diff.con commit Merge branch 'maint' (07873dc)
   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 = 200;
  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 struct diff_options default_diff_options;
  35
  36static char diff_colors[][COLOR_MAXLEN] = {
  37        GIT_COLOR_RESET,
  38        GIT_COLOR_NORMAL,       /* PLAIN */
  39        GIT_COLOR_BOLD,         /* METAINFO */
  40        GIT_COLOR_CYAN,         /* FRAGINFO */
  41        GIT_COLOR_RED,          /* OLD */
  42        GIT_COLOR_GREEN,        /* NEW */
  43        GIT_COLOR_YELLOW,       /* COMMIT */
  44        GIT_COLOR_BG_RED,       /* WHITESPACE */
  45        GIT_COLOR_NORMAL,       /* FUNCINFO */
  46};
  47
  48static int parse_diff_color_slot(const char *var, int ofs)
  49{
  50        if (!strcasecmp(var+ofs, "plain"))
  51                return DIFF_PLAIN;
  52        if (!strcasecmp(var+ofs, "meta"))
  53                return DIFF_METAINFO;
  54        if (!strcasecmp(var+ofs, "frag"))
  55                return DIFF_FRAGINFO;
  56        if (!strcasecmp(var+ofs, "old"))
  57                return DIFF_FILE_OLD;
  58        if (!strcasecmp(var+ofs, "new"))
  59                return DIFF_FILE_NEW;
  60        if (!strcasecmp(var+ofs, "commit"))
  61                return DIFF_COMMIT;
  62        if (!strcasecmp(var+ofs, "whitespace"))
  63                return DIFF_WHITESPACE;
  64        if (!strcasecmp(var+ofs, "func"))
  65                return DIFF_FUNCINFO;
  66        return -1;
  67}
  68
  69static int git_config_rename(const char *var, const char *value)
  70{
  71        if (!value)
  72                return DIFF_DETECT_RENAME;
  73        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
  74                return  DIFF_DETECT_COPY;
  75        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
  76}
  77
  78/*
  79 * These are to give UI layer defaults.
  80 * The core-level commands such as git-diff-files should
  81 * never be affected by the setting of diff.renames
  82 * the user happens to have in the configuration file.
  83 */
  84int git_diff_ui_config(const char *var, const char *value, void *cb)
  85{
  86        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
  87                diff_use_color_default = git_config_colorbool(var, value, -1);
  88                return 0;
  89        }
  90        if (!strcmp(var, "diff.renames")) {
  91                diff_detect_rename_default = git_config_rename(var, value);
  92                return 0;
  93        }
  94        if (!strcmp(var, "diff.autorefreshindex")) {
  95                diff_auto_refresh_index = git_config_bool(var, value);
  96                return 0;
  97        }
  98        if (!strcmp(var, "diff.mnemonicprefix")) {
  99                diff_mnemonic_prefix = git_config_bool(var, value);
 100                return 0;
 101        }
 102        if (!strcmp(var, "diff.noprefix")) {
 103                diff_no_prefix = git_config_bool(var, value);
 104                return 0;
 105        }
 106        if (!strcmp(var, "diff.external"))
 107                return git_config_string(&external_diff_cmd_cfg, var, value);
 108        if (!strcmp(var, "diff.wordregex"))
 109                return git_config_string(&diff_word_regex_cfg, var, value);
 110
 111        if (!strcmp(var, "diff.ignoresubmodules"))
 112                handle_ignore_submodules_arg(&default_diff_options, value);
 113
 114        return git_diff_basic_config(var, value, cb);
 115}
 116
 117int git_diff_basic_config(const char *var, const char *value, void *cb)
 118{
 119        if (!strcmp(var, "diff.renamelimit")) {
 120                diff_rename_limit_default = git_config_int(var, value);
 121                return 0;
 122        }
 123
 124        switch (userdiff_config(var, value)) {
 125                case 0: break;
 126                case -1: return -1;
 127                default: return 0;
 128        }
 129
 130        if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
 131                int slot = parse_diff_color_slot(var, 11);
 132                if (slot < 0)
 133                        return 0;
 134                if (!value)
 135                        return config_error_nonbool(var);
 136                color_parse(value, var, diff_colors[slot]);
 137                return 0;
 138        }
 139
 140        /* like GNU diff's --suppress-blank-empty option  */
 141        if (!strcmp(var, "diff.suppressblankempty") ||
 142                        /* for backwards compatibility */
 143                        !strcmp(var, "diff.suppress-blank-empty")) {
 144                diff_suppress_blank_empty = git_config_bool(var, value);
 145                return 0;
 146        }
 147
 148        if (!prefixcmp(var, "submodule."))
 149                return parse_submodule_config_option(var, value);
 150
 151        return git_color_default_config(var, value, cb);
 152}
 153
 154static char *quote_two(const char *one, const char *two)
 155{
 156        int need_one = quote_c_style(one, NULL, NULL, 1);
 157        int need_two = quote_c_style(two, NULL, NULL, 1);
 158        struct strbuf res = STRBUF_INIT;
 159
 160        if (need_one + need_two) {
 161                strbuf_addch(&res, '"');
 162                quote_c_style(one, &res, NULL, 1);
 163                quote_c_style(two, &res, NULL, 1);
 164                strbuf_addch(&res, '"');
 165        } else {
 166                strbuf_addstr(&res, one);
 167                strbuf_addstr(&res, two);
 168        }
 169        return strbuf_detach(&res, NULL);
 170}
 171
 172static const char *external_diff(void)
 173{
 174        static const char *external_diff_cmd = NULL;
 175        static int done_preparing = 0;
 176
 177        if (done_preparing)
 178                return external_diff_cmd;
 179        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 180        if (!external_diff_cmd)
 181                external_diff_cmd = external_diff_cmd_cfg;
 182        done_preparing = 1;
 183        return external_diff_cmd;
 184}
 185
 186static struct diff_tempfile {
 187        const char *name; /* filename external diff should read from */
 188        char hex[41];
 189        char mode[10];
 190        char tmp_path[PATH_MAX];
 191} diff_temp[2];
 192
 193typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 194
 195struct emit_callback {
 196        int color_diff;
 197        unsigned ws_rule;
 198        int blank_at_eof_in_preimage;
 199        int blank_at_eof_in_postimage;
 200        int lno_in_preimage;
 201        int lno_in_postimage;
 202        sane_truncate_fn truncate;
 203        const char **label_path;
 204        struct diff_words_data *diff_words;
 205        struct diff_options *opt;
 206        int *found_changesp;
 207        struct strbuf *header;
 208};
 209
 210static int count_lines(const char *data, int size)
 211{
 212        int count, ch, completely_empty = 1, nl_just_seen = 0;
 213        count = 0;
 214        while (0 < size--) {
 215                ch = *data++;
 216                if (ch == '\n') {
 217                        count++;
 218                        nl_just_seen = 1;
 219                        completely_empty = 0;
 220                }
 221                else {
 222                        nl_just_seen = 0;
 223                        completely_empty = 0;
 224                }
 225        }
 226        if (completely_empty)
 227                return 0;
 228        if (!nl_just_seen)
 229                count++; /* no trailing newline */
 230        return count;
 231}
 232
 233static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 234{
 235        if (!DIFF_FILE_VALID(one)) {
 236                mf->ptr = (char *)""; /* does not matter */
 237                mf->size = 0;
 238                return 0;
 239        }
 240        else if (diff_populate_filespec(one, 0))
 241                return -1;
 242
 243        mf->ptr = one->data;
 244        mf->size = one->size;
 245        return 0;
 246}
 247
 248/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 249static unsigned long diff_filespec_size(struct diff_filespec *one)
 250{
 251        if (!DIFF_FILE_VALID(one))
 252                return 0;
 253        diff_populate_filespec(one, 1);
 254        return one->size;
 255}
 256
 257static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 258{
 259        char *ptr = mf->ptr;
 260        long size = mf->size;
 261        int cnt = 0;
 262
 263        if (!size)
 264                return cnt;
 265        ptr += size - 1; /* pointing at the very end */
 266        if (*ptr != '\n')
 267                ; /* incomplete line */
 268        else
 269                ptr--; /* skip the last LF */
 270        while (mf->ptr < ptr) {
 271                char *prev_eol;
 272                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 273                        if (*prev_eol == '\n')
 274                                break;
 275                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 276                        break;
 277                cnt++;
 278                ptr = prev_eol - 1;
 279        }
 280        return cnt;
 281}
 282
 283static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 284                               struct emit_callback *ecbdata)
 285{
 286        int l1, l2, at;
 287        unsigned ws_rule = ecbdata->ws_rule;
 288        l1 = count_trailing_blank(mf1, ws_rule);
 289        l2 = count_trailing_blank(mf2, ws_rule);
 290        if (l2 <= l1) {
 291                ecbdata->blank_at_eof_in_preimage = 0;
 292                ecbdata->blank_at_eof_in_postimage = 0;
 293                return;
 294        }
 295        at = count_lines(mf1->ptr, mf1->size);
 296        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 297
 298        at = count_lines(mf2->ptr, mf2->size);
 299        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 300}
 301
 302static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 303                        int first, const char *line, int len)
 304{
 305        int has_trailing_newline, has_trailing_carriage_return;
 306        int nofirst;
 307        FILE *file = o->file;
 308
 309        if (o->output_prefix) {
 310                struct strbuf *msg = NULL;
 311                msg = o->output_prefix(o, o->output_prefix_data);
 312                assert(msg);
 313                fwrite(msg->buf, msg->len, 1, file);
 314        }
 315
 316        if (len == 0) {
 317                has_trailing_newline = (first == '\n');
 318                has_trailing_carriage_return = (!has_trailing_newline &&
 319                                                (first == '\r'));
 320                nofirst = has_trailing_newline || has_trailing_carriage_return;
 321        } else {
 322                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 323                if (has_trailing_newline)
 324                        len--;
 325                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 326                if (has_trailing_carriage_return)
 327                        len--;
 328                nofirst = 0;
 329        }
 330
 331        if (len || !nofirst) {
 332                fputs(set, file);
 333                if (!nofirst)
 334                        fputc(first, file);
 335                fwrite(line, len, 1, file);
 336                fputs(reset, file);
 337        }
 338        if (has_trailing_carriage_return)
 339                fputc('\r', file);
 340        if (has_trailing_newline)
 341                fputc('\n', file);
 342}
 343
 344static void emit_line(struct diff_options *o, const char *set, const char *reset,
 345                      const char *line, int len)
 346{
 347        emit_line_0(o, set, reset, line[0], line+1, len-1);
 348}
 349
 350static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 351{
 352        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 353              ecbdata->blank_at_eof_in_preimage &&
 354              ecbdata->blank_at_eof_in_postimage &&
 355              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 356              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 357                return 0;
 358        return ws_blank_line(line, len, ecbdata->ws_rule);
 359}
 360
 361static void emit_add_line(const char *reset,
 362                          struct emit_callback *ecbdata,
 363                          const char *line, int len)
 364{
 365        const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 366        const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 367
 368        if (!*ws)
 369                emit_line_0(ecbdata->opt, set, reset, '+', line, len);
 370        else if (new_blank_line_at_eof(ecbdata, line, len))
 371                /* Blank line at EOF - paint '+' as well */
 372                emit_line_0(ecbdata->opt, ws, reset, '+', line, len);
 373        else {
 374                /* Emit just the prefix, then the rest. */
 375                emit_line_0(ecbdata->opt, set, reset, '+', "", 0);
 376                ws_check_emit(line, len, ecbdata->ws_rule,
 377                              ecbdata->opt->file, set, reset, ws);
 378        }
 379}
 380
 381static void emit_hunk_header(struct emit_callback *ecbdata,
 382                             const char *line, int len)
 383{
 384        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 385        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 386        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 387        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 388        static const char atat[2] = { '@', '@' };
 389        const char *cp, *ep;
 390        struct strbuf msgbuf = STRBUF_INIT;
 391        int org_len = len;
 392        int i = 1;
 393
 394        /*
 395         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 396         * it always is at least 10 bytes long.
 397         */
 398        if (len < 10 ||
 399            memcmp(line, atat, 2) ||
 400            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 401                emit_line(ecbdata->opt, plain, reset, line, len);
 402                return;
 403        }
 404        ep += 2; /* skip over @@ */
 405
 406        /* The hunk header in fraginfo color */
 407        strbuf_add(&msgbuf, frag, strlen(frag));
 408        strbuf_add(&msgbuf, line, ep - line);
 409        strbuf_add(&msgbuf, reset, strlen(reset));
 410
 411        /*
 412         * trailing "\r\n"
 413         */
 414        for ( ; i < 3; i++)
 415                if (line[len - i] == '\r' || line[len - i] == '\n')
 416                        len--;
 417
 418        /* blank before the func header */
 419        for (cp = ep; ep - line < len; ep++)
 420                if (*ep != ' ' && *ep != '\t')
 421                        break;
 422        if (ep != cp) {
 423                strbuf_add(&msgbuf, plain, strlen(plain));
 424                strbuf_add(&msgbuf, cp, ep - cp);
 425                strbuf_add(&msgbuf, reset, strlen(reset));
 426        }
 427
 428        if (ep < line + len) {
 429                strbuf_add(&msgbuf, func, strlen(func));
 430                strbuf_add(&msgbuf, ep, line + len - ep);
 431                strbuf_add(&msgbuf, reset, strlen(reset));
 432        }
 433
 434        strbuf_add(&msgbuf, line + len, org_len - len);
 435        emit_line(ecbdata->opt, "", "", msgbuf.buf, msgbuf.len);
 436        strbuf_release(&msgbuf);
 437}
 438
 439static struct diff_tempfile *claim_diff_tempfile(void) {
 440        int i;
 441        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 442                if (!diff_temp[i].name)
 443                        return diff_temp + i;
 444        die("BUG: diff is failing to clean up its tempfiles");
 445}
 446
 447static int remove_tempfile_installed;
 448
 449static void remove_tempfile(void)
 450{
 451        int i;
 452        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 453                if (diff_temp[i].name == diff_temp[i].tmp_path)
 454                        unlink_or_warn(diff_temp[i].name);
 455                diff_temp[i].name = NULL;
 456        }
 457}
 458
 459static void remove_tempfile_on_signal(int signo)
 460{
 461        remove_tempfile();
 462        sigchain_pop(signo);
 463        raise(signo);
 464}
 465
 466static void print_line_count(FILE *file, int count)
 467{
 468        switch (count) {
 469        case 0:
 470                fprintf(file, "0,0");
 471                break;
 472        case 1:
 473                fprintf(file, "1");
 474                break;
 475        default:
 476                fprintf(file, "1,%d", count);
 477                break;
 478        }
 479}
 480
 481static void emit_rewrite_lines(struct emit_callback *ecb,
 482                               int prefix, const char *data, int size)
 483{
 484        const char *endp = NULL;
 485        static const char *nneof = " No newline at end of file\n";
 486        const char *old = diff_get_color(ecb->color_diff, DIFF_FILE_OLD);
 487        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 488
 489        while (0 < size) {
 490                int len;
 491
 492                endp = memchr(data, '\n', size);
 493                len = endp ? (endp - data + 1) : size;
 494                if (prefix != '+') {
 495                        ecb->lno_in_preimage++;
 496                        emit_line_0(ecb->opt, old, reset, '-',
 497                                    data, len);
 498                } else {
 499                        ecb->lno_in_postimage++;
 500                        emit_add_line(reset, ecb, data, len);
 501                }
 502                size -= len;
 503                data += len;
 504        }
 505        if (!endp) {
 506                const char *plain = diff_get_color(ecb->color_diff,
 507                                                   DIFF_PLAIN);
 508                emit_line_0(ecb->opt, plain, reset, '\\',
 509                            nneof, strlen(nneof));
 510        }
 511}
 512
 513static void emit_rewrite_diff(const char *name_a,
 514                              const char *name_b,
 515                              struct diff_filespec *one,
 516                              struct diff_filespec *two,
 517                              struct userdiff_driver *textconv_one,
 518                              struct userdiff_driver *textconv_two,
 519                              struct diff_options *o)
 520{
 521        int lc_a, lc_b;
 522        int color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
 523        const char *name_a_tab, *name_b_tab;
 524        const char *metainfo = diff_get_color(color_diff, DIFF_METAINFO);
 525        const char *fraginfo = diff_get_color(color_diff, DIFF_FRAGINFO);
 526        const char *reset = diff_get_color(color_diff, DIFF_RESET);
 527        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 528        const char *a_prefix, *b_prefix;
 529        char *data_one, *data_two;
 530        size_t size_one, size_two;
 531        struct emit_callback ecbdata;
 532        char *line_prefix = "";
 533        struct strbuf *msgbuf;
 534
 535        if (o && o->output_prefix) {
 536                msgbuf = o->output_prefix(o, o->output_prefix_data);
 537                line_prefix = msgbuf->buf;
 538        }
 539
 540        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 541                a_prefix = o->b_prefix;
 542                b_prefix = o->a_prefix;
 543        } else {
 544                a_prefix = o->a_prefix;
 545                b_prefix = o->b_prefix;
 546        }
 547
 548        name_a += (*name_a == '/');
 549        name_b += (*name_b == '/');
 550        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 551        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 552
 553        strbuf_reset(&a_name);
 554        strbuf_reset(&b_name);
 555        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 556        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 557
 558        size_one = fill_textconv(textconv_one, one, &data_one);
 559        size_two = fill_textconv(textconv_two, two, &data_two);
 560
 561        memset(&ecbdata, 0, sizeof(ecbdata));
 562        ecbdata.color_diff = color_diff;
 563        ecbdata.found_changesp = &o->found_changes;
 564        ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
 565        ecbdata.opt = o;
 566        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 567                mmfile_t mf1, mf2;
 568                mf1.ptr = (char *)data_one;
 569                mf2.ptr = (char *)data_two;
 570                mf1.size = size_one;
 571                mf2.size = size_two;
 572                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 573        }
 574        ecbdata.lno_in_preimage = 1;
 575        ecbdata.lno_in_postimage = 1;
 576
 577        lc_a = count_lines(data_one, size_one);
 578        lc_b = count_lines(data_two, size_two);
 579        fprintf(o->file,
 580                "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
 581                line_prefix, metainfo, a_name.buf, name_a_tab, reset,
 582                line_prefix, metainfo, b_name.buf, name_b_tab, reset,
 583                line_prefix, fraginfo);
 584        print_line_count(o->file, lc_a);
 585        fprintf(o->file, " +");
 586        print_line_count(o->file, lc_b);
 587        fprintf(o->file, " @@%s\n", reset);
 588        if (lc_a)
 589                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 590        if (lc_b)
 591                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 592        if (textconv_one)
 593                free((char *)data_one);
 594        if (textconv_two)
 595                free((char *)data_two);
 596}
 597
 598struct diff_words_buffer {
 599        mmfile_t text;
 600        long alloc;
 601        struct diff_words_orig {
 602                const char *begin, *end;
 603        } *orig;
 604        int orig_nr, orig_alloc;
 605};
 606
 607static void diff_words_append(char *line, unsigned long len,
 608                struct diff_words_buffer *buffer)
 609{
 610        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 611        line++;
 612        len--;
 613        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 614        buffer->text.size += len;
 615        buffer->text.ptr[buffer->text.size] = '\0';
 616}
 617
 618struct diff_words_style_elem
 619{
 620        const char *prefix;
 621        const char *suffix;
 622        const char *color; /* NULL; filled in by the setup code if
 623                            * color is enabled */
 624};
 625
 626struct diff_words_style
 627{
 628        enum diff_words_type type;
 629        struct diff_words_style_elem new, old, ctx;
 630        const char *newline;
 631};
 632
 633struct diff_words_style diff_words_styles[] = {
 634        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 635        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 636        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 637};
 638
 639struct diff_words_data {
 640        struct diff_words_buffer minus, plus;
 641        const char *current_plus;
 642        int last_minus;
 643        struct diff_options *opt;
 644        regex_t *word_regex;
 645        enum diff_words_type type;
 646        struct diff_words_style *style;
 647};
 648
 649static int fn_out_diff_words_write_helper(FILE *fp,
 650                                          struct diff_words_style_elem *st_el,
 651                                          const char *newline,
 652                                          size_t count, const char *buf,
 653                                          const char *line_prefix)
 654{
 655        int print = 0;
 656
 657        while (count) {
 658                char *p = memchr(buf, '\n', count);
 659                if (print)
 660                        fputs(line_prefix, fp);
 661                if (p != buf) {
 662                        if (st_el->color && fputs(st_el->color, fp) < 0)
 663                                return -1;
 664                        if (fputs(st_el->prefix, fp) < 0 ||
 665                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 666                            fputs(st_el->suffix, fp) < 0)
 667                                return -1;
 668                        if (st_el->color && *st_el->color
 669                            && fputs(GIT_COLOR_RESET, fp) < 0)
 670                                return -1;
 671                }
 672                if (!p)
 673                        return 0;
 674                if (fputs(newline, fp) < 0)
 675                        return -1;
 676                count -= p + 1 - buf;
 677                buf = p + 1;
 678                print = 1;
 679        }
 680        return 0;
 681}
 682
 683/*
 684 * '--color-words' algorithm can be described as:
 685 *
 686 *   1. collect a the minus/plus lines of a diff hunk, divided into
 687 *      minus-lines and plus-lines;
 688 *
 689 *   2. break both minus-lines and plus-lines into words and
 690 *      place them into two mmfile_t with one word for each line;
 691 *
 692 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
 693 *
 694 * And for the common parts of the both file, we output the plus side text.
 695 * diff_words->current_plus is used to trace the current position of the plus file
 696 * which printed. diff_words->last_minus is used to trace the last minus word
 697 * printed.
 698 *
 699 * For '--graph' to work with '--color-words', we need to output the graph prefix
 700 * on each line of color words output. Generally, there are two conditions on
 701 * which we should output the prefix.
 702 *
 703 *   1. diff_words->last_minus == 0 &&
 704 *      diff_words->current_plus == diff_words->plus.text.ptr
 705 *
 706 *      that is: the plus text must start as a new line, and if there is no minus
 707 *      word printed, a graph prefix must be printed.
 708 *
 709 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
 710 *      *(diff_words->current_plus - 1) == '\n'
 711 *
 712 *      that is: a graph prefix must be printed following a '\n'
 713 */
 714static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
 715{
 716        if ((diff_words->last_minus == 0 &&
 717                diff_words->current_plus == diff_words->plus.text.ptr) ||
 718                (diff_words->current_plus > diff_words->plus.text.ptr &&
 719                *(diff_words->current_plus - 1) == '\n')) {
 720                return 1;
 721        } else {
 722                return 0;
 723        }
 724}
 725
 726static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 727{
 728        struct diff_words_data *diff_words = priv;
 729        struct diff_words_style *style = diff_words->style;
 730        int minus_first, minus_len, plus_first, plus_len;
 731        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 732        struct diff_options *opt = diff_words->opt;
 733        struct strbuf *msgbuf;
 734        char *line_prefix = "";
 735
 736        if (line[0] != '@' || parse_hunk_header(line, len,
 737                        &minus_first, &minus_len, &plus_first, &plus_len))
 738                return;
 739
 740        assert(opt);
 741        if (opt->output_prefix) {
 742                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 743                line_prefix = msgbuf->buf;
 744        }
 745
 746        /* POSIX requires that first be decremented by one if len == 0... */
 747        if (minus_len) {
 748                minus_begin = diff_words->minus.orig[minus_first].begin;
 749                minus_end =
 750                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 751        } else
 752                minus_begin = minus_end =
 753                        diff_words->minus.orig[minus_first].end;
 754
 755        if (plus_len) {
 756                plus_begin = diff_words->plus.orig[plus_first].begin;
 757                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 758        } else
 759                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 760
 761        if (color_words_output_graph_prefix(diff_words)) {
 762                fputs(line_prefix, diff_words->opt->file);
 763        }
 764        if (diff_words->current_plus != plus_begin) {
 765                fn_out_diff_words_write_helper(diff_words->opt->file,
 766                                &style->ctx, style->newline,
 767                                plus_begin - diff_words->current_plus,
 768                                diff_words->current_plus, line_prefix);
 769                if (*(plus_begin - 1) == '\n')
 770                        fputs(line_prefix, diff_words->opt->file);
 771        }
 772        if (minus_begin != minus_end) {
 773                fn_out_diff_words_write_helper(diff_words->opt->file,
 774                                &style->old, style->newline,
 775                                minus_end - minus_begin, minus_begin,
 776                                line_prefix);
 777        }
 778        if (plus_begin != plus_end) {
 779                fn_out_diff_words_write_helper(diff_words->opt->file,
 780                                &style->new, style->newline,
 781                                plus_end - plus_begin, plus_begin,
 782                                line_prefix);
 783        }
 784
 785        diff_words->current_plus = plus_end;
 786        diff_words->last_minus = minus_first;
 787}
 788
 789/* This function starts looking at *begin, and returns 0 iff a word was found. */
 790static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 791                int *begin, int *end)
 792{
 793        if (word_regex && *begin < buffer->size) {
 794                regmatch_t match[1];
 795                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 796                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 797                                        '\n', match[0].rm_eo - match[0].rm_so);
 798                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 799                        *begin += match[0].rm_so;
 800                        return *begin >= *end;
 801                }
 802                return -1;
 803        }
 804
 805        /* find the next word */
 806        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 807                (*begin)++;
 808        if (*begin >= buffer->size)
 809                return -1;
 810
 811        /* find the end of the word */
 812        *end = *begin + 1;
 813        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 814                (*end)++;
 815
 816        return 0;
 817}
 818
 819/*
 820 * This function splits the words in buffer->text, stores the list with
 821 * newline separator into out, and saves the offsets of the original words
 822 * in buffer->orig.
 823 */
 824static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 825                regex_t *word_regex)
 826{
 827        int i, j;
 828        long alloc = 0;
 829
 830        out->size = 0;
 831        out->ptr = NULL;
 832
 833        /* fake an empty "0th" word */
 834        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 835        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 836        buffer->orig_nr = 1;
 837
 838        for (i = 0; i < buffer->text.size; i++) {
 839                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 840                        return;
 841
 842                /* store original boundaries */
 843                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 844                                buffer->orig_alloc);
 845                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 846                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 847                buffer->orig_nr++;
 848
 849                /* store one word */
 850                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 851                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 852                out->ptr[out->size + j - i] = '\n';
 853                out->size += j - i + 1;
 854
 855                i = j - 1;
 856        }
 857}
 858
 859/* this executes the word diff on the accumulated buffers */
 860static void diff_words_show(struct diff_words_data *diff_words)
 861{
 862        xpparam_t xpp;
 863        xdemitconf_t xecfg;
 864        mmfile_t minus, plus;
 865        struct diff_words_style *style = diff_words->style;
 866
 867        struct diff_options *opt = diff_words->opt;
 868        struct strbuf *msgbuf;
 869        char *line_prefix = "";
 870
 871        assert(opt);
 872        if (opt->output_prefix) {
 873                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 874                line_prefix = msgbuf->buf;
 875        }
 876
 877        /* special case: only removal */
 878        if (!diff_words->plus.text.size) {
 879                fputs(line_prefix, diff_words->opt->file);
 880                fn_out_diff_words_write_helper(diff_words->opt->file,
 881                        &style->old, style->newline,
 882                        diff_words->minus.text.size,
 883                        diff_words->minus.text.ptr, line_prefix);
 884                diff_words->minus.text.size = 0;
 885                return;
 886        }
 887
 888        diff_words->current_plus = diff_words->plus.text.ptr;
 889        diff_words->last_minus = 0;
 890
 891        memset(&xpp, 0, sizeof(xpp));
 892        memset(&xecfg, 0, sizeof(xecfg));
 893        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
 894        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
 895        xpp.flags = 0;
 896        /* as only the hunk header will be parsed, we need a 0-context */
 897        xecfg.ctxlen = 0;
 898        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 899                      &xpp, &xecfg);
 900        free(minus.ptr);
 901        free(plus.ptr);
 902        if (diff_words->current_plus != diff_words->plus.text.ptr +
 903                        diff_words->plus.text.size) {
 904                if (color_words_output_graph_prefix(diff_words))
 905                        fputs(line_prefix, diff_words->opt->file);
 906                fn_out_diff_words_write_helper(diff_words->opt->file,
 907                        &style->ctx, style->newline,
 908                        diff_words->plus.text.ptr + diff_words->plus.text.size
 909                        - diff_words->current_plus, diff_words->current_plus,
 910                        line_prefix);
 911        }
 912        diff_words->minus.text.size = diff_words->plus.text.size = 0;
 913}
 914
 915/* In "color-words" mode, show word-diff of words accumulated in the buffer */
 916static void diff_words_flush(struct emit_callback *ecbdata)
 917{
 918        if (ecbdata->diff_words->minus.text.size ||
 919            ecbdata->diff_words->plus.text.size)
 920                diff_words_show(ecbdata->diff_words);
 921}
 922
 923static void free_diff_words_data(struct emit_callback *ecbdata)
 924{
 925        if (ecbdata->diff_words) {
 926                diff_words_flush(ecbdata);
 927                free (ecbdata->diff_words->minus.text.ptr);
 928                free (ecbdata->diff_words->minus.orig);
 929                free (ecbdata->diff_words->plus.text.ptr);
 930                free (ecbdata->diff_words->plus.orig);
 931                if (ecbdata->diff_words->word_regex) {
 932                        regfree(ecbdata->diff_words->word_regex);
 933                        free(ecbdata->diff_words->word_regex);
 934                }
 935                free(ecbdata->diff_words);
 936                ecbdata->diff_words = NULL;
 937        }
 938}
 939
 940const char *diff_get_color(int diff_use_color, enum color_diff ix)
 941{
 942        if (diff_use_color)
 943                return diff_colors[ix];
 944        return "";
 945}
 946
 947static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
 948{
 949        const char *cp;
 950        unsigned long allot;
 951        size_t l = len;
 952
 953        if (ecb->truncate)
 954                return ecb->truncate(line, len);
 955        cp = line;
 956        allot = l;
 957        while (0 < l) {
 958                (void) utf8_width(&cp, &l);
 959                if (!cp)
 960                        break; /* truncated in the middle? */
 961        }
 962        return allot - l;
 963}
 964
 965static void find_lno(const char *line, struct emit_callback *ecbdata)
 966{
 967        const char *p;
 968        ecbdata->lno_in_preimage = 0;
 969        ecbdata->lno_in_postimage = 0;
 970        p = strchr(line, '-');
 971        if (!p)
 972                return; /* cannot happen */
 973        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
 974        p = strchr(p, '+');
 975        if (!p)
 976                return; /* cannot happen */
 977        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
 978}
 979
 980static void fn_out_consume(void *priv, char *line, unsigned long len)
 981{
 982        struct emit_callback *ecbdata = priv;
 983        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
 984        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 985        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 986        struct diff_options *o = ecbdata->opt;
 987        char *line_prefix = "";
 988        struct strbuf *msgbuf;
 989
 990        if (o && o->output_prefix) {
 991                msgbuf = o->output_prefix(o, o->output_prefix_data);
 992                line_prefix = msgbuf->buf;
 993        }
 994
 995        if (ecbdata->header) {
 996                fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
 997                strbuf_reset(ecbdata->header);
 998                ecbdata->header = NULL;
 999        }
1000        *(ecbdata->found_changesp) = 1;
1001
1002        if (ecbdata->label_path[0]) {
1003                const char *name_a_tab, *name_b_tab;
1004
1005                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
1006                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
1007
1008                fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
1009                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
1010                fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
1011                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1012                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1013        }
1014
1015        if (diff_suppress_blank_empty
1016            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1017                line[0] = '\n';
1018                len = 1;
1019        }
1020
1021        if (line[0] == '@') {
1022                if (ecbdata->diff_words)
1023                        diff_words_flush(ecbdata);
1024                len = sane_truncate_line(ecbdata, line, len);
1025                find_lno(line, ecbdata);
1026                emit_hunk_header(ecbdata, line, len);
1027                if (line[len-1] != '\n')
1028                        putc('\n', ecbdata->opt->file);
1029                return;
1030        }
1031
1032        if (len < 1) {
1033                emit_line(ecbdata->opt, reset, reset, line, len);
1034                if (ecbdata->diff_words
1035                    && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
1036                        fputs("~\n", ecbdata->opt->file);
1037                return;
1038        }
1039
1040        if (ecbdata->diff_words) {
1041                if (line[0] == '-') {
1042                        diff_words_append(line, len,
1043                                          &ecbdata->diff_words->minus);
1044                        return;
1045                } else if (line[0] == '+') {
1046                        diff_words_append(line, len,
1047                                          &ecbdata->diff_words->plus);
1048                        return;
1049                }
1050                diff_words_flush(ecbdata);
1051                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1052                        emit_line(ecbdata->opt, plain, reset, line, len);
1053                        fputs("~\n", ecbdata->opt->file);
1054                } else {
1055                        /* don't print the prefix character */
1056                        emit_line(ecbdata->opt, plain, reset, line+1, len-1);
1057                }
1058                return;
1059        }
1060
1061        if (line[0] != '+') {
1062                const char *color =
1063                        diff_get_color(ecbdata->color_diff,
1064                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
1065                ecbdata->lno_in_preimage++;
1066                if (line[0] == ' ')
1067                        ecbdata->lno_in_postimage++;
1068                emit_line(ecbdata->opt, color, reset, line, len);
1069        } else {
1070                ecbdata->lno_in_postimage++;
1071                emit_add_line(reset, ecbdata, line + 1, len - 1);
1072        }
1073}
1074
1075static char *pprint_rename(const char *a, const char *b)
1076{
1077        const char *old = a;
1078        const char *new = b;
1079        struct strbuf name = STRBUF_INIT;
1080        int pfx_length, sfx_length;
1081        int len_a = strlen(a);
1082        int len_b = strlen(b);
1083        int a_midlen, b_midlen;
1084        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1085        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1086
1087        if (qlen_a || qlen_b) {
1088                quote_c_style(a, &name, NULL, 0);
1089                strbuf_addstr(&name, " => ");
1090                quote_c_style(b, &name, NULL, 0);
1091                return strbuf_detach(&name, NULL);
1092        }
1093
1094        /* Find common prefix */
1095        pfx_length = 0;
1096        while (*old && *new && *old == *new) {
1097                if (*old == '/')
1098                        pfx_length = old - a + 1;
1099                old++;
1100                new++;
1101        }
1102
1103        /* Find common suffix */
1104        old = a + len_a;
1105        new = b + len_b;
1106        sfx_length = 0;
1107        while (a <= old && b <= new && *old == *new) {
1108                if (*old == '/')
1109                        sfx_length = len_a - (old - a);
1110                old--;
1111                new--;
1112        }
1113
1114        /*
1115         * pfx{mid-a => mid-b}sfx
1116         * {pfx-a => pfx-b}sfx
1117         * pfx{sfx-a => sfx-b}
1118         * name-a => name-b
1119         */
1120        a_midlen = len_a - pfx_length - sfx_length;
1121        b_midlen = len_b - pfx_length - sfx_length;
1122        if (a_midlen < 0)
1123                a_midlen = 0;
1124        if (b_midlen < 0)
1125                b_midlen = 0;
1126
1127        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1128        if (pfx_length + sfx_length) {
1129                strbuf_add(&name, a, pfx_length);
1130                strbuf_addch(&name, '{');
1131        }
1132        strbuf_add(&name, a + pfx_length, a_midlen);
1133        strbuf_addstr(&name, " => ");
1134        strbuf_add(&name, b + pfx_length, b_midlen);
1135        if (pfx_length + sfx_length) {
1136                strbuf_addch(&name, '}');
1137                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1138        }
1139        return strbuf_detach(&name, NULL);
1140}
1141
1142struct diffstat_t {
1143        int nr;
1144        int alloc;
1145        struct diffstat_file {
1146                char *from_name;
1147                char *name;
1148                char *print_name;
1149                unsigned is_unmerged:1;
1150                unsigned is_binary:1;
1151                unsigned is_renamed:1;
1152                uintmax_t added, deleted;
1153        } **files;
1154};
1155
1156static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1157                                          const char *name_a,
1158                                          const char *name_b)
1159{
1160        struct diffstat_file *x;
1161        x = xcalloc(sizeof (*x), 1);
1162        if (diffstat->nr == diffstat->alloc) {
1163                diffstat->alloc = alloc_nr(diffstat->alloc);
1164                diffstat->files = xrealloc(diffstat->files,
1165                                diffstat->alloc * sizeof(x));
1166        }
1167        diffstat->files[diffstat->nr++] = x;
1168        if (name_b) {
1169                x->from_name = xstrdup(name_a);
1170                x->name = xstrdup(name_b);
1171                x->is_renamed = 1;
1172        }
1173        else {
1174                x->from_name = NULL;
1175                x->name = xstrdup(name_a);
1176        }
1177        return x;
1178}
1179
1180static void diffstat_consume(void *priv, char *line, unsigned long len)
1181{
1182        struct diffstat_t *diffstat = priv;
1183        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1184
1185        if (line[0] == '+')
1186                x->added++;
1187        else if (line[0] == '-')
1188                x->deleted++;
1189}
1190
1191const char mime_boundary_leader[] = "------------";
1192
1193static int scale_linear(int it, int width, int max_change)
1194{
1195        /*
1196         * make sure that at least one '-' is printed if there were deletions,
1197         * and likewise for '+'.
1198         */
1199        if (max_change < 2)
1200                return it;
1201        return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
1202}
1203
1204static void show_name(FILE *file,
1205                      const char *prefix, const char *name, int len)
1206{
1207        fprintf(file, " %s%-*s |", prefix, len, name);
1208}
1209
1210static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1211{
1212        if (cnt <= 0)
1213                return;
1214        fprintf(file, "%s", set);
1215        while (cnt--)
1216                putc(ch, file);
1217        fprintf(file, "%s", reset);
1218}
1219
1220static void fill_print_name(struct diffstat_file *file)
1221{
1222        char *pname;
1223
1224        if (file->print_name)
1225                return;
1226
1227        if (!file->is_renamed) {
1228                struct strbuf buf = STRBUF_INIT;
1229                if (quote_c_style(file->name, &buf, NULL, 0)) {
1230                        pname = strbuf_detach(&buf, NULL);
1231                } else {
1232                        pname = file->name;
1233                        strbuf_release(&buf);
1234                }
1235        } else {
1236                pname = pprint_rename(file->from_name, file->name);
1237        }
1238        file->print_name = pname;
1239}
1240
1241static void show_stats(struct diffstat_t *data, struct diff_options *options)
1242{
1243        int i, len, add, del, adds = 0, dels = 0;
1244        uintmax_t max_change = 0, max_len = 0;
1245        int total_files = data->nr;
1246        int width, name_width;
1247        const char *reset, *set, *add_c, *del_c;
1248        const char *line_prefix = "";
1249        struct strbuf *msg = NULL;
1250
1251        if (data->nr == 0)
1252                return;
1253
1254        if (options->output_prefix) {
1255                msg = options->output_prefix(options, options->output_prefix_data);
1256                line_prefix = msg->buf;
1257        }
1258
1259        width = options->stat_width ? options->stat_width : 80;
1260        name_width = options->stat_name_width ? options->stat_name_width : 50;
1261
1262        /* Sanity: give at least 5 columns to the graph,
1263         * but leave at least 10 columns for the name.
1264         */
1265        if (width < 25)
1266                width = 25;
1267        if (name_width < 10)
1268                name_width = 10;
1269        else if (width < name_width + 15)
1270                name_width = width - 15;
1271
1272        /* Find the longest filename and max number of changes */
1273        reset = diff_get_color_opt(options, DIFF_RESET);
1274        set   = diff_get_color_opt(options, DIFF_PLAIN);
1275        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1276        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1277
1278        for (i = 0; i < data->nr; i++) {
1279                struct diffstat_file *file = data->files[i];
1280                uintmax_t change = file->added + file->deleted;
1281                fill_print_name(file);
1282                len = strlen(file->print_name);
1283                if (max_len < len)
1284                        max_len = len;
1285
1286                if (file->is_binary || file->is_unmerged)
1287                        continue;
1288                if (max_change < change)
1289                        max_change = change;
1290        }
1291
1292        /* Compute the width of the graph part;
1293         * 10 is for one blank at the beginning of the line plus
1294         * " | count " between the name and the graph.
1295         *
1296         * From here on, name_width is the width of the name area,
1297         * and width is the width of the graph area.
1298         */
1299        name_width = (name_width < max_len) ? name_width : max_len;
1300        if (width < (name_width + 10) + max_change)
1301                width = width - (name_width + 10);
1302        else
1303                width = max_change;
1304
1305        for (i = 0; i < data->nr; i++) {
1306                const char *prefix = "";
1307                char *name = data->files[i]->print_name;
1308                uintmax_t added = data->files[i]->added;
1309                uintmax_t deleted = data->files[i]->deleted;
1310                int name_len;
1311
1312                /*
1313                 * "scale" the filename
1314                 */
1315                len = name_width;
1316                name_len = strlen(name);
1317                if (name_width < name_len) {
1318                        char *slash;
1319                        prefix = "...";
1320                        len -= 3;
1321                        name += name_len - len;
1322                        slash = strchr(name, '/');
1323                        if (slash)
1324                                name = slash;
1325                }
1326
1327                if (data->files[i]->is_binary) {
1328                        fprintf(options->file, "%s", line_prefix);
1329                        show_name(options->file, prefix, name, len);
1330                        fprintf(options->file, "  Bin ");
1331                        fprintf(options->file, "%s%"PRIuMAX"%s",
1332                                del_c, deleted, reset);
1333                        fprintf(options->file, " -> ");
1334                        fprintf(options->file, "%s%"PRIuMAX"%s",
1335                                add_c, added, reset);
1336                        fprintf(options->file, " bytes");
1337                        fprintf(options->file, "\n");
1338                        continue;
1339                }
1340                else if (data->files[i]->is_unmerged) {
1341                        fprintf(options->file, "%s", line_prefix);
1342                        show_name(options->file, prefix, name, len);
1343                        fprintf(options->file, "  Unmerged\n");
1344                        continue;
1345                }
1346                else if (!data->files[i]->is_renamed &&
1347                         (added + deleted == 0)) {
1348                        total_files--;
1349                        continue;
1350                }
1351
1352                /*
1353                 * scale the add/delete
1354                 */
1355                add = added;
1356                del = deleted;
1357                adds += add;
1358                dels += del;
1359
1360                if (width <= max_change) {
1361                        add = scale_linear(add, width, max_change);
1362                        del = scale_linear(del, width, max_change);
1363                }
1364                fprintf(options->file, "%s", line_prefix);
1365                show_name(options->file, prefix, name, len);
1366                fprintf(options->file, "%5"PRIuMAX"%s", added + deleted,
1367                                added + deleted ? " " : "");
1368                show_graph(options->file, '+', add, add_c, reset);
1369                show_graph(options->file, '-', del, del_c, reset);
1370                fprintf(options->file, "\n");
1371        }
1372        fprintf(options->file, "%s", line_prefix);
1373        fprintf(options->file,
1374               " %d files changed, %d insertions(+), %d deletions(-)\n",
1375               total_files, adds, dels);
1376}
1377
1378static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1379{
1380        int i, adds = 0, dels = 0, total_files = data->nr;
1381
1382        if (data->nr == 0)
1383                return;
1384
1385        for (i = 0; i < data->nr; i++) {
1386                if (!data->files[i]->is_binary &&
1387                    !data->files[i]->is_unmerged) {
1388                        int added = data->files[i]->added;
1389                        int deleted= data->files[i]->deleted;
1390                        if (!data->files[i]->is_renamed &&
1391                            (added + deleted == 0)) {
1392                                total_files--;
1393                        } else {
1394                                adds += added;
1395                                dels += deleted;
1396                        }
1397                }
1398        }
1399        if (options->output_prefix) {
1400                struct strbuf *msg = NULL;
1401                msg = options->output_prefix(options,
1402                                options->output_prefix_data);
1403                fprintf(options->file, "%s", msg->buf);
1404        }
1405        fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
1406               total_files, adds, dels);
1407}
1408
1409static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1410{
1411        int i;
1412
1413        if (data->nr == 0)
1414                return;
1415
1416        for (i = 0; i < data->nr; i++) {
1417                struct diffstat_file *file = data->files[i];
1418
1419                if (options->output_prefix) {
1420                        struct strbuf *msg = NULL;
1421                        msg = options->output_prefix(options,
1422                                        options->output_prefix_data);
1423                        fprintf(options->file, "%s", msg->buf);
1424                }
1425
1426                if (file->is_binary)
1427                        fprintf(options->file, "-\t-\t");
1428                else
1429                        fprintf(options->file,
1430                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1431                                file->added, file->deleted);
1432                if (options->line_termination) {
1433                        fill_print_name(file);
1434                        if (!file->is_renamed)
1435                                write_name_quoted(file->name, options->file,
1436                                                  options->line_termination);
1437                        else {
1438                                fputs(file->print_name, options->file);
1439                                putc(options->line_termination, options->file);
1440                        }
1441                } else {
1442                        if (file->is_renamed) {
1443                                putc('\0', options->file);
1444                                write_name_quoted(file->from_name, options->file, '\0');
1445                        }
1446                        write_name_quoted(file->name, options->file, '\0');
1447                }
1448        }
1449}
1450
1451struct dirstat_file {
1452        const char *name;
1453        unsigned long changed;
1454};
1455
1456struct dirstat_dir {
1457        struct dirstat_file *files;
1458        int alloc, nr, percent, cumulative;
1459};
1460
1461static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1462                unsigned long changed, const char *base, int baselen)
1463{
1464        unsigned long this_dir = 0;
1465        unsigned int sources = 0;
1466        const char *line_prefix = "";
1467        struct strbuf *msg = NULL;
1468
1469        if (opt->output_prefix) {
1470                msg = opt->output_prefix(opt, opt->output_prefix_data);
1471                line_prefix = msg->buf;
1472        }
1473
1474        while (dir->nr) {
1475                struct dirstat_file *f = dir->files;
1476                int namelen = strlen(f->name);
1477                unsigned long this;
1478                char *slash;
1479
1480                if (namelen < baselen)
1481                        break;
1482                if (memcmp(f->name, base, baselen))
1483                        break;
1484                slash = strchr(f->name + baselen, '/');
1485                if (slash) {
1486                        int newbaselen = slash + 1 - f->name;
1487                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1488                        sources++;
1489                } else {
1490                        this = f->changed;
1491                        dir->files++;
1492                        dir->nr--;
1493                        sources += 2;
1494                }
1495                this_dir += this;
1496        }
1497
1498        /*
1499         * We don't report dirstat's for
1500         *  - the top level
1501         *  - or cases where everything came from a single directory
1502         *    under this directory (sources == 1).
1503         */
1504        if (baselen && sources != 1) {
1505                int permille = this_dir * 1000 / changed;
1506                if (permille) {
1507                        int percent = permille / 10;
1508                        if (percent >= dir->percent) {
1509                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1510                                        percent, permille % 10, baselen, base);
1511                                if (!dir->cumulative)
1512                                        return 0;
1513                        }
1514                }
1515        }
1516        return this_dir;
1517}
1518
1519static int dirstat_compare(const void *_a, const void *_b)
1520{
1521        const struct dirstat_file *a = _a;
1522        const struct dirstat_file *b = _b;
1523        return strcmp(a->name, b->name);
1524}
1525
1526static void show_dirstat(struct diff_options *options)
1527{
1528        int i;
1529        unsigned long changed;
1530        struct dirstat_dir dir;
1531        struct diff_queue_struct *q = &diff_queued_diff;
1532
1533        dir.files = NULL;
1534        dir.alloc = 0;
1535        dir.nr = 0;
1536        dir.percent = options->dirstat_percent;
1537        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1538
1539        changed = 0;
1540        for (i = 0; i < q->nr; i++) {
1541                struct diff_filepair *p = q->queue[i];
1542                const char *name;
1543                unsigned long copied, added, damage;
1544
1545                name = p->one->path ? p->one->path : p->two->path;
1546
1547                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1548                        diff_populate_filespec(p->one, 0);
1549                        diff_populate_filespec(p->two, 0);
1550                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1551                                               &copied, &added);
1552                        diff_free_filespec_data(p->one);
1553                        diff_free_filespec_data(p->two);
1554                } else if (DIFF_FILE_VALID(p->one)) {
1555                        diff_populate_filespec(p->one, 1);
1556                        copied = added = 0;
1557                        diff_free_filespec_data(p->one);
1558                } else if (DIFF_FILE_VALID(p->two)) {
1559                        diff_populate_filespec(p->two, 1);
1560                        copied = 0;
1561                        added = p->two->size;
1562                        diff_free_filespec_data(p->two);
1563                } else
1564                        continue;
1565
1566                /*
1567                 * Original minus copied is the removed material,
1568                 * added is the new material.  They are both damages
1569                 * made to the preimage. In --dirstat-by-file mode, count
1570                 * damaged files, not damaged lines. This is done by
1571                 * counting only a single damaged line per file.
1572                 */
1573                damage = (p->one->size - copied) + added;
1574                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE) && damage > 0)
1575                        damage = 1;
1576
1577                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1578                dir.files[dir.nr].name = name;
1579                dir.files[dir.nr].changed = damage;
1580                changed += damage;
1581                dir.nr++;
1582        }
1583
1584        /* This can happen even with many files, if everything was renames */
1585        if (!changed)
1586                return;
1587
1588        /* Show all directories with more than x% of the changes */
1589        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1590        gather_dirstat(options, &dir, changed, "", 0);
1591}
1592
1593static void free_diffstat_info(struct diffstat_t *diffstat)
1594{
1595        int i;
1596        for (i = 0; i < diffstat->nr; i++) {
1597                struct diffstat_file *f = diffstat->files[i];
1598                if (f->name != f->print_name)
1599                        free(f->print_name);
1600                free(f->name);
1601                free(f->from_name);
1602                free(f);
1603        }
1604        free(diffstat->files);
1605}
1606
1607struct checkdiff_t {
1608        const char *filename;
1609        int lineno;
1610        int conflict_marker_size;
1611        struct diff_options *o;
1612        unsigned ws_rule;
1613        unsigned status;
1614};
1615
1616static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1617{
1618        char firstchar;
1619        int cnt;
1620
1621        if (len < marker_size + 1)
1622                return 0;
1623        firstchar = line[0];
1624        switch (firstchar) {
1625        case '=': case '>': case '<': case '|':
1626                break;
1627        default:
1628                return 0;
1629        }
1630        for (cnt = 1; cnt < marker_size; cnt++)
1631                if (line[cnt] != firstchar)
1632                        return 0;
1633        /* line[1] thru line[marker_size-1] are same as firstchar */
1634        if (len < marker_size + 1 || !isspace(line[marker_size]))
1635                return 0;
1636        return 1;
1637}
1638
1639static void checkdiff_consume(void *priv, char *line, unsigned long len)
1640{
1641        struct checkdiff_t *data = priv;
1642        int color_diff = DIFF_OPT_TST(data->o, COLOR_DIFF);
1643        int marker_size = data->conflict_marker_size;
1644        const char *ws = diff_get_color(color_diff, DIFF_WHITESPACE);
1645        const char *reset = diff_get_color(color_diff, DIFF_RESET);
1646        const char *set = diff_get_color(color_diff, DIFF_FILE_NEW);
1647        char *err;
1648        char *line_prefix = "";
1649        struct strbuf *msgbuf;
1650
1651        assert(data->o);
1652        if (data->o->output_prefix) {
1653                msgbuf = data->o->output_prefix(data->o,
1654                        data->o->output_prefix_data);
1655                line_prefix = msgbuf->buf;
1656        }
1657
1658        if (line[0] == '+') {
1659                unsigned bad;
1660                data->lineno++;
1661                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
1662                        data->status |= 1;
1663                        fprintf(data->o->file,
1664                                "%s%s:%d: leftover conflict marker\n",
1665                                line_prefix, data->filename, data->lineno);
1666                }
1667                bad = ws_check(line + 1, len - 1, data->ws_rule);
1668                if (!bad)
1669                        return;
1670                data->status |= bad;
1671                err = whitespace_error_string(bad);
1672                fprintf(data->o->file, "%s%s:%d: %s.\n",
1673                        line_prefix, data->filename, data->lineno, err);
1674                free(err);
1675                emit_line(data->o, set, reset, line, 1);
1676                ws_check_emit(line + 1, len - 1, data->ws_rule,
1677                              data->o->file, set, reset, ws);
1678        } else if (line[0] == ' ') {
1679                data->lineno++;
1680        } else if (line[0] == '@') {
1681                char *plus = strchr(line, '+');
1682                if (plus)
1683                        data->lineno = strtol(plus, NULL, 10) - 1;
1684                else
1685                        die("invalid diff");
1686        }
1687}
1688
1689static unsigned char *deflate_it(char *data,
1690                                 unsigned long size,
1691                                 unsigned long *result_size)
1692{
1693        int bound;
1694        unsigned char *deflated;
1695        z_stream stream;
1696
1697        memset(&stream, 0, sizeof(stream));
1698        deflateInit(&stream, zlib_compression_level);
1699        bound = deflateBound(&stream, size);
1700        deflated = xmalloc(bound);
1701        stream.next_out = deflated;
1702        stream.avail_out = bound;
1703
1704        stream.next_in = (unsigned char *)data;
1705        stream.avail_in = size;
1706        while (deflate(&stream, Z_FINISH) == Z_OK)
1707                ; /* nothing */
1708        deflateEnd(&stream);
1709        *result_size = stream.total_out;
1710        return deflated;
1711}
1712
1713static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1714{
1715        void *cp;
1716        void *delta;
1717        void *deflated;
1718        void *data;
1719        unsigned long orig_size;
1720        unsigned long delta_size;
1721        unsigned long deflate_size;
1722        unsigned long data_size;
1723
1724        /* We could do deflated delta, or we could do just deflated two,
1725         * whichever is smaller.
1726         */
1727        delta = NULL;
1728        deflated = deflate_it(two->ptr, two->size, &deflate_size);
1729        if (one->size && two->size) {
1730                delta = diff_delta(one->ptr, one->size,
1731                                   two->ptr, two->size,
1732                                   &delta_size, deflate_size);
1733                if (delta) {
1734                        void *to_free = delta;
1735                        orig_size = delta_size;
1736                        delta = deflate_it(delta, delta_size, &delta_size);
1737                        free(to_free);
1738                }
1739        }
1740
1741        if (delta && delta_size < deflate_size) {
1742                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
1743                free(deflated);
1744                data = delta;
1745                data_size = delta_size;
1746        }
1747        else {
1748                fprintf(file, "%sliteral %lu\n", prefix, two->size);
1749                free(delta);
1750                data = deflated;
1751                data_size = deflate_size;
1752        }
1753
1754        /* emit data encoded in base85 */
1755        cp = data;
1756        while (data_size) {
1757                int bytes = (52 < data_size) ? 52 : data_size;
1758                char line[70];
1759                data_size -= bytes;
1760                if (bytes <= 26)
1761                        line[0] = bytes + 'A' - 1;
1762                else
1763                        line[0] = bytes - 26 + 'a' - 1;
1764                encode_85(line + 1, cp, bytes);
1765                cp = (char *) cp + bytes;
1766                fprintf(file, "%s", prefix);
1767                fputs(line, file);
1768                fputc('\n', file);
1769        }
1770        fprintf(file, "%s\n", prefix);
1771        free(data);
1772}
1773
1774static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1775{
1776        fprintf(file, "%sGIT binary patch\n", prefix);
1777        emit_binary_diff_body(file, one, two, prefix);
1778        emit_binary_diff_body(file, two, one, prefix);
1779}
1780
1781static void diff_filespec_load_driver(struct diff_filespec *one)
1782{
1783        /* Use already-loaded driver */
1784        if (one->driver)
1785                return;
1786
1787        if (S_ISREG(one->mode))
1788                one->driver = userdiff_find_by_path(one->path);
1789
1790        /* Fallback to default settings */
1791        if (!one->driver)
1792                one->driver = userdiff_find_by_name("default");
1793}
1794
1795int diff_filespec_is_binary(struct diff_filespec *one)
1796{
1797        if (one->is_binary == -1) {
1798                diff_filespec_load_driver(one);
1799                if (one->driver->binary != -1)
1800                        one->is_binary = one->driver->binary;
1801                else {
1802                        if (!one->data && DIFF_FILE_VALID(one))
1803                                diff_populate_filespec(one, 0);
1804                        if (one->data)
1805                                one->is_binary = buffer_is_binary(one->data,
1806                                                one->size);
1807                        if (one->is_binary == -1)
1808                                one->is_binary = 0;
1809                }
1810        }
1811        return one->is_binary;
1812}
1813
1814static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
1815{
1816        diff_filespec_load_driver(one);
1817        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
1818}
1819
1820static const char *userdiff_word_regex(struct diff_filespec *one)
1821{
1822        diff_filespec_load_driver(one);
1823        return one->driver->word_regex;
1824}
1825
1826void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
1827{
1828        if (!options->a_prefix)
1829                options->a_prefix = a;
1830        if (!options->b_prefix)
1831                options->b_prefix = b;
1832}
1833
1834struct userdiff_driver *get_textconv(struct diff_filespec *one)
1835{
1836        if (!DIFF_FILE_VALID(one))
1837                return NULL;
1838
1839        diff_filespec_load_driver(one);
1840        if (!one->driver->textconv)
1841                return NULL;
1842
1843        if (one->driver->textconv_want_cache && !one->driver->textconv_cache) {
1844                struct notes_cache *c = xmalloc(sizeof(*c));
1845                struct strbuf name = STRBUF_INIT;
1846
1847                strbuf_addf(&name, "textconv/%s", one->driver->name);
1848                notes_cache_init(c, name.buf, one->driver->textconv);
1849                one->driver->textconv_cache = c;
1850        }
1851
1852        return one->driver;
1853}
1854
1855static void builtin_diff(const char *name_a,
1856                         const char *name_b,
1857                         struct diff_filespec *one,
1858                         struct diff_filespec *two,
1859                         const char *xfrm_msg,
1860                         int must_show_header,
1861                         struct diff_options *o,
1862                         int complete_rewrite)
1863{
1864        mmfile_t mf1, mf2;
1865        const char *lbl[2];
1866        char *a_one, *b_two;
1867        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1868        const char *reset = diff_get_color_opt(o, DIFF_RESET);
1869        const char *a_prefix, *b_prefix;
1870        struct userdiff_driver *textconv_one = NULL;
1871        struct userdiff_driver *textconv_two = NULL;
1872        struct strbuf header = STRBUF_INIT;
1873        struct strbuf *msgbuf;
1874        char *line_prefix = "";
1875
1876        if (o->output_prefix) {
1877                msgbuf = o->output_prefix(o, o->output_prefix_data);
1878                line_prefix = msgbuf->buf;
1879        }
1880
1881        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
1882                        (!one->mode || S_ISGITLINK(one->mode)) &&
1883                        (!two->mode || S_ISGITLINK(two->mode))) {
1884                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
1885                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
1886                show_submodule_summary(o->file, one ? one->path : two->path,
1887                                one->sha1, two->sha1, two->dirty_submodule,
1888                                del, add, reset);
1889                return;
1890        }
1891
1892        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
1893                textconv_one = get_textconv(one);
1894                textconv_two = get_textconv(two);
1895        }
1896
1897        diff_set_mnemonic_prefix(o, "a/", "b/");
1898        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
1899                a_prefix = o->b_prefix;
1900                b_prefix = o->a_prefix;
1901        } else {
1902                a_prefix = o->a_prefix;
1903                b_prefix = o->b_prefix;
1904        }
1905
1906        /* Never use a non-valid filename anywhere if at all possible */
1907        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
1908        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
1909
1910        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
1911        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
1912        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1913        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1914        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
1915        if (lbl[0][0] == '/') {
1916                /* /dev/null */
1917                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
1918                if (xfrm_msg)
1919                        strbuf_addstr(&header, xfrm_msg);
1920                must_show_header = 1;
1921        }
1922        else if (lbl[1][0] == '/') {
1923                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
1924                if (xfrm_msg)
1925                        strbuf_addstr(&header, xfrm_msg);
1926                must_show_header = 1;
1927        }
1928        else {
1929                if (one->mode != two->mode) {
1930                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
1931                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
1932                        must_show_header = 1;
1933                }
1934                if (xfrm_msg)
1935                        strbuf_addstr(&header, xfrm_msg);
1936
1937                /*
1938                 * we do not run diff between different kind
1939                 * of objects.
1940                 */
1941                if ((one->mode ^ two->mode) & S_IFMT)
1942                        goto free_ab_and_return;
1943                if (complete_rewrite &&
1944                    (textconv_one || !diff_filespec_is_binary(one)) &&
1945                    (textconv_two || !diff_filespec_is_binary(two))) {
1946                        fprintf(o->file, "%s", header.buf);
1947                        strbuf_reset(&header);
1948                        emit_rewrite_diff(name_a, name_b, one, two,
1949                                                textconv_one, textconv_two, o);
1950                        o->found_changes = 1;
1951                        goto free_ab_and_return;
1952                }
1953        }
1954
1955        if (!DIFF_OPT_TST(o, TEXT) &&
1956            ( (!textconv_one && diff_filespec_is_binary(one)) ||
1957              (!textconv_two && diff_filespec_is_binary(two)) )) {
1958                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1959                        die("unable to read files to diff");
1960                /* Quite common confusing case */
1961                if (mf1.size == mf2.size &&
1962                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
1963                        if (must_show_header)
1964                                fprintf(o->file, "%s", header.buf);
1965                        goto free_ab_and_return;
1966                }
1967                fprintf(o->file, "%s", header.buf);
1968                strbuf_reset(&header);
1969                if (DIFF_OPT_TST(o, BINARY))
1970                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
1971                else
1972                        fprintf(o->file, "%sBinary files %s and %s differ\n",
1973                                line_prefix, lbl[0], lbl[1]);
1974                o->found_changes = 1;
1975        }
1976        else {
1977                /* Crazy xdl interfaces.. */
1978                const char *diffopts = getenv("GIT_DIFF_OPTS");
1979                xpparam_t xpp;
1980                xdemitconf_t xecfg;
1981                struct emit_callback ecbdata;
1982                const struct userdiff_funcname *pe;
1983
1984                if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS) || must_show_header) {
1985                        fprintf(o->file, "%s", header.buf);
1986                        strbuf_reset(&header);
1987                }
1988
1989                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
1990                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
1991
1992                pe = diff_funcname_pattern(one);
1993                if (!pe)
1994                        pe = diff_funcname_pattern(two);
1995
1996                memset(&xpp, 0, sizeof(xpp));
1997                memset(&xecfg, 0, sizeof(xecfg));
1998                memset(&ecbdata, 0, sizeof(ecbdata));
1999                ecbdata.label_path = lbl;
2000                ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
2001                ecbdata.found_changesp = &o->found_changes;
2002                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
2003                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2004                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2005                ecbdata.opt = o;
2006                ecbdata.header = header.len ? &header : NULL;
2007                xpp.flags = o->xdl_opts;
2008                xecfg.ctxlen = o->context;
2009                xecfg.interhunkctxlen = o->interhunkcontext;
2010                xecfg.flags = XDL_EMIT_FUNCNAMES;
2011                if (pe)
2012                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2013                if (!diffopts)
2014                        ;
2015                else if (!prefixcmp(diffopts, "--unified="))
2016                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2017                else if (!prefixcmp(diffopts, "-u"))
2018                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2019                if (o->word_diff) {
2020                        int i;
2021
2022                        ecbdata.diff_words =
2023                                xcalloc(1, sizeof(struct diff_words_data));
2024                        ecbdata.diff_words->type = o->word_diff;
2025                        ecbdata.diff_words->opt = o;
2026                        if (!o->word_regex)
2027                                o->word_regex = userdiff_word_regex(one);
2028                        if (!o->word_regex)
2029                                o->word_regex = userdiff_word_regex(two);
2030                        if (!o->word_regex)
2031                                o->word_regex = diff_word_regex_cfg;
2032                        if (o->word_regex) {
2033                                ecbdata.diff_words->word_regex = (regex_t *)
2034                                        xmalloc(sizeof(regex_t));
2035                                if (regcomp(ecbdata.diff_words->word_regex,
2036                                                o->word_regex,
2037                                                REG_EXTENDED | REG_NEWLINE))
2038                                        die ("Invalid regular expression: %s",
2039                                                        o->word_regex);
2040                        }
2041                        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2042                                if (o->word_diff == diff_words_styles[i].type) {
2043                                        ecbdata.diff_words->style =
2044                                                &diff_words_styles[i];
2045                                        break;
2046                                }
2047                        }
2048                        if (DIFF_OPT_TST(o, COLOR_DIFF)) {
2049                                struct diff_words_style *st = ecbdata.diff_words->style;
2050                                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2051                                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2052                                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
2053                        }
2054                }
2055                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2056                              &xpp, &xecfg);
2057                if (o->word_diff)
2058                        free_diff_words_data(&ecbdata);
2059                if (textconv_one)
2060                        free(mf1.ptr);
2061                if (textconv_two)
2062                        free(mf2.ptr);
2063                xdiff_clear_find_func(&xecfg);
2064        }
2065
2066 free_ab_and_return:
2067        strbuf_release(&header);
2068        diff_free_filespec_data(one);
2069        diff_free_filespec_data(two);
2070        free(a_one);
2071        free(b_two);
2072        return;
2073}
2074
2075static void builtin_diffstat(const char *name_a, const char *name_b,
2076                             struct diff_filespec *one,
2077                             struct diff_filespec *two,
2078                             struct diffstat_t *diffstat,
2079                             struct diff_options *o,
2080                             int complete_rewrite)
2081{
2082        mmfile_t mf1, mf2;
2083        struct diffstat_file *data;
2084
2085        data = diffstat_add(diffstat, name_a, name_b);
2086
2087        if (!one || !two) {
2088                data->is_unmerged = 1;
2089                return;
2090        }
2091
2092        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2093                data->is_binary = 1;
2094                data->added = diff_filespec_size(two);
2095                data->deleted = diff_filespec_size(one);
2096        }
2097
2098        else if (complete_rewrite) {
2099                diff_populate_filespec(one, 0);
2100                diff_populate_filespec(two, 0);
2101                data->deleted = count_lines(one->data, one->size);
2102                data->added = count_lines(two->data, two->size);
2103        }
2104
2105        else {
2106                /* Crazy xdl interfaces.. */
2107                xpparam_t xpp;
2108                xdemitconf_t xecfg;
2109
2110                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2111                        die("unable to read files to diff");
2112
2113                memset(&xpp, 0, sizeof(xpp));
2114                memset(&xecfg, 0, sizeof(xecfg));
2115                xpp.flags = o->xdl_opts;
2116                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2117                              &xpp, &xecfg);
2118        }
2119
2120        diff_free_filespec_data(one);
2121        diff_free_filespec_data(two);
2122}
2123
2124static void builtin_checkdiff(const char *name_a, const char *name_b,
2125                              const char *attr_path,
2126                              struct diff_filespec *one,
2127                              struct diff_filespec *two,
2128                              struct diff_options *o)
2129{
2130        mmfile_t mf1, mf2;
2131        struct checkdiff_t data;
2132
2133        if (!two)
2134                return;
2135
2136        memset(&data, 0, sizeof(data));
2137        data.filename = name_b ? name_b : name_a;
2138        data.lineno = 0;
2139        data.o = o;
2140        data.ws_rule = whitespace_rule(attr_path);
2141        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2142
2143        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2144                die("unable to read files to diff");
2145
2146        /*
2147         * All the other codepaths check both sides, but not checking
2148         * the "old" side here is deliberate.  We are checking the newly
2149         * introduced changes, and as long as the "new" side is text, we
2150         * can and should check what it introduces.
2151         */
2152        if (diff_filespec_is_binary(two))
2153                goto free_and_return;
2154        else {
2155                /* Crazy xdl interfaces.. */
2156                xpparam_t xpp;
2157                xdemitconf_t xecfg;
2158
2159                memset(&xpp, 0, sizeof(xpp));
2160                memset(&xecfg, 0, sizeof(xecfg));
2161                xecfg.ctxlen = 1; /* at least one context line */
2162                xpp.flags = 0;
2163                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2164                              &xpp, &xecfg);
2165
2166                if (data.ws_rule & WS_BLANK_AT_EOF) {
2167                        struct emit_callback ecbdata;
2168                        int blank_at_eof;
2169
2170                        ecbdata.ws_rule = data.ws_rule;
2171                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2172                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2173
2174                        if (blank_at_eof) {
2175                                static char *err;
2176                                if (!err)
2177                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2178                                fprintf(o->file, "%s:%d: %s.\n",
2179                                        data.filename, blank_at_eof, err);
2180                                data.status = 1; /* report errors */
2181                        }
2182                }
2183        }
2184 free_and_return:
2185        diff_free_filespec_data(one);
2186        diff_free_filespec_data(two);
2187        if (data.status)
2188                DIFF_OPT_SET(o, CHECK_FAILED);
2189}
2190
2191struct diff_filespec *alloc_filespec(const char *path)
2192{
2193        int namelen = strlen(path);
2194        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2195
2196        memset(spec, 0, sizeof(*spec));
2197        spec->path = (char *)(spec + 1);
2198        memcpy(spec->path, path, namelen+1);
2199        spec->count = 1;
2200        spec->is_binary = -1;
2201        return spec;
2202}
2203
2204void free_filespec(struct diff_filespec *spec)
2205{
2206        if (!--spec->count) {
2207                diff_free_filespec_data(spec);
2208                free(spec);
2209        }
2210}
2211
2212void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2213                   unsigned short mode)
2214{
2215        if (mode) {
2216                spec->mode = canon_mode(mode);
2217                hashcpy(spec->sha1, sha1);
2218                spec->sha1_valid = !is_null_sha1(sha1);
2219        }
2220}
2221
2222/*
2223 * Given a name and sha1 pair, if the index tells us the file in
2224 * the work tree has that object contents, return true, so that
2225 * prepare_temp_file() does not have to inflate and extract.
2226 */
2227static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2228{
2229        struct cache_entry *ce;
2230        struct stat st;
2231        int pos, len;
2232
2233        /*
2234         * We do not read the cache ourselves here, because the
2235         * benchmark with my previous version that always reads cache
2236         * shows that it makes things worse for diff-tree comparing
2237         * two linux-2.6 kernel trees in an already checked out work
2238         * tree.  This is because most diff-tree comparisons deal with
2239         * only a small number of files, while reading the cache is
2240         * expensive for a large project, and its cost outweighs the
2241         * savings we get by not inflating the object to a temporary
2242         * file.  Practically, this code only helps when we are used
2243         * by diff-cache --cached, which does read the cache before
2244         * calling us.
2245         */
2246        if (!active_cache)
2247                return 0;
2248
2249        /* We want to avoid the working directory if our caller
2250         * doesn't need the data in a normal file, this system
2251         * is rather slow with its stat/open/mmap/close syscalls,
2252         * and the object is contained in a pack file.  The pack
2253         * is probably already open and will be faster to obtain
2254         * the data through than the working directory.  Loose
2255         * objects however would tend to be slower as they need
2256         * to be individually opened and inflated.
2257         */
2258        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2259                return 0;
2260
2261        len = strlen(name);
2262        pos = cache_name_pos(name, len);
2263        if (pos < 0)
2264                return 0;
2265        ce = active_cache[pos];
2266
2267        /*
2268         * This is not the sha1 we are looking for, or
2269         * unreusable because it is not a regular file.
2270         */
2271        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2272                return 0;
2273
2274        /*
2275         * If ce is marked as "assume unchanged", there is no
2276         * guarantee that work tree matches what we are looking for.
2277         */
2278        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2279                return 0;
2280
2281        /*
2282         * If ce matches the file in the work tree, we can reuse it.
2283         */
2284        if (ce_uptodate(ce) ||
2285            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2286                return 1;
2287
2288        return 0;
2289}
2290
2291static int populate_from_stdin(struct diff_filespec *s)
2292{
2293        struct strbuf buf = STRBUF_INIT;
2294        size_t size = 0;
2295
2296        if (strbuf_read(&buf, 0, 0) < 0)
2297                return error("error while reading from stdin %s",
2298                                     strerror(errno));
2299
2300        s->should_munmap = 0;
2301        s->data = strbuf_detach(&buf, &size);
2302        s->size = size;
2303        s->should_free = 1;
2304        return 0;
2305}
2306
2307static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2308{
2309        int len;
2310        char *data = xmalloc(100), *dirty = "";
2311
2312        /* Are we looking at the work tree? */
2313        if (s->dirty_submodule)
2314                dirty = "-dirty";
2315
2316        len = snprintf(data, 100,
2317                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2318        s->data = data;
2319        s->size = len;
2320        s->should_free = 1;
2321        if (size_only) {
2322                s->data = NULL;
2323                free(data);
2324        }
2325        return 0;
2326}
2327
2328/*
2329 * While doing rename detection and pickaxe operation, we may need to
2330 * grab the data for the blob (or file) for our own in-core comparison.
2331 * diff_filespec has data and size fields for this purpose.
2332 */
2333int diff_populate_filespec(struct diff_filespec *s, int size_only)
2334{
2335        int err = 0;
2336        if (!DIFF_FILE_VALID(s))
2337                die("internal error: asking to populate invalid file.");
2338        if (S_ISDIR(s->mode))
2339                return -1;
2340
2341        if (s->data)
2342                return 0;
2343
2344        if (size_only && 0 < s->size)
2345                return 0;
2346
2347        if (S_ISGITLINK(s->mode))
2348                return diff_populate_gitlink(s, size_only);
2349
2350        if (!s->sha1_valid ||
2351            reuse_worktree_file(s->path, s->sha1, 0)) {
2352                struct strbuf buf = STRBUF_INIT;
2353                struct stat st;
2354                int fd;
2355
2356                if (!strcmp(s->path, "-"))
2357                        return populate_from_stdin(s);
2358
2359                if (lstat(s->path, &st) < 0) {
2360                        if (errno == ENOENT) {
2361                        err_empty:
2362                                err = -1;
2363                        empty:
2364                                s->data = (char *)"";
2365                                s->size = 0;
2366                                return err;
2367                        }
2368                }
2369                s->size = xsize_t(st.st_size);
2370                if (!s->size)
2371                        goto empty;
2372                if (S_ISLNK(st.st_mode)) {
2373                        struct strbuf sb = STRBUF_INIT;
2374
2375                        if (strbuf_readlink(&sb, s->path, s->size))
2376                                goto err_empty;
2377                        s->size = sb.len;
2378                        s->data = strbuf_detach(&sb, NULL);
2379                        s->should_free = 1;
2380                        return 0;
2381                }
2382                if (size_only)
2383                        return 0;
2384                fd = open(s->path, O_RDONLY);
2385                if (fd < 0)
2386                        goto err_empty;
2387                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2388                close(fd);
2389                s->should_munmap = 1;
2390
2391                /*
2392                 * Convert from working tree format to canonical git format
2393                 */
2394                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2395                        size_t size = 0;
2396                        munmap(s->data, s->size);
2397                        s->should_munmap = 0;
2398                        s->data = strbuf_detach(&buf, &size);
2399                        s->size = size;
2400                        s->should_free = 1;
2401                }
2402        }
2403        else {
2404                enum object_type type;
2405                if (size_only) {
2406                        type = sha1_object_info(s->sha1, &s->size);
2407                        if (type < 0)
2408                                die("unable to read %s", sha1_to_hex(s->sha1));
2409                } else {
2410                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2411                        if (!s->data)
2412                                die("unable to read %s", sha1_to_hex(s->sha1));
2413                        s->should_free = 1;
2414                }
2415        }
2416        return 0;
2417}
2418
2419void diff_free_filespec_blob(struct diff_filespec *s)
2420{
2421        if (s->should_free)
2422                free(s->data);
2423        else if (s->should_munmap)
2424                munmap(s->data, s->size);
2425
2426        if (s->should_free || s->should_munmap) {
2427                s->should_free = s->should_munmap = 0;
2428                s->data = NULL;
2429        }
2430}
2431
2432void diff_free_filespec_data(struct diff_filespec *s)
2433{
2434        diff_free_filespec_blob(s);
2435        free(s->cnt_data);
2436        s->cnt_data = NULL;
2437}
2438
2439static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2440                           void *blob,
2441                           unsigned long size,
2442                           const unsigned char *sha1,
2443                           int mode)
2444{
2445        int fd;
2446        struct strbuf buf = STRBUF_INIT;
2447        struct strbuf template = STRBUF_INIT;
2448        char *path_dup = xstrdup(path);
2449        const char *base = basename(path_dup);
2450
2451        /* Generate "XXXXXX_basename.ext" */
2452        strbuf_addstr(&template, "XXXXXX_");
2453        strbuf_addstr(&template, base);
2454
2455        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2456                        strlen(base) + 1);
2457        if (fd < 0)
2458                die_errno("unable to create temp-file");
2459        if (convert_to_working_tree(path,
2460                        (const char *)blob, (size_t)size, &buf)) {
2461                blob = buf.buf;
2462                size = buf.len;
2463        }
2464        if (write_in_full(fd, blob, size) != size)
2465                die_errno("unable to write temp-file");
2466        close(fd);
2467        temp->name = temp->tmp_path;
2468        strcpy(temp->hex, sha1_to_hex(sha1));
2469        temp->hex[40] = 0;
2470        sprintf(temp->mode, "%06o", mode);
2471        strbuf_release(&buf);
2472        strbuf_release(&template);
2473        free(path_dup);
2474}
2475
2476static struct diff_tempfile *prepare_temp_file(const char *name,
2477                struct diff_filespec *one)
2478{
2479        struct diff_tempfile *temp = claim_diff_tempfile();
2480
2481        if (!DIFF_FILE_VALID(one)) {
2482        not_a_valid_file:
2483                /* A '-' entry produces this for file-2, and
2484                 * a '+' entry produces this for file-1.
2485                 */
2486                temp->name = "/dev/null";
2487                strcpy(temp->hex, ".");
2488                strcpy(temp->mode, ".");
2489                return temp;
2490        }
2491
2492        if (!remove_tempfile_installed) {
2493                atexit(remove_tempfile);
2494                sigchain_push_common(remove_tempfile_on_signal);
2495                remove_tempfile_installed = 1;
2496        }
2497
2498        if (!one->sha1_valid ||
2499            reuse_worktree_file(name, one->sha1, 1)) {
2500                struct stat st;
2501                if (lstat(name, &st) < 0) {
2502                        if (errno == ENOENT)
2503                                goto not_a_valid_file;
2504                        die_errno("stat(%s)", name);
2505                }
2506                if (S_ISLNK(st.st_mode)) {
2507                        struct strbuf sb = STRBUF_INIT;
2508                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2509                                die_errno("readlink(%s)", name);
2510                        prep_temp_blob(name, temp, sb.buf, sb.len,
2511                                       (one->sha1_valid ?
2512                                        one->sha1 : null_sha1),
2513                                       (one->sha1_valid ?
2514                                        one->mode : S_IFLNK));
2515                        strbuf_release(&sb);
2516                }
2517                else {
2518                        /* we can borrow from the file in the work tree */
2519                        temp->name = name;
2520                        if (!one->sha1_valid)
2521                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2522                        else
2523                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2524                        /* Even though we may sometimes borrow the
2525                         * contents from the work tree, we always want
2526                         * one->mode.  mode is trustworthy even when
2527                         * !(one->sha1_valid), as long as
2528                         * DIFF_FILE_VALID(one).
2529                         */
2530                        sprintf(temp->mode, "%06o", one->mode);
2531                }
2532                return temp;
2533        }
2534        else {
2535                if (diff_populate_filespec(one, 0))
2536                        die("cannot read data blob for %s", one->path);
2537                prep_temp_blob(name, temp, one->data, one->size,
2538                               one->sha1, one->mode);
2539        }
2540        return temp;
2541}
2542
2543/* An external diff command takes:
2544 *
2545 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2546 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2547 *
2548 */
2549static void run_external_diff(const char *pgm,
2550                              const char *name,
2551                              const char *other,
2552                              struct diff_filespec *one,
2553                              struct diff_filespec *two,
2554                              const char *xfrm_msg,
2555                              int complete_rewrite)
2556{
2557        const char *spawn_arg[10];
2558        int retval;
2559        const char **arg = &spawn_arg[0];
2560
2561        if (one && two) {
2562                struct diff_tempfile *temp_one, *temp_two;
2563                const char *othername = (other ? other : name);
2564                temp_one = prepare_temp_file(name, one);
2565                temp_two = prepare_temp_file(othername, two);
2566                *arg++ = pgm;
2567                *arg++ = name;
2568                *arg++ = temp_one->name;
2569                *arg++ = temp_one->hex;
2570                *arg++ = temp_one->mode;
2571                *arg++ = temp_two->name;
2572                *arg++ = temp_two->hex;
2573                *arg++ = temp_two->mode;
2574                if (other) {
2575                        *arg++ = other;
2576                        *arg++ = xfrm_msg;
2577                }
2578        } else {
2579                *arg++ = pgm;
2580                *arg++ = name;
2581        }
2582        *arg = NULL;
2583        fflush(NULL);
2584        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2585        remove_tempfile();
2586        if (retval) {
2587                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2588                exit(1);
2589        }
2590}
2591
2592static int similarity_index(struct diff_filepair *p)
2593{
2594        return p->score * 100 / MAX_SCORE;
2595}
2596
2597static void fill_metainfo(struct strbuf *msg,
2598                          const char *name,
2599                          const char *other,
2600                          struct diff_filespec *one,
2601                          struct diff_filespec *two,
2602                          struct diff_options *o,
2603                          struct diff_filepair *p,
2604                          int *must_show_header,
2605                          int use_color)
2606{
2607        const char *set = diff_get_color(use_color, DIFF_METAINFO);
2608        const char *reset = diff_get_color(use_color, DIFF_RESET);
2609        struct strbuf *msgbuf;
2610        char *line_prefix = "";
2611
2612        *must_show_header = 1;
2613        if (o->output_prefix) {
2614                msgbuf = o->output_prefix(o, o->output_prefix_data);
2615                line_prefix = msgbuf->buf;
2616        }
2617        strbuf_init(msg, PATH_MAX * 2 + 300);
2618        switch (p->status) {
2619        case DIFF_STATUS_COPIED:
2620                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2621                            line_prefix, set, similarity_index(p));
2622                strbuf_addf(msg, "%s\n%s%scopy from ",
2623                            reset,  line_prefix, set);
2624                quote_c_style(name, msg, NULL, 0);
2625                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2626                quote_c_style(other, msg, NULL, 0);
2627                strbuf_addf(msg, "%s\n", reset);
2628                break;
2629        case DIFF_STATUS_RENAMED:
2630                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2631                            line_prefix, set, similarity_index(p));
2632                strbuf_addf(msg, "%s\n%s%srename from ",
2633                            reset, line_prefix, set);
2634                quote_c_style(name, msg, NULL, 0);
2635                strbuf_addf(msg, "%s\n%s%srename to ",
2636                            reset, line_prefix, set);
2637                quote_c_style(other, msg, NULL, 0);
2638                strbuf_addf(msg, "%s\n", reset);
2639                break;
2640        case DIFF_STATUS_MODIFIED:
2641                if (p->score) {
2642                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2643                                    line_prefix,
2644                                    set, similarity_index(p), reset);
2645                        break;
2646                }
2647                /* fallthru */
2648        default:
2649                *must_show_header = 0;
2650        }
2651        if (one && two && hashcmp(one->sha1, two->sha1)) {
2652                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2653
2654                if (DIFF_OPT_TST(o, BINARY)) {
2655                        mmfile_t mf;
2656                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2657                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2658                                abbrev = 40;
2659                }
2660                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2661                            find_unique_abbrev(one->sha1, abbrev));
2662                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2663                if (one->mode == two->mode)
2664                        strbuf_addf(msg, " %06o", one->mode);
2665                strbuf_addf(msg, "%s\n", reset);
2666        }
2667}
2668
2669static void run_diff_cmd(const char *pgm,
2670                         const char *name,
2671                         const char *other,
2672                         const char *attr_path,
2673                         struct diff_filespec *one,
2674                         struct diff_filespec *two,
2675                         struct strbuf *msg,
2676                         struct diff_options *o,
2677                         struct diff_filepair *p)
2678{
2679        const char *xfrm_msg = NULL;
2680        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2681        int must_show_header = 0;
2682
2683        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2684                pgm = NULL;
2685        else {
2686                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2687                if (drv && drv->external)
2688                        pgm = drv->external;
2689        }
2690
2691        if (msg) {
2692                /*
2693                 * don't use colors when the header is intended for an
2694                 * external diff driver
2695                 */
2696                fill_metainfo(msg, name, other, one, two, o, p,
2697                              &must_show_header,
2698                              DIFF_OPT_TST(o, COLOR_DIFF) && !pgm);
2699                xfrm_msg = msg->len ? msg->buf : NULL;
2700        }
2701
2702        if (pgm) {
2703                run_external_diff(pgm, name, other, one, two, xfrm_msg,
2704                                  complete_rewrite);
2705                return;
2706        }
2707        if (one && two)
2708                builtin_diff(name, other ? other : name,
2709                             one, two, xfrm_msg, must_show_header,
2710                             o, complete_rewrite);
2711        else
2712                fprintf(o->file, "* Unmerged path %s\n", name);
2713}
2714
2715static void diff_fill_sha1_info(struct diff_filespec *one)
2716{
2717        if (DIFF_FILE_VALID(one)) {
2718                if (!one->sha1_valid) {
2719                        struct stat st;
2720                        if (!strcmp(one->path, "-")) {
2721                                hashcpy(one->sha1, null_sha1);
2722                                return;
2723                        }
2724                        if (lstat(one->path, &st) < 0)
2725                                die_errno("stat '%s'", one->path);
2726                        if (index_path(one->sha1, one->path, &st, 0))
2727                                die("cannot hash %s", one->path);
2728                }
2729        }
2730        else
2731                hashclr(one->sha1);
2732}
2733
2734static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2735{
2736        /* Strip the prefix but do not molest /dev/null and absolute paths */
2737        if (*namep && **namep != '/') {
2738                *namep += prefix_length;
2739                if (**namep == '/')
2740                        ++*namep;
2741        }
2742        if (*otherp && **otherp != '/') {
2743                *otherp += prefix_length;
2744                if (**otherp == '/')
2745                        ++*otherp;
2746        }
2747}
2748
2749static void run_diff(struct diff_filepair *p, struct diff_options *o)
2750{
2751        const char *pgm = external_diff();
2752        struct strbuf msg;
2753        struct diff_filespec *one = p->one;
2754        struct diff_filespec *two = p->two;
2755        const char *name;
2756        const char *other;
2757        const char *attr_path;
2758
2759        name  = p->one->path;
2760        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2761        attr_path = name;
2762        if (o->prefix_length)
2763                strip_prefix(o->prefix_length, &name, &other);
2764
2765        if (DIFF_PAIR_UNMERGED(p)) {
2766                run_diff_cmd(pgm, name, NULL, attr_path,
2767                             NULL, NULL, NULL, o, p);
2768                return;
2769        }
2770
2771        diff_fill_sha1_info(one);
2772        diff_fill_sha1_info(two);
2773
2774        if (!pgm &&
2775            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2776            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2777                /*
2778                 * a filepair that changes between file and symlink
2779                 * needs to be split into deletion and creation.
2780                 */
2781                struct diff_filespec *null = alloc_filespec(two->path);
2782                run_diff_cmd(NULL, name, other, attr_path,
2783                             one, null, &msg, o, p);
2784                free(null);
2785                strbuf_release(&msg);
2786
2787                null = alloc_filespec(one->path);
2788                run_diff_cmd(NULL, name, other, attr_path,
2789                             null, two, &msg, o, p);
2790                free(null);
2791        }
2792        else
2793                run_diff_cmd(pgm, name, other, attr_path,
2794                             one, two, &msg, o, p);
2795
2796        strbuf_release(&msg);
2797}
2798
2799static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2800                         struct diffstat_t *diffstat)
2801{
2802        const char *name;
2803        const char *other;
2804        int complete_rewrite = 0;
2805
2806        if (DIFF_PAIR_UNMERGED(p)) {
2807                /* unmerged */
2808                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2809                return;
2810        }
2811
2812        name = p->one->path;
2813        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2814
2815        if (o->prefix_length)
2816                strip_prefix(o->prefix_length, &name, &other);
2817
2818        diff_fill_sha1_info(p->one);
2819        diff_fill_sha1_info(p->two);
2820
2821        if (p->status == DIFF_STATUS_MODIFIED && p->score)
2822                complete_rewrite = 1;
2823        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2824}
2825
2826static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2827{
2828        const char *name;
2829        const char *other;
2830        const char *attr_path;
2831
2832        if (DIFF_PAIR_UNMERGED(p)) {
2833                /* unmerged */
2834                return;
2835        }
2836
2837        name = p->one->path;
2838        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2839        attr_path = other ? other : name;
2840
2841        if (o->prefix_length)
2842                strip_prefix(o->prefix_length, &name, &other);
2843
2844        diff_fill_sha1_info(p->one);
2845        diff_fill_sha1_info(p->two);
2846
2847        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2848}
2849
2850void diff_setup(struct diff_options *options)
2851{
2852        memcpy(options, &default_diff_options, sizeof(*options));
2853
2854        options->file = stdout;
2855
2856        options->line_termination = '\n';
2857        options->break_opt = -1;
2858        options->rename_limit = -1;
2859        options->dirstat_percent = 3;
2860        options->context = 3;
2861
2862        options->change = diff_change;
2863        options->add_remove = diff_addremove;
2864        if (diff_use_color_default > 0)
2865                DIFF_OPT_SET(options, COLOR_DIFF);
2866        options->detect_rename = diff_detect_rename_default;
2867
2868        if (diff_no_prefix) {
2869                options->a_prefix = options->b_prefix = "";
2870        } else if (!diff_mnemonic_prefix) {
2871                options->a_prefix = "a/";
2872                options->b_prefix = "b/";
2873        }
2874}
2875
2876int diff_setup_done(struct diff_options *options)
2877{
2878        int count = 0;
2879
2880        if (options->output_format & DIFF_FORMAT_NAME)
2881                count++;
2882        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
2883                count++;
2884        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
2885                count++;
2886        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
2887                count++;
2888        if (count > 1)
2889                die("--name-only, --name-status, --check and -s are mutually exclusive");
2890
2891        /*
2892         * Most of the time we can say "there are changes"
2893         * only by checking if there are changed paths, but
2894         * --ignore-whitespace* options force us to look
2895         * inside contents.
2896         */
2897
2898        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
2899            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
2900            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
2901                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
2902        else
2903                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
2904
2905        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
2906                options->detect_rename = DIFF_DETECT_COPY;
2907
2908        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
2909                options->prefix = NULL;
2910        if (options->prefix)
2911                options->prefix_length = strlen(options->prefix);
2912        else
2913                options->prefix_length = 0;
2914
2915        if (options->output_format & (DIFF_FORMAT_NAME |
2916                                      DIFF_FORMAT_NAME_STATUS |
2917                                      DIFF_FORMAT_CHECKDIFF |
2918                                      DIFF_FORMAT_NO_OUTPUT))
2919                options->output_format &= ~(DIFF_FORMAT_RAW |
2920                                            DIFF_FORMAT_NUMSTAT |
2921                                            DIFF_FORMAT_DIFFSTAT |
2922                                            DIFF_FORMAT_SHORTSTAT |
2923                                            DIFF_FORMAT_DIRSTAT |
2924                                            DIFF_FORMAT_SUMMARY |
2925                                            DIFF_FORMAT_PATCH);
2926
2927        /*
2928         * These cases always need recursive; we do not drop caller-supplied
2929         * recursive bits for other formats here.
2930         */
2931        if (options->output_format & (DIFF_FORMAT_PATCH |
2932                                      DIFF_FORMAT_NUMSTAT |
2933                                      DIFF_FORMAT_DIFFSTAT |
2934                                      DIFF_FORMAT_SHORTSTAT |
2935                                      DIFF_FORMAT_DIRSTAT |
2936                                      DIFF_FORMAT_SUMMARY |
2937                                      DIFF_FORMAT_CHECKDIFF))
2938                DIFF_OPT_SET(options, RECURSIVE);
2939        /*
2940         * Also pickaxe would not work very well if you do not say recursive
2941         */
2942        if (options->pickaxe)
2943                DIFF_OPT_SET(options, RECURSIVE);
2944        /*
2945         * When patches are generated, submodules diffed against the work tree
2946         * must be checked for dirtiness too so it can be shown in the output
2947         */
2948        if (options->output_format & DIFF_FORMAT_PATCH)
2949                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
2950
2951        if (options->detect_rename && options->rename_limit < 0)
2952                options->rename_limit = diff_rename_limit_default;
2953        if (options->setup & DIFF_SETUP_USE_CACHE) {
2954                if (!active_cache)
2955                        /* read-cache does not die even when it fails
2956                         * so it is safe for us to do this here.  Also
2957                         * it does not smudge active_cache or active_nr
2958                         * when it fails, so we do not have to worry about
2959                         * cleaning it up ourselves either.
2960                         */
2961                        read_cache();
2962        }
2963        if (options->abbrev <= 0 || 40 < options->abbrev)
2964                options->abbrev = 40; /* full */
2965
2966        /*
2967         * It does not make sense to show the first hit we happened
2968         * to have found.  It does not make sense not to return with
2969         * exit code in such a case either.
2970         */
2971        if (DIFF_OPT_TST(options, QUICK)) {
2972                options->output_format = DIFF_FORMAT_NO_OUTPUT;
2973                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2974        }
2975
2976        return 0;
2977}
2978
2979static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
2980{
2981        char c, *eq;
2982        int len;
2983
2984        if (*arg != '-')
2985                return 0;
2986        c = *++arg;
2987        if (!c)
2988                return 0;
2989        if (c == arg_short) {
2990                c = *++arg;
2991                if (!c)
2992                        return 1;
2993                if (val && isdigit(c)) {
2994                        char *end;
2995                        int n = strtoul(arg, &end, 10);
2996                        if (*end)
2997                                return 0;
2998                        *val = n;
2999                        return 1;
3000                }
3001                return 0;
3002        }
3003        if (c != '-')
3004                return 0;
3005        arg++;
3006        eq = strchr(arg, '=');
3007        if (eq)
3008                len = eq - arg;
3009        else
3010                len = strlen(arg);
3011        if (!len || strncmp(arg, arg_long, len))
3012                return 0;
3013        if (eq) {
3014                int n;
3015                char *end;
3016                if (!isdigit(*++eq))
3017                        return 0;
3018                n = strtoul(eq, &end, 10);
3019                if (*end)
3020                        return 0;
3021                *val = n;
3022        }
3023        return 1;
3024}
3025
3026static int diff_scoreopt_parse(const char *opt);
3027
3028static inline int short_opt(char opt, const char **argv,
3029                            const char **optarg)
3030{
3031        const char *arg = argv[0];
3032        if (arg[0] != '-' || arg[1] != opt)
3033                return 0;
3034        if (arg[2] != '\0') {
3035                *optarg = arg + 2;
3036                return 1;
3037        }
3038        if (!argv[1])
3039                die("Option '%c' requires a value", opt);
3040        *optarg = argv[1];
3041        return 2;
3042}
3043
3044int parse_long_opt(const char *opt, const char **argv,
3045                   const char **optarg)
3046{
3047        const char *arg = argv[0];
3048        if (arg[0] != '-' || arg[1] != '-')
3049                return 0;
3050        arg += strlen("--");
3051        if (prefixcmp(arg, opt))
3052                return 0;
3053        arg += strlen(opt);
3054        if (*arg == '=') { /* sticked form: --option=value */
3055                *optarg = arg + 1;
3056                return 1;
3057        }
3058        if (*arg != '\0')
3059                return 0;
3060        /* separate form: --option value */
3061        if (!argv[1])
3062                die("Option '--%s' requires a value", opt);
3063        *optarg = argv[1];
3064        return 2;
3065}
3066
3067static int stat_opt(struct diff_options *options, const char **av)
3068{
3069        const char *arg = av[0];
3070        char *end;
3071        int width = options->stat_width;
3072        int name_width = options->stat_name_width;
3073        int argcount = 1;
3074
3075        arg += strlen("--stat");
3076        end = (char *)arg;
3077
3078        switch (*arg) {
3079        case '-':
3080                if (!prefixcmp(arg, "-width")) {
3081                        arg += strlen("-width");
3082                        if (*arg == '=')
3083                                width = strtoul(arg + 1, &end, 10);
3084                        else if (!*arg && !av[1])
3085                                die("Option '--stat-width' requires a value");
3086                        else if (!*arg) {
3087                                width = strtoul(av[1], &end, 10);
3088                                argcount = 2;
3089                        }
3090                } else if (!prefixcmp(arg, "-name-width")) {
3091                        arg += strlen("-name-width");
3092                        if (*arg == '=')
3093                                name_width = strtoul(arg + 1, &end, 10);
3094                        else if (!*arg && !av[1])
3095                                die("Option '--stat-name-width' requires a value");
3096                        else if (!*arg) {
3097                                name_width = strtoul(av[1], &end, 10);
3098                                argcount = 2;
3099                        }
3100                }
3101                break;
3102        case '=':
3103                width = strtoul(arg+1, &end, 10);
3104                if (*end == ',')
3105                        name_width = strtoul(end+1, &end, 10);
3106        }
3107
3108        /* Important! This checks all the error cases! */
3109        if (*end)
3110                return 0;
3111        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3112        options->stat_name_width = name_width;
3113        options->stat_width = width;
3114        return argcount;
3115}
3116
3117int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3118{
3119        const char *arg = av[0];
3120        const char *optarg;
3121        int argcount;
3122
3123        /* Output format options */
3124        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3125                options->output_format |= DIFF_FORMAT_PATCH;
3126        else if (opt_arg(arg, 'U', "unified", &options->context))
3127                options->output_format |= DIFF_FORMAT_PATCH;
3128        else if (!strcmp(arg, "--raw"))
3129                options->output_format |= DIFF_FORMAT_RAW;
3130        else if (!strcmp(arg, "--patch-with-raw"))
3131                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3132        else if (!strcmp(arg, "--numstat"))
3133                options->output_format |= DIFF_FORMAT_NUMSTAT;
3134        else if (!strcmp(arg, "--shortstat"))
3135                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3136        else if (opt_arg(arg, 'X', "dirstat", &options->dirstat_percent))
3137                options->output_format |= DIFF_FORMAT_DIRSTAT;
3138        else if (!strcmp(arg, "--cumulative")) {
3139                options->output_format |= DIFF_FORMAT_DIRSTAT;
3140                DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
3141        } else if (opt_arg(arg, 0, "dirstat-by-file",
3142                           &options->dirstat_percent)) {
3143                options->output_format |= DIFF_FORMAT_DIRSTAT;
3144                DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
3145        }
3146        else if (!strcmp(arg, "--check"))
3147                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3148        else if (!strcmp(arg, "--summary"))
3149                options->output_format |= DIFF_FORMAT_SUMMARY;
3150        else if (!strcmp(arg, "--patch-with-stat"))
3151                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3152        else if (!strcmp(arg, "--name-only"))
3153                options->output_format |= DIFF_FORMAT_NAME;
3154        else if (!strcmp(arg, "--name-status"))
3155                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3156        else if (!strcmp(arg, "-s"))
3157                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3158        else if (!prefixcmp(arg, "--stat"))
3159                /* --stat, --stat-width, or --stat-name-width */
3160                return stat_opt(options, av);
3161
3162        /* renames options */
3163        else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
3164                 !strcmp(arg, "--break-rewrites")) {
3165                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3166                        return error("invalid argument to -B: %s", arg+2);
3167        }
3168        else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--find-renames=") ||
3169                 !strcmp(arg, "--find-renames")) {
3170                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3171                        return error("invalid argument to -M: %s", arg+2);
3172                options->detect_rename = DIFF_DETECT_RENAME;
3173        }
3174        else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
3175                 !strcmp(arg, "--find-copies")) {
3176                if (options->detect_rename == DIFF_DETECT_COPY)
3177                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3178                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3179                        return error("invalid argument to -C: %s", arg+2);
3180                options->detect_rename = DIFF_DETECT_COPY;
3181        }
3182        else if (!strcmp(arg, "--no-renames"))
3183                options->detect_rename = 0;
3184        else if (!strcmp(arg, "--relative"))
3185                DIFF_OPT_SET(options, RELATIVE_NAME);
3186        else if (!prefixcmp(arg, "--relative=")) {
3187                DIFF_OPT_SET(options, RELATIVE_NAME);
3188                options->prefix = arg + 11;
3189        }
3190
3191        /* xdiff options */
3192        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3193                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3194        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3195                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3196        else if (!strcmp(arg, "--ignore-space-at-eol"))
3197                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3198        else if (!strcmp(arg, "--patience"))
3199                DIFF_XDL_SET(options, PATIENCE_DIFF);
3200
3201        /* flags options */
3202        else if (!strcmp(arg, "--binary")) {
3203                options->output_format |= DIFF_FORMAT_PATCH;
3204                DIFF_OPT_SET(options, BINARY);
3205        }
3206        else if (!strcmp(arg, "--full-index"))
3207                DIFF_OPT_SET(options, FULL_INDEX);
3208        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3209                DIFF_OPT_SET(options, TEXT);
3210        else if (!strcmp(arg, "-R"))
3211                DIFF_OPT_SET(options, REVERSE_DIFF);
3212        else if (!strcmp(arg, "--find-copies-harder"))
3213                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3214        else if (!strcmp(arg, "--follow"))
3215                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3216        else if (!strcmp(arg, "--color"))
3217                DIFF_OPT_SET(options, COLOR_DIFF);
3218        else if (!prefixcmp(arg, "--color=")) {
3219                int value = git_config_colorbool(NULL, arg+8, -1);
3220                if (value == 0)
3221                        DIFF_OPT_CLR(options, COLOR_DIFF);
3222                else if (value > 0)
3223                        DIFF_OPT_SET(options, COLOR_DIFF);
3224                else
3225                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3226        }
3227        else if (!strcmp(arg, "--no-color"))
3228                DIFF_OPT_CLR(options, COLOR_DIFF);
3229        else if (!strcmp(arg, "--color-words")) {
3230                DIFF_OPT_SET(options, COLOR_DIFF);
3231                options->word_diff = DIFF_WORDS_COLOR;
3232        }
3233        else if (!prefixcmp(arg, "--color-words=")) {
3234                DIFF_OPT_SET(options, COLOR_DIFF);
3235                options->word_diff = DIFF_WORDS_COLOR;
3236                options->word_regex = arg + 14;
3237        }
3238        else if (!strcmp(arg, "--word-diff")) {
3239                if (options->word_diff == DIFF_WORDS_NONE)
3240                        options->word_diff = DIFF_WORDS_PLAIN;
3241        }
3242        else if (!prefixcmp(arg, "--word-diff=")) {
3243                const char *type = arg + 12;
3244                if (!strcmp(type, "plain"))
3245                        options->word_diff = DIFF_WORDS_PLAIN;
3246                else if (!strcmp(type, "color")) {
3247                        DIFF_OPT_SET(options, COLOR_DIFF);
3248                        options->word_diff = DIFF_WORDS_COLOR;
3249                }
3250                else if (!strcmp(type, "porcelain"))
3251                        options->word_diff = DIFF_WORDS_PORCELAIN;
3252                else if (!strcmp(type, "none"))
3253                        options->word_diff = DIFF_WORDS_NONE;
3254                else
3255                        die("bad --word-diff argument: %s", type);
3256        }
3257        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3258                if (options->word_diff == DIFF_WORDS_NONE)
3259                        options->word_diff = DIFF_WORDS_PLAIN;
3260                options->word_regex = optarg;
3261                return argcount;
3262        }
3263        else if (!strcmp(arg, "--exit-code"))
3264                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3265        else if (!strcmp(arg, "--quiet"))
3266                DIFF_OPT_SET(options, QUICK);
3267        else if (!strcmp(arg, "--ext-diff"))
3268                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3269        else if (!strcmp(arg, "--no-ext-diff"))
3270                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3271        else if (!strcmp(arg, "--textconv"))
3272                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3273        else if (!strcmp(arg, "--no-textconv"))
3274                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3275        else if (!strcmp(arg, "--ignore-submodules")) {
3276                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3277                handle_ignore_submodules_arg(options, "all");
3278        } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3279                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3280                handle_ignore_submodules_arg(options, arg + 20);
3281        } else if (!strcmp(arg, "--submodule"))
3282                DIFF_OPT_SET(options, SUBMODULE_LOG);
3283        else if (!prefixcmp(arg, "--submodule=")) {
3284                if (!strcmp(arg + 12, "log"))
3285                        DIFF_OPT_SET(options, SUBMODULE_LOG);
3286        }
3287
3288        /* misc options */
3289        else if (!strcmp(arg, "-z"))
3290                options->line_termination = 0;
3291        else if ((argcount = short_opt('l', av, &optarg))) {
3292                options->rename_limit = strtoul(optarg, NULL, 10);
3293                return argcount;
3294        }
3295        else if ((argcount = short_opt('S', av, &optarg))) {
3296                options->pickaxe = optarg;
3297                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3298                return argcount;
3299        } else if ((argcount = short_opt('G', av, &optarg))) {
3300                options->pickaxe = optarg;
3301                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3302                return argcount;
3303        }
3304        else if (!strcmp(arg, "--pickaxe-all"))
3305                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3306        else if (!strcmp(arg, "--pickaxe-regex"))
3307                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3308        else if ((argcount = short_opt('O', av, &optarg))) {
3309                options->orderfile = optarg;
3310                return argcount;
3311        }
3312        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3313                options->filter = optarg;
3314                return argcount;
3315        }
3316        else if (!strcmp(arg, "--abbrev"))
3317                options->abbrev = DEFAULT_ABBREV;
3318        else if (!prefixcmp(arg, "--abbrev=")) {
3319                options->abbrev = strtoul(arg + 9, NULL, 10);
3320                if (options->abbrev < MINIMUM_ABBREV)
3321                        options->abbrev = MINIMUM_ABBREV;
3322                else if (40 < options->abbrev)
3323                        options->abbrev = 40;
3324        }
3325        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3326                options->a_prefix = optarg;
3327                return argcount;
3328        }
3329        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3330                options->b_prefix = optarg;
3331                return argcount;
3332        }
3333        else if (!strcmp(arg, "--no-prefix"))
3334                options->a_prefix = options->b_prefix = "";
3335        else if (opt_arg(arg, '\0', "inter-hunk-context",
3336                         &options->interhunkcontext))
3337                ;
3338        else if ((argcount = parse_long_opt("output", av, &optarg))) {
3339                options->file = fopen(optarg, "w");
3340                if (!options->file)
3341                        die_errno("Could not open '%s'", optarg);
3342                options->close_file = 1;
3343                return argcount;
3344        } else
3345                return 0;
3346        return 1;
3347}
3348
3349int parse_rename_score(const char **cp_p)
3350{
3351        unsigned long num, scale;
3352        int ch, dot;
3353        const char *cp = *cp_p;
3354
3355        num = 0;
3356        scale = 1;
3357        dot = 0;
3358        for (;;) {
3359                ch = *cp;
3360                if ( !dot && ch == '.' ) {
3361                        scale = 1;
3362                        dot = 1;
3363                } else if ( ch == '%' ) {
3364                        scale = dot ? scale*100 : 100;
3365                        cp++;   /* % is always at the end */
3366                        break;
3367                } else if ( ch >= '0' && ch <= '9' ) {
3368                        if ( scale < 100000 ) {
3369                                scale *= 10;
3370                                num = (num*10) + (ch-'0');
3371                        }
3372                } else {
3373                        break;
3374                }
3375                cp++;
3376        }
3377        *cp_p = cp;
3378
3379        /* user says num divided by scale and we say internally that
3380         * is MAX_SCORE * num / scale.
3381         */
3382        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3383}
3384
3385static int diff_scoreopt_parse(const char *opt)
3386{
3387        int opt1, opt2, cmd;
3388
3389        if (*opt++ != '-')
3390                return -1;
3391        cmd = *opt++;
3392        if (cmd == '-') {
3393                /* convert the long-form arguments into short-form versions */
3394                if (!prefixcmp(opt, "break-rewrites")) {
3395                        opt += strlen("break-rewrites");
3396                        if (*opt == 0 || *opt++ == '=')
3397                                cmd = 'B';
3398                } else if (!prefixcmp(opt, "find-copies")) {
3399                        opt += strlen("find-copies");
3400                        if (*opt == 0 || *opt++ == '=')
3401                                cmd = 'C';
3402                } else if (!prefixcmp(opt, "find-renames")) {
3403                        opt += strlen("find-renames");
3404                        if (*opt == 0 || *opt++ == '=')
3405                                cmd = 'M';
3406                }
3407        }
3408        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3409                return -1; /* that is not a -M, -C nor -B option */
3410
3411        opt1 = parse_rename_score(&opt);
3412        if (cmd != 'B')
3413                opt2 = 0;
3414        else {
3415                if (*opt == 0)
3416                        opt2 = 0;
3417                else if (*opt != '/')
3418                        return -1; /* we expect -B80/99 or -B80 */
3419                else {
3420                        opt++;
3421                        opt2 = parse_rename_score(&opt);
3422                }
3423        }
3424        if (*opt != 0)
3425                return -1;
3426        return opt1 | (opt2 << 16);
3427}
3428
3429struct diff_queue_struct diff_queued_diff;
3430
3431void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3432{
3433        if (queue->alloc <= queue->nr) {
3434                queue->alloc = alloc_nr(queue->alloc);
3435                queue->queue = xrealloc(queue->queue,
3436                                        sizeof(dp) * queue->alloc);
3437        }
3438        queue->queue[queue->nr++] = dp;
3439}
3440
3441struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3442                                 struct diff_filespec *one,
3443                                 struct diff_filespec *two)
3444{
3445        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3446        dp->one = one;
3447        dp->two = two;
3448        if (queue)
3449                diff_q(queue, dp);
3450        return dp;
3451}
3452
3453void diff_free_filepair(struct diff_filepair *p)
3454{
3455        free_filespec(p->one);
3456        free_filespec(p->two);
3457        free(p);
3458}
3459
3460/* This is different from find_unique_abbrev() in that
3461 * it stuffs the result with dots for alignment.
3462 */
3463const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3464{
3465        int abblen;
3466        const char *abbrev;
3467        if (len == 40)
3468                return sha1_to_hex(sha1);
3469
3470        abbrev = find_unique_abbrev(sha1, len);
3471        abblen = strlen(abbrev);
3472        if (abblen < 37) {
3473                static char hex[41];
3474                if (len < abblen && abblen <= len + 2)
3475                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3476                else
3477                        sprintf(hex, "%s...", abbrev);
3478                return hex;
3479        }
3480        return sha1_to_hex(sha1);
3481}
3482
3483static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3484{
3485        int line_termination = opt->line_termination;
3486        int inter_name_termination = line_termination ? '\t' : '\0';
3487        if (opt->output_prefix) {
3488                struct strbuf *msg = NULL;
3489                msg = opt->output_prefix(opt, opt->output_prefix_data);
3490                fprintf(opt->file, "%s", msg->buf);
3491        }
3492
3493        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3494                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3495                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3496                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3497        }
3498        if (p->score) {
3499                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3500                        inter_name_termination);
3501        } else {
3502                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3503        }
3504
3505        if (p->status == DIFF_STATUS_COPIED ||
3506            p->status == DIFF_STATUS_RENAMED) {
3507                const char *name_a, *name_b;
3508                name_a = p->one->path;
3509                name_b = p->two->path;
3510                strip_prefix(opt->prefix_length, &name_a, &name_b);
3511                write_name_quoted(name_a, opt->file, inter_name_termination);
3512                write_name_quoted(name_b, opt->file, line_termination);
3513        } else {
3514                const char *name_a, *name_b;
3515                name_a = p->one->mode ? p->one->path : p->two->path;
3516                name_b = NULL;
3517                strip_prefix(opt->prefix_length, &name_a, &name_b);
3518                write_name_quoted(name_a, opt->file, line_termination);
3519        }
3520}
3521
3522int diff_unmodified_pair(struct diff_filepair *p)
3523{
3524        /* This function is written stricter than necessary to support
3525         * the currently implemented transformers, but the idea is to
3526         * let transformers to produce diff_filepairs any way they want,
3527         * and filter and clean them up here before producing the output.
3528         */
3529        struct diff_filespec *one = p->one, *two = p->two;
3530
3531        if (DIFF_PAIR_UNMERGED(p))
3532                return 0; /* unmerged is interesting */
3533
3534        /* deletion, addition, mode or type change
3535         * and rename are all interesting.
3536         */
3537        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3538            DIFF_PAIR_MODE_CHANGED(p) ||
3539            strcmp(one->path, two->path))
3540                return 0;
3541
3542        /* both are valid and point at the same path.  that is, we are
3543         * dealing with a change.
3544         */
3545        if (one->sha1_valid && two->sha1_valid &&
3546            !hashcmp(one->sha1, two->sha1) &&
3547            !one->dirty_submodule && !two->dirty_submodule)
3548                return 1; /* no change */
3549        if (!one->sha1_valid && !two->sha1_valid)
3550                return 1; /* both look at the same file on the filesystem. */
3551        return 0;
3552}
3553
3554static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3555{
3556        if (diff_unmodified_pair(p))
3557                return;
3558
3559        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3560            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3561                return; /* no tree diffs in patch format */
3562
3563        run_diff(p, o);
3564}
3565
3566static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3567                            struct diffstat_t *diffstat)
3568{
3569        if (diff_unmodified_pair(p))
3570                return;
3571
3572        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3573            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3574                return; /* no useful stat for tree diffs */
3575
3576        run_diffstat(p, o, diffstat);
3577}
3578
3579static void diff_flush_checkdiff(struct diff_filepair *p,
3580                struct diff_options *o)
3581{
3582        if (diff_unmodified_pair(p))
3583                return;
3584
3585        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3586            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3587                return; /* nothing to check in tree diffs */
3588
3589        run_checkdiff(p, o);
3590}
3591
3592int diff_queue_is_empty(void)
3593{
3594        struct diff_queue_struct *q = &diff_queued_diff;
3595        int i;
3596        for (i = 0; i < q->nr; i++)
3597                if (!diff_unmodified_pair(q->queue[i]))
3598                        return 0;
3599        return 1;
3600}
3601
3602#if DIFF_DEBUG
3603void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3604{
3605        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3606                x, one ? one : "",
3607                s->path,
3608                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3609                s->mode,
3610                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3611        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3612                x, one ? one : "",
3613                s->size, s->xfrm_flags);
3614}
3615
3616void diff_debug_filepair(const struct diff_filepair *p, int i)
3617{
3618        diff_debug_filespec(p->one, i, "one");
3619        diff_debug_filespec(p->two, i, "two");
3620        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3621                p->score, p->status ? p->status : '?',
3622                p->one->rename_used, p->broken_pair);
3623}
3624
3625void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3626{
3627        int i;
3628        if (msg)
3629                fprintf(stderr, "%s\n", msg);
3630        fprintf(stderr, "q->nr = %d\n", q->nr);
3631        for (i = 0; i < q->nr; i++) {
3632                struct diff_filepair *p = q->queue[i];
3633                diff_debug_filepair(p, i);
3634        }
3635}
3636#endif
3637
3638static void diff_resolve_rename_copy(void)
3639{
3640        int i;
3641        struct diff_filepair *p;
3642        struct diff_queue_struct *q = &diff_queued_diff;
3643
3644        diff_debug_queue("resolve-rename-copy", q);
3645
3646        for (i = 0; i < q->nr; i++) {
3647                p = q->queue[i];
3648                p->status = 0; /* undecided */
3649                if (DIFF_PAIR_UNMERGED(p))
3650                        p->status = DIFF_STATUS_UNMERGED;
3651                else if (!DIFF_FILE_VALID(p->one))
3652                        p->status = DIFF_STATUS_ADDED;
3653                else if (!DIFF_FILE_VALID(p->two))
3654                        p->status = DIFF_STATUS_DELETED;
3655                else if (DIFF_PAIR_TYPE_CHANGED(p))
3656                        p->status = DIFF_STATUS_TYPE_CHANGED;
3657
3658                /* from this point on, we are dealing with a pair
3659                 * whose both sides are valid and of the same type, i.e.
3660                 * either in-place edit or rename/copy edit.
3661                 */
3662                else if (DIFF_PAIR_RENAME(p)) {
3663                        /*
3664                         * A rename might have re-connected a broken
3665                         * pair up, causing the pathnames to be the
3666                         * same again. If so, that's not a rename at
3667                         * all, just a modification..
3668                         *
3669                         * Otherwise, see if this source was used for
3670                         * multiple renames, in which case we decrement
3671                         * the count, and call it a copy.
3672                         */
3673                        if (!strcmp(p->one->path, p->two->path))
3674                                p->status = DIFF_STATUS_MODIFIED;
3675                        else if (--p->one->rename_used > 0)
3676                                p->status = DIFF_STATUS_COPIED;
3677                        else
3678                                p->status = DIFF_STATUS_RENAMED;
3679                }
3680                else if (hashcmp(p->one->sha1, p->two->sha1) ||
3681                         p->one->mode != p->two->mode ||
3682                         p->one->dirty_submodule ||
3683                         p->two->dirty_submodule ||
3684                         is_null_sha1(p->one->sha1))
3685                        p->status = DIFF_STATUS_MODIFIED;
3686                else {
3687                        /* This is a "no-change" entry and should not
3688                         * happen anymore, but prepare for broken callers.
3689                         */
3690                        error("feeding unmodified %s to diffcore",
3691                              p->one->path);
3692                        p->status = DIFF_STATUS_UNKNOWN;
3693                }
3694        }
3695        diff_debug_queue("resolve-rename-copy done", q);
3696}
3697
3698static int check_pair_status(struct diff_filepair *p)
3699{
3700        switch (p->status) {
3701        case DIFF_STATUS_UNKNOWN:
3702                return 0;
3703        case 0:
3704                die("internal error in diff-resolve-rename-copy");
3705        default:
3706                return 1;
3707        }
3708}
3709
3710static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3711{
3712        int fmt = opt->output_format;
3713
3714        if (fmt & DIFF_FORMAT_CHECKDIFF)
3715                diff_flush_checkdiff(p, opt);
3716        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3717                diff_flush_raw(p, opt);
3718        else if (fmt & DIFF_FORMAT_NAME) {
3719                const char *name_a, *name_b;
3720                name_a = p->two->path;
3721                name_b = NULL;
3722                strip_prefix(opt->prefix_length, &name_a, &name_b);
3723                write_name_quoted(name_a, opt->file, opt->line_termination);
3724        }
3725}
3726
3727static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
3728{
3729        if (fs->mode)
3730                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
3731        else
3732                fprintf(file, " %s ", newdelete);
3733        write_name_quoted(fs->path, file, '\n');
3734}
3735
3736
3737static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
3738                const char *line_prefix)
3739{
3740        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
3741                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
3742                        p->two->mode, show_name ? ' ' : '\n');
3743                if (show_name) {
3744                        write_name_quoted(p->two->path, file, '\n');
3745                }
3746        }
3747}
3748
3749static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
3750                        const char *line_prefix)
3751{
3752        char *names = pprint_rename(p->one->path, p->two->path);
3753
3754        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
3755        free(names);
3756        show_mode_change(file, p, 0, line_prefix);
3757}
3758
3759static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
3760{
3761        FILE *file = opt->file;
3762        char *line_prefix = "";
3763
3764        if (opt->output_prefix) {
3765                struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
3766                line_prefix = buf->buf;
3767        }
3768
3769        switch(p->status) {
3770        case DIFF_STATUS_DELETED:
3771                fputs(line_prefix, file);
3772                show_file_mode_name(file, "delete", p->one);
3773                break;
3774        case DIFF_STATUS_ADDED:
3775                fputs(line_prefix, file);
3776                show_file_mode_name(file, "create", p->two);
3777                break;
3778        case DIFF_STATUS_COPIED:
3779                fputs(line_prefix, file);
3780                show_rename_copy(file, "copy", p, line_prefix);
3781                break;
3782        case DIFF_STATUS_RENAMED:
3783                fputs(line_prefix, file);
3784                show_rename_copy(file, "rename", p, line_prefix);
3785                break;
3786        default:
3787                if (p->score) {
3788                        fprintf(file, "%s rewrite ", line_prefix);
3789                        write_name_quoted(p->two->path, file, ' ');
3790                        fprintf(file, "(%d%%)\n", similarity_index(p));
3791                }
3792                show_mode_change(file, p, !p->score, line_prefix);
3793                break;
3794        }
3795}
3796
3797struct patch_id_t {
3798        git_SHA_CTX *ctx;
3799        int patchlen;
3800};
3801
3802static int remove_space(char *line, int len)
3803{
3804        int i;
3805        char *dst = line;
3806        unsigned char c;
3807
3808        for (i = 0; i < len; i++)
3809                if (!isspace((c = line[i])))
3810                        *dst++ = c;
3811
3812        return dst - line;
3813}
3814
3815static void patch_id_consume(void *priv, char *line, unsigned long len)
3816{
3817        struct patch_id_t *data = priv;
3818        int new_len;
3819
3820        /* Ignore line numbers when computing the SHA1 of the patch */
3821        if (!prefixcmp(line, "@@ -"))
3822                return;
3823
3824        new_len = remove_space(line, len);
3825
3826        git_SHA1_Update(data->ctx, line, new_len);
3827        data->patchlen += new_len;
3828}
3829
3830/* returns 0 upon success, and writes result into sha1 */
3831static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
3832{
3833        struct diff_queue_struct *q = &diff_queued_diff;
3834        int i;
3835        git_SHA_CTX ctx;
3836        struct patch_id_t data;
3837        char buffer[PATH_MAX * 4 + 20];
3838
3839        git_SHA1_Init(&ctx);
3840        memset(&data, 0, sizeof(struct patch_id_t));
3841        data.ctx = &ctx;
3842
3843        for (i = 0; i < q->nr; i++) {
3844                xpparam_t xpp;
3845                xdemitconf_t xecfg;
3846                mmfile_t mf1, mf2;
3847                struct diff_filepair *p = q->queue[i];
3848                int len1, len2;
3849
3850                memset(&xpp, 0, sizeof(xpp));
3851                memset(&xecfg, 0, sizeof(xecfg));
3852                if (p->status == 0)
3853                        return error("internal diff status error");
3854                if (p->status == DIFF_STATUS_UNKNOWN)
3855                        continue;
3856                if (diff_unmodified_pair(p))
3857                        continue;
3858                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3859                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3860                        continue;
3861                if (DIFF_PAIR_UNMERGED(p))
3862                        continue;
3863
3864                diff_fill_sha1_info(p->one);
3865                diff_fill_sha1_info(p->two);
3866                if (fill_mmfile(&mf1, p->one) < 0 ||
3867                                fill_mmfile(&mf2, p->two) < 0)
3868                        return error("unable to read files to diff");
3869
3870                len1 = remove_space(p->one->path, strlen(p->one->path));
3871                len2 = remove_space(p->two->path, strlen(p->two->path));
3872                if (p->one->mode == 0)
3873                        len1 = snprintf(buffer, sizeof(buffer),
3874                                        "diff--gita/%.*sb/%.*s"
3875                                        "newfilemode%06o"
3876                                        "---/dev/null"
3877                                        "+++b/%.*s",
3878                                        len1, p->one->path,
3879                                        len2, p->two->path,
3880                                        p->two->mode,
3881                                        len2, p->two->path);
3882                else if (p->two->mode == 0)
3883                        len1 = snprintf(buffer, sizeof(buffer),
3884                                        "diff--gita/%.*sb/%.*s"
3885                                        "deletedfilemode%06o"
3886                                        "---a/%.*s"
3887                                        "+++/dev/null",
3888                                        len1, p->one->path,
3889                                        len2, p->two->path,
3890                                        p->one->mode,
3891                                        len1, p->one->path);
3892                else
3893                        len1 = snprintf(buffer, sizeof(buffer),
3894                                        "diff--gita/%.*sb/%.*s"
3895                                        "---a/%.*s"
3896                                        "+++b/%.*s",
3897                                        len1, p->one->path,
3898                                        len2, p->two->path,
3899                                        len1, p->one->path,
3900                                        len2, p->two->path);
3901                git_SHA1_Update(&ctx, buffer, len1);
3902
3903                if (diff_filespec_is_binary(p->one) ||
3904                    diff_filespec_is_binary(p->two)) {
3905                        git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
3906                        git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
3907                        continue;
3908                }
3909
3910                xpp.flags = 0;
3911                xecfg.ctxlen = 3;
3912                xecfg.flags = 0;
3913                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
3914                              &xpp, &xecfg);
3915        }
3916
3917        git_SHA1_Final(sha1, &ctx);
3918        return 0;
3919}
3920
3921int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
3922{
3923        struct diff_queue_struct *q = &diff_queued_diff;
3924        int i;
3925        int result = diff_get_patch_id(options, sha1);
3926
3927        for (i = 0; i < q->nr; i++)
3928                diff_free_filepair(q->queue[i]);
3929
3930        free(q->queue);
3931        DIFF_QUEUE_CLEAR(q);
3932
3933        return result;
3934}
3935
3936static int is_summary_empty(const struct diff_queue_struct *q)
3937{
3938        int i;
3939
3940        for (i = 0; i < q->nr; i++) {
3941                const struct diff_filepair *p = q->queue[i];
3942
3943                switch (p->status) {
3944                case DIFF_STATUS_DELETED:
3945                case DIFF_STATUS_ADDED:
3946                case DIFF_STATUS_COPIED:
3947                case DIFF_STATUS_RENAMED:
3948                        return 0;
3949                default:
3950                        if (p->score)
3951                                return 0;
3952                        if (p->one->mode && p->two->mode &&
3953                            p->one->mode != p->two->mode)
3954                                return 0;
3955                        break;
3956                }
3957        }
3958        return 1;
3959}
3960
3961void diff_flush(struct diff_options *options)
3962{
3963        struct diff_queue_struct *q = &diff_queued_diff;
3964        int i, output_format = options->output_format;
3965        int separator = 0;
3966
3967        /*
3968         * Order: raw, stat, summary, patch
3969         * or:    name/name-status/checkdiff (other bits clear)
3970         */
3971        if (!q->nr)
3972                goto free_queue;
3973
3974        if (output_format & (DIFF_FORMAT_RAW |
3975                             DIFF_FORMAT_NAME |
3976                             DIFF_FORMAT_NAME_STATUS |
3977                             DIFF_FORMAT_CHECKDIFF)) {
3978                for (i = 0; i < q->nr; i++) {
3979                        struct diff_filepair *p = q->queue[i];
3980                        if (check_pair_status(p))
3981                                flush_one_pair(p, options);
3982                }
3983                separator++;
3984        }
3985
3986        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
3987                struct diffstat_t diffstat;
3988
3989                memset(&diffstat, 0, sizeof(struct diffstat_t));
3990                for (i = 0; i < q->nr; i++) {
3991                        struct diff_filepair *p = q->queue[i];
3992                        if (check_pair_status(p))
3993                                diff_flush_stat(p, options, &diffstat);
3994                }
3995                if (output_format & DIFF_FORMAT_NUMSTAT)
3996                        show_numstat(&diffstat, options);
3997                if (output_format & DIFF_FORMAT_DIFFSTAT)
3998                        show_stats(&diffstat, options);
3999                if (output_format & DIFF_FORMAT_SHORTSTAT)
4000                        show_shortstats(&diffstat, options);
4001                free_diffstat_info(&diffstat);
4002                separator++;
4003        }
4004        if (output_format & DIFF_FORMAT_DIRSTAT)
4005                show_dirstat(options);
4006
4007        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4008                for (i = 0; i < q->nr; i++) {
4009                        diff_summary(options, q->queue[i]);
4010                }
4011                separator++;
4012        }
4013
4014        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4015            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4016            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4017                /*
4018                 * run diff_flush_patch for the exit status. setting
4019                 * options->file to /dev/null should be safe, becaue we
4020                 * aren't supposed to produce any output anyway.
4021                 */
4022                if (options->close_file)
4023                        fclose(options->file);
4024                options->file = fopen("/dev/null", "w");
4025                if (!options->file)
4026                        die_errno("Could not open /dev/null");
4027                options->close_file = 1;
4028                for (i = 0; i < q->nr; i++) {
4029                        struct diff_filepair *p = q->queue[i];
4030                        if (check_pair_status(p))
4031                                diff_flush_patch(p, options);
4032                        if (options->found_changes)
4033                                break;
4034                }
4035        }
4036
4037        if (output_format & DIFF_FORMAT_PATCH) {
4038                if (separator) {
4039                        putc(options->line_termination, options->file);
4040                        if (options->stat_sep) {
4041                                /* attach patch instead of inline */
4042                                fputs(options->stat_sep, options->file);
4043                        }
4044                }
4045
4046                for (i = 0; i < q->nr; i++) {
4047                        struct diff_filepair *p = q->queue[i];
4048                        if (check_pair_status(p))
4049                                diff_flush_patch(p, options);
4050                }
4051        }
4052
4053        if (output_format & DIFF_FORMAT_CALLBACK)
4054                options->format_callback(q, options, options->format_callback_data);
4055
4056        for (i = 0; i < q->nr; i++)
4057                diff_free_filepair(q->queue[i]);
4058free_queue:
4059        free(q->queue);
4060        DIFF_QUEUE_CLEAR(q);
4061        if (options->close_file)
4062                fclose(options->file);
4063
4064        /*
4065         * Report the content-level differences with HAS_CHANGES;
4066         * diff_addremove/diff_change does not set the bit when
4067         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4068         */
4069        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4070                if (options->found_changes)
4071                        DIFF_OPT_SET(options, HAS_CHANGES);
4072                else
4073                        DIFF_OPT_CLR(options, HAS_CHANGES);
4074        }
4075}
4076
4077static void diffcore_apply_filter(const char *filter)
4078{
4079        int i;
4080        struct diff_queue_struct *q = &diff_queued_diff;
4081        struct diff_queue_struct outq;
4082        DIFF_QUEUE_CLEAR(&outq);
4083
4084        if (!filter)
4085                return;
4086
4087        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
4088                int found;
4089                for (i = found = 0; !found && i < q->nr; i++) {
4090                        struct diff_filepair *p = q->queue[i];
4091                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4092                             ((p->score &&
4093                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4094                              (!p->score &&
4095                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4096                            ((p->status != DIFF_STATUS_MODIFIED) &&
4097                             strchr(filter, p->status)))
4098                                found++;
4099                }
4100                if (found)
4101                        return;
4102
4103                /* otherwise we will clear the whole queue
4104                 * by copying the empty outq at the end of this
4105                 * function, but first clear the current entries
4106                 * in the queue.
4107                 */
4108                for (i = 0; i < q->nr; i++)
4109                        diff_free_filepair(q->queue[i]);
4110        }
4111        else {
4112                /* Only the matching ones */
4113                for (i = 0; i < q->nr; i++) {
4114                        struct diff_filepair *p = q->queue[i];
4115
4116                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4117                             ((p->score &&
4118                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4119                              (!p->score &&
4120                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4121                            ((p->status != DIFF_STATUS_MODIFIED) &&
4122                             strchr(filter, p->status)))
4123                                diff_q(&outq, p);
4124                        else
4125                                diff_free_filepair(p);
4126                }
4127        }
4128        free(q->queue);
4129        *q = outq;
4130}
4131
4132/* Check whether two filespecs with the same mode and size are identical */
4133static int diff_filespec_is_identical(struct diff_filespec *one,
4134                                      struct diff_filespec *two)
4135{
4136        if (S_ISGITLINK(one->mode))
4137                return 0;
4138        if (diff_populate_filespec(one, 0))
4139                return 0;
4140        if (diff_populate_filespec(two, 0))
4141                return 0;
4142        return !memcmp(one->data, two->data, one->size);
4143}
4144
4145static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4146{
4147        int i;
4148        struct diff_queue_struct *q = &diff_queued_diff;
4149        struct diff_queue_struct outq;
4150        DIFF_QUEUE_CLEAR(&outq);
4151
4152        for (i = 0; i < q->nr; i++) {
4153                struct diff_filepair *p = q->queue[i];
4154
4155                /*
4156                 * 1. Entries that come from stat info dirtiness
4157                 *    always have both sides (iow, not create/delete),
4158                 *    one side of the object name is unknown, with
4159                 *    the same mode and size.  Keep the ones that
4160                 *    do not match these criteria.  They have real
4161                 *    differences.
4162                 *
4163                 * 2. At this point, the file is known to be modified,
4164                 *    with the same mode and size, and the object
4165                 *    name of one side is unknown.  Need to inspect
4166                 *    the identical contents.
4167                 */
4168                if (!DIFF_FILE_VALID(p->one) || /* (1) */
4169                    !DIFF_FILE_VALID(p->two) ||
4170                    (p->one->sha1_valid && p->two->sha1_valid) ||
4171                    (p->one->mode != p->two->mode) ||
4172                    diff_populate_filespec(p->one, 1) ||
4173                    diff_populate_filespec(p->two, 1) ||
4174                    (p->one->size != p->two->size) ||
4175                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4176                        diff_q(&outq, p);
4177                else {
4178                        /*
4179                         * The caller can subtract 1 from skip_stat_unmatch
4180                         * to determine how many paths were dirty only
4181                         * due to stat info mismatch.
4182                         */
4183                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4184                                diffopt->skip_stat_unmatch++;
4185                        diff_free_filepair(p);
4186                }
4187        }
4188        free(q->queue);
4189        *q = outq;
4190}
4191
4192static int diffnamecmp(const void *a_, const void *b_)
4193{
4194        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4195        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4196        const char *name_a, *name_b;
4197
4198        name_a = a->one ? a->one->path : a->two->path;
4199        name_b = b->one ? b->one->path : b->two->path;
4200        return strcmp(name_a, name_b);
4201}
4202
4203void diffcore_fix_diff_index(struct diff_options *options)
4204{
4205        struct diff_queue_struct *q = &diff_queued_diff;
4206        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4207}
4208
4209void diffcore_std(struct diff_options *options)
4210{
4211        if (options->skip_stat_unmatch)
4212                diffcore_skip_stat_unmatch(options);
4213        if (!options->found_follow) {
4214                /* See try_to_follow_renames() in tree-diff.c */
4215                if (options->break_opt != -1)
4216                        diffcore_break(options->break_opt);
4217                if (options->detect_rename)
4218                        diffcore_rename(options);
4219                if (options->break_opt != -1)
4220                        diffcore_merge_broken();
4221        }
4222        if (options->pickaxe)
4223                diffcore_pickaxe(options);
4224        if (options->orderfile)
4225                diffcore_order(options->orderfile);
4226        if (!options->found_follow)
4227                /* See try_to_follow_renames() in tree-diff.c */
4228                diff_resolve_rename_copy();
4229        diffcore_apply_filter(options->filter);
4230
4231        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4232                DIFF_OPT_SET(options, HAS_CHANGES);
4233        else
4234                DIFF_OPT_CLR(options, HAS_CHANGES);
4235
4236        options->found_follow = 0;
4237}
4238
4239int diff_result_code(struct diff_options *opt, int status)
4240{
4241        int result = 0;
4242        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4243            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4244                return status;
4245        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4246            DIFF_OPT_TST(opt, HAS_CHANGES))
4247                result |= 01;
4248        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4249            DIFF_OPT_TST(opt, CHECK_FAILED))
4250                result |= 02;
4251        return result;
4252}
4253
4254/*
4255 * Shall changes to this submodule be ignored?
4256 *
4257 * Submodule changes can be configured to be ignored separately for each path,
4258 * but that configuration can be overridden from the command line.
4259 */
4260static int is_submodule_ignored(const char *path, struct diff_options *options)
4261{
4262        int ignored = 0;
4263        unsigned orig_flags = options->flags;
4264        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4265                set_diffopt_flags_from_submodule_config(options, path);
4266        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4267                ignored = 1;
4268        options->flags = orig_flags;
4269        return ignored;
4270}
4271
4272void diff_addremove(struct diff_options *options,
4273                    int addremove, unsigned mode,
4274                    const unsigned char *sha1,
4275                    const char *concatpath, unsigned dirty_submodule)
4276{
4277        struct diff_filespec *one, *two;
4278
4279        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4280                return;
4281
4282        /* This may look odd, but it is a preparation for
4283         * feeding "there are unchanged files which should
4284         * not produce diffs, but when you are doing copy
4285         * detection you would need them, so here they are"
4286         * entries to the diff-core.  They will be prefixed
4287         * with something like '=' or '*' (I haven't decided
4288         * which but should not make any difference).
4289         * Feeding the same new and old to diff_change()
4290         * also has the same effect.
4291         * Before the final output happens, they are pruned after
4292         * merged into rename/copy pairs as appropriate.
4293         */
4294        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4295                addremove = (addremove == '+' ? '-' :
4296                             addremove == '-' ? '+' : addremove);
4297
4298        if (options->prefix &&
4299            strncmp(concatpath, options->prefix, options->prefix_length))
4300                return;
4301
4302        one = alloc_filespec(concatpath);
4303        two = alloc_filespec(concatpath);
4304
4305        if (addremove != '+')
4306                fill_filespec(one, sha1, mode);
4307        if (addremove != '-') {
4308                fill_filespec(two, sha1, mode);
4309                two->dirty_submodule = dirty_submodule;
4310        }
4311
4312        diff_queue(&diff_queued_diff, one, two);
4313        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4314                DIFF_OPT_SET(options, HAS_CHANGES);
4315}
4316
4317void diff_change(struct diff_options *options,
4318                 unsigned old_mode, unsigned new_mode,
4319                 const unsigned char *old_sha1,
4320                 const unsigned char *new_sha1,
4321                 const char *concatpath,
4322                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4323{
4324        struct diff_filespec *one, *two;
4325
4326        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4327            is_submodule_ignored(concatpath, options))
4328                return;
4329
4330        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4331                unsigned tmp;
4332                const unsigned char *tmp_c;
4333                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4334                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4335                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4336                        new_dirty_submodule = tmp;
4337        }
4338
4339        if (options->prefix &&
4340            strncmp(concatpath, options->prefix, options->prefix_length))
4341                return;
4342
4343        one = alloc_filespec(concatpath);
4344        two = alloc_filespec(concatpath);
4345        fill_filespec(one, old_sha1, old_mode);
4346        fill_filespec(two, new_sha1, new_mode);
4347        one->dirty_submodule = old_dirty_submodule;
4348        two->dirty_submodule = new_dirty_submodule;
4349
4350        diff_queue(&diff_queued_diff, one, two);
4351        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4352                DIFF_OPT_SET(options, HAS_CHANGES);
4353}
4354
4355void diff_unmerge(struct diff_options *options,
4356                  const char *path,
4357                  unsigned mode, const unsigned char *sha1)
4358{
4359        struct diff_filespec *one, *two;
4360
4361        if (options->prefix &&
4362            strncmp(path, options->prefix, options->prefix_length))
4363                return;
4364
4365        one = alloc_filespec(path);
4366        two = alloc_filespec(path);
4367        fill_filespec(one, sha1, mode);
4368        diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;
4369}
4370
4371static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4372                size_t *outsize)
4373{
4374        struct diff_tempfile *temp;
4375        const char *argv[3];
4376        const char **arg = argv;
4377        struct child_process child;
4378        struct strbuf buf = STRBUF_INIT;
4379        int err = 0;
4380
4381        temp = prepare_temp_file(spec->path, spec);
4382        *arg++ = pgm;
4383        *arg++ = temp->name;
4384        *arg = NULL;
4385
4386        memset(&child, 0, sizeof(child));
4387        child.use_shell = 1;
4388        child.argv = argv;
4389        child.out = -1;
4390        if (start_command(&child)) {
4391                remove_tempfile();
4392                return NULL;
4393        }
4394
4395        if (strbuf_read(&buf, child.out, 0) < 0)
4396                err = error("error reading from textconv command '%s'", pgm);
4397        close(child.out);
4398
4399        if (finish_command(&child) || err) {
4400                strbuf_release(&buf);
4401                remove_tempfile();
4402                return NULL;
4403        }
4404        remove_tempfile();
4405
4406        return strbuf_detach(&buf, outsize);
4407}
4408
4409size_t fill_textconv(struct userdiff_driver *driver,
4410                     struct diff_filespec *df,
4411                     char **outbuf)
4412{
4413        size_t size;
4414
4415        if (!driver || !driver->textconv) {
4416                if (!DIFF_FILE_VALID(df)) {
4417                        *outbuf = "";
4418                        return 0;
4419                }
4420                if (diff_populate_filespec(df, 0))
4421                        die("unable to read files to diff");
4422                *outbuf = df->data;
4423                return df->size;
4424        }
4425
4426        if (driver->textconv_cache && df->sha1_valid) {
4427                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4428                                          &size);
4429                if (*outbuf)
4430                        return size;
4431        }
4432
4433        *outbuf = run_textconv(driver->textconv, df, &size);
4434        if (!*outbuf)
4435                die("unable to read files to diff");
4436
4437        if (driver->textconv_cache && df->sha1_valid) {
4438                /* ignore errors, as we might be in a readonly repository */
4439                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4440                                size);
4441                /*
4442                 * we could save up changes and flush them all at the end,
4443                 * but we would need an extra call after all diffing is done.
4444                 * Since generating a cache entry is the slow path anyway,
4445                 * this extra overhead probably isn't a big deal.
4446                 */
4447                notes_cache_write(driver->textconv_cache);
4448        }
4449
4450        return size;
4451}