diff.con commit string-list: rename the include guard to STRING_LIST_H (0afcb5f)
   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
  18#ifdef NO_FAST_WORKING_DIRECTORY
  19#define FAST_WORKING_DIRECTORY 0
  20#else
  21#define FAST_WORKING_DIRECTORY 1
  22#endif
  23
  24static int diff_detect_rename_default;
  25static int diff_rename_limit_default = 200;
  26static int diff_suppress_blank_empty;
  27int diff_use_color_default = -1;
  28static const char *diff_word_regex_cfg;
  29static const char *external_diff_cmd_cfg;
  30int diff_auto_refresh_index = 1;
  31static int diff_mnemonic_prefix;
  32
  33static char diff_colors[][COLOR_MAXLEN] = {
  34        GIT_COLOR_RESET,
  35        GIT_COLOR_NORMAL,       /* PLAIN */
  36        GIT_COLOR_BOLD,         /* METAINFO */
  37        GIT_COLOR_CYAN,         /* FRAGINFO */
  38        GIT_COLOR_RED,          /* OLD */
  39        GIT_COLOR_GREEN,        /* NEW */
  40        GIT_COLOR_YELLOW,       /* COMMIT */
  41        GIT_COLOR_BG_RED,       /* WHITESPACE */
  42        GIT_COLOR_NORMAL,       /* FUNCINFO */
  43};
  44
  45static void diff_filespec_load_driver(struct diff_filespec *one);
  46static char *run_textconv(const char *, struct diff_filespec *, size_t *);
  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.external"))
 103                return git_config_string(&external_diff_cmd_cfg, var, value);
 104        if (!strcmp(var, "diff.wordregex"))
 105                return git_config_string(&diff_word_regex_cfg, var, value);
 106
 107        return git_diff_basic_config(var, value, cb);
 108}
 109
 110int git_diff_basic_config(const char *var, const char *value, void *cb)
 111{
 112        if (!strcmp(var, "diff.renamelimit")) {
 113                diff_rename_limit_default = git_config_int(var, value);
 114                return 0;
 115        }
 116
 117        switch (userdiff_config(var, value)) {
 118                case 0: break;
 119                case -1: return -1;
 120                default: return 0;
 121        }
 122
 123        if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
 124                int slot = parse_diff_color_slot(var, 11);
 125                if (slot < 0)
 126                        return 0;
 127                if (!value)
 128                        return config_error_nonbool(var);
 129                color_parse(value, var, diff_colors[slot]);
 130                return 0;
 131        }
 132
 133        /* like GNU diff's --suppress-blank-empty option  */
 134        if (!strcmp(var, "diff.suppressblankempty") ||
 135                        /* for backwards compatibility */
 136                        !strcmp(var, "diff.suppress-blank-empty")) {
 137                diff_suppress_blank_empty = git_config_bool(var, value);
 138                return 0;
 139        }
 140
 141        return git_color_default_config(var, value, cb);
 142}
 143
 144static char *quote_two(const char *one, const char *two)
 145{
 146        int need_one = quote_c_style(one, NULL, NULL, 1);
 147        int need_two = quote_c_style(two, NULL, NULL, 1);
 148        struct strbuf res = STRBUF_INIT;
 149
 150        if (need_one + need_two) {
 151                strbuf_addch(&res, '"');
 152                quote_c_style(one, &res, NULL, 1);
 153                quote_c_style(two, &res, NULL, 1);
 154                strbuf_addch(&res, '"');
 155        } else {
 156                strbuf_addstr(&res, one);
 157                strbuf_addstr(&res, two);
 158        }
 159        return strbuf_detach(&res, NULL);
 160}
 161
 162static const char *external_diff(void)
 163{
 164        static const char *external_diff_cmd = NULL;
 165        static int done_preparing = 0;
 166
 167        if (done_preparing)
 168                return external_diff_cmd;
 169        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 170        if (!external_diff_cmd)
 171                external_diff_cmd = external_diff_cmd_cfg;
 172        done_preparing = 1;
 173        return external_diff_cmd;
 174}
 175
 176static struct diff_tempfile {
 177        const char *name; /* filename external diff should read from */
 178        char hex[41];
 179        char mode[10];
 180        char tmp_path[PATH_MAX];
 181} diff_temp[2];
 182
 183typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 184
 185struct emit_callback {
 186        int color_diff;
 187        unsigned ws_rule;
 188        int blank_at_eof_in_preimage;
 189        int blank_at_eof_in_postimage;
 190        int lno_in_preimage;
 191        int lno_in_postimage;
 192        sane_truncate_fn truncate;
 193        const char **label_path;
 194        struct diff_words_data *diff_words;
 195        int *found_changesp;
 196        FILE *file;
 197        struct strbuf *header;
 198};
 199
 200static int count_lines(const char *data, int size)
 201{
 202        int count, ch, completely_empty = 1, nl_just_seen = 0;
 203        count = 0;
 204        while (0 < size--) {
 205                ch = *data++;
 206                if (ch == '\n') {
 207                        count++;
 208                        nl_just_seen = 1;
 209                        completely_empty = 0;
 210                }
 211                else {
 212                        nl_just_seen = 0;
 213                        completely_empty = 0;
 214                }
 215        }
 216        if (completely_empty)
 217                return 0;
 218        if (!nl_just_seen)
 219                count++; /* no trailing newline */
 220        return count;
 221}
 222
 223static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 224{
 225        if (!DIFF_FILE_VALID(one)) {
 226                mf->ptr = (char *)""; /* does not matter */
 227                mf->size = 0;
 228                return 0;
 229        }
 230        else if (diff_populate_filespec(one, 0))
 231                return -1;
 232
 233        mf->ptr = one->data;
 234        mf->size = one->size;
 235        return 0;
 236}
 237
 238static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 239{
 240        char *ptr = mf->ptr;
 241        long size = mf->size;
 242        int cnt = 0;
 243
 244        if (!size)
 245                return cnt;
 246        ptr += size - 1; /* pointing at the very end */
 247        if (*ptr != '\n')
 248                ; /* incomplete line */
 249        else
 250                ptr--; /* skip the last LF */
 251        while (mf->ptr < ptr) {
 252                char *prev_eol;
 253                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 254                        if (*prev_eol == '\n')
 255                                break;
 256                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 257                        break;
 258                cnt++;
 259                ptr = prev_eol - 1;
 260        }
 261        return cnt;
 262}
 263
 264static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 265                               struct emit_callback *ecbdata)
 266{
 267        int l1, l2, at;
 268        unsigned ws_rule = ecbdata->ws_rule;
 269        l1 = count_trailing_blank(mf1, ws_rule);
 270        l2 = count_trailing_blank(mf2, ws_rule);
 271        if (l2 <= l1) {
 272                ecbdata->blank_at_eof_in_preimage = 0;
 273                ecbdata->blank_at_eof_in_postimage = 0;
 274                return;
 275        }
 276        at = count_lines(mf1->ptr, mf1->size);
 277        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 278
 279        at = count_lines(mf2->ptr, mf2->size);
 280        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 281}
 282
 283static void emit_line_0(FILE *file, const char *set, const char *reset,
 284                        int first, const char *line, int len)
 285{
 286        int has_trailing_newline, has_trailing_carriage_return;
 287        int nofirst;
 288
 289        if (len == 0) {
 290                has_trailing_newline = (first == '\n');
 291                has_trailing_carriage_return = (!has_trailing_newline &&
 292                                                (first == '\r'));
 293                nofirst = has_trailing_newline || has_trailing_carriage_return;
 294        } else {
 295                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 296                if (has_trailing_newline)
 297                        len--;
 298                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 299                if (has_trailing_carriage_return)
 300                        len--;
 301                nofirst = 0;
 302        }
 303
 304        if (len || !nofirst) {
 305                fputs(set, file);
 306                if (!nofirst)
 307                        fputc(first, file);
 308                fwrite(line, len, 1, file);
 309                fputs(reset, file);
 310        }
 311        if (has_trailing_carriage_return)
 312                fputc('\r', file);
 313        if (has_trailing_newline)
 314                fputc('\n', file);
 315}
 316
 317static void emit_line(FILE *file, const char *set, const char *reset,
 318                      const char *line, int len)
 319{
 320        emit_line_0(file, set, reset, line[0], line+1, len-1);
 321}
 322
 323static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 324{
 325        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 326              ecbdata->blank_at_eof_in_preimage &&
 327              ecbdata->blank_at_eof_in_postimage &&
 328              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 329              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 330                return 0;
 331        return ws_blank_line(line, len, ecbdata->ws_rule);
 332}
 333
 334static void emit_add_line(const char *reset,
 335                          struct emit_callback *ecbdata,
 336                          const char *line, int len)
 337{
 338        const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 339        const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 340
 341        if (!*ws)
 342                emit_line_0(ecbdata->file, set, reset, '+', line, len);
 343        else if (new_blank_line_at_eof(ecbdata, line, len))
 344                /* Blank line at EOF - paint '+' as well */
 345                emit_line_0(ecbdata->file, ws, reset, '+', line, len);
 346        else {
 347                /* Emit just the prefix, then the rest. */
 348                emit_line_0(ecbdata->file, set, reset, '+', "", 0);
 349                ws_check_emit(line, len, ecbdata->ws_rule,
 350                              ecbdata->file, set, reset, ws);
 351        }
 352}
 353
 354static void emit_hunk_header(struct emit_callback *ecbdata,
 355                             const char *line, int len)
 356{
 357        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 358        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 359        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 360        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 361        static const char atat[2] = { '@', '@' };
 362        const char *cp, *ep;
 363
 364        /*
 365         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 366         * it always is at least 10 bytes long.
 367         */
 368        if (len < 10 ||
 369            memcmp(line, atat, 2) ||
 370            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 371                emit_line(ecbdata->file, plain, reset, line, len);
 372                return;
 373        }
 374        ep += 2; /* skip over @@ */
 375
 376        /* The hunk header in fraginfo color */
 377        emit_line(ecbdata->file, frag, reset, line, ep - line);
 378
 379        /* blank before the func header */
 380        for (cp = ep; ep - line < len; ep++)
 381                if (*ep != ' ' && *ep != '\t')
 382                        break;
 383        if (ep != cp)
 384                emit_line(ecbdata->file, plain, reset, cp, ep - cp);
 385
 386        if (ep < line + len)
 387                emit_line(ecbdata->file, func, reset, ep, line + len - ep);
 388}
 389
 390static struct diff_tempfile *claim_diff_tempfile(void) {
 391        int i;
 392        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 393                if (!diff_temp[i].name)
 394                        return diff_temp + i;
 395        die("BUG: diff is failing to clean up its tempfiles");
 396}
 397
 398static int remove_tempfile_installed;
 399
 400static void remove_tempfile(void)
 401{
 402        int i;
 403        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 404                if (diff_temp[i].name == diff_temp[i].tmp_path)
 405                        unlink_or_warn(diff_temp[i].name);
 406                diff_temp[i].name = NULL;
 407        }
 408}
 409
 410static void remove_tempfile_on_signal(int signo)
 411{
 412        remove_tempfile();
 413        sigchain_pop(signo);
 414        raise(signo);
 415}
 416
 417static void print_line_count(FILE *file, int count)
 418{
 419        switch (count) {
 420        case 0:
 421                fprintf(file, "0,0");
 422                break;
 423        case 1:
 424                fprintf(file, "1");
 425                break;
 426        default:
 427                fprintf(file, "1,%d", count);
 428                break;
 429        }
 430}
 431
 432static void emit_rewrite_lines(struct emit_callback *ecb,
 433                               int prefix, const char *data, int size)
 434{
 435        const char *endp = NULL;
 436        static const char *nneof = " No newline at end of file\n";
 437        const char *old = diff_get_color(ecb->color_diff, DIFF_FILE_OLD);
 438        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 439
 440        while (0 < size) {
 441                int len;
 442
 443                endp = memchr(data, '\n', size);
 444                len = endp ? (endp - data + 1) : size;
 445                if (prefix != '+') {
 446                        ecb->lno_in_preimage++;
 447                        emit_line_0(ecb->file, old, reset, '-',
 448                                    data, len);
 449                } else {
 450                        ecb->lno_in_postimage++;
 451                        emit_add_line(reset, ecb, data, len);
 452                }
 453                size -= len;
 454                data += len;
 455        }
 456        if (!endp) {
 457                const char *plain = diff_get_color(ecb->color_diff,
 458                                                   DIFF_PLAIN);
 459                emit_line_0(ecb->file, plain, reset, '\\',
 460                            nneof, strlen(nneof));
 461        }
 462}
 463
 464static void emit_rewrite_diff(const char *name_a,
 465                              const char *name_b,
 466                              struct diff_filespec *one,
 467                              struct diff_filespec *two,
 468                              const char *textconv_one,
 469                              const char *textconv_two,
 470                              struct diff_options *o)
 471{
 472        int lc_a, lc_b;
 473        int color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
 474        const char *name_a_tab, *name_b_tab;
 475        const char *metainfo = diff_get_color(color_diff, DIFF_METAINFO);
 476        const char *fraginfo = diff_get_color(color_diff, DIFF_FRAGINFO);
 477        const char *reset = diff_get_color(color_diff, DIFF_RESET);
 478        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 479        const char *a_prefix, *b_prefix;
 480        const char *data_one, *data_two;
 481        size_t size_one, size_two;
 482        struct emit_callback ecbdata;
 483
 484        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 485                a_prefix = o->b_prefix;
 486                b_prefix = o->a_prefix;
 487        } else {
 488                a_prefix = o->a_prefix;
 489                b_prefix = o->b_prefix;
 490        }
 491
 492        name_a += (*name_a == '/');
 493        name_b += (*name_b == '/');
 494        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 495        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 496
 497        strbuf_reset(&a_name);
 498        strbuf_reset(&b_name);
 499        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 500        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 501
 502        diff_populate_filespec(one, 0);
 503        diff_populate_filespec(two, 0);
 504        if (textconv_one) {
 505                data_one = run_textconv(textconv_one, one, &size_one);
 506                if (!data_one)
 507                        die("unable to read files to diff");
 508        }
 509        else {
 510                data_one = one->data;
 511                size_one = one->size;
 512        }
 513        if (textconv_two) {
 514                data_two = run_textconv(textconv_two, two, &size_two);
 515                if (!data_two)
 516                        die("unable to read files to diff");
 517        }
 518        else {
 519                data_two = two->data;
 520                size_two = two->size;
 521        }
 522
 523        memset(&ecbdata, 0, sizeof(ecbdata));
 524        ecbdata.color_diff = color_diff;
 525        ecbdata.found_changesp = &o->found_changes;
 526        ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
 527        ecbdata.file = o->file;
 528        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 529                mmfile_t mf1, mf2;
 530                mf1.ptr = (char *)data_one;
 531                mf2.ptr = (char *)data_two;
 532                mf1.size = size_one;
 533                mf2.size = size_two;
 534                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 535        }
 536        ecbdata.lno_in_preimage = 1;
 537        ecbdata.lno_in_postimage = 1;
 538
 539        lc_a = count_lines(data_one, size_one);
 540        lc_b = count_lines(data_two, size_two);
 541        fprintf(o->file,
 542                "%s--- %s%s%s\n%s+++ %s%s%s\n%s@@ -",
 543                metainfo, a_name.buf, name_a_tab, reset,
 544                metainfo, b_name.buf, name_b_tab, reset, fraginfo);
 545        print_line_count(o->file, lc_a);
 546        fprintf(o->file, " +");
 547        print_line_count(o->file, lc_b);
 548        fprintf(o->file, " @@%s\n", reset);
 549        if (lc_a)
 550                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 551        if (lc_b)
 552                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 553}
 554
 555struct diff_words_buffer {
 556        mmfile_t text;
 557        long alloc;
 558        struct diff_words_orig {
 559                const char *begin, *end;
 560        } *orig;
 561        int orig_nr, orig_alloc;
 562};
 563
 564static void diff_words_append(char *line, unsigned long len,
 565                struct diff_words_buffer *buffer)
 566{
 567        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 568        line++;
 569        len--;
 570        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 571        buffer->text.size += len;
 572        buffer->text.ptr[buffer->text.size] = '\0';
 573}
 574
 575struct diff_words_data {
 576        struct diff_words_buffer minus, plus;
 577        const char *current_plus;
 578        FILE *file;
 579        regex_t *word_regex;
 580};
 581
 582static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 583{
 584        struct diff_words_data *diff_words = priv;
 585        int minus_first, minus_len, plus_first, plus_len;
 586        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 587
 588        if (line[0] != '@' || parse_hunk_header(line, len,
 589                        &minus_first, &minus_len, &plus_first, &plus_len))
 590                return;
 591
 592        /* POSIX requires that first be decremented by one if len == 0... */
 593        if (minus_len) {
 594                minus_begin = diff_words->minus.orig[minus_first].begin;
 595                minus_end =
 596                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 597        } else
 598                minus_begin = minus_end =
 599                        diff_words->minus.orig[minus_first].end;
 600
 601        if (plus_len) {
 602                plus_begin = diff_words->plus.orig[plus_first].begin;
 603                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 604        } else
 605                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 606
 607        if (diff_words->current_plus != plus_begin)
 608                fwrite(diff_words->current_plus,
 609                                plus_begin - diff_words->current_plus, 1,
 610                                diff_words->file);
 611        if (minus_begin != minus_end)
 612                color_fwrite_lines(diff_words->file,
 613                                diff_get_color(1, DIFF_FILE_OLD),
 614                                minus_end - minus_begin, minus_begin);
 615        if (plus_begin != plus_end)
 616                color_fwrite_lines(diff_words->file,
 617                                diff_get_color(1, DIFF_FILE_NEW),
 618                                plus_end - plus_begin, plus_begin);
 619
 620        diff_words->current_plus = plus_end;
 621}
 622
 623/* This function starts looking at *begin, and returns 0 iff a word was found. */
 624static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 625                int *begin, int *end)
 626{
 627        if (word_regex && *begin < buffer->size) {
 628                regmatch_t match[1];
 629                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 630                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 631                                        '\n', match[0].rm_eo - match[0].rm_so);
 632                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 633                        *begin += match[0].rm_so;
 634                        return *begin >= *end;
 635                }
 636                return -1;
 637        }
 638
 639        /* find the next word */
 640        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 641                (*begin)++;
 642        if (*begin >= buffer->size)
 643                return -1;
 644
 645        /* find the end of the word */
 646        *end = *begin + 1;
 647        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 648                (*end)++;
 649
 650        return 0;
 651}
 652
 653/*
 654 * This function splits the words in buffer->text, stores the list with
 655 * newline separator into out, and saves the offsets of the original words
 656 * in buffer->orig.
 657 */
 658static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 659                regex_t *word_regex)
 660{
 661        int i, j;
 662        long alloc = 0;
 663
 664        out->size = 0;
 665        out->ptr = NULL;
 666
 667        /* fake an empty "0th" word */
 668        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 669        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 670        buffer->orig_nr = 1;
 671
 672        for (i = 0; i < buffer->text.size; i++) {
 673                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 674                        return;
 675
 676                /* store original boundaries */
 677                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 678                                buffer->orig_alloc);
 679                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 680                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 681                buffer->orig_nr++;
 682
 683                /* store one word */
 684                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 685                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 686                out->ptr[out->size + j - i] = '\n';
 687                out->size += j - i + 1;
 688
 689                i = j - 1;
 690        }
 691}
 692
 693/* this executes the word diff on the accumulated buffers */
 694static void diff_words_show(struct diff_words_data *diff_words)
 695{
 696        xpparam_t xpp;
 697        xdemitconf_t xecfg;
 698        xdemitcb_t ecb;
 699        mmfile_t minus, plus;
 700
 701        /* special case: only removal */
 702        if (!diff_words->plus.text.size) {
 703                color_fwrite_lines(diff_words->file,
 704                        diff_get_color(1, DIFF_FILE_OLD),
 705                        diff_words->minus.text.size, diff_words->minus.text.ptr);
 706                diff_words->minus.text.size = 0;
 707                return;
 708        }
 709
 710        diff_words->current_plus = diff_words->plus.text.ptr;
 711
 712        memset(&xpp, 0, sizeof(xpp));
 713        memset(&xecfg, 0, sizeof(xecfg));
 714        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
 715        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
 716        xpp.flags = XDF_NEED_MINIMAL;
 717        /* as only the hunk header will be parsed, we need a 0-context */
 718        xecfg.ctxlen = 0;
 719        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 720                      &xpp, &xecfg, &ecb);
 721        free(minus.ptr);
 722        free(plus.ptr);
 723        if (diff_words->current_plus != diff_words->plus.text.ptr +
 724                        diff_words->plus.text.size)
 725                fwrite(diff_words->current_plus,
 726                        diff_words->plus.text.ptr + diff_words->plus.text.size
 727                        - diff_words->current_plus, 1,
 728                        diff_words->file);
 729        diff_words->minus.text.size = diff_words->plus.text.size = 0;
 730}
 731
 732/* In "color-words" mode, show word-diff of words accumulated in the buffer */
 733static void diff_words_flush(struct emit_callback *ecbdata)
 734{
 735        if (ecbdata->diff_words->minus.text.size ||
 736            ecbdata->diff_words->plus.text.size)
 737                diff_words_show(ecbdata->diff_words);
 738}
 739
 740static void free_diff_words_data(struct emit_callback *ecbdata)
 741{
 742        if (ecbdata->diff_words) {
 743                diff_words_flush(ecbdata);
 744                free (ecbdata->diff_words->minus.text.ptr);
 745                free (ecbdata->diff_words->minus.orig);
 746                free (ecbdata->diff_words->plus.text.ptr);
 747                free (ecbdata->diff_words->plus.orig);
 748                free(ecbdata->diff_words->word_regex);
 749                free(ecbdata->diff_words);
 750                ecbdata->diff_words = NULL;
 751        }
 752}
 753
 754const char *diff_get_color(int diff_use_color, enum color_diff ix)
 755{
 756        if (diff_use_color)
 757                return diff_colors[ix];
 758        return "";
 759}
 760
 761static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
 762{
 763        const char *cp;
 764        unsigned long allot;
 765        size_t l = len;
 766
 767        if (ecb->truncate)
 768                return ecb->truncate(line, len);
 769        cp = line;
 770        allot = l;
 771        while (0 < l) {
 772                (void) utf8_width(&cp, &l);
 773                if (!cp)
 774                        break; /* truncated in the middle? */
 775        }
 776        return allot - l;
 777}
 778
 779static void find_lno(const char *line, struct emit_callback *ecbdata)
 780{
 781        const char *p;
 782        ecbdata->lno_in_preimage = 0;
 783        ecbdata->lno_in_postimage = 0;
 784        p = strchr(line, '-');
 785        if (!p)
 786                return; /* cannot happen */
 787        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
 788        p = strchr(p, '+');
 789        if (!p)
 790                return; /* cannot happen */
 791        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
 792}
 793
 794static void fn_out_consume(void *priv, char *line, unsigned long len)
 795{
 796        struct emit_callback *ecbdata = priv;
 797        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
 798        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 799        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 800
 801        if (ecbdata->header) {
 802                fprintf(ecbdata->file, "%s", ecbdata->header->buf);
 803                strbuf_reset(ecbdata->header);
 804                ecbdata->header = NULL;
 805        }
 806        *(ecbdata->found_changesp) = 1;
 807
 808        if (ecbdata->label_path[0]) {
 809                const char *name_a_tab, *name_b_tab;
 810
 811                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
 812                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
 813
 814                fprintf(ecbdata->file, "%s--- %s%s%s\n",
 815                        meta, ecbdata->label_path[0], reset, name_a_tab);
 816                fprintf(ecbdata->file, "%s+++ %s%s%s\n",
 817                        meta, ecbdata->label_path[1], reset, name_b_tab);
 818                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
 819        }
 820
 821        if (diff_suppress_blank_empty
 822            && len == 2 && line[0] == ' ' && line[1] == '\n') {
 823                line[0] = '\n';
 824                len = 1;
 825        }
 826
 827        if (line[0] == '@') {
 828                if (ecbdata->diff_words)
 829                        diff_words_flush(ecbdata);
 830                len = sane_truncate_line(ecbdata, line, len);
 831                find_lno(line, ecbdata);
 832                emit_hunk_header(ecbdata, line, len);
 833                if (line[len-1] != '\n')
 834                        putc('\n', ecbdata->file);
 835                return;
 836        }
 837
 838        if (len < 1) {
 839                emit_line(ecbdata->file, reset, reset, line, len);
 840                return;
 841        }
 842
 843        if (ecbdata->diff_words) {
 844                if (line[0] == '-') {
 845                        diff_words_append(line, len,
 846                                          &ecbdata->diff_words->minus);
 847                        return;
 848                } else if (line[0] == '+') {
 849                        diff_words_append(line, len,
 850                                          &ecbdata->diff_words->plus);
 851                        return;
 852                }
 853                diff_words_flush(ecbdata);
 854                line++;
 855                len--;
 856                emit_line(ecbdata->file, plain, reset, line, len);
 857                return;
 858        }
 859
 860        if (line[0] != '+') {
 861                const char *color =
 862                        diff_get_color(ecbdata->color_diff,
 863                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
 864                ecbdata->lno_in_preimage++;
 865                if (line[0] == ' ')
 866                        ecbdata->lno_in_postimage++;
 867                emit_line(ecbdata->file, color, reset, line, len);
 868        } else {
 869                ecbdata->lno_in_postimage++;
 870                emit_add_line(reset, ecbdata, line + 1, len - 1);
 871        }
 872}
 873
 874static char *pprint_rename(const char *a, const char *b)
 875{
 876        const char *old = a;
 877        const char *new = b;
 878        struct strbuf name = STRBUF_INIT;
 879        int pfx_length, sfx_length;
 880        int len_a = strlen(a);
 881        int len_b = strlen(b);
 882        int a_midlen, b_midlen;
 883        int qlen_a = quote_c_style(a, NULL, NULL, 0);
 884        int qlen_b = quote_c_style(b, NULL, NULL, 0);
 885
 886        if (qlen_a || qlen_b) {
 887                quote_c_style(a, &name, NULL, 0);
 888                strbuf_addstr(&name, " => ");
 889                quote_c_style(b, &name, NULL, 0);
 890                return strbuf_detach(&name, NULL);
 891        }
 892
 893        /* Find common prefix */
 894        pfx_length = 0;
 895        while (*old && *new && *old == *new) {
 896                if (*old == '/')
 897                        pfx_length = old - a + 1;
 898                old++;
 899                new++;
 900        }
 901
 902        /* Find common suffix */
 903        old = a + len_a;
 904        new = b + len_b;
 905        sfx_length = 0;
 906        while (a <= old && b <= new && *old == *new) {
 907                if (*old == '/')
 908                        sfx_length = len_a - (old - a);
 909                old--;
 910                new--;
 911        }
 912
 913        /*
 914         * pfx{mid-a => mid-b}sfx
 915         * {pfx-a => pfx-b}sfx
 916         * pfx{sfx-a => sfx-b}
 917         * name-a => name-b
 918         */
 919        a_midlen = len_a - pfx_length - sfx_length;
 920        b_midlen = len_b - pfx_length - sfx_length;
 921        if (a_midlen < 0)
 922                a_midlen = 0;
 923        if (b_midlen < 0)
 924                b_midlen = 0;
 925
 926        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
 927        if (pfx_length + sfx_length) {
 928                strbuf_add(&name, a, pfx_length);
 929                strbuf_addch(&name, '{');
 930        }
 931        strbuf_add(&name, a + pfx_length, a_midlen);
 932        strbuf_addstr(&name, " => ");
 933        strbuf_add(&name, b + pfx_length, b_midlen);
 934        if (pfx_length + sfx_length) {
 935                strbuf_addch(&name, '}');
 936                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
 937        }
 938        return strbuf_detach(&name, NULL);
 939}
 940
 941struct diffstat_t {
 942        int nr;
 943        int alloc;
 944        struct diffstat_file {
 945                char *from_name;
 946                char *name;
 947                char *print_name;
 948                unsigned is_unmerged:1;
 949                unsigned is_binary:1;
 950                unsigned is_renamed:1;
 951                unsigned int added, deleted;
 952        } **files;
 953};
 954
 955static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
 956                                          const char *name_a,
 957                                          const char *name_b)
 958{
 959        struct diffstat_file *x;
 960        x = xcalloc(sizeof (*x), 1);
 961        if (diffstat->nr == diffstat->alloc) {
 962                diffstat->alloc = alloc_nr(diffstat->alloc);
 963                diffstat->files = xrealloc(diffstat->files,
 964                                diffstat->alloc * sizeof(x));
 965        }
 966        diffstat->files[diffstat->nr++] = x;
 967        if (name_b) {
 968                x->from_name = xstrdup(name_a);
 969                x->name = xstrdup(name_b);
 970                x->is_renamed = 1;
 971        }
 972        else {
 973                x->from_name = NULL;
 974                x->name = xstrdup(name_a);
 975        }
 976        return x;
 977}
 978
 979static void diffstat_consume(void *priv, char *line, unsigned long len)
 980{
 981        struct diffstat_t *diffstat = priv;
 982        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
 983
 984        if (line[0] == '+')
 985                x->added++;
 986        else if (line[0] == '-')
 987                x->deleted++;
 988}
 989
 990const char mime_boundary_leader[] = "------------";
 991
 992static int scale_linear(int it, int width, int max_change)
 993{
 994        /*
 995         * make sure that at least one '-' is printed if there were deletions,
 996         * and likewise for '+'.
 997         */
 998        if (max_change < 2)
 999                return it;
1000        return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
1001}
1002
1003static void show_name(FILE *file,
1004                      const char *prefix, const char *name, int len)
1005{
1006        fprintf(file, " %s%-*s |", prefix, len, name);
1007}
1008
1009static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1010{
1011        if (cnt <= 0)
1012                return;
1013        fprintf(file, "%s", set);
1014        while (cnt--)
1015                putc(ch, file);
1016        fprintf(file, "%s", reset);
1017}
1018
1019static void fill_print_name(struct diffstat_file *file)
1020{
1021        char *pname;
1022
1023        if (file->print_name)
1024                return;
1025
1026        if (!file->is_renamed) {
1027                struct strbuf buf = STRBUF_INIT;
1028                if (quote_c_style(file->name, &buf, NULL, 0)) {
1029                        pname = strbuf_detach(&buf, NULL);
1030                } else {
1031                        pname = file->name;
1032                        strbuf_release(&buf);
1033                }
1034        } else {
1035                pname = pprint_rename(file->from_name, file->name);
1036        }
1037        file->print_name = pname;
1038}
1039
1040static void show_stats(struct diffstat_t *data, struct diff_options *options)
1041{
1042        int i, len, add, del, adds = 0, dels = 0;
1043        int max_change = 0, max_len = 0;
1044        int total_files = data->nr;
1045        int width, name_width;
1046        const char *reset, *set, *add_c, *del_c;
1047
1048        if (data->nr == 0)
1049                return;
1050
1051        width = options->stat_width ? options->stat_width : 80;
1052        name_width = options->stat_name_width ? options->stat_name_width : 50;
1053
1054        /* Sanity: give at least 5 columns to the graph,
1055         * but leave at least 10 columns for the name.
1056         */
1057        if (width < 25)
1058                width = 25;
1059        if (name_width < 10)
1060                name_width = 10;
1061        else if (width < name_width + 15)
1062                name_width = width - 15;
1063
1064        /* Find the longest filename and max number of changes */
1065        reset = diff_get_color_opt(options, DIFF_RESET);
1066        set   = diff_get_color_opt(options, DIFF_PLAIN);
1067        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1068        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1069
1070        for (i = 0; i < data->nr; i++) {
1071                struct diffstat_file *file = data->files[i];
1072                int change = file->added + file->deleted;
1073                fill_print_name(file);
1074                len = strlen(file->print_name);
1075                if (max_len < len)
1076                        max_len = len;
1077
1078                if (file->is_binary || file->is_unmerged)
1079                        continue;
1080                if (max_change < change)
1081                        max_change = change;
1082        }
1083
1084        /* Compute the width of the graph part;
1085         * 10 is for one blank at the beginning of the line plus
1086         * " | count " between the name and the graph.
1087         *
1088         * From here on, name_width is the width of the name area,
1089         * and width is the width of the graph area.
1090         */
1091        name_width = (name_width < max_len) ? name_width : max_len;
1092        if (width < (name_width + 10) + max_change)
1093                width = width - (name_width + 10);
1094        else
1095                width = max_change;
1096
1097        for (i = 0; i < data->nr; i++) {
1098                const char *prefix = "";
1099                char *name = data->files[i]->print_name;
1100                int added = data->files[i]->added;
1101                int deleted = data->files[i]->deleted;
1102                int name_len;
1103
1104                /*
1105                 * "scale" the filename
1106                 */
1107                len = name_width;
1108                name_len = strlen(name);
1109                if (name_width < name_len) {
1110                        char *slash;
1111                        prefix = "...";
1112                        len -= 3;
1113                        name += name_len - len;
1114                        slash = strchr(name, '/');
1115                        if (slash)
1116                                name = slash;
1117                }
1118
1119                if (data->files[i]->is_binary) {
1120                        show_name(options->file, prefix, name, len);
1121                        fprintf(options->file, "  Bin ");
1122                        fprintf(options->file, "%s%d%s", del_c, deleted, reset);
1123                        fprintf(options->file, " -> ");
1124                        fprintf(options->file, "%s%d%s", add_c, added, reset);
1125                        fprintf(options->file, " bytes");
1126                        fprintf(options->file, "\n");
1127                        continue;
1128                }
1129                else if (data->files[i]->is_unmerged) {
1130                        show_name(options->file, prefix, name, len);
1131                        fprintf(options->file, "  Unmerged\n");
1132                        continue;
1133                }
1134                else if (!data->files[i]->is_renamed &&
1135                         (added + deleted == 0)) {
1136                        total_files--;
1137                        continue;
1138                }
1139
1140                /*
1141                 * scale the add/delete
1142                 */
1143                add = added;
1144                del = deleted;
1145                adds += add;
1146                dels += del;
1147
1148                if (width <= max_change) {
1149                        add = scale_linear(add, width, max_change);
1150                        del = scale_linear(del, width, max_change);
1151                }
1152                show_name(options->file, prefix, name, len);
1153                fprintf(options->file, "%5d%s", added + deleted,
1154                                added + deleted ? " " : "");
1155                show_graph(options->file, '+', add, add_c, reset);
1156                show_graph(options->file, '-', del, del_c, reset);
1157                fprintf(options->file, "\n");
1158        }
1159        fprintf(options->file,
1160               " %d files changed, %d insertions(+), %d deletions(-)\n",
1161               total_files, adds, dels);
1162}
1163
1164static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1165{
1166        int i, adds = 0, dels = 0, total_files = data->nr;
1167
1168        if (data->nr == 0)
1169                return;
1170
1171        for (i = 0; i < data->nr; i++) {
1172                if (!data->files[i]->is_binary &&
1173                    !data->files[i]->is_unmerged) {
1174                        int added = data->files[i]->added;
1175                        int deleted= data->files[i]->deleted;
1176                        if (!data->files[i]->is_renamed &&
1177                            (added + deleted == 0)) {
1178                                total_files--;
1179                        } else {
1180                                adds += added;
1181                                dels += deleted;
1182                        }
1183                }
1184        }
1185        fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
1186               total_files, adds, dels);
1187}
1188
1189static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1190{
1191        int i;
1192
1193        if (data->nr == 0)
1194                return;
1195
1196        for (i = 0; i < data->nr; i++) {
1197                struct diffstat_file *file = data->files[i];
1198
1199                if (file->is_binary)
1200                        fprintf(options->file, "-\t-\t");
1201                else
1202                        fprintf(options->file,
1203                                "%d\t%d\t", file->added, file->deleted);
1204                if (options->line_termination) {
1205                        fill_print_name(file);
1206                        if (!file->is_renamed)
1207                                write_name_quoted(file->name, options->file,
1208                                                  options->line_termination);
1209                        else {
1210                                fputs(file->print_name, options->file);
1211                                putc(options->line_termination, options->file);
1212                        }
1213                } else {
1214                        if (file->is_renamed) {
1215                                putc('\0', options->file);
1216                                write_name_quoted(file->from_name, options->file, '\0');
1217                        }
1218                        write_name_quoted(file->name, options->file, '\0');
1219                }
1220        }
1221}
1222
1223struct dirstat_file {
1224        const char *name;
1225        unsigned long changed;
1226};
1227
1228struct dirstat_dir {
1229        struct dirstat_file *files;
1230        int alloc, nr, percent, cumulative;
1231};
1232
1233static long gather_dirstat(FILE *file, struct dirstat_dir *dir, unsigned long changed, const char *base, int baselen)
1234{
1235        unsigned long this_dir = 0;
1236        unsigned int sources = 0;
1237
1238        while (dir->nr) {
1239                struct dirstat_file *f = dir->files;
1240                int namelen = strlen(f->name);
1241                unsigned long this;
1242                char *slash;
1243
1244                if (namelen < baselen)
1245                        break;
1246                if (memcmp(f->name, base, baselen))
1247                        break;
1248                slash = strchr(f->name + baselen, '/');
1249                if (slash) {
1250                        int newbaselen = slash + 1 - f->name;
1251                        this = gather_dirstat(file, dir, changed, f->name, newbaselen);
1252                        sources++;
1253                } else {
1254                        this = f->changed;
1255                        dir->files++;
1256                        dir->nr--;
1257                        sources += 2;
1258                }
1259                this_dir += this;
1260        }
1261
1262        /*
1263         * We don't report dirstat's for
1264         *  - the top level
1265         *  - or cases where everything came from a single directory
1266         *    under this directory (sources == 1).
1267         */
1268        if (baselen && sources != 1) {
1269                int permille = this_dir * 1000 / changed;
1270                if (permille) {
1271                        int percent = permille / 10;
1272                        if (percent >= dir->percent) {
1273                                fprintf(file, "%4d.%01d%% %.*s\n", percent, permille % 10, baselen, base);
1274                                if (!dir->cumulative)
1275                                        return 0;
1276                        }
1277                }
1278        }
1279        return this_dir;
1280}
1281
1282static int dirstat_compare(const void *_a, const void *_b)
1283{
1284        const struct dirstat_file *a = _a;
1285        const struct dirstat_file *b = _b;
1286        return strcmp(a->name, b->name);
1287}
1288
1289static void show_dirstat(struct diff_options *options)
1290{
1291        int i;
1292        unsigned long changed;
1293        struct dirstat_dir dir;
1294        struct diff_queue_struct *q = &diff_queued_diff;
1295
1296        dir.files = NULL;
1297        dir.alloc = 0;
1298        dir.nr = 0;
1299        dir.percent = options->dirstat_percent;
1300        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1301
1302        changed = 0;
1303        for (i = 0; i < q->nr; i++) {
1304                struct diff_filepair *p = q->queue[i];
1305                const char *name;
1306                unsigned long copied, added, damage;
1307
1308                name = p->one->path ? p->one->path : p->two->path;
1309
1310                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1311                        diff_populate_filespec(p->one, 0);
1312                        diff_populate_filespec(p->two, 0);
1313                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1314                                               &copied, &added);
1315                        diff_free_filespec_data(p->one);
1316                        diff_free_filespec_data(p->two);
1317                } else if (DIFF_FILE_VALID(p->one)) {
1318                        diff_populate_filespec(p->one, 1);
1319                        copied = added = 0;
1320                        diff_free_filespec_data(p->one);
1321                } else if (DIFF_FILE_VALID(p->two)) {
1322                        diff_populate_filespec(p->two, 1);
1323                        copied = 0;
1324                        added = p->two->size;
1325                        diff_free_filespec_data(p->two);
1326                } else
1327                        continue;
1328
1329                /*
1330                 * Original minus copied is the removed material,
1331                 * added is the new material.  They are both damages
1332                 * made to the preimage. In --dirstat-by-file mode, count
1333                 * damaged files, not damaged lines. This is done by
1334                 * counting only a single damaged line per file.
1335                 */
1336                damage = (p->one->size - copied) + added;
1337                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE) && damage > 0)
1338                        damage = 1;
1339
1340                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1341                dir.files[dir.nr].name = name;
1342                dir.files[dir.nr].changed = damage;
1343                changed += damage;
1344                dir.nr++;
1345        }
1346
1347        /* This can happen even with many files, if everything was renames */
1348        if (!changed)
1349                return;
1350
1351        /* Show all directories with more than x% of the changes */
1352        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1353        gather_dirstat(options->file, &dir, changed, "", 0);
1354}
1355
1356static void free_diffstat_info(struct diffstat_t *diffstat)
1357{
1358        int i;
1359        for (i = 0; i < diffstat->nr; i++) {
1360                struct diffstat_file *f = diffstat->files[i];
1361                if (f->name != f->print_name)
1362                        free(f->print_name);
1363                free(f->name);
1364                free(f->from_name);
1365                free(f);
1366        }
1367        free(diffstat->files);
1368}
1369
1370struct checkdiff_t {
1371        const char *filename;
1372        int lineno;
1373        struct diff_options *o;
1374        unsigned ws_rule;
1375        unsigned status;
1376};
1377
1378static int is_conflict_marker(const char *line, unsigned long len)
1379{
1380        char firstchar;
1381        int cnt;
1382
1383        if (len < 8)
1384                return 0;
1385        firstchar = line[0];
1386        switch (firstchar) {
1387        case '=': case '>': case '<':
1388                break;
1389        default:
1390                return 0;
1391        }
1392        for (cnt = 1; cnt < 7; cnt++)
1393                if (line[cnt] != firstchar)
1394                        return 0;
1395        /* line[0] thru line[6] are same as firstchar */
1396        if (firstchar == '=') {
1397                /* divider between ours and theirs? */
1398                if (len != 8 || line[7] != '\n')
1399                        return 0;
1400        } else if (len < 8 || !isspace(line[7])) {
1401                /* not divider before ours nor after theirs */
1402                return 0;
1403        }
1404        return 1;
1405}
1406
1407static void checkdiff_consume(void *priv, char *line, unsigned long len)
1408{
1409        struct checkdiff_t *data = priv;
1410        int color_diff = DIFF_OPT_TST(data->o, COLOR_DIFF);
1411        const char *ws = diff_get_color(color_diff, DIFF_WHITESPACE);
1412        const char *reset = diff_get_color(color_diff, DIFF_RESET);
1413        const char *set = diff_get_color(color_diff, DIFF_FILE_NEW);
1414        char *err;
1415
1416        if (line[0] == '+') {
1417                unsigned bad;
1418                data->lineno++;
1419                if (is_conflict_marker(line + 1, len - 1)) {
1420                        data->status |= 1;
1421                        fprintf(data->o->file,
1422                                "%s:%d: leftover conflict marker\n",
1423                                data->filename, data->lineno);
1424                }
1425                bad = ws_check(line + 1, len - 1, data->ws_rule);
1426                if (!bad)
1427                        return;
1428                data->status |= bad;
1429                err = whitespace_error_string(bad);
1430                fprintf(data->o->file, "%s:%d: %s.\n",
1431                        data->filename, data->lineno, err);
1432                free(err);
1433                emit_line(data->o->file, set, reset, line, 1);
1434                ws_check_emit(line + 1, len - 1, data->ws_rule,
1435                              data->o->file, set, reset, ws);
1436        } else if (line[0] == ' ') {
1437                data->lineno++;
1438        } else if (line[0] == '@') {
1439                char *plus = strchr(line, '+');
1440                if (plus)
1441                        data->lineno = strtol(plus, NULL, 10) - 1;
1442                else
1443                        die("invalid diff");
1444        }
1445}
1446
1447static unsigned char *deflate_it(char *data,
1448                                 unsigned long size,
1449                                 unsigned long *result_size)
1450{
1451        int bound;
1452        unsigned char *deflated;
1453        z_stream stream;
1454
1455        memset(&stream, 0, sizeof(stream));
1456        deflateInit(&stream, zlib_compression_level);
1457        bound = deflateBound(&stream, size);
1458        deflated = xmalloc(bound);
1459        stream.next_out = deflated;
1460        stream.avail_out = bound;
1461
1462        stream.next_in = (unsigned char *)data;
1463        stream.avail_in = size;
1464        while (deflate(&stream, Z_FINISH) == Z_OK)
1465                ; /* nothing */
1466        deflateEnd(&stream);
1467        *result_size = stream.total_out;
1468        return deflated;
1469}
1470
1471static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two)
1472{
1473        void *cp;
1474        void *delta;
1475        void *deflated;
1476        void *data;
1477        unsigned long orig_size;
1478        unsigned long delta_size;
1479        unsigned long deflate_size;
1480        unsigned long data_size;
1481
1482        /* We could do deflated delta, or we could do just deflated two,
1483         * whichever is smaller.
1484         */
1485        delta = NULL;
1486        deflated = deflate_it(two->ptr, two->size, &deflate_size);
1487        if (one->size && two->size) {
1488                delta = diff_delta(one->ptr, one->size,
1489                                   two->ptr, two->size,
1490                                   &delta_size, deflate_size);
1491                if (delta) {
1492                        void *to_free = delta;
1493                        orig_size = delta_size;
1494                        delta = deflate_it(delta, delta_size, &delta_size);
1495                        free(to_free);
1496                }
1497        }
1498
1499        if (delta && delta_size < deflate_size) {
1500                fprintf(file, "delta %lu\n", orig_size);
1501                free(deflated);
1502                data = delta;
1503                data_size = delta_size;
1504        }
1505        else {
1506                fprintf(file, "literal %lu\n", two->size);
1507                free(delta);
1508                data = deflated;
1509                data_size = deflate_size;
1510        }
1511
1512        /* emit data encoded in base85 */
1513        cp = data;
1514        while (data_size) {
1515                int bytes = (52 < data_size) ? 52 : data_size;
1516                char line[70];
1517                data_size -= bytes;
1518                if (bytes <= 26)
1519                        line[0] = bytes + 'A' - 1;
1520                else
1521                        line[0] = bytes - 26 + 'a' - 1;
1522                encode_85(line + 1, cp, bytes);
1523                cp = (char *) cp + bytes;
1524                fputs(line, file);
1525                fputc('\n', file);
1526        }
1527        fprintf(file, "\n");
1528        free(data);
1529}
1530
1531static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two)
1532{
1533        fprintf(file, "GIT binary patch\n");
1534        emit_binary_diff_body(file, one, two);
1535        emit_binary_diff_body(file, two, one);
1536}
1537
1538static void diff_filespec_load_driver(struct diff_filespec *one)
1539{
1540        if (!one->driver)
1541                one->driver = userdiff_find_by_path(one->path);
1542        if (!one->driver)
1543                one->driver = userdiff_find_by_name("default");
1544}
1545
1546int diff_filespec_is_binary(struct diff_filespec *one)
1547{
1548        if (one->is_binary == -1) {
1549                diff_filespec_load_driver(one);
1550                if (one->driver->binary != -1)
1551                        one->is_binary = one->driver->binary;
1552                else {
1553                        if (!one->data && DIFF_FILE_VALID(one))
1554                                diff_populate_filespec(one, 0);
1555                        if (one->data)
1556                                one->is_binary = buffer_is_binary(one->data,
1557                                                one->size);
1558                        if (one->is_binary == -1)
1559                                one->is_binary = 0;
1560                }
1561        }
1562        return one->is_binary;
1563}
1564
1565static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
1566{
1567        diff_filespec_load_driver(one);
1568        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
1569}
1570
1571static const char *userdiff_word_regex(struct diff_filespec *one)
1572{
1573        diff_filespec_load_driver(one);
1574        return one->driver->word_regex;
1575}
1576
1577void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
1578{
1579        if (!options->a_prefix)
1580                options->a_prefix = a;
1581        if (!options->b_prefix)
1582                options->b_prefix = b;
1583}
1584
1585static const char *get_textconv(struct diff_filespec *one)
1586{
1587        if (!DIFF_FILE_VALID(one))
1588                return NULL;
1589        if (!S_ISREG(one->mode))
1590                return NULL;
1591        diff_filespec_load_driver(one);
1592        return one->driver->textconv;
1593}
1594
1595static void builtin_diff(const char *name_a,
1596                         const char *name_b,
1597                         struct diff_filespec *one,
1598                         struct diff_filespec *two,
1599                         const char *xfrm_msg,
1600                         struct diff_options *o,
1601                         int complete_rewrite)
1602{
1603        mmfile_t mf1, mf2;
1604        const char *lbl[2];
1605        char *a_one, *b_two;
1606        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1607        const char *reset = diff_get_color_opt(o, DIFF_RESET);
1608        const char *a_prefix, *b_prefix;
1609        const char *textconv_one = NULL, *textconv_two = NULL;
1610        struct strbuf header = STRBUF_INIT;
1611
1612        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
1613                        (!one->mode || S_ISGITLINK(one->mode)) &&
1614                        (!two->mode || S_ISGITLINK(two->mode))) {
1615                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
1616                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
1617                show_submodule_summary(o->file, one ? one->path : two->path,
1618                                one->sha1, two->sha1,
1619                                del, add, reset);
1620                return;
1621        }
1622
1623        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
1624                textconv_one = get_textconv(one);
1625                textconv_two = get_textconv(two);
1626        }
1627
1628        diff_set_mnemonic_prefix(o, "a/", "b/");
1629        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
1630                a_prefix = o->b_prefix;
1631                b_prefix = o->a_prefix;
1632        } else {
1633                a_prefix = o->a_prefix;
1634                b_prefix = o->b_prefix;
1635        }
1636
1637        /* Never use a non-valid filename anywhere if at all possible */
1638        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
1639        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
1640
1641        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
1642        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
1643        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1644        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1645        strbuf_addf(&header, "%sdiff --git %s %s%s\n", set, a_one, b_two, reset);
1646        if (lbl[0][0] == '/') {
1647                /* /dev/null */
1648                strbuf_addf(&header, "%snew file mode %06o%s\n", set, two->mode, reset);
1649                if (xfrm_msg && xfrm_msg[0])
1650                        strbuf_addf(&header, "%s%s%s\n", set, xfrm_msg, reset);
1651        }
1652        else if (lbl[1][0] == '/') {
1653                strbuf_addf(&header, "%sdeleted file mode %06o%s\n", set, one->mode, reset);
1654                if (xfrm_msg && xfrm_msg[0])
1655                        strbuf_addf(&header, "%s%s%s\n", set, xfrm_msg, reset);
1656        }
1657        else {
1658                if (one->mode != two->mode) {
1659                        strbuf_addf(&header, "%sold mode %06o%s\n", set, one->mode, reset);
1660                        strbuf_addf(&header, "%snew mode %06o%s\n", set, two->mode, reset);
1661                }
1662                if (xfrm_msg && xfrm_msg[0])
1663                        strbuf_addf(&header, "%s%s%s\n", set, xfrm_msg, reset);
1664
1665                /*
1666                 * we do not run diff between different kind
1667                 * of objects.
1668                 */
1669                if ((one->mode ^ two->mode) & S_IFMT)
1670                        goto free_ab_and_return;
1671                if (complete_rewrite &&
1672                    (textconv_one || !diff_filespec_is_binary(one)) &&
1673                    (textconv_two || !diff_filespec_is_binary(two))) {
1674                        fprintf(o->file, "%s", header.buf);
1675                        strbuf_reset(&header);
1676                        emit_rewrite_diff(name_a, name_b, one, two,
1677                                                textconv_one, textconv_two, o);
1678                        o->found_changes = 1;
1679                        goto free_ab_and_return;
1680                }
1681        }
1682
1683        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1684                die("unable to read files to diff");
1685
1686        if (!DIFF_OPT_TST(o, TEXT) &&
1687            ( (diff_filespec_is_binary(one) && !textconv_one) ||
1688              (diff_filespec_is_binary(two) && !textconv_two) )) {
1689                /* Quite common confusing case */
1690                if (mf1.size == mf2.size &&
1691                    !memcmp(mf1.ptr, mf2.ptr, mf1.size))
1692                        goto free_ab_and_return;
1693                fprintf(o->file, "%s", header.buf);
1694                strbuf_reset(&header);
1695                if (DIFF_OPT_TST(o, BINARY))
1696                        emit_binary_diff(o->file, &mf1, &mf2);
1697                else
1698                        fprintf(o->file, "Binary files %s and %s differ\n",
1699                                lbl[0], lbl[1]);
1700                o->found_changes = 1;
1701        }
1702        else {
1703                /* Crazy xdl interfaces.. */
1704                const char *diffopts = getenv("GIT_DIFF_OPTS");
1705                xpparam_t xpp;
1706                xdemitconf_t xecfg;
1707                xdemitcb_t ecb;
1708                struct emit_callback ecbdata;
1709                const struct userdiff_funcname *pe;
1710
1711                if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS)) {
1712                        fprintf(o->file, "%s", header.buf);
1713                        strbuf_reset(&header);
1714                }
1715
1716                if (textconv_one) {
1717                        size_t size;
1718                        mf1.ptr = run_textconv(textconv_one, one, &size);
1719                        if (!mf1.ptr)
1720                                die("unable to read files to diff");
1721                        mf1.size = size;
1722                }
1723                if (textconv_two) {
1724                        size_t size;
1725                        mf2.ptr = run_textconv(textconv_two, two, &size);
1726                        if (!mf2.ptr)
1727                                die("unable to read files to diff");
1728                        mf2.size = size;
1729                }
1730
1731                pe = diff_funcname_pattern(one);
1732                if (!pe)
1733                        pe = diff_funcname_pattern(two);
1734
1735                memset(&xpp, 0, sizeof(xpp));
1736                memset(&xecfg, 0, sizeof(xecfg));
1737                memset(&ecbdata, 0, sizeof(ecbdata));
1738                ecbdata.label_path = lbl;
1739                ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
1740                ecbdata.found_changesp = &o->found_changes;
1741                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
1742                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
1743                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
1744                ecbdata.file = o->file;
1745                ecbdata.header = header.len ? &header : NULL;
1746                xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1747                xecfg.ctxlen = o->context;
1748                xecfg.interhunkctxlen = o->interhunkcontext;
1749                xecfg.flags = XDL_EMIT_FUNCNAMES;
1750                if (pe)
1751                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
1752                if (!diffopts)
1753                        ;
1754                else if (!prefixcmp(diffopts, "--unified="))
1755                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
1756                else if (!prefixcmp(diffopts, "-u"))
1757                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
1758                if (DIFF_OPT_TST(o, COLOR_DIFF_WORDS)) {
1759                        ecbdata.diff_words =
1760                                xcalloc(1, sizeof(struct diff_words_data));
1761                        ecbdata.diff_words->file = o->file;
1762                        if (!o->word_regex)
1763                                o->word_regex = userdiff_word_regex(one);
1764                        if (!o->word_regex)
1765                                o->word_regex = userdiff_word_regex(two);
1766                        if (!o->word_regex)
1767                                o->word_regex = diff_word_regex_cfg;
1768                        if (o->word_regex) {
1769                                ecbdata.diff_words->word_regex = (regex_t *)
1770                                        xmalloc(sizeof(regex_t));
1771                                if (regcomp(ecbdata.diff_words->word_regex,
1772                                                o->word_regex,
1773                                                REG_EXTENDED | REG_NEWLINE))
1774                                        die ("Invalid regular expression: %s",
1775                                                        o->word_regex);
1776                        }
1777                }
1778                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
1779                              &xpp, &xecfg, &ecb);
1780                if (DIFF_OPT_TST(o, COLOR_DIFF_WORDS))
1781                        free_diff_words_data(&ecbdata);
1782                if (textconv_one)
1783                        free(mf1.ptr);
1784                if (textconv_two)
1785                        free(mf2.ptr);
1786                xdiff_clear_find_func(&xecfg);
1787        }
1788
1789 free_ab_and_return:
1790        strbuf_release(&header);
1791        diff_free_filespec_data(one);
1792        diff_free_filespec_data(two);
1793        free(a_one);
1794        free(b_two);
1795        return;
1796}
1797
1798static void builtin_diffstat(const char *name_a, const char *name_b,
1799                             struct diff_filespec *one,
1800                             struct diff_filespec *two,
1801                             struct diffstat_t *diffstat,
1802                             struct diff_options *o,
1803                             int complete_rewrite)
1804{
1805        mmfile_t mf1, mf2;
1806        struct diffstat_file *data;
1807
1808        data = diffstat_add(diffstat, name_a, name_b);
1809
1810        if (!one || !two) {
1811                data->is_unmerged = 1;
1812                return;
1813        }
1814        if (complete_rewrite) {
1815                diff_populate_filespec(one, 0);
1816                diff_populate_filespec(two, 0);
1817                data->deleted = count_lines(one->data, one->size);
1818                data->added = count_lines(two->data, two->size);
1819                goto free_and_return;
1820        }
1821        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1822                die("unable to read files to diff");
1823
1824        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
1825                data->is_binary = 1;
1826                data->added = mf2.size;
1827                data->deleted = mf1.size;
1828        } else {
1829                /* Crazy xdl interfaces.. */
1830                xpparam_t xpp;
1831                xdemitconf_t xecfg;
1832                xdemitcb_t ecb;
1833
1834                memset(&xpp, 0, sizeof(xpp));
1835                memset(&xecfg, 0, sizeof(xecfg));
1836                xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1837                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
1838                              &xpp, &xecfg, &ecb);
1839        }
1840
1841 free_and_return:
1842        diff_free_filespec_data(one);
1843        diff_free_filespec_data(two);
1844}
1845
1846static void builtin_checkdiff(const char *name_a, const char *name_b,
1847                              const char *attr_path,
1848                              struct diff_filespec *one,
1849                              struct diff_filespec *two,
1850                              struct diff_options *o)
1851{
1852        mmfile_t mf1, mf2;
1853        struct checkdiff_t data;
1854
1855        if (!two)
1856                return;
1857
1858        memset(&data, 0, sizeof(data));
1859        data.filename = name_b ? name_b : name_a;
1860        data.lineno = 0;
1861        data.o = o;
1862        data.ws_rule = whitespace_rule(attr_path);
1863
1864        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1865                die("unable to read files to diff");
1866
1867        /*
1868         * All the other codepaths check both sides, but not checking
1869         * the "old" side here is deliberate.  We are checking the newly
1870         * introduced changes, and as long as the "new" side is text, we
1871         * can and should check what it introduces.
1872         */
1873        if (diff_filespec_is_binary(two))
1874                goto free_and_return;
1875        else {
1876                /* Crazy xdl interfaces.. */
1877                xpparam_t xpp;
1878                xdemitconf_t xecfg;
1879                xdemitcb_t ecb;
1880
1881                memset(&xpp, 0, sizeof(xpp));
1882                memset(&xecfg, 0, sizeof(xecfg));
1883                xecfg.ctxlen = 1; /* at least one context line */
1884                xpp.flags = XDF_NEED_MINIMAL;
1885                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
1886                              &xpp, &xecfg, &ecb);
1887
1888                if (data.ws_rule & WS_BLANK_AT_EOF) {
1889                        struct emit_callback ecbdata;
1890                        int blank_at_eof;
1891
1892                        ecbdata.ws_rule = data.ws_rule;
1893                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
1894                        blank_at_eof = ecbdata.blank_at_eof_in_preimage;
1895
1896                        if (blank_at_eof) {
1897                                static char *err;
1898                                if (!err)
1899                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
1900                                fprintf(o->file, "%s:%d: %s.\n",
1901                                        data.filename, blank_at_eof, err);
1902                                data.status = 1; /* report errors */
1903                        }
1904                }
1905        }
1906 free_and_return:
1907        diff_free_filespec_data(one);
1908        diff_free_filespec_data(two);
1909        if (data.status)
1910                DIFF_OPT_SET(o, CHECK_FAILED);
1911}
1912
1913struct diff_filespec *alloc_filespec(const char *path)
1914{
1915        int namelen = strlen(path);
1916        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
1917
1918        memset(spec, 0, sizeof(*spec));
1919        spec->path = (char *)(spec + 1);
1920        memcpy(spec->path, path, namelen+1);
1921        spec->count = 1;
1922        spec->is_binary = -1;
1923        return spec;
1924}
1925
1926void free_filespec(struct diff_filespec *spec)
1927{
1928        if (!--spec->count) {
1929                diff_free_filespec_data(spec);
1930                free(spec);
1931        }
1932}
1933
1934void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
1935                   unsigned short mode)
1936{
1937        if (mode) {
1938                spec->mode = canon_mode(mode);
1939                hashcpy(spec->sha1, sha1);
1940                spec->sha1_valid = !is_null_sha1(sha1);
1941        }
1942}
1943
1944/*
1945 * Given a name and sha1 pair, if the index tells us the file in
1946 * the work tree has that object contents, return true, so that
1947 * prepare_temp_file() does not have to inflate and extract.
1948 */
1949static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
1950{
1951        struct cache_entry *ce;
1952        struct stat st;
1953        int pos, len;
1954
1955        /*
1956         * We do not read the cache ourselves here, because the
1957         * benchmark with my previous version that always reads cache
1958         * shows that it makes things worse for diff-tree comparing
1959         * two linux-2.6 kernel trees in an already checked out work
1960         * tree.  This is because most diff-tree comparisons deal with
1961         * only a small number of files, while reading the cache is
1962         * expensive for a large project, and its cost outweighs the
1963         * savings we get by not inflating the object to a temporary
1964         * file.  Practically, this code only helps when we are used
1965         * by diff-cache --cached, which does read the cache before
1966         * calling us.
1967         */
1968        if (!active_cache)
1969                return 0;
1970
1971        /* We want to avoid the working directory if our caller
1972         * doesn't need the data in a normal file, this system
1973         * is rather slow with its stat/open/mmap/close syscalls,
1974         * and the object is contained in a pack file.  The pack
1975         * is probably already open and will be faster to obtain
1976         * the data through than the working directory.  Loose
1977         * objects however would tend to be slower as they need
1978         * to be individually opened and inflated.
1979         */
1980        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
1981                return 0;
1982
1983        len = strlen(name);
1984        pos = cache_name_pos(name, len);
1985        if (pos < 0)
1986                return 0;
1987        ce = active_cache[pos];
1988
1989        /*
1990         * This is not the sha1 we are looking for, or
1991         * unreusable because it is not a regular file.
1992         */
1993        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
1994                return 0;
1995
1996        /*
1997         * If ce is marked as "assume unchanged", there is no
1998         * guarantee that work tree matches what we are looking for.
1999         */
2000        if (ce->ce_flags & CE_VALID)
2001                return 0;
2002
2003        /*
2004         * If ce matches the file in the work tree, we can reuse it.
2005         */
2006        if (ce_uptodate(ce) ||
2007            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2008                return 1;
2009
2010        return 0;
2011}
2012
2013static int populate_from_stdin(struct diff_filespec *s)
2014{
2015        struct strbuf buf = STRBUF_INIT;
2016        size_t size = 0;
2017
2018        if (strbuf_read(&buf, 0, 0) < 0)
2019                return error("error while reading from stdin %s",
2020                                     strerror(errno));
2021
2022        s->should_munmap = 0;
2023        s->data = strbuf_detach(&buf, &size);
2024        s->size = size;
2025        s->should_free = 1;
2026        return 0;
2027}
2028
2029static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2030{
2031        int len;
2032        char *data = xmalloc(100);
2033        len = snprintf(data, 100,
2034                "Subproject commit %s\n", sha1_to_hex(s->sha1));
2035        s->data = data;
2036        s->size = len;
2037        s->should_free = 1;
2038        if (size_only) {
2039                s->data = NULL;
2040                free(data);
2041        }
2042        return 0;
2043}
2044
2045/*
2046 * While doing rename detection and pickaxe operation, we may need to
2047 * grab the data for the blob (or file) for our own in-core comparison.
2048 * diff_filespec has data and size fields for this purpose.
2049 */
2050int diff_populate_filespec(struct diff_filespec *s, int size_only)
2051{
2052        int err = 0;
2053        if (!DIFF_FILE_VALID(s))
2054                die("internal error: asking to populate invalid file.");
2055        if (S_ISDIR(s->mode))
2056                return -1;
2057
2058        if (s->data)
2059                return 0;
2060
2061        if (size_only && 0 < s->size)
2062                return 0;
2063
2064        if (S_ISGITLINK(s->mode))
2065                return diff_populate_gitlink(s, size_only);
2066
2067        if (!s->sha1_valid ||
2068            reuse_worktree_file(s->path, s->sha1, 0)) {
2069                struct strbuf buf = STRBUF_INIT;
2070                struct stat st;
2071                int fd;
2072
2073                if (!strcmp(s->path, "-"))
2074                        return populate_from_stdin(s);
2075
2076                if (lstat(s->path, &st) < 0) {
2077                        if (errno == ENOENT) {
2078                        err_empty:
2079                                err = -1;
2080                        empty:
2081                                s->data = (char *)"";
2082                                s->size = 0;
2083                                return err;
2084                        }
2085                }
2086                s->size = xsize_t(st.st_size);
2087                if (!s->size)
2088                        goto empty;
2089                if (S_ISLNK(st.st_mode)) {
2090                        struct strbuf sb = STRBUF_INIT;
2091
2092                        if (strbuf_readlink(&sb, s->path, s->size))
2093                                goto err_empty;
2094                        s->size = sb.len;
2095                        s->data = strbuf_detach(&sb, NULL);
2096                        s->should_free = 1;
2097                        return 0;
2098                }
2099                if (size_only)
2100                        return 0;
2101                fd = open(s->path, O_RDONLY);
2102                if (fd < 0)
2103                        goto err_empty;
2104                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2105                close(fd);
2106                s->should_munmap = 1;
2107
2108                /*
2109                 * Convert from working tree format to canonical git format
2110                 */
2111                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2112                        size_t size = 0;
2113                        munmap(s->data, s->size);
2114                        s->should_munmap = 0;
2115                        s->data = strbuf_detach(&buf, &size);
2116                        s->size = size;
2117                        s->should_free = 1;
2118                }
2119        }
2120        else {
2121                enum object_type type;
2122                if (size_only)
2123                        type = sha1_object_info(s->sha1, &s->size);
2124                else {
2125                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2126                        s->should_free = 1;
2127                }
2128        }
2129        return 0;
2130}
2131
2132void diff_free_filespec_blob(struct diff_filespec *s)
2133{
2134        if (s->should_free)
2135                free(s->data);
2136        else if (s->should_munmap)
2137                munmap(s->data, s->size);
2138
2139        if (s->should_free || s->should_munmap) {
2140                s->should_free = s->should_munmap = 0;
2141                s->data = NULL;
2142        }
2143}
2144
2145void diff_free_filespec_data(struct diff_filespec *s)
2146{
2147        diff_free_filespec_blob(s);
2148        free(s->cnt_data);
2149        s->cnt_data = NULL;
2150}
2151
2152static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2153                           void *blob,
2154                           unsigned long size,
2155                           const unsigned char *sha1,
2156                           int mode)
2157{
2158        int fd;
2159        struct strbuf buf = STRBUF_INIT;
2160        struct strbuf template = STRBUF_INIT;
2161        char *path_dup = xstrdup(path);
2162        const char *base = basename(path_dup);
2163
2164        /* Generate "XXXXXX_basename.ext" */
2165        strbuf_addstr(&template, "XXXXXX_");
2166        strbuf_addstr(&template, base);
2167
2168        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2169                        strlen(base) + 1);
2170        if (fd < 0)
2171                die_errno("unable to create temp-file");
2172        if (convert_to_working_tree(path,
2173                        (const char *)blob, (size_t)size, &buf)) {
2174                blob = buf.buf;
2175                size = buf.len;
2176        }
2177        if (write_in_full(fd, blob, size) != size)
2178                die_errno("unable to write temp-file");
2179        close(fd);
2180        temp->name = temp->tmp_path;
2181        strcpy(temp->hex, sha1_to_hex(sha1));
2182        temp->hex[40] = 0;
2183        sprintf(temp->mode, "%06o", mode);
2184        strbuf_release(&buf);
2185        strbuf_release(&template);
2186        free(path_dup);
2187}
2188
2189static struct diff_tempfile *prepare_temp_file(const char *name,
2190                struct diff_filespec *one)
2191{
2192        struct diff_tempfile *temp = claim_diff_tempfile();
2193
2194        if (!DIFF_FILE_VALID(one)) {
2195        not_a_valid_file:
2196                /* A '-' entry produces this for file-2, and
2197                 * a '+' entry produces this for file-1.
2198                 */
2199                temp->name = "/dev/null";
2200                strcpy(temp->hex, ".");
2201                strcpy(temp->mode, ".");
2202                return temp;
2203        }
2204
2205        if (!remove_tempfile_installed) {
2206                atexit(remove_tempfile);
2207                sigchain_push_common(remove_tempfile_on_signal);
2208                remove_tempfile_installed = 1;
2209        }
2210
2211        if (!one->sha1_valid ||
2212            reuse_worktree_file(name, one->sha1, 1)) {
2213                struct stat st;
2214                if (lstat(name, &st) < 0) {
2215                        if (errno == ENOENT)
2216                                goto not_a_valid_file;
2217                        die_errno("stat(%s)", name);
2218                }
2219                if (S_ISLNK(st.st_mode)) {
2220                        struct strbuf sb = STRBUF_INIT;
2221                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2222                                die_errno("readlink(%s)", name);
2223                        prep_temp_blob(name, temp, sb.buf, sb.len,
2224                                       (one->sha1_valid ?
2225                                        one->sha1 : null_sha1),
2226                                       (one->sha1_valid ?
2227                                        one->mode : S_IFLNK));
2228                        strbuf_release(&sb);
2229                }
2230                else {
2231                        /* we can borrow from the file in the work tree */
2232                        temp->name = name;
2233                        if (!one->sha1_valid)
2234                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2235                        else
2236                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2237                        /* Even though we may sometimes borrow the
2238                         * contents from the work tree, we always want
2239                         * one->mode.  mode is trustworthy even when
2240                         * !(one->sha1_valid), as long as
2241                         * DIFF_FILE_VALID(one).
2242                         */
2243                        sprintf(temp->mode, "%06o", one->mode);
2244                }
2245                return temp;
2246        }
2247        else {
2248                if (diff_populate_filespec(one, 0))
2249                        die("cannot read data blob for %s", one->path);
2250                prep_temp_blob(name, temp, one->data, one->size,
2251                               one->sha1, one->mode);
2252        }
2253        return temp;
2254}
2255
2256/* An external diff command takes:
2257 *
2258 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2259 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2260 *
2261 */
2262static void run_external_diff(const char *pgm,
2263                              const char *name,
2264                              const char *other,
2265                              struct diff_filespec *one,
2266                              struct diff_filespec *two,
2267                              const char *xfrm_msg,
2268                              int complete_rewrite)
2269{
2270        const char *spawn_arg[10];
2271        int retval;
2272        const char **arg = &spawn_arg[0];
2273
2274        if (one && two) {
2275                struct diff_tempfile *temp_one, *temp_two;
2276                const char *othername = (other ? other : name);
2277                temp_one = prepare_temp_file(name, one);
2278                temp_two = prepare_temp_file(othername, two);
2279                *arg++ = pgm;
2280                *arg++ = name;
2281                *arg++ = temp_one->name;
2282                *arg++ = temp_one->hex;
2283                *arg++ = temp_one->mode;
2284                *arg++ = temp_two->name;
2285                *arg++ = temp_two->hex;
2286                *arg++ = temp_two->mode;
2287                if (other) {
2288                        *arg++ = other;
2289                        *arg++ = xfrm_msg;
2290                }
2291        } else {
2292                *arg++ = pgm;
2293                *arg++ = name;
2294        }
2295        *arg = NULL;
2296        fflush(NULL);
2297        retval = run_command_v_opt(spawn_arg, 0);
2298        remove_tempfile();
2299        if (retval) {
2300                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2301                exit(1);
2302        }
2303}
2304
2305static int similarity_index(struct diff_filepair *p)
2306{
2307        return p->score * 100 / MAX_SCORE;
2308}
2309
2310static void fill_metainfo(struct strbuf *msg,
2311                          const char *name,
2312                          const char *other,
2313                          struct diff_filespec *one,
2314                          struct diff_filespec *two,
2315                          struct diff_options *o,
2316                          struct diff_filepair *p)
2317{
2318        strbuf_init(msg, PATH_MAX * 2 + 300);
2319        switch (p->status) {
2320        case DIFF_STATUS_COPIED:
2321                strbuf_addf(msg, "similarity index %d%%", similarity_index(p));
2322                strbuf_addstr(msg, "\ncopy from ");
2323                quote_c_style(name, msg, NULL, 0);
2324                strbuf_addstr(msg, "\ncopy to ");
2325                quote_c_style(other, msg, NULL, 0);
2326                strbuf_addch(msg, '\n');
2327                break;
2328        case DIFF_STATUS_RENAMED:
2329                strbuf_addf(msg, "similarity index %d%%", similarity_index(p));
2330                strbuf_addstr(msg, "\nrename from ");
2331                quote_c_style(name, msg, NULL, 0);
2332                strbuf_addstr(msg, "\nrename to ");
2333                quote_c_style(other, msg, NULL, 0);
2334                strbuf_addch(msg, '\n');
2335                break;
2336        case DIFF_STATUS_MODIFIED:
2337                if (p->score) {
2338                        strbuf_addf(msg, "dissimilarity index %d%%\n",
2339                                    similarity_index(p));
2340                        break;
2341                }
2342                /* fallthru */
2343        default:
2344                /* nothing */
2345                ;
2346        }
2347        if (one && two && hashcmp(one->sha1, two->sha1)) {
2348                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2349
2350                if (DIFF_OPT_TST(o, BINARY)) {
2351                        mmfile_t mf;
2352                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2353                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2354                                abbrev = 40;
2355                }
2356                strbuf_addf(msg, "index %.*s..%.*s",
2357                            abbrev, sha1_to_hex(one->sha1),
2358                            abbrev, sha1_to_hex(two->sha1));
2359                if (one->mode == two->mode)
2360                        strbuf_addf(msg, " %06o", one->mode);
2361                strbuf_addch(msg, '\n');
2362        }
2363        if (msg->len)
2364                strbuf_setlen(msg, msg->len - 1);
2365}
2366
2367static void run_diff_cmd(const char *pgm,
2368                         const char *name,
2369                         const char *other,
2370                         const char *attr_path,
2371                         struct diff_filespec *one,
2372                         struct diff_filespec *two,
2373                         struct strbuf *msg,
2374                         struct diff_options *o,
2375                         struct diff_filepair *p)
2376{
2377        const char *xfrm_msg = NULL;
2378        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2379
2380        if (msg) {
2381                fill_metainfo(msg, name, other, one, two, o, p);
2382                xfrm_msg = msg->len ? msg->buf : NULL;
2383        }
2384
2385        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2386                pgm = NULL;
2387        else {
2388                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2389                if (drv && drv->external)
2390                        pgm = drv->external;
2391        }
2392
2393        if (pgm) {
2394                run_external_diff(pgm, name, other, one, two, xfrm_msg,
2395                                  complete_rewrite);
2396                return;
2397        }
2398        if (one && two)
2399                builtin_diff(name, other ? other : name,
2400                             one, two, xfrm_msg, o, complete_rewrite);
2401        else
2402                fprintf(o->file, "* Unmerged path %s\n", name);
2403}
2404
2405static void diff_fill_sha1_info(struct diff_filespec *one)
2406{
2407        if (DIFF_FILE_VALID(one)) {
2408                if (!one->sha1_valid) {
2409                        struct stat st;
2410                        if (!strcmp(one->path, "-")) {
2411                                hashcpy(one->sha1, null_sha1);
2412                                return;
2413                        }
2414                        if (lstat(one->path, &st) < 0)
2415                                die_errno("stat '%s'", one->path);
2416                        if (index_path(one->sha1, one->path, &st, 0))
2417                                die("cannot hash %s", one->path);
2418                }
2419        }
2420        else
2421                hashclr(one->sha1);
2422}
2423
2424static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2425{
2426        /* Strip the prefix but do not molest /dev/null and absolute paths */
2427        if (*namep && **namep != '/')
2428                *namep += prefix_length;
2429        if (*otherp && **otherp != '/')
2430                *otherp += prefix_length;
2431}
2432
2433static void run_diff(struct diff_filepair *p, struct diff_options *o)
2434{
2435        const char *pgm = external_diff();
2436        struct strbuf msg;
2437        struct diff_filespec *one = p->one;
2438        struct diff_filespec *two = p->two;
2439        const char *name;
2440        const char *other;
2441        const char *attr_path;
2442
2443        name  = p->one->path;
2444        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2445        attr_path = name;
2446        if (o->prefix_length)
2447                strip_prefix(o->prefix_length, &name, &other);
2448
2449        if (DIFF_PAIR_UNMERGED(p)) {
2450                run_diff_cmd(pgm, name, NULL, attr_path,
2451                             NULL, NULL, NULL, o, p);
2452                return;
2453        }
2454
2455        diff_fill_sha1_info(one);
2456        diff_fill_sha1_info(two);
2457
2458        if (!pgm &&
2459            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2460            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2461                /*
2462                 * a filepair that changes between file and symlink
2463                 * needs to be split into deletion and creation.
2464                 */
2465                struct diff_filespec *null = alloc_filespec(two->path);
2466                run_diff_cmd(NULL, name, other, attr_path,
2467                             one, null, &msg, o, p);
2468                free(null);
2469                strbuf_release(&msg);
2470
2471                null = alloc_filespec(one->path);
2472                run_diff_cmd(NULL, name, other, attr_path,
2473                             null, two, &msg, o, p);
2474                free(null);
2475        }
2476        else
2477                run_diff_cmd(pgm, name, other, attr_path,
2478                             one, two, &msg, o, p);
2479
2480        strbuf_release(&msg);
2481}
2482
2483static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2484                         struct diffstat_t *diffstat)
2485{
2486        const char *name;
2487        const char *other;
2488        int complete_rewrite = 0;
2489
2490        if (DIFF_PAIR_UNMERGED(p)) {
2491                /* unmerged */
2492                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2493                return;
2494        }
2495
2496        name = p->one->path;
2497        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2498
2499        if (o->prefix_length)
2500                strip_prefix(o->prefix_length, &name, &other);
2501
2502        diff_fill_sha1_info(p->one);
2503        diff_fill_sha1_info(p->two);
2504
2505        if (p->status == DIFF_STATUS_MODIFIED && p->score)
2506                complete_rewrite = 1;
2507        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2508}
2509
2510static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2511{
2512        const char *name;
2513        const char *other;
2514        const char *attr_path;
2515
2516        if (DIFF_PAIR_UNMERGED(p)) {
2517                /* unmerged */
2518                return;
2519        }
2520
2521        name = p->one->path;
2522        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2523        attr_path = other ? other : name;
2524
2525        if (o->prefix_length)
2526                strip_prefix(o->prefix_length, &name, &other);
2527
2528        diff_fill_sha1_info(p->one);
2529        diff_fill_sha1_info(p->two);
2530
2531        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2532}
2533
2534void diff_setup(struct diff_options *options)
2535{
2536        memset(options, 0, sizeof(*options));
2537
2538        options->file = stdout;
2539
2540        options->line_termination = '\n';
2541        options->break_opt = -1;
2542        options->rename_limit = -1;
2543        options->dirstat_percent = 3;
2544        options->context = 3;
2545
2546        options->change = diff_change;
2547        options->add_remove = diff_addremove;
2548        if (diff_use_color_default > 0)
2549                DIFF_OPT_SET(options, COLOR_DIFF);
2550        options->detect_rename = diff_detect_rename_default;
2551
2552        if (!diff_mnemonic_prefix) {
2553                options->a_prefix = "a/";
2554                options->b_prefix = "b/";
2555        }
2556}
2557
2558int diff_setup_done(struct diff_options *options)
2559{
2560        int count = 0;
2561
2562        if (options->output_format & DIFF_FORMAT_NAME)
2563                count++;
2564        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
2565                count++;
2566        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
2567                count++;
2568        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
2569                count++;
2570        if (count > 1)
2571                die("--name-only, --name-status, --check and -s are mutually exclusive");
2572
2573        /*
2574         * Most of the time we can say "there are changes"
2575         * only by checking if there are changed paths, but
2576         * --ignore-whitespace* options force us to look
2577         * inside contents.
2578         */
2579
2580        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
2581            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
2582            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
2583                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
2584        else
2585                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
2586
2587        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
2588                options->detect_rename = DIFF_DETECT_COPY;
2589
2590        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
2591                options->prefix = NULL;
2592        if (options->prefix)
2593                options->prefix_length = strlen(options->prefix);
2594        else
2595                options->prefix_length = 0;
2596
2597        if (options->output_format & (DIFF_FORMAT_NAME |
2598                                      DIFF_FORMAT_NAME_STATUS |
2599                                      DIFF_FORMAT_CHECKDIFF |
2600                                      DIFF_FORMAT_NO_OUTPUT))
2601                options->output_format &= ~(DIFF_FORMAT_RAW |
2602                                            DIFF_FORMAT_NUMSTAT |
2603                                            DIFF_FORMAT_DIFFSTAT |
2604                                            DIFF_FORMAT_SHORTSTAT |
2605                                            DIFF_FORMAT_DIRSTAT |
2606                                            DIFF_FORMAT_SUMMARY |
2607                                            DIFF_FORMAT_PATCH);
2608
2609        /*
2610         * These cases always need recursive; we do not drop caller-supplied
2611         * recursive bits for other formats here.
2612         */
2613        if (options->output_format & (DIFF_FORMAT_PATCH |
2614                                      DIFF_FORMAT_NUMSTAT |
2615                                      DIFF_FORMAT_DIFFSTAT |
2616                                      DIFF_FORMAT_SHORTSTAT |
2617                                      DIFF_FORMAT_DIRSTAT |
2618                                      DIFF_FORMAT_SUMMARY |
2619                                      DIFF_FORMAT_CHECKDIFF))
2620                DIFF_OPT_SET(options, RECURSIVE);
2621        /*
2622         * Also pickaxe would not work very well if you do not say recursive
2623         */
2624        if (options->pickaxe)
2625                DIFF_OPT_SET(options, RECURSIVE);
2626
2627        if (options->detect_rename && options->rename_limit < 0)
2628                options->rename_limit = diff_rename_limit_default;
2629        if (options->setup & DIFF_SETUP_USE_CACHE) {
2630                if (!active_cache)
2631                        /* read-cache does not die even when it fails
2632                         * so it is safe for us to do this here.  Also
2633                         * it does not smudge active_cache or active_nr
2634                         * when it fails, so we do not have to worry about
2635                         * cleaning it up ourselves either.
2636                         */
2637                        read_cache();
2638        }
2639        if (options->abbrev <= 0 || 40 < options->abbrev)
2640                options->abbrev = 40; /* full */
2641
2642        /*
2643         * It does not make sense to show the first hit we happened
2644         * to have found.  It does not make sense not to return with
2645         * exit code in such a case either.
2646         */
2647        if (DIFF_OPT_TST(options, QUICK)) {
2648                options->output_format = DIFF_FORMAT_NO_OUTPUT;
2649                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2650        }
2651
2652        return 0;
2653}
2654
2655static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
2656{
2657        char c, *eq;
2658        int len;
2659
2660        if (*arg != '-')
2661                return 0;
2662        c = *++arg;
2663        if (!c)
2664                return 0;
2665        if (c == arg_short) {
2666                c = *++arg;
2667                if (!c)
2668                        return 1;
2669                if (val && isdigit(c)) {
2670                        char *end;
2671                        int n = strtoul(arg, &end, 10);
2672                        if (*end)
2673                                return 0;
2674                        *val = n;
2675                        return 1;
2676                }
2677                return 0;
2678        }
2679        if (c != '-')
2680                return 0;
2681        arg++;
2682        eq = strchr(arg, '=');
2683        if (eq)
2684                len = eq - arg;
2685        else
2686                len = strlen(arg);
2687        if (!len || strncmp(arg, arg_long, len))
2688                return 0;
2689        if (eq) {
2690                int n;
2691                char *end;
2692                if (!isdigit(*++eq))
2693                        return 0;
2694                n = strtoul(eq, &end, 10);
2695                if (*end)
2696                        return 0;
2697                *val = n;
2698        }
2699        return 1;
2700}
2701
2702static int diff_scoreopt_parse(const char *opt);
2703
2704int diff_opt_parse(struct diff_options *options, const char **av, int ac)
2705{
2706        const char *arg = av[0];
2707
2708        /* Output format options */
2709        if (!strcmp(arg, "-p") || !strcmp(arg, "-u"))
2710                options->output_format |= DIFF_FORMAT_PATCH;
2711        else if (opt_arg(arg, 'U', "unified", &options->context))
2712                options->output_format |= DIFF_FORMAT_PATCH;
2713        else if (!strcmp(arg, "--raw"))
2714                options->output_format |= DIFF_FORMAT_RAW;
2715        else if (!strcmp(arg, "--patch-with-raw"))
2716                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
2717        else if (!strcmp(arg, "--numstat"))
2718                options->output_format |= DIFF_FORMAT_NUMSTAT;
2719        else if (!strcmp(arg, "--shortstat"))
2720                options->output_format |= DIFF_FORMAT_SHORTSTAT;
2721        else if (opt_arg(arg, 'X', "dirstat", &options->dirstat_percent))
2722                options->output_format |= DIFF_FORMAT_DIRSTAT;
2723        else if (!strcmp(arg, "--cumulative")) {
2724                options->output_format |= DIFF_FORMAT_DIRSTAT;
2725                DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
2726        } else if (opt_arg(arg, 0, "dirstat-by-file",
2727                           &options->dirstat_percent)) {
2728                options->output_format |= DIFF_FORMAT_DIRSTAT;
2729                DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
2730        }
2731        else if (!strcmp(arg, "--check"))
2732                options->output_format |= DIFF_FORMAT_CHECKDIFF;
2733        else if (!strcmp(arg, "--summary"))
2734                options->output_format |= DIFF_FORMAT_SUMMARY;
2735        else if (!strcmp(arg, "--patch-with-stat"))
2736                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
2737        else if (!strcmp(arg, "--name-only"))
2738                options->output_format |= DIFF_FORMAT_NAME;
2739        else if (!strcmp(arg, "--name-status"))
2740                options->output_format |= DIFF_FORMAT_NAME_STATUS;
2741        else if (!strcmp(arg, "-s"))
2742                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
2743        else if (!prefixcmp(arg, "--stat")) {
2744                char *end;
2745                int width = options->stat_width;
2746                int name_width = options->stat_name_width;
2747                arg += 6;
2748                end = (char *)arg;
2749
2750                switch (*arg) {
2751                case '-':
2752                        if (!prefixcmp(arg, "-width="))
2753                                width = strtoul(arg + 7, &end, 10);
2754                        else if (!prefixcmp(arg, "-name-width="))
2755                                name_width = strtoul(arg + 12, &end, 10);
2756                        break;
2757                case '=':
2758                        width = strtoul(arg+1, &end, 10);
2759                        if (*end == ',')
2760                                name_width = strtoul(end+1, &end, 10);
2761                }
2762
2763                /* Important! This checks all the error cases! */
2764                if (*end)
2765                        return 0;
2766                options->output_format |= DIFF_FORMAT_DIFFSTAT;
2767                options->stat_name_width = name_width;
2768                options->stat_width = width;
2769        }
2770
2771        /* renames options */
2772        else if (!prefixcmp(arg, "-B")) {
2773                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
2774                        return -1;
2775        }
2776        else if (!prefixcmp(arg, "-M")) {
2777                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2778                        return -1;
2779                options->detect_rename = DIFF_DETECT_RENAME;
2780        }
2781        else if (!prefixcmp(arg, "-C")) {
2782                if (options->detect_rename == DIFF_DETECT_COPY)
2783                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2784                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2785                        return -1;
2786                options->detect_rename = DIFF_DETECT_COPY;
2787        }
2788        else if (!strcmp(arg, "--no-renames"))
2789                options->detect_rename = 0;
2790        else if (!strcmp(arg, "--relative"))
2791                DIFF_OPT_SET(options, RELATIVE_NAME);
2792        else if (!prefixcmp(arg, "--relative=")) {
2793                DIFF_OPT_SET(options, RELATIVE_NAME);
2794                options->prefix = arg + 11;
2795        }
2796
2797        /* xdiff options */
2798        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
2799                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
2800        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
2801                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
2802        else if (!strcmp(arg, "--ignore-space-at-eol"))
2803                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
2804        else if (!strcmp(arg, "--patience"))
2805                DIFF_XDL_SET(options, PATIENCE_DIFF);
2806
2807        /* flags options */
2808        else if (!strcmp(arg, "--binary")) {
2809                options->output_format |= DIFF_FORMAT_PATCH;
2810                DIFF_OPT_SET(options, BINARY);
2811        }
2812        else if (!strcmp(arg, "--full-index"))
2813                DIFF_OPT_SET(options, FULL_INDEX);
2814        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
2815                DIFF_OPT_SET(options, TEXT);
2816        else if (!strcmp(arg, "-R"))
2817                DIFF_OPT_SET(options, REVERSE_DIFF);
2818        else if (!strcmp(arg, "--find-copies-harder"))
2819                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2820        else if (!strcmp(arg, "--follow"))
2821                DIFF_OPT_SET(options, FOLLOW_RENAMES);
2822        else if (!strcmp(arg, "--color"))
2823                DIFF_OPT_SET(options, COLOR_DIFF);
2824        else if (!strcmp(arg, "--no-color"))
2825                DIFF_OPT_CLR(options, COLOR_DIFF);
2826        else if (!strcmp(arg, "--color-words")) {
2827                DIFF_OPT_SET(options, COLOR_DIFF);
2828                DIFF_OPT_SET(options, COLOR_DIFF_WORDS);
2829        }
2830        else if (!prefixcmp(arg, "--color-words=")) {
2831                DIFF_OPT_SET(options, COLOR_DIFF);
2832                DIFF_OPT_SET(options, COLOR_DIFF_WORDS);
2833                options->word_regex = arg + 14;
2834        }
2835        else if (!strcmp(arg, "--exit-code"))
2836                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2837        else if (!strcmp(arg, "--quiet"))
2838                DIFF_OPT_SET(options, QUICK);
2839        else if (!strcmp(arg, "--ext-diff"))
2840                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
2841        else if (!strcmp(arg, "--no-ext-diff"))
2842                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
2843        else if (!strcmp(arg, "--textconv"))
2844                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
2845        else if (!strcmp(arg, "--no-textconv"))
2846                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
2847        else if (!strcmp(arg, "--ignore-submodules"))
2848                DIFF_OPT_SET(options, IGNORE_SUBMODULES);
2849        else if (!strcmp(arg, "--submodule"))
2850                DIFF_OPT_SET(options, SUBMODULE_LOG);
2851        else if (!prefixcmp(arg, "--submodule=")) {
2852                if (!strcmp(arg + 12, "log"))
2853                        DIFF_OPT_SET(options, SUBMODULE_LOG);
2854        }
2855
2856        /* misc options */
2857        else if (!strcmp(arg, "-z"))
2858                options->line_termination = 0;
2859        else if (!prefixcmp(arg, "-l"))
2860                options->rename_limit = strtoul(arg+2, NULL, 10);
2861        else if (!prefixcmp(arg, "-S"))
2862                options->pickaxe = arg + 2;
2863        else if (!strcmp(arg, "--pickaxe-all"))
2864                options->pickaxe_opts = DIFF_PICKAXE_ALL;
2865        else if (!strcmp(arg, "--pickaxe-regex"))
2866                options->pickaxe_opts = DIFF_PICKAXE_REGEX;
2867        else if (!prefixcmp(arg, "-O"))
2868                options->orderfile = arg + 2;
2869        else if (!prefixcmp(arg, "--diff-filter="))
2870                options->filter = arg + 14;
2871        else if (!strcmp(arg, "--abbrev"))
2872                options->abbrev = DEFAULT_ABBREV;
2873        else if (!prefixcmp(arg, "--abbrev=")) {
2874                options->abbrev = strtoul(arg + 9, NULL, 10);
2875                if (options->abbrev < MINIMUM_ABBREV)
2876                        options->abbrev = MINIMUM_ABBREV;
2877                else if (40 < options->abbrev)
2878                        options->abbrev = 40;
2879        }
2880        else if (!prefixcmp(arg, "--src-prefix="))
2881                options->a_prefix = arg + 13;
2882        else if (!prefixcmp(arg, "--dst-prefix="))
2883                options->b_prefix = arg + 13;
2884        else if (!strcmp(arg, "--no-prefix"))
2885                options->a_prefix = options->b_prefix = "";
2886        else if (opt_arg(arg, '\0', "inter-hunk-context",
2887                         &options->interhunkcontext))
2888                ;
2889        else if (!prefixcmp(arg, "--output=")) {
2890                options->file = fopen(arg + strlen("--output="), "w");
2891                options->close_file = 1;
2892        } else
2893                return 0;
2894        return 1;
2895}
2896
2897static int parse_num(const char **cp_p)
2898{
2899        unsigned long num, scale;
2900        int ch, dot;
2901        const char *cp = *cp_p;
2902
2903        num = 0;
2904        scale = 1;
2905        dot = 0;
2906        for (;;) {
2907                ch = *cp;
2908                if ( !dot && ch == '.' ) {
2909                        scale = 1;
2910                        dot = 1;
2911                } else if ( ch == '%' ) {
2912                        scale = dot ? scale*100 : 100;
2913                        cp++;   /* % is always at the end */
2914                        break;
2915                } else if ( ch >= '0' && ch <= '9' ) {
2916                        if ( scale < 100000 ) {
2917                                scale *= 10;
2918                                num = (num*10) + (ch-'0');
2919                        }
2920                } else {
2921                        break;
2922                }
2923                cp++;
2924        }
2925        *cp_p = cp;
2926
2927        /* user says num divided by scale and we say internally that
2928         * is MAX_SCORE * num / scale.
2929         */
2930        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
2931}
2932
2933static int diff_scoreopt_parse(const char *opt)
2934{
2935        int opt1, opt2, cmd;
2936
2937        if (*opt++ != '-')
2938                return -1;
2939        cmd = *opt++;
2940        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
2941                return -1; /* that is not a -M, -C nor -B option */
2942
2943        opt1 = parse_num(&opt);
2944        if (cmd != 'B')
2945                opt2 = 0;
2946        else {
2947                if (*opt == 0)
2948                        opt2 = 0;
2949                else if (*opt != '/')
2950                        return -1; /* we expect -B80/99 or -B80 */
2951                else {
2952                        opt++;
2953                        opt2 = parse_num(&opt);
2954                }
2955        }
2956        if (*opt != 0)
2957                return -1;
2958        return opt1 | (opt2 << 16);
2959}
2960
2961struct diff_queue_struct diff_queued_diff;
2962
2963void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
2964{
2965        if (queue->alloc <= queue->nr) {
2966                queue->alloc = alloc_nr(queue->alloc);
2967                queue->queue = xrealloc(queue->queue,
2968                                        sizeof(dp) * queue->alloc);
2969        }
2970        queue->queue[queue->nr++] = dp;
2971}
2972
2973struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
2974                                 struct diff_filespec *one,
2975                                 struct diff_filespec *two)
2976{
2977        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
2978        dp->one = one;
2979        dp->two = two;
2980        if (queue)
2981                diff_q(queue, dp);
2982        return dp;
2983}
2984
2985void diff_free_filepair(struct diff_filepair *p)
2986{
2987        free_filespec(p->one);
2988        free_filespec(p->two);
2989        free(p);
2990}
2991
2992/* This is different from find_unique_abbrev() in that
2993 * it stuffs the result with dots for alignment.
2994 */
2995const char *diff_unique_abbrev(const unsigned char *sha1, int len)
2996{
2997        int abblen;
2998        const char *abbrev;
2999        if (len == 40)
3000                return sha1_to_hex(sha1);
3001
3002        abbrev = find_unique_abbrev(sha1, len);
3003        abblen = strlen(abbrev);
3004        if (abblen < 37) {
3005                static char hex[41];
3006                if (len < abblen && abblen <= len + 2)
3007                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3008                else
3009                        sprintf(hex, "%s...", abbrev);
3010                return hex;
3011        }
3012        return sha1_to_hex(sha1);
3013}
3014
3015static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3016{
3017        int line_termination = opt->line_termination;
3018        int inter_name_termination = line_termination ? '\t' : '\0';
3019
3020        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3021                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3022                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3023                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3024        }
3025        if (p->score) {
3026                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3027                        inter_name_termination);
3028        } else {
3029                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3030        }
3031
3032        if (p->status == DIFF_STATUS_COPIED ||
3033            p->status == DIFF_STATUS_RENAMED) {
3034                const char *name_a, *name_b;
3035                name_a = p->one->path;
3036                name_b = p->two->path;
3037                strip_prefix(opt->prefix_length, &name_a, &name_b);
3038                write_name_quoted(name_a, opt->file, inter_name_termination);
3039                write_name_quoted(name_b, opt->file, line_termination);
3040        } else {
3041                const char *name_a, *name_b;
3042                name_a = p->one->mode ? p->one->path : p->two->path;
3043                name_b = NULL;
3044                strip_prefix(opt->prefix_length, &name_a, &name_b);
3045                write_name_quoted(name_a, opt->file, line_termination);
3046        }
3047}
3048
3049int diff_unmodified_pair(struct diff_filepair *p)
3050{
3051        /* This function is written stricter than necessary to support
3052         * the currently implemented transformers, but the idea is to
3053         * let transformers to produce diff_filepairs any way they want,
3054         * and filter and clean them up here before producing the output.
3055         */
3056        struct diff_filespec *one = p->one, *two = p->two;
3057
3058        if (DIFF_PAIR_UNMERGED(p))
3059                return 0; /* unmerged is interesting */
3060
3061        /* deletion, addition, mode or type change
3062         * and rename are all interesting.
3063         */
3064        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3065            DIFF_PAIR_MODE_CHANGED(p) ||
3066            strcmp(one->path, two->path))
3067                return 0;
3068
3069        /* both are valid and point at the same path.  that is, we are
3070         * dealing with a change.
3071         */
3072        if (one->sha1_valid && two->sha1_valid &&
3073            !hashcmp(one->sha1, two->sha1))
3074                return 1; /* no change */
3075        if (!one->sha1_valid && !two->sha1_valid)
3076                return 1; /* both look at the same file on the filesystem. */
3077        return 0;
3078}
3079
3080static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3081{
3082        if (diff_unmodified_pair(p))
3083                return;
3084
3085        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3086            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3087                return; /* no tree diffs in patch format */
3088
3089        run_diff(p, o);
3090}
3091
3092static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3093                            struct diffstat_t *diffstat)
3094{
3095        if (diff_unmodified_pair(p))
3096                return;
3097
3098        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3099            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3100                return; /* no tree diffs in patch format */
3101
3102        run_diffstat(p, o, diffstat);
3103}
3104
3105static void diff_flush_checkdiff(struct diff_filepair *p,
3106                struct diff_options *o)
3107{
3108        if (diff_unmodified_pair(p))
3109                return;
3110
3111        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3112            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3113                return; /* no tree diffs in patch format */
3114
3115        run_checkdiff(p, o);
3116}
3117
3118int diff_queue_is_empty(void)
3119{
3120        struct diff_queue_struct *q = &diff_queued_diff;
3121        int i;
3122        for (i = 0; i < q->nr; i++)
3123                if (!diff_unmodified_pair(q->queue[i]))
3124                        return 0;
3125        return 1;
3126}
3127
3128#if DIFF_DEBUG
3129void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3130{
3131        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3132                x, one ? one : "",
3133                s->path,
3134                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3135                s->mode,
3136                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3137        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3138                x, one ? one : "",
3139                s->size, s->xfrm_flags);
3140}
3141
3142void diff_debug_filepair(const struct diff_filepair *p, int i)
3143{
3144        diff_debug_filespec(p->one, i, "one");
3145        diff_debug_filespec(p->two, i, "two");
3146        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3147                p->score, p->status ? p->status : '?',
3148                p->one->rename_used, p->broken_pair);
3149}
3150
3151void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3152{
3153        int i;
3154        if (msg)
3155                fprintf(stderr, "%s\n", msg);
3156        fprintf(stderr, "q->nr = %d\n", q->nr);
3157        for (i = 0; i < q->nr; i++) {
3158                struct diff_filepair *p = q->queue[i];
3159                diff_debug_filepair(p, i);
3160        }
3161}
3162#endif
3163
3164static void diff_resolve_rename_copy(void)
3165{
3166        int i;
3167        struct diff_filepair *p;
3168        struct diff_queue_struct *q = &diff_queued_diff;
3169
3170        diff_debug_queue("resolve-rename-copy", q);
3171
3172        for (i = 0; i < q->nr; i++) {
3173                p = q->queue[i];
3174                p->status = 0; /* undecided */
3175                if (DIFF_PAIR_UNMERGED(p))
3176                        p->status = DIFF_STATUS_UNMERGED;
3177                else if (!DIFF_FILE_VALID(p->one))
3178                        p->status = DIFF_STATUS_ADDED;
3179                else if (!DIFF_FILE_VALID(p->two))
3180                        p->status = DIFF_STATUS_DELETED;
3181                else if (DIFF_PAIR_TYPE_CHANGED(p))
3182                        p->status = DIFF_STATUS_TYPE_CHANGED;
3183
3184                /* from this point on, we are dealing with a pair
3185                 * whose both sides are valid and of the same type, i.e.
3186                 * either in-place edit or rename/copy edit.
3187                 */
3188                else if (DIFF_PAIR_RENAME(p)) {
3189                        /*
3190                         * A rename might have re-connected a broken
3191                         * pair up, causing the pathnames to be the
3192                         * same again. If so, that's not a rename at
3193                         * all, just a modification..
3194                         *
3195                         * Otherwise, see if this source was used for
3196                         * multiple renames, in which case we decrement
3197                         * the count, and call it a copy.
3198                         */
3199                        if (!strcmp(p->one->path, p->two->path))
3200                                p->status = DIFF_STATUS_MODIFIED;
3201                        else if (--p->one->rename_used > 0)
3202                                p->status = DIFF_STATUS_COPIED;
3203                        else
3204                                p->status = DIFF_STATUS_RENAMED;
3205                }
3206                else if (hashcmp(p->one->sha1, p->two->sha1) ||
3207                         p->one->mode != p->two->mode ||
3208                         is_null_sha1(p->one->sha1))
3209                        p->status = DIFF_STATUS_MODIFIED;
3210                else {
3211                        /* This is a "no-change" entry and should not
3212                         * happen anymore, but prepare for broken callers.
3213                         */
3214                        error("feeding unmodified %s to diffcore",
3215                              p->one->path);
3216                        p->status = DIFF_STATUS_UNKNOWN;
3217                }
3218        }
3219        diff_debug_queue("resolve-rename-copy done", q);
3220}
3221
3222static int check_pair_status(struct diff_filepair *p)
3223{
3224        switch (p->status) {
3225        case DIFF_STATUS_UNKNOWN:
3226                return 0;
3227        case 0:
3228                die("internal error in diff-resolve-rename-copy");
3229        default:
3230                return 1;
3231        }
3232}
3233
3234static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3235{
3236        int fmt = opt->output_format;
3237
3238        if (fmt & DIFF_FORMAT_CHECKDIFF)
3239                diff_flush_checkdiff(p, opt);
3240        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3241                diff_flush_raw(p, opt);
3242        else if (fmt & DIFF_FORMAT_NAME) {
3243                const char *name_a, *name_b;
3244                name_a = p->two->path;
3245                name_b = NULL;
3246                strip_prefix(opt->prefix_length, &name_a, &name_b);
3247                write_name_quoted(name_a, opt->file, opt->line_termination);
3248        }
3249}
3250
3251static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
3252{
3253        if (fs->mode)
3254                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
3255        else
3256                fprintf(file, " %s ", newdelete);
3257        write_name_quoted(fs->path, file, '\n');
3258}
3259
3260
3261static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name)
3262{
3263        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
3264                fprintf(file, " mode change %06o => %06o%c", p->one->mode, p->two->mode,
3265                        show_name ? ' ' : '\n');
3266                if (show_name) {
3267                        write_name_quoted(p->two->path, file, '\n');
3268                }
3269        }
3270}
3271
3272static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p)
3273{
3274        char *names = pprint_rename(p->one->path, p->two->path);
3275
3276        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
3277        free(names);
3278        show_mode_change(file, p, 0);
3279}
3280
3281static void diff_summary(FILE *file, struct diff_filepair *p)
3282{
3283        switch(p->status) {
3284        case DIFF_STATUS_DELETED:
3285                show_file_mode_name(file, "delete", p->one);
3286                break;
3287        case DIFF_STATUS_ADDED:
3288                show_file_mode_name(file, "create", p->two);
3289                break;
3290        case DIFF_STATUS_COPIED:
3291                show_rename_copy(file, "copy", p);
3292                break;
3293        case DIFF_STATUS_RENAMED:
3294                show_rename_copy(file, "rename", p);
3295                break;
3296        default:
3297                if (p->score) {
3298                        fputs(" rewrite ", file);
3299                        write_name_quoted(p->two->path, file, ' ');
3300                        fprintf(file, "(%d%%)\n", similarity_index(p));
3301                }
3302                show_mode_change(file, p, !p->score);
3303                break;
3304        }
3305}
3306
3307struct patch_id_t {
3308        git_SHA_CTX *ctx;
3309        int patchlen;
3310};
3311
3312static int remove_space(char *line, int len)
3313{
3314        int i;
3315        char *dst = line;
3316        unsigned char c;
3317
3318        for (i = 0; i < len; i++)
3319                if (!isspace((c = line[i])))
3320                        *dst++ = c;
3321
3322        return dst - line;
3323}
3324
3325static void patch_id_consume(void *priv, char *line, unsigned long len)
3326{
3327        struct patch_id_t *data = priv;
3328        int new_len;
3329
3330        /* Ignore line numbers when computing the SHA1 of the patch */
3331        if (!prefixcmp(line, "@@ -"))
3332                return;
3333
3334        new_len = remove_space(line, len);
3335
3336        git_SHA1_Update(data->ctx, line, new_len);
3337        data->patchlen += new_len;
3338}
3339
3340/* returns 0 upon success, and writes result into sha1 */
3341static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
3342{
3343        struct diff_queue_struct *q = &diff_queued_diff;
3344        int i;
3345        git_SHA_CTX ctx;
3346        struct patch_id_t data;
3347        char buffer[PATH_MAX * 4 + 20];
3348
3349        git_SHA1_Init(&ctx);
3350        memset(&data, 0, sizeof(struct patch_id_t));
3351        data.ctx = &ctx;
3352
3353        for (i = 0; i < q->nr; i++) {
3354                xpparam_t xpp;
3355                xdemitconf_t xecfg;
3356                xdemitcb_t ecb;
3357                mmfile_t mf1, mf2;
3358                struct diff_filepair *p = q->queue[i];
3359                int len1, len2;
3360
3361                memset(&xpp, 0, sizeof(xpp));
3362                memset(&xecfg, 0, sizeof(xecfg));
3363                if (p->status == 0)
3364                        return error("internal diff status error");
3365                if (p->status == DIFF_STATUS_UNKNOWN)
3366                        continue;
3367                if (diff_unmodified_pair(p))
3368                        continue;
3369                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3370                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3371                        continue;
3372                if (DIFF_PAIR_UNMERGED(p))
3373                        continue;
3374
3375                diff_fill_sha1_info(p->one);
3376                diff_fill_sha1_info(p->two);
3377                if (fill_mmfile(&mf1, p->one) < 0 ||
3378                                fill_mmfile(&mf2, p->two) < 0)
3379                        return error("unable to read files to diff");
3380
3381                len1 = remove_space(p->one->path, strlen(p->one->path));
3382                len2 = remove_space(p->two->path, strlen(p->two->path));
3383                if (p->one->mode == 0)
3384                        len1 = snprintf(buffer, sizeof(buffer),
3385                                        "diff--gita/%.*sb/%.*s"
3386                                        "newfilemode%06o"
3387                                        "---/dev/null"
3388                                        "+++b/%.*s",
3389                                        len1, p->one->path,
3390                                        len2, p->two->path,
3391                                        p->two->mode,
3392                                        len2, p->two->path);
3393                else if (p->two->mode == 0)
3394                        len1 = snprintf(buffer, sizeof(buffer),
3395                                        "diff--gita/%.*sb/%.*s"
3396                                        "deletedfilemode%06o"
3397                                        "---a/%.*s"
3398                                        "+++/dev/null",
3399                                        len1, p->one->path,
3400                                        len2, p->two->path,
3401                                        p->one->mode,
3402                                        len1, p->one->path);
3403                else
3404                        len1 = snprintf(buffer, sizeof(buffer),
3405                                        "diff--gita/%.*sb/%.*s"
3406                                        "---a/%.*s"
3407                                        "+++b/%.*s",
3408                                        len1, p->one->path,
3409                                        len2, p->two->path,
3410                                        len1, p->one->path,
3411                                        len2, p->two->path);
3412                git_SHA1_Update(&ctx, buffer, len1);
3413
3414                xpp.flags = XDF_NEED_MINIMAL;
3415                xecfg.ctxlen = 3;
3416                xecfg.flags = XDL_EMIT_FUNCNAMES;
3417                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
3418                              &xpp, &xecfg, &ecb);
3419        }
3420
3421        git_SHA1_Final(sha1, &ctx);
3422        return 0;
3423}
3424
3425int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
3426{
3427        struct diff_queue_struct *q = &diff_queued_diff;
3428        int i;
3429        int result = diff_get_patch_id(options, sha1);
3430
3431        for (i = 0; i < q->nr; i++)
3432                diff_free_filepair(q->queue[i]);
3433
3434        free(q->queue);
3435        q->queue = NULL;
3436        q->nr = q->alloc = 0;
3437
3438        return result;
3439}
3440
3441static int is_summary_empty(const struct diff_queue_struct *q)
3442{
3443        int i;
3444
3445        for (i = 0; i < q->nr; i++) {
3446                const struct diff_filepair *p = q->queue[i];
3447
3448                switch (p->status) {
3449                case DIFF_STATUS_DELETED:
3450                case DIFF_STATUS_ADDED:
3451                case DIFF_STATUS_COPIED:
3452                case DIFF_STATUS_RENAMED:
3453                        return 0;
3454                default:
3455                        if (p->score)
3456                                return 0;
3457                        if (p->one->mode && p->two->mode &&
3458                            p->one->mode != p->two->mode)
3459                                return 0;
3460                        break;
3461                }
3462        }
3463        return 1;
3464}
3465
3466void diff_flush(struct diff_options *options)
3467{
3468        struct diff_queue_struct *q = &diff_queued_diff;
3469        int i, output_format = options->output_format;
3470        int separator = 0;
3471
3472        /*
3473         * Order: raw, stat, summary, patch
3474         * or:    name/name-status/checkdiff (other bits clear)
3475         */
3476        if (!q->nr)
3477                goto free_queue;
3478
3479        if (output_format & (DIFF_FORMAT_RAW |
3480                             DIFF_FORMAT_NAME |
3481                             DIFF_FORMAT_NAME_STATUS |
3482                             DIFF_FORMAT_CHECKDIFF)) {
3483                for (i = 0; i < q->nr; i++) {
3484                        struct diff_filepair *p = q->queue[i];
3485                        if (check_pair_status(p))
3486                                flush_one_pair(p, options);
3487                }
3488                separator++;
3489        }
3490
3491        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
3492                struct diffstat_t diffstat;
3493
3494                memset(&diffstat, 0, sizeof(struct diffstat_t));
3495                for (i = 0; i < q->nr; i++) {
3496                        struct diff_filepair *p = q->queue[i];
3497                        if (check_pair_status(p))
3498                                diff_flush_stat(p, options, &diffstat);
3499                }
3500                if (output_format & DIFF_FORMAT_NUMSTAT)
3501                        show_numstat(&diffstat, options);
3502                if (output_format & DIFF_FORMAT_DIFFSTAT)
3503                        show_stats(&diffstat, options);
3504                if (output_format & DIFF_FORMAT_SHORTSTAT)
3505                        show_shortstats(&diffstat, options);
3506                free_diffstat_info(&diffstat);
3507                separator++;
3508        }
3509        if (output_format & DIFF_FORMAT_DIRSTAT)
3510                show_dirstat(options);
3511
3512        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
3513                for (i = 0; i < q->nr; i++)
3514                        diff_summary(options->file, q->queue[i]);
3515                separator++;
3516        }
3517
3518        if (output_format & DIFF_FORMAT_PATCH) {
3519                if (separator) {
3520                        putc(options->line_termination, options->file);
3521                        if (options->stat_sep) {
3522                                /* attach patch instead of inline */
3523                                fputs(options->stat_sep, options->file);
3524                        }
3525                }
3526
3527                for (i = 0; i < q->nr; i++) {
3528                        struct diff_filepair *p = q->queue[i];
3529                        if (check_pair_status(p))
3530                                diff_flush_patch(p, options);
3531                }
3532        }
3533
3534        if (output_format & DIFF_FORMAT_CALLBACK)
3535                options->format_callback(q, options, options->format_callback_data);
3536
3537        for (i = 0; i < q->nr; i++)
3538                diff_free_filepair(q->queue[i]);
3539free_queue:
3540        free(q->queue);
3541        q->queue = NULL;
3542        q->nr = q->alloc = 0;
3543        if (options->close_file)
3544                fclose(options->file);
3545
3546        /*
3547         * Report the content-level differences with HAS_CHANGES;
3548         * diff_addremove/diff_change does not set the bit when
3549         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
3550         */
3551        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
3552                if (options->found_changes)
3553                        DIFF_OPT_SET(options, HAS_CHANGES);
3554                else
3555                        DIFF_OPT_CLR(options, HAS_CHANGES);
3556        }
3557}
3558
3559static void diffcore_apply_filter(const char *filter)
3560{
3561        int i;
3562        struct diff_queue_struct *q = &diff_queued_diff;
3563        struct diff_queue_struct outq;
3564        outq.queue = NULL;
3565        outq.nr = outq.alloc = 0;
3566
3567        if (!filter)
3568                return;
3569
3570        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
3571                int found;
3572                for (i = found = 0; !found && i < q->nr; i++) {
3573                        struct diff_filepair *p = q->queue[i];
3574                        if (((p->status == DIFF_STATUS_MODIFIED) &&
3575                             ((p->score &&
3576                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3577                              (!p->score &&
3578                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3579                            ((p->status != DIFF_STATUS_MODIFIED) &&
3580                             strchr(filter, p->status)))
3581                                found++;
3582                }
3583                if (found)
3584                        return;
3585
3586                /* otherwise we will clear the whole queue
3587                 * by copying the empty outq at the end of this
3588                 * function, but first clear the current entries
3589                 * in the queue.
3590                 */
3591                for (i = 0; i < q->nr; i++)
3592                        diff_free_filepair(q->queue[i]);
3593        }
3594        else {
3595                /* Only the matching ones */
3596                for (i = 0; i < q->nr; i++) {
3597                        struct diff_filepair *p = q->queue[i];
3598
3599                        if (((p->status == DIFF_STATUS_MODIFIED) &&
3600                             ((p->score &&
3601                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3602                              (!p->score &&
3603                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3604                            ((p->status != DIFF_STATUS_MODIFIED) &&
3605                             strchr(filter, p->status)))
3606                                diff_q(&outq, p);
3607                        else
3608                                diff_free_filepair(p);
3609                }
3610        }
3611        free(q->queue);
3612        *q = outq;
3613}
3614
3615/* Check whether two filespecs with the same mode and size are identical */
3616static int diff_filespec_is_identical(struct diff_filespec *one,
3617                                      struct diff_filespec *two)
3618{
3619        if (S_ISGITLINK(one->mode))
3620                return 0;
3621        if (diff_populate_filespec(one, 0))
3622                return 0;
3623        if (diff_populate_filespec(two, 0))
3624                return 0;
3625        return !memcmp(one->data, two->data, one->size);
3626}
3627
3628static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
3629{
3630        int i;
3631        struct diff_queue_struct *q = &diff_queued_diff;
3632        struct diff_queue_struct outq;
3633        outq.queue = NULL;
3634        outq.nr = outq.alloc = 0;
3635
3636        for (i = 0; i < q->nr; i++) {
3637                struct diff_filepair *p = q->queue[i];
3638
3639                /*
3640                 * 1. Entries that come from stat info dirtyness
3641                 *    always have both sides (iow, not create/delete),
3642                 *    one side of the object name is unknown, with
3643                 *    the same mode and size.  Keep the ones that
3644                 *    do not match these criteria.  They have real
3645                 *    differences.
3646                 *
3647                 * 2. At this point, the file is known to be modified,
3648                 *    with the same mode and size, and the object
3649                 *    name of one side is unknown.  Need to inspect
3650                 *    the identical contents.
3651                 */
3652                if (!DIFF_FILE_VALID(p->one) || /* (1) */
3653                    !DIFF_FILE_VALID(p->two) ||
3654                    (p->one->sha1_valid && p->two->sha1_valid) ||
3655                    (p->one->mode != p->two->mode) ||
3656                    diff_populate_filespec(p->one, 1) ||
3657                    diff_populate_filespec(p->two, 1) ||
3658                    (p->one->size != p->two->size) ||
3659                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
3660                        diff_q(&outq, p);
3661                else {
3662                        /*
3663                         * The caller can subtract 1 from skip_stat_unmatch
3664                         * to determine how many paths were dirty only
3665                         * due to stat info mismatch.
3666                         */
3667                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
3668                                diffopt->skip_stat_unmatch++;
3669                        diff_free_filepair(p);
3670                }
3671        }
3672        free(q->queue);
3673        *q = outq;
3674}
3675
3676void diffcore_std(struct diff_options *options)
3677{
3678        if (options->skip_stat_unmatch)
3679                diffcore_skip_stat_unmatch(options);
3680        if (options->break_opt != -1)
3681                diffcore_break(options->break_opt);
3682        if (options->detect_rename)
3683                diffcore_rename(options);
3684        if (options->break_opt != -1)
3685                diffcore_merge_broken();
3686        if (options->pickaxe)
3687                diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
3688        if (options->orderfile)
3689                diffcore_order(options->orderfile);
3690        diff_resolve_rename_copy();
3691        diffcore_apply_filter(options->filter);
3692
3693        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
3694                DIFF_OPT_SET(options, HAS_CHANGES);
3695        else
3696                DIFF_OPT_CLR(options, HAS_CHANGES);
3697}
3698
3699int diff_result_code(struct diff_options *opt, int status)
3700{
3701        int result = 0;
3702        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
3703            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
3704                return status;
3705        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
3706            DIFF_OPT_TST(opt, HAS_CHANGES))
3707                result |= 01;
3708        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
3709            DIFF_OPT_TST(opt, CHECK_FAILED))
3710                result |= 02;
3711        return result;
3712}
3713
3714void diff_addremove(struct diff_options *options,
3715                    int addremove, unsigned mode,
3716                    const unsigned char *sha1,
3717                    const char *concatpath)
3718{
3719        struct diff_filespec *one, *two;
3720
3721        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES) && S_ISGITLINK(mode))
3722                return;
3723
3724        /* This may look odd, but it is a preparation for
3725         * feeding "there are unchanged files which should
3726         * not produce diffs, but when you are doing copy
3727         * detection you would need them, so here they are"
3728         * entries to the diff-core.  They will be prefixed
3729         * with something like '=' or '*' (I haven't decided
3730         * which but should not make any difference).
3731         * Feeding the same new and old to diff_change()
3732         * also has the same effect.
3733         * Before the final output happens, they are pruned after
3734         * merged into rename/copy pairs as appropriate.
3735         */
3736        if (DIFF_OPT_TST(options, REVERSE_DIFF))
3737                addremove = (addremove == '+' ? '-' :
3738                             addremove == '-' ? '+' : addremove);
3739
3740        if (options->prefix &&
3741            strncmp(concatpath, options->prefix, options->prefix_length))
3742                return;
3743
3744        one = alloc_filespec(concatpath);
3745        two = alloc_filespec(concatpath);
3746
3747        if (addremove != '+')
3748                fill_filespec(one, sha1, mode);
3749        if (addremove != '-')
3750                fill_filespec(two, sha1, mode);
3751
3752        diff_queue(&diff_queued_diff, one, two);
3753        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
3754                DIFF_OPT_SET(options, HAS_CHANGES);
3755}
3756
3757void diff_change(struct diff_options *options,
3758                 unsigned old_mode, unsigned new_mode,
3759                 const unsigned char *old_sha1,
3760                 const unsigned char *new_sha1,
3761                 const char *concatpath)
3762{
3763        struct diff_filespec *one, *two;
3764
3765        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES) && S_ISGITLINK(old_mode)
3766                        && S_ISGITLINK(new_mode))
3767                return;
3768
3769        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
3770                unsigned tmp;
3771                const unsigned char *tmp_c;
3772                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
3773                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
3774        }
3775
3776        if (options->prefix &&
3777            strncmp(concatpath, options->prefix, options->prefix_length))
3778                return;
3779
3780        one = alloc_filespec(concatpath);
3781        two = alloc_filespec(concatpath);
3782        fill_filespec(one, old_sha1, old_mode);
3783        fill_filespec(two, new_sha1, new_mode);
3784
3785        diff_queue(&diff_queued_diff, one, two);
3786        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
3787                DIFF_OPT_SET(options, HAS_CHANGES);
3788}
3789
3790void diff_unmerge(struct diff_options *options,
3791                  const char *path,
3792                  unsigned mode, const unsigned char *sha1)
3793{
3794        struct diff_filespec *one, *two;
3795
3796        if (options->prefix &&
3797            strncmp(path, options->prefix, options->prefix_length))
3798                return;
3799
3800        one = alloc_filespec(path);
3801        two = alloc_filespec(path);
3802        fill_filespec(one, sha1, mode);
3803        diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;
3804}
3805
3806static char *run_textconv(const char *pgm, struct diff_filespec *spec,
3807                size_t *outsize)
3808{
3809        struct diff_tempfile *temp;
3810        const char *argv[3];
3811        const char **arg = argv;
3812        struct child_process child;
3813        struct strbuf buf = STRBUF_INIT;
3814
3815        temp = prepare_temp_file(spec->path, spec);
3816        *arg++ = pgm;
3817        *arg++ = temp->name;
3818        *arg = NULL;
3819
3820        memset(&child, 0, sizeof(child));
3821        child.argv = argv;
3822        child.out = -1;
3823        if (start_command(&child) != 0 ||
3824            strbuf_read(&buf, child.out, 0) < 0 ||
3825            finish_command(&child) != 0) {
3826                close(child.out);
3827                strbuf_release(&buf);
3828                remove_tempfile();
3829                error("error running textconv command '%s'", pgm);
3830                return NULL;
3831        }
3832        close(child.out);
3833        remove_tempfile();
3834
3835        return strbuf_detach(&buf, outsize);
3836}