diff.con commit Documentation: Grammar correction, wording fixes and cleanup (3d3d282)
   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, -1);
 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        return git_diff_basic_config(var, value, cb);
 168}
 169
 170int git_diff_basic_config(const char *var, const char *value, void *cb)
 171{
 172        if (!strcmp(var, "diff.renamelimit")) {
 173                diff_rename_limit_default = git_config_int(var, value);
 174                return 0;
 175        }
 176
 177        switch (userdiff_config(var, value)) {
 178                case 0: break;
 179                case -1: return -1;
 180                default: return 0;
 181        }
 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_color_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        int color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
 587        const char *name_a_tab, *name_b_tab;
 588        const char *metainfo = diff_get_color(color_diff, DIFF_METAINFO);
 589        const char *fraginfo = diff_get_color(color_diff, DIFF_FRAGINFO);
 590        const char *reset = diff_get_color(color_diff, DIFF_RESET);
 591        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 592        const char *a_prefix, *b_prefix;
 593        char *data_one, *data_two;
 594        size_t size_one, size_two;
 595        struct emit_callback ecbdata;
 596        char *line_prefix = "";
 597        struct strbuf *msgbuf;
 598
 599        if (o && o->output_prefix) {
 600                msgbuf = o->output_prefix(o, o->output_prefix_data);
 601                line_prefix = msgbuf->buf;
 602        }
 603
 604        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 605                a_prefix = o->b_prefix;
 606                b_prefix = o->a_prefix;
 607        } else {
 608                a_prefix = o->a_prefix;
 609                b_prefix = o->b_prefix;
 610        }
 611
 612        name_a += (*name_a == '/');
 613        name_b += (*name_b == '/');
 614        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 615        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 616
 617        strbuf_reset(&a_name);
 618        strbuf_reset(&b_name);
 619        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 620        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 621
 622        size_one = fill_textconv(textconv_one, one, &data_one);
 623        size_two = fill_textconv(textconv_two, two, &data_two);
 624
 625        memset(&ecbdata, 0, sizeof(ecbdata));
 626        ecbdata.color_diff = color_diff;
 627        ecbdata.found_changesp = &o->found_changes;
 628        ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
 629        ecbdata.opt = o;
 630        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 631                mmfile_t mf1, mf2;
 632                mf1.ptr = (char *)data_one;
 633                mf2.ptr = (char *)data_two;
 634                mf1.size = size_one;
 635                mf2.size = size_two;
 636                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 637        }
 638        ecbdata.lno_in_preimage = 1;
 639        ecbdata.lno_in_postimage = 1;
 640
 641        lc_a = count_lines(data_one, size_one);
 642        lc_b = count_lines(data_two, size_two);
 643        fprintf(o->file,
 644                "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
 645                line_prefix, metainfo, a_name.buf, name_a_tab, reset,
 646                line_prefix, metainfo, b_name.buf, name_b_tab, reset,
 647                line_prefix, fraginfo);
 648        if (!o->irreversible_delete)
 649                print_line_count(o->file, lc_a);
 650        else
 651                fprintf(o->file, "?,?");
 652        fprintf(o->file, " +");
 653        print_line_count(o->file, lc_b);
 654        fprintf(o->file, " @@%s\n", reset);
 655        if (lc_a && !o->irreversible_delete)
 656                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 657        if (lc_b)
 658                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 659        if (textconv_one)
 660                free((char *)data_one);
 661        if (textconv_two)
 662                free((char *)data_two);
 663}
 664
 665struct diff_words_buffer {
 666        mmfile_t text;
 667        long alloc;
 668        struct diff_words_orig {
 669                const char *begin, *end;
 670        } *orig;
 671        int orig_nr, orig_alloc;
 672};
 673
 674static void diff_words_append(char *line, unsigned long len,
 675                struct diff_words_buffer *buffer)
 676{
 677        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 678        line++;
 679        len--;
 680        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 681        buffer->text.size += len;
 682        buffer->text.ptr[buffer->text.size] = '\0';
 683}
 684
 685struct diff_words_style_elem {
 686        const char *prefix;
 687        const char *suffix;
 688        const char *color; /* NULL; filled in by the setup code if
 689                            * color is enabled */
 690};
 691
 692struct diff_words_style {
 693        enum diff_words_type type;
 694        struct diff_words_style_elem new, old, ctx;
 695        const char *newline;
 696};
 697
 698static struct diff_words_style diff_words_styles[] = {
 699        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 700        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 701        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 702};
 703
 704struct diff_words_data {
 705        struct diff_words_buffer minus, plus;
 706        const char *current_plus;
 707        int last_minus;
 708        struct diff_options *opt;
 709        regex_t *word_regex;
 710        enum diff_words_type type;
 711        struct diff_words_style *style;
 712};
 713
 714static int fn_out_diff_words_write_helper(FILE *fp,
 715                                          struct diff_words_style_elem *st_el,
 716                                          const char *newline,
 717                                          size_t count, const char *buf,
 718                                          const char *line_prefix)
 719{
 720        int print = 0;
 721
 722        while (count) {
 723                char *p = memchr(buf, '\n', count);
 724                if (print)
 725                        fputs(line_prefix, fp);
 726                if (p != buf) {
 727                        if (st_el->color && fputs(st_el->color, fp) < 0)
 728                                return -1;
 729                        if (fputs(st_el->prefix, fp) < 0 ||
 730                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 731                            fputs(st_el->suffix, fp) < 0)
 732                                return -1;
 733                        if (st_el->color && *st_el->color
 734                            && fputs(GIT_COLOR_RESET, fp) < 0)
 735                                return -1;
 736                }
 737                if (!p)
 738                        return 0;
 739                if (fputs(newline, fp) < 0)
 740                        return -1;
 741                count -= p + 1 - buf;
 742                buf = p + 1;
 743                print = 1;
 744        }
 745        return 0;
 746}
 747
 748/*
 749 * '--color-words' algorithm can be described as:
 750 *
 751 *   1. collect a the minus/plus lines of a diff hunk, divided into
 752 *      minus-lines and plus-lines;
 753 *
 754 *   2. break both minus-lines and plus-lines into words and
 755 *      place them into two mmfile_t with one word for each line;
 756 *
 757 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
 758 *
 759 * And for the common parts of the both file, we output the plus side text.
 760 * diff_words->current_plus is used to trace the current position of the plus file
 761 * which printed. diff_words->last_minus is used to trace the last minus word
 762 * printed.
 763 *
 764 * For '--graph' to work with '--color-words', we need to output the graph prefix
 765 * on each line of color words output. Generally, there are two conditions on
 766 * which we should output the prefix.
 767 *
 768 *   1. diff_words->last_minus == 0 &&
 769 *      diff_words->current_plus == diff_words->plus.text.ptr
 770 *
 771 *      that is: the plus text must start as a new line, and if there is no minus
 772 *      word printed, a graph prefix must be printed.
 773 *
 774 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
 775 *      *(diff_words->current_plus - 1) == '\n'
 776 *
 777 *      that is: a graph prefix must be printed following a '\n'
 778 */
 779static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
 780{
 781        if ((diff_words->last_minus == 0 &&
 782                diff_words->current_plus == diff_words->plus.text.ptr) ||
 783                (diff_words->current_plus > diff_words->plus.text.ptr &&
 784                *(diff_words->current_plus - 1) == '\n')) {
 785                return 1;
 786        } else {
 787                return 0;
 788        }
 789}
 790
 791static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 792{
 793        struct diff_words_data *diff_words = priv;
 794        struct diff_words_style *style = diff_words->style;
 795        int minus_first, minus_len, plus_first, plus_len;
 796        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 797        struct diff_options *opt = diff_words->opt;
 798        struct strbuf *msgbuf;
 799        char *line_prefix = "";
 800
 801        if (line[0] != '@' || parse_hunk_header(line, len,
 802                        &minus_first, &minus_len, &plus_first, &plus_len))
 803                return;
 804
 805        assert(opt);
 806        if (opt->output_prefix) {
 807                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 808                line_prefix = msgbuf->buf;
 809        }
 810
 811        /* POSIX requires that first be decremented by one if len == 0... */
 812        if (minus_len) {
 813                minus_begin = diff_words->minus.orig[minus_first].begin;
 814                minus_end =
 815                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 816        } else
 817                minus_begin = minus_end =
 818                        diff_words->minus.orig[minus_first].end;
 819
 820        if (plus_len) {
 821                plus_begin = diff_words->plus.orig[plus_first].begin;
 822                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 823        } else
 824                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 825
 826        if (color_words_output_graph_prefix(diff_words)) {
 827                fputs(line_prefix, diff_words->opt->file);
 828        }
 829        if (diff_words->current_plus != plus_begin) {
 830                fn_out_diff_words_write_helper(diff_words->opt->file,
 831                                &style->ctx, style->newline,
 832                                plus_begin - diff_words->current_plus,
 833                                diff_words->current_plus, line_prefix);
 834                if (*(plus_begin - 1) == '\n')
 835                        fputs(line_prefix, diff_words->opt->file);
 836        }
 837        if (minus_begin != minus_end) {
 838                fn_out_diff_words_write_helper(diff_words->opt->file,
 839                                &style->old, style->newline,
 840                                minus_end - minus_begin, minus_begin,
 841                                line_prefix);
 842        }
 843        if (plus_begin != plus_end) {
 844                fn_out_diff_words_write_helper(diff_words->opt->file,
 845                                &style->new, style->newline,
 846                                plus_end - plus_begin, plus_begin,
 847                                line_prefix);
 848        }
 849
 850        diff_words->current_plus = plus_end;
 851        diff_words->last_minus = minus_first;
 852}
 853
 854/* This function starts looking at *begin, and returns 0 iff a word was found. */
 855static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 856                int *begin, int *end)
 857{
 858        if (word_regex && *begin < buffer->size) {
 859                regmatch_t match[1];
 860                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 861                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 862                                        '\n', match[0].rm_eo - match[0].rm_so);
 863                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 864                        *begin += match[0].rm_so;
 865                        return *begin >= *end;
 866                }
 867                return -1;
 868        }
 869
 870        /* find the next word */
 871        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 872                (*begin)++;
 873        if (*begin >= buffer->size)
 874                return -1;
 875
 876        /* find the end of the word */
 877        *end = *begin + 1;
 878        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 879                (*end)++;
 880
 881        return 0;
 882}
 883
 884/*
 885 * This function splits the words in buffer->text, stores the list with
 886 * newline separator into out, and saves the offsets of the original words
 887 * in buffer->orig.
 888 */
 889static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 890                regex_t *word_regex)
 891{
 892        int i, j;
 893        long alloc = 0;
 894
 895        out->size = 0;
 896        out->ptr = NULL;
 897
 898        /* fake an empty "0th" word */
 899        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 900        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 901        buffer->orig_nr = 1;
 902
 903        for (i = 0; i < buffer->text.size; i++) {
 904                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 905                        return;
 906
 907                /* store original boundaries */
 908                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 909                                buffer->orig_alloc);
 910                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 911                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 912                buffer->orig_nr++;
 913
 914                /* store one word */
 915                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 916                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 917                out->ptr[out->size + j - i] = '\n';
 918                out->size += j - i + 1;
 919
 920                i = j - 1;
 921        }
 922}
 923
 924/* this executes the word diff on the accumulated buffers */
 925static void diff_words_show(struct diff_words_data *diff_words)
 926{
 927        xpparam_t xpp;
 928        xdemitconf_t xecfg;
 929        mmfile_t minus, plus;
 930        struct diff_words_style *style = diff_words->style;
 931
 932        struct diff_options *opt = diff_words->opt;
 933        struct strbuf *msgbuf;
 934        char *line_prefix = "";
 935
 936        assert(opt);
 937        if (opt->output_prefix) {
 938                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 939                line_prefix = msgbuf->buf;
 940        }
 941
 942        /* special case: only removal */
 943        if (!diff_words->plus.text.size) {
 944                fputs(line_prefix, diff_words->opt->file);
 945                fn_out_diff_words_write_helper(diff_words->opt->file,
 946                        &style->old, style->newline,
 947                        diff_words->minus.text.size,
 948                        diff_words->minus.text.ptr, line_prefix);
 949                diff_words->minus.text.size = 0;
 950                return;
 951        }
 952
 953        diff_words->current_plus = diff_words->plus.text.ptr;
 954        diff_words->last_minus = 0;
 955
 956        memset(&xpp, 0, sizeof(xpp));
 957        memset(&xecfg, 0, sizeof(xecfg));
 958        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
 959        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
 960        xpp.flags = 0;
 961        /* as only the hunk header will be parsed, we need a 0-context */
 962        xecfg.ctxlen = 0;
 963        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 964                      &xpp, &xecfg);
 965        free(minus.ptr);
 966        free(plus.ptr);
 967        if (diff_words->current_plus != diff_words->plus.text.ptr +
 968                        diff_words->plus.text.size) {
 969                if (color_words_output_graph_prefix(diff_words))
 970                        fputs(line_prefix, diff_words->opt->file);
 971                fn_out_diff_words_write_helper(diff_words->opt->file,
 972                        &style->ctx, style->newline,
 973                        diff_words->plus.text.ptr + diff_words->plus.text.size
 974                        - diff_words->current_plus, diff_words->current_plus,
 975                        line_prefix);
 976        }
 977        diff_words->minus.text.size = diff_words->plus.text.size = 0;
 978}
 979
 980/* In "color-words" mode, show word-diff of words accumulated in the buffer */
 981static void diff_words_flush(struct emit_callback *ecbdata)
 982{
 983        if (ecbdata->diff_words->minus.text.size ||
 984            ecbdata->diff_words->plus.text.size)
 985                diff_words_show(ecbdata->diff_words);
 986}
 987
 988static void free_diff_words_data(struct emit_callback *ecbdata)
 989{
 990        if (ecbdata->diff_words) {
 991                diff_words_flush(ecbdata);
 992                free (ecbdata->diff_words->minus.text.ptr);
 993                free (ecbdata->diff_words->minus.orig);
 994                free (ecbdata->diff_words->plus.text.ptr);
 995                free (ecbdata->diff_words->plus.orig);
 996                if (ecbdata->diff_words->word_regex) {
 997                        regfree(ecbdata->diff_words->word_regex);
 998                        free(ecbdata->diff_words->word_regex);
 999                }
1000                free(ecbdata->diff_words);
1001                ecbdata->diff_words = NULL;
1002        }
1003}
1004
1005const char *diff_get_color(int diff_use_color, enum color_diff ix)
1006{
1007        if (diff_use_color)
1008                return diff_colors[ix];
1009        return "";
1010}
1011
1012static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
1013{
1014        const char *cp;
1015        unsigned long allot;
1016        size_t l = len;
1017
1018        if (ecb->truncate)
1019                return ecb->truncate(line, len);
1020        cp = line;
1021        allot = l;
1022        while (0 < l) {
1023                (void) utf8_width(&cp, &l);
1024                if (!cp)
1025                        break; /* truncated in the middle? */
1026        }
1027        return allot - l;
1028}
1029
1030static void find_lno(const char *line, struct emit_callback *ecbdata)
1031{
1032        const char *p;
1033        ecbdata->lno_in_preimage = 0;
1034        ecbdata->lno_in_postimage = 0;
1035        p = strchr(line, '-');
1036        if (!p)
1037                return; /* cannot happen */
1038        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1039        p = strchr(p, '+');
1040        if (!p)
1041                return; /* cannot happen */
1042        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
1043}
1044
1045static void fn_out_consume(void *priv, char *line, unsigned long len)
1046{
1047        struct emit_callback *ecbdata = priv;
1048        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
1049        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
1050        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1051        struct diff_options *o = ecbdata->opt;
1052        char *line_prefix = "";
1053        struct strbuf *msgbuf;
1054
1055        if (o && o->output_prefix) {
1056                msgbuf = o->output_prefix(o, o->output_prefix_data);
1057                line_prefix = msgbuf->buf;
1058        }
1059
1060        if (ecbdata->header) {
1061                fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
1062                strbuf_reset(ecbdata->header);
1063                ecbdata->header = NULL;
1064        }
1065        *(ecbdata->found_changesp) = 1;
1066
1067        if (ecbdata->label_path[0]) {
1068                const char *name_a_tab, *name_b_tab;
1069
1070                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
1071                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
1072
1073                fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
1074                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
1075                fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
1076                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1077                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1078        }
1079
1080        if (diff_suppress_blank_empty
1081            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1082                line[0] = '\n';
1083                len = 1;
1084        }
1085
1086        if (line[0] == '@') {
1087                if (ecbdata->diff_words)
1088                        diff_words_flush(ecbdata);
1089                len = sane_truncate_line(ecbdata, line, len);
1090                find_lno(line, ecbdata);
1091                emit_hunk_header(ecbdata, line, len);
1092                if (line[len-1] != '\n')
1093                        putc('\n', ecbdata->opt->file);
1094                return;
1095        }
1096
1097        if (len < 1) {
1098                emit_line(ecbdata->opt, reset, reset, line, len);
1099                if (ecbdata->diff_words
1100                    && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
1101                        fputs("~\n", ecbdata->opt->file);
1102                return;
1103        }
1104
1105        if (ecbdata->diff_words) {
1106                if (line[0] == '-') {
1107                        diff_words_append(line, len,
1108                                          &ecbdata->diff_words->minus);
1109                        return;
1110                } else if (line[0] == '+') {
1111                        diff_words_append(line, len,
1112                                          &ecbdata->diff_words->plus);
1113                        return;
1114                }
1115                diff_words_flush(ecbdata);
1116                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1117                        emit_line(ecbdata->opt, plain, reset, line, len);
1118                        fputs("~\n", ecbdata->opt->file);
1119                } else {
1120                        /*
1121                         * Skip the prefix character, if any.  With
1122                         * diff_suppress_blank_empty, there may be
1123                         * none.
1124                         */
1125                        if (line[0] != '\n') {
1126                              line++;
1127                              len--;
1128                        }
1129                        emit_line(ecbdata->opt, plain, reset, line, len);
1130                }
1131                return;
1132        }
1133
1134        if (line[0] != '+') {
1135                const char *color =
1136                        diff_get_color(ecbdata->color_diff,
1137                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
1138                ecbdata->lno_in_preimage++;
1139                if (line[0] == ' ')
1140                        ecbdata->lno_in_postimage++;
1141                emit_line(ecbdata->opt, color, reset, line, len);
1142        } else {
1143                ecbdata->lno_in_postimage++;
1144                emit_add_line(reset, ecbdata, line + 1, len - 1);
1145        }
1146}
1147
1148static char *pprint_rename(const char *a, const char *b)
1149{
1150        const char *old = a;
1151        const char *new = b;
1152        struct strbuf name = STRBUF_INIT;
1153        int pfx_length, sfx_length;
1154        int len_a = strlen(a);
1155        int len_b = strlen(b);
1156        int a_midlen, b_midlen;
1157        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1158        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1159
1160        if (qlen_a || qlen_b) {
1161                quote_c_style(a, &name, NULL, 0);
1162                strbuf_addstr(&name, " => ");
1163                quote_c_style(b, &name, NULL, 0);
1164                return strbuf_detach(&name, NULL);
1165        }
1166
1167        /* Find common prefix */
1168        pfx_length = 0;
1169        while (*old && *new && *old == *new) {
1170                if (*old == '/')
1171                        pfx_length = old - a + 1;
1172                old++;
1173                new++;
1174        }
1175
1176        /* Find common suffix */
1177        old = a + len_a;
1178        new = b + len_b;
1179        sfx_length = 0;
1180        while (a <= old && b <= new && *old == *new) {
1181                if (*old == '/')
1182                        sfx_length = len_a - (old - a);
1183                old--;
1184                new--;
1185        }
1186
1187        /*
1188         * pfx{mid-a => mid-b}sfx
1189         * {pfx-a => pfx-b}sfx
1190         * pfx{sfx-a => sfx-b}
1191         * name-a => name-b
1192         */
1193        a_midlen = len_a - pfx_length - sfx_length;
1194        b_midlen = len_b - pfx_length - sfx_length;
1195        if (a_midlen < 0)
1196                a_midlen = 0;
1197        if (b_midlen < 0)
1198                b_midlen = 0;
1199
1200        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1201        if (pfx_length + sfx_length) {
1202                strbuf_add(&name, a, pfx_length);
1203                strbuf_addch(&name, '{');
1204        }
1205        strbuf_add(&name, a + pfx_length, a_midlen);
1206        strbuf_addstr(&name, " => ");
1207        strbuf_add(&name, b + pfx_length, b_midlen);
1208        if (pfx_length + sfx_length) {
1209                strbuf_addch(&name, '}');
1210                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1211        }
1212        return strbuf_detach(&name, NULL);
1213}
1214
1215struct diffstat_t {
1216        int nr;
1217        int alloc;
1218        struct diffstat_file {
1219                char *from_name;
1220                char *name;
1221                char *print_name;
1222                unsigned is_unmerged:1;
1223                unsigned is_binary:1;
1224                unsigned is_renamed:1;
1225                uintmax_t added, deleted;
1226        } **files;
1227};
1228
1229static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1230                                          const char *name_a,
1231                                          const char *name_b)
1232{
1233        struct diffstat_file *x;
1234        x = xcalloc(sizeof (*x), 1);
1235        if (diffstat->nr == diffstat->alloc) {
1236                diffstat->alloc = alloc_nr(diffstat->alloc);
1237                diffstat->files = xrealloc(diffstat->files,
1238                                diffstat->alloc * sizeof(x));
1239        }
1240        diffstat->files[diffstat->nr++] = x;
1241        if (name_b) {
1242                x->from_name = xstrdup(name_a);
1243                x->name = xstrdup(name_b);
1244                x->is_renamed = 1;
1245        }
1246        else {
1247                x->from_name = NULL;
1248                x->name = xstrdup(name_a);
1249        }
1250        return x;
1251}
1252
1253static void diffstat_consume(void *priv, char *line, unsigned long len)
1254{
1255        struct diffstat_t *diffstat = priv;
1256        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1257
1258        if (line[0] == '+')
1259                x->added++;
1260        else if (line[0] == '-')
1261                x->deleted++;
1262}
1263
1264const char mime_boundary_leader[] = "------------";
1265
1266static int scale_linear(int it, int width, int max_change)
1267{
1268        /*
1269         * make sure that at least one '-' is printed if there were deletions,
1270         * and likewise for '+'.
1271         */
1272        if (max_change < 2)
1273                return it;
1274        return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
1275}
1276
1277static void show_name(FILE *file,
1278                      const char *prefix, const char *name, int len)
1279{
1280        fprintf(file, " %s%-*s |", prefix, len, name);
1281}
1282
1283static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1284{
1285        if (cnt <= 0)
1286                return;
1287        fprintf(file, "%s", set);
1288        while (cnt--)
1289                putc(ch, file);
1290        fprintf(file, "%s", reset);
1291}
1292
1293static void fill_print_name(struct diffstat_file *file)
1294{
1295        char *pname;
1296
1297        if (file->print_name)
1298                return;
1299
1300        if (!file->is_renamed) {
1301                struct strbuf buf = STRBUF_INIT;
1302                if (quote_c_style(file->name, &buf, NULL, 0)) {
1303                        pname = strbuf_detach(&buf, NULL);
1304                } else {
1305                        pname = file->name;
1306                        strbuf_release(&buf);
1307                }
1308        } else {
1309                pname = pprint_rename(file->from_name, file->name);
1310        }
1311        file->print_name = pname;
1312}
1313
1314static void show_stats(struct diffstat_t *data, struct diff_options *options)
1315{
1316        int i, len, add, del, adds = 0, dels = 0;
1317        uintmax_t max_change = 0, max_len = 0;
1318        int total_files = data->nr;
1319        int width, name_width;
1320        const char *reset, *add_c, *del_c;
1321        const char *line_prefix = "";
1322        struct strbuf *msg = NULL;
1323
1324        if (data->nr == 0)
1325                return;
1326
1327        if (options->output_prefix) {
1328                msg = options->output_prefix(options, options->output_prefix_data);
1329                line_prefix = msg->buf;
1330        }
1331
1332        width = options->stat_width ? options->stat_width : 80;
1333        name_width = options->stat_name_width ? options->stat_name_width : 50;
1334
1335        /* Sanity: give at least 5 columns to the graph,
1336         * but leave at least 10 columns for the name.
1337         */
1338        if (width < 25)
1339                width = 25;
1340        if (name_width < 10)
1341                name_width = 10;
1342        else if (width < name_width + 15)
1343                name_width = width - 15;
1344
1345        /* Find the longest filename and max number of changes */
1346        reset = diff_get_color_opt(options, DIFF_RESET);
1347        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1348        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1349
1350        for (i = 0; i < data->nr; i++) {
1351                struct diffstat_file *file = data->files[i];
1352                uintmax_t change = file->added + file->deleted;
1353                fill_print_name(file);
1354                len = strlen(file->print_name);
1355                if (max_len < len)
1356                        max_len = len;
1357
1358                if (file->is_binary || file->is_unmerged)
1359                        continue;
1360                if (max_change < change)
1361                        max_change = change;
1362        }
1363
1364        /* Compute the width of the graph part;
1365         * 10 is for one blank at the beginning of the line plus
1366         * " | count " between the name and the graph.
1367         *
1368         * From here on, name_width is the width of the name area,
1369         * and width is the width of the graph area.
1370         */
1371        name_width = (name_width < max_len) ? name_width : max_len;
1372        if (width < (name_width + 10) + max_change)
1373                width = width - (name_width + 10);
1374        else
1375                width = max_change;
1376
1377        for (i = 0; i < data->nr; i++) {
1378                const char *prefix = "";
1379                char *name = data->files[i]->print_name;
1380                uintmax_t added = data->files[i]->added;
1381                uintmax_t deleted = data->files[i]->deleted;
1382                int name_len;
1383
1384                /*
1385                 * "scale" the filename
1386                 */
1387                len = name_width;
1388                name_len = strlen(name);
1389                if (name_width < name_len) {
1390                        char *slash;
1391                        prefix = "...";
1392                        len -= 3;
1393                        name += name_len - len;
1394                        slash = strchr(name, '/');
1395                        if (slash)
1396                                name = slash;
1397                }
1398
1399                if (data->files[i]->is_binary) {
1400                        fprintf(options->file, "%s", line_prefix);
1401                        show_name(options->file, prefix, name, len);
1402                        fprintf(options->file, "  Bin ");
1403                        fprintf(options->file, "%s%"PRIuMAX"%s",
1404                                del_c, deleted, reset);
1405                        fprintf(options->file, " -> ");
1406                        fprintf(options->file, "%s%"PRIuMAX"%s",
1407                                add_c, added, reset);
1408                        fprintf(options->file, " bytes");
1409                        fprintf(options->file, "\n");
1410                        continue;
1411                }
1412                else if (data->files[i]->is_unmerged) {
1413                        fprintf(options->file, "%s", line_prefix);
1414                        show_name(options->file, prefix, name, len);
1415                        fprintf(options->file, "  Unmerged\n");
1416                        continue;
1417                }
1418                else if (!data->files[i]->is_renamed &&
1419                         (added + deleted == 0)) {
1420                        total_files--;
1421                        continue;
1422                }
1423
1424                /*
1425                 * scale the add/delete
1426                 */
1427                add = added;
1428                del = deleted;
1429                adds += add;
1430                dels += del;
1431
1432                if (width <= max_change) {
1433                        add = scale_linear(add, width, max_change);
1434                        del = scale_linear(del, width, max_change);
1435                }
1436                fprintf(options->file, "%s", line_prefix);
1437                show_name(options->file, prefix, name, len);
1438                fprintf(options->file, "%5"PRIuMAX"%s", added + deleted,
1439                                added + deleted ? " " : "");
1440                show_graph(options->file, '+', add, add_c, reset);
1441                show_graph(options->file, '-', del, del_c, reset);
1442                fprintf(options->file, "\n");
1443        }
1444        fprintf(options->file, "%s", line_prefix);
1445        fprintf(options->file,
1446               " %d files changed, %d insertions(+), %d deletions(-)\n",
1447               total_files, adds, dels);
1448}
1449
1450static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1451{
1452        int i, adds = 0, dels = 0, total_files = data->nr;
1453
1454        if (data->nr == 0)
1455                return;
1456
1457        for (i = 0; i < data->nr; i++) {
1458                if (!data->files[i]->is_binary &&
1459                    !data->files[i]->is_unmerged) {
1460                        int added = data->files[i]->added;
1461                        int deleted= data->files[i]->deleted;
1462                        if (!data->files[i]->is_renamed &&
1463                            (added + deleted == 0)) {
1464                                total_files--;
1465                        } else {
1466                                adds += added;
1467                                dels += deleted;
1468                        }
1469                }
1470        }
1471        if (options->output_prefix) {
1472                struct strbuf *msg = NULL;
1473                msg = options->output_prefix(options,
1474                                options->output_prefix_data);
1475                fprintf(options->file, "%s", msg->buf);
1476        }
1477        fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
1478               total_files, adds, dels);
1479}
1480
1481static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1482{
1483        int i;
1484
1485        if (data->nr == 0)
1486                return;
1487
1488        for (i = 0; i < data->nr; i++) {
1489                struct diffstat_file *file = data->files[i];
1490
1491                if (options->output_prefix) {
1492                        struct strbuf *msg = NULL;
1493                        msg = options->output_prefix(options,
1494                                        options->output_prefix_data);
1495                        fprintf(options->file, "%s", msg->buf);
1496                }
1497
1498                if (file->is_binary)
1499                        fprintf(options->file, "-\t-\t");
1500                else
1501                        fprintf(options->file,
1502                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1503                                file->added, file->deleted);
1504                if (options->line_termination) {
1505                        fill_print_name(file);
1506                        if (!file->is_renamed)
1507                                write_name_quoted(file->name, options->file,
1508                                                  options->line_termination);
1509                        else {
1510                                fputs(file->print_name, options->file);
1511                                putc(options->line_termination, options->file);
1512                        }
1513                } else {
1514                        if (file->is_renamed) {
1515                                putc('\0', options->file);
1516                                write_name_quoted(file->from_name, options->file, '\0');
1517                        }
1518                        write_name_quoted(file->name, options->file, '\0');
1519                }
1520        }
1521}
1522
1523struct dirstat_file {
1524        const char *name;
1525        unsigned long changed;
1526};
1527
1528struct dirstat_dir {
1529        struct dirstat_file *files;
1530        int alloc, nr, permille, cumulative;
1531};
1532
1533static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1534                unsigned long changed, const char *base, int baselen)
1535{
1536        unsigned long this_dir = 0;
1537        unsigned int sources = 0;
1538        const char *line_prefix = "";
1539        struct strbuf *msg = NULL;
1540
1541        if (opt->output_prefix) {
1542                msg = opt->output_prefix(opt, opt->output_prefix_data);
1543                line_prefix = msg->buf;
1544        }
1545
1546        while (dir->nr) {
1547                struct dirstat_file *f = dir->files;
1548                int namelen = strlen(f->name);
1549                unsigned long this;
1550                char *slash;
1551
1552                if (namelen < baselen)
1553                        break;
1554                if (memcmp(f->name, base, baselen))
1555                        break;
1556                slash = strchr(f->name + baselen, '/');
1557                if (slash) {
1558                        int newbaselen = slash + 1 - f->name;
1559                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1560                        sources++;
1561                } else {
1562                        this = f->changed;
1563                        dir->files++;
1564                        dir->nr--;
1565                        sources += 2;
1566                }
1567                this_dir += this;
1568        }
1569
1570        /*
1571         * We don't report dirstat's for
1572         *  - the top level
1573         *  - or cases where everything came from a single directory
1574         *    under this directory (sources == 1).
1575         */
1576        if (baselen && sources != 1) {
1577                if (this_dir) {
1578                        int permille = this_dir * 1000 / changed;
1579                        if (permille >= dir->permille) {
1580                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1581                                        permille / 10, permille % 10, baselen, base);
1582                                if (!dir->cumulative)
1583                                        return 0;
1584                        }
1585                }
1586        }
1587        return this_dir;
1588}
1589
1590static int dirstat_compare(const void *_a, const void *_b)
1591{
1592        const struct dirstat_file *a = _a;
1593        const struct dirstat_file *b = _b;
1594        return strcmp(a->name, b->name);
1595}
1596
1597static void show_dirstat(struct diff_options *options)
1598{
1599        int i;
1600        unsigned long changed;
1601        struct dirstat_dir dir;
1602        struct diff_queue_struct *q = &diff_queued_diff;
1603
1604        dir.files = NULL;
1605        dir.alloc = 0;
1606        dir.nr = 0;
1607        dir.permille = options->dirstat_permille;
1608        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1609
1610        changed = 0;
1611        for (i = 0; i < q->nr; i++) {
1612                struct diff_filepair *p = q->queue[i];
1613                const char *name;
1614                unsigned long copied, added, damage;
1615                int content_changed;
1616
1617                name = p->two->path ? p->two->path : p->one->path;
1618
1619                if (p->one->sha1_valid && p->two->sha1_valid)
1620                        content_changed = hashcmp(p->one->sha1, p->two->sha1);
1621                else
1622                        content_changed = 1;
1623
1624                if (!content_changed) {
1625                        /*
1626                         * The SHA1 has not changed, so pre-/post-content is
1627                         * identical. We can therefore skip looking at the
1628                         * file contents altogether.
1629                         */
1630                        damage = 0;
1631                        goto found_damage;
1632                }
1633
1634                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1635                        /*
1636                         * In --dirstat-by-file mode, we don't really need to
1637                         * look at the actual file contents at all.
1638                         * The fact that the SHA1 changed is enough for us to
1639                         * add this file to the list of results
1640                         * (with each file contributing equal damage).
1641                         */
1642                        damage = 1;
1643                        goto found_damage;
1644                }
1645
1646                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1647                        diff_populate_filespec(p->one, 0);
1648                        diff_populate_filespec(p->two, 0);
1649                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1650                                               &copied, &added);
1651                        diff_free_filespec_data(p->one);
1652                        diff_free_filespec_data(p->two);
1653                } else if (DIFF_FILE_VALID(p->one)) {
1654                        diff_populate_filespec(p->one, 1);
1655                        copied = added = 0;
1656                        diff_free_filespec_data(p->one);
1657                } else if (DIFF_FILE_VALID(p->two)) {
1658                        diff_populate_filespec(p->two, 1);
1659                        copied = 0;
1660                        added = p->two->size;
1661                        diff_free_filespec_data(p->two);
1662                } else
1663                        continue;
1664
1665                /*
1666                 * Original minus copied is the removed material,
1667                 * added is the new material.  They are both damages
1668                 * made to the preimage.
1669                 * If the resulting damage is zero, we know that
1670                 * diffcore_count_changes() considers the two entries to
1671                 * be identical, but since content_changed is true, we
1672                 * know that there must have been _some_ kind of change,
1673                 * so we force all entries to have damage > 0.
1674                 */
1675                damage = (p->one->size - copied) + added;
1676                if (!damage)
1677                        damage = 1;
1678
1679found_damage:
1680                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1681                dir.files[dir.nr].name = name;
1682                dir.files[dir.nr].changed = damage;
1683                changed += damage;
1684                dir.nr++;
1685        }
1686
1687        /* This can happen even with many files, if everything was renames */
1688        if (!changed)
1689                return;
1690
1691        /* Show all directories with more than x% of the changes */
1692        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1693        gather_dirstat(options, &dir, changed, "", 0);
1694}
1695
1696static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
1697{
1698        int i;
1699        unsigned long changed;
1700        struct dirstat_dir dir;
1701
1702        if (data->nr == 0)
1703                return;
1704
1705        dir.files = NULL;
1706        dir.alloc = 0;
1707        dir.nr = 0;
1708        dir.permille = options->dirstat_permille;
1709        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1710
1711        changed = 0;
1712        for (i = 0; i < data->nr; i++) {
1713                struct diffstat_file *file = data->files[i];
1714                unsigned long damage = file->added + file->deleted;
1715                if (file->is_binary)
1716                        /*
1717                         * binary files counts bytes, not lines. Must find some
1718                         * way to normalize binary bytes vs. textual lines.
1719                         * The following heuristic assumes that there are 64
1720                         * bytes per "line".
1721                         * This is stupid and ugly, but very cheap...
1722                         */
1723                        damage = (damage + 63) / 64;
1724                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1725                dir.files[dir.nr].name = file->name;
1726                dir.files[dir.nr].changed = damage;
1727                changed += damage;
1728                dir.nr++;
1729        }
1730
1731        /* This can happen even with many files, if everything was renames */
1732        if (!changed)
1733                return;
1734
1735        /* Show all directories with more than x% of the changes */
1736        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1737        gather_dirstat(options, &dir, changed, "", 0);
1738}
1739
1740static void free_diffstat_info(struct diffstat_t *diffstat)
1741{
1742        int i;
1743        for (i = 0; i < diffstat->nr; i++) {
1744                struct diffstat_file *f = diffstat->files[i];
1745                if (f->name != f->print_name)
1746                        free(f->print_name);
1747                free(f->name);
1748                free(f->from_name);
1749                free(f);
1750        }
1751        free(diffstat->files);
1752}
1753
1754struct checkdiff_t {
1755        const char *filename;
1756        int lineno;
1757        int conflict_marker_size;
1758        struct diff_options *o;
1759        unsigned ws_rule;
1760        unsigned status;
1761};
1762
1763static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1764{
1765        char firstchar;
1766        int cnt;
1767
1768        if (len < marker_size + 1)
1769                return 0;
1770        firstchar = line[0];
1771        switch (firstchar) {
1772        case '=': case '>': case '<': case '|':
1773                break;
1774        default:
1775                return 0;
1776        }
1777        for (cnt = 1; cnt < marker_size; cnt++)
1778                if (line[cnt] != firstchar)
1779                        return 0;
1780        /* line[1] thru line[marker_size-1] are same as firstchar */
1781        if (len < marker_size + 1 || !isspace(line[marker_size]))
1782                return 0;
1783        return 1;
1784}
1785
1786static void checkdiff_consume(void *priv, char *line, unsigned long len)
1787{
1788        struct checkdiff_t *data = priv;
1789        int color_diff = DIFF_OPT_TST(data->o, COLOR_DIFF);
1790        int marker_size = data->conflict_marker_size;
1791        const char *ws = diff_get_color(color_diff, DIFF_WHITESPACE);
1792        const char *reset = diff_get_color(color_diff, DIFF_RESET);
1793        const char *set = diff_get_color(color_diff, DIFF_FILE_NEW);
1794        char *err;
1795        char *line_prefix = "";
1796        struct strbuf *msgbuf;
1797
1798        assert(data->o);
1799        if (data->o->output_prefix) {
1800                msgbuf = data->o->output_prefix(data->o,
1801                        data->o->output_prefix_data);
1802                line_prefix = msgbuf->buf;
1803        }
1804
1805        if (line[0] == '+') {
1806                unsigned bad;
1807                data->lineno++;
1808                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
1809                        data->status |= 1;
1810                        fprintf(data->o->file,
1811                                "%s%s:%d: leftover conflict marker\n",
1812                                line_prefix, data->filename, data->lineno);
1813                }
1814                bad = ws_check(line + 1, len - 1, data->ws_rule);
1815                if (!bad)
1816                        return;
1817                data->status |= bad;
1818                err = whitespace_error_string(bad);
1819                fprintf(data->o->file, "%s%s:%d: %s.\n",
1820                        line_prefix, data->filename, data->lineno, err);
1821                free(err);
1822                emit_line(data->o, set, reset, line, 1);
1823                ws_check_emit(line + 1, len - 1, data->ws_rule,
1824                              data->o->file, set, reset, ws);
1825        } else if (line[0] == ' ') {
1826                data->lineno++;
1827        } else if (line[0] == '@') {
1828                char *plus = strchr(line, '+');
1829                if (plus)
1830                        data->lineno = strtol(plus, NULL, 10) - 1;
1831                else
1832                        die("invalid diff");
1833        }
1834}
1835
1836static unsigned char *deflate_it(char *data,
1837                                 unsigned long size,
1838                                 unsigned long *result_size)
1839{
1840        int bound;
1841        unsigned char *deflated;
1842        git_zstream stream;
1843
1844        memset(&stream, 0, sizeof(stream));
1845        git_deflate_init(&stream, zlib_compression_level);
1846        bound = git_deflate_bound(&stream, size);
1847        deflated = xmalloc(bound);
1848        stream.next_out = deflated;
1849        stream.avail_out = bound;
1850
1851        stream.next_in = (unsigned char *)data;
1852        stream.avail_in = size;
1853        while (git_deflate(&stream, Z_FINISH) == Z_OK)
1854                ; /* nothing */
1855        git_deflate_end(&stream);
1856        *result_size = stream.total_out;
1857        return deflated;
1858}
1859
1860static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1861{
1862        void *cp;
1863        void *delta;
1864        void *deflated;
1865        void *data;
1866        unsigned long orig_size;
1867        unsigned long delta_size;
1868        unsigned long deflate_size;
1869        unsigned long data_size;
1870
1871        /* We could do deflated delta, or we could do just deflated two,
1872         * whichever is smaller.
1873         */
1874        delta = NULL;
1875        deflated = deflate_it(two->ptr, two->size, &deflate_size);
1876        if (one->size && two->size) {
1877                delta = diff_delta(one->ptr, one->size,
1878                                   two->ptr, two->size,
1879                                   &delta_size, deflate_size);
1880                if (delta) {
1881                        void *to_free = delta;
1882                        orig_size = delta_size;
1883                        delta = deflate_it(delta, delta_size, &delta_size);
1884                        free(to_free);
1885                }
1886        }
1887
1888        if (delta && delta_size < deflate_size) {
1889                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
1890                free(deflated);
1891                data = delta;
1892                data_size = delta_size;
1893        }
1894        else {
1895                fprintf(file, "%sliteral %lu\n", prefix, two->size);
1896                free(delta);
1897                data = deflated;
1898                data_size = deflate_size;
1899        }
1900
1901        /* emit data encoded in base85 */
1902        cp = data;
1903        while (data_size) {
1904                int bytes = (52 < data_size) ? 52 : data_size;
1905                char line[70];
1906                data_size -= bytes;
1907                if (bytes <= 26)
1908                        line[0] = bytes + 'A' - 1;
1909                else
1910                        line[0] = bytes - 26 + 'a' - 1;
1911                encode_85(line + 1, cp, bytes);
1912                cp = (char *) cp + bytes;
1913                fprintf(file, "%s", prefix);
1914                fputs(line, file);
1915                fputc('\n', file);
1916        }
1917        fprintf(file, "%s\n", prefix);
1918        free(data);
1919}
1920
1921static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1922{
1923        fprintf(file, "%sGIT binary patch\n", prefix);
1924        emit_binary_diff_body(file, one, two, prefix);
1925        emit_binary_diff_body(file, two, one, prefix);
1926}
1927
1928static void diff_filespec_load_driver(struct diff_filespec *one)
1929{
1930        /* Use already-loaded driver */
1931        if (one->driver)
1932                return;
1933
1934        if (S_ISREG(one->mode))
1935                one->driver = userdiff_find_by_path(one->path);
1936
1937        /* Fallback to default settings */
1938        if (!one->driver)
1939                one->driver = userdiff_find_by_name("default");
1940}
1941
1942int diff_filespec_is_binary(struct diff_filespec *one)
1943{
1944        if (one->is_binary == -1) {
1945                diff_filespec_load_driver(one);
1946                if (one->driver->binary != -1)
1947                        one->is_binary = one->driver->binary;
1948                else {
1949                        if (!one->data && DIFF_FILE_VALID(one))
1950                                diff_populate_filespec(one, 0);
1951                        if (one->data)
1952                                one->is_binary = buffer_is_binary(one->data,
1953                                                one->size);
1954                        if (one->is_binary == -1)
1955                                one->is_binary = 0;
1956                }
1957        }
1958        return one->is_binary;
1959}
1960
1961static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
1962{
1963        diff_filespec_load_driver(one);
1964        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
1965}
1966
1967static const char *userdiff_word_regex(struct diff_filespec *one)
1968{
1969        diff_filespec_load_driver(one);
1970        return one->driver->word_regex;
1971}
1972
1973void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
1974{
1975        if (!options->a_prefix)
1976                options->a_prefix = a;
1977        if (!options->b_prefix)
1978                options->b_prefix = b;
1979}
1980
1981struct userdiff_driver *get_textconv(struct diff_filespec *one)
1982{
1983        if (!DIFF_FILE_VALID(one))
1984                return NULL;
1985
1986        diff_filespec_load_driver(one);
1987        return userdiff_get_textconv(one->driver);
1988}
1989
1990static void builtin_diff(const char *name_a,
1991                         const char *name_b,
1992                         struct diff_filespec *one,
1993                         struct diff_filespec *two,
1994                         const char *xfrm_msg,
1995                         int must_show_header,
1996                         struct diff_options *o,
1997                         int complete_rewrite)
1998{
1999        mmfile_t mf1, mf2;
2000        const char *lbl[2];
2001        char *a_one, *b_two;
2002        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
2003        const char *reset = diff_get_color_opt(o, DIFF_RESET);
2004        const char *a_prefix, *b_prefix;
2005        struct userdiff_driver *textconv_one = NULL;
2006        struct userdiff_driver *textconv_two = NULL;
2007        struct strbuf header = STRBUF_INIT;
2008        struct strbuf *msgbuf;
2009        char *line_prefix = "";
2010
2011        if (o->output_prefix) {
2012                msgbuf = o->output_prefix(o, o->output_prefix_data);
2013                line_prefix = msgbuf->buf;
2014        }
2015
2016        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
2017                        (!one->mode || S_ISGITLINK(one->mode)) &&
2018                        (!two->mode || S_ISGITLINK(two->mode))) {
2019                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2020                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2021                show_submodule_summary(o->file, one ? one->path : two->path,
2022                                one->sha1, two->sha1, two->dirty_submodule,
2023                                del, add, reset);
2024                return;
2025        }
2026
2027        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
2028                textconv_one = get_textconv(one);
2029                textconv_two = get_textconv(two);
2030        }
2031
2032        diff_set_mnemonic_prefix(o, "a/", "b/");
2033        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
2034                a_prefix = o->b_prefix;
2035                b_prefix = o->a_prefix;
2036        } else {
2037                a_prefix = o->a_prefix;
2038                b_prefix = o->b_prefix;
2039        }
2040
2041        /* Never use a non-valid filename anywhere if at all possible */
2042        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
2043        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
2044
2045        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
2046        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
2047        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
2048        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
2049        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
2050        if (lbl[0][0] == '/') {
2051                /* /dev/null */
2052                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
2053                if (xfrm_msg)
2054                        strbuf_addstr(&header, xfrm_msg);
2055                must_show_header = 1;
2056        }
2057        else if (lbl[1][0] == '/') {
2058                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
2059                if (xfrm_msg)
2060                        strbuf_addstr(&header, xfrm_msg);
2061                must_show_header = 1;
2062        }
2063        else {
2064                if (one->mode != two->mode) {
2065                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
2066                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
2067                        must_show_header = 1;
2068                }
2069                if (xfrm_msg)
2070                        strbuf_addstr(&header, xfrm_msg);
2071
2072                /*
2073                 * we do not run diff between different kind
2074                 * of objects.
2075                 */
2076                if ((one->mode ^ two->mode) & S_IFMT)
2077                        goto free_ab_and_return;
2078                if (complete_rewrite &&
2079                    (textconv_one || !diff_filespec_is_binary(one)) &&
2080                    (textconv_two || !diff_filespec_is_binary(two))) {
2081                        fprintf(o->file, "%s", header.buf);
2082                        strbuf_reset(&header);
2083                        emit_rewrite_diff(name_a, name_b, one, two,
2084                                                textconv_one, textconv_two, o);
2085                        o->found_changes = 1;
2086                        goto free_ab_and_return;
2087                }
2088        }
2089
2090        if (o->irreversible_delete && lbl[1][0] == '/') {
2091                fprintf(o->file, "%s", header.buf);
2092                strbuf_reset(&header);
2093                goto free_ab_and_return;
2094        } else if (!DIFF_OPT_TST(o, TEXT) &&
2095            ( (!textconv_one && diff_filespec_is_binary(one)) ||
2096              (!textconv_two && diff_filespec_is_binary(two)) )) {
2097                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2098                        die("unable to read files to diff");
2099                /* Quite common confusing case */
2100                if (mf1.size == mf2.size &&
2101                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2102                        if (must_show_header)
2103                                fprintf(o->file, "%s", header.buf);
2104                        goto free_ab_and_return;
2105                }
2106                fprintf(o->file, "%s", header.buf);
2107                strbuf_reset(&header);
2108                if (DIFF_OPT_TST(o, BINARY))
2109                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2110                else
2111                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2112                                line_prefix, lbl[0], lbl[1]);
2113                o->found_changes = 1;
2114        } else {
2115                /* Crazy xdl interfaces.. */
2116                const char *diffopts = getenv("GIT_DIFF_OPTS");
2117                xpparam_t xpp;
2118                xdemitconf_t xecfg;
2119                struct emit_callback ecbdata;
2120                const struct userdiff_funcname *pe;
2121
2122                if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS) || must_show_header) {
2123                        fprintf(o->file, "%s", header.buf);
2124                        strbuf_reset(&header);
2125                }
2126
2127                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2128                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2129
2130                pe = diff_funcname_pattern(one);
2131                if (!pe)
2132                        pe = diff_funcname_pattern(two);
2133
2134                memset(&xpp, 0, sizeof(xpp));
2135                memset(&xecfg, 0, sizeof(xecfg));
2136                memset(&ecbdata, 0, sizeof(ecbdata));
2137                ecbdata.label_path = lbl;
2138                ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
2139                ecbdata.found_changesp = &o->found_changes;
2140                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
2141                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2142                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2143                ecbdata.opt = o;
2144                ecbdata.header = header.len ? &header : NULL;
2145                xpp.flags = o->xdl_opts;
2146                xecfg.ctxlen = o->context;
2147                xecfg.interhunkctxlen = o->interhunkcontext;
2148                xecfg.flags = XDL_EMIT_FUNCNAMES;
2149                if (pe)
2150                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2151                if (!diffopts)
2152                        ;
2153                else if (!prefixcmp(diffopts, "--unified="))
2154                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2155                else if (!prefixcmp(diffopts, "-u"))
2156                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2157                if (o->word_diff) {
2158                        int i;
2159
2160                        ecbdata.diff_words =
2161                                xcalloc(1, sizeof(struct diff_words_data));
2162                        ecbdata.diff_words->type = o->word_diff;
2163                        ecbdata.diff_words->opt = o;
2164                        if (!o->word_regex)
2165                                o->word_regex = userdiff_word_regex(one);
2166                        if (!o->word_regex)
2167                                o->word_regex = userdiff_word_regex(two);
2168                        if (!o->word_regex)
2169                                o->word_regex = diff_word_regex_cfg;
2170                        if (o->word_regex) {
2171                                ecbdata.diff_words->word_regex = (regex_t *)
2172                                        xmalloc(sizeof(regex_t));
2173                                if (regcomp(ecbdata.diff_words->word_regex,
2174                                                o->word_regex,
2175                                                REG_EXTENDED | REG_NEWLINE))
2176                                        die ("Invalid regular expression: %s",
2177                                                        o->word_regex);
2178                        }
2179                        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2180                                if (o->word_diff == diff_words_styles[i].type) {
2181                                        ecbdata.diff_words->style =
2182                                                &diff_words_styles[i];
2183                                        break;
2184                                }
2185                        }
2186                        if (DIFF_OPT_TST(o, COLOR_DIFF)) {
2187                                struct diff_words_style *st = ecbdata.diff_words->style;
2188                                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2189                                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2190                                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
2191                        }
2192                }
2193                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2194                              &xpp, &xecfg);
2195                if (o->word_diff)
2196                        free_diff_words_data(&ecbdata);
2197                if (textconv_one)
2198                        free(mf1.ptr);
2199                if (textconv_two)
2200                        free(mf2.ptr);
2201                xdiff_clear_find_func(&xecfg);
2202        }
2203
2204 free_ab_and_return:
2205        strbuf_release(&header);
2206        diff_free_filespec_data(one);
2207        diff_free_filespec_data(two);
2208        free(a_one);
2209        free(b_two);
2210        return;
2211}
2212
2213static void builtin_diffstat(const char *name_a, const char *name_b,
2214                             struct diff_filespec *one,
2215                             struct diff_filespec *two,
2216                             struct diffstat_t *diffstat,
2217                             struct diff_options *o,
2218                             int complete_rewrite)
2219{
2220        mmfile_t mf1, mf2;
2221        struct diffstat_file *data;
2222
2223        data = diffstat_add(diffstat, name_a, name_b);
2224
2225        if (!one || !two) {
2226                data->is_unmerged = 1;
2227                return;
2228        }
2229
2230        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2231                data->is_binary = 1;
2232                data->added = diff_filespec_size(two);
2233                data->deleted = diff_filespec_size(one);
2234        }
2235
2236        else if (complete_rewrite) {
2237                diff_populate_filespec(one, 0);
2238                diff_populate_filespec(two, 0);
2239                data->deleted = count_lines(one->data, one->size);
2240                data->added = count_lines(two->data, two->size);
2241        }
2242
2243        else {
2244                /* Crazy xdl interfaces.. */
2245                xpparam_t xpp;
2246                xdemitconf_t xecfg;
2247
2248                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2249                        die("unable to read files to diff");
2250
2251                memset(&xpp, 0, sizeof(xpp));
2252                memset(&xecfg, 0, sizeof(xecfg));
2253                xpp.flags = o->xdl_opts;
2254                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2255                              &xpp, &xecfg);
2256        }
2257
2258        diff_free_filespec_data(one);
2259        diff_free_filespec_data(two);
2260}
2261
2262static void builtin_checkdiff(const char *name_a, const char *name_b,
2263                              const char *attr_path,
2264                              struct diff_filespec *one,
2265                              struct diff_filespec *two,
2266                              struct diff_options *o)
2267{
2268        mmfile_t mf1, mf2;
2269        struct checkdiff_t data;
2270
2271        if (!two)
2272                return;
2273
2274        memset(&data, 0, sizeof(data));
2275        data.filename = name_b ? name_b : name_a;
2276        data.lineno = 0;
2277        data.o = o;
2278        data.ws_rule = whitespace_rule(attr_path);
2279        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2280
2281        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2282                die("unable to read files to diff");
2283
2284        /*
2285         * All the other codepaths check both sides, but not checking
2286         * the "old" side here is deliberate.  We are checking the newly
2287         * introduced changes, and as long as the "new" side is text, we
2288         * can and should check what it introduces.
2289         */
2290        if (diff_filespec_is_binary(two))
2291                goto free_and_return;
2292        else {
2293                /* Crazy xdl interfaces.. */
2294                xpparam_t xpp;
2295                xdemitconf_t xecfg;
2296
2297                memset(&xpp, 0, sizeof(xpp));
2298                memset(&xecfg, 0, sizeof(xecfg));
2299                xecfg.ctxlen = 1; /* at least one context line */
2300                xpp.flags = 0;
2301                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2302                              &xpp, &xecfg);
2303
2304                if (data.ws_rule & WS_BLANK_AT_EOF) {
2305                        struct emit_callback ecbdata;
2306                        int blank_at_eof;
2307
2308                        ecbdata.ws_rule = data.ws_rule;
2309                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2310                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2311
2312                        if (blank_at_eof) {
2313                                static char *err;
2314                                if (!err)
2315                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2316                                fprintf(o->file, "%s:%d: %s.\n",
2317                                        data.filename, blank_at_eof, err);
2318                                data.status = 1; /* report errors */
2319                        }
2320                }
2321        }
2322 free_and_return:
2323        diff_free_filespec_data(one);
2324        diff_free_filespec_data(two);
2325        if (data.status)
2326                DIFF_OPT_SET(o, CHECK_FAILED);
2327}
2328
2329struct diff_filespec *alloc_filespec(const char *path)
2330{
2331        int namelen = strlen(path);
2332        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2333
2334        memset(spec, 0, sizeof(*spec));
2335        spec->path = (char *)(spec + 1);
2336        memcpy(spec->path, path, namelen+1);
2337        spec->count = 1;
2338        spec->is_binary = -1;
2339        return spec;
2340}
2341
2342void free_filespec(struct diff_filespec *spec)
2343{
2344        if (!--spec->count) {
2345                diff_free_filespec_data(spec);
2346                free(spec);
2347        }
2348}
2349
2350void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2351                   unsigned short mode)
2352{
2353        if (mode) {
2354                spec->mode = canon_mode(mode);
2355                hashcpy(spec->sha1, sha1);
2356                spec->sha1_valid = !is_null_sha1(sha1);
2357        }
2358}
2359
2360/*
2361 * Given a name and sha1 pair, if the index tells us the file in
2362 * the work tree has that object contents, return true, so that
2363 * prepare_temp_file() does not have to inflate and extract.
2364 */
2365static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2366{
2367        struct cache_entry *ce;
2368        struct stat st;
2369        int pos, len;
2370
2371        /*
2372         * We do not read the cache ourselves here, because the
2373         * benchmark with my previous version that always reads cache
2374         * shows that it makes things worse for diff-tree comparing
2375         * two linux-2.6 kernel trees in an already checked out work
2376         * tree.  This is because most diff-tree comparisons deal with
2377         * only a small number of files, while reading the cache is
2378         * expensive for a large project, and its cost outweighs the
2379         * savings we get by not inflating the object to a temporary
2380         * file.  Practically, this code only helps when we are used
2381         * by diff-cache --cached, which does read the cache before
2382         * calling us.
2383         */
2384        if (!active_cache)
2385                return 0;
2386
2387        /* We want to avoid the working directory if our caller
2388         * doesn't need the data in a normal file, this system
2389         * is rather slow with its stat/open/mmap/close syscalls,
2390         * and the object is contained in a pack file.  The pack
2391         * is probably already open and will be faster to obtain
2392         * the data through than the working directory.  Loose
2393         * objects however would tend to be slower as they need
2394         * to be individually opened and inflated.
2395         */
2396        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2397                return 0;
2398
2399        len = strlen(name);
2400        pos = cache_name_pos(name, len);
2401        if (pos < 0)
2402                return 0;
2403        ce = active_cache[pos];
2404
2405        /*
2406         * This is not the sha1 we are looking for, or
2407         * unreusable because it is not a regular file.
2408         */
2409        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2410                return 0;
2411
2412        /*
2413         * If ce is marked as "assume unchanged", there is no
2414         * guarantee that work tree matches what we are looking for.
2415         */
2416        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2417                return 0;
2418
2419        /*
2420         * If ce matches the file in the work tree, we can reuse it.
2421         */
2422        if (ce_uptodate(ce) ||
2423            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2424                return 1;
2425
2426        return 0;
2427}
2428
2429static int populate_from_stdin(struct diff_filespec *s)
2430{
2431        struct strbuf buf = STRBUF_INIT;
2432        size_t size = 0;
2433
2434        if (strbuf_read(&buf, 0, 0) < 0)
2435                return error("error while reading from stdin %s",
2436                                     strerror(errno));
2437
2438        s->should_munmap = 0;
2439        s->data = strbuf_detach(&buf, &size);
2440        s->size = size;
2441        s->should_free = 1;
2442        return 0;
2443}
2444
2445static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2446{
2447        int len;
2448        char *data = xmalloc(100), *dirty = "";
2449
2450        /* Are we looking at the work tree? */
2451        if (s->dirty_submodule)
2452                dirty = "-dirty";
2453
2454        len = snprintf(data, 100,
2455                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2456        s->data = data;
2457        s->size = len;
2458        s->should_free = 1;
2459        if (size_only) {
2460                s->data = NULL;
2461                free(data);
2462        }
2463        return 0;
2464}
2465
2466/*
2467 * While doing rename detection and pickaxe operation, we may need to
2468 * grab the data for the blob (or file) for our own in-core comparison.
2469 * diff_filespec has data and size fields for this purpose.
2470 */
2471int diff_populate_filespec(struct diff_filespec *s, int size_only)
2472{
2473        int err = 0;
2474        if (!DIFF_FILE_VALID(s))
2475                die("internal error: asking to populate invalid file.");
2476        if (S_ISDIR(s->mode))
2477                return -1;
2478
2479        if (s->data)
2480                return 0;
2481
2482        if (size_only && 0 < s->size)
2483                return 0;
2484
2485        if (S_ISGITLINK(s->mode))
2486                return diff_populate_gitlink(s, size_only);
2487
2488        if (!s->sha1_valid ||
2489            reuse_worktree_file(s->path, s->sha1, 0)) {
2490                struct strbuf buf = STRBUF_INIT;
2491                struct stat st;
2492                int fd;
2493
2494                if (!strcmp(s->path, "-"))
2495                        return populate_from_stdin(s);
2496
2497                if (lstat(s->path, &st) < 0) {
2498                        if (errno == ENOENT) {
2499                        err_empty:
2500                                err = -1;
2501                        empty:
2502                                s->data = (char *)"";
2503                                s->size = 0;
2504                                return err;
2505                        }
2506                }
2507                s->size = xsize_t(st.st_size);
2508                if (!s->size)
2509                        goto empty;
2510                if (S_ISLNK(st.st_mode)) {
2511                        struct strbuf sb = STRBUF_INIT;
2512
2513                        if (strbuf_readlink(&sb, s->path, s->size))
2514                                goto err_empty;
2515                        s->size = sb.len;
2516                        s->data = strbuf_detach(&sb, NULL);
2517                        s->should_free = 1;
2518                        return 0;
2519                }
2520                if (size_only)
2521                        return 0;
2522                fd = open(s->path, O_RDONLY);
2523                if (fd < 0)
2524                        goto err_empty;
2525                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2526                close(fd);
2527                s->should_munmap = 1;
2528
2529                /*
2530                 * Convert from working tree format to canonical git format
2531                 */
2532                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2533                        size_t size = 0;
2534                        munmap(s->data, s->size);
2535                        s->should_munmap = 0;
2536                        s->data = strbuf_detach(&buf, &size);
2537                        s->size = size;
2538                        s->should_free = 1;
2539                }
2540        }
2541        else {
2542                enum object_type type;
2543                if (size_only) {
2544                        type = sha1_object_info(s->sha1, &s->size);
2545                        if (type < 0)
2546                                die("unable to read %s", sha1_to_hex(s->sha1));
2547                } else {
2548                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2549                        if (!s->data)
2550                                die("unable to read %s", sha1_to_hex(s->sha1));
2551                        s->should_free = 1;
2552                }
2553        }
2554        return 0;
2555}
2556
2557void diff_free_filespec_blob(struct diff_filespec *s)
2558{
2559        if (s->should_free)
2560                free(s->data);
2561        else if (s->should_munmap)
2562                munmap(s->data, s->size);
2563
2564        if (s->should_free || s->should_munmap) {
2565                s->should_free = s->should_munmap = 0;
2566                s->data = NULL;
2567        }
2568}
2569
2570void diff_free_filespec_data(struct diff_filespec *s)
2571{
2572        diff_free_filespec_blob(s);
2573        free(s->cnt_data);
2574        s->cnt_data = NULL;
2575}
2576
2577static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2578                           void *blob,
2579                           unsigned long size,
2580                           const unsigned char *sha1,
2581                           int mode)
2582{
2583        int fd;
2584        struct strbuf buf = STRBUF_INIT;
2585        struct strbuf template = STRBUF_INIT;
2586        char *path_dup = xstrdup(path);
2587        const char *base = basename(path_dup);
2588
2589        /* Generate "XXXXXX_basename.ext" */
2590        strbuf_addstr(&template, "XXXXXX_");
2591        strbuf_addstr(&template, base);
2592
2593        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2594                        strlen(base) + 1);
2595        if (fd < 0)
2596                die_errno("unable to create temp-file");
2597        if (convert_to_working_tree(path,
2598                        (const char *)blob, (size_t)size, &buf)) {
2599                blob = buf.buf;
2600                size = buf.len;
2601        }
2602        if (write_in_full(fd, blob, size) != size)
2603                die_errno("unable to write temp-file");
2604        close(fd);
2605        temp->name = temp->tmp_path;
2606        strcpy(temp->hex, sha1_to_hex(sha1));
2607        temp->hex[40] = 0;
2608        sprintf(temp->mode, "%06o", mode);
2609        strbuf_release(&buf);
2610        strbuf_release(&template);
2611        free(path_dup);
2612}
2613
2614static struct diff_tempfile *prepare_temp_file(const char *name,
2615                struct diff_filespec *one)
2616{
2617        struct diff_tempfile *temp = claim_diff_tempfile();
2618
2619        if (!DIFF_FILE_VALID(one)) {
2620        not_a_valid_file:
2621                /* A '-' entry produces this for file-2, and
2622                 * a '+' entry produces this for file-1.
2623                 */
2624                temp->name = "/dev/null";
2625                strcpy(temp->hex, ".");
2626                strcpy(temp->mode, ".");
2627                return temp;
2628        }
2629
2630        if (!remove_tempfile_installed) {
2631                atexit(remove_tempfile);
2632                sigchain_push_common(remove_tempfile_on_signal);
2633                remove_tempfile_installed = 1;
2634        }
2635
2636        if (!one->sha1_valid ||
2637            reuse_worktree_file(name, one->sha1, 1)) {
2638                struct stat st;
2639                if (lstat(name, &st) < 0) {
2640                        if (errno == ENOENT)
2641                                goto not_a_valid_file;
2642                        die_errno("stat(%s)", name);
2643                }
2644                if (S_ISLNK(st.st_mode)) {
2645                        struct strbuf sb = STRBUF_INIT;
2646                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2647                                die_errno("readlink(%s)", name);
2648                        prep_temp_blob(name, temp, sb.buf, sb.len,
2649                                       (one->sha1_valid ?
2650                                        one->sha1 : null_sha1),
2651                                       (one->sha1_valid ?
2652                                        one->mode : S_IFLNK));
2653                        strbuf_release(&sb);
2654                }
2655                else {
2656                        /* we can borrow from the file in the work tree */
2657                        temp->name = name;
2658                        if (!one->sha1_valid)
2659                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2660                        else
2661                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2662                        /* Even though we may sometimes borrow the
2663                         * contents from the work tree, we always want
2664                         * one->mode.  mode is trustworthy even when
2665                         * !(one->sha1_valid), as long as
2666                         * DIFF_FILE_VALID(one).
2667                         */
2668                        sprintf(temp->mode, "%06o", one->mode);
2669                }
2670                return temp;
2671        }
2672        else {
2673                if (diff_populate_filespec(one, 0))
2674                        die("cannot read data blob for %s", one->path);
2675                prep_temp_blob(name, temp, one->data, one->size,
2676                               one->sha1, one->mode);
2677        }
2678        return temp;
2679}
2680
2681/* An external diff command takes:
2682 *
2683 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2684 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2685 *
2686 */
2687static void run_external_diff(const char *pgm,
2688                              const char *name,
2689                              const char *other,
2690                              struct diff_filespec *one,
2691                              struct diff_filespec *two,
2692                              const char *xfrm_msg,
2693                              int complete_rewrite)
2694{
2695        const char *spawn_arg[10];
2696        int retval;
2697        const char **arg = &spawn_arg[0];
2698
2699        if (one && two) {
2700                struct diff_tempfile *temp_one, *temp_two;
2701                const char *othername = (other ? other : name);
2702                temp_one = prepare_temp_file(name, one);
2703                temp_two = prepare_temp_file(othername, two);
2704                *arg++ = pgm;
2705                *arg++ = name;
2706                *arg++ = temp_one->name;
2707                *arg++ = temp_one->hex;
2708                *arg++ = temp_one->mode;
2709                *arg++ = temp_two->name;
2710                *arg++ = temp_two->hex;
2711                *arg++ = temp_two->mode;
2712                if (other) {
2713                        *arg++ = other;
2714                        *arg++ = xfrm_msg;
2715                }
2716        } else {
2717                *arg++ = pgm;
2718                *arg++ = name;
2719        }
2720        *arg = NULL;
2721        fflush(NULL);
2722        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2723        remove_tempfile();
2724        if (retval) {
2725                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2726                exit(1);
2727        }
2728}
2729
2730static int similarity_index(struct diff_filepair *p)
2731{
2732        return p->score * 100 / MAX_SCORE;
2733}
2734
2735static void fill_metainfo(struct strbuf *msg,
2736                          const char *name,
2737                          const char *other,
2738                          struct diff_filespec *one,
2739                          struct diff_filespec *two,
2740                          struct diff_options *o,
2741                          struct diff_filepair *p,
2742                          int *must_show_header,
2743                          int use_color)
2744{
2745        const char *set = diff_get_color(use_color, DIFF_METAINFO);
2746        const char *reset = diff_get_color(use_color, DIFF_RESET);
2747        struct strbuf *msgbuf;
2748        char *line_prefix = "";
2749
2750        *must_show_header = 1;
2751        if (o->output_prefix) {
2752                msgbuf = o->output_prefix(o, o->output_prefix_data);
2753                line_prefix = msgbuf->buf;
2754        }
2755        strbuf_init(msg, PATH_MAX * 2 + 300);
2756        switch (p->status) {
2757        case DIFF_STATUS_COPIED:
2758                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2759                            line_prefix, set, similarity_index(p));
2760                strbuf_addf(msg, "%s\n%s%scopy from ",
2761                            reset,  line_prefix, set);
2762                quote_c_style(name, msg, NULL, 0);
2763                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2764                quote_c_style(other, msg, NULL, 0);
2765                strbuf_addf(msg, "%s\n", reset);
2766                break;
2767        case DIFF_STATUS_RENAMED:
2768                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2769                            line_prefix, set, similarity_index(p));
2770                strbuf_addf(msg, "%s\n%s%srename from ",
2771                            reset, line_prefix, set);
2772                quote_c_style(name, msg, NULL, 0);
2773                strbuf_addf(msg, "%s\n%s%srename to ",
2774                            reset, line_prefix, set);
2775                quote_c_style(other, msg, NULL, 0);
2776                strbuf_addf(msg, "%s\n", reset);
2777                break;
2778        case DIFF_STATUS_MODIFIED:
2779                if (p->score) {
2780                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2781                                    line_prefix,
2782                                    set, similarity_index(p), reset);
2783                        break;
2784                }
2785                /* fallthru */
2786        default:
2787                *must_show_header = 0;
2788        }
2789        if (one && two && hashcmp(one->sha1, two->sha1)) {
2790                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2791
2792                if (DIFF_OPT_TST(o, BINARY)) {
2793                        mmfile_t mf;
2794                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2795                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2796                                abbrev = 40;
2797                }
2798                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2799                            find_unique_abbrev(one->sha1, abbrev));
2800                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2801                if (one->mode == two->mode)
2802                        strbuf_addf(msg, " %06o", one->mode);
2803                strbuf_addf(msg, "%s\n", reset);
2804        }
2805}
2806
2807static void run_diff_cmd(const char *pgm,
2808                         const char *name,
2809                         const char *other,
2810                         const char *attr_path,
2811                         struct diff_filespec *one,
2812                         struct diff_filespec *two,
2813                         struct strbuf *msg,
2814                         struct diff_options *o,
2815                         struct diff_filepair *p)
2816{
2817        const char *xfrm_msg = NULL;
2818        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2819        int must_show_header = 0;
2820
2821        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2822                pgm = NULL;
2823        else {
2824                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2825                if (drv && drv->external)
2826                        pgm = drv->external;
2827        }
2828
2829        if (msg) {
2830                /*
2831                 * don't use colors when the header is intended for an
2832                 * external diff driver
2833                 */
2834                fill_metainfo(msg, name, other, one, two, o, p,
2835                              &must_show_header,
2836                              DIFF_OPT_TST(o, COLOR_DIFF) && !pgm);
2837                xfrm_msg = msg->len ? msg->buf : NULL;
2838        }
2839
2840        if (pgm) {
2841                run_external_diff(pgm, name, other, one, two, xfrm_msg,
2842                                  complete_rewrite);
2843                return;
2844        }
2845        if (one && two)
2846                builtin_diff(name, other ? other : name,
2847                             one, two, xfrm_msg, must_show_header,
2848                             o, complete_rewrite);
2849        else
2850                fprintf(o->file, "* Unmerged path %s\n", name);
2851}
2852
2853static void diff_fill_sha1_info(struct diff_filespec *one)
2854{
2855        if (DIFF_FILE_VALID(one)) {
2856                if (!one->sha1_valid) {
2857                        struct stat st;
2858                        if (!strcmp(one->path, "-")) {
2859                                hashcpy(one->sha1, null_sha1);
2860                                return;
2861                        }
2862                        if (lstat(one->path, &st) < 0)
2863                                die_errno("stat '%s'", one->path);
2864                        if (index_path(one->sha1, one->path, &st, 0))
2865                                die("cannot hash %s", one->path);
2866                }
2867        }
2868        else
2869                hashclr(one->sha1);
2870}
2871
2872static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2873{
2874        /* Strip the prefix but do not molest /dev/null and absolute paths */
2875        if (*namep && **namep != '/') {
2876                *namep += prefix_length;
2877                if (**namep == '/')
2878                        ++*namep;
2879        }
2880        if (*otherp && **otherp != '/') {
2881                *otherp += prefix_length;
2882                if (**otherp == '/')
2883                        ++*otherp;
2884        }
2885}
2886
2887static void run_diff(struct diff_filepair *p, struct diff_options *o)
2888{
2889        const char *pgm = external_diff();
2890        struct strbuf msg;
2891        struct diff_filespec *one = p->one;
2892        struct diff_filespec *two = p->two;
2893        const char *name;
2894        const char *other;
2895        const char *attr_path;
2896
2897        name  = p->one->path;
2898        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2899        attr_path = name;
2900        if (o->prefix_length)
2901                strip_prefix(o->prefix_length, &name, &other);
2902
2903        if (DIFF_PAIR_UNMERGED(p)) {
2904                run_diff_cmd(pgm, name, NULL, attr_path,
2905                             NULL, NULL, NULL, o, p);
2906                return;
2907        }
2908
2909        diff_fill_sha1_info(one);
2910        diff_fill_sha1_info(two);
2911
2912        if (!pgm &&
2913            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2914            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2915                /*
2916                 * a filepair that changes between file and symlink
2917                 * needs to be split into deletion and creation.
2918                 */
2919                struct diff_filespec *null = alloc_filespec(two->path);
2920                run_diff_cmd(NULL, name, other, attr_path,
2921                             one, null, &msg, o, p);
2922                free(null);
2923                strbuf_release(&msg);
2924
2925                null = alloc_filespec(one->path);
2926                run_diff_cmd(NULL, name, other, attr_path,
2927                             null, two, &msg, o, p);
2928                free(null);
2929        }
2930        else
2931                run_diff_cmd(pgm, name, other, attr_path,
2932                             one, two, &msg, o, p);
2933
2934        strbuf_release(&msg);
2935}
2936
2937static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2938                         struct diffstat_t *diffstat)
2939{
2940        const char *name;
2941        const char *other;
2942        int complete_rewrite = 0;
2943
2944        if (DIFF_PAIR_UNMERGED(p)) {
2945                /* unmerged */
2946                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2947                return;
2948        }
2949
2950        name = p->one->path;
2951        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2952
2953        if (o->prefix_length)
2954                strip_prefix(o->prefix_length, &name, &other);
2955
2956        diff_fill_sha1_info(p->one);
2957        diff_fill_sha1_info(p->two);
2958
2959        if (p->status == DIFF_STATUS_MODIFIED && p->score)
2960                complete_rewrite = 1;
2961        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2962}
2963
2964static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2965{
2966        const char *name;
2967        const char *other;
2968        const char *attr_path;
2969
2970        if (DIFF_PAIR_UNMERGED(p)) {
2971                /* unmerged */
2972                return;
2973        }
2974
2975        name = p->one->path;
2976        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2977        attr_path = other ? other : name;
2978
2979        if (o->prefix_length)
2980                strip_prefix(o->prefix_length, &name, &other);
2981
2982        diff_fill_sha1_info(p->one);
2983        diff_fill_sha1_info(p->two);
2984
2985        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2986}
2987
2988void diff_setup(struct diff_options *options)
2989{
2990        memcpy(options, &default_diff_options, sizeof(*options));
2991
2992        options->file = stdout;
2993
2994        options->line_termination = '\n';
2995        options->break_opt = -1;
2996        options->rename_limit = -1;
2997        options->dirstat_permille = diff_dirstat_permille_default;
2998        options->context = 3;
2999
3000        options->change = diff_change;
3001        options->add_remove = diff_addremove;
3002        if (diff_use_color_default > 0)
3003                DIFF_OPT_SET(options, COLOR_DIFF);
3004        options->detect_rename = diff_detect_rename_default;
3005
3006        if (diff_no_prefix) {
3007                options->a_prefix = options->b_prefix = "";
3008        } else if (!diff_mnemonic_prefix) {
3009                options->a_prefix = "a/";
3010                options->b_prefix = "b/";
3011        }
3012}
3013
3014int diff_setup_done(struct diff_options *options)
3015{
3016        int count = 0;
3017
3018        if (options->output_format & DIFF_FORMAT_NAME)
3019                count++;
3020        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
3021                count++;
3022        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
3023                count++;
3024        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
3025                count++;
3026        if (count > 1)
3027                die("--name-only, --name-status, --check and -s are mutually exclusive");
3028
3029        /*
3030         * Most of the time we can say "there are changes"
3031         * only by checking if there are changed paths, but
3032         * --ignore-whitespace* options force us to look
3033         * inside contents.
3034         */
3035
3036        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
3037            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
3038            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
3039                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
3040        else
3041                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
3042
3043        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3044                options->detect_rename = DIFF_DETECT_COPY;
3045
3046        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
3047                options->prefix = NULL;
3048        if (options->prefix)
3049                options->prefix_length = strlen(options->prefix);
3050        else
3051                options->prefix_length = 0;
3052
3053        if (options->output_format & (DIFF_FORMAT_NAME |
3054                                      DIFF_FORMAT_NAME_STATUS |
3055                                      DIFF_FORMAT_CHECKDIFF |
3056                                      DIFF_FORMAT_NO_OUTPUT))
3057                options->output_format &= ~(DIFF_FORMAT_RAW |
3058                                            DIFF_FORMAT_NUMSTAT |
3059                                            DIFF_FORMAT_DIFFSTAT |
3060                                            DIFF_FORMAT_SHORTSTAT |
3061                                            DIFF_FORMAT_DIRSTAT |
3062                                            DIFF_FORMAT_SUMMARY |
3063                                            DIFF_FORMAT_PATCH);
3064
3065        /*
3066         * These cases always need recursive; we do not drop caller-supplied
3067         * recursive bits for other formats here.
3068         */
3069        if (options->output_format & (DIFF_FORMAT_PATCH |
3070                                      DIFF_FORMAT_NUMSTAT |
3071                                      DIFF_FORMAT_DIFFSTAT |
3072                                      DIFF_FORMAT_SHORTSTAT |
3073                                      DIFF_FORMAT_DIRSTAT |
3074                                      DIFF_FORMAT_SUMMARY |
3075                                      DIFF_FORMAT_CHECKDIFF))
3076                DIFF_OPT_SET(options, RECURSIVE);
3077        /*
3078         * Also pickaxe would not work very well if you do not say recursive
3079         */
3080        if (options->pickaxe)
3081                DIFF_OPT_SET(options, RECURSIVE);
3082        /*
3083         * When patches are generated, submodules diffed against the work tree
3084         * must be checked for dirtiness too so it can be shown in the output
3085         */
3086        if (options->output_format & DIFF_FORMAT_PATCH)
3087                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3088
3089        if (options->detect_rename && options->rename_limit < 0)
3090                options->rename_limit = diff_rename_limit_default;
3091        if (options->setup & DIFF_SETUP_USE_CACHE) {
3092                if (!active_cache)
3093                        /* read-cache does not die even when it fails
3094                         * so it is safe for us to do this here.  Also
3095                         * it does not smudge active_cache or active_nr
3096                         * when it fails, so we do not have to worry about
3097                         * cleaning it up ourselves either.
3098                         */
3099                        read_cache();
3100        }
3101        if (options->abbrev <= 0 || 40 < options->abbrev)
3102                options->abbrev = 40; /* full */
3103
3104        /*
3105         * It does not make sense to show the first hit we happened
3106         * to have found.  It does not make sense not to return with
3107         * exit code in such a case either.
3108         */
3109        if (DIFF_OPT_TST(options, QUICK)) {
3110                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3111                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3112        }
3113
3114        return 0;
3115}
3116
3117static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3118{
3119        char c, *eq;
3120        int len;
3121
3122        if (*arg != '-')
3123                return 0;
3124        c = *++arg;
3125        if (!c)
3126                return 0;
3127        if (c == arg_short) {
3128                c = *++arg;
3129                if (!c)
3130                        return 1;
3131                if (val && isdigit(c)) {
3132                        char *end;
3133                        int n = strtoul(arg, &end, 10);
3134                        if (*end)
3135                                return 0;
3136                        *val = n;
3137                        return 1;
3138                }
3139                return 0;
3140        }
3141        if (c != '-')
3142                return 0;
3143        arg++;
3144        eq = strchr(arg, '=');
3145        if (eq)
3146                len = eq - arg;
3147        else
3148                len = strlen(arg);
3149        if (!len || strncmp(arg, arg_long, len))
3150                return 0;
3151        if (eq) {
3152                int n;
3153                char *end;
3154                if (!isdigit(*++eq))
3155                        return 0;
3156                n = strtoul(eq, &end, 10);
3157                if (*end)
3158                        return 0;
3159                *val = n;
3160        }
3161        return 1;
3162}
3163
3164static int diff_scoreopt_parse(const char *opt);
3165
3166static inline int short_opt(char opt, const char **argv,
3167                            const char **optarg)
3168{
3169        const char *arg = argv[0];
3170        if (arg[0] != '-' || arg[1] != opt)
3171                return 0;
3172        if (arg[2] != '\0') {
3173                *optarg = arg + 2;
3174                return 1;
3175        }
3176        if (!argv[1])
3177                die("Option '%c' requires a value", opt);
3178        *optarg = argv[1];
3179        return 2;
3180}
3181
3182int parse_long_opt(const char *opt, const char **argv,
3183                   const char **optarg)
3184{
3185        const char *arg = argv[0];
3186        if (arg[0] != '-' || arg[1] != '-')
3187                return 0;
3188        arg += strlen("--");
3189        if (prefixcmp(arg, opt))
3190                return 0;
3191        arg += strlen(opt);
3192        if (*arg == '=') { /* sticked form: --option=value */
3193                *optarg = arg + 1;
3194                return 1;
3195        }
3196        if (*arg != '\0')
3197                return 0;
3198        /* separate form: --option value */
3199        if (!argv[1])
3200                die("Option '--%s' requires a value", opt);
3201        *optarg = argv[1];
3202        return 2;
3203}
3204
3205static int stat_opt(struct diff_options *options, const char **av)
3206{
3207        const char *arg = av[0];
3208        char *end;
3209        int width = options->stat_width;
3210        int name_width = options->stat_name_width;
3211        int argcount = 1;
3212
3213        arg += strlen("--stat");
3214        end = (char *)arg;
3215
3216        switch (*arg) {
3217        case '-':
3218                if (!prefixcmp(arg, "-width")) {
3219                        arg += strlen("-width");
3220                        if (*arg == '=')
3221                                width = strtoul(arg + 1, &end, 10);
3222                        else if (!*arg && !av[1])
3223                                die("Option '--stat-width' requires a value");
3224                        else if (!*arg) {
3225                                width = strtoul(av[1], &end, 10);
3226                                argcount = 2;
3227                        }
3228                } else if (!prefixcmp(arg, "-name-width")) {
3229                        arg += strlen("-name-width");
3230                        if (*arg == '=')
3231                                name_width = strtoul(arg + 1, &end, 10);
3232                        else if (!*arg && !av[1])
3233                                die("Option '--stat-name-width' requires a value");
3234                        else if (!*arg) {
3235                                name_width = strtoul(av[1], &end, 10);
3236                                argcount = 2;
3237                        }
3238                }
3239                break;
3240        case '=':
3241                width = strtoul(arg+1, &end, 10);
3242                if (*end == ',')
3243                        name_width = strtoul(end+1, &end, 10);
3244        }
3245
3246        /* Important! This checks all the error cases! */
3247        if (*end)
3248                return 0;
3249        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3250        options->stat_name_width = name_width;
3251        options->stat_width = width;
3252        return argcount;
3253}
3254
3255static int parse_dirstat_opt(struct diff_options *options, const char *params)
3256{
3257        struct strbuf errmsg = STRBUF_INIT;
3258        if (parse_dirstat_params(options, params, &errmsg))
3259                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
3260                    errmsg.buf);
3261        strbuf_release(&errmsg);
3262        /*
3263         * The caller knows a dirstat-related option is given from the command
3264         * line; allow it to say "return this_function();"
3265         */
3266        options->output_format |= DIFF_FORMAT_DIRSTAT;
3267        return 1;
3268}
3269
3270int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3271{
3272        const char *arg = av[0];
3273        const char *optarg;
3274        int argcount;
3275
3276        /* Output format options */
3277        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3278                options->output_format |= DIFF_FORMAT_PATCH;
3279        else if (opt_arg(arg, 'U', "unified", &options->context))
3280                options->output_format |= DIFF_FORMAT_PATCH;
3281        else if (!strcmp(arg, "--raw"))
3282                options->output_format |= DIFF_FORMAT_RAW;
3283        else if (!strcmp(arg, "--patch-with-raw"))
3284                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3285        else if (!strcmp(arg, "--numstat"))
3286                options->output_format |= DIFF_FORMAT_NUMSTAT;
3287        else if (!strcmp(arg, "--shortstat"))
3288                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3289        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
3290                return parse_dirstat_opt(options, "");
3291        else if (!prefixcmp(arg, "-X"))
3292                return parse_dirstat_opt(options, arg + 2);
3293        else if (!prefixcmp(arg, "--dirstat="))
3294                return parse_dirstat_opt(options, arg + 10);
3295        else if (!strcmp(arg, "--cumulative"))
3296                return parse_dirstat_opt(options, "cumulative");
3297        else if (!strcmp(arg, "--dirstat-by-file"))
3298                return parse_dirstat_opt(options, "files");
3299        else if (!prefixcmp(arg, "--dirstat-by-file=")) {
3300                parse_dirstat_opt(options, "files");
3301                return parse_dirstat_opt(options, arg + 18);
3302        }
3303        else if (!strcmp(arg, "--check"))
3304                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3305        else if (!strcmp(arg, "--summary"))
3306                options->output_format |= DIFF_FORMAT_SUMMARY;
3307        else if (!strcmp(arg, "--patch-with-stat"))
3308                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3309        else if (!strcmp(arg, "--name-only"))
3310                options->output_format |= DIFF_FORMAT_NAME;
3311        else if (!strcmp(arg, "--name-status"))
3312                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3313        else if (!strcmp(arg, "-s"))
3314                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3315        else if (!prefixcmp(arg, "--stat"))
3316                /* --stat, --stat-width, or --stat-name-width */
3317                return stat_opt(options, av);
3318
3319        /* renames options */
3320        else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
3321                 !strcmp(arg, "--break-rewrites")) {
3322                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3323                        return error("invalid argument to -B: %s", arg+2);
3324        }
3325        else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--find-renames=") ||
3326                 !strcmp(arg, "--find-renames")) {
3327                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3328                        return error("invalid argument to -M: %s", arg+2);
3329                options->detect_rename = DIFF_DETECT_RENAME;
3330        }
3331        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3332                options->irreversible_delete = 1;
3333        }
3334        else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
3335                 !strcmp(arg, "--find-copies")) {
3336                if (options->detect_rename == DIFF_DETECT_COPY)
3337                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3338                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3339                        return error("invalid argument to -C: %s", arg+2);
3340                options->detect_rename = DIFF_DETECT_COPY;
3341        }
3342        else if (!strcmp(arg, "--no-renames"))
3343                options->detect_rename = 0;
3344        else if (!strcmp(arg, "--relative"))
3345                DIFF_OPT_SET(options, RELATIVE_NAME);
3346        else if (!prefixcmp(arg, "--relative=")) {
3347                DIFF_OPT_SET(options, RELATIVE_NAME);
3348                options->prefix = arg + 11;
3349        }
3350
3351        /* xdiff options */
3352        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3353                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3354        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3355                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3356        else if (!strcmp(arg, "--ignore-space-at-eol"))
3357                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3358        else if (!strcmp(arg, "--patience"))
3359                DIFF_XDL_SET(options, PATIENCE_DIFF);
3360
3361        /* flags options */
3362        else if (!strcmp(arg, "--binary")) {
3363                options->output_format |= DIFF_FORMAT_PATCH;
3364                DIFF_OPT_SET(options, BINARY);
3365        }
3366        else if (!strcmp(arg, "--full-index"))
3367                DIFF_OPT_SET(options, FULL_INDEX);
3368        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3369                DIFF_OPT_SET(options, TEXT);
3370        else if (!strcmp(arg, "-R"))
3371                DIFF_OPT_SET(options, REVERSE_DIFF);
3372        else if (!strcmp(arg, "--find-copies-harder"))
3373                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3374        else if (!strcmp(arg, "--follow"))
3375                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3376        else if (!strcmp(arg, "--color"))
3377                DIFF_OPT_SET(options, COLOR_DIFF);
3378        else if (!prefixcmp(arg, "--color=")) {
3379                int value = git_config_colorbool(NULL, arg+8, -1);
3380                if (value == 0)
3381                        DIFF_OPT_CLR(options, COLOR_DIFF);
3382                else if (value > 0)
3383                        DIFF_OPT_SET(options, COLOR_DIFF);
3384                else
3385                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3386        }
3387        else if (!strcmp(arg, "--no-color"))
3388                DIFF_OPT_CLR(options, COLOR_DIFF);
3389        else if (!strcmp(arg, "--color-words")) {
3390                DIFF_OPT_SET(options, COLOR_DIFF);
3391                options->word_diff = DIFF_WORDS_COLOR;
3392        }
3393        else if (!prefixcmp(arg, "--color-words=")) {
3394                DIFF_OPT_SET(options, COLOR_DIFF);
3395                options->word_diff = DIFF_WORDS_COLOR;
3396                options->word_regex = arg + 14;
3397        }
3398        else if (!strcmp(arg, "--word-diff")) {
3399                if (options->word_diff == DIFF_WORDS_NONE)
3400                        options->word_diff = DIFF_WORDS_PLAIN;
3401        }
3402        else if (!prefixcmp(arg, "--word-diff=")) {
3403                const char *type = arg + 12;
3404                if (!strcmp(type, "plain"))
3405                        options->word_diff = DIFF_WORDS_PLAIN;
3406                else if (!strcmp(type, "color")) {
3407                        DIFF_OPT_SET(options, COLOR_DIFF);
3408                        options->word_diff = DIFF_WORDS_COLOR;
3409                }
3410                else if (!strcmp(type, "porcelain"))
3411                        options->word_diff = DIFF_WORDS_PORCELAIN;
3412                else if (!strcmp(type, "none"))
3413                        options->word_diff = DIFF_WORDS_NONE;
3414                else
3415                        die("bad --word-diff argument: %s", type);
3416        }
3417        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3418                if (options->word_diff == DIFF_WORDS_NONE)
3419                        options->word_diff = DIFF_WORDS_PLAIN;
3420                options->word_regex = optarg;
3421                return argcount;
3422        }
3423        else if (!strcmp(arg, "--exit-code"))
3424                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3425        else if (!strcmp(arg, "--quiet"))
3426                DIFF_OPT_SET(options, QUICK);
3427        else if (!strcmp(arg, "--ext-diff"))
3428                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3429        else if (!strcmp(arg, "--no-ext-diff"))
3430                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3431        else if (!strcmp(arg, "--textconv"))
3432                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3433        else if (!strcmp(arg, "--no-textconv"))
3434                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3435        else if (!strcmp(arg, "--ignore-submodules")) {
3436                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3437                handle_ignore_submodules_arg(options, "all");
3438        } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3439                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3440                handle_ignore_submodules_arg(options, arg + 20);
3441        } else if (!strcmp(arg, "--submodule"))
3442                DIFF_OPT_SET(options, SUBMODULE_LOG);
3443        else if (!prefixcmp(arg, "--submodule=")) {
3444                if (!strcmp(arg + 12, "log"))
3445                        DIFF_OPT_SET(options, SUBMODULE_LOG);
3446        }
3447
3448        /* misc options */
3449        else if (!strcmp(arg, "-z"))
3450                options->line_termination = 0;
3451        else if ((argcount = short_opt('l', av, &optarg))) {
3452                options->rename_limit = strtoul(optarg, NULL, 10);
3453                return argcount;
3454        }
3455        else if ((argcount = short_opt('S', av, &optarg))) {
3456                options->pickaxe = optarg;
3457                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3458                return argcount;
3459        } else if ((argcount = short_opt('G', av, &optarg))) {
3460                options->pickaxe = optarg;
3461                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3462                return argcount;
3463        }
3464        else if (!strcmp(arg, "--pickaxe-all"))
3465                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3466        else if (!strcmp(arg, "--pickaxe-regex"))
3467                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3468        else if ((argcount = short_opt('O', av, &optarg))) {
3469                options->orderfile = optarg;
3470                return argcount;
3471        }
3472        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3473                options->filter = optarg;
3474                return argcount;
3475        }
3476        else if (!strcmp(arg, "--abbrev"))
3477                options->abbrev = DEFAULT_ABBREV;
3478        else if (!prefixcmp(arg, "--abbrev=")) {
3479                options->abbrev = strtoul(arg + 9, NULL, 10);
3480                if (options->abbrev < MINIMUM_ABBREV)
3481                        options->abbrev = MINIMUM_ABBREV;
3482                else if (40 < options->abbrev)
3483                        options->abbrev = 40;
3484        }
3485        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3486                options->a_prefix = optarg;
3487                return argcount;
3488        }
3489        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3490                options->b_prefix = optarg;
3491                return argcount;
3492        }
3493        else if (!strcmp(arg, "--no-prefix"))
3494                options->a_prefix = options->b_prefix = "";
3495        else if (opt_arg(arg, '\0', "inter-hunk-context",
3496                         &options->interhunkcontext))
3497                ;
3498        else if ((argcount = parse_long_opt("output", av, &optarg))) {
3499                options->file = fopen(optarg, "w");
3500                if (!options->file)
3501                        die_errno("Could not open '%s'", optarg);
3502                options->close_file = 1;
3503                return argcount;
3504        } else
3505                return 0;
3506        return 1;
3507}
3508
3509int parse_rename_score(const char **cp_p)
3510{
3511        unsigned long num, scale;
3512        int ch, dot;
3513        const char *cp = *cp_p;
3514
3515        num = 0;
3516        scale = 1;
3517        dot = 0;
3518        for (;;) {
3519                ch = *cp;
3520                if ( !dot && ch == '.' ) {
3521                        scale = 1;
3522                        dot = 1;
3523                } else if ( ch == '%' ) {
3524                        scale = dot ? scale*100 : 100;
3525                        cp++;   /* % is always at the end */
3526                        break;
3527                } else if ( ch >= '0' && ch <= '9' ) {
3528                        if ( scale < 100000 ) {
3529                                scale *= 10;
3530                                num = (num*10) + (ch-'0');
3531                        }
3532                } else {
3533                        break;
3534                }
3535                cp++;
3536        }
3537        *cp_p = cp;
3538
3539        /* user says num divided by scale and we say internally that
3540         * is MAX_SCORE * num / scale.
3541         */
3542        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3543}
3544
3545static int diff_scoreopt_parse(const char *opt)
3546{
3547        int opt1, opt2, cmd;
3548
3549        if (*opt++ != '-')
3550                return -1;
3551        cmd = *opt++;
3552        if (cmd == '-') {
3553                /* convert the long-form arguments into short-form versions */
3554                if (!prefixcmp(opt, "break-rewrites")) {
3555                        opt += strlen("break-rewrites");
3556                        if (*opt == 0 || *opt++ == '=')
3557                                cmd = 'B';
3558                } else if (!prefixcmp(opt, "find-copies")) {
3559                        opt += strlen("find-copies");
3560                        if (*opt == 0 || *opt++ == '=')
3561                                cmd = 'C';
3562                } else if (!prefixcmp(opt, "find-renames")) {
3563                        opt += strlen("find-renames");
3564                        if (*opt == 0 || *opt++ == '=')
3565                                cmd = 'M';
3566                }
3567        }
3568        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3569                return -1; /* that is not a -M, -C nor -B option */
3570
3571        opt1 = parse_rename_score(&opt);
3572        if (cmd != 'B')
3573                opt2 = 0;
3574        else {
3575                if (*opt == 0)
3576                        opt2 = 0;
3577                else if (*opt != '/')
3578                        return -1; /* we expect -B80/99 or -B80 */
3579                else {
3580                        opt++;
3581                        opt2 = parse_rename_score(&opt);
3582                }
3583        }
3584        if (*opt != 0)
3585                return -1;
3586        return opt1 | (opt2 << 16);
3587}
3588
3589struct diff_queue_struct diff_queued_diff;
3590
3591void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3592{
3593        if (queue->alloc <= queue->nr) {
3594                queue->alloc = alloc_nr(queue->alloc);
3595                queue->queue = xrealloc(queue->queue,
3596                                        sizeof(dp) * queue->alloc);
3597        }
3598        queue->queue[queue->nr++] = dp;
3599}
3600
3601struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3602                                 struct diff_filespec *one,
3603                                 struct diff_filespec *two)
3604{
3605        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3606        dp->one = one;
3607        dp->two = two;
3608        if (queue)
3609                diff_q(queue, dp);
3610        return dp;
3611}
3612
3613void diff_free_filepair(struct diff_filepair *p)
3614{
3615        free_filespec(p->one);
3616        free_filespec(p->two);
3617        free(p);
3618}
3619
3620/* This is different from find_unique_abbrev() in that
3621 * it stuffs the result with dots for alignment.
3622 */
3623const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3624{
3625        int abblen;
3626        const char *abbrev;
3627        if (len == 40)
3628                return sha1_to_hex(sha1);
3629
3630        abbrev = find_unique_abbrev(sha1, len);
3631        abblen = strlen(abbrev);
3632        if (abblen < 37) {
3633                static char hex[41];
3634                if (len < abblen && abblen <= len + 2)
3635                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3636                else
3637                        sprintf(hex, "%s...", abbrev);
3638                return hex;
3639        }
3640        return sha1_to_hex(sha1);
3641}
3642
3643static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3644{
3645        int line_termination = opt->line_termination;
3646        int inter_name_termination = line_termination ? '\t' : '\0';
3647        if (opt->output_prefix) {
3648                struct strbuf *msg = NULL;
3649                msg = opt->output_prefix(opt, opt->output_prefix_data);
3650                fprintf(opt->file, "%s", msg->buf);
3651        }
3652
3653        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3654                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3655                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3656                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3657        }
3658        if (p->score) {
3659                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3660                        inter_name_termination);
3661        } else {
3662                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3663        }
3664
3665        if (p->status == DIFF_STATUS_COPIED ||
3666            p->status == DIFF_STATUS_RENAMED) {
3667                const char *name_a, *name_b;
3668                name_a = p->one->path;
3669                name_b = p->two->path;
3670                strip_prefix(opt->prefix_length, &name_a, &name_b);
3671                write_name_quoted(name_a, opt->file, inter_name_termination);
3672                write_name_quoted(name_b, opt->file, line_termination);
3673        } else {
3674                const char *name_a, *name_b;
3675                name_a = p->one->mode ? p->one->path : p->two->path;
3676                name_b = NULL;
3677                strip_prefix(opt->prefix_length, &name_a, &name_b);
3678                write_name_quoted(name_a, opt->file, line_termination);
3679        }
3680}
3681
3682int diff_unmodified_pair(struct diff_filepair *p)
3683{
3684        /* This function is written stricter than necessary to support
3685         * the currently implemented transformers, but the idea is to
3686         * let transformers to produce diff_filepairs any way they want,
3687         * and filter and clean them up here before producing the output.
3688         */
3689        struct diff_filespec *one = p->one, *two = p->two;
3690
3691        if (DIFF_PAIR_UNMERGED(p))
3692                return 0; /* unmerged is interesting */
3693
3694        /* deletion, addition, mode or type change
3695         * and rename are all interesting.
3696         */
3697        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3698            DIFF_PAIR_MODE_CHANGED(p) ||
3699            strcmp(one->path, two->path))
3700                return 0;
3701
3702        /* both are valid and point at the same path.  that is, we are
3703         * dealing with a change.
3704         */
3705        if (one->sha1_valid && two->sha1_valid &&
3706            !hashcmp(one->sha1, two->sha1) &&
3707            !one->dirty_submodule && !two->dirty_submodule)
3708                return 1; /* no change */
3709        if (!one->sha1_valid && !two->sha1_valid)
3710                return 1; /* both look at the same file on the filesystem. */
3711        return 0;
3712}
3713
3714static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3715{
3716        if (diff_unmodified_pair(p))
3717                return;
3718
3719        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3720            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3721                return; /* no tree diffs in patch format */
3722
3723        run_diff(p, o);
3724}
3725
3726static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3727                            struct diffstat_t *diffstat)
3728{
3729        if (diff_unmodified_pair(p))
3730                return;
3731
3732        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3733            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3734                return; /* no useful stat for tree diffs */
3735
3736        run_diffstat(p, o, diffstat);
3737}
3738
3739static void diff_flush_checkdiff(struct diff_filepair *p,
3740                struct diff_options *o)
3741{
3742        if (diff_unmodified_pair(p))
3743                return;
3744
3745        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3746            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3747                return; /* nothing to check in tree diffs */
3748
3749        run_checkdiff(p, o);
3750}
3751
3752int diff_queue_is_empty(void)
3753{
3754        struct diff_queue_struct *q = &diff_queued_diff;
3755        int i;
3756        for (i = 0; i < q->nr; i++)
3757                if (!diff_unmodified_pair(q->queue[i]))
3758                        return 0;
3759        return 1;
3760}
3761
3762#if DIFF_DEBUG
3763void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3764{
3765        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3766                x, one ? one : "",
3767                s->path,
3768                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3769                s->mode,
3770                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3771        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3772                x, one ? one : "",
3773                s->size, s->xfrm_flags);
3774}
3775
3776void diff_debug_filepair(const struct diff_filepair *p, int i)
3777{
3778        diff_debug_filespec(p->one, i, "one");
3779        diff_debug_filespec(p->two, i, "two");
3780        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3781                p->score, p->status ? p->status : '?',
3782                p->one->rename_used, p->broken_pair);
3783}
3784
3785void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3786{
3787        int i;
3788        if (msg)
3789                fprintf(stderr, "%s\n", msg);
3790        fprintf(stderr, "q->nr = %d\n", q->nr);
3791        for (i = 0; i < q->nr; i++) {
3792                struct diff_filepair *p = q->queue[i];
3793                diff_debug_filepair(p, i);
3794        }
3795}
3796#endif
3797
3798static void diff_resolve_rename_copy(void)
3799{
3800        int i;
3801        struct diff_filepair *p;
3802        struct diff_queue_struct *q = &diff_queued_diff;
3803
3804        diff_debug_queue("resolve-rename-copy", q);
3805
3806        for (i = 0; i < q->nr; i++) {
3807                p = q->queue[i];
3808                p->status = 0; /* undecided */
3809                if (DIFF_PAIR_UNMERGED(p))
3810                        p->status = DIFF_STATUS_UNMERGED;
3811                else if (!DIFF_FILE_VALID(p->one))
3812                        p->status = DIFF_STATUS_ADDED;
3813                else if (!DIFF_FILE_VALID(p->two))
3814                        p->status = DIFF_STATUS_DELETED;
3815                else if (DIFF_PAIR_TYPE_CHANGED(p))
3816                        p->status = DIFF_STATUS_TYPE_CHANGED;
3817
3818                /* from this point on, we are dealing with a pair
3819                 * whose both sides are valid and of the same type, i.e.
3820                 * either in-place edit or rename/copy edit.
3821                 */
3822                else if (DIFF_PAIR_RENAME(p)) {
3823                        /*
3824                         * A rename might have re-connected a broken
3825                         * pair up, causing the pathnames to be the
3826                         * same again. If so, that's not a rename at
3827                         * all, just a modification..
3828                         *
3829                         * Otherwise, see if this source was used for
3830                         * multiple renames, in which case we decrement
3831                         * the count, and call it a copy.
3832                         */
3833                        if (!strcmp(p->one->path, p->two->path))
3834                                p->status = DIFF_STATUS_MODIFIED;
3835                        else if (--p->one->rename_used > 0)
3836                                p->status = DIFF_STATUS_COPIED;
3837                        else
3838                                p->status = DIFF_STATUS_RENAMED;
3839                }
3840                else if (hashcmp(p->one->sha1, p->two->sha1) ||
3841                         p->one->mode != p->two->mode ||
3842                         p->one->dirty_submodule ||
3843                         p->two->dirty_submodule ||
3844                         is_null_sha1(p->one->sha1))
3845                        p->status = DIFF_STATUS_MODIFIED;
3846                else {
3847                        /* This is a "no-change" entry and should not
3848                         * happen anymore, but prepare for broken callers.
3849                         */
3850                        error("feeding unmodified %s to diffcore",
3851                              p->one->path);
3852                        p->status = DIFF_STATUS_UNKNOWN;
3853                }
3854        }
3855        diff_debug_queue("resolve-rename-copy done", q);
3856}
3857
3858static int check_pair_status(struct diff_filepair *p)
3859{
3860        switch (p->status) {
3861        case DIFF_STATUS_UNKNOWN:
3862                return 0;
3863        case 0:
3864                die("internal error in diff-resolve-rename-copy");
3865        default:
3866                return 1;
3867        }
3868}
3869
3870static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3871{
3872        int fmt = opt->output_format;
3873
3874        if (fmt & DIFF_FORMAT_CHECKDIFF)
3875                diff_flush_checkdiff(p, opt);
3876        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3877                diff_flush_raw(p, opt);
3878        else if (fmt & DIFF_FORMAT_NAME) {
3879                const char *name_a, *name_b;
3880                name_a = p->two->path;
3881                name_b = NULL;
3882                strip_prefix(opt->prefix_length, &name_a, &name_b);
3883                write_name_quoted(name_a, opt->file, opt->line_termination);
3884        }
3885}
3886
3887static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
3888{
3889        if (fs->mode)
3890                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
3891        else
3892                fprintf(file, " %s ", newdelete);
3893        write_name_quoted(fs->path, file, '\n');
3894}
3895
3896
3897static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
3898                const char *line_prefix)
3899{
3900        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
3901                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
3902                        p->two->mode, show_name ? ' ' : '\n');
3903                if (show_name) {
3904                        write_name_quoted(p->two->path, file, '\n');
3905                }
3906        }
3907}
3908
3909static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
3910                        const char *line_prefix)
3911{
3912        char *names = pprint_rename(p->one->path, p->two->path);
3913
3914        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
3915        free(names);
3916        show_mode_change(file, p, 0, line_prefix);
3917}
3918
3919static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
3920{
3921        FILE *file = opt->file;
3922        char *line_prefix = "";
3923
3924        if (opt->output_prefix) {
3925                struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
3926                line_prefix = buf->buf;
3927        }
3928
3929        switch(p->status) {
3930        case DIFF_STATUS_DELETED:
3931                fputs(line_prefix, file);
3932                show_file_mode_name(file, "delete", p->one);
3933                break;
3934        case DIFF_STATUS_ADDED:
3935                fputs(line_prefix, file);
3936                show_file_mode_name(file, "create", p->two);
3937                break;
3938        case DIFF_STATUS_COPIED:
3939                fputs(line_prefix, file);
3940                show_rename_copy(file, "copy", p, line_prefix);
3941                break;
3942        case DIFF_STATUS_RENAMED:
3943                fputs(line_prefix, file);
3944                show_rename_copy(file, "rename", p, line_prefix);
3945                break;
3946        default:
3947                if (p->score) {
3948                        fprintf(file, "%s rewrite ", line_prefix);
3949                        write_name_quoted(p->two->path, file, ' ');
3950                        fprintf(file, "(%d%%)\n", similarity_index(p));
3951                }
3952                show_mode_change(file, p, !p->score, line_prefix);
3953                break;
3954        }
3955}
3956
3957struct patch_id_t {
3958        git_SHA_CTX *ctx;
3959        int patchlen;
3960};
3961
3962static int remove_space(char *line, int len)
3963{
3964        int i;
3965        char *dst = line;
3966        unsigned char c;
3967
3968        for (i = 0; i < len; i++)
3969                if (!isspace((c = line[i])))
3970                        *dst++ = c;
3971
3972        return dst - line;
3973}
3974
3975static void patch_id_consume(void *priv, char *line, unsigned long len)
3976{
3977        struct patch_id_t *data = priv;
3978        int new_len;
3979
3980        /* Ignore line numbers when computing the SHA1 of the patch */
3981        if (!prefixcmp(line, "@@ -"))
3982                return;
3983
3984        new_len = remove_space(line, len);
3985
3986        git_SHA1_Update(data->ctx, line, new_len);
3987        data->patchlen += new_len;
3988}
3989
3990/* returns 0 upon success, and writes result into sha1 */
3991static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
3992{
3993        struct diff_queue_struct *q = &diff_queued_diff;
3994        int i;
3995        git_SHA_CTX ctx;
3996        struct patch_id_t data;
3997        char buffer[PATH_MAX * 4 + 20];
3998
3999        git_SHA1_Init(&ctx);
4000        memset(&data, 0, sizeof(struct patch_id_t));
4001        data.ctx = &ctx;
4002
4003        for (i = 0; i < q->nr; i++) {
4004                xpparam_t xpp;
4005                xdemitconf_t xecfg;
4006                mmfile_t mf1, mf2;
4007                struct diff_filepair *p = q->queue[i];
4008                int len1, len2;
4009
4010                memset(&xpp, 0, sizeof(xpp));
4011                memset(&xecfg, 0, sizeof(xecfg));
4012                if (p->status == 0)
4013                        return error("internal diff status error");
4014                if (p->status == DIFF_STATUS_UNKNOWN)
4015                        continue;
4016                if (diff_unmodified_pair(p))
4017                        continue;
4018                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4019                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4020                        continue;
4021                if (DIFF_PAIR_UNMERGED(p))
4022                        continue;
4023
4024                diff_fill_sha1_info(p->one);
4025                diff_fill_sha1_info(p->two);
4026                if (fill_mmfile(&mf1, p->one) < 0 ||
4027                                fill_mmfile(&mf2, p->two) < 0)
4028                        return error("unable to read files to diff");
4029
4030                len1 = remove_space(p->one->path, strlen(p->one->path));
4031                len2 = remove_space(p->two->path, strlen(p->two->path));
4032                if (p->one->mode == 0)
4033                        len1 = snprintf(buffer, sizeof(buffer),
4034                                        "diff--gita/%.*sb/%.*s"
4035                                        "newfilemode%06o"
4036                                        "---/dev/null"
4037                                        "+++b/%.*s",
4038                                        len1, p->one->path,
4039                                        len2, p->two->path,
4040                                        p->two->mode,
4041                                        len2, p->two->path);
4042                else if (p->two->mode == 0)
4043                        len1 = snprintf(buffer, sizeof(buffer),
4044                                        "diff--gita/%.*sb/%.*s"
4045                                        "deletedfilemode%06o"
4046                                        "---a/%.*s"
4047                                        "+++/dev/null",
4048                                        len1, p->one->path,
4049                                        len2, p->two->path,
4050                                        p->one->mode,
4051                                        len1, p->one->path);
4052                else
4053                        len1 = snprintf(buffer, sizeof(buffer),
4054                                        "diff--gita/%.*sb/%.*s"
4055                                        "---a/%.*s"
4056                                        "+++b/%.*s",
4057                                        len1, p->one->path,
4058                                        len2, p->two->path,
4059                                        len1, p->one->path,
4060                                        len2, p->two->path);
4061                git_SHA1_Update(&ctx, buffer, len1);
4062
4063                if (diff_filespec_is_binary(p->one) ||
4064                    diff_filespec_is_binary(p->two)) {
4065                        git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
4066                        git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
4067                        continue;
4068                }
4069
4070                xpp.flags = 0;
4071                xecfg.ctxlen = 3;
4072                xecfg.flags = 0;
4073                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4074                              &xpp, &xecfg);
4075        }
4076
4077        git_SHA1_Final(sha1, &ctx);
4078        return 0;
4079}
4080
4081int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
4082{
4083        struct diff_queue_struct *q = &diff_queued_diff;
4084        int i;
4085        int result = diff_get_patch_id(options, sha1);
4086
4087        for (i = 0; i < q->nr; i++)
4088                diff_free_filepair(q->queue[i]);
4089
4090        free(q->queue);
4091        DIFF_QUEUE_CLEAR(q);
4092
4093        return result;
4094}
4095
4096static int is_summary_empty(const struct diff_queue_struct *q)
4097{
4098        int i;
4099
4100        for (i = 0; i < q->nr; i++) {
4101                const struct diff_filepair *p = q->queue[i];
4102
4103                switch (p->status) {
4104                case DIFF_STATUS_DELETED:
4105                case DIFF_STATUS_ADDED:
4106                case DIFF_STATUS_COPIED:
4107                case DIFF_STATUS_RENAMED:
4108                        return 0;
4109                default:
4110                        if (p->score)
4111                                return 0;
4112                        if (p->one->mode && p->two->mode &&
4113                            p->one->mode != p->two->mode)
4114                                return 0;
4115                        break;
4116                }
4117        }
4118        return 1;
4119}
4120
4121static const char rename_limit_warning[] =
4122"inexact rename detection was skipped due to too many files.";
4123
4124static const char degrade_cc_to_c_warning[] =
4125"only found copies from modified paths due to too many files.";
4126
4127static const char rename_limit_advice[] =
4128"you may want to set your %s variable to at least "
4129"%d and retry the command.";
4130
4131void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4132{
4133        if (degraded_cc)
4134                warning(degrade_cc_to_c_warning);
4135        else if (needed)
4136                warning(rename_limit_warning);
4137        else
4138                return;
4139        if (0 < needed && needed < 32767)
4140                warning(rename_limit_advice, varname, needed);
4141}
4142
4143void diff_flush(struct diff_options *options)
4144{
4145        struct diff_queue_struct *q = &diff_queued_diff;
4146        int i, output_format = options->output_format;
4147        int separator = 0;
4148        int dirstat_by_line = 0;
4149
4150        /*
4151         * Order: raw, stat, summary, patch
4152         * or:    name/name-status/checkdiff (other bits clear)
4153         */
4154        if (!q->nr)
4155                goto free_queue;
4156
4157        if (output_format & (DIFF_FORMAT_RAW |
4158                             DIFF_FORMAT_NAME |
4159                             DIFF_FORMAT_NAME_STATUS |
4160                             DIFF_FORMAT_CHECKDIFF)) {
4161                for (i = 0; i < q->nr; i++) {
4162                        struct diff_filepair *p = q->queue[i];
4163                        if (check_pair_status(p))
4164                                flush_one_pair(p, options);
4165                }
4166                separator++;
4167        }
4168
4169        if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
4170                dirstat_by_line = 1;
4171
4172        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
4173            dirstat_by_line) {
4174                struct diffstat_t diffstat;
4175
4176                memset(&diffstat, 0, sizeof(struct diffstat_t));
4177                for (i = 0; i < q->nr; i++) {
4178                        struct diff_filepair *p = q->queue[i];
4179                        if (check_pair_status(p))
4180                                diff_flush_stat(p, options, &diffstat);
4181                }
4182                if (output_format & DIFF_FORMAT_NUMSTAT)
4183                        show_numstat(&diffstat, options);
4184                if (output_format & DIFF_FORMAT_DIFFSTAT)
4185                        show_stats(&diffstat, options);
4186                if (output_format & DIFF_FORMAT_SHORTSTAT)
4187                        show_shortstats(&diffstat, options);
4188                if (output_format & DIFF_FORMAT_DIRSTAT)
4189                        show_dirstat_by_line(&diffstat, options);
4190                free_diffstat_info(&diffstat);
4191                separator++;
4192        }
4193        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
4194                show_dirstat(options);
4195
4196        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4197                for (i = 0; i < q->nr; i++) {
4198                        diff_summary(options, q->queue[i]);
4199                }
4200                separator++;
4201        }
4202
4203        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4204            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4205            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4206                /*
4207                 * run diff_flush_patch for the exit status. setting
4208                 * options->file to /dev/null should be safe, becaue we
4209                 * aren't supposed to produce any output anyway.
4210                 */
4211                if (options->close_file)
4212                        fclose(options->file);
4213                options->file = fopen("/dev/null", "w");
4214                if (!options->file)
4215                        die_errno("Could not open /dev/null");
4216                options->close_file = 1;
4217                for (i = 0; i < q->nr; i++) {
4218                        struct diff_filepair *p = q->queue[i];
4219                        if (check_pair_status(p))
4220                                diff_flush_patch(p, options);
4221                        if (options->found_changes)
4222                                break;
4223                }
4224        }
4225
4226        if (output_format & DIFF_FORMAT_PATCH) {
4227                if (separator) {
4228                        putc(options->line_termination, options->file);
4229                        if (options->stat_sep) {
4230                                /* attach patch instead of inline */
4231                                fputs(options->stat_sep, options->file);
4232                        }
4233                }
4234
4235                for (i = 0; i < q->nr; i++) {
4236                        struct diff_filepair *p = q->queue[i];
4237                        if (check_pair_status(p))
4238                                diff_flush_patch(p, options);
4239                }
4240        }
4241
4242        if (output_format & DIFF_FORMAT_CALLBACK)
4243                options->format_callback(q, options, options->format_callback_data);
4244
4245        for (i = 0; i < q->nr; i++)
4246                diff_free_filepair(q->queue[i]);
4247free_queue:
4248        free(q->queue);
4249        DIFF_QUEUE_CLEAR(q);
4250        if (options->close_file)
4251                fclose(options->file);
4252
4253        /*
4254         * Report the content-level differences with HAS_CHANGES;
4255         * diff_addremove/diff_change does not set the bit when
4256         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4257         */
4258        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4259                if (options->found_changes)
4260                        DIFF_OPT_SET(options, HAS_CHANGES);
4261                else
4262                        DIFF_OPT_CLR(options, HAS_CHANGES);
4263        }
4264}
4265
4266static void diffcore_apply_filter(const char *filter)
4267{
4268        int i;
4269        struct diff_queue_struct *q = &diff_queued_diff;
4270        struct diff_queue_struct outq;
4271        DIFF_QUEUE_CLEAR(&outq);
4272
4273        if (!filter)
4274                return;
4275
4276        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
4277                int found;
4278                for (i = found = 0; !found && i < q->nr; i++) {
4279                        struct diff_filepair *p = q->queue[i];
4280                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4281                             ((p->score &&
4282                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4283                              (!p->score &&
4284                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4285                            ((p->status != DIFF_STATUS_MODIFIED) &&
4286                             strchr(filter, p->status)))
4287                                found++;
4288                }
4289                if (found)
4290                        return;
4291
4292                /* otherwise we will clear the whole queue
4293                 * by copying the empty outq at the end of this
4294                 * function, but first clear the current entries
4295                 * in the queue.
4296                 */
4297                for (i = 0; i < q->nr; i++)
4298                        diff_free_filepair(q->queue[i]);
4299        }
4300        else {
4301                /* Only the matching ones */
4302                for (i = 0; i < q->nr; i++) {
4303                        struct diff_filepair *p = q->queue[i];
4304
4305                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4306                             ((p->score &&
4307                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4308                              (!p->score &&
4309                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4310                            ((p->status != DIFF_STATUS_MODIFIED) &&
4311                             strchr(filter, p->status)))
4312                                diff_q(&outq, p);
4313                        else
4314                                diff_free_filepair(p);
4315                }
4316        }
4317        free(q->queue);
4318        *q = outq;
4319}
4320
4321/* Check whether two filespecs with the same mode and size are identical */
4322static int diff_filespec_is_identical(struct diff_filespec *one,
4323                                      struct diff_filespec *two)
4324{
4325        if (S_ISGITLINK(one->mode))
4326                return 0;
4327        if (diff_populate_filespec(one, 0))
4328                return 0;
4329        if (diff_populate_filespec(two, 0))
4330                return 0;
4331        return !memcmp(one->data, two->data, one->size);
4332}
4333
4334static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4335{
4336        int i;
4337        struct diff_queue_struct *q = &diff_queued_diff;
4338        struct diff_queue_struct outq;
4339        DIFF_QUEUE_CLEAR(&outq);
4340
4341        for (i = 0; i < q->nr; i++) {
4342                struct diff_filepair *p = q->queue[i];
4343
4344                /*
4345                 * 1. Entries that come from stat info dirtiness
4346                 *    always have both sides (iow, not create/delete),
4347                 *    one side of the object name is unknown, with
4348                 *    the same mode and size.  Keep the ones that
4349                 *    do not match these criteria.  They have real
4350                 *    differences.
4351                 *
4352                 * 2. At this point, the file is known to be modified,
4353                 *    with the same mode and size, and the object
4354                 *    name of one side is unknown.  Need to inspect
4355                 *    the identical contents.
4356                 */
4357                if (!DIFF_FILE_VALID(p->one) || /* (1) */
4358                    !DIFF_FILE_VALID(p->two) ||
4359                    (p->one->sha1_valid && p->two->sha1_valid) ||
4360                    (p->one->mode != p->two->mode) ||
4361                    diff_populate_filespec(p->one, 1) ||
4362                    diff_populate_filespec(p->two, 1) ||
4363                    (p->one->size != p->two->size) ||
4364                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4365                        diff_q(&outq, p);
4366                else {
4367                        /*
4368                         * The caller can subtract 1 from skip_stat_unmatch
4369                         * to determine how many paths were dirty only
4370                         * due to stat info mismatch.
4371                         */
4372                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4373                                diffopt->skip_stat_unmatch++;
4374                        diff_free_filepair(p);
4375                }
4376        }
4377        free(q->queue);
4378        *q = outq;
4379}
4380
4381static int diffnamecmp(const void *a_, const void *b_)
4382{
4383        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4384        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4385        const char *name_a, *name_b;
4386
4387        name_a = a->one ? a->one->path : a->two->path;
4388        name_b = b->one ? b->one->path : b->two->path;
4389        return strcmp(name_a, name_b);
4390}
4391
4392void diffcore_fix_diff_index(struct diff_options *options)
4393{
4394        struct diff_queue_struct *q = &diff_queued_diff;
4395        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4396}
4397
4398void diffcore_std(struct diff_options *options)
4399{
4400        if (options->skip_stat_unmatch)
4401                diffcore_skip_stat_unmatch(options);
4402        if (!options->found_follow) {
4403                /* See try_to_follow_renames() in tree-diff.c */
4404                if (options->break_opt != -1)
4405                        diffcore_break(options->break_opt);
4406                if (options->detect_rename)
4407                        diffcore_rename(options);
4408                if (options->break_opt != -1)
4409                        diffcore_merge_broken();
4410        }
4411        if (options->pickaxe)
4412                diffcore_pickaxe(options);
4413        if (options->orderfile)
4414                diffcore_order(options->orderfile);
4415        if (!options->found_follow)
4416                /* See try_to_follow_renames() in tree-diff.c */
4417                diff_resolve_rename_copy();
4418        diffcore_apply_filter(options->filter);
4419
4420        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4421                DIFF_OPT_SET(options, HAS_CHANGES);
4422        else
4423                DIFF_OPT_CLR(options, HAS_CHANGES);
4424
4425        options->found_follow = 0;
4426}
4427
4428int diff_result_code(struct diff_options *opt, int status)
4429{
4430        int result = 0;
4431
4432        diff_warn_rename_limit("diff.renamelimit",
4433                               opt->needed_rename_limit,
4434                               opt->degraded_cc_to_c);
4435        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4436            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4437                return status;
4438        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4439            DIFF_OPT_TST(opt, HAS_CHANGES))
4440                result |= 01;
4441        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4442            DIFF_OPT_TST(opt, CHECK_FAILED))
4443                result |= 02;
4444        return result;
4445}
4446
4447int diff_can_quit_early(struct diff_options *opt)
4448{
4449        return (DIFF_OPT_TST(opt, QUICK) &&
4450                !opt->filter &&
4451                DIFF_OPT_TST(opt, HAS_CHANGES));
4452}
4453
4454/*
4455 * Shall changes to this submodule be ignored?
4456 *
4457 * Submodule changes can be configured to be ignored separately for each path,
4458 * but that configuration can be overridden from the command line.
4459 */
4460static int is_submodule_ignored(const char *path, struct diff_options *options)
4461{
4462        int ignored = 0;
4463        unsigned orig_flags = options->flags;
4464        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4465                set_diffopt_flags_from_submodule_config(options, path);
4466        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4467                ignored = 1;
4468        options->flags = orig_flags;
4469        return ignored;
4470}
4471
4472void diff_addremove(struct diff_options *options,
4473                    int addremove, unsigned mode,
4474                    const unsigned char *sha1,
4475                    const char *concatpath, unsigned dirty_submodule)
4476{
4477        struct diff_filespec *one, *two;
4478
4479        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4480                return;
4481
4482        /* This may look odd, but it is a preparation for
4483         * feeding "there are unchanged files which should
4484         * not produce diffs, but when you are doing copy
4485         * detection you would need them, so here they are"
4486         * entries to the diff-core.  They will be prefixed
4487         * with something like '=' or '*' (I haven't decided
4488         * which but should not make any difference).
4489         * Feeding the same new and old to diff_change()
4490         * also has the same effect.
4491         * Before the final output happens, they are pruned after
4492         * merged into rename/copy pairs as appropriate.
4493         */
4494        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4495                addremove = (addremove == '+' ? '-' :
4496                             addremove == '-' ? '+' : addremove);
4497
4498        if (options->prefix &&
4499            strncmp(concatpath, options->prefix, options->prefix_length))
4500                return;
4501
4502        one = alloc_filespec(concatpath);
4503        two = alloc_filespec(concatpath);
4504
4505        if (addremove != '+')
4506                fill_filespec(one, sha1, mode);
4507        if (addremove != '-') {
4508                fill_filespec(two, sha1, mode);
4509                two->dirty_submodule = dirty_submodule;
4510        }
4511
4512        diff_queue(&diff_queued_diff, one, two);
4513        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4514                DIFF_OPT_SET(options, HAS_CHANGES);
4515}
4516
4517void diff_change(struct diff_options *options,
4518                 unsigned old_mode, unsigned new_mode,
4519                 const unsigned char *old_sha1,
4520                 const unsigned char *new_sha1,
4521                 const char *concatpath,
4522                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4523{
4524        struct diff_filespec *one, *two;
4525
4526        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4527            is_submodule_ignored(concatpath, options))
4528                return;
4529
4530        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4531                unsigned tmp;
4532                const unsigned char *tmp_c;
4533                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4534                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4535                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4536                        new_dirty_submodule = tmp;
4537        }
4538
4539        if (options->prefix &&
4540            strncmp(concatpath, options->prefix, options->prefix_length))
4541                return;
4542
4543        one = alloc_filespec(concatpath);
4544        two = alloc_filespec(concatpath);
4545        fill_filespec(one, old_sha1, old_mode);
4546        fill_filespec(two, new_sha1, new_mode);
4547        one->dirty_submodule = old_dirty_submodule;
4548        two->dirty_submodule = new_dirty_submodule;
4549
4550        diff_queue(&diff_queued_diff, one, two);
4551        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4552                DIFF_OPT_SET(options, HAS_CHANGES);
4553}
4554
4555struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
4556{
4557        struct diff_filepair *pair;
4558        struct diff_filespec *one, *two;
4559
4560        if (options->prefix &&
4561            strncmp(path, options->prefix, options->prefix_length))
4562                return NULL;
4563
4564        one = alloc_filespec(path);
4565        two = alloc_filespec(path);
4566        pair = diff_queue(&diff_queued_diff, one, two);
4567        pair->is_unmerged = 1;
4568        return pair;
4569}
4570
4571static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4572                size_t *outsize)
4573{
4574        struct diff_tempfile *temp;
4575        const char *argv[3];
4576        const char **arg = argv;
4577        struct child_process child;
4578        struct strbuf buf = STRBUF_INIT;
4579        int err = 0;
4580
4581        temp = prepare_temp_file(spec->path, spec);
4582        *arg++ = pgm;
4583        *arg++ = temp->name;
4584        *arg = NULL;
4585
4586        memset(&child, 0, sizeof(child));
4587        child.use_shell = 1;
4588        child.argv = argv;
4589        child.out = -1;
4590        if (start_command(&child)) {
4591                remove_tempfile();
4592                return NULL;
4593        }
4594
4595        if (strbuf_read(&buf, child.out, 0) < 0)
4596                err = error("error reading from textconv command '%s'", pgm);
4597        close(child.out);
4598
4599        if (finish_command(&child) || err) {
4600                strbuf_release(&buf);
4601                remove_tempfile();
4602                return NULL;
4603        }
4604        remove_tempfile();
4605
4606        return strbuf_detach(&buf, outsize);
4607}
4608
4609size_t fill_textconv(struct userdiff_driver *driver,
4610                     struct diff_filespec *df,
4611                     char **outbuf)
4612{
4613        size_t size;
4614
4615        if (!driver || !driver->textconv) {
4616                if (!DIFF_FILE_VALID(df)) {
4617                        *outbuf = "";
4618                        return 0;
4619                }
4620                if (diff_populate_filespec(df, 0))
4621                        die("unable to read files to diff");
4622                *outbuf = df->data;
4623                return df->size;
4624        }
4625
4626        if (driver->textconv_cache && df->sha1_valid) {
4627                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4628                                          &size);
4629                if (*outbuf)
4630                        return size;
4631        }
4632
4633        *outbuf = run_textconv(driver->textconv, df, &size);
4634        if (!*outbuf)
4635                die("unable to read files to diff");
4636
4637        if (driver->textconv_cache && df->sha1_valid) {
4638                /* ignore errors, as we might be in a readonly repository */
4639                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4640                                size);
4641                /*
4642                 * we could save up changes and flush them all at the end,
4643                 * but we would need an extra call after all diffing is done.
4644                 * Since generating a cache entry is the slow path anyway,
4645                 * this extra overhead probably isn't a big deal.
4646                 */
4647                notes_cache_write(driver->textconv_cache);
4648        }
4649
4650        return size;
4651}