diff.con commit remove prefix argument from pathspec_prefix (5879f56)
   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        z_stream stream;
1843
1844        memset(&stream, 0, sizeof(stream));
1845        deflateInit(&stream, zlib_compression_level);
1846        bound = deflateBound(&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 (deflate(&stream, Z_FINISH) == Z_OK)
1854                ; /* nothing */
1855        deflateEnd(&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        if (!one->driver->textconv)
1988                return NULL;
1989
1990        if (one->driver->textconv_want_cache && !one->driver->textconv_cache) {
1991                struct notes_cache *c = xmalloc(sizeof(*c));
1992                struct strbuf name = STRBUF_INIT;
1993
1994                strbuf_addf(&name, "textconv/%s", one->driver->name);
1995                notes_cache_init(c, name.buf, one->driver->textconv);
1996                one->driver->textconv_cache = c;
1997        }
1998
1999        return one->driver;
2000}
2001
2002static void builtin_diff(const char *name_a,
2003                         const char *name_b,
2004                         struct diff_filespec *one,
2005                         struct diff_filespec *two,
2006                         const char *xfrm_msg,
2007                         int must_show_header,
2008                         struct diff_options *o,
2009                         int complete_rewrite)
2010{
2011        mmfile_t mf1, mf2;
2012        const char *lbl[2];
2013        char *a_one, *b_two;
2014        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
2015        const char *reset = diff_get_color_opt(o, DIFF_RESET);
2016        const char *a_prefix, *b_prefix;
2017        struct userdiff_driver *textconv_one = NULL;
2018        struct userdiff_driver *textconv_two = NULL;
2019        struct strbuf header = STRBUF_INIT;
2020        struct strbuf *msgbuf;
2021        char *line_prefix = "";
2022
2023        if (o->output_prefix) {
2024                msgbuf = o->output_prefix(o, o->output_prefix_data);
2025                line_prefix = msgbuf->buf;
2026        }
2027
2028        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
2029                        (!one->mode || S_ISGITLINK(one->mode)) &&
2030                        (!two->mode || S_ISGITLINK(two->mode))) {
2031                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2032                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2033                show_submodule_summary(o->file, one ? one->path : two->path,
2034                                one->sha1, two->sha1, two->dirty_submodule,
2035                                del, add, reset);
2036                return;
2037        }
2038
2039        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
2040                textconv_one = get_textconv(one);
2041                textconv_two = get_textconv(two);
2042        }
2043
2044        diff_set_mnemonic_prefix(o, "a/", "b/");
2045        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
2046                a_prefix = o->b_prefix;
2047                b_prefix = o->a_prefix;
2048        } else {
2049                a_prefix = o->a_prefix;
2050                b_prefix = o->b_prefix;
2051        }
2052
2053        /* Never use a non-valid filename anywhere if at all possible */
2054        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
2055        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
2056
2057        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
2058        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
2059        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
2060        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
2061        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
2062        if (lbl[0][0] == '/') {
2063                /* /dev/null */
2064                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
2065                if (xfrm_msg)
2066                        strbuf_addstr(&header, xfrm_msg);
2067                must_show_header = 1;
2068        }
2069        else if (lbl[1][0] == '/') {
2070                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
2071                if (xfrm_msg)
2072                        strbuf_addstr(&header, xfrm_msg);
2073                must_show_header = 1;
2074        }
2075        else {
2076                if (one->mode != two->mode) {
2077                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
2078                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
2079                        must_show_header = 1;
2080                }
2081                if (xfrm_msg)
2082                        strbuf_addstr(&header, xfrm_msg);
2083
2084                /*
2085                 * we do not run diff between different kind
2086                 * of objects.
2087                 */
2088                if ((one->mode ^ two->mode) & S_IFMT)
2089                        goto free_ab_and_return;
2090                if (complete_rewrite &&
2091                    (textconv_one || !diff_filespec_is_binary(one)) &&
2092                    (textconv_two || !diff_filespec_is_binary(two))) {
2093                        fprintf(o->file, "%s", header.buf);
2094                        strbuf_reset(&header);
2095                        emit_rewrite_diff(name_a, name_b, one, two,
2096                                                textconv_one, textconv_two, o);
2097                        o->found_changes = 1;
2098                        goto free_ab_and_return;
2099                }
2100        }
2101
2102        if (o->irreversible_delete && lbl[1][0] == '/') {
2103                fprintf(o->file, "%s", header.buf);
2104                strbuf_reset(&header);
2105                goto free_ab_and_return;
2106        } else if (!DIFF_OPT_TST(o, TEXT) &&
2107            ( (!textconv_one && diff_filespec_is_binary(one)) ||
2108              (!textconv_two && diff_filespec_is_binary(two)) )) {
2109                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2110                        die("unable to read files to diff");
2111                /* Quite common confusing case */
2112                if (mf1.size == mf2.size &&
2113                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2114                        if (must_show_header)
2115                                fprintf(o->file, "%s", header.buf);
2116                        goto free_ab_and_return;
2117                }
2118                fprintf(o->file, "%s", header.buf);
2119                strbuf_reset(&header);
2120                if (DIFF_OPT_TST(o, BINARY))
2121                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2122                else
2123                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2124                                line_prefix, lbl[0], lbl[1]);
2125                o->found_changes = 1;
2126        } else {
2127                /* Crazy xdl interfaces.. */
2128                const char *diffopts = getenv("GIT_DIFF_OPTS");
2129                xpparam_t xpp;
2130                xdemitconf_t xecfg;
2131                struct emit_callback ecbdata;
2132                const struct userdiff_funcname *pe;
2133
2134                if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS) || must_show_header) {
2135                        fprintf(o->file, "%s", header.buf);
2136                        strbuf_reset(&header);
2137                }
2138
2139                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2140                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2141
2142                pe = diff_funcname_pattern(one);
2143                if (!pe)
2144                        pe = diff_funcname_pattern(two);
2145
2146                memset(&xpp, 0, sizeof(xpp));
2147                memset(&xecfg, 0, sizeof(xecfg));
2148                memset(&ecbdata, 0, sizeof(ecbdata));
2149                ecbdata.label_path = lbl;
2150                ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
2151                ecbdata.found_changesp = &o->found_changes;
2152                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
2153                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2154                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2155                ecbdata.opt = o;
2156                ecbdata.header = header.len ? &header : NULL;
2157                xpp.flags = o->xdl_opts;
2158                xecfg.ctxlen = o->context;
2159                xecfg.interhunkctxlen = o->interhunkcontext;
2160                xecfg.flags = XDL_EMIT_FUNCNAMES;
2161                if (pe)
2162                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2163                if (!diffopts)
2164                        ;
2165                else if (!prefixcmp(diffopts, "--unified="))
2166                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2167                else if (!prefixcmp(diffopts, "-u"))
2168                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2169                if (o->word_diff) {
2170                        int i;
2171
2172                        ecbdata.diff_words =
2173                                xcalloc(1, sizeof(struct diff_words_data));
2174                        ecbdata.diff_words->type = o->word_diff;
2175                        ecbdata.diff_words->opt = o;
2176                        if (!o->word_regex)
2177                                o->word_regex = userdiff_word_regex(one);
2178                        if (!o->word_regex)
2179                                o->word_regex = userdiff_word_regex(two);
2180                        if (!o->word_regex)
2181                                o->word_regex = diff_word_regex_cfg;
2182                        if (o->word_regex) {
2183                                ecbdata.diff_words->word_regex = (regex_t *)
2184                                        xmalloc(sizeof(regex_t));
2185                                if (regcomp(ecbdata.diff_words->word_regex,
2186                                                o->word_regex,
2187                                                REG_EXTENDED | REG_NEWLINE))
2188                                        die ("Invalid regular expression: %s",
2189                                                        o->word_regex);
2190                        }
2191                        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2192                                if (o->word_diff == diff_words_styles[i].type) {
2193                                        ecbdata.diff_words->style =
2194                                                &diff_words_styles[i];
2195                                        break;
2196                                }
2197                        }
2198                        if (DIFF_OPT_TST(o, COLOR_DIFF)) {
2199                                struct diff_words_style *st = ecbdata.diff_words->style;
2200                                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2201                                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2202                                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
2203                        }
2204                }
2205                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2206                              &xpp, &xecfg);
2207                if (o->word_diff)
2208                        free_diff_words_data(&ecbdata);
2209                if (textconv_one)
2210                        free(mf1.ptr);
2211                if (textconv_two)
2212                        free(mf2.ptr);
2213                xdiff_clear_find_func(&xecfg);
2214        }
2215
2216 free_ab_and_return:
2217        strbuf_release(&header);
2218        diff_free_filespec_data(one);
2219        diff_free_filespec_data(two);
2220        free(a_one);
2221        free(b_two);
2222        return;
2223}
2224
2225static void builtin_diffstat(const char *name_a, const char *name_b,
2226                             struct diff_filespec *one,
2227                             struct diff_filespec *two,
2228                             struct diffstat_t *diffstat,
2229                             struct diff_options *o,
2230                             int complete_rewrite)
2231{
2232        mmfile_t mf1, mf2;
2233        struct diffstat_file *data;
2234
2235        data = diffstat_add(diffstat, name_a, name_b);
2236
2237        if (!one || !two) {
2238                data->is_unmerged = 1;
2239                return;
2240        }
2241
2242        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2243                data->is_binary = 1;
2244                data->added = diff_filespec_size(two);
2245                data->deleted = diff_filespec_size(one);
2246        }
2247
2248        else if (complete_rewrite) {
2249                diff_populate_filespec(one, 0);
2250                diff_populate_filespec(two, 0);
2251                data->deleted = count_lines(one->data, one->size);
2252                data->added = count_lines(two->data, two->size);
2253        }
2254
2255        else {
2256                /* Crazy xdl interfaces.. */
2257                xpparam_t xpp;
2258                xdemitconf_t xecfg;
2259
2260                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2261                        die("unable to read files to diff");
2262
2263                memset(&xpp, 0, sizeof(xpp));
2264                memset(&xecfg, 0, sizeof(xecfg));
2265                xpp.flags = o->xdl_opts;
2266                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2267                              &xpp, &xecfg);
2268        }
2269
2270        diff_free_filespec_data(one);
2271        diff_free_filespec_data(two);
2272}
2273
2274static void builtin_checkdiff(const char *name_a, const char *name_b,
2275                              const char *attr_path,
2276                              struct diff_filespec *one,
2277                              struct diff_filespec *two,
2278                              struct diff_options *o)
2279{
2280        mmfile_t mf1, mf2;
2281        struct checkdiff_t data;
2282
2283        if (!two)
2284                return;
2285
2286        memset(&data, 0, sizeof(data));
2287        data.filename = name_b ? name_b : name_a;
2288        data.lineno = 0;
2289        data.o = o;
2290        data.ws_rule = whitespace_rule(attr_path);
2291        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2292
2293        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2294                die("unable to read files to diff");
2295
2296        /*
2297         * All the other codepaths check both sides, but not checking
2298         * the "old" side here is deliberate.  We are checking the newly
2299         * introduced changes, and as long as the "new" side is text, we
2300         * can and should check what it introduces.
2301         */
2302        if (diff_filespec_is_binary(two))
2303                goto free_and_return;
2304        else {
2305                /* Crazy xdl interfaces.. */
2306                xpparam_t xpp;
2307                xdemitconf_t xecfg;
2308
2309                memset(&xpp, 0, sizeof(xpp));
2310                memset(&xecfg, 0, sizeof(xecfg));
2311                xecfg.ctxlen = 1; /* at least one context line */
2312                xpp.flags = 0;
2313                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2314                              &xpp, &xecfg);
2315
2316                if (data.ws_rule & WS_BLANK_AT_EOF) {
2317                        struct emit_callback ecbdata;
2318                        int blank_at_eof;
2319
2320                        ecbdata.ws_rule = data.ws_rule;
2321                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2322                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2323
2324                        if (blank_at_eof) {
2325                                static char *err;
2326                                if (!err)
2327                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2328                                fprintf(o->file, "%s:%d: %s.\n",
2329                                        data.filename, blank_at_eof, err);
2330                                data.status = 1; /* report errors */
2331                        }
2332                }
2333        }
2334 free_and_return:
2335        diff_free_filespec_data(one);
2336        diff_free_filespec_data(two);
2337        if (data.status)
2338                DIFF_OPT_SET(o, CHECK_FAILED);
2339}
2340
2341struct diff_filespec *alloc_filespec(const char *path)
2342{
2343        int namelen = strlen(path);
2344        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2345
2346        memset(spec, 0, sizeof(*spec));
2347        spec->path = (char *)(spec + 1);
2348        memcpy(spec->path, path, namelen+1);
2349        spec->count = 1;
2350        spec->is_binary = -1;
2351        return spec;
2352}
2353
2354void free_filespec(struct diff_filespec *spec)
2355{
2356        if (!--spec->count) {
2357                diff_free_filespec_data(spec);
2358                free(spec);
2359        }
2360}
2361
2362void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2363                   unsigned short mode)
2364{
2365        if (mode) {
2366                spec->mode = canon_mode(mode);
2367                hashcpy(spec->sha1, sha1);
2368                spec->sha1_valid = !is_null_sha1(sha1);
2369        }
2370}
2371
2372/*
2373 * Given a name and sha1 pair, if the index tells us the file in
2374 * the work tree has that object contents, return true, so that
2375 * prepare_temp_file() does not have to inflate and extract.
2376 */
2377static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2378{
2379        struct cache_entry *ce;
2380        struct stat st;
2381        int pos, len;
2382
2383        /*
2384         * We do not read the cache ourselves here, because the
2385         * benchmark with my previous version that always reads cache
2386         * shows that it makes things worse for diff-tree comparing
2387         * two linux-2.6 kernel trees in an already checked out work
2388         * tree.  This is because most diff-tree comparisons deal with
2389         * only a small number of files, while reading the cache is
2390         * expensive for a large project, and its cost outweighs the
2391         * savings we get by not inflating the object to a temporary
2392         * file.  Practically, this code only helps when we are used
2393         * by diff-cache --cached, which does read the cache before
2394         * calling us.
2395         */
2396        if (!active_cache)
2397                return 0;
2398
2399        /* We want to avoid the working directory if our caller
2400         * doesn't need the data in a normal file, this system
2401         * is rather slow with its stat/open/mmap/close syscalls,
2402         * and the object is contained in a pack file.  The pack
2403         * is probably already open and will be faster to obtain
2404         * the data through than the working directory.  Loose
2405         * objects however would tend to be slower as they need
2406         * to be individually opened and inflated.
2407         */
2408        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2409                return 0;
2410
2411        len = strlen(name);
2412        pos = cache_name_pos(name, len);
2413        if (pos < 0)
2414                return 0;
2415        ce = active_cache[pos];
2416
2417        /*
2418         * This is not the sha1 we are looking for, or
2419         * unreusable because it is not a regular file.
2420         */
2421        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2422                return 0;
2423
2424        /*
2425         * If ce is marked as "assume unchanged", there is no
2426         * guarantee that work tree matches what we are looking for.
2427         */
2428        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2429                return 0;
2430
2431        /*
2432         * If ce matches the file in the work tree, we can reuse it.
2433         */
2434        if (ce_uptodate(ce) ||
2435            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2436                return 1;
2437
2438        return 0;
2439}
2440
2441static int populate_from_stdin(struct diff_filespec *s)
2442{
2443        struct strbuf buf = STRBUF_INIT;
2444        size_t size = 0;
2445
2446        if (strbuf_read(&buf, 0, 0) < 0)
2447                return error("error while reading from stdin %s",
2448                                     strerror(errno));
2449
2450        s->should_munmap = 0;
2451        s->data = strbuf_detach(&buf, &size);
2452        s->size = size;
2453        s->should_free = 1;
2454        return 0;
2455}
2456
2457static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2458{
2459        int len;
2460        char *data = xmalloc(100), *dirty = "";
2461
2462        /* Are we looking at the work tree? */
2463        if (s->dirty_submodule)
2464                dirty = "-dirty";
2465
2466        len = snprintf(data, 100,
2467                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2468        s->data = data;
2469        s->size = len;
2470        s->should_free = 1;
2471        if (size_only) {
2472                s->data = NULL;
2473                free(data);
2474        }
2475        return 0;
2476}
2477
2478/*
2479 * While doing rename detection and pickaxe operation, we may need to
2480 * grab the data for the blob (or file) for our own in-core comparison.
2481 * diff_filespec has data and size fields for this purpose.
2482 */
2483int diff_populate_filespec(struct diff_filespec *s, int size_only)
2484{
2485        int err = 0;
2486        if (!DIFF_FILE_VALID(s))
2487                die("internal error: asking to populate invalid file.");
2488        if (S_ISDIR(s->mode))
2489                return -1;
2490
2491        if (s->data)
2492                return 0;
2493
2494        if (size_only && 0 < s->size)
2495                return 0;
2496
2497        if (S_ISGITLINK(s->mode))
2498                return diff_populate_gitlink(s, size_only);
2499
2500        if (!s->sha1_valid ||
2501            reuse_worktree_file(s->path, s->sha1, 0)) {
2502                struct strbuf buf = STRBUF_INIT;
2503                struct stat st;
2504                int fd;
2505
2506                if (!strcmp(s->path, "-"))
2507                        return populate_from_stdin(s);
2508
2509                if (lstat(s->path, &st) < 0) {
2510                        if (errno == ENOENT) {
2511                        err_empty:
2512                                err = -1;
2513                        empty:
2514                                s->data = (char *)"";
2515                                s->size = 0;
2516                                return err;
2517                        }
2518                }
2519                s->size = xsize_t(st.st_size);
2520                if (!s->size)
2521                        goto empty;
2522                if (S_ISLNK(st.st_mode)) {
2523                        struct strbuf sb = STRBUF_INIT;
2524
2525                        if (strbuf_readlink(&sb, s->path, s->size))
2526                                goto err_empty;
2527                        s->size = sb.len;
2528                        s->data = strbuf_detach(&sb, NULL);
2529                        s->should_free = 1;
2530                        return 0;
2531                }
2532                if (size_only)
2533                        return 0;
2534                fd = open(s->path, O_RDONLY);
2535                if (fd < 0)
2536                        goto err_empty;
2537                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2538                close(fd);
2539                s->should_munmap = 1;
2540
2541                /*
2542                 * Convert from working tree format to canonical git format
2543                 */
2544                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2545                        size_t size = 0;
2546                        munmap(s->data, s->size);
2547                        s->should_munmap = 0;
2548                        s->data = strbuf_detach(&buf, &size);
2549                        s->size = size;
2550                        s->should_free = 1;
2551                }
2552        }
2553        else {
2554                enum object_type type;
2555                if (size_only) {
2556                        type = sha1_object_info(s->sha1, &s->size);
2557                        if (type < 0)
2558                                die("unable to read %s", sha1_to_hex(s->sha1));
2559                } else {
2560                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2561                        if (!s->data)
2562                                die("unable to read %s", sha1_to_hex(s->sha1));
2563                        s->should_free = 1;
2564                }
2565        }
2566        return 0;
2567}
2568
2569void diff_free_filespec_blob(struct diff_filespec *s)
2570{
2571        if (s->should_free)
2572                free(s->data);
2573        else if (s->should_munmap)
2574                munmap(s->data, s->size);
2575
2576        if (s->should_free || s->should_munmap) {
2577                s->should_free = s->should_munmap = 0;
2578                s->data = NULL;
2579        }
2580}
2581
2582void diff_free_filespec_data(struct diff_filespec *s)
2583{
2584        diff_free_filespec_blob(s);
2585        free(s->cnt_data);
2586        s->cnt_data = NULL;
2587}
2588
2589static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2590                           void *blob,
2591                           unsigned long size,
2592                           const unsigned char *sha1,
2593                           int mode)
2594{
2595        int fd;
2596        struct strbuf buf = STRBUF_INIT;
2597        struct strbuf template = STRBUF_INIT;
2598        char *path_dup = xstrdup(path);
2599        const char *base = basename(path_dup);
2600
2601        /* Generate "XXXXXX_basename.ext" */
2602        strbuf_addstr(&template, "XXXXXX_");
2603        strbuf_addstr(&template, base);
2604
2605        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2606                        strlen(base) + 1);
2607        if (fd < 0)
2608                die_errno("unable to create temp-file");
2609        if (convert_to_working_tree(path,
2610                        (const char *)blob, (size_t)size, &buf)) {
2611                blob = buf.buf;
2612                size = buf.len;
2613        }
2614        if (write_in_full(fd, blob, size) != size)
2615                die_errno("unable to write temp-file");
2616        close(fd);
2617        temp->name = temp->tmp_path;
2618        strcpy(temp->hex, sha1_to_hex(sha1));
2619        temp->hex[40] = 0;
2620        sprintf(temp->mode, "%06o", mode);
2621        strbuf_release(&buf);
2622        strbuf_release(&template);
2623        free(path_dup);
2624}
2625
2626static struct diff_tempfile *prepare_temp_file(const char *name,
2627                struct diff_filespec *one)
2628{
2629        struct diff_tempfile *temp = claim_diff_tempfile();
2630
2631        if (!DIFF_FILE_VALID(one)) {
2632        not_a_valid_file:
2633                /* A '-' entry produces this for file-2, and
2634                 * a '+' entry produces this for file-1.
2635                 */
2636                temp->name = "/dev/null";
2637                strcpy(temp->hex, ".");
2638                strcpy(temp->mode, ".");
2639                return temp;
2640        }
2641
2642        if (!remove_tempfile_installed) {
2643                atexit(remove_tempfile);
2644                sigchain_push_common(remove_tempfile_on_signal);
2645                remove_tempfile_installed = 1;
2646        }
2647
2648        if (!one->sha1_valid ||
2649            reuse_worktree_file(name, one->sha1, 1)) {
2650                struct stat st;
2651                if (lstat(name, &st) < 0) {
2652                        if (errno == ENOENT)
2653                                goto not_a_valid_file;
2654                        die_errno("stat(%s)", name);
2655                }
2656                if (S_ISLNK(st.st_mode)) {
2657                        struct strbuf sb = STRBUF_INIT;
2658                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2659                                die_errno("readlink(%s)", name);
2660                        prep_temp_blob(name, temp, sb.buf, sb.len,
2661                                       (one->sha1_valid ?
2662                                        one->sha1 : null_sha1),
2663                                       (one->sha1_valid ?
2664                                        one->mode : S_IFLNK));
2665                        strbuf_release(&sb);
2666                }
2667                else {
2668                        /* we can borrow from the file in the work tree */
2669                        temp->name = name;
2670                        if (!one->sha1_valid)
2671                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2672                        else
2673                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2674                        /* Even though we may sometimes borrow the
2675                         * contents from the work tree, we always want
2676                         * one->mode.  mode is trustworthy even when
2677                         * !(one->sha1_valid), as long as
2678                         * DIFF_FILE_VALID(one).
2679                         */
2680                        sprintf(temp->mode, "%06o", one->mode);
2681                }
2682                return temp;
2683        }
2684        else {
2685                if (diff_populate_filespec(one, 0))
2686                        die("cannot read data blob for %s", one->path);
2687                prep_temp_blob(name, temp, one->data, one->size,
2688                               one->sha1, one->mode);
2689        }
2690        return temp;
2691}
2692
2693/* An external diff command takes:
2694 *
2695 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2696 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2697 *
2698 */
2699static void run_external_diff(const char *pgm,
2700                              const char *name,
2701                              const char *other,
2702                              struct diff_filespec *one,
2703                              struct diff_filespec *two,
2704                              const char *xfrm_msg,
2705                              int complete_rewrite)
2706{
2707        const char *spawn_arg[10];
2708        int retval;
2709        const char **arg = &spawn_arg[0];
2710
2711        if (one && two) {
2712                struct diff_tempfile *temp_one, *temp_two;
2713                const char *othername = (other ? other : name);
2714                temp_one = prepare_temp_file(name, one);
2715                temp_two = prepare_temp_file(othername, two);
2716                *arg++ = pgm;
2717                *arg++ = name;
2718                *arg++ = temp_one->name;
2719                *arg++ = temp_one->hex;
2720                *arg++ = temp_one->mode;
2721                *arg++ = temp_two->name;
2722                *arg++ = temp_two->hex;
2723                *arg++ = temp_two->mode;
2724                if (other) {
2725                        *arg++ = other;
2726                        *arg++ = xfrm_msg;
2727                }
2728        } else {
2729                *arg++ = pgm;
2730                *arg++ = name;
2731        }
2732        *arg = NULL;
2733        fflush(NULL);
2734        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2735        remove_tempfile();
2736        if (retval) {
2737                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2738                exit(1);
2739        }
2740}
2741
2742static int similarity_index(struct diff_filepair *p)
2743{
2744        return p->score * 100 / MAX_SCORE;
2745}
2746
2747static void fill_metainfo(struct strbuf *msg,
2748                          const char *name,
2749                          const char *other,
2750                          struct diff_filespec *one,
2751                          struct diff_filespec *two,
2752                          struct diff_options *o,
2753                          struct diff_filepair *p,
2754                          int *must_show_header,
2755                          int use_color)
2756{
2757        const char *set = diff_get_color(use_color, DIFF_METAINFO);
2758        const char *reset = diff_get_color(use_color, DIFF_RESET);
2759        struct strbuf *msgbuf;
2760        char *line_prefix = "";
2761
2762        *must_show_header = 1;
2763        if (o->output_prefix) {
2764                msgbuf = o->output_prefix(o, o->output_prefix_data);
2765                line_prefix = msgbuf->buf;
2766        }
2767        strbuf_init(msg, PATH_MAX * 2 + 300);
2768        switch (p->status) {
2769        case DIFF_STATUS_COPIED:
2770                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2771                            line_prefix, set, similarity_index(p));
2772                strbuf_addf(msg, "%s\n%s%scopy from ",
2773                            reset,  line_prefix, set);
2774                quote_c_style(name, msg, NULL, 0);
2775                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2776                quote_c_style(other, msg, NULL, 0);
2777                strbuf_addf(msg, "%s\n", reset);
2778                break;
2779        case DIFF_STATUS_RENAMED:
2780                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2781                            line_prefix, set, similarity_index(p));
2782                strbuf_addf(msg, "%s\n%s%srename from ",
2783                            reset, line_prefix, set);
2784                quote_c_style(name, msg, NULL, 0);
2785                strbuf_addf(msg, "%s\n%s%srename to ",
2786                            reset, line_prefix, set);
2787                quote_c_style(other, msg, NULL, 0);
2788                strbuf_addf(msg, "%s\n", reset);
2789                break;
2790        case DIFF_STATUS_MODIFIED:
2791                if (p->score) {
2792                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2793                                    line_prefix,
2794                                    set, similarity_index(p), reset);
2795                        break;
2796                }
2797                /* fallthru */
2798        default:
2799                *must_show_header = 0;
2800        }
2801        if (one && two && hashcmp(one->sha1, two->sha1)) {
2802                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2803
2804                if (DIFF_OPT_TST(o, BINARY)) {
2805                        mmfile_t mf;
2806                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2807                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2808                                abbrev = 40;
2809                }
2810                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2811                            find_unique_abbrev(one->sha1, abbrev));
2812                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2813                if (one->mode == two->mode)
2814                        strbuf_addf(msg, " %06o", one->mode);
2815                strbuf_addf(msg, "%s\n", reset);
2816        }
2817}
2818
2819static void run_diff_cmd(const char *pgm,
2820                         const char *name,
2821                         const char *other,
2822                         const char *attr_path,
2823                         struct diff_filespec *one,
2824                         struct diff_filespec *two,
2825                         struct strbuf *msg,
2826                         struct diff_options *o,
2827                         struct diff_filepair *p)
2828{
2829        const char *xfrm_msg = NULL;
2830        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2831        int must_show_header = 0;
2832
2833        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2834                pgm = NULL;
2835        else {
2836                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2837                if (drv && drv->external)
2838                        pgm = drv->external;
2839        }
2840
2841        if (msg) {
2842                /*
2843                 * don't use colors when the header is intended for an
2844                 * external diff driver
2845                 */
2846                fill_metainfo(msg, name, other, one, two, o, p,
2847                              &must_show_header,
2848                              DIFF_OPT_TST(o, COLOR_DIFF) && !pgm);
2849                xfrm_msg = msg->len ? msg->buf : NULL;
2850        }
2851
2852        if (pgm) {
2853                run_external_diff(pgm, name, other, one, two, xfrm_msg,
2854                                  complete_rewrite);
2855                return;
2856        }
2857        if (one && two)
2858                builtin_diff(name, other ? other : name,
2859                             one, two, xfrm_msg, must_show_header,
2860                             o, complete_rewrite);
2861        else
2862                fprintf(o->file, "* Unmerged path %s\n", name);
2863}
2864
2865static void diff_fill_sha1_info(struct diff_filespec *one)
2866{
2867        if (DIFF_FILE_VALID(one)) {
2868                if (!one->sha1_valid) {
2869                        struct stat st;
2870                        if (!strcmp(one->path, "-")) {
2871                                hashcpy(one->sha1, null_sha1);
2872                                return;
2873                        }
2874                        if (lstat(one->path, &st) < 0)
2875                                die_errno("stat '%s'", one->path);
2876                        if (index_path(one->sha1, one->path, &st, 0))
2877                                die("cannot hash %s", one->path);
2878                }
2879        }
2880        else
2881                hashclr(one->sha1);
2882}
2883
2884static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2885{
2886        /* Strip the prefix but do not molest /dev/null and absolute paths */
2887        if (*namep && **namep != '/') {
2888                *namep += prefix_length;
2889                if (**namep == '/')
2890                        ++*namep;
2891        }
2892        if (*otherp && **otherp != '/') {
2893                *otherp += prefix_length;
2894                if (**otherp == '/')
2895                        ++*otherp;
2896        }
2897}
2898
2899static void run_diff(struct diff_filepair *p, struct diff_options *o)
2900{
2901        const char *pgm = external_diff();
2902        struct strbuf msg;
2903        struct diff_filespec *one = p->one;
2904        struct diff_filespec *two = p->two;
2905        const char *name;
2906        const char *other;
2907        const char *attr_path;
2908
2909        name  = p->one->path;
2910        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2911        attr_path = name;
2912        if (o->prefix_length)
2913                strip_prefix(o->prefix_length, &name, &other);
2914
2915        if (DIFF_PAIR_UNMERGED(p)) {
2916                run_diff_cmd(pgm, name, NULL, attr_path,
2917                             NULL, NULL, NULL, o, p);
2918                return;
2919        }
2920
2921        diff_fill_sha1_info(one);
2922        diff_fill_sha1_info(two);
2923
2924        if (!pgm &&
2925            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2926            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2927                /*
2928                 * a filepair that changes between file and symlink
2929                 * needs to be split into deletion and creation.
2930                 */
2931                struct diff_filespec *null = alloc_filespec(two->path);
2932                run_diff_cmd(NULL, name, other, attr_path,
2933                             one, null, &msg, o, p);
2934                free(null);
2935                strbuf_release(&msg);
2936
2937                null = alloc_filespec(one->path);
2938                run_diff_cmd(NULL, name, other, attr_path,
2939                             null, two, &msg, o, p);
2940                free(null);
2941        }
2942        else
2943                run_diff_cmd(pgm, name, other, attr_path,
2944                             one, two, &msg, o, p);
2945
2946        strbuf_release(&msg);
2947}
2948
2949static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2950                         struct diffstat_t *diffstat)
2951{
2952        const char *name;
2953        const char *other;
2954        int complete_rewrite = 0;
2955
2956        if (DIFF_PAIR_UNMERGED(p)) {
2957                /* unmerged */
2958                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2959                return;
2960        }
2961
2962        name = p->one->path;
2963        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2964
2965        if (o->prefix_length)
2966                strip_prefix(o->prefix_length, &name, &other);
2967
2968        diff_fill_sha1_info(p->one);
2969        diff_fill_sha1_info(p->two);
2970
2971        if (p->status == DIFF_STATUS_MODIFIED && p->score)
2972                complete_rewrite = 1;
2973        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2974}
2975
2976static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2977{
2978        const char *name;
2979        const char *other;
2980        const char *attr_path;
2981
2982        if (DIFF_PAIR_UNMERGED(p)) {
2983                /* unmerged */
2984                return;
2985        }
2986
2987        name = p->one->path;
2988        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2989        attr_path = other ? other : name;
2990
2991        if (o->prefix_length)
2992                strip_prefix(o->prefix_length, &name, &other);
2993
2994        diff_fill_sha1_info(p->one);
2995        diff_fill_sha1_info(p->two);
2996
2997        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2998}
2999
3000void diff_setup(struct diff_options *options)
3001{
3002        memcpy(options, &default_diff_options, sizeof(*options));
3003
3004        options->file = stdout;
3005
3006        options->line_termination = '\n';
3007        options->break_opt = -1;
3008        options->rename_limit = -1;
3009        options->dirstat_permille = diff_dirstat_permille_default;
3010        options->context = 3;
3011
3012        options->change = diff_change;
3013        options->add_remove = diff_addremove;
3014        if (diff_use_color_default > 0)
3015                DIFF_OPT_SET(options, COLOR_DIFF);
3016        options->detect_rename = diff_detect_rename_default;
3017
3018        if (diff_no_prefix) {
3019                options->a_prefix = options->b_prefix = "";
3020        } else if (!diff_mnemonic_prefix) {
3021                options->a_prefix = "a/";
3022                options->b_prefix = "b/";
3023        }
3024}
3025
3026int diff_setup_done(struct diff_options *options)
3027{
3028        int count = 0;
3029
3030        if (options->output_format & DIFF_FORMAT_NAME)
3031                count++;
3032        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
3033                count++;
3034        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
3035                count++;
3036        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
3037                count++;
3038        if (count > 1)
3039                die("--name-only, --name-status, --check and -s are mutually exclusive");
3040
3041        /*
3042         * Most of the time we can say "there are changes"
3043         * only by checking if there are changed paths, but
3044         * --ignore-whitespace* options force us to look
3045         * inside contents.
3046         */
3047
3048        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
3049            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
3050            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
3051                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
3052        else
3053                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
3054
3055        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3056                options->detect_rename = DIFF_DETECT_COPY;
3057
3058        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
3059                options->prefix = NULL;
3060        if (options->prefix)
3061                options->prefix_length = strlen(options->prefix);
3062        else
3063                options->prefix_length = 0;
3064
3065        if (options->output_format & (DIFF_FORMAT_NAME |
3066                                      DIFF_FORMAT_NAME_STATUS |
3067                                      DIFF_FORMAT_CHECKDIFF |
3068                                      DIFF_FORMAT_NO_OUTPUT))
3069                options->output_format &= ~(DIFF_FORMAT_RAW |
3070                                            DIFF_FORMAT_NUMSTAT |
3071                                            DIFF_FORMAT_DIFFSTAT |
3072                                            DIFF_FORMAT_SHORTSTAT |
3073                                            DIFF_FORMAT_DIRSTAT |
3074                                            DIFF_FORMAT_SUMMARY |
3075                                            DIFF_FORMAT_PATCH);
3076
3077        /*
3078         * These cases always need recursive; we do not drop caller-supplied
3079         * recursive bits for other formats here.
3080         */
3081        if (options->output_format & (DIFF_FORMAT_PATCH |
3082                                      DIFF_FORMAT_NUMSTAT |
3083                                      DIFF_FORMAT_DIFFSTAT |
3084                                      DIFF_FORMAT_SHORTSTAT |
3085                                      DIFF_FORMAT_DIRSTAT |
3086                                      DIFF_FORMAT_SUMMARY |
3087                                      DIFF_FORMAT_CHECKDIFF))
3088                DIFF_OPT_SET(options, RECURSIVE);
3089        /*
3090         * Also pickaxe would not work very well if you do not say recursive
3091         */
3092        if (options->pickaxe)
3093                DIFF_OPT_SET(options, RECURSIVE);
3094        /*
3095         * When patches are generated, submodules diffed against the work tree
3096         * must be checked for dirtiness too so it can be shown in the output
3097         */
3098        if (options->output_format & DIFF_FORMAT_PATCH)
3099                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3100
3101        if (options->detect_rename && options->rename_limit < 0)
3102                options->rename_limit = diff_rename_limit_default;
3103        if (options->setup & DIFF_SETUP_USE_CACHE) {
3104                if (!active_cache)
3105                        /* read-cache does not die even when it fails
3106                         * so it is safe for us to do this here.  Also
3107                         * it does not smudge active_cache or active_nr
3108                         * when it fails, so we do not have to worry about
3109                         * cleaning it up ourselves either.
3110                         */
3111                        read_cache();
3112        }
3113        if (options->abbrev <= 0 || 40 < options->abbrev)
3114                options->abbrev = 40; /* full */
3115
3116        /*
3117         * It does not make sense to show the first hit we happened
3118         * to have found.  It does not make sense not to return with
3119         * exit code in such a case either.
3120         */
3121        if (DIFF_OPT_TST(options, QUICK)) {
3122                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3123                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3124        }
3125
3126        return 0;
3127}
3128
3129static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3130{
3131        char c, *eq;
3132        int len;
3133
3134        if (*arg != '-')
3135                return 0;
3136        c = *++arg;
3137        if (!c)
3138                return 0;
3139        if (c == arg_short) {
3140                c = *++arg;
3141                if (!c)
3142                        return 1;
3143                if (val && isdigit(c)) {
3144                        char *end;
3145                        int n = strtoul(arg, &end, 10);
3146                        if (*end)
3147                                return 0;
3148                        *val = n;
3149                        return 1;
3150                }
3151                return 0;
3152        }
3153        if (c != '-')
3154                return 0;
3155        arg++;
3156        eq = strchr(arg, '=');
3157        if (eq)
3158                len = eq - arg;
3159        else
3160                len = strlen(arg);
3161        if (!len || strncmp(arg, arg_long, len))
3162                return 0;
3163        if (eq) {
3164                int n;
3165                char *end;
3166                if (!isdigit(*++eq))
3167                        return 0;
3168                n = strtoul(eq, &end, 10);
3169                if (*end)
3170                        return 0;
3171                *val = n;
3172        }
3173        return 1;
3174}
3175
3176static int diff_scoreopt_parse(const char *opt);
3177
3178static inline int short_opt(char opt, const char **argv,
3179                            const char **optarg)
3180{
3181        const char *arg = argv[0];
3182        if (arg[0] != '-' || arg[1] != opt)
3183                return 0;
3184        if (arg[2] != '\0') {
3185                *optarg = arg + 2;
3186                return 1;
3187        }
3188        if (!argv[1])
3189                die("Option '%c' requires a value", opt);
3190        *optarg = argv[1];
3191        return 2;
3192}
3193
3194int parse_long_opt(const char *opt, const char **argv,
3195                   const char **optarg)
3196{
3197        const char *arg = argv[0];
3198        if (arg[0] != '-' || arg[1] != '-')
3199                return 0;
3200        arg += strlen("--");
3201        if (prefixcmp(arg, opt))
3202                return 0;
3203        arg += strlen(opt);
3204        if (*arg == '=') { /* sticked form: --option=value */
3205                *optarg = arg + 1;
3206                return 1;
3207        }
3208        if (*arg != '\0')
3209                return 0;
3210        /* separate form: --option value */
3211        if (!argv[1])
3212                die("Option '--%s' requires a value", opt);
3213        *optarg = argv[1];
3214        return 2;
3215}
3216
3217static int stat_opt(struct diff_options *options, const char **av)
3218{
3219        const char *arg = av[0];
3220        char *end;
3221        int width = options->stat_width;
3222        int name_width = options->stat_name_width;
3223        int argcount = 1;
3224
3225        arg += strlen("--stat");
3226        end = (char *)arg;
3227
3228        switch (*arg) {
3229        case '-':
3230                if (!prefixcmp(arg, "-width")) {
3231                        arg += strlen("-width");
3232                        if (*arg == '=')
3233                                width = strtoul(arg + 1, &end, 10);
3234                        else if (!*arg && !av[1])
3235                                die("Option '--stat-width' requires a value");
3236                        else if (!*arg) {
3237                                width = strtoul(av[1], &end, 10);
3238                                argcount = 2;
3239                        }
3240                } else if (!prefixcmp(arg, "-name-width")) {
3241                        arg += strlen("-name-width");
3242                        if (*arg == '=')
3243                                name_width = strtoul(arg + 1, &end, 10);
3244                        else if (!*arg && !av[1])
3245                                die("Option '--stat-name-width' requires a value");
3246                        else if (!*arg) {
3247                                name_width = strtoul(av[1], &end, 10);
3248                                argcount = 2;
3249                        }
3250                }
3251                break;
3252        case '=':
3253                width = strtoul(arg+1, &end, 10);
3254                if (*end == ',')
3255                        name_width = strtoul(end+1, &end, 10);
3256        }
3257
3258        /* Important! This checks all the error cases! */
3259        if (*end)
3260                return 0;
3261        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3262        options->stat_name_width = name_width;
3263        options->stat_width = width;
3264        return argcount;
3265}
3266
3267static int parse_dirstat_opt(struct diff_options *options, const char *params)
3268{
3269        struct strbuf errmsg = STRBUF_INIT;
3270        if (parse_dirstat_params(options, params, &errmsg))
3271                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
3272                    errmsg.buf);
3273        strbuf_release(&errmsg);
3274        /*
3275         * The caller knows a dirstat-related option is given from the command
3276         * line; allow it to say "return this_function();"
3277         */
3278        options->output_format |= DIFF_FORMAT_DIRSTAT;
3279        return 1;
3280}
3281
3282int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3283{
3284        const char *arg = av[0];
3285        const char *optarg;
3286        int argcount;
3287
3288        /* Output format options */
3289        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3290                options->output_format |= DIFF_FORMAT_PATCH;
3291        else if (opt_arg(arg, 'U', "unified", &options->context))
3292                options->output_format |= DIFF_FORMAT_PATCH;
3293        else if (!strcmp(arg, "--raw"))
3294                options->output_format |= DIFF_FORMAT_RAW;
3295        else if (!strcmp(arg, "--patch-with-raw"))
3296                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3297        else if (!strcmp(arg, "--numstat"))
3298                options->output_format |= DIFF_FORMAT_NUMSTAT;
3299        else if (!strcmp(arg, "--shortstat"))
3300                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3301        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
3302                return parse_dirstat_opt(options, "");
3303        else if (!prefixcmp(arg, "-X"))
3304                return parse_dirstat_opt(options, arg + 2);
3305        else if (!prefixcmp(arg, "--dirstat="))
3306                return parse_dirstat_opt(options, arg + 10);
3307        else if (!strcmp(arg, "--cumulative"))
3308                return parse_dirstat_opt(options, "cumulative");
3309        else if (!strcmp(arg, "--dirstat-by-file"))
3310                return parse_dirstat_opt(options, "files");
3311        else if (!prefixcmp(arg, "--dirstat-by-file=")) {
3312                parse_dirstat_opt(options, "files");
3313                return parse_dirstat_opt(options, arg + 18);
3314        }
3315        else if (!strcmp(arg, "--check"))
3316                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3317        else if (!strcmp(arg, "--summary"))
3318                options->output_format |= DIFF_FORMAT_SUMMARY;
3319        else if (!strcmp(arg, "--patch-with-stat"))
3320                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3321        else if (!strcmp(arg, "--name-only"))
3322                options->output_format |= DIFF_FORMAT_NAME;
3323        else if (!strcmp(arg, "--name-status"))
3324                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3325        else if (!strcmp(arg, "-s"))
3326                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3327        else if (!prefixcmp(arg, "--stat"))
3328                /* --stat, --stat-width, or --stat-name-width */
3329                return stat_opt(options, av);
3330
3331        /* renames options */
3332        else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
3333                 !strcmp(arg, "--break-rewrites")) {
3334                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3335                        return error("invalid argument to -B: %s", arg+2);
3336        }
3337        else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--find-renames=") ||
3338                 !strcmp(arg, "--find-renames")) {
3339                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3340                        return error("invalid argument to -M: %s", arg+2);
3341                options->detect_rename = DIFF_DETECT_RENAME;
3342        }
3343        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3344                options->irreversible_delete = 1;
3345        }
3346        else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
3347                 !strcmp(arg, "--find-copies")) {
3348                if (options->detect_rename == DIFF_DETECT_COPY)
3349                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3350                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3351                        return error("invalid argument to -C: %s", arg+2);
3352                options->detect_rename = DIFF_DETECT_COPY;
3353        }
3354        else if (!strcmp(arg, "--no-renames"))
3355                options->detect_rename = 0;
3356        else if (!strcmp(arg, "--relative"))
3357                DIFF_OPT_SET(options, RELATIVE_NAME);
3358        else if (!prefixcmp(arg, "--relative=")) {
3359                DIFF_OPT_SET(options, RELATIVE_NAME);
3360                options->prefix = arg + 11;
3361        }
3362
3363        /* xdiff options */
3364        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3365                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3366        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3367                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3368        else if (!strcmp(arg, "--ignore-space-at-eol"))
3369                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3370        else if (!strcmp(arg, "--patience"))
3371                DIFF_XDL_SET(options, PATIENCE_DIFF);
3372
3373        /* flags options */
3374        else if (!strcmp(arg, "--binary")) {
3375                options->output_format |= DIFF_FORMAT_PATCH;
3376                DIFF_OPT_SET(options, BINARY);
3377        }
3378        else if (!strcmp(arg, "--full-index"))
3379                DIFF_OPT_SET(options, FULL_INDEX);
3380        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3381                DIFF_OPT_SET(options, TEXT);
3382        else if (!strcmp(arg, "-R"))
3383                DIFF_OPT_SET(options, REVERSE_DIFF);
3384        else if (!strcmp(arg, "--find-copies-harder"))
3385                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3386        else if (!strcmp(arg, "--follow"))
3387                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3388        else if (!strcmp(arg, "--color"))
3389                DIFF_OPT_SET(options, COLOR_DIFF);
3390        else if (!prefixcmp(arg, "--color=")) {
3391                int value = git_config_colorbool(NULL, arg+8, -1);
3392                if (value == 0)
3393                        DIFF_OPT_CLR(options, COLOR_DIFF);
3394                else if (value > 0)
3395                        DIFF_OPT_SET(options, COLOR_DIFF);
3396                else
3397                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3398        }
3399        else if (!strcmp(arg, "--no-color"))
3400                DIFF_OPT_CLR(options, COLOR_DIFF);
3401        else if (!strcmp(arg, "--color-words")) {
3402                DIFF_OPT_SET(options, COLOR_DIFF);
3403                options->word_diff = DIFF_WORDS_COLOR;
3404        }
3405        else if (!prefixcmp(arg, "--color-words=")) {
3406                DIFF_OPT_SET(options, COLOR_DIFF);
3407                options->word_diff = DIFF_WORDS_COLOR;
3408                options->word_regex = arg + 14;
3409        }
3410        else if (!strcmp(arg, "--word-diff")) {
3411                if (options->word_diff == DIFF_WORDS_NONE)
3412                        options->word_diff = DIFF_WORDS_PLAIN;
3413        }
3414        else if (!prefixcmp(arg, "--word-diff=")) {
3415                const char *type = arg + 12;
3416                if (!strcmp(type, "plain"))
3417                        options->word_diff = DIFF_WORDS_PLAIN;
3418                else if (!strcmp(type, "color")) {
3419                        DIFF_OPT_SET(options, COLOR_DIFF);
3420                        options->word_diff = DIFF_WORDS_COLOR;
3421                }
3422                else if (!strcmp(type, "porcelain"))
3423                        options->word_diff = DIFF_WORDS_PORCELAIN;
3424                else if (!strcmp(type, "none"))
3425                        options->word_diff = DIFF_WORDS_NONE;
3426                else
3427                        die("bad --word-diff argument: %s", type);
3428        }
3429        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3430                if (options->word_diff == DIFF_WORDS_NONE)
3431                        options->word_diff = DIFF_WORDS_PLAIN;
3432                options->word_regex = optarg;
3433                return argcount;
3434        }
3435        else if (!strcmp(arg, "--exit-code"))
3436                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3437        else if (!strcmp(arg, "--quiet"))
3438                DIFF_OPT_SET(options, QUICK);
3439        else if (!strcmp(arg, "--ext-diff"))
3440                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3441        else if (!strcmp(arg, "--no-ext-diff"))
3442                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3443        else if (!strcmp(arg, "--textconv"))
3444                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3445        else if (!strcmp(arg, "--no-textconv"))
3446                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3447        else if (!strcmp(arg, "--ignore-submodules")) {
3448                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3449                handle_ignore_submodules_arg(options, "all");
3450        } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3451                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3452                handle_ignore_submodules_arg(options, arg + 20);
3453        } else if (!strcmp(arg, "--submodule"))
3454                DIFF_OPT_SET(options, SUBMODULE_LOG);
3455        else if (!prefixcmp(arg, "--submodule=")) {
3456                if (!strcmp(arg + 12, "log"))
3457                        DIFF_OPT_SET(options, SUBMODULE_LOG);
3458        }
3459
3460        /* misc options */
3461        else if (!strcmp(arg, "-z"))
3462                options->line_termination = 0;
3463        else if ((argcount = short_opt('l', av, &optarg))) {
3464                options->rename_limit = strtoul(optarg, NULL, 10);
3465                return argcount;
3466        }
3467        else if ((argcount = short_opt('S', av, &optarg))) {
3468                options->pickaxe = optarg;
3469                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3470                return argcount;
3471        } else if ((argcount = short_opt('G', av, &optarg))) {
3472                options->pickaxe = optarg;
3473                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3474                return argcount;
3475        }
3476        else if (!strcmp(arg, "--pickaxe-all"))
3477                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3478        else if (!strcmp(arg, "--pickaxe-regex"))
3479                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3480        else if ((argcount = short_opt('O', av, &optarg))) {
3481                options->orderfile = optarg;
3482                return argcount;
3483        }
3484        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3485                options->filter = optarg;
3486                return argcount;
3487        }
3488        else if (!strcmp(arg, "--abbrev"))
3489                options->abbrev = DEFAULT_ABBREV;
3490        else if (!prefixcmp(arg, "--abbrev=")) {
3491                options->abbrev = strtoul(arg + 9, NULL, 10);
3492                if (options->abbrev < MINIMUM_ABBREV)
3493                        options->abbrev = MINIMUM_ABBREV;
3494                else if (40 < options->abbrev)
3495                        options->abbrev = 40;
3496        }
3497        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3498                options->a_prefix = optarg;
3499                return argcount;
3500        }
3501        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3502                options->b_prefix = optarg;
3503                return argcount;
3504        }
3505        else if (!strcmp(arg, "--no-prefix"))
3506                options->a_prefix = options->b_prefix = "";
3507        else if (opt_arg(arg, '\0', "inter-hunk-context",
3508                         &options->interhunkcontext))
3509                ;
3510        else if ((argcount = parse_long_opt("output", av, &optarg))) {
3511                options->file = fopen(optarg, "w");
3512                if (!options->file)
3513                        die_errno("Could not open '%s'", optarg);
3514                options->close_file = 1;
3515                return argcount;
3516        } else
3517                return 0;
3518        return 1;
3519}
3520
3521int parse_rename_score(const char **cp_p)
3522{
3523        unsigned long num, scale;
3524        int ch, dot;
3525        const char *cp = *cp_p;
3526
3527        num = 0;
3528        scale = 1;
3529        dot = 0;
3530        for (;;) {
3531                ch = *cp;
3532                if ( !dot && ch == '.' ) {
3533                        scale = 1;
3534                        dot = 1;
3535                } else if ( ch == '%' ) {
3536                        scale = dot ? scale*100 : 100;
3537                        cp++;   /* % is always at the end */
3538                        break;
3539                } else if ( ch >= '0' && ch <= '9' ) {
3540                        if ( scale < 100000 ) {
3541                                scale *= 10;
3542                                num = (num*10) + (ch-'0');
3543                        }
3544                } else {
3545                        break;
3546                }
3547                cp++;
3548        }
3549        *cp_p = cp;
3550
3551        /* user says num divided by scale and we say internally that
3552         * is MAX_SCORE * num / scale.
3553         */
3554        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3555}
3556
3557static int diff_scoreopt_parse(const char *opt)
3558{
3559        int opt1, opt2, cmd;
3560
3561        if (*opt++ != '-')
3562                return -1;
3563        cmd = *opt++;
3564        if (cmd == '-') {
3565                /* convert the long-form arguments into short-form versions */
3566                if (!prefixcmp(opt, "break-rewrites")) {
3567                        opt += strlen("break-rewrites");
3568                        if (*opt == 0 || *opt++ == '=')
3569                                cmd = 'B';
3570                } else if (!prefixcmp(opt, "find-copies")) {
3571                        opt += strlen("find-copies");
3572                        if (*opt == 0 || *opt++ == '=')
3573                                cmd = 'C';
3574                } else if (!prefixcmp(opt, "find-renames")) {
3575                        opt += strlen("find-renames");
3576                        if (*opt == 0 || *opt++ == '=')
3577                                cmd = 'M';
3578                }
3579        }
3580        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3581                return -1; /* that is not a -M, -C nor -B option */
3582
3583        opt1 = parse_rename_score(&opt);
3584        if (cmd != 'B')
3585                opt2 = 0;
3586        else {
3587                if (*opt == 0)
3588                        opt2 = 0;
3589                else if (*opt != '/')
3590                        return -1; /* we expect -B80/99 or -B80 */
3591                else {
3592                        opt++;
3593                        opt2 = parse_rename_score(&opt);
3594                }
3595        }
3596        if (*opt != 0)
3597                return -1;
3598        return opt1 | (opt2 << 16);
3599}
3600
3601struct diff_queue_struct diff_queued_diff;
3602
3603void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3604{
3605        if (queue->alloc <= queue->nr) {
3606                queue->alloc = alloc_nr(queue->alloc);
3607                queue->queue = xrealloc(queue->queue,
3608                                        sizeof(dp) * queue->alloc);
3609        }
3610        queue->queue[queue->nr++] = dp;
3611}
3612
3613struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3614                                 struct diff_filespec *one,
3615                                 struct diff_filespec *two)
3616{
3617        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3618        dp->one = one;
3619        dp->two = two;
3620        if (queue)
3621                diff_q(queue, dp);
3622        return dp;
3623}
3624
3625void diff_free_filepair(struct diff_filepair *p)
3626{
3627        free_filespec(p->one);
3628        free_filespec(p->two);
3629        free(p);
3630}
3631
3632/* This is different from find_unique_abbrev() in that
3633 * it stuffs the result with dots for alignment.
3634 */
3635const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3636{
3637        int abblen;
3638        const char *abbrev;
3639        if (len == 40)
3640                return sha1_to_hex(sha1);
3641
3642        abbrev = find_unique_abbrev(sha1, len);
3643        abblen = strlen(abbrev);
3644        if (abblen < 37) {
3645                static char hex[41];
3646                if (len < abblen && abblen <= len + 2)
3647                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3648                else
3649                        sprintf(hex, "%s...", abbrev);
3650                return hex;
3651        }
3652        return sha1_to_hex(sha1);
3653}
3654
3655static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3656{
3657        int line_termination = opt->line_termination;
3658        int inter_name_termination = line_termination ? '\t' : '\0';
3659        if (opt->output_prefix) {
3660                struct strbuf *msg = NULL;
3661                msg = opt->output_prefix(opt, opt->output_prefix_data);
3662                fprintf(opt->file, "%s", msg->buf);
3663        }
3664
3665        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3666                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3667                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3668                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3669        }
3670        if (p->score) {
3671                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3672                        inter_name_termination);
3673        } else {
3674                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3675        }
3676
3677        if (p->status == DIFF_STATUS_COPIED ||
3678            p->status == DIFF_STATUS_RENAMED) {
3679                const char *name_a, *name_b;
3680                name_a = p->one->path;
3681                name_b = p->two->path;
3682                strip_prefix(opt->prefix_length, &name_a, &name_b);
3683                write_name_quoted(name_a, opt->file, inter_name_termination);
3684                write_name_quoted(name_b, opt->file, line_termination);
3685        } else {
3686                const char *name_a, *name_b;
3687                name_a = p->one->mode ? p->one->path : p->two->path;
3688                name_b = NULL;
3689                strip_prefix(opt->prefix_length, &name_a, &name_b);
3690                write_name_quoted(name_a, opt->file, line_termination);
3691        }
3692}
3693
3694int diff_unmodified_pair(struct diff_filepair *p)
3695{
3696        /* This function is written stricter than necessary to support
3697         * the currently implemented transformers, but the idea is to
3698         * let transformers to produce diff_filepairs any way they want,
3699         * and filter and clean them up here before producing the output.
3700         */
3701        struct diff_filespec *one = p->one, *two = p->two;
3702
3703        if (DIFF_PAIR_UNMERGED(p))
3704                return 0; /* unmerged is interesting */
3705
3706        /* deletion, addition, mode or type change
3707         * and rename are all interesting.
3708         */
3709        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3710            DIFF_PAIR_MODE_CHANGED(p) ||
3711            strcmp(one->path, two->path))
3712                return 0;
3713
3714        /* both are valid and point at the same path.  that is, we are
3715         * dealing with a change.
3716         */
3717        if (one->sha1_valid && two->sha1_valid &&
3718            !hashcmp(one->sha1, two->sha1) &&
3719            !one->dirty_submodule && !two->dirty_submodule)
3720                return 1; /* no change */
3721        if (!one->sha1_valid && !two->sha1_valid)
3722                return 1; /* both look at the same file on the filesystem. */
3723        return 0;
3724}
3725
3726static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3727{
3728        if (diff_unmodified_pair(p))
3729                return;
3730
3731        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3732            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3733                return; /* no tree diffs in patch format */
3734
3735        run_diff(p, o);
3736}
3737
3738static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3739                            struct diffstat_t *diffstat)
3740{
3741        if (diff_unmodified_pair(p))
3742                return;
3743
3744        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3745            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3746                return; /* no useful stat for tree diffs */
3747
3748        run_diffstat(p, o, diffstat);
3749}
3750
3751static void diff_flush_checkdiff(struct diff_filepair *p,
3752                struct diff_options *o)
3753{
3754        if (diff_unmodified_pair(p))
3755                return;
3756
3757        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3758            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3759                return; /* nothing to check in tree diffs */
3760
3761        run_checkdiff(p, o);
3762}
3763
3764int diff_queue_is_empty(void)
3765{
3766        struct diff_queue_struct *q = &diff_queued_diff;
3767        int i;
3768        for (i = 0; i < q->nr; i++)
3769                if (!diff_unmodified_pair(q->queue[i]))
3770                        return 0;
3771        return 1;
3772}
3773
3774#if DIFF_DEBUG
3775void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3776{
3777        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3778                x, one ? one : "",
3779                s->path,
3780                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3781                s->mode,
3782                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3783        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3784                x, one ? one : "",
3785                s->size, s->xfrm_flags);
3786}
3787
3788void diff_debug_filepair(const struct diff_filepair *p, int i)
3789{
3790        diff_debug_filespec(p->one, i, "one");
3791        diff_debug_filespec(p->two, i, "two");
3792        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3793                p->score, p->status ? p->status : '?',
3794                p->one->rename_used, p->broken_pair);
3795}
3796
3797void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3798{
3799        int i;
3800        if (msg)
3801                fprintf(stderr, "%s\n", msg);
3802        fprintf(stderr, "q->nr = %d\n", q->nr);
3803        for (i = 0; i < q->nr; i++) {
3804                struct diff_filepair *p = q->queue[i];
3805                diff_debug_filepair(p, i);
3806        }
3807}
3808#endif
3809
3810static void diff_resolve_rename_copy(void)
3811{
3812        int i;
3813        struct diff_filepair *p;
3814        struct diff_queue_struct *q = &diff_queued_diff;
3815
3816        diff_debug_queue("resolve-rename-copy", q);
3817
3818        for (i = 0; i < q->nr; i++) {
3819                p = q->queue[i];
3820                p->status = 0; /* undecided */
3821                if (DIFF_PAIR_UNMERGED(p))
3822                        p->status = DIFF_STATUS_UNMERGED;
3823                else if (!DIFF_FILE_VALID(p->one))
3824                        p->status = DIFF_STATUS_ADDED;
3825                else if (!DIFF_FILE_VALID(p->two))
3826                        p->status = DIFF_STATUS_DELETED;
3827                else if (DIFF_PAIR_TYPE_CHANGED(p))
3828                        p->status = DIFF_STATUS_TYPE_CHANGED;
3829
3830                /* from this point on, we are dealing with a pair
3831                 * whose both sides are valid and of the same type, i.e.
3832                 * either in-place edit or rename/copy edit.
3833                 */
3834                else if (DIFF_PAIR_RENAME(p)) {
3835                        /*
3836                         * A rename might have re-connected a broken
3837                         * pair up, causing the pathnames to be the
3838                         * same again. If so, that's not a rename at
3839                         * all, just a modification..
3840                         *
3841                         * Otherwise, see if this source was used for
3842                         * multiple renames, in which case we decrement
3843                         * the count, and call it a copy.
3844                         */
3845                        if (!strcmp(p->one->path, p->two->path))
3846                                p->status = DIFF_STATUS_MODIFIED;
3847                        else if (--p->one->rename_used > 0)
3848                                p->status = DIFF_STATUS_COPIED;
3849                        else
3850                                p->status = DIFF_STATUS_RENAMED;
3851                }
3852                else if (hashcmp(p->one->sha1, p->two->sha1) ||
3853                         p->one->mode != p->two->mode ||
3854                         p->one->dirty_submodule ||
3855                         p->two->dirty_submodule ||
3856                         is_null_sha1(p->one->sha1))
3857                        p->status = DIFF_STATUS_MODIFIED;
3858                else {
3859                        /* This is a "no-change" entry and should not
3860                         * happen anymore, but prepare for broken callers.
3861                         */
3862                        error("feeding unmodified %s to diffcore",
3863                              p->one->path);
3864                        p->status = DIFF_STATUS_UNKNOWN;
3865                }
3866        }
3867        diff_debug_queue("resolve-rename-copy done", q);
3868}
3869
3870static int check_pair_status(struct diff_filepair *p)
3871{
3872        switch (p->status) {
3873        case DIFF_STATUS_UNKNOWN:
3874                return 0;
3875        case 0:
3876                die("internal error in diff-resolve-rename-copy");
3877        default:
3878                return 1;
3879        }
3880}
3881
3882static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3883{
3884        int fmt = opt->output_format;
3885
3886        if (fmt & DIFF_FORMAT_CHECKDIFF)
3887                diff_flush_checkdiff(p, opt);
3888        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3889                diff_flush_raw(p, opt);
3890        else if (fmt & DIFF_FORMAT_NAME) {
3891                const char *name_a, *name_b;
3892                name_a = p->two->path;
3893                name_b = NULL;
3894                strip_prefix(opt->prefix_length, &name_a, &name_b);
3895                write_name_quoted(name_a, opt->file, opt->line_termination);
3896        }
3897}
3898
3899static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
3900{
3901        if (fs->mode)
3902                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
3903        else
3904                fprintf(file, " %s ", newdelete);
3905        write_name_quoted(fs->path, file, '\n');
3906}
3907
3908
3909static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
3910                const char *line_prefix)
3911{
3912        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
3913                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
3914                        p->two->mode, show_name ? ' ' : '\n');
3915                if (show_name) {
3916                        write_name_quoted(p->two->path, file, '\n');
3917                }
3918        }
3919}
3920
3921static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
3922                        const char *line_prefix)
3923{
3924        char *names = pprint_rename(p->one->path, p->two->path);
3925
3926        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
3927        free(names);
3928        show_mode_change(file, p, 0, line_prefix);
3929}
3930
3931static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
3932{
3933        FILE *file = opt->file;
3934        char *line_prefix = "";
3935
3936        if (opt->output_prefix) {
3937                struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
3938                line_prefix = buf->buf;
3939        }
3940
3941        switch(p->status) {
3942        case DIFF_STATUS_DELETED:
3943                fputs(line_prefix, file);
3944                show_file_mode_name(file, "delete", p->one);
3945                break;
3946        case DIFF_STATUS_ADDED:
3947                fputs(line_prefix, file);
3948                show_file_mode_name(file, "create", p->two);
3949                break;
3950        case DIFF_STATUS_COPIED:
3951                fputs(line_prefix, file);
3952                show_rename_copy(file, "copy", p, line_prefix);
3953                break;
3954        case DIFF_STATUS_RENAMED:
3955                fputs(line_prefix, file);
3956                show_rename_copy(file, "rename", p, line_prefix);
3957                break;
3958        default:
3959                if (p->score) {
3960                        fprintf(file, "%s rewrite ", line_prefix);
3961                        write_name_quoted(p->two->path, file, ' ');
3962                        fprintf(file, "(%d%%)\n", similarity_index(p));
3963                }
3964                show_mode_change(file, p, !p->score, line_prefix);
3965                break;
3966        }
3967}
3968
3969struct patch_id_t {
3970        git_SHA_CTX *ctx;
3971        int patchlen;
3972};
3973
3974static int remove_space(char *line, int len)
3975{
3976        int i;
3977        char *dst = line;
3978        unsigned char c;
3979
3980        for (i = 0; i < len; i++)
3981                if (!isspace((c = line[i])))
3982                        *dst++ = c;
3983
3984        return dst - line;
3985}
3986
3987static void patch_id_consume(void *priv, char *line, unsigned long len)
3988{
3989        struct patch_id_t *data = priv;
3990        int new_len;
3991
3992        /* Ignore line numbers when computing the SHA1 of the patch */
3993        if (!prefixcmp(line, "@@ -"))
3994                return;
3995
3996        new_len = remove_space(line, len);
3997
3998        git_SHA1_Update(data->ctx, line, new_len);
3999        data->patchlen += new_len;
4000}
4001
4002/* returns 0 upon success, and writes result into sha1 */
4003static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
4004{
4005        struct diff_queue_struct *q = &diff_queued_diff;
4006        int i;
4007        git_SHA_CTX ctx;
4008        struct patch_id_t data;
4009        char buffer[PATH_MAX * 4 + 20];
4010
4011        git_SHA1_Init(&ctx);
4012        memset(&data, 0, sizeof(struct patch_id_t));
4013        data.ctx = &ctx;
4014
4015        for (i = 0; i < q->nr; i++) {
4016                xpparam_t xpp;
4017                xdemitconf_t xecfg;
4018                mmfile_t mf1, mf2;
4019                struct diff_filepair *p = q->queue[i];
4020                int len1, len2;
4021
4022                memset(&xpp, 0, sizeof(xpp));
4023                memset(&xecfg, 0, sizeof(xecfg));
4024                if (p->status == 0)
4025                        return error("internal diff status error");
4026                if (p->status == DIFF_STATUS_UNKNOWN)
4027                        continue;
4028                if (diff_unmodified_pair(p))
4029                        continue;
4030                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4031                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4032                        continue;
4033                if (DIFF_PAIR_UNMERGED(p))
4034                        continue;
4035
4036                diff_fill_sha1_info(p->one);
4037                diff_fill_sha1_info(p->two);
4038                if (fill_mmfile(&mf1, p->one) < 0 ||
4039                                fill_mmfile(&mf2, p->two) < 0)
4040                        return error("unable to read files to diff");
4041
4042                len1 = remove_space(p->one->path, strlen(p->one->path));
4043                len2 = remove_space(p->two->path, strlen(p->two->path));
4044                if (p->one->mode == 0)
4045                        len1 = snprintf(buffer, sizeof(buffer),
4046                                        "diff--gita/%.*sb/%.*s"
4047                                        "newfilemode%06o"
4048                                        "---/dev/null"
4049                                        "+++b/%.*s",
4050                                        len1, p->one->path,
4051                                        len2, p->two->path,
4052                                        p->two->mode,
4053                                        len2, p->two->path);
4054                else if (p->two->mode == 0)
4055                        len1 = snprintf(buffer, sizeof(buffer),
4056                                        "diff--gita/%.*sb/%.*s"
4057                                        "deletedfilemode%06o"
4058                                        "---a/%.*s"
4059                                        "+++/dev/null",
4060                                        len1, p->one->path,
4061                                        len2, p->two->path,
4062                                        p->one->mode,
4063                                        len1, p->one->path);
4064                else
4065                        len1 = snprintf(buffer, sizeof(buffer),
4066                                        "diff--gita/%.*sb/%.*s"
4067                                        "---a/%.*s"
4068                                        "+++b/%.*s",
4069                                        len1, p->one->path,
4070                                        len2, p->two->path,
4071                                        len1, p->one->path,
4072                                        len2, p->two->path);
4073                git_SHA1_Update(&ctx, buffer, len1);
4074
4075                if (diff_filespec_is_binary(p->one) ||
4076                    diff_filespec_is_binary(p->two)) {
4077                        git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
4078                        git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
4079                        continue;
4080                }
4081
4082                xpp.flags = 0;
4083                xecfg.ctxlen = 3;
4084                xecfg.flags = 0;
4085                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4086                              &xpp, &xecfg);
4087        }
4088
4089        git_SHA1_Final(sha1, &ctx);
4090        return 0;
4091}
4092
4093int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
4094{
4095        struct diff_queue_struct *q = &diff_queued_diff;
4096        int i;
4097        int result = diff_get_patch_id(options, sha1);
4098
4099        for (i = 0; i < q->nr; i++)
4100                diff_free_filepair(q->queue[i]);
4101
4102        free(q->queue);
4103        DIFF_QUEUE_CLEAR(q);
4104
4105        return result;
4106}
4107
4108static int is_summary_empty(const struct diff_queue_struct *q)
4109{
4110        int i;
4111
4112        for (i = 0; i < q->nr; i++) {
4113                const struct diff_filepair *p = q->queue[i];
4114
4115                switch (p->status) {
4116                case DIFF_STATUS_DELETED:
4117                case DIFF_STATUS_ADDED:
4118                case DIFF_STATUS_COPIED:
4119                case DIFF_STATUS_RENAMED:
4120                        return 0;
4121                default:
4122                        if (p->score)
4123                                return 0;
4124                        if (p->one->mode && p->two->mode &&
4125                            p->one->mode != p->two->mode)
4126                                return 0;
4127                        break;
4128                }
4129        }
4130        return 1;
4131}
4132
4133static const char rename_limit_warning[] =
4134"inexact rename detection was skipped due to too many files.";
4135
4136static const char degrade_cc_to_c_warning[] =
4137"only found copies from modified paths due to too many files.";
4138
4139static const char rename_limit_advice[] =
4140"you may want to set your %s variable to at least "
4141"%d and retry the command.";
4142
4143void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4144{
4145        if (degraded_cc)
4146                warning(degrade_cc_to_c_warning);
4147        else if (needed)
4148                warning(rename_limit_warning);
4149        else
4150                return;
4151        if (0 < needed && needed < 32767)
4152                warning(rename_limit_advice, varname, needed);
4153}
4154
4155void diff_flush(struct diff_options *options)
4156{
4157        struct diff_queue_struct *q = &diff_queued_diff;
4158        int i, output_format = options->output_format;
4159        int separator = 0;
4160        int dirstat_by_line = 0;
4161
4162        /*
4163         * Order: raw, stat, summary, patch
4164         * or:    name/name-status/checkdiff (other bits clear)
4165         */
4166        if (!q->nr)
4167                goto free_queue;
4168
4169        if (output_format & (DIFF_FORMAT_RAW |
4170                             DIFF_FORMAT_NAME |
4171                             DIFF_FORMAT_NAME_STATUS |
4172                             DIFF_FORMAT_CHECKDIFF)) {
4173                for (i = 0; i < q->nr; i++) {
4174                        struct diff_filepair *p = q->queue[i];
4175                        if (check_pair_status(p))
4176                                flush_one_pair(p, options);
4177                }
4178                separator++;
4179        }
4180
4181        if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
4182                dirstat_by_line = 1;
4183
4184        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
4185            dirstat_by_line) {
4186                struct diffstat_t diffstat;
4187
4188                memset(&diffstat, 0, sizeof(struct diffstat_t));
4189                for (i = 0; i < q->nr; i++) {
4190                        struct diff_filepair *p = q->queue[i];
4191                        if (check_pair_status(p))
4192                                diff_flush_stat(p, options, &diffstat);
4193                }
4194                if (output_format & DIFF_FORMAT_NUMSTAT)
4195                        show_numstat(&diffstat, options);
4196                if (output_format & DIFF_FORMAT_DIFFSTAT)
4197                        show_stats(&diffstat, options);
4198                if (output_format & DIFF_FORMAT_SHORTSTAT)
4199                        show_shortstats(&diffstat, options);
4200                if (output_format & DIFF_FORMAT_DIRSTAT)
4201                        show_dirstat_by_line(&diffstat, options);
4202                free_diffstat_info(&diffstat);
4203                separator++;
4204        }
4205        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
4206                show_dirstat(options);
4207
4208        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4209                for (i = 0; i < q->nr; i++) {
4210                        diff_summary(options, q->queue[i]);
4211                }
4212                separator++;
4213        }
4214
4215        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4216            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4217            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4218                /*
4219                 * run diff_flush_patch for the exit status. setting
4220                 * options->file to /dev/null should be safe, becaue we
4221                 * aren't supposed to produce any output anyway.
4222                 */
4223                if (options->close_file)
4224                        fclose(options->file);
4225                options->file = fopen("/dev/null", "w");
4226                if (!options->file)
4227                        die_errno("Could not open /dev/null");
4228                options->close_file = 1;
4229                for (i = 0; i < q->nr; i++) {
4230                        struct diff_filepair *p = q->queue[i];
4231                        if (check_pair_status(p))
4232                                diff_flush_patch(p, options);
4233                        if (options->found_changes)
4234                                break;
4235                }
4236        }
4237
4238        if (output_format & DIFF_FORMAT_PATCH) {
4239                if (separator) {
4240                        putc(options->line_termination, options->file);
4241                        if (options->stat_sep) {
4242                                /* attach patch instead of inline */
4243                                fputs(options->stat_sep, options->file);
4244                        }
4245                }
4246
4247                for (i = 0; i < q->nr; i++) {
4248                        struct diff_filepair *p = q->queue[i];
4249                        if (check_pair_status(p))
4250                                diff_flush_patch(p, options);
4251                }
4252        }
4253
4254        if (output_format & DIFF_FORMAT_CALLBACK)
4255                options->format_callback(q, options, options->format_callback_data);
4256
4257        for (i = 0; i < q->nr; i++)
4258                diff_free_filepair(q->queue[i]);
4259free_queue:
4260        free(q->queue);
4261        DIFF_QUEUE_CLEAR(q);
4262        if (options->close_file)
4263                fclose(options->file);
4264
4265        /*
4266         * Report the content-level differences with HAS_CHANGES;
4267         * diff_addremove/diff_change does not set the bit when
4268         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4269         */
4270        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4271                if (options->found_changes)
4272                        DIFF_OPT_SET(options, HAS_CHANGES);
4273                else
4274                        DIFF_OPT_CLR(options, HAS_CHANGES);
4275        }
4276}
4277
4278static void diffcore_apply_filter(const char *filter)
4279{
4280        int i;
4281        struct diff_queue_struct *q = &diff_queued_diff;
4282        struct diff_queue_struct outq;
4283        DIFF_QUEUE_CLEAR(&outq);
4284
4285        if (!filter)
4286                return;
4287
4288        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
4289                int found;
4290                for (i = found = 0; !found && i < q->nr; i++) {
4291                        struct diff_filepair *p = q->queue[i];
4292                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4293                             ((p->score &&
4294                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4295                              (!p->score &&
4296                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4297                            ((p->status != DIFF_STATUS_MODIFIED) &&
4298                             strchr(filter, p->status)))
4299                                found++;
4300                }
4301                if (found)
4302                        return;
4303
4304                /* otherwise we will clear the whole queue
4305                 * by copying the empty outq at the end of this
4306                 * function, but first clear the current entries
4307                 * in the queue.
4308                 */
4309                for (i = 0; i < q->nr; i++)
4310                        diff_free_filepair(q->queue[i]);
4311        }
4312        else {
4313                /* Only the matching ones */
4314                for (i = 0; i < q->nr; i++) {
4315                        struct diff_filepair *p = q->queue[i];
4316
4317                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4318                             ((p->score &&
4319                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4320                              (!p->score &&
4321                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4322                            ((p->status != DIFF_STATUS_MODIFIED) &&
4323                             strchr(filter, p->status)))
4324                                diff_q(&outq, p);
4325                        else
4326                                diff_free_filepair(p);
4327                }
4328        }
4329        free(q->queue);
4330        *q = outq;
4331}
4332
4333/* Check whether two filespecs with the same mode and size are identical */
4334static int diff_filespec_is_identical(struct diff_filespec *one,
4335                                      struct diff_filespec *two)
4336{
4337        if (S_ISGITLINK(one->mode))
4338                return 0;
4339        if (diff_populate_filespec(one, 0))
4340                return 0;
4341        if (diff_populate_filespec(two, 0))
4342                return 0;
4343        return !memcmp(one->data, two->data, one->size);
4344}
4345
4346static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4347{
4348        int i;
4349        struct diff_queue_struct *q = &diff_queued_diff;
4350        struct diff_queue_struct outq;
4351        DIFF_QUEUE_CLEAR(&outq);
4352
4353        for (i = 0; i < q->nr; i++) {
4354                struct diff_filepair *p = q->queue[i];
4355
4356                /*
4357                 * 1. Entries that come from stat info dirtiness
4358                 *    always have both sides (iow, not create/delete),
4359                 *    one side of the object name is unknown, with
4360                 *    the same mode and size.  Keep the ones that
4361                 *    do not match these criteria.  They have real
4362                 *    differences.
4363                 *
4364                 * 2. At this point, the file is known to be modified,
4365                 *    with the same mode and size, and the object
4366                 *    name of one side is unknown.  Need to inspect
4367                 *    the identical contents.
4368                 */
4369                if (!DIFF_FILE_VALID(p->one) || /* (1) */
4370                    !DIFF_FILE_VALID(p->two) ||
4371                    (p->one->sha1_valid && p->two->sha1_valid) ||
4372                    (p->one->mode != p->two->mode) ||
4373                    diff_populate_filespec(p->one, 1) ||
4374                    diff_populate_filespec(p->two, 1) ||
4375                    (p->one->size != p->two->size) ||
4376                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4377                        diff_q(&outq, p);
4378                else {
4379                        /*
4380                         * The caller can subtract 1 from skip_stat_unmatch
4381                         * to determine how many paths were dirty only
4382                         * due to stat info mismatch.
4383                         */
4384                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4385                                diffopt->skip_stat_unmatch++;
4386                        diff_free_filepair(p);
4387                }
4388        }
4389        free(q->queue);
4390        *q = outq;
4391}
4392
4393static int diffnamecmp(const void *a_, const void *b_)
4394{
4395        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4396        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4397        const char *name_a, *name_b;
4398
4399        name_a = a->one ? a->one->path : a->two->path;
4400        name_b = b->one ? b->one->path : b->two->path;
4401        return strcmp(name_a, name_b);
4402}
4403
4404void diffcore_fix_diff_index(struct diff_options *options)
4405{
4406        struct diff_queue_struct *q = &diff_queued_diff;
4407        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4408}
4409
4410void diffcore_std(struct diff_options *options)
4411{
4412        if (options->skip_stat_unmatch)
4413                diffcore_skip_stat_unmatch(options);
4414        if (!options->found_follow) {
4415                /* See try_to_follow_renames() in tree-diff.c */
4416                if (options->break_opt != -1)
4417                        diffcore_break(options->break_opt);
4418                if (options->detect_rename)
4419                        diffcore_rename(options);
4420                if (options->break_opt != -1)
4421                        diffcore_merge_broken();
4422        }
4423        if (options->pickaxe)
4424                diffcore_pickaxe(options);
4425        if (options->orderfile)
4426                diffcore_order(options->orderfile);
4427        if (!options->found_follow)
4428                /* See try_to_follow_renames() in tree-diff.c */
4429                diff_resolve_rename_copy();
4430        diffcore_apply_filter(options->filter);
4431
4432        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4433                DIFF_OPT_SET(options, HAS_CHANGES);
4434        else
4435                DIFF_OPT_CLR(options, HAS_CHANGES);
4436
4437        options->found_follow = 0;
4438}
4439
4440int diff_result_code(struct diff_options *opt, int status)
4441{
4442        int result = 0;
4443
4444        diff_warn_rename_limit("diff.renamelimit",
4445                               opt->needed_rename_limit,
4446                               opt->degraded_cc_to_c);
4447        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4448            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4449                return status;
4450        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4451            DIFF_OPT_TST(opt, HAS_CHANGES))
4452                result |= 01;
4453        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4454            DIFF_OPT_TST(opt, CHECK_FAILED))
4455                result |= 02;
4456        return result;
4457}
4458
4459int diff_can_quit_early(struct diff_options *opt)
4460{
4461        return (DIFF_OPT_TST(opt, QUICK) &&
4462                !opt->filter &&
4463                DIFF_OPT_TST(opt, HAS_CHANGES));
4464}
4465
4466/*
4467 * Shall changes to this submodule be ignored?
4468 *
4469 * Submodule changes can be configured to be ignored separately for each path,
4470 * but that configuration can be overridden from the command line.
4471 */
4472static int is_submodule_ignored(const char *path, struct diff_options *options)
4473{
4474        int ignored = 0;
4475        unsigned orig_flags = options->flags;
4476        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4477                set_diffopt_flags_from_submodule_config(options, path);
4478        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4479                ignored = 1;
4480        options->flags = orig_flags;
4481        return ignored;
4482}
4483
4484void diff_addremove(struct diff_options *options,
4485                    int addremove, unsigned mode,
4486                    const unsigned char *sha1,
4487                    const char *concatpath, unsigned dirty_submodule)
4488{
4489        struct diff_filespec *one, *two;
4490
4491        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4492                return;
4493
4494        /* This may look odd, but it is a preparation for
4495         * feeding "there are unchanged files which should
4496         * not produce diffs, but when you are doing copy
4497         * detection you would need them, so here they are"
4498         * entries to the diff-core.  They will be prefixed
4499         * with something like '=' or '*' (I haven't decided
4500         * which but should not make any difference).
4501         * Feeding the same new and old to diff_change()
4502         * also has the same effect.
4503         * Before the final output happens, they are pruned after
4504         * merged into rename/copy pairs as appropriate.
4505         */
4506        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4507                addremove = (addremove == '+' ? '-' :
4508                             addremove == '-' ? '+' : addremove);
4509
4510        if (options->prefix &&
4511            strncmp(concatpath, options->prefix, options->prefix_length))
4512                return;
4513
4514        one = alloc_filespec(concatpath);
4515        two = alloc_filespec(concatpath);
4516
4517        if (addremove != '+')
4518                fill_filespec(one, sha1, mode);
4519        if (addremove != '-') {
4520                fill_filespec(two, sha1, mode);
4521                two->dirty_submodule = dirty_submodule;
4522        }
4523
4524        diff_queue(&diff_queued_diff, one, two);
4525        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4526                DIFF_OPT_SET(options, HAS_CHANGES);
4527}
4528
4529void diff_change(struct diff_options *options,
4530                 unsigned old_mode, unsigned new_mode,
4531                 const unsigned char *old_sha1,
4532                 const unsigned char *new_sha1,
4533                 const char *concatpath,
4534                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4535{
4536        struct diff_filespec *one, *two;
4537
4538        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4539            is_submodule_ignored(concatpath, options))
4540                return;
4541
4542        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4543                unsigned tmp;
4544                const unsigned char *tmp_c;
4545                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4546                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4547                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4548                        new_dirty_submodule = tmp;
4549        }
4550
4551        if (options->prefix &&
4552            strncmp(concatpath, options->prefix, options->prefix_length))
4553                return;
4554
4555        one = alloc_filespec(concatpath);
4556        two = alloc_filespec(concatpath);
4557        fill_filespec(one, old_sha1, old_mode);
4558        fill_filespec(two, new_sha1, new_mode);
4559        one->dirty_submodule = old_dirty_submodule;
4560        two->dirty_submodule = new_dirty_submodule;
4561
4562        diff_queue(&diff_queued_diff, one, two);
4563        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4564                DIFF_OPT_SET(options, HAS_CHANGES);
4565}
4566
4567struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
4568{
4569        struct diff_filepair *pair;
4570        struct diff_filespec *one, *two;
4571
4572        if (options->prefix &&
4573            strncmp(path, options->prefix, options->prefix_length))
4574                return NULL;
4575
4576        one = alloc_filespec(path);
4577        two = alloc_filespec(path);
4578        pair = diff_queue(&diff_queued_diff, one, two);
4579        pair->is_unmerged = 1;
4580        return pair;
4581}
4582
4583static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4584                size_t *outsize)
4585{
4586        struct diff_tempfile *temp;
4587        const char *argv[3];
4588        const char **arg = argv;
4589        struct child_process child;
4590        struct strbuf buf = STRBUF_INIT;
4591        int err = 0;
4592
4593        temp = prepare_temp_file(spec->path, spec);
4594        *arg++ = pgm;
4595        *arg++ = temp->name;
4596        *arg = NULL;
4597
4598        memset(&child, 0, sizeof(child));
4599        child.use_shell = 1;
4600        child.argv = argv;
4601        child.out = -1;
4602        if (start_command(&child)) {
4603                remove_tempfile();
4604                return NULL;
4605        }
4606
4607        if (strbuf_read(&buf, child.out, 0) < 0)
4608                err = error("error reading from textconv command '%s'", pgm);
4609        close(child.out);
4610
4611        if (finish_command(&child) || err) {
4612                strbuf_release(&buf);
4613                remove_tempfile();
4614                return NULL;
4615        }
4616        remove_tempfile();
4617
4618        return strbuf_detach(&buf, outsize);
4619}
4620
4621size_t fill_textconv(struct userdiff_driver *driver,
4622                     struct diff_filespec *df,
4623                     char **outbuf)
4624{
4625        size_t size;
4626
4627        if (!driver || !driver->textconv) {
4628                if (!DIFF_FILE_VALID(df)) {
4629                        *outbuf = "";
4630                        return 0;
4631                }
4632                if (diff_populate_filespec(df, 0))
4633                        die("unable to read files to diff");
4634                *outbuf = df->data;
4635                return df->size;
4636        }
4637
4638        if (driver->textconv_cache && df->sha1_valid) {
4639                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4640                                          &size);
4641                if (*outbuf)
4642                        return size;
4643        }
4644
4645        *outbuf = run_textconv(driver->textconv, df, &size);
4646        if (!*outbuf)
4647                die("unable to read files to diff");
4648
4649        if (driver->textconv_cache && df->sha1_valid) {
4650                /* ignore errors, as we might be in a readonly repository */
4651                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4652                                size);
4653                /*
4654                 * we could save up changes and flush them all at the end,
4655                 * but we would need an extra call after all diffing is done.
4656                 * Since generating a cache entry is the slow path anyway,
4657                 * this extra overhead probably isn't a big deal.
4658                 */
4659                notes_cache_write(driver->textconv_cache);
4660        }
4661
4662        return size;
4663}