919a16d89e83bdd256fc0bb43e7e22d34036627b
   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{
  72        const char *p = params;
  73        while (*p) {
  74                if (!prefixcmp(p, "changes")) {
  75                        p += 7;
  76                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
  77                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
  78                } else if (!prefixcmp(p, "lines")) {
  79                        p += 5;
  80                        DIFF_OPT_SET(options, DIRSTAT_BY_LINE);
  81                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
  82                } else if (!prefixcmp(p, "files")) {
  83                        p += 5;
  84                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
  85                        DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
  86                } else if (!prefixcmp(p, "noncumulative")) {
  87                        p += 13;
  88                        DIFF_OPT_CLR(options, DIRSTAT_CUMULATIVE);
  89                } else if (!prefixcmp(p, "cumulative")) {
  90                        p += 10;
  91                        DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
  92                } else if (isdigit(*p)) {
  93                        char *end;
  94                        options->dirstat_permille = strtoul(p, &end, 10) * 10;
  95                        p = end;
  96                        if (*p == '.' && isdigit(*++p)) {
  97                                /* only use first digit */
  98                                options->dirstat_permille += *p - '0';
  99                                /* .. and ignore any further digits */
 100                                while (isdigit(*++p))
 101                                        ; /* nothing */
 102                        }
 103                } else
 104                        return error("Unknown --dirstat parameter '%s'", p);
 105
 106                if (*p) {
 107                        /* more parameters, swallow separator */
 108                        if (*p != ',')
 109                                return error("Missing comma separator at char "
 110                                        "%"PRIuMAX" of '%s'",
 111                                        (uintmax_t) (p - params), params);
 112                        p++;
 113                }
 114        }
 115        return 0;
 116}
 117
 118static int git_config_rename(const char *var, const char *value)
 119{
 120        if (!value)
 121                return DIFF_DETECT_RENAME;
 122        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 123                return  DIFF_DETECT_COPY;
 124        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 125}
 126
 127/*
 128 * These are to give UI layer defaults.
 129 * The core-level commands such as git-diff-files should
 130 * never be affected by the setting of diff.renames
 131 * the user happens to have in the configuration file.
 132 */
 133int git_diff_ui_config(const char *var, const char *value, void *cb)
 134{
 135        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 136                diff_use_color_default = git_config_colorbool(var, value, -1);
 137                return 0;
 138        }
 139        if (!strcmp(var, "diff.renames")) {
 140                diff_detect_rename_default = git_config_rename(var, value);
 141                return 0;
 142        }
 143        if (!strcmp(var, "diff.autorefreshindex")) {
 144                diff_auto_refresh_index = git_config_bool(var, value);
 145                return 0;
 146        }
 147        if (!strcmp(var, "diff.mnemonicprefix")) {
 148                diff_mnemonic_prefix = git_config_bool(var, value);
 149                return 0;
 150        }
 151        if (!strcmp(var, "diff.noprefix")) {
 152                diff_no_prefix = git_config_bool(var, value);
 153                return 0;
 154        }
 155        if (!strcmp(var, "diff.external"))
 156                return git_config_string(&external_diff_cmd_cfg, var, value);
 157        if (!strcmp(var, "diff.wordregex"))
 158                return git_config_string(&diff_word_regex_cfg, var, value);
 159
 160        if (!strcmp(var, "diff.ignoresubmodules"))
 161                handle_ignore_submodules_arg(&default_diff_options, value);
 162
 163        return git_diff_basic_config(var, value, cb);
 164}
 165
 166int git_diff_basic_config(const char *var, const char *value, void *cb)
 167{
 168        if (!strcmp(var, "diff.renamelimit")) {
 169                diff_rename_limit_default = git_config_int(var, value);
 170                return 0;
 171        }
 172
 173        switch (userdiff_config(var, value)) {
 174                case 0: break;
 175                case -1: return -1;
 176                default: return 0;
 177        }
 178
 179        if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
 180                int slot = parse_diff_color_slot(var, 11);
 181                if (slot < 0)
 182                        return 0;
 183                if (!value)
 184                        return config_error_nonbool(var);
 185                color_parse(value, var, diff_colors[slot]);
 186                return 0;
 187        }
 188
 189        /* like GNU diff's --suppress-blank-empty option  */
 190        if (!strcmp(var, "diff.suppressblankempty") ||
 191                        /* for backwards compatibility */
 192                        !strcmp(var, "diff.suppress-blank-empty")) {
 193                diff_suppress_blank_empty = git_config_bool(var, value);
 194                return 0;
 195        }
 196
 197        if (!strcmp(var, "diff.dirstat")) {
 198                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 199                (void) parse_dirstat_params(&default_diff_options, value);
 200                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 201                return 0;
 202        }
 203
 204        if (!prefixcmp(var, "submodule."))
 205                return parse_submodule_config_option(var, value);
 206
 207        return git_color_default_config(var, value, cb);
 208}
 209
 210static char *quote_two(const char *one, const char *two)
 211{
 212        int need_one = quote_c_style(one, NULL, NULL, 1);
 213        int need_two = quote_c_style(two, NULL, NULL, 1);
 214        struct strbuf res = STRBUF_INIT;
 215
 216        if (need_one + need_two) {
 217                strbuf_addch(&res, '"');
 218                quote_c_style(one, &res, NULL, 1);
 219                quote_c_style(two, &res, NULL, 1);
 220                strbuf_addch(&res, '"');
 221        } else {
 222                strbuf_addstr(&res, one);
 223                strbuf_addstr(&res, two);
 224        }
 225        return strbuf_detach(&res, NULL);
 226}
 227
 228static const char *external_diff(void)
 229{
 230        static const char *external_diff_cmd = NULL;
 231        static int done_preparing = 0;
 232
 233        if (done_preparing)
 234                return external_diff_cmd;
 235        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 236        if (!external_diff_cmd)
 237                external_diff_cmd = external_diff_cmd_cfg;
 238        done_preparing = 1;
 239        return external_diff_cmd;
 240}
 241
 242static struct diff_tempfile {
 243        const char *name; /* filename external diff should read from */
 244        char hex[41];
 245        char mode[10];
 246        char tmp_path[PATH_MAX];
 247} diff_temp[2];
 248
 249typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 250
 251struct emit_callback {
 252        int color_diff;
 253        unsigned ws_rule;
 254        int blank_at_eof_in_preimage;
 255        int blank_at_eof_in_postimage;
 256        int lno_in_preimage;
 257        int lno_in_postimage;
 258        sane_truncate_fn truncate;
 259        const char **label_path;
 260        struct diff_words_data *diff_words;
 261        struct diff_options *opt;
 262        int *found_changesp;
 263        struct strbuf *header;
 264};
 265
 266static int count_lines(const char *data, int size)
 267{
 268        int count, ch, completely_empty = 1, nl_just_seen = 0;
 269        count = 0;
 270        while (0 < size--) {
 271                ch = *data++;
 272                if (ch == '\n') {
 273                        count++;
 274                        nl_just_seen = 1;
 275                        completely_empty = 0;
 276                }
 277                else {
 278                        nl_just_seen = 0;
 279                        completely_empty = 0;
 280                }
 281        }
 282        if (completely_empty)
 283                return 0;
 284        if (!nl_just_seen)
 285                count++; /* no trailing newline */
 286        return count;
 287}
 288
 289static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 290{
 291        if (!DIFF_FILE_VALID(one)) {
 292                mf->ptr = (char *)""; /* does not matter */
 293                mf->size = 0;
 294                return 0;
 295        }
 296        else if (diff_populate_filespec(one, 0))
 297                return -1;
 298
 299        mf->ptr = one->data;
 300        mf->size = one->size;
 301        return 0;
 302}
 303
 304/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 305static unsigned long diff_filespec_size(struct diff_filespec *one)
 306{
 307        if (!DIFF_FILE_VALID(one))
 308                return 0;
 309        diff_populate_filespec(one, 1);
 310        return one->size;
 311}
 312
 313static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 314{
 315        char *ptr = mf->ptr;
 316        long size = mf->size;
 317        int cnt = 0;
 318
 319        if (!size)
 320                return cnt;
 321        ptr += size - 1; /* pointing at the very end */
 322        if (*ptr != '\n')
 323                ; /* incomplete line */
 324        else
 325                ptr--; /* skip the last LF */
 326        while (mf->ptr < ptr) {
 327                char *prev_eol;
 328                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 329                        if (*prev_eol == '\n')
 330                                break;
 331                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 332                        break;
 333                cnt++;
 334                ptr = prev_eol - 1;
 335        }
 336        return cnt;
 337}
 338
 339static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 340                               struct emit_callback *ecbdata)
 341{
 342        int l1, l2, at;
 343        unsigned ws_rule = ecbdata->ws_rule;
 344        l1 = count_trailing_blank(mf1, ws_rule);
 345        l2 = count_trailing_blank(mf2, ws_rule);
 346        if (l2 <= l1) {
 347                ecbdata->blank_at_eof_in_preimage = 0;
 348                ecbdata->blank_at_eof_in_postimage = 0;
 349                return;
 350        }
 351        at = count_lines(mf1->ptr, mf1->size);
 352        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 353
 354        at = count_lines(mf2->ptr, mf2->size);
 355        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 356}
 357
 358static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 359                        int first, const char *line, int len)
 360{
 361        int has_trailing_newline, has_trailing_carriage_return;
 362        int nofirst;
 363        FILE *file = o->file;
 364
 365        if (o->output_prefix) {
 366                struct strbuf *msg = NULL;
 367                msg = o->output_prefix(o, o->output_prefix_data);
 368                assert(msg);
 369                fwrite(msg->buf, msg->len, 1, file);
 370        }
 371
 372        if (len == 0) {
 373                has_trailing_newline = (first == '\n');
 374                has_trailing_carriage_return = (!has_trailing_newline &&
 375                                                (first == '\r'));
 376                nofirst = has_trailing_newline || has_trailing_carriage_return;
 377        } else {
 378                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 379                if (has_trailing_newline)
 380                        len--;
 381                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 382                if (has_trailing_carriage_return)
 383                        len--;
 384                nofirst = 0;
 385        }
 386
 387        if (len || !nofirst) {
 388                fputs(set, file);
 389                if (!nofirst)
 390                        fputc(first, file);
 391                fwrite(line, len, 1, file);
 392                fputs(reset, file);
 393        }
 394        if (has_trailing_carriage_return)
 395                fputc('\r', file);
 396        if (has_trailing_newline)
 397                fputc('\n', file);
 398}
 399
 400static void emit_line(struct diff_options *o, const char *set, const char *reset,
 401                      const char *line, int len)
 402{
 403        emit_line_0(o, set, reset, line[0], line+1, len-1);
 404}
 405
 406static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 407{
 408        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 409              ecbdata->blank_at_eof_in_preimage &&
 410              ecbdata->blank_at_eof_in_postimage &&
 411              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 412              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 413                return 0;
 414        return ws_blank_line(line, len, ecbdata->ws_rule);
 415}
 416
 417static void emit_add_line(const char *reset,
 418                          struct emit_callback *ecbdata,
 419                          const char *line, int len)
 420{
 421        const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 422        const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 423
 424        if (!*ws)
 425                emit_line_0(ecbdata->opt, set, reset, '+', line, len);
 426        else if (new_blank_line_at_eof(ecbdata, line, len))
 427                /* Blank line at EOF - paint '+' as well */
 428                emit_line_0(ecbdata->opt, ws, reset, '+', line, len);
 429        else {
 430                /* Emit just the prefix, then the rest. */
 431                emit_line_0(ecbdata->opt, set, reset, '+', "", 0);
 432                ws_check_emit(line, len, ecbdata->ws_rule,
 433                              ecbdata->opt->file, set, reset, ws);
 434        }
 435}
 436
 437static void emit_hunk_header(struct emit_callback *ecbdata,
 438                             const char *line, int len)
 439{
 440        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 441        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 442        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 443        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 444        static const char atat[2] = { '@', '@' };
 445        const char *cp, *ep;
 446        struct strbuf msgbuf = STRBUF_INIT;
 447        int org_len = len;
 448        int i = 1;
 449
 450        /*
 451         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 452         * it always is at least 10 bytes long.
 453         */
 454        if (len < 10 ||
 455            memcmp(line, atat, 2) ||
 456            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 457                emit_line(ecbdata->opt, plain, reset, line, len);
 458                return;
 459        }
 460        ep += 2; /* skip over @@ */
 461
 462        /* The hunk header in fraginfo color */
 463        strbuf_add(&msgbuf, frag, strlen(frag));
 464        strbuf_add(&msgbuf, line, ep - line);
 465        strbuf_add(&msgbuf, reset, strlen(reset));
 466
 467        /*
 468         * trailing "\r\n"
 469         */
 470        for ( ; i < 3; i++)
 471                if (line[len - i] == '\r' || line[len - i] == '\n')
 472                        len--;
 473
 474        /* blank before the func header */
 475        for (cp = ep; ep - line < len; ep++)
 476                if (*ep != ' ' && *ep != '\t')
 477                        break;
 478        if (ep != cp) {
 479                strbuf_add(&msgbuf, plain, strlen(plain));
 480                strbuf_add(&msgbuf, cp, ep - cp);
 481                strbuf_add(&msgbuf, reset, strlen(reset));
 482        }
 483
 484        if (ep < line + len) {
 485                strbuf_add(&msgbuf, func, strlen(func));
 486                strbuf_add(&msgbuf, ep, line + len - ep);
 487                strbuf_add(&msgbuf, reset, strlen(reset));
 488        }
 489
 490        strbuf_add(&msgbuf, line + len, org_len - len);
 491        emit_line(ecbdata->opt, "", "", msgbuf.buf, msgbuf.len);
 492        strbuf_release(&msgbuf);
 493}
 494
 495static struct diff_tempfile *claim_diff_tempfile(void) {
 496        int i;
 497        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 498                if (!diff_temp[i].name)
 499                        return diff_temp + i;
 500        die("BUG: diff is failing to clean up its tempfiles");
 501}
 502
 503static int remove_tempfile_installed;
 504
 505static void remove_tempfile(void)
 506{
 507        int i;
 508        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 509                if (diff_temp[i].name == diff_temp[i].tmp_path)
 510                        unlink_or_warn(diff_temp[i].name);
 511                diff_temp[i].name = NULL;
 512        }
 513}
 514
 515static void remove_tempfile_on_signal(int signo)
 516{
 517        remove_tempfile();
 518        sigchain_pop(signo);
 519        raise(signo);
 520}
 521
 522static void print_line_count(FILE *file, int count)
 523{
 524        switch (count) {
 525        case 0:
 526                fprintf(file, "0,0");
 527                break;
 528        case 1:
 529                fprintf(file, "1");
 530                break;
 531        default:
 532                fprintf(file, "1,%d", count);
 533                break;
 534        }
 535}
 536
 537static void emit_rewrite_lines(struct emit_callback *ecb,
 538                               int prefix, const char *data, int size)
 539{
 540        const char *endp = NULL;
 541        static const char *nneof = " No newline at end of file\n";
 542        const char *old = diff_get_color(ecb->color_diff, DIFF_FILE_OLD);
 543        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 544
 545        while (0 < size) {
 546                int len;
 547
 548                endp = memchr(data, '\n', size);
 549                len = endp ? (endp - data + 1) : size;
 550                if (prefix != '+') {
 551                        ecb->lno_in_preimage++;
 552                        emit_line_0(ecb->opt, old, reset, '-',
 553                                    data, len);
 554                } else {
 555                        ecb->lno_in_postimage++;
 556                        emit_add_line(reset, ecb, data, len);
 557                }
 558                size -= len;
 559                data += len;
 560        }
 561        if (!endp) {
 562                const char *plain = diff_get_color(ecb->color_diff,
 563                                                   DIFF_PLAIN);
 564                emit_line_0(ecb->opt, plain, reset, '\\',
 565                            nneof, strlen(nneof));
 566        }
 567}
 568
 569static void emit_rewrite_diff(const char *name_a,
 570                              const char *name_b,
 571                              struct diff_filespec *one,
 572                              struct diff_filespec *two,
 573                              struct userdiff_driver *textconv_one,
 574                              struct userdiff_driver *textconv_two,
 575                              struct diff_options *o)
 576{
 577        int lc_a, lc_b;
 578        int color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
 579        const char *name_a_tab, *name_b_tab;
 580        const char *metainfo = diff_get_color(color_diff, DIFF_METAINFO);
 581        const char *fraginfo = diff_get_color(color_diff, DIFF_FRAGINFO);
 582        const char *reset = diff_get_color(color_diff, DIFF_RESET);
 583        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 584        const char *a_prefix, *b_prefix;
 585        char *data_one, *data_two;
 586        size_t size_one, size_two;
 587        struct emit_callback ecbdata;
 588        char *line_prefix = "";
 589        struct strbuf *msgbuf;
 590
 591        if (o && o->output_prefix) {
 592                msgbuf = o->output_prefix(o, o->output_prefix_data);
 593                line_prefix = msgbuf->buf;
 594        }
 595
 596        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 597                a_prefix = o->b_prefix;
 598                b_prefix = o->a_prefix;
 599        } else {
 600                a_prefix = o->a_prefix;
 601                b_prefix = o->b_prefix;
 602        }
 603
 604        name_a += (*name_a == '/');
 605        name_b += (*name_b == '/');
 606        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 607        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 608
 609        strbuf_reset(&a_name);
 610        strbuf_reset(&b_name);
 611        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 612        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 613
 614        size_one = fill_textconv(textconv_one, one, &data_one);
 615        size_two = fill_textconv(textconv_two, two, &data_two);
 616
 617        memset(&ecbdata, 0, sizeof(ecbdata));
 618        ecbdata.color_diff = color_diff;
 619        ecbdata.found_changesp = &o->found_changes;
 620        ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
 621        ecbdata.opt = o;
 622        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 623                mmfile_t mf1, mf2;
 624                mf1.ptr = (char *)data_one;
 625                mf2.ptr = (char *)data_two;
 626                mf1.size = size_one;
 627                mf2.size = size_two;
 628                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 629        }
 630        ecbdata.lno_in_preimage = 1;
 631        ecbdata.lno_in_postimage = 1;
 632
 633        lc_a = count_lines(data_one, size_one);
 634        lc_b = count_lines(data_two, size_two);
 635        fprintf(o->file,
 636                "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
 637                line_prefix, metainfo, a_name.buf, name_a_tab, reset,
 638                line_prefix, metainfo, b_name.buf, name_b_tab, reset,
 639                line_prefix, fraginfo);
 640        if (!o->irreversible_delete)
 641                print_line_count(o->file, lc_a);
 642        else
 643                fprintf(o->file, "?,?");
 644        fprintf(o->file, " +");
 645        print_line_count(o->file, lc_b);
 646        fprintf(o->file, " @@%s\n", reset);
 647        if (lc_a && !o->irreversible_delete)
 648                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 649        if (lc_b)
 650                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 651        if (textconv_one)
 652                free((char *)data_one);
 653        if (textconv_two)
 654                free((char *)data_two);
 655}
 656
 657struct diff_words_buffer {
 658        mmfile_t text;
 659        long alloc;
 660        struct diff_words_orig {
 661                const char *begin, *end;
 662        } *orig;
 663        int orig_nr, orig_alloc;
 664};
 665
 666static void diff_words_append(char *line, unsigned long len,
 667                struct diff_words_buffer *buffer)
 668{
 669        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 670        line++;
 671        len--;
 672        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 673        buffer->text.size += len;
 674        buffer->text.ptr[buffer->text.size] = '\0';
 675}
 676
 677struct diff_words_style_elem {
 678        const char *prefix;
 679        const char *suffix;
 680        const char *color; /* NULL; filled in by the setup code if
 681                            * color is enabled */
 682};
 683
 684struct diff_words_style {
 685        enum diff_words_type type;
 686        struct diff_words_style_elem new, old, ctx;
 687        const char *newline;
 688};
 689
 690static struct diff_words_style diff_words_styles[] = {
 691        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 692        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 693        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 694};
 695
 696struct diff_words_data {
 697        struct diff_words_buffer minus, plus;
 698        const char *current_plus;
 699        int last_minus;
 700        struct diff_options *opt;
 701        regex_t *word_regex;
 702        enum diff_words_type type;
 703        struct diff_words_style *style;
 704};
 705
 706static int fn_out_diff_words_write_helper(FILE *fp,
 707                                          struct diff_words_style_elem *st_el,
 708                                          const char *newline,
 709                                          size_t count, const char *buf,
 710                                          const char *line_prefix)
 711{
 712        int print = 0;
 713
 714        while (count) {
 715                char *p = memchr(buf, '\n', count);
 716                if (print)
 717                        fputs(line_prefix, fp);
 718                if (p != buf) {
 719                        if (st_el->color && fputs(st_el->color, fp) < 0)
 720                                return -1;
 721                        if (fputs(st_el->prefix, fp) < 0 ||
 722                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 723                            fputs(st_el->suffix, fp) < 0)
 724                                return -1;
 725                        if (st_el->color && *st_el->color
 726                            && fputs(GIT_COLOR_RESET, fp) < 0)
 727                                return -1;
 728                }
 729                if (!p)
 730                        return 0;
 731                if (fputs(newline, fp) < 0)
 732                        return -1;
 733                count -= p + 1 - buf;
 734                buf = p + 1;
 735                print = 1;
 736        }
 737        return 0;
 738}
 739
 740/*
 741 * '--color-words' algorithm can be described as:
 742 *
 743 *   1. collect a the minus/plus lines of a diff hunk, divided into
 744 *      minus-lines and plus-lines;
 745 *
 746 *   2. break both minus-lines and plus-lines into words and
 747 *      place them into two mmfile_t with one word for each line;
 748 *
 749 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
 750 *
 751 * And for the common parts of the both file, we output the plus side text.
 752 * diff_words->current_plus is used to trace the current position of the plus file
 753 * which printed. diff_words->last_minus is used to trace the last minus word
 754 * printed.
 755 *
 756 * For '--graph' to work with '--color-words', we need to output the graph prefix
 757 * on each line of color words output. Generally, there are two conditions on
 758 * which we should output the prefix.
 759 *
 760 *   1. diff_words->last_minus == 0 &&
 761 *      diff_words->current_plus == diff_words->plus.text.ptr
 762 *
 763 *      that is: the plus text must start as a new line, and if there is no minus
 764 *      word printed, a graph prefix must be printed.
 765 *
 766 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
 767 *      *(diff_words->current_plus - 1) == '\n'
 768 *
 769 *      that is: a graph prefix must be printed following a '\n'
 770 */
 771static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
 772{
 773        if ((diff_words->last_minus == 0 &&
 774                diff_words->current_plus == diff_words->plus.text.ptr) ||
 775                (diff_words->current_plus > diff_words->plus.text.ptr &&
 776                *(diff_words->current_plus - 1) == '\n')) {
 777                return 1;
 778        } else {
 779                return 0;
 780        }
 781}
 782
 783static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 784{
 785        struct diff_words_data *diff_words = priv;
 786        struct diff_words_style *style = diff_words->style;
 787        int minus_first, minus_len, plus_first, plus_len;
 788        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 789        struct diff_options *opt = diff_words->opt;
 790        struct strbuf *msgbuf;
 791        char *line_prefix = "";
 792
 793        if (line[0] != '@' || parse_hunk_header(line, len,
 794                        &minus_first, &minus_len, &plus_first, &plus_len))
 795                return;
 796
 797        assert(opt);
 798        if (opt->output_prefix) {
 799                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 800                line_prefix = msgbuf->buf;
 801        }
 802
 803        /* POSIX requires that first be decremented by one if len == 0... */
 804        if (minus_len) {
 805                minus_begin = diff_words->minus.orig[minus_first].begin;
 806                minus_end =
 807                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 808        } else
 809                minus_begin = minus_end =
 810                        diff_words->minus.orig[minus_first].end;
 811
 812        if (plus_len) {
 813                plus_begin = diff_words->plus.orig[plus_first].begin;
 814                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 815        } else
 816                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 817
 818        if (color_words_output_graph_prefix(diff_words)) {
 819                fputs(line_prefix, diff_words->opt->file);
 820        }
 821        if (diff_words->current_plus != plus_begin) {
 822                fn_out_diff_words_write_helper(diff_words->opt->file,
 823                                &style->ctx, style->newline,
 824                                plus_begin - diff_words->current_plus,
 825                                diff_words->current_plus, line_prefix);
 826                if (*(plus_begin - 1) == '\n')
 827                        fputs(line_prefix, diff_words->opt->file);
 828        }
 829        if (minus_begin != minus_end) {
 830                fn_out_diff_words_write_helper(diff_words->opt->file,
 831                                &style->old, style->newline,
 832                                minus_end - minus_begin, minus_begin,
 833                                line_prefix);
 834        }
 835        if (plus_begin != plus_end) {
 836                fn_out_diff_words_write_helper(diff_words->opt->file,
 837                                &style->new, style->newline,
 838                                plus_end - plus_begin, plus_begin,
 839                                line_prefix);
 840        }
 841
 842        diff_words->current_plus = plus_end;
 843        diff_words->last_minus = minus_first;
 844}
 845
 846/* This function starts looking at *begin, and returns 0 iff a word was found. */
 847static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 848                int *begin, int *end)
 849{
 850        if (word_regex && *begin < buffer->size) {
 851                regmatch_t match[1];
 852                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 853                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 854                                        '\n', match[0].rm_eo - match[0].rm_so);
 855                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 856                        *begin += match[0].rm_so;
 857                        return *begin >= *end;
 858                }
 859                return -1;
 860        }
 861
 862        /* find the next word */
 863        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 864                (*begin)++;
 865        if (*begin >= buffer->size)
 866                return -1;
 867
 868        /* find the end of the word */
 869        *end = *begin + 1;
 870        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 871                (*end)++;
 872
 873        return 0;
 874}
 875
 876/*
 877 * This function splits the words in buffer->text, stores the list with
 878 * newline separator into out, and saves the offsets of the original words
 879 * in buffer->orig.
 880 */
 881static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 882                regex_t *word_regex)
 883{
 884        int i, j;
 885        long alloc = 0;
 886
 887        out->size = 0;
 888        out->ptr = NULL;
 889
 890        /* fake an empty "0th" word */
 891        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 892        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 893        buffer->orig_nr = 1;
 894
 895        for (i = 0; i < buffer->text.size; i++) {
 896                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 897                        return;
 898
 899                /* store original boundaries */
 900                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 901                                buffer->orig_alloc);
 902                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 903                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 904                buffer->orig_nr++;
 905
 906                /* store one word */
 907                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 908                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 909                out->ptr[out->size + j - i] = '\n';
 910                out->size += j - i + 1;
 911
 912                i = j - 1;
 913        }
 914}
 915
 916/* this executes the word diff on the accumulated buffers */
 917static void diff_words_show(struct diff_words_data *diff_words)
 918{
 919        xpparam_t xpp;
 920        xdemitconf_t xecfg;
 921        mmfile_t minus, plus;
 922        struct diff_words_style *style = diff_words->style;
 923
 924        struct diff_options *opt = diff_words->opt;
 925        struct strbuf *msgbuf;
 926        char *line_prefix = "";
 927
 928        assert(opt);
 929        if (opt->output_prefix) {
 930                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 931                line_prefix = msgbuf->buf;
 932        }
 933
 934        /* special case: only removal */
 935        if (!diff_words->plus.text.size) {
 936                fputs(line_prefix, diff_words->opt->file);
 937                fn_out_diff_words_write_helper(diff_words->opt->file,
 938                        &style->old, style->newline,
 939                        diff_words->minus.text.size,
 940                        diff_words->minus.text.ptr, line_prefix);
 941                diff_words->minus.text.size = 0;
 942                return;
 943        }
 944
 945        diff_words->current_plus = diff_words->plus.text.ptr;
 946        diff_words->last_minus = 0;
 947
 948        memset(&xpp, 0, sizeof(xpp));
 949        memset(&xecfg, 0, sizeof(xecfg));
 950        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
 951        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
 952        xpp.flags = 0;
 953        /* as only the hunk header will be parsed, we need a 0-context */
 954        xecfg.ctxlen = 0;
 955        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 956                      &xpp, &xecfg);
 957        free(minus.ptr);
 958        free(plus.ptr);
 959        if (diff_words->current_plus != diff_words->plus.text.ptr +
 960                        diff_words->plus.text.size) {
 961                if (color_words_output_graph_prefix(diff_words))
 962                        fputs(line_prefix, diff_words->opt->file);
 963                fn_out_diff_words_write_helper(diff_words->opt->file,
 964                        &style->ctx, style->newline,
 965                        diff_words->plus.text.ptr + diff_words->plus.text.size
 966                        - diff_words->current_plus, diff_words->current_plus,
 967                        line_prefix);
 968        }
 969        diff_words->minus.text.size = diff_words->plus.text.size = 0;
 970}
 971
 972/* In "color-words" mode, show word-diff of words accumulated in the buffer */
 973static void diff_words_flush(struct emit_callback *ecbdata)
 974{
 975        if (ecbdata->diff_words->minus.text.size ||
 976            ecbdata->diff_words->plus.text.size)
 977                diff_words_show(ecbdata->diff_words);
 978}
 979
 980static void free_diff_words_data(struct emit_callback *ecbdata)
 981{
 982        if (ecbdata->diff_words) {
 983                diff_words_flush(ecbdata);
 984                free (ecbdata->diff_words->minus.text.ptr);
 985                free (ecbdata->diff_words->minus.orig);
 986                free (ecbdata->diff_words->plus.text.ptr);
 987                free (ecbdata->diff_words->plus.orig);
 988                if (ecbdata->diff_words->word_regex) {
 989                        regfree(ecbdata->diff_words->word_regex);
 990                        free(ecbdata->diff_words->word_regex);
 991                }
 992                free(ecbdata->diff_words);
 993                ecbdata->diff_words = NULL;
 994        }
 995}
 996
 997const char *diff_get_color(int diff_use_color, enum color_diff ix)
 998{
 999        if (diff_use_color)
1000                return diff_colors[ix];
1001        return "";
1002}
1003
1004static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
1005{
1006        const char *cp;
1007        unsigned long allot;
1008        size_t l = len;
1009
1010        if (ecb->truncate)
1011                return ecb->truncate(line, len);
1012        cp = line;
1013        allot = l;
1014        while (0 < l) {
1015                (void) utf8_width(&cp, &l);
1016                if (!cp)
1017                        break; /* truncated in the middle? */
1018        }
1019        return allot - l;
1020}
1021
1022static void find_lno(const char *line, struct emit_callback *ecbdata)
1023{
1024        const char *p;
1025        ecbdata->lno_in_preimage = 0;
1026        ecbdata->lno_in_postimage = 0;
1027        p = strchr(line, '-');
1028        if (!p)
1029                return; /* cannot happen */
1030        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1031        p = strchr(p, '+');
1032        if (!p)
1033                return; /* cannot happen */
1034        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
1035}
1036
1037static void fn_out_consume(void *priv, char *line, unsigned long len)
1038{
1039        struct emit_callback *ecbdata = priv;
1040        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
1041        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
1042        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1043        struct diff_options *o = ecbdata->opt;
1044        char *line_prefix = "";
1045        struct strbuf *msgbuf;
1046
1047        if (o && o->output_prefix) {
1048                msgbuf = o->output_prefix(o, o->output_prefix_data);
1049                line_prefix = msgbuf->buf;
1050        }
1051
1052        if (ecbdata->header) {
1053                fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
1054                strbuf_reset(ecbdata->header);
1055                ecbdata->header = NULL;
1056        }
1057        *(ecbdata->found_changesp) = 1;
1058
1059        if (ecbdata->label_path[0]) {
1060                const char *name_a_tab, *name_b_tab;
1061
1062                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
1063                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
1064
1065                fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
1066                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
1067                fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
1068                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1069                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1070        }
1071
1072        if (diff_suppress_blank_empty
1073            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1074                line[0] = '\n';
1075                len = 1;
1076        }
1077
1078        if (line[0] == '@') {
1079                if (ecbdata->diff_words)
1080                        diff_words_flush(ecbdata);
1081                len = sane_truncate_line(ecbdata, line, len);
1082                find_lno(line, ecbdata);
1083                emit_hunk_header(ecbdata, line, len);
1084                if (line[len-1] != '\n')
1085                        putc('\n', ecbdata->opt->file);
1086                return;
1087        }
1088
1089        if (len < 1) {
1090                emit_line(ecbdata->opt, reset, reset, line, len);
1091                if (ecbdata->diff_words
1092                    && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
1093                        fputs("~\n", ecbdata->opt->file);
1094                return;
1095        }
1096
1097        if (ecbdata->diff_words) {
1098                if (line[0] == '-') {
1099                        diff_words_append(line, len,
1100                                          &ecbdata->diff_words->minus);
1101                        return;
1102                } else if (line[0] == '+') {
1103                        diff_words_append(line, len,
1104                                          &ecbdata->diff_words->plus);
1105                        return;
1106                }
1107                diff_words_flush(ecbdata);
1108                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1109                        emit_line(ecbdata->opt, plain, reset, line, len);
1110                        fputs("~\n", ecbdata->opt->file);
1111                } else {
1112                        /* don't print the prefix character */
1113                        emit_line(ecbdata->opt, plain, reset, line+1, len-1);
1114                }
1115                return;
1116        }
1117
1118        if (line[0] != '+') {
1119                const char *color =
1120                        diff_get_color(ecbdata->color_diff,
1121                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
1122                ecbdata->lno_in_preimage++;
1123                if (line[0] == ' ')
1124                        ecbdata->lno_in_postimage++;
1125                emit_line(ecbdata->opt, color, reset, line, len);
1126        } else {
1127                ecbdata->lno_in_postimage++;
1128                emit_add_line(reset, ecbdata, line + 1, len - 1);
1129        }
1130}
1131
1132static char *pprint_rename(const char *a, const char *b)
1133{
1134        const char *old = a;
1135        const char *new = b;
1136        struct strbuf name = STRBUF_INIT;
1137        int pfx_length, sfx_length;
1138        int len_a = strlen(a);
1139        int len_b = strlen(b);
1140        int a_midlen, b_midlen;
1141        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1142        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1143
1144        if (qlen_a || qlen_b) {
1145                quote_c_style(a, &name, NULL, 0);
1146                strbuf_addstr(&name, " => ");
1147                quote_c_style(b, &name, NULL, 0);
1148                return strbuf_detach(&name, NULL);
1149        }
1150
1151        /* Find common prefix */
1152        pfx_length = 0;
1153        while (*old && *new && *old == *new) {
1154                if (*old == '/')
1155                        pfx_length = old - a + 1;
1156                old++;
1157                new++;
1158        }
1159
1160        /* Find common suffix */
1161        old = a + len_a;
1162        new = b + len_b;
1163        sfx_length = 0;
1164        while (a <= old && b <= new && *old == *new) {
1165                if (*old == '/')
1166                        sfx_length = len_a - (old - a);
1167                old--;
1168                new--;
1169        }
1170
1171        /*
1172         * pfx{mid-a => mid-b}sfx
1173         * {pfx-a => pfx-b}sfx
1174         * pfx{sfx-a => sfx-b}
1175         * name-a => name-b
1176         */
1177        a_midlen = len_a - pfx_length - sfx_length;
1178        b_midlen = len_b - pfx_length - sfx_length;
1179        if (a_midlen < 0)
1180                a_midlen = 0;
1181        if (b_midlen < 0)
1182                b_midlen = 0;
1183
1184        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1185        if (pfx_length + sfx_length) {
1186                strbuf_add(&name, a, pfx_length);
1187                strbuf_addch(&name, '{');
1188        }
1189        strbuf_add(&name, a + pfx_length, a_midlen);
1190        strbuf_addstr(&name, " => ");
1191        strbuf_add(&name, b + pfx_length, b_midlen);
1192        if (pfx_length + sfx_length) {
1193                strbuf_addch(&name, '}');
1194                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1195        }
1196        return strbuf_detach(&name, NULL);
1197}
1198
1199struct diffstat_t {
1200        int nr;
1201        int alloc;
1202        struct diffstat_file {
1203                char *from_name;
1204                char *name;
1205                char *print_name;
1206                unsigned is_unmerged:1;
1207                unsigned is_binary:1;
1208                unsigned is_renamed:1;
1209                uintmax_t added, deleted;
1210        } **files;
1211};
1212
1213static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1214                                          const char *name_a,
1215                                          const char *name_b)
1216{
1217        struct diffstat_file *x;
1218        x = xcalloc(sizeof (*x), 1);
1219        if (diffstat->nr == diffstat->alloc) {
1220                diffstat->alloc = alloc_nr(diffstat->alloc);
1221                diffstat->files = xrealloc(diffstat->files,
1222                                diffstat->alloc * sizeof(x));
1223        }
1224        diffstat->files[diffstat->nr++] = x;
1225        if (name_b) {
1226                x->from_name = xstrdup(name_a);
1227                x->name = xstrdup(name_b);
1228                x->is_renamed = 1;
1229        }
1230        else {
1231                x->from_name = NULL;
1232                x->name = xstrdup(name_a);
1233        }
1234        return x;
1235}
1236
1237static void diffstat_consume(void *priv, char *line, unsigned long len)
1238{
1239        struct diffstat_t *diffstat = priv;
1240        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1241
1242        if (line[0] == '+')
1243                x->added++;
1244        else if (line[0] == '-')
1245                x->deleted++;
1246}
1247
1248const char mime_boundary_leader[] = "------------";
1249
1250static int scale_linear(int it, int width, int max_change)
1251{
1252        /*
1253         * make sure that at least one '-' is printed if there were deletions,
1254         * and likewise for '+'.
1255         */
1256        if (max_change < 2)
1257                return it;
1258        return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
1259}
1260
1261static void show_name(FILE *file,
1262                      const char *prefix, const char *name, int len)
1263{
1264        fprintf(file, " %s%-*s |", prefix, len, name);
1265}
1266
1267static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1268{
1269        if (cnt <= 0)
1270                return;
1271        fprintf(file, "%s", set);
1272        while (cnt--)
1273                putc(ch, file);
1274        fprintf(file, "%s", reset);
1275}
1276
1277static void fill_print_name(struct diffstat_file *file)
1278{
1279        char *pname;
1280
1281        if (file->print_name)
1282                return;
1283
1284        if (!file->is_renamed) {
1285                struct strbuf buf = STRBUF_INIT;
1286                if (quote_c_style(file->name, &buf, NULL, 0)) {
1287                        pname = strbuf_detach(&buf, NULL);
1288                } else {
1289                        pname = file->name;
1290                        strbuf_release(&buf);
1291                }
1292        } else {
1293                pname = pprint_rename(file->from_name, file->name);
1294        }
1295        file->print_name = pname;
1296}
1297
1298static void show_stats(struct diffstat_t *data, struct diff_options *options)
1299{
1300        int i, len, add, del, adds = 0, dels = 0;
1301        uintmax_t max_change = 0, max_len = 0;
1302        int total_files = data->nr;
1303        int width, name_width;
1304        const char *reset, *add_c, *del_c;
1305        const char *line_prefix = "";
1306        struct strbuf *msg = NULL;
1307
1308        if (data->nr == 0)
1309                return;
1310
1311        if (options->output_prefix) {
1312                msg = options->output_prefix(options, options->output_prefix_data);
1313                line_prefix = msg->buf;
1314        }
1315
1316        width = options->stat_width ? options->stat_width : 80;
1317        name_width = options->stat_name_width ? options->stat_name_width : 50;
1318
1319        /* Sanity: give at least 5 columns to the graph,
1320         * but leave at least 10 columns for the name.
1321         */
1322        if (width < 25)
1323                width = 25;
1324        if (name_width < 10)
1325                name_width = 10;
1326        else if (width < name_width + 15)
1327                name_width = width - 15;
1328
1329        /* Find the longest filename and max number of changes */
1330        reset = diff_get_color_opt(options, DIFF_RESET);
1331        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1332        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1333
1334        for (i = 0; i < data->nr; i++) {
1335                struct diffstat_file *file = data->files[i];
1336                uintmax_t change = file->added + file->deleted;
1337                fill_print_name(file);
1338                len = strlen(file->print_name);
1339                if (max_len < len)
1340                        max_len = len;
1341
1342                if (file->is_binary || file->is_unmerged)
1343                        continue;
1344                if (max_change < change)
1345                        max_change = change;
1346        }
1347
1348        /* Compute the width of the graph part;
1349         * 10 is for one blank at the beginning of the line plus
1350         * " | count " between the name and the graph.
1351         *
1352         * From here on, name_width is the width of the name area,
1353         * and width is the width of the graph area.
1354         */
1355        name_width = (name_width < max_len) ? name_width : max_len;
1356        if (width < (name_width + 10) + max_change)
1357                width = width - (name_width + 10);
1358        else
1359                width = max_change;
1360
1361        for (i = 0; i < data->nr; i++) {
1362                const char *prefix = "";
1363                char *name = data->files[i]->print_name;
1364                uintmax_t added = data->files[i]->added;
1365                uintmax_t deleted = data->files[i]->deleted;
1366                int name_len;
1367
1368                /*
1369                 * "scale" the filename
1370                 */
1371                len = name_width;
1372                name_len = strlen(name);
1373                if (name_width < name_len) {
1374                        char *slash;
1375                        prefix = "...";
1376                        len -= 3;
1377                        name += name_len - len;
1378                        slash = strchr(name, '/');
1379                        if (slash)
1380                                name = slash;
1381                }
1382
1383                if (data->files[i]->is_binary) {
1384                        fprintf(options->file, "%s", line_prefix);
1385                        show_name(options->file, prefix, name, len);
1386                        fprintf(options->file, "  Bin ");
1387                        fprintf(options->file, "%s%"PRIuMAX"%s",
1388                                del_c, deleted, reset);
1389                        fprintf(options->file, " -> ");
1390                        fprintf(options->file, "%s%"PRIuMAX"%s",
1391                                add_c, added, reset);
1392                        fprintf(options->file, " bytes");
1393                        fprintf(options->file, "\n");
1394                        continue;
1395                }
1396                else if (data->files[i]->is_unmerged) {
1397                        fprintf(options->file, "%s", line_prefix);
1398                        show_name(options->file, prefix, name, len);
1399                        fprintf(options->file, "  Unmerged\n");
1400                        continue;
1401                }
1402                else if (!data->files[i]->is_renamed &&
1403                         (added + deleted == 0)) {
1404                        total_files--;
1405                        continue;
1406                }
1407
1408                /*
1409                 * scale the add/delete
1410                 */
1411                add = added;
1412                del = deleted;
1413                adds += add;
1414                dels += del;
1415
1416                if (width <= max_change) {
1417                        add = scale_linear(add, width, max_change);
1418                        del = scale_linear(del, width, max_change);
1419                }
1420                fprintf(options->file, "%s", line_prefix);
1421                show_name(options->file, prefix, name, len);
1422                fprintf(options->file, "%5"PRIuMAX"%s", added + deleted,
1423                                added + deleted ? " " : "");
1424                show_graph(options->file, '+', add, add_c, reset);
1425                show_graph(options->file, '-', del, del_c, reset);
1426                fprintf(options->file, "\n");
1427        }
1428        fprintf(options->file, "%s", line_prefix);
1429        fprintf(options->file,
1430               " %d files changed, %d insertions(+), %d deletions(-)\n",
1431               total_files, adds, dels);
1432}
1433
1434static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1435{
1436        int i, adds = 0, dels = 0, total_files = data->nr;
1437
1438        if (data->nr == 0)
1439                return;
1440
1441        for (i = 0; i < data->nr; i++) {
1442                if (!data->files[i]->is_binary &&
1443                    !data->files[i]->is_unmerged) {
1444                        int added = data->files[i]->added;
1445                        int deleted= data->files[i]->deleted;
1446                        if (!data->files[i]->is_renamed &&
1447                            (added + deleted == 0)) {
1448                                total_files--;
1449                        } else {
1450                                adds += added;
1451                                dels += deleted;
1452                        }
1453                }
1454        }
1455        if (options->output_prefix) {
1456                struct strbuf *msg = NULL;
1457                msg = options->output_prefix(options,
1458                                options->output_prefix_data);
1459                fprintf(options->file, "%s", msg->buf);
1460        }
1461        fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
1462               total_files, adds, dels);
1463}
1464
1465static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1466{
1467        int i;
1468
1469        if (data->nr == 0)
1470                return;
1471
1472        for (i = 0; i < data->nr; i++) {
1473                struct diffstat_file *file = data->files[i];
1474
1475                if (options->output_prefix) {
1476                        struct strbuf *msg = NULL;
1477                        msg = options->output_prefix(options,
1478                                        options->output_prefix_data);
1479                        fprintf(options->file, "%s", msg->buf);
1480                }
1481
1482                if (file->is_binary)
1483                        fprintf(options->file, "-\t-\t");
1484                else
1485                        fprintf(options->file,
1486                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1487                                file->added, file->deleted);
1488                if (options->line_termination) {
1489                        fill_print_name(file);
1490                        if (!file->is_renamed)
1491                                write_name_quoted(file->name, options->file,
1492                                                  options->line_termination);
1493                        else {
1494                                fputs(file->print_name, options->file);
1495                                putc(options->line_termination, options->file);
1496                        }
1497                } else {
1498                        if (file->is_renamed) {
1499                                putc('\0', options->file);
1500                                write_name_quoted(file->from_name, options->file, '\0');
1501                        }
1502                        write_name_quoted(file->name, options->file, '\0');
1503                }
1504        }
1505}
1506
1507struct dirstat_file {
1508        const char *name;
1509        unsigned long changed;
1510};
1511
1512struct dirstat_dir {
1513        struct dirstat_file *files;
1514        int alloc, nr, permille, cumulative;
1515};
1516
1517static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1518                unsigned long changed, const char *base, int baselen)
1519{
1520        unsigned long this_dir = 0;
1521        unsigned int sources = 0;
1522        const char *line_prefix = "";
1523        struct strbuf *msg = NULL;
1524
1525        if (opt->output_prefix) {
1526                msg = opt->output_prefix(opt, opt->output_prefix_data);
1527                line_prefix = msg->buf;
1528        }
1529
1530        while (dir->nr) {
1531                struct dirstat_file *f = dir->files;
1532                int namelen = strlen(f->name);
1533                unsigned long this;
1534                char *slash;
1535
1536                if (namelen < baselen)
1537                        break;
1538                if (memcmp(f->name, base, baselen))
1539                        break;
1540                slash = strchr(f->name + baselen, '/');
1541                if (slash) {
1542                        int newbaselen = slash + 1 - f->name;
1543                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1544                        sources++;
1545                } else {
1546                        this = f->changed;
1547                        dir->files++;
1548                        dir->nr--;
1549                        sources += 2;
1550                }
1551                this_dir += this;
1552        }
1553
1554        /*
1555         * We don't report dirstat's for
1556         *  - the top level
1557         *  - or cases where everything came from a single directory
1558         *    under this directory (sources == 1).
1559         */
1560        if (baselen && sources != 1) {
1561                if (this_dir) {
1562                        int permille = this_dir * 1000 / changed;
1563                        if (permille >= dir->permille) {
1564                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1565                                        permille / 10, permille % 10, baselen, base);
1566                                if (!dir->cumulative)
1567                                        return 0;
1568                        }
1569                }
1570        }
1571        return this_dir;
1572}
1573
1574static int dirstat_compare(const void *_a, const void *_b)
1575{
1576        const struct dirstat_file *a = _a;
1577        const struct dirstat_file *b = _b;
1578        return strcmp(a->name, b->name);
1579}
1580
1581static void show_dirstat(struct diff_options *options)
1582{
1583        int i;
1584        unsigned long changed;
1585        struct dirstat_dir dir;
1586        struct diff_queue_struct *q = &diff_queued_diff;
1587
1588        dir.files = NULL;
1589        dir.alloc = 0;
1590        dir.nr = 0;
1591        dir.permille = options->dirstat_permille;
1592        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1593
1594        changed = 0;
1595        for (i = 0; i < q->nr; i++) {
1596                struct diff_filepair *p = q->queue[i];
1597                const char *name;
1598                unsigned long copied, added, damage;
1599                int content_changed;
1600
1601                name = p->two->path ? p->two->path : p->one->path;
1602
1603                if (p->one->sha1_valid && p->two->sha1_valid)
1604                        content_changed = hashcmp(p->one->sha1, p->two->sha1);
1605                else
1606                        content_changed = 1;
1607
1608                if (!content_changed) {
1609                        /*
1610                         * The SHA1 has not changed, so pre-/post-content is
1611                         * identical. We can therefore skip looking at the
1612                         * file contents altogether.
1613                         */
1614                        damage = 0;
1615                        goto found_damage;
1616                }
1617
1618                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1619                        /*
1620                         * In --dirstat-by-file mode, we don't really need to
1621                         * look at the actual file contents at all.
1622                         * The fact that the SHA1 changed is enough for us to
1623                         * add this file to the list of results
1624                         * (with each file contributing equal damage).
1625                         */
1626                        damage = 1;
1627                        goto found_damage;
1628                }
1629
1630                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1631                        diff_populate_filespec(p->one, 0);
1632                        diff_populate_filespec(p->two, 0);
1633                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1634                                               &copied, &added);
1635                        diff_free_filespec_data(p->one);
1636                        diff_free_filespec_data(p->two);
1637                } else if (DIFF_FILE_VALID(p->one)) {
1638                        diff_populate_filespec(p->one, 1);
1639                        copied = added = 0;
1640                        diff_free_filespec_data(p->one);
1641                } else if (DIFF_FILE_VALID(p->two)) {
1642                        diff_populate_filespec(p->two, 1);
1643                        copied = 0;
1644                        added = p->two->size;
1645                        diff_free_filespec_data(p->two);
1646                } else
1647                        continue;
1648
1649                /*
1650                 * Original minus copied is the removed material,
1651                 * added is the new material.  They are both damages
1652                 * made to the preimage.
1653                 * If the resulting damage is zero, we know that
1654                 * diffcore_count_changes() considers the two entries to
1655                 * be identical, but since content_changed is true, we
1656                 * know that there must have been _some_ kind of change,
1657                 * so we force all entries to have damage > 0.
1658                 */
1659                damage = (p->one->size - copied) + added;
1660                if (!damage)
1661                        damage = 1;
1662
1663found_damage:
1664                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1665                dir.files[dir.nr].name = name;
1666                dir.files[dir.nr].changed = damage;
1667                changed += damage;
1668                dir.nr++;
1669        }
1670
1671        /* This can happen even with many files, if everything was renames */
1672        if (!changed)
1673                return;
1674
1675        /* Show all directories with more than x% of the changes */
1676        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1677        gather_dirstat(options, &dir, changed, "", 0);
1678}
1679
1680static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
1681{
1682        int i;
1683        unsigned long changed;
1684        struct dirstat_dir dir;
1685
1686        if (data->nr == 0)
1687                return;
1688
1689        dir.files = NULL;
1690        dir.alloc = 0;
1691        dir.nr = 0;
1692        dir.permille = options->dirstat_permille;
1693        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1694
1695        changed = 0;
1696        for (i = 0; i < data->nr; i++) {
1697                struct diffstat_file *file = data->files[i];
1698                unsigned long damage = file->added + file->deleted;
1699                if (file->is_binary)
1700                        /*
1701                         * binary files counts bytes, not lines. Must find some
1702                         * way to normalize binary bytes vs. textual lines.
1703                         * The following heuristic assumes that there are 64
1704                         * bytes per "line".
1705                         * This is stupid and ugly, but very cheap...
1706                         */
1707                        damage = (damage + 63) / 64;
1708                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1709                dir.files[dir.nr].name = file->name;
1710                dir.files[dir.nr].changed = damage;
1711                changed += damage;
1712                dir.nr++;
1713        }
1714
1715        /* This can happen even with many files, if everything was renames */
1716        if (!changed)
1717                return;
1718
1719        /* Show all directories with more than x% of the changes */
1720        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1721        gather_dirstat(options, &dir, changed, "", 0);
1722}
1723
1724static void free_diffstat_info(struct diffstat_t *diffstat)
1725{
1726        int i;
1727        for (i = 0; i < diffstat->nr; i++) {
1728                struct diffstat_file *f = diffstat->files[i];
1729                if (f->name != f->print_name)
1730                        free(f->print_name);
1731                free(f->name);
1732                free(f->from_name);
1733                free(f);
1734        }
1735        free(diffstat->files);
1736}
1737
1738struct checkdiff_t {
1739        const char *filename;
1740        int lineno;
1741        int conflict_marker_size;
1742        struct diff_options *o;
1743        unsigned ws_rule;
1744        unsigned status;
1745};
1746
1747static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1748{
1749        char firstchar;
1750        int cnt;
1751
1752        if (len < marker_size + 1)
1753                return 0;
1754        firstchar = line[0];
1755        switch (firstchar) {
1756        case '=': case '>': case '<': case '|':
1757                break;
1758        default:
1759                return 0;
1760        }
1761        for (cnt = 1; cnt < marker_size; cnt++)
1762                if (line[cnt] != firstchar)
1763                        return 0;
1764        /* line[1] thru line[marker_size-1] are same as firstchar */
1765        if (len < marker_size + 1 || !isspace(line[marker_size]))
1766                return 0;
1767        return 1;
1768}
1769
1770static void checkdiff_consume(void *priv, char *line, unsigned long len)
1771{
1772        struct checkdiff_t *data = priv;
1773        int color_diff = DIFF_OPT_TST(data->o, COLOR_DIFF);
1774        int marker_size = data->conflict_marker_size;
1775        const char *ws = diff_get_color(color_diff, DIFF_WHITESPACE);
1776        const char *reset = diff_get_color(color_diff, DIFF_RESET);
1777        const char *set = diff_get_color(color_diff, DIFF_FILE_NEW);
1778        char *err;
1779        char *line_prefix = "";
1780        struct strbuf *msgbuf;
1781
1782        assert(data->o);
1783        if (data->o->output_prefix) {
1784                msgbuf = data->o->output_prefix(data->o,
1785                        data->o->output_prefix_data);
1786                line_prefix = msgbuf->buf;
1787        }
1788
1789        if (line[0] == '+') {
1790                unsigned bad;
1791                data->lineno++;
1792                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
1793                        data->status |= 1;
1794                        fprintf(data->o->file,
1795                                "%s%s:%d: leftover conflict marker\n",
1796                                line_prefix, data->filename, data->lineno);
1797                }
1798                bad = ws_check(line + 1, len - 1, data->ws_rule);
1799                if (!bad)
1800                        return;
1801                data->status |= bad;
1802                err = whitespace_error_string(bad);
1803                fprintf(data->o->file, "%s%s:%d: %s.\n",
1804                        line_prefix, data->filename, data->lineno, err);
1805                free(err);
1806                emit_line(data->o, set, reset, line, 1);
1807                ws_check_emit(line + 1, len - 1, data->ws_rule,
1808                              data->o->file, set, reset, ws);
1809        } else if (line[0] == ' ') {
1810                data->lineno++;
1811        } else if (line[0] == '@') {
1812                char *plus = strchr(line, '+');
1813                if (plus)
1814                        data->lineno = strtol(plus, NULL, 10) - 1;
1815                else
1816                        die("invalid diff");
1817        }
1818}
1819
1820static unsigned char *deflate_it(char *data,
1821                                 unsigned long size,
1822                                 unsigned long *result_size)
1823{
1824        int bound;
1825        unsigned char *deflated;
1826        z_stream stream;
1827
1828        memset(&stream, 0, sizeof(stream));
1829        deflateInit(&stream, zlib_compression_level);
1830        bound = deflateBound(&stream, size);
1831        deflated = xmalloc(bound);
1832        stream.next_out = deflated;
1833        stream.avail_out = bound;
1834
1835        stream.next_in = (unsigned char *)data;
1836        stream.avail_in = size;
1837        while (deflate(&stream, Z_FINISH) == Z_OK)
1838                ; /* nothing */
1839        deflateEnd(&stream);
1840        *result_size = stream.total_out;
1841        return deflated;
1842}
1843
1844static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1845{
1846        void *cp;
1847        void *delta;
1848        void *deflated;
1849        void *data;
1850        unsigned long orig_size;
1851        unsigned long delta_size;
1852        unsigned long deflate_size;
1853        unsigned long data_size;
1854
1855        /* We could do deflated delta, or we could do just deflated two,
1856         * whichever is smaller.
1857         */
1858        delta = NULL;
1859        deflated = deflate_it(two->ptr, two->size, &deflate_size);
1860        if (one->size && two->size) {
1861                delta = diff_delta(one->ptr, one->size,
1862                                   two->ptr, two->size,
1863                                   &delta_size, deflate_size);
1864                if (delta) {
1865                        void *to_free = delta;
1866                        orig_size = delta_size;
1867                        delta = deflate_it(delta, delta_size, &delta_size);
1868                        free(to_free);
1869                }
1870        }
1871
1872        if (delta && delta_size < deflate_size) {
1873                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
1874                free(deflated);
1875                data = delta;
1876                data_size = delta_size;
1877        }
1878        else {
1879                fprintf(file, "%sliteral %lu\n", prefix, two->size);
1880                free(delta);
1881                data = deflated;
1882                data_size = deflate_size;
1883        }
1884
1885        /* emit data encoded in base85 */
1886        cp = data;
1887        while (data_size) {
1888                int bytes = (52 < data_size) ? 52 : data_size;
1889                char line[70];
1890                data_size -= bytes;
1891                if (bytes <= 26)
1892                        line[0] = bytes + 'A' - 1;
1893                else
1894                        line[0] = bytes - 26 + 'a' - 1;
1895                encode_85(line + 1, cp, bytes);
1896                cp = (char *) cp + bytes;
1897                fprintf(file, "%s", prefix);
1898                fputs(line, file);
1899                fputc('\n', file);
1900        }
1901        fprintf(file, "%s\n", prefix);
1902        free(data);
1903}
1904
1905static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1906{
1907        fprintf(file, "%sGIT binary patch\n", prefix);
1908        emit_binary_diff_body(file, one, two, prefix);
1909        emit_binary_diff_body(file, two, one, prefix);
1910}
1911
1912static void diff_filespec_load_driver(struct diff_filespec *one)
1913{
1914        /* Use already-loaded driver */
1915        if (one->driver)
1916                return;
1917
1918        if (S_ISREG(one->mode))
1919                one->driver = userdiff_find_by_path(one->path);
1920
1921        /* Fallback to default settings */
1922        if (!one->driver)
1923                one->driver = userdiff_find_by_name("default");
1924}
1925
1926int diff_filespec_is_binary(struct diff_filespec *one)
1927{
1928        if (one->is_binary == -1) {
1929                diff_filespec_load_driver(one);
1930                if (one->driver->binary != -1)
1931                        one->is_binary = one->driver->binary;
1932                else {
1933                        if (!one->data && DIFF_FILE_VALID(one))
1934                                diff_populate_filespec(one, 0);
1935                        if (one->data)
1936                                one->is_binary = buffer_is_binary(one->data,
1937                                                one->size);
1938                        if (one->is_binary == -1)
1939                                one->is_binary = 0;
1940                }
1941        }
1942        return one->is_binary;
1943}
1944
1945static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
1946{
1947        diff_filespec_load_driver(one);
1948        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
1949}
1950
1951static const char *userdiff_word_regex(struct diff_filespec *one)
1952{
1953        diff_filespec_load_driver(one);
1954        return one->driver->word_regex;
1955}
1956
1957void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
1958{
1959        if (!options->a_prefix)
1960                options->a_prefix = a;
1961        if (!options->b_prefix)
1962                options->b_prefix = b;
1963}
1964
1965struct userdiff_driver *get_textconv(struct diff_filespec *one)
1966{
1967        if (!DIFF_FILE_VALID(one))
1968                return NULL;
1969
1970        diff_filespec_load_driver(one);
1971        if (!one->driver->textconv)
1972                return NULL;
1973
1974        if (one->driver->textconv_want_cache && !one->driver->textconv_cache) {
1975                struct notes_cache *c = xmalloc(sizeof(*c));
1976                struct strbuf name = STRBUF_INIT;
1977
1978                strbuf_addf(&name, "textconv/%s", one->driver->name);
1979                notes_cache_init(c, name.buf, one->driver->textconv);
1980                one->driver->textconv_cache = c;
1981        }
1982
1983        return one->driver;
1984}
1985
1986static void builtin_diff(const char *name_a,
1987                         const char *name_b,
1988                         struct diff_filespec *one,
1989                         struct diff_filespec *two,
1990                         const char *xfrm_msg,
1991                         int must_show_header,
1992                         struct diff_options *o,
1993                         int complete_rewrite)
1994{
1995        mmfile_t mf1, mf2;
1996        const char *lbl[2];
1997        char *a_one, *b_two;
1998        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1999        const char *reset = diff_get_color_opt(o, DIFF_RESET);
2000        const char *a_prefix, *b_prefix;
2001        struct userdiff_driver *textconv_one = NULL;
2002        struct userdiff_driver *textconv_two = NULL;
2003        struct strbuf header = STRBUF_INIT;
2004        struct strbuf *msgbuf;
2005        char *line_prefix = "";
2006
2007        if (o->output_prefix) {
2008                msgbuf = o->output_prefix(o, o->output_prefix_data);
2009                line_prefix = msgbuf->buf;
2010        }
2011
2012        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
2013                        (!one->mode || S_ISGITLINK(one->mode)) &&
2014                        (!two->mode || S_ISGITLINK(two->mode))) {
2015                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2016                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2017                show_submodule_summary(o->file, one ? one->path : two->path,
2018                                one->sha1, two->sha1, two->dirty_submodule,
2019                                del, add, reset);
2020                return;
2021        }
2022
2023        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
2024                textconv_one = get_textconv(one);
2025                textconv_two = get_textconv(two);
2026        }
2027
2028        diff_set_mnemonic_prefix(o, "a/", "b/");
2029        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
2030                a_prefix = o->b_prefix;
2031                b_prefix = o->a_prefix;
2032        } else {
2033                a_prefix = o->a_prefix;
2034                b_prefix = o->b_prefix;
2035        }
2036
2037        /* Never use a non-valid filename anywhere if at all possible */
2038        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
2039        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
2040
2041        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
2042        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
2043        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
2044        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
2045        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
2046        if (lbl[0][0] == '/') {
2047                /* /dev/null */
2048                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
2049                if (xfrm_msg)
2050                        strbuf_addstr(&header, xfrm_msg);
2051                must_show_header = 1;
2052        }
2053        else if (lbl[1][0] == '/') {
2054                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
2055                if (xfrm_msg)
2056                        strbuf_addstr(&header, xfrm_msg);
2057                must_show_header = 1;
2058        }
2059        else {
2060                if (one->mode != two->mode) {
2061                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
2062                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
2063                        must_show_header = 1;
2064                }
2065                if (xfrm_msg)
2066                        strbuf_addstr(&header, xfrm_msg);
2067
2068                /*
2069                 * we do not run diff between different kind
2070                 * of objects.
2071                 */
2072                if ((one->mode ^ two->mode) & S_IFMT)
2073                        goto free_ab_and_return;
2074                if (complete_rewrite &&
2075                    (textconv_one || !diff_filespec_is_binary(one)) &&
2076                    (textconv_two || !diff_filespec_is_binary(two))) {
2077                        fprintf(o->file, "%s", header.buf);
2078                        strbuf_reset(&header);
2079                        emit_rewrite_diff(name_a, name_b, one, two,
2080                                                textconv_one, textconv_two, o);
2081                        o->found_changes = 1;
2082                        goto free_ab_and_return;
2083                }
2084        }
2085
2086        if (o->irreversible_delete && lbl[1][0] == '/') {
2087                fprintf(o->file, "%s", header.buf);
2088                strbuf_reset(&header);
2089                goto free_ab_and_return;
2090        } else if (!DIFF_OPT_TST(o, TEXT) &&
2091            ( (!textconv_one && diff_filespec_is_binary(one)) ||
2092              (!textconv_two && diff_filespec_is_binary(two)) )) {
2093                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2094                        die("unable to read files to diff");
2095                /* Quite common confusing case */
2096                if (mf1.size == mf2.size &&
2097                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2098                        if (must_show_header)
2099                                fprintf(o->file, "%s", header.buf);
2100                        goto free_ab_and_return;
2101                }
2102                fprintf(o->file, "%s", header.buf);
2103                strbuf_reset(&header);
2104                if (DIFF_OPT_TST(o, BINARY))
2105                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2106                else
2107                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2108                                line_prefix, lbl[0], lbl[1]);
2109                o->found_changes = 1;
2110        } else {
2111                /* Crazy xdl interfaces.. */
2112                const char *diffopts = getenv("GIT_DIFF_OPTS");
2113                xpparam_t xpp;
2114                xdemitconf_t xecfg;
2115                struct emit_callback ecbdata;
2116                const struct userdiff_funcname *pe;
2117
2118                if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS) || must_show_header) {
2119                        fprintf(o->file, "%s", header.buf);
2120                        strbuf_reset(&header);
2121                }
2122
2123                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2124                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2125
2126                pe = diff_funcname_pattern(one);
2127                if (!pe)
2128                        pe = diff_funcname_pattern(two);
2129
2130                memset(&xpp, 0, sizeof(xpp));
2131                memset(&xecfg, 0, sizeof(xecfg));
2132                memset(&ecbdata, 0, sizeof(ecbdata));
2133                ecbdata.label_path = lbl;
2134                ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
2135                ecbdata.found_changesp = &o->found_changes;
2136                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
2137                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2138                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2139                ecbdata.opt = o;
2140                ecbdata.header = header.len ? &header : NULL;
2141                xpp.flags = o->xdl_opts;
2142                xecfg.ctxlen = o->context;
2143                xecfg.interhunkctxlen = o->interhunkcontext;
2144                xecfg.flags = XDL_EMIT_FUNCNAMES;
2145                if (pe)
2146                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2147                if (!diffopts)
2148                        ;
2149                else if (!prefixcmp(diffopts, "--unified="))
2150                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2151                else if (!prefixcmp(diffopts, "-u"))
2152                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2153                if (o->word_diff) {
2154                        int i;
2155
2156                        ecbdata.diff_words =
2157                                xcalloc(1, sizeof(struct diff_words_data));
2158                        ecbdata.diff_words->type = o->word_diff;
2159                        ecbdata.diff_words->opt = o;
2160                        if (!o->word_regex)
2161                                o->word_regex = userdiff_word_regex(one);
2162                        if (!o->word_regex)
2163                                o->word_regex = userdiff_word_regex(two);
2164                        if (!o->word_regex)
2165                                o->word_regex = diff_word_regex_cfg;
2166                        if (o->word_regex) {
2167                                ecbdata.diff_words->word_regex = (regex_t *)
2168                                        xmalloc(sizeof(regex_t));
2169                                if (regcomp(ecbdata.diff_words->word_regex,
2170                                                o->word_regex,
2171                                                REG_EXTENDED | REG_NEWLINE))
2172                                        die ("Invalid regular expression: %s",
2173                                                        o->word_regex);
2174                        }
2175                        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2176                                if (o->word_diff == diff_words_styles[i].type) {
2177                                        ecbdata.diff_words->style =
2178                                                &diff_words_styles[i];
2179                                        break;
2180                                }
2181                        }
2182                        if (DIFF_OPT_TST(o, COLOR_DIFF)) {
2183                                struct diff_words_style *st = ecbdata.diff_words->style;
2184                                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2185                                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2186                                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
2187                        }
2188                }
2189                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2190                              &xpp, &xecfg);
2191                if (o->word_diff)
2192                        free_diff_words_data(&ecbdata);
2193                if (textconv_one)
2194                        free(mf1.ptr);
2195                if (textconv_two)
2196                        free(mf2.ptr);
2197                xdiff_clear_find_func(&xecfg);
2198        }
2199
2200 free_ab_and_return:
2201        strbuf_release(&header);
2202        diff_free_filespec_data(one);
2203        diff_free_filespec_data(two);
2204        free(a_one);
2205        free(b_two);
2206        return;
2207}
2208
2209static void builtin_diffstat(const char *name_a, const char *name_b,
2210                             struct diff_filespec *one,
2211                             struct diff_filespec *two,
2212                             struct diffstat_t *diffstat,
2213                             struct diff_options *o,
2214                             int complete_rewrite)
2215{
2216        mmfile_t mf1, mf2;
2217        struct diffstat_file *data;
2218
2219        data = diffstat_add(diffstat, name_a, name_b);
2220
2221        if (!one || !two) {
2222                data->is_unmerged = 1;
2223                return;
2224        }
2225
2226        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2227                data->is_binary = 1;
2228                data->added = diff_filespec_size(two);
2229                data->deleted = diff_filespec_size(one);
2230        }
2231
2232        else if (complete_rewrite) {
2233                diff_populate_filespec(one, 0);
2234                diff_populate_filespec(two, 0);
2235                data->deleted = count_lines(one->data, one->size);
2236                data->added = count_lines(two->data, two->size);
2237        }
2238
2239        else {
2240                /* Crazy xdl interfaces.. */
2241                xpparam_t xpp;
2242                xdemitconf_t xecfg;
2243
2244                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2245                        die("unable to read files to diff");
2246
2247                memset(&xpp, 0, sizeof(xpp));
2248                memset(&xecfg, 0, sizeof(xecfg));
2249                xpp.flags = o->xdl_opts;
2250                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2251                              &xpp, &xecfg);
2252        }
2253
2254        diff_free_filespec_data(one);
2255        diff_free_filespec_data(two);
2256}
2257
2258static void builtin_checkdiff(const char *name_a, const char *name_b,
2259                              const char *attr_path,
2260                              struct diff_filespec *one,
2261                              struct diff_filespec *two,
2262                              struct diff_options *o)
2263{
2264        mmfile_t mf1, mf2;
2265        struct checkdiff_t data;
2266
2267        if (!two)
2268                return;
2269
2270        memset(&data, 0, sizeof(data));
2271        data.filename = name_b ? name_b : name_a;
2272        data.lineno = 0;
2273        data.o = o;
2274        data.ws_rule = whitespace_rule(attr_path);
2275        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2276
2277        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2278                die("unable to read files to diff");
2279
2280        /*
2281         * All the other codepaths check both sides, but not checking
2282         * the "old" side here is deliberate.  We are checking the newly
2283         * introduced changes, and as long as the "new" side is text, we
2284         * can and should check what it introduces.
2285         */
2286        if (diff_filespec_is_binary(two))
2287                goto free_and_return;
2288        else {
2289                /* Crazy xdl interfaces.. */
2290                xpparam_t xpp;
2291                xdemitconf_t xecfg;
2292
2293                memset(&xpp, 0, sizeof(xpp));
2294                memset(&xecfg, 0, sizeof(xecfg));
2295                xecfg.ctxlen = 1; /* at least one context line */
2296                xpp.flags = 0;
2297                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2298                              &xpp, &xecfg);
2299
2300                if (data.ws_rule & WS_BLANK_AT_EOF) {
2301                        struct emit_callback ecbdata;
2302                        int blank_at_eof;
2303
2304                        ecbdata.ws_rule = data.ws_rule;
2305                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2306                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2307
2308                        if (blank_at_eof) {
2309                                static char *err;
2310                                if (!err)
2311                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2312                                fprintf(o->file, "%s:%d: %s.\n",
2313                                        data.filename, blank_at_eof, err);
2314                                data.status = 1; /* report errors */
2315                        }
2316                }
2317        }
2318 free_and_return:
2319        diff_free_filespec_data(one);
2320        diff_free_filespec_data(two);
2321        if (data.status)
2322                DIFF_OPT_SET(o, CHECK_FAILED);
2323}
2324
2325struct diff_filespec *alloc_filespec(const char *path)
2326{
2327        int namelen = strlen(path);
2328        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2329
2330        memset(spec, 0, sizeof(*spec));
2331        spec->path = (char *)(spec + 1);
2332        memcpy(spec->path, path, namelen+1);
2333        spec->count = 1;
2334        spec->is_binary = -1;
2335        return spec;
2336}
2337
2338void free_filespec(struct diff_filespec *spec)
2339{
2340        if (!--spec->count) {
2341                diff_free_filespec_data(spec);
2342                free(spec);
2343        }
2344}
2345
2346void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2347                   unsigned short mode)
2348{
2349        if (mode) {
2350                spec->mode = canon_mode(mode);
2351                hashcpy(spec->sha1, sha1);
2352                spec->sha1_valid = !is_null_sha1(sha1);
2353        }
2354}
2355
2356/*
2357 * Given a name and sha1 pair, if the index tells us the file in
2358 * the work tree has that object contents, return true, so that
2359 * prepare_temp_file() does not have to inflate and extract.
2360 */
2361static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2362{
2363        struct cache_entry *ce;
2364        struct stat st;
2365        int pos, len;
2366
2367        /*
2368         * We do not read the cache ourselves here, because the
2369         * benchmark with my previous version that always reads cache
2370         * shows that it makes things worse for diff-tree comparing
2371         * two linux-2.6 kernel trees in an already checked out work
2372         * tree.  This is because most diff-tree comparisons deal with
2373         * only a small number of files, while reading the cache is
2374         * expensive for a large project, and its cost outweighs the
2375         * savings we get by not inflating the object to a temporary
2376         * file.  Practically, this code only helps when we are used
2377         * by diff-cache --cached, which does read the cache before
2378         * calling us.
2379         */
2380        if (!active_cache)
2381                return 0;
2382
2383        /* We want to avoid the working directory if our caller
2384         * doesn't need the data in a normal file, this system
2385         * is rather slow with its stat/open/mmap/close syscalls,
2386         * and the object is contained in a pack file.  The pack
2387         * is probably already open and will be faster to obtain
2388         * the data through than the working directory.  Loose
2389         * objects however would tend to be slower as they need
2390         * to be individually opened and inflated.
2391         */
2392        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2393                return 0;
2394
2395        len = strlen(name);
2396        pos = cache_name_pos(name, len);
2397        if (pos < 0)
2398                return 0;
2399        ce = active_cache[pos];
2400
2401        /*
2402         * This is not the sha1 we are looking for, or
2403         * unreusable because it is not a regular file.
2404         */
2405        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2406                return 0;
2407
2408        /*
2409         * If ce is marked as "assume unchanged", there is no
2410         * guarantee that work tree matches what we are looking for.
2411         */
2412        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2413                return 0;
2414
2415        /*
2416         * If ce matches the file in the work tree, we can reuse it.
2417         */
2418        if (ce_uptodate(ce) ||
2419            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2420                return 1;
2421
2422        return 0;
2423}
2424
2425static int populate_from_stdin(struct diff_filespec *s)
2426{
2427        struct strbuf buf = STRBUF_INIT;
2428        size_t size = 0;
2429
2430        if (strbuf_read(&buf, 0, 0) < 0)
2431                return error("error while reading from stdin %s",
2432                                     strerror(errno));
2433
2434        s->should_munmap = 0;
2435        s->data = strbuf_detach(&buf, &size);
2436        s->size = size;
2437        s->should_free = 1;
2438        return 0;
2439}
2440
2441static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2442{
2443        int len;
2444        char *data = xmalloc(100), *dirty = "";
2445
2446        /* Are we looking at the work tree? */
2447        if (s->dirty_submodule)
2448                dirty = "-dirty";
2449
2450        len = snprintf(data, 100,
2451                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2452        s->data = data;
2453        s->size = len;
2454        s->should_free = 1;
2455        if (size_only) {
2456                s->data = NULL;
2457                free(data);
2458        }
2459        return 0;
2460}
2461
2462/*
2463 * While doing rename detection and pickaxe operation, we may need to
2464 * grab the data for the blob (or file) for our own in-core comparison.
2465 * diff_filespec has data and size fields for this purpose.
2466 */
2467int diff_populate_filespec(struct diff_filespec *s, int size_only)
2468{
2469        int err = 0;
2470        if (!DIFF_FILE_VALID(s))
2471                die("internal error: asking to populate invalid file.");
2472        if (S_ISDIR(s->mode))
2473                return -1;
2474
2475        if (s->data)
2476                return 0;
2477
2478        if (size_only && 0 < s->size)
2479                return 0;
2480
2481        if (S_ISGITLINK(s->mode))
2482                return diff_populate_gitlink(s, size_only);
2483
2484        if (!s->sha1_valid ||
2485            reuse_worktree_file(s->path, s->sha1, 0)) {
2486                struct strbuf buf = STRBUF_INIT;
2487                struct stat st;
2488                int fd;
2489
2490                if (!strcmp(s->path, "-"))
2491                        return populate_from_stdin(s);
2492
2493                if (lstat(s->path, &st) < 0) {
2494                        if (errno == ENOENT) {
2495                        err_empty:
2496                                err = -1;
2497                        empty:
2498                                s->data = (char *)"";
2499                                s->size = 0;
2500                                return err;
2501                        }
2502                }
2503                s->size = xsize_t(st.st_size);
2504                if (!s->size)
2505                        goto empty;
2506                if (S_ISLNK(st.st_mode)) {
2507                        struct strbuf sb = STRBUF_INIT;
2508
2509                        if (strbuf_readlink(&sb, s->path, s->size))
2510                                goto err_empty;
2511                        s->size = sb.len;
2512                        s->data = strbuf_detach(&sb, NULL);
2513                        s->should_free = 1;
2514                        return 0;
2515                }
2516                if (size_only)
2517                        return 0;
2518                fd = open(s->path, O_RDONLY);
2519                if (fd < 0)
2520                        goto err_empty;
2521                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2522                close(fd);
2523                s->should_munmap = 1;
2524
2525                /*
2526                 * Convert from working tree format to canonical git format
2527                 */
2528                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2529                        size_t size = 0;
2530                        munmap(s->data, s->size);
2531                        s->should_munmap = 0;
2532                        s->data = strbuf_detach(&buf, &size);
2533                        s->size = size;
2534                        s->should_free = 1;
2535                }
2536        }
2537        else {
2538                enum object_type type;
2539                if (size_only) {
2540                        type = sha1_object_info(s->sha1, &s->size);
2541                        if (type < 0)
2542                                die("unable to read %s", sha1_to_hex(s->sha1));
2543                } else {
2544                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2545                        if (!s->data)
2546                                die("unable to read %s", sha1_to_hex(s->sha1));
2547                        s->should_free = 1;
2548                }
2549        }
2550        return 0;
2551}
2552
2553void diff_free_filespec_blob(struct diff_filespec *s)
2554{
2555        if (s->should_free)
2556                free(s->data);
2557        else if (s->should_munmap)
2558                munmap(s->data, s->size);
2559
2560        if (s->should_free || s->should_munmap) {
2561                s->should_free = s->should_munmap = 0;
2562                s->data = NULL;
2563        }
2564}
2565
2566void diff_free_filespec_data(struct diff_filespec *s)
2567{
2568        diff_free_filespec_blob(s);
2569        free(s->cnt_data);
2570        s->cnt_data = NULL;
2571}
2572
2573static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2574                           void *blob,
2575                           unsigned long size,
2576                           const unsigned char *sha1,
2577                           int mode)
2578{
2579        int fd;
2580        struct strbuf buf = STRBUF_INIT;
2581        struct strbuf template = STRBUF_INIT;
2582        char *path_dup = xstrdup(path);
2583        const char *base = basename(path_dup);
2584
2585        /* Generate "XXXXXX_basename.ext" */
2586        strbuf_addstr(&template, "XXXXXX_");
2587        strbuf_addstr(&template, base);
2588
2589        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2590                        strlen(base) + 1);
2591        if (fd < 0)
2592                die_errno("unable to create temp-file");
2593        if (convert_to_working_tree(path,
2594                        (const char *)blob, (size_t)size, &buf)) {
2595                blob = buf.buf;
2596                size = buf.len;
2597        }
2598        if (write_in_full(fd, blob, size) != size)
2599                die_errno("unable to write temp-file");
2600        close(fd);
2601        temp->name = temp->tmp_path;
2602        strcpy(temp->hex, sha1_to_hex(sha1));
2603        temp->hex[40] = 0;
2604        sprintf(temp->mode, "%06o", mode);
2605        strbuf_release(&buf);
2606        strbuf_release(&template);
2607        free(path_dup);
2608}
2609
2610static struct diff_tempfile *prepare_temp_file(const char *name,
2611                struct diff_filespec *one)
2612{
2613        struct diff_tempfile *temp = claim_diff_tempfile();
2614
2615        if (!DIFF_FILE_VALID(one)) {
2616        not_a_valid_file:
2617                /* A '-' entry produces this for file-2, and
2618                 * a '+' entry produces this for file-1.
2619                 */
2620                temp->name = "/dev/null";
2621                strcpy(temp->hex, ".");
2622                strcpy(temp->mode, ".");
2623                return temp;
2624        }
2625
2626        if (!remove_tempfile_installed) {
2627                atexit(remove_tempfile);
2628                sigchain_push_common(remove_tempfile_on_signal);
2629                remove_tempfile_installed = 1;
2630        }
2631
2632        if (!one->sha1_valid ||
2633            reuse_worktree_file(name, one->sha1, 1)) {
2634                struct stat st;
2635                if (lstat(name, &st) < 0) {
2636                        if (errno == ENOENT)
2637                                goto not_a_valid_file;
2638                        die_errno("stat(%s)", name);
2639                }
2640                if (S_ISLNK(st.st_mode)) {
2641                        struct strbuf sb = STRBUF_INIT;
2642                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2643                                die_errno("readlink(%s)", name);
2644                        prep_temp_blob(name, temp, sb.buf, sb.len,
2645                                       (one->sha1_valid ?
2646                                        one->sha1 : null_sha1),
2647                                       (one->sha1_valid ?
2648                                        one->mode : S_IFLNK));
2649                        strbuf_release(&sb);
2650                }
2651                else {
2652                        /* we can borrow from the file in the work tree */
2653                        temp->name = name;
2654                        if (!one->sha1_valid)
2655                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2656                        else
2657                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2658                        /* Even though we may sometimes borrow the
2659                         * contents from the work tree, we always want
2660                         * one->mode.  mode is trustworthy even when
2661                         * !(one->sha1_valid), as long as
2662                         * DIFF_FILE_VALID(one).
2663                         */
2664                        sprintf(temp->mode, "%06o", one->mode);
2665                }
2666                return temp;
2667        }
2668        else {
2669                if (diff_populate_filespec(one, 0))
2670                        die("cannot read data blob for %s", one->path);
2671                prep_temp_blob(name, temp, one->data, one->size,
2672                               one->sha1, one->mode);
2673        }
2674        return temp;
2675}
2676
2677/* An external diff command takes:
2678 *
2679 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2680 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2681 *
2682 */
2683static void run_external_diff(const char *pgm,
2684                              const char *name,
2685                              const char *other,
2686                              struct diff_filespec *one,
2687                              struct diff_filespec *two,
2688                              const char *xfrm_msg,
2689                              int complete_rewrite)
2690{
2691        const char *spawn_arg[10];
2692        int retval;
2693        const char **arg = &spawn_arg[0];
2694
2695        if (one && two) {
2696                struct diff_tempfile *temp_one, *temp_two;
2697                const char *othername = (other ? other : name);
2698                temp_one = prepare_temp_file(name, one);
2699                temp_two = prepare_temp_file(othername, two);
2700                *arg++ = pgm;
2701                *arg++ = name;
2702                *arg++ = temp_one->name;
2703                *arg++ = temp_one->hex;
2704                *arg++ = temp_one->mode;
2705                *arg++ = temp_two->name;
2706                *arg++ = temp_two->hex;
2707                *arg++ = temp_two->mode;
2708                if (other) {
2709                        *arg++ = other;
2710                        *arg++ = xfrm_msg;
2711                }
2712        } else {
2713                *arg++ = pgm;
2714                *arg++ = name;
2715        }
2716        *arg = NULL;
2717        fflush(NULL);
2718        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2719        remove_tempfile();
2720        if (retval) {
2721                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2722                exit(1);
2723        }
2724}
2725
2726static int similarity_index(struct diff_filepair *p)
2727{
2728        return p->score * 100 / MAX_SCORE;
2729}
2730
2731static void fill_metainfo(struct strbuf *msg,
2732                          const char *name,
2733                          const char *other,
2734                          struct diff_filespec *one,
2735                          struct diff_filespec *two,
2736                          struct diff_options *o,
2737                          struct diff_filepair *p,
2738                          int *must_show_header,
2739                          int use_color)
2740{
2741        const char *set = diff_get_color(use_color, DIFF_METAINFO);
2742        const char *reset = diff_get_color(use_color, DIFF_RESET);
2743        struct strbuf *msgbuf;
2744        char *line_prefix = "";
2745
2746        *must_show_header = 1;
2747        if (o->output_prefix) {
2748                msgbuf = o->output_prefix(o, o->output_prefix_data);
2749                line_prefix = msgbuf->buf;
2750        }
2751        strbuf_init(msg, PATH_MAX * 2 + 300);
2752        switch (p->status) {
2753        case DIFF_STATUS_COPIED:
2754                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2755                            line_prefix, set, similarity_index(p));
2756                strbuf_addf(msg, "%s\n%s%scopy from ",
2757                            reset,  line_prefix, set);
2758                quote_c_style(name, msg, NULL, 0);
2759                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2760                quote_c_style(other, msg, NULL, 0);
2761                strbuf_addf(msg, "%s\n", reset);
2762                break;
2763        case DIFF_STATUS_RENAMED:
2764                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2765                            line_prefix, set, similarity_index(p));
2766                strbuf_addf(msg, "%s\n%s%srename from ",
2767                            reset, line_prefix, set);
2768                quote_c_style(name, msg, NULL, 0);
2769                strbuf_addf(msg, "%s\n%s%srename to ",
2770                            reset, line_prefix, set);
2771                quote_c_style(other, msg, NULL, 0);
2772                strbuf_addf(msg, "%s\n", reset);
2773                break;
2774        case DIFF_STATUS_MODIFIED:
2775                if (p->score) {
2776                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2777                                    line_prefix,
2778                                    set, similarity_index(p), reset);
2779                        break;
2780                }
2781                /* fallthru */
2782        default:
2783                *must_show_header = 0;
2784        }
2785        if (one && two && hashcmp(one->sha1, two->sha1)) {
2786                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2787
2788                if (DIFF_OPT_TST(o, BINARY)) {
2789                        mmfile_t mf;
2790                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2791                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2792                                abbrev = 40;
2793                }
2794                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2795                            find_unique_abbrev(one->sha1, abbrev));
2796                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2797                if (one->mode == two->mode)
2798                        strbuf_addf(msg, " %06o", one->mode);
2799                strbuf_addf(msg, "%s\n", reset);
2800        }
2801}
2802
2803static void run_diff_cmd(const char *pgm,
2804                         const char *name,
2805                         const char *other,
2806                         const char *attr_path,
2807                         struct diff_filespec *one,
2808                         struct diff_filespec *two,
2809                         struct strbuf *msg,
2810                         struct diff_options *o,
2811                         struct diff_filepair *p)
2812{
2813        const char *xfrm_msg = NULL;
2814        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2815        int must_show_header = 0;
2816
2817        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2818                pgm = NULL;
2819        else {
2820                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2821                if (drv && drv->external)
2822                        pgm = drv->external;
2823        }
2824
2825        if (msg) {
2826                /*
2827                 * don't use colors when the header is intended for an
2828                 * external diff driver
2829                 */
2830                fill_metainfo(msg, name, other, one, two, o, p,
2831                              &must_show_header,
2832                              DIFF_OPT_TST(o, COLOR_DIFF) && !pgm);
2833                xfrm_msg = msg->len ? msg->buf : NULL;
2834        }
2835
2836        if (pgm) {
2837                run_external_diff(pgm, name, other, one, two, xfrm_msg,
2838                                  complete_rewrite);
2839                return;
2840        }
2841        if (one && two)
2842                builtin_diff(name, other ? other : name,
2843                             one, two, xfrm_msg, must_show_header,
2844                             o, complete_rewrite);
2845        else
2846                fprintf(o->file, "* Unmerged path %s\n", name);
2847}
2848
2849static void diff_fill_sha1_info(struct diff_filespec *one)
2850{
2851        if (DIFF_FILE_VALID(one)) {
2852                if (!one->sha1_valid) {
2853                        struct stat st;
2854                        if (!strcmp(one->path, "-")) {
2855                                hashcpy(one->sha1, null_sha1);
2856                                return;
2857                        }
2858                        if (lstat(one->path, &st) < 0)
2859                                die_errno("stat '%s'", one->path);
2860                        if (index_path(one->sha1, one->path, &st, 0))
2861                                die("cannot hash %s", one->path);
2862                }
2863        }
2864        else
2865                hashclr(one->sha1);
2866}
2867
2868static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2869{
2870        /* Strip the prefix but do not molest /dev/null and absolute paths */
2871        if (*namep && **namep != '/') {
2872                *namep += prefix_length;
2873                if (**namep == '/')
2874                        ++*namep;
2875        }
2876        if (*otherp && **otherp != '/') {
2877                *otherp += prefix_length;
2878                if (**otherp == '/')
2879                        ++*otherp;
2880        }
2881}
2882
2883static void run_diff(struct diff_filepair *p, struct diff_options *o)
2884{
2885        const char *pgm = external_diff();
2886        struct strbuf msg;
2887        struct diff_filespec *one = p->one;
2888        struct diff_filespec *two = p->two;
2889        const char *name;
2890        const char *other;
2891        const char *attr_path;
2892
2893        name  = p->one->path;
2894        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2895        attr_path = name;
2896        if (o->prefix_length)
2897                strip_prefix(o->prefix_length, &name, &other);
2898
2899        if (DIFF_PAIR_UNMERGED(p)) {
2900                run_diff_cmd(pgm, name, NULL, attr_path,
2901                             NULL, NULL, NULL, o, p);
2902                return;
2903        }
2904
2905        diff_fill_sha1_info(one);
2906        diff_fill_sha1_info(two);
2907
2908        if (!pgm &&
2909            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2910            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2911                /*
2912                 * a filepair that changes between file and symlink
2913                 * needs to be split into deletion and creation.
2914                 */
2915                struct diff_filespec *null = alloc_filespec(two->path);
2916                run_diff_cmd(NULL, name, other, attr_path,
2917                             one, null, &msg, o, p);
2918                free(null);
2919                strbuf_release(&msg);
2920
2921                null = alloc_filespec(one->path);
2922                run_diff_cmd(NULL, name, other, attr_path,
2923                             null, two, &msg, o, p);
2924                free(null);
2925        }
2926        else
2927                run_diff_cmd(pgm, name, other, attr_path,
2928                             one, two, &msg, o, p);
2929
2930        strbuf_release(&msg);
2931}
2932
2933static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2934                         struct diffstat_t *diffstat)
2935{
2936        const char *name;
2937        const char *other;
2938        int complete_rewrite = 0;
2939
2940        if (DIFF_PAIR_UNMERGED(p)) {
2941                /* unmerged */
2942                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2943                return;
2944        }
2945
2946        name = p->one->path;
2947        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2948
2949        if (o->prefix_length)
2950                strip_prefix(o->prefix_length, &name, &other);
2951
2952        diff_fill_sha1_info(p->one);
2953        diff_fill_sha1_info(p->two);
2954
2955        if (p->status == DIFF_STATUS_MODIFIED && p->score)
2956                complete_rewrite = 1;
2957        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2958}
2959
2960static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2961{
2962        const char *name;
2963        const char *other;
2964        const char *attr_path;
2965
2966        if (DIFF_PAIR_UNMERGED(p)) {
2967                /* unmerged */
2968                return;
2969        }
2970
2971        name = p->one->path;
2972        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2973        attr_path = other ? other : name;
2974
2975        if (o->prefix_length)
2976                strip_prefix(o->prefix_length, &name, &other);
2977
2978        diff_fill_sha1_info(p->one);
2979        diff_fill_sha1_info(p->two);
2980
2981        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2982}
2983
2984void diff_setup(struct diff_options *options)
2985{
2986        memcpy(options, &default_diff_options, sizeof(*options));
2987
2988        options->file = stdout;
2989
2990        options->line_termination = '\n';
2991        options->break_opt = -1;
2992        options->rename_limit = -1;
2993        options->dirstat_permille = diff_dirstat_permille_default;
2994        options->context = 3;
2995
2996        options->change = diff_change;
2997        options->add_remove = diff_addremove;
2998        if (diff_use_color_default > 0)
2999                DIFF_OPT_SET(options, COLOR_DIFF);
3000        options->detect_rename = diff_detect_rename_default;
3001
3002        if (diff_no_prefix) {
3003                options->a_prefix = options->b_prefix = "";
3004        } else if (!diff_mnemonic_prefix) {
3005                options->a_prefix = "a/";
3006                options->b_prefix = "b/";
3007        }
3008}
3009
3010int diff_setup_done(struct diff_options *options)
3011{
3012        int count = 0;
3013
3014        if (options->output_format & DIFF_FORMAT_NAME)
3015                count++;
3016        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
3017                count++;
3018        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
3019                count++;
3020        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
3021                count++;
3022        if (count > 1)
3023                die("--name-only, --name-status, --check and -s are mutually exclusive");
3024
3025        /*
3026         * Most of the time we can say "there are changes"
3027         * only by checking if there are changed paths, but
3028         * --ignore-whitespace* options force us to look
3029         * inside contents.
3030         */
3031
3032        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
3033            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
3034            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
3035                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
3036        else
3037                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
3038
3039        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3040                options->detect_rename = DIFF_DETECT_COPY;
3041
3042        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
3043                options->prefix = NULL;
3044        if (options->prefix)
3045                options->prefix_length = strlen(options->prefix);
3046        else
3047                options->prefix_length = 0;
3048
3049        if (options->output_format & (DIFF_FORMAT_NAME |
3050                                      DIFF_FORMAT_NAME_STATUS |
3051                                      DIFF_FORMAT_CHECKDIFF |
3052                                      DIFF_FORMAT_NO_OUTPUT))
3053                options->output_format &= ~(DIFF_FORMAT_RAW |
3054                                            DIFF_FORMAT_NUMSTAT |
3055                                            DIFF_FORMAT_DIFFSTAT |
3056                                            DIFF_FORMAT_SHORTSTAT |
3057                                            DIFF_FORMAT_DIRSTAT |
3058                                            DIFF_FORMAT_SUMMARY |
3059                                            DIFF_FORMAT_PATCH);
3060
3061        /*
3062         * These cases always need recursive; we do not drop caller-supplied
3063         * recursive bits for other formats here.
3064         */
3065        if (options->output_format & (DIFF_FORMAT_PATCH |
3066                                      DIFF_FORMAT_NUMSTAT |
3067                                      DIFF_FORMAT_DIFFSTAT |
3068                                      DIFF_FORMAT_SHORTSTAT |
3069                                      DIFF_FORMAT_DIRSTAT |
3070                                      DIFF_FORMAT_SUMMARY |
3071                                      DIFF_FORMAT_CHECKDIFF))
3072                DIFF_OPT_SET(options, RECURSIVE);
3073        /*
3074         * Also pickaxe would not work very well if you do not say recursive
3075         */
3076        if (options->pickaxe)
3077                DIFF_OPT_SET(options, RECURSIVE);
3078        /*
3079         * When patches are generated, submodules diffed against the work tree
3080         * must be checked for dirtiness too so it can be shown in the output
3081         */
3082        if (options->output_format & DIFF_FORMAT_PATCH)
3083                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3084
3085        if (options->detect_rename && options->rename_limit < 0)
3086                options->rename_limit = diff_rename_limit_default;
3087        if (options->setup & DIFF_SETUP_USE_CACHE) {
3088                if (!active_cache)
3089                        /* read-cache does not die even when it fails
3090                         * so it is safe for us to do this here.  Also
3091                         * it does not smudge active_cache or active_nr
3092                         * when it fails, so we do not have to worry about
3093                         * cleaning it up ourselves either.
3094                         */
3095                        read_cache();
3096        }
3097        if (options->abbrev <= 0 || 40 < options->abbrev)
3098                options->abbrev = 40; /* full */
3099
3100        /*
3101         * It does not make sense to show the first hit we happened
3102         * to have found.  It does not make sense not to return with
3103         * exit code in such a case either.
3104         */
3105        if (DIFF_OPT_TST(options, QUICK)) {
3106                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3107                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3108        }
3109
3110        return 0;
3111}
3112
3113static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3114{
3115        char c, *eq;
3116        int len;
3117
3118        if (*arg != '-')
3119                return 0;
3120        c = *++arg;
3121        if (!c)
3122                return 0;
3123        if (c == arg_short) {
3124                c = *++arg;
3125                if (!c)
3126                        return 1;
3127                if (val && isdigit(c)) {
3128                        char *end;
3129                        int n = strtoul(arg, &end, 10);
3130                        if (*end)
3131                                return 0;
3132                        *val = n;
3133                        return 1;
3134                }
3135                return 0;
3136        }
3137        if (c != '-')
3138                return 0;
3139        arg++;
3140        eq = strchr(arg, '=');
3141        if (eq)
3142                len = eq - arg;
3143        else
3144                len = strlen(arg);
3145        if (!len || strncmp(arg, arg_long, len))
3146                return 0;
3147        if (eq) {
3148                int n;
3149                char *end;
3150                if (!isdigit(*++eq))
3151                        return 0;
3152                n = strtoul(eq, &end, 10);
3153                if (*end)
3154                        return 0;
3155                *val = n;
3156        }
3157        return 1;
3158}
3159
3160static int diff_scoreopt_parse(const char *opt);
3161
3162static inline int short_opt(char opt, const char **argv,
3163                            const char **optarg)
3164{
3165        const char *arg = argv[0];
3166        if (arg[0] != '-' || arg[1] != opt)
3167                return 0;
3168        if (arg[2] != '\0') {
3169                *optarg = arg + 2;
3170                return 1;
3171        }
3172        if (!argv[1])
3173                die("Option '%c' requires a value", opt);
3174        *optarg = argv[1];
3175        return 2;
3176}
3177
3178int parse_long_opt(const char *opt, const char **argv,
3179                   const char **optarg)
3180{
3181        const char *arg = argv[0];
3182        if (arg[0] != '-' || arg[1] != '-')
3183                return 0;
3184        arg += strlen("--");
3185        if (prefixcmp(arg, opt))
3186                return 0;
3187        arg += strlen(opt);
3188        if (*arg == '=') { /* sticked form: --option=value */
3189                *optarg = arg + 1;
3190                return 1;
3191        }
3192        if (*arg != '\0')
3193                return 0;
3194        /* separate form: --option value */
3195        if (!argv[1])
3196                die("Option '--%s' requires a value", opt);
3197        *optarg = argv[1];
3198        return 2;
3199}
3200
3201static int stat_opt(struct diff_options *options, const char **av)
3202{
3203        const char *arg = av[0];
3204        char *end;
3205        int width = options->stat_width;
3206        int name_width = options->stat_name_width;
3207        int argcount = 1;
3208
3209        arg += strlen("--stat");
3210        end = (char *)arg;
3211
3212        switch (*arg) {
3213        case '-':
3214                if (!prefixcmp(arg, "-width")) {
3215                        arg += strlen("-width");
3216                        if (*arg == '=')
3217                                width = strtoul(arg + 1, &end, 10);
3218                        else if (!*arg && !av[1])
3219                                die("Option '--stat-width' requires a value");
3220                        else if (!*arg) {
3221                                width = strtoul(av[1], &end, 10);
3222                                argcount = 2;
3223                        }
3224                } else if (!prefixcmp(arg, "-name-width")) {
3225                        arg += strlen("-name-width");
3226                        if (*arg == '=')
3227                                name_width = strtoul(arg + 1, &end, 10);
3228                        else if (!*arg && !av[1])
3229                                die("Option '--stat-name-width' requires a value");
3230                        else if (!*arg) {
3231                                name_width = strtoul(av[1], &end, 10);
3232                                argcount = 2;
3233                        }
3234                }
3235                break;
3236        case '=':
3237                width = strtoul(arg+1, &end, 10);
3238                if (*end == ',')
3239                        name_width = strtoul(end+1, &end, 10);
3240        }
3241
3242        /* Important! This checks all the error cases! */
3243        if (*end)
3244                return 0;
3245        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3246        options->stat_name_width = name_width;
3247        options->stat_width = width;
3248        return argcount;
3249}
3250
3251static int parse_dirstat_opt(struct diff_options *options, const char *params)
3252{
3253        if (parse_dirstat_params(options, params))
3254                die("Failed to parse --dirstat/-X option parameter");
3255        /*
3256         * The caller knows a dirstat-related option is given from the command
3257         * line; allow it to say "return this_function();"
3258         */
3259        options->output_format |= DIFF_FORMAT_DIRSTAT;
3260        return 1;
3261}
3262
3263int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3264{
3265        const char *arg = av[0];
3266        const char *optarg;
3267        int argcount;
3268
3269        /* Output format options */
3270        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3271                options->output_format |= DIFF_FORMAT_PATCH;
3272        else if (opt_arg(arg, 'U', "unified", &options->context))
3273                options->output_format |= DIFF_FORMAT_PATCH;
3274        else if (!strcmp(arg, "--raw"))
3275                options->output_format |= DIFF_FORMAT_RAW;
3276        else if (!strcmp(arg, "--patch-with-raw"))
3277                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3278        else if (!strcmp(arg, "--numstat"))
3279                options->output_format |= DIFF_FORMAT_NUMSTAT;
3280        else if (!strcmp(arg, "--shortstat"))
3281                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3282        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
3283                return parse_dirstat_opt(options, "");
3284        else if (!prefixcmp(arg, "-X"))
3285                return parse_dirstat_opt(options, arg + 2);
3286        else if (!prefixcmp(arg, "--dirstat="))
3287                return parse_dirstat_opt(options, arg + 10);
3288        else if (!strcmp(arg, "--cumulative"))
3289                return parse_dirstat_opt(options, "cumulative");
3290        else if (!strcmp(arg, "--dirstat-by-file"))
3291                return parse_dirstat_opt(options, "files");
3292        else if (!prefixcmp(arg, "--dirstat-by-file=")) {
3293                parse_dirstat_opt(options, "files");
3294                return parse_dirstat_opt(options, arg + 18);
3295        }
3296        else if (!strcmp(arg, "--check"))
3297                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3298        else if (!strcmp(arg, "--summary"))
3299                options->output_format |= DIFF_FORMAT_SUMMARY;
3300        else if (!strcmp(arg, "--patch-with-stat"))
3301                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3302        else if (!strcmp(arg, "--name-only"))
3303                options->output_format |= DIFF_FORMAT_NAME;
3304        else if (!strcmp(arg, "--name-status"))
3305                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3306        else if (!strcmp(arg, "-s"))
3307                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3308        else if (!prefixcmp(arg, "--stat"))
3309                /* --stat, --stat-width, or --stat-name-width */
3310                return stat_opt(options, av);
3311
3312        /* renames options */
3313        else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
3314                 !strcmp(arg, "--break-rewrites")) {
3315                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3316                        return error("invalid argument to -B: %s", arg+2);
3317        }
3318        else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--find-renames=") ||
3319                 !strcmp(arg, "--find-renames")) {
3320                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3321                        return error("invalid argument to -M: %s", arg+2);
3322                options->detect_rename = DIFF_DETECT_RENAME;
3323        }
3324        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3325                options->irreversible_delete = 1;
3326        }
3327        else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
3328                 !strcmp(arg, "--find-copies")) {
3329                if (options->detect_rename == DIFF_DETECT_COPY)
3330                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3331                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3332                        return error("invalid argument to -C: %s", arg+2);
3333                options->detect_rename = DIFF_DETECT_COPY;
3334        }
3335        else if (!strcmp(arg, "--no-renames"))
3336                options->detect_rename = 0;
3337        else if (!strcmp(arg, "--relative"))
3338                DIFF_OPT_SET(options, RELATIVE_NAME);
3339        else if (!prefixcmp(arg, "--relative=")) {
3340                DIFF_OPT_SET(options, RELATIVE_NAME);
3341                options->prefix = arg + 11;
3342        }
3343
3344        /* xdiff options */
3345        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3346                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3347        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3348                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3349        else if (!strcmp(arg, "--ignore-space-at-eol"))
3350                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3351        else if (!strcmp(arg, "--patience"))
3352                DIFF_XDL_SET(options, PATIENCE_DIFF);
3353
3354        /* flags options */
3355        else if (!strcmp(arg, "--binary")) {
3356                options->output_format |= DIFF_FORMAT_PATCH;
3357                DIFF_OPT_SET(options, BINARY);
3358        }
3359        else if (!strcmp(arg, "--full-index"))
3360                DIFF_OPT_SET(options, FULL_INDEX);
3361        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3362                DIFF_OPT_SET(options, TEXT);
3363        else if (!strcmp(arg, "-R"))
3364                DIFF_OPT_SET(options, REVERSE_DIFF);
3365        else if (!strcmp(arg, "--find-copies-harder"))
3366                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3367        else if (!strcmp(arg, "--follow"))
3368                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3369        else if (!strcmp(arg, "--color"))
3370                DIFF_OPT_SET(options, COLOR_DIFF);
3371        else if (!prefixcmp(arg, "--color=")) {
3372                int value = git_config_colorbool(NULL, arg+8, -1);
3373                if (value == 0)
3374                        DIFF_OPT_CLR(options, COLOR_DIFF);
3375                else if (value > 0)
3376                        DIFF_OPT_SET(options, COLOR_DIFF);
3377                else
3378                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3379        }
3380        else if (!strcmp(arg, "--no-color"))
3381                DIFF_OPT_CLR(options, COLOR_DIFF);
3382        else if (!strcmp(arg, "--color-words")) {
3383                DIFF_OPT_SET(options, COLOR_DIFF);
3384                options->word_diff = DIFF_WORDS_COLOR;
3385        }
3386        else if (!prefixcmp(arg, "--color-words=")) {
3387                DIFF_OPT_SET(options, COLOR_DIFF);
3388                options->word_diff = DIFF_WORDS_COLOR;
3389                options->word_regex = arg + 14;
3390        }
3391        else if (!strcmp(arg, "--word-diff")) {
3392                if (options->word_diff == DIFF_WORDS_NONE)
3393                        options->word_diff = DIFF_WORDS_PLAIN;
3394        }
3395        else if (!prefixcmp(arg, "--word-diff=")) {
3396                const char *type = arg + 12;
3397                if (!strcmp(type, "plain"))
3398                        options->word_diff = DIFF_WORDS_PLAIN;
3399                else if (!strcmp(type, "color")) {
3400                        DIFF_OPT_SET(options, COLOR_DIFF);
3401                        options->word_diff = DIFF_WORDS_COLOR;
3402                }
3403                else if (!strcmp(type, "porcelain"))
3404                        options->word_diff = DIFF_WORDS_PORCELAIN;
3405                else if (!strcmp(type, "none"))
3406                        options->word_diff = DIFF_WORDS_NONE;
3407                else
3408                        die("bad --word-diff argument: %s", type);
3409        }
3410        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3411                if (options->word_diff == DIFF_WORDS_NONE)
3412                        options->word_diff = DIFF_WORDS_PLAIN;
3413                options->word_regex = optarg;
3414                return argcount;
3415        }
3416        else if (!strcmp(arg, "--exit-code"))
3417                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3418        else if (!strcmp(arg, "--quiet"))
3419                DIFF_OPT_SET(options, QUICK);
3420        else if (!strcmp(arg, "--ext-diff"))
3421                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3422        else if (!strcmp(arg, "--no-ext-diff"))
3423                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3424        else if (!strcmp(arg, "--textconv"))
3425                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3426        else if (!strcmp(arg, "--no-textconv"))
3427                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3428        else if (!strcmp(arg, "--ignore-submodules")) {
3429                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3430                handle_ignore_submodules_arg(options, "all");
3431        } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3432                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3433                handle_ignore_submodules_arg(options, arg + 20);
3434        } else if (!strcmp(arg, "--submodule"))
3435                DIFF_OPT_SET(options, SUBMODULE_LOG);
3436        else if (!prefixcmp(arg, "--submodule=")) {
3437                if (!strcmp(arg + 12, "log"))
3438                        DIFF_OPT_SET(options, SUBMODULE_LOG);
3439        }
3440
3441        /* misc options */
3442        else if (!strcmp(arg, "-z"))
3443                options->line_termination = 0;
3444        else if ((argcount = short_opt('l', av, &optarg))) {
3445                options->rename_limit = strtoul(optarg, NULL, 10);
3446                return argcount;
3447        }
3448        else if ((argcount = short_opt('S', av, &optarg))) {
3449                options->pickaxe = optarg;
3450                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3451                return argcount;
3452        } else if ((argcount = short_opt('G', av, &optarg))) {
3453                options->pickaxe = optarg;
3454                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3455                return argcount;
3456        }
3457        else if (!strcmp(arg, "--pickaxe-all"))
3458                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3459        else if (!strcmp(arg, "--pickaxe-regex"))
3460                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3461        else if ((argcount = short_opt('O', av, &optarg))) {
3462                options->orderfile = optarg;
3463                return argcount;
3464        }
3465        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3466                options->filter = optarg;
3467                return argcount;
3468        }
3469        else if (!strcmp(arg, "--abbrev"))
3470                options->abbrev = DEFAULT_ABBREV;
3471        else if (!prefixcmp(arg, "--abbrev=")) {
3472                options->abbrev = strtoul(arg + 9, NULL, 10);
3473                if (options->abbrev < MINIMUM_ABBREV)
3474                        options->abbrev = MINIMUM_ABBREV;
3475                else if (40 < options->abbrev)
3476                        options->abbrev = 40;
3477        }
3478        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3479                options->a_prefix = optarg;
3480                return argcount;
3481        }
3482        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3483                options->b_prefix = optarg;
3484                return argcount;
3485        }
3486        else if (!strcmp(arg, "--no-prefix"))
3487                options->a_prefix = options->b_prefix = "";
3488        else if (opt_arg(arg, '\0', "inter-hunk-context",
3489                         &options->interhunkcontext))
3490                ;
3491        else if ((argcount = parse_long_opt("output", av, &optarg))) {
3492                options->file = fopen(optarg, "w");
3493                if (!options->file)
3494                        die_errno("Could not open '%s'", optarg);
3495                options->close_file = 1;
3496                return argcount;
3497        } else
3498                return 0;
3499        return 1;
3500}
3501
3502int parse_rename_score(const char **cp_p)
3503{
3504        unsigned long num, scale;
3505        int ch, dot;
3506        const char *cp = *cp_p;
3507
3508        num = 0;
3509        scale = 1;
3510        dot = 0;
3511        for (;;) {
3512                ch = *cp;
3513                if ( !dot && ch == '.' ) {
3514                        scale = 1;
3515                        dot = 1;
3516                } else if ( ch == '%' ) {
3517                        scale = dot ? scale*100 : 100;
3518                        cp++;   /* % is always at the end */
3519                        break;
3520                } else if ( ch >= '0' && ch <= '9' ) {
3521                        if ( scale < 100000 ) {
3522                                scale *= 10;
3523                                num = (num*10) + (ch-'0');
3524                        }
3525                } else {
3526                        break;
3527                }
3528                cp++;
3529        }
3530        *cp_p = cp;
3531
3532        /* user says num divided by scale and we say internally that
3533         * is MAX_SCORE * num / scale.
3534         */
3535        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3536}
3537
3538static int diff_scoreopt_parse(const char *opt)
3539{
3540        int opt1, opt2, cmd;
3541
3542        if (*opt++ != '-')
3543                return -1;
3544        cmd = *opt++;
3545        if (cmd == '-') {
3546                /* convert the long-form arguments into short-form versions */
3547                if (!prefixcmp(opt, "break-rewrites")) {
3548                        opt += strlen("break-rewrites");
3549                        if (*opt == 0 || *opt++ == '=')
3550                                cmd = 'B';
3551                } else if (!prefixcmp(opt, "find-copies")) {
3552                        opt += strlen("find-copies");
3553                        if (*opt == 0 || *opt++ == '=')
3554                                cmd = 'C';
3555                } else if (!prefixcmp(opt, "find-renames")) {
3556                        opt += strlen("find-renames");
3557                        if (*opt == 0 || *opt++ == '=')
3558                                cmd = 'M';
3559                }
3560        }
3561        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3562                return -1; /* that is not a -M, -C nor -B option */
3563
3564        opt1 = parse_rename_score(&opt);
3565        if (cmd != 'B')
3566                opt2 = 0;
3567        else {
3568                if (*opt == 0)
3569                        opt2 = 0;
3570                else if (*opt != '/')
3571                        return -1; /* we expect -B80/99 or -B80 */
3572                else {
3573                        opt++;
3574                        opt2 = parse_rename_score(&opt);
3575                }
3576        }
3577        if (*opt != 0)
3578                return -1;
3579        return opt1 | (opt2 << 16);
3580}
3581
3582struct diff_queue_struct diff_queued_diff;
3583
3584void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3585{
3586        if (queue->alloc <= queue->nr) {
3587                queue->alloc = alloc_nr(queue->alloc);
3588                queue->queue = xrealloc(queue->queue,
3589                                        sizeof(dp) * queue->alloc);
3590        }
3591        queue->queue[queue->nr++] = dp;
3592}
3593
3594struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3595                                 struct diff_filespec *one,
3596                                 struct diff_filespec *two)
3597{
3598        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3599        dp->one = one;
3600        dp->two = two;
3601        if (queue)
3602                diff_q(queue, dp);
3603        return dp;
3604}
3605
3606void diff_free_filepair(struct diff_filepair *p)
3607{
3608        free_filespec(p->one);
3609        free_filespec(p->two);
3610        free(p);
3611}
3612
3613/* This is different from find_unique_abbrev() in that
3614 * it stuffs the result with dots for alignment.
3615 */
3616const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3617{
3618        int abblen;
3619        const char *abbrev;
3620        if (len == 40)
3621                return sha1_to_hex(sha1);
3622
3623        abbrev = find_unique_abbrev(sha1, len);
3624        abblen = strlen(abbrev);
3625        if (abblen < 37) {
3626                static char hex[41];
3627                if (len < abblen && abblen <= len + 2)
3628                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3629                else
3630                        sprintf(hex, "%s...", abbrev);
3631                return hex;
3632        }
3633        return sha1_to_hex(sha1);
3634}
3635
3636static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3637{
3638        int line_termination = opt->line_termination;
3639        int inter_name_termination = line_termination ? '\t' : '\0';
3640        if (opt->output_prefix) {
3641                struct strbuf *msg = NULL;
3642                msg = opt->output_prefix(opt, opt->output_prefix_data);
3643                fprintf(opt->file, "%s", msg->buf);
3644        }
3645
3646        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3647                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3648                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3649                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3650        }
3651        if (p->score) {
3652                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3653                        inter_name_termination);
3654        } else {
3655                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3656        }
3657
3658        if (p->status == DIFF_STATUS_COPIED ||
3659            p->status == DIFF_STATUS_RENAMED) {
3660                const char *name_a, *name_b;
3661                name_a = p->one->path;
3662                name_b = p->two->path;
3663                strip_prefix(opt->prefix_length, &name_a, &name_b);
3664                write_name_quoted(name_a, opt->file, inter_name_termination);
3665                write_name_quoted(name_b, opt->file, line_termination);
3666        } else {
3667                const char *name_a, *name_b;
3668                name_a = p->one->mode ? p->one->path : p->two->path;
3669                name_b = NULL;
3670                strip_prefix(opt->prefix_length, &name_a, &name_b);
3671                write_name_quoted(name_a, opt->file, line_termination);
3672        }
3673}
3674
3675int diff_unmodified_pair(struct diff_filepair *p)
3676{
3677        /* This function is written stricter than necessary to support
3678         * the currently implemented transformers, but the idea is to
3679         * let transformers to produce diff_filepairs any way they want,
3680         * and filter and clean them up here before producing the output.
3681         */
3682        struct diff_filespec *one = p->one, *two = p->two;
3683
3684        if (DIFF_PAIR_UNMERGED(p))
3685                return 0; /* unmerged is interesting */
3686
3687        /* deletion, addition, mode or type change
3688         * and rename are all interesting.
3689         */
3690        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3691            DIFF_PAIR_MODE_CHANGED(p) ||
3692            strcmp(one->path, two->path))
3693                return 0;
3694
3695        /* both are valid and point at the same path.  that is, we are
3696         * dealing with a change.
3697         */
3698        if (one->sha1_valid && two->sha1_valid &&
3699            !hashcmp(one->sha1, two->sha1) &&
3700            !one->dirty_submodule && !two->dirty_submodule)
3701                return 1; /* no change */
3702        if (!one->sha1_valid && !two->sha1_valid)
3703                return 1; /* both look at the same file on the filesystem. */
3704        return 0;
3705}
3706
3707static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3708{
3709        if (diff_unmodified_pair(p))
3710                return;
3711
3712        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3713            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3714                return; /* no tree diffs in patch format */
3715
3716        run_diff(p, o);
3717}
3718
3719static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3720                            struct diffstat_t *diffstat)
3721{
3722        if (diff_unmodified_pair(p))
3723                return;
3724
3725        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3726            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3727                return; /* no useful stat for tree diffs */
3728
3729        run_diffstat(p, o, diffstat);
3730}
3731
3732static void diff_flush_checkdiff(struct diff_filepair *p,
3733                struct diff_options *o)
3734{
3735        if (diff_unmodified_pair(p))
3736                return;
3737
3738        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3739            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3740                return; /* nothing to check in tree diffs */
3741
3742        run_checkdiff(p, o);
3743}
3744
3745int diff_queue_is_empty(void)
3746{
3747        struct diff_queue_struct *q = &diff_queued_diff;
3748        int i;
3749        for (i = 0; i < q->nr; i++)
3750                if (!diff_unmodified_pair(q->queue[i]))
3751                        return 0;
3752        return 1;
3753}
3754
3755#if DIFF_DEBUG
3756void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3757{
3758        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3759                x, one ? one : "",
3760                s->path,
3761                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3762                s->mode,
3763                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3764        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3765                x, one ? one : "",
3766                s->size, s->xfrm_flags);
3767}
3768
3769void diff_debug_filepair(const struct diff_filepair *p, int i)
3770{
3771        diff_debug_filespec(p->one, i, "one");
3772        diff_debug_filespec(p->two, i, "two");
3773        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3774                p->score, p->status ? p->status : '?',
3775                p->one->rename_used, p->broken_pair);
3776}
3777
3778void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3779{
3780        int i;
3781        if (msg)
3782                fprintf(stderr, "%s\n", msg);
3783        fprintf(stderr, "q->nr = %d\n", q->nr);
3784        for (i = 0; i < q->nr; i++) {
3785                struct diff_filepair *p = q->queue[i];
3786                diff_debug_filepair(p, i);
3787        }
3788}
3789#endif
3790
3791static void diff_resolve_rename_copy(void)
3792{
3793        int i;
3794        struct diff_filepair *p;
3795        struct diff_queue_struct *q = &diff_queued_diff;
3796
3797        diff_debug_queue("resolve-rename-copy", q);
3798
3799        for (i = 0; i < q->nr; i++) {
3800                p = q->queue[i];
3801                p->status = 0; /* undecided */
3802                if (DIFF_PAIR_UNMERGED(p))
3803                        p->status = DIFF_STATUS_UNMERGED;
3804                else if (!DIFF_FILE_VALID(p->one))
3805                        p->status = DIFF_STATUS_ADDED;
3806                else if (!DIFF_FILE_VALID(p->two))
3807                        p->status = DIFF_STATUS_DELETED;
3808                else if (DIFF_PAIR_TYPE_CHANGED(p))
3809                        p->status = DIFF_STATUS_TYPE_CHANGED;
3810
3811                /* from this point on, we are dealing with a pair
3812                 * whose both sides are valid and of the same type, i.e.
3813                 * either in-place edit or rename/copy edit.
3814                 */
3815                else if (DIFF_PAIR_RENAME(p)) {
3816                        /*
3817                         * A rename might have re-connected a broken
3818                         * pair up, causing the pathnames to be the
3819                         * same again. If so, that's not a rename at
3820                         * all, just a modification..
3821                         *
3822                         * Otherwise, see if this source was used for
3823                         * multiple renames, in which case we decrement
3824                         * the count, and call it a copy.
3825                         */
3826                        if (!strcmp(p->one->path, p->two->path))
3827                                p->status = DIFF_STATUS_MODIFIED;
3828                        else if (--p->one->rename_used > 0)
3829                                p->status = DIFF_STATUS_COPIED;
3830                        else
3831                                p->status = DIFF_STATUS_RENAMED;
3832                }
3833                else if (hashcmp(p->one->sha1, p->two->sha1) ||
3834                         p->one->mode != p->two->mode ||
3835                         p->one->dirty_submodule ||
3836                         p->two->dirty_submodule ||
3837                         is_null_sha1(p->one->sha1))
3838                        p->status = DIFF_STATUS_MODIFIED;
3839                else {
3840                        /* This is a "no-change" entry and should not
3841                         * happen anymore, but prepare for broken callers.
3842                         */
3843                        error("feeding unmodified %s to diffcore",
3844                              p->one->path);
3845                        p->status = DIFF_STATUS_UNKNOWN;
3846                }
3847        }
3848        diff_debug_queue("resolve-rename-copy done", q);
3849}
3850
3851static int check_pair_status(struct diff_filepair *p)
3852{
3853        switch (p->status) {
3854        case DIFF_STATUS_UNKNOWN:
3855                return 0;
3856        case 0:
3857                die("internal error in diff-resolve-rename-copy");
3858        default:
3859                return 1;
3860        }
3861}
3862
3863static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3864{
3865        int fmt = opt->output_format;
3866
3867        if (fmt & DIFF_FORMAT_CHECKDIFF)
3868                diff_flush_checkdiff(p, opt);
3869        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3870                diff_flush_raw(p, opt);
3871        else if (fmt & DIFF_FORMAT_NAME) {
3872                const char *name_a, *name_b;
3873                name_a = p->two->path;
3874                name_b = NULL;
3875                strip_prefix(opt->prefix_length, &name_a, &name_b);
3876                write_name_quoted(name_a, opt->file, opt->line_termination);
3877        }
3878}
3879
3880static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
3881{
3882        if (fs->mode)
3883                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
3884        else
3885                fprintf(file, " %s ", newdelete);
3886        write_name_quoted(fs->path, file, '\n');
3887}
3888
3889
3890static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
3891                const char *line_prefix)
3892{
3893        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
3894                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
3895                        p->two->mode, show_name ? ' ' : '\n');
3896                if (show_name) {
3897                        write_name_quoted(p->two->path, file, '\n');
3898                }
3899        }
3900}
3901
3902static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
3903                        const char *line_prefix)
3904{
3905        char *names = pprint_rename(p->one->path, p->two->path);
3906
3907        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
3908        free(names);
3909        show_mode_change(file, p, 0, line_prefix);
3910}
3911
3912static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
3913{
3914        FILE *file = opt->file;
3915        char *line_prefix = "";
3916
3917        if (opt->output_prefix) {
3918                struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
3919                line_prefix = buf->buf;
3920        }
3921
3922        switch(p->status) {
3923        case DIFF_STATUS_DELETED:
3924                fputs(line_prefix, file);
3925                show_file_mode_name(file, "delete", p->one);
3926                break;
3927        case DIFF_STATUS_ADDED:
3928                fputs(line_prefix, file);
3929                show_file_mode_name(file, "create", p->two);
3930                break;
3931        case DIFF_STATUS_COPIED:
3932                fputs(line_prefix, file);
3933                show_rename_copy(file, "copy", p, line_prefix);
3934                break;
3935        case DIFF_STATUS_RENAMED:
3936                fputs(line_prefix, file);
3937                show_rename_copy(file, "rename", p, line_prefix);
3938                break;
3939        default:
3940                if (p->score) {
3941                        fprintf(file, "%s rewrite ", line_prefix);
3942                        write_name_quoted(p->two->path, file, ' ');
3943                        fprintf(file, "(%d%%)\n", similarity_index(p));
3944                }
3945                show_mode_change(file, p, !p->score, line_prefix);
3946                break;
3947        }
3948}
3949
3950struct patch_id_t {
3951        git_SHA_CTX *ctx;
3952        int patchlen;
3953};
3954
3955static int remove_space(char *line, int len)
3956{
3957        int i;
3958        char *dst = line;
3959        unsigned char c;
3960
3961        for (i = 0; i < len; i++)
3962                if (!isspace((c = line[i])))
3963                        *dst++ = c;
3964
3965        return dst - line;
3966}
3967
3968static void patch_id_consume(void *priv, char *line, unsigned long len)
3969{
3970        struct patch_id_t *data = priv;
3971        int new_len;
3972
3973        /* Ignore line numbers when computing the SHA1 of the patch */
3974        if (!prefixcmp(line, "@@ -"))
3975                return;
3976
3977        new_len = remove_space(line, len);
3978
3979        git_SHA1_Update(data->ctx, line, new_len);
3980        data->patchlen += new_len;
3981}
3982
3983/* returns 0 upon success, and writes result into sha1 */
3984static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
3985{
3986        struct diff_queue_struct *q = &diff_queued_diff;
3987        int i;
3988        git_SHA_CTX ctx;
3989        struct patch_id_t data;
3990        char buffer[PATH_MAX * 4 + 20];
3991
3992        git_SHA1_Init(&ctx);
3993        memset(&data, 0, sizeof(struct patch_id_t));
3994        data.ctx = &ctx;
3995
3996        for (i = 0; i < q->nr; i++) {
3997                xpparam_t xpp;
3998                xdemitconf_t xecfg;
3999                mmfile_t mf1, mf2;
4000                struct diff_filepair *p = q->queue[i];
4001                int len1, len2;
4002
4003                memset(&xpp, 0, sizeof(xpp));
4004                memset(&xecfg, 0, sizeof(xecfg));
4005                if (p->status == 0)
4006                        return error("internal diff status error");
4007                if (p->status == DIFF_STATUS_UNKNOWN)
4008                        continue;
4009                if (diff_unmodified_pair(p))
4010                        continue;
4011                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4012                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4013                        continue;
4014                if (DIFF_PAIR_UNMERGED(p))
4015                        continue;
4016
4017                diff_fill_sha1_info(p->one);
4018                diff_fill_sha1_info(p->two);
4019                if (fill_mmfile(&mf1, p->one) < 0 ||
4020                                fill_mmfile(&mf2, p->two) < 0)
4021                        return error("unable to read files to diff");
4022
4023                len1 = remove_space(p->one->path, strlen(p->one->path));
4024                len2 = remove_space(p->two->path, strlen(p->two->path));
4025                if (p->one->mode == 0)
4026                        len1 = snprintf(buffer, sizeof(buffer),
4027                                        "diff--gita/%.*sb/%.*s"
4028                                        "newfilemode%06o"
4029                                        "---/dev/null"
4030                                        "+++b/%.*s",
4031                                        len1, p->one->path,
4032                                        len2, p->two->path,
4033                                        p->two->mode,
4034                                        len2, p->two->path);
4035                else if (p->two->mode == 0)
4036                        len1 = snprintf(buffer, sizeof(buffer),
4037                                        "diff--gita/%.*sb/%.*s"
4038                                        "deletedfilemode%06o"
4039                                        "---a/%.*s"
4040                                        "+++/dev/null",
4041                                        len1, p->one->path,
4042                                        len2, p->two->path,
4043                                        p->one->mode,
4044                                        len1, p->one->path);
4045                else
4046                        len1 = snprintf(buffer, sizeof(buffer),
4047                                        "diff--gita/%.*sb/%.*s"
4048                                        "---a/%.*s"
4049                                        "+++b/%.*s",
4050                                        len1, p->one->path,
4051                                        len2, p->two->path,
4052                                        len1, p->one->path,
4053                                        len2, p->two->path);
4054                git_SHA1_Update(&ctx, buffer, len1);
4055
4056                if (diff_filespec_is_binary(p->one) ||
4057                    diff_filespec_is_binary(p->two)) {
4058                        git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
4059                        git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
4060                        continue;
4061                }
4062
4063                xpp.flags = 0;
4064                xecfg.ctxlen = 3;
4065                xecfg.flags = 0;
4066                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4067                              &xpp, &xecfg);
4068        }
4069
4070        git_SHA1_Final(sha1, &ctx);
4071        return 0;
4072}
4073
4074int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
4075{
4076        struct diff_queue_struct *q = &diff_queued_diff;
4077        int i;
4078        int result = diff_get_patch_id(options, sha1);
4079
4080        for (i = 0; i < q->nr; i++)
4081                diff_free_filepair(q->queue[i]);
4082
4083        free(q->queue);
4084        DIFF_QUEUE_CLEAR(q);
4085
4086        return result;
4087}
4088
4089static int is_summary_empty(const struct diff_queue_struct *q)
4090{
4091        int i;
4092
4093        for (i = 0; i < q->nr; i++) {
4094                const struct diff_filepair *p = q->queue[i];
4095
4096                switch (p->status) {
4097                case DIFF_STATUS_DELETED:
4098                case DIFF_STATUS_ADDED:
4099                case DIFF_STATUS_COPIED:
4100                case DIFF_STATUS_RENAMED:
4101                        return 0;
4102                default:
4103                        if (p->score)
4104                                return 0;
4105                        if (p->one->mode && p->two->mode &&
4106                            p->one->mode != p->two->mode)
4107                                return 0;
4108                        break;
4109                }
4110        }
4111        return 1;
4112}
4113
4114static const char rename_limit_warning[] =
4115"inexact rename detection was skipped due to too many files.";
4116
4117static const char degrade_cc_to_c_warning[] =
4118"only found copies from modified paths due to too many files.";
4119
4120static const char rename_limit_advice[] =
4121"you may want to set your %s variable to at least "
4122"%d and retry the command.";
4123
4124void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4125{
4126        if (degraded_cc)
4127                warning(degrade_cc_to_c_warning);
4128        else if (needed)
4129                warning(rename_limit_warning);
4130        else
4131                return;
4132        if (0 < needed && needed < 32767)
4133                warning(rename_limit_advice, varname, needed);
4134}
4135
4136void diff_flush(struct diff_options *options)
4137{
4138        struct diff_queue_struct *q = &diff_queued_diff;
4139        int i, output_format = options->output_format;
4140        int separator = 0;
4141        int dirstat_by_line = 0;
4142
4143        /*
4144         * Order: raw, stat, summary, patch
4145         * or:    name/name-status/checkdiff (other bits clear)
4146         */
4147        if (!q->nr)
4148                goto free_queue;
4149
4150        if (output_format & (DIFF_FORMAT_RAW |
4151                             DIFF_FORMAT_NAME |
4152                             DIFF_FORMAT_NAME_STATUS |
4153                             DIFF_FORMAT_CHECKDIFF)) {
4154                for (i = 0; i < q->nr; i++) {
4155                        struct diff_filepair *p = q->queue[i];
4156                        if (check_pair_status(p))
4157                                flush_one_pair(p, options);
4158                }
4159                separator++;
4160        }
4161
4162        if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
4163                dirstat_by_line = 1;
4164
4165        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
4166            dirstat_by_line) {
4167                struct diffstat_t diffstat;
4168
4169                memset(&diffstat, 0, sizeof(struct diffstat_t));
4170                for (i = 0; i < q->nr; i++) {
4171                        struct diff_filepair *p = q->queue[i];
4172                        if (check_pair_status(p))
4173                                diff_flush_stat(p, options, &diffstat);
4174                }
4175                if (output_format & DIFF_FORMAT_NUMSTAT)
4176                        show_numstat(&diffstat, options);
4177                if (output_format & DIFF_FORMAT_DIFFSTAT)
4178                        show_stats(&diffstat, options);
4179                if (output_format & DIFF_FORMAT_SHORTSTAT)
4180                        show_shortstats(&diffstat, options);
4181                if (output_format & DIFF_FORMAT_DIRSTAT)
4182                        show_dirstat_by_line(&diffstat, options);
4183                free_diffstat_info(&diffstat);
4184                separator++;
4185        }
4186        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
4187                show_dirstat(options);
4188
4189        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4190                for (i = 0; i < q->nr; i++) {
4191                        diff_summary(options, q->queue[i]);
4192                }
4193                separator++;
4194        }
4195
4196        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4197            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4198            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4199                /*
4200                 * run diff_flush_patch for the exit status. setting
4201                 * options->file to /dev/null should be safe, becaue we
4202                 * aren't supposed to produce any output anyway.
4203                 */
4204                if (options->close_file)
4205                        fclose(options->file);
4206                options->file = fopen("/dev/null", "w");
4207                if (!options->file)
4208                        die_errno("Could not open /dev/null");
4209                options->close_file = 1;
4210                for (i = 0; i < q->nr; i++) {
4211                        struct diff_filepair *p = q->queue[i];
4212                        if (check_pair_status(p))
4213                                diff_flush_patch(p, options);
4214                        if (options->found_changes)
4215                                break;
4216                }
4217        }
4218
4219        if (output_format & DIFF_FORMAT_PATCH) {
4220                if (separator) {
4221                        putc(options->line_termination, options->file);
4222                        if (options->stat_sep) {
4223                                /* attach patch instead of inline */
4224                                fputs(options->stat_sep, options->file);
4225                        }
4226                }
4227
4228                for (i = 0; i < q->nr; i++) {
4229                        struct diff_filepair *p = q->queue[i];
4230                        if (check_pair_status(p))
4231                                diff_flush_patch(p, options);
4232                }
4233        }
4234
4235        if (output_format & DIFF_FORMAT_CALLBACK)
4236                options->format_callback(q, options, options->format_callback_data);
4237
4238        for (i = 0; i < q->nr; i++)
4239                diff_free_filepair(q->queue[i]);
4240free_queue:
4241        free(q->queue);
4242        DIFF_QUEUE_CLEAR(q);
4243        if (options->close_file)
4244                fclose(options->file);
4245
4246        /*
4247         * Report the content-level differences with HAS_CHANGES;
4248         * diff_addremove/diff_change does not set the bit when
4249         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4250         */
4251        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4252                if (options->found_changes)
4253                        DIFF_OPT_SET(options, HAS_CHANGES);
4254                else
4255                        DIFF_OPT_CLR(options, HAS_CHANGES);
4256        }
4257}
4258
4259static void diffcore_apply_filter(const char *filter)
4260{
4261        int i;
4262        struct diff_queue_struct *q = &diff_queued_diff;
4263        struct diff_queue_struct outq;
4264        DIFF_QUEUE_CLEAR(&outq);
4265
4266        if (!filter)
4267                return;
4268
4269        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
4270                int found;
4271                for (i = found = 0; !found && i < q->nr; i++) {
4272                        struct diff_filepair *p = q->queue[i];
4273                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4274                             ((p->score &&
4275                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4276                              (!p->score &&
4277                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4278                            ((p->status != DIFF_STATUS_MODIFIED) &&
4279                             strchr(filter, p->status)))
4280                                found++;
4281                }
4282                if (found)
4283                        return;
4284
4285                /* otherwise we will clear the whole queue
4286                 * by copying the empty outq at the end of this
4287                 * function, but first clear the current entries
4288                 * in the queue.
4289                 */
4290                for (i = 0; i < q->nr; i++)
4291                        diff_free_filepair(q->queue[i]);
4292        }
4293        else {
4294                /* Only the matching ones */
4295                for (i = 0; i < q->nr; i++) {
4296                        struct diff_filepair *p = q->queue[i];
4297
4298                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4299                             ((p->score &&
4300                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4301                              (!p->score &&
4302                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4303                            ((p->status != DIFF_STATUS_MODIFIED) &&
4304                             strchr(filter, p->status)))
4305                                diff_q(&outq, p);
4306                        else
4307                                diff_free_filepair(p);
4308                }
4309        }
4310        free(q->queue);
4311        *q = outq;
4312}
4313
4314/* Check whether two filespecs with the same mode and size are identical */
4315static int diff_filespec_is_identical(struct diff_filespec *one,
4316                                      struct diff_filespec *two)
4317{
4318        if (S_ISGITLINK(one->mode))
4319                return 0;
4320        if (diff_populate_filespec(one, 0))
4321                return 0;
4322        if (diff_populate_filespec(two, 0))
4323                return 0;
4324        return !memcmp(one->data, two->data, one->size);
4325}
4326
4327static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4328{
4329        int i;
4330        struct diff_queue_struct *q = &diff_queued_diff;
4331        struct diff_queue_struct outq;
4332        DIFF_QUEUE_CLEAR(&outq);
4333
4334        for (i = 0; i < q->nr; i++) {
4335                struct diff_filepair *p = q->queue[i];
4336
4337                /*
4338                 * 1. Entries that come from stat info dirtiness
4339                 *    always have both sides (iow, not create/delete),
4340                 *    one side of the object name is unknown, with
4341                 *    the same mode and size.  Keep the ones that
4342                 *    do not match these criteria.  They have real
4343                 *    differences.
4344                 *
4345                 * 2. At this point, the file is known to be modified,
4346                 *    with the same mode and size, and the object
4347                 *    name of one side is unknown.  Need to inspect
4348                 *    the identical contents.
4349                 */
4350                if (!DIFF_FILE_VALID(p->one) || /* (1) */
4351                    !DIFF_FILE_VALID(p->two) ||
4352                    (p->one->sha1_valid && p->two->sha1_valid) ||
4353                    (p->one->mode != p->two->mode) ||
4354                    diff_populate_filespec(p->one, 1) ||
4355                    diff_populate_filespec(p->two, 1) ||
4356                    (p->one->size != p->two->size) ||
4357                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4358                        diff_q(&outq, p);
4359                else {
4360                        /*
4361                         * The caller can subtract 1 from skip_stat_unmatch
4362                         * to determine how many paths were dirty only
4363                         * due to stat info mismatch.
4364                         */
4365                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4366                                diffopt->skip_stat_unmatch++;
4367                        diff_free_filepair(p);
4368                }
4369        }
4370        free(q->queue);
4371        *q = outq;
4372}
4373
4374static int diffnamecmp(const void *a_, const void *b_)
4375{
4376        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4377        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4378        const char *name_a, *name_b;
4379
4380        name_a = a->one ? a->one->path : a->two->path;
4381        name_b = b->one ? b->one->path : b->two->path;
4382        return strcmp(name_a, name_b);
4383}
4384
4385void diffcore_fix_diff_index(struct diff_options *options)
4386{
4387        struct diff_queue_struct *q = &diff_queued_diff;
4388        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4389}
4390
4391void diffcore_std(struct diff_options *options)
4392{
4393        if (options->skip_stat_unmatch)
4394                diffcore_skip_stat_unmatch(options);
4395        if (!options->found_follow) {
4396                /* See try_to_follow_renames() in tree-diff.c */
4397                if (options->break_opt != -1)
4398                        diffcore_break(options->break_opt);
4399                if (options->detect_rename)
4400                        diffcore_rename(options);
4401                if (options->break_opt != -1)
4402                        diffcore_merge_broken();
4403        }
4404        if (options->pickaxe)
4405                diffcore_pickaxe(options);
4406        if (options->orderfile)
4407                diffcore_order(options->orderfile);
4408        if (!options->found_follow)
4409                /* See try_to_follow_renames() in tree-diff.c */
4410                diff_resolve_rename_copy();
4411        diffcore_apply_filter(options->filter);
4412
4413        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4414                DIFF_OPT_SET(options, HAS_CHANGES);
4415        else
4416                DIFF_OPT_CLR(options, HAS_CHANGES);
4417
4418        options->found_follow = 0;
4419}
4420
4421int diff_result_code(struct diff_options *opt, int status)
4422{
4423        int result = 0;
4424
4425        diff_warn_rename_limit("diff.renamelimit",
4426                               opt->needed_rename_limit,
4427                               opt->degraded_cc_to_c);
4428        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4429            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4430                return status;
4431        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4432            DIFF_OPT_TST(opt, HAS_CHANGES))
4433                result |= 01;
4434        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4435            DIFF_OPT_TST(opt, CHECK_FAILED))
4436                result |= 02;
4437        return result;
4438}
4439
4440/*
4441 * Shall changes to this submodule be ignored?
4442 *
4443 * Submodule changes can be configured to be ignored separately for each path,
4444 * but that configuration can be overridden from the command line.
4445 */
4446static int is_submodule_ignored(const char *path, struct diff_options *options)
4447{
4448        int ignored = 0;
4449        unsigned orig_flags = options->flags;
4450        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4451                set_diffopt_flags_from_submodule_config(options, path);
4452        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4453                ignored = 1;
4454        options->flags = orig_flags;
4455        return ignored;
4456}
4457
4458void diff_addremove(struct diff_options *options,
4459                    int addremove, unsigned mode,
4460                    const unsigned char *sha1,
4461                    const char *concatpath, unsigned dirty_submodule)
4462{
4463        struct diff_filespec *one, *two;
4464
4465        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4466                return;
4467
4468        /* This may look odd, but it is a preparation for
4469         * feeding "there are unchanged files which should
4470         * not produce diffs, but when you are doing copy
4471         * detection you would need them, so here they are"
4472         * entries to the diff-core.  They will be prefixed
4473         * with something like '=' or '*' (I haven't decided
4474         * which but should not make any difference).
4475         * Feeding the same new and old to diff_change()
4476         * also has the same effect.
4477         * Before the final output happens, they are pruned after
4478         * merged into rename/copy pairs as appropriate.
4479         */
4480        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4481                addremove = (addremove == '+' ? '-' :
4482                             addremove == '-' ? '+' : addremove);
4483
4484        if (options->prefix &&
4485            strncmp(concatpath, options->prefix, options->prefix_length))
4486                return;
4487
4488        one = alloc_filespec(concatpath);
4489        two = alloc_filespec(concatpath);
4490
4491        if (addremove != '+')
4492                fill_filespec(one, sha1, mode);
4493        if (addremove != '-') {
4494                fill_filespec(two, sha1, mode);
4495                two->dirty_submodule = dirty_submodule;
4496        }
4497
4498        diff_queue(&diff_queued_diff, one, two);
4499        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4500                DIFF_OPT_SET(options, HAS_CHANGES);
4501}
4502
4503void diff_change(struct diff_options *options,
4504                 unsigned old_mode, unsigned new_mode,
4505                 const unsigned char *old_sha1,
4506                 const unsigned char *new_sha1,
4507                 const char *concatpath,
4508                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4509{
4510        struct diff_filespec *one, *two;
4511
4512        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4513            is_submodule_ignored(concatpath, options))
4514                return;
4515
4516        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4517                unsigned tmp;
4518                const unsigned char *tmp_c;
4519                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4520                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4521                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4522                        new_dirty_submodule = tmp;
4523        }
4524
4525        if (options->prefix &&
4526            strncmp(concatpath, options->prefix, options->prefix_length))
4527                return;
4528
4529        one = alloc_filespec(concatpath);
4530        two = alloc_filespec(concatpath);
4531        fill_filespec(one, old_sha1, old_mode);
4532        fill_filespec(two, new_sha1, new_mode);
4533        one->dirty_submodule = old_dirty_submodule;
4534        two->dirty_submodule = new_dirty_submodule;
4535
4536        diff_queue(&diff_queued_diff, one, two);
4537        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4538                DIFF_OPT_SET(options, HAS_CHANGES);
4539}
4540
4541void diff_unmerge(struct diff_options *options,
4542                  const char *path,
4543                  unsigned mode, const unsigned char *sha1)
4544{
4545        struct diff_filespec *one, *two;
4546
4547        if (options->prefix &&
4548            strncmp(path, options->prefix, options->prefix_length))
4549                return;
4550
4551        one = alloc_filespec(path);
4552        two = alloc_filespec(path);
4553        fill_filespec(one, sha1, mode);
4554        diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;
4555}
4556
4557static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4558                size_t *outsize)
4559{
4560        struct diff_tempfile *temp;
4561        const char *argv[3];
4562        const char **arg = argv;
4563        struct child_process child;
4564        struct strbuf buf = STRBUF_INIT;
4565        int err = 0;
4566
4567        temp = prepare_temp_file(spec->path, spec);
4568        *arg++ = pgm;
4569        *arg++ = temp->name;
4570        *arg = NULL;
4571
4572        memset(&child, 0, sizeof(child));
4573        child.use_shell = 1;
4574        child.argv = argv;
4575        child.out = -1;
4576        if (start_command(&child)) {
4577                remove_tempfile();
4578                return NULL;
4579        }
4580
4581        if (strbuf_read(&buf, child.out, 0) < 0)
4582                err = error("error reading from textconv command '%s'", pgm);
4583        close(child.out);
4584
4585        if (finish_command(&child) || err) {
4586                strbuf_release(&buf);
4587                remove_tempfile();
4588                return NULL;
4589        }
4590        remove_tempfile();
4591
4592        return strbuf_detach(&buf, outsize);
4593}
4594
4595size_t fill_textconv(struct userdiff_driver *driver,
4596                     struct diff_filespec *df,
4597                     char **outbuf)
4598{
4599        size_t size;
4600
4601        if (!driver || !driver->textconv) {
4602                if (!DIFF_FILE_VALID(df)) {
4603                        *outbuf = "";
4604                        return 0;
4605                }
4606                if (diff_populate_filespec(df, 0))
4607                        die("unable to read files to diff");
4608                *outbuf = df->data;
4609                return df->size;
4610        }
4611
4612        if (driver->textconv_cache && df->sha1_valid) {
4613                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4614                                          &size);
4615                if (*outbuf)
4616                        return size;
4617        }
4618
4619        *outbuf = run_textconv(driver->textconv, df, &size);
4620        if (!*outbuf)
4621                die("unable to read files to diff");
4622
4623        if (driver->textconv_cache && df->sha1_valid) {
4624                /* ignore errors, as we might be in a readonly repository */
4625                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4626                                size);
4627                /*
4628                 * we could save up changes and flush them all at the end,
4629                 * but we would need an extra call after all diffing is done.
4630                 * Since generating a cache entry is the slow path anyway,
4631                 * this extra overhead probably isn't a big deal.
4632                 */
4633                notes_cache_write(driver->textconv_cache);
4634        }
4635
4636        return size;
4637}