolute paths */
3082        if (*namep && **namep != '/') {
3083                *namep += prefix_length;
3084                if (**namep == '/')
3085                        ++*namep;
3086        }
3087        if (*otherp && **otherp != '/') {
3088                *otherp += prefix_length;
3089                if (**otherp == '/')
3090                        ++*otherp;
3091        }
3092}
3093
3094static void run_diff(struct diff_filepair *p, struct diff_options *o)
3095{
3096        const char *pgm = external_diff();
3097        struct strbuf msg;
3098        struct diff_filespec *one = p->one;
3099        struct diff_filespec *two = p->two;
3100        const char *name;
3101        const char *other;
3102        const char *attr_path;
3103
3104        name  = p->one->path;
3105        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3106        attr_path = name;
3107        if (o->prefix_length)
3108                strip_prefix(o->prefix_length, &name, &other);
3109
3110        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
3111                pgm = NULL;
3112
3113        if (DIFF_PAIR_UNMERGED(p)) {
3114                run_diff_cmd(pgm, name, NULL, attr_path,
3115                             NULL, NULL, NULL, o, p);
3116                return;
3117        }
3118
3119        diff_fill_sha1_info(one);
3120        diff_fill_sha1_info(two);
3121
3122        if (!pgm &&
3123            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
3124            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
3125                /*
3126                 * a filepair that changes between file and symlink
3127                 * needs to be split into deletion and creation.
3128                 */
3129                struct diff_filespec *null = alloc_filespec(two->path);
3130                run_diff_cmd(NULL, name, other, attr_path,
3131                             one, null, &msg, o, p);
3132                free(null);
3133                strbuf_release(&msg);
3134
3135                null = alloc_filespec(one->path);
3136                run_diff_cmd(NULL, name, other, attr_path,
3137                             null, two, &msg, o, p);
3138                free(null);
3139        }
3140        else
3141                run_diff_cmd(pgm, name, other, attr_path,
3142                             one, two, &msg, o, p);
3143
3144        strbuf_release(&msg);
3145}
3146
3147static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
3148                         struct diffstat_t *diffstat)
3149{
3150        const char *name;
3151        const char *other;
3152
3153        if (DIFF_PAIR_UNMERGED(p)) {
3154                /* unmerged */
3155                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, p);
3156                return;
3157        }
3158
3159        name = p->one->path;
3160        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3161
3162        if (o->prefix_length)
3163                strip_prefix(o->prefix_length, &name, &other);
3164
3165        diff_fill_sha1_info(p->one);
3166        diff_fill_sha1_info(p->two);
3167
3168        builtin_diffstat(name, other, p->one, p->two, diffstat, o, p);
3169}
3170
3171static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
3172{
3173        const char *name;
3174        const char *other;
3175        const char *attr_path;
3176
3177        if (DIFF_PAIR_UNMERGED(p)) {
3178                /* unmerged */
3179                return;
3180        }
3181
3182        name = p->one->path;
3183        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3184        attr_path = other ? other : name;
3185
3186        if (o->prefix_length)
3187                strip_prefix(o->prefix_length, &name, &other);
3188
3189        diff_fill_sha1_info(p->one);
3190        diff_fill_sha1_info(p->two);
3191
3192        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
3193}
3194
3195void diff_setup(struct diff_options *options)
3196{
3197        memcpy(options, &default_diff_options, sizeof(*options));
3198
3199        options->file = stdout;
3200
3201        options->line_termination = '\n';
3202        options->break_opt = -1;
3203        options->rename_limit = -1;
3204        options->dirstat_permille = diff_dirstat_permille_default;
3205        options->context = diff_context_default;
3206        DIFF_OPT_SET(options, RENAME_EMPTY);
3207
3208        options->change = diff_change;
3209        options->add_remove = diff_addremove;
3210        options->use_color = diff_use_color_default;
3211        options->detect_rename = diff_detect_rename_default;
3212
3213        if (diff_no_prefix) {
3214                options->a_prefix = options->b_prefix = "";
3215        } else if (!diff_mnemonic_prefix) {
3216                options->a_prefix = "a/";
3217                options->b_prefix = "b/";
3218        }
3219}
3220
3221void diff_setup_done(struct diff_options *options)
3222{
3223        int count = 0;
3224
3225        if (options->output_format & DIFF_FORMAT_NAME)
3226                count++;
3227        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
3228                count++;
3229        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
3230                count++;
3231        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
3232                count++;
3233        if (count > 1)
3234                die("--name-only, --name-status, --check and -s are mutually exclusive");
3235
3236        /*
3237         * Most of the time we can say "there are changes"
3238         * only by checking if there are changed paths, but
3239         * --ignore-whitespace* options force us to look
3240         * inside contents.
3241         */
3242
3243        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
3244            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
3245            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
3246                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
3247        else
3248                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
3249
3250        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3251                options->detect_rename = DIFF_DETECT_COPY;
3252
3253        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
3254                options->prefix = NULL;
3255        if (options->prefix)
3256                options->prefix_length = strlen(options->prefix);
3257        else
3258                options->prefix_length = 0;
3259
3260        if (options->output_format & (DIFF_FORMAT_NAME |
3261                                      DIFF_FORMAT_NAME_STATUS |
3262                                      DIFF_FORMAT_CHECKDIFF |
3263                                      DIFF_FORMAT_NO_OUTPUT))
3264                options->output_format &= ~(DIFF_FORMAT_RAW |
3265                                            DIFF_FORMAT_NUMSTAT |
3266                                            DIFF_FORMAT_DIFFSTAT |
3267                                            DIFF_FORMAT_SHORTSTAT |
3268                                            DIFF_FORMAT_DIRSTAT |
3269                                            DIFF_FORMAT_SUMMARY |
3270                                            DIFF_FORMAT_PATCH);
3271
3272        /*
3273         * These cases always need recursive; we do not drop caller-supplied
3274         * recursive bits for other formats here.
3275         */
3276        if (options->output_format & (DIFF_FORMAT_PATCH |
3277                                      DIFF_FORMAT_NUMSTAT |
3278                                      DIFF_FORMAT_DIFFSTAT |
3279                                      DIFF_FORMAT_SHORTSTAT |
3280                                      DIFF_FORMAT_DIRSTAT |
3281                                      DIFF_FORMAT_SUMMARY |
3282                                      DIFF_FORMAT_CHECKDIFF))
3283                DIFF_OPT_SET(options, RECURSIVE);
3284        /*
3285         * Also pickaxe would not work very well if you do not say recursive
3286         */
3287        if (options->pickaxe)
3288                DIFF_OPT_SET(options, RECURSIVE);
3289        /*
3290         * When patches are generated, submodules diffed against the work tree
3291         * must be checked for dirtiness too so it can be shown in the output
3292         */
3293        if (options->output_format & DIFF_FORMAT_PATCH)
3294                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3295
3296        if (options->detect_rename && options->rename_limit < 0)
3297                options->rename_limit = diff_rename_limit_default;
3298        if (options->setup & DIFF_SETUP_USE_CACHE) {
3299                if (!active_cache)
3300                        /* read-cache does not die even when it fails
3301                         * so it is safe for us to do this here.  Also
3302                         * it does not smudge active_cache or active_nr
3303                         * when it fails, so we do not have to worry about
3304                         * cleaning it up ourselves either.
3305                         */
3306                        read_cache();
3307        }
3308        if (options->abbrev <= 0 || 40 < options->abbrev)
3309                options->abbrev = 40; /* full */
3310
3311        /*
3312         * It does not make sense to show the first hit we happened
3313         * to have found.  It does not make sense not to return with
3314         * exit code in such a case either.
3315         */
3316        if (DIFF_OPT_TST(options, QUICK)) {
3317                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3318                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3319        }
3320}
3321
3322static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3323{
3324        char c, *eq;
3325        int len;
3326
3327        if (*arg != '-')
3328                return 0;
3329        c = *++arg;
3330        if (!c)
3331                return 0;
3332        if (c == arg_short) {
3333                c = *++arg;
3334                if (!c)
3335                        return 1;
3336                if (val && isdigit(c)) {
3337                        char *end;
3338                        int n = strtoul(arg, &end, 10);
3339                        if (*end)
3340                                return 0;
3341                        *val = n;
3342                        return 1;
3343                }
3344                return 0;
3345        }
3346        if (c != '-')
3347                return 0;
3348        arg++;
3349        eq = strchr(arg, '=');
3350        if (eq)
3351                len = eq - arg;
3352        else
3353                len = strlen(arg);
3354        if (!len || strncmp(arg, arg_long, len))
3355                return 0;
3356        if (eq) {
3357                int n;
3358                char *end;
3359                if (!isdigit(*++eq))
3360                        return 0;
3361                n = strtoul(eq, &end, 10);
3362                if (*end)
3363                        return 0;
3364                *val = n;
3365        }
3366        return 1;
3367}
3368
3369static int diff_scoreopt_parse(const char *opt);
3370
3371static inline int short_opt(char opt, const char **argv,
3372                            const char **optarg)
3373{
3374        const char *arg = argv[0];
3375        if (arg[0] != '-' || arg[1] != opt)
3376                return 0;
3377        if (arg[2] != '\0') {
3378                *optarg = arg + 2;
3379                return 1;
3380        }
3381        if (!argv[1])
3382                die("Option '%c' requires a value", opt);
3383        *optarg = argv[1];
3384        return 2;
3385}
3386
3387int parse_long_opt(const char *opt, const char **argv,
3388                   const char **optarg)
3389{
3390        const char *arg = argv[0];
3391        if (arg[0] != '-' || arg[1] != '-')
3392                return 0;
3393        arg += strlen("--");
3394        if (prefixcmp(arg, opt))
3395                return 0;
3396        arg += strlen(opt);
3397        if (*arg == '=') { /* sticked form: --option=value */
3398                *optarg = arg + 1;
3399                return 1;
3400        }
3401        if (*arg != '\0')
3402                return 0;
3403        /* separate form: --option value */
3404        if (!argv[1])
3405                die("Option '--%s' requires a value", opt);
3406        *optarg = argv[1];
3407        return 2;
3408}
3409
3410static int stat_opt(struct diff_options *options, const char **av)
3411{
3412        const char *arg = av[0];
3413        char *end;
3414        int width = options->stat_width;
3415        int name_width = options->stat_name_width;
3416        int graph_width = options->stat_graph_width;
3417        int count = options->stat_count;
3418        int argcount = 1;
3419
3420        arg += strlen("--stat");
3421        end = (char *)arg;
3422
3423        switch (*arg) {
3424        case '-':
3425                if (!prefixcmp(arg, "-width")) {
3426                        arg += strlen("-width");
3427                        if (*arg == '=')
3428                                width = strtoul(arg + 1, &end, 10);
3429                        else if (!*arg && !av[1])
3430                                die("Option '--stat-width' requires a value");
3431                        else if (!*arg) {
3432                                width = strtoul(av[1], &end, 10);
3433                                argcount = 2;
3434                        }
3435                } else if (!prefixcmp(arg, "-name-width")) {
3436                        arg += strlen("-name-width");
3437                        if (*arg == '=')
3438                                name_width = strtoul(arg + 1, &end, 10);
3439                        else if (!*arg && !av[1])
3440                                die("Option '--stat-name-width' requires a value");
3441                        else if (!*arg) {
3442                                name_width = strtoul(av[1], &end, 10);
3443                                argcount = 2;
3444                        }
3445                } else if (!prefixcmp(arg, "-graph-width")) {
3446                        arg += strlen("-graph-width");
3447                        if (*arg == '=')
3448                                graph_width = strtoul(arg + 1, &end, 10);
3449                        else if (!*arg && !av[1])
3450                                die("Option '--stat-graph-width' requires a value");
3451                        else if (!*arg) {
3452                                graph_width = strtoul(av[1], &end, 10);
3453                                argcount = 2;
3454                        }
3455                } else if (!prefixcmp(arg, "-count")) {
3456                        arg += strlen("-count");
3457                        if (*arg == '=')
3458                                count = strtoul(arg + 1, &end, 10);
3459                        else if (!*arg && !av[1])
3460                                die("Option '--stat-count' requires a value");
3461                        else if (!*arg) {
3462                                count = strtoul(av[1], &end, 10);
3463                                argcount = 2;
3464                        }
3465                }
3466                break;
3467        case '=':
3468                width = strtoul(arg+1, &end, 10);
3469                if (*end == ',')
3470                        name_width = strtoul(end+1, &end, 10);
3471                if (*end == ',')
3472                        count = strtoul(end+1, &end, 10);
3473        }
3474
3475        /* Important! This checks all the error cases! */
3476        if (*end)
3477                return 0;
3478        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3479        options->stat_name_width = name_width;
3480        options->stat_graph_width = graph_width;
3481        options->stat_width = width;
3482        options->stat_count = count;
3483        return argcount;
3484}
3485
3486static int parse_dirstat_opt(struct diff_options *options, const char *params)
3487{
3488        struct strbuf errmsg = STRBUF_INIT;
3489        if (parse_dirstat_params(options, params, &errmsg))
3490                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
3491                    errmsg.buf);
3492        strbuf_release(&errmsg);
3493        /*
3494         * The caller knows a dirstat-related option is given from the command
3495         * line; allow it to say "return this_function();"
3496         */
3497        options->output_format |= DIFF_FORMAT_DIRSTAT;
3498        return 1;
3499}
3500
3501static int parse_submodule_opt(struct diff_options *options, const char *value)
3502{
3503        if (parse_submodule_params(options, value))
3504                die(_("Failed to parse --submodule option parameter: '%s'"),
3505                        value);
3506        return 1;
3507}
3508
3509int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3510{
3511        const char *arg = av[0];
3512        const char *optarg;
3513        int argcount;
3514
3515        /* Output format options */
3516        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3517                options->output_format |= DIFF_FORMAT_PATCH;
3518        else if (opt_arg(arg, 'U', "unified", &options->context))
3519                options->output_format |= DIFF_FORMAT_PATCH;
3520        else if (!strcmp(arg, "--raw"))
3521                options->output_format |= DIFF_FORMAT_RAW;
3522        else if (!strcmp(arg, "--patch-with-raw"))
3523                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3524        else if (!strcmp(arg, "--numstat"))
3525                options->output_format |= DIFF_FORMAT_NUMSTAT;
3526        else if (!strcmp(arg, "--shortstat"))
3527                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3528        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
3529                return parse_dirstat_opt(options, "");
3530        else if (!prefixcmp(arg, "-X"))
3531                return parse_dirstat_opt(options, arg + 2);
3532        else if (!prefixcmp(arg, "--dirstat="))
3533                return parse_dirstat_opt(options, arg + 10);
3534        else if (!strcmp(arg, "--cumulative"))
3535                return parse_dirstat_opt(options, "cumulative");
3536        else if (!strcmp(arg, "--dirstat-by-file"))
3537                return parse_dirstat_opt(options, "files");
3538        else if (!prefixcmp(arg, "--dirstat-by-file=")) {
3539                parse_dirstat_opt(options, "files");
3540                return parse_dirstat_opt(options, arg + 18);
3541        }
3542        else if (!strcmp(arg, "--check"))
3543                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3544        else if (!strcmp(arg, "--summary"))
3545                options->output_format |= DIFF_FORMAT_SUMMARY;
3546        else if (!strcmp(arg, "--patch-with-stat"))
3547                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3548        else if (!strcmp(arg, "--name-only"))
3549                options->output_format |= DIFF_FORMAT_NAME;
3550        else if (!strcmp(arg, "--name-status"))
3551                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3552        else if (!strcmp(arg, "-s"))
3553                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3554        else if (!prefixcmp(arg, "--stat"))
3555                /* --stat, --stat-width, --stat-name-width, or --stat-count */
3556                return stat_opt(options, av);
3557
3558        /* renames options */
3559        else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
3560                 !strcmp(arg, "--break-rewrites")) {
3561                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3562                        return error("invalid argument to -B: %s", arg+2);
3563        }
3564        else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--find-renames=") ||
3565                 !strcmp(arg, "--find-renames")) {
3566                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3567                        return error("invalid argument to -M: %s", arg+2);
3568                options->detect_rename = DIFF_DETECT_RENAME;
3569        }
3570        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3571                options->irreversible_delete = 1;
3572        }
3573        else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
3574                 !strcmp(arg, "--find-copies")) {
3575                if (options->detect_rename == DIFF_DETECT_COPY)
3576                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3577                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3578                        return error("invalid argument to -C: %s", arg+2);
3579                options->detect_rename = DIFF_DETECT_COPY;
3580        }
3581        else if (!strcmp(arg, "--no-renames"))
3582                options->detect_rename = 0;
3583        else if (!strcmp(arg, "--rename-empty"))
3584                DIFF_OPT_SET(options, RENAME_EMPTY);
3585        else if (!strcmp(arg, "--no-rename-empty"))
3586                DIFF_OPT_CLR(options, RENAME_EMPTY);
3587        else if (!strcmp(arg, "--relative"))
3588                DIFF_OPT_SET(options, RELATIVE_NAME);
3589        else if (!prefixcmp(arg, "--relative=")) {
3590                DIFF_OPT_SET(options, RELATIVE_NAME);
3591                options->prefix = arg + 11;
3592        }
3593
3594        /* xdiff options */
3595        else if (!strcmp(arg, "--minimal"))
3596                DIFF_XDL_SET(options, NEED_MINIMAL);
3597        else if (!strcmp(arg, "--no-minimal"))
3598                DIFF_XDL_CLR(options, NEED_MINIMAL);
3599        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3600                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3601        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3602                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3603        else if (!strcmp(arg, "--ignore-space-at-eol"))
3604                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3605        else if (!strcmp(arg, "--patience"))
3606                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
3607        else if (!strcmp(arg, "--histogram"))
3608                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
3609
3610        /* flags options */
3611        else if (!strcmp(arg, "--binary")) {
3612                options->output_format |= DIFF_FORMAT_PATCH;
3613                DIFF_OPT_SET(options, BINARY);
3614        }
3615        else if (!strcmp(arg, "--full-index"))
3616                DIFF_OPT_SET(options, FULL_INDEX);
3617        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3618                DIFF_OPT_SET(options, TEXT);
3619        else if (!strcmp(arg, "-R"))
3620                DIFF_OPT_SET(options, REVERSE_DIFF);
3621        else if (!strcmp(arg, "--find-copies-harder"))
3622                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3623        else if (!strcmp(arg, "--follow"))
3624                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3625        else if (!strcmp(arg, "--color"))
3626                options->use_color = 1;
3627        else if (!prefixcmp(arg, "--color=")) {
3628                int value = git_config_colorbool(NULL, arg+8);
3629                if (value < 0)
3630                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3631                options->use_color = value;
3632        }
3633        else if (!strcmp(arg, "--no-color"))
3634                options->use_color = 0;
3635        else if (!strcmp(arg, "--color-words")) {
3636                options->use_color = 1;
3637                options->word_diff = DIFF_WORDS_COLOR;
3638        }
3639        else if (!prefixcmp(arg, "--color-words=")) {
3640                options->use_color = 1;
3641                options->word_diff = DIFF_WORDS_COLOR;
3642                options->word_regex = arg + 14;
3643        }
3644        else if (!strcmp(arg, "--word-diff")) {
3645                if (options->word_diff == DIFF_WORDS_NONE)
3646                        options->word_diff = DIFF_WORDS_PLAIN;
3647        }
3648        else if (!prefixcmp(arg, "--word-diff=")) {
3649                const char *type = arg + 12;
3650                if (!strcmp(type, "plain"))
3651                        options->word_diff = DIFF_WORDS_PLAIN;
3652                else if (!strcmp(type, "color")) {
3653                        options->use_color = 1;
3654                        options->word_diff = DIFF_WORDS_COLOR;
3655                }
3656                else if (!strcmp(type, "porcelain"))
3657                        options->word_diff = DIFF_WORDS_PORCELAIN;
3658                else if (!strcmp(type, "none"))
3659                        options->word_diff = DIFF_WORDS_NONE;
3660                else
3661                        die("bad --word-diff argument: %s", type);
3662        }
3663        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3664                if (options->word_diff == DIFF_WORDS_NONE)
3665                        options->word_diff = DIFF_WORDS_PLAIN;
3666                options->word_regex = optarg;
3667                return argcount;
3668        }
3669        else if (!strcmp(arg, "--exit-code"))
3670                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3671        else if (!strcmp(arg, "--quiet"))
3672                DIFF_OPT_SET(options, QUICK);
3673        else if (!strcmp(arg, "--ext-diff"))
3674                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3675        else if (!strcmp(arg, "--no-ext-diff"))
3676                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3677        else if (!strcmp(arg, "--textconv"))
3678                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3679        else if (!strcmp(arg, "--no-textconv"))
3680                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3681        else if (!strcmp(arg, "--ignore-submodules")) {
3682                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3683                handle_ignore_submodules_arg(options, "all");
3684        } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3685                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3686                handle_ignore_submodules_arg(options, arg + 20);
3687        } else if (!strcmp(arg, "--submodule"))
3688                DIFF_OPT_SET(options, SUBMODULE_LOG);
3689        else if (!prefixcmp(arg, "--submodule="))
3690                return parse_submodule_opt(options, arg + 12);
3691
3692        /* misc options */
3693        else if (!strcmp(arg, "-z"))
3694                options->line_termination = 0;
3695        else if ((argcount = short_opt('l', av, &optarg))) {
3696                options->rename_limit = strtoul(optarg, NULL, 10);
3697                return argcount;
3698        }
3699        else if ((argcount = short_opt('S', av, &optarg))) {
3700                options->pickaxe = optarg;
3701                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3702                return argcount;
3703        } else if ((argcount = short_opt('G', av, &optarg))) {
3704                options->pickaxe = optarg;
3705                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3706                return argcount;
3707        }
3708        else if (!strcmp(arg, "--pickaxe-all"))
3709                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3710        else if (!strcmp(arg, "--pickaxe-regex"))
3711                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3712        else if ((argcount = short_opt('O', av, &optarg))) {
3713                options->orderfile = optarg;
3714                return argcount;
3715        }
3716        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3717                options->filter = optarg;
3718                return argcount;
3719        }
3720        else if (!strcmp(arg, "--abbrev"))
3721                options->abbrev = DEFAULT_ABBREV;
3722        else if (!prefixcmp(arg, "--abbrev=")) {
3723                options->abbrev = strtoul(arg + 9, NULL, 10);
3724                if (options->abbrev < MINIMUM_ABBREV)
3725                        options->abbrev = MINIMUM_ABBREV;
3726                else if (40 < options->abbrev)
3727                        options->abbrev = 40;
3728        }
3729        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3730                options->a_prefix = optarg;
3731                return argcount;
3732        }
3733        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3734                options->b_prefix = optarg;
3735                return argcount;
3736        }
3737        else if (!strcmp(arg, "--no-prefix"))
3738                options->a_prefix = options->b_prefix = "";
3739        else if (opt_arg(arg, '\0', "inter-hunk-context",
3740                         &options->interhunkcontext))
3741                ;
3742        else if (!strcmp(arg, "-W"))
3743                DIFF_OPT_SET(options, FUNCCONTEXT);
3744        else if (!strcmp(arg, "--function-context"))
3745                DIFF_OPT_SET(options, FUNCCONTEXT);
3746        else if (!strcmp(arg, "--no-function-context"))
3747                DIFF_OPT_CLR(options, FUNCCONTEXT);
3748        else if ((argcount = parse_long_opt("output", av, &optarg))) {
3749                options->file = fopen(optarg, "w");
3750                if (!options->file)
3751                        die_errno("Could not open '%s'", optarg);
3752                options->close_file = 1;
3753                return argcount;
3754        } else
3755                return 0;
3756        return 1;
3757}
3758
3759int parse_rename_score(const char **cp_p)
3760{
3761        unsigned long num, scale;
3762        int ch, dot;
3763        const char *cp = *cp_p;
3764
3765        num = 0;
3766        scale = 1;
3767        dot = 0;
3768        for (;;) {
3769                ch = *cp;
3770                if ( !dot && ch == '.' ) {
3771                        scale = 1;
3772                        dot = 1;
3773                } else if ( ch == '%' ) {
3774                        scale = dot ? scale*100 : 100;
3775                        cp++;   /* % is always at the end */
3776                        break;
3777                } else if ( ch >= '0' && ch <= '9' ) {
3778                        if ( scale < 100000 ) {
3779                                scale *= 10;
3780                                num = (num*10) + (ch-'0');
3781                        }
3782                } else {
3783                        break;
3784                }
3785                cp++;
3786        }
3787        *cp_p = cp;
3788
3789        /* user says num divided by scale and we say internally that
3790         * is MAX_SCORE * num / scale.
3791         */
3792        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3793}
3794
3795static int diff_scoreopt_parse(const char *opt)
3796{
3797        int opt1, opt2, cmd;
3798
3799        if (*opt++ != '-')
3800                return -1;
3801        cmd = *opt++;
3802        if (cmd == '-') {
3803                /* convert the long-form arguments into short-form versions */
3804                if (!prefixcmp(opt, "break-rewrites")) {
3805                        opt += strlen("break-rewrites");
3806                        if (*opt == 0 || *opt++ == '=')
3807                                cmd = 'B';
3808                } else if (!prefixcmp(opt, "find-copies")) {
3809                        opt += strlen("find-copies");
3810                        if (*opt == 0 || *opt++ == '=')
3811                                cmd = 'C';
3812                } else if (!prefixcmp(opt, "find-renames")) {
3813                        opt += strlen("find-renames");
3814                        if (*opt == 0 || *opt++ == '=')
3815                                cmd = 'M';
3816                }
3817        }
3818        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3819                return -1; /* that is not a -M, -C nor -B option */
3820
3821        opt1 = parse_rename_score(&opt);
3822        if (cmd != 'B')
3823                opt2 = 0;
3824        else {
3825                if (*opt == 0)
3826                        opt2 = 0;
3827                else if (*opt != '/')
3828                        return -1; /* we expect -B80/99 or -B80 */
3829                else {
3830                        opt++;
3831                        opt2 = parse_rename_score(&opt);
3832                }
3833        }
3834        if (*opt != 0)
3835                return -1;
3836        return opt1 | (opt2 << 16);
3837}
3838
3839struct diff_queue_struct diff_queued_diff;
3840
3841void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3842{
3843        if (queue->alloc <= queue->nr) {
3844                queue->alloc = alloc_nr(queue->alloc);
3845                queue->queue = xrealloc(queue->queue,
3846                                        sizeof(dp) * queue->alloc);
3847        }
3848        queue->queue[queue->nr++] = dp;
3849}
3850
3851struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3852                                 struct diff_filespec *one,
3853                                 struct diff_filespec *two)
3854{
3855        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3856        dp->one = one;
3857        dp->two = two;
3858        if (queue)
3859                diff_q(queue, dp);
3860        return dp;
3861}
3862
3863void diff_free_filepair(struct diff_filepair *p)
3864{
3865        free_filespec(p->one);
3866        free_filespec(p->two);
3867        free(p);
3868}
3869
3870/* This is different from find_unique_abbrev() in that
3871 * it stuffs the result with dots for alignment.
3872 */
3873const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3874{
3875        int abblen;
3876        const char *abbrev;
3877        if (len == 40)
3878                return sha1_to_hex(sha1);
3879
3880        abbrev = find_unique_abbrev(sha1, len);
3881        abblen = strlen(abbrev);
3882        if (abblen < 37) {
3883                static char hex[41];
3884                if (len < abblen && abblen <= len + 2)
3885                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3886                else
3887                        sprintf(hex, "%s...", abbrev);
3888                return hex;
3889        }
3890        return sha1_to_hex(sha1);
3891}
3892
3893static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3894{
3895        int line_termination = opt->line_termination;
3896        int inter_name_termination = line_termination ? '\t' : '\0';
3897        if (opt->output_prefix) {
3898                struct strbuf *msg = NULL;
3899                msg = opt->output_prefix(opt, opt->output_prefix_data);
3900                fprintf(opt->file, "%s", msg->buf);
3901        }
3902
3903        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3904                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3905                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3906                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3907        }
3908        if (p->score) {
3909                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3910                        inter_name_termination);
3911        } else {
3912                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3913        }
3914
3915        if (p->status == DIFF_STATUS_COPIED ||
3916            p->status == DIFF_STATUS_RENAMED) {
3917                const char *name_a, *name_b;
3918                name_a = p->one->path;
3919                name_b = p->two->path;
3920                strip_prefix(opt->prefix_length, &name_a, &name_b);
3921                write_name_quoted(name_a, opt->file, inter_name_termination);
3922                write_name_quoted(name_b, opt->file, line_termination);
3923        } else {
3924                const char *name_a, *name_b;
3925                name_a = p->one->mode ? p->one->path : p->two->path;
3926                name_b = NULL;
3927                strip_prefix(opt->prefix_length, &name_a, &name_b);
3928                write_name_quoted(name_a, opt->file, line_termination);
3929        }
3930}
3931
3932int diff_unmodified_pair(struct diff_filepair *p)
3933{
3934        /* This function is written stricter than necessary to support
3935         * the currently implemented transformers, but the idea is to
3936         * let transformers to produce diff_filepairs any way they want,
3937         * and filter and clean them up here before producing the output.
3938         */
3939        struct diff_filespec *one = p->one, *two = p->two;
3940
3941        if (DIFF_PAIR_UNMERGED(p))
3942                return 0; /* unmerged is interesting */
3943
3944        /* deletion, addition, mode or type change
3945         * and rename are all interesting.
3946         */
3947        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3948            DIFF_PAIR_MODE_CHANGED(p) ||
3949            strcmp(one->path, two->path))
3950                return 0;
3951
3952        /* both are valid and point at the same path.  that is, we are
3953         * dealing with a change.
3954         */
3955        if (one->sha1_valid && two->sha1_valid &&
3956            !hashcmp(one->sha1, two->sha1) &&
3957            !one->dirty_submodule && !two->dirty_submodule)
3958                return 1; /* no change */
3959        if (!one->sha1_valid && !two->sha1_valid)
3960                return 1; /* both look at the same file on the filesystem. */
3961        return 0;
3962}
3963
3964static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3965{
3966        if (diff_unmodified_pair(p))
3967                return;
3968
3969        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3970            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3971                return; /* no tree diffs in patch format */
3972
3973        run_diff(p, o);
3974}
3975
3976static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3977                            struct diffstat_t *diffstat)
3978{
3979        if (diff_unmodified_pair(p))
3980                return;
3981
3982        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3983            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3984                return; /* no useful stat for tree diffs */
3985
3986        run_diffstat(p, o, diffstat);
3987}
3988
3989static void diff_flush_checkdiff(struct diff_filepair *p,
3990                struct diff_options *o)
3991{
3992        if (diff_unmodified_pair(p))
3993                return;
3994
3995        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3996            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3997                return; /* nothing to check in tree diffs */
3998
3999        run_checkdiff(p, o);
4000}
4001
4002int diff_queue_is_empty(void)
4003{
4004        struct diff_queue_struct *q = &diff_queued_diff;
4005        int i;
4006        for (i = 0; i < q->nr; i++)
4007                if (!diff_unmodified_pair(q->queue[i]))
4008                        return 0;
4009        return 1;
4010}
4011
4012#if DIFF_DEBUG
4013void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
4014{
4015        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
4016                x, one ? one : "",
4017                s->path,
4018                DIFF_FILE_VALID(s) ? "valid" : "invalid",
4019                s->mode,
4020                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
4021        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
4022                x, one ? one : "",
4023                s->size, s->xfrm_flags);
4024}
4025
4026void diff_debug_filepair(const struct diff_filepair *p, int i)
4027{
4028        diff_debug_filespec(p->one, i, "one");
4029        diff_debug_filespec(p->two, i, "two");
4030        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
4031                p->score, p->status ? p->status : '?',
4032                p->one->rename_used, p->broken_pair);
4033}
4034
4035void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
4036{
4037        int i;
4038        if (msg)
4039                fprintf(stderr, "%s\n", msg);
4040        fprintf(stderr, "q->nr = %d\n", q->nr);
4041        for (i = 0; i < q->nr; i++) {
4042                struct diff_filepair *p = q->queue[i];
4043                diff_debug_filepair(p, i);
4044        }
4045}
4046#endif
4047
4048static void diff_resolve_rename_copy(void)
4049{
4050        int i;
4051        struct diff_filepair *p;
4052        struct diff_queue_struct *q = &diff_queued_diff;
4053
4054        diff_debug_queue("resolve-rename-copy", q);
4055
4056        for (i = 0; i < q->nr; i++) {
4057                p = q->queue[i];
4058                p->status = 0; /* undecided */
4059                if (DIFF_PAIR_UNMERGED(p))
4060                        p->status = DIFF_STATUS_UNMERGED;
4061                else if (!DIFF_FILE_VALID(p->one))
4062                        p->status = DIFF_STATUS_ADDED;
4063                else if (!DIFF_FILE_VALID(p->two))
4064                        p->status = DIFF_STATUS_DELETED;
4065                else if (DIFF_PAIR_TYPE_CHANGED(p))
4066                        p->status = DIFF_STATUS_TYPE_CHANGED;
4067
4068                /* from this point on, we are dealing with a pair
4069                 * whose both sides are valid and of the same type, i.e.
4070                 * either in-place edit or rename/copy edit.
4071                 */
4072                else if (DIFF_PAIR_RENAME(p)) {
4073                        /*
4074                         * A rename might have re-connected a broken
4075                         * pair up, causing the pathnames to be the
4076                         * same again. If so, that's not a rename at
4077                         * all, just a modification..
4078                         *
4079                         * Otherwise, see if this source was used for
4080                         * multiple renames, in which case we decrement
4081                         * the count, and call it a copy.
4082                         */
4083                        if (!strcmp(p->one->path, p->two->path))
4084                                p->status = DIFF_STATUS_MODIFIED;
4085                        else if (--p->one->rename_used > 0)
4086                                p->status = DIFF_STATUS_COPIED;
4087                        else
4088                                p->status = DIFF_STATUS_RENAMED;
4089                }
4090                else if (hashcmp(p->one->sha1, p->two->sha1) ||
4091                         p->one->mode != p->two->mode ||
4092                         p->one->dirty_submodule ||
4093                         p->two->dirty_submodule ||
4094                         is_null_sha1(p->one->sha1))
4095                        p->status = DIFF_STATUS_MODIFIED;
4096                else {
4097                        /* This is a "no-change" entry and should not
4098                         * happen anymore, but prepare for broken callers.
4099                         */
4100                        error("feeding unmodified %s to diffcore",
4101                              p->one->path);
4102                        p->status = DIFF_STATUS_UNKNOWN;
4103                }
4104        }
4105        diff_debug_queue("resolve-rename-copy done", q);
4106}
4107
4108static int check_pair_status(struct diff_filepair *p)
4109{
4110        switch (p->status) {
4111        case DIFF_STATUS_UNKNOWN:
4112                return 0;
4113        case 0:
4114                die("internal error in diff-resolve-rename-copy");
4115        default:
4116                return 1;
4117        }
4118}
4119
4120static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
4121{
4122        int fmt = opt->output_format;
4123
4124        if (fmt & DIFF_FORMAT_CHECKDIFF)
4125                diff_flush_checkdiff(p, opt);
4126        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
4127                diff_flush_raw(p, opt);
4128        else if (fmt & DIFF_FORMAT_NAME) {
4129                const char *name_a, *name_b;
4130                name_a = p->two->path;
4131                name_b = NULL;
4132                strip_prefix(opt->prefix_length, &name_a, &name_b);
4133                write_name_quoted(name_a, opt->file, opt->line_termination);
4134        }
4135}
4136
4137static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
4138{
4139        if (fs->mode)
4140                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
4141        else
4142                fprintf(file, " %s ", newdelete);
4143        write_name_quoted(fs->path, file, '\n');
4144}
4145
4146
4147static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
4148                const char *line_prefix)
4149{
4150        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
4151                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
4152                        p->two->mode, show_name ? ' ' : '\n');
4153                if (show_name) {
4154                        write_name_quoted(p->two->path, file, '\n');
4155                }
4156        }
4157}
4158
4159static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
4160                        const char *line_prefix)
4161{
4162        char *names = pprint_rename(p->one->path, p->two->path);
4163
4164        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
4165        free(names);
4166        show_mode_change(file, p, 0, line_prefix);
4167}
4168
4169static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
4170{
4171        FILE *file = opt->file;
4172        char *line_prefix = "";
4173
4174        if (opt->output_prefix) {
4175                struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
4176                line_prefix = buf->buf;
4177        }
4178
4179        switch(p->status) {
4180        case DIFF_STATUS_DELETED:
4181                fputs(line_prefix, file);
4182                show_file_mode_name(file, "delete", p->one);
4183                break;
4184        case DIFF_STATUS_ADDED:
4185                fputs(line_prefix, file);
4186                show_file_mode_name(file, "create", p->two);
4187                break;
4188        case DIFF_STATUS_COPIED:
4189                fputs(line_prefix, file);
4190                show_rename_copy(file, "copy", p, line_prefix);
4191                break;
4192        case DIFF_STATUS_RENAMED:
4193                fputs(line_prefix, file);
4194                show_rename_copy(file, "rename", p, line_prefix);
4195                break;
4196        default:
4197                if (p->score) {
4198                        fprintf(file, "%s rewrite ", line_prefix);
4199                        write_name_quoted(p->two->path, file, ' ');
4200                        fprintf(file, "(%d%%)\n", similarity_index(p));
4201                }
4202                show_mode_change(file, p, !p->score, line_prefix);
4203                break;
4204        }
4205}
4206
4207struct patch_id_t {
4208        git_SHA_CTX *ctx;
4209        int patchlen;
4210};
4211
4212static int remove_space(char *line, int len)
4213{
4214        int i;
4215        char *dst = line;
4216        unsigned char c;
4217
4218        for (i = 0; i < len; i++)
4219                if (!isspace((c = line[i])))
4220                        *dst++ = c;
4221
4222        return dst - line;
4223}
4224
4225static void patch_id_consume(void *priv, char *line, unsigned long len)
4226{
4227        struct patch_id_t *data = priv;
4228        int new_len;
4229
4230        /* Ignore line numbers when computing the SHA1 of the patch */
4231        if (!prefixcmp(line, "@@ -"))
4232                return;
4233
4234        new_len = remove_space(line, len);
4235
4236        git_SHA1_Update(data->ctx, line, new_len);
4237        data->patchlen += new_len;
4238}
4239
4240/* returns 0 upon success, and writes result into sha1 */
4241static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
4242{
4243        struct diff_queue_struct *q = &diff_queued_diff;
4244        int i;
4245        git_SHA_CTX ctx;
4246        struct patch_id_t data;
4247        char buffer[PATH_MAX * 4 + 20];
4248
4249        git_SHA1_Init(&ctx);
4250        memset(&data, 0, sizeof(struct patch_id_t));
4251        data.ctx = &ctx;
4252
4253        for (i = 0; i < q->nr; i++) {
4254                xpparam_t xpp;
4255                xdemitconf_t xecfg;
4256                mmfile_t mf1, mf2;
4257                struct diff_filepair *p = q->queue[i];
4258                int len1, len2;
4259
4260                memset(&xpp, 0, sizeof(xpp));
4261                memset(&xecfg, 0, sizeof(xecfg));
4262                if (p->status == 0)
4263                        return error("internal diff status error");
4264                if (p->status == DIFF_STATUS_UNKNOWN)
4265                        continue;
4266                if (diff_unmodified_pair(p))
4267                        continue;
4268                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4269                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4270                        continue;
4271                if (DIFF_PAIR_UNMERGED(p))
4272                        continue;
4273
4274                diff_fill_sha1_info(p->one);
4275                diff_fill_sha1_info(p->two);
4276                if (fill_mmfile(&mf1, p->one) < 0 ||
4277                                fill_mmfile(&mf2, p->two) < 0)
4278                        return error("unable to read files to diff");
4279
4280                len1 = remove_space(p->one->path, strlen(p->one->path));
4281                len2 = remove_space(p->two->path, strlen(p->two->path));
4282                if (p->one->mode == 0)
4283                        len1 = snprintf(buffer, sizeof(buffer),
4284                                        "diff--gita/%.*sb/%.*s"
4285                                        "newfilemode%06o"
4286                                        "---/dev/null"
4287                                        "+++b/%.*s",
4288                                        len1, p->one->path,
4289                                        len2, p->two->path,
4290                                        p->two->mode,
4291                                        len2, p->two->path);
4292                else if (p->two->mode == 0)
4293                        len1 = snprintf(buffer, sizeof(buffer),
4294                                        "diff--gita/%.*sb/%.*s"
4295                                        "deletedfilemode%06o"
4296                                        "---a/%.*s"
4297                                        "+++/dev/null",
4298                                        len1, p->one->path,
4299                                        len2, p->two->path,
4300                                        p->one->mode,
4301                                        len1, p->one->path);
4302                else
4303                        len1 = snprintf(buffer, sizeof(buffer),
4304                                        "diff--gita/%.*sb/%.*s"
4305                                        "---a/%.*s"
4306                                        "+++b/%.*s",
4307                                        len1, p->one->path,
4308                                        len2, p->two->path,
4309                                        len1, p->one->path,
4310                                        len2, p->two->path);
4311                git_SHA1_Update(&ctx, buffer, len1);
4312
4313                if (diff_filespec_is_binary(p->one) ||
4314                    diff_filespec_is_binary(p->two)) {
4315                        git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
4316                        git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
4317                        continue;
4318                }
4319
4320                xpp.flags = 0;
4321                xecfg.ctxlen = 3;
4322                xecfg.flags = 0;
4323                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4324                              &xpp, &xecfg);
4325        }
4326
4327        git_SHA1_Final(sha1, &ctx);
4328        return 0;
4329}
4330
4331int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
4332{
4333        struct diff_queue_struct *q = &diff_queued_diff;
4334        int i;
4335        int result = diff_get_patch_id(options, sha1);
4336
4337        for (i = 0; i < q->nr; i++)
4338                diff_free_filepair(q->queue[i]);
4339
4340        free(q->queue);
4341        DIFF_QUEUE_CLEAR(q);
4342
4343        return result;
4344}
4345
4346static int is_summary_empty(const struct diff_queue_struct *q)
4347{
4348        int i;
4349
4350        for (i = 0; i < q->nr; i++) {
4351                const struct diff_filepair *p = q->queue[i];
4352
4353                switch (p->status) {
4354                case DIFF_STATUS_DELETED:
4355                case DIFF_STATUS_ADDED:
4356                case DIFF_STATUS_COPIED:
4357                case DIFF_STATUS_RENAMED:
4358                        return 0;
4359                default:
4360                        if (p->score)
4361                                return 0;
4362                        if (p->one->mode && p->two->mode &&
4363                            p->one->mode != p->two->mode)
4364                                return 0;
4365                        break;
4366                }
4367        }
4368        return 1;
4369}
4370
4371static const char rename_limit_warning[] =
4372"inexact rename detection was skipped due to too many files.";
4373
4374static const char degrade_cc_to_c_warning[] =
4375"only found copies from modified paths due to too many files.";
4376
4377static const char rename_limit_advice[] =
4378"you may want to set your %s variable to at least "
4379"%d and retry the command.";
4380
4381void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4382{
4383        if (degraded_cc)
4384                warning(degrade_cc_to_c_warning);
4385        else if (needed)
4386                warning(rename_limit_warning);
4387        else
4388                return;
4389        if (0 < needed && needed < 32767)
4390                warning(rename_limit_advice, varname, needed);
4391}
4392
4393void diff_flush(struct diff_options *options)
4394{
4395        struct diff_queue_struct *q = &diff_queued_diff;
4396        int i, output_format = options->output_format;
4397        int separator = 0;
4398        int dirstat_by_line = 0;
4399
4400        /*
4401         * Order: raw, stat, summary, patch
4402         * or:    name/name-status/checkdiff (other bits clear)
4403         */
4404        if (!q->nr)
4405                goto free_queue;
4406
4407        if (output_format & (DIFF_FORMAT_RAW |
4408                             DIFF_FORMAT_NAME |
4409                             DIFF_FORMAT_NAME_STATUS |
4410                             DIFF_FORMAT_CHECKDIFF)) {
4411                for (i = 0; i < q->nr; i++) {
4412                        struct diff_filepair *p = q->queue[i];
4413                        if (check_pair_status(p))
4414                                flush_one_pair(p, options);
4415                }
4416                separator++;
4417        }
4418
4419        if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
4420                dirstat_by_line = 1;
4421
4422        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
4423            dirstat_by_line) {
4424                struct diffstat_t diffstat;
4425
4426                memset(&diffstat, 0, sizeof(struct diffstat_t));
4427                for (i = 0; i < q->nr; i++) {
4428                        struct diff_filepair *p = q->queue[i];
4429                        if (check_pair_status(p))
4430                                diff_flush_stat(p, options, &diffstat);
4431                }
4432                if (output_format & DIFF_FORMAT_NUMSTAT)
4433                        show_numstat(&diffstat, options);
4434                if (output_format & DIFF_FORMAT_DIFFSTAT)
4435                        show_stats(&diffstat, options);
4436                if (output_format & DIFF_FORMAT_SHORTSTAT)
4437                        show_shortstats(&diffstat, options);
4438                if (output_format & DIFF_FORMAT_DIRSTAT)
4439                        show_dirstat_by_line(&diffstat, options);
4440                free_diffstat_info(&diffstat);
4441                separator++;
4442        }
4443        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
4444                show_dirstat(options);
4445
4446        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4447                for (i = 0; i < q->nr; i++) {
4448                        diff_summary(options, q->queue[i]);
4449                }
4450                separator++;
4451        }
4452
4453        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4454            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4455            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4456                /*
4457                 * run diff_flush_patch for the exit status. setting
4458                 * options->file to /dev/null should be safe, becaue we
4459                 * aren't supposed to produce any output anyway.
4460                 */
4461                if (options->close_file)
4462                        fclose(options->file);
4463                options->file = fopen("/dev/null", "w");
4464                if (!options->file)
4465                        die_errno("Could not open /dev/null");
4466                options->close_file = 1;
4467                for (i = 0; i < q->nr; i++) {
4468                        struct diff_filepair *p = q->queue[i];
4469                        if (check_pair_status(p))
4470                                diff_flush_patch(p, options);
4471                        if (options->found_changes)
4472                                break;
4473                }
4474        }
4475
4476        if (output_format & DIFF_FORMAT_PATCH) {
4477                if (separator) {
4478                        if (options->output_prefix) {
4479                                struct strbuf *msg = NULL;
4480                                msg = options->output_prefix(options,
4481                                        options->output_prefix_data);
4482                                fwrite(msg->buf, msg->len, 1, stdout);
4483                        }
4484                        putc(options->line_termination, options->file);
4485                        if (options->stat_sep) {
4486                                /* attach patch instead of inline */
4487                                fputs(options->stat_sep, options->file);
4488                        }
4489                }
4490
4491                for (i = 0; i < q->nr; i++) {
4492                        struct diff_filepair *p = q->queue[i];
4493                        if (check_pair_status(p))
4494                                diff_flush_patch(p, options);
4495                }
4496        }
4497
4498        if (output_format & DIFF_FORMAT_CALLBACK)
4499                options->format_callback(q, options, options->format_callback_data);
4500
4501        for (i = 0; i < q->nr; i++)
4502                diff_free_filepair(q->queue[i]);
4503free_queue:
4504        free(q->queue);
4505        DIFF_QUEUE_CLEAR(q);
4506        if (options->close_file)
4507                fclose(options->file);
4508
4509        /*
4510         * Report the content-level differences with HAS_CHANGES;
4511         * diff_addremove/diff_change does not set the bit when
4512         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4513         */
4514        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4515                if (options->found_changes)
4516                        DIFF_OPT_SET(options, HAS_CHANGES);
4517                else
4518                        DIFF_OPT_CLR(options, HAS_CHANGES);
4519        }
4520}
4521
4522static void diffcore_apply_filter(const char *filter)
4523{
4524        int i;
4525        struct diff_queue_struct *q = &diff_queued_diff;
4526        struct diff_queue_struct outq;
4527        DIFF_QUEUE_CLEAR(&outq);
4528
4529        if (!filter)
4530                return;
4531
4532        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
4533                int found;
4534                for (i = found = 0; !found && i < q->nr; i++) {
4535                        struct diff_filepair *p = q->queue[i];
4536                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4537                             ((p->score &&
4538                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4539                              (!p->score &&
4540                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4541                            ((p->status != DIFF_STATUS_MODIFIED) &&
4542                             strchr(filter, p->status)))
4543                                found++;
4544                }
4545                if (found)
4546                        return;
4547
4548                /* otherwise we will clear the whole queue
4549                 * by copying the empty outq at the end of this
4550                 * function, but first clear the current entries
4551                 * in the queue.
4552                 */
4553                for (i = 0; i < q->nr; i++)
4554                        diff_free_filepair(q->queue[i]);
4555        }
4556        else {
4557                /* Only the matching ones */
4558                for (i = 0; i < q->nr; i++) {
4559                        struct diff_filepair *p = q->queue[i];
4560
4561                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4562                             ((p->score &&
4563                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4564                              (!p->score &&
4565                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4566                            ((p->status != DIFF_STATUS_MODIFIED) &&
4567                             strchr(filter, p->status)))
4568                                diff_q(&outq, p);
4569                        else
4570                                diff_free_filepair(p);
4571                }
4572        }
4573        free(q->queue);
4574        *q = outq;
4575}
4576
4577/* Check whether two filespecs with the same mode and size are identical */
4578static int diff_filespec_is_identical(struct diff_filespec *one,
4579                                      struct diff_filespec *two)
4580{
4581        if (S_ISGITLINK(one->mode))
4582                return 0;
4583        if (diff_populate_filespec(one, 0))
4584                return 0;
4585        if (diff_populate_filespec(two, 0))
4586                return 0;
4587        return !memcmp(one->data, two->data, one->size);
4588}
4589
4590static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4591{
4592        int i;
4593        struct diff_queue_struct *q = &diff_queued_diff;
4594        struct diff_queue_struct outq;
4595        DIFF_QUEUE_CLEAR(&outq);
4596
4597        for (i = 0; i < q->nr; i++) {
4598                struct diff_filepair *p = q->queue[i];
4599
4600                /*
4601                 * 1. Entries that come from stat info dirtiness
4602                 *    always have both sides (iow, not create/delete),
4603                 *    one side of the object name is unknown, with
4604                 *    the same mode and size.  Keep the ones that
4605                 *    do not match these criteria.  They have real
4606                 *    differences.
4607                 *
4608                 * 2. At this point, the file is known to be modified,
4609                 *    with the same mode and size, and the object
4610                 *    name of one side is unknown.  Need to inspect
4611                 *    the identical contents.
4612                 */
4613                if (!DIFF_FILE_VALID(p->one) || /* (1) */
4614                    !DIFF_FILE_VALID(p->two) ||
4615                    (p->one->sha1_valid && p->two->sha1_valid) ||
4616                    (p->one->mode != p->two->mode) ||
4617                    diff_populate_filespec(p->one, 1) ||
4618                    diff_populate_filespec(p->two, 1) ||
4619                    (p->one->size != p->two->size) ||
4620                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4621                        diff_q(&outq, p);
4622                else {
4623                        /*
4624                         * The caller can subtract 1 from skip_stat_unmatch
4625                         * to determine how many paths were dirty only
4626                         * due to stat info mismatch.
4627                         */
4628                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4629                                diffopt->skip_stat_unmatch++;
4630                        diff_free_filepair(p);
4631                }
4632        }
4633        free(q->queue);
4634        *q = outq;
4635}
4636
4637static int diffnamecmp(const void *a_, const void *b_)
4638{
4639        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4640        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4641        const char *name_a, *name_b;
4642
4643        name_a = a->one ? a->one->path : a->two->path;
4644        name_b = b->one ? b->one->path : b->two->path;
4645        return strcmp(name_a, name_b);
4646}
4647
4648void diffcore_fix_diff_index(struct diff_options *options)
4649{
4650        struct diff_queue_struct *q = &diff_queued_diff;
4651        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4652}
4653
4654void diffcore_std(struct diff_options *options)
4655{
4656        if (options->skip_stat_unmatch)
4657                diffcore_skip_stat_unmatch(options);
4658        if (!options->found_follow) {
4659                /* See try_to_follow_renames() in tree-diff.c */
4660                if (options->break_opt != -1)
4661                        diffcore_break(options->break_opt);
4662                if (options->detect_rename)
4663                        diffcore_rename(options);
4664                if (options->break_opt != -1)
4665                        diffcore_merge_broken();
4666        }
4667        if (options->pickaxe)
4668                diffcore_pickaxe(options);
4669        if (options->orderfile)
4670                diffcore_order(options->orderfile);
4671        if (!options->found_follow)
4672                /* See try_to_follow_renames() in tree-diff.c */
4673                diff_resolve_rename_copy();
4674        diffcore_apply_filter(options->filter);
4675
4676        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4677                DIFF_OPT_SET(options, HAS_CHANGES);
4678        else
4679                DIFF_OPT_CLR(options, HAS_CHANGES);
4680
4681        options->found_follow = 0;
4682}
4683
4684int diff_result_code(struct diff_options *opt, int status)
4685{
4686        int result = 0;
4687
4688        diff_warn_rename_limit("diff.renamelimit",
4689                               opt->needed_rename_limit,
4690                               opt->degraded_cc_to_c);
4691        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4692            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4693                return status;
4694        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4695            DIFF_OPT_TST(opt, HAS_CHANGES))
4696                result |= 01;
4697        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4698            DIFF_OPT_TST(opt, CHECK_FAILED))
4699                result |= 02;
4700        return result;
4701}
4702
4703int diff_can_quit_early(struct diff_options *opt)
4704{
4705        return (DIFF_OPT_TST(opt, QUICK) &&
4706                !opt->filter &&
4707                DIFF_OPT_TST(opt, HAS_CHANGES));
4708}
4709
4710/*
4711 * Shall changes to this submodule be ignored?
4712 *
4713 * Submodule changes can be configured to be ignored separately for each path,
4714 * but that configuration can be overridden from the command line.
4715 */
4716static int is_submodule_ignored(const char *path, struct diff_options *options)
4717{
4718        int ignored = 0;
4719        unsigned orig_flags = options->flags;
4720        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4721                set_diffopt_flags_from_submodule_config(options, path);
4722        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4723                ignored = 1;
4724        options->flags = orig_flags;
4725        return ignored;
4726}
4727
4728void diff_addremove(struct diff_options *options,
4729                    int addremove, unsigned mode,
4730                    const unsigned char *sha1,
4731                    int sha1_valid,
4732                    const char *concatpath, unsigned dirty_submodule)
4733{
4734        struct diff_filespec *one, *two;
4735
4736        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4737                return;
4738
4739        /* This may look odd, but it is a preparation for
4740         * feeding "there are unchanged files which should
4741         * not produce diffs, but when you are doing copy
4742         * detection you would need them, so here they are"
4743         * entries to the diff-core.  They will be prefixed
4744         * with something like '=' or '*' (I haven't decided
4745         * which but should not make any difference).
4746         * Feeding the same new and old to diff_change()
4747         * also has the same effect.
4748         * Before the final output happens, they are pruned after
4749         * merged into rename/copy pairs as appropriate.
4750         */
4751        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4752                addremove = (addremove == '+' ? '-' :
4753                             addremove == '-' ? '+' : addremove);
4754
4755        if (options->prefix &&
4756            strncmp(concatpath, options->prefix, options->prefix_length))
4757                return;
4758
4759        one = alloc_filespec(concatpath);
4760        two = alloc_filespec(concatpath);
4761
4762        if (addremove != '+')
4763                fill_filespec(one, sha1, sha1_valid, mode);
4764        if (addremove != '-') {
4765                fill_filespec(two, sha1, sha1_valid, mode);
4766                two->dirty_submodule = dirty_submodule;
4767        }
4768
4769        diff_queue(&diff_queued_diff, one, two);
4770        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4771                DIFF_OPT_SET(options, HAS_CHANGES);
4772}
4773
4774void diff_change(struct diff_options *options,
4775                 unsigned old_mode, unsigned new_mode,
4776                 const unsigned char *old_sha1,
4777                 const unsigned char *new_sha1,
4778                 int old_sha1_valid, int new_sha1_valid,
4779                 const char *concatpath,
4780                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4781{
4782        struct diff_filespec *one, *two;
4783
4784        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4785            is_submodule_ignored(concatpath, options))
4786                return;
4787
4788        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4789                unsigned tmp;
4790                const unsigned char *tmp_c;
4791                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4792                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4793                tmp = old_sha1_valid; old_sha1_valid = new_sha1_valid;
4794                        new_sha1_valid = tmp;
4795                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4796                        new_dirty_submodule = tmp;
4797        }
4798
4799        if (options->prefix &&
4800            strncmp(concatpath, options->prefix, options->prefix_length))
4801                return;
4802
4803        one = alloc_filespec(concatpath);
4804        two = alloc_filespec(concatpath);
4805        fill_filespec(one, old_sha1, old_sha1_valid, old_mode);
4806        fill_filespec(two, new_sha1, new_sha1_valid, new_mode);
4807        one->dirty_submodule = old_dirty_submodule;
4808        two->dirty_submodule = new_dirty_submodule;
4809
4810        diff_queue(&diff_queued_diff, one, two);
4811        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4812                DIFF_OPT_SET(options, HAS_CHANGES);
4813}
4814
4815struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
4816{
4817        struct diff_filepair *pair;
4818        struct diff_filespec *one, *two;
4819
4820        if (options->prefix &&
4821            strncmp(path, options->prefix, options->prefix_length))
4822                return NULL;
4823
4824        one = alloc_filespec(path);
4825        two = alloc_filespec(path);
4826        pair = diff_queue(&diff_queued_diff, one, two);
4827        pair->is_unmerged = 1;
4828        return pair;
4829}
4830
4831static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4832                size_t *outsize)
4833{
4834        struct diff_tempfile *temp;
4835        const char *argv[3];
4836        const char **arg = argv;
4837        struct child_process child;
4838        struct strbuf buf = STRBUF_INIT;
4839        int err = 0;
4840
4841        temp = prepare_temp_file(spec->path, spec);
4842        *arg++ = pgm;
4843        *arg++ = temp->name;
4844        *arg = NULL;
4845
4846        memset(&child, 0, sizeof(child));
4847        child.use_shell = 1;
4848        child.argv = argv;
4849        child.out = -1;
4850        if (start_command(&child)) {
4851                remove_tempfile();
4852                return NULL;
4853        }
4854
4855        if (strbuf_read(&buf, child.out, 0) < 0)
4856                err = error("error reading from textconv command '%s'", pgm);
4857        close(child.out);
4858
4859        if (finish_command(&child) || err) {
4860                strbuf_release(&buf);
4861                remove_tempfile();
4862                return NULL;
4863        }
4864        remove_tempfile();
4865
4866        return strbuf_detach(&buf, outsize);
4867}
4868
4869size_t fill_textconv(struct userdiff_driver *driver,
4870                     struct diff_filespec *df,
4871                     char **outbuf)
4872{
4873        size_t size;
4874
4875        if (!driver || !driver->textconv) {
4876                if (!DIFF_FILE_VALID(df)) {
4877                        *outbuf = "";
4878                        return 0;
4879                }
4880                if (diff_populate_filespec(df, 0))
4881                        die("unable to read files to diff");
4882                *outbuf = df->data;
4883                return df->size;
4884        }
4885
4886        if (driver->textconv_cache && df->sha1_valid) {
4887                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4888                                          &size);
4889                if (*outbuf)
4890                        return size;
4891        }
4892
4893        *outbuf = run_textconv(driver->textconv, df, &size);
4894        if (!*outbuf)
4895                die("unable to read files to diff");
4896
4897        if (driver->textconv_cache && df->sha1_valid) {
4898                /* ignore errors, as we might be in a readonly repository */
4899                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4900                                size);
4901                /*
4902                 * we could save up changes and flush them all at the end,
4903                 * but we would need an extra call after all diffing is done.
4904                 * Since generating a cache entry is the slow path anyway,
4905                 * this extra overhead probably isn't a big deal.
4906                 */
4907                notes_cache_write(driver->textconv_cache);
4908        }
4909
4910        return size;
4911}
4912
4913void setup_diff_pager(struct diff_options *opt)
4914{
4915        /*
4916         * If the user asked for our exit code, then either they want --quiet
4917         * or --exit-code. We should definitely not bother with a pager in the
4918         * former case, as we will generate no output. Since we still properly
4919         * report our exit code even when a pager is run, we _could_ run a
4920         * pager with --exit-code. But since we have not done so historically,
4921         * and because it is easy to find people oneline advising "git diff
4922         * --exit-code" in hooks and other scripts, we do not do so.
4923         */
4924        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4925            check_pager_config("diff") != 0)
4926                setup_pager();
4927}