diff.con commit Merge branch 'jk/maint-avoid-streaming-filtered-contents' (31e3d83)
   1/*
   2 * Copyright (C) 2005 Junio C Hamano
   3 */
   4#include "cache.h"
   5#include "quote.h"
   6#include "diff.h"
   7#include "diffcore.h"
   8#include "delta.h"
   9#include "xdiff-interface.h"
  10#include "color.h"
  11#include "attr.h"
  12#include "run-command.h"
  13#include "utf8.h"
  14#include "userdiff.h"
  15#include "sigchain.h"
  16#include "submodule.h"
  17#include "ll-merge.h"
  18
  19#ifdef NO_FAST_WORKING_DIRECTORY
  20#define FAST_WORKING_DIRECTORY 0
  21#else
  22#define FAST_WORKING_DIRECTORY 1
  23#endif
  24
  25static int diff_detect_rename_default;
  26static int diff_rename_limit_default = 400;
  27static int diff_suppress_blank_empty;
  28int diff_use_color_default = -1;
  29static const char *diff_word_regex_cfg;
  30static const char *external_diff_cmd_cfg;
  31int diff_auto_refresh_index = 1;
  32static int diff_mnemonic_prefix;
  33static int diff_no_prefix;
  34static int diff_dirstat_permille_default = 30;
  35static struct diff_options default_diff_options;
  36
  37static char diff_colors[][COLOR_MAXLEN] = {
  38        GIT_COLOR_RESET,
  39        GIT_COLOR_NORMAL,       /* PLAIN */
  40        GIT_COLOR_BOLD,         /* METAINFO */
  41        GIT_COLOR_CYAN,         /* FRAGINFO */
  42        GIT_COLOR_RED,          /* OLD */
  43        GIT_COLOR_GREEN,        /* NEW */
  44        GIT_COLOR_YELLOW,       /* COMMIT */
  45        GIT_COLOR_BG_RED,       /* WHITESPACE */
  46        GIT_COLOR_NORMAL,       /* FUNCINFO */
  47};
  48
  49static int parse_diff_color_slot(const char *var, int ofs)
  50{
  51        if (!strcasecmp(var+ofs, "plain"))
  52                return DIFF_PLAIN;
  53        if (!strcasecmp(var+ofs, "meta"))
  54                return DIFF_METAINFO;
  55        if (!strcasecmp(var+ofs, "frag"))
  56                return DIFF_FRAGINFO;
  57        if (!strcasecmp(var+ofs, "old"))
  58                return DIFF_FILE_OLD;
  59        if (!strcasecmp(var+ofs, "new"))
  60                return DIFF_FILE_NEW;
  61        if (!strcasecmp(var+ofs, "commit"))
  62                return DIFF_COMMIT;
  63        if (!strcasecmp(var+ofs, "whitespace"))
  64                return DIFF_WHITESPACE;
  65        if (!strcasecmp(var+ofs, "func"))
  66                return DIFF_FUNCINFO;
  67        return -1;
  68}
  69
  70static int parse_dirstat_params(struct diff_options *options, const char *params,
  71                                struct strbuf *errmsg)
  72{
  73        const char *p = params;
  74        int p_len, ret = 0;
  75
  76        while (*p) {
  77                p_len = strchrnul(p, ',') - p;
  78                if (!memcmp(p, "changes", p_len)) {
  79                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
  80                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
  81                } else if (!memcmp(p, "lines", p_len)) {
  82                        DIFF_OPT_SET(options, DIRSTAT_BY_LINE);
  83                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
  84                } else if (!memcmp(p, "files", p_len)) {
  85                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
  86                        DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
  87                } else if (!memcmp(p, "noncumulative", p_len)) {
  88                        DIFF_OPT_CLR(options, DIRSTAT_CUMULATIVE);
  89                } else if (!memcmp(p, "cumulative", p_len)) {
  90                        DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
  91                } else if (isdigit(*p)) {
  92                        char *end;
  93                        int permille = strtoul(p, &end, 10) * 10;
  94                        if (*end == '.' && isdigit(*++end)) {
  95                                /* only use first digit */
  96                                permille += *end - '0';
  97                                /* .. and ignore any further digits */
  98                                while (isdigit(*++end))
  99                                        ; /* nothing */
 100                        }
 101                        if (end - p == p_len)
 102                                options->dirstat_permille = permille;
 103                        else {
 104                                strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%.*s'\n"),
 105                                            p_len, p);
 106                                ret++;
 107                        }
 108                } else {
 109                        strbuf_addf(errmsg, _("  Unknown dirstat parameter '%.*s'\n"),
 110                                    p_len, p);
 111                        ret++;
 112                }
 113
 114                p += p_len;
 115
 116                if (*p)
 117                        p++; /* more parameters, swallow separator */
 118        }
 119        return ret;
 120}
 121
 122static int git_config_rename(const char *var, const char *value)
 123{
 124        if (!value)
 125                return DIFF_DETECT_RENAME;
 126        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 127                return  DIFF_DETECT_COPY;
 128        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 129}
 130
 131/*
 132 * These are to give UI layer defaults.
 133 * The core-level commands such as git-diff-files should
 134 * never be affected by the setting of diff.renames
 135 * the user happens to have in the configuration file.
 136 */
 137int git_diff_ui_config(const char *var, const char *value, void *cb)
 138{
 139        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 140                diff_use_color_default = git_config_colorbool(var, value);
 141                return 0;
 142        }
 143        if (!strcmp(var, "diff.renames")) {
 144                diff_detect_rename_default = git_config_rename(var, value);
 145                return 0;
 146        }
 147        if (!strcmp(var, "diff.autorefreshindex")) {
 148                diff_auto_refresh_index = git_config_bool(var, value);
 149                return 0;
 150        }
 151        if (!strcmp(var, "diff.mnemonicprefix")) {
 152                diff_mnemonic_prefix = git_config_bool(var, value);
 153                return 0;
 154        }
 155        if (!strcmp(var, "diff.noprefix")) {
 156                diff_no_prefix = git_config_bool(var, value);
 157                return 0;
 158        }
 159        if (!strcmp(var, "diff.external"))
 160                return git_config_string(&external_diff_cmd_cfg, var, value);
 161        if (!strcmp(var, "diff.wordregex"))
 162                return git_config_string(&diff_word_regex_cfg, var, value);
 163
 164        if (!strcmp(var, "diff.ignoresubmodules"))
 165                handle_ignore_submodules_arg(&default_diff_options, value);
 166
 167        if (git_color_config(var, value, cb) < 0)
 168                return -1;
 169
 170        return git_diff_basic_config(var, value, cb);
 171}
 172
 173int git_diff_basic_config(const char *var, const char *value, void *cb)
 174{
 175        if (!strcmp(var, "diff.renamelimit")) {
 176                diff_rename_limit_default = git_config_int(var, value);
 177                return 0;
 178        }
 179
 180        if (userdiff_config(var, value) < 0)
 181                return -1;
 182
 183        if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
 184                int slot = parse_diff_color_slot(var, 11);
 185                if (slot < 0)
 186                        return 0;
 187                if (!value)
 188                        return config_error_nonbool(var);
 189                color_parse(value, var, diff_colors[slot]);
 190                return 0;
 191        }
 192
 193        /* like GNU diff's --suppress-blank-empty option  */
 194        if (!strcmp(var, "diff.suppressblankempty") ||
 195                        /* for backwards compatibility */
 196                        !strcmp(var, "diff.suppress-blank-empty")) {
 197                diff_suppress_blank_empty = git_config_bool(var, value);
 198                return 0;
 199        }
 200
 201        if (!strcmp(var, "diff.dirstat")) {
 202                struct strbuf errmsg = STRBUF_INIT;
 203                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 204                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 205                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 206                                errmsg.buf);
 207                strbuf_release(&errmsg);
 208                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 209                return 0;
 210        }
 211
 212        if (!prefixcmp(var, "submodule."))
 213                return parse_submodule_config_option(var, value);
 214
 215        return git_default_config(var, value, cb);
 216}
 217
 218static char *quote_two(const char *one, const char *two)
 219{
 220        int need_one = quote_c_style(one, NULL, NULL, 1);
 221        int need_two = quote_c_style(two, NULL, NULL, 1);
 222        struct strbuf res = STRBUF_INIT;
 223
 224        if (need_one + need_two) {
 225                strbuf_addch(&res, '"');
 226                quote_c_style(one, &res, NULL, 1);
 227                quote_c_style(two, &res, NULL, 1);
 228                strbuf_addch(&res, '"');
 229        } else {
 230                strbuf_addstr(&res, one);
 231                strbuf_addstr(&res, two);
 232        }
 233        return strbuf_detach(&res, NULL);
 234}
 235
 236static const char *external_diff(void)
 237{
 238        static const char *external_diff_cmd = NULL;
 239        static int done_preparing = 0;
 240
 241        if (done_preparing)
 242                return external_diff_cmd;
 243        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 244        if (!external_diff_cmd)
 245                external_diff_cmd = external_diff_cmd_cfg;
 246        done_preparing = 1;
 247        return external_diff_cmd;
 248}
 249
 250static struct diff_tempfile {
 251        const char *name; /* filename external diff should read from */
 252        char hex[41];
 253        char mode[10];
 254        char tmp_path[PATH_MAX];
 255} diff_temp[2];
 256
 257typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 258
 259struct emit_callback {
 260        int color_diff;
 261        unsigned ws_rule;
 262        int blank_at_eof_in_preimage;
 263        int blank_at_eof_in_postimage;
 264        int lno_in_preimage;
 265        int lno_in_postimage;
 266        sane_truncate_fn truncate;
 267        const char **label_path;
 268        struct diff_words_data *diff_words;
 269        struct diff_options *opt;
 270        int *found_changesp;
 271        struct strbuf *header;
 272};
 273
 274static int count_lines(const char *data, int size)
 275{
 276        int count, ch, completely_empty = 1, nl_just_seen = 0;
 277        count = 0;
 278        while (0 < size--) {
 279                ch = *data++;
 280                if (ch == '\n') {
 281                        count++;
 282                        nl_just_seen = 1;
 283                        completely_empty = 0;
 284                }
 285                else {
 286                        nl_just_seen = 0;
 287                        completely_empty = 0;
 288                }
 289        }
 290        if (completely_empty)
 291                return 0;
 292        if (!nl_just_seen)
 293                count++; /* no trailing newline */
 294        return count;
 295}
 296
 297static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 298{
 299        if (!DIFF_FILE_VALID(one)) {
 300                mf->ptr = (char *)""; /* does not matter */
 301                mf->size = 0;
 302                return 0;
 303        }
 304        else if (diff_populate_filespec(one, 0))
 305                return -1;
 306
 307        mf->ptr = one->data;
 308        mf->size = one->size;
 309        return 0;
 310}
 311
 312/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 313static unsigned long diff_filespec_size(struct diff_filespec *one)
 314{
 315        if (!DIFF_FILE_VALID(one))
 316                return 0;
 317        diff_populate_filespec(one, 1);
 318        return one->size;
 319}
 320
 321static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 322{
 323        char *ptr = mf->ptr;
 324        long size = mf->size;
 325        int cnt = 0;
 326
 327        if (!size)
 328                return cnt;
 329        ptr += size - 1; /* pointing at the very end */
 330        if (*ptr != '\n')
 331                ; /* incomplete line */
 332        else
 333                ptr--; /* skip the last LF */
 334        while (mf->ptr < ptr) {
 335                char *prev_eol;
 336                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 337                        if (*prev_eol == '\n')
 338                                break;
 339                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 340                        break;
 341                cnt++;
 342                ptr = prev_eol - 1;
 343        }
 344        return cnt;
 345}
 346
 347static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 348                               struct emit_callback *ecbdata)
 349{
 350        int l1, l2, at;
 351        unsigned ws_rule = ecbdata->ws_rule;
 352        l1 = count_trailing_blank(mf1, ws_rule);
 353        l2 = count_trailing_blank(mf2, ws_rule);
 354        if (l2 <= l1) {
 355                ecbdata->blank_at_eof_in_preimage = 0;
 356                ecbdata->blank_at_eof_in_postimage = 0;
 357                return;
 358        }
 359        at = count_lines(mf1->ptr, mf1->size);
 360        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 361
 362        at = count_lines(mf2->ptr, mf2->size);
 363        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 364}
 365
 366static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 367                        int first, const char *line, int len)
 368{
 369        int has_trailing_newline, has_trailing_carriage_return;
 370        int nofirst;
 371        FILE *file = o->file;
 372
 373        if (o->output_prefix) {
 374                struct strbuf *msg = NULL;
 375                msg = o->output_prefix(o, o->output_prefix_data);
 376                assert(msg);
 377                fwrite(msg->buf, msg->len, 1, file);
 378        }
 379
 380        if (len == 0) {
 381                has_trailing_newline = (first == '\n');
 382                has_trailing_carriage_return = (!has_trailing_newline &&
 383                                                (first == '\r'));
 384                nofirst = has_trailing_newline || has_trailing_carriage_return;
 385        } else {
 386                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 387                if (has_trailing_newline)
 388                        len--;
 389                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 390                if (has_trailing_carriage_return)
 391                        len--;
 392                nofirst = 0;
 393        }
 394
 395        if (len || !nofirst) {
 396                fputs(set, file);
 397                if (!nofirst)
 398                        fputc(first, file);
 399                fwrite(line, len, 1, file);
 400                fputs(reset, file);
 401        }
 402        if (has_trailing_carriage_return)
 403                fputc('\r', file);
 404        if (has_trailing_newline)
 405                fputc('\n', file);
 406}
 407
 408static void emit_line(struct diff_options *o, const char *set, const char *reset,
 409                      const char *line, int len)
 410{
 411        emit_line_0(o, set, reset, line[0], line+1, len-1);
 412}
 413
 414static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 415{
 416        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 417              ecbdata->blank_at_eof_in_preimage &&
 418              ecbdata->blank_at_eof_in_postimage &&
 419              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 420              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 421                return 0;
 422        return ws_blank_line(line, len, ecbdata->ws_rule);
 423}
 424
 425static void emit_add_line(const char *reset,
 426                          struct emit_callback *ecbdata,
 427                          const char *line, int len)
 428{
 429        const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 430        const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 431
 432        if (!*ws)
 433                emit_line_0(ecbdata->opt, set, reset, '+', line, len);
 434        else if (new_blank_line_at_eof(ecbdata, line, len))
 435                /* Blank line at EOF - paint '+' as well */
 436                emit_line_0(ecbdata->opt, ws, reset, '+', line, len);
 437        else {
 438                /* Emit just the prefix, then the rest. */
 439                emit_line_0(ecbdata->opt, set, reset, '+', "", 0);
 440                ws_check_emit(line, len, ecbdata->ws_rule,
 441                              ecbdata->opt->file, set, reset, ws);
 442        }
 443}
 444
 445static void emit_hunk_header(struct emit_callback *ecbdata,
 446                             const char *line, int len)
 447{
 448        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 449        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 450        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 451        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 452        static const char atat[2] = { '@', '@' };
 453        const char *cp, *ep;
 454        struct strbuf msgbuf = STRBUF_INIT;
 455        int org_len = len;
 456        int i = 1;
 457
 458        /*
 459         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 460         * it always is at least 10 bytes long.
 461         */
 462        if (len < 10 ||
 463            memcmp(line, atat, 2) ||
 464            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 465                emit_line(ecbdata->opt, plain, reset, line, len);
 466                return;
 467        }
 468        ep += 2; /* skip over @@ */
 469
 470        /* The hunk header in fraginfo color */
 471        strbuf_add(&msgbuf, frag, strlen(frag));
 472        strbuf_add(&msgbuf, line, ep - line);
 473        strbuf_add(&msgbuf, reset, strlen(reset));
 474
 475        /*
 476         * trailing "\r\n"
 477         */
 478        for ( ; i < 3; i++)
 479                if (line[len - i] == '\r' || line[len - i] == '\n')
 480                        len--;
 481
 482        /* blank before the func header */
 483        for (cp = ep; ep - line < len; ep++)
 484                if (*ep != ' ' && *ep != '\t')
 485                        break;
 486        if (ep != cp) {
 487                strbuf_add(&msgbuf, plain, strlen(plain));
 488                strbuf_add(&msgbuf, cp, ep - cp);
 489                strbuf_add(&msgbuf, reset, strlen(reset));
 490        }
 491
 492        if (ep < line + len) {
 493                strbuf_add(&msgbuf, func, strlen(func));
 494                strbuf_add(&msgbuf, ep, line + len - ep);
 495                strbuf_add(&msgbuf, reset, strlen(reset));
 496        }
 497
 498        strbuf_add(&msgbuf, line + len, org_len - len);
 499        emit_line(ecbdata->opt, "", "", msgbuf.buf, msgbuf.len);
 500        strbuf_release(&msgbuf);
 501}
 502
 503static struct diff_tempfile *claim_diff_tempfile(void) {
 504        int i;
 505        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 506                if (!diff_temp[i].name)
 507                        return diff_temp + i;
 508        die("BUG: diff is failing to clean up its tempfiles");
 509}
 510
 511static int remove_tempfile_installed;
 512
 513static void remove_tempfile(void)
 514{
 515        int i;
 516        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 517                if (diff_temp[i].name == diff_temp[i].tmp_path)
 518                        unlink_or_warn(diff_temp[i].name);
 519                diff_temp[i].name = NULL;
 520        }
 521}
 522
 523static void remove_tempfile_on_signal(int signo)
 524{
 525        remove_tempfile();
 526        sigchain_pop(signo);
 527        raise(signo);
 528}
 529
 530static void print_line_count(FILE *file, int count)
 531{
 532        switch (count) {
 533        case 0:
 534                fprintf(file, "0,0");
 535                break;
 536        case 1:
 537                fprintf(file, "1");
 538                break;
 539        default:
 540                fprintf(file, "1,%d", count);
 541                break;
 542        }
 543}
 544
 545static void emit_rewrite_lines(struct emit_callback *ecb,
 546                               int prefix, const char *data, int size)
 547{
 548        const char *endp = NULL;
 549        static const char *nneof = " No newline at end of file\n";
 550        const char *old = diff_get_color(ecb->color_diff, DIFF_FILE_OLD);
 551        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 552
 553        while (0 < size) {
 554                int len;
 555
 556                endp = memchr(data, '\n', size);
 557                len = endp ? (endp - data + 1) : size;
 558                if (prefix != '+') {
 559                        ecb->lno_in_preimage++;
 560                        emit_line_0(ecb->opt, old, reset, '-',
 561                                    data, len);
 562                } else {
 563                        ecb->lno_in_postimage++;
 564                        emit_add_line(reset, ecb, data, len);
 565                }
 566                size -= len;
 567                data += len;
 568        }
 569        if (!endp) {
 570                const char *plain = diff_get_color(ecb->color_diff,
 571                                                   DIFF_PLAIN);
 572                emit_line_0(ecb->opt, plain, reset, '\\',
 573                            nneof, strlen(nneof));
 574        }
 575}
 576
 577static void emit_rewrite_diff(const char *name_a,
 578                              const char *name_b,
 579                              struct diff_filespec *one,
 580                              struct diff_filespec *two,
 581                              struct userdiff_driver *textconv_one,
 582                              struct userdiff_driver *textconv_two,
 583                              struct diff_options *o)
 584{
 585        int lc_a, lc_b;
 586        const char *name_a_tab, *name_b_tab;
 587        const char *metainfo = diff_get_color(o->use_color, DIFF_METAINFO);
 588        const char *fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
 589        const char *reset = diff_get_color(o->use_color, DIFF_RESET);
 590        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 591        const char *a_prefix, *b_prefix;
 592        char *data_one, *data_two;
 593        size_t size_one, size_two;
 594        struct emit_callback ecbdata;
 595        char *line_prefix = "";
 596        struct strbuf *msgbuf;
 597
 598        if (o && o->output_prefix) {
 599                msgbuf = o->output_prefix(o, o->output_prefix_data);
 600                line_prefix = msgbuf->buf;
 601        }
 602
 603        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 604                a_prefix = o->b_prefix;
 605                b_prefix = o->a_prefix;
 606        } else {
 607                a_prefix = o->a_prefix;
 608                b_prefix = o->b_prefix;
 609        }
 610
 611        name_a += (*name_a == '/');
 612        name_b += (*name_b == '/');
 613        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 614        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 615
 616        strbuf_reset(&a_name);
 617        strbuf_reset(&b_name);
 618        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 619        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 620
 621        size_one = fill_textconv(textconv_one, one, &data_one);
 622        size_two = fill_textconv(textconv_two, two, &data_two);
 623
 624        memset(&ecbdata, 0, sizeof(ecbdata));
 625        ecbdata.color_diff = want_color(o->use_color);
 626        ecbdata.found_changesp = &o->found_changes;
 627        ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
 628        ecbdata.opt = o;
 629        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 630                mmfile_t mf1, mf2;
 631                mf1.ptr = (char *)data_one;
 632                mf2.ptr = (char *)data_two;
 633                mf1.size = size_one;
 634                mf2.size = size_two;
 635                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 636        }
 637        ecbdata.lno_in_preimage = 1;
 638        ecbdata.lno_in_postimage = 1;
 639
 640        lc_a = count_lines(data_one, size_one);
 641        lc_b = count_lines(data_two, size_two);
 642        fprintf(o->file,
 643                "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
 644                line_prefix, metainfo, a_name.buf, name_a_tab, reset,
 645                line_prefix, metainfo, b_name.buf, name_b_tab, reset,
 646                line_prefix, fraginfo);
 647        if (!o->irreversible_delete)
 648                print_line_count(o->file, lc_a);
 649        else
 650                fprintf(o->file, "?,?");
 651        fprintf(o->file, " +");
 652        print_line_count(o->file, lc_b);
 653        fprintf(o->file, " @@%s\n", reset);
 654        if (lc_a && !o->irreversible_delete)
 655                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 656        if (lc_b)
 657                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 658        if (textconv_one)
 659                free((char *)data_one);
 660        if (textconv_two)
 661                free((char *)data_two);
 662}
 663
 664struct diff_words_buffer {
 665        mmfile_t text;
 666        long alloc;
 667        struct diff_words_orig {
 668                const char *begin, *end;
 669        } *orig;
 670        int orig_nr, orig_alloc;
 671};
 672
 673static void diff_words_append(char *line, unsigned long len,
 674                struct diff_words_buffer *buffer)
 675{
 676        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 677        line++;
 678        len--;
 679        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 680        buffer->text.size += len;
 681        buffer->text.ptr[buffer->text.size] = '\0';
 682}
 683
 684struct diff_words_style_elem {
 685        const char *prefix;
 686        const char *suffix;
 687        const char *color; /* NULL; filled in by the setup code if
 688                            * color is enabled */
 689};
 690
 691struct diff_words_style {
 692        enum diff_words_type type;
 693        struct diff_words_style_elem new, old, ctx;
 694        const char *newline;
 695};
 696
 697static struct diff_words_style diff_words_styles[] = {
 698        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 699        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 700        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 701};
 702
 703struct diff_words_data {
 704        struct diff_words_buffer minus, plus;
 705        const char *current_plus;
 706        int last_minus;
 707        struct diff_options *opt;
 708        regex_t *word_regex;
 709        enum diff_words_type type;
 710        struct diff_words_style *style;
 711};
 712
 713static int fn_out_diff_words_write_helper(FILE *fp,
 714                                          struct diff_words_style_elem *st_el,
 715                                          const char *newline,
 716                                          size_t count, const char *buf,
 717                                          const char *line_prefix)
 718{
 719        int print = 0;
 720
 721        while (count) {
 722                char *p = memchr(buf, '\n', count);
 723                if (print)
 724                        fputs(line_prefix, fp);
 725                if (p != buf) {
 726                        if (st_el->color && fputs(st_el->color, fp) < 0)
 727                                return -1;
 728                        if (fputs(st_el->prefix, fp) < 0 ||
 729                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 730                            fputs(st_el->suffix, fp) < 0)
 731                                return -1;
 732                        if (st_el->color && *st_el->color
 733                            && fputs(GIT_COLOR_RESET, fp) < 0)
 734                                return -1;
 735                }
 736                if (!p)
 737                        return 0;
 738                if (fputs(newline, fp) < 0)
 739                        return -1;
 740                count -= p + 1 - buf;
 741                buf = p + 1;
 742                print = 1;
 743        }
 744        return 0;
 745}
 746
 747/*
 748 * '--color-words' algorithm can be described as:
 749 *
 750 *   1. collect a the minus/plus lines of a diff hunk, divided into
 751 *      minus-lines and plus-lines;
 752 *
 753 *   2. break both minus-lines and plus-lines into words and
 754 *      place them into two mmfile_t with one word for each line;
 755 *
 756 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
 757 *
 758 * And for the common parts of the both file, we output the plus side text.
 759 * diff_words->current_plus is used to trace the current position of the plus file
 760 * which printed. diff_words->last_minus is used to trace the last minus word
 761 * printed.
 762 *
 763 * For '--graph' to work with '--color-words', we need to output the graph prefix
 764 * on each line of color words output. Generally, there are two conditions on
 765 * which we should output the prefix.
 766 *
 767 *   1. diff_words->last_minus == 0 &&
 768 *      diff_words->current_plus == diff_words->plus.text.ptr
 769 *
 770 *      that is: the plus text must start as a new line, and if there is no minus
 771 *      word printed, a graph prefix must be printed.
 772 *
 773 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
 774 *      *(diff_words->current_plus - 1) == '\n'
 775 *
 776 *      that is: a graph prefix must be printed following a '\n'
 777 */
 778static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
 779{
 780        if ((diff_words->last_minus == 0 &&
 781                diff_words->current_plus == diff_words->plus.text.ptr) ||
 782                (diff_words->current_plus > diff_words->plus.text.ptr &&
 783                *(diff_words->current_plus - 1) == '\n')) {
 784                return 1;
 785        } else {
 786                return 0;
 787        }
 788}
 789
 790static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 791{
 792        struct diff_words_data *diff_words = priv;
 793        struct diff_words_style *style = diff_words->style;
 794        int minus_first, minus_len, plus_first, plus_len;
 795        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 796        struct diff_options *opt = diff_words->opt;
 797        struct strbuf *msgbuf;
 798        char *line_prefix = "";
 799
 800        if (line[0] != '@' || parse_hunk_header(line, len,
 801                        &minus_first, &minus_len, &plus_first, &plus_len))
 802                return;
 803
 804        assert(opt);
 805        if (opt->output_prefix) {
 806                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 807                line_prefix = msgbuf->buf;
 808        }
 809
 810        /* POSIX requires that first be decremented by one if len == 0... */
 811        if (minus_len) {
 812                minus_begin = diff_words->minus.orig[minus_first].begin;
 813                minus_end =
 814                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 815        } else
 816                minus_begin = minus_end =
 817                        diff_words->minus.orig[minus_first].end;
 818
 819        if (plus_len) {
 820                plus_begin = diff_words->plus.orig[plus_first].begin;
 821                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 822        } else
 823                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 824
 825        if (color_words_output_graph_prefix(diff_words)) {
 826                fputs(line_prefix, diff_words->opt->file);
 827        }
 828        if (diff_words->current_plus != plus_begin) {
 829                fn_out_diff_words_write_helper(diff_words->opt->file,
 830                                &style->ctx, style->newline,
 831                                plus_begin - diff_words->current_plus,
 832                                diff_words->current_plus, line_prefix);
 833                if (*(plus_begin - 1) == '\n')
 834                        fputs(line_prefix, diff_words->opt->file);
 835        }
 836        if (minus_begin != minus_end) {
 837                fn_out_diff_words_write_helper(diff_words->opt->file,
 838                                &style->old, style->newline,
 839                                minus_end - minus_begin, minus_begin,
 840                                line_prefix);
 841        }
 842        if (plus_begin != plus_end) {
 843                fn_out_diff_words_write_helper(diff_words->opt->file,
 844                                &style->new, style->newline,
 845                                plus_end - plus_begin, plus_begin,
 846                                line_prefix);
 847        }
 848
 849        diff_words->current_plus = plus_end;
 850        diff_words->last_minus = minus_first;
 851}
 852
 853/* This function starts looking at *begin, and returns 0 iff a word was found. */
 854static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 855                int *begin, int *end)
 856{
 857        if (word_regex && *begin < buffer->size) {
 858                regmatch_t match[1];
 859                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 860                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 861                                        '\n', match[0].rm_eo - match[0].rm_so);
 862                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 863                        *begin += match[0].rm_so;
 864                        return *begin >= *end;
 865                }
 866                return -1;
 867        }
 868
 869        /* find the next word */
 870        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 871                (*begin)++;
 872        if (*begin >= buffer->size)
 873                return -1;
 874
 875        /* find the end of the word */
 876        *end = *begin + 1;
 877        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 878                (*end)++;
 879
 880        return 0;
 881}
 882
 883/*
 884 * This function splits the words in buffer->text, stores the list with
 885 * newline separator into out, and saves the offsets of the original words
 886 * in buffer->orig.
 887 */
 888static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 889                regex_t *word_regex)
 890{
 891        int i, j;
 892        long alloc = 0;
 893
 894        out->size = 0;
 895        out->ptr = NULL;
 896
 897        /* fake an empty "0th" word */
 898        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 899        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 900        buffer->orig_nr = 1;
 901
 902        for (i = 0; i < buffer->text.size; i++) {
 903                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 904                        return;
 905
 906                /* store original boundaries */
 907                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 908                                buffer->orig_alloc);
 909                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 910                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 911                buffer->orig_nr++;
 912
 913                /* store one word */
 914                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 915                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 916                out->ptr[out->size + j - i] = '\n';
 917                out->size += j - i + 1;
 918
 919                i = j - 1;
 920        }
 921}
 922
 923/* this executes the word diff on the accumulated buffers */
 924static void diff_words_show(struct diff_words_data *diff_words)
 925{
 926        xpparam_t xpp;
 927        xdemitconf_t xecfg;
 928        mmfile_t minus, plus;
 929        struct diff_words_style *style = diff_words->style;
 930
 931        struct diff_options *opt = diff_words->opt;
 932        struct strbuf *msgbuf;
 933        char *line_prefix = "";
 934
 935        assert(opt);
 936        if (opt->output_prefix) {
 937                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 938                line_prefix = msgbuf->buf;
 939        }
 940
 941        /* special case: only removal */
 942        if (!diff_words->plus.text.size) {
 943                fputs(line_prefix, diff_words->opt->file);
 944                fn_out_diff_words_write_helper(diff_words->opt->file,
 945                        &style->old, style->newline,
 946                        diff_words->minus.text.size,
 947                        diff_words->minus.text.ptr, line_prefix);
 948                diff_words->minus.text.size = 0;
 949                return;
 950        }
 951
 952        diff_words->current_plus = diff_words->plus.text.ptr;
 953        diff_words->last_minus = 0;
 954
 955        memset(&xpp, 0, sizeof(xpp));
 956        memset(&xecfg, 0, sizeof(xecfg));
 957        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
 958        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
 959        xpp.flags = 0;
 960        /* as only the hunk header will be parsed, we need a 0-context */
 961        xecfg.ctxlen = 0;
 962        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 963                      &xpp, &xecfg);
 964        free(minus.ptr);
 965        free(plus.ptr);
 966        if (diff_words->current_plus != diff_words->plus.text.ptr +
 967                        diff_words->plus.text.size) {
 968                if (color_words_output_graph_prefix(diff_words))
 969                        fputs(line_prefix, diff_words->opt->file);
 970                fn_out_diff_words_write_helper(diff_words->opt->file,
 971                        &style->ctx, style->newline,
 972                        diff_words->plus.text.ptr + diff_words->plus.text.size
 973                        - diff_words->current_plus, diff_words->current_plus,
 974                        line_prefix);
 975        }
 976        diff_words->minus.text.size = diff_words->plus.text.size = 0;
 977}
 978
 979/* In "color-words" mode, show word-diff of words accumulated in the buffer */
 980static void diff_words_flush(struct emit_callback *ecbdata)
 981{
 982        if (ecbdata->diff_words->minus.text.size ||
 983            ecbdata->diff_words->plus.text.size)
 984                diff_words_show(ecbdata->diff_words);
 985}
 986
 987static void free_diff_words_data(struct emit_callback *ecbdata)
 988{
 989        if (ecbdata->diff_words) {
 990                diff_words_flush(ecbdata);
 991                free (ecbdata->diff_words->minus.text.ptr);
 992                free (ecbdata->diff_words->minus.orig);
 993                free (ecbdata->diff_words->plus.text.ptr);
 994                free (ecbdata->diff_words->plus.orig);
 995                if (ecbdata->diff_words->word_regex) {
 996                        regfree(ecbdata->diff_words->word_regex);
 997                        free(ecbdata->diff_words->word_regex);
 998                }
 999                free(ecbdata->diff_words);
1000                ecbdata->diff_words = NULL;
1001        }
1002}
1003
1004const char *diff_get_color(int diff_use_color, enum color_diff ix)
1005{
1006        if (want_color(diff_use_color))
1007                return diff_colors[ix];
1008        return "";
1009}
1010
1011static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
1012{
1013        const char *cp;
1014        unsigned long allot;
1015        size_t l = len;
1016
1017        if (ecb->truncate)
1018                return ecb->truncate(line, len);
1019        cp = line;
1020        allot = l;
1021        while (0 < l) {
1022                (void) utf8_width(&cp, &l);
1023                if (!cp)
1024                        break; /* truncated in the middle? */
1025        }
1026        return allot - l;
1027}
1028
1029static void find_lno(const char *line, struct emit_callback *ecbdata)
1030{
1031        const char *p;
1032        ecbdata->lno_in_preimage = 0;
1033        ecbdata->lno_in_postimage = 0;
1034        p = strchr(line, '-');
1035        if (!p)
1036                return; /* cannot happen */
1037        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1038        p = strchr(p, '+');
1039        if (!p)
1040                return; /* cannot happen */
1041        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
1042}
1043
1044static void fn_out_consume(void *priv, char *line, unsigned long len)
1045{
1046        struct emit_callback *ecbdata = priv;
1047        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
1048        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
1049        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1050        struct diff_options *o = ecbdata->opt;
1051        char *line_prefix = "";
1052        struct strbuf *msgbuf;
1053
1054        if (o && o->output_prefix) {
1055                msgbuf = o->output_prefix(o, o->output_prefix_data);
1056                line_prefix = msgbuf->buf;
1057        }
1058
1059        if (ecbdata->header) {
1060                fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
1061                strbuf_reset(ecbdata->header);
1062                ecbdata->header = NULL;
1063        }
1064        *(ecbdata->found_changesp) = 1;
1065
1066        if (ecbdata->label_path[0]) {
1067                const char *name_a_tab, *name_b_tab;
1068
1069                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
1070                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
1071
1072                fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
1073                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
1074                fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
1075                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1076                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1077        }
1078
1079        if (diff_suppress_blank_empty
1080            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1081                line[0] = '\n';
1082                len = 1;
1083        }
1084
1085        if (line[0] == '@') {
1086                if (ecbdata->diff_words)
1087                        diff_words_flush(ecbdata);
1088                len = sane_truncate_line(ecbdata, line, len);
1089                find_lno(line, ecbdata);
1090                emit_hunk_header(ecbdata, line, len);
1091                if (line[len-1] != '\n')
1092                        putc('\n', ecbdata->opt->file);
1093                return;
1094        }
1095
1096        if (len < 1) {
1097                emit_line(ecbdata->opt, reset, reset, line, len);
1098                if (ecbdata->diff_words
1099                    && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
1100                        fputs("~\n", ecbdata->opt->file);
1101                return;
1102        }
1103
1104        if (ecbdata->diff_words) {
1105                if (line[0] == '-') {
1106                        diff_words_append(line, len,
1107                                          &ecbdata->diff_words->minus);
1108                        return;
1109                } else if (line[0] == '+') {
1110                        diff_words_append(line, len,
1111                                          &ecbdata->diff_words->plus);
1112                        return;
1113                } else if (!prefixcmp(line, "\\ ")) {
1114                        /*
1115                         * Eat the "no newline at eof" marker as if we
1116                         * saw a "+" or "-" line with nothing on it,
1117                         * and return without diff_words_flush() to
1118                         * defer processing. If this is the end of
1119                         * preimage, more "+" lines may come after it.
1120                         */
1121                        return;
1122                }
1123                diff_words_flush(ecbdata);
1124                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1125                        emit_line(ecbdata->opt, plain, reset, line, len);
1126                        fputs("~\n", ecbdata->opt->file);
1127                } else {
1128                        /*
1129                         * Skip the prefix character, if any.  With
1130                         * diff_suppress_blank_empty, there may be
1131                         * none.
1132                         */
1133                        if (line[0] != '\n') {
1134                              line++;
1135                              len--;
1136                        }
1137                        emit_line(ecbdata->opt, plain, reset, line, len);
1138                }
1139                return;
1140        }
1141
1142        if (line[0] != '+') {
1143                const char *color =
1144                        diff_get_color(ecbdata->color_diff,
1145                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
1146                ecbdata->lno_in_preimage++;
1147                if (line[0] == ' ')
1148                        ecbdata->lno_in_postimage++;
1149                emit_line(ecbdata->opt, color, reset, line, len);
1150        } else {
1151                ecbdata->lno_in_postimage++;
1152                emit_add_line(reset, ecbdata, line + 1, len - 1);
1153        }
1154}
1155
1156static char *pprint_rename(const char *a, const char *b)
1157{
1158        const char *old = a;
1159        const char *new = b;
1160        struct strbuf name = STRBUF_INIT;
1161        int pfx_length, sfx_length;
1162        int len_a = strlen(a);
1163        int len_b = strlen(b);
1164        int a_midlen, b_midlen;
1165        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1166        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1167
1168        if (qlen_a || qlen_b) {
1169                quote_c_style(a, &name, NULL, 0);
1170                strbuf_addstr(&name, " => ");
1171                quote_c_style(b, &name, NULL, 0);
1172                return strbuf_detach(&name, NULL);
1173        }
1174
1175        /* Find common prefix */
1176        pfx_length = 0;
1177        while (*old && *new && *old == *new) {
1178                if (*old == '/')
1179                        pfx_length = old - a + 1;
1180                old++;
1181                new++;
1182        }
1183
1184        /* Find common suffix */
1185        old = a + len_a;
1186        new = b + len_b;
1187        sfx_length = 0;
1188        while (a <= old && b <= new && *old == *new) {
1189                if (*old == '/')
1190                        sfx_length = len_a - (old - a);
1191                old--;
1192                new--;
1193        }
1194
1195        /*
1196         * pfx{mid-a => mid-b}sfx
1197         * {pfx-a => pfx-b}sfx
1198         * pfx{sfx-a => sfx-b}
1199         * name-a => name-b
1200         */
1201        a_midlen = len_a - pfx_length - sfx_length;
1202        b_midlen = len_b - pfx_length - sfx_length;
1203        if (a_midlen < 0)
1204                a_midlen = 0;
1205        if (b_midlen < 0)
1206                b_midlen = 0;
1207
1208        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1209        if (pfx_length + sfx_length) {
1210                strbuf_add(&name, a, pfx_length);
1211                strbuf_addch(&name, '{');
1212        }
1213        strbuf_add(&name, a + pfx_length, a_midlen);
1214        strbuf_addstr(&name, " => ");
1215        strbuf_add(&name, b + pfx_length, b_midlen);
1216        if (pfx_length + sfx_length) {
1217                strbuf_addch(&name, '}');
1218                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1219        }
1220        return strbuf_detach(&name, NULL);
1221}
1222
1223struct diffstat_t {
1224        int nr;
1225        int alloc;
1226        struct diffstat_file {
1227                char *from_name;
1228                char *name;
1229                char *print_name;
1230                unsigned is_unmerged:1;
1231                unsigned is_binary:1;
1232                unsigned is_renamed:1;
1233                uintmax_t added, deleted;
1234        } **files;
1235};
1236
1237static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1238                                          const char *name_a,
1239                                          const char *name_b)
1240{
1241        struct diffstat_file *x;
1242        x = xcalloc(sizeof (*x), 1);
1243        if (diffstat->nr == diffstat->alloc) {
1244                diffstat->alloc = alloc_nr(diffstat->alloc);
1245                diffstat->files = xrealloc(diffstat->files,
1246                                diffstat->alloc * sizeof(x));
1247        }
1248        diffstat->files[diffstat->nr++] = x;
1249        if (name_b) {
1250                x->from_name = xstrdup(name_a);
1251                x->name = xstrdup(name_b);
1252                x->is_renamed = 1;
1253        }
1254        else {
1255                x->from_name = NULL;
1256                x->name = xstrdup(name_a);
1257        }
1258        return x;
1259}
1260
1261static void diffstat_consume(void *priv, char *line, unsigned long len)
1262{
1263        struct diffstat_t *diffstat = priv;
1264        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1265
1266        if (line[0] == '+')
1267                x->added++;
1268        else if (line[0] == '-')
1269                x->deleted++;
1270}
1271
1272const char mime_boundary_leader[] = "------------";
1273
1274static int scale_linear(int it, int width, int max_change)
1275{
1276        if (!it)
1277                return 0;
1278        /*
1279         * make sure that at least one '-' or '+' is printed if
1280         * there is any change to this path. The easiest way is to
1281         * scale linearly as if the alloted width is one column shorter
1282         * than it is, and then add 1 to the result.
1283         */
1284        return 1 + (it * (width - 1) / max_change);
1285}
1286
1287static void show_name(FILE *file,
1288                      const char *prefix, const char *name, int len)
1289{
1290        fprintf(file, " %s%-*s |", prefix, len, name);
1291}
1292
1293static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1294{
1295        if (cnt <= 0)
1296                return;
1297        fprintf(file, "%s", set);
1298        while (cnt--)
1299                putc(ch, file);
1300        fprintf(file, "%s", reset);
1301}
1302
1303static void fill_print_name(struct diffstat_file *file)
1304{
1305        char *pname;
1306
1307        if (file->print_name)
1308                return;
1309
1310        if (!file->is_renamed) {
1311                struct strbuf buf = STRBUF_INIT;
1312                if (quote_c_style(file->name, &buf, NULL, 0)) {
1313                        pname = strbuf_detach(&buf, NULL);
1314                } else {
1315                        pname = file->name;
1316                        strbuf_release(&buf);
1317                }
1318        } else {
1319                pname = pprint_rename(file->from_name, file->name);
1320        }
1321        file->print_name = pname;
1322}
1323
1324int print_stat_summary(FILE *fp, int files, int insertions, int deletions)
1325{
1326        struct strbuf sb = STRBUF_INIT;
1327        int ret;
1328
1329        if (!files) {
1330                assert(insertions == 0 && deletions == 0);
1331                return fputs(_(" 0 files changed\n"), fp);
1332        }
1333
1334        strbuf_addf(&sb,
1335                    Q_(" %d file changed", " %d files changed", files),
1336                    files);
1337
1338        /*
1339         * For binary diff, the caller may want to print "x files
1340         * changed" with insertions == 0 && deletions == 0.
1341         *
1342         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
1343         * is probably less confusing (i.e skip over "2 files changed
1344         * but nothing about added/removed lines? Is this a bug in Git?").
1345         */
1346        if (insertions || deletions == 0) {
1347                /*
1348                 * TRANSLATORS: "+" in (+) is a line addition marker;
1349                 * do not translate it.
1350                 */
1351                strbuf_addf(&sb,
1352                            Q_(", %d insertion(+)", ", %d insertions(+)",
1353                               insertions),
1354                            insertions);
1355        }
1356
1357        if (deletions || insertions == 0) {
1358                /*
1359                 * TRANSLATORS: "-" in (-) is a line removal marker;
1360                 * do not translate it.
1361                 */
1362                strbuf_addf(&sb,
1363                            Q_(", %d deletion(-)", ", %d deletions(-)",
1364                               deletions),
1365                            deletions);
1366        }
1367        strbuf_addch(&sb, '\n');
1368        ret = fputs(sb.buf, fp);
1369        strbuf_release(&sb);
1370        return ret;
1371}
1372
1373static void show_stats(struct diffstat_t *data, struct diff_options *options)
1374{
1375        int i, len, add, del, adds = 0, dels = 0;
1376        uintmax_t max_change = 0, max_len = 0;
1377        int total_files = data->nr;
1378        int width, name_width, count;
1379        const char *reset, *add_c, *del_c;
1380        const char *line_prefix = "";
1381        int extra_shown = 0;
1382        struct strbuf *msg = NULL;
1383
1384        if (data->nr == 0)
1385                return;
1386
1387        if (options->output_prefix) {
1388                msg = options->output_prefix(options, options->output_prefix_data);
1389                line_prefix = msg->buf;
1390        }
1391
1392        width = options->stat_width ? options->stat_width : 80;
1393        name_width = options->stat_name_width ? options->stat_name_width : 50;
1394        count = options->stat_count ? options->stat_count : data->nr;
1395
1396        /* Sanity: give at least 5 columns to the graph,
1397         * but leave at least 10 columns for the name.
1398         */
1399        if (width < 25)
1400                width = 25;
1401        if (name_width < 10)
1402                name_width = 10;
1403        else if (width < name_width + 15)
1404                name_width = width - 15;
1405
1406        /* Find the longest filename and max number of changes */
1407        reset = diff_get_color_opt(options, DIFF_RESET);
1408        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1409        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1410
1411        for (i = 0; (i < count) && (i < data->nr); i++) {
1412                struct diffstat_file *file = data->files[i];
1413                uintmax_t change = file->added + file->deleted;
1414                if (!data->files[i]->is_renamed &&
1415                         (change == 0)) {
1416                        count++; /* not shown == room for one more */
1417                        continue;
1418                }
1419                fill_print_name(file);
1420                len = strlen(file->print_name);
1421                if (max_len < len)
1422                        max_len = len;
1423
1424                if (file->is_binary || file->is_unmerged)
1425                        continue;
1426                if (max_change < change)
1427                        max_change = change;
1428        }
1429        count = i; /* min(count, data->nr) */
1430
1431        /* Compute the width of the graph part;
1432         * 10 is for one blank at the beginning of the line plus
1433         * " | count " between the name and the graph.
1434         *
1435         * From here on, name_width is the width of the name area,
1436         * and width is the width of the graph area.
1437         */
1438        name_width = (name_width < max_len) ? name_width : max_len;
1439        if (width < (name_width + 10) + max_change)
1440                width = width - (name_width + 10);
1441        else
1442                width = max_change;
1443
1444        for (i = 0; i < count; i++) {
1445                const char *prefix = "";
1446                char *name = data->files[i]->print_name;
1447                uintmax_t added = data->files[i]->added;
1448                uintmax_t deleted = data->files[i]->deleted;
1449                int name_len;
1450
1451                if (!data->files[i]->is_renamed &&
1452                         (added + deleted == 0)) {
1453                        total_files--;
1454                        continue;
1455                }
1456                /*
1457                 * "scale" the filename
1458                 */
1459                len = name_width;
1460                name_len = strlen(name);
1461                if (name_width < name_len) {
1462                        char *slash;
1463                        prefix = "...";
1464                        len -= 3;
1465                        name += name_len - len;
1466                        slash = strchr(name, '/');
1467                        if (slash)
1468                                name = slash;
1469                }
1470
1471                if (data->files[i]->is_binary) {
1472                        fprintf(options->file, "%s", line_prefix);
1473                        show_name(options->file, prefix, name, len);
1474                        fprintf(options->file, "  Bin ");
1475                        fprintf(options->file, "%s%"PRIuMAX"%s",
1476                                del_c, deleted, reset);
1477                        fprintf(options->file, " -> ");
1478                        fprintf(options->file, "%s%"PRIuMAX"%s",
1479                                add_c, added, reset);
1480                        fprintf(options->file, " bytes");
1481                        fprintf(options->file, "\n");
1482                        continue;
1483                }
1484                else if (data->files[i]->is_unmerged) {
1485                        fprintf(options->file, "%s", line_prefix);
1486                        show_name(options->file, prefix, name, len);
1487                        fprintf(options->file, "  Unmerged\n");
1488                        continue;
1489                }
1490
1491                /*
1492                 * scale the add/delete
1493                 */
1494                add = added;
1495                del = deleted;
1496                adds += add;
1497                dels += del;
1498
1499                if (width <= max_change) {
1500                        int total = add + del;
1501
1502                        total = scale_linear(add + del, width, max_change);
1503                        if (total < 2 && add && del)
1504                                /* width >= 2 due to the sanity check */
1505                                total = 2;
1506                        if (add < del) {
1507                                add = scale_linear(add, width, max_change);
1508                                del = total - add;
1509                        } else {
1510                                del = scale_linear(del, width, max_change);
1511                                add = total - del;
1512                        }
1513                }
1514                fprintf(options->file, "%s", line_prefix);
1515                show_name(options->file, prefix, name, len);
1516                fprintf(options->file, "%5"PRIuMAX"%s", added + deleted,
1517                                added + deleted ? " " : "");
1518                show_graph(options->file, '+', add, add_c, reset);
1519                show_graph(options->file, '-', del, del_c, reset);
1520                fprintf(options->file, "\n");
1521        }
1522        for (i = count; i < data->nr; i++) {
1523                uintmax_t added = data->files[i]->added;
1524                uintmax_t deleted = data->files[i]->deleted;
1525                if (!data->files[i]->is_renamed &&
1526                         (added + deleted == 0)) {
1527                        total_files--;
1528                        continue;
1529                }
1530                adds += added;
1531                dels += deleted;
1532                if (!extra_shown)
1533                        fprintf(options->file, "%s ...\n", line_prefix);
1534                extra_shown = 1;
1535        }
1536        fprintf(options->file, "%s", line_prefix);
1537        print_stat_summary(options->file, total_files, adds, dels);
1538}
1539
1540static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1541{
1542        int i, adds = 0, dels = 0, total_files = data->nr;
1543
1544        if (data->nr == 0)
1545                return;
1546
1547        for (i = 0; i < data->nr; i++) {
1548                if (!data->files[i]->is_binary &&
1549                    !data->files[i]->is_unmerged) {
1550                        int added = data->files[i]->added;
1551                        int deleted= data->files[i]->deleted;
1552                        if (!data->files[i]->is_renamed &&
1553                            (added + deleted == 0)) {
1554                                total_files--;
1555                        } else {
1556                                adds += added;
1557                                dels += deleted;
1558                        }
1559                }
1560        }
1561        if (options->output_prefix) {
1562                struct strbuf *msg = NULL;
1563                msg = options->output_prefix(options,
1564                                options->output_prefix_data);
1565                fprintf(options->file, "%s", msg->buf);
1566        }
1567        print_stat_summary(options->file, total_files, adds, dels);
1568}
1569
1570static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1571{
1572        int i;
1573
1574        if (data->nr == 0)
1575                return;
1576
1577        for (i = 0; i < data->nr; i++) {
1578                struct diffstat_file *file = data->files[i];
1579
1580                if (options->output_prefix) {
1581                        struct strbuf *msg = NULL;
1582                        msg = options->output_prefix(options,
1583                                        options->output_prefix_data);
1584                        fprintf(options->file, "%s", msg->buf);
1585                }
1586
1587                if (file->is_binary)
1588                        fprintf(options->file, "-\t-\t");
1589                else
1590                        fprintf(options->file,
1591                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1592                                file->added, file->deleted);
1593                if (options->line_termination) {
1594                        fill_print_name(file);
1595                        if (!file->is_renamed)
1596                                write_name_quoted(file->name, options->file,
1597                                                  options->line_termination);
1598                        else {
1599                                fputs(file->print_name, options->file);
1600                                putc(options->line_termination, options->file);
1601                        }
1602                } else {
1603                        if (file->is_renamed) {
1604                                putc('\0', options->file);
1605                                write_name_quoted(file->from_name, options->file, '\0');
1606                        }
1607                        write_name_quoted(file->name, options->file, '\0');
1608                }
1609        }
1610}
1611
1612struct dirstat_file {
1613        const char *name;
1614        unsigned long changed;
1615};
1616
1617struct dirstat_dir {
1618        struct dirstat_file *files;
1619        int alloc, nr, permille, cumulative;
1620};
1621
1622static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1623                unsigned long changed, const char *base, int baselen)
1624{
1625        unsigned long this_dir = 0;
1626        unsigned int sources = 0;
1627        const char *line_prefix = "";
1628        struct strbuf *msg = NULL;
1629
1630        if (opt->output_prefix) {
1631                msg = opt->output_prefix(opt, opt->output_prefix_data);
1632                line_prefix = msg->buf;
1633        }
1634
1635        while (dir->nr) {
1636                struct dirstat_file *f = dir->files;
1637                int namelen = strlen(f->name);
1638                unsigned long this;
1639                char *slash;
1640
1641                if (namelen < baselen)
1642                        break;
1643                if (memcmp(f->name, base, baselen))
1644                        break;
1645                slash = strchr(f->name + baselen, '/');
1646                if (slash) {
1647                        int newbaselen = slash + 1 - f->name;
1648                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1649                        sources++;
1650                } else {
1651                        this = f->changed;
1652                        dir->files++;
1653                        dir->nr--;
1654                        sources += 2;
1655                }
1656                this_dir += this;
1657        }
1658
1659        /*
1660         * We don't report dirstat's for
1661         *  - the top level
1662         *  - or cases where everything came from a single directory
1663         *    under this directory (sources == 1).
1664         */
1665        if (baselen && sources != 1) {
1666                if (this_dir) {
1667                        int permille = this_dir * 1000 / changed;
1668                        if (permille >= dir->permille) {
1669                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1670                                        permille / 10, permille % 10, baselen, base);
1671                                if (!dir->cumulative)
1672                                        return 0;
1673                        }
1674                }
1675        }
1676        return this_dir;
1677}
1678
1679static int dirstat_compare(const void *_a, const void *_b)
1680{
1681        const struct dirstat_file *a = _a;
1682        const struct dirstat_file *b = _b;
1683        return strcmp(a->name, b->name);
1684}
1685
1686static void show_dirstat(struct diff_options *options)
1687{
1688        int i;
1689        unsigned long changed;
1690        struct dirstat_dir dir;
1691        struct diff_queue_struct *q = &diff_queued_diff;
1692
1693        dir.files = NULL;
1694        dir.alloc = 0;
1695        dir.nr = 0;
1696        dir.permille = options->dirstat_permille;
1697        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1698
1699        changed = 0;
1700        for (i = 0; i < q->nr; i++) {
1701                struct diff_filepair *p = q->queue[i];
1702                const char *name;
1703                unsigned long copied, added, damage;
1704                int content_changed;
1705
1706                name = p->two->path ? p->two->path : p->one->path;
1707
1708                if (p->one->sha1_valid && p->two->sha1_valid)
1709                        content_changed = hashcmp(p->one->sha1, p->two->sha1);
1710                else
1711                        content_changed = 1;
1712
1713                if (!content_changed) {
1714                        /*
1715                         * The SHA1 has not changed, so pre-/post-content is
1716                         * identical. We can therefore skip looking at the
1717                         * file contents altogether.
1718                         */
1719                        damage = 0;
1720                        goto found_damage;
1721                }
1722
1723                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1724                        /*
1725                         * In --dirstat-by-file mode, we don't really need to
1726                         * look at the actual file contents at all.
1727                         * The fact that the SHA1 changed is enough for us to
1728                         * add this file to the list of results
1729                         * (with each file contributing equal damage).
1730                         */
1731                        damage = 1;
1732                        goto found_damage;
1733                }
1734
1735                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1736                        diff_populate_filespec(p->one, 0);
1737                        diff_populate_filespec(p->two, 0);
1738                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1739                                               &copied, &added);
1740                        diff_free_filespec_data(p->one);
1741                        diff_free_filespec_data(p->two);
1742                } else if (DIFF_FILE_VALID(p->one)) {
1743                        diff_populate_filespec(p->one, 1);
1744                        copied = added = 0;
1745                        diff_free_filespec_data(p->one);
1746                } else if (DIFF_FILE_VALID(p->two)) {
1747                        diff_populate_filespec(p->two, 1);
1748                        copied = 0;
1749                        added = p->two->size;
1750                        diff_free_filespec_data(p->two);
1751                } else
1752                        continue;
1753
1754                /*
1755                 * Original minus copied is the removed material,
1756                 * added is the new material.  They are both damages
1757                 * made to the preimage.
1758                 * If the resulting damage is zero, we know that
1759                 * diffcore_count_changes() considers the two entries to
1760                 * be identical, but since content_changed is true, we
1761                 * know that there must have been _some_ kind of change,
1762                 * so we force all entries to have damage > 0.
1763                 */
1764                damage = (p->one->size - copied) + added;
1765                if (!damage)
1766                        damage = 1;
1767
1768found_damage:
1769                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1770                dir.files[dir.nr].name = name;
1771                dir.files[dir.nr].changed = damage;
1772                changed += damage;
1773                dir.nr++;
1774        }
1775
1776        /* This can happen even with many files, if everything was renames */
1777        if (!changed)
1778                return;
1779
1780        /* Show all directories with more than x% of the changes */
1781        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1782        gather_dirstat(options, &dir, changed, "", 0);
1783}
1784
1785static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
1786{
1787        int i;
1788        unsigned long changed;
1789        struct dirstat_dir dir;
1790
1791        if (data->nr == 0)
1792                return;
1793
1794        dir.files = NULL;
1795        dir.alloc = 0;
1796        dir.nr = 0;
1797        dir.permille = options->dirstat_permille;
1798        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1799
1800        changed = 0;
1801        for (i = 0; i < data->nr; i++) {
1802                struct diffstat_file *file = data->files[i];
1803                unsigned long damage = file->added + file->deleted;
1804                if (file->is_binary)
1805                        /*
1806                         * binary files counts bytes, not lines. Must find some
1807                         * way to normalize binary bytes vs. textual lines.
1808                         * The following heuristic assumes that there are 64
1809                         * bytes per "line".
1810                         * This is stupid and ugly, but very cheap...
1811                         */
1812                        damage = (damage + 63) / 64;
1813                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1814                dir.files[dir.nr].name = file->name;
1815                dir.files[dir.nr].changed = damage;
1816                changed += damage;
1817                dir.nr++;
1818        }
1819
1820        /* This can happen even with many files, if everything was renames */
1821        if (!changed)
1822                return;
1823
1824        /* Show all directories with more than x% of the changes */
1825        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1826        gather_dirstat(options, &dir, changed, "", 0);
1827}
1828
1829static void free_diffstat_info(struct diffstat_t *diffstat)
1830{
1831        int i;
1832        for (i = 0; i < diffstat->nr; i++) {
1833                struct diffstat_file *f = diffstat->files[i];
1834                if (f->name != f->print_name)
1835                        free(f->print_name);
1836                free(f->name);
1837                free(f->from_name);
1838                free(f);
1839        }
1840        free(diffstat->files);
1841}
1842
1843struct checkdiff_t {
1844        const char *filename;
1845        int lineno;
1846        int conflict_marker_size;
1847        struct diff_options *o;
1848        unsigned ws_rule;
1849        unsigned status;
1850};
1851
1852static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1853{
1854        char firstchar;
1855        int cnt;
1856
1857        if (len < marker_size + 1)
1858                return 0;
1859        firstchar = line[0];
1860        switch (firstchar) {
1861        case '=': case '>': case '<': case '|':
1862                break;
1863        default:
1864                return 0;
1865        }
1866        for (cnt = 1; cnt < marker_size; cnt++)
1867                if (line[cnt] != firstchar)
1868                        return 0;
1869        /* line[1] thru line[marker_size-1] are same as firstchar */
1870        if (len < marker_size + 1 || !isspace(line[marker_size]))
1871                return 0;
1872        return 1;
1873}
1874
1875static void checkdiff_consume(void *priv, char *line, unsigned long len)
1876{
1877        struct checkdiff_t *data = priv;
1878        int marker_size = data->conflict_marker_size;
1879        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
1880        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
1881        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
1882        char *err;
1883        char *line_prefix = "";
1884        struct strbuf *msgbuf;
1885
1886        assert(data->o);
1887        if (data->o->output_prefix) {
1888                msgbuf = data->o->output_prefix(data->o,
1889                        data->o->output_prefix_data);
1890                line_prefix = msgbuf->buf;
1891        }
1892
1893        if (line[0] == '+') {
1894                unsigned bad;
1895                data->lineno++;
1896                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
1897                        data->status |= 1;
1898                        fprintf(data->o->file,
1899                                "%s%s:%d: leftover conflict marker\n",
1900                                line_prefix, data->filename, data->lineno);
1901                }
1902                bad = ws_check(line + 1, len - 1, data->ws_rule);
1903                if (!bad)
1904                        return;
1905                data->status |= bad;
1906                err = whitespace_error_string(bad);
1907                fprintf(data->o->file, "%s%s:%d: %s.\n",
1908                        line_prefix, data->filename, data->lineno, err);
1909                free(err);
1910                emit_line(data->o, set, reset, line, 1);
1911                ws_check_emit(line + 1, len - 1, data->ws_rule,
1912                              data->o->file, set, reset, ws);
1913        } else if (line[0] == ' ') {
1914                data->lineno++;
1915        } else if (line[0] == '@') {
1916                char *plus = strchr(line, '+');
1917                if (plus)
1918                        data->lineno = strtol(plus, NULL, 10) - 1;
1919                else
1920                        die("invalid diff");
1921        }
1922}
1923
1924static unsigned char *deflate_it(char *data,
1925                                 unsigned long size,
1926                                 unsigned long *result_size)
1927{
1928        int bound;
1929        unsigned char *deflated;
1930        git_zstream stream;
1931
1932        memset(&stream, 0, sizeof(stream));
1933        git_deflate_init(&stream, zlib_compression_level);
1934        bound = git_deflate_bound(&stream, size);
1935        deflated = xmalloc(bound);
1936        stream.next_out = deflated;
1937        stream.avail_out = bound;
1938
1939        stream.next_in = (unsigned char *)data;
1940        stream.avail_in = size;
1941        while (git_deflate(&stream, Z_FINISH) == Z_OK)
1942                ; /* nothing */
1943        git_deflate_end(&stream);
1944        *result_size = stream.total_out;
1945        return deflated;
1946}
1947
1948static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1949{
1950        void *cp;
1951        void *delta;
1952        void *deflated;
1953        void *data;
1954        unsigned long orig_size;
1955        unsigned long delta_size;
1956        unsigned long deflate_size;
1957        unsigned long data_size;
1958
1959        /* We could do deflated delta, or we could do just deflated two,
1960         * whichever is smaller.
1961         */
1962        delta = NULL;
1963        deflated = deflate_it(two->ptr, two->size, &deflate_size);
1964        if (one->size && two->size) {
1965                delta = diff_delta(one->ptr, one->size,
1966                                   two->ptr, two->size,
1967                                   &delta_size, deflate_size);
1968                if (delta) {
1969                        void *to_free = delta;
1970                        orig_size = delta_size;
1971                        delta = deflate_it(delta, delta_size, &delta_size);
1972                        free(to_free);
1973                }
1974        }
1975
1976        if (delta && delta_size < deflate_size) {
1977                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
1978                free(deflated);
1979                data = delta;
1980                data_size = delta_size;
1981        }
1982        else {
1983                fprintf(file, "%sliteral %lu\n", prefix, two->size);
1984                free(delta);
1985                data = deflated;
1986                data_size = deflate_size;
1987        }
1988
1989        /* emit data encoded in base85 */
1990        cp = data;
1991        while (data_size) {
1992                int bytes = (52 < data_size) ? 52 : data_size;
1993                char line[70];
1994                data_size -= bytes;
1995                if (bytes <= 26)
1996                        line[0] = bytes + 'A' - 1;
1997                else
1998                        line[0] = bytes - 26 + 'a' - 1;
1999                encode_85(line + 1, cp, bytes);
2000                cp = (char *) cp + bytes;
2001                fprintf(file, "%s", prefix);
2002                fputs(line, file);
2003                fputc('\n', file);
2004        }
2005        fprintf(file, "%s\n", prefix);
2006        free(data);
2007}
2008
2009static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
2010{
2011        fprintf(file, "%sGIT binary patch\n", prefix);
2012        emit_binary_diff_body(file, one, two, prefix);
2013        emit_binary_diff_body(file, two, one, prefix);
2014}
2015
2016static void diff_filespec_load_driver(struct diff_filespec *one)
2017{
2018        /* Use already-loaded driver */
2019        if (one->driver)
2020                return;
2021
2022        if (S_ISREG(one->mode))
2023                one->driver = userdiff_find_by_path(one->path);
2024
2025        /* Fallback to default settings */
2026        if (!one->driver)
2027                one->driver = userdiff_find_by_name("default");
2028}
2029
2030int diff_filespec_is_binary(struct diff_filespec *one)
2031{
2032        if (one->is_binary == -1) {
2033                diff_filespec_load_driver(one);
2034                if (one->driver->binary != -1)
2035                        one->is_binary = one->driver->binary;
2036                else {
2037                        if (!one->data && DIFF_FILE_VALID(one))
2038                                diff_populate_filespec(one, 0);
2039                        if (one->data)
2040                                one->is_binary = buffer_is_binary(one->data,
2041                                                one->size);
2042                        if (one->is_binary == -1)
2043                                one->is_binary = 0;
2044                }
2045        }
2046        return one->is_binary;
2047}
2048
2049static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
2050{
2051        diff_filespec_load_driver(one);
2052        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
2053}
2054
2055static const char *userdiff_word_regex(struct diff_filespec *one)
2056{
2057        diff_filespec_load_driver(one);
2058        return one->driver->word_regex;
2059}
2060
2061void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
2062{
2063        if (!options->a_prefix)
2064                options->a_prefix = a;
2065        if (!options->b_prefix)
2066                options->b_prefix = b;
2067}
2068
2069struct userdiff_driver *get_textconv(struct diff_filespec *one)
2070{
2071        if (!DIFF_FILE_VALID(one))
2072                return NULL;
2073
2074        diff_filespec_load_driver(one);
2075        return userdiff_get_textconv(one->driver);
2076}
2077
2078static void builtin_diff(const char *name_a,
2079                         const char *name_b,
2080                         struct diff_filespec *one,
2081                         struct diff_filespec *two,
2082                         const char *xfrm_msg,
2083                         int must_show_header,
2084                         struct diff_options *o,
2085                         int complete_rewrite)
2086{
2087        mmfile_t mf1, mf2;
2088        const char *lbl[2];
2089        char *a_one, *b_two;
2090        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
2091        const char *reset = diff_get_color_opt(o, DIFF_RESET);
2092        const char *a_prefix, *b_prefix;
2093        struct userdiff_driver *textconv_one = NULL;
2094        struct userdiff_driver *textconv_two = NULL;
2095        struct strbuf header = STRBUF_INIT;
2096        struct strbuf *msgbuf;
2097        char *line_prefix = "";
2098
2099        if (o->output_prefix) {
2100                msgbuf = o->output_prefix(o, o->output_prefix_data);
2101                line_prefix = msgbuf->buf;
2102        }
2103
2104        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
2105                        (!one->mode || S_ISGITLINK(one->mode)) &&
2106                        (!two->mode || S_ISGITLINK(two->mode))) {
2107                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2108                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2109                show_submodule_summary(o->file, one ? one->path : two->path,
2110                                one->sha1, two->sha1, two->dirty_submodule,
2111                                del, add, reset);
2112                return;
2113        }
2114
2115        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
2116                textconv_one = get_textconv(one);
2117                textconv_two = get_textconv(two);
2118        }
2119
2120        diff_set_mnemonic_prefix(o, "a/", "b/");
2121        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
2122                a_prefix = o->b_prefix;
2123                b_prefix = o->a_prefix;
2124        } else {
2125                a_prefix = o->a_prefix;
2126                b_prefix = o->b_prefix;
2127        }
2128
2129        /* Never use a non-valid filename anywhere if at all possible */
2130        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
2131        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
2132
2133        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
2134        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
2135        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
2136        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
2137        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
2138        if (lbl[0][0] == '/') {
2139                /* /dev/null */
2140                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
2141                if (xfrm_msg)
2142                        strbuf_addstr(&header, xfrm_msg);
2143                must_show_header = 1;
2144        }
2145        else if (lbl[1][0] == '/') {
2146                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
2147                if (xfrm_msg)
2148                        strbuf_addstr(&header, xfrm_msg);
2149                must_show_header = 1;
2150        }
2151        else {
2152                if (one->mode != two->mode) {
2153                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
2154                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
2155                        must_show_header = 1;
2156                }
2157                if (xfrm_msg)
2158                        strbuf_addstr(&header, xfrm_msg);
2159
2160                /*
2161                 * we do not run diff between different kind
2162                 * of objects.
2163                 */
2164                if ((one->mode ^ two->mode) & S_IFMT)
2165                        goto free_ab_and_return;
2166                if (complete_rewrite &&
2167                    (textconv_one || !diff_filespec_is_binary(one)) &&
2168                    (textconv_two || !diff_filespec_is_binary(two))) {
2169                        fprintf(o->file, "%s", header.buf);
2170                        strbuf_reset(&header);
2171                        emit_rewrite_diff(name_a, name_b, one, two,
2172                                                textconv_one, textconv_two, o);
2173                        o->found_changes = 1;
2174                        goto free_ab_and_return;
2175                }
2176        }
2177
2178        if (o->irreversible_delete && lbl[1][0] == '/') {
2179                fprintf(o->file, "%s", header.buf);
2180                strbuf_reset(&header);
2181                goto free_ab_and_return;
2182        } else if (!DIFF_OPT_TST(o, TEXT) &&
2183            ( (!textconv_one && diff_filespec_is_binary(one)) ||
2184              (!textconv_two && diff_filespec_is_binary(two)) )) {
2185                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2186                        die("unable to read files to diff");
2187                /* Quite common confusing case */
2188                if (mf1.size == mf2.size &&
2189                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2190                        if (must_show_header)
2191                                fprintf(o->file, "%s", header.buf);
2192                        goto free_ab_and_return;
2193                }
2194                fprintf(o->file, "%s", header.buf);
2195                strbuf_reset(&header);
2196                if (DIFF_OPT_TST(o, BINARY))
2197                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2198                else
2199                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2200                                line_prefix, lbl[0], lbl[1]);
2201                o->found_changes = 1;
2202        } else {
2203                /* Crazy xdl interfaces.. */
2204                const char *diffopts = getenv("GIT_DIFF_OPTS");
2205                xpparam_t xpp;
2206                xdemitconf_t xecfg;
2207                struct emit_callback ecbdata;
2208                const struct userdiff_funcname *pe;
2209
2210                if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS) || must_show_header) {
2211                        fprintf(o->file, "%s", header.buf);
2212                        strbuf_reset(&header);
2213                }
2214
2215                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2216                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2217
2218                pe = diff_funcname_pattern(one);
2219                if (!pe)
2220                        pe = diff_funcname_pattern(two);
2221
2222                memset(&xpp, 0, sizeof(xpp));
2223                memset(&xecfg, 0, sizeof(xecfg));
2224                memset(&ecbdata, 0, sizeof(ecbdata));
2225                ecbdata.label_path = lbl;
2226                ecbdata.color_diff = want_color(o->use_color);
2227                ecbdata.found_changesp = &o->found_changes;
2228                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
2229                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2230                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2231                ecbdata.opt = o;
2232                ecbdata.header = header.len ? &header : NULL;
2233                xpp.flags = o->xdl_opts;
2234                xecfg.ctxlen = o->context;
2235                xecfg.interhunkctxlen = o->interhunkcontext;
2236                xecfg.flags = XDL_EMIT_FUNCNAMES;
2237                if (DIFF_OPT_TST(o, FUNCCONTEXT))
2238                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
2239                if (pe)
2240                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2241                if (!diffopts)
2242                        ;
2243                else if (!prefixcmp(diffopts, "--unified="))
2244                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2245                else if (!prefixcmp(diffopts, "-u"))
2246                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2247                if (o->word_diff) {
2248                        int i;
2249
2250                        ecbdata.diff_words =
2251                                xcalloc(1, sizeof(struct diff_words_data));
2252                        ecbdata.diff_words->type = o->word_diff;
2253                        ecbdata.diff_words->opt = o;
2254                        if (!o->word_regex)
2255                                o->word_regex = userdiff_word_regex(one);
2256                        if (!o->word_regex)
2257                                o->word_regex = userdiff_word_regex(two);
2258                        if (!o->word_regex)
2259                                o->word_regex = diff_word_regex_cfg;
2260                        if (o->word_regex) {
2261                                ecbdata.diff_words->word_regex = (regex_t *)
2262                                        xmalloc(sizeof(regex_t));
2263                                if (regcomp(ecbdata.diff_words->word_regex,
2264                                                o->word_regex,
2265                                                REG_EXTENDED | REG_NEWLINE))
2266                                        die ("Invalid regular expression: %s",
2267                                                        o->word_regex);
2268                        }
2269                        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2270                                if (o->word_diff == diff_words_styles[i].type) {
2271                                        ecbdata.diff_words->style =
2272                                                &diff_words_styles[i];
2273                                        break;
2274                                }
2275                        }
2276                        if (want_color(o->use_color)) {
2277                                struct diff_words_style *st = ecbdata.diff_words->style;
2278                                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2279                                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2280                                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
2281                        }
2282                }
2283                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2284                              &xpp, &xecfg);
2285                if (o->word_diff)
2286                        free_diff_words_data(&ecbdata);
2287                if (textconv_one)
2288                        free(mf1.ptr);
2289                if (textconv_two)
2290                        free(mf2.ptr);
2291                xdiff_clear_find_func(&xecfg);
2292        }
2293
2294 free_ab_and_return:
2295        strbuf_release(&header);
2296        diff_free_filespec_data(one);
2297        diff_free_filespec_data(two);
2298        free(a_one);
2299        free(b_two);
2300        return;
2301}
2302
2303static void builtin_diffstat(const char *name_a, const char *name_b,
2304                             struct diff_filespec *one,
2305                             struct diff_filespec *two,
2306                             struct diffstat_t *diffstat,
2307                             struct diff_options *o,
2308                             int complete_rewrite)
2309{
2310        mmfile_t mf1, mf2;
2311        struct diffstat_file *data;
2312
2313        data = diffstat_add(diffstat, name_a, name_b);
2314
2315        if (!one || !two) {
2316                data->is_unmerged = 1;
2317                return;
2318        }
2319
2320        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2321                data->is_binary = 1;
2322                data->added = diff_filespec_size(two);
2323                data->deleted = diff_filespec_size(one);
2324        }
2325
2326        else if (complete_rewrite) {
2327                diff_populate_filespec(one, 0);
2328                diff_populate_filespec(two, 0);
2329                data->deleted = count_lines(one->data, one->size);
2330                data->added = count_lines(two->data, two->size);
2331        }
2332
2333        else {
2334                /* Crazy xdl interfaces.. */
2335                xpparam_t xpp;
2336                xdemitconf_t xecfg;
2337
2338                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2339                        die("unable to read files to diff");
2340
2341                memset(&xpp, 0, sizeof(xpp));
2342                memset(&xecfg, 0, sizeof(xecfg));
2343                xpp.flags = o->xdl_opts;
2344                xecfg.ctxlen = o->context;
2345                xecfg.interhunkctxlen = o->interhunkcontext;
2346                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2347                              &xpp, &xecfg);
2348        }
2349
2350        diff_free_filespec_data(one);
2351        diff_free_filespec_data(two);
2352}
2353
2354static void builtin_checkdiff(const char *name_a, const char *name_b,
2355                              const char *attr_path,
2356                              struct diff_filespec *one,
2357                              struct diff_filespec *two,
2358                              struct diff_options *o)
2359{
2360        mmfile_t mf1, mf2;
2361        struct checkdiff_t data;
2362
2363        if (!two)
2364                return;
2365
2366        memset(&data, 0, sizeof(data));
2367        data.filename = name_b ? name_b : name_a;
2368        data.lineno = 0;
2369        data.o = o;
2370        data.ws_rule = whitespace_rule(attr_path);
2371        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2372
2373        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2374                die("unable to read files to diff");
2375
2376        /*
2377         * All the other codepaths check both sides, but not checking
2378         * the "old" side here is deliberate.  We are checking the newly
2379         * introduced changes, and as long as the "new" side is text, we
2380         * can and should check what it introduces.
2381         */
2382        if (diff_filespec_is_binary(two))
2383                goto free_and_return;
2384        else {
2385                /* Crazy xdl interfaces.. */
2386                xpparam_t xpp;
2387                xdemitconf_t xecfg;
2388
2389                memset(&xpp, 0, sizeof(xpp));
2390                memset(&xecfg, 0, sizeof(xecfg));
2391                xecfg.ctxlen = 1; /* at least one context line */
2392                xpp.flags = 0;
2393                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2394                              &xpp, &xecfg);
2395
2396                if (data.ws_rule & WS_BLANK_AT_EOF) {
2397                        struct emit_callback ecbdata;
2398                        int blank_at_eof;
2399
2400                        ecbdata.ws_rule = data.ws_rule;
2401                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2402                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2403
2404                        if (blank_at_eof) {
2405                                static char *err;
2406                                if (!err)
2407                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2408                                fprintf(o->file, "%s:%d: %s.\n",
2409                                        data.filename, blank_at_eof, err);
2410                                data.status = 1; /* report errors */
2411                        }
2412                }
2413        }
2414 free_and_return:
2415        diff_free_filespec_data(one);
2416        diff_free_filespec_data(two);
2417        if (data.status)
2418                DIFF_OPT_SET(o, CHECK_FAILED);
2419}
2420
2421struct diff_filespec *alloc_filespec(const char *path)
2422{
2423        int namelen = strlen(path);
2424        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2425
2426        memset(spec, 0, sizeof(*spec));
2427        spec->path = (char *)(spec + 1);
2428        memcpy(spec->path, path, namelen+1);
2429        spec->count = 1;
2430        spec->is_binary = -1;
2431        return spec;
2432}
2433
2434void free_filespec(struct diff_filespec *spec)
2435{
2436        if (!--spec->count) {
2437                diff_free_filespec_data(spec);
2438                free(spec);
2439        }
2440}
2441
2442void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2443                   unsigned short mode)
2444{
2445        if (mode) {
2446                spec->mode = canon_mode(mode);
2447                hashcpy(spec->sha1, sha1);
2448                spec->sha1_valid = !is_null_sha1(sha1);
2449        }
2450}
2451
2452/*
2453 * Given a name and sha1 pair, if the index tells us the file in
2454 * the work tree has that object contents, return true, so that
2455 * prepare_temp_file() does not have to inflate and extract.
2456 */
2457static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2458{
2459        struct cache_entry *ce;
2460        struct stat st;
2461        int pos, len;
2462
2463        /*
2464         * We do not read the cache ourselves here, because the
2465         * benchmark with my previous version that always reads cache
2466         * shows that it makes things worse for diff-tree comparing
2467         * two linux-2.6 kernel trees in an already checked out work
2468         * tree.  This is because most diff-tree comparisons deal with
2469         * only a small number of files, while reading the cache is
2470         * expensive for a large project, and its cost outweighs the
2471         * savings we get by not inflating the object to a temporary
2472         * file.  Practically, this code only helps when we are used
2473         * by diff-cache --cached, which does read the cache before
2474         * calling us.
2475         */
2476        if (!active_cache)
2477                return 0;
2478
2479        /* We want to avoid the working directory if our caller
2480         * doesn't need the data in a normal file, this system
2481         * is rather slow with its stat/open/mmap/close syscalls,
2482         * and the object is contained in a pack file.  The pack
2483         * is probably already open and will be faster to obtain
2484         * the data through than the working directory.  Loose
2485         * objects however would tend to be slower as they need
2486         * to be individually opened and inflated.
2487         */
2488        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2489                return 0;
2490
2491        len = strlen(name);
2492        pos = cache_name_pos(name, len);
2493        if (pos < 0)
2494                return 0;
2495        ce = active_cache[pos];
2496
2497        /*
2498         * This is not the sha1 we are looking for, or
2499         * unreusable because it is not a regular file.
2500         */
2501        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2502                return 0;
2503
2504        /*
2505         * If ce is marked as "assume unchanged", there is no
2506         * guarantee that work tree matches what we are looking for.
2507         */
2508        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2509                return 0;
2510
2511        /*
2512         * If ce matches the file in the work tree, we can reuse it.
2513         */
2514        if (ce_uptodate(ce) ||
2515            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2516                return 1;
2517
2518        return 0;
2519}
2520
2521static int populate_from_stdin(struct diff_filespec *s)
2522{
2523        struct strbuf buf = STRBUF_INIT;
2524        size_t size = 0;
2525
2526        if (strbuf_read(&buf, 0, 0) < 0)
2527                return error("error while reading from stdin %s",
2528                                     strerror(errno));
2529
2530        s->should_munmap = 0;
2531        s->data = strbuf_detach(&buf, &size);
2532        s->size = size;
2533        s->should_free = 1;
2534        return 0;
2535}
2536
2537static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2538{
2539        int len;
2540        char *data = xmalloc(100), *dirty = "";
2541
2542        /* Are we looking at the work tree? */
2543        if (s->dirty_submodule)
2544                dirty = "-dirty";
2545
2546        len = snprintf(data, 100,
2547                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2548        s->data = data;
2549        s->size = len;
2550        s->should_free = 1;
2551        if (size_only) {
2552                s->data = NULL;
2553                free(data);
2554        }
2555        return 0;
2556}
2557
2558/*
2559 * While doing rename detection and pickaxe operation, we may need to
2560 * grab the data for the blob (or file) for our own in-core comparison.
2561 * diff_filespec has data and size fields for this purpose.
2562 */
2563int diff_populate_filespec(struct diff_filespec *s, int size_only)
2564{
2565        int err = 0;
2566        if (!DIFF_FILE_VALID(s))
2567                die("internal error: asking to populate invalid file.");
2568        if (S_ISDIR(s->mode))
2569                return -1;
2570
2571        if (s->data)
2572                return 0;
2573
2574        if (size_only && 0 < s->size)
2575                return 0;
2576
2577        if (S_ISGITLINK(s->mode))
2578                return diff_populate_gitlink(s, size_only);
2579
2580        if (!s->sha1_valid ||
2581            reuse_worktree_file(s->path, s->sha1, 0)) {
2582                struct strbuf buf = STRBUF_INIT;
2583                struct stat st;
2584                int fd;
2585
2586                if (!strcmp(s->path, "-"))
2587                        return populate_from_stdin(s);
2588
2589                if (lstat(s->path, &st) < 0) {
2590                        if (errno == ENOENT) {
2591                        err_empty:
2592                                err = -1;
2593                        empty:
2594                                s->data = (char *)"";
2595                                s->size = 0;
2596                                return err;
2597                        }
2598                }
2599                s->size = xsize_t(st.st_size);
2600                if (!s->size)
2601                        goto empty;
2602                if (S_ISLNK(st.st_mode)) {
2603                        struct strbuf sb = STRBUF_INIT;
2604
2605                        if (strbuf_readlink(&sb, s->path, s->size))
2606                                goto err_empty;
2607                        s->size = sb.len;
2608                        s->data = strbuf_detach(&sb, NULL);
2609                        s->should_free = 1;
2610                        return 0;
2611                }
2612                if (size_only)
2613                        return 0;
2614                fd = open(s->path, O_RDONLY);
2615                if (fd < 0)
2616                        goto err_empty;
2617                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2618                close(fd);
2619                s->should_munmap = 1;
2620
2621                /*
2622                 * Convert from working tree format to canonical git format
2623                 */
2624                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2625                        size_t size = 0;
2626                        munmap(s->data, s->size);
2627                        s->should_munmap = 0;
2628                        s->data = strbuf_detach(&buf, &size);
2629                        s->size = size;
2630                        s->should_free = 1;
2631                }
2632        }
2633        else {
2634                enum object_type type;
2635                if (size_only) {
2636                        type = sha1_object_info(s->sha1, &s->size);
2637                        if (type < 0)
2638                                die("unable to read %s", sha1_to_hex(s->sha1));
2639                } else {
2640                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2641                        if (!s->data)
2642                                die("unable to read %s", sha1_to_hex(s->sha1));
2643                        s->should_free = 1;
2644                }
2645        }
2646        return 0;
2647}
2648
2649void diff_free_filespec_blob(struct diff_filespec *s)
2650{
2651        if (s->should_free)
2652                free(s->data);
2653        else if (s->should_munmap)
2654                munmap(s->data, s->size);
2655
2656        if (s->should_free || s->should_munmap) {
2657                s->should_free = s->should_munmap = 0;
2658                s->data = NULL;
2659        }
2660}
2661
2662void diff_free_filespec_data(struct diff_filespec *s)
2663{
2664        diff_free_filespec_blob(s);
2665        free(s->cnt_data);
2666        s->cnt_data = NULL;
2667}
2668
2669static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2670                           void *blob,
2671                           unsigned long size,
2672                           const unsigned char *sha1,
2673                           int mode)
2674{
2675        int fd;
2676        struct strbuf buf = STRBUF_INIT;
2677        struct strbuf template = STRBUF_INIT;
2678        char *path_dup = xstrdup(path);
2679        const char *base = basename(path_dup);
2680
2681        /* Generate "XXXXXX_basename.ext" */
2682        strbuf_addstr(&template, "XXXXXX_");
2683        strbuf_addstr(&template, base);
2684
2685        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2686                        strlen(base) + 1);
2687        if (fd < 0)
2688                die_errno("unable to create temp-file");
2689        if (convert_to_working_tree(path,
2690                        (const char *)blob, (size_t)size, &buf)) {
2691                blob = buf.buf;
2692                size = buf.len;
2693        }
2694        if (write_in_full(fd, blob, size) != size)
2695                die_errno("unable to write temp-file");
2696        close(fd);
2697        temp->name = temp->tmp_path;
2698        strcpy(temp->hex, sha1_to_hex(sha1));
2699        temp->hex[40] = 0;
2700        sprintf(temp->mode, "%06o", mode);
2701        strbuf_release(&buf);
2702        strbuf_release(&template);
2703        free(path_dup);
2704}
2705
2706static struct diff_tempfile *prepare_temp_file(const char *name,
2707                struct diff_filespec *one)
2708{
2709        struct diff_tempfile *temp = claim_diff_tempfile();
2710
2711        if (!DIFF_FILE_VALID(one)) {
2712        not_a_valid_file:
2713                /* A '-' entry produces this for file-2, and
2714                 * a '+' entry produces this for file-1.
2715                 */
2716                temp->name = "/dev/null";
2717                strcpy(temp->hex, ".");
2718                strcpy(temp->mode, ".");
2719                return temp;
2720        }
2721
2722        if (!remove_tempfile_installed) {
2723                atexit(remove_tempfile);
2724                sigchain_push_common(remove_tempfile_on_signal);
2725                remove_tempfile_installed = 1;
2726        }
2727
2728        if (!one->sha1_valid ||
2729            reuse_worktree_file(name, one->sha1, 1)) {
2730                struct stat st;
2731                if (lstat(name, &st) < 0) {
2732                        if (errno == ENOENT)
2733                                goto not_a_valid_file;
2734                        die_errno("stat(%s)", name);
2735                }
2736                if (S_ISLNK(st.st_mode)) {
2737                        struct strbuf sb = STRBUF_INIT;
2738                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2739                                die_errno("readlink(%s)", name);
2740                        prep_temp_blob(name, temp, sb.buf, sb.len,
2741                                       (one->sha1_valid ?
2742                                        one->sha1 : null_sha1),
2743                                       (one->sha1_valid ?
2744                                        one->mode : S_IFLNK));
2745                        strbuf_release(&sb);
2746                }
2747                else {
2748                        /* we can borrow from the file in the work tree */
2749                        temp->name = name;
2750                        if (!one->sha1_valid)
2751                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2752                        else
2753                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2754                        /* Even though we may sometimes borrow the
2755                         * contents from the work tree, we always want
2756                         * one->mode.  mode is trustworthy even when
2757                         * !(one->sha1_valid), as long as
2758                         * DIFF_FILE_VALID(one).
2759                         */
2760                        sprintf(temp->mode, "%06o", one->mode);
2761                }
2762                return temp;
2763        }
2764        else {
2765                if (diff_populate_filespec(one, 0))
2766                        die("cannot read data blob for %s", one->path);
2767                prep_temp_blob(name, temp, one->data, one->size,
2768                               one->sha1, one->mode);
2769        }
2770        return temp;
2771}
2772
2773/* An external diff command takes:
2774 *
2775 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2776 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2777 *
2778 */
2779static void run_external_diff(const char *pgm,
2780                              const char *name,
2781                              const char *other,
2782                              struct diff_filespec *one,
2783                              struct diff_filespec *two,
2784                              const char *xfrm_msg,
2785                              int complete_rewrite)
2786{
2787        const char *spawn_arg[10];
2788        int retval;
2789        const char **arg = &spawn_arg[0];
2790
2791        if (one && two) {
2792                struct diff_tempfile *temp_one, *temp_two;
2793                const char *othername = (other ? other : name);
2794                temp_one = prepare_temp_file(name, one);
2795                temp_two = prepare_temp_file(othername, two);
2796                *arg++ = pgm;
2797                *arg++ = name;
2798                *arg++ = temp_one->name;
2799                *arg++ = temp_one->hex;
2800                *arg++ = temp_one->mode;
2801                *arg++ = temp_two->name;
2802                *arg++ = temp_two->hex;
2803                *arg++ = temp_two->mode;
2804                if (other) {
2805                        *arg++ = other;
2806                        *arg++ = xfrm_msg;
2807                }
2808        } else {
2809                *arg++ = pgm;
2810                *arg++ = name;
2811        }
2812        *arg = NULL;
2813        fflush(NULL);
2814        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2815        remove_tempfile();
2816        if (retval) {
2817                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2818                exit(1);
2819        }
2820}
2821
2822static int similarity_index(struct diff_filepair *p)
2823{
2824        return p->score * 100 / MAX_SCORE;
2825}
2826
2827static void fill_metainfo(struct strbuf *msg,
2828                          const char *name,
2829                          const char *other,
2830                          struct diff_filespec *one,
2831                          struct diff_filespec *two,
2832                          struct diff_options *o,
2833                          struct diff_filepair *p,
2834                          int *must_show_header,
2835                          int use_color)
2836{
2837        const char *set = diff_get_color(use_color, DIFF_METAINFO);
2838        const char *reset = diff_get_color(use_color, DIFF_RESET);
2839        struct strbuf *msgbuf;
2840        char *line_prefix = "";
2841
2842        *must_show_header = 1;
2843        if (o->output_prefix) {
2844                msgbuf = o->output_prefix(o, o->output_prefix_data);
2845                line_prefix = msgbuf->buf;
2846        }
2847        strbuf_init(msg, PATH_MAX * 2 + 300);
2848        switch (p->status) {
2849        case DIFF_STATUS_COPIED:
2850                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2851                            line_prefix, set, similarity_index(p));
2852                strbuf_addf(msg, "%s\n%s%scopy from ",
2853                            reset,  line_prefix, set);
2854                quote_c_style(name, msg, NULL, 0);
2855                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2856                quote_c_style(other, msg, NULL, 0);
2857                strbuf_addf(msg, "%s\n", reset);
2858                break;
2859        case DIFF_STATUS_RENAMED:
2860                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2861                            line_prefix, set, similarity_index(p));
2862                strbuf_addf(msg, "%s\n%s%srename from ",
2863                            reset, line_prefix, set);
2864                quote_c_style(name, msg, NULL, 0);
2865                strbuf_addf(msg, "%s\n%s%srename to ",
2866                            reset, line_prefix, set);
2867                quote_c_style(other, msg, NULL, 0);
2868                strbuf_addf(msg, "%s\n", reset);
2869                break;
2870        case DIFF_STATUS_MODIFIED:
2871                if (p->score) {
2872                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2873                                    line_prefix,
2874                                    set, similarity_index(p), reset);
2875                        break;
2876                }
2877                /* fallthru */
2878        default:
2879                *must_show_header = 0;
2880        }
2881        if (one && two && hashcmp(one->sha1, two->sha1)) {
2882                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2883
2884                if (DIFF_OPT_TST(o, BINARY)) {
2885                        mmfile_t mf;
2886                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2887                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2888                                abbrev = 40;
2889                }
2890                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2891                            find_unique_abbrev(one->sha1, abbrev));
2892                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2893                if (one->mode == two->mode)
2894                        strbuf_addf(msg, " %06o", one->mode);
2895                strbuf_addf(msg, "%s\n", reset);
2896        }
2897}
2898
2899static void run_diff_cmd(const char *pgm,
2900                         const char *name,
2901                         const char *other,
2902                         const char *attr_path,
2903                         struct diff_filespec *one,
2904                         struct diff_filespec *two,
2905                         struct strbuf *msg,
2906                         struct diff_options *o,
2907                         struct diff_filepair *p)
2908{
2909        const char *xfrm_msg = NULL;
2910        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2911        int must_show_header = 0;
2912
2913        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2914                pgm = NULL;
2915        else {
2916                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2917                if (drv && drv->external)
2918                        pgm = drv->external;
2919        }
2920
2921        if (msg) {
2922                /*
2923                 * don't use colors when the header is intended for an
2924                 * external diff driver
2925                 */
2926                fill_metainfo(msg, name, other, one, two, o, p,
2927                              &must_show_header,
2928                              want_color(o->use_color) && !pgm);
2929                xfrm_msg = msg->len ? msg->buf : NULL;
2930        }
2931
2932        if (pgm) {
2933                run_external_diff(pgm, name, other, one, two, xfrm_msg,
2934                                  complete_rewrite);
2935                return;
2936        }
2937        if (one && two)
2938                builtin_diff(name, other ? other : name,
2939                             one, two, xfrm_msg, must_show_header,
2940                             o, complete_rewrite);
2941        else
2942                fprintf(o->file, "* Unmerged path %s\n", name);
2943}
2944
2945static void diff_fill_sha1_info(struct diff_filespec *one)
2946{
2947        if (DIFF_FILE_VALID(one)) {
2948                if (!one->sha1_valid) {
2949                        struct stat st;
2950                        if (!strcmp(one->path, "-")) {
2951                                hashcpy(one->sha1, null_sha1);
2952                                return;
2953                        }
2954                        if (lstat(one->path, &st) < 0)
2955                                die_errno("stat '%s'", one->path);
2956                        if (index_path(one->sha1, one->path, &st, 0))
2957                                die("cannot hash %s", one->path);
2958                }
2959        }
2960        else
2961                hashclr(one->sha1);
2962}
2963
2964static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2965{
2966        /* Strip the prefix but do not molest /dev/null and absolute paths */
2967        if (*namep && **namep != '/') {
2968                *namep += prefix_length;
2969                if (**namep == '/')
2970                        ++*namep;
2971        }
2972        if (*otherp && **otherp != '/') {
2973                *otherp += prefix_length;
2974                if (**otherp == '/')
2975                        ++*otherp;
2976        }
2977}
2978
2979static void run_diff(struct diff_filepair *p, struct diff_options *o)
2980{
2981        const char *pgm = external_diff();
2982        struct strbuf msg;
2983        struct diff_filespec *one = p->one;
2984        struct diff_filespec *two = p->two;
2985        const char *name;
2986        const char *other;
2987        const char *attr_path;
2988
2989        name  = p->one->path;
2990        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2991        attr_path = name;
2992        if (o->prefix_length)
2993                strip_prefix(o->prefix_length, &name, &other);
2994
2995        if (DIFF_PAIR_UNMERGED(p)) {
2996                run_diff_cmd(pgm, name, NULL, attr_path,
2997                             NULL, NULL, NULL, o, p);
2998                return;
2999        }
3000
3001        diff_fill_sha1_info(one);
3002        diff_fill_sha1_info(two);
3003
3004        if (!pgm &&
3005            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
3006            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
3007                /*
3008                 * a filepair that changes between file and symlink
3009                 * needs to be split into deletion and creation.
3010                 */
3011                struct diff_filespec *null = alloc_filespec(two->path);
3012                run_diff_cmd(NULL, name, other, attr_path,
3013                             one, null, &msg, o, p);
3014                free(null);
3015                strbuf_release(&msg);
3016
3017                null = alloc_filespec(one->path);
3018                run_diff_cmd(NULL, name, other, attr_path,
3019                             null, two, &msg, o, p);
3020                free(null);
3021        }
3022        else
3023                run_diff_cmd(pgm, name, other, attr_path,
3024                             one, two, &msg, o, p);
3025
3026        strbuf_release(&msg);
3027}
3028
3029static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
3030                         struct diffstat_t *diffstat)
3031{
3032        const char *name;
3033        const char *other;
3034        int complete_rewrite = 0;
3035
3036        if (DIFF_PAIR_UNMERGED(p)) {
3037                /* unmerged */
3038                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
3039                return;
3040        }
3041
3042        name = p->one->path;
3043        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3044
3045        if (o->prefix_length)
3046                strip_prefix(o->prefix_length, &name, &other);
3047
3048        diff_fill_sha1_info(p->one);
3049        diff_fill_sha1_info(p->two);
3050
3051        if (p->status == DIFF_STATUS_MODIFIED && p->score)
3052                complete_rewrite = 1;
3053        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
3054}
3055
3056static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
3057{
3058        const char *name;
3059        const char *other;
3060        const char *attr_path;
3061
3062        if (DIFF_PAIR_UNMERGED(p)) {
3063                /* unmerged */
3064                return;
3065        }
3066
3067        name = p->one->path;
3068        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3069        attr_path = other ? other : name;
3070
3071        if (o->prefix_length)
3072                strip_prefix(o->prefix_length, &name, &other);
3073
3074        diff_fill_sha1_info(p->one);
3075        diff_fill_sha1_info(p->two);
3076
3077        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
3078}
3079
3080void diff_setup(struct diff_options *options)
3081{
3082        memcpy(options, &default_diff_options, sizeof(*options));
3083
3084        options->file = stdout;
3085
3086        options->line_termination = '\n';
3087        options->break_opt = -1;
3088        options->rename_limit = -1;
3089        options->dirstat_permille = diff_dirstat_permille_default;
3090        options->context = 3;
3091
3092        options->change = diff_change;
3093        options->add_remove = diff_addremove;
3094        options->use_color = diff_use_color_default;
3095        options->detect_rename = diff_detect_rename_default;
3096
3097        if (diff_no_prefix) {
3098                options->a_prefix = options->b_prefix = "";
3099        } else if (!diff_mnemonic_prefix) {
3100                options->a_prefix = "a/";
3101                options->b_prefix = "b/";
3102        }
3103}
3104
3105int diff_setup_done(struct diff_options *options)
3106{
3107        int count = 0;
3108
3109        if (options->output_format & DIFF_FORMAT_NAME)
3110                count++;
3111        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
3112                count++;
3113        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
3114                count++;
3115        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
3116                count++;
3117        if (count > 1)
3118                die("--name-only, --name-status, --check and -s are mutually exclusive");
3119
3120        /*
3121         * Most of the time we can say "there are changes"
3122         * only by checking if there are changed paths, but
3123         * --ignore-whitespace* options force us to look
3124         * inside contents.
3125         */
3126
3127        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
3128            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
3129            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
3130                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
3131        else
3132                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
3133
3134        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3135                options->detect_rename = DIFF_DETECT_COPY;
3136
3137        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
3138                options->prefix = NULL;
3139        if (options->prefix)
3140                options->prefix_length = strlen(options->prefix);
3141        else
3142                options->prefix_length = 0;
3143
3144        if (options->output_format & (DIFF_FORMAT_NAME |
3145                                      DIFF_FORMAT_NAME_STATUS |
3146                                      DIFF_FORMAT_CHECKDIFF |
3147                                      DIFF_FORMAT_NO_OUTPUT))
3148                options->output_format &= ~(DIFF_FORMAT_RAW |
3149                                            DIFF_FORMAT_NUMSTAT |
3150                                            DIFF_FORMAT_DIFFSTAT |
3151                                            DIFF_FORMAT_SHORTSTAT |
3152                                            DIFF_FORMAT_DIRSTAT |
3153                                            DIFF_FORMAT_SUMMARY |
3154                                            DIFF_FORMAT_PATCH);
3155
3156        /*
3157         * These cases always need recursive; we do not drop caller-supplied
3158         * recursive bits for other formats here.
3159         */
3160        if (options->output_format & (DIFF_FORMAT_PATCH |
3161                                      DIFF_FORMAT_NUMSTAT |
3162                                      DIFF_FORMAT_DIFFSTAT |
3163                                      DIFF_FORMAT_SHORTSTAT |
3164                                      DIFF_FORMAT_DIRSTAT |
3165                                      DIFF_FORMAT_SUMMARY |
3166                                      DIFF_FORMAT_CHECKDIFF))
3167                DIFF_OPT_SET(options, RECURSIVE);
3168        /*
3169         * Also pickaxe would not work very well if you do not say recursive
3170         */
3171        if (options->pickaxe)
3172                DIFF_OPT_SET(options, RECURSIVE);
3173        /*
3174         * When patches are generated, submodules diffed against the work tree
3175         * must be checked for dirtiness too so it can be shown in the output
3176         */
3177        if (options->output_format & DIFF_FORMAT_PATCH)
3178                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3179
3180        if (options->detect_rename && options->rename_limit < 0)
3181                options->rename_limit = diff_rename_limit_default;
3182        if (options->setup & DIFF_SETUP_USE_CACHE) {
3183                if (!active_cache)
3184                        /* read-cache does not die even when it fails
3185                         * so it is safe for us to do this here.  Also
3186                         * it does not smudge active_cache or active_nr
3187                         * when it fails, so we do not have to worry about
3188                         * cleaning it up ourselves either.
3189                         */
3190                        read_cache();
3191        }
3192        if (options->abbrev <= 0 || 40 < options->abbrev)
3193                options->abbrev = 40; /* full */
3194
3195        /*
3196         * It does not make sense to show the first hit we happened
3197         * to have found.  It does not make sense not to return with
3198         * exit code in such a case either.
3199         */
3200        if (DIFF_OPT_TST(options, QUICK)) {
3201                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3202                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3203        }
3204
3205        return 0;
3206}
3207
3208static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3209{
3210        char c, *eq;
3211        int len;
3212
3213        if (*arg != '-')
3214                return 0;
3215        c = *++arg;
3216        if (!c)
3217                return 0;
3218        if (c == arg_short) {
3219                c = *++arg;
3220                if (!c)
3221                        return 1;
3222                if (val && isdigit(c)) {
3223                        char *end;
3224                        int n = strtoul(arg, &end, 10);
3225                        if (*end)
3226                                return 0;
3227                        *val = n;
3228                        return 1;
3229                }
3230                return 0;
3231        }
3232        if (c != '-')
3233                return 0;
3234        arg++;
3235        eq = strchr(arg, '=');
3236        if (eq)
3237                len = eq - arg;
3238        else
3239                len = strlen(arg);
3240        if (!len || strncmp(arg, arg_long, len))
3241                return 0;
3242        if (eq) {
3243                int n;
3244                char *end;
3245                if (!isdigit(*++eq))
3246                        return 0;
3247                n = strtoul(eq, &end, 10);
3248                if (*end)
3249                        return 0;
3250                *val = n;
3251        }
3252        return 1;
3253}
3254
3255static int diff_scoreopt_parse(const char *opt);
3256
3257static inline int short_opt(char opt, const char **argv,
3258                            const char **optarg)
3259{
3260        const char *arg = argv[0];
3261        if (arg[0] != '-' || arg[1] != opt)
3262                return 0;
3263        if (arg[2] != '\0') {
3264                *optarg = arg + 2;
3265                return 1;
3266        }
3267        if (!argv[1])
3268                die("Option '%c' requires a value", opt);
3269        *optarg = argv[1];
3270        return 2;
3271}
3272
3273int parse_long_opt(const char *opt, const char **argv,
3274                   const char **optarg)
3275{
3276        const char *arg = argv[0];
3277        if (arg[0] != '-' || arg[1] != '-')
3278                return 0;
3279        arg += strlen("--");
3280        if (prefixcmp(arg, opt))
3281                return 0;
3282        arg += strlen(opt);
3283        if (*arg == '=') { /* sticked form: --option=value */
3284                *optarg = arg + 1;
3285                return 1;
3286        }
3287        if (*arg != '\0')
3288                return 0;
3289        /* separate form: --option value */
3290        if (!argv[1])
3291                die("Option '--%s' requires a value", opt);
3292        *optarg = argv[1];
3293        return 2;
3294}
3295
3296static int stat_opt(struct diff_options *options, const char **av)
3297{
3298        const char *arg = av[0];
3299        char *end;
3300        int width = options->stat_width;
3301        int name_width = options->stat_name_width;
3302        int count = options->stat_count;
3303        int argcount = 1;
3304
3305        arg += strlen("--stat");
3306        end = (char *)arg;
3307
3308        switch (*arg) {
3309        case '-':
3310                if (!prefixcmp(arg, "-width")) {
3311                        arg += strlen("-width");
3312                        if (*arg == '=')
3313                                width = strtoul(arg + 1, &end, 10);
3314                        else if (!*arg && !av[1])
3315                                die("Option '--stat-width' requires a value");
3316                        else if (!*arg) {
3317                                width = strtoul(av[1], &end, 10);
3318                                argcount = 2;
3319                        }
3320                } else if (!prefixcmp(arg, "-name-width")) {
3321                        arg += strlen("-name-width");
3322                        if (*arg == '=')
3323                                name_width = strtoul(arg + 1, &end, 10);
3324                        else if (!*arg && !av[1])
3325                                die("Option '--stat-name-width' requires a value");
3326                        else if (!*arg) {
3327                                name_width = strtoul(av[1], &end, 10);
3328                                argcount = 2;
3329                        }
3330                } else if (!prefixcmp(arg, "-count")) {
3331                        arg += strlen("-count");
3332                        if (*arg == '=')
3333                                count = strtoul(arg + 1, &end, 10);
3334                        else if (!*arg && !av[1])
3335                                die("Option '--stat-count' requires a value");
3336                        else if (!*arg) {
3337                                count = strtoul(av[1], &end, 10);
3338                                argcount = 2;
3339                        }
3340                }
3341                break;
3342        case '=':
3343                width = strtoul(arg+1, &end, 10);
3344                if (*end == ',')
3345                        name_width = strtoul(end+1, &end, 10);
3346                if (*end == ',')
3347                        count = strtoul(end+1, &end, 10);
3348        }
3349
3350        /* Important! This checks all the error cases! */
3351        if (*end)
3352                return 0;
3353        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3354        options->stat_name_width = name_width;
3355        options->stat_width = width;
3356        options->stat_count = count;
3357        return argcount;
3358}
3359
3360static int parse_dirstat_opt(struct diff_options *options, const char *params)
3361{
3362        struct strbuf errmsg = STRBUF_INIT;
3363        if (parse_dirstat_params(options, params, &errmsg))
3364                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
3365                    errmsg.buf);
3366        strbuf_release(&errmsg);
3367        /*
3368         * The caller knows a dirstat-related option is given from the command
3369         * line; allow it to say "return this_function();"
3370         */
3371        options->output_format |= DIFF_FORMAT_DIRSTAT;
3372        return 1;
3373}
3374
3375int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3376{
3377        const char *arg = av[0];
3378        const char *optarg;
3379        int argcount;
3380
3381        /* Output format options */
3382        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3383                options->output_format |= DIFF_FORMAT_PATCH;
3384        else if (opt_arg(arg, 'U', "unified", &options->context))
3385                options->output_format |= DIFF_FORMAT_PATCH;
3386        else if (!strcmp(arg, "--raw"))
3387                options->output_format |= DIFF_FORMAT_RAW;
3388        else if (!strcmp(arg, "--patch-with-raw"))
3389                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3390        else if (!strcmp(arg, "--numstat"))
3391                options->output_format |= DIFF_FORMAT_NUMSTAT;
3392        else if (!strcmp(arg, "--shortstat"))
3393                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3394        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
3395                return parse_dirstat_opt(options, "");
3396        else if (!prefixcmp(arg, "-X"))
3397                return parse_dirstat_opt(options, arg + 2);
3398        else if (!prefixcmp(arg, "--dirstat="))
3399                return parse_dirstat_opt(options, arg + 10);
3400        else if (!strcmp(arg, "--cumulative"))
3401                return parse_dirstat_opt(options, "cumulative");
3402        else if (!strcmp(arg, "--dirstat-by-file"))
3403                return parse_dirstat_opt(options, "files");
3404        else if (!prefixcmp(arg, "--dirstat-by-file=")) {
3405                parse_dirstat_opt(options, "files");
3406                return parse_dirstat_opt(options, arg + 18);
3407        }
3408        else if (!strcmp(arg, "--check"))
3409                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3410        else if (!strcmp(arg, "--summary"))
3411                options->output_format |= DIFF_FORMAT_SUMMARY;
3412        else if (!strcmp(arg, "--patch-with-stat"))
3413                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3414        else if (!strcmp(arg, "--name-only"))
3415                options->output_format |= DIFF_FORMAT_NAME;
3416        else if (!strcmp(arg, "--name-status"))
3417                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3418        else if (!strcmp(arg, "-s"))
3419                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3420        else if (!prefixcmp(arg, "--stat"))
3421                /* --stat, --stat-width, --stat-name-width, or --stat-count */
3422                return stat_opt(options, av);
3423
3424        /* renames options */
3425        else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
3426                 !strcmp(arg, "--break-rewrites")) {
3427                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3428                        return error("invalid argument to -B: %s", arg+2);
3429        }
3430        else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--find-renames=") ||
3431                 !strcmp(arg, "--find-renames")) {
3432                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3433                        return error("invalid argument to -M: %s", arg+2);
3434                options->detect_rename = DIFF_DETECT_RENAME;
3435        }
3436        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3437                options->irreversible_delete = 1;
3438        }
3439        else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
3440                 !strcmp(arg, "--find-copies")) {
3441                if (options->detect_rename == DIFF_DETECT_COPY)
3442                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3443                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3444                        return error("invalid argument to -C: %s", arg+2);
3445                options->detect_rename = DIFF_DETECT_COPY;
3446        }
3447        else if (!strcmp(arg, "--no-renames"))
3448                options->detect_rename = 0;
3449        else if (!strcmp(arg, "--relative"))
3450                DIFF_OPT_SET(options, RELATIVE_NAME);
3451        else if (!prefixcmp(arg, "--relative=")) {
3452                DIFF_OPT_SET(options, RELATIVE_NAME);
3453                options->prefix = arg + 11;
3454        }
3455
3456        /* xdiff options */
3457        else if (!strcmp(arg, "--minimal"))
3458                DIFF_XDL_SET(options, NEED_MINIMAL);
3459        else if (!strcmp(arg, "--no-minimal"))
3460                DIFF_XDL_CLR(options, NEED_MINIMAL);
3461        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3462                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3463        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3464                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3465        else if (!strcmp(arg, "--ignore-space-at-eol"))
3466                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3467        else if (!strcmp(arg, "--patience"))
3468                DIFF_XDL_SET(options, PATIENCE_DIFF);
3469        else if (!strcmp(arg, "--histogram"))
3470                DIFF_XDL_SET(options, HISTOGRAM_DIFF);
3471
3472        /* flags options */
3473        else if (!strcmp(arg, "--binary")) {
3474                options->output_format |= DIFF_FORMAT_PATCH;
3475                DIFF_OPT_SET(options, BINARY);
3476        }
3477        else if (!strcmp(arg, "--full-index"))
3478                DIFF_OPT_SET(options, FULL_INDEX);
3479        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3480                DIFF_OPT_SET(options, TEXT);
3481        else if (!strcmp(arg, "-R"))
3482                DIFF_OPT_SET(options, REVERSE_DIFF);
3483        else if (!strcmp(arg, "--find-copies-harder"))
3484                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3485        else if (!strcmp(arg, "--follow"))
3486                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3487        else if (!strcmp(arg, "--color"))
3488                options->use_color = 1;
3489        else if (!prefixcmp(arg, "--color=")) {
3490                int value = git_config_colorbool(NULL, arg+8);
3491                if (value < 0)
3492                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3493                options->use_color = value;
3494        }
3495        else if (!strcmp(arg, "--no-color"))
3496                options->use_color = 0;
3497        else if (!strcmp(arg, "--color-words")) {
3498                options->use_color = 1;
3499                options->word_diff = DIFF_WORDS_COLOR;
3500        }
3501        else if (!prefixcmp(arg, "--color-words=")) {
3502                options->use_color = 1;
3503                options->word_diff = DIFF_WORDS_COLOR;
3504                options->word_regex = arg + 14;
3505        }
3506        else if (!strcmp(arg, "--word-diff")) {
3507                if (options->word_diff == DIFF_WORDS_NONE)
3508                        options->word_diff = DIFF_WORDS_PLAIN;
3509        }
3510        else if (!prefixcmp(arg, "--word-diff=")) {
3511                const char *type = arg + 12;
3512                if (!strcmp(type, "plain"))
3513                        options->word_diff = DIFF_WORDS_PLAIN;
3514                else if (!strcmp(type, "color")) {
3515                        options->use_color = 1;
3516                        options->word_diff = DIFF_WORDS_COLOR;
3517                }
3518                else if (!strcmp(type, "porcelain"))
3519                        options->word_diff = DIFF_WORDS_PORCELAIN;
3520                else if (!strcmp(type, "none"))
3521                        options->word_diff = DIFF_WORDS_NONE;
3522                else
3523                        die("bad --word-diff argument: %s", type);
3524        }
3525        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3526                if (options->word_diff == DIFF_WORDS_NONE)
3527                        options->word_diff = DIFF_WORDS_PLAIN;
3528                options->word_regex = optarg;
3529                return argcount;
3530        }
3531        else if (!strcmp(arg, "--exit-code"))
3532                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3533        else if (!strcmp(arg, "--quiet"))
3534                DIFF_OPT_SET(options, QUICK);
3535        else if (!strcmp(arg, "--ext-diff"))
3536                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3537        else if (!strcmp(arg, "--no-ext-diff"))
3538                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3539        else if (!strcmp(arg, "--textconv"))
3540                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3541        else if (!strcmp(arg, "--no-textconv"))
3542                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3543        else if (!strcmp(arg, "--ignore-submodules")) {
3544                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3545                handle_ignore_submodules_arg(options, "all");
3546        } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3547                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3548                handle_ignore_submodules_arg(options, arg + 20);
3549        } else if (!strcmp(arg, "--submodule"))
3550                DIFF_OPT_SET(options, SUBMODULE_LOG);
3551        else if (!prefixcmp(arg, "--submodule=")) {
3552                if (!strcmp(arg + 12, "log"))
3553                        DIFF_OPT_SET(options, SUBMODULE_LOG);
3554        }
3555
3556        /* misc options */
3557        else if (!strcmp(arg, "-z"))
3558                options->line_termination = 0;
3559        else if ((argcount = short_opt('l', av, &optarg))) {
3560                options->rename_limit = strtoul(optarg, NULL, 10);
3561                return argcount;
3562        }
3563        else if ((argcount = short_opt('S', av, &optarg))) {
3564                options->pickaxe = optarg;
3565                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3566                return argcount;
3567        } else if ((argcount = short_opt('G', av, &optarg))) {
3568                options->pickaxe = optarg;
3569                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3570                return argcount;
3571        }
3572        else if (!strcmp(arg, "--pickaxe-all"))
3573                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3574        else if (!strcmp(arg, "--pickaxe-regex"))
3575                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3576        else if ((argcount = short_opt('O', av, &optarg))) {
3577                options->orderfile = optarg;
3578                return argcount;
3579        }
3580        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3581                options->filter = optarg;
3582                return argcount;
3583        }
3584        else if (!strcmp(arg, "--abbrev"))
3585                options->abbrev = DEFAULT_ABBREV;
3586        else if (!prefixcmp(arg, "--abbrev=")) {
3587                options->abbrev = strtoul(arg + 9, NULL, 10);
3588                if (options->abbrev < MINIMUM_ABBREV)
3589                        options->abbrev = MINIMUM_ABBREV;
3590                else if (40 < options->abbrev)
3591                        options->abbrev = 40;
3592        }
3593        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3594                options->a_prefix = optarg;
3595                return argcount;
3596        }
3597        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3598                options->b_prefix = optarg;
3599                return argcount;
3600        }
3601        else if (!strcmp(arg, "--no-prefix"))
3602                options->a_prefix = options->b_prefix = "";
3603        else if (opt_arg(arg, '\0', "inter-hunk-context",
3604                         &options->interhunkcontext))
3605                ;
3606        else if (!strcmp(arg, "-W"))
3607                DIFF_OPT_SET(options, FUNCCONTEXT);
3608        else if (!strcmp(arg, "--function-context"))
3609                DIFF_OPT_SET(options, FUNCCONTEXT);
3610        else if (!strcmp(arg, "--no-function-context"))
3611                DIFF_OPT_CLR(options, FUNCCONTEXT);
3612        else if ((argcount = parse_long_opt("output", av, &optarg))) {
3613                options->file = fopen(optarg, "w");
3614                if (!options->file)
3615                        die_errno("Could not open '%s'", optarg);
3616                options->close_file = 1;
3617                return argcount;
3618        } else
3619                return 0;
3620        return 1;
3621}
3622
3623int parse_rename_score(const char **cp_p)
3624{
3625        unsigned long num, scale;
3626        int ch, dot;
3627        const char *cp = *cp_p;
3628
3629        num = 0;
3630        scale = 1;
3631        dot = 0;
3632        for (;;) {
3633                ch = *cp;
3634                if ( !dot && ch == '.' ) {
3635                        scale = 1;
3636                        dot = 1;
3637                } else if ( ch == '%' ) {
3638                        scale = dot ? scale*100 : 100;
3639                        cp++;   /* % is always at the end */
3640                        break;
3641                } else if ( ch >= '0' && ch <= '9' ) {
3642                        if ( scale < 100000 ) {
3643                                scale *= 10;
3644                                num = (num*10) + (ch-'0');
3645                        }
3646                } else {
3647                        break;
3648                }
3649                cp++;
3650        }
3651        *cp_p = cp;
3652
3653        /* user says num divided by scale and we say internally that
3654         * is MAX_SCORE * num / scale.
3655         */
3656        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3657}
3658
3659static int diff_scoreopt_parse(const char *opt)
3660{
3661        int opt1, opt2, cmd;
3662
3663        if (*opt++ != '-')
3664                return -1;
3665        cmd = *opt++;
3666        if (cmd == '-') {
3667                /* convert the long-form arguments into short-form versions */
3668                if (!prefixcmp(opt, "break-rewrites")) {
3669                        opt += strlen("break-rewrites");
3670                        if (*opt == 0 || *opt++ == '=')
3671                                cmd = 'B';
3672                } else if (!prefixcmp(opt, "find-copies")) {
3673                        opt += strlen("find-copies");
3674                        if (*opt == 0 || *opt++ == '=')
3675                                cmd = 'C';
3676                } else if (!prefixcmp(opt, "find-renames")) {
3677                        opt += strlen("find-renames");
3678                        if (*opt == 0 || *opt++ == '=')
3679                                cmd = 'M';
3680                }
3681        }
3682        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3683                return -1; /* that is not a -M, -C nor -B option */
3684
3685        opt1 = parse_rename_score(&opt);
3686        if (cmd != 'B')
3687                opt2 = 0;
3688        else {
3689                if (*opt == 0)
3690                        opt2 = 0;
3691                else if (*opt != '/')
3692                        return -1; /* we expect -B80/99 or -B80 */
3693                else {
3694                        opt++;
3695                        opt2 = parse_rename_score(&opt);
3696                }
3697        }
3698        if (*opt != 0)
3699                return -1;
3700        return opt1 | (opt2 << 16);
3701}
3702
3703struct diff_queue_struct diff_queued_diff;
3704
3705void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3706{
3707        if (queue->alloc <= queue->nr) {
3708                queue->alloc = alloc_nr(queue->alloc);
3709                queue->queue = xrealloc(queue->queue,
3710                                        sizeof(dp) * queue->alloc);
3711        }
3712        queue->queue[queue->nr++] = dp;
3713}
3714
3715struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3716                                 struct diff_filespec *one,
3717                                 struct diff_filespec *two)
3718{
3719        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3720        dp->one = one;
3721        dp->two = two;
3722        if (queue)
3723                diff_q(queue, dp);
3724        return dp;
3725}
3726
3727void diff_free_filepair(struct diff_filepair *p)
3728{
3729        free_filespec(p->one);
3730        free_filespec(p->two);
3731        free(p);
3732}
3733
3734/* This is different from find_unique_abbrev() in that
3735 * it stuffs the result with dots for alignment.
3736 */
3737const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3738{
3739        int abblen;
3740        const char *abbrev;
3741        if (len == 40)
3742                return sha1_to_hex(sha1);
3743
3744        abbrev = find_unique_abbrev(sha1, len);
3745        abblen = strlen(abbrev);
3746        if (abblen < 37) {
3747                static char hex[41];
3748                if (len < abblen && abblen <= len + 2)
3749                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3750                else
3751                        sprintf(hex, "%s...", abbrev);
3752                return hex;
3753        }
3754        return sha1_to_hex(sha1);
3755}
3756
3757static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3758{
3759        int line_termination = opt->line_termination;
3760        int inter_name_termination = line_termination ? '\t' : '\0';
3761        if (opt->output_prefix) {
3762                struct strbuf *msg = NULL;
3763                msg = opt->output_prefix(opt, opt->output_prefix_data);
3764                fprintf(opt->file, "%s", msg->buf);
3765        }
3766
3767        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3768                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3769                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3770                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3771        }
3772        if (p->score) {
3773                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3774                        inter_name_termination);
3775        } else {
3776                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3777        }
3778
3779        if (p->status == DIFF_STATUS_COPIED ||
3780            p->status == DIFF_STATUS_RENAMED) {
3781                const char *name_a, *name_b;
3782                name_a = p->one->path;
3783                name_b = p->two->path;
3784                strip_prefix(opt->prefix_length, &name_a, &name_b);
3785                write_name_quoted(name_a, opt->file, inter_name_termination);
3786                write_name_quoted(name_b, opt->file, line_termination);
3787        } else {
3788                const char *name_a, *name_b;
3789                name_a = p->one->mode ? p->one->path : p->two->path;
3790                name_b = NULL;
3791                strip_prefix(opt->prefix_length, &name_a, &name_b);
3792                write_name_quoted(name_a, opt->file, line_termination);
3793        }
3794}
3795
3796int diff_unmodified_pair(struct diff_filepair *p)
3797{
3798        /* This function is written stricter than necessary to support
3799         * the currently implemented transformers, but the idea is to
3800         * let transformers to produce diff_filepairs any way they want,
3801         * and filter and clean them up here before producing the output.
3802         */
3803        struct diff_filespec *one = p->one, *two = p->two;
3804
3805        if (DIFF_PAIR_UNMERGED(p))
3806                return 0; /* unmerged is interesting */
3807
3808        /* deletion, addition, mode or type change
3809         * and rename are all interesting.
3810         */
3811        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3812            DIFF_PAIR_MODE_CHANGED(p) ||
3813            strcmp(one->path, two->path))
3814                return 0;
3815
3816        /* both are valid and point at the same path.  that is, we are
3817         * dealing with a change.
3818         */
3819        if (one->sha1_valid && two->sha1_valid &&
3820            !hashcmp(one->sha1, two->sha1) &&
3821            !one->dirty_submodule && !two->dirty_submodule)
3822                return 1; /* no change */
3823        if (!one->sha1_valid && !two->sha1_valid)
3824                return 1; /* both look at the same file on the filesystem. */
3825        return 0;
3826}
3827
3828static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3829{
3830        if (diff_unmodified_pair(p))
3831                return;
3832
3833        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3834            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3835                return; /* no tree diffs in patch format */
3836
3837        run_diff(p, o);
3838}
3839
3840static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3841                            struct diffstat_t *diffstat)
3842{
3843        if (diff_unmodified_pair(p))
3844                return;
3845
3846        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3847            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3848                return; /* no useful stat for tree diffs */
3849
3850        run_diffstat(p, o, diffstat);
3851}
3852
3853static void diff_flush_checkdiff(struct diff_filepair *p,
3854                struct diff_options *o)
3855{
3856        if (diff_unmodified_pair(p))
3857                return;
3858
3859        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3860            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3861                return; /* nothing to check in tree diffs */
3862
3863        run_checkdiff(p, o);
3864}
3865
3866int diff_queue_is_empty(void)
3867{
3868        struct diff_queue_struct *q = &diff_queued_diff;
3869        int i;
3870        for (i = 0; i < q->nr; i++)
3871                if (!diff_unmodified_pair(q->queue[i]))
3872                        return 0;
3873        return 1;
3874}
3875
3876#if DIFF_DEBUG
3877void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3878{
3879        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3880                x, one ? one : "",
3881                s->path,
3882                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3883                s->mode,
3884                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3885        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3886                x, one ? one : "",
3887                s->size, s->xfrm_flags);
3888}
3889
3890void diff_debug_filepair(const struct diff_filepair *p, int i)
3891{
3892        diff_debug_filespec(p->one, i, "one");
3893        diff_debug_filespec(p->two, i, "two");
3894        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3895                p->score, p->status ? p->status : '?',
3896                p->one->rename_used, p->broken_pair);
3897}
3898
3899void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3900{
3901        int i;
3902        if (msg)
3903                fprintf(stderr, "%s\n", msg);
3904        fprintf(stderr, "q->nr = %d\n", q->nr);
3905        for (i = 0; i < q->nr; i++) {
3906                struct diff_filepair *p = q->queue[i];
3907                diff_debug_filepair(p, i);
3908        }
3909}
3910#endif
3911
3912static void diff_resolve_rename_copy(void)
3913{
3914        int i;
3915        struct diff_filepair *p;
3916        struct diff_queue_struct *q = &diff_queued_diff;
3917
3918        diff_debug_queue("resolve-rename-copy", q);
3919
3920        for (i = 0; i < q->nr; i++) {
3921                p = q->queue[i];
3922                p->status = 0; /* undecided */
3923                if (DIFF_PAIR_UNMERGED(p))
3924                        p->status = DIFF_STATUS_UNMERGED;
3925                else if (!DIFF_FILE_VALID(p->one))
3926                        p->status = DIFF_STATUS_ADDED;
3927                else if (!DIFF_FILE_VALID(p->two))
3928                        p->status = DIFF_STATUS_DELETED;
3929                else if (DIFF_PAIR_TYPE_CHANGED(p))
3930                        p->status = DIFF_STATUS_TYPE_CHANGED;
3931
3932                /* from this point on, we are dealing with a pair
3933                 * whose both sides are valid and of the same type, i.e.
3934                 * either in-place edit or rename/copy edit.
3935                 */
3936                else if (DIFF_PAIR_RENAME(p)) {
3937                        /*
3938                         * A rename might have re-connected a broken
3939                         * pair up, causing the pathnames to be the
3940                         * same again. If so, that's not a rename at
3941                         * all, just a modification..
3942                         *
3943                         * Otherwise, see if this source was used for
3944                         * multiple renames, in which case we decrement
3945                         * the count, and call it a copy.
3946                         */
3947                        if (!strcmp(p->one->path, p->two->path))
3948                                p->status = DIFF_STATUS_MODIFIED;
3949                        else if (--p->one->rename_used > 0)
3950                                p->status = DIFF_STATUS_COPIED;
3951                        else
3952                                p->status = DIFF_STATUS_RENAMED;
3953                }
3954                else if (hashcmp(p->one->sha1, p->two->sha1) ||
3955                         p->one->mode != p->two->mode ||
3956                         p->one->dirty_submodule ||
3957                         p->two->dirty_submodule ||
3958                         is_null_sha1(p->one->sha1))
3959                        p->status = DIFF_STATUS_MODIFIED;
3960                else {
3961                        /* This is a "no-change" entry and should not
3962                         * happen anymore, but prepare for broken callers.
3963                         */
3964                        error("feeding unmodified %s to diffcore",
3965                              p->one->path);
3966                        p->status = DIFF_STATUS_UNKNOWN;
3967                }
3968        }
3969        diff_debug_queue("resolve-rename-copy done", q);
3970}
3971
3972static int check_pair_status(struct diff_filepair *p)
3973{
3974        switch (p->status) {
3975        case DIFF_STATUS_UNKNOWN:
3976                return 0;
3977        case 0:
3978                die("internal error in diff-resolve-rename-copy");
3979        default:
3980                return 1;
3981        }
3982}
3983
3984static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3985{
3986        int fmt = opt->output_format;
3987
3988        if (fmt & DIFF_FORMAT_CHECKDIFF)
3989                diff_flush_checkdiff(p, opt);
3990        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3991                diff_flush_raw(p, opt);
3992        else if (fmt & DIFF_FORMAT_NAME) {
3993                const char *name_a, *name_b;
3994                name_a = p->two->path;
3995                name_b = NULL;
3996                strip_prefix(opt->prefix_length, &name_a, &name_b);
3997                write_name_quoted(name_a, opt->file, opt->line_termination);
3998        }
3999}
4000
4001static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
4002{
4003        if (fs->mode)
4004                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
4005        else
4006                fprintf(file, " %s ", newdelete);
4007        write_name_quoted(fs->path, file, '\n');
4008}
4009
4010
4011static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
4012                const char *line_prefix)
4013{
4014        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
4015                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
4016                        p->two->mode, show_name ? ' ' : '\n');
4017                if (show_name) {
4018                        write_name_quoted(p->two->path, file, '\n');
4019                }
4020        }
4021}
4022
4023static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
4024                        const char *line_prefix)
4025{
4026        char *names = pprint_rename(p->one->path, p->two->path);
4027
4028        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
4029        free(names);
4030        show_mode_change(file, p, 0, line_prefix);
4031}
4032
4033static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
4034{
4035        FILE *file = opt->file;
4036        char *line_prefix = "";
4037
4038        if (opt->output_prefix) {
4039                struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
4040                line_prefix = buf->buf;
4041        }
4042
4043        switch(p->status) {
4044        case DIFF_STATUS_DELETED:
4045                fputs(line_prefix, file);
4046                show_file_mode_name(file, "delete", p->one);
4047                break;
4048        case DIFF_STATUS_ADDED:
4049                fputs(line_prefix, file);
4050                show_file_mode_name(file, "create", p->two);
4051                break;
4052        case DIFF_STATUS_COPIED:
4053                fputs(line_prefix, file);
4054                show_rename_copy(file, "copy", p, line_prefix);
4055                break;
4056        case DIFF_STATUS_RENAMED:
4057                fputs(line_prefix, file);
4058                show_rename_copy(file, "rename", p, line_prefix);
4059                break;
4060        default:
4061                if (p->score) {
4062                        fprintf(file, "%s rewrite ", line_prefix);
4063                        write_name_quoted(p->two->path, file, ' ');
4064                        fprintf(file, "(%d%%)\n", similarity_index(p));
4065                }
4066                show_mode_change(file, p, !p->score, line_prefix);
4067                break;
4068        }
4069}
4070
4071struct patch_id_t {
4072        git_SHA_CTX *ctx;
4073        int patchlen;
4074};
4075
4076static int remove_space(char *line, int len)
4077{
4078        int i;
4079        char *dst = line;
4080        unsigned char c;
4081
4082        for (i = 0; i < len; i++)
4083                if (!isspace((c = line[i])))
4084                        *dst++ = c;
4085
4086        return dst - line;
4087}
4088
4089static void patch_id_consume(void *priv, char *line, unsigned long len)
4090{
4091        struct patch_id_t *data = priv;
4092        int new_len;
4093
4094        /* Ignore line numbers when computing the SHA1 of the patch */
4095        if (!prefixcmp(line, "@@ -"))
4096                return;
4097
4098        new_len = remove_space(line, len);
4099
4100        git_SHA1_Update(data->ctx, line, new_len);
4101        data->patchlen += new_len;
4102}
4103
4104/* returns 0 upon success, and writes result into sha1 */
4105static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
4106{
4107        struct diff_queue_struct *q = &diff_queued_diff;
4108        int i;
4109        git_SHA_CTX ctx;
4110        struct patch_id_t data;
4111        char buffer[PATH_MAX * 4 + 20];
4112
4113        git_SHA1_Init(&ctx);
4114        memset(&data, 0, sizeof(struct patch_id_t));
4115        data.ctx = &ctx;
4116
4117        for (i = 0; i < q->nr; i++) {
4118                xpparam_t xpp;
4119                xdemitconf_t xecfg;
4120                mmfile_t mf1, mf2;
4121                struct diff_filepair *p = q->queue[i];
4122                int len1, len2;
4123
4124                memset(&xpp, 0, sizeof(xpp));
4125                memset(&xecfg, 0, sizeof(xecfg));
4126                if (p->status == 0)
4127                        return error("internal diff status error");
4128                if (p->status == DIFF_STATUS_UNKNOWN)
4129                        continue;
4130                if (diff_unmodified_pair(p))
4131                        continue;
4132                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4133                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4134                        continue;
4135                if (DIFF_PAIR_UNMERGED(p))
4136                        continue;
4137
4138                diff_fill_sha1_info(p->one);
4139                diff_fill_sha1_info(p->two);
4140                if (fill_mmfile(&mf1, p->one) < 0 ||
4141                                fill_mmfile(&mf2, p->two) < 0)
4142                        return error("unable to read files to diff");
4143
4144                len1 = remove_space(p->one->path, strlen(p->one->path));
4145                len2 = remove_space(p->two->path, strlen(p->two->path));
4146                if (p->one->mode == 0)
4147                        len1 = snprintf(buffer, sizeof(buffer),
4148                                        "diff--gita/%.*sb/%.*s"
4149                                        "newfilemode%06o"
4150                                        "---/dev/null"
4151                                        "+++b/%.*s",
4152                                        len1, p->one->path,
4153                                        len2, p->two->path,
4154                                        p->two->mode,
4155                                        len2, p->two->path);
4156                else if (p->two->mode == 0)
4157                        len1 = snprintf(buffer, sizeof(buffer),
4158                                        "diff--gita/%.*sb/%.*s"
4159                                        "deletedfilemode%06o"
4160                                        "---a/%.*s"
4161                                        "+++/dev/null",
4162                                        len1, p->one->path,
4163                                        len2, p->two->path,
4164                                        p->one->mode,
4165                                        len1, p->one->path);
4166                else
4167                        len1 = snprintf(buffer, sizeof(buffer),
4168                                        "diff--gita/%.*sb/%.*s"
4169                                        "---a/%.*s"
4170                                        "+++b/%.*s",
4171                                        len1, p->one->path,
4172                                        len2, p->two->path,
4173                                        len1, p->one->path,
4174                                        len2, p->two->path);
4175                git_SHA1_Update(&ctx, buffer, len1);
4176
4177                if (diff_filespec_is_binary(p->one) ||
4178                    diff_filespec_is_binary(p->two)) {
4179                        git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
4180                        git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
4181                        continue;
4182                }
4183
4184                xpp.flags = 0;
4185                xecfg.ctxlen = 3;
4186                xecfg.flags = 0;
4187                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4188                              &xpp, &xecfg);
4189        }
4190
4191        git_SHA1_Final(sha1, &ctx);
4192        return 0;
4193}
4194
4195int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
4196{
4197        struct diff_queue_struct *q = &diff_queued_diff;
4198        int i;
4199        int result = diff_get_patch_id(options, sha1);
4200
4201        for (i = 0; i < q->nr; i++)
4202                diff_free_filepair(q->queue[i]);
4203
4204        free(q->queue);
4205        DIFF_QUEUE_CLEAR(q);
4206
4207        return result;
4208}
4209
4210static int is_summary_empty(const struct diff_queue_struct *q)
4211{
4212        int i;
4213
4214        for (i = 0; i < q->nr; i++) {
4215                const struct diff_filepair *p = q->queue[i];
4216
4217                switch (p->status) {
4218                case DIFF_STATUS_DELETED:
4219                case DIFF_STATUS_ADDED:
4220                case DIFF_STATUS_COPIED:
4221                case DIFF_STATUS_RENAMED:
4222                        return 0;
4223                default:
4224                        if (p->score)
4225                                return 0;
4226                        if (p->one->mode && p->two->mode &&
4227                            p->one->mode != p->two->mode)
4228                                return 0;
4229                        break;
4230                }
4231        }
4232        return 1;
4233}
4234
4235static const char rename_limit_warning[] =
4236"inexact rename detection was skipped due to too many files.";
4237
4238static const char degrade_cc_to_c_warning[] =
4239"only found copies from modified paths due to too many files.";
4240
4241static const char rename_limit_advice[] =
4242"you may want to set your %s variable to at least "
4243"%d and retry the command.";
4244
4245void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4246{
4247        if (degraded_cc)
4248                warning(degrade_cc_to_c_warning);
4249        else if (needed)
4250                warning(rename_limit_warning);
4251        else
4252                return;
4253        if (0 < needed && needed < 32767)
4254                warning(rename_limit_advice, varname, needed);
4255}
4256
4257void diff_flush(struct diff_options *options)
4258{
4259        struct diff_queue_struct *q = &diff_queued_diff;
4260        int i, output_format = options->output_format;
4261        int separator = 0;
4262        int dirstat_by_line = 0;
4263
4264        /*
4265         * Order: raw, stat, summary, patch
4266         * or:    name/name-status/checkdiff (other bits clear)
4267         */
4268        if (!q->nr)
4269                goto free_queue;
4270
4271        if (output_format & (DIFF_FORMAT_RAW |
4272                             DIFF_FORMAT_NAME |
4273                             DIFF_FORMAT_NAME_STATUS |
4274                             DIFF_FORMAT_CHECKDIFF)) {
4275                for (i = 0; i < q->nr; i++) {
4276                        struct diff_filepair *p = q->queue[i];
4277                        if (check_pair_status(p))
4278                                flush_one_pair(p, options);
4279                }
4280                separator++;
4281        }
4282
4283        if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
4284                dirstat_by_line = 1;
4285
4286        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
4287            dirstat_by_line) {
4288                struct diffstat_t diffstat;
4289
4290                memset(&diffstat, 0, sizeof(struct diffstat_t));
4291                for (i = 0; i < q->nr; i++) {
4292                        struct diff_filepair *p = q->queue[i];
4293                        if (check_pair_status(p))
4294                                diff_flush_stat(p, options, &diffstat);
4295                }
4296                if (output_format & DIFF_FORMAT_NUMSTAT)
4297                        show_numstat(&diffstat, options);
4298                if (output_format & DIFF_FORMAT_DIFFSTAT)
4299                        show_stats(&diffstat, options);
4300                if (output_format & DIFF_FORMAT_SHORTSTAT)
4301                        show_shortstats(&diffstat, options);
4302                if (output_format & DIFF_FORMAT_DIRSTAT)
4303                        show_dirstat_by_line(&diffstat, options);
4304                free_diffstat_info(&diffstat);
4305                separator++;
4306        }
4307        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
4308                show_dirstat(options);
4309
4310        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4311                for (i = 0; i < q->nr; i++) {
4312                        diff_summary(options, q->queue[i]);
4313                }
4314                separator++;
4315        }
4316
4317        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4318            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4319            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4320                /*
4321                 * run diff_flush_patch for the exit status. setting
4322                 * options->file to /dev/null should be safe, becaue we
4323                 * aren't supposed to produce any output anyway.
4324                 */
4325                if (options->close_file)
4326                        fclose(options->file);
4327                options->file = fopen("/dev/null", "w");
4328                if (!options->file)
4329                        die_errno("Could not open /dev/null");
4330                options->close_file = 1;
4331                for (i = 0; i < q->nr; i++) {
4332                        struct diff_filepair *p = q->queue[i];
4333                        if (check_pair_status(p))
4334                                diff_flush_patch(p, options);
4335                        if (options->found_changes)
4336                                break;
4337                }
4338        }
4339
4340        if (output_format & DIFF_FORMAT_PATCH) {
4341                if (separator) {
4342                        putc(options->line_termination, options->file);
4343                        if (options->stat_sep) {
4344                                /* attach patch instead of inline */
4345                                fputs(options->stat_sep, options->file);
4346                        }
4347                }
4348
4349                for (i = 0; i < q->nr; i++) {
4350                        struct diff_filepair *p = q->queue[i];
4351                        if (check_pair_status(p))
4352                                diff_flush_patch(p, options);
4353                }
4354        }
4355
4356        if (output_format & DIFF_FORMAT_CALLBACK)
4357                options->format_callback(q, options, options->format_callback_data);
4358
4359        for (i = 0; i < q->nr; i++)
4360                diff_free_filepair(q->queue[i]);
4361free_queue:
4362        free(q->queue);
4363        DIFF_QUEUE_CLEAR(q);
4364        if (options->close_file)
4365                fclose(options->file);
4366
4367        /*
4368         * Report the content-level differences with HAS_CHANGES;
4369         * diff_addremove/diff_change does not set the bit when
4370         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4371         */
4372        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4373                if (options->found_changes)
4374                        DIFF_OPT_SET(options, HAS_CHANGES);
4375                else
4376                        DIFF_OPT_CLR(options, HAS_CHANGES);
4377        }
4378}
4379
4380static void diffcore_apply_filter(const char *filter)
4381{
4382        int i;
4383        struct diff_queue_struct *q = &diff_queued_diff;
4384        struct diff_queue_struct outq;
4385        DIFF_QUEUE_CLEAR(&outq);
4386
4387        if (!filter)
4388                return;
4389
4390        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
4391                int found;
4392                for (i = found = 0; !found && i < q->nr; i++) {
4393                        struct diff_filepair *p = q->queue[i];
4394                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4395                             ((p->score &&
4396                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4397                              (!p->score &&
4398                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4399                            ((p->status != DIFF_STATUS_MODIFIED) &&
4400                             strchr(filter, p->status)))
4401                                found++;
4402                }
4403                if (found)
4404                        return;
4405
4406                /* otherwise we will clear the whole queue
4407                 * by copying the empty outq at the end of this
4408                 * function, but first clear the current entries
4409                 * in the queue.
4410                 */
4411                for (i = 0; i < q->nr; i++)
4412                        diff_free_filepair(q->queue[i]);
4413        }
4414        else {
4415                /* Only the matching ones */
4416                for (i = 0; i < q->nr; i++) {
4417                        struct diff_filepair *p = q->queue[i];
4418
4419                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4420                             ((p->score &&
4421                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4422                              (!p->score &&
4423                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4424                            ((p->status != DIFF_STATUS_MODIFIED) &&
4425                             strchr(filter, p->status)))
4426                                diff_q(&outq, p);
4427                        else
4428                                diff_free_filepair(p);
4429                }
4430        }
4431        free(q->queue);
4432        *q = outq;
4433}
4434
4435/* Check whether two filespecs with the same mode and size are identical */
4436static int diff_filespec_is_identical(struct diff_filespec *one,
4437                                      struct diff_filespec *two)
4438{
4439        if (S_ISGITLINK(one->mode))
4440                return 0;
4441        if (diff_populate_filespec(one, 0))
4442                return 0;
4443        if (diff_populate_filespec(two, 0))
4444                return 0;
4445        return !memcmp(one->data, two->data, one->size);
4446}
4447
4448static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4449{
4450        int i;
4451        struct diff_queue_struct *q = &diff_queued_diff;
4452        struct diff_queue_struct outq;
4453        DIFF_QUEUE_CLEAR(&outq);
4454
4455        for (i = 0; i < q->nr; i++) {
4456                struct diff_filepair *p = q->queue[i];
4457
4458                /*
4459                 * 1. Entries that come from stat info dirtiness
4460                 *    always have both sides (iow, not create/delete),
4461                 *    one side of the object name is unknown, with
4462                 *    the same mode and size.  Keep the ones that
4463                 *    do not match these criteria.  They have real
4464                 *    differences.
4465                 *
4466                 * 2. At this point, the file is known to be modified,
4467                 *    with the same mode and size, and the object
4468                 *    name of one side is unknown.  Need to inspect
4469                 *    the identical contents.
4470                 */
4471                if (!DIFF_FILE_VALID(p->one) || /* (1) */
4472                    !DIFF_FILE_VALID(p->two) ||
4473                    (p->one->sha1_valid && p->two->sha1_valid) ||
4474                    (p->one->mode != p->two->mode) ||
4475                    diff_populate_filespec(p->one, 1) ||
4476                    diff_populate_filespec(p->two, 1) ||
4477                    (p->one->size != p->two->size) ||
4478                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4479                        diff_q(&outq, p);
4480                else {
4481                        /*
4482                         * The caller can subtract 1 from skip_stat_unmatch
4483                         * to determine how many paths were dirty only
4484                         * due to stat info mismatch.
4485                         */
4486                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4487                                diffopt->skip_stat_unmatch++;
4488                        diff_free_filepair(p);
4489                }
4490        }
4491        free(q->queue);
4492        *q = outq;
4493}
4494
4495static int diffnamecmp(const void *a_, const void *b_)
4496{
4497        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4498        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4499        const char *name_a, *name_b;
4500
4501        name_a = a->one ? a->one->path : a->two->path;
4502        name_b = b->one ? b->one->path : b->two->path;
4503        return strcmp(name_a, name_b);
4504}
4505
4506void diffcore_fix_diff_index(struct diff_options *options)
4507{
4508        struct diff_queue_struct *q = &diff_queued_diff;
4509        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4510}
4511
4512void diffcore_std(struct diff_options *options)
4513{
4514        if (options->skip_stat_unmatch)
4515                diffcore_skip_stat_unmatch(options);
4516        if (!options->found_follow) {
4517                /* See try_to_follow_renames() in tree-diff.c */
4518                if (options->break_opt != -1)
4519                        diffcore_break(options->break_opt);
4520                if (options->detect_rename)
4521                        diffcore_rename(options);
4522                if (options->break_opt != -1)
4523                        diffcore_merge_broken();
4524        }
4525        if (options->pickaxe)
4526                diffcore_pickaxe(options);
4527        if (options->orderfile)
4528                diffcore_order(options->orderfile);
4529        if (!options->found_follow)
4530                /* See try_to_follow_renames() in tree-diff.c */
4531                diff_resolve_rename_copy();
4532        diffcore_apply_filter(options->filter);
4533
4534        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4535                DIFF_OPT_SET(options, HAS_CHANGES);
4536        else
4537                DIFF_OPT_CLR(options, HAS_CHANGES);
4538
4539        options->found_follow = 0;
4540}
4541
4542int diff_result_code(struct diff_options *opt, int status)
4543{
4544        int result = 0;
4545
4546        diff_warn_rename_limit("diff.renamelimit",
4547                               opt->needed_rename_limit,
4548                               opt->degraded_cc_to_c);
4549        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4550            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4551                return status;
4552        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4553            DIFF_OPT_TST(opt, HAS_CHANGES))
4554                result |= 01;
4555        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4556            DIFF_OPT_TST(opt, CHECK_FAILED))
4557                result |= 02;
4558        return result;
4559}
4560
4561int diff_can_quit_early(struct diff_options *opt)
4562{
4563        return (DIFF_OPT_TST(opt, QUICK) &&
4564                !opt->filter &&
4565                DIFF_OPT_TST(opt, HAS_CHANGES));
4566}
4567
4568/*
4569 * Shall changes to this submodule be ignored?
4570 *
4571 * Submodule changes can be configured to be ignored separately for each path,
4572 * but that configuration can be overridden from the command line.
4573 */
4574static int is_submodule_ignored(const char *path, struct diff_options *options)
4575{
4576        int ignored = 0;
4577        unsigned orig_flags = options->flags;
4578        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4579                set_diffopt_flags_from_submodule_config(options, path);
4580        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4581                ignored = 1;
4582        options->flags = orig_flags;
4583        return ignored;
4584}
4585
4586void diff_addremove(struct diff_options *options,
4587                    int addremove, unsigned mode,
4588                    const unsigned char *sha1,
4589                    const char *concatpath, unsigned dirty_submodule)
4590{
4591        struct diff_filespec *one, *two;
4592
4593        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4594                return;
4595
4596        /* This may look odd, but it is a preparation for
4597         * feeding "there are unchanged files which should
4598         * not produce diffs, but when you are doing copy
4599         * detection you would need them, so here they are"
4600         * entries to the diff-core.  They will be prefixed
4601         * with something like '=' or '*' (I haven't decided
4602         * which but should not make any difference).
4603         * Feeding the same new and old to diff_change()
4604         * also has the same effect.
4605         * Before the final output happens, they are pruned after
4606         * merged into rename/copy pairs as appropriate.
4607         */
4608        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4609                addremove = (addremove == '+' ? '-' :
4610                             addremove == '-' ? '+' : addremove);
4611
4612        if (options->prefix &&
4613            strncmp(concatpath, options->prefix, options->prefix_length))
4614                return;
4615
4616        one = alloc_filespec(concatpath);
4617        two = alloc_filespec(concatpath);
4618
4619        if (addremove != '+')
4620                fill_filespec(one, sha1, mode);
4621        if (addremove != '-') {
4622                fill_filespec(two, sha1, mode);
4623                two->dirty_submodule = dirty_submodule;
4624        }
4625
4626        diff_queue(&diff_queued_diff, one, two);
4627        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4628                DIFF_OPT_SET(options, HAS_CHANGES);
4629}
4630
4631void diff_change(struct diff_options *options,
4632                 unsigned old_mode, unsigned new_mode,
4633                 const unsigned char *old_sha1,
4634                 const unsigned char *new_sha1,
4635                 const char *concatpath,
4636                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4637{
4638        struct diff_filespec *one, *two;
4639
4640        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4641            is_submodule_ignored(concatpath, options))
4642                return;
4643
4644        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4645                unsigned tmp;
4646                const unsigned char *tmp_c;
4647                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4648                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4649                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4650                        new_dirty_submodule = tmp;
4651        }
4652
4653        if (options->prefix &&
4654            strncmp(concatpath, options->prefix, options->prefix_length))
4655                return;
4656
4657        one = alloc_filespec(concatpath);
4658        two = alloc_filespec(concatpath);
4659        fill_filespec(one, old_sha1, old_mode);
4660        fill_filespec(two, new_sha1, new_mode);
4661        one->dirty_submodule = old_dirty_submodule;
4662        two->dirty_submodule = new_dirty_submodule;
4663
4664        diff_queue(&diff_queued_diff, one, two);
4665        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4666                DIFF_OPT_SET(options, HAS_CHANGES);
4667}
4668
4669struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
4670{
4671        struct diff_filepair *pair;
4672        struct diff_filespec *one, *two;
4673
4674        if (options->prefix &&
4675            strncmp(path, options->prefix, options->prefix_length))
4676                return NULL;
4677
4678        one = alloc_filespec(path);
4679        two = alloc_filespec(path);
4680        pair = diff_queue(&diff_queued_diff, one, two);
4681        pair->is_unmerged = 1;
4682        return pair;
4683}
4684
4685static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4686                size_t *outsize)
4687{
4688        struct diff_tempfile *temp;
4689        const char *argv[3];
4690        const char **arg = argv;
4691        struct child_process child;
4692        struct strbuf buf = STRBUF_INIT;
4693        int err = 0;
4694
4695        temp = prepare_temp_file(spec->path, spec);
4696        *arg++ = pgm;
4697        *arg++ = temp->name;
4698        *arg = NULL;
4699
4700        memset(&child, 0, sizeof(child));
4701        child.use_shell = 1;
4702        child.argv = argv;
4703        child.out = -1;
4704        if (start_command(&child)) {
4705                remove_tempfile();
4706                return NULL;
4707        }
4708
4709        if (strbuf_read(&buf, child.out, 0) < 0)
4710                err = error("error reading from textconv command '%s'", pgm);
4711        close(child.out);
4712
4713        if (finish_command(&child) || err) {
4714                strbuf_release(&buf);
4715                remove_tempfile();
4716                return NULL;
4717        }
4718        remove_tempfile();
4719
4720        return strbuf_detach(&buf, outsize);
4721}
4722
4723size_t fill_textconv(struct userdiff_driver *driver,
4724                     struct diff_filespec *df,
4725                     char **outbuf)
4726{
4727        size_t size;
4728
4729        if (!driver || !driver->textconv) {
4730                if (!DIFF_FILE_VALID(df)) {
4731                        *outbuf = "";
4732                        return 0;
4733                }
4734                if (diff_populate_filespec(df, 0))
4735                        die("unable to read files to diff");
4736                *outbuf = df->data;
4737                return df->size;
4738        }
4739
4740        if (driver->textconv_cache && df->sha1_valid) {
4741                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4742                                          &size);
4743                if (*outbuf)
4744                        return size;
4745        }
4746
4747        *outbuf = run_textconv(driver->textconv, df, &size);
4748        if (!*outbuf)
4749                die("unable to read files to diff");
4750
4751        if (driver->textconv_cache && df->sha1_valid) {
4752                /* ignore errors, as we might be in a readonly repository */
4753                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4754                                size);
4755                /*
4756                 * we could save up changes and flush them all at the end,
4757                 * but we would need an extra call after all diffing is done.
4758                 * Since generating a cache entry is the slow path anyway,
4759                 * this extra overhead probably isn't a big deal.
4760                 */
4761                notes_cache_write(driver->textconv_cache);
4762        }
4763
4764        return size;
4765}