diff.con commit gitweb: Highlight matched part of shortened project description (e607b79)
   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
  19#ifdef NO_FAST_WORKING_DIRECTORY
  20#define FAST_WORKING_DIRECTORY 0
  21#else
  22#define FAST_WORKING_DIRECTORY 1
  23#endif
  24
  25static int diff_detect_rename_default;
  26static int diff_rename_limit_default = 400;
  27static int diff_suppress_blank_empty;
  28int diff_use_color_default = -1;
  29static const char *diff_word_regex_cfg;
  30static const char *external_diff_cmd_cfg;
  31int diff_auto_refresh_index = 1;
  32static int diff_mnemonic_prefix;
  33static int diff_no_prefix;
  34static int diff_dirstat_permille_default = 30;
  35static struct diff_options default_diff_options;
  36
  37static char diff_colors[][COLOR_MAXLEN] = {
  38        GIT_COLOR_RESET,
  39        GIT_COLOR_NORMAL,       /* PLAIN */
  40        GIT_COLOR_BOLD,         /* METAINFO */
  41        GIT_COLOR_CYAN,         /* FRAGINFO */
  42        GIT_COLOR_RED,          /* OLD */
  43        GIT_COLOR_GREEN,        /* NEW */
  44        GIT_COLOR_YELLOW,       /* COMMIT */
  45        GIT_COLOR_BG_RED,       /* WHITESPACE */
  46        GIT_COLOR_NORMAL,       /* FUNCINFO */
  47};
  48
  49static int parse_diff_color_slot(const char *var, int ofs)
  50{
  51        if (!strcasecmp(var+ofs, "plain"))
  52                return DIFF_PLAIN;
  53        if (!strcasecmp(var+ofs, "meta"))
  54                return DIFF_METAINFO;
  55        if (!strcasecmp(var+ofs, "frag"))
  56                return DIFF_FRAGINFO;
  57        if (!strcasecmp(var+ofs, "old"))
  58                return DIFF_FILE_OLD;
  59        if (!strcasecmp(var+ofs, "new"))
  60                return DIFF_FILE_NEW;
  61        if (!strcasecmp(var+ofs, "commit"))
  62                return DIFF_COMMIT;
  63        if (!strcasecmp(var+ofs, "whitespace"))
  64                return DIFF_WHITESPACE;
  65        if (!strcasecmp(var+ofs, "func"))
  66                return DIFF_FUNCINFO;
  67        return -1;
  68}
  69
  70static int parse_dirstat_params(struct diff_options *options, const char *params,
  71                                struct strbuf *errmsg)
  72{
  73        const char *p = params;
  74        int p_len, ret = 0;
  75
  76        while (*p) {
  77                p_len = strchrnul(p, ',') - p;
  78                if (!memcmp(p, "changes", p_len)) {
  79                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
  80                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
  81                } else if (!memcmp(p, "lines", p_len)) {
  82                        DIFF_OPT_SET(options, DIRSTAT_BY_LINE);
  83                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
  84                } else if (!memcmp(p, "files", p_len)) {
  85                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
  86                        DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
  87                } else if (!memcmp(p, "noncumulative", p_len)) {
  88                        DIFF_OPT_CLR(options, DIRSTAT_CUMULATIVE);
  89                } else if (!memcmp(p, "cumulative", p_len)) {
  90                        DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
  91                } else if (isdigit(*p)) {
  92                        char *end;
  93                        int permille = strtoul(p, &end, 10) * 10;
  94                        if (*end == '.' && isdigit(*++end)) {
  95                                /* only use first digit */
  96                                permille += *end - '0';
  97                                /* .. and ignore any further digits */
  98                                while (isdigit(*++end))
  99                                        ; /* nothing */
 100                        }
 101                        if (end - p == p_len)
 102                                options->dirstat_permille = permille;
 103                        else {
 104                                strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%.*s'\n"),
 105                                            p_len, p);
 106                                ret++;
 107                        }
 108                } else {
 109                        strbuf_addf(errmsg, _("  Unknown dirstat parameter '%.*s'\n"),
 110                                    p_len, p);
 111                        ret++;
 112                }
 113
 114                p += p_len;
 115
 116                if (*p)
 117                        p++; /* more parameters, swallow separator */
 118        }
 119        return ret;
 120}
 121
 122static int git_config_rename(const char *var, const char *value)
 123{
 124        if (!value)
 125                return DIFF_DETECT_RENAME;
 126        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 127                return  DIFF_DETECT_COPY;
 128        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 129}
 130
 131/*
 132 * These are to give UI layer defaults.
 133 * The core-level commands such as git-diff-files should
 134 * never be affected by the setting of diff.renames
 135 * the user happens to have in the configuration file.
 136 */
 137int git_diff_ui_config(const char *var, const char *value, void *cb)
 138{
 139        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 140                diff_use_color_default = git_config_colorbool(var, value);
 141                return 0;
 142        }
 143        if (!strcmp(var, "diff.renames")) {
 144                diff_detect_rename_default = git_config_rename(var, value);
 145                return 0;
 146        }
 147        if (!strcmp(var, "diff.autorefreshindex")) {
 148                diff_auto_refresh_index = git_config_bool(var, value);
 149                return 0;
 150        }
 151        if (!strcmp(var, "diff.mnemonicprefix")) {
 152                diff_mnemonic_prefix = git_config_bool(var, value);
 153                return 0;
 154        }
 155        if (!strcmp(var, "diff.noprefix")) {
 156                diff_no_prefix = git_config_bool(var, value);
 157                return 0;
 158        }
 159        if (!strcmp(var, "diff.external"))
 160                return git_config_string(&external_diff_cmd_cfg, var, value);
 161        if (!strcmp(var, "diff.wordregex"))
 162                return git_config_string(&diff_word_regex_cfg, var, value);
 163
 164        if (!strcmp(var, "diff.ignoresubmodules"))
 165                handle_ignore_submodules_arg(&default_diff_options, value);
 166
 167        if (git_color_config(var, value, cb) < 0)
 168                return -1;
 169
 170        return git_diff_basic_config(var, value, cb);
 171}
 172
 173int git_diff_basic_config(const char *var, const char *value, void *cb)
 174{
 175        if (!strcmp(var, "diff.renamelimit")) {
 176                diff_rename_limit_default = git_config_int(var, value);
 177                return 0;
 178        }
 179
 180        if (userdiff_config(var, value) < 0)
 181                return -1;
 182
 183        if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
 184                int slot = parse_diff_color_slot(var, 11);
 185                if (slot < 0)
 186                        return 0;
 187                if (!value)
 188                        return config_error_nonbool(var);
 189                color_parse(value, var, diff_colors[slot]);
 190                return 0;
 191        }
 192
 193        /* like GNU diff's --suppress-blank-empty option  */
 194        if (!strcmp(var, "diff.suppressblankempty") ||
 195                        /* for backwards compatibility */
 196                        !strcmp(var, "diff.suppress-blank-empty")) {
 197                diff_suppress_blank_empty = git_config_bool(var, value);
 198                return 0;
 199        }
 200
 201        if (!strcmp(var, "diff.dirstat")) {
 202                struct strbuf errmsg = STRBUF_INIT;
 203                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 204                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 205                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 206                                errmsg.buf);
 207                strbuf_release(&errmsg);
 208                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 209                return 0;
 210        }
 211
 212        if (!prefixcmp(var, "submodule."))
 213                return parse_submodule_config_option(var, value);
 214
 215        return git_default_config(var, value, cb);
 216}
 217
 218static char *quote_two(const char *one, const char *two)
 219{
 220        int need_one = quote_c_style(one, NULL, NULL, 1);
 221        int need_two = quote_c_style(two, NULL, NULL, 1);
 222        struct strbuf res = STRBUF_INIT;
 223
 224        if (need_one + need_two) {
 225                strbuf_addch(&res, '"');
 226                quote_c_style(one, &res, NULL, 1);
 227                quote_c_style(two, &res, NULL, 1);
 228                strbuf_addch(&res, '"');
 229        } else {
 230                strbuf_addstr(&res, one);
 231                strbuf_addstr(&res, two);
 232        }
 233        return strbuf_detach(&res, NULL);
 234}
 235
 236static const char *external_diff(void)
 237{
 238        static const char *external_diff_cmd = NULL;
 239        static int done_preparing = 0;
 240
 241        if (done_preparing)
 242                return external_diff_cmd;
 243        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 244        if (!external_diff_cmd)
 245                external_diff_cmd = external_diff_cmd_cfg;
 246        done_preparing = 1;
 247        return external_diff_cmd;
 248}
 249
 250static struct diff_tempfile {
 251        const char *name; /* filename external diff should read from */
 252        char hex[41];
 253        char mode[10];
 254        char tmp_path[PATH_MAX];
 255} diff_temp[2];
 256
 257typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 258
 259struct emit_callback {
 260        int color_diff;
 261        unsigned ws_rule;
 262        int blank_at_eof_in_preimage;
 263        int blank_at_eof_in_postimage;
 264        int lno_in_preimage;
 265        int lno_in_postimage;
 266        sane_truncate_fn truncate;
 267        const char **label_path;
 268        struct diff_words_data *diff_words;
 269        struct diff_options *opt;
 270        int *found_changesp;
 271        struct strbuf *header;
 272};
 273
 274static int count_lines(const char *data, int size)
 275{
 276        int count, ch, completely_empty = 1, nl_just_seen = 0;
 277        count = 0;
 278        while (0 < size--) {
 279                ch = *data++;
 280                if (ch == '\n') {
 281                        count++;
 282                        nl_just_seen = 1;
 283                        completely_empty = 0;
 284                }
 285                else {
 286                        nl_just_seen = 0;
 287                        completely_empty = 0;
 288                }
 289        }
 290        if (completely_empty)
 291                return 0;
 292        if (!nl_just_seen)
 293                count++; /* no trailing newline */
 294        return count;
 295}
 296
 297static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 298{
 299        if (!DIFF_FILE_VALID(one)) {
 300                mf->ptr = (char *)""; /* does not matter */
 301                mf->size = 0;
 302                return 0;
 303        }
 304        else if (diff_populate_filespec(one, 0))
 305                return -1;
 306
 307        mf->ptr = one->data;
 308        mf->size = one->size;
 309        return 0;
 310}
 311
 312/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 313static unsigned long diff_filespec_size(struct diff_filespec *one)
 314{
 315        if (!DIFF_FILE_VALID(one))
 316                return 0;
 317        diff_populate_filespec(one, 1);
 318        return one->size;
 319}
 320
 321static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 322{
 323        char *ptr = mf->ptr;
 324        long size = mf->size;
 325        int cnt = 0;
 326
 327        if (!size)
 328                return cnt;
 329        ptr += size - 1; /* pointing at the very end */
 330        if (*ptr != '\n')
 331                ; /* incomplete line */
 332        else
 333                ptr--; /* skip the last LF */
 334        while (mf->ptr < ptr) {
 335                char *prev_eol;
 336                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 337                        if (*prev_eol == '\n')
 338                                break;
 339                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 340                        break;
 341                cnt++;
 342                ptr = prev_eol - 1;
 343        }
 344        return cnt;
 345}
 346
 347static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 348                               struct emit_callback *ecbdata)
 349{
 350        int l1, l2, at;
 351        unsigned ws_rule = ecbdata->ws_rule;
 352        l1 = count_trailing_blank(mf1, ws_rule);
 353        l2 = count_trailing_blank(mf2, ws_rule);
 354        if (l2 <= l1) {
 355                ecbdata->blank_at_eof_in_preimage = 0;
 356                ecbdata->blank_at_eof_in_postimage = 0;
 357                return;
 358        }
 359        at = count_lines(mf1->ptr, mf1->size);
 360        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 361
 362        at = count_lines(mf2->ptr, mf2->size);
 363        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 364}
 365
 366static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 367                        int first, const char *line, int len)
 368{
 369        int has_trailing_newline, has_trailing_carriage_return;
 370        int nofirst;
 371        FILE *file = o->file;
 372
 373        if (o->output_prefix) {
 374                struct strbuf *msg = NULL;
 375                msg = o->output_prefix(o, o->output_prefix_data);
 376                assert(msg);
 377                fwrite(msg->buf, msg->len, 1, file);
 378        }
 379
 380        if (len == 0) {
 381                has_trailing_newline = (first == '\n');
 382                has_trailing_carriage_return = (!has_trailing_newline &&
 383                                                (first == '\r'));
 384                nofirst = has_trailing_newline || has_trailing_carriage_return;
 385        } else {
 386                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 387                if (has_trailing_newline)
 388                        len--;
 389                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 390                if (has_trailing_carriage_return)
 391                        len--;
 392                nofirst = 0;
 393        }
 394
 395        if (len || !nofirst) {
 396                fputs(set, file);
 397                if (!nofirst)
 398                        fputc(first, file);
 399                fwrite(line, len, 1, file);
 400                fputs(reset, file);
 401        }
 402        if (has_trailing_carriage_return)
 403                fputc('\r', file);
 404        if (has_trailing_newline)
 405                fputc('\n', file);
 406}
 407
 408static void emit_line(struct diff_options *o, const char *set, const char *reset,
 409                      const char *line, int len)
 410{
 411        emit_line_0(o, set, reset, line[0], line+1, len-1);
 412}
 413
 414static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 415{
 416        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 417              ecbdata->blank_at_eof_in_preimage &&
 418              ecbdata->blank_at_eof_in_postimage &&
 419              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 420              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 421                return 0;
 422        return ws_blank_line(line, len, ecbdata->ws_rule);
 423}
 424
 425static void emit_add_line(const char *reset,
 426                          struct emit_callback *ecbdata,
 427                          const char *line, int len)
 428{
 429        const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 430        const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 431
 432        if (!*ws)
 433                emit_line_0(ecbdata->opt, set, reset, '+', line, len);
 434        else if (new_blank_line_at_eof(ecbdata, line, len))
 435                /* Blank line at EOF - paint '+' as well */
 436                emit_line_0(ecbdata->opt, ws, reset, '+', line, len);
 437        else {
 438                /* Emit just the prefix, then the rest. */
 439                emit_line_0(ecbdata->opt, set, reset, '+', "", 0);
 440                ws_check_emit(line, len, ecbdata->ws_rule,
 441                              ecbdata->opt->file, set, reset, ws);
 442        }
 443}
 444
 445static void emit_hunk_header(struct emit_callback *ecbdata,
 446                             const char *line, int len)
 447{
 448        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 449        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 450        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 451        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 452        static const char atat[2] = { '@', '@' };
 453        const char *cp, *ep;
 454        struct strbuf msgbuf = STRBUF_INIT;
 455        int org_len = len;
 456        int i = 1;
 457
 458        /*
 459         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 460         * it always is at least 10 bytes long.
 461         */
 462        if (len < 10 ||
 463            memcmp(line, atat, 2) ||
 464            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 465                emit_line(ecbdata->opt, plain, reset, line, len);
 466                return;
 467        }
 468        ep += 2; /* skip over @@ */
 469
 470        /* The hunk header in fraginfo color */
 471        strbuf_add(&msgbuf, frag, strlen(frag));
 472        strbuf_add(&msgbuf, line, ep - line);
 473        strbuf_add(&msgbuf, reset, strlen(reset));
 474
 475        /*
 476         * trailing "\r\n"
 477         */
 478        for ( ; i < 3; i++)
 479                if (line[len - i] == '\r' || line[len - i] == '\n')
 480                        len--;
 481
 482        /* blank before the func header */
 483        for (cp = ep; ep - line < len; ep++)
 484                if (*ep != ' ' && *ep != '\t')
 485                        break;
 486        if (ep != cp) {
 487                strbuf_add(&msgbuf, plain, strlen(plain));
 488                strbuf_add(&msgbuf, cp, ep - cp);
 489                strbuf_add(&msgbuf, reset, strlen(reset));
 490        }
 491
 492        if (ep < line + len) {
 493                strbuf_add(&msgbuf, func, strlen(func));
 494                strbuf_add(&msgbuf, ep, line + len - ep);
 495                strbuf_add(&msgbuf, reset, strlen(reset));
 496        }
 497
 498        strbuf_add(&msgbuf, line + len, org_len - len);
 499        emit_line(ecbdata->opt, "", "", msgbuf.buf, msgbuf.len);
 500        strbuf_release(&msgbuf);
 501}
 502
 503static struct diff_tempfile *claim_diff_tempfile(void) {
 504        int i;
 505        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 506                if (!diff_temp[i].name)
 507                        return diff_temp + i;
 508        die("BUG: diff is failing to clean up its tempfiles");
 509}
 510
 511static int remove_tempfile_installed;
 512
 513static void remove_tempfile(void)
 514{
 515        int i;
 516        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 517                if (diff_temp[i].name == diff_temp[i].tmp_path)
 518                        unlink_or_warn(diff_temp[i].name);
 519                diff_temp[i].name = NULL;
 520        }
 521}
 522
 523static void remove_tempfile_on_signal(int signo)
 524{
 525        remove_tempfile();
 526        sigchain_pop(signo);
 527        raise(signo);
 528}
 529
 530static void print_line_count(FILE *file, int count)
 531{
 532        switch (count) {
 533        case 0:
 534                fprintf(file, "0,0");
 535                break;
 536        case 1:
 537                fprintf(file, "1");
 538                break;
 539        default:
 540                fprintf(file, "1,%d", count);
 541                break;
 542        }
 543}
 544
 545static void emit_rewrite_lines(struct emit_callback *ecb,
 546                               int prefix, const char *data, int size)
 547{
 548        const char *endp = NULL;
 549        static const char *nneof = " No newline at end of file\n";
 550        const char *old = diff_get_color(ecb->color_diff, DIFF_FILE_OLD);
 551        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 552
 553        while (0 < size) {
 554                int len;
 555
 556                endp = memchr(data, '\n', size);
 557                len = endp ? (endp - data + 1) : size;
 558                if (prefix != '+') {
 559                        ecb->lno_in_preimage++;
 560                        emit_line_0(ecb->opt, old, reset, '-',
 561                                    data, len);
 562                } else {
 563                        ecb->lno_in_postimage++;
 564                        emit_add_line(reset, ecb, data, len);
 565                }
 566                size -= len;
 567                data += len;
 568        }
 569        if (!endp) {
 570                const char *plain = diff_get_color(ecb->color_diff,
 571                                                   DIFF_PLAIN);
 572                emit_line_0(ecb->opt, plain, reset, '\\',
 573                            nneof, strlen(nneof));
 574        }
 575}
 576
 577static void emit_rewrite_diff(const char *name_a,
 578                              const char *name_b,
 579                              struct diff_filespec *one,
 580                              struct diff_filespec *two,
 581                              struct userdiff_driver *textconv_one,
 582                              struct userdiff_driver *textconv_two,
 583                              struct diff_options *o)
 584{
 585        int lc_a, lc_b;
 586        const char *name_a_tab, *name_b_tab;
 587        const char *metainfo = diff_get_color(o->use_color, DIFF_METAINFO);
 588        const char *fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
 589        const char *reset = diff_get_color(o->use_color, DIFF_RESET);
 590        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 591        const char *a_prefix, *b_prefix;
 592        char *data_one, *data_two;
 593        size_t size_one, size_two;
 594        struct emit_callback ecbdata;
 595        char *line_prefix = "";
 596        struct strbuf *msgbuf;
 597
 598        if (o && o->output_prefix) {
 599                msgbuf = o->output_prefix(o, o->output_prefix_data);
 600                line_prefix = msgbuf->buf;
 601        }
 602
 603        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 604                a_prefix = o->b_prefix;
 605                b_prefix = o->a_prefix;
 606        } else {
 607                a_prefix = o->a_prefix;
 608                b_prefix = o->b_prefix;
 609        }
 610
 611        name_a += (*name_a == '/');
 612        name_b += (*name_b == '/');
 613        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 614        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 615
 616        strbuf_reset(&a_name);
 617        strbuf_reset(&b_name);
 618        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 619        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 620
 621        size_one = fill_textconv(textconv_one, one, &data_one);
 622        size_two = fill_textconv(textconv_two, two, &data_two);
 623
 624        memset(&ecbdata, 0, sizeof(ecbdata));
 625        ecbdata.color_diff = want_color(o->use_color);
 626        ecbdata.found_changesp = &o->found_changes;
 627        ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
 628        ecbdata.opt = o;
 629        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 630                mmfile_t mf1, mf2;
 631                mf1.ptr = (char *)data_one;
 632                mf2.ptr = (char *)data_two;
 633                mf1.size = size_one;
 634                mf2.size = size_two;
 635                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 636        }
 637        ecbdata.lno_in_preimage = 1;
 638        ecbdata.lno_in_postimage = 1;
 639
 640        lc_a = count_lines(data_one, size_one);
 641        lc_b = count_lines(data_two, size_two);
 642        fprintf(o->file,
 643                "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
 644                line_prefix, metainfo, a_name.buf, name_a_tab, reset,
 645                line_prefix, metainfo, b_name.buf, name_b_tab, reset,
 646                line_prefix, fraginfo);
 647        if (!o->irreversible_delete)
 648                print_line_count(o->file, lc_a);
 649        else
 650                fprintf(o->file, "?,?");
 651        fprintf(o->file, " +");
 652        print_line_count(o->file, lc_b);
 653        fprintf(o->file, " @@%s\n", reset);
 654        if (lc_a && !o->irreversible_delete)
 655                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 656        if (lc_b)
 657                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 658        if (textconv_one)
 659                free((char *)data_one);
 660        if (textconv_two)
 661                free((char *)data_two);
 662}
 663
 664struct diff_words_buffer {
 665        mmfile_t text;
 666        long alloc;
 667        struct diff_words_orig {
 668                const char *begin, *end;
 669        } *orig;
 670        int orig_nr, orig_alloc;
 671};
 672
 673static void diff_words_append(char *line, unsigned long len,
 674                struct diff_words_buffer *buffer)
 675{
 676        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 677        line++;
 678        len--;
 679        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 680        buffer->text.size += len;
 681        buffer->text.ptr[buffer->text.size] = '\0';
 682}
 683
 684struct diff_words_style_elem {
 685        const char *prefix;
 686        const char *suffix;
 687        const char *color; /* NULL; filled in by the setup code if
 688                            * color is enabled */
 689};
 690
 691struct diff_words_style {
 692        enum diff_words_type type;
 693        struct diff_words_style_elem new, old, ctx;
 694        const char *newline;
 695};
 696
 697static struct diff_words_style diff_words_styles[] = {
 698        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 699        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 700        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 701};
 702
 703struct diff_words_data {
 704        struct diff_words_buffer minus, plus;
 705        const char *current_plus;
 706        int last_minus;
 707        struct diff_options *opt;
 708        regex_t *word_regex;
 709        enum diff_words_type type;
 710        struct diff_words_style *style;
 711};
 712
 713static int fn_out_diff_words_write_helper(FILE *fp,
 714                                          struct diff_words_style_elem *st_el,
 715                                          const char *newline,
 716                                          size_t count, const char *buf,
 717                                          const char *line_prefix)
 718{
 719        int print = 0;
 720
 721        while (count) {
 722                char *p = memchr(buf, '\n', count);
 723                if (print)
 724                        fputs(line_prefix, fp);
 725                if (p != buf) {
 726                        if (st_el->color && fputs(st_el->color, fp) < 0)
 727                                return -1;
 728                        if (fputs(st_el->prefix, fp) < 0 ||
 729                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 730                            fputs(st_el->suffix, fp) < 0)
 731                                return -1;
 732                        if (st_el->color && *st_el->color
 733                            && fputs(GIT_COLOR_RESET, fp) < 0)
 734                                return -1;
 735                }
 736                if (!p)
 737                        return 0;
 738                if (fputs(newline, fp) < 0)
 739                        return -1;
 740                count -= p + 1 - buf;
 741                buf = p + 1;
 742                print = 1;
 743        }
 744        return 0;
 745}
 746
 747/*
 748 * '--color-words' algorithm can be described as:
 749 *
 750 *   1. collect a the minus/plus lines of a diff hunk, divided into
 751 *      minus-lines and plus-lines;
 752 *
 753 *   2. break both minus-lines and plus-lines into words and
 754 *      place them into two mmfile_t with one word for each line;
 755 *
 756 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
 757 *
 758 * And for the common parts of the both file, we output the plus side text.
 759 * diff_words->current_plus is used to trace the current position of the plus file
 760 * which printed. diff_words->last_minus is used to trace the last minus word
 761 * printed.
 762 *
 763 * For '--graph' to work with '--color-words', we need to output the graph prefix
 764 * on each line of color words output. Generally, there are two conditions on
 765 * which we should output the prefix.
 766 *
 767 *   1. diff_words->last_minus == 0 &&
 768 *      diff_words->current_plus == diff_words->plus.text.ptr
 769 *
 770 *      that is: the plus text must start as a new line, and if there is no minus
 771 *      word printed, a graph prefix must be printed.
 772 *
 773 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
 774 *      *(diff_words->current_plus - 1) == '\n'
 775 *
 776 *      that is: a graph prefix must be printed following a '\n'
 777 */
 778static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
 779{
 780        if ((diff_words->last_minus == 0 &&
 781                diff_words->current_plus == diff_words->plus.text.ptr) ||
 782                (diff_words->current_plus > diff_words->plus.text.ptr &&
 783                *(diff_words->current_plus - 1) == '\n')) {
 784                return 1;
 785        } else {
 786                return 0;
 787        }
 788}
 789
 790static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 791{
 792        struct diff_words_data *diff_words = priv;
 793        struct diff_words_style *style = diff_words->style;
 794        int minus_first, minus_len, plus_first, plus_len;
 795        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 796        struct diff_options *opt = diff_words->opt;
 797        struct strbuf *msgbuf;
 798        char *line_prefix = "";
 799
 800        if (line[0] != '@' || parse_hunk_header(line, len,
 801                        &minus_first, &minus_len, &plus_first, &plus_len))
 802                return;
 803
 804        assert(opt);
 805        if (opt->output_prefix) {
 806                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 807                line_prefix = msgbuf->buf;
 808        }
 809
 810        /* POSIX requires that first be decremented by one if len == 0... */
 811        if (minus_len) {
 812                minus_begin = diff_words->minus.orig[minus_first].begin;
 813                minus_end =
 814                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 815        } else
 816                minus_begin = minus_end =
 817                        diff_words->minus.orig[minus_first].end;
 818
 819        if (plus_len) {
 820                plus_begin = diff_words->plus.orig[plus_first].begin;
 821                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 822        } else
 823                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 824
 825        if (color_words_output_graph_prefix(diff_words)) {
 826                fputs(line_prefix, diff_words->opt->file);
 827        }
 828        if (diff_words->current_plus != plus_begin) {
 829                fn_out_diff_words_write_helper(diff_words->opt->file,
 830                                &style->ctx, style->newline,
 831                                plus_begin - diff_words->current_plus,
 832                                diff_words->current_plus, line_prefix);
 833                if (*(plus_begin - 1) == '\n')
 834                        fputs(line_prefix, diff_words->opt->file);
 835        }
 836        if (minus_begin != minus_end) {
 837                fn_out_diff_words_write_helper(diff_words->opt->file,
 838                                &style->old, style->newline,
 839                                minus_end - minus_begin, minus_begin,
 840                                line_prefix);
 841        }
 842        if (plus_begin != plus_end) {
 843                fn_out_diff_words_write_helper(diff_words->opt->file,
 844                                &style->new, style->newline,
 845                                plus_end - plus_begin, plus_begin,
 846                                line_prefix);
 847        }
 848
 849        diff_words->current_plus = plus_end;
 850        diff_words->last_minus = minus_first;
 851}
 852
 853/* This function starts looking at *begin, and returns 0 iff a word was found. */
 854static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 855                int *begin, int *end)
 856{
 857        if (word_regex && *begin < buffer->size) {
 858                regmatch_t match[1];
 859                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 860                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 861                                        '\n', match[0].rm_eo - match[0].rm_so);
 862                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 863                        *begin += match[0].rm_so;
 864                        return *begin >= *end;
 865                }
 866                return -1;
 867        }
 868
 869        /* find the next word */
 870        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 871                (*begin)++;
 872        if (*begin >= buffer->size)
 873                return -1;
 874
 875        /* find the end of the word */
 876        *end = *begin + 1;
 877        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 878                (*end)++;
 879
 880        return 0;
 881}
 882
 883/*
 884 * This function splits the words in buffer->text, stores the list with
 885 * newline separator into out, and saves the offsets of the original words
 886 * in buffer->orig.
 887 */
 888static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 889                regex_t *word_regex)
 890{
 891        int i, j;
 892        long alloc = 0;
 893
 894        out->size = 0;
 895        out->ptr = NULL;
 896
 897        /* fake an empty "0th" word */
 898        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 899        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 900        buffer->orig_nr = 1;
 901
 902        for (i = 0; i < buffer->text.size; i++) {
 903                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 904                        return;
 905
 906                /* store original boundaries */
 907                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 908                                buffer->orig_alloc);
 909                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 910                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 911                buffer->orig_nr++;
 912
 913                /* store one word */
 914                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 915                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 916                out->ptr[out->size + j - i] = '\n';
 917                out->size += j - i + 1;
 918
 919                i = j - 1;
 920        }
 921}
 922
 923/* this executes the word diff on the accumulated buffers */
 924static void diff_words_show(struct diff_words_data *diff_words)
 925{
 926        xpparam_t xpp;
 927        xdemitconf_t xecfg;
 928        mmfile_t minus, plus;
 929        struct diff_words_style *style = diff_words->style;
 930
 931        struct diff_options *opt = diff_words->opt;
 932        struct strbuf *msgbuf;
 933        char *line_prefix = "";
 934
 935        assert(opt);
 936        if (opt->output_prefix) {
 937                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 938                line_prefix = msgbuf->buf;
 939        }
 940
 941        /* special case: only removal */
 942        if (!diff_words->plus.text.size) {
 943                fputs(line_prefix, diff_words->opt->file);
 944                fn_out_diff_words_write_helper(diff_words->opt->file,
 945                        &style->old, style->newline,
 946                        diff_words->minus.text.size,
 947                        diff_words->minus.text.ptr, line_prefix);
 948                diff_words->minus.text.size = 0;
 949                return;
 950        }
 951
 952        diff_words->current_plus = diff_words->plus.text.ptr;
 953        diff_words->last_minus = 0;
 954
 955        memset(&xpp, 0, sizeof(xpp));
 956        memset(&xecfg, 0, sizeof(xecfg));
 957        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
 958        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
 959        xpp.flags = 0;
 960        /* as only the hunk header will be parsed, we need a 0-context */
 961        xecfg.ctxlen = 0;
 962        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 963                      &xpp, &xecfg);
 964        free(minus.ptr);
 965        free(plus.ptr);
 966        if (diff_words->current_plus != diff_words->plus.text.ptr +
 967                        diff_words->plus.text.size) {
 968                if (color_words_output_graph_prefix(diff_words))
 969                        fputs(line_prefix, diff_words->opt->file);
 970                fn_out_diff_words_write_helper(diff_words->opt->file,
 971                        &style->ctx, style->newline,
 972                        diff_words->plus.text.ptr + diff_words->plus.text.size
 973                        - diff_words->current_plus, diff_words->current_plus,
 974                        line_prefix);
 975        }
 976        diff_words->minus.text.size = diff_words->plus.text.size = 0;
 977}
 978
 979/* In "color-words" mode, show word-diff of words accumulated in the buffer */
 980static void diff_words_flush(struct emit_callback *ecbdata)
 981{
 982        if (ecbdata->diff_words->minus.text.size ||
 983            ecbdata->diff_words->plus.text.size)
 984                diff_words_show(ecbdata->diff_words);
 985}
 986
 987static void free_diff_words_data(struct emit_callback *ecbdata)
 988{
 989        if (ecbdata->diff_words) {
 990                diff_words_flush(ecbdata);
 991                free (ecbdata->diff_words->minus.text.ptr);
 992                free (ecbdata->diff_words->minus.orig);
 993                free (ecbdata->diff_words->plus.text.ptr);
 994                free (ecbdata->diff_words->plus.orig);
 995                if (ecbdata->diff_words->word_regex) {
 996                        regfree(ecbdata->diff_words->word_regex);
 997                        free(ecbdata->diff_words->word_regex);
 998                }
 999                free(ecbdata->diff_words);
1000                ecbdata->diff_words = NULL;
1001        }
1002}
1003
1004const char *diff_get_color(int diff_use_color, enum color_diff ix)
1005{
1006        if (want_color(diff_use_color))
1007                return diff_colors[ix];
1008        return "";
1009}
1010
1011static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
1012{
1013        const char *cp;
1014        unsigned long allot;
1015        size_t l = len;
1016
1017        if (ecb->truncate)
1018                return ecb->truncate(line, len);
1019        cp = line;
1020        allot = l;
1021        while (0 < l) {
1022                (void) utf8_width(&cp, &l);
1023                if (!cp)
1024                        break; /* truncated in the middle? */
1025        }
1026        return allot - l;
1027}
1028
1029static void find_lno(const char *line, struct emit_callback *ecbdata)
1030{
1031        const char *p;
1032        ecbdata->lno_in_preimage = 0;
1033        ecbdata->lno_in_postimage = 0;
1034        p = strchr(line, '-');
1035        if (!p)
1036                return; /* cannot happen */
1037        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1038        p = strchr(p, '+');
1039        if (!p)
1040                return; /* cannot happen */
1041        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
1042}
1043
1044static void fn_out_consume(void *priv, char *line, unsigned long len)
1045{
1046        struct emit_callback *ecbdata = priv;
1047        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
1048        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
1049        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1050        struct diff_options *o = ecbdata->opt;
1051        char *line_prefix = "";
1052        struct strbuf *msgbuf;
1053
1054        if (o && o->output_prefix) {
1055                msgbuf = o->output_prefix(o, o->output_prefix_data);
1056                line_prefix = msgbuf->buf;
1057        }
1058
1059        if (ecbdata->header) {
1060                fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
1061                strbuf_reset(ecbdata->header);
1062                ecbdata->header = NULL;
1063        }
1064        *(ecbdata->found_changesp) = 1;
1065
1066        if (ecbdata->label_path[0]) {
1067                const char *name_a_tab, *name_b_tab;
1068
1069                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
1070                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
1071
1072                fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
1073                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
1074                fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
1075                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1076                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1077        }
1078
1079        if (diff_suppress_blank_empty
1080            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1081                line[0] = '\n';
1082                len = 1;
1083        }
1084
1085        if (line[0] == '@') {
1086                if (ecbdata->diff_words)
1087                        diff_words_flush(ecbdata);
1088                len = sane_truncate_line(ecbdata, line, len);
1089                find_lno(line, ecbdata);
1090                emit_hunk_header(ecbdata, line, len);
1091                if (line[len-1] != '\n')
1092                        putc('\n', ecbdata->opt->file);
1093                return;
1094        }
1095
1096        if (len < 1) {
1097                emit_line(ecbdata->opt, reset, reset, line, len);
1098                if (ecbdata->diff_words
1099                    && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
1100                        fputs("~\n", ecbdata->opt->file);
1101                return;
1102        }
1103
1104        if (ecbdata->diff_words) {
1105                if (line[0] == '-') {
1106                        diff_words_append(line, len,
1107                                          &ecbdata->diff_words->minus);
1108                        return;
1109                } else if (line[0] == '+') {
1110                        diff_words_append(line, len,
1111                                          &ecbdata->diff_words->plus);
1112                        return;
1113                } else if (!prefixcmp(line, "\\ ")) {
1114                        /*
1115                         * Eat the "no newline at eof" marker as if we
1116                         * saw a "+" or "-" line with nothing on it,
1117                         * and return without diff_words_flush() to
1118                         * defer processing. If this is the end of
1119                         * preimage, more "+" lines may come after it.
1120                         */
1121                        return;
1122                }
1123                diff_words_flush(ecbdata);
1124                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1125                        emit_line(ecbdata->opt, plain, reset, line, len);
1126                        fputs("~\n", ecbdata->opt->file);
1127                } else {
1128                        /*
1129                         * Skip the prefix character, if any.  With
1130                         * diff_suppress_blank_empty, there may be
1131                         * none.
1132                         */
1133                        if (line[0] != '\n') {
1134                              line++;
1135                              len--;
1136                        }
1137                        emit_line(ecbdata->opt, plain, reset, line, len);
1138                }
1139                return;
1140        }
1141
1142        if (line[0] != '+') {
1143                const char *color =
1144                        diff_get_color(ecbdata->color_diff,
1145                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
1146                ecbdata->lno_in_preimage++;
1147                if (line[0] == ' ')
1148                        ecbdata->lno_in_postimage++;
1149                emit_line(ecbdata->opt, color, reset, line, len);
1150        } else {
1151                ecbdata->lno_in_postimage++;
1152                emit_add_line(reset, ecbdata, line + 1, len - 1);
1153        }
1154}
1155
1156static char *pprint_rename(const char *a, const char *b)
1157{
1158        const char *old = a;
1159        const char *new = b;
1160        struct strbuf name = STRBUF_INIT;
1161        int pfx_length, sfx_length;
1162        int len_a = strlen(a);
1163        int len_b = strlen(b);
1164        int a_midlen, b_midlen;
1165        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1166        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1167
1168        if (qlen_a || qlen_b) {
1169                quote_c_style(a, &name, NULL, 0);
1170                strbuf_addstr(&name, " => ");
1171                quote_c_style(b, &name, NULL, 0);
1172                return strbuf_detach(&name, NULL);
1173        }
1174
1175        /* Find common prefix */
1176        pfx_length = 0;
1177        while (*old && *new && *old == *new) {
1178                if (*old == '/')
1179                        pfx_length = old - a + 1;
1180                old++;
1181                new++;
1182        }
1183
1184        /* Find common suffix */
1185        old = a + len_a;
1186        new = b + len_b;
1187        sfx_length = 0;
1188        while (a <= old && b <= new && *old == *new) {
1189                if (*old == '/')
1190                        sfx_length = len_a - (old - a);
1191                old--;
1192                new--;
1193        }
1194
1195        /*
1196         * pfx{mid-a => mid-b}sfx
1197         * {pfx-a => pfx-b}sfx
1198         * pfx{sfx-a => sfx-b}
1199         * name-a => name-b
1200         */
1201        a_midlen = len_a - pfx_length - sfx_length;
1202        b_midlen = len_b - pfx_length - sfx_length;
1203        if (a_midlen < 0)
1204                a_midlen = 0;
1205        if (b_midlen < 0)
1206                b_midlen = 0;
1207
1208        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1209        if (pfx_length + sfx_length) {
1210                strbuf_add(&name, a, pfx_length);
1211                strbuf_addch(&name, '{');
1212        }
1213        strbuf_add(&name, a + pfx_length, a_midlen);
1214        strbuf_addstr(&name, " => ");
1215        strbuf_add(&name, b + pfx_length, b_midlen);
1216        if (pfx_length + sfx_length) {
1217                strbuf_addch(&name, '}');
1218                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1219        }
1220        return strbuf_detach(&name, NULL);
1221}
1222
1223struct diffstat_t {
1224        int nr;
1225        int alloc;
1226        struct diffstat_file {
1227                char *from_name;
1228                char *name;
1229                char *print_name;
1230                unsigned is_unmerged:1;
1231                unsigned is_binary:1;
1232                unsigned is_renamed:1;
1233                uintmax_t added, deleted;
1234        } **files;
1235};
1236
1237static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1238                                          const char *name_a,
1239                                          const char *name_b)
1240{
1241        struct diffstat_file *x;
1242        x = xcalloc(sizeof (*x), 1);
1243        if (diffstat->nr == diffstat->alloc) {
1244                diffstat->alloc = alloc_nr(diffstat->alloc);
1245                diffstat->files = xrealloc(diffstat->files,
1246                                diffstat->alloc * sizeof(x));
1247        }
1248        diffstat->files[diffstat->nr++] = x;
1249        if (name_b) {
1250                x->from_name = xstrdup(name_a);
1251                x->name = xstrdup(name_b);
1252                x->is_renamed = 1;
1253        }
1254        else {
1255                x->from_name = NULL;
1256                x->name = xstrdup(name_a);
1257        }
1258        return x;
1259}
1260
1261static void diffstat_consume(void *priv, char *line, unsigned long len)
1262{
1263        struct diffstat_t *diffstat = priv;
1264        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1265
1266        if (line[0] == '+')
1267                x->added++;
1268        else if (line[0] == '-')
1269                x->deleted++;
1270}
1271
1272const char mime_boundary_leader[] = "------------";
1273
1274static int scale_linear(int it, int width, int max_change)
1275{
1276        /*
1277         * make sure that at least one '-' is printed if there were deletions,
1278         * and likewise for '+'.
1279         */
1280        if (max_change < 2)
1281                return it;
1282        return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
1283}
1284
1285static void show_name(FILE *file,
1286                      const char *prefix, const char *name, int len)
1287{
1288        fprintf(file, " %s%-*s |", prefix, len, name);
1289}
1290
1291static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1292{
1293        if (cnt <= 0)
1294                return;
1295        fprintf(file, "%s", set);
1296        while (cnt--)
1297                putc(ch, file);
1298        fprintf(file, "%s", reset);
1299}
1300
1301static void fill_print_name(struct diffstat_file *file)
1302{
1303        char *pname;
1304
1305        if (file->print_name)
1306                return;
1307
1308        if (!file->is_renamed) {
1309                struct strbuf buf = STRBUF_INIT;
1310                if (quote_c_style(file->name, &buf, NULL, 0)) {
1311                        pname = strbuf_detach(&buf, NULL);
1312                } else {
1313                        pname = file->name;
1314                        strbuf_release(&buf);
1315                }
1316        } else {
1317                pname = pprint_rename(file->from_name, file->name);
1318        }
1319        file->print_name = pname;
1320}
1321
1322int print_stat_summary(FILE *fp, int files, int insertions, int deletions)
1323{
1324        struct strbuf sb = STRBUF_INIT;
1325        int ret;
1326
1327        if (!files) {
1328                assert(insertions == 0 && deletions == 0);
1329                return fputs(_(" 0 files changed\n"), fp);
1330        }
1331
1332        strbuf_addf(&sb,
1333                    Q_(" %d file changed", " %d files changed", files),
1334                    files);
1335
1336        /*
1337         * For binary diff, the caller may want to print "x files
1338         * changed" with insertions == 0 && deletions == 0.
1339         *
1340         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
1341         * is probably less confusing (i.e skip over "2 files changed
1342         * but nothing about added/removed lines? Is this a bug in Git?").
1343         */
1344        if (insertions || deletions == 0) {
1345                /*
1346                 * TRANSLATORS: "+" in (+) is a line addition marker;
1347                 * do not translate it.
1348                 */
1349                strbuf_addf(&sb,
1350                            Q_(", %d insertion(+)", ", %d insertions(+)",
1351                               insertions),
1352                            insertions);
1353        }
1354
1355        if (deletions || insertions == 0) {
1356                /*
1357                 * TRANSLATORS: "-" in (-) is a line removal marker;
1358                 * do not translate it.
1359                 */
1360                strbuf_addf(&sb,
1361                            Q_(", %d deletion(-)", ", %d deletions(-)",
1362                               deletions),
1363                            deletions);
1364        }
1365        strbuf_addch(&sb, '\n');
1366        ret = fputs(sb.buf, fp);
1367        strbuf_release(&sb);
1368        return ret;
1369}
1370
1371static void show_stats(struct diffstat_t *data, struct diff_options *options)
1372{
1373        int i, len, add, del, adds = 0, dels = 0;
1374        uintmax_t max_change = 0, max_len = 0;
1375        int total_files = data->nr;
1376        int width, name_width, count;
1377        const char *reset, *add_c, *del_c;
1378        const char *line_prefix = "";
1379        int extra_shown = 0;
1380        struct strbuf *msg = NULL;
1381
1382        if (data->nr == 0)
1383                return;
1384
1385        if (options->output_prefix) {
1386                msg = options->output_prefix(options, options->output_prefix_data);
1387                line_prefix = msg->buf;
1388        }
1389
1390        width = options->stat_width ? options->stat_width : 80;
1391        name_width = options->stat_name_width ? options->stat_name_width : 50;
1392        count = options->stat_count ? options->stat_count : data->nr;
1393
1394        /* Sanity: give at least 5 columns to the graph,
1395         * but leave at least 10 columns for the name.
1396         */
1397        if (width < 25)
1398                width = 25;
1399        if (name_width < 10)
1400                name_width = 10;
1401        else if (width < name_width + 15)
1402                name_width = width - 15;
1403
1404        /* Find the longest filename and max number of changes */
1405        reset = diff_get_color_opt(options, DIFF_RESET);
1406        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1407        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1408
1409        for (i = 0; (i < count) && (i < data->nr); i++) {
1410                struct diffstat_file *file = data->files[i];
1411                uintmax_t change = file->added + file->deleted;
1412                if (!data->files[i]->is_renamed &&
1413                         (change == 0)) {
1414                        count++; /* not shown == room for one more */
1415                        continue;
1416                }
1417                fill_print_name(file);
1418                len = strlen(file->print_name);
1419                if (max_len < len)
1420                        max_len = len;
1421
1422                if (file->is_binary || file->is_unmerged)
1423                        continue;
1424                if (max_change < change)
1425                        max_change = change;
1426        }
1427        count = i; /* min(count, data->nr) */
1428
1429        /* Compute the width of the graph part;
1430         * 10 is for one blank at the beginning of the line plus
1431         * " | count " between the name and the graph.
1432         *
1433         * From here on, name_width is the width of the name area,
1434         * and width is the width of the graph area.
1435         */
1436        name_width = (name_width < max_len) ? name_width : max_len;
1437        if (width < (name_width + 10) + max_change)
1438                width = width - (name_width + 10);
1439        else
1440                width = max_change;
1441
1442        for (i = 0; i < count; i++) {
1443                const char *prefix = "";
1444                char *name = data->files[i]->print_name;
1445                uintmax_t added = data->files[i]->added;
1446                uintmax_t deleted = data->files[i]->deleted;
1447                int name_len;
1448
1449                if (!data->files[i]->is_renamed &&
1450                         (added + deleted == 0)) {
1451                        total_files--;
1452                        continue;
1453                }
1454                /*
1455                 * "scale" the filename
1456                 */
1457                len = name_width;
1458                name_len = strlen(name);
1459                if (name_width < name_len) {
1460                        char *slash;
1461                        prefix = "...";
1462                        len -= 3;
1463                        name += name_len - len;
1464                        slash = strchr(name, '/');
1465                        if (slash)
1466                                name = slash;
1467                }
1468
1469                if (data->files[i]->is_binary) {
1470                        fprintf(options->file, "%s", line_prefix);
1471                        show_name(options->file, prefix, name, len);
1472                        fprintf(options->file, "  Bin ");
1473                        fprintf(options->file, "%s%"PRIuMAX"%s",
1474                                del_c, deleted, reset);
1475                        fprintf(options->file, " -> ");
1476                        fprintf(options->file, "%s%"PRIuMAX"%s",
1477                                add_c, added, reset);
1478                        fprintf(options->file, " bytes");
1479                        fprintf(options->file, "\n");
1480                        continue;
1481                }
1482                else if (data->files[i]->is_unmerged) {
1483                        fprintf(options->file, "%s", line_prefix);
1484                        show_name(options->file, prefix, name, len);
1485                        fprintf(options->file, "  Unmerged\n");
1486                        continue;
1487                }
1488
1489                /*
1490                 * scale the add/delete
1491                 */
1492                add = added;
1493                del = deleted;
1494                adds += add;
1495                dels += del;
1496
1497                if (width <= max_change) {
1498                        add = scale_linear(add, width, max_change);
1499                        del = scale_linear(del, width, max_change);
1500                }
1501                fprintf(options->file, "%s", line_prefix);
1502                show_name(options->file, prefix, name, len);
1503                fprintf(options->file, "%5"PRIuMAX"%s", added + deleted,
1504                                added + deleted ? " " : "");
1505                show_graph(options->file, '+', add, add_c, reset);
1506                show_graph(options->file, '-', del, del_c, reset);
1507                fprintf(options->file, "\n");
1508        }
1509        for (i = count; i < data->nr; i++) {
1510                uintmax_t added = data->files[i]->added;
1511                uintmax_t deleted = data->files[i]->deleted;
1512                if (!data->files[i]->is_renamed &&
1513                         (added + deleted == 0)) {
1514                        total_files--;
1515                        continue;
1516                }
1517                adds += added;
1518                dels += deleted;
1519                if (!extra_shown)
1520                        fprintf(options->file, "%s ...\n", line_prefix);
1521                extra_shown = 1;
1522        }
1523        fprintf(options->file, "%s", line_prefix);
1524        print_stat_summary(options->file, total_files, adds, dels);
1525}
1526
1527static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1528{
1529        int i, adds = 0, dels = 0, total_files = data->nr;
1530
1531        if (data->nr == 0)
1532                return;
1533
1534        for (i = 0; i < data->nr; i++) {
1535                if (!data->files[i]->is_binary &&
1536                    !data->files[i]->is_unmerged) {
1537                        int added = data->files[i]->added;
1538                        int deleted= data->files[i]->deleted;
1539                        if (!data->files[i]->is_renamed &&
1540                            (added + deleted == 0)) {
1541                                total_files--;
1542                        } else {
1543                                adds += added;
1544                                dels += deleted;
1545                        }
1546                }
1547        }
1548        if (options->output_prefix) {
1549                struct strbuf *msg = NULL;
1550                msg = options->output_prefix(options,
1551                                options->output_prefix_data);
1552                fprintf(options->file, "%s", msg->buf);
1553        }
1554        print_stat_summary(options->file, total_files, adds, dels);
1555}
1556
1557static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1558{
1559        int i;
1560
1561        if (data->nr == 0)
1562                return;
1563
1564        for (i = 0; i < data->nr; i++) {
1565                struct diffstat_file *file = data->files[i];
1566
1567                if (options->output_prefix) {
1568                        struct strbuf *msg = NULL;
1569                        msg = options->output_prefix(options,
1570                                        options->output_prefix_data);
1571                        fprintf(options->file, "%s", msg->buf);
1572                }
1573
1574                if (file->is_binary)
1575                        fprintf(options->file, "-\t-\t");
1576                else
1577                        fprintf(options->file,
1578                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1579                                file->added, file->deleted);
1580                if (options->line_termination) {
1581                        fill_print_name(file);
1582                        if (!file->is_renamed)
1583                                write_name_quoted(file->name, options->file,
1584                                                  options->line_termination);
1585                        else {
1586                                fputs(file->print_name, options->file);
1587                                putc(options->line_termination, options->file);
1588                        }
1589                } else {
1590                        if (file->is_renamed) {
1591                                putc('\0', options->file);
1592                                write_name_quoted(file->from_name, options->file, '\0');
1593                        }
1594                        write_name_quoted(file->name, options->file, '\0');
1595                }
1596        }
1597}
1598
1599struct dirstat_file {
1600        const char *name;
1601        unsigned long changed;
1602};
1603
1604struct dirstat_dir {
1605        struct dirstat_file *files;
1606        int alloc, nr, permille, cumulative;
1607};
1608
1609static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1610                unsigned long changed, const char *base, int baselen)
1611{
1612        unsigned long this_dir = 0;
1613        unsigned int sources = 0;
1614        const char *line_prefix = "";
1615        struct strbuf *msg = NULL;
1616
1617        if (opt->output_prefix) {
1618                msg = opt->output_prefix(opt, opt->output_prefix_data);
1619                line_prefix = msg->buf;
1620        }
1621
1622        while (dir->nr) {
1623                struct dirstat_file *f = dir->files;
1624                int namelen = strlen(f->name);
1625                unsigned long this;
1626                char *slash;
1627
1628                if (namelen < baselen)
1629                        break;
1630                if (memcmp(f->name, base, baselen))
1631                        break;
1632                slash = strchr(f->name + baselen, '/');
1633                if (slash) {
1634                        int newbaselen = slash + 1 - f->name;
1635                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1636                        sources++;
1637                } else {
1638                        this = f->changed;
1639                        dir->files++;
1640                        dir->nr--;
1641                        sources += 2;
1642                }
1643                this_dir += this;
1644        }
1645
1646        /*
1647         * We don't report dirstat's for
1648         *  - the top level
1649         *  - or cases where everything came from a single directory
1650         *    under this directory (sources == 1).
1651         */
1652        if (baselen && sources != 1) {
1653                if (this_dir) {
1654                        int permille = this_dir * 1000 / changed;
1655                        if (permille >= dir->permille) {
1656                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1657                                        permille / 10, permille % 10, baselen, base);
1658                                if (!dir->cumulative)
1659                                        return 0;
1660                        }
1661                }
1662        }
1663        return this_dir;
1664}
1665
1666static int dirstat_compare(const void *_a, const void *_b)
1667{
1668        const struct dirstat_file *a = _a;
1669        const struct dirstat_file *b = _b;
1670        return strcmp(a->name, b->name);
1671}
1672
1673static void show_dirstat(struct diff_options *options)
1674{
1675        int i;
1676        unsigned long changed;
1677        struct dirstat_dir dir;
1678        struct diff_queue_struct *q = &diff_queued_diff;
1679
1680        dir.files = NULL;
1681        dir.alloc = 0;
1682        dir.nr = 0;
1683        dir.permille = options->dirstat_permille;
1684        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1685
1686        changed = 0;
1687        for (i = 0; i < q->nr; i++) {
1688                struct diff_filepair *p = q->queue[i];
1689                const char *name;
1690                unsigned long copied, added, damage;
1691                int content_changed;
1692
1693                name = p->two->path ? p->two->path : p->one->path;
1694
1695                if (p->one->sha1_valid && p->two->sha1_valid)
1696                        content_changed = hashcmp(p->one->sha1, p->two->sha1);
1697                else
1698                        content_changed = 1;
1699
1700                if (!content_changed) {
1701                        /*
1702                         * The SHA1 has not changed, so pre-/post-content is
1703                         * identical. We can therefore skip looking at the
1704                         * file contents altogether.
1705                         */
1706                        damage = 0;
1707                        goto found_damage;
1708                }
1709
1710                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1711                        /*
1712                         * In --dirstat-by-file mode, we don't really need to
1713                         * look at the actual file contents at all.
1714                         * The fact that the SHA1 changed is enough for us to
1715                         * add this file to the list of results
1716                         * (with each file contributing equal damage).
1717                         */
1718                        damage = 1;
1719                        goto found_damage;
1720                }
1721
1722                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1723                        diff_populate_filespec(p->one, 0);
1724                        diff_populate_filespec(p->two, 0);
1725                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1726                                               &copied, &added);
1727                        diff_free_filespec_data(p->one);
1728                        diff_free_filespec_data(p->two);
1729                } else if (DIFF_FILE_VALID(p->one)) {
1730                        diff_populate_filespec(p->one, 1);
1731                        copied = added = 0;
1732                        diff_free_filespec_data(p->one);
1733                } else if (DIFF_FILE_VALID(p->two)) {
1734                        diff_populate_filespec(p->two, 1);
1735                        copied = 0;
1736                        added = p->two->size;
1737                        diff_free_filespec_data(p->two);
1738                } else
1739                        continue;
1740
1741                /*
1742                 * Original minus copied is the removed material,
1743                 * added is the new material.  They are both damages
1744                 * made to the preimage.
1745                 * If the resulting damage is zero, we know that
1746                 * diffcore_count_changes() considers the two entries to
1747                 * be identical, but since content_changed is true, we
1748                 * know that there must have been _some_ kind of change,
1749                 * so we force all entries to have damage > 0.
1750                 */
1751                damage = (p->one->size - copied) + added;
1752                if (!damage)
1753                        damage = 1;
1754
1755found_damage:
1756                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1757                dir.files[dir.nr].name = name;
1758                dir.files[dir.nr].changed = damage;
1759                changed += damage;
1760                dir.nr++;
1761        }
1762
1763        /* This can happen even with many files, if everything was renames */
1764        if (!changed)
1765                return;
1766
1767        /* Show all directories with more than x% of the changes */
1768        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1769        gather_dirstat(options, &dir, changed, "", 0);
1770}
1771
1772static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
1773{
1774        int i;
1775        unsigned long changed;
1776        struct dirstat_dir dir;
1777
1778        if (data->nr == 0)
1779                return;
1780
1781        dir.files = NULL;
1782        dir.alloc = 0;
1783        dir.nr = 0;
1784        dir.permille = options->dirstat_permille;
1785        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1786
1787        changed = 0;
1788        for (i = 0; i < data->nr; i++) {
1789                struct diffstat_file *file = data->files[i];
1790                unsigned long damage = file->added + file->deleted;
1791                if (file->is_binary)
1792                        /*
1793                         * binary files counts bytes, not lines. Must find some
1794                         * way to normalize binary bytes vs. textual lines.
1795                         * The following heuristic assumes that there are 64
1796                         * bytes per "line".
1797                         * This is stupid and ugly, but very cheap...
1798                         */
1799                        damage = (damage + 63) / 64;
1800                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1801                dir.files[dir.nr].name = file->name;
1802                dir.files[dir.nr].changed = damage;
1803                changed += damage;
1804                dir.nr++;
1805        }
1806
1807        /* This can happen even with many files, if everything was renames */
1808        if (!changed)
1809                return;
1810
1811        /* Show all directories with more than x% of the changes */
1812        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1813        gather_dirstat(options, &dir, changed, "", 0);
1814}
1815
1816static void free_diffstat_info(struct diffstat_t *diffstat)
1817{
1818        int i;
1819        for (i = 0; i < diffstat->nr; i++) {
1820                struct diffstat_file *f = diffstat->files[i];
1821                if (f->name != f->print_name)
1822                        free(f->print_name);
1823                free(f->name);
1824                free(f->from_name);
1825                free(f);
1826        }
1827        free(diffstat->files);
1828}
1829
1830struct checkdiff_t {
1831        const char *filename;
1832        int lineno;
1833        int conflict_marker_size;
1834        struct diff_options *o;
1835        unsigned ws_rule;
1836        unsigned status;
1837};
1838
1839static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1840{
1841        char firstchar;
1842        int cnt;
1843
1844        if (len < marker_size + 1)
1845                return 0;
1846        firstchar = line[0];
1847        switch (firstchar) {
1848        case '=': case '>': case '<': case '|':
1849                break;
1850        default:
1851                return 0;
1852        }
1853        for (cnt = 1; cnt < marker_size; cnt++)
1854                if (line[cnt] != firstchar)
1855                        return 0;
1856        /* line[1] thru line[marker_size-1] are same as firstchar */
1857        if (len < marker_size + 1 || !isspace(line[marker_size]))
1858                return 0;
1859        return 1;
1860}
1861
1862static void checkdiff_consume(void *priv, char *line, unsigned long len)
1863{
1864        struct checkdiff_t *data = priv;
1865        int marker_size = data->conflict_marker_size;
1866        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
1867        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
1868        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
1869        char *err;
1870        char *line_prefix = "";
1871        struct strbuf *msgbuf;
1872
1873        assert(data->o);
1874        if (data->o->output_prefix) {
1875                msgbuf = data->o->output_prefix(data->o,
1876                        data->o->output_prefix_data);
1877                line_prefix = msgbuf->buf;
1878        }
1879
1880        if (line[0] == '+') {
1881                unsigned bad;
1882                data->lineno++;
1883                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
1884                        data->status |= 1;
1885                        fprintf(data->o->file,
1886                                "%s%s:%d: leftover conflict marker\n",
1887                                line_prefix, data->filename, data->lineno);
1888                }
1889                bad = ws_check(line + 1, len - 1, data->ws_rule);
1890                if (!bad)
1891                        return;
1892                data->status |= bad;
1893                err = whitespace_error_string(bad);
1894                fprintf(data->o->file, "%s%s:%d: %s.\n",
1895                        line_prefix, data->filename, data->lineno, err);
1896                free(err);
1897                emit_line(data->o, set, reset, line, 1);
1898                ws_check_emit(line + 1, len - 1, data->ws_rule,
1899                              data->o->file, set, reset, ws);
1900        } else if (line[0] == ' ') {
1901                data->lineno++;
1902        } else if (line[0] == '@') {
1903                char *plus = strchr(line, '+');
1904                if (plus)
1905                        data->lineno = strtol(plus, NULL, 10) - 1;
1906                else
1907                        die("invalid diff");
1908        }
1909}
1910
1911static unsigned char *deflate_it(char *data,
1912                                 unsigned long size,
1913                                 unsigned long *result_size)
1914{
1915        int bound;
1916        unsigned char *deflated;
1917        git_zstream stream;
1918
1919        memset(&stream, 0, sizeof(stream));
1920        git_deflate_init(&stream, zlib_compression_level);
1921        bound = git_deflate_bound(&stream, size);
1922        deflated = xmalloc(bound);
1923        stream.next_out = deflated;
1924        stream.avail_out = bound;
1925
1926        stream.next_in = (unsigned char *)data;
1927        stream.avail_in = size;
1928        while (git_deflate(&stream, Z_FINISH) == Z_OK)
1929                ; /* nothing */
1930        git_deflate_end(&stream);
1931        *result_size = stream.total_out;
1932        return deflated;
1933}
1934
1935static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1936{
1937        void *cp;
1938        void *delta;
1939        void *deflated;
1940        void *data;
1941        unsigned long orig_size;
1942        unsigned long delta_size;
1943        unsigned long deflate_size;
1944        unsigned long data_size;
1945
1946        /* We could do deflated delta, or we could do just deflated two,
1947         * whichever is smaller.
1948         */
1949        delta = NULL;
1950        deflated = deflate_it(two->ptr, two->size, &deflate_size);
1951        if (one->size && two->size) {
1952                delta = diff_delta(one->ptr, one->size,
1953                                   two->ptr, two->size,
1954                                   &delta_size, deflate_size);
1955                if (delta) {
1956                        void *to_free = delta;
1957                        orig_size = delta_size;
1958                        delta = deflate_it(delta, delta_size, &delta_size);
1959                        free(to_free);
1960                }
1961        }
1962
1963        if (delta && delta_size < deflate_size) {
1964                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
1965                free(deflated);
1966                data = delta;
1967                data_size = delta_size;
1968        }
1969        else {
1970                fprintf(file, "%sliteral %lu\n", prefix, two->size);
1971                free(delta);
1972                data = deflated;
1973                data_size = deflate_size;
1974        }
1975
1976        /* emit data encoded in base85 */
1977        cp = data;
1978        while (data_size) {
1979                int bytes = (52 < data_size) ? 52 : data_size;
1980                char line[70];
1981                data_size -= bytes;
1982                if (bytes <= 26)
1983                        line[0] = bytes + 'A' - 1;
1984                else
1985                        line[0] = bytes - 26 + 'a' - 1;
1986                encode_85(line + 1, cp, bytes);
1987                cp = (char *) cp + bytes;
1988                fprintf(file, "%s", prefix);
1989                fputs(line, file);
1990                fputc('\n', file);
1991        }
1992        fprintf(file, "%s\n", prefix);
1993        free(data);
1994}
1995
1996static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1997{
1998        fprintf(file, "%sGIT binary patch\n", prefix);
1999        emit_binary_diff_body(file, one, two, prefix);
2000        emit_binary_diff_body(file, two, one, prefix);
2001}
2002
2003static void diff_filespec_load_driver(struct diff_filespec *one)
2004{
2005        /* Use already-loaded driver */
2006        if (one->driver)
2007                return;
2008
2009        if (S_ISREG(one->mode))
2010                one->driver = userdiff_find_by_path(one->path);
2011
2012        /* Fallback to default settings */
2013        if (!one->driver)
2014                one->driver = userdiff_find_by_name("default");
2015}
2016
2017int diff_filespec_is_binary(struct diff_filespec *one)
2018{
2019        if (one->is_binary == -1) {
2020                diff_filespec_load_driver(one);
2021                if (one->driver->binary != -1)
2022                        one->is_binary = one->driver->binary;
2023                else {
2024                        if (!one->data && DIFF_FILE_VALID(one))
2025                                diff_populate_filespec(one, 0);
2026                        if (one->data)
2027                                one->is_binary = buffer_is_binary(one->data,
2028                                                one->size);
2029                        if (one->is_binary == -1)
2030                                one->is_binary = 0;
2031                }
2032        }
2033        return one->is_binary;
2034}
2035
2036static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
2037{
2038        diff_filespec_load_driver(one);
2039        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
2040}
2041
2042static const char *userdiff_word_regex(struct diff_filespec *one)
2043{
2044        diff_filespec_load_driver(one);
2045        return one->driver->word_regex;
2046}
2047
2048void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
2049{
2050        if (!options->a_prefix)
2051                options->a_prefix = a;
2052        if (!options->b_prefix)
2053                options->b_prefix = b;
2054}
2055
2056struct userdiff_driver *get_textconv(struct diff_filespec *one)
2057{
2058        if (!DIFF_FILE_VALID(one))
2059                return NULL;
2060
2061        diff_filespec_load_driver(one);
2062        return userdiff_get_textconv(one->driver);
2063}
2064
2065static void builtin_diff(const char *name_a,
2066                         const char *name_b,
2067                         struct diff_filespec *one,
2068                         struct diff_filespec *two,
2069                         const char *xfrm_msg,
2070                         int must_show_header,
2071                         struct diff_options *o,
2072                         int complete_rewrite)
2073{
2074        mmfile_t mf1, mf2;
2075        const char *lbl[2];
2076        char *a_one, *b_two;
2077        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
2078        const char *reset = diff_get_color_opt(o, DIFF_RESET);
2079        const char *a_prefix, *b_prefix;
2080        struct userdiff_driver *textconv_one = NULL;
2081        struct userdiff_driver *textconv_two = NULL;
2082        struct strbuf header = STRBUF_INIT;
2083        struct strbuf *msgbuf;
2084        char *line_prefix = "";
2085
2086        if (o->output_prefix) {
2087                msgbuf = o->output_prefix(o, o->output_prefix_data);
2088                line_prefix = msgbuf->buf;
2089        }
2090
2091        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
2092                        (!one->mode || S_ISGITLINK(one->mode)) &&
2093                        (!two->mode || S_ISGITLINK(two->mode))) {
2094                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2095                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2096                show_submodule_summary(o->file, one ? one->path : two->path,
2097                                one->sha1, two->sha1, two->dirty_submodule,
2098                                del, add, reset);
2099                return;
2100        }
2101
2102        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
2103                textconv_one = get_textconv(one);
2104                textconv_two = get_textconv(two);
2105        }
2106
2107        diff_set_mnemonic_prefix(o, "a/", "b/");
2108        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
2109                a_prefix = o->b_prefix;
2110                b_prefix = o->a_prefix;
2111        } else {
2112                a_prefix = o->a_prefix;
2113                b_prefix = o->b_prefix;
2114        }
2115
2116        /* Never use a non-valid filename anywhere if at all possible */
2117        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
2118        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
2119
2120        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
2121        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
2122        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
2123        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
2124        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
2125        if (lbl[0][0] == '/') {
2126                /* /dev/null */
2127                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
2128                if (xfrm_msg)
2129                        strbuf_addstr(&header, xfrm_msg);
2130                must_show_header = 1;
2131        }
2132        else if (lbl[1][0] == '/') {
2133                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
2134                if (xfrm_msg)
2135                        strbuf_addstr(&header, xfrm_msg);
2136                must_show_header = 1;
2137        }
2138        else {
2139                if (one->mode != two->mode) {
2140                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
2141                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
2142                        must_show_header = 1;
2143                }
2144                if (xfrm_msg)
2145                        strbuf_addstr(&header, xfrm_msg);
2146
2147                /*
2148                 * we do not run diff between different kind
2149                 * of objects.
2150                 */
2151                if ((one->mode ^ two->mode) & S_IFMT)
2152                        goto free_ab_and_return;
2153                if (complete_rewrite &&
2154                    (textconv_one || !diff_filespec_is_binary(one)) &&
2155                    (textconv_two || !diff_filespec_is_binary(two))) {
2156                        fprintf(o->file, "%s", header.buf);
2157                        strbuf_reset(&header);
2158                        emit_rewrite_diff(name_a, name_b, one, two,
2159                                                textconv_one, textconv_two, o);
2160                        o->found_changes = 1;
2161                        goto free_ab_and_return;
2162                }
2163        }
2164
2165        if (o->irreversible_delete && lbl[1][0] == '/') {
2166                fprintf(o->file, "%s", header.buf);
2167                strbuf_reset(&header);
2168                goto free_ab_and_return;
2169        } else if (!DIFF_OPT_TST(o, TEXT) &&
2170            ( (!textconv_one && diff_filespec_is_binary(one)) ||
2171              (!textconv_two && diff_filespec_is_binary(two)) )) {
2172                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2173                        die("unable to read files to diff");
2174                /* Quite common confusing case */
2175                if (mf1.size == mf2.size &&
2176                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2177                        if (must_show_header)
2178                                fprintf(o->file, "%s", header.buf);
2179                        goto free_ab_and_return;
2180                }
2181                fprintf(o->file, "%s", header.buf);
2182                strbuf_reset(&header);
2183                if (DIFF_OPT_TST(o, BINARY))
2184                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2185                else
2186                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2187                                line_prefix, lbl[0], lbl[1]);
2188                o->found_changes = 1;
2189        } else {
2190                /* Crazy xdl interfaces.. */
2191                const char *diffopts = getenv("GIT_DIFF_OPTS");
2192                xpparam_t xpp;
2193                xdemitconf_t xecfg;
2194                struct emit_callback ecbdata;
2195                const struct userdiff_funcname *pe;
2196
2197                if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS) || must_show_header) {
2198                        fprintf(o->file, "%s", header.buf);
2199                        strbuf_reset(&header);
2200                }
2201
2202                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2203                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2204
2205                pe = diff_funcname_pattern(one);
2206                if (!pe)
2207                        pe = diff_funcname_pattern(two);
2208
2209                memset(&xpp, 0, sizeof(xpp));
2210                memset(&xecfg, 0, sizeof(xecfg));
2211                memset(&ecbdata, 0, sizeof(ecbdata));
2212                ecbdata.label_path = lbl;
2213                ecbdata.color_diff = want_color(o->use_color);
2214                ecbdata.found_changesp = &o->found_changes;
2215                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
2216                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2217                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2218                ecbdata.opt = o;
2219                ecbdata.header = header.len ? &header : NULL;
2220                xpp.flags = o->xdl_opts;
2221                xecfg.ctxlen = o->context;
2222                xecfg.interhunkctxlen = o->interhunkcontext;
2223                xecfg.flags = XDL_EMIT_FUNCNAMES;
2224                if (DIFF_OPT_TST(o, FUNCCONTEXT))
2225                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
2226                if (pe)
2227                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2228                if (!diffopts)
2229                        ;
2230                else if (!prefixcmp(diffopts, "--unified="))
2231                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2232                else if (!prefixcmp(diffopts, "-u"))
2233                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2234                if (o->word_diff) {
2235                        int i;
2236
2237                        ecbdata.diff_words =
2238                                xcalloc(1, sizeof(struct diff_words_data));
2239                        ecbdata.diff_words->type = o->word_diff;
2240                        ecbdata.diff_words->opt = o;
2241                        if (!o->word_regex)
2242                                o->word_regex = userdiff_word_regex(one);
2243                        if (!o->word_regex)
2244                                o->word_regex = userdiff_word_regex(two);
2245                        if (!o->word_regex)
2246                                o->word_regex = diff_word_regex_cfg;
2247                        if (o->word_regex) {
2248                                ecbdata.diff_words->word_regex = (regex_t *)
2249                                        xmalloc(sizeof(regex_t));
2250                                if (regcomp(ecbdata.diff_words->word_regex,
2251                                                o->word_regex,
2252                                                REG_EXTENDED | REG_NEWLINE))
2253                                        die ("Invalid regular expression: %s",
2254                                                        o->word_regex);
2255                        }
2256                        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2257                                if (o->word_diff == diff_words_styles[i].type) {
2258                                        ecbdata.diff_words->style =
2259                                                &diff_words_styles[i];
2260                                        break;
2261                                }
2262                        }
2263                        if (want_color(o->use_color)) {
2264                                struct diff_words_style *st = ecbdata.diff_words->style;
2265                                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2266                                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2267                                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
2268                        }
2269                }
2270                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2271                              &xpp, &xecfg);
2272                if (o->word_diff)
2273                        free_diff_words_data(&ecbdata);
2274                if (textconv_one)
2275                        free(mf1.ptr);
2276                if (textconv_two)
2277                        free(mf2.ptr);
2278                xdiff_clear_find_func(&xecfg);
2279        }
2280
2281 free_ab_and_return:
2282        strbuf_release(&header);
2283        diff_free_filespec_data(one);
2284        diff_free_filespec_data(two);
2285        free(a_one);
2286        free(b_two);
2287        return;
2288}
2289
2290static void builtin_diffstat(const char *name_a, const char *name_b,
2291                             struct diff_filespec *one,
2292                             struct diff_filespec *two,
2293                             struct diffstat_t *diffstat,
2294                             struct diff_options *o,
2295                             int complete_rewrite)
2296{
2297        mmfile_t mf1, mf2;
2298        struct diffstat_file *data;
2299
2300        data = diffstat_add(diffstat, name_a, name_b);
2301
2302        if (!one || !two) {
2303                data->is_unmerged = 1;
2304                return;
2305        }
2306
2307        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2308                data->is_binary = 1;
2309                data->added = diff_filespec_size(two);
2310                data->deleted = diff_filespec_size(one);
2311        }
2312
2313        else if (complete_rewrite) {
2314                diff_populate_filespec(one, 0);
2315                diff_populate_filespec(two, 0);
2316                data->deleted = count_lines(one->data, one->size);
2317                data->added = count_lines(two->data, two->size);
2318        }
2319
2320        else {
2321                /* Crazy xdl interfaces.. */
2322                xpparam_t xpp;
2323                xdemitconf_t xecfg;
2324
2325                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2326                        die("unable to read files to diff");
2327
2328                memset(&xpp, 0, sizeof(xpp));
2329                memset(&xecfg, 0, sizeof(xecfg));
2330                xpp.flags = o->xdl_opts;
2331                xecfg.ctxlen = o->context;
2332                xecfg.interhunkctxlen = o->interhunkcontext;
2333                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2334                              &xpp, &xecfg);
2335        }
2336
2337        diff_free_filespec_data(one);
2338        diff_free_filespec_data(two);
2339}
2340
2341static void builtin_checkdiff(const char *name_a, const char *name_b,
2342                              const char *attr_path,
2343                              struct diff_filespec *one,
2344                              struct diff_filespec *two,
2345                              struct diff_options *o)
2346{
2347        mmfile_t mf1, mf2;
2348        struct checkdiff_t data;
2349
2350        if (!two)
2351                return;
2352
2353        memset(&data, 0, sizeof(data));
2354        data.filename = name_b ? name_b : name_a;
2355        data.lineno = 0;
2356        data.o = o;
2357        data.ws_rule = whitespace_rule(attr_path);
2358        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2359
2360        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2361                die("unable to read files to diff");
2362
2363        /*
2364         * All the other codepaths check both sides, but not checking
2365         * the "old" side here is deliberate.  We are checking the newly
2366         * introduced changes, and as long as the "new" side is text, we
2367         * can and should check what it introduces.
2368         */
2369        if (diff_filespec_is_binary(two))
2370                goto free_and_return;
2371        else {
2372                /* Crazy xdl interfaces.. */
2373                xpparam_t xpp;
2374                xdemitconf_t xecfg;
2375
2376                memset(&xpp, 0, sizeof(xpp));
2377                memset(&xecfg, 0, sizeof(xecfg));
2378                xecfg.ctxlen = 1; /* at least one context line */
2379                xpp.flags = 0;
2380                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2381                              &xpp, &xecfg);
2382
2383                if (data.ws_rule & WS_BLANK_AT_EOF) {
2384                        struct emit_callback ecbdata;
2385                        int blank_at_eof;
2386
2387                        ecbdata.ws_rule = data.ws_rule;
2388                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2389                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2390
2391                        if (blank_at_eof) {
2392                                static char *err;
2393                                if (!err)
2394                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2395                                fprintf(o->file, "%s:%d: %s.\n",
2396                                        data.filename, blank_at_eof, err);
2397                                data.status = 1; /* report errors */
2398                        }
2399                }
2400        }
2401 free_and_return:
2402        diff_free_filespec_data(one);
2403        diff_free_filespec_data(two);
2404        if (data.status)
2405                DIFF_OPT_SET(o, CHECK_FAILED);
2406}
2407
2408struct diff_filespec *alloc_filespec(const char *path)
2409{
2410        int namelen = strlen(path);
2411        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2412
2413        memset(spec, 0, sizeof(*spec));
2414        spec->path = (char *)(spec + 1);
2415        memcpy(spec->path, path, namelen+1);
2416        spec->count = 1;
2417        spec->is_binary = -1;
2418        return spec;
2419}
2420
2421void free_filespec(struct diff_filespec *spec)
2422{
2423        if (!--spec->count) {
2424                diff_free_filespec_data(spec);
2425                free(spec);
2426        }
2427}
2428
2429void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2430                   unsigned short mode)
2431{
2432        if (mode) {
2433                spec->mode = canon_mode(mode);
2434                hashcpy(spec->sha1, sha1);
2435                spec->sha1_valid = !is_null_sha1(sha1);
2436        }
2437}
2438
2439/*
2440 * Given a name and sha1 pair, if the index tells us the file in
2441 * the work tree has that object contents, return true, so that
2442 * prepare_temp_file() does not have to inflate and extract.
2443 */
2444static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2445{
2446        struct cache_entry *ce;
2447        struct stat st;
2448        int pos, len;
2449
2450        /*
2451         * We do not read the cache ourselves here, because the
2452         * benchmark with my previous version that always reads cache
2453         * shows that it makes things worse for diff-tree comparing
2454         * two linux-2.6 kernel trees in an already checked out work
2455         * tree.  This is because most diff-tree comparisons deal with
2456         * only a small number of files, while reading the cache is
2457         * expensive for a large project, and its cost outweighs the
2458         * savings we get by not inflating the object to a temporary
2459         * file.  Practically, this code only helps when we are used
2460         * by diff-cache --cached, which does read the cache before
2461         * calling us.
2462         */
2463        if (!active_cache)
2464                return 0;
2465
2466        /* We want to avoid the working directory if our caller
2467         * doesn't need the data in a normal file, this system
2468         * is rather slow with its stat/open/mmap/close syscalls,
2469         * and the object is contained in a pack file.  The pack
2470         * is probably already open and will be faster to obtain
2471         * the data through than the working directory.  Loose
2472         * objects however would tend to be slower as they need
2473         * to be individually opened and inflated.
2474         */
2475        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2476                return 0;
2477
2478        len = strlen(name);
2479        pos = cache_name_pos(name, len);
2480        if (pos < 0)
2481                return 0;
2482        ce = active_cache[pos];
2483
2484        /*
2485         * This is not the sha1 we are looking for, or
2486         * unreusable because it is not a regular file.
2487         */
2488        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2489                return 0;
2490
2491        /*
2492         * If ce is marked as "assume unchanged", there is no
2493         * guarantee that work tree matches what we are looking for.
2494         */
2495        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2496                return 0;
2497
2498        /*
2499         * If ce matches the file in the work tree, we can reuse it.
2500         */
2501        if (ce_uptodate(ce) ||
2502            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2503                return 1;
2504
2505        return 0;
2506}
2507
2508static int populate_from_stdin(struct diff_filespec *s)
2509{
2510        struct strbuf buf = STRBUF_INIT;
2511        size_t size = 0;
2512
2513        if (strbuf_read(&buf, 0, 0) < 0)
2514                return error("error while reading from stdin %s",
2515                                     strerror(errno));
2516
2517        s->should_munmap = 0;
2518        s->data = strbuf_detach(&buf, &size);
2519        s->size = size;
2520        s->should_free = 1;
2521        return 0;
2522}
2523
2524static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2525{
2526        int len;
2527        char *data = xmalloc(100), *dirty = "";
2528
2529        /* Are we looking at the work tree? */
2530        if (s->dirty_submodule)
2531                dirty = "-dirty";
2532
2533        len = snprintf(data, 100,
2534                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2535        s->data = data;
2536        s->size = len;
2537        s->should_free = 1;
2538        if (size_only) {
2539                s->data = NULL;
2540                free(data);
2541        }
2542        return 0;
2543}
2544
2545/*
2546 * While doing rename detection and pickaxe operation, we may need to
2547 * grab the data for the blob (or file) for our own in-core comparison.
2548 * diff_filespec has data and size fields for this purpose.
2549 */
2550int diff_populate_filespec(struct diff_filespec *s, int size_only)
2551{
2552        int err = 0;
2553        if (!DIFF_FILE_VALID(s))
2554                die("internal error: asking to populate invalid file.");
2555        if (S_ISDIR(s->mode))
2556                return -1;
2557
2558        if (s->data)
2559                return 0;
2560
2561        if (size_only && 0 < s->size)
2562                return 0;
2563
2564        if (S_ISGITLINK(s->mode))
2565                return diff_populate_gitlink(s, size_only);
2566
2567        if (!s->sha1_valid ||
2568            reuse_worktree_file(s->path, s->sha1, 0)) {
2569                struct strbuf buf = STRBUF_INIT;
2570                struct stat st;
2571                int fd;
2572
2573                if (!strcmp(s->path, "-"))
2574                        return populate_from_stdin(s);
2575
2576                if (lstat(s->path, &st) < 0) {
2577                        if (errno == ENOENT) {
2578                        err_empty:
2579                                err = -1;
2580                        empty:
2581                                s->data = (char *)"";
2582                                s->size = 0;
2583                                return err;
2584                        }
2585                }
2586                s->size = xsize_t(st.st_size);
2587                if (!s->size)
2588                        goto empty;
2589                if (S_ISLNK(st.st_mode)) {
2590                        struct strbuf sb = STRBUF_INIT;
2591
2592                        if (strbuf_readlink(&sb, s->path, s->size))
2593                                goto err_empty;
2594                        s->size = sb.len;
2595                        s->data = strbuf_detach(&sb, NULL);
2596                        s->should_free = 1;
2597                        return 0;
2598                }
2599                if (size_only)
2600                        return 0;
2601                fd = open(s->path, O_RDONLY);
2602                if (fd < 0)
2603                        goto err_empty;
2604                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2605                close(fd);
2606                s->should_munmap = 1;
2607
2608                /*
2609                 * Convert from working tree format to canonical git format
2610                 */
2611                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2612                        size_t size = 0;
2613                        munmap(s->data, s->size);
2614                        s->should_munmap = 0;
2615                        s->data = strbuf_detach(&buf, &size);
2616                        s->size = size;
2617                        s->should_free = 1;
2618                }
2619        }
2620        else {
2621                enum object_type type;
2622                if (size_only) {
2623                        type = sha1_object_info(s->sha1, &s->size);
2624                        if (type < 0)
2625                                die("unable to read %s", sha1_to_hex(s->sha1));
2626                } else {
2627                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2628                        if (!s->data)
2629                                die("unable to read %s", sha1_to_hex(s->sha1));
2630                        s->should_free = 1;
2631                }
2632        }
2633        return 0;
2634}
2635
2636void diff_free_filespec_blob(struct diff_filespec *s)
2637{
2638        if (s->should_free)
2639                free(s->data);
2640        else if (s->should_munmap)
2641                munmap(s->data, s->size);
2642
2643        if (s->should_free || s->should_munmap) {
2644                s->should_free = s->should_munmap = 0;
2645                s->data = NULL;
2646        }
2647}
2648
2649void diff_free_filespec_data(struct diff_filespec *s)
2650{
2651        diff_free_filespec_blob(s);
2652        free(s->cnt_data);
2653        s->cnt_data = NULL;
2654}
2655
2656static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2657                           void *blob,
2658                           unsigned long size,
2659                           const unsigned char *sha1,
2660                           int mode)
2661{
2662        int fd;
2663        struct strbuf buf = STRBUF_INIT;
2664        struct strbuf template = STRBUF_INIT;
2665        char *path_dup = xstrdup(path);
2666        const char *base = basename(path_dup);
2667
2668        /* Generate "XXXXXX_basename.ext" */
2669        strbuf_addstr(&template, "XXXXXX_");
2670        strbuf_addstr(&template, base);
2671
2672        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2673                        strlen(base) + 1);
2674        if (fd < 0)
2675                die_errno("unable to create temp-file");
2676        if (convert_to_working_tree(path,
2677                        (const char *)blob, (size_t)size, &buf)) {
2678                blob = buf.buf;
2679                size = buf.len;
2680        }
2681        if (write_in_full(fd, blob, size) != size)
2682                die_errno("unable to write temp-file");
2683        close(fd);
2684        temp->name = temp->tmp_path;
2685        strcpy(temp->hex, sha1_to_hex(sha1));
2686        temp->hex[40] = 0;
2687        sprintf(temp->mode, "%06o", mode);
2688        strbuf_release(&buf);
2689        strbuf_release(&template);
2690        free(path_dup);
2691}
2692
2693static struct diff_tempfile *prepare_temp_file(const char *name,
2694                struct diff_filespec *one)
2695{
2696        struct diff_tempfile *temp = claim_diff_tempfile();
2697
2698        if (!DIFF_FILE_VALID(one)) {
2699        not_a_valid_file:
2700                /* A '-' entry produces this for file-2, and
2701                 * a '+' entry produces this for file-1.
2702                 */
2703                temp->name = "/dev/null";
2704                strcpy(temp->hex, ".");
2705                strcpy(temp->mode, ".");
2706                return temp;
2707        }
2708
2709        if (!remove_tempfile_installed) {
2710                atexit(remove_tempfile);
2711                sigchain_push_common(remove_tempfile_on_signal);
2712                remove_tempfile_installed = 1;
2713        }
2714
2715        if (!one->sha1_valid ||
2716            reuse_worktree_file(name, one->sha1, 1)) {
2717                struct stat st;
2718                if (lstat(name, &st) < 0) {
2719                        if (errno == ENOENT)
2720                                goto not_a_valid_file;
2721                        die_errno("stat(%s)", name);
2722                }
2723                if (S_ISLNK(st.st_mode)) {
2724                        struct strbuf sb = STRBUF_INIT;
2725                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2726                                die_errno("readlink(%s)", name);
2727                        prep_temp_blob(name, temp, sb.buf, sb.len,
2728                                       (one->sha1_valid ?
2729                                        one->sha1 : null_sha1),
2730                                       (one->sha1_valid ?
2731                                        one->mode : S_IFLNK));
2732                        strbuf_release(&sb);
2733                }
2734                else {
2735                        /* we can borrow from the file in the work tree */
2736                        temp->name = name;
2737                        if (!one->sha1_valid)
2738                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2739                        else
2740                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2741                        /* Even though we may sometimes borrow the
2742                         * contents from the work tree, we always want
2743                         * one->mode.  mode is trustworthy even when
2744                         * !(one->sha1_valid), as long as
2745                         * DIFF_FILE_VALID(one).
2746                         */
2747                        sprintf(temp->mode, "%06o", one->mode);
2748                }
2749                return temp;
2750        }
2751        else {
2752                if (diff_populate_filespec(one, 0))
2753                        die("cannot read data blob for %s", one->path);
2754                prep_temp_blob(name, temp, one->data, one->size,
2755                               one->sha1, one->mode);
2756        }
2757        return temp;
2758}
2759
2760/* An external diff command takes:
2761 *
2762 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2763 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2764 *
2765 */
2766static void run_external_diff(const char *pgm,
2767                              const char *name,
2768                              const char *other,
2769                              struct diff_filespec *one,
2770                              struct diff_filespec *two,
2771                              const char *xfrm_msg,
2772                              int complete_rewrite)
2773{
2774        const char *spawn_arg[10];
2775        int retval;
2776        const char **arg = &spawn_arg[0];
2777
2778        if (one && two) {
2779                struct diff_tempfile *temp_one, *temp_two;
2780                const char *othername = (other ? other : name);
2781                temp_one = prepare_temp_file(name, one);
2782                temp_two = prepare_temp_file(othername, two);
2783                *arg++ = pgm;
2784                *arg++ = name;
2785                *arg++ = temp_one->name;
2786                *arg++ = temp_one->hex;
2787                *arg++ = temp_one->mode;
2788                *arg++ = temp_two->name;
2789                *arg++ = temp_two->hex;
2790                *arg++ = temp_two->mode;
2791                if (other) {
2792                        *arg++ = other;
2793                        *arg++ = xfrm_msg;
2794                }
2795        } else {
2796                *arg++ = pgm;
2797                *arg++ = name;
2798        }
2799        *arg = NULL;
2800        fflush(NULL);
2801        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2802        remove_tempfile();
2803        if (retval) {
2804                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2805                exit(1);
2806        }
2807}
2808
2809static int similarity_index(struct diff_filepair *p)
2810{
2811        return p->score * 100 / MAX_SCORE;
2812}
2813
2814static void fill_metainfo(struct strbuf *msg,
2815                          const char *name,
2816                          const char *other,
2817                          struct diff_filespec *one,
2818                          struct diff_filespec *two,
2819                          struct diff_options *o,
2820                          struct diff_filepair *p,
2821                          int *must_show_header,
2822                          int use_color)
2823{
2824        const char *set = diff_get_color(use_color, DIFF_METAINFO);
2825        const char *reset = diff_get_color(use_color, DIFF_RESET);
2826        struct strbuf *msgbuf;
2827        char *line_prefix = "";
2828
2829        *must_show_header = 1;
2830        if (o->output_prefix) {
2831                msgbuf = o->output_prefix(o, o->output_prefix_data);
2832                line_prefix = msgbuf->buf;
2833        }
2834        strbuf_init(msg, PATH_MAX * 2 + 300);
2835        switch (p->status) {
2836        case DIFF_STATUS_COPIED:
2837                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2838                            line_prefix, set, similarity_index(p));
2839                strbuf_addf(msg, "%s\n%s%scopy from ",
2840                            reset,  line_prefix, set);
2841                quote_c_style(name, msg, NULL, 0);
2842                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2843                quote_c_style(other, msg, NULL, 0);
2844                strbuf_addf(msg, "%s\n", reset);
2845                break;
2846        case DIFF_STATUS_RENAMED:
2847                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2848                            line_prefix, set, similarity_index(p));
2849                strbuf_addf(msg, "%s\n%s%srename from ",
2850                            reset, line_prefix, set);
2851                quote_c_style(name, msg, NULL, 0);
2852                strbuf_addf(msg, "%s\n%s%srename to ",
2853                            reset, line_prefix, set);
2854                quote_c_style(other, msg, NULL, 0);
2855                strbuf_addf(msg, "%s\n", reset);
2856                break;
2857        case DIFF_STATUS_MODIFIED:
2858                if (p->score) {
2859                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2860                                    line_prefix,
2861                                    set, similarity_index(p), reset);
2862                        break;
2863                }
2864                /* fallthru */
2865        default:
2866                *must_show_header = 0;
2867        }
2868        if (one && two && hashcmp(one->sha1, two->sha1)) {
2869                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2870
2871                if (DIFF_OPT_TST(o, BINARY)) {
2872                        mmfile_t mf;
2873                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2874                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2875                                abbrev = 40;
2876                }
2877                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2878                            find_unique_abbrev(one->sha1, abbrev));
2879                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2880                if (one->mode == two->mode)
2881                        strbuf_addf(msg, " %06o", one->mode);
2882                strbuf_addf(msg, "%s\n", reset);
2883        }
2884}
2885
2886static void run_diff_cmd(const char *pgm,
2887                         const char *name,
2888                         const char *other,
2889                         const char *attr_path,
2890                         struct diff_filespec *one,
2891                         struct diff_filespec *two,
2892                         struct strbuf *msg,
2893                         struct diff_options *o,
2894                         struct diff_filepair *p)
2895{
2896        const char *xfrm_msg = NULL;
2897        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2898        int must_show_header = 0;
2899
2900        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2901                pgm = NULL;
2902        else {
2903                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2904                if (drv && drv->external)
2905                        pgm = drv->external;
2906        }
2907
2908        if (msg) {
2909                /*
2910                 * don't use colors when the header is intended for an
2911                 * external diff driver
2912                 */
2913                fill_metainfo(msg, name, other, one, two, o, p,
2914                              &must_show_header,
2915                              want_color(o->use_color) && !pgm);
2916                xfrm_msg = msg->len ? msg->buf : NULL;
2917        }
2918
2919        if (pgm) {
2920                run_external_diff(pgm, name, other, one, two, xfrm_msg,
2921                                  complete_rewrite);
2922                return;
2923        }
2924        if (one && two)
2925                builtin_diff(name, other ? other : name,
2926                             one, two, xfrm_msg, must_show_header,
2927                             o, complete_rewrite);
2928        else
2929                fprintf(o->file, "* Unmerged path %s\n", name);
2930}
2931
2932static void diff_fill_sha1_info(struct diff_filespec *one)
2933{
2934        if (DIFF_FILE_VALID(one)) {
2935                if (!one->sha1_valid) {
2936                        struct stat st;
2937                        if (!strcmp(one->path, "-")) {
2938                                hashcpy(one->sha1, null_sha1);
2939                                return;
2940                        }
2941                        if (lstat(one->path, &st) < 0)
2942                                die_errno("stat '%s'", one->path);
2943                        if (index_path(one->sha1, one->path, &st, 0))
2944                                die("cannot hash %s", one->path);
2945                }
2946        }
2947        else
2948                hashclr(one->sha1);
2949}
2950
2951static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2952{
2953        /* Strip the prefix but do not molest /dev/null and absolute paths */
2954        if (*namep && **namep != '/') {
2955                *namep += prefix_length;
2956                if (**namep == '/')
2957                        ++*namep;
2958        }
2959        if (*otherp && **otherp != '/') {
2960                *otherp += prefix_length;
2961                if (**otherp == '/')
2962                        ++*otherp;
2963        }
2964}
2965
2966static void run_diff(struct diff_filepair *p, struct diff_options *o)
2967{
2968        const char *pgm = external_diff();
2969        struct strbuf msg;
2970        struct diff_filespec *one = p->one;
2971        struct diff_filespec *two = p->two;
2972        const char *name;
2973        const char *other;
2974        const char *attr_path;
2975
2976        name  = p->one->path;
2977        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2978        attr_path = name;
2979        if (o->prefix_length)
2980                strip_prefix(o->prefix_length, &name, &other);
2981
2982        if (DIFF_PAIR_UNMERGED(p)) {
2983                run_diff_cmd(pgm, name, NULL, attr_path,
2984                             NULL, NULL, NULL, o, p);
2985                return;
2986        }
2987
2988        diff_fill_sha1_info(one);
2989        diff_fill_sha1_info(two);
2990
2991        if (!pgm &&
2992            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2993            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2994                /*
2995                 * a filepair that changes between file and symlink
2996                 * needs to be split into deletion and creation.
2997                 */
2998                struct diff_filespec *null = alloc_filespec(two->path);
2999                run_diff_cmd(NULL, name, other, attr_path,
3000                             one, null, &msg, o, p);
3001                free(null);
3002                strbuf_release(&msg);
3003
3004                null = alloc_filespec(one->path);
3005                run_diff_cmd(NULL, name, other, attr_path,
3006                             null, two, &msg, o, p);
3007                free(null);
3008        }
3009        else
3010                run_diff_cmd(pgm, name, other, attr_path,
3011                             one, two, &msg, o, p);
3012
3013        strbuf_release(&msg);
3014}
3015
3016static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
3017                         struct diffstat_t *diffstat)
3018{
3019        const char *name;
3020        const char *other;
3021        int complete_rewrite = 0;
3022
3023        if (DIFF_PAIR_UNMERGED(p)) {
3024                /* unmerged */
3025                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
3026                return;
3027        }
3028
3029        name = p->one->path;
3030        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3031
3032        if (o->prefix_length)
3033                strip_prefix(o->prefix_length, &name, &other);
3034
3035        diff_fill_sha1_info(p->one);
3036        diff_fill_sha1_info(p->two);
3037
3038        if (p->status == DIFF_STATUS_MODIFIED && p->score)
3039                complete_rewrite = 1;
3040        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
3041}
3042
3043static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
3044{
3045        const char *name;
3046        const char *other;
3047        const char *attr_path;
3048
3049        if (DIFF_PAIR_UNMERGED(p)) {
3050                /* unmerged */
3051                return;
3052        }
3053
3054        name = p->one->path;
3055        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3056        attr_path = other ? other : name;
3057
3058        if (o->prefix_length)
3059                strip_prefix(o->prefix_length, &name, &other);
3060
3061        diff_fill_sha1_info(p->one);
3062        diff_fill_sha1_info(p->two);
3063
3064        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
3065}
3066
3067void diff_setup(struct diff_options *options)
3068{
3069        memcpy(options, &default_diff_options, sizeof(*options));
3070
3071        options->file = stdout;
3072
3073        options->line_termination = '\n';
3074        options->break_opt = -1;
3075        options->rename_limit = -1;
3076        options->dirstat_permille = diff_dirstat_permille_default;
3077        options->context = 3;
3078
3079        options->change = diff_change;
3080        options->add_remove = diff_addremove;
3081        options->use_color = diff_use_color_default;
3082        options->detect_rename = diff_detect_rename_default;
3083
3084        if (diff_no_prefix) {
3085                options->a_prefix = options->b_prefix = "";
3086        } else if (!diff_mnemonic_prefix) {
3087                options->a_prefix = "a/";
3088                options->b_prefix = "b/";
3089        }
3090}
3091
3092int diff_setup_done(struct diff_options *options)
3093{
3094        int count = 0;
3095
3096        if (options->output_format & DIFF_FORMAT_NAME)
3097                count++;
3098        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
3099                count++;
3100        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
3101                count++;
3102        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
3103                count++;
3104        if (count > 1)
3105                die("--name-only, --name-status, --check and -s are mutually exclusive");
3106
3107        /*
3108         * Most of the time we can say "there are changes"
3109         * only by checking if there are changed paths, but
3110         * --ignore-whitespace* options force us to look
3111         * inside contents.
3112         */
3113
3114        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
3115            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
3116            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
3117                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
3118        else
3119                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
3120
3121        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3122                options->detect_rename = DIFF_DETECT_COPY;
3123
3124        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
3125                options->prefix = NULL;
3126        if (options->prefix)
3127                options->prefix_length = strlen(options->prefix);
3128        else
3129                options->prefix_length = 0;
3130
3131        if (options->output_format & (DIFF_FORMAT_NAME |
3132                                      DIFF_FORMAT_NAME_STATUS |
3133                                      DIFF_FORMAT_CHECKDIFF |
3134                                      DIFF_FORMAT_NO_OUTPUT))
3135                options->output_format &= ~(DIFF_FORMAT_RAW |
3136                                            DIFF_FORMAT_NUMSTAT |
3137                                            DIFF_FORMAT_DIFFSTAT |
3138                                            DIFF_FORMAT_SHORTSTAT |
3139                                            DIFF_FORMAT_DIRSTAT |
3140                                            DIFF_FORMAT_SUMMARY |
3141                                            DIFF_FORMAT_PATCH);
3142
3143        /*
3144         * These cases always need recursive; we do not drop caller-supplied
3145         * recursive bits for other formats here.
3146         */
3147        if (options->output_format & (DIFF_FORMAT_PATCH |
3148                                      DIFF_FORMAT_NUMSTAT |
3149                                      DIFF_FORMAT_DIFFSTAT |
3150                                      DIFF_FORMAT_SHORTSTAT |
3151                                      DIFF_FORMAT_DIRSTAT |
3152                                      DIFF_FORMAT_SUMMARY |
3153                                      DIFF_FORMAT_CHECKDIFF))
3154                DIFF_OPT_SET(options, RECURSIVE);
3155        /*
3156         * Also pickaxe would not work very well if you do not say recursive
3157         */
3158        if (options->pickaxe)
3159                DIFF_OPT_SET(options, RECURSIVE);
3160        /*
3161         * When patches are generated, submodules diffed against the work tree
3162         * must be checked for dirtiness too so it can be shown in the output
3163         */
3164        if (options->output_format & DIFF_FORMAT_PATCH)
3165                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3166
3167        if (options->detect_rename && options->rename_limit < 0)
3168                options->rename_limit = diff_rename_limit_default;
3169        if (options->setup & DIFF_SETUP_USE_CACHE) {
3170                if (!active_cache)
3171                        /* read-cache does not die even when it fails
3172                         * so it is safe for us to do this here.  Also
3173                         * it does not smudge active_cache or active_nr
3174                         * when it fails, so we do not have to worry about
3175                         * cleaning it up ourselves either.
3176                         */
3177                        read_cache();
3178        }
3179        if (options->abbrev <= 0 || 40 < options->abbrev)
3180                options->abbrev = 40; /* full */
3181
3182        /*
3183         * It does not make sense to show the first hit we happened
3184         * to have found.  It does not make sense not to return with
3185         * exit code in such a case either.
3186         */
3187        if (DIFF_OPT_TST(options, QUICK)) {
3188                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3189                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3190        }
3191
3192        return 0;
3193}
3194
3195static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3196{
3197        char c, *eq;
3198        int len;
3199
3200        if (*arg != '-')
3201                return 0;
3202        c = *++arg;
3203        if (!c)
3204                return 0;
3205        if (c == arg_short) {
3206                c = *++arg;
3207                if (!c)
3208                        return 1;
3209                if (val && isdigit(c)) {
3210                        char *end;
3211                        int n = strtoul(arg, &end, 10);
3212                        if (*end)
3213                                return 0;
3214                        *val = n;
3215                        return 1;
3216                }
3217                return 0;
3218        }
3219        if (c != '-')
3220                return 0;
3221        arg++;
3222        eq = strchr(arg, '=');
3223        if (eq)
3224                len = eq - arg;
3225        else
3226                len = strlen(arg);
3227        if (!len || strncmp(arg, arg_long, len))
3228                return 0;
3229        if (eq) {
3230                int n;
3231                char *end;
3232                if (!isdigit(*++eq))
3233                        return 0;
3234                n = strtoul(eq, &end, 10);
3235                if (*end)
3236                        return 0;
3237                *val = n;
3238        }
3239        return 1;
3240}
3241
3242static int diff_scoreopt_parse(const char *opt);
3243
3244static inline int short_opt(char opt, const char **argv,
3245                            const char **optarg)
3246{
3247        const char *arg = argv[0];
3248        if (arg[0] != '-' || arg[1] != opt)
3249                return 0;
3250        if (arg[2] != '\0') {
3251                *optarg = arg + 2;
3252                return 1;
3253        }
3254        if (!argv[1])
3255                die("Option '%c' requires a value", opt);
3256        *optarg = argv[1];
3257        return 2;
3258}
3259
3260int parse_long_opt(const char *opt, const char **argv,
3261                   const char **optarg)
3262{
3263        const char *arg = argv[0];
3264        if (arg[0] != '-' || arg[1] != '-')
3265                return 0;
3266        arg += strlen("--");
3267        if (prefixcmp(arg, opt))
3268                return 0;
3269        arg += strlen(opt);
3270        if (*arg == '=') { /* sticked form: --option=value */
3271                *optarg = arg + 1;
3272                return 1;
3273        }
3274        if (*arg != '\0')
3275                return 0;
3276        /* separate form: --option value */
3277        if (!argv[1])
3278                die("Option '--%s' requires a value", opt);
3279        *optarg = argv[1];
3280        return 2;
3281}
3282
3283static int stat_opt(struct diff_options *options, const char **av)
3284{
3285        const char *arg = av[0];
3286        char *end;
3287        int width = options->stat_width;
3288        int name_width = options->stat_name_width;
3289        int count = options->stat_count;
3290        int argcount = 1;
3291
3292        arg += strlen("--stat");
3293        end = (char *)arg;
3294
3295        switch (*arg) {
3296        case '-':
3297                if (!prefixcmp(arg, "-width")) {
3298                        arg += strlen("-width");
3299                        if (*arg == '=')
3300                                width = strtoul(arg + 1, &end, 10);
3301                        else if (!*arg && !av[1])
3302                                die("Option '--stat-width' requires a value");
3303                        else if (!*arg) {
3304                                width = strtoul(av[1], &end, 10);
3305                                argcount = 2;
3306                        }
3307                } else if (!prefixcmp(arg, "-name-width")) {
3308                        arg += strlen("-name-width");
3309                        if (*arg == '=')
3310                                name_width = strtoul(arg + 1, &end, 10);
3311                        else if (!*arg && !av[1])
3312                                die("Option '--stat-name-width' requires a value");
3313                        else if (!*arg) {
3314                                name_width = strtoul(av[1], &end, 10);
3315                                argcount = 2;
3316                        }
3317                } else if (!prefixcmp(arg, "-count")) {
3318                        arg += strlen("-count");
3319                        if (*arg == '=')
3320                                count = strtoul(arg + 1, &end, 10);
3321                        else if (!*arg && !av[1])
3322                                die("Option '--stat-count' requires a value");
3323                        else if (!*arg) {
3324                                count = strtoul(av[1], &end, 10);
3325                                argcount = 2;
3326                        }
3327                }
3328                break;
3329        case '=':
3330                width = strtoul(arg+1, &end, 10);
3331                if (*end == ',')
3332                        name_width = strtoul(end+1, &end, 10);
3333                if (*end == ',')
3334                        count = strtoul(end+1, &end, 10);
3335        }
3336
3337        /* Important! This checks all the error cases! */
3338        if (*end)
3339                return 0;
3340        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3341        options->stat_name_width = name_width;
3342        options->stat_width = width;
3343        options->stat_count = count;
3344        return argcount;
3345}
3346
3347static int parse_dirstat_opt(struct diff_options *options, const char *params)
3348{
3349        struct strbuf errmsg = STRBUF_INIT;
3350        if (parse_dirstat_params(options, params, &errmsg))
3351                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
3352                    errmsg.buf);
3353        strbuf_release(&errmsg);
3354        /*
3355         * The caller knows a dirstat-related option is given from the command
3356         * line; allow it to say "return this_function();"
3357         */
3358        options->output_format |= DIFF_FORMAT_DIRSTAT;
3359        return 1;
3360}
3361
3362int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3363{
3364        const char *arg = av[0];
3365        const char *optarg;
3366        int argcount;
3367
3368        /* Output format options */
3369        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3370                options->output_format |= DIFF_FORMAT_PATCH;
3371        else if (opt_arg(arg, 'U', "unified", &options->context))
3372                options->output_format |= DIFF_FORMAT_PATCH;
3373        else if (!strcmp(arg, "--raw"))
3374                options->output_format |= DIFF_FORMAT_RAW;
3375        else if (!strcmp(arg, "--patch-with-raw"))
3376                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3377        else if (!strcmp(arg, "--numstat"))
3378                options->output_format |= DIFF_FORMAT_NUMSTAT;
3379        else if (!strcmp(arg, "--shortstat"))
3380                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3381        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
3382                return parse_dirstat_opt(options, "");
3383        else if (!prefixcmp(arg, "-X"))
3384                return parse_dirstat_opt(options, arg + 2);
3385        else if (!prefixcmp(arg, "--dirstat="))
3386                return parse_dirstat_opt(options, arg + 10);
3387        else if (!strcmp(arg, "--cumulative"))
3388                return parse_dirstat_opt(options, "cumulative");
3389        else if (!strcmp(arg, "--dirstat-by-file"))
3390                return parse_dirstat_opt(options, "files");
3391        else if (!prefixcmp(arg, "--dirstat-by-file=")) {
3392                parse_dirstat_opt(options, "files");
3393                return parse_dirstat_opt(options, arg + 18);
3394        }
3395        else if (!strcmp(arg, "--check"))
3396                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3397        else if (!strcmp(arg, "--summary"))
3398                options->output_format |= DIFF_FORMAT_SUMMARY;
3399        else if (!strcmp(arg, "--patch-with-stat"))
3400                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3401        else if (!strcmp(arg, "--name-only"))
3402                options->output_format |= DIFF_FORMAT_NAME;
3403        else if (!strcmp(arg, "--name-status"))
3404                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3405        else if (!strcmp(arg, "-s"))
3406                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3407        else if (!prefixcmp(arg, "--stat"))
3408                /* --stat, --stat-width, --stat-name-width, or --stat-count */
3409                return stat_opt(options, av);
3410
3411        /* renames options */
3412        else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
3413                 !strcmp(arg, "--break-rewrites")) {
3414                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3415                        return error("invalid argument to -B: %s", arg+2);
3416        }
3417        else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--find-renames=") ||
3418                 !strcmp(arg, "--find-renames")) {
3419                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3420                        return error("invalid argument to -M: %s", arg+2);
3421                options->detect_rename = DIFF_DETECT_RENAME;
3422        }
3423        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3424                options->irreversible_delete = 1;
3425        }
3426        else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
3427                 !strcmp(arg, "--find-copies")) {
3428                if (options->detect_rename == DIFF_DETECT_COPY)
3429                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3430                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3431                        return error("invalid argument to -C: %s", arg+2);
3432                options->detect_rename = DIFF_DETECT_COPY;
3433        }
3434        else if (!strcmp(arg, "--no-renames"))
3435                options->detect_rename = 0;
3436        else if (!strcmp(arg, "--relative"))
3437                DIFF_OPT_SET(options, RELATIVE_NAME);
3438        else if (!prefixcmp(arg, "--relative=")) {
3439                DIFF_OPT_SET(options, RELATIVE_NAME);
3440                options->prefix = arg + 11;
3441        }
3442
3443        /* xdiff options */
3444        else if (!strcmp(arg, "--minimal"))
3445                DIFF_XDL_SET(options, NEED_MINIMAL);
3446        else if (!strcmp(arg, "--no-minimal"))
3447                DIFF_XDL_CLR(options, NEED_MINIMAL);
3448        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3449                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3450        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3451                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3452        else if (!strcmp(arg, "--ignore-space-at-eol"))
3453                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3454        else if (!strcmp(arg, "--patience"))
3455                DIFF_XDL_SET(options, PATIENCE_DIFF);
3456        else if (!strcmp(arg, "--histogram"))
3457                DIFF_XDL_SET(options, HISTOGRAM_DIFF);
3458
3459        /* flags options */
3460        else if (!strcmp(arg, "--binary")) {
3461                options->output_format |= DIFF_FORMAT_PATCH;
3462                DIFF_OPT_SET(options, BINARY);
3463        }
3464        else if (!strcmp(arg, "--full-index"))
3465                DIFF_OPT_SET(options, FULL_INDEX);
3466        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3467                DIFF_OPT_SET(options, TEXT);
3468        else if (!strcmp(arg, "-R"))
3469                DIFF_OPT_SET(options, REVERSE_DIFF);
3470        else if (!strcmp(arg, "--find-copies-harder"))
3471                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3472        else if (!strcmp(arg, "--follow"))
3473                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3474        else if (!strcmp(arg, "--color"))
3475                options->use_color = 1;
3476        else if (!prefixcmp(arg, "--color=")) {
3477                int value = git_config_colorbool(NULL, arg+8);
3478                if (value < 0)
3479                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3480                options->use_color = value;
3481        }
3482        else if (!strcmp(arg, "--no-color"))
3483                options->use_color = 0;
3484        else if (!strcmp(arg, "--color-words")) {
3485                options->use_color = 1;
3486                options->word_diff = DIFF_WORDS_COLOR;
3487        }
3488        else if (!prefixcmp(arg, "--color-words=")) {
3489                options->use_color = 1;
3490                options->word_diff = DIFF_WORDS_COLOR;
3491                options->word_regex = arg + 14;
3492        }
3493        else if (!strcmp(arg, "--word-diff")) {
3494                if (options->word_diff == DIFF_WORDS_NONE)
3495                        options->word_diff = DIFF_WORDS_PLAIN;
3496        }
3497        else if (!prefixcmp(arg, "--word-diff=")) {
3498                const char *type = arg + 12;
3499                if (!strcmp(type, "plain"))
3500                        options->word_diff = DIFF_WORDS_PLAIN;
3501                else if (!strcmp(type, "color")) {
3502                        options->use_color = 1;
3503                        options->word_diff = DIFF_WORDS_COLOR;
3504                }
3505                else if (!strcmp(type, "porcelain"))
3506                        options->word_diff = DIFF_WORDS_PORCELAIN;
3507                else if (!strcmp(type, "none"))
3508                        options->word_diff = DIFF_WORDS_NONE;
3509                else
3510                        die("bad --word-diff argument: %s", type);
3511        }
3512        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3513                if (options->word_diff == DIFF_WORDS_NONE)
3514                        options->word_diff = DIFF_WORDS_PLAIN;
3515                options->word_regex = optarg;
3516                return argcount;
3517        }
3518        else if (!strcmp(arg, "--exit-code"))
3519                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3520        else if (!strcmp(arg, "--quiet"))
3521                DIFF_OPT_SET(options, QUICK);
3522        else if (!strcmp(arg, "--ext-diff"))
3523                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3524        else if (!strcmp(arg, "--no-ext-diff"))
3525                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3526        else if (!strcmp(arg, "--textconv"))
3527                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3528        else if (!strcmp(arg, "--no-textconv"))
3529                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3530        else if (!strcmp(arg, "--ignore-submodules")) {
3531                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3532                handle_ignore_submodules_arg(options, "all");
3533        } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3534                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3535                handle_ignore_submodules_arg(options, arg + 20);
3536        } else if (!strcmp(arg, "--submodule"))
3537                DIFF_OPT_SET(options, SUBMODULE_LOG);
3538        else if (!prefixcmp(arg, "--submodule=")) {
3539                if (!strcmp(arg + 12, "log"))
3540                        DIFF_OPT_SET(options, SUBMODULE_LOG);
3541        }
3542
3543        /* misc options */
3544        else if (!strcmp(arg, "-z"))
3545                options->line_termination = 0;
3546        else if ((argcount = short_opt('l', av, &optarg))) {
3547                options->rename_limit = strtoul(optarg, NULL, 10);
3548                return argcount;
3549        }
3550        else if ((argcount = short_opt('S', av, &optarg))) {
3551                options->pickaxe = optarg;
3552                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3553                return argcount;
3554        } else if ((argcount = short_opt('G', av, &optarg))) {
3555                options->pickaxe = optarg;
3556                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3557                return argcount;
3558        }
3559        else if (!strcmp(arg, "--pickaxe-all"))
3560                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3561        else if (!strcmp(arg, "--pickaxe-regex"))
3562                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3563        else if ((argcount = short_opt('O', av, &optarg))) {
3564                options->orderfile = optarg;
3565                return argcount;
3566        }
3567        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3568                options->filter = optarg;
3569                return argcount;
3570        }
3571        else if (!strcmp(arg, "--abbrev"))
3572                options->abbrev = DEFAULT_ABBREV;
3573        else if (!prefixcmp(arg, "--abbrev=")) {
3574                options->abbrev = strtoul(arg + 9, NULL, 10);
3575                if (options->abbrev < MINIMUM_ABBREV)
3576                        options->abbrev = MINIMUM_ABBREV;
3577                else if (40 < options->abbrev)
3578                        options->abbrev = 40;
3579        }
3580        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3581                options->a_prefix = optarg;
3582                return argcount;
3583        }
3584        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3585                options->b_prefix = optarg;
3586                return argcount;
3587        }
3588        else if (!strcmp(arg, "--no-prefix"))
3589                options->a_prefix = options->b_prefix = "";
3590        else if (opt_arg(arg, '\0', "inter-hunk-context",
3591                         &options->interhunkcontext))
3592                ;
3593        else if (!strcmp(arg, "-W"))
3594                DIFF_OPT_SET(options, FUNCCONTEXT);
3595        else if (!strcmp(arg, "--function-context"))
3596                DIFF_OPT_SET(options, FUNCCONTEXT);
3597        else if (!strcmp(arg, "--no-function-context"))
3598                DIFF_OPT_CLR(options, FUNCCONTEXT);
3599        else if ((argcount = parse_long_opt("output", av, &optarg))) {
3600                options->file = fopen(optarg, "w");
3601                if (!options->file)
3602                        die_errno("Could not open '%s'", optarg);
3603                options->close_file = 1;
3604                return argcount;
3605        } else
3606                return 0;
3607        return 1;
3608}
3609
3610int parse_rename_score(const char **cp_p)
3611{
3612        unsigned long num, scale;
3613        int ch, dot;
3614        const char *cp = *cp_p;
3615
3616        num = 0;
3617        scale = 1;
3618        dot = 0;
3619        for (;;) {
3620                ch = *cp;
3621                if ( !dot && ch == '.' ) {
3622                        scale = 1;
3623                        dot = 1;
3624                } else if ( ch == '%' ) {
3625                        scale = dot ? scale*100 : 100;
3626                        cp++;   /* % is always at the end */
3627                        break;
3628                } else if ( ch >= '0' && ch <= '9' ) {
3629                        if ( scale < 100000 ) {
3630                                scale *= 10;
3631                                num = (num*10) + (ch-'0');
3632                        }
3633                } else {
3634                        break;
3635                }
3636                cp++;
3637        }
3638        *cp_p = cp;
3639
3640        /* user says num divided by scale and we say internally that
3641         * is MAX_SCORE * num / scale.
3642         */
3643        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3644}
3645
3646static int diff_scoreopt_parse(const char *opt)
3647{
3648        int opt1, opt2, cmd;
3649
3650        if (*opt++ != '-')
3651                return -1;
3652        cmd = *opt++;
3653        if (cmd == '-') {
3654                /* convert the long-form arguments into short-form versions */
3655                if (!prefixcmp(opt, "break-rewrites")) {
3656                        opt += strlen("break-rewrites");
3657                        if (*opt == 0 || *opt++ == '=')
3658                                cmd = 'B';
3659                } else if (!prefixcmp(opt, "find-copies")) {
3660                        opt += strlen("find-copies");
3661                        if (*opt == 0 || *opt++ == '=')
3662                                cmd = 'C';
3663                } else if (!prefixcmp(opt, "find-renames")) {
3664                        opt += strlen("find-renames");
3665                        if (*opt == 0 || *opt++ == '=')
3666                                cmd = 'M';
3667                }
3668        }
3669        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3670                return -1; /* that is not a -M, -C nor -B option */
3671
3672        opt1 = parse_rename_score(&opt);
3673        if (cmd != 'B')
3674                opt2 = 0;
3675        else {
3676                if (*opt == 0)
3677                        opt2 = 0;
3678                else if (*opt != '/')
3679                        return -1; /* we expect -B80/99 or -B80 */
3680                else {
3681                        opt++;
3682                        opt2 = parse_rename_score(&opt);
3683                }
3684        }
3685        if (*opt != 0)
3686                return -1;
3687        return opt1 | (opt2 << 16);
3688}
3689
3690struct diff_queue_struct diff_queued_diff;
3691
3692void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3693{
3694        if (queue->alloc <= queue->nr) {
3695                queue->alloc = alloc_nr(queue->alloc);
3696                queue->queue = xrealloc(queue->queue,
3697                                        sizeof(dp) * queue->alloc);
3698        }
3699        queue->queue[queue->nr++] = dp;
3700}
3701
3702struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3703                                 struct diff_filespec *one,
3704                                 struct diff_filespec *two)
3705{
3706        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3707        dp->one = one;
3708        dp->two = two;
3709        if (queue)
3710                diff_q(queue, dp);
3711        return dp;
3712}
3713
3714void diff_free_filepair(struct diff_filepair *p)
3715{
3716        free_filespec(p->one);
3717        free_filespec(p->two);
3718        free(p);
3719}
3720
3721/* This is different from find_unique_abbrev() in that
3722 * it stuffs the result with dots for alignment.
3723 */
3724const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3725{
3726        int abblen;
3727        const char *abbrev;
3728        if (len == 40)
3729                return sha1_to_hex(sha1);
3730
3731        abbrev = find_unique_abbrev(sha1, len);
3732        abblen = strlen(abbrev);
3733        if (abblen < 37) {
3734                static char hex[41];
3735                if (len < abblen && abblen <= len + 2)
3736                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3737                else
3738                        sprintf(hex, "%s...", abbrev);
3739                return hex;
3740        }
3741        return sha1_to_hex(sha1);
3742}
3743
3744static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3745{
3746        int line_termination = opt->line_termination;
3747        int inter_name_termination = line_termination ? '\t' : '\0';
3748        if (opt->output_prefix) {
3749                struct strbuf *msg = NULL;
3750                msg = opt->output_prefix(opt, opt->output_prefix_data);
3751                fprintf(opt->file, "%s", msg->buf);
3752        }
3753
3754        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3755                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3756                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3757                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3758        }
3759        if (p->score) {
3760                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3761                        inter_name_termination);
3762        } else {
3763                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3764        }
3765
3766        if (p->status == DIFF_STATUS_COPIED ||
3767            p->status == DIFF_STATUS_RENAMED) {
3768                const char *name_a, *name_b;
3769                name_a = p->one->path;
3770                name_b = p->two->path;
3771                strip_prefix(opt->prefix_length, &name_a, &name_b);
3772                write_name_quoted(name_a, opt->file, inter_name_termination);
3773                write_name_quoted(name_b, opt->file, line_termination);
3774        } else {
3775                const char *name_a, *name_b;
3776                name_a = p->one->mode ? p->one->path : p->two->path;
3777                name_b = NULL;
3778                strip_prefix(opt->prefix_length, &name_a, &name_b);
3779                write_name_quoted(name_a, opt->file, line_termination);
3780        }
3781}
3782
3783int diff_unmodified_pair(struct diff_filepair *p)
3784{
3785        /* This function is written stricter than necessary to support
3786         * the currently implemented transformers, but the idea is to
3787         * let transformers to produce diff_filepairs any way they want,
3788         * and filter and clean them up here before producing the output.
3789         */
3790        struct diff_filespec *one = p->one, *two = p->two;
3791
3792        if (DIFF_PAIR_UNMERGED(p))
3793                return 0; /* unmerged is interesting */
3794
3795        /* deletion, addition, mode or type change
3796         * and rename are all interesting.
3797         */
3798        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3799            DIFF_PAIR_MODE_CHANGED(p) ||
3800            strcmp(one->path, two->path))
3801                return 0;
3802
3803        /* both are valid and point at the same path.  that is, we are
3804         * dealing with a change.
3805         */
3806        if (one->sha1_valid && two->sha1_valid &&
3807            !hashcmp(one->sha1, two->sha1) &&
3808            !one->dirty_submodule && !two->dirty_submodule)
3809                return 1; /* no change */
3810        if (!one->sha1_valid && !two->sha1_valid)
3811                return 1; /* both look at the same file on the filesystem. */
3812        return 0;
3813}
3814
3815static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3816{
3817        if (diff_unmodified_pair(p))
3818                return;
3819
3820        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3821            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3822                return; /* no tree diffs in patch format */
3823
3824        run_diff(p, o);
3825}
3826
3827static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3828                            struct diffstat_t *diffstat)
3829{
3830        if (diff_unmodified_pair(p))
3831                return;
3832
3833        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3834            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3835                return; /* no useful stat for tree diffs */
3836
3837        run_diffstat(p, o, diffstat);
3838}
3839
3840static void diff_flush_checkdiff(struct diff_filepair *p,
3841                struct diff_options *o)
3842{
3843        if (diff_unmodified_pair(p))
3844                return;
3845
3846        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3847            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3848                return; /* nothing to check in tree diffs */
3849
3850        run_checkdiff(p, o);
3851}
3852
3853int diff_queue_is_empty(void)
3854{
3855        struct diff_queue_struct *q = &diff_queued_diff;
3856        int i;
3857        for (i = 0; i < q->nr; i++)
3858                if (!diff_unmodified_pair(q->queue[i]))
3859                        return 0;
3860        return 1;
3861}
3862
3863#if DIFF_DEBUG
3864void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3865{
3866        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3867                x, one ? one : "",
3868                s->path,
3869                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3870                s->mode,
3871                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3872        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3873                x, one ? one : "",
3874                s->size, s->xfrm_flags);
3875}
3876
3877void diff_debug_filepair(const struct diff_filepair *p, int i)
3878{
3879        diff_debug_filespec(p->one, i, "one");
3880        diff_debug_filespec(p->two, i, "two");
3881        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3882                p->score, p->status ? p->status : '?',
3883                p->one->rename_used, p->broken_pair);
3884}
3885
3886void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3887{
3888        int i;
3889        if (msg)
3890                fprintf(stderr, "%s\n", msg);
3891        fprintf(stderr, "q->nr = %d\n", q->nr);
3892        for (i = 0; i < q->nr; i++) {
3893                struct diff_filepair *p = q->queue[i];
3894                diff_debug_filepair(p, i);
3895        }
3896}
3897#endif
3898
3899static void diff_resolve_rename_copy(void)
3900{
3901        int i;
3902        struct diff_filepair *p;
3903        struct diff_queue_struct *q = &diff_queued_diff;
3904
3905        diff_debug_queue("resolve-rename-copy", q);
3906
3907        for (i = 0; i < q->nr; i++) {
3908                p = q->queue[i];
3909                p->status = 0; /* undecided */
3910                if (DIFF_PAIR_UNMERGED(p))
3911                        p->status = DIFF_STATUS_UNMERGED;
3912                else if (!DIFF_FILE_VALID(p->one))
3913                        p->status = DIFF_STATUS_ADDED;
3914                else if (!DIFF_FILE_VALID(p->two))
3915                        p->status = DIFF_STATUS_DELETED;
3916                else if (DIFF_PAIR_TYPE_CHANGED(p))
3917                        p->status = DIFF_STATUS_TYPE_CHANGED;
3918
3919                /* from this point on, we are dealing with a pair
3920                 * whose both sides are valid and of the same type, i.e.
3921                 * either in-place edit or rename/copy edit.
3922                 */
3923                else if (DIFF_PAIR_RENAME(p)) {
3924                        /*
3925                         * A rename might have re-connected a broken
3926                         * pair up, causing the pathnames to be the
3927                         * same again. If so, that's not a rename at
3928                         * all, just a modification..
3929                         *
3930                         * Otherwise, see if this source was used for
3931                         * multiple renames, in which case we decrement
3932                         * the count, and call it a copy.
3933                         */
3934                        if (!strcmp(p->one->path, p->two->path))
3935                                p->status = DIFF_STATUS_MODIFIED;
3936                        else if (--p->one->rename_used > 0)
3937                                p->status = DIFF_STATUS_COPIED;
3938                        else
3939                                p->status = DIFF_STATUS_RENAMED;
3940                }
3941                else if (hashcmp(p->one->sha1, p->two->sha1) ||
3942                         p->one->mode != p->two->mode ||
3943                         p->one->dirty_submodule ||
3944                         p->two->dirty_submodule ||
3945                         is_null_sha1(p->one->sha1))
3946                        p->status = DIFF_STATUS_MODIFIED;
3947                else {
3948                        /* This is a "no-change" entry and should not
3949                         * happen anymore, but prepare for broken callers.
3950                         */
3951                        error("feeding unmodified %s to diffcore",
3952                              p->one->path);
3953                        p->status = DIFF_STATUS_UNKNOWN;
3954                }
3955        }
3956        diff_debug_queue("resolve-rename-copy done", q);
3957}
3958
3959static int check_pair_status(struct diff_filepair *p)
3960{
3961        switch (p->status) {
3962        case DIFF_STATUS_UNKNOWN:
3963                return 0;
3964        case 0:
3965                die("internal error in diff-resolve-rename-copy");
3966        default:
3967                return 1;
3968        }
3969}
3970
3971static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3972{
3973        int fmt = opt->output_format;
3974
3975        if (fmt & DIFF_FORMAT_CHECKDIFF)
3976                diff_flush_checkdiff(p, opt);
3977        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3978                diff_flush_raw(p, opt);
3979        else if (fmt & DIFF_FORMAT_NAME) {
3980                const char *name_a, *name_b;
3981                name_a = p->two->path;
3982                name_b = NULL;
3983                strip_prefix(opt->prefix_length, &name_a, &name_b);
3984                write_name_quoted(name_a, opt->file, opt->line_termination);
3985        }
3986}
3987
3988static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
3989{
3990        if (fs->mode)
3991                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
3992        else
3993                fprintf(file, " %s ", newdelete);
3994        write_name_quoted(fs->path, file, '\n');
3995}
3996
3997
3998static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
3999                const char *line_prefix)
4000{
4001        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
4002                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
4003                        p->two->mode, show_name ? ' ' : '\n');
4004                if (show_name) {
4005                        write_name_quoted(p->two->path, file, '\n');
4006                }
4007        }
4008}
4009
4010static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
4011                        const char *line_prefix)
4012{
4013        char *names = pprint_rename(p->one->path, p->two->path);
4014
4015        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
4016        free(names);
4017        show_mode_change(file, p, 0, line_prefix);
4018}
4019
4020static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
4021{
4022        FILE *file = opt->file;
4023        char *line_prefix = "";
4024
4025        if (opt->output_prefix) {
4026                struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
4027                line_prefix = buf->buf;
4028        }
4029
4030        switch(p->status) {
4031        case DIFF_STATUS_DELETED:
4032                fputs(line_prefix, file);
4033                show_file_mode_name(file, "delete", p->one);
4034                break;
4035        case DIFF_STATUS_ADDED:
4036                fputs(line_prefix, file);
4037                show_file_mode_name(file, "create", p->two);
4038                break;
4039        case DIFF_STATUS_COPIED:
4040                fputs(line_prefix, file);
4041                show_rename_copy(file, "copy", p, line_prefix);
4042                break;
4043        case DIFF_STATUS_RENAMED:
4044                fputs(line_prefix, file);
4045                show_rename_copy(file, "rename", p, line_prefix);
4046                break;
4047        default:
4048                if (p->score) {
4049                        fprintf(file, "%s rewrite ", line_prefix);
4050                        write_name_quoted(p->two->path, file, ' ');
4051                        fprintf(file, "(%d%%)\n", similarity_index(p));
4052                }
4053                show_mode_change(file, p, !p->score, line_prefix);
4054                break;
4055        }
4056}
4057
4058struct patch_id_t {
4059        git_SHA_CTX *ctx;
4060        int patchlen;
4061};
4062
4063static int remove_space(char *line, int len)
4064{
4065        int i;
4066        char *dst = line;
4067        unsigned char c;
4068
4069        for (i = 0; i < len; i++)
4070                if (!isspace((c = line[i])))
4071                        *dst++ = c;
4072
4073        return dst - line;
4074}
4075
4076static void patch_id_consume(void *priv, char *line, unsigned long len)
4077{
4078        struct patch_id_t *data = priv;
4079        int new_len;
4080
4081        /* Ignore line numbers when computing the SHA1 of the patch */
4082        if (!prefixcmp(line, "@@ -"))
4083                return;
4084
4085        new_len = remove_space(line, len);
4086
4087        git_SHA1_Update(data->ctx, line, new_len);
4088        data->patchlen += new_len;
4089}
4090
4091/* returns 0 upon success, and writes result into sha1 */
4092static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
4093{
4094        struct diff_queue_struct *q = &diff_queued_diff;
4095        int i;
4096        git_SHA_CTX ctx;
4097        struct patch_id_t data;
4098        char buffer[PATH_MAX * 4 + 20];
4099
4100        git_SHA1_Init(&ctx);
4101        memset(&data, 0, sizeof(struct patch_id_t));
4102        data.ctx = &ctx;
4103
4104        for (i = 0; i < q->nr; i++) {
4105                xpparam_t xpp;
4106                xdemitconf_t xecfg;
4107                mmfile_t mf1, mf2;
4108                struct diff_filepair *p = q->queue[i];
4109                int len1, len2;
4110
4111                memset(&xpp, 0, sizeof(xpp));
4112                memset(&xecfg, 0, sizeof(xecfg));
4113                if (p->status == 0)
4114                        return error("internal diff status error");
4115                if (p->status == DIFF_STATUS_UNKNOWN)
4116                        continue;
4117                if (diff_unmodified_pair(p))
4118                        continue;
4119                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4120                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4121                        continue;
4122                if (DIFF_PAIR_UNMERGED(p))
4123                        continue;
4124
4125                diff_fill_sha1_info(p->one);
4126                diff_fill_sha1_info(p->two);
4127                if (fill_mmfile(&mf1, p->one) < 0 ||
4128                                fill_mmfile(&mf2, p->two) < 0)
4129                        return error("unable to read files to diff");
4130
4131                len1 = remove_space(p->one->path, strlen(p->one->path));
4132                len2 = remove_space(p->two->path, strlen(p->two->path));
4133                if (p->one->mode == 0)
4134                        len1 = snprintf(buffer, sizeof(buffer),
4135                                        "diff--gita/%.*sb/%.*s"
4136                                        "newfilemode%06o"
4137                                        "---/dev/null"
4138                                        "+++b/%.*s",
4139                                        len1, p->one->path,
4140                                        len2, p->two->path,
4141                                        p->two->mode,
4142                                        len2, p->two->path);
4143                else if (p->two->mode == 0)
4144                        len1 = snprintf(buffer, sizeof(buffer),
4145                                        "diff--gita/%.*sb/%.*s"
4146                                        "deletedfilemode%06o"
4147                                        "---a/%.*s"
4148                                        "+++/dev/null",
4149                                        len1, p->one->path,
4150                                        len2, p->two->path,
4151                                        p->one->mode,
4152                                        len1, p->one->path);
4153                else
4154                        len1 = snprintf(buffer, sizeof(buffer),
4155                                        "diff--gita/%.*sb/%.*s"
4156                                        "---a/%.*s"
4157                                        "+++b/%.*s",
4158                                        len1, p->one->path,
4159                                        len2, p->two->path,
4160                                        len1, p->one->path,
4161                                        len2, p->two->path);
4162                git_SHA1_Update(&ctx, buffer, len1);
4163
4164                if (diff_filespec_is_binary(p->one) ||
4165                    diff_filespec_is_binary(p->two)) {
4166                        git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
4167                        git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
4168                        continue;
4169                }
4170
4171                xpp.flags = 0;
4172                xecfg.ctxlen = 3;
4173                xecfg.flags = 0;
4174                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4175                              &xpp, &xecfg);
4176        }
4177
4178        git_SHA1_Final(sha1, &ctx);
4179        return 0;
4180}
4181
4182int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
4183{
4184        struct diff_queue_struct *q = &diff_queued_diff;
4185        int i;
4186        int result = diff_get_patch_id(options, sha1);
4187
4188        for (i = 0; i < q->nr; i++)
4189                diff_free_filepair(q->queue[i]);
4190
4191        free(q->queue);
4192        DIFF_QUEUE_CLEAR(q);
4193
4194        return result;
4195}
4196
4197static int is_summary_empty(const struct diff_queue_struct *q)
4198{
4199        int i;
4200
4201        for (i = 0; i < q->nr; i++) {
4202                const struct diff_filepair *p = q->queue[i];
4203
4204                switch (p->status) {
4205                case DIFF_STATUS_DELETED:
4206                case DIFF_STATUS_ADDED:
4207                case DIFF_STATUS_COPIED:
4208                case DIFF_STATUS_RENAMED:
4209                        return 0;
4210                default:
4211                        if (p->score)
4212                                return 0;
4213                        if (p->one->mode && p->two->mode &&
4214                            p->one->mode != p->two->mode)
4215                                return 0;
4216                        break;
4217                }
4218        }
4219        return 1;
4220}
4221
4222static const char rename_limit_warning[] =
4223"inexact rename detection was skipped due to too many files.";
4224
4225static const char degrade_cc_to_c_warning[] =
4226"only found copies from modified paths due to too many files.";
4227
4228static const char rename_limit_advice[] =
4229"you may want to set your %s variable to at least "
4230"%d and retry the command.";
4231
4232void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4233{
4234        if (degraded_cc)
4235                warning(degrade_cc_to_c_warning);
4236        else if (needed)
4237                warning(rename_limit_warning);
4238        else
4239                return;
4240        if (0 < needed && needed < 32767)
4241                warning(rename_limit_advice, varname, needed);
4242}
4243
4244void diff_flush(struct diff_options *options)
4245{
4246        struct diff_queue_struct *q = &diff_queued_diff;
4247        int i, output_format = options->output_format;
4248        int separator = 0;
4249        int dirstat_by_line = 0;
4250
4251        /*
4252         * Order: raw, stat, summary, patch
4253         * or:    name/name-status/checkdiff (other bits clear)
4254         */
4255        if (!q->nr)
4256                goto free_queue;
4257
4258        if (output_format & (DIFF_FORMAT_RAW |
4259                             DIFF_FORMAT_NAME |
4260                             DIFF_FORMAT_NAME_STATUS |
4261                             DIFF_FORMAT_CHECKDIFF)) {
4262                for (i = 0; i < q->nr; i++) {
4263                        struct diff_filepair *p = q->queue[i];
4264                        if (check_pair_status(p))
4265                                flush_one_pair(p, options);
4266                }
4267                separator++;
4268        }
4269
4270        if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
4271                dirstat_by_line = 1;
4272
4273        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
4274            dirstat_by_line) {
4275                struct diffstat_t diffstat;
4276
4277                memset(&diffstat, 0, sizeof(struct diffstat_t));
4278                for (i = 0; i < q->nr; i++) {
4279                        struct diff_filepair *p = q->queue[i];
4280                        if (check_pair_status(p))
4281                                diff_flush_stat(p, options, &diffstat);
4282                }
4283                if (output_format & DIFF_FORMAT_NUMSTAT)
4284                        show_numstat(&diffstat, options);
4285                if (output_format & DIFF_FORMAT_DIFFSTAT)
4286                        show_stats(&diffstat, options);
4287                if (output_format & DIFF_FORMAT_SHORTSTAT)
4288                        show_shortstats(&diffstat, options);
4289                if (output_format & DIFF_FORMAT_DIRSTAT)
4290                        show_dirstat_by_line(&diffstat, options);
4291                free_diffstat_info(&diffstat);
4292                separator++;
4293        }
4294        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
4295                show_dirstat(options);
4296
4297        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4298                for (i = 0; i < q->nr; i++) {
4299                        diff_summary(options, q->queue[i]);
4300                }
4301                separator++;
4302        }
4303
4304        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4305            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4306            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4307                /*
4308                 * run diff_flush_patch for the exit status. setting
4309                 * options->file to /dev/null should be safe, becaue we
4310                 * aren't supposed to produce any output anyway.
4311                 */
4312                if (options->close_file)
4313                        fclose(options->file);
4314                options->file = fopen("/dev/null", "w");
4315                if (!options->file)
4316                        die_errno("Could not open /dev/null");
4317                options->close_file = 1;
4318                for (i = 0; i < q->nr; i++) {
4319                        struct diff_filepair *p = q->queue[i];
4320                        if (check_pair_status(p))
4321                                diff_flush_patch(p, options);
4322                        if (options->found_changes)
4323                                break;
4324                }
4325        }
4326
4327        if (output_format & DIFF_FORMAT_PATCH) {
4328                if (separator) {
4329                        putc(options->line_termination, options->file);
4330                        if (options->stat_sep) {
4331                                /* attach patch instead of inline */
4332                                fputs(options->stat_sep, options->file);
4333                        }
4334                }
4335
4336                for (i = 0; i < q->nr; i++) {
4337                        struct diff_filepair *p = q->queue[i];
4338                        if (check_pair_status(p))
4339                                diff_flush_patch(p, options);
4340                }
4341        }
4342
4343        if (output_format & DIFF_FORMAT_CALLBACK)
4344                options->format_callback(q, options, options->format_callback_data);
4345
4346        for (i = 0; i < q->nr; i++)
4347                diff_free_filepair(q->queue[i]);
4348free_queue:
4349        free(q->queue);
4350        DIFF_QUEUE_CLEAR(q);
4351        if (options->close_file)
4352                fclose(options->file);
4353
4354        /*
4355         * Report the content-level differences with HAS_CHANGES;
4356         * diff_addremove/diff_change does not set the bit when
4357         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4358         */
4359        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4360                if (options->found_changes)
4361                        DIFF_OPT_SET(options, HAS_CHANGES);
4362                else
4363                        DIFF_OPT_CLR(options, HAS_CHANGES);
4364        }
4365}
4366
4367static void diffcore_apply_filter(const char *filter)
4368{
4369        int i;
4370        struct diff_queue_struct *q = &diff_queued_diff;
4371        struct diff_queue_struct outq;
4372        DIFF_QUEUE_CLEAR(&outq);
4373
4374        if (!filter)
4375                return;
4376
4377        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
4378                int found;
4379                for (i = found = 0; !found && i < q->nr; i++) {
4380                        struct diff_filepair *p = q->queue[i];
4381                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4382                             ((p->score &&
4383                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4384                              (!p->score &&
4385                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4386                            ((p->status != DIFF_STATUS_MODIFIED) &&
4387                             strchr(filter, p->status)))
4388                                found++;
4389                }
4390                if (found)
4391                        return;
4392
4393                /* otherwise we will clear the whole queue
4394                 * by copying the empty outq at the end of this
4395                 * function, but first clear the current entries
4396                 * in the queue.
4397                 */
4398                for (i = 0; i < q->nr; i++)
4399                        diff_free_filepair(q->queue[i]);
4400        }
4401        else {
4402                /* Only the matching ones */
4403                for (i = 0; i < q->nr; i++) {
4404                        struct diff_filepair *p = q->queue[i];
4405
4406                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4407                             ((p->score &&
4408                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4409                              (!p->score &&
4410                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4411                            ((p->status != DIFF_STATUS_MODIFIED) &&
4412                             strchr(filter, p->status)))
4413                                diff_q(&outq, p);
4414                        else
4415                                diff_free_filepair(p);
4416                }
4417        }
4418        free(q->queue);
4419        *q = outq;
4420}
4421
4422/* Check whether two filespecs with the same mode and size are identical */
4423static int diff_filespec_is_identical(struct diff_filespec *one,
4424                                      struct diff_filespec *two)
4425{
4426        if (S_ISGITLINK(one->mode))
4427                return 0;
4428        if (diff_populate_filespec(one, 0))
4429                return 0;
4430        if (diff_populate_filespec(two, 0))
4431                return 0;
4432        return !memcmp(one->data, two->data, one->size);
4433}
4434
4435static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4436{
4437        int i;
4438        struct diff_queue_struct *q = &diff_queued_diff;
4439        struct diff_queue_struct outq;
4440        DIFF_QUEUE_CLEAR(&outq);
4441
4442        for (i = 0; i < q->nr; i++) {
4443                struct diff_filepair *p = q->queue[i];
4444
4445                /*
4446                 * 1. Entries that come from stat info dirtiness
4447                 *    always have both sides (iow, not create/delete),
4448                 *    one side of the object name is unknown, with
4449                 *    the same mode and size.  Keep the ones that
4450                 *    do not match these criteria.  They have real
4451                 *    differences.
4452                 *
4453                 * 2. At this point, the file is known to be modified,
4454                 *    with the same mode and size, and the object
4455                 *    name of one side is unknown.  Need to inspect
4456                 *    the identical contents.
4457                 */
4458                if (!DIFF_FILE_VALID(p->one) || /* (1) */
4459                    !DIFF_FILE_VALID(p->two) ||
4460                    (p->one->sha1_valid && p->two->sha1_valid) ||
4461                    (p->one->mode != p->two->mode) ||
4462                    diff_populate_filespec(p->one, 1) ||
4463                    diff_populate_filespec(p->two, 1) ||
4464                    (p->one->size != p->two->size) ||
4465                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4466                        diff_q(&outq, p);
4467                else {
4468                        /*
4469                         * The caller can subtract 1 from skip_stat_unmatch
4470                         * to determine how many paths were dirty only
4471                         * due to stat info mismatch.
4472                         */
4473                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4474                                diffopt->skip_stat_unmatch++;
4475                        diff_free_filepair(p);
4476                }
4477        }
4478        free(q->queue);
4479        *q = outq;
4480}
4481
4482static int diffnamecmp(const void *a_, const void *b_)
4483{
4484        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4485        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4486        const char *name_a, *name_b;
4487
4488        name_a = a->one ? a->one->path : a->two->path;
4489        name_b = b->one ? b->one->path : b->two->path;
4490        return strcmp(name_a, name_b);
4491}
4492
4493void diffcore_fix_diff_index(struct diff_options *options)
4494{
4495        struct diff_queue_struct *q = &diff_queued_diff;
4496        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4497}
4498
4499void diffcore_std(struct diff_options *options)
4500{
4501        if (options->skip_stat_unmatch)
4502                diffcore_skip_stat_unmatch(options);
4503        if (!options->found_follow) {
4504                /* See try_to_follow_renames() in tree-diff.c */
4505                if (options->break_opt != -1)
4506                        diffcore_break(options->break_opt);
4507                if (options->detect_rename)
4508                        diffcore_rename(options);
4509                if (options->break_opt != -1)
4510                        diffcore_merge_broken();
4511        }
4512        if (options->pickaxe)
4513                diffcore_pickaxe(options);
4514        if (options->orderfile)
4515                diffcore_order(options->orderfile);
4516        if (!options->found_follow)
4517                /* See try_to_follow_renames() in tree-diff.c */
4518                diff_resolve_rename_copy();
4519        diffcore_apply_filter(options->filter);
4520
4521        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4522                DIFF_OPT_SET(options, HAS_CHANGES);
4523        else
4524                DIFF_OPT_CLR(options, HAS_CHANGES);
4525
4526        options->found_follow = 0;
4527}
4528
4529int diff_result_code(struct diff_options *opt, int status)
4530{
4531        int result = 0;
4532
4533        diff_warn_rename_limit("diff.renamelimit",
4534                               opt->needed_rename_limit,
4535                               opt->degraded_cc_to_c);
4536        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4537            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4538                return status;
4539        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4540            DIFF_OPT_TST(opt, HAS_CHANGES))
4541                result |= 01;
4542        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4543            DIFF_OPT_TST(opt, CHECK_FAILED))
4544                result |= 02;
4545        return result;
4546}
4547
4548int diff_can_quit_early(struct diff_options *opt)
4549{
4550        return (DIFF_OPT_TST(opt, QUICK) &&
4551                !opt->filter &&
4552                DIFF_OPT_TST(opt, HAS_CHANGES));
4553}
4554
4555/*
4556 * Shall changes to this submodule be ignored?
4557 *
4558 * Submodule changes can be configured to be ignored separately for each path,
4559 * but that configuration can be overridden from the command line.
4560 */
4561static int is_submodule_ignored(const char *path, struct diff_options *options)
4562{
4563        int ignored = 0;
4564        unsigned orig_flags = options->flags;
4565        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4566                set_diffopt_flags_from_submodule_config(options, path);
4567        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4568                ignored = 1;
4569        options->flags = orig_flags;
4570        return ignored;
4571}
4572
4573void diff_addremove(struct diff_options *options,
4574                    int addremove, unsigned mode,
4575                    const unsigned char *sha1,
4576                    const char *concatpath, unsigned dirty_submodule)
4577{
4578        struct diff_filespec *one, *two;
4579
4580        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4581                return;
4582
4583        /* This may look odd, but it is a preparation for
4584         * feeding "there are unchanged files which should
4585         * not produce diffs, but when you are doing copy
4586         * detection you would need them, so here they are"
4587         * entries to the diff-core.  They will be prefixed
4588         * with something like '=' or '*' (I haven't decided
4589         * which but should not make any difference).
4590         * Feeding the same new and old to diff_change()
4591         * also has the same effect.
4592         * Before the final output happens, they are pruned after
4593         * merged into rename/copy pairs as appropriate.
4594         */
4595        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4596                addremove = (addremove == '+' ? '-' :
4597                             addremove == '-' ? '+' : addremove);
4598
4599        if (options->prefix &&
4600            strncmp(concatpath, options->prefix, options->prefix_length))
4601                return;
4602
4603        one = alloc_filespec(concatpath);
4604        two = alloc_filespec(concatpath);
4605
4606        if (addremove != '+')
4607                fill_filespec(one, sha1, mode);
4608        if (addremove != '-') {
4609                fill_filespec(two, sha1, mode);
4610                two->dirty_submodule = dirty_submodule;
4611        }
4612
4613        diff_queue(&diff_queued_diff, one, two);
4614        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4615                DIFF_OPT_SET(options, HAS_CHANGES);
4616}
4617
4618void diff_change(struct diff_options *options,
4619                 unsigned old_mode, unsigned new_mode,
4620                 const unsigned char *old_sha1,
4621                 const unsigned char *new_sha1,
4622                 const char *concatpath,
4623                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4624{
4625        struct diff_filespec *one, *two;
4626
4627        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4628            is_submodule_ignored(concatpath, options))
4629                return;
4630
4631        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4632                unsigned tmp;
4633                const unsigned char *tmp_c;
4634                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4635                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4636                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4637                        new_dirty_submodule = tmp;
4638        }
4639
4640        if (options->prefix &&
4641            strncmp(concatpath, options->prefix, options->prefix_length))
4642                return;
4643
4644        one = alloc_filespec(concatpath);
4645        two = alloc_filespec(concatpath);
4646        fill_filespec(one, old_sha1, old_mode);
4647        fill_filespec(two, new_sha1, new_mode);
4648        one->dirty_submodule = old_dirty_submodule;
4649        two->dirty_submodule = new_dirty_submodule;
4650
4651        diff_queue(&diff_queued_diff, one, two);
4652        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4653                DIFF_OPT_SET(options, HAS_CHANGES);
4654}
4655
4656struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
4657{
4658        struct diff_filepair *pair;
4659        struct diff_filespec *one, *two;
4660
4661        if (options->prefix &&
4662            strncmp(path, options->prefix, options->prefix_length))
4663                return NULL;
4664
4665        one = alloc_filespec(path);
4666        two = alloc_filespec(path);
4667        pair = diff_queue(&diff_queued_diff, one, two);
4668        pair->is_unmerged = 1;
4669        return pair;
4670}
4671
4672static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4673                size_t *outsize)
4674{
4675        struct diff_tempfile *temp;
4676        const char *argv[3];
4677        const char **arg = argv;
4678        struct child_process child;
4679        struct strbuf buf = STRBUF_INIT;
4680        int err = 0;
4681
4682        temp = prepare_temp_file(spec->path, spec);
4683        *arg++ = pgm;
4684        *arg++ = temp->name;
4685        *arg = NULL;
4686
4687        memset(&child, 0, sizeof(child));
4688        child.use_shell = 1;
4689        child.argv = argv;
4690        child.out = -1;
4691        if (start_command(&child)) {
4692                remove_tempfile();
4693                return NULL;
4694        }
4695
4696        if (strbuf_read(&buf, child.out, 0) < 0)
4697                err = error("error reading from textconv command '%s'", pgm);
4698        close(child.out);
4699
4700        if (finish_command(&child) || err) {
4701                strbuf_release(&buf);
4702                remove_tempfile();
4703                return NULL;
4704        }
4705        remove_tempfile();
4706
4707        return strbuf_detach(&buf, outsize);
4708}
4709
4710size_t fill_textconv(struct userdiff_driver *driver,
4711                     struct diff_filespec *df,
4712                     char **outbuf)
4713{
4714        size_t size;
4715
4716        if (!driver || !driver->textconv) {
4717                if (!DIFF_FILE_VALID(df)) {
4718                        *outbuf = "";
4719                        return 0;
4720                }
4721                if (diff_populate_filespec(df, 0))
4722                        die("unable to read files to diff");
4723                *outbuf = df->data;
4724                return df->size;
4725        }
4726
4727        if (driver->textconv_cache && df->sha1_valid) {
4728                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4729                                          &size);
4730                if (*outbuf)
4731                        return size;
4732        }
4733
4734        *outbuf = run_textconv(driver->textconv, df, &size);
4735        if (!*outbuf)
4736                die("unable to read files to diff");
4737
4738        if (driver->textconv_cache && df->sha1_valid) {
4739                /* ignore errors, as we might be in a readonly repository */
4740                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4741                                size);
4742                /*
4743                 * we could save up changes and flush them all at the end,
4744                 * but we would need an extra call after all diffing is done.
4745                 * Since generating a cache entry is the slow path anyway,
4746                 * this extra overhead probably isn't a big deal.
4747                 */
4748                notes_cache_write(driver->textconv_cache);
4749        }
4750
4751        return size;
4752}