4f5270b8dbc05c820c24075b499fe26afacf52a8
   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        const char *prefix;
 620        const char *suffix;
 621        const char *color; /* NULL; filled in by the setup code if
 622                            * color is enabled */
 623};
 624
 625struct diff_words_style {
 626        enum diff_words_type type;
 627        struct diff_words_style_elem new, old, ctx;
 628        const char *newline;
 629};
 630
 631struct diff_words_style diff_words_styles[] = {
 632        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 633        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 634        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 635};
 636
 637struct diff_words_data {
 638        struct diff_words_buffer minus, plus;
 639        const char *current_plus;
 640        int last_minus;
 641        struct diff_options *opt;
 642        regex_t *word_regex;
 643        enum diff_words_type type;
 644        struct diff_words_style *style;
 645};
 646
 647static int fn_out_diff_words_write_helper(FILE *fp,
 648                                          struct diff_words_style_elem *st_el,
 649                                          const char *newline,
 650                                          size_t count, const char *buf,
 651                                          const char *line_prefix)
 652{
 653        int print = 0;
 654
 655        while (count) {
 656                char *p = memchr(buf, '\n', count);
 657                if (print)
 658                        fputs(line_prefix, fp);
 659                if (p != buf) {
 660                        if (st_el->color && fputs(st_el->color, fp) < 0)
 661                                return -1;
 662                        if (fputs(st_el->prefix, fp) < 0 ||
 663                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 664                            fputs(st_el->suffix, fp) < 0)
 665                                return -1;
 666                        if (st_el->color && *st_el->color
 667                            && fputs(GIT_COLOR_RESET, fp) < 0)
 668                                return -1;
 669                }
 670                if (!p)
 671                        return 0;
 672                if (fputs(newline, fp) < 0)
 673                        return -1;
 674                count -= p + 1 - buf;
 675                buf = p + 1;
 676                print = 1;
 677        }
 678        return 0;
 679}
 680
 681/*
 682 * '--color-words' algorithm can be described as:
 683 *
 684 *   1. collect a the minus/plus lines of a diff hunk, divided into
 685 *      minus-lines and plus-lines;
 686 *
 687 *   2. break both minus-lines and plus-lines into words and
 688 *      place them into two mmfile_t with one word for each line;
 689 *
 690 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
 691 *
 692 * And for the common parts of the both file, we output the plus side text.
 693 * diff_words->current_plus is used to trace the current position of the plus file
 694 * which printed. diff_words->last_minus is used to trace the last minus word
 695 * printed.
 696 *
 697 * For '--graph' to work with '--color-words', we need to output the graph prefix
 698 * on each line of color words output. Generally, there are two conditions on
 699 * which we should output the prefix.
 700 *
 701 *   1. diff_words->last_minus == 0 &&
 702 *      diff_words->current_plus == diff_words->plus.text.ptr
 703 *
 704 *      that is: the plus text must start as a new line, and if there is no minus
 705 *      word printed, a graph prefix must be printed.
 706 *
 707 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
 708 *      *(diff_words->current_plus - 1) == '\n'
 709 *
 710 *      that is: a graph prefix must be printed following a '\n'
 711 */
 712static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
 713{
 714        if ((diff_words->last_minus == 0 &&
 715                diff_words->current_plus == diff_words->plus.text.ptr) ||
 716                (diff_words->current_plus > diff_words->plus.text.ptr &&
 717                *(diff_words->current_plus - 1) == '\n')) {
 718                return 1;
 719        } else {
 720                return 0;
 721        }
 722}
 723
 724static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 725{
 726        struct diff_words_data *diff_words = priv;
 727        struct diff_words_style *style = diff_words->style;
 728        int minus_first, minus_len, plus_first, plus_len;
 729        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 730        struct diff_options *opt = diff_words->opt;
 731        struct strbuf *msgbuf;
 732        char *line_prefix = "";
 733
 734        if (line[0] != '@' || parse_hunk_header(line, len,
 735                        &minus_first, &minus_len, &plus_first, &plus_len))
 736                return;
 737
 738        assert(opt);
 739        if (opt->output_prefix) {
 740                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 741                line_prefix = msgbuf->buf;
 742        }
 743
 744        /* POSIX requires that first be decremented by one if len == 0... */
 745        if (minus_len) {
 746                minus_begin = diff_words->minus.orig[minus_first].begin;
 747                minus_end =
 748                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 749        } else
 750                minus_begin = minus_end =
 751                        diff_words->minus.orig[minus_first].end;
 752
 753        if (plus_len) {
 754                plus_begin = diff_words->plus.orig[plus_first].begin;
 755                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 756        } else
 757                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 758
 759        if (color_words_output_graph_prefix(diff_words)) {
 760                fputs(line_prefix, diff_words->opt->file);
 761        }
 762        if (diff_words->current_plus != plus_begin) {
 763                fn_out_diff_words_write_helper(diff_words->opt->file,
 764                                &style->ctx, style->newline,
 765                                plus_begin - diff_words->current_plus,
 766                                diff_words->current_plus, line_prefix);
 767                if (*(plus_begin - 1) == '\n')
 768                        fputs(line_prefix, diff_words->opt->file);
 769        }
 770        if (minus_begin != minus_end) {
 771                fn_out_diff_words_write_helper(diff_words->opt->file,
 772                                &style->old, style->newline,
 773                                minus_end - minus_begin, minus_begin,
 774                                line_prefix);
 775        }
 776        if (plus_begin != plus_end) {
 777                fn_out_diff_words_write_helper(diff_words->opt->file,
 778                                &style->new, style->newline,
 779                                plus_end - plus_begin, plus_begin,
 780                                line_prefix);
 781        }
 782
 783        diff_words->current_plus = plus_end;
 784        diff_words->last_minus = minus_first;
 785}
 786
 787/* This function starts looking at *begin, and returns 0 iff a word was found. */
 788static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 789                int *begin, int *end)
 790{
 791        if (word_regex && *begin < buffer->size) {
 792                regmatch_t match[1];
 793                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 794                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 795                                        '\n', match[0].rm_eo - match[0].rm_so);
 796                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 797                        *begin += match[0].rm_so;
 798                        return *begin >= *end;
 799                }
 800                return -1;
 801        }
 802
 803        /* find the next word */
 804        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 805                (*begin)++;
 806        if (*begin >= buffer->size)
 807                return -1;
 808
 809        /* find the end of the word */
 810        *end = *begin + 1;
 811        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 812                (*end)++;
 813
 814        return 0;
 815}
 816
 817/*
 818 * This function splits the words in buffer->text, stores the list with
 819 * newline separator into out, and saves the offsets of the original words
 820 * in buffer->orig.
 821 */
 822static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 823                regex_t *word_regex)
 824{
 825        int i, j;
 826        long alloc = 0;
 827
 828        out->size = 0;
 829        out->ptr = NULL;
 830
 831        /* fake an empty "0th" word */
 832        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 833        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 834        buffer->orig_nr = 1;
 835
 836        for (i = 0; i < buffer->text.size; i++) {
 837                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 838                        return;
 839
 840                /* store original boundaries */
 841                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 842                                buffer->orig_alloc);
 843                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 844                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 845                buffer->orig_nr++;
 846
 847                /* store one word */
 848                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 849                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 850                out->ptr[out->size + j - i] = '\n';
 851                out->size += j - i + 1;
 852
 853                i = j - 1;
 854        }
 855}
 856
 857/* this executes the word diff on the accumulated buffers */
 858static void diff_words_show(struct diff_words_data *diff_words)
 859{
 860        xpparam_t xpp;
 861        xdemitconf_t xecfg;
 862        mmfile_t minus, plus;
 863        struct diff_words_style *style = diff_words->style;
 864
 865        struct diff_options *opt = diff_words->opt;
 866        struct strbuf *msgbuf;
 867        char *line_prefix = "";
 868
 869        assert(opt);
 870        if (opt->output_prefix) {
 871                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 872                line_prefix = msgbuf->buf;
 873        }
 874
 875        /* special case: only removal */
 876        if (!diff_words->plus.text.size) {
 877                fputs(line_prefix, diff_words->opt->file);
 878                fn_out_diff_words_write_helper(diff_words->opt->file,
 879                        &style->old, style->newline,
 880                        diff_words->minus.text.size,
 881                        diff_words->minus.text.ptr, line_prefix);
 882                diff_words->minus.text.size = 0;
 883                return;
 884        }
 885
 886        diff_words->current_plus = diff_words->plus.text.ptr;
 887        diff_words->last_minus = 0;
 888
 889        memset(&xpp, 0, sizeof(xpp));
 890        memset(&xecfg, 0, sizeof(xecfg));
 891        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
 892        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
 893        xpp.flags = 0;
 894        /* as only the hunk header will be parsed, we need a 0-context */
 895        xecfg.ctxlen = 0;
 896        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 897                      &xpp, &xecfg);
 898        free(minus.ptr);
 899        free(plus.ptr);
 900        if (diff_words->current_plus != diff_words->plus.text.ptr +
 901                        diff_words->plus.text.size) {
 902                if (color_words_output_graph_prefix(diff_words))
 903                        fputs(line_prefix, diff_words->opt->file);
 904                fn_out_diff_words_write_helper(diff_words->opt->file,
 905                        &style->ctx, style->newline,
 906                        diff_words->plus.text.ptr + diff_words->plus.text.size
 907                        - diff_words->current_plus, diff_words->current_plus,
 908                        line_prefix);
 909        }
 910        diff_words->minus.text.size = diff_words->plus.text.size = 0;
 911}
 912
 913/* In "color-words" mode, show word-diff of words accumulated in the buffer */
 914static void diff_words_flush(struct emit_callback *ecbdata)
 915{
 916        if (ecbdata->diff_words->minus.text.size ||
 917            ecbdata->diff_words->plus.text.size)
 918                diff_words_show(ecbdata->diff_words);
 919}
 920
 921static void free_diff_words_data(struct emit_callback *ecbdata)
 922{
 923        if (ecbdata->diff_words) {
 924                diff_words_flush(ecbdata);
 925                free (ecbdata->diff_words->minus.text.ptr);
 926                free (ecbdata->diff_words->minus.orig);
 927                free (ecbdata->diff_words->plus.text.ptr);
 928                free (ecbdata->diff_words->plus.orig);
 929                if (ecbdata->diff_words->word_regex) {
 930                        regfree(ecbdata->diff_words->word_regex);
 931                        free(ecbdata->diff_words->word_regex);
 932                }
 933                free(ecbdata->diff_words);
 934                ecbdata->diff_words = NULL;
 935        }
 936}
 937
 938const char *diff_get_color(int diff_use_color, enum color_diff ix)
 939{
 940        if (diff_use_color)
 941                return diff_colors[ix];
 942        return "";
 943}
 944
 945static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
 946{
 947        const char *cp;
 948        unsigned long allot;
 949        size_t l = len;
 950
 951        if (ecb->truncate)
 952                return ecb->truncate(line, len);
 953        cp = line;
 954        allot = l;
 955        while (0 < l) {
 956                (void) utf8_width(&cp, &l);
 957                if (!cp)
 958                        break; /* truncated in the middle? */
 959        }
 960        return allot - l;
 961}
 962
 963static void find_lno(const char *line, struct emit_callback *ecbdata)
 964{
 965        const char *p;
 966        ecbdata->lno_in_preimage = 0;
 967        ecbdata->lno_in_postimage = 0;
 968        p = strchr(line, '-');
 969        if (!p)
 970                return; /* cannot happen */
 971        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
 972        p = strchr(p, '+');
 973        if (!p)
 974                return; /* cannot happen */
 975        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
 976}
 977
 978static void fn_out_consume(void *priv, char *line, unsigned long len)
 979{
 980        struct emit_callback *ecbdata = priv;
 981        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
 982        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 983        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 984        struct diff_options *o = ecbdata->opt;
 985        char *line_prefix = "";
 986        struct strbuf *msgbuf;
 987
 988        if (o && o->output_prefix) {
 989                msgbuf = o->output_prefix(o, o->output_prefix_data);
 990                line_prefix = msgbuf->buf;
 991        }
 992
 993        if (ecbdata->header) {
 994                fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
 995                strbuf_reset(ecbdata->header);
 996                ecbdata->header = NULL;
 997        }
 998        *(ecbdata->found_changesp) = 1;
 999
1000        if (ecbdata->label_path[0]) {
1001                const char *name_a_tab, *name_b_tab;
1002
1003                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
1004                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
1005
1006                fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
1007                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
1008                fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
1009                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1010                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1011        }
1012
1013        if (diff_suppress_blank_empty
1014            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1015                line[0] = '\n';
1016                len = 1;
1017        }
1018
1019        if (line[0] == '@') {
1020                if (ecbdata->diff_words)
1021                        diff_words_flush(ecbdata);
1022                len = sane_truncate_line(ecbdata, line, len);
1023                find_lno(line, ecbdata);
1024                emit_hunk_header(ecbdata, line, len);
1025                if (line[len-1] != '\n')
1026                        putc('\n', ecbdata->opt->file);
1027                return;
1028        }
1029
1030        if (len < 1) {
1031                emit_line(ecbdata->opt, reset, reset, line, len);
1032                if (ecbdata->diff_words
1033                    && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
1034                        fputs("~\n", ecbdata->opt->file);
1035                return;
1036        }
1037
1038        if (ecbdata->diff_words) {
1039                if (line[0] == '-') {
1040                        diff_words_append(line, len,
1041                                          &ecbdata->diff_words->minus);
1042                        return;
1043                } else if (line[0] == '+') {
1044                        diff_words_append(line, len,
1045                                          &ecbdata->diff_words->plus);
1046                        return;
1047                }
1048                diff_words_flush(ecbdata);
1049                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1050                        emit_line(ecbdata->opt, plain, reset, line, len);
1051                        fputs("~\n", ecbdata->opt->file);
1052                } else {
1053                        /* don't print the prefix character */
1054                        emit_line(ecbdata->opt, plain, reset, line+1, len-1);
1055                }
1056                return;
1057        }
1058
1059        if (line[0] != '+') {
1060                const char *color =
1061                        diff_get_color(ecbdata->color_diff,
1062                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
1063                ecbdata->lno_in_preimage++;
1064                if (line[0] == ' ')
1065                        ecbdata->lno_in_postimage++;
1066                emit_line(ecbdata->opt, color, reset, line, len);
1067        } else {
1068                ecbdata->lno_in_postimage++;
1069                emit_add_line(reset, ecbdata, line + 1, len - 1);
1070        }
1071}
1072
1073static char *pprint_rename(const char *a, const char *b)
1074{
1075        const char *old = a;
1076        const char *new = b;
1077        struct strbuf name = STRBUF_INIT;
1078        int pfx_length, sfx_length;
1079        int len_a = strlen(a);
1080        int len_b = strlen(b);
1081        int a_midlen, b_midlen;
1082        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1083        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1084
1085        if (qlen_a || qlen_b) {
1086                quote_c_style(a, &name, NULL, 0);
1087                strbuf_addstr(&name, " => ");
1088                quote_c_style(b, &name, NULL, 0);
1089                return strbuf_detach(&name, NULL);
1090        }
1091
1092        /* Find common prefix */
1093        pfx_length = 0;
1094        while (*old && *new && *old == *new) {
1095                if (*old == '/')
1096                        pfx_length = old - a + 1;
1097                old++;
1098                new++;
1099        }
1100
1101        /* Find common suffix */
1102        old = a + len_a;
1103        new = b + len_b;
1104        sfx_length = 0;
1105        while (a <= old && b <= new && *old == *new) {
1106                if (*old == '/')
1107                        sfx_length = len_a - (old - a);
1108                old--;
1109                new--;
1110        }
1111
1112        /*
1113         * pfx{mid-a => mid-b}sfx
1114         * {pfx-a => pfx-b}sfx
1115         * pfx{sfx-a => sfx-b}
1116         * name-a => name-b
1117         */
1118        a_midlen = len_a - pfx_length - sfx_length;
1119        b_midlen = len_b - pfx_length - sfx_length;
1120        if (a_midlen < 0)
1121                a_midlen = 0;
1122        if (b_midlen < 0)
1123                b_midlen = 0;
1124
1125        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1126        if (pfx_length + sfx_length) {
1127                strbuf_add(&name, a, pfx_length);
1128                strbuf_addch(&name, '{');
1129        }
1130        strbuf_add(&name, a + pfx_length, a_midlen);
1131        strbuf_addstr(&name, " => ");
1132        strbuf_add(&name, b + pfx_length, b_midlen);
1133        if (pfx_length + sfx_length) {
1134                strbuf_addch(&name, '}');
1135                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1136        }
1137        return strbuf_detach(&name, NULL);
1138}
1139
1140struct diffstat_t {
1141        int nr;
1142        int alloc;
1143        struct diffstat_file {
1144                char *from_name;
1145                char *name;
1146                char *print_name;
1147                unsigned is_unmerged:1;
1148                unsigned is_binary:1;
1149                unsigned is_renamed:1;
1150                uintmax_t added, deleted;
1151        } **files;
1152};
1153
1154static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1155                                          const char *name_a,
1156                                          const char *name_b)
1157{
1158        struct diffstat_file *x;
1159        x = xcalloc(sizeof (*x), 1);
1160        if (diffstat->nr == diffstat->alloc) {
1161                diffstat->alloc = alloc_nr(diffstat->alloc);
1162                diffstat->files = xrealloc(diffstat->files,
1163                                diffstat->alloc * sizeof(x));
1164        }
1165        diffstat->files[diffstat->nr++] = x;
1166        if (name_b) {
1167                x->from_name = xstrdup(name_a);
1168                x->name = xstrdup(name_b);
1169                x->is_renamed = 1;
1170        }
1171        else {
1172                x->from_name = NULL;
1173                x->name = xstrdup(name_a);
1174        }
1175        return x;
1176}
1177
1178static void diffstat_consume(void *priv, char *line, unsigned long len)
1179{
1180        struct diffstat_t *diffstat = priv;
1181        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1182
1183        if (line[0] == '+')
1184                x->added++;
1185        else if (line[0] == '-')
1186                x->deleted++;
1187}
1188
1189const char mime_boundary_leader[] = "------------";
1190
1191static int scale_linear(int it, int width, int max_change)
1192{
1193        /*
1194         * make sure that at least one '-' is printed if there were deletions,
1195         * and likewise for '+'.
1196         */
1197        if (max_change < 2)
1198                return it;
1199        return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
1200}
1201
1202static void show_name(FILE *file,
1203                      const char *prefix, const char *name, int len)
1204{
1205        fprintf(file, " %s%-*s |", prefix, len, name);
1206}
1207
1208static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1209{
1210        if (cnt <= 0)
1211                return;
1212        fprintf(file, "%s", set);
1213        while (cnt--)
1214                putc(ch, file);
1215        fprintf(file, "%s", reset);
1216}
1217
1218static void fill_print_name(struct diffstat_file *file)
1219{
1220        char *pname;
1221
1222        if (file->print_name)
1223                return;
1224
1225        if (!file->is_renamed) {
1226                struct strbuf buf = STRBUF_INIT;
1227                if (quote_c_style(file->name, &buf, NULL, 0)) {
1228                        pname = strbuf_detach(&buf, NULL);
1229                } else {
1230                        pname = file->name;
1231                        strbuf_release(&buf);
1232                }
1233        } else {
1234                pname = pprint_rename(file->from_name, file->name);
1235        }
1236        file->print_name = pname;
1237}
1238
1239static void show_stats(struct diffstat_t *data, struct diff_options *options)
1240{
1241        int i, len, add, del, adds = 0, dels = 0;
1242        uintmax_t max_change = 0, max_len = 0;
1243        int total_files = data->nr;
1244        int width, name_width;
1245        const char *reset, *set, *add_c, *del_c;
1246        const char *line_prefix = "";
1247        struct strbuf *msg = NULL;
1248
1249        if (data->nr == 0)
1250                return;
1251
1252        if (options->output_prefix) {
1253                msg = options->output_prefix(options, options->output_prefix_data);
1254                line_prefix = msg->buf;
1255        }
1256
1257        width = options->stat_width ? options->stat_width : 80;
1258        name_width = options->stat_name_width ? options->stat_name_width : 50;
1259
1260        /* Sanity: give at least 5 columns to the graph,
1261         * but leave at least 10 columns for the name.
1262         */
1263        if (width < 25)
1264                width = 25;
1265        if (name_width < 10)
1266                name_width = 10;
1267        else if (width < name_width + 15)
1268                name_width = width - 15;
1269
1270        /* Find the longest filename and max number of changes */
1271        reset = diff_get_color_opt(options, DIFF_RESET);
1272        set   = diff_get_color_opt(options, DIFF_PLAIN);
1273        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1274        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1275
1276        for (i = 0; i < data->nr; i++) {
1277                struct diffstat_file *file = data->files[i];
1278                uintmax_t change = file->added + file->deleted;
1279                fill_print_name(file);
1280                len = strlen(file->print_name);
1281                if (max_len < len)
1282                        max_len = len;
1283
1284                if (file->is_binary || file->is_unmerged)
1285                        continue;
1286                if (max_change < change)
1287                        max_change = change;
1288        }
1289
1290        /* Compute the width of the graph part;
1291         * 10 is for one blank at the beginning of the line plus
1292         * " | count " between the name and the graph.
1293         *
1294         * From here on, name_width is the width of the name area,
1295         * and width is the width of the graph area.
1296         */
1297        name_width = (name_width < max_len) ? name_width : max_len;
1298        if (width < (name_width + 10) + max_change)
1299                width = width - (name_width + 10);
1300        else
1301                width = max_change;
1302
1303        for (i = 0; i < data->nr; i++) {
1304                const char *prefix = "";
1305                char *name = data->files[i]->print_name;
1306                uintmax_t added = data->files[i]->added;
1307                uintmax_t deleted = data->files[i]->deleted;
1308                int name_len;
1309
1310                /*
1311                 * "scale" the filename
1312                 */
1313                len = name_width;
1314                name_len = strlen(name);
1315                if (name_width < name_len) {
1316                        char *slash;
1317                        prefix = "...";
1318                        len -= 3;
1319                        name += name_len - len;
1320                        slash = strchr(name, '/');
1321                        if (slash)
1322                                name = slash;
1323                }
1324
1325                if (data->files[i]->is_binary) {
1326                        fprintf(options->file, "%s", line_prefix);
1327                        show_name(options->file, prefix, name, len);
1328                        fprintf(options->file, "  Bin ");
1329                        fprintf(options->file, "%s%"PRIuMAX"%s",
1330                                del_c, deleted, reset);
1331                        fprintf(options->file, " -> ");
1332                        fprintf(options->file, "%s%"PRIuMAX"%s",
1333                                add_c, added, reset);
1334                        fprintf(options->file, " bytes");
1335                        fprintf(options->file, "\n");
1336                        continue;
1337                }
1338                else if (data->files[i]->is_unmerged) {
1339                        fprintf(options->file, "%s", line_prefix);
1340                        show_name(options->file, prefix, name, len);
1341                        fprintf(options->file, "  Unmerged\n");
1342                        continue;
1343                }
1344                else if (!data->files[i]->is_renamed &&
1345                         (added + deleted == 0)) {
1346                        total_files--;
1347                        continue;
1348                }
1349
1350                /*
1351                 * scale the add/delete
1352                 */
1353                add = added;
1354                del = deleted;
1355                adds += add;
1356                dels += del;
1357
1358                if (width <= max_change) {
1359                        add = scale_linear(add, width, max_change);
1360                        del = scale_linear(del, width, max_change);
1361                }
1362                fprintf(options->file, "%s", line_prefix);
1363                show_name(options->file, prefix, name, len);
1364                fprintf(options->file, "%5"PRIuMAX"%s", added + deleted,
1365                                added + deleted ? " " : "");
1366                show_graph(options->file, '+', add, add_c, reset);
1367                show_graph(options->file, '-', del, del_c, reset);
1368                fprintf(options->file, "\n");
1369        }
1370        fprintf(options->file, "%s", line_prefix);
1371        fprintf(options->file,
1372               " %d files changed, %d insertions(+), %d deletions(-)\n",
1373               total_files, adds, dels);
1374}
1375
1376static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1377{
1378        int i, adds = 0, dels = 0, total_files = data->nr;
1379
1380        if (data->nr == 0)
1381                return;
1382
1383        for (i = 0; i < data->nr; i++) {
1384                if (!data->files[i]->is_binary &&
1385                    !data->files[i]->is_unmerged) {
1386                        int added = data->files[i]->added;
1387                        int deleted= data->files[i]->deleted;
1388                        if (!data->files[i]->is_renamed &&
1389                            (added + deleted == 0)) {
1390                                total_files--;
1391                        } else {
1392                                adds += added;
1393                                dels += deleted;
1394                        }
1395                }
1396        }
1397        if (options->output_prefix) {
1398                struct strbuf *msg = NULL;
1399                msg = options->output_prefix(options,
1400                                options->output_prefix_data);
1401                fprintf(options->file, "%s", msg->buf);
1402        }
1403        fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
1404               total_files, adds, dels);
1405}
1406
1407static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1408{
1409        int i;
1410
1411        if (data->nr == 0)
1412                return;
1413
1414        for (i = 0; i < data->nr; i++) {
1415                struct diffstat_file *file = data->files[i];
1416
1417                if (options->output_prefix) {
1418                        struct strbuf *msg = NULL;
1419                        msg = options->output_prefix(options,
1420                                        options->output_prefix_data);
1421                        fprintf(options->file, "%s", msg->buf);
1422                }
1423
1424                if (file->is_binary)
1425                        fprintf(options->file, "-\t-\t");
1426                else
1427                        fprintf(options->file,
1428                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1429                                file->added, file->deleted);
1430                if (options->line_termination) {
1431                        fill_print_name(file);
1432                        if (!file->is_renamed)
1433                                write_name_quoted(file->name, options->file,
1434                                                  options->line_termination);
1435                        else {
1436                                fputs(file->print_name, options->file);
1437                                putc(options->line_termination, options->file);
1438                        }
1439                } else {
1440                        if (file->is_renamed) {
1441                                putc('\0', options->file);
1442                                write_name_quoted(file->from_name, options->file, '\0');
1443                        }
1444                        write_name_quoted(file->name, options->file, '\0');
1445                }
1446        }
1447}
1448
1449struct dirstat_file {
1450        const char *name;
1451        unsigned long changed;
1452};
1453
1454struct dirstat_dir {
1455        struct dirstat_file *files;
1456        int alloc, nr, percent, cumulative;
1457};
1458
1459static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1460                unsigned long changed, const char *base, int baselen)
1461{
1462        unsigned long this_dir = 0;
1463        unsigned int sources = 0;
1464        const char *line_prefix = "";
1465        struct strbuf *msg = NULL;
1466
1467        if (opt->output_prefix) {
1468                msg = opt->output_prefix(opt, opt->output_prefix_data);
1469                line_prefix = msg->buf;
1470        }
1471
1472        while (dir->nr) {
1473                struct dirstat_file *f = dir->files;
1474                int namelen = strlen(f->name);
1475                unsigned long this;
1476                char *slash;
1477
1478                if (namelen < baselen)
1479                        break;
1480                if (memcmp(f->name, base, baselen))
1481                        break;
1482                slash = strchr(f->name + baselen, '/');
1483                if (slash) {
1484                        int newbaselen = slash + 1 - f->name;
1485                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1486                        sources++;
1487                } else {
1488                        this = f->changed;
1489                        dir->files++;
1490                        dir->nr--;
1491                        sources += 2;
1492                }
1493                this_dir += this;
1494        }
1495
1496        /*
1497         * We don't report dirstat's for
1498         *  - the top level
1499         *  - or cases where everything came from a single directory
1500         *    under this directory (sources == 1).
1501         */
1502        if (baselen && sources != 1) {
1503                int permille = this_dir * 1000 / changed;
1504                if (permille) {
1505                        int percent = permille / 10;
1506                        if (percent >= dir->percent) {
1507                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1508                                        percent, permille % 10, baselen, base);
1509                                if (!dir->cumulative)
1510                                        return 0;
1511                        }
1512                }
1513        }
1514        return this_dir;
1515}
1516
1517static int dirstat_compare(const void *_a, const void *_b)
1518{
1519        const struct dirstat_file *a = _a;
1520        const struct dirstat_file *b = _b;
1521        return strcmp(a->name, b->name);
1522}
1523
1524static void show_dirstat(struct diff_options *options)
1525{
1526        int i;
1527        unsigned long changed;
1528        struct dirstat_dir dir;
1529        struct diff_queue_struct *q = &diff_queued_diff;
1530
1531        dir.files = NULL;
1532        dir.alloc = 0;
1533        dir.nr = 0;
1534        dir.percent = options->dirstat_percent;
1535        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1536
1537        changed = 0;
1538        for (i = 0; i < q->nr; i++) {
1539                struct diff_filepair *p = q->queue[i];
1540                const char *name;
1541                unsigned long copied, added, damage;
1542                int content_changed;
1543
1544                name = p->one->path ? p->one->path : p->two->path;
1545
1546                if (p->one->sha1_valid && p->two->sha1_valid)
1547                        content_changed = hashcmp(p->one->sha1, p->two->sha1);
1548                else
1549                        content_changed = 1;
1550
1551                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1552                        /*
1553                         * In --dirstat-by-file mode, we don't really need to
1554                         * look at the actual file contents at all.
1555                         * The fact that the SHA1 changed is enough for us to
1556                         * add this file to the list of results
1557                         * (with each file contributing equal damage).
1558                         */
1559                        damage = content_changed ? 1 : 0;
1560                        goto found_damage;
1561                }
1562
1563                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1564                        diff_populate_filespec(p->one, 0);
1565                        diff_populate_filespec(p->two, 0);
1566                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1567                                               &copied, &added);
1568                        diff_free_filespec_data(p->one);
1569                        diff_free_filespec_data(p->two);
1570                } else if (DIFF_FILE_VALID(p->one)) {
1571                        diff_populate_filespec(p->one, 1);
1572                        copied = added = 0;
1573                        diff_free_filespec_data(p->one);
1574                } else if (DIFF_FILE_VALID(p->two)) {
1575                        diff_populate_filespec(p->two, 1);
1576                        copied = 0;
1577                        added = p->two->size;
1578                        diff_free_filespec_data(p->two);
1579                } else
1580                        continue;
1581
1582                /*
1583                 * Original minus copied is the removed material,
1584                 * added is the new material.  They are both damages
1585                 * made to the preimage.
1586                 */
1587                damage = (p->one->size - copied) + added;
1588
1589found_damage:
1590                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1591                dir.files[dir.nr].name = name;
1592                dir.files[dir.nr].changed = damage;
1593                changed += damage;
1594                dir.nr++;
1595        }
1596
1597        /* This can happen even with many files, if everything was renames */
1598        if (!changed)
1599                return;
1600
1601        /* Show all directories with more than x% of the changes */
1602        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1603        gather_dirstat(options, &dir, changed, "", 0);
1604}
1605
1606static void free_diffstat_info(struct diffstat_t *diffstat)
1607{
1608        int i;
1609        for (i = 0; i < diffstat->nr; i++) {
1610                struct diffstat_file *f = diffstat->files[i];
1611                if (f->name != f->print_name)
1612                        free(f->print_name);
1613                free(f->name);
1614                free(f->from_name);
1615                free(f);
1616        }
1617        free(diffstat->files);
1618}
1619
1620struct checkdiff_t {
1621        const char *filename;
1622        int lineno;
1623        int conflict_marker_size;
1624        struct diff_options *o;
1625        unsigned ws_rule;
1626        unsigned status;
1627};
1628
1629static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1630{
1631        char firstchar;
1632        int cnt;
1633
1634        if (len < marker_size + 1)
1635                return 0;
1636        firstchar = line[0];
1637        switch (firstchar) {
1638        case '=': case '>': case '<': case '|':
1639                break;
1640        default:
1641                return 0;
1642        }
1643        for (cnt = 1; cnt < marker_size; cnt++)
1644                if (line[cnt] != firstchar)
1645                        return 0;
1646        /* line[1] thru line[marker_size-1] are same as firstchar */
1647        if (len < marker_size + 1 || !isspace(line[marker_size]))
1648                return 0;
1649        return 1;
1650}
1651
1652static void checkdiff_consume(void *priv, char *line, unsigned long len)
1653{
1654        struct checkdiff_t *data = priv;
1655        int color_diff = DIFF_OPT_TST(data->o, COLOR_DIFF);
1656        int marker_size = data->conflict_marker_size;
1657        const char *ws = diff_get_color(color_diff, DIFF_WHITESPACE);
1658        const char *reset = diff_get_color(color_diff, DIFF_RESET);
1659        const char *set = diff_get_color(color_diff, DIFF_FILE_NEW);
1660        char *err;
1661        char *line_prefix = "";
1662        struct strbuf *msgbuf;
1663
1664        assert(data->o);
1665        if (data->o->output_prefix) {
1666                msgbuf = data->o->output_prefix(data->o,
1667                        data->o->output_prefix_data);
1668                line_prefix = msgbuf->buf;
1669        }
1670
1671        if (line[0] == '+') {
1672                unsigned bad;
1673                data->lineno++;
1674                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
1675                        data->status |= 1;
1676                        fprintf(data->o->file,
1677                                "%s%s:%d: leftover conflict marker\n",
1678                                line_prefix, data->filename, data->lineno);
1679                }
1680                bad = ws_check(line + 1, len - 1, data->ws_rule);
1681                if (!bad)
1682                        return;
1683                data->status |= bad;
1684                err = whitespace_error_string(bad);
1685                fprintf(data->o->file, "%s%s:%d: %s.\n",
1686                        line_prefix, data->filename, data->lineno, err);
1687                free(err);
1688                emit_line(data->o, set, reset, line, 1);
1689                ws_check_emit(line + 1, len - 1, data->ws_rule,
1690                              data->o->file, set, reset, ws);
1691        } else if (line[0] == ' ') {
1692                data->lineno++;
1693        } else if (line[0] == '@') {
1694                char *plus = strchr(line, '+');
1695                if (plus)
1696                        data->lineno = strtol(plus, NULL, 10) - 1;
1697                else
1698                        die("invalid diff");
1699        }
1700}
1701
1702static unsigned char *deflate_it(char *data,
1703                                 unsigned long size,
1704                                 unsigned long *result_size)
1705{
1706        int bound;
1707        unsigned char *deflated;
1708        z_stream stream;
1709
1710        memset(&stream, 0, sizeof(stream));
1711        deflateInit(&stream, zlib_compression_level);
1712        bound = deflateBound(&stream, size);
1713        deflated = xmalloc(bound);
1714        stream.next_out = deflated;
1715        stream.avail_out = bound;
1716
1717        stream.next_in = (unsigned char *)data;
1718        stream.avail_in = size;
1719        while (deflate(&stream, Z_FINISH) == Z_OK)
1720                ; /* nothing */
1721        deflateEnd(&stream);
1722        *result_size = stream.total_out;
1723        return deflated;
1724}
1725
1726static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1727{
1728        void *cp;
1729        void *delta;
1730        void *deflated;
1731        void *data;
1732        unsigned long orig_size;
1733        unsigned long delta_size;
1734        unsigned long deflate_size;
1735        unsigned long data_size;
1736
1737        /* We could do deflated delta, or we could do just deflated two,
1738         * whichever is smaller.
1739         */
1740        delta = NULL;
1741        deflated = deflate_it(two->ptr, two->size, &deflate_size);
1742        if (one->size && two->size) {
1743                delta = diff_delta(one->ptr, one->size,
1744                                   two->ptr, two->size,
1745                                   &delta_size, deflate_size);
1746                if (delta) {
1747                        void *to_free = delta;
1748                        orig_size = delta_size;
1749                        delta = deflate_it(delta, delta_size, &delta_size);
1750                        free(to_free);
1751                }
1752        }
1753
1754        if (delta && delta_size < deflate_size) {
1755                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
1756                free(deflated);
1757                data = delta;
1758                data_size = delta_size;
1759        }
1760        else {
1761                fprintf(file, "%sliteral %lu\n", prefix, two->size);
1762                free(delta);
1763                data = deflated;
1764                data_size = deflate_size;
1765        }
1766
1767        /* emit data encoded in base85 */
1768        cp = data;
1769        while (data_size) {
1770                int bytes = (52 < data_size) ? 52 : data_size;
1771                char line[70];
1772                data_size -= bytes;
1773                if (bytes <= 26)
1774                        line[0] = bytes + 'A' - 1;
1775                else
1776                        line[0] = bytes - 26 + 'a' - 1;
1777                encode_85(line + 1, cp, bytes);
1778                cp = (char *) cp + bytes;
1779                fprintf(file, "%s", prefix);
1780                fputs(line, file);
1781                fputc('\n', file);
1782        }
1783        fprintf(file, "%s\n", prefix);
1784        free(data);
1785}
1786
1787static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1788{
1789        fprintf(file, "%sGIT binary patch\n", prefix);
1790        emit_binary_diff_body(file, one, two, prefix);
1791        emit_binary_diff_body(file, two, one, prefix);
1792}
1793
1794static void diff_filespec_load_driver(struct diff_filespec *one)
1795{
1796        /* Use already-loaded driver */
1797        if (one->driver)
1798                return;
1799
1800        if (S_ISREG(one->mode))
1801                one->driver = userdiff_find_by_path(one->path);
1802
1803        /* Fallback to default settings */
1804        if (!one->driver)
1805                one->driver = userdiff_find_by_name("default");
1806}
1807
1808int diff_filespec_is_binary(struct diff_filespec *one)
1809{
1810        if (one->is_binary == -1) {
1811                diff_filespec_load_driver(one);
1812                if (one->driver->binary != -1)
1813                        one->is_binary = one->driver->binary;
1814                else {
1815                        if (!one->data && DIFF_FILE_VALID(one))
1816                                diff_populate_filespec(one, 0);
1817                        if (one->data)
1818                                one->is_binary = buffer_is_binary(one->data,
1819                                                one->size);
1820                        if (one->is_binary == -1)
1821                                one->is_binary = 0;
1822                }
1823        }
1824        return one->is_binary;
1825}
1826
1827static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
1828{
1829        diff_filespec_load_driver(one);
1830        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
1831}
1832
1833static const char *userdiff_word_regex(struct diff_filespec *one)
1834{
1835        diff_filespec_load_driver(one);
1836        return one->driver->word_regex;
1837}
1838
1839void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
1840{
1841        if (!options->a_prefix)
1842                options->a_prefix = a;
1843        if (!options->b_prefix)
1844                options->b_prefix = b;
1845}
1846
1847struct userdiff_driver *get_textconv(struct diff_filespec *one)
1848{
1849        if (!DIFF_FILE_VALID(one))
1850                return NULL;
1851
1852        diff_filespec_load_driver(one);
1853        if (!one->driver->textconv)
1854                return NULL;
1855
1856        if (one->driver->textconv_want_cache && !one->driver->textconv_cache) {
1857                struct notes_cache *c = xmalloc(sizeof(*c));
1858                struct strbuf name = STRBUF_INIT;
1859
1860                strbuf_addf(&name, "textconv/%s", one->driver->name);
1861                notes_cache_init(c, name.buf, one->driver->textconv);
1862                one->driver->textconv_cache = c;
1863        }
1864
1865        return one->driver;
1866}
1867
1868static void builtin_diff(const char *name_a,
1869                         const char *name_b,
1870                         struct diff_filespec *one,
1871                         struct diff_filespec *two,
1872                         const char *xfrm_msg,
1873                         int must_show_header,
1874                         struct diff_options *o,
1875                         int complete_rewrite)
1876{
1877        mmfile_t mf1, mf2;
1878        const char *lbl[2];
1879        char *a_one, *b_two;
1880        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1881        const char *reset = diff_get_color_opt(o, DIFF_RESET);
1882        const char *a_prefix, *b_prefix;
1883        struct userdiff_driver *textconv_one = NULL;
1884        struct userdiff_driver *textconv_two = NULL;
1885        struct strbuf header = STRBUF_INIT;
1886        struct strbuf *msgbuf;
1887        char *line_prefix = "";
1888
1889        if (o->output_prefix) {
1890                msgbuf = o->output_prefix(o, o->output_prefix_data);
1891                line_prefix = msgbuf->buf;
1892        }
1893
1894        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
1895                        (!one->mode || S_ISGITLINK(one->mode)) &&
1896                        (!two->mode || S_ISGITLINK(two->mode))) {
1897                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
1898                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
1899                show_submodule_summary(o->file, one ? one->path : two->path,
1900                                one->sha1, two->sha1, two->dirty_submodule,
1901                                del, add, reset);
1902                return;
1903        }
1904
1905        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
1906                textconv_one = get_textconv(one);
1907                textconv_two = get_textconv(two);
1908        }
1909
1910        diff_set_mnemonic_prefix(o, "a/", "b/");
1911        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
1912                a_prefix = o->b_prefix;
1913                b_prefix = o->a_prefix;
1914        } else {
1915                a_prefix = o->a_prefix;
1916                b_prefix = o->b_prefix;
1917        }
1918
1919        /* Never use a non-valid filename anywhere if at all possible */
1920        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
1921        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
1922
1923        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
1924        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
1925        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1926        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1927        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
1928        if (lbl[0][0] == '/') {
1929                /* /dev/null */
1930                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
1931                if (xfrm_msg)
1932                        strbuf_addstr(&header, xfrm_msg);
1933                must_show_header = 1;
1934        }
1935        else if (lbl[1][0] == '/') {
1936                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
1937                if (xfrm_msg)
1938                        strbuf_addstr(&header, xfrm_msg);
1939                must_show_header = 1;
1940        }
1941        else {
1942                if (one->mode != two->mode) {
1943                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
1944                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
1945                        must_show_header = 1;
1946                }
1947                if (xfrm_msg)
1948                        strbuf_addstr(&header, xfrm_msg);
1949
1950                /*
1951                 * we do not run diff between different kind
1952                 * of objects.
1953                 */
1954                if ((one->mode ^ two->mode) & S_IFMT)
1955                        goto free_ab_and_return;
1956                if (complete_rewrite &&
1957                    (textconv_one || !diff_filespec_is_binary(one)) &&
1958                    (textconv_two || !diff_filespec_is_binary(two))) {
1959                        fprintf(o->file, "%s", header.buf);
1960                        strbuf_reset(&header);
1961                        emit_rewrite_diff(name_a, name_b, one, two,
1962                                                textconv_one, textconv_two, o);
1963                        o->found_changes = 1;
1964                        goto free_ab_and_return;
1965                }
1966        }
1967
1968        if (!DIFF_OPT_TST(o, TEXT) &&
1969            ( (!textconv_one && diff_filespec_is_binary(one)) ||
1970              (!textconv_two && diff_filespec_is_binary(two)) )) {
1971                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1972                        die("unable to read files to diff");
1973                /* Quite common confusing case */
1974                if (mf1.size == mf2.size &&
1975                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
1976                        if (must_show_header)
1977                                fprintf(o->file, "%s", header.buf);
1978                        goto free_ab_and_return;
1979                }
1980                fprintf(o->file, "%s", header.buf);
1981                strbuf_reset(&header);
1982                if (DIFF_OPT_TST(o, BINARY))
1983                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
1984                else
1985                        fprintf(o->file, "%sBinary files %s and %s differ\n",
1986                                line_prefix, lbl[0], lbl[1]);
1987                o->found_changes = 1;
1988        }
1989        else {
1990                /* Crazy xdl interfaces.. */
1991                const char *diffopts = getenv("GIT_DIFF_OPTS");
1992                xpparam_t xpp;
1993                xdemitconf_t xecfg;
1994                struct emit_callback ecbdata;
1995                const struct userdiff_funcname *pe;
1996
1997                if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS) || must_show_header) {
1998                        fprintf(o->file, "%s", header.buf);
1999                        strbuf_reset(&header);
2000                }
2001
2002                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2003                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2004
2005                pe = diff_funcname_pattern(one);
2006                if (!pe)
2007                        pe = diff_funcname_pattern(two);
2008
2009                memset(&xpp, 0, sizeof(xpp));
2010                memset(&xecfg, 0, sizeof(xecfg));
2011                memset(&ecbdata, 0, sizeof(ecbdata));
2012                ecbdata.label_path = lbl;
2013                ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
2014                ecbdata.found_changesp = &o->found_changes;
2015                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
2016                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2017                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2018                ecbdata.opt = o;
2019                ecbdata.header = header.len ? &header : NULL;
2020                xpp.flags = o->xdl_opts;
2021                xecfg.ctxlen = o->context;
2022                xecfg.interhunkctxlen = o->interhunkcontext;
2023                xecfg.flags = XDL_EMIT_FUNCNAMES;
2024                if (pe)
2025                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2026                if (!diffopts)
2027                        ;
2028                else if (!prefixcmp(diffopts, "--unified="))
2029                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2030                else if (!prefixcmp(diffopts, "-u"))
2031                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2032                if (o->word_diff) {
2033                        int i;
2034
2035                        ecbdata.diff_words =
2036                                xcalloc(1, sizeof(struct diff_words_data));
2037                        ecbdata.diff_words->type = o->word_diff;
2038                        ecbdata.diff_words->opt = o;
2039                        if (!o->word_regex)
2040                                o->word_regex = userdiff_word_regex(one);
2041                        if (!o->word_regex)
2042                                o->word_regex = userdiff_word_regex(two);
2043                        if (!o->word_regex)
2044                                o->word_regex = diff_word_regex_cfg;
2045                        if (o->word_regex) {
2046                                ecbdata.diff_words->word_regex = (regex_t *)
2047                                        xmalloc(sizeof(regex_t));
2048                                if (regcomp(ecbdata.diff_words->word_regex,
2049                                                o->word_regex,
2050                                                REG_EXTENDED | REG_NEWLINE))
2051                                        die ("Invalid regular expression: %s",
2052                                                        o->word_regex);
2053                        }
2054                        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2055                                if (o->word_diff == diff_words_styles[i].type) {
2056                                        ecbdata.diff_words->style =
2057                                                &diff_words_styles[i];
2058                                        break;
2059                                }
2060                        }
2061                        if (DIFF_OPT_TST(o, COLOR_DIFF)) {
2062                                struct diff_words_style *st = ecbdata.diff_words->style;
2063                                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2064                                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2065                                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
2066                        }
2067                }
2068                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2069                              &xpp, &xecfg);
2070                if (o->word_diff)
2071                        free_diff_words_data(&ecbdata);
2072                if (textconv_one)
2073                        free(mf1.ptr);
2074                if (textconv_two)
2075                        free(mf2.ptr);
2076                xdiff_clear_find_func(&xecfg);
2077        }
2078
2079 free_ab_and_return:
2080        strbuf_release(&header);
2081        diff_free_filespec_data(one);
2082        diff_free_filespec_data(two);
2083        free(a_one);
2084        free(b_two);
2085        return;
2086}
2087
2088static void builtin_diffstat(const char *name_a, const char *name_b,
2089                             struct diff_filespec *one,
2090                             struct diff_filespec *two,
2091                             struct diffstat_t *diffstat,
2092                             struct diff_options *o,
2093                             int complete_rewrite)
2094{
2095        mmfile_t mf1, mf2;
2096        struct diffstat_file *data;
2097
2098        data = diffstat_add(diffstat, name_a, name_b);
2099
2100        if (!one || !two) {
2101                data->is_unmerged = 1;
2102                return;
2103        }
2104
2105        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2106                data->is_binary = 1;
2107                data->added = diff_filespec_size(two);
2108                data->deleted = diff_filespec_size(one);
2109        }
2110
2111        else if (complete_rewrite) {
2112                diff_populate_filespec(one, 0);
2113                diff_populate_filespec(two, 0);
2114                data->deleted = count_lines(one->data, one->size);
2115                data->added = count_lines(two->data, two->size);
2116        }
2117
2118        else {
2119                /* Crazy xdl interfaces.. */
2120                xpparam_t xpp;
2121                xdemitconf_t xecfg;
2122
2123                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2124                        die("unable to read files to diff");
2125
2126                memset(&xpp, 0, sizeof(xpp));
2127                memset(&xecfg, 0, sizeof(xecfg));
2128                xpp.flags = o->xdl_opts;
2129                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2130                              &xpp, &xecfg);
2131        }
2132
2133        diff_free_filespec_data(one);
2134        diff_free_filespec_data(two);
2135}
2136
2137static void builtin_checkdiff(const char *name_a, const char *name_b,
2138                              const char *attr_path,
2139                              struct diff_filespec *one,
2140                              struct diff_filespec *two,
2141                              struct diff_options *o)
2142{
2143        mmfile_t mf1, mf2;
2144        struct checkdiff_t data;
2145
2146        if (!two)
2147                return;
2148
2149        memset(&data, 0, sizeof(data));
2150        data.filename = name_b ? name_b : name_a;
2151        data.lineno = 0;
2152        data.o = o;
2153        data.ws_rule = whitespace_rule(attr_path);
2154        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2155
2156        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2157                die("unable to read files to diff");
2158
2159        /*
2160         * All the other codepaths check both sides, but not checking
2161         * the "old" side here is deliberate.  We are checking the newly
2162         * introduced changes, and as long as the "new" side is text, we
2163         * can and should check what it introduces.
2164         */
2165        if (diff_filespec_is_binary(two))
2166                goto free_and_return;
2167        else {
2168                /* Crazy xdl interfaces.. */
2169                xpparam_t xpp;
2170                xdemitconf_t xecfg;
2171
2172                memset(&xpp, 0, sizeof(xpp));
2173                memset(&xecfg, 0, sizeof(xecfg));
2174                xecfg.ctxlen = 1; /* at least one context line */
2175                xpp.flags = 0;
2176                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2177                              &xpp, &xecfg);
2178
2179                if (data.ws_rule & WS_BLANK_AT_EOF) {
2180                        struct emit_callback ecbdata;
2181                        int blank_at_eof;
2182
2183                        ecbdata.ws_rule = data.ws_rule;
2184                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2185                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2186
2187                        if (blank_at_eof) {
2188                                static char *err;
2189                                if (!err)
2190                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2191                                fprintf(o->file, "%s:%d: %s.\n",
2192                                        data.filename, blank_at_eof, err);
2193                                data.status = 1; /* report errors */
2194                        }
2195                }
2196        }
2197 free_and_return:
2198        diff_free_filespec_data(one);
2199        diff_free_filespec_data(two);
2200        if (data.status)
2201                DIFF_OPT_SET(o, CHECK_FAILED);
2202}
2203
2204struct diff_filespec *alloc_filespec(const char *path)
2205{
2206        int namelen = strlen(path);
2207        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2208
2209        memset(spec, 0, sizeof(*spec));
2210        spec->path = (char *)(spec + 1);
2211        memcpy(spec->path, path, namelen+1);
2212        spec->count = 1;
2213        spec->is_binary = -1;
2214        return spec;
2215}
2216
2217void free_filespec(struct diff_filespec *spec)
2218{
2219        if (!--spec->count) {
2220                diff_free_filespec_data(spec);
2221                free(spec);
2222        }
2223}
2224
2225void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2226                   unsigned short mode)
2227{
2228        if (mode) {
2229                spec->mode = canon_mode(mode);
2230                hashcpy(spec->sha1, sha1);
2231                spec->sha1_valid = !is_null_sha1(sha1);
2232        }
2233}
2234
2235/*
2236 * Given a name and sha1 pair, if the index tells us the file in
2237 * the work tree has that object contents, return true, so that
2238 * prepare_temp_file() does not have to inflate and extract.
2239 */
2240static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2241{
2242        struct cache_entry *ce;
2243        struct stat st;
2244        int pos, len;
2245
2246        /*
2247         * We do not read the cache ourselves here, because the
2248         * benchmark with my previous version that always reads cache
2249         * shows that it makes things worse for diff-tree comparing
2250         * two linux-2.6 kernel trees in an already checked out work
2251         * tree.  This is because most diff-tree comparisons deal with
2252         * only a small number of files, while reading the cache is
2253         * expensive for a large project, and its cost outweighs the
2254         * savings we get by not inflating the object to a temporary
2255         * file.  Practically, this code only helps when we are used
2256         * by diff-cache --cached, which does read the cache before
2257         * calling us.
2258         */
2259        if (!active_cache)
2260                return 0;
2261
2262        /* We want to avoid the working directory if our caller
2263         * doesn't need the data in a normal file, this system
2264         * is rather slow with its stat/open/mmap/close syscalls,
2265         * and the object is contained in a pack file.  The pack
2266         * is probably already open and will be faster to obtain
2267         * the data through than the working directory.  Loose
2268         * objects however would tend to be slower as they need
2269         * to be individually opened and inflated.
2270         */
2271        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2272                return 0;
2273
2274        len = strlen(name);
2275        pos = cache_name_pos(name, len);
2276        if (pos < 0)
2277                return 0;
2278        ce = active_cache[pos];
2279
2280        /*
2281         * This is not the sha1 we are looking for, or
2282         * unreusable because it is not a regular file.
2283         */
2284        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2285                return 0;
2286
2287        /*
2288         * If ce is marked as "assume unchanged", there is no
2289         * guarantee that work tree matches what we are looking for.
2290         */
2291        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2292                return 0;
2293
2294        /*
2295         * If ce matches the file in the work tree, we can reuse it.
2296         */
2297        if (ce_uptodate(ce) ||
2298            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2299                return 1;
2300
2301        return 0;
2302}
2303
2304static int populate_from_stdin(struct diff_filespec *s)
2305{
2306        struct strbuf buf = STRBUF_INIT;
2307        size_t size = 0;
2308
2309        if (strbuf_read(&buf, 0, 0) < 0)
2310                return error("error while reading from stdin %s",
2311                                     strerror(errno));
2312
2313        s->should_munmap = 0;
2314        s->data = strbuf_detach(&buf, &size);
2315        s->size = size;
2316        s->should_free = 1;
2317        return 0;
2318}
2319
2320static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2321{
2322        int len;
2323        char *data = xmalloc(100), *dirty = "";
2324
2325        /* Are we looking at the work tree? */
2326        if (s->dirty_submodule)
2327                dirty = "-dirty";
2328
2329        len = snprintf(data, 100,
2330                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2331        s->data = data;
2332        s->size = len;
2333        s->should_free = 1;
2334        if (size_only) {
2335                s->data = NULL;
2336                free(data);
2337        }
2338        return 0;
2339}
2340
2341/*
2342 * While doing rename detection and pickaxe operation, we may need to
2343 * grab the data for the blob (or file) for our own in-core comparison.
2344 * diff_filespec has data and size fields for this purpose.
2345 */
2346int diff_populate_filespec(struct diff_filespec *s, int size_only)
2347{
2348        int err = 0;
2349        if (!DIFF_FILE_VALID(s))
2350                die("internal error: asking to populate invalid file.");
2351        if (S_ISDIR(s->mode))
2352                return -1;
2353
2354        if (s->data)
2355                return 0;
2356
2357        if (size_only && 0 < s->size)
2358                return 0;
2359
2360        if (S_ISGITLINK(s->mode))
2361                return diff_populate_gitlink(s, size_only);
2362
2363        if (!s->sha1_valid ||
2364            reuse_worktree_file(s->path, s->sha1, 0)) {
2365                struct strbuf buf = STRBUF_INIT;
2366                struct stat st;
2367                int fd;
2368
2369                if (!strcmp(s->path, "-"))
2370                        return populate_from_stdin(s);
2371
2372                if (lstat(s->path, &st) < 0) {
2373                        if (errno == ENOENT) {
2374                        err_empty:
2375                                err = -1;
2376                        empty:
2377                                s->data = (char *)"";
2378                                s->size = 0;
2379                                return err;
2380                        }
2381                }
2382                s->size = xsize_t(st.st_size);
2383                if (!s->size)
2384                        goto empty;
2385                if (S_ISLNK(st.st_mode)) {
2386                        struct strbuf sb = STRBUF_INIT;
2387
2388                        if (strbuf_readlink(&sb, s->path, s->size))
2389                                goto err_empty;
2390                        s->size = sb.len;
2391                        s->data = strbuf_detach(&sb, NULL);
2392                        s->should_free = 1;
2393                        return 0;
2394                }
2395                if (size_only)
2396                        return 0;
2397                fd = open(s->path, O_RDONLY);
2398                if (fd < 0)
2399                        goto err_empty;
2400                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2401                close(fd);
2402                s->should_munmap = 1;
2403
2404                /*
2405                 * Convert from working tree format to canonical git format
2406                 */
2407                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2408                        size_t size = 0;
2409                        munmap(s->data, s->size);
2410                        s->should_munmap = 0;
2411                        s->data = strbuf_detach(&buf, &size);
2412                        s->size = size;
2413                        s->should_free = 1;
2414                }
2415        }
2416        else {
2417                enum object_type type;
2418                if (size_only) {
2419                        type = sha1_object_info(s->sha1, &s->size);
2420                        if (type < 0)
2421                                die("unable to read %s", sha1_to_hex(s->sha1));
2422                } else {
2423                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2424                        if (!s->data)
2425                                die("unable to read %s", sha1_to_hex(s->sha1));
2426                        s->should_free = 1;
2427                }
2428        }
2429        return 0;
2430}
2431
2432void diff_free_filespec_blob(struct diff_filespec *s)
2433{
2434        if (s->should_free)
2435                free(s->data);
2436        else if (s->should_munmap)
2437                munmap(s->data, s->size);
2438
2439        if (s->should_free || s->should_munmap) {
2440                s->should_free = s->should_munmap = 0;
2441                s->data = NULL;
2442        }
2443}
2444
2445void diff_free_filespec_data(struct diff_filespec *s)
2446{
2447        diff_free_filespec_blob(s);
2448        free(s->cnt_data);
2449        s->cnt_data = NULL;
2450}
2451
2452static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2453                           void *blob,
2454                           unsigned long size,
2455                           const unsigned char *sha1,
2456                           int mode)
2457{
2458        int fd;
2459        struct strbuf buf = STRBUF_INIT;
2460        struct strbuf template = STRBUF_INIT;
2461        char *path_dup = xstrdup(path);
2462        const char *base = basename(path_dup);
2463
2464        /* Generate "XXXXXX_basename.ext" */
2465        strbuf_addstr(&template, "XXXXXX_");
2466        strbuf_addstr(&template, base);
2467
2468        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2469                        strlen(base) + 1);
2470        if (fd < 0)
2471                die_errno("unable to create temp-file");
2472        if (convert_to_working_tree(path,
2473                        (const char *)blob, (size_t)size, &buf)) {
2474                blob = buf.buf;
2475                size = buf.len;
2476        }
2477        if (write_in_full(fd, blob, size) != size)
2478                die_errno("unable to write temp-file");
2479        close(fd);
2480        temp->name = temp->tmp_path;
2481        strcpy(temp->hex, sha1_to_hex(sha1));
2482        temp->hex[40] = 0;
2483        sprintf(temp->mode, "%06o", mode);
2484        strbuf_release(&buf);
2485        strbuf_release(&template);
2486        free(path_dup);
2487}
2488
2489static struct diff_tempfile *prepare_temp_file(const char *name,
2490                struct diff_filespec *one)
2491{
2492        struct diff_tempfile *temp = claim_diff_tempfile();
2493
2494        if (!DIFF_FILE_VALID(one)) {
2495        not_a_valid_file:
2496                /* A '-' entry produces this for file-2, and
2497                 * a '+' entry produces this for file-1.
2498                 */
2499                temp->name = "/dev/null";
2500                strcpy(temp->hex, ".");
2501                strcpy(temp->mode, ".");
2502                return temp;
2503        }
2504
2505        if (!remove_tempfile_installed) {
2506                atexit(remove_tempfile);
2507                sigchain_push_common(remove_tempfile_on_signal);
2508                remove_tempfile_installed = 1;
2509        }
2510
2511        if (!one->sha1_valid ||
2512            reuse_worktree_file(name, one->sha1, 1)) {
2513                struct stat st;
2514                if (lstat(name, &st) < 0) {
2515                        if (errno == ENOENT)
2516                                goto not_a_valid_file;
2517                        die_errno("stat(%s)", name);
2518                }
2519                if (S_ISLNK(st.st_mode)) {
2520                        struct strbuf sb = STRBUF_INIT;
2521                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2522                                die_errno("readlink(%s)", name);
2523                        prep_temp_blob(name, temp, sb.buf, sb.len,
2524                                       (one->sha1_valid ?
2525                                        one->sha1 : null_sha1),
2526                                       (one->sha1_valid ?
2527                                        one->mode : S_IFLNK));
2528                        strbuf_release(&sb);
2529                }
2530                else {
2531                        /* we can borrow from the file in the work tree */
2532                        temp->name = name;
2533                        if (!one->sha1_valid)
2534                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2535                        else
2536                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2537                        /* Even though we may sometimes borrow the
2538                         * contents from the work tree, we always want
2539                         * one->mode.  mode is trustworthy even when
2540                         * !(one->sha1_valid), as long as
2541                         * DIFF_FILE_VALID(one).
2542                         */
2543                        sprintf(temp->mode, "%06o", one->mode);
2544                }
2545                return temp;
2546        }
2547        else {
2548                if (diff_populate_filespec(one, 0))
2549                        die("cannot read data blob for %s", one->path);
2550                prep_temp_blob(name, temp, one->data, one->size,
2551                               one->sha1, one->mode);
2552        }
2553        return temp;
2554}
2555
2556/* An external diff command takes:
2557 *
2558 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2559 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2560 *
2561 */
2562static void run_external_diff(const char *pgm,
2563                              const char *name,
2564                              const char *other,
2565                              struct diff_filespec *one,
2566                              struct diff_filespec *two,
2567                              const char *xfrm_msg,
2568                              int complete_rewrite)
2569{
2570        const char *spawn_arg[10];
2571        int retval;
2572        const char **arg = &spawn_arg[0];
2573
2574        if (one && two) {
2575                struct diff_tempfile *temp_one, *temp_two;
2576                const char *othername = (other ? other : name);
2577                temp_one = prepare_temp_file(name, one);
2578                temp_two = prepare_temp_file(othername, two);
2579                *arg++ = pgm;
2580                *arg++ = name;
2581                *arg++ = temp_one->name;
2582                *arg++ = temp_one->hex;
2583                *arg++ = temp_one->mode;
2584                *arg++ = temp_two->name;
2585                *arg++ = temp_two->hex;
2586                *arg++ = temp_two->mode;
2587                if (other) {
2588                        *arg++ = other;
2589                        *arg++ = xfrm_msg;
2590                }
2591        } else {
2592                *arg++ = pgm;
2593                *arg++ = name;
2594        }
2595        *arg = NULL;
2596        fflush(NULL);
2597        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2598        remove_tempfile();
2599        if (retval) {
2600                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2601                exit(1);
2602        }
2603}
2604
2605static int similarity_index(struct diff_filepair *p)
2606{
2607        return p->score * 100 / MAX_SCORE;
2608}
2609
2610static void fill_metainfo(struct strbuf *msg,
2611                          const char *name,
2612                          const char *other,
2613                          struct diff_filespec *one,
2614                          struct diff_filespec *two,
2615                          struct diff_options *o,
2616                          struct diff_filepair *p,
2617                          int *must_show_header,
2618                          int use_color)
2619{
2620        const char *set = diff_get_color(use_color, DIFF_METAINFO);
2621        const char *reset = diff_get_color(use_color, DIFF_RESET);
2622        struct strbuf *msgbuf;
2623        char *line_prefix = "";
2624
2625        *must_show_header = 1;
2626        if (o->output_prefix) {
2627                msgbuf = o->output_prefix(o, o->output_prefix_data);
2628                line_prefix = msgbuf->buf;
2629        }
2630        strbuf_init(msg, PATH_MAX * 2 + 300);
2631        switch (p->status) {
2632        case DIFF_STATUS_COPIED:
2633                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2634                            line_prefix, set, similarity_index(p));
2635                strbuf_addf(msg, "%s\n%s%scopy from ",
2636                            reset,  line_prefix, set);
2637                quote_c_style(name, msg, NULL, 0);
2638                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2639                quote_c_style(other, msg, NULL, 0);
2640                strbuf_addf(msg, "%s\n", reset);
2641                break;
2642        case DIFF_STATUS_RENAMED:
2643                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2644                            line_prefix, set, similarity_index(p));
2645                strbuf_addf(msg, "%s\n%s%srename from ",
2646                            reset, line_prefix, set);
2647                quote_c_style(name, msg, NULL, 0);
2648                strbuf_addf(msg, "%s\n%s%srename to ",
2649                            reset, line_prefix, set);
2650                quote_c_style(other, msg, NULL, 0);
2651                strbuf_addf(msg, "%s\n", reset);
2652                break;
2653        case DIFF_STATUS_MODIFIED:
2654                if (p->score) {
2655                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2656                                    line_prefix,
2657                                    set, similarity_index(p), reset);
2658                        break;
2659                }
2660                /* fallthru */
2661        default:
2662                *must_show_header = 0;
2663        }
2664        if (one && two && hashcmp(one->sha1, two->sha1)) {
2665                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2666
2667                if (DIFF_OPT_TST(o, BINARY)) {
2668                        mmfile_t mf;
2669                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2670                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2671                                abbrev = 40;
2672                }
2673                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2674                            find_unique_abbrev(one->sha1, abbrev));
2675                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2676                if (one->mode == two->mode)
2677                        strbuf_addf(msg, " %06o", one->mode);
2678                strbuf_addf(msg, "%s\n", reset);
2679        }
2680}
2681
2682static void run_diff_cmd(const char *pgm,
2683                         const char *name,
2684                         const char *other,
2685                         const char *attr_path,
2686                         struct diff_filespec *one,
2687                         struct diff_filespec *two,
2688                         struct strbuf *msg,
2689                         struct diff_options *o,
2690                         struct diff_filepair *p)
2691{
2692        const char *xfrm_msg = NULL;
2693        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2694        int must_show_header = 0;
2695
2696        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2697                pgm = NULL;
2698        else {
2699                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2700                if (drv && drv->external)
2701                        pgm = drv->external;
2702        }
2703
2704        if (msg) {
2705                /*
2706                 * don't use colors when the header is intended for an
2707                 * external diff driver
2708                 */
2709                fill_metainfo(msg, name, other, one, two, o, p,
2710                              &must_show_header,
2711                              DIFF_OPT_TST(o, COLOR_DIFF) && !pgm);
2712                xfrm_msg = msg->len ? msg->buf : NULL;
2713        }
2714
2715        if (pgm) {
2716                run_external_diff(pgm, name, other, one, two, xfrm_msg,
2717                                  complete_rewrite);
2718                return;
2719        }
2720        if (one && two)
2721                builtin_diff(name, other ? other : name,
2722                             one, two, xfrm_msg, must_show_header,
2723                             o, complete_rewrite);
2724        else
2725                fprintf(o->file, "* Unmerged path %s\n", name);
2726}
2727
2728static void diff_fill_sha1_info(struct diff_filespec *one)
2729{
2730        if (DIFF_FILE_VALID(one)) {
2731                if (!one->sha1_valid) {
2732                        struct stat st;
2733                        if (!strcmp(one->path, "-")) {
2734                                hashcpy(one->sha1, null_sha1);
2735                                return;
2736                        }
2737                        if (lstat(one->path, &st) < 0)
2738                                die_errno("stat '%s'", one->path);
2739                        if (index_path(one->sha1, one->path, &st, 0))
2740                                die("cannot hash %s", one->path);
2741                }
2742        }
2743        else
2744                hashclr(one->sha1);
2745}
2746
2747static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2748{
2749        /* Strip the prefix but do not molest /dev/null and absolute paths */
2750        if (*namep && **namep != '/') {
2751                *namep += prefix_length;
2752                if (**namep == '/')
2753                        ++*namep;
2754        }
2755        if (*otherp && **otherp != '/') {
2756                *otherp += prefix_length;
2757                if (**otherp == '/')
2758                        ++*otherp;
2759        }
2760}
2761
2762static void run_diff(struct diff_filepair *p, struct diff_options *o)
2763{
2764        const char *pgm = external_diff();
2765        struct strbuf msg;
2766        struct diff_filespec *one = p->one;
2767        struct diff_filespec *two = p->two;
2768        const char *name;
2769        const char *other;
2770        const char *attr_path;
2771
2772        name  = p->one->path;
2773        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2774        attr_path = name;
2775        if (o->prefix_length)
2776                strip_prefix(o->prefix_length, &name, &other);
2777
2778        if (DIFF_PAIR_UNMERGED(p)) {
2779                run_diff_cmd(pgm, name, NULL, attr_path,
2780                             NULL, NULL, NULL, o, p);
2781                return;
2782        }
2783
2784        diff_fill_sha1_info(one);
2785        diff_fill_sha1_info(two);
2786
2787        if (!pgm &&
2788            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2789            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2790                /*
2791                 * a filepair that changes between file and symlink
2792                 * needs to be split into deletion and creation.
2793                 */
2794                struct diff_filespec *null = alloc_filespec(two->path);
2795                run_diff_cmd(NULL, name, other, attr_path,
2796                             one, null, &msg, o, p);
2797                free(null);
2798                strbuf_release(&msg);
2799
2800                null = alloc_filespec(one->path);
2801                run_diff_cmd(NULL, name, other, attr_path,
2802                             null, two, &msg, o, p);
2803                free(null);
2804        }
2805        else
2806                run_diff_cmd(pgm, name, other, attr_path,
2807                             one, two, &msg, o, p);
2808
2809        strbuf_release(&msg);
2810}
2811
2812static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2813                         struct diffstat_t *diffstat)
2814{
2815        const char *name;
2816        const char *other;
2817        int complete_rewrite = 0;
2818
2819        if (DIFF_PAIR_UNMERGED(p)) {
2820                /* unmerged */
2821                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2822                return;
2823        }
2824
2825        name = p->one->path;
2826        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2827
2828        if (o->prefix_length)
2829                strip_prefix(o->prefix_length, &name, &other);
2830
2831        diff_fill_sha1_info(p->one);
2832        diff_fill_sha1_info(p->two);
2833
2834        if (p->status == DIFF_STATUS_MODIFIED && p->score)
2835                complete_rewrite = 1;
2836        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2837}
2838
2839static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2840{
2841        const char *name;
2842        const char *other;
2843        const char *attr_path;
2844
2845        if (DIFF_PAIR_UNMERGED(p)) {
2846                /* unmerged */
2847                return;
2848        }
2849
2850        name = p->one->path;
2851        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2852        attr_path = other ? other : name;
2853
2854        if (o->prefix_length)
2855                strip_prefix(o->prefix_length, &name, &other);
2856
2857        diff_fill_sha1_info(p->one);
2858        diff_fill_sha1_info(p->two);
2859
2860        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2861}
2862
2863void diff_setup(struct diff_options *options)
2864{
2865        memcpy(options, &default_diff_options, sizeof(*options));
2866
2867        options->file = stdout;
2868
2869        options->line_termination = '\n';
2870        options->break_opt = -1;
2871        options->rename_limit = -1;
2872        options->dirstat_percent = 3;
2873        options->context = 3;
2874
2875        options->change = diff_change;
2876        options->add_remove = diff_addremove;
2877        if (diff_use_color_default > 0)
2878                DIFF_OPT_SET(options, COLOR_DIFF);
2879        options->detect_rename = diff_detect_rename_default;
2880
2881        if (diff_no_prefix) {
2882                options->a_prefix = options->b_prefix = "";
2883        } else if (!diff_mnemonic_prefix) {
2884                options->a_prefix = "a/";
2885                options->b_prefix = "b/";
2886        }
2887}
2888
2889int diff_setup_done(struct diff_options *options)
2890{
2891        int count = 0;
2892
2893        if (options->output_format & DIFF_FORMAT_NAME)
2894                count++;
2895        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
2896                count++;
2897        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
2898                count++;
2899        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
2900                count++;
2901        if (count > 1)
2902                die("--name-only, --name-status, --check and -s are mutually exclusive");
2903
2904        /*
2905         * Most of the time we can say "there are changes"
2906         * only by checking if there are changed paths, but
2907         * --ignore-whitespace* options force us to look
2908         * inside contents.
2909         */
2910
2911        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
2912            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
2913            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
2914                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
2915        else
2916                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
2917
2918        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
2919                options->detect_rename = DIFF_DETECT_COPY;
2920
2921        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
2922                options->prefix = NULL;
2923        if (options->prefix)
2924                options->prefix_length = strlen(options->prefix);
2925        else
2926                options->prefix_length = 0;
2927
2928        if (options->output_format & (DIFF_FORMAT_NAME |
2929                                      DIFF_FORMAT_NAME_STATUS |
2930                                      DIFF_FORMAT_CHECKDIFF |
2931                                      DIFF_FORMAT_NO_OUTPUT))
2932                options->output_format &= ~(DIFF_FORMAT_RAW |
2933                                            DIFF_FORMAT_NUMSTAT |
2934                                            DIFF_FORMAT_DIFFSTAT |
2935                                            DIFF_FORMAT_SHORTSTAT |
2936                                            DIFF_FORMAT_DIRSTAT |
2937                                            DIFF_FORMAT_SUMMARY |
2938                                            DIFF_FORMAT_PATCH);
2939
2940        /*
2941         * These cases always need recursive; we do not drop caller-supplied
2942         * recursive bits for other formats here.
2943         */
2944        if (options->output_format & (DIFF_FORMAT_PATCH |
2945                                      DIFF_FORMAT_NUMSTAT |
2946                                      DIFF_FORMAT_DIFFSTAT |
2947                                      DIFF_FORMAT_SHORTSTAT |
2948                                      DIFF_FORMAT_DIRSTAT |
2949                                      DIFF_FORMAT_SUMMARY |
2950                                      DIFF_FORMAT_CHECKDIFF))
2951                DIFF_OPT_SET(options, RECURSIVE);
2952        /*
2953         * Also pickaxe would not work very well if you do not say recursive
2954         */
2955        if (options->pickaxe)
2956                DIFF_OPT_SET(options, RECURSIVE);
2957        /*
2958         * When patches are generated, submodules diffed against the work tree
2959         * must be checked for dirtiness too so it can be shown in the output
2960         */
2961        if (options->output_format & DIFF_FORMAT_PATCH)
2962                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
2963
2964        if (options->detect_rename && options->rename_limit < 0)
2965                options->rename_limit = diff_rename_limit_default;
2966        if (options->setup & DIFF_SETUP_USE_CACHE) {
2967                if (!active_cache)
2968                        /* read-cache does not die even when it fails
2969                         * so it is safe for us to do this here.  Also
2970                         * it does not smudge active_cache or active_nr
2971                         * when it fails, so we do not have to worry about
2972                         * cleaning it up ourselves either.
2973                         */
2974                        read_cache();
2975        }
2976        if (options->abbrev <= 0 || 40 < options->abbrev)
2977                options->abbrev = 40; /* full */
2978
2979        /*
2980         * It does not make sense to show the first hit we happened
2981         * to have found.  It does not make sense not to return with
2982         * exit code in such a case either.
2983         */
2984        if (DIFF_OPT_TST(options, QUICK)) {
2985                options->output_format = DIFF_FORMAT_NO_OUTPUT;
2986                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2987        }
2988
2989        return 0;
2990}
2991
2992static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
2993{
2994        char c, *eq;
2995        int len;
2996
2997        if (*arg != '-')
2998                return 0;
2999        c = *++arg;
3000        if (!c)
3001                return 0;
3002        if (c == arg_short) {
3003                c = *++arg;
3004                if (!c)
3005                        return 1;
3006                if (val && isdigit(c)) {
3007                        char *end;
3008                        int n = strtoul(arg, &end, 10);
3009                        if (*end)
3010                                return 0;
3011                        *val = n;
3012                        return 1;
3013                }
3014                return 0;
3015        }
3016        if (c != '-')
3017                return 0;
3018        arg++;
3019        eq = strchr(arg, '=');
3020        if (eq)
3021                len = eq - arg;
3022        else
3023                len = strlen(arg);
3024        if (!len || strncmp(arg, arg_long, len))
3025                return 0;
3026        if (eq) {
3027                int n;
3028                char *end;
3029                if (!isdigit(*++eq))
3030                        return 0;
3031                n = strtoul(eq, &end, 10);
3032                if (*end)
3033                        return 0;
3034                *val = n;
3035        }
3036        return 1;
3037}
3038
3039static int diff_scoreopt_parse(const char *opt);
3040
3041static inline int short_opt(char opt, const char **argv,
3042                            const char **optarg)
3043{
3044        const char *arg = argv[0];
3045        if (arg[0] != '-' || arg[1] != opt)
3046                return 0;
3047        if (arg[2] != '\0') {
3048                *optarg = arg + 2;
3049                return 1;
3050        }
3051        if (!argv[1])
3052                die("Option '%c' requires a value", opt);
3053        *optarg = argv[1];
3054        return 2;
3055}
3056
3057int parse_long_opt(const char *opt, const char **argv,
3058                   const char **optarg)
3059{
3060        const char *arg = argv[0];
3061        if (arg[0] != '-' || arg[1] != '-')
3062                return 0;
3063        arg += strlen("--");
3064        if (prefixcmp(arg, opt))
3065                return 0;
3066        arg += strlen(opt);
3067        if (*arg == '=') { /* sticked form: --option=value */
3068                *optarg = arg + 1;
3069                return 1;
3070        }
3071        if (*arg != '\0')
3072                return 0;
3073        /* separate form: --option value */
3074        if (!argv[1])
3075                die("Option '--%s' requires a value", opt);
3076        *optarg = argv[1];
3077        return 2;
3078}
3079
3080static int stat_opt(struct diff_options *options, const char **av)
3081{
3082        const char *arg = av[0];
3083        char *end;
3084        int width = options->stat_width;
3085        int name_width = options->stat_name_width;
3086        int argcount = 1;
3087
3088        arg += strlen("--stat");
3089        end = (char *)arg;
3090
3091        switch (*arg) {
3092        case '-':
3093                if (!prefixcmp(arg, "-width")) {
3094                        arg += strlen("-width");
3095                        if (*arg == '=')
3096                                width = strtoul(arg + 1, &end, 10);
3097                        else if (!*arg && !av[1])
3098                                die("Option '--stat-width' requires a value");
3099                        else if (!*arg) {
3100                                width = strtoul(av[1], &end, 10);
3101                                argcount = 2;
3102                        }
3103                } else if (!prefixcmp(arg, "-name-width")) {
3104                        arg += strlen("-name-width");
3105                        if (*arg == '=')
3106                                name_width = strtoul(arg + 1, &end, 10);
3107                        else if (!*arg && !av[1])
3108                                die("Option '--stat-name-width' requires a value");
3109                        else if (!*arg) {
3110                                name_width = strtoul(av[1], &end, 10);
3111                                argcount = 2;
3112                        }
3113                }
3114                break;
3115        case '=':
3116                width = strtoul(arg+1, &end, 10);
3117                if (*end == ',')
3118                        name_width = strtoul(end+1, &end, 10);
3119        }
3120
3121        /* Important! This checks all the error cases! */
3122        if (*end)
3123                return 0;
3124        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3125        options->stat_name_width = name_width;
3126        options->stat_width = width;
3127        return argcount;
3128}
3129
3130int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3131{
3132        const char *arg = av[0];
3133        const char *optarg;
3134        int argcount;
3135
3136        /* Output format options */
3137        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3138                options->output_format |= DIFF_FORMAT_PATCH;
3139        else if (opt_arg(arg, 'U', "unified", &options->context))
3140                options->output_format |= DIFF_FORMAT_PATCH;
3141        else if (!strcmp(arg, "--raw"))
3142                options->output_format |= DIFF_FORMAT_RAW;
3143        else if (!strcmp(arg, "--patch-with-raw"))
3144                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3145        else if (!strcmp(arg, "--numstat"))
3146                options->output_format |= DIFF_FORMAT_NUMSTAT;
3147        else if (!strcmp(arg, "--shortstat"))
3148                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3149        else if (opt_arg(arg, 'X', "dirstat", &options->dirstat_percent))
3150                options->output_format |= DIFF_FORMAT_DIRSTAT;
3151        else if (!strcmp(arg, "--cumulative")) {
3152                options->output_format |= DIFF_FORMAT_DIRSTAT;
3153                DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
3154        } else if (opt_arg(arg, 0, "dirstat-by-file",
3155                           &options->dirstat_percent)) {
3156                options->output_format |= DIFF_FORMAT_DIRSTAT;
3157                DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
3158        }
3159        else if (!strcmp(arg, "--check"))
3160                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3161        else if (!strcmp(arg, "--summary"))
3162                options->output_format |= DIFF_FORMAT_SUMMARY;
3163        else if (!strcmp(arg, "--patch-with-stat"))
3164                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3165        else if (!strcmp(arg, "--name-only"))
3166                options->output_format |= DIFF_FORMAT_NAME;
3167        else if (!strcmp(arg, "--name-status"))
3168                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3169        else if (!strcmp(arg, "-s"))
3170                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3171        else if (!prefixcmp(arg, "--stat"))
3172                /* --stat, --stat-width, or --stat-name-width */
3173                return stat_opt(options, av);
3174
3175        /* renames options */
3176        else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
3177                 !strcmp(arg, "--break-rewrites")) {
3178                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3179                        return error("invalid argument to -B: %s", arg+2);
3180        }
3181        else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--find-renames=") ||
3182                 !strcmp(arg, "--find-renames")) {
3183                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3184                        return error("invalid argument to -M: %s", arg+2);
3185                options->detect_rename = DIFF_DETECT_RENAME;
3186        }
3187        else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
3188                 !strcmp(arg, "--find-copies")) {
3189                if (options->detect_rename == DIFF_DETECT_COPY)
3190                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3191                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3192                        return error("invalid argument to -C: %s", arg+2);
3193                options->detect_rename = DIFF_DETECT_COPY;
3194        }
3195        else if (!strcmp(arg, "--no-renames"))
3196                options->detect_rename = 0;
3197        else if (!strcmp(arg, "--relative"))
3198                DIFF_OPT_SET(options, RELATIVE_NAME);
3199        else if (!prefixcmp(arg, "--relative=")) {
3200                DIFF_OPT_SET(options, RELATIVE_NAME);
3201                options->prefix = arg + 11;
3202        }
3203
3204        /* xdiff options */
3205        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3206                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3207        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3208                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3209        else if (!strcmp(arg, "--ignore-space-at-eol"))
3210                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3211        else if (!strcmp(arg, "--patience"))
3212                DIFF_XDL_SET(options, PATIENCE_DIFF);
3213
3214        /* flags options */
3215        else if (!strcmp(arg, "--binary")) {
3216                options->output_format |= DIFF_FORMAT_PATCH;
3217                DIFF_OPT_SET(options, BINARY);
3218        }
3219        else if (!strcmp(arg, "--full-index"))
3220                DIFF_OPT_SET(options, FULL_INDEX);
3221        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3222                DIFF_OPT_SET(options, TEXT);
3223        else if (!strcmp(arg, "-R"))
3224                DIFF_OPT_SET(options, REVERSE_DIFF);
3225        else if (!strcmp(arg, "--find-copies-harder"))
3226                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3227        else if (!strcmp(arg, "--follow"))
3228                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3229        else if (!strcmp(arg, "--color"))
3230                DIFF_OPT_SET(options, COLOR_DIFF);
3231        else if (!prefixcmp(arg, "--color=")) {
3232                int value = git_config_colorbool(NULL, arg+8, -1);
3233                if (value == 0)
3234                        DIFF_OPT_CLR(options, COLOR_DIFF);
3235                else if (value > 0)
3236                        DIFF_OPT_SET(options, COLOR_DIFF);
3237                else
3238                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3239        }
3240        else if (!strcmp(arg, "--no-color"))
3241                DIFF_OPT_CLR(options, COLOR_DIFF);
3242        else if (!strcmp(arg, "--color-words")) {
3243                DIFF_OPT_SET(options, COLOR_DIFF);
3244                options->word_diff = DIFF_WORDS_COLOR;
3245        }
3246        else if (!prefixcmp(arg, "--color-words=")) {
3247                DIFF_OPT_SET(options, COLOR_DIFF);
3248                options->word_diff = DIFF_WORDS_COLOR;
3249                options->word_regex = arg + 14;
3250        }
3251        else if (!strcmp(arg, "--word-diff")) {
3252                if (options->word_diff == DIFF_WORDS_NONE)
3253                        options->word_diff = DIFF_WORDS_PLAIN;
3254        }
3255        else if (!prefixcmp(arg, "--word-diff=")) {
3256                const char *type = arg + 12;
3257                if (!strcmp(type, "plain"))
3258                        options->word_diff = DIFF_WORDS_PLAIN;
3259                else if (!strcmp(type, "color")) {
3260                        DIFF_OPT_SET(options, COLOR_DIFF);
3261                        options->word_diff = DIFF_WORDS_COLOR;
3262                }
3263                else if (!strcmp(type, "porcelain"))
3264                        options->word_diff = DIFF_WORDS_PORCELAIN;
3265                else if (!strcmp(type, "none"))
3266                        options->word_diff = DIFF_WORDS_NONE;
3267                else
3268                        die("bad --word-diff argument: %s", type);
3269        }
3270        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3271                if (options->word_diff == DIFF_WORDS_NONE)
3272                        options->word_diff = DIFF_WORDS_PLAIN;
3273                options->word_regex = optarg;
3274                return argcount;
3275        }
3276        else if (!strcmp(arg, "--exit-code"))
3277                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3278        else if (!strcmp(arg, "--quiet"))
3279                DIFF_OPT_SET(options, QUICK);
3280        else if (!strcmp(arg, "--ext-diff"))
3281                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3282        else if (!strcmp(arg, "--no-ext-diff"))
3283                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3284        else if (!strcmp(arg, "--textconv"))
3285                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3286        else if (!strcmp(arg, "--no-textconv"))
3287                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3288        else if (!strcmp(arg, "--ignore-submodules")) {
3289                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3290                handle_ignore_submodules_arg(options, "all");
3291        } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3292                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3293                handle_ignore_submodules_arg(options, arg + 20);
3294        } else if (!strcmp(arg, "--submodule"))
3295                DIFF_OPT_SET(options, SUBMODULE_LOG);
3296        else if (!prefixcmp(arg, "--submodule=")) {
3297                if (!strcmp(arg + 12, "log"))
3298                        DIFF_OPT_SET(options, SUBMODULE_LOG);
3299        }
3300
3301        /* misc options */
3302        else if (!strcmp(arg, "-z"))
3303                options->line_termination = 0;
3304        else if ((argcount = short_opt('l', av, &optarg))) {
3305                options->rename_limit = strtoul(optarg, NULL, 10);
3306                return argcount;
3307        }
3308        else if ((argcount = short_opt('S', av, &optarg))) {
3309                options->pickaxe = optarg;
3310                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3311                return argcount;
3312        } else if ((argcount = short_opt('G', av, &optarg))) {
3313                options->pickaxe = optarg;
3314                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3315                return argcount;
3316        }
3317        else if (!strcmp(arg, "--pickaxe-all"))
3318                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3319        else if (!strcmp(arg, "--pickaxe-regex"))
3320                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3321        else if ((argcount = short_opt('O', av, &optarg))) {
3322                options->orderfile = optarg;
3323                return argcount;
3324        }
3325        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3326                options->filter = optarg;
3327                return argcount;
3328        }
3329        else if (!strcmp(arg, "--abbrev"))
3330                options->abbrev = DEFAULT_ABBREV;
3331        else if (!prefixcmp(arg, "--abbrev=")) {
3332                options->abbrev = strtoul(arg + 9, NULL, 10);
3333                if (options->abbrev < MINIMUM_ABBREV)
3334                        options->abbrev = MINIMUM_ABBREV;
3335                else if (40 < options->abbrev)
3336                        options->abbrev = 40;
3337        }
3338        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3339                options->a_prefix = optarg;
3340                return argcount;
3341        }
3342        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3343                options->b_prefix = optarg;
3344                return argcount;
3345        }
3346        else if (!strcmp(arg, "--no-prefix"))
3347                options->a_prefix = options->b_prefix = "";
3348        else if (opt_arg(arg, '\0', "inter-hunk-context",
3349                         &options->interhunkcontext))
3350                ;
3351        else if ((argcount = parse_long_opt("output", av, &optarg))) {
3352                options->file = fopen(optarg, "w");
3353                if (!options->file)
3354                        die_errno("Could not open '%s'", optarg);
3355                options->close_file = 1;
3356                return argcount;
3357        } else
3358                return 0;
3359        return 1;
3360}
3361
3362int parse_rename_score(const char **cp_p)
3363{
3364        unsigned long num, scale;
3365        int ch, dot;
3366        const char *cp = *cp_p;
3367
3368        num = 0;
3369        scale = 1;
3370        dot = 0;
3371        for (;;) {
3372                ch = *cp;
3373                if ( !dot && ch == '.' ) {
3374                        scale = 1;
3375                        dot = 1;
3376                } else if ( ch == '%' ) {
3377                        scale = dot ? scale*100 : 100;
3378                        cp++;   /* % is always at the end */
3379                        break;
3380                } else if ( ch >= '0' && ch <= '9' ) {
3381                        if ( scale < 100000 ) {
3382                                scale *= 10;
3383                                num = (num*10) + (ch-'0');
3384                        }
3385                } else {
3386                        break;
3387                }
3388                cp++;
3389        }
3390        *cp_p = cp;
3391
3392        /* user says num divided by scale and we say internally that
3393         * is MAX_SCORE * num / scale.
3394         */
3395        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3396}
3397
3398static int diff_scoreopt_parse(const char *opt)
3399{
3400        int opt1, opt2, cmd;
3401
3402        if (*opt++ != '-')
3403                return -1;
3404        cmd = *opt++;
3405        if (cmd == '-') {
3406                /* convert the long-form arguments into short-form versions */
3407                if (!prefixcmp(opt, "break-rewrites")) {
3408                        opt += strlen("break-rewrites");
3409                        if (*opt == 0 || *opt++ == '=')
3410                                cmd = 'B';
3411                } else if (!prefixcmp(opt, "find-copies")) {
3412                        opt += strlen("find-copies");
3413                        if (*opt == 0 || *opt++ == '=')
3414                                cmd = 'C';
3415                } else if (!prefixcmp(opt, "find-renames")) {
3416                        opt += strlen("find-renames");
3417                        if (*opt == 0 || *opt++ == '=')
3418                                cmd = 'M';
3419                }
3420        }
3421        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3422                return -1; /* that is not a -M, -C nor -B option */
3423
3424        opt1 = parse_rename_score(&opt);
3425        if (cmd != 'B')
3426                opt2 = 0;
3427        else {
3428                if (*opt == 0)
3429                        opt2 = 0;
3430                else if (*opt != '/')
3431                        return -1; /* we expect -B80/99 or -B80 */
3432                else {
3433                        opt++;
3434                        opt2 = parse_rename_score(&opt);
3435                }
3436        }
3437        if (*opt != 0)
3438                return -1;
3439        return opt1 | (opt2 << 16);
3440}
3441
3442struct diff_queue_struct diff_queued_diff;
3443
3444void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3445{
3446        if (queue->alloc <= queue->nr) {
3447                queue->alloc = alloc_nr(queue->alloc);
3448                queue->queue = xrealloc(queue->queue,
3449                                        sizeof(dp) * queue->alloc);
3450        }
3451        queue->queue[queue->nr++] = dp;
3452}
3453
3454struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3455                                 struct diff_filespec *one,
3456                                 struct diff_filespec *two)
3457{
3458        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3459        dp->one = one;
3460        dp->two = two;
3461        if (queue)
3462                diff_q(queue, dp);
3463        return dp;
3464}
3465
3466void diff_free_filepair(struct diff_filepair *p)
3467{
3468        free_filespec(p->one);
3469        free_filespec(p->two);
3470        free(p);
3471}
3472
3473/* This is different from find_unique_abbrev() in that
3474 * it stuffs the result with dots for alignment.
3475 */
3476const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3477{
3478        int abblen;
3479        const char *abbrev;
3480        if (len == 40)
3481                return sha1_to_hex(sha1);
3482
3483        abbrev = find_unique_abbrev(sha1, len);
3484        abblen = strlen(abbrev);
3485        if (abblen < 37) {
3486                static char hex[41];
3487                if (len < abblen && abblen <= len + 2)
3488                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3489                else
3490                        sprintf(hex, "%s...", abbrev);
3491                return hex;
3492        }
3493        return sha1_to_hex(sha1);
3494}
3495
3496static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3497{
3498        int line_termination = opt->line_termination;
3499        int inter_name_termination = line_termination ? '\t' : '\0';
3500        if (opt->output_prefix) {
3501                struct strbuf *msg = NULL;
3502                msg = opt->output_prefix(opt, opt->output_prefix_data);
3503                fprintf(opt->file, "%s", msg->buf);
3504        }
3505
3506        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3507                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3508                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3509                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3510        }
3511        if (p->score) {
3512                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3513                        inter_name_termination);
3514        } else {
3515                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3516        }
3517
3518        if (p->status == DIFF_STATUS_COPIED ||
3519            p->status == DIFF_STATUS_RENAMED) {
3520                const char *name_a, *name_b;
3521                name_a = p->one->path;
3522                name_b = p->two->path;
3523                strip_prefix(opt->prefix_length, &name_a, &name_b);
3524                write_name_quoted(name_a, opt->file, inter_name_termination);
3525                write_name_quoted(name_b, opt->file, line_termination);
3526        } else {
3527                const char *name_a, *name_b;
3528                name_a = p->one->mode ? p->one->path : p->two->path;
3529                name_b = NULL;
3530                strip_prefix(opt->prefix_length, &name_a, &name_b);
3531                write_name_quoted(name_a, opt->file, line_termination);
3532        }
3533}
3534
3535int diff_unmodified_pair(struct diff_filepair *p)
3536{
3537        /* This function is written stricter than necessary to support
3538         * the currently implemented transformers, but the idea is to
3539         * let transformers to produce diff_filepairs any way they want,
3540         * and filter and clean them up here before producing the output.
3541         */
3542        struct diff_filespec *one = p->one, *two = p->two;
3543
3544        if (DIFF_PAIR_UNMERGED(p))
3545                return 0; /* unmerged is interesting */
3546
3547        /* deletion, addition, mode or type change
3548         * and rename are all interesting.
3549         */
3550        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3551            DIFF_PAIR_MODE_CHANGED(p) ||
3552            strcmp(one->path, two->path))
3553                return 0;
3554
3555        /* both are valid and point at the same path.  that is, we are
3556         * dealing with a change.
3557         */
3558        if (one->sha1_valid && two->sha1_valid &&
3559            !hashcmp(one->sha1, two->sha1) &&
3560            !one->dirty_submodule && !two->dirty_submodule)
3561                return 1; /* no change */
3562        if (!one->sha1_valid && !two->sha1_valid)
3563                return 1; /* both look at the same file on the filesystem. */
3564        return 0;
3565}
3566
3567static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
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 tree diffs in patch format */
3575
3576        run_diff(p, o);
3577}
3578
3579static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3580                            struct diffstat_t *diffstat)
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; /* no useful stat for tree diffs */
3588
3589        run_diffstat(p, o, diffstat);
3590}
3591
3592static void diff_flush_checkdiff(struct diff_filepair *p,
3593                struct diff_options *o)
3594{
3595        if (diff_unmodified_pair(p))
3596                return;
3597
3598        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3599            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3600                return; /* nothing to check in tree diffs */
3601
3602        run_checkdiff(p, o);
3603}
3604
3605int diff_queue_is_empty(void)
3606{
3607        struct diff_queue_struct *q = &diff_queued_diff;
3608        int i;
3609        for (i = 0; i < q->nr; i++)
3610                if (!diff_unmodified_pair(q->queue[i]))
3611                        return 0;
3612        return 1;
3613}
3614
3615#if DIFF_DEBUG
3616void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3617{
3618        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3619                x, one ? one : "",
3620                s->path,
3621                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3622                s->mode,
3623                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3624        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3625                x, one ? one : "",
3626                s->size, s->xfrm_flags);
3627}
3628
3629void diff_debug_filepair(const struct diff_filepair *p, int i)
3630{
3631        diff_debug_filespec(p->one, i, "one");
3632        diff_debug_filespec(p->two, i, "two");
3633        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3634                p->score, p->status ? p->status : '?',
3635                p->one->rename_used, p->broken_pair);
3636}
3637
3638void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3639{
3640        int i;
3641        if (msg)
3642                fprintf(stderr, "%s\n", msg);
3643        fprintf(stderr, "q->nr = %d\n", q->nr);
3644        for (i = 0; i < q->nr; i++) {
3645                struct diff_filepair *p = q->queue[i];
3646                diff_debug_filepair(p, i);
3647        }
3648}
3649#endif
3650
3651static void diff_resolve_rename_copy(void)
3652{
3653        int i;
3654        struct diff_filepair *p;
3655        struct diff_queue_struct *q = &diff_queued_diff;
3656
3657        diff_debug_queue("resolve-rename-copy", q);
3658
3659        for (i = 0; i < q->nr; i++) {
3660                p = q->queue[i];
3661                p->status = 0; /* undecided */
3662                if (DIFF_PAIR_UNMERGED(p))
3663                        p->status = DIFF_STATUS_UNMERGED;
3664                else if (!DIFF_FILE_VALID(p->one))
3665                        p->status = DIFF_STATUS_ADDED;
3666                else if (!DIFF_FILE_VALID(p->two))
3667                        p->status = DIFF_STATUS_DELETED;
3668                else if (DIFF_PAIR_TYPE_CHANGED(p))
3669                        p->status = DIFF_STATUS_TYPE_CHANGED;
3670
3671                /* from this point on, we are dealing with a pair
3672                 * whose both sides are valid and of the same type, i.e.
3673                 * either in-place edit or rename/copy edit.
3674                 */
3675                else if (DIFF_PAIR_RENAME(p)) {
3676                        /*
3677                         * A rename might have re-connected a broken
3678                         * pair up, causing the pathnames to be the
3679                         * same again. If so, that's not a rename at
3680                         * all, just a modification..
3681                         *
3682                         * Otherwise, see if this source was used for
3683                         * multiple renames, in which case we decrement
3684                         * the count, and call it a copy.
3685                         */
3686                        if (!strcmp(p->one->path, p->two->path))
3687                                p->status = DIFF_STATUS_MODIFIED;
3688                        else if (--p->one->rename_used > 0)
3689                                p->status = DIFF_STATUS_COPIED;
3690                        else
3691                                p->status = DIFF_STATUS_RENAMED;
3692                }
3693                else if (hashcmp(p->one->sha1, p->two->sha1) ||
3694                         p->one->mode != p->two->mode ||
3695                         p->one->dirty_submodule ||
3696                         p->two->dirty_submodule ||
3697                         is_null_sha1(p->one->sha1))
3698                        p->status = DIFF_STATUS_MODIFIED;
3699                else {
3700                        /* This is a "no-change" entry and should not
3701                         * happen anymore, but prepare for broken callers.
3702                         */
3703                        error("feeding unmodified %s to diffcore",
3704                              p->one->path);
3705                        p->status = DIFF_STATUS_UNKNOWN;
3706                }
3707        }
3708        diff_debug_queue("resolve-rename-copy done", q);
3709}
3710
3711static int check_pair_status(struct diff_filepair *p)
3712{
3713        switch (p->status) {
3714        case DIFF_STATUS_UNKNOWN:
3715                return 0;
3716        case 0:
3717                die("internal error in diff-resolve-rename-copy");
3718        default:
3719                return 1;
3720        }
3721}
3722
3723static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3724{
3725        int fmt = opt->output_format;
3726
3727        if (fmt & DIFF_FORMAT_CHECKDIFF)
3728                diff_flush_checkdiff(p, opt);
3729        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3730                diff_flush_raw(p, opt);
3731        else if (fmt & DIFF_FORMAT_NAME) {
3732                const char *name_a, *name_b;
3733                name_a = p->two->path;
3734                name_b = NULL;
3735                strip_prefix(opt->prefix_length, &name_a, &name_b);
3736                write_name_quoted(name_a, opt->file, opt->line_termination);
3737        }
3738}
3739
3740static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
3741{
3742        if (fs->mode)
3743                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
3744        else
3745                fprintf(file, " %s ", newdelete);
3746        write_name_quoted(fs->path, file, '\n');
3747}
3748
3749
3750static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
3751                const char *line_prefix)
3752{
3753        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
3754                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
3755                        p->two->mode, show_name ? ' ' : '\n');
3756                if (show_name) {
3757                        write_name_quoted(p->two->path, file, '\n');
3758                }
3759        }
3760}
3761
3762static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
3763                        const char *line_prefix)
3764{
3765        char *names = pprint_rename(p->one->path, p->two->path);
3766
3767        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
3768        free(names);
3769        show_mode_change(file, p, 0, line_prefix);
3770}
3771
3772static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
3773{
3774        FILE *file = opt->file;
3775        char *line_prefix = "";
3776
3777        if (opt->output_prefix) {
3778                struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
3779                line_prefix = buf->buf;
3780        }
3781
3782        switch(p->status) {
3783        case DIFF_STATUS_DELETED:
3784                fputs(line_prefix, file);
3785                show_file_mode_name(file, "delete", p->one);
3786                break;
3787        case DIFF_STATUS_ADDED:
3788                fputs(line_prefix, file);
3789                show_file_mode_name(file, "create", p->two);
3790                break;
3791        case DIFF_STATUS_COPIED:
3792                fputs(line_prefix, file);
3793                show_rename_copy(file, "copy", p, line_prefix);
3794                break;
3795        case DIFF_STATUS_RENAMED:
3796                fputs(line_prefix, file);
3797                show_rename_copy(file, "rename", p, line_prefix);
3798                break;
3799        default:
3800                if (p->score) {
3801                        fprintf(file, "%s rewrite ", line_prefix);
3802                        write_name_quoted(p->two->path, file, ' ');
3803                        fprintf(file, "(%d%%)\n", similarity_index(p));
3804                }
3805                show_mode_change(file, p, !p->score, line_prefix);
3806                break;
3807        }
3808}
3809
3810struct patch_id_t {
3811        git_SHA_CTX *ctx;
3812        int patchlen;
3813};
3814
3815static int remove_space(char *line, int len)
3816{
3817        int i;
3818        char *dst = line;
3819        unsigned char c;
3820
3821        for (i = 0; i < len; i++)
3822                if (!isspace((c = line[i])))
3823                        *dst++ = c;
3824
3825        return dst - line;
3826}
3827
3828static void patch_id_consume(void *priv, char *line, unsigned long len)
3829{
3830        struct patch_id_t *data = priv;
3831        int new_len;
3832
3833        /* Ignore line numbers when computing the SHA1 of the patch */
3834        if (!prefixcmp(line, "@@ -"))
3835                return;
3836
3837        new_len = remove_space(line, len);
3838
3839        git_SHA1_Update(data->ctx, line, new_len);
3840        data->patchlen += new_len;
3841}
3842
3843/* returns 0 upon success, and writes result into sha1 */
3844static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
3845{
3846        struct diff_queue_struct *q = &diff_queued_diff;
3847        int i;
3848        git_SHA_CTX ctx;
3849        struct patch_id_t data;
3850        char buffer[PATH_MAX * 4 + 20];
3851
3852        git_SHA1_Init(&ctx);
3853        memset(&data, 0, sizeof(struct patch_id_t));
3854        data.ctx = &ctx;
3855
3856        for (i = 0; i < q->nr; i++) {
3857                xpparam_t xpp;
3858                xdemitconf_t xecfg;
3859                mmfile_t mf1, mf2;
3860                struct diff_filepair *p = q->queue[i];
3861                int len1, len2;
3862
3863                memset(&xpp, 0, sizeof(xpp));
3864                memset(&xecfg, 0, sizeof(xecfg));
3865                if (p->status == 0)
3866                        return error("internal diff status error");
3867                if (p->status == DIFF_STATUS_UNKNOWN)
3868                        continue;
3869                if (diff_unmodified_pair(p))
3870                        continue;
3871                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3872                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3873                        continue;
3874                if (DIFF_PAIR_UNMERGED(p))
3875                        continue;
3876
3877                diff_fill_sha1_info(p->one);
3878                diff_fill_sha1_info(p->two);
3879                if (fill_mmfile(&mf1, p->one) < 0 ||
3880                                fill_mmfile(&mf2, p->two) < 0)
3881                        return error("unable to read files to diff");
3882
3883                len1 = remove_space(p->one->path, strlen(p->one->path));
3884                len2 = remove_space(p->two->path, strlen(p->two->path));
3885                if (p->one->mode == 0)
3886                        len1 = snprintf(buffer, sizeof(buffer),
3887                                        "diff--gita/%.*sb/%.*s"
3888                                        "newfilemode%06o"
3889                                        "---/dev/null"
3890                                        "+++b/%.*s",
3891                                        len1, p->one->path,
3892                                        len2, p->two->path,
3893                                        p->two->mode,
3894                                        len2, p->two->path);
3895                else if (p->two->mode == 0)
3896                        len1 = snprintf(buffer, sizeof(buffer),
3897                                        "diff--gita/%.*sb/%.*s"
3898                                        "deletedfilemode%06o"
3899                                        "---a/%.*s"
3900                                        "+++/dev/null",
3901                                        len1, p->one->path,
3902                                        len2, p->two->path,
3903                                        p->one->mode,
3904                                        len1, p->one->path);
3905                else
3906                        len1 = snprintf(buffer, sizeof(buffer),
3907                                        "diff--gita/%.*sb/%.*s"
3908                                        "---a/%.*s"
3909                                        "+++b/%.*s",
3910                                        len1, p->one->path,
3911                                        len2, p->two->path,
3912                                        len1, p->one->path,
3913                                        len2, p->two->path);
3914                git_SHA1_Update(&ctx, buffer, len1);
3915
3916                if (diff_filespec_is_binary(p->one) ||
3917                    diff_filespec_is_binary(p->two)) {
3918                        git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
3919                        git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
3920                        continue;
3921                }
3922
3923                xpp.flags = 0;
3924                xecfg.ctxlen = 3;
3925                xecfg.flags = 0;
3926                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
3927                              &xpp, &xecfg);
3928        }
3929
3930        git_SHA1_Final(sha1, &ctx);
3931        return 0;
3932}
3933
3934int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
3935{
3936        struct diff_queue_struct *q = &diff_queued_diff;
3937        int i;
3938        int result = diff_get_patch_id(options, sha1);
3939
3940        for (i = 0; i < q->nr; i++)
3941                diff_free_filepair(q->queue[i]);
3942
3943        free(q->queue);
3944        DIFF_QUEUE_CLEAR(q);
3945
3946        return result;
3947}
3948
3949static int is_summary_empty(const struct diff_queue_struct *q)
3950{
3951        int i;
3952
3953        for (i = 0; i < q->nr; i++) {
3954                const struct diff_filepair *p = q->queue[i];
3955
3956                switch (p->status) {
3957                case DIFF_STATUS_DELETED:
3958                case DIFF_STATUS_ADDED:
3959                case DIFF_STATUS_COPIED:
3960                case DIFF_STATUS_RENAMED:
3961                        return 0;
3962                default:
3963                        if (p->score)
3964                                return 0;
3965                        if (p->one->mode && p->two->mode &&
3966                            p->one->mode != p->two->mode)
3967                                return 0;
3968                        break;
3969                }
3970        }
3971        return 1;
3972}
3973
3974void diff_flush(struct diff_options *options)
3975{
3976        struct diff_queue_struct *q = &diff_queued_diff;
3977        int i, output_format = options->output_format;
3978        int separator = 0;
3979
3980        /*
3981         * Order: raw, stat, summary, patch
3982         * or:    name/name-status/checkdiff (other bits clear)
3983         */
3984        if (!q->nr)
3985                goto free_queue;
3986
3987        if (output_format & (DIFF_FORMAT_RAW |
3988                             DIFF_FORMAT_NAME |
3989                             DIFF_FORMAT_NAME_STATUS |
3990                             DIFF_FORMAT_CHECKDIFF)) {
3991                for (i = 0; i < q->nr; i++) {
3992                        struct diff_filepair *p = q->queue[i];
3993                        if (check_pair_status(p))
3994                                flush_one_pair(p, options);
3995                }
3996                separator++;
3997        }
3998
3999        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
4000                struct diffstat_t diffstat;
4001
4002                memset(&diffstat, 0, sizeof(struct diffstat_t));
4003                for (i = 0; i < q->nr; i++) {
4004                        struct diff_filepair *p = q->queue[i];
4005                        if (check_pair_status(p))
4006                                diff_flush_stat(p, options, &diffstat);
4007                }
4008                if (output_format & DIFF_FORMAT_NUMSTAT)
4009                        show_numstat(&diffstat, options);
4010                if (output_format & DIFF_FORMAT_DIFFSTAT)
4011                        show_stats(&diffstat, options);
4012                if (output_format & DIFF_FORMAT_SHORTSTAT)
4013                        show_shortstats(&diffstat, options);
4014                free_diffstat_info(&diffstat);
4015                separator++;
4016        }
4017        if (output_format & DIFF_FORMAT_DIRSTAT)
4018                show_dirstat(options);
4019
4020        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4021                for (i = 0; i < q->nr; i++) {
4022                        diff_summary(options, q->queue[i]);
4023                }
4024                separator++;
4025        }
4026
4027        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4028            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4029            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4030                /*
4031                 * run diff_flush_patch for the exit status. setting
4032                 * options->file to /dev/null should be safe, becaue we
4033                 * aren't supposed to produce any output anyway.
4034                 */
4035                if (options->close_file)
4036                        fclose(options->file);
4037                options->file = fopen("/dev/null", "w");
4038                if (!options->file)
4039                        die_errno("Could not open /dev/null");
4040                options->close_file = 1;
4041                for (i = 0; i < q->nr; i++) {
4042                        struct diff_filepair *p = q->queue[i];
4043                        if (check_pair_status(p))
4044                                diff_flush_patch(p, options);
4045                        if (options->found_changes)
4046                                break;
4047                }
4048        }
4049
4050        if (output_format & DIFF_FORMAT_PATCH) {
4051                if (separator) {
4052                        putc(options->line_termination, options->file);
4053                        if (options->stat_sep) {
4054                                /* attach patch instead of inline */
4055                                fputs(options->stat_sep, options->file);
4056                        }
4057                }
4058
4059                for (i = 0; i < q->nr; i++) {
4060                        struct diff_filepair *p = q->queue[i];
4061                        if (check_pair_status(p))
4062                                diff_flush_patch(p, options);
4063                }
4064        }
4065
4066        if (output_format & DIFF_FORMAT_CALLBACK)
4067                options->format_callback(q, options, options->format_callback_data);
4068
4069        for (i = 0; i < q->nr; i++)
4070                diff_free_filepair(q->queue[i]);
4071free_queue:
4072        free(q->queue);
4073        DIFF_QUEUE_CLEAR(q);
4074        if (options->close_file)
4075                fclose(options->file);
4076
4077        /*
4078         * Report the content-level differences with HAS_CHANGES;
4079         * diff_addremove/diff_change does not set the bit when
4080         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4081         */
4082        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4083                if (options->found_changes)
4084                        DIFF_OPT_SET(options, HAS_CHANGES);
4085                else
4086                        DIFF_OPT_CLR(options, HAS_CHANGES);
4087        }
4088}
4089
4090static void diffcore_apply_filter(const char *filter)
4091{
4092        int i;
4093        struct diff_queue_struct *q = &diff_queued_diff;
4094        struct diff_queue_struct outq;
4095        DIFF_QUEUE_CLEAR(&outq);
4096
4097        if (!filter)
4098                return;
4099
4100        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
4101                int found;
4102                for (i = found = 0; !found && i < q->nr; i++) {
4103                        struct diff_filepair *p = q->queue[i];
4104                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4105                             ((p->score &&
4106                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4107                              (!p->score &&
4108                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4109                            ((p->status != DIFF_STATUS_MODIFIED) &&
4110                             strchr(filter, p->status)))
4111                                found++;
4112                }
4113                if (found)
4114                        return;
4115
4116                /* otherwise we will clear the whole queue
4117                 * by copying the empty outq at the end of this
4118                 * function, but first clear the current entries
4119                 * in the queue.
4120                 */
4121                for (i = 0; i < q->nr; i++)
4122                        diff_free_filepair(q->queue[i]);
4123        }
4124        else {
4125                /* Only the matching ones */
4126                for (i = 0; i < q->nr; i++) {
4127                        struct diff_filepair *p = q->queue[i];
4128
4129                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4130                             ((p->score &&
4131                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4132                              (!p->score &&
4133                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4134                            ((p->status != DIFF_STATUS_MODIFIED) &&
4135                             strchr(filter, p->status)))
4136                                diff_q(&outq, p);
4137                        else
4138                                diff_free_filepair(p);
4139                }
4140        }
4141        free(q->queue);
4142        *q = outq;
4143}
4144
4145/* Check whether two filespecs with the same mode and size are identical */
4146static int diff_filespec_is_identical(struct diff_filespec *one,
4147                                      struct diff_filespec *two)
4148{
4149        if (S_ISGITLINK(one->mode))
4150                return 0;
4151        if (diff_populate_filespec(one, 0))
4152                return 0;
4153        if (diff_populate_filespec(two, 0))
4154                return 0;
4155        return !memcmp(one->data, two->data, one->size);
4156}
4157
4158static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4159{
4160        int i;
4161        struct diff_queue_struct *q = &diff_queued_diff;
4162        struct diff_queue_struct outq;
4163        DIFF_QUEUE_CLEAR(&outq);
4164
4165        for (i = 0; i < q->nr; i++) {
4166                struct diff_filepair *p = q->queue[i];
4167
4168                /*
4169                 * 1. Entries that come from stat info dirtiness
4170                 *    always have both sides (iow, not create/delete),
4171                 *    one side of the object name is unknown, with
4172                 *    the same mode and size.  Keep the ones that
4173                 *    do not match these criteria.  They have real
4174                 *    differences.
4175                 *
4176                 * 2. At this point, the file is known to be modified,
4177                 *    with the same mode and size, and the object
4178                 *    name of one side is unknown.  Need to inspect
4179                 *    the identical contents.
4180                 */
4181                if (!DIFF_FILE_VALID(p->one) || /* (1) */
4182                    !DIFF_FILE_VALID(p->two) ||
4183                    (p->one->sha1_valid && p->two->sha1_valid) ||
4184                    (p->one->mode != p->two->mode) ||
4185                    diff_populate_filespec(p->one, 1) ||
4186                    diff_populate_filespec(p->two, 1) ||
4187                    (p->one->size != p->two->size) ||
4188                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4189                        diff_q(&outq, p);
4190                else {
4191                        /*
4192                         * The caller can subtract 1 from skip_stat_unmatch
4193                         * to determine how many paths were dirty only
4194                         * due to stat info mismatch.
4195                         */
4196                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4197                                diffopt->skip_stat_unmatch++;
4198                        diff_free_filepair(p);
4199                }
4200        }
4201        free(q->queue);
4202        *q = outq;
4203}
4204
4205static int diffnamecmp(const void *a_, const void *b_)
4206{
4207        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4208        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4209        const char *name_a, *name_b;
4210
4211        name_a = a->one ? a->one->path : a->two->path;
4212        name_b = b->one ? b->one->path : b->two->path;
4213        return strcmp(name_a, name_b);
4214}
4215
4216void diffcore_fix_diff_index(struct diff_options *options)
4217{
4218        struct diff_queue_struct *q = &diff_queued_diff;
4219        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4220}
4221
4222void diffcore_std(struct diff_options *options)
4223{
4224        if (options->skip_stat_unmatch)
4225                diffcore_skip_stat_unmatch(options);
4226        if (!options->found_follow) {
4227                /* See try_to_follow_renames() in tree-diff.c */
4228                if (options->break_opt != -1)
4229                        diffcore_break(options->break_opt);
4230                if (options->detect_rename)
4231                        diffcore_rename(options);
4232                if (options->break_opt != -1)
4233                        diffcore_merge_broken();
4234        }
4235        if (options->pickaxe)
4236                diffcore_pickaxe(options);
4237        if (options->orderfile)
4238                diffcore_order(options->orderfile);
4239        if (!options->found_follow)
4240                /* See try_to_follow_renames() in tree-diff.c */
4241                diff_resolve_rename_copy();
4242        diffcore_apply_filter(options->filter);
4243
4244        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4245                DIFF_OPT_SET(options, HAS_CHANGES);
4246        else
4247                DIFF_OPT_CLR(options, HAS_CHANGES);
4248
4249        options->found_follow = 0;
4250}
4251
4252int diff_result_code(struct diff_options *opt, int status)
4253{
4254        int result = 0;
4255        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4256            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4257                return status;
4258        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4259            DIFF_OPT_TST(opt, HAS_CHANGES))
4260                result |= 01;
4261        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4262            DIFF_OPT_TST(opt, CHECK_FAILED))
4263                result |= 02;
4264        return result;
4265}
4266
4267/*
4268 * Shall changes to this submodule be ignored?
4269 *
4270 * Submodule changes can be configured to be ignored separately for each path,
4271 * but that configuration can be overridden from the command line.
4272 */
4273static int is_submodule_ignored(const char *path, struct diff_options *options)
4274{
4275        int ignored = 0;
4276        unsigned orig_flags = options->flags;
4277        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4278                set_diffopt_flags_from_submodule_config(options, path);
4279        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4280                ignored = 1;
4281        options->flags = orig_flags;
4282        return ignored;
4283}
4284
4285void diff_addremove(struct diff_options *options,
4286                    int addremove, unsigned mode,
4287                    const unsigned char *sha1,
4288                    const char *concatpath, unsigned dirty_submodule)
4289{
4290        struct diff_filespec *one, *two;
4291
4292        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4293                return;
4294
4295        /* This may look odd, but it is a preparation for
4296         * feeding "there are unchanged files which should
4297         * not produce diffs, but when you are doing copy
4298         * detection you would need them, so here they are"
4299         * entries to the diff-core.  They will be prefixed
4300         * with something like '=' or '*' (I haven't decided
4301         * which but should not make any difference).
4302         * Feeding the same new and old to diff_change()
4303         * also has the same effect.
4304         * Before the final output happens, they are pruned after
4305         * merged into rename/copy pairs as appropriate.
4306         */
4307        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4308                addremove = (addremove == '+' ? '-' :
4309                             addremove == '-' ? '+' : addremove);
4310
4311        if (options->prefix &&
4312            strncmp(concatpath, options->prefix, options->prefix_length))
4313                return;
4314
4315        one = alloc_filespec(concatpath);
4316        two = alloc_filespec(concatpath);
4317
4318        if (addremove != '+')
4319                fill_filespec(one, sha1, mode);
4320        if (addremove != '-') {
4321                fill_filespec(two, sha1, mode);
4322                two->dirty_submodule = dirty_submodule;
4323        }
4324
4325        diff_queue(&diff_queued_diff, one, two);
4326        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4327                DIFF_OPT_SET(options, HAS_CHANGES);
4328}
4329
4330void diff_change(struct diff_options *options,
4331                 unsigned old_mode, unsigned new_mode,
4332                 const unsigned char *old_sha1,
4333                 const unsigned char *new_sha1,
4334                 const char *concatpath,
4335                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4336{
4337        struct diff_filespec *one, *two;
4338
4339        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4340            is_submodule_ignored(concatpath, options))
4341                return;
4342
4343        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4344                unsigned tmp;
4345                const unsigned char *tmp_c;
4346                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4347                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4348                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4349                        new_dirty_submodule = tmp;
4350        }
4351
4352        if (options->prefix &&
4353            strncmp(concatpath, options->prefix, options->prefix_length))
4354                return;
4355
4356        one = alloc_filespec(concatpath);
4357        two = alloc_filespec(concatpath);
4358        fill_filespec(one, old_sha1, old_mode);
4359        fill_filespec(two, new_sha1, new_mode);
4360        one->dirty_submodule = old_dirty_submodule;
4361        two->dirty_submodule = new_dirty_submodule;
4362
4363        diff_queue(&diff_queued_diff, one, two);
4364        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4365                DIFF_OPT_SET(options, HAS_CHANGES);
4366}
4367
4368void diff_unmerge(struct diff_options *options,
4369                  const char *path,
4370                  unsigned mode, const unsigned char *sha1)
4371{
4372        struct diff_filespec *one, *two;
4373
4374        if (options->prefix &&
4375            strncmp(path, options->prefix, options->prefix_length))
4376                return;
4377
4378        one = alloc_filespec(path);
4379        two = alloc_filespec(path);
4380        fill_filespec(one, sha1, mode);
4381        diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;
4382}
4383
4384static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4385                size_t *outsize)
4386{
4387        struct diff_tempfile *temp;
4388        const char *argv[3];
4389        const char **arg = argv;
4390        struct child_process child;
4391        struct strbuf buf = STRBUF_INIT;
4392        int err = 0;
4393
4394        temp = prepare_temp_file(spec->path, spec);
4395        *arg++ = pgm;
4396        *arg++ = temp->name;
4397        *arg = NULL;
4398
4399        memset(&child, 0, sizeof(child));
4400        child.use_shell = 1;
4401        child.argv = argv;
4402        child.out = -1;
4403        if (start_command(&child)) {
4404                remove_tempfile();
4405                return NULL;
4406        }
4407
4408        if (strbuf_read(&buf, child.out, 0) < 0)
4409                err = error("error reading from textconv command '%s'", pgm);
4410        close(child.out);
4411
4412        if (finish_command(&child) || err) {
4413                strbuf_release(&buf);
4414                remove_tempfile();
4415                return NULL;
4416        }
4417        remove_tempfile();
4418
4419        return strbuf_detach(&buf, outsize);
4420}
4421
4422size_t fill_textconv(struct userdiff_driver *driver,
4423                     struct diff_filespec *df,
4424                     char **outbuf)
4425{
4426        size_t size;
4427
4428        if (!driver || !driver->textconv) {
4429                if (!DIFF_FILE_VALID(df)) {
4430                        *outbuf = "";
4431                        return 0;
4432                }
4433                if (diff_populate_filespec(df, 0))
4434                        die("unable to read files to diff");
4435                *outbuf = df->data;
4436                return df->size;
4437        }
4438
4439        if (driver->textconv_cache && df->sha1_valid) {
4440                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4441                                          &size);
4442                if (*outbuf)
4443                        return size;
4444        }
4445
4446        *outbuf = run_textconv(driver->textconv, df, &size);
4447        if (!*outbuf)
4448                die("unable to read files to diff");
4449
4450        if (driver->textconv_cache && df->sha1_valid) {
4451                /* ignore errors, as we might be in a readonly repository */
4452                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4453                                size);
4454                /*
4455                 * we could save up changes and flush them all at the end,
4456                 * but we would need an extra call after all diffing is done.
4457                 * Since generating a cache entry is the slow path anyway,
4458                 * this extra overhead probably isn't a big deal.
4459                 */
4460                notes_cache_write(driver->textconv_cache);
4461        }
4462
4463        return size;
4464}