e1d82c9672599072fb946d157d54bd72aa0fa7db
   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        /*
1181         * Note:
1182         * if pfx_length is 0, old/new will never reach a - 1 because it
1183         * would mean the whole string is common suffix. But then, the
1184         * whole string would also be a common prefix, and we would not
1185         * have pfx_length equals 0.
1186         */
1187        while (a + pfx_length - 1 <= old &&
1188               b + pfx_length - 1 <= new &&
1189               *old == *new) {
1190                if (*old == '/')
1191                        sfx_length = len_a - (old - a);
1192                old--;
1193                new--;
1194        }
1195
1196        /*
1197         * pfx{mid-a => mid-b}sfx
1198         * {pfx-a => pfx-b}sfx
1199         * pfx{sfx-a => sfx-b}
1200         * name-a => name-b
1201         */
1202        a_midlen = len_a - pfx_length - sfx_length;
1203        b_midlen = len_b - pfx_length - sfx_length;
1204        if (a_midlen < 0)
1205                a_midlen = 0;
1206        if (b_midlen < 0)
1207                b_midlen = 0;
1208
1209        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1210        if (pfx_length + sfx_length) {
1211                strbuf_add(&name, a, pfx_length);
1212                strbuf_addch(&name, '{');
1213        }
1214        strbuf_add(&name, a + pfx_length, a_midlen);
1215        strbuf_addstr(&name, " => ");
1216        strbuf_add(&name, b + pfx_length, b_midlen);
1217        if (pfx_length + sfx_length) {
1218                strbuf_addch(&name, '}');
1219                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1220        }
1221        return strbuf_detach(&name, NULL);
1222}
1223
1224struct diffstat_t {
1225        int nr;
1226        int alloc;
1227        struct diffstat_file {
1228                char *from_name;
1229                char *name;
1230                char *print_name;
1231                unsigned is_unmerged:1;
1232                unsigned is_binary:1;
1233                unsigned is_renamed:1;
1234                uintmax_t added, deleted;
1235        } **files;
1236};
1237
1238static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1239                                          const char *name_a,
1240                                          const char *name_b)
1241{
1242        struct diffstat_file *x;
1243        x = xcalloc(sizeof (*x), 1);
1244        if (diffstat->nr == diffstat->alloc) {
1245                diffstat->alloc = alloc_nr(diffstat->alloc);
1246                diffstat->files = xrealloc(diffstat->files,
1247                                diffstat->alloc * sizeof(x));
1248        }
1249        diffstat->files[diffstat->nr++] = x;
1250        if (name_b) {
1251                x->from_name = xstrdup(name_a);
1252                x->name = xstrdup(name_b);
1253                x->is_renamed = 1;
1254        }
1255        else {
1256                x->from_name = NULL;
1257                x->name = xstrdup(name_a);
1258        }
1259        return x;
1260}
1261
1262static void diffstat_consume(void *priv, char *line, unsigned long len)
1263{
1264        struct diffstat_t *diffstat = priv;
1265        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1266
1267        if (line[0] == '+')
1268                x->added++;
1269        else if (line[0] == '-')
1270                x->deleted++;
1271}
1272
1273const char mime_boundary_leader[] = "------------";
1274
1275static int scale_linear(int it, int width, int max_change)
1276{
1277        /*
1278         * make sure that at least one '-' is printed if there were deletions,
1279         * and likewise for '+'.
1280         */
1281        if (max_change < 2)
1282                return it;
1283        return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
1284}
1285
1286static void show_name(FILE *file,
1287                      const char *prefix, const char *name, int len)
1288{
1289        fprintf(file, " %s%-*s |", prefix, len, name);
1290}
1291
1292static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1293{
1294        if (cnt <= 0)
1295                return;
1296        fprintf(file, "%s", set);
1297        while (cnt--)
1298                putc(ch, file);
1299        fprintf(file, "%s", reset);
1300}
1301
1302static void fill_print_name(struct diffstat_file *file)
1303{
1304        char *pname;
1305
1306        if (file->print_name)
1307                return;
1308
1309        if (!file->is_renamed) {
1310                struct strbuf buf = STRBUF_INIT;
1311                if (quote_c_style(file->name, &buf, NULL, 0)) {
1312                        pname = strbuf_detach(&buf, NULL);
1313                } else {
1314                        pname = file->name;
1315                        strbuf_release(&buf);
1316                }
1317        } else {
1318                pname = pprint_rename(file->from_name, file->name);
1319        }
1320        file->print_name = pname;
1321}
1322
1323static void show_stats(struct diffstat_t *data, struct diff_options *options)
1324{
1325        int i, len, add, del, adds = 0, dels = 0;
1326        uintmax_t max_change = 0, max_len = 0;
1327        int total_files = data->nr;
1328        int width, name_width;
1329        const char *reset, *add_c, *del_c;
1330        const char *line_prefix = "";
1331        struct strbuf *msg = NULL;
1332
1333        if (data->nr == 0)
1334                return;
1335
1336        if (options->output_prefix) {
1337                msg = options->output_prefix(options, options->output_prefix_data);
1338                line_prefix = msg->buf;
1339        }
1340
1341        width = options->stat_width ? options->stat_width : 80;
1342        name_width = options->stat_name_width ? options->stat_name_width : 50;
1343
1344        /* Sanity: give at least 5 columns to the graph,
1345         * but leave at least 10 columns for the name.
1346         */
1347        if (width < 25)
1348                width = 25;
1349        if (name_width < 10)
1350                name_width = 10;
1351        else if (width < name_width + 15)
1352                name_width = width - 15;
1353
1354        /* Find the longest filename and max number of changes */
1355        reset = diff_get_color_opt(options, DIFF_RESET);
1356        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1357        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1358
1359        for (i = 0; i < data->nr; i++) {
1360                struct diffstat_file *file = data->files[i];
1361                uintmax_t change = file->added + file->deleted;
1362                fill_print_name(file);
1363                len = strlen(file->print_name);
1364                if (max_len < len)
1365                        max_len = len;
1366
1367                if (file->is_binary || file->is_unmerged)
1368                        continue;
1369                if (max_change < change)
1370                        max_change = change;
1371        }
1372
1373        /* Compute the width of the graph part;
1374         * 10 is for one blank at the beginning of the line plus
1375         * " | count " between the name and the graph.
1376         *
1377         * From here on, name_width is the width of the name area,
1378         * and width is the width of the graph area.
1379         */
1380        name_width = (name_width < max_len) ? name_width : max_len;
1381        if (width < (name_width + 10) + max_change)
1382                width = width - (name_width + 10);
1383        else
1384                width = max_change;
1385
1386        for (i = 0; i < data->nr; i++) {
1387                const char *prefix = "";
1388                char *name = data->files[i]->print_name;
1389                uintmax_t added = data->files[i]->added;
1390                uintmax_t deleted = data->files[i]->deleted;
1391                int name_len;
1392
1393                /*
1394                 * "scale" the filename
1395                 */
1396                len = name_width;
1397                name_len = strlen(name);
1398                if (name_width < name_len) {
1399                        char *slash;
1400                        prefix = "...";
1401                        len -= 3;
1402                        name += name_len - len;
1403                        slash = strchr(name, '/');
1404                        if (slash)
1405                                name = slash;
1406                }
1407
1408                if (data->files[i]->is_binary) {
1409                        fprintf(options->file, "%s", line_prefix);
1410                        show_name(options->file, prefix, name, len);
1411                        fprintf(options->file, "  Bin ");
1412                        fprintf(options->file, "%s%"PRIuMAX"%s",
1413                                del_c, deleted, reset);
1414                        fprintf(options->file, " -> ");
1415                        fprintf(options->file, "%s%"PRIuMAX"%s",
1416                                add_c, added, reset);
1417                        fprintf(options->file, " bytes");
1418                        fprintf(options->file, "\n");
1419                        continue;
1420                }
1421                else if (data->files[i]->is_unmerged) {
1422                        fprintf(options->file, "%s", line_prefix);
1423                        show_name(options->file, prefix, name, len);
1424                        fprintf(options->file, "  Unmerged\n");
1425                        continue;
1426                }
1427                else if (!data->files[i]->is_renamed &&
1428                         (added + deleted == 0)) {
1429                        total_files--;
1430                        continue;
1431                }
1432
1433                /*
1434                 * scale the add/delete
1435                 */
1436                add = added;
1437                del = deleted;
1438                adds += add;
1439                dels += del;
1440
1441                if (width <= max_change) {
1442                        add = scale_linear(add, width, max_change);
1443                        del = scale_linear(del, width, max_change);
1444                }
1445                fprintf(options->file, "%s", line_prefix);
1446                show_name(options->file, prefix, name, len);
1447                fprintf(options->file, "%5"PRIuMAX"%s", added + deleted,
1448                                added + deleted ? " " : "");
1449                show_graph(options->file, '+', add, add_c, reset);
1450                show_graph(options->file, '-', del, del_c, reset);
1451                fprintf(options->file, "\n");
1452        }
1453        fprintf(options->file, "%s", line_prefix);
1454        fprintf(options->file,
1455               " %d files changed, %d insertions(+), %d deletions(-)\n",
1456               total_files, adds, dels);
1457}
1458
1459static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1460{
1461        int i, adds = 0, dels = 0, total_files = data->nr;
1462
1463        if (data->nr == 0)
1464                return;
1465
1466        for (i = 0; i < data->nr; i++) {
1467                if (!data->files[i]->is_binary &&
1468                    !data->files[i]->is_unmerged) {
1469                        int added = data->files[i]->added;
1470                        int deleted= data->files[i]->deleted;
1471                        if (!data->files[i]->is_renamed &&
1472                            (added + deleted == 0)) {
1473                                total_files--;
1474                        } else {
1475                                adds += added;
1476                                dels += deleted;
1477                        }
1478                }
1479        }
1480        if (options->output_prefix) {
1481                struct strbuf *msg = NULL;
1482                msg = options->output_prefix(options,
1483                                options->output_prefix_data);
1484                fprintf(options->file, "%s", msg->buf);
1485        }
1486        fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
1487               total_files, adds, dels);
1488}
1489
1490static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1491{
1492        int i;
1493
1494        if (data->nr == 0)
1495                return;
1496
1497        for (i = 0; i < data->nr; i++) {
1498                struct diffstat_file *file = data->files[i];
1499
1500                if (options->output_prefix) {
1501                        struct strbuf *msg = NULL;
1502                        msg = options->output_prefix(options,
1503                                        options->output_prefix_data);
1504                        fprintf(options->file, "%s", msg->buf);
1505                }
1506
1507                if (file->is_binary)
1508                        fprintf(options->file, "-\t-\t");
1509                else
1510                        fprintf(options->file,
1511                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1512                                file->added, file->deleted);
1513                if (options->line_termination) {
1514                        fill_print_name(file);
1515                        if (!file->is_renamed)
1516                                write_name_quoted(file->name, options->file,
1517                                                  options->line_termination);
1518                        else {
1519                                fputs(file->print_name, options->file);
1520                                putc(options->line_termination, options->file);
1521                        }
1522                } else {
1523                        if (file->is_renamed) {
1524                                putc('\0', options->file);
1525                                write_name_quoted(file->from_name, options->file, '\0');
1526                        }
1527                        write_name_quoted(file->name, options->file, '\0');
1528                }
1529        }
1530}
1531
1532struct dirstat_file {
1533        const char *name;
1534        unsigned long changed;
1535};
1536
1537struct dirstat_dir {
1538        struct dirstat_file *files;
1539        int alloc, nr, permille, cumulative;
1540};
1541
1542static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1543                unsigned long changed, const char *base, int baselen)
1544{
1545        unsigned long this_dir = 0;
1546        unsigned int sources = 0;
1547        const char *line_prefix = "";
1548        struct strbuf *msg = NULL;
1549
1550        if (opt->output_prefix) {
1551                msg = opt->output_prefix(opt, opt->output_prefix_data);
1552                line_prefix = msg->buf;
1553        }
1554
1555        while (dir->nr) {
1556                struct dirstat_file *f = dir->files;
1557                int namelen = strlen(f->name);
1558                unsigned long this;
1559                char *slash;
1560
1561                if (namelen < baselen)
1562                        break;
1563                if (memcmp(f->name, base, baselen))
1564                        break;
1565                slash = strchr(f->name + baselen, '/');
1566                if (slash) {
1567                        int newbaselen = slash + 1 - f->name;
1568                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1569                        sources++;
1570                } else {
1571                        this = f->changed;
1572                        dir->files++;
1573                        dir->nr--;
1574                        sources += 2;
1575                }
1576                this_dir += this;
1577        }
1578
1579        /*
1580         * We don't report dirstat's for
1581         *  - the top level
1582         *  - or cases where everything came from a single directory
1583         *    under this directory (sources == 1).
1584         */
1585        if (baselen && sources != 1) {
1586                if (this_dir) {
1587                        int permille = this_dir * 1000 / changed;
1588                        if (permille >= dir->permille) {
1589                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1590                                        permille / 10, permille % 10, baselen, base);
1591                                if (!dir->cumulative)
1592                                        return 0;
1593                        }
1594                }
1595        }
1596        return this_dir;
1597}
1598
1599static int dirstat_compare(const void *_a, const void *_b)
1600{
1601        const struct dirstat_file *a = _a;
1602        const struct dirstat_file *b = _b;
1603        return strcmp(a->name, b->name);
1604}
1605
1606static void show_dirstat(struct diff_options *options)
1607{
1608        int i;
1609        unsigned long changed;
1610        struct dirstat_dir dir;
1611        struct diff_queue_struct *q = &diff_queued_diff;
1612
1613        dir.files = NULL;
1614        dir.alloc = 0;
1615        dir.nr = 0;
1616        dir.permille = options->dirstat_permille;
1617        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1618
1619        changed = 0;
1620        for (i = 0; i < q->nr; i++) {
1621                struct diff_filepair *p = q->queue[i];
1622                const char *name;
1623                unsigned long copied, added, damage;
1624                int content_changed;
1625
1626                name = p->two->path ? p->two->path : p->one->path;
1627
1628                if (p->one->sha1_valid && p->two->sha1_valid)
1629                        content_changed = hashcmp(p->one->sha1, p->two->sha1);
1630                else
1631                        content_changed = 1;
1632
1633                if (!content_changed) {
1634                        /*
1635                         * The SHA1 has not changed, so pre-/post-content is
1636                         * identical. We can therefore skip looking at the
1637                         * file contents altogether.
1638                         */
1639                        damage = 0;
1640                        goto found_damage;
1641                }
1642
1643                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1644                        /*
1645                         * In --dirstat-by-file mode, we don't really need to
1646                         * look at the actual file contents at all.
1647                         * The fact that the SHA1 changed is enough for us to
1648                         * add this file to the list of results
1649                         * (with each file contributing equal damage).
1650                         */
1651                        damage = 1;
1652                        goto found_damage;
1653                }
1654
1655                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1656                        diff_populate_filespec(p->one, 0);
1657                        diff_populate_filespec(p->two, 0);
1658                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1659                                               &copied, &added);
1660                        diff_free_filespec_data(p->one);
1661                        diff_free_filespec_data(p->two);
1662                } else if (DIFF_FILE_VALID(p->one)) {
1663                        diff_populate_filespec(p->one, 1);
1664                        copied = added = 0;
1665                        diff_free_filespec_data(p->one);
1666                } else if (DIFF_FILE_VALID(p->two)) {
1667                        diff_populate_filespec(p->two, 1);
1668                        copied = 0;
1669                        added = p->two->size;
1670                        diff_free_filespec_data(p->two);
1671                } else
1672                        continue;
1673
1674                /*
1675                 * Original minus copied is the removed material,
1676                 * added is the new material.  They are both damages
1677                 * made to the preimage.
1678                 * If the resulting damage is zero, we know that
1679                 * diffcore_count_changes() considers the two entries to
1680                 * be identical, but since content_changed is true, we
1681                 * know that there must have been _some_ kind of change,
1682                 * so we force all entries to have damage > 0.
1683                 */
1684                damage = (p->one->size - copied) + added;
1685                if (!damage)
1686                        damage = 1;
1687
1688found_damage:
1689                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1690                dir.files[dir.nr].name = name;
1691                dir.files[dir.nr].changed = damage;
1692                changed += damage;
1693                dir.nr++;
1694        }
1695
1696        /* This can happen even with many files, if everything was renames */
1697        if (!changed)
1698                return;
1699
1700        /* Show all directories with more than x% of the changes */
1701        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1702        gather_dirstat(options, &dir, changed, "", 0);
1703}
1704
1705static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
1706{
1707        int i;
1708        unsigned long changed;
1709        struct dirstat_dir dir;
1710
1711        if (data->nr == 0)
1712                return;
1713
1714        dir.files = NULL;
1715        dir.alloc = 0;
1716        dir.nr = 0;
1717        dir.permille = options->dirstat_permille;
1718        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1719
1720        changed = 0;
1721        for (i = 0; i < data->nr; i++) {
1722                struct diffstat_file *file = data->files[i];
1723                unsigned long damage = file->added + file->deleted;
1724                if (file->is_binary)
1725                        /*
1726                         * binary files counts bytes, not lines. Must find some
1727                         * way to normalize binary bytes vs. textual lines.
1728                         * The following heuristic assumes that there are 64
1729                         * bytes per "line".
1730                         * This is stupid and ugly, but very cheap...
1731                         */
1732                        damage = (damage + 63) / 64;
1733                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1734                dir.files[dir.nr].name = file->name;
1735                dir.files[dir.nr].changed = damage;
1736                changed += damage;
1737                dir.nr++;
1738        }
1739
1740        /* This can happen even with many files, if everything was renames */
1741        if (!changed)
1742                return;
1743
1744        /* Show all directories with more than x% of the changes */
1745        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1746        gather_dirstat(options, &dir, changed, "", 0);
1747}
1748
1749static void free_diffstat_info(struct diffstat_t *diffstat)
1750{
1751        int i;
1752        for (i = 0; i < diffstat->nr; i++) {
1753                struct diffstat_file *f = diffstat->files[i];
1754                if (f->name != f->print_name)
1755                        free(f->print_name);
1756                free(f->name);
1757                free(f->from_name);
1758                free(f);
1759        }
1760        free(diffstat->files);
1761}
1762
1763struct checkdiff_t {
1764        const char *filename;
1765        int lineno;
1766        int conflict_marker_size;
1767        struct diff_options *o;
1768        unsigned ws_rule;
1769        unsigned status;
1770};
1771
1772static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1773{
1774        char firstchar;
1775        int cnt;
1776
1777        if (len < marker_size + 1)
1778                return 0;
1779        firstchar = line[0];
1780        switch (firstchar) {
1781        case '=': case '>': case '<': case '|':
1782                break;
1783        default:
1784                return 0;
1785        }
1786        for (cnt = 1; cnt < marker_size; cnt++)
1787                if (line[cnt] != firstchar)
1788                        return 0;
1789        /* line[1] thru line[marker_size-1] are same as firstchar */
1790        if (len < marker_size + 1 || !isspace(line[marker_size]))
1791                return 0;
1792        return 1;
1793}
1794
1795static void checkdiff_consume(void *priv, char *line, unsigned long len)
1796{
1797        struct checkdiff_t *data = priv;
1798        int color_diff = DIFF_OPT_TST(data->o, COLOR_DIFF);
1799        int marker_size = data->conflict_marker_size;
1800        const char *ws = diff_get_color(color_diff, DIFF_WHITESPACE);
1801        const char *reset = diff_get_color(color_diff, DIFF_RESET);
1802        const char *set = diff_get_color(color_diff, DIFF_FILE_NEW);
1803        char *err;
1804        char *line_prefix = "";
1805        struct strbuf *msgbuf;
1806
1807        assert(data->o);
1808        if (data->o->output_prefix) {
1809                msgbuf = data->o->output_prefix(data->o,
1810                        data->o->output_prefix_data);
1811                line_prefix = msgbuf->buf;
1812        }
1813
1814        if (line[0] == '+') {
1815                unsigned bad;
1816                data->lineno++;
1817                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
1818                        data->status |= 1;
1819                        fprintf(data->o->file,
1820                                "%s%s:%d: leftover conflict marker\n",
1821                                line_prefix, data->filename, data->lineno);
1822                }
1823                bad = ws_check(line + 1, len - 1, data->ws_rule);
1824                if (!bad)
1825                        return;
1826                data->status |= bad;
1827                err = whitespace_error_string(bad);
1828                fprintf(data->o->file, "%s%s:%d: %s.\n",
1829                        line_prefix, data->filename, data->lineno, err);
1830                free(err);
1831                emit_line(data->o, set, reset, line, 1);
1832                ws_check_emit(line + 1, len - 1, data->ws_rule,
1833                              data->o->file, set, reset, ws);
1834        } else if (line[0] == ' ') {
1835                data->lineno++;
1836        } else if (line[0] == '@') {
1837                char *plus = strchr(line, '+');
1838                if (plus)
1839                        data->lineno = strtol(plus, NULL, 10) - 1;
1840                else
1841                        die("invalid diff");
1842        }
1843}
1844
1845static unsigned char *deflate_it(char *data,
1846                                 unsigned long size,
1847                                 unsigned long *result_size)
1848{
1849        int bound;
1850        unsigned char *deflated;
1851        git_zstream stream;
1852
1853        memset(&stream, 0, sizeof(stream));
1854        git_deflate_init(&stream, zlib_compression_level);
1855        bound = git_deflate_bound(&stream, size);
1856        deflated = xmalloc(bound);
1857        stream.next_out = deflated;
1858        stream.avail_out = bound;
1859
1860        stream.next_in = (unsigned char *)data;
1861        stream.avail_in = size;
1862        while (git_deflate(&stream, Z_FINISH) == Z_OK)
1863                ; /* nothing */
1864        git_deflate_end(&stream);
1865        *result_size = stream.total_out;
1866        return deflated;
1867}
1868
1869static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1870{
1871        void *cp;
1872        void *delta;
1873        void *deflated;
1874        void *data;
1875        unsigned long orig_size;
1876        unsigned long delta_size;
1877        unsigned long deflate_size;
1878        unsigned long data_size;
1879
1880        /* We could do deflated delta, or we could do just deflated two,
1881         * whichever is smaller.
1882         */
1883        delta = NULL;
1884        deflated = deflate_it(two->ptr, two->size, &deflate_size);
1885        if (one->size && two->size) {
1886                delta = diff_delta(one->ptr, one->size,
1887                                   two->ptr, two->size,
1888                                   &delta_size, deflate_size);
1889                if (delta) {
1890                        void *to_free = delta;
1891                        orig_size = delta_size;
1892                        delta = deflate_it(delta, delta_size, &delta_size);
1893                        free(to_free);
1894                }
1895        }
1896
1897        if (delta && delta_size < deflate_size) {
1898                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
1899                free(deflated);
1900                data = delta;
1901                data_size = delta_size;
1902        }
1903        else {
1904                fprintf(file, "%sliteral %lu\n", prefix, two->size);
1905                free(delta);
1906                data = deflated;
1907                data_size = deflate_size;
1908        }
1909
1910        /* emit data encoded in base85 */
1911        cp = data;
1912        while (data_size) {
1913                int bytes = (52 < data_size) ? 52 : data_size;
1914                char line[70];
1915                data_size -= bytes;
1916                if (bytes <= 26)
1917                        line[0] = bytes + 'A' - 1;
1918                else
1919                        line[0] = bytes - 26 + 'a' - 1;
1920                encode_85(line + 1, cp, bytes);
1921                cp = (char *) cp + bytes;
1922                fprintf(file, "%s", prefix);
1923                fputs(line, file);
1924                fputc('\n', file);
1925        }
1926        fprintf(file, "%s\n", prefix);
1927        free(data);
1928}
1929
1930static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1931{
1932        fprintf(file, "%sGIT binary patch\n", prefix);
1933        emit_binary_diff_body(file, one, two, prefix);
1934        emit_binary_diff_body(file, two, one, prefix);
1935}
1936
1937static void diff_filespec_load_driver(struct diff_filespec *one)
1938{
1939        /* Use already-loaded driver */
1940        if (one->driver)
1941                return;
1942
1943        if (S_ISREG(one->mode))
1944                one->driver = userdiff_find_by_path(one->path);
1945
1946        /* Fallback to default settings */
1947        if (!one->driver)
1948                one->driver = userdiff_find_by_name("default");
1949}
1950
1951int diff_filespec_is_binary(struct diff_filespec *one)
1952{
1953        if (one->is_binary == -1) {
1954                diff_filespec_load_driver(one);
1955                if (one->driver->binary != -1)
1956                        one->is_binary = one->driver->binary;
1957                else {
1958                        if (!one->data && DIFF_FILE_VALID(one))
1959                                diff_populate_filespec(one, 0);
1960                        if (one->data)
1961                                one->is_binary = buffer_is_binary(one->data,
1962                                                one->size);
1963                        if (one->is_binary == -1)
1964                                one->is_binary = 0;
1965                }
1966        }
1967        return one->is_binary;
1968}
1969
1970static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
1971{
1972        diff_filespec_load_driver(one);
1973        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
1974}
1975
1976static const char *userdiff_word_regex(struct diff_filespec *one)
1977{
1978        diff_filespec_load_driver(one);
1979        return one->driver->word_regex;
1980}
1981
1982void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
1983{
1984        if (!options->a_prefix)
1985                options->a_prefix = a;
1986        if (!options->b_prefix)
1987                options->b_prefix = b;
1988}
1989
1990struct userdiff_driver *get_textconv(struct diff_filespec *one)
1991{
1992        if (!DIFF_FILE_VALID(one))
1993                return NULL;
1994
1995        diff_filespec_load_driver(one);
1996        return userdiff_get_textconv(one->driver);
1997}
1998
1999static void builtin_diff(const char *name_a,
2000                         const char *name_b,
2001                         struct diff_filespec *one,
2002                         struct diff_filespec *two,
2003                         const char *xfrm_msg,
2004                         int must_show_header,
2005                         struct diff_options *o,
2006                         int complete_rewrite)
2007{
2008        mmfile_t mf1, mf2;
2009        const char *lbl[2];
2010        char *a_one, *b_two;
2011        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
2012        const char *reset = diff_get_color_opt(o, DIFF_RESET);
2013        const char *a_prefix, *b_prefix;
2014        struct userdiff_driver *textconv_one = NULL;
2015        struct userdiff_driver *textconv_two = NULL;
2016        struct strbuf header = STRBUF_INIT;
2017        struct strbuf *msgbuf;
2018        char *line_prefix = "";
2019
2020        if (o->output_prefix) {
2021                msgbuf = o->output_prefix(o, o->output_prefix_data);
2022                line_prefix = msgbuf->buf;
2023        }
2024
2025        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
2026                        (!one->mode || S_ISGITLINK(one->mode)) &&
2027                        (!two->mode || S_ISGITLINK(two->mode))) {
2028                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2029                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2030                show_submodule_summary(o->file, one ? one->path : two->path,
2031                                one->sha1, two->sha1, two->dirty_submodule,
2032                                del, add, reset);
2033                return;
2034        }
2035
2036        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
2037                textconv_one = get_textconv(one);
2038                textconv_two = get_textconv(two);
2039        }
2040
2041        diff_set_mnemonic_prefix(o, "a/", "b/");
2042        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
2043                a_prefix = o->b_prefix;
2044                b_prefix = o->a_prefix;
2045        } else {
2046                a_prefix = o->a_prefix;
2047                b_prefix = o->b_prefix;
2048        }
2049
2050        /* Never use a non-valid filename anywhere if at all possible */
2051        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
2052        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
2053
2054        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
2055        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
2056        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
2057        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
2058        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
2059        if (lbl[0][0] == '/') {
2060                /* /dev/null */
2061                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
2062                if (xfrm_msg)
2063                        strbuf_addstr(&header, xfrm_msg);
2064                must_show_header = 1;
2065        }
2066        else if (lbl[1][0] == '/') {
2067                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
2068                if (xfrm_msg)
2069                        strbuf_addstr(&header, xfrm_msg);
2070                must_show_header = 1;
2071        }
2072        else {
2073                if (one->mode != two->mode) {
2074                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
2075                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
2076                        must_show_header = 1;
2077                }
2078                if (xfrm_msg)
2079                        strbuf_addstr(&header, xfrm_msg);
2080
2081                /*
2082                 * we do not run diff between different kind
2083                 * of objects.
2084                 */
2085                if ((one->mode ^ two->mode) & S_IFMT)
2086                        goto free_ab_and_return;
2087                if (complete_rewrite &&
2088                    (textconv_one || !diff_filespec_is_binary(one)) &&
2089                    (textconv_two || !diff_filespec_is_binary(two))) {
2090                        fprintf(o->file, "%s", header.buf);
2091                        strbuf_reset(&header);
2092                        emit_rewrite_diff(name_a, name_b, one, two,
2093                                                textconv_one, textconv_two, o);
2094                        o->found_changes = 1;
2095                        goto free_ab_and_return;
2096                }
2097        }
2098
2099        if (o->irreversible_delete && lbl[1][0] == '/') {
2100                fprintf(o->file, "%s", header.buf);
2101                strbuf_reset(&header);
2102                goto free_ab_and_return;
2103        } else if (!DIFF_OPT_TST(o, TEXT) &&
2104            ( (!textconv_one && diff_filespec_is_binary(one)) ||
2105              (!textconv_two && diff_filespec_is_binary(two)) )) {
2106                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2107                        die("unable to read files to diff");
2108                /* Quite common confusing case */
2109                if (mf1.size == mf2.size &&
2110                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2111                        if (must_show_header)
2112                                fprintf(o->file, "%s", header.buf);
2113                        goto free_ab_and_return;
2114                }
2115                fprintf(o->file, "%s", header.buf);
2116                strbuf_reset(&header);
2117                if (DIFF_OPT_TST(o, BINARY))
2118                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2119                else
2120                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2121                                line_prefix, lbl[0], lbl[1]);
2122                o->found_changes = 1;
2123        } else {
2124                /* Crazy xdl interfaces.. */
2125                const char *diffopts = getenv("GIT_DIFF_OPTS");
2126                xpparam_t xpp;
2127                xdemitconf_t xecfg;
2128                struct emit_callback ecbdata;
2129                const struct userdiff_funcname *pe;
2130
2131                if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS) || must_show_header) {
2132                        fprintf(o->file, "%s", header.buf);
2133                        strbuf_reset(&header);
2134                }
2135
2136                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2137                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2138
2139                pe = diff_funcname_pattern(one);
2140                if (!pe)
2141                        pe = diff_funcname_pattern(two);
2142
2143                memset(&xpp, 0, sizeof(xpp));
2144                memset(&xecfg, 0, sizeof(xecfg));
2145                memset(&ecbdata, 0, sizeof(ecbdata));
2146                ecbdata.label_path = lbl;
2147                ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
2148                ecbdata.found_changesp = &o->found_changes;
2149                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
2150                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2151                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2152                ecbdata.opt = o;
2153                ecbdata.header = header.len ? &header : NULL;
2154                xpp.flags = o->xdl_opts;
2155                xecfg.ctxlen = o->context;
2156                xecfg.interhunkctxlen = o->interhunkcontext;
2157                xecfg.flags = XDL_EMIT_FUNCNAMES;
2158                if (pe)
2159                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2160                if (!diffopts)
2161                        ;
2162                else if (!prefixcmp(diffopts, "--unified="))
2163                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2164                else if (!prefixcmp(diffopts, "-u"))
2165                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2166                if (o->word_diff) {
2167                        int i;
2168
2169                        ecbdata.diff_words =
2170                                xcalloc(1, sizeof(struct diff_words_data));
2171                        ecbdata.diff_words->type = o->word_diff;
2172                        ecbdata.diff_words->opt = o;
2173                        if (!o->word_regex)
2174                                o->word_regex = userdiff_word_regex(one);
2175                        if (!o->word_regex)
2176                                o->word_regex = userdiff_word_regex(two);
2177                        if (!o->word_regex)
2178                                o->word_regex = diff_word_regex_cfg;
2179                        if (o->word_regex) {
2180                                ecbdata.diff_words->word_regex = (regex_t *)
2181                                        xmalloc(sizeof(regex_t));
2182                                if (regcomp(ecbdata.diff_words->word_regex,
2183                                                o->word_regex,
2184                                                REG_EXTENDED | REG_NEWLINE))
2185                                        die ("Invalid regular expression: %s",
2186                                                        o->word_regex);
2187                        }
2188                        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2189                                if (o->word_diff == diff_words_styles[i].type) {
2190                                        ecbdata.diff_words->style =
2191                                                &diff_words_styles[i];
2192                                        break;
2193                                }
2194                        }
2195                        if (DIFF_OPT_TST(o, COLOR_DIFF)) {
2196                                struct diff_words_style *st = ecbdata.diff_words->style;
2197                                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2198                                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2199                                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
2200                        }
2201                }
2202                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2203                              &xpp, &xecfg);
2204                if (o->word_diff)
2205                        free_diff_words_data(&ecbdata);
2206                if (textconv_one)
2207                        free(mf1.ptr);
2208                if (textconv_two)
2209                        free(mf2.ptr);
2210                xdiff_clear_find_func(&xecfg);
2211        }
2212
2213 free_ab_and_return:
2214        strbuf_release(&header);
2215        diff_free_filespec_data(one);
2216        diff_free_filespec_data(two);
2217        free(a_one);
2218        free(b_two);
2219        return;
2220}
2221
2222static void builtin_diffstat(const char *name_a, const char *name_b,
2223                             struct diff_filespec *one,
2224                             struct diff_filespec *two,
2225                             struct diffstat_t *diffstat,
2226                             struct diff_options *o,
2227                             int complete_rewrite)
2228{
2229        mmfile_t mf1, mf2;
2230        struct diffstat_file *data;
2231
2232        data = diffstat_add(diffstat, name_a, name_b);
2233
2234        if (!one || !two) {
2235                data->is_unmerged = 1;
2236                return;
2237        }
2238
2239        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2240                data->is_binary = 1;
2241                data->added = diff_filespec_size(two);
2242                data->deleted = diff_filespec_size(one);
2243        }
2244
2245        else if (complete_rewrite) {
2246                diff_populate_filespec(one, 0);
2247                diff_populate_filespec(two, 0);
2248                data->deleted = count_lines(one->data, one->size);
2249                data->added = count_lines(two->data, two->size);
2250        }
2251
2252        else {
2253                /* Crazy xdl interfaces.. */
2254                xpparam_t xpp;
2255                xdemitconf_t xecfg;
2256
2257                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2258                        die("unable to read files to diff");
2259
2260                memset(&xpp, 0, sizeof(xpp));
2261                memset(&xecfg, 0, sizeof(xecfg));
2262                xpp.flags = o->xdl_opts;
2263                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2264                              &xpp, &xecfg);
2265        }
2266
2267        diff_free_filespec_data(one);
2268        diff_free_filespec_data(two);
2269}
2270
2271static void builtin_checkdiff(const char *name_a, const char *name_b,
2272                              const char *attr_path,
2273                              struct diff_filespec *one,
2274                              struct diff_filespec *two,
2275                              struct diff_options *o)
2276{
2277        mmfile_t mf1, mf2;
2278        struct checkdiff_t data;
2279
2280        if (!two)
2281                return;
2282
2283        memset(&data, 0, sizeof(data));
2284        data.filename = name_b ? name_b : name_a;
2285        data.lineno = 0;
2286        data.o = o;
2287        data.ws_rule = whitespace_rule(attr_path);
2288        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2289
2290        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2291                die("unable to read files to diff");
2292
2293        /*
2294         * All the other codepaths check both sides, but not checking
2295         * the "old" side here is deliberate.  We are checking the newly
2296         * introduced changes, and as long as the "new" side is text, we
2297         * can and should check what it introduces.
2298         */
2299        if (diff_filespec_is_binary(two))
2300                goto free_and_return;
2301        else {
2302                /* Crazy xdl interfaces.. */
2303                xpparam_t xpp;
2304                xdemitconf_t xecfg;
2305
2306                memset(&xpp, 0, sizeof(xpp));
2307                memset(&xecfg, 0, sizeof(xecfg));
2308                xecfg.ctxlen = 1; /* at least one context line */
2309                xpp.flags = 0;
2310                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2311                              &xpp, &xecfg);
2312
2313                if (data.ws_rule & WS_BLANK_AT_EOF) {
2314                        struct emit_callback ecbdata;
2315                        int blank_at_eof;
2316
2317                        ecbdata.ws_rule = data.ws_rule;
2318                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2319                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2320
2321                        if (blank_at_eof) {
2322                                static char *err;
2323                                if (!err)
2324                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2325                                fprintf(o->file, "%s:%d: %s.\n",
2326                                        data.filename, blank_at_eof, err);
2327                                data.status = 1; /* report errors */
2328                        }
2329                }
2330        }
2331 free_and_return:
2332        diff_free_filespec_data(one);
2333        diff_free_filespec_data(two);
2334        if (data.status)
2335                DIFF_OPT_SET(o, CHECK_FAILED);
2336}
2337
2338struct diff_filespec *alloc_filespec(const char *path)
2339{
2340        int namelen = strlen(path);
2341        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2342
2343        memset(spec, 0, sizeof(*spec));
2344        spec->path = (char *)(spec + 1);
2345        memcpy(spec->path, path, namelen+1);
2346        spec->count = 1;
2347        spec->is_binary = -1;
2348        return spec;
2349}
2350
2351void free_filespec(struct diff_filespec *spec)
2352{
2353        if (!--spec->count) {
2354                diff_free_filespec_data(spec);
2355                free(spec);
2356        }
2357}
2358
2359void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2360                   unsigned short mode)
2361{
2362        if (mode) {
2363                spec->mode = canon_mode(mode);
2364                hashcpy(spec->sha1, sha1);
2365                spec->sha1_valid = !is_null_sha1(sha1);
2366        }
2367}
2368
2369/*
2370 * Given a name and sha1 pair, if the index tells us the file in
2371 * the work tree has that object contents, return true, so that
2372 * prepare_temp_file() does not have to inflate and extract.
2373 */
2374static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2375{
2376        struct cache_entry *ce;
2377        struct stat st;
2378        int pos, len;
2379
2380        /*
2381         * We do not read the cache ourselves here, because the
2382         * benchmark with my previous version that always reads cache
2383         * shows that it makes things worse for diff-tree comparing
2384         * two linux-2.6 kernel trees in an already checked out work
2385         * tree.  This is because most diff-tree comparisons deal with
2386         * only a small number of files, while reading the cache is
2387         * expensive for a large project, and its cost outweighs the
2388         * savings we get by not inflating the object to a temporary
2389         * file.  Practically, this code only helps when we are used
2390         * by diff-cache --cached, which does read the cache before
2391         * calling us.
2392         */
2393        if (!active_cache)
2394                return 0;
2395
2396        /* We want to avoid the working directory if our caller
2397         * doesn't need the data in a normal file, this system
2398         * is rather slow with its stat/open/mmap/close syscalls,
2399         * and the object is contained in a pack file.  The pack
2400         * is probably already open and will be faster to obtain
2401         * the data through than the working directory.  Loose
2402         * objects however would tend to be slower as they need
2403         * to be individually opened and inflated.
2404         */
2405        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2406                return 0;
2407
2408        len = strlen(name);
2409        pos = cache_name_pos(name, len);
2410        if (pos < 0)
2411                return 0;
2412        ce = active_cache[pos];
2413
2414        /*
2415         * This is not the sha1 we are looking for, or
2416         * unreusable because it is not a regular file.
2417         */
2418        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2419                return 0;
2420
2421        /*
2422         * If ce is marked as "assume unchanged", there is no
2423         * guarantee that work tree matches what we are looking for.
2424         */
2425        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2426                return 0;
2427
2428        /*
2429         * If ce matches the file in the work tree, we can reuse it.
2430         */
2431        if (ce_uptodate(ce) ||
2432            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2433                return 1;
2434
2435        return 0;
2436}
2437
2438static int populate_from_stdin(struct diff_filespec *s)
2439{
2440        struct strbuf buf = STRBUF_INIT;
2441        size_t size = 0;
2442
2443        if (strbuf_read(&buf, 0, 0) < 0)
2444                return error("error while reading from stdin %s",
2445                                     strerror(errno));
2446
2447        s->should_munmap = 0;
2448        s->data = strbuf_detach(&buf, &size);
2449        s->size = size;
2450        s->should_free = 1;
2451        return 0;
2452}
2453
2454static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2455{
2456        int len;
2457        char *data = xmalloc(100), *dirty = "";
2458
2459        /* Are we looking at the work tree? */
2460        if (s->dirty_submodule)
2461                dirty = "-dirty";
2462
2463        len = snprintf(data, 100,
2464                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2465        s->data = data;
2466        s->size = len;
2467        s->should_free = 1;
2468        if (size_only) {
2469                s->data = NULL;
2470                free(data);
2471        }
2472        return 0;
2473}
2474
2475/*
2476 * While doing rename detection and pickaxe operation, we may need to
2477 * grab the data for the blob (or file) for our own in-core comparison.
2478 * diff_filespec has data and size fields for this purpose.
2479 */
2480int diff_populate_filespec(struct diff_filespec *s, int size_only)
2481{
2482        int err = 0;
2483        if (!DIFF_FILE_VALID(s))
2484                die("internal error: asking to populate invalid file.");
2485        if (S_ISDIR(s->mode))
2486                return -1;
2487
2488        if (s->data)
2489                return 0;
2490
2491        if (size_only && 0 < s->size)
2492                return 0;
2493
2494        if (S_ISGITLINK(s->mode))
2495                return diff_populate_gitlink(s, size_only);
2496
2497        if (!s->sha1_valid ||
2498            reuse_worktree_file(s->path, s->sha1, 0)) {
2499                struct strbuf buf = STRBUF_INIT;
2500                struct stat st;
2501                int fd;
2502
2503                if (!strcmp(s->path, "-"))
2504                        return populate_from_stdin(s);
2505
2506                if (lstat(s->path, &st) < 0) {
2507                        if (errno == ENOENT) {
2508                        err_empty:
2509                                err = -1;
2510                        empty:
2511                                s->data = (char *)"";
2512                                s->size = 0;
2513                                return err;
2514                        }
2515                }
2516                s->size = xsize_t(st.st_size);
2517                if (!s->size)
2518                        goto empty;
2519                if (S_ISLNK(st.st_mode)) {
2520                        struct strbuf sb = STRBUF_INIT;
2521
2522                        if (strbuf_readlink(&sb, s->path, s->size))
2523                                goto err_empty;
2524                        s->size = sb.len;
2525                        s->data = strbuf_detach(&sb, NULL);
2526                        s->should_free = 1;
2527                        return 0;
2528                }
2529                if (size_only)
2530                        return 0;
2531                fd = open(s->path, O_RDONLY);
2532                if (fd < 0)
2533                        goto err_empty;
2534                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2535                close(fd);
2536                s->should_munmap = 1;
2537
2538                /*
2539                 * Convert from working tree format to canonical git format
2540                 */
2541                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2542                        size_t size = 0;
2543                        munmap(s->data, s->size);
2544                        s->should_munmap = 0;
2545                        s->data = strbuf_detach(&buf, &size);
2546                        s->size = size;
2547                        s->should_free = 1;
2548                }
2549        }
2550        else {
2551                enum object_type type;
2552                if (size_only) {
2553                        type = sha1_object_info(s->sha1, &s->size);
2554                        if (type < 0)
2555                                die("unable to read %s", sha1_to_hex(s->sha1));
2556                } else {
2557                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2558                        if (!s->data)
2559                                die("unable to read %s", sha1_to_hex(s->sha1));
2560                        s->should_free = 1;
2561                }
2562        }
2563        return 0;
2564}
2565
2566void diff_free_filespec_blob(struct diff_filespec *s)
2567{
2568        if (s->should_free)
2569                free(s->data);
2570        else if (s->should_munmap)
2571                munmap(s->data, s->size);
2572
2573        if (s->should_free || s->should_munmap) {
2574                s->should_free = s->should_munmap = 0;
2575                s->data = NULL;
2576        }
2577}
2578
2579void diff_free_filespec_data(struct diff_filespec *s)
2580{
2581        diff_free_filespec_blob(s);
2582        free(s->cnt_data);
2583        s->cnt_data = NULL;
2584}
2585
2586static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2587                           void *blob,
2588                           unsigned long size,
2589                           const unsigned char *sha1,
2590                           int mode)
2591{
2592        int fd;
2593        struct strbuf buf = STRBUF_INIT;
2594        struct strbuf template = STRBUF_INIT;
2595        char *path_dup = xstrdup(path);
2596        const char *base = basename(path_dup);
2597
2598        /* Generate "XXXXXX_basename.ext" */
2599        strbuf_addstr(&template, "XXXXXX_");
2600        strbuf_addstr(&template, base);
2601
2602        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2603                        strlen(base) + 1);
2604        if (fd < 0)
2605                die_errno("unable to create temp-file");
2606        if (convert_to_working_tree(path,
2607                        (const char *)blob, (size_t)size, &buf)) {
2608                blob = buf.buf;
2609                size = buf.len;
2610        }
2611        if (write_in_full(fd, blob, size) != size)
2612                die_errno("unable to write temp-file");
2613        close(fd);
2614        temp->name = temp->tmp_path;
2615        strcpy(temp->hex, sha1_to_hex(sha1));
2616        temp->hex[40] = 0;
2617        sprintf(temp->mode, "%06o", mode);
2618        strbuf_release(&buf);
2619        strbuf_release(&template);
2620        free(path_dup);
2621}
2622
2623static struct diff_tempfile *prepare_temp_file(const char *name,
2624                struct diff_filespec *one)
2625{
2626        struct diff_tempfile *temp = claim_diff_tempfile();
2627
2628        if (!DIFF_FILE_VALID(one)) {
2629        not_a_valid_file:
2630                /* A '-' entry produces this for file-2, and
2631                 * a '+' entry produces this for file-1.
2632                 */
2633                temp->name = "/dev/null";
2634                strcpy(temp->hex, ".");
2635                strcpy(temp->mode, ".");
2636                return temp;
2637        }
2638
2639        if (!remove_tempfile_installed) {
2640                atexit(remove_tempfile);
2641                sigchain_push_common(remove_tempfile_on_signal);
2642                remove_tempfile_installed = 1;
2643        }
2644
2645        if (!one->sha1_valid ||
2646            reuse_worktree_file(name, one->sha1, 1)) {
2647                struct stat st;
2648                if (lstat(name, &st) < 0) {
2649                        if (errno == ENOENT)
2650                                goto not_a_valid_file;
2651                        die_errno("stat(%s)", name);
2652                }
2653                if (S_ISLNK(st.st_mode)) {
2654                        struct strbuf sb = STRBUF_INIT;
2655                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2656                                die_errno("readlink(%s)", name);
2657                        prep_temp_blob(name, temp, sb.buf, sb.len,
2658                                       (one->sha1_valid ?
2659                                        one->sha1 : null_sha1),
2660                                       (one->sha1_valid ?
2661                                        one->mode : S_IFLNK));
2662                        strbuf_release(&sb);
2663                }
2664                else {
2665                        /* we can borrow from the file in the work tree */
2666                        temp->name = name;
2667                        if (!one->sha1_valid)
2668                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2669                        else
2670                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2671                        /* Even though we may sometimes borrow the
2672                         * contents from the work tree, we always want
2673                         * one->mode.  mode is trustworthy even when
2674                         * !(one->sha1_valid), as long as
2675                         * DIFF_FILE_VALID(one).
2676                         */
2677                        sprintf(temp->mode, "%06o", one->mode);
2678                }
2679                return temp;
2680        }
2681        else {
2682                if (diff_populate_filespec(one, 0))
2683                        die("cannot read data blob for %s", one->path);
2684                prep_temp_blob(name, temp, one->data, one->size,
2685                               one->sha1, one->mode);
2686        }
2687        return temp;
2688}
2689
2690/* An external diff command takes:
2691 *
2692 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2693 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2694 *
2695 */
2696static void run_external_diff(const char *pgm,
2697                              const char *name,
2698                              const char *other,
2699                              struct diff_filespec *one,
2700                              struct diff_filespec *two,
2701                              const char *xfrm_msg,
2702                              int complete_rewrite)
2703{
2704        const char *spawn_arg[10];
2705        int retval;
2706        const char **arg = &spawn_arg[0];
2707
2708        if (one && two) {
2709                struct diff_tempfile *temp_one, *temp_two;
2710                const char *othername = (other ? other : name);
2711                temp_one = prepare_temp_file(name, one);
2712                temp_two = prepare_temp_file(othername, two);
2713                *arg++ = pgm;
2714                *arg++ = name;
2715                *arg++ = temp_one->name;
2716                *arg++ = temp_one->hex;
2717                *arg++ = temp_one->mode;
2718                *arg++ = temp_two->name;
2719                *arg++ = temp_two->hex;
2720                *arg++ = temp_two->mode;
2721                if (other) {
2722                        *arg++ = other;
2723                        *arg++ = xfrm_msg;
2724                }
2725        } else {
2726                *arg++ = pgm;
2727                *arg++ = name;
2728        }
2729        *arg = NULL;
2730        fflush(NULL);
2731        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2732        remove_tempfile();
2733        if (retval) {
2734                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2735                exit(1);
2736        }
2737}
2738
2739static int similarity_index(struct diff_filepair *p)
2740{
2741        return p->score * 100 / MAX_SCORE;
2742}
2743
2744static void fill_metainfo(struct strbuf *msg,
2745                          const char *name,
2746                          const char *other,
2747                          struct diff_filespec *one,
2748                          struct diff_filespec *two,
2749                          struct diff_options *o,
2750                          struct diff_filepair *p,
2751                          int *must_show_header,
2752                          int use_color)
2753{
2754        const char *set = diff_get_color(use_color, DIFF_METAINFO);
2755        const char *reset = diff_get_color(use_color, DIFF_RESET);
2756        struct strbuf *msgbuf;
2757        char *line_prefix = "";
2758
2759        *must_show_header = 1;
2760        if (o->output_prefix) {
2761                msgbuf = o->output_prefix(o, o->output_prefix_data);
2762                line_prefix = msgbuf->buf;
2763        }
2764        strbuf_init(msg, PATH_MAX * 2 + 300);
2765        switch (p->status) {
2766        case DIFF_STATUS_COPIED:
2767                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2768                            line_prefix, set, similarity_index(p));
2769                strbuf_addf(msg, "%s\n%s%scopy from ",
2770                            reset,  line_prefix, set);
2771                quote_c_style(name, msg, NULL, 0);
2772                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2773                quote_c_style(other, msg, NULL, 0);
2774                strbuf_addf(msg, "%s\n", reset);
2775                break;
2776        case DIFF_STATUS_RENAMED:
2777                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2778                            line_prefix, set, similarity_index(p));
2779                strbuf_addf(msg, "%s\n%s%srename from ",
2780                            reset, line_prefix, set);
2781                quote_c_style(name, msg, NULL, 0);
2782                strbuf_addf(msg, "%s\n%s%srename to ",
2783                            reset, line_prefix, set);
2784                quote_c_style(other, msg, NULL, 0);
2785                strbuf_addf(msg, "%s\n", reset);
2786                break;
2787        case DIFF_STATUS_MODIFIED:
2788                if (p->score) {
2789                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2790                                    line_prefix,
2791                                    set, similarity_index(p), reset);
2792                        break;
2793                }
2794                /* fallthru */
2795        default:
2796                *must_show_header = 0;
2797        }
2798        if (one && two && hashcmp(one->sha1, two->sha1)) {
2799                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2800
2801                if (DIFF_OPT_TST(o, BINARY)) {
2802                        mmfile_t mf;
2803                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2804                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2805                                abbrev = 40;
2806                }
2807                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2808                            find_unique_abbrev(one->sha1, abbrev));
2809                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2810                if (one->mode == two->mode)
2811                        strbuf_addf(msg, " %06o", one->mode);
2812                strbuf_addf(msg, "%s\n", reset);
2813        }
2814}
2815
2816static void run_diff_cmd(const char *pgm,
2817                         const char *name,
2818                         const char *other,
2819                         const char *attr_path,
2820                         struct diff_filespec *one,
2821                         struct diff_filespec *two,
2822                         struct strbuf *msg,
2823                         struct diff_options *o,
2824                         struct diff_filepair *p)
2825{
2826        const char *xfrm_msg = NULL;
2827        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2828        int must_show_header = 0;
2829
2830        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2831                pgm = NULL;
2832        else {
2833                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2834                if (drv && drv->external)
2835                        pgm = drv->external;
2836        }
2837
2838        if (msg) {
2839                /*
2840                 * don't use colors when the header is intended for an
2841                 * external diff driver
2842                 */
2843                fill_metainfo(msg, name, other, one, two, o, p,
2844                              &must_show_header,
2845                              DIFF_OPT_TST(o, COLOR_DIFF) && !pgm);
2846                xfrm_msg = msg->len ? msg->buf : NULL;
2847        }
2848
2849        if (pgm) {
2850                run_external_diff(pgm, name, other, one, two, xfrm_msg,
2851                                  complete_rewrite);
2852                return;
2853        }
2854        if (one && two)
2855                builtin_diff(name, other ? other : name,
2856                             one, two, xfrm_msg, must_show_header,
2857                             o, complete_rewrite);
2858        else
2859                fprintf(o->file, "* Unmerged path %s\n", name);
2860}
2861
2862static void diff_fill_sha1_info(struct diff_filespec *one)
2863{
2864        if (DIFF_FILE_VALID(one)) {
2865                if (!one->sha1_valid) {
2866                        struct stat st;
2867                        if (!strcmp(one->path, "-")) {
2868                                hashcpy(one->sha1, null_sha1);
2869                                return;
2870                        }
2871                        if (lstat(one->path, &st) < 0)
2872                                die_errno("stat '%s'", one->path);
2873                        if (index_path(one->sha1, one->path, &st, 0))
2874                                die("cannot hash %s", one->path);
2875                }
2876        }
2877        else
2878                hashclr(one->sha1);
2879}
2880
2881static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2882{
2883        /* Strip the prefix but do not molest /dev/null and absolute paths */
2884        if (*namep && **namep != '/') {
2885                *namep += prefix_length;
2886                if (**namep == '/')
2887                        ++*namep;
2888        }
2889        if (*otherp && **otherp != '/') {
2890                *otherp += prefix_length;
2891                if (**otherp == '/')
2892                        ++*otherp;
2893        }
2894}
2895
2896static void run_diff(struct diff_filepair *p, struct diff_options *o)
2897{
2898        const char *pgm = external_diff();
2899        struct strbuf msg;
2900        struct diff_filespec *one = p->one;
2901        struct diff_filespec *two = p->two;
2902        const char *name;
2903        const char *other;
2904        const char *attr_path;
2905
2906        name  = p->one->path;
2907        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2908        attr_path = name;
2909        if (o->prefix_length)
2910                strip_prefix(o->prefix_length, &name, &other);
2911
2912        if (DIFF_PAIR_UNMERGED(p)) {
2913                run_diff_cmd(pgm, name, NULL, attr_path,
2914                             NULL, NULL, NULL, o, p);
2915                return;
2916        }
2917
2918        diff_fill_sha1_info(one);
2919        diff_fill_sha1_info(two);
2920
2921        if (!pgm &&
2922            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2923            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2924                /*
2925                 * a filepair that changes between file and symlink
2926                 * needs to be split into deletion and creation.
2927                 */
2928                struct diff_filespec *null = alloc_filespec(two->path);
2929                run_diff_cmd(NULL, name, other, attr_path,
2930                             one, null, &msg, o, p);
2931                free(null);
2932                strbuf_release(&msg);
2933
2934                null = alloc_filespec(one->path);
2935                run_diff_cmd(NULL, name, other, attr_path,
2936                             null, two, &msg, o, p);
2937                free(null);
2938        }
2939        else
2940                run_diff_cmd(pgm, name, other, attr_path,
2941                             one, two, &msg, o, p);
2942
2943        strbuf_release(&msg);
2944}
2945
2946static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2947                         struct diffstat_t *diffstat)
2948{
2949        const char *name;
2950        const char *other;
2951        int complete_rewrite = 0;
2952
2953        if (DIFF_PAIR_UNMERGED(p)) {
2954                /* unmerged */
2955                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2956                return;
2957        }
2958
2959        name = p->one->path;
2960        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2961
2962        if (o->prefix_length)
2963                strip_prefix(o->prefix_length, &name, &other);
2964
2965        diff_fill_sha1_info(p->one);
2966        diff_fill_sha1_info(p->two);
2967
2968        if (p->status == DIFF_STATUS_MODIFIED && p->score)
2969                complete_rewrite = 1;
2970        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2971}
2972
2973static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2974{
2975        const char *name;
2976        const char *other;
2977        const char *attr_path;
2978
2979        if (DIFF_PAIR_UNMERGED(p)) {
2980                /* unmerged */
2981                return;
2982        }
2983
2984        name = p->one->path;
2985        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2986        attr_path = other ? other : name;
2987
2988        if (o->prefix_length)
2989                strip_prefix(o->prefix_length, &name, &other);
2990
2991        diff_fill_sha1_info(p->one);
2992        diff_fill_sha1_info(p->two);
2993
2994        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2995}
2996
2997void diff_setup(struct diff_options *options)
2998{
2999        memcpy(options, &default_diff_options, sizeof(*options));
3000
3001        options->file = stdout;
3002
3003        options->line_termination = '\n';
3004        options->break_opt = -1;
3005        options->rename_limit = -1;
3006        options->dirstat_permille = diff_dirstat_permille_default;
3007        options->context = 3;
3008
3009        options->change = diff_change;
3010        options->add_remove = diff_addremove;
3011        if (diff_use_color_default > 0)
3012                DIFF_OPT_SET(options, COLOR_DIFF);
3013        options->detect_rename = diff_detect_rename_default;
3014
3015        if (diff_no_prefix) {
3016                options->a_prefix = options->b_prefix = "";
3017        } else if (!diff_mnemonic_prefix) {
3018                options->a_prefix = "a/";
3019                options->b_prefix = "b/";
3020        }
3021}
3022
3023int diff_setup_done(struct diff_options *options)
3024{
3025        int count = 0;
3026
3027        if (options->output_format & DIFF_FORMAT_NAME)
3028                count++;
3029        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
3030                count++;
3031        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
3032                count++;
3033        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
3034                count++;
3035        if (count > 1)
3036                die("--name-only, --name-status, --check and -s are mutually exclusive");
3037
3038        /*
3039         * Most of the time we can say "there are changes"
3040         * only by checking if there are changed paths, but
3041         * --ignore-whitespace* options force us to look
3042         * inside contents.
3043         */
3044
3045        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
3046            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
3047            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
3048                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
3049        else
3050                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
3051
3052        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3053                options->detect_rename = DIFF_DETECT_COPY;
3054
3055        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
3056                options->prefix = NULL;
3057        if (options->prefix)
3058                options->prefix_length = strlen(options->prefix);
3059        else
3060                options->prefix_length = 0;
3061
3062        if (options->output_format & (DIFF_FORMAT_NAME |
3063                                      DIFF_FORMAT_NAME_STATUS |
3064                                      DIFF_FORMAT_CHECKDIFF |
3065                                      DIFF_FORMAT_NO_OUTPUT))
3066                options->output_format &= ~(DIFF_FORMAT_RAW |
3067                                            DIFF_FORMAT_NUMSTAT |
3068                                            DIFF_FORMAT_DIFFSTAT |
3069                                            DIFF_FORMAT_SHORTSTAT |
3070                                            DIFF_FORMAT_DIRSTAT |
3071                                            DIFF_FORMAT_SUMMARY |
3072                                            DIFF_FORMAT_PATCH);
3073
3074        /*
3075         * These cases always need recursive; we do not drop caller-supplied
3076         * recursive bits for other formats here.
3077         */
3078        if (options->output_format & (DIFF_FORMAT_PATCH |
3079                                      DIFF_FORMAT_NUMSTAT |
3080                                      DIFF_FORMAT_DIFFSTAT |
3081                                      DIFF_FORMAT_SHORTSTAT |
3082                                      DIFF_FORMAT_DIRSTAT |
3083                                      DIFF_FORMAT_SUMMARY |
3084                                      DIFF_FORMAT_CHECKDIFF))
3085                DIFF_OPT_SET(options, RECURSIVE);
3086        /*
3087         * Also pickaxe would not work very well if you do not say recursive
3088         */
3089        if (options->pickaxe)
3090                DIFF_OPT_SET(options, RECURSIVE);
3091        /*
3092         * When patches are generated, submodules diffed against the work tree
3093         * must be checked for dirtiness too so it can be shown in the output
3094         */
3095        if (options->output_format & DIFF_FORMAT_PATCH)
3096                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3097
3098        if (options->detect_rename && options->rename_limit < 0)
3099                options->rename_limit = diff_rename_limit_default;
3100        if (options->setup & DIFF_SETUP_USE_CACHE) {
3101                if (!active_cache)
3102                        /* read-cache does not die even when it fails
3103                         * so it is safe for us to do this here.  Also
3104                         * it does not smudge active_cache or active_nr
3105                         * when it fails, so we do not have to worry about
3106                         * cleaning it up ourselves either.
3107                         */
3108                        read_cache();
3109        }
3110        if (options->abbrev <= 0 || 40 < options->abbrev)
3111                options->abbrev = 40; /* full */
3112
3113        /*
3114         * It does not make sense to show the first hit we happened
3115         * to have found.  It does not make sense not to return with
3116         * exit code in such a case either.
3117         */
3118        if (DIFF_OPT_TST(options, QUICK)) {
3119                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3120                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3121        }
3122
3123        return 0;
3124}
3125
3126static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3127{
3128        char c, *eq;
3129        int len;
3130
3131        if (*arg != '-')
3132                return 0;
3133        c = *++arg;
3134        if (!c)
3135                return 0;
3136        if (c == arg_short) {
3137                c = *++arg;
3138                if (!c)
3139                        return 1;
3140                if (val && isdigit(c)) {
3141                        char *end;
3142                        int n = strtoul(arg, &end, 10);
3143                        if (*end)
3144                                return 0;
3145                        *val = n;
3146                        return 1;
3147                }
3148                return 0;
3149        }
3150        if (c != '-')
3151                return 0;
3152        arg++;
3153        eq = strchr(arg, '=');
3154        if (eq)
3155                len = eq - arg;
3156        else
3157                len = strlen(arg);
3158        if (!len || strncmp(arg, arg_long, len))
3159                return 0;
3160        if (eq) {
3161                int n;
3162                char *end;
3163                if (!isdigit(*++eq))
3164                        return 0;
3165                n = strtoul(eq, &end, 10);
3166                if (*end)
3167                        return 0;
3168                *val = n;
3169        }
3170        return 1;
3171}
3172
3173static int diff_scoreopt_parse(const char *opt);
3174
3175static inline int short_opt(char opt, const char **argv,
3176                            const char **optarg)
3177{
3178        const char *arg = argv[0];
3179        if (arg[0] != '-' || arg[1] != opt)
3180                return 0;
3181        if (arg[2] != '\0') {
3182                *optarg = arg + 2;
3183                return 1;
3184        }
3185        if (!argv[1])
3186                die("Option '%c' requires a value", opt);
3187        *optarg = argv[1];
3188        return 2;
3189}
3190
3191int parse_long_opt(const char *opt, const char **argv,
3192                   const char **optarg)
3193{
3194        const char *arg = argv[0];
3195        if (arg[0] != '-' || arg[1] != '-')
3196                return 0;
3197        arg += strlen("--");
3198        if (prefixcmp(arg, opt))
3199                return 0;
3200        arg += strlen(opt);
3201        if (*arg == '=') { /* sticked form: --option=value */
3202                *optarg = arg + 1;
3203                return 1;
3204        }
3205        if (*arg != '\0')
3206                return 0;
3207        /* separate form: --option value */
3208        if (!argv[1])
3209                die("Option '--%s' requires a value", opt);
3210        *optarg = argv[1];
3211        return 2;
3212}
3213
3214static int stat_opt(struct diff_options *options, const char **av)
3215{
3216        const char *arg = av[0];
3217        char *end;
3218        int width = options->stat_width;
3219        int name_width = options->stat_name_width;
3220        int argcount = 1;
3221
3222        arg += strlen("--stat");
3223        end = (char *)arg;
3224
3225        switch (*arg) {
3226        case '-':
3227                if (!prefixcmp(arg, "-width")) {
3228                        arg += strlen("-width");
3229                        if (*arg == '=')
3230                                width = strtoul(arg + 1, &end, 10);
3231                        else if (!*arg && !av[1])
3232                                die("Option '--stat-width' requires a value");
3233                        else if (!*arg) {
3234                                width = strtoul(av[1], &end, 10);
3235                                argcount = 2;
3236                        }
3237                } else if (!prefixcmp(arg, "-name-width")) {
3238                        arg += strlen("-name-width");
3239                        if (*arg == '=')
3240                                name_width = strtoul(arg + 1, &end, 10);
3241                        else if (!*arg && !av[1])
3242                                die("Option '--stat-name-width' requires a value");
3243                        else if (!*arg) {
3244                                name_width = strtoul(av[1], &end, 10);
3245                                argcount = 2;
3246                        }
3247                }
3248                break;
3249        case '=':
3250                width = strtoul(arg+1, &end, 10);
3251                if (*end == ',')
3252                        name_width = strtoul(end+1, &end, 10);
3253        }
3254
3255        /* Important! This checks all the error cases! */
3256        if (*end)
3257                return 0;
3258        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3259        options->stat_name_width = name_width;
3260        options->stat_width = width;
3261        return argcount;
3262}
3263
3264static int parse_dirstat_opt(struct diff_options *options, const char *params)
3265{
3266        struct strbuf errmsg = STRBUF_INIT;
3267        if (parse_dirstat_params(options, params, &errmsg))
3268                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
3269                    errmsg.buf);
3270        strbuf_release(&errmsg);
3271        /*
3272         * The caller knows a dirstat-related option is given from the command
3273         * line; allow it to say "return this_function();"
3274         */
3275        options->output_format |= DIFF_FORMAT_DIRSTAT;
3276        return 1;
3277}
3278
3279int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3280{
3281        const char *arg = av[0];
3282        const char *optarg;
3283        int argcount;
3284
3285        /* Output format options */
3286        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3287                options->output_format |= DIFF_FORMAT_PATCH;
3288        else if (opt_arg(arg, 'U', "unified", &options->context))
3289                options->output_format |= DIFF_FORMAT_PATCH;
3290        else if (!strcmp(arg, "--raw"))
3291                options->output_format |= DIFF_FORMAT_RAW;
3292        else if (!strcmp(arg, "--patch-with-raw"))
3293                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3294        else if (!strcmp(arg, "--numstat"))
3295                options->output_format |= DIFF_FORMAT_NUMSTAT;
3296        else if (!strcmp(arg, "--shortstat"))
3297                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3298        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
3299                return parse_dirstat_opt(options, "");
3300        else if (!prefixcmp(arg, "-X"))
3301                return parse_dirstat_opt(options, arg + 2);
3302        else if (!prefixcmp(arg, "--dirstat="))
3303                return parse_dirstat_opt(options, arg + 10);
3304        else if (!strcmp(arg, "--cumulative"))
3305                return parse_dirstat_opt(options, "cumulative");
3306        else if (!strcmp(arg, "--dirstat-by-file"))
3307                return parse_dirstat_opt(options, "files");
3308        else if (!prefixcmp(arg, "--dirstat-by-file=")) {
3309                parse_dirstat_opt(options, "files");
3310                return parse_dirstat_opt(options, arg + 18);
3311        }
3312        else if (!strcmp(arg, "--check"))
3313                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3314        else if (!strcmp(arg, "--summary"))
3315                options->output_format |= DIFF_FORMAT_SUMMARY;
3316        else if (!strcmp(arg, "--patch-with-stat"))
3317                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3318        else if (!strcmp(arg, "--name-only"))
3319                options->output_format |= DIFF_FORMAT_NAME;
3320        else if (!strcmp(arg, "--name-status"))
3321                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3322        else if (!strcmp(arg, "-s"))
3323                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3324        else if (!prefixcmp(arg, "--stat"))
3325                /* --stat, --stat-width, or --stat-name-width */
3326                return stat_opt(options, av);
3327
3328        /* renames options */
3329        else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
3330                 !strcmp(arg, "--break-rewrites")) {
3331                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3332                        return error("invalid argument to -B: %s", arg+2);
3333        }
3334        else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--find-renames=") ||
3335                 !strcmp(arg, "--find-renames")) {
3336                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3337                        return error("invalid argument to -M: %s", arg+2);
3338                options->detect_rename = DIFF_DETECT_RENAME;
3339        }
3340        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3341                options->irreversible_delete = 1;
3342        }
3343        else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
3344                 !strcmp(arg, "--find-copies")) {
3345                if (options->detect_rename == DIFF_DETECT_COPY)
3346                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3347                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3348                        return error("invalid argument to -C: %s", arg+2);
3349                options->detect_rename = DIFF_DETECT_COPY;
3350        }
3351        else if (!strcmp(arg, "--no-renames"))
3352                options->detect_rename = 0;
3353        else if (!strcmp(arg, "--relative"))
3354                DIFF_OPT_SET(options, RELATIVE_NAME);
3355        else if (!prefixcmp(arg, "--relative=")) {
3356                DIFF_OPT_SET(options, RELATIVE_NAME);
3357                options->prefix = arg + 11;
3358        }
3359
3360        /* xdiff options */
3361        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3362                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3363        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3364                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3365        else if (!strcmp(arg, "--ignore-space-at-eol"))
3366                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3367        else if (!strcmp(arg, "--patience"))
3368                DIFF_XDL_SET(options, PATIENCE_DIFF);
3369
3370        /* flags options */
3371        else if (!strcmp(arg, "--binary")) {
3372                options->output_format |= DIFF_FORMAT_PATCH;
3373                DIFF_OPT_SET(options, BINARY);
3374        }
3375        else if (!strcmp(arg, "--full-index"))
3376                DIFF_OPT_SET(options, FULL_INDEX);
3377        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3378                DIFF_OPT_SET(options, TEXT);
3379        else if (!strcmp(arg, "-R"))
3380                DIFF_OPT_SET(options, REVERSE_DIFF);
3381        else if (!strcmp(arg, "--find-copies-harder"))
3382                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3383        else if (!strcmp(arg, "--follow"))
3384                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3385        else if (!strcmp(arg, "--color"))
3386                DIFF_OPT_SET(options, COLOR_DIFF);
3387        else if (!prefixcmp(arg, "--color=")) {
3388                int value = git_config_colorbool(NULL, arg+8, -1);
3389                if (value == 0)
3390                        DIFF_OPT_CLR(options, COLOR_DIFF);
3391                else if (value > 0)
3392                        DIFF_OPT_SET(options, COLOR_DIFF);
3393                else
3394                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3395        }
3396        else if (!strcmp(arg, "--no-color"))
3397                DIFF_OPT_CLR(options, COLOR_DIFF);
3398        else if (!strcmp(arg, "--color-words")) {
3399                DIFF_OPT_SET(options, COLOR_DIFF);
3400                options->word_diff = DIFF_WORDS_COLOR;
3401        }
3402        else if (!prefixcmp(arg, "--color-words=")) {
3403                DIFF_OPT_SET(options, COLOR_DIFF);
3404                options->word_diff = DIFF_WORDS_COLOR;
3405                options->word_regex = arg + 14;
3406        }
3407        else if (!strcmp(arg, "--word-diff")) {
3408                if (options->word_diff == DIFF_WORDS_NONE)
3409                        options->word_diff = DIFF_WORDS_PLAIN;
3410        }
3411        else if (!prefixcmp(arg, "--word-diff=")) {
3412                const char *type = arg + 12;
3413                if (!strcmp(type, "plain"))
3414                        options->word_diff = DIFF_WORDS_PLAIN;
3415                else if (!strcmp(type, "color")) {
3416                        DIFF_OPT_SET(options, COLOR_DIFF);
3417                        options->word_diff = DIFF_WORDS_COLOR;
3418                }
3419                else if (!strcmp(type, "porcelain"))
3420                        options->word_diff = DIFF_WORDS_PORCELAIN;
3421                else if (!strcmp(type, "none"))
3422                        options->word_diff = DIFF_WORDS_NONE;
3423                else
3424                        die("bad --word-diff argument: %s", type);
3425        }
3426        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3427                if (options->word_diff == DIFF_WORDS_NONE)
3428                        options->word_diff = DIFF_WORDS_PLAIN;
3429                options->word_regex = optarg;
3430                return argcount;
3431        }
3432        else if (!strcmp(arg, "--exit-code"))
3433                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3434        else if (!strcmp(arg, "--quiet"))
3435                DIFF_OPT_SET(options, QUICK);
3436        else if (!strcmp(arg, "--ext-diff"))
3437                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3438        else if (!strcmp(arg, "--no-ext-diff"))
3439                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3440        else if (!strcmp(arg, "--textconv"))
3441                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3442        else if (!strcmp(arg, "--no-textconv"))
3443                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3444        else if (!strcmp(arg, "--ignore-submodules")) {
3445                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3446                handle_ignore_submodules_arg(options, "all");
3447        } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3448                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3449                handle_ignore_submodules_arg(options, arg + 20);
3450        } else if (!strcmp(arg, "--submodule"))
3451                DIFF_OPT_SET(options, SUBMODULE_LOG);
3452        else if (!prefixcmp(arg, "--submodule=")) {
3453                if (!strcmp(arg + 12, "log"))
3454                        DIFF_OPT_SET(options, SUBMODULE_LOG);
3455        }
3456
3457        /* misc options */
3458        else if (!strcmp(arg, "-z"))
3459                options->line_termination = 0;
3460        else if ((argcount = short_opt('l', av, &optarg))) {
3461                options->rename_limit = strtoul(optarg, NULL, 10);
3462                return argcount;
3463        }
3464        else if ((argcount = short_opt('S', av, &optarg))) {
3465                options->pickaxe = optarg;
3466                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3467                return argcount;
3468        } else if ((argcount = short_opt('G', av, &optarg))) {
3469                options->pickaxe = optarg;
3470                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3471                return argcount;
3472        }
3473        else if (!strcmp(arg, "--pickaxe-all"))
3474                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3475        else if (!strcmp(arg, "--pickaxe-regex"))
3476                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3477        else if ((argcount = short_opt('O', av, &optarg))) {
3478                options->orderfile = optarg;
3479                return argcount;
3480        }
3481        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3482                options->filter = optarg;
3483                return argcount;
3484        }
3485        else if (!strcmp(arg, "--abbrev"))
3486                options->abbrev = DEFAULT_ABBREV;
3487        else if (!prefixcmp(arg, "--abbrev=")) {
3488                options->abbrev = strtoul(arg + 9, NULL, 10);
3489                if (options->abbrev < MINIMUM_ABBREV)
3490                        options->abbrev = MINIMUM_ABBREV;
3491                else if (40 < options->abbrev)
3492                        options->abbrev = 40;
3493        }
3494        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3495                options->a_prefix = optarg;
3496                return argcount;
3497        }
3498        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3499                options->b_prefix = optarg;
3500                return argcount;
3501        }
3502        else if (!strcmp(arg, "--no-prefix"))
3503                options->a_prefix = options->b_prefix = "";
3504        else if (opt_arg(arg, '\0', "inter-hunk-context",
3505                         &options->interhunkcontext))
3506                ;
3507        else if ((argcount = parse_long_opt("output", av, &optarg))) {
3508                options->file = fopen(optarg, "w");
3509                if (!options->file)
3510                        die_errno("Could not open '%s'", optarg);
3511                options->close_file = 1;
3512                return argcount;
3513        } else
3514                return 0;
3515        return 1;
3516}
3517
3518int parse_rename_score(const char **cp_p)
3519{
3520        unsigned long num, scale;
3521        int ch, dot;
3522        const char *cp = *cp_p;
3523
3524        num = 0;
3525        scale = 1;
3526        dot = 0;
3527        for (;;) {
3528                ch = *cp;
3529                if ( !dot && ch == '.' ) {
3530                        scale = 1;
3531                        dot = 1;
3532                } else if ( ch == '%' ) {
3533                        scale = dot ? scale*100 : 100;
3534                        cp++;   /* % is always at the end */
3535                        break;
3536                } else if ( ch >= '0' && ch <= '9' ) {
3537                        if ( scale < 100000 ) {
3538                                scale *= 10;
3539                                num = (num*10) + (ch-'0');
3540                        }
3541                } else {
3542                        break;
3543                }
3544                cp++;
3545        }
3546        *cp_p = cp;
3547
3548        /* user says num divided by scale and we say internally that
3549         * is MAX_SCORE * num / scale.
3550         */
3551        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3552}
3553
3554static int diff_scoreopt_parse(const char *opt)
3555{
3556        int opt1, opt2, cmd;
3557
3558        if (*opt++ != '-')
3559                return -1;
3560        cmd = *opt++;
3561        if (cmd == '-') {
3562                /* convert the long-form arguments into short-form versions */
3563                if (!prefixcmp(opt, "break-rewrites")) {
3564                        opt += strlen("break-rewrites");
3565                        if (*opt == 0 || *opt++ == '=')
3566                                cmd = 'B';
3567                } else if (!prefixcmp(opt, "find-copies")) {
3568                        opt += strlen("find-copies");
3569                        if (*opt == 0 || *opt++ == '=')
3570                                cmd = 'C';
3571                } else if (!prefixcmp(opt, "find-renames")) {
3572                        opt += strlen("find-renames");
3573                        if (*opt == 0 || *opt++ == '=')
3574                                cmd = 'M';
3575                }
3576        }
3577        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3578                return -1; /* that is not a -M, -C nor -B option */
3579
3580        opt1 = parse_rename_score(&opt);
3581        if (cmd != 'B')
3582                opt2 = 0;
3583        else {
3584                if (*opt == 0)
3585                        opt2 = 0;
3586                else if (*opt != '/')
3587                        return -1; /* we expect -B80/99 or -B80 */
3588                else {
3589                        opt++;
3590                        opt2 = parse_rename_score(&opt);
3591                }
3592        }
3593        if (*opt != 0)
3594                return -1;
3595        return opt1 | (opt2 << 16);
3596}
3597
3598struct diff_queue_struct diff_queued_diff;
3599
3600void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3601{
3602        if (queue->alloc <= queue->nr) {
3603                queue->alloc = alloc_nr(queue->alloc);
3604                queue->queue = xrealloc(queue->queue,
3605                                        sizeof(dp) * queue->alloc);
3606        }
3607        queue->queue[queue->nr++] = dp;
3608}
3609
3610struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3611                                 struct diff_filespec *one,
3612                                 struct diff_filespec *two)
3613{
3614        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3615        dp->one = one;
3616        dp->two = two;
3617        if (queue)
3618                diff_q(queue, dp);
3619        return dp;
3620}
3621
3622void diff_free_filepair(struct diff_filepair *p)
3623{
3624        free_filespec(p->one);
3625        free_filespec(p->two);
3626        free(p);
3627}
3628
3629/* This is different from find_unique_abbrev() in that
3630 * it stuffs the result with dots for alignment.
3631 */
3632const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3633{
3634        int abblen;
3635        const char *abbrev;
3636        if (len == 40)
3637                return sha1_to_hex(sha1);
3638
3639        abbrev = find_unique_abbrev(sha1, len);
3640        abblen = strlen(abbrev);
3641        if (abblen < 37) {
3642                static char hex[41];
3643                if (len < abblen && abblen <= len + 2)
3644                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3645                else
3646                        sprintf(hex, "%s...", abbrev);
3647                return hex;
3648        }
3649        return sha1_to_hex(sha1);
3650}
3651
3652static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3653{
3654        int line_termination = opt->line_termination;
3655        int inter_name_termination = line_termination ? '\t' : '\0';
3656        if (opt->output_prefix) {
3657                struct strbuf *msg = NULL;
3658                msg = opt->output_prefix(opt, opt->output_prefix_data);
3659                fprintf(opt->file, "%s", msg->buf);
3660        }
3661
3662        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3663                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3664                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3665                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3666        }
3667        if (p->score) {
3668                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3669                        inter_name_termination);
3670        } else {
3671                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3672        }
3673
3674        if (p->status == DIFF_STATUS_COPIED ||
3675            p->status == DIFF_STATUS_RENAMED) {
3676                const char *name_a, *name_b;
3677                name_a = p->one->path;
3678                name_b = p->two->path;
3679                strip_prefix(opt->prefix_length, &name_a, &name_b);
3680                write_name_quoted(name_a, opt->file, inter_name_termination);
3681                write_name_quoted(name_b, opt->file, line_termination);
3682        } else {
3683                const char *name_a, *name_b;
3684                name_a = p->one->mode ? p->one->path : p->two->path;
3685                name_b = NULL;
3686                strip_prefix(opt->prefix_length, &name_a, &name_b);
3687                write_name_quoted(name_a, opt->file, line_termination);
3688        }
3689}
3690
3691int diff_unmodified_pair(struct diff_filepair *p)
3692{
3693        /* This function is written stricter than necessary to support
3694         * the currently implemented transformers, but the idea is to
3695         * let transformers to produce diff_filepairs any way they want,
3696         * and filter and clean them up here before producing the output.
3697         */
3698        struct diff_filespec *one = p->one, *two = p->two;
3699
3700        if (DIFF_PAIR_UNMERGED(p))
3701                return 0; /* unmerged is interesting */
3702
3703        /* deletion, addition, mode or type change
3704         * and rename are all interesting.
3705         */
3706        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3707            DIFF_PAIR_MODE_CHANGED(p) ||
3708            strcmp(one->path, two->path))
3709                return 0;
3710
3711        /* both are valid and point at the same path.  that is, we are
3712         * dealing with a change.
3713         */
3714        if (one->sha1_valid && two->sha1_valid &&
3715            !hashcmp(one->sha1, two->sha1) &&
3716            !one->dirty_submodule && !two->dirty_submodule)
3717                return 1; /* no change */
3718        if (!one->sha1_valid && !two->sha1_valid)
3719                return 1; /* both look at the same file on the filesystem. */
3720        return 0;
3721}
3722
3723static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3724{
3725        if (diff_unmodified_pair(p))
3726                return;
3727
3728        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3729            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3730                return; /* no tree diffs in patch format */
3731
3732        run_diff(p, o);
3733}
3734
3735static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3736                            struct diffstat_t *diffstat)
3737{
3738        if (diff_unmodified_pair(p))
3739                return;
3740
3741        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3742            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3743                return; /* no useful stat for tree diffs */
3744
3745        run_diffstat(p, o, diffstat);
3746}
3747
3748static void diff_flush_checkdiff(struct diff_filepair *p,
3749                struct diff_options *o)
3750{
3751        if (diff_unmodified_pair(p))
3752                return;
3753
3754        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3755            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3756                return; /* nothing to check in tree diffs */
3757
3758        run_checkdiff(p, o);
3759}
3760
3761int diff_queue_is_empty(void)
3762{
3763        struct diff_queue_struct *q = &diff_queued_diff;
3764        int i;
3765        for (i = 0; i < q->nr; i++)
3766                if (!diff_unmodified_pair(q->queue[i]))
3767                        return 0;
3768        return 1;
3769}
3770
3771#if DIFF_DEBUG
3772void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3773{
3774        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3775                x, one ? one : "",
3776                s->path,
3777                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3778                s->mode,
3779                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3780        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3781                x, one ? one : "",
3782                s->size, s->xfrm_flags);
3783}
3784
3785void diff_debug_filepair(const struct diff_filepair *p, int i)
3786{
3787        diff_debug_filespec(p->one, i, "one");
3788        diff_debug_filespec(p->two, i, "two");
3789        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3790                p->score, p->status ? p->status : '?',
3791                p->one->rename_used, p->broken_pair);
3792}
3793
3794void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3795{
3796        int i;
3797        if (msg)
3798                fprintf(stderr, "%s\n", msg);
3799        fprintf(stderr, "q->nr = %d\n", q->nr);
3800        for (i = 0; i < q->nr; i++) {
3801                struct diff_filepair *p = q->queue[i];
3802                diff_debug_filepair(p, i);
3803        }
3804}
3805#endif
3806
3807static void diff_resolve_rename_copy(void)
3808{
3809        int i;
3810        struct diff_filepair *p;
3811        struct diff_queue_struct *q = &diff_queued_diff;
3812
3813        diff_debug_queue("resolve-rename-copy", q);
3814
3815        for (i = 0; i < q->nr; i++) {
3816                p = q->queue[i];
3817                p->status = 0; /* undecided */
3818                if (DIFF_PAIR_UNMERGED(p))
3819                        p->status = DIFF_STATUS_UNMERGED;
3820                else if (!DIFF_FILE_VALID(p->one))
3821                        p->status = DIFF_STATUS_ADDED;
3822                else if (!DIFF_FILE_VALID(p->two))
3823                        p->status = DIFF_STATUS_DELETED;
3824                else if (DIFF_PAIR_TYPE_CHANGED(p))
3825                        p->status = DIFF_STATUS_TYPE_CHANGED;
3826
3827                /* from this point on, we are dealing with a pair
3828                 * whose both sides are valid and of the same type, i.e.
3829                 * either in-place edit or rename/copy edit.
3830                 */
3831                else if (DIFF_PAIR_RENAME(p)) {
3832                        /*
3833                         * A rename might have re-connected a broken
3834                         * pair up, causing the pathnames to be the
3835                         * same again. If so, that's not a rename at
3836                         * all, just a modification..
3837                         *
3838                         * Otherwise, see if this source was used for
3839                         * multiple renames, in which case we decrement
3840                         * the count, and call it a copy.
3841                         */
3842                        if (!strcmp(p->one->path, p->two->path))
3843                                p->status = DIFF_STATUS_MODIFIED;
3844                        else if (--p->one->rename_used > 0)
3845                                p->status = DIFF_STATUS_COPIED;
3846                        else
3847                                p->status = DIFF_STATUS_RENAMED;
3848                }
3849                else if (hashcmp(p->one->sha1, p->two->sha1) ||
3850                         p->one->mode != p->two->mode ||
3851                         p->one->dirty_submodule ||
3852                         p->two->dirty_submodule ||
3853                         is_null_sha1(p->one->sha1))
3854                        p->status = DIFF_STATUS_MODIFIED;
3855                else {
3856                        /* This is a "no-change" entry and should not
3857                         * happen anymore, but prepare for broken callers.
3858                         */
3859                        error("feeding unmodified %s to diffcore",
3860                              p->one->path);
3861                        p->status = DIFF_STATUS_UNKNOWN;
3862                }
3863        }
3864        diff_debug_queue("resolve-rename-copy done", q);
3865}
3866
3867static int check_pair_status(struct diff_filepair *p)
3868{
3869        switch (p->status) {
3870        case DIFF_STATUS_UNKNOWN:
3871                return 0;
3872        case 0:
3873                die("internal error in diff-resolve-rename-copy");
3874        default:
3875                return 1;
3876        }
3877}
3878
3879static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3880{
3881        int fmt = opt->output_format;
3882
3883        if (fmt & DIFF_FORMAT_CHECKDIFF)
3884                diff_flush_checkdiff(p, opt);
3885        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3886                diff_flush_raw(p, opt);
3887        else if (fmt & DIFF_FORMAT_NAME) {
3888                const char *name_a, *name_b;
3889                name_a = p->two->path;
3890                name_b = NULL;
3891                strip_prefix(opt->prefix_length, &name_a, &name_b);
3892                write_name_quoted(name_a, opt->file, opt->line_termination);
3893        }
3894}
3895
3896static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
3897{
3898        if (fs->mode)
3899                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
3900        else
3901                fprintf(file, " %s ", newdelete);
3902        write_name_quoted(fs->path, file, '\n');
3903}
3904
3905
3906static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
3907                const char *line_prefix)
3908{
3909        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
3910                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
3911                        p->two->mode, show_name ? ' ' : '\n');
3912                if (show_name) {
3913                        write_name_quoted(p->two->path, file, '\n');
3914                }
3915        }
3916}
3917
3918static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
3919                        const char *line_prefix)
3920{
3921        char *names = pprint_rename(p->one->path, p->two->path);
3922
3923        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
3924        free(names);
3925        show_mode_change(file, p, 0, line_prefix);
3926}
3927
3928static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
3929{
3930        FILE *file = opt->file;
3931        char *line_prefix = "";
3932
3933        if (opt->output_prefix) {
3934                struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
3935                line_prefix = buf->buf;
3936        }
3937
3938        switch(p->status) {
3939        case DIFF_STATUS_DELETED:
3940                fputs(line_prefix, file);
3941                show_file_mode_name(file, "delete", p->one);
3942                break;
3943        case DIFF_STATUS_ADDED:
3944                fputs(line_prefix, file);
3945                show_file_mode_name(file, "create", p->two);
3946                break;
3947        case DIFF_STATUS_COPIED:
3948                fputs(line_prefix, file);
3949                show_rename_copy(file, "copy", p, line_prefix);
3950                break;
3951        case DIFF_STATUS_RENAMED:
3952                fputs(line_prefix, file);
3953                show_rename_copy(file, "rename", p, line_prefix);
3954                break;
3955        default:
3956                if (p->score) {
3957                        fprintf(file, "%s rewrite ", line_prefix);
3958                        write_name_quoted(p->two->path, file, ' ');
3959                        fprintf(file, "(%d%%)\n", similarity_index(p));
3960                }
3961                show_mode_change(file, p, !p->score, line_prefix);
3962                break;
3963        }
3964}
3965
3966struct patch_id_t {
3967        git_SHA_CTX *ctx;
3968        int patchlen;
3969};
3970
3971static int remove_space(char *line, int len)
3972{
3973        int i;
3974        char *dst = line;
3975        unsigned char c;
3976
3977        for (i = 0; i < len; i++)
3978                if (!isspace((c = line[i])))
3979                        *dst++ = c;
3980
3981        return dst - line;
3982}
3983
3984static void patch_id_consume(void *priv, char *line, unsigned long len)
3985{
3986        struct patch_id_t *data = priv;
3987        int new_len;
3988
3989        /* Ignore line numbers when computing the SHA1 of the patch */
3990        if (!prefixcmp(line, "@@ -"))
3991                return;
3992
3993        new_len = remove_space(line, len);
3994
3995        git_SHA1_Update(data->ctx, line, new_len);
3996        data->patchlen += new_len;
3997}
3998
3999/* returns 0 upon success, and writes result into sha1 */
4000static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
4001{
4002        struct diff_queue_struct *q = &diff_queued_diff;
4003        int i;
4004        git_SHA_CTX ctx;
4005        struct patch_id_t data;
4006        char buffer[PATH_MAX * 4 + 20];
4007
4008        git_SHA1_Init(&ctx);
4009        memset(&data, 0, sizeof(struct patch_id_t));
4010        data.ctx = &ctx;
4011
4012        for (i = 0; i < q->nr; i++) {
4013                xpparam_t xpp;
4014                xdemitconf_t xecfg;
4015                mmfile_t mf1, mf2;
4016                struct diff_filepair *p = q->queue[i];
4017                int len1, len2;
4018
4019                memset(&xpp, 0, sizeof(xpp));
4020                memset(&xecfg, 0, sizeof(xecfg));
4021                if (p->status == 0)
4022                        return error("internal diff status error");
4023                if (p->status == DIFF_STATUS_UNKNOWN)
4024                        continue;
4025                if (diff_unmodified_pair(p))
4026                        continue;
4027                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4028                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4029                        continue;
4030                if (DIFF_PAIR_UNMERGED(p))
4031                        continue;
4032
4033                diff_fill_sha1_info(p->one);
4034                diff_fill_sha1_info(p->two);
4035                if (fill_mmfile(&mf1, p->one) < 0 ||
4036                                fill_mmfile(&mf2, p->two) < 0)
4037                        return error("unable to read files to diff");
4038
4039                len1 = remove_space(p->one->path, strlen(p->one->path));
4040                len2 = remove_space(p->two->path, strlen(p->two->path));
4041                if (p->one->mode == 0)
4042                        len1 = snprintf(buffer, sizeof(buffer),
4043                                        "diff--gita/%.*sb/%.*s"
4044                                        "newfilemode%06o"
4045                                        "---/dev/null"
4046                                        "+++b/%.*s",
4047                                        len1, p->one->path,
4048                                        len2, p->two->path,
4049                                        p->two->mode,
4050                                        len2, p->two->path);
4051                else if (p->two->mode == 0)
4052                        len1 = snprintf(buffer, sizeof(buffer),
4053                                        "diff--gita/%.*sb/%.*s"
4054                                        "deletedfilemode%06o"
4055                                        "---a/%.*s"
4056                                        "+++/dev/null",
4057                                        len1, p->one->path,
4058                                        len2, p->two->path,
4059                                        p->one->mode,
4060                                        len1, p->one->path);
4061                else
4062                        len1 = snprintf(buffer, sizeof(buffer),
4063                                        "diff--gita/%.*sb/%.*s"
4064                                        "---a/%.*s"
4065                                        "+++b/%.*s",
4066                                        len1, p->one->path,
4067                                        len2, p->two->path,
4068                                        len1, p->one->path,
4069                                        len2, p->two->path);
4070                git_SHA1_Update(&ctx, buffer, len1);
4071
4072                if (diff_filespec_is_binary(p->one) ||
4073                    diff_filespec_is_binary(p->two)) {
4074                        git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
4075                        git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
4076                        continue;
4077                }
4078
4079                xpp.flags = 0;
4080                xecfg.ctxlen = 3;
4081                xecfg.flags = 0;
4082                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4083                              &xpp, &xecfg);
4084        }
4085
4086        git_SHA1_Final(sha1, &ctx);
4087        return 0;
4088}
4089
4090int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
4091{
4092        struct diff_queue_struct *q = &diff_queued_diff;
4093        int i;
4094        int result = diff_get_patch_id(options, sha1);
4095
4096        for (i = 0; i < q->nr; i++)
4097                diff_free_filepair(q->queue[i]);
4098
4099        free(q->queue);
4100        DIFF_QUEUE_CLEAR(q);
4101
4102        return result;
4103}
4104
4105static int is_summary_empty(const struct diff_queue_struct *q)
4106{
4107        int i;
4108
4109        for (i = 0; i < q->nr; i++) {
4110                const struct diff_filepair *p = q->queue[i];
4111
4112                switch (p->status) {
4113                case DIFF_STATUS_DELETED:
4114                case DIFF_STATUS_ADDED:
4115                case DIFF_STATUS_COPIED:
4116                case DIFF_STATUS_RENAMED:
4117                        return 0;
4118                default:
4119                        if (p->score)
4120                                return 0;
4121                        if (p->one->mode && p->two->mode &&
4122                            p->one->mode != p->two->mode)
4123                                return 0;
4124                        break;
4125                }
4126        }
4127        return 1;
4128}
4129
4130static const char rename_limit_warning[] =
4131"inexact rename detection was skipped due to too many files.";
4132
4133static const char degrade_cc_to_c_warning[] =
4134"only found copies from modified paths due to too many files.";
4135
4136static const char rename_limit_advice[] =
4137"you may want to set your %s variable to at least "
4138"%d and retry the command.";
4139
4140void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4141{
4142        if (degraded_cc)
4143                warning(degrade_cc_to_c_warning);
4144        else if (needed)
4145                warning(rename_limit_warning);
4146        else
4147                return;
4148        if (0 < needed && needed < 32767)
4149                warning(rename_limit_advice, varname, needed);
4150}
4151
4152void diff_flush(struct diff_options *options)
4153{
4154        struct diff_queue_struct *q = &diff_queued_diff;
4155        int i, output_format = options->output_format;
4156        int separator = 0;
4157        int dirstat_by_line = 0;
4158
4159        /*
4160         * Order: raw, stat, summary, patch
4161         * or:    name/name-status/checkdiff (other bits clear)
4162         */
4163        if (!q->nr)
4164                goto free_queue;
4165
4166        if (output_format & (DIFF_FORMAT_RAW |
4167                             DIFF_FORMAT_NAME |
4168                             DIFF_FORMAT_NAME_STATUS |
4169                             DIFF_FORMAT_CHECKDIFF)) {
4170                for (i = 0; i < q->nr; i++) {
4171                        struct diff_filepair *p = q->queue[i];
4172                        if (check_pair_status(p))
4173                                flush_one_pair(p, options);
4174                }
4175                separator++;
4176        }
4177
4178        if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
4179                dirstat_by_line = 1;
4180
4181        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
4182            dirstat_by_line) {
4183                struct diffstat_t diffstat;
4184
4185                memset(&diffstat, 0, sizeof(struct diffstat_t));
4186                for (i = 0; i < q->nr; i++) {
4187                        struct diff_filepair *p = q->queue[i];
4188                        if (check_pair_status(p))
4189                                diff_flush_stat(p, options, &diffstat);
4190                }
4191                if (output_format & DIFF_FORMAT_NUMSTAT)
4192                        show_numstat(&diffstat, options);
4193                if (output_format & DIFF_FORMAT_DIFFSTAT)
4194                        show_stats(&diffstat, options);
4195                if (output_format & DIFF_FORMAT_SHORTSTAT)
4196                        show_shortstats(&diffstat, options);
4197                if (output_format & DIFF_FORMAT_DIRSTAT)
4198                        show_dirstat_by_line(&diffstat, options);
4199                free_diffstat_info(&diffstat);
4200                separator++;
4201        }
4202        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
4203                show_dirstat(options);
4204
4205        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4206                for (i = 0; i < q->nr; i++) {
4207                        diff_summary(options, q->queue[i]);
4208                }
4209                separator++;
4210        }
4211
4212        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4213            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4214            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4215                /*
4216                 * run diff_flush_patch for the exit status. setting
4217                 * options->file to /dev/null should be safe, becaue we
4218                 * aren't supposed to produce any output anyway.
4219                 */
4220                if (options->close_file)
4221                        fclose(options->file);
4222                options->file = fopen("/dev/null", "w");
4223                if (!options->file)
4224                        die_errno("Could not open /dev/null");
4225                options->close_file = 1;
4226                for (i = 0; i < q->nr; i++) {
4227                        struct diff_filepair *p = q->queue[i];
4228                        if (check_pair_status(p))
4229                                diff_flush_patch(p, options);
4230                        if (options->found_changes)
4231                                break;
4232                }
4233        }
4234
4235        if (output_format & DIFF_FORMAT_PATCH) {
4236                if (separator) {
4237                        putc(options->line_termination, options->file);
4238                        if (options->stat_sep) {
4239                                /* attach patch instead of inline */
4240                                fputs(options->stat_sep, options->file);
4241                        }
4242                }
4243
4244                for (i = 0; i < q->nr; i++) {
4245                        struct diff_filepair *p = q->queue[i];
4246                        if (check_pair_status(p))
4247                                diff_flush_patch(p, options);
4248                }
4249        }
4250
4251        if (output_format & DIFF_FORMAT_CALLBACK)
4252                options->format_callback(q, options, options->format_callback_data);
4253
4254        for (i = 0; i < q->nr; i++)
4255                diff_free_filepair(q->queue[i]);
4256free_queue:
4257        free(q->queue);
4258        DIFF_QUEUE_CLEAR(q);
4259        if (options->close_file)
4260                fclose(options->file);
4261
4262        /*
4263         * Report the content-level differences with HAS_CHANGES;
4264         * diff_addremove/diff_change does not set the bit when
4265         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4266         */
4267        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4268                if (options->found_changes)
4269                        DIFF_OPT_SET(options, HAS_CHANGES);
4270                else
4271                        DIFF_OPT_CLR(options, HAS_CHANGES);
4272        }
4273}
4274
4275static void diffcore_apply_filter(const char *filter)
4276{
4277        int i;
4278        struct diff_queue_struct *q = &diff_queued_diff;
4279        struct diff_queue_struct outq;
4280        DIFF_QUEUE_CLEAR(&outq);
4281
4282        if (!filter)
4283                return;
4284
4285        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
4286                int found;
4287                for (i = found = 0; !found && i < q->nr; i++) {
4288                        struct diff_filepair *p = q->queue[i];
4289                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4290                             ((p->score &&
4291                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4292                              (!p->score &&
4293                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4294                            ((p->status != DIFF_STATUS_MODIFIED) &&
4295                             strchr(filter, p->status)))
4296                                found++;
4297                }
4298                if (found)
4299                        return;
4300
4301                /* otherwise we will clear the whole queue
4302                 * by copying the empty outq at the end of this
4303                 * function, but first clear the current entries
4304                 * in the queue.
4305                 */
4306                for (i = 0; i < q->nr; i++)
4307                        diff_free_filepair(q->queue[i]);
4308        }
4309        else {
4310                /* Only the matching ones */
4311                for (i = 0; i < q->nr; i++) {
4312                        struct diff_filepair *p = q->queue[i];
4313
4314                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4315                             ((p->score &&
4316                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4317                              (!p->score &&
4318                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4319                            ((p->status != DIFF_STATUS_MODIFIED) &&
4320                             strchr(filter, p->status)))
4321                                diff_q(&outq, p);
4322                        else
4323                                diff_free_filepair(p);
4324                }
4325        }
4326        free(q->queue);
4327        *q = outq;
4328}
4329
4330/* Check whether two filespecs with the same mode and size are identical */
4331static int diff_filespec_is_identical(struct diff_filespec *one,
4332                                      struct diff_filespec *two)
4333{
4334        if (S_ISGITLINK(one->mode))
4335                return 0;
4336        if (diff_populate_filespec(one, 0))
4337                return 0;
4338        if (diff_populate_filespec(two, 0))
4339                return 0;
4340        return !memcmp(one->data, two->data, one->size);
4341}
4342
4343static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4344{
4345        int i;
4346        struct diff_queue_struct *q = &diff_queued_diff;
4347        struct diff_queue_struct outq;
4348        DIFF_QUEUE_CLEAR(&outq);
4349
4350        for (i = 0; i < q->nr; i++) {
4351                struct diff_filepair *p = q->queue[i];
4352
4353                /*
4354                 * 1. Entries that come from stat info dirtiness
4355                 *    always have both sides (iow, not create/delete),
4356                 *    one side of the object name is unknown, with
4357                 *    the same mode and size.  Keep the ones that
4358                 *    do not match these criteria.  They have real
4359                 *    differences.
4360                 *
4361                 * 2. At this point, the file is known to be modified,
4362                 *    with the same mode and size, and the object
4363                 *    name of one side is unknown.  Need to inspect
4364                 *    the identical contents.
4365                 */
4366                if (!DIFF_FILE_VALID(p->one) || /* (1) */
4367                    !DIFF_FILE_VALID(p->two) ||
4368                    (p->one->sha1_valid && p->two->sha1_valid) ||
4369                    (p->one->mode != p->two->mode) ||
4370                    diff_populate_filespec(p->one, 1) ||
4371                    diff_populate_filespec(p->two, 1) ||
4372                    (p->one->size != p->two->size) ||
4373                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4374                        diff_q(&outq, p);
4375                else {
4376                        /*
4377                         * The caller can subtract 1 from skip_stat_unmatch
4378                         * to determine how many paths were dirty only
4379                         * due to stat info mismatch.
4380                         */
4381                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4382                                diffopt->skip_stat_unmatch++;
4383                        diff_free_filepair(p);
4384                }
4385        }
4386        free(q->queue);
4387        *q = outq;
4388}
4389
4390static int diffnamecmp(const void *a_, const void *b_)
4391{
4392        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4393        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4394        const char *name_a, *name_b;
4395
4396        name_a = a->one ? a->one->path : a->two->path;
4397        name_b = b->one ? b->one->path : b->two->path;
4398        return strcmp(name_a, name_b);
4399}
4400
4401void diffcore_fix_diff_index(struct diff_options *options)
4402{
4403        struct diff_queue_struct *q = &diff_queued_diff;
4404        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4405}
4406
4407void diffcore_std(struct diff_options *options)
4408{
4409        if (options->skip_stat_unmatch)
4410                diffcore_skip_stat_unmatch(options);
4411        if (!options->found_follow) {
4412                /* See try_to_follow_renames() in tree-diff.c */
4413                if (options->break_opt != -1)
4414                        diffcore_break(options->break_opt);
4415                if (options->detect_rename)
4416                        diffcore_rename(options);
4417                if (options->break_opt != -1)
4418                        diffcore_merge_broken();
4419        }
4420        if (options->pickaxe)
4421                diffcore_pickaxe(options);
4422        if (options->orderfile)
4423                diffcore_order(options->orderfile);
4424        if (!options->found_follow)
4425                /* See try_to_follow_renames() in tree-diff.c */
4426                diff_resolve_rename_copy();
4427        diffcore_apply_filter(options->filter);
4428
4429        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4430                DIFF_OPT_SET(options, HAS_CHANGES);
4431        else
4432                DIFF_OPT_CLR(options, HAS_CHANGES);
4433
4434        options->found_follow = 0;
4435}
4436
4437int diff_result_code(struct diff_options *opt, int status)
4438{
4439        int result = 0;
4440
4441        diff_warn_rename_limit("diff.renamelimit",
4442                               opt->needed_rename_limit,
4443                               opt->degraded_cc_to_c);
4444        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4445            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4446                return status;
4447        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4448            DIFF_OPT_TST(opt, HAS_CHANGES))
4449                result |= 01;
4450        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4451            DIFF_OPT_TST(opt, CHECK_FAILED))
4452                result |= 02;
4453        return result;
4454}
4455
4456int diff_can_quit_early(struct diff_options *opt)
4457{
4458        return (DIFF_OPT_TST(opt, QUICK) &&
4459                !opt->filter &&
4460                DIFF_OPT_TST(opt, HAS_CHANGES));
4461}
4462
4463/*
4464 * Shall changes to this submodule be ignored?
4465 *
4466 * Submodule changes can be configured to be ignored separately for each path,
4467 * but that configuration can be overridden from the command line.
4468 */
4469static int is_submodule_ignored(const char *path, struct diff_options *options)
4470{
4471        int ignored = 0;
4472        unsigned orig_flags = options->flags;
4473        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4474                set_diffopt_flags_from_submodule_config(options, path);
4475        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4476                ignored = 1;
4477        options->flags = orig_flags;
4478        return ignored;
4479}
4480
4481void diff_addremove(struct diff_options *options,
4482                    int addremove, unsigned mode,
4483                    const unsigned char *sha1,
4484                    const char *concatpath, unsigned dirty_submodule)
4485{
4486        struct diff_filespec *one, *two;
4487
4488        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4489                return;
4490
4491        /* This may look odd, but it is a preparation for
4492         * feeding "there are unchanged files which should
4493         * not produce diffs, but when you are doing copy
4494         * detection you would need them, so here they are"
4495         * entries to the diff-core.  They will be prefixed
4496         * with something like '=' or '*' (I haven't decided
4497         * which but should not make any difference).
4498         * Feeding the same new and old to diff_change()
4499         * also has the same effect.
4500         * Before the final output happens, they are pruned after
4501         * merged into rename/copy pairs as appropriate.
4502         */
4503        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4504                addremove = (addremove == '+' ? '-' :
4505                             addremove == '-' ? '+' : addremove);
4506
4507        if (options->prefix &&
4508            strncmp(concatpath, options->prefix, options->prefix_length))
4509                return;
4510
4511        one = alloc_filespec(concatpath);
4512        two = alloc_filespec(concatpath);
4513
4514        if (addremove != '+')
4515                fill_filespec(one, sha1, mode);
4516        if (addremove != '-') {
4517                fill_filespec(two, sha1, mode);
4518                two->dirty_submodule = dirty_submodule;
4519        }
4520
4521        diff_queue(&diff_queued_diff, one, two);
4522        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4523                DIFF_OPT_SET(options, HAS_CHANGES);
4524}
4525
4526void diff_change(struct diff_options *options,
4527                 unsigned old_mode, unsigned new_mode,
4528                 const unsigned char *old_sha1,
4529                 const unsigned char *new_sha1,
4530                 const char *concatpath,
4531                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4532{
4533        struct diff_filespec *one, *two;
4534
4535        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4536            is_submodule_ignored(concatpath, options))
4537                return;
4538
4539        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4540                unsigned tmp;
4541                const unsigned char *tmp_c;
4542                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4543                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4544                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4545                        new_dirty_submodule = tmp;
4546        }
4547
4548        if (options->prefix &&
4549            strncmp(concatpath, options->prefix, options->prefix_length))
4550                return;
4551
4552        one = alloc_filespec(concatpath);
4553        two = alloc_filespec(concatpath);
4554        fill_filespec(one, old_sha1, old_mode);
4555        fill_filespec(two, new_sha1, new_mode);
4556        one->dirty_submodule = old_dirty_submodule;
4557        two->dirty_submodule = new_dirty_submodule;
4558
4559        diff_queue(&diff_queued_diff, one, two);
4560        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4561                DIFF_OPT_SET(options, HAS_CHANGES);
4562}
4563
4564struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
4565{
4566        struct diff_filepair *pair;
4567        struct diff_filespec *one, *two;
4568
4569        if (options->prefix &&
4570            strncmp(path, options->prefix, options->prefix_length))
4571                return NULL;
4572
4573        one = alloc_filespec(path);
4574        two = alloc_filespec(path);
4575        pair = diff_queue(&diff_queued_diff, one, two);
4576        pair->is_unmerged = 1;
4577        return pair;
4578}
4579
4580static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4581                size_t *outsize)
4582{
4583        struct diff_tempfile *temp;
4584        const char *argv[3];
4585        const char **arg = argv;
4586        struct child_process child;
4587        struct strbuf buf = STRBUF_INIT;
4588        int err = 0;
4589
4590        temp = prepare_temp_file(spec->path, spec);
4591        *arg++ = pgm;
4592        *arg++ = temp->name;
4593        *arg = NULL;
4594
4595        memset(&child, 0, sizeof(child));
4596        child.use_shell = 1;
4597        child.argv = argv;
4598        child.out = -1;
4599        if (start_command(&child)) {
4600                remove_tempfile();
4601                return NULL;
4602        }
4603
4604        if (strbuf_read(&buf, child.out, 0) < 0)
4605                err = error("error reading from textconv command '%s'", pgm);
4606        close(child.out);
4607
4608        if (finish_command(&child) || err) {
4609                strbuf_release(&buf);
4610                remove_tempfile();
4611                return NULL;
4612        }
4613        remove_tempfile();
4614
4615        return strbuf_detach(&buf, outsize);
4616}
4617
4618size_t fill_textconv(struct userdiff_driver *driver,
4619                     struct diff_filespec *df,
4620                     char **outbuf)
4621{
4622        size_t size;
4623
4624        if (!driver || !driver->textconv) {
4625                if (!DIFF_FILE_VALID(df)) {
4626                        *outbuf = "";
4627                        return 0;
4628                }
4629                if (diff_populate_filespec(df, 0))
4630                        die("unable to read files to diff");
4631                *outbuf = df->data;
4632                return df->size;
4633        }
4634
4635        if (driver->textconv_cache && df->sha1_valid) {
4636                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4637                                          &size);
4638                if (*outbuf)
4639                        return size;
4640        }
4641
4642        *outbuf = run_textconv(driver->textconv, df, &size);
4643        if (!*outbuf)
4644                die("unable to read files to diff");
4645
4646        if (driver->textconv_cache && df->sha1_valid) {
4647                /* ignore errors, as we might be in a readonly repository */
4648                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4649                                size);
4650                /*
4651                 * we could save up changes and flush them all at the end,
4652                 * but we would need an extra call after all diffing is done.
4653                 * Since generating a cache entry is the slow path anyway,
4654                 * this extra overhead probably isn't a big deal.
4655                 */
4656                notes_cache_write(driver->textconv_cache);
4657        }
4658
4659        return size;
4660}