diff.con commit tag.c: Refactor parse_tag_buffer to be saner to program (28de5b6)
   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};
 198
 199static int count_lines(const char *data, int size)
 200{
 201        int count, ch, completely_empty = 1, nl_just_seen = 0;
 202        count = 0;
 203        while (0 < size--) {
 204                ch = *data++;
 205                if (ch == '\n') {
 206                        count++;
 207                        nl_just_seen = 1;
 208                        completely_empty = 0;
 209                }
 210                else {
 211                        nl_just_seen = 0;
 212                        completely_empty = 0;
 213                }
 214        }
 215        if (completely_empty)
 216                return 0;
 217        if (!nl_just_seen)
 218                count++; /* no trailing newline */
 219        return count;
 220}
 221
 222static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 223{
 224        if (!DIFF_FILE_VALID(one)) {
 225                mf->ptr = (char *)""; /* does not matter */
 226                mf->size = 0;
 227                return 0;
 228        }
 229        else if (diff_populate_filespec(one, 0))
 230                return -1;
 231
 232        mf->ptr = one->data;
 233        mf->size = one->size;
 234        return 0;
 235}
 236
 237static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 238{
 239        char *ptr = mf->ptr;
 240        long size = mf->size;
 241        int cnt = 0;
 242
 243        if (!size)
 244                return cnt;
 245        ptr += size - 1; /* pointing at the very end */
 246        if (*ptr != '\n')
 247                ; /* incomplete line */
 248        else
 249                ptr--; /* skip the last LF */
 250        while (mf->ptr < ptr) {
 251                char *prev_eol;
 252                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 253                        if (*prev_eol == '\n')
 254                                break;
 255                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 256                        break;
 257                cnt++;
 258                ptr = prev_eol - 1;
 259        }
 260        return cnt;
 261}
 262
 263static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 264                               struct emit_callback *ecbdata)
 265{
 266        int l1, l2, at;
 267        unsigned ws_rule = ecbdata->ws_rule;
 268        l1 = count_trailing_blank(mf1, ws_rule);
 269        l2 = count_trailing_blank(mf2, ws_rule);
 270        if (l2 <= l1) {
 271                ecbdata->blank_at_eof_in_preimage = 0;
 272                ecbdata->blank_at_eof_in_postimage = 0;
 273                return;
 274        }
 275        at = count_lines(mf1->ptr, mf1->size);
 276        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 277
 278        at = count_lines(mf2->ptr, mf2->size);
 279        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 280}
 281
 282static void emit_line_0(FILE *file, const char *set, const char *reset,
 283                        int first, const char *line, int len)
 284{
 285        int has_trailing_newline, has_trailing_carriage_return;
 286        int nofirst;
 287
 288        if (len == 0) {
 289                has_trailing_newline = (first == '\n');
 290                has_trailing_carriage_return = (!has_trailing_newline &&
 291                                                (first == '\r'));
 292                nofirst = has_trailing_newline || has_trailing_carriage_return;
 293        } else {
 294                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 295                if (has_trailing_newline)
 296                        len--;
 297                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 298                if (has_trailing_carriage_return)
 299                        len--;
 300                nofirst = 0;
 301        }
 302
 303        if (len || !nofirst) {
 304                fputs(set, file);
 305                if (!nofirst)
 306                        fputc(first, file);
 307                fwrite(line, len, 1, file);
 308                fputs(reset, file);
 309        }
 310        if (has_trailing_carriage_return)
 311                fputc('\r', file);
 312        if (has_trailing_newline)
 313                fputc('\n', file);
 314}
 315
 316static void emit_line(FILE *file, const char *set, const char *reset,
 317                      const char *line, int len)
 318{
 319        emit_line_0(file, set, reset, line[0], line+1, len-1);
 320}
 321
 322static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 323{
 324        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 325              ecbdata->blank_at_eof_in_preimage &&
 326              ecbdata->blank_at_eof_in_postimage &&
 327              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 328              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 329                return 0;
 330        return ws_blank_line(line, len, ecbdata->ws_rule);
 331}
 332
 333static void emit_add_line(const char *reset,
 334                          struct emit_callback *ecbdata,
 335                          const char *line, int len)
 336{
 337        const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 338        const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 339
 340        if (!*ws)
 341                emit_line_0(ecbdata->file, set, reset, '+', line, len);
 342        else if (new_blank_line_at_eof(ecbdata, line, len))
 343                /* Blank line at EOF - paint '+' as well */
 344                emit_line_0(ecbdata->file, ws, reset, '+', line, len);
 345        else {
 346                /* Emit just the prefix, then the rest. */
 347                emit_line_0(ecbdata->file, set, reset, '+', "", 0);
 348                ws_check_emit(line, len, ecbdata->ws_rule,
 349                              ecbdata->file, set, reset, ws);
 350        }
 351}
 352
 353static void emit_hunk_header(struct emit_callback *ecbdata,
 354                             const char *line, int len)
 355{
 356        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 357        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 358        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 359        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 360        static const char atat[2] = { '@', '@' };
 361        const char *cp, *ep;
 362
 363        /*
 364         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 365         * it always is at least 10 bytes long.
 366         */
 367        if (len < 10 ||
 368            memcmp(line, atat, 2) ||
 369            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 370                emit_line(ecbdata->file, plain, reset, line, len);
 371                return;
 372        }
 373        ep += 2; /* skip over @@ */
 374
 375        /* The hunk header in fraginfo color */
 376        emit_line(ecbdata->file, frag, reset, line, ep - line);
 377
 378        /* blank before the func header */
 379        for (cp = ep; ep - line < len; ep++)
 380                if (*ep != ' ' && *ep != '\t')
 381                        break;
 382        if (ep != cp)
 383                emit_line(ecbdata->file, plain, reset, cp, ep - cp);
 384
 385        if (ep < line + len)
 386                emit_line(ecbdata->file, func, reset, ep, line + len - ep);
 387}
 388
 389static struct diff_tempfile *claim_diff_tempfile(void) {
 390        int i;
 391        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 392                if (!diff_temp[i].name)
 393                        return diff_temp + i;
 394        die("BUG: diff is failing to clean up its tempfiles");
 395}
 396
 397static int remove_tempfile_installed;
 398
 399static void remove_tempfile(void)
 400{
 401        int i;
 402        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 403                if (diff_temp[i].name == diff_temp[i].tmp_path)
 404                        unlink_or_warn(diff_temp[i].name);
 405                diff_temp[i].name = NULL;
 406        }
 407}
 408
 409static void remove_tempfile_on_signal(int signo)
 410{
 411        remove_tempfile();
 412        sigchain_pop(signo);
 413        raise(signo);
 414}
 415
 416static void print_line_count(FILE *file, int count)
 417{
 418        switch (count) {
 419        case 0:
 420                fprintf(file, "0,0");
 421                break;
 422        case 1:
 423                fprintf(file, "1");
 424                break;
 425        default:
 426                fprintf(file, "1,%d", count);
 427                break;
 428        }
 429}
 430
 431static void emit_rewrite_lines(struct emit_callback *ecb,
 432                               int prefix, const char *data, int size)
 433{
 434        const char *endp = NULL;
 435        static const char *nneof = " No newline at end of file\n";
 436        const char *old = diff_get_color(ecb->color_diff, DIFF_FILE_OLD);
 437        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 438
 439        while (0 < size) {
 440                int len;
 441
 442                endp = memchr(data, '\n', size);
 443                len = endp ? (endp - data + 1) : size;
 444                if (prefix != '+') {
 445                        ecb->lno_in_preimage++;
 446                        emit_line_0(ecb->file, old, reset, '-',
 447                                    data, len);
 448                } else {
 449                        ecb->lno_in_postimage++;
 450                        emit_add_line(reset, ecb, data, len);
 451                }
 452                size -= len;
 453                data += len;
 454        }
 455        if (!endp) {
 456                const char *plain = diff_get_color(ecb->color_diff,
 457                                                   DIFF_PLAIN);
 458                emit_line_0(ecb->file, plain, reset, '\\',
 459                            nneof, strlen(nneof));
 460        }
 461}
 462
 463static void emit_rewrite_diff(const char *name_a,
 464                              const char *name_b,
 465                              struct diff_filespec *one,
 466                              struct diff_filespec *two,
 467                              const char *textconv_one,
 468                              const char *textconv_two,
 469                              struct diff_options *o)
 470{
 471        int lc_a, lc_b;
 472        int color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
 473        const char *name_a_tab, *name_b_tab;
 474        const char *metainfo = diff_get_color(color_diff, DIFF_METAINFO);
 475        const char *fraginfo = diff_get_color(color_diff, DIFF_FRAGINFO);
 476        const char *reset = diff_get_color(color_diff, DIFF_RESET);
 477        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 478        const char *a_prefix, *b_prefix;
 479        const char *data_one, *data_two;
 480        size_t size_one, size_two;
 481        struct emit_callback ecbdata;
 482
 483        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 484                a_prefix = o->b_prefix;
 485                b_prefix = o->a_prefix;
 486        } else {
 487                a_prefix = o->a_prefix;
 488                b_prefix = o->b_prefix;
 489        }
 490
 491        name_a += (*name_a == '/');
 492        name_b += (*name_b == '/');
 493        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 494        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 495
 496        strbuf_reset(&a_name);
 497        strbuf_reset(&b_name);
 498        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 499        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 500
 501        diff_populate_filespec(one, 0);
 502        diff_populate_filespec(two, 0);
 503        if (textconv_one) {
 504                data_one = run_textconv(textconv_one, one, &size_one);
 505                if (!data_one)
 506                        die("unable to read files to diff");
 507        }
 508        else {
 509                data_one = one->data;
 510                size_one = one->size;
 511        }
 512        if (textconv_two) {
 513                data_two = run_textconv(textconv_two, two, &size_two);
 514                if (!data_two)
 515                        die("unable to read files to diff");
 516        }
 517        else {
 518                data_two = two->data;
 519                size_two = two->size;
 520        }
 521
 522        memset(&ecbdata, 0, sizeof(ecbdata));
 523        ecbdata.color_diff = color_diff;
 524        ecbdata.found_changesp = &o->found_changes;
 525        ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
 526        ecbdata.file = o->file;
 527        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 528                mmfile_t mf1, mf2;
 529                mf1.ptr = (char *)data_one;
 530                mf2.ptr = (char *)data_two;
 531                mf1.size = size_one;
 532                mf2.size = size_two;
 533                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 534        }
 535        ecbdata.lno_in_preimage = 1;
 536        ecbdata.lno_in_postimage = 1;
 537
 538        lc_a = count_lines(data_one, size_one);
 539        lc_b = count_lines(data_two, size_two);
 540        fprintf(o->file,
 541                "%s--- %s%s%s\n%s+++ %s%s%s\n%s@@ -",
 542                metainfo, a_name.buf, name_a_tab, reset,
 543                metainfo, b_name.buf, name_b_tab, reset, fraginfo);
 544        print_line_count(o->file, lc_a);
 545        fprintf(o->file, " +");
 546        print_line_count(o->file, lc_b);
 547        fprintf(o->file, " @@%s\n", reset);
 548        if (lc_a)
 549                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 550        if (lc_b)
 551                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 552}
 553
 554struct diff_words_buffer {
 555        mmfile_t text;
 556        long alloc;
 557        struct diff_words_orig {
 558                const char *begin, *end;
 559        } *orig;
 560        int orig_nr, orig_alloc;
 561};
 562
 563static void diff_words_append(char *line, unsigned long len,
 564                struct diff_words_buffer *buffer)
 565{
 566        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 567        line++;
 568        len--;
 569        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 570        buffer->text.size += len;
 571        buffer->text.ptr[buffer->text.size] = '\0';
 572}
 573
 574struct diff_words_data {
 575        struct diff_words_buffer minus, plus;
 576        const char *current_plus;
 577        FILE *file;
 578        regex_t *word_regex;
 579};
 580
 581static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 582{
 583        struct diff_words_data *diff_words = priv;
 584        int minus_first, minus_len, plus_first, plus_len;
 585        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 586
 587        if (line[0] != '@' || parse_hunk_header(line, len,
 588                        &minus_first, &minus_len, &plus_first, &plus_len))
 589                return;
 590
 591        /* POSIX requires that first be decremented by one if len == 0... */
 592        if (minus_len) {
 593                minus_begin = diff_words->minus.orig[minus_first].begin;
 594                minus_end =
 595                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 596        } else
 597                minus_begin = minus_end =
 598                        diff_words->minus.orig[minus_first].end;
 599
 600        if (plus_len) {
 601                plus_begin = diff_words->plus.orig[plus_first].begin;
 602                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 603        } else
 604                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 605
 606        if (diff_words->current_plus != plus_begin)
 607                fwrite(diff_words->current_plus,
 608                                plus_begin - diff_words->current_plus, 1,
 609                                diff_words->file);
 610        if (minus_begin != minus_end)
 611                color_fwrite_lines(diff_words->file,
 612                                diff_get_color(1, DIFF_FILE_OLD),
 613                                minus_end - minus_begin, minus_begin);
 614        if (plus_begin != plus_end)
 615                color_fwrite_lines(diff_words->file,
 616                                diff_get_color(1, DIFF_FILE_NEW),
 617                                plus_end - plus_begin, plus_begin);
 618
 619        diff_words->current_plus = plus_end;
 620}
 621
 622/* This function starts looking at *begin, and returns 0 iff a word was found. */
 623static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 624                int *begin, int *end)
 625{
 626        if (word_regex && *begin < buffer->size) {
 627                regmatch_t match[1];
 628                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 629                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 630                                        '\n', match[0].rm_eo - match[0].rm_so);
 631                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 632                        *begin += match[0].rm_so;
 633                        return *begin >= *end;
 634                }
 635                return -1;
 636        }
 637
 638        /* find the next word */
 639        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 640                (*begin)++;
 641        if (*begin >= buffer->size)
 642                return -1;
 643
 644        /* find the end of the word */
 645        *end = *begin + 1;
 646        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 647                (*end)++;
 648
 649        return 0;
 650}
 651
 652/*
 653 * This function splits the words in buffer->text, stores the list with
 654 * newline separator into out, and saves the offsets of the original words
 655 * in buffer->orig.
 656 */
 657static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 658                regex_t *word_regex)
 659{
 660        int i, j;
 661        long alloc = 0;
 662
 663        out->size = 0;
 664        out->ptr = NULL;
 665
 666        /* fake an empty "0th" word */
 667        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 668        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 669        buffer->orig_nr = 1;
 670
 671        for (i = 0; i < buffer->text.size; i++) {
 672                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 673                        return;
 674
 675                /* store original boundaries */
 676                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 677                                buffer->orig_alloc);
 678                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 679                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 680                buffer->orig_nr++;
 681
 682                /* store one word */
 683                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 684                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 685                out->ptr[out->size + j - i] = '\n';
 686                out->size += j - i + 1;
 687
 688                i = j - 1;
 689        }
 690}
 691
 692/* this executes the word diff on the accumulated buffers */
 693static void diff_words_show(struct diff_words_data *diff_words)
 694{
 695        xpparam_t xpp;
 696        xdemitconf_t xecfg;
 697        xdemitcb_t ecb;
 698        mmfile_t minus, plus;
 699
 700        /* special case: only removal */
 701        if (!diff_words->plus.text.size) {
 702                color_fwrite_lines(diff_words->file,
 703                        diff_get_color(1, DIFF_FILE_OLD),
 704                        diff_words->minus.text.size, diff_words->minus.text.ptr);
 705                diff_words->minus.text.size = 0;
 706                return;
 707        }
 708
 709        diff_words->current_plus = diff_words->plus.text.ptr;
 710
 711        memset(&xpp, 0, sizeof(xpp));
 712        memset(&xecfg, 0, sizeof(xecfg));
 713        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
 714        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
 715        xpp.flags = XDF_NEED_MINIMAL;
 716        /* as only the hunk header will be parsed, we need a 0-context */
 717        xecfg.ctxlen = 0;
 718        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 719                      &xpp, &xecfg, &ecb);
 720        free(minus.ptr);
 721        free(plus.ptr);
 722        if (diff_words->current_plus != diff_words->plus.text.ptr +
 723                        diff_words->plus.text.size)
 724                fwrite(diff_words->current_plus,
 725                        diff_words->plus.text.ptr + diff_words->plus.text.size
 726                        - diff_words->current_plus, 1,
 727                        diff_words->file);
 728        diff_words->minus.text.size = diff_words->plus.text.size = 0;
 729}
 730
 731/* In "color-words" mode, show word-diff of words accumulated in the buffer */
 732static void diff_words_flush(struct emit_callback *ecbdata)
 733{
 734        if (ecbdata->diff_words->minus.text.size ||
 735            ecbdata->diff_words->plus.text.size)
 736                diff_words_show(ecbdata->diff_words);
 737}
 738
 739static void free_diff_words_data(struct emit_callback *ecbdata)
 740{
 741        if (ecbdata->diff_words) {
 742                diff_words_flush(ecbdata);
 743                free (ecbdata->diff_words->minus.text.ptr);
 744                free (ecbdata->diff_words->minus.orig);
 745                free (ecbdata->diff_words->plus.text.ptr);
 746                free (ecbdata->diff_words->plus.orig);
 747                free(ecbdata->diff_words->word_regex);
 748                free(ecbdata->diff_words);
 749                ecbdata->diff_words = NULL;
 750        }
 751}
 752
 753const char *diff_get_color(int diff_use_color, enum color_diff ix)
 754{
 755        if (diff_use_color)
 756                return diff_colors[ix];
 757        return "";
 758}
 759
 760static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
 761{
 762        const char *cp;
 763        unsigned long allot;
 764        size_t l = len;
 765
 766        if (ecb->truncate)
 767                return ecb->truncate(line, len);
 768        cp = line;
 769        allot = l;
 770        while (0 < l) {
 771                (void) utf8_width(&cp, &l);
 772                if (!cp)
 773                        break; /* truncated in the middle? */
 774        }
 775        return allot - l;
 776}
 777
 778static void find_lno(const char *line, struct emit_callback *ecbdata)
 779{
 780        const char *p;
 781        ecbdata->lno_in_preimage = 0;
 782        ecbdata->lno_in_postimage = 0;
 783        p = strchr(line, '-');
 784        if (!p)
 785                return; /* cannot happen */
 786        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
 787        p = strchr(p, '+');
 788        if (!p)
 789                return; /* cannot happen */
 790        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
 791}
 792
 793static void fn_out_consume(void *priv, char *line, unsigned long len)
 794{
 795        struct emit_callback *ecbdata = priv;
 796        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
 797        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 798        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 799
 800        *(ecbdata->found_changesp) = 1;
 801
 802        if (ecbdata->label_path[0]) {
 803                const char *name_a_tab, *name_b_tab;
 804
 805                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
 806                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
 807
 808                fprintf(ecbdata->file, "%s--- %s%s%s\n",
 809                        meta, ecbdata->label_path[0], reset, name_a_tab);
 810                fprintf(ecbdata->file, "%s+++ %s%s%s\n",
 811                        meta, ecbdata->label_path[1], reset, name_b_tab);
 812                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
 813        }
 814
 815        if (diff_suppress_blank_empty
 816            && len == 2 && line[0] == ' ' && line[1] == '\n') {
 817                line[0] = '\n';
 818                len = 1;
 819        }
 820
 821        if (line[0] == '@') {
 822                if (ecbdata->diff_words)
 823                        diff_words_flush(ecbdata);
 824                len = sane_truncate_line(ecbdata, line, len);
 825                find_lno(line, ecbdata);
 826                emit_hunk_header(ecbdata, line, len);
 827                if (line[len-1] != '\n')
 828                        putc('\n', ecbdata->file);
 829                return;
 830        }
 831
 832        if (len < 1) {
 833                emit_line(ecbdata->file, reset, reset, line, len);
 834                return;
 835        }
 836
 837        if (ecbdata->diff_words) {
 838                if (line[0] == '-') {
 839                        diff_words_append(line, len,
 840                                          &ecbdata->diff_words->minus);
 841                        return;
 842                } else if (line[0] == '+') {
 843                        diff_words_append(line, len,
 844                                          &ecbdata->diff_words->plus);
 845                        return;
 846                }
 847                diff_words_flush(ecbdata);
 848                line++;
 849                len--;
 850                emit_line(ecbdata->file, plain, reset, line, len);
 851                return;
 852        }
 853
 854        if (line[0] != '+') {
 855                const char *color =
 856                        diff_get_color(ecbdata->color_diff,
 857                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
 858                ecbdata->lno_in_preimage++;
 859                if (line[0] == ' ')
 860                        ecbdata->lno_in_postimage++;
 861                emit_line(ecbdata->file, color, reset, line, len);
 862        } else {
 863                ecbdata->lno_in_postimage++;
 864                emit_add_line(reset, ecbdata, line + 1, len - 1);
 865        }
 866}
 867
 868static char *pprint_rename(const char *a, const char *b)
 869{
 870        const char *old = a;
 871        const char *new = b;
 872        struct strbuf name = STRBUF_INIT;
 873        int pfx_length, sfx_length;
 874        int len_a = strlen(a);
 875        int len_b = strlen(b);
 876        int a_midlen, b_midlen;
 877        int qlen_a = quote_c_style(a, NULL, NULL, 0);
 878        int qlen_b = quote_c_style(b, NULL, NULL, 0);
 879
 880        if (qlen_a || qlen_b) {
 881                quote_c_style(a, &name, NULL, 0);
 882                strbuf_addstr(&name, " => ");
 883                quote_c_style(b, &name, NULL, 0);
 884                return strbuf_detach(&name, NULL);
 885        }
 886
 887        /* Find common prefix */
 888        pfx_length = 0;
 889        while (*old && *new && *old == *new) {
 890                if (*old == '/')
 891                        pfx_length = old - a + 1;
 892                old++;
 893                new++;
 894        }
 895
 896        /* Find common suffix */
 897        old = a + len_a;
 898        new = b + len_b;
 899        sfx_length = 0;
 900        while (a <= old && b <= new && *old == *new) {
 901                if (*old == '/')
 902                        sfx_length = len_a - (old - a);
 903                old--;
 904                new--;
 905        }
 906
 907        /*
 908         * pfx{mid-a => mid-b}sfx
 909         * {pfx-a => pfx-b}sfx
 910         * pfx{sfx-a => sfx-b}
 911         * name-a => name-b
 912         */
 913        a_midlen = len_a - pfx_length - sfx_length;
 914        b_midlen = len_b - pfx_length - sfx_length;
 915        if (a_midlen < 0)
 916                a_midlen = 0;
 917        if (b_midlen < 0)
 918                b_midlen = 0;
 919
 920        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
 921        if (pfx_length + sfx_length) {
 922                strbuf_add(&name, a, pfx_length);
 923                strbuf_addch(&name, '{');
 924        }
 925        strbuf_add(&name, a + pfx_length, a_midlen);
 926        strbuf_addstr(&name, " => ");
 927        strbuf_add(&name, b + pfx_length, b_midlen);
 928        if (pfx_length + sfx_length) {
 929                strbuf_addch(&name, '}');
 930                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
 931        }
 932        return strbuf_detach(&name, NULL);
 933}
 934
 935struct diffstat_t {
 936        int nr;
 937        int alloc;
 938        struct diffstat_file {
 939                char *from_name;
 940                char *name;
 941                char *print_name;
 942                unsigned is_unmerged:1;
 943                unsigned is_binary:1;
 944                unsigned is_renamed:1;
 945                unsigned int added, deleted;
 946        } **files;
 947};
 948
 949static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
 950                                          const char *name_a,
 951                                          const char *name_b)
 952{
 953        struct diffstat_file *x;
 954        x = xcalloc(sizeof (*x), 1);
 955        if (diffstat->nr == diffstat->alloc) {
 956                diffstat->alloc = alloc_nr(diffstat->alloc);
 957                diffstat->files = xrealloc(diffstat->files,
 958                                diffstat->alloc * sizeof(x));
 959        }
 960        diffstat->files[diffstat->nr++] = x;
 961        if (name_b) {
 962                x->from_name = xstrdup(name_a);
 963                x->name = xstrdup(name_b);
 964                x->is_renamed = 1;
 965        }
 966        else {
 967                x->from_name = NULL;
 968                x->name = xstrdup(name_a);
 969        }
 970        return x;
 971}
 972
 973static void diffstat_consume(void *priv, char *line, unsigned long len)
 974{
 975        struct diffstat_t *diffstat = priv;
 976        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
 977
 978        if (line[0] == '+')
 979                x->added++;
 980        else if (line[0] == '-')
 981                x->deleted++;
 982}
 983
 984const char mime_boundary_leader[] = "------------";
 985
 986static int scale_linear(int it, int width, int max_change)
 987{
 988        /*
 989         * make sure that at least one '-' is printed if there were deletions,
 990         * and likewise for '+'.
 991         */
 992        if (max_change < 2)
 993                return it;
 994        return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
 995}
 996
 997static void show_name(FILE *file,
 998                      const char *prefix, const char *name, int len)
 999{
1000        fprintf(file, " %s%-*s |", prefix, len, name);
1001}
1002
1003static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1004{
1005        if (cnt <= 0)
1006                return;
1007        fprintf(file, "%s", set);
1008        while (cnt--)
1009                putc(ch, file);
1010        fprintf(file, "%s", reset);
1011}
1012
1013static void fill_print_name(struct diffstat_file *file)
1014{
1015        char *pname;
1016
1017        if (file->print_name)
1018                return;
1019
1020        if (!file->is_renamed) {
1021                struct strbuf buf = STRBUF_INIT;
1022                if (quote_c_style(file->name, &buf, NULL, 0)) {
1023                        pname = strbuf_detach(&buf, NULL);
1024                } else {
1025                        pname = file->name;
1026                        strbuf_release(&buf);
1027                }
1028        } else {
1029                pname = pprint_rename(file->from_name, file->name);
1030        }
1031        file->print_name = pname;
1032}
1033
1034static void show_stats(struct diffstat_t *data, struct diff_options *options)
1035{
1036        int i, len, add, del, adds = 0, dels = 0;
1037        int max_change = 0, max_len = 0;
1038        int total_files = data->nr;
1039        int width, name_width;
1040        const char *reset, *set, *add_c, *del_c;
1041
1042        if (data->nr == 0)
1043                return;
1044
1045        width = options->stat_width ? options->stat_width : 80;
1046        name_width = options->stat_name_width ? options->stat_name_width : 50;
1047
1048        /* Sanity: give at least 5 columns to the graph,
1049         * but leave at least 10 columns for the name.
1050         */
1051        if (width < 25)
1052                width = 25;
1053        if (name_width < 10)
1054                name_width = 10;
1055        else if (width < name_width + 15)
1056                name_width = width - 15;
1057
1058        /* Find the longest filename and max number of changes */
1059        reset = diff_get_color_opt(options, DIFF_RESET);
1060        set   = diff_get_color_opt(options, DIFF_PLAIN);
1061        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1062        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1063
1064        for (i = 0; i < data->nr; i++) {
1065                struct diffstat_file *file = data->files[i];
1066                int change = file->added + file->deleted;
1067                fill_print_name(file);
1068                len = strlen(file->print_name);
1069                if (max_len < len)
1070                        max_len = len;
1071
1072                if (file->is_binary || file->is_unmerged)
1073                        continue;
1074                if (max_change < change)
1075                        max_change = change;
1076        }
1077
1078        /* Compute the width of the graph part;
1079         * 10 is for one blank at the beginning of the line plus
1080         * " | count " between the name and the graph.
1081         *
1082         * From here on, name_width is the width of the name area,
1083         * and width is the width of the graph area.
1084         */
1085        name_width = (name_width < max_len) ? name_width : max_len;
1086        if (width < (name_width + 10) + max_change)
1087                width = width - (name_width + 10);
1088        else
1089                width = max_change;
1090
1091        for (i = 0; i < data->nr; i++) {
1092                const char *prefix = "";
1093                char *name = data->files[i]->print_name;
1094                int added = data->files[i]->added;
1095                int deleted = data->files[i]->deleted;
1096                int name_len;
1097
1098                /*
1099                 * "scale" the filename
1100                 */
1101                len = name_width;
1102                name_len = strlen(name);
1103                if (name_width < name_len) {
1104                        char *slash;
1105                        prefix = "...";
1106                        len -= 3;
1107                        name += name_len - len;
1108                        slash = strchr(name, '/');
1109                        if (slash)
1110                                name = slash;
1111                }
1112
1113                if (data->files[i]->is_binary) {
1114                        show_name(options->file, prefix, name, len);
1115                        fprintf(options->file, "  Bin ");
1116                        fprintf(options->file, "%s%d%s", del_c, deleted, reset);
1117                        fprintf(options->file, " -> ");
1118                        fprintf(options->file, "%s%d%s", add_c, added, reset);
1119                        fprintf(options->file, " bytes");
1120                        fprintf(options->file, "\n");
1121                        continue;
1122                }
1123                else if (data->files[i]->is_unmerged) {
1124                        show_name(options->file, prefix, name, len);
1125                        fprintf(options->file, "  Unmerged\n");
1126                        continue;
1127                }
1128                else if (!data->files[i]->is_renamed &&
1129                         (added + deleted == 0)) {
1130                        total_files--;
1131                        continue;
1132                }
1133
1134                /*
1135                 * scale the add/delete
1136                 */
1137                add = added;
1138                del = deleted;
1139                adds += add;
1140                dels += del;
1141
1142                if (width <= max_change) {
1143                        add = scale_linear(add, width, max_change);
1144                        del = scale_linear(del, width, max_change);
1145                }
1146                show_name(options->file, prefix, name, len);
1147                fprintf(options->file, "%5d%s", added + deleted,
1148                                added + deleted ? " " : "");
1149                show_graph(options->file, '+', add, add_c, reset);
1150                show_graph(options->file, '-', del, del_c, reset);
1151                fprintf(options->file, "\n");
1152        }
1153        fprintf(options->file,
1154               " %d files changed, %d insertions(+), %d deletions(-)\n",
1155               total_files, adds, dels);
1156}
1157
1158static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1159{
1160        int i, adds = 0, dels = 0, total_files = data->nr;
1161
1162        if (data->nr == 0)
1163                return;
1164
1165        for (i = 0; i < data->nr; i++) {
1166                if (!data->files[i]->is_binary &&
1167                    !data->files[i]->is_unmerged) {
1168                        int added = data->files[i]->added;
1169                        int deleted= data->files[i]->deleted;
1170                        if (!data->files[i]->is_renamed &&
1171                            (added + deleted == 0)) {
1172                                total_files--;
1173                        } else {
1174                                adds += added;
1175                                dels += deleted;
1176                        }
1177                }
1178        }
1179        fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
1180               total_files, adds, dels);
1181}
1182
1183static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1184{
1185        int i;
1186
1187        if (data->nr == 0)
1188                return;
1189
1190        for (i = 0; i < data->nr; i++) {
1191                struct diffstat_file *file = data->files[i];
1192
1193                if (file->is_binary)
1194                        fprintf(options->file, "-\t-\t");
1195                else
1196                        fprintf(options->file,
1197                                "%d\t%d\t", file->added, file->deleted);
1198                if (options->line_termination) {
1199                        fill_print_name(file);
1200                        if (!file->is_renamed)
1201                                write_name_quoted(file->name, options->file,
1202                                                  options->line_termination);
1203                        else {
1204                                fputs(file->print_name, options->file);
1205                                putc(options->line_termination, options->file);
1206                        }
1207                } else {
1208                        if (file->is_renamed) {
1209                                putc('\0', options->file);
1210                                write_name_quoted(file->from_name, options->file, '\0');
1211                        }
1212                        write_name_quoted(file->name, options->file, '\0');
1213                }
1214        }
1215}
1216
1217struct dirstat_file {
1218        const char *name;
1219        unsigned long changed;
1220};
1221
1222struct dirstat_dir {
1223        struct dirstat_file *files;
1224        int alloc, nr, percent, cumulative;
1225};
1226
1227static long gather_dirstat(FILE *file, struct dirstat_dir *dir, unsigned long changed, const char *base, int baselen)
1228{
1229        unsigned long this_dir = 0;
1230        unsigned int sources = 0;
1231
1232        while (dir->nr) {
1233                struct dirstat_file *f = dir->files;
1234                int namelen = strlen(f->name);
1235                unsigned long this;
1236                char *slash;
1237
1238                if (namelen < baselen)
1239                        break;
1240                if (memcmp(f->name, base, baselen))
1241                        break;
1242                slash = strchr(f->name + baselen, '/');
1243                if (slash) {
1244                        int newbaselen = slash + 1 - f->name;
1245                        this = gather_dirstat(file, dir, changed, f->name, newbaselen);
1246                        sources++;
1247                } else {
1248                        this = f->changed;
1249                        dir->files++;
1250                        dir->nr--;
1251                        sources += 2;
1252                }
1253                this_dir += this;
1254        }
1255
1256        /*
1257         * We don't report dirstat's for
1258         *  - the top level
1259         *  - or cases where everything came from a single directory
1260         *    under this directory (sources == 1).
1261         */
1262        if (baselen && sources != 1) {
1263                int permille = this_dir * 1000 / changed;
1264                if (permille) {
1265                        int percent = permille / 10;
1266                        if (percent >= dir->percent) {
1267                                fprintf(file, "%4d.%01d%% %.*s\n", percent, permille % 10, baselen, base);
1268                                if (!dir->cumulative)
1269                                        return 0;
1270                        }
1271                }
1272        }
1273        return this_dir;
1274}
1275
1276static int dirstat_compare(const void *_a, const void *_b)
1277{
1278        const struct dirstat_file *a = _a;
1279        const struct dirstat_file *b = _b;
1280        return strcmp(a->name, b->name);
1281}
1282
1283static void show_dirstat(struct diff_options *options)
1284{
1285        int i;
1286        unsigned long changed;
1287        struct dirstat_dir dir;
1288        struct diff_queue_struct *q = &diff_queued_diff;
1289
1290        dir.files = NULL;
1291        dir.alloc = 0;
1292        dir.nr = 0;
1293        dir.percent = options->dirstat_percent;
1294        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1295
1296        changed = 0;
1297        for (i = 0; i < q->nr; i++) {
1298                struct diff_filepair *p = q->queue[i];
1299                const char *name;
1300                unsigned long copied, added, damage;
1301
1302                name = p->one->path ? p->one->path : p->two->path;
1303
1304                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1305                        diff_populate_filespec(p->one, 0);
1306                        diff_populate_filespec(p->two, 0);
1307                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1308                                               &copied, &added);
1309                        diff_free_filespec_data(p->one);
1310                        diff_free_filespec_data(p->two);
1311                } else if (DIFF_FILE_VALID(p->one)) {
1312                        diff_populate_filespec(p->one, 1);
1313                        copied = added = 0;
1314                        diff_free_filespec_data(p->one);
1315                } else if (DIFF_FILE_VALID(p->two)) {
1316                        diff_populate_filespec(p->two, 1);
1317                        copied = 0;
1318                        added = p->two->size;
1319                        diff_free_filespec_data(p->two);
1320                } else
1321                        continue;
1322
1323                /*
1324                 * Original minus copied is the removed material,
1325                 * added is the new material.  They are both damages
1326                 * made to the preimage. In --dirstat-by-file mode, count
1327                 * damaged files, not damaged lines. This is done by
1328                 * counting only a single damaged line per file.
1329                 */
1330                damage = (p->one->size - copied) + added;
1331                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE) && damage > 0)
1332                        damage = 1;
1333
1334                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1335                dir.files[dir.nr].name = name;
1336                dir.files[dir.nr].changed = damage;
1337                changed += damage;
1338                dir.nr++;
1339        }
1340
1341        /* This can happen even with many files, if everything was renames */
1342        if (!changed)
1343                return;
1344
1345        /* Show all directories with more than x% of the changes */
1346        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1347        gather_dirstat(options->file, &dir, changed, "", 0);
1348}
1349
1350static void free_diffstat_info(struct diffstat_t *diffstat)
1351{
1352        int i;
1353        for (i = 0; i < diffstat->nr; i++) {
1354                struct diffstat_file *f = diffstat->files[i];
1355                if (f->name != f->print_name)
1356                        free(f->print_name);
1357                free(f->name);
1358                free(f->from_name);
1359                free(f);
1360        }
1361        free(diffstat->files);
1362}
1363
1364struct checkdiff_t {
1365        const char *filename;
1366        int lineno;
1367        struct diff_options *o;
1368        unsigned ws_rule;
1369        unsigned status;
1370};
1371
1372static int is_conflict_marker(const char *line, unsigned long len)
1373{
1374        char firstchar;
1375        int cnt;
1376
1377        if (len < 8)
1378                return 0;
1379        firstchar = line[0];
1380        switch (firstchar) {
1381        case '=': case '>': case '<':
1382                break;
1383        default:
1384                return 0;
1385        }
1386        for (cnt = 1; cnt < 7; cnt++)
1387                if (line[cnt] != firstchar)
1388                        return 0;
1389        /* line[0] thru line[6] are same as firstchar */
1390        if (firstchar == '=') {
1391                /* divider between ours and theirs? */
1392                if (len != 8 || line[7] != '\n')
1393                        return 0;
1394        } else if (len < 8 || !isspace(line[7])) {
1395                /* not divider before ours nor after theirs */
1396                return 0;
1397        }
1398        return 1;
1399}
1400
1401static void checkdiff_consume(void *priv, char *line, unsigned long len)
1402{
1403        struct checkdiff_t *data = priv;
1404        int color_diff = DIFF_OPT_TST(data->o, COLOR_DIFF);
1405        const char *ws = diff_get_color(color_diff, DIFF_WHITESPACE);
1406        const char *reset = diff_get_color(color_diff, DIFF_RESET);
1407        const char *set = diff_get_color(color_diff, DIFF_FILE_NEW);
1408        char *err;
1409
1410        if (line[0] == '+') {
1411                unsigned bad;
1412                data->lineno++;
1413                if (is_conflict_marker(line + 1, len - 1)) {
1414                        data->status |= 1;
1415                        fprintf(data->o->file,
1416                                "%s:%d: leftover conflict marker\n",
1417                                data->filename, data->lineno);
1418                }
1419                bad = ws_check(line + 1, len - 1, data->ws_rule);
1420                if (!bad)
1421                        return;
1422                data->status |= bad;
1423                err = whitespace_error_string(bad);
1424                fprintf(data->o->file, "%s:%d: %s.\n",
1425                        data->filename, data->lineno, err);
1426                free(err);
1427                emit_line(data->o->file, set, reset, line, 1);
1428                ws_check_emit(line + 1, len - 1, data->ws_rule,
1429                              data->o->file, set, reset, ws);
1430        } else if (line[0] == ' ') {
1431                data->lineno++;
1432        } else if (line[0] == '@') {
1433                char *plus = strchr(line, '+');
1434                if (plus)
1435                        data->lineno = strtol(plus, NULL, 10) - 1;
1436                else
1437                        die("invalid diff");
1438        }
1439}
1440
1441static unsigned char *deflate_it(char *data,
1442                                 unsigned long size,
1443                                 unsigned long *result_size)
1444{
1445        int bound;
1446        unsigned char *deflated;
1447        z_stream stream;
1448
1449        memset(&stream, 0, sizeof(stream));
1450        deflateInit(&stream, zlib_compression_level);
1451        bound = deflateBound(&stream, size);
1452        deflated = xmalloc(bound);
1453        stream.next_out = deflated;
1454        stream.avail_out = bound;
1455
1456        stream.next_in = (unsigned char *)data;
1457        stream.avail_in = size;
1458        while (deflate(&stream, Z_FINISH) == Z_OK)
1459                ; /* nothing */
1460        deflateEnd(&stream);
1461        *result_size = stream.total_out;
1462        return deflated;
1463}
1464
1465static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two)
1466{
1467        void *cp;
1468        void *delta;
1469        void *deflated;
1470        void *data;
1471        unsigned long orig_size;
1472        unsigned long delta_size;
1473        unsigned long deflate_size;
1474        unsigned long data_size;
1475
1476        /* We could do deflated delta, or we could do just deflated two,
1477         * whichever is smaller.
1478         */
1479        delta = NULL;
1480        deflated = deflate_it(two->ptr, two->size, &deflate_size);
1481        if (one->size && two->size) {
1482                delta = diff_delta(one->ptr, one->size,
1483                                   two->ptr, two->size,
1484                                   &delta_size, deflate_size);
1485                if (delta) {
1486                        void *to_free = delta;
1487                        orig_size = delta_size;
1488                        delta = deflate_it(delta, delta_size, &delta_size);
1489                        free(to_free);
1490                }
1491        }
1492
1493        if (delta && delta_size < deflate_size) {
1494                fprintf(file, "delta %lu\n", orig_size);
1495                free(deflated);
1496                data = delta;
1497                data_size = delta_size;
1498        }
1499        else {
1500                fprintf(file, "literal %lu\n", two->size);
1501                free(delta);
1502                data = deflated;
1503                data_size = deflate_size;
1504        }
1505
1506        /* emit data encoded in base85 */
1507        cp = data;
1508        while (data_size) {
1509                int bytes = (52 < data_size) ? 52 : data_size;
1510                char line[70];
1511                data_size -= bytes;
1512                if (bytes <= 26)
1513                        line[0] = bytes + 'A' - 1;
1514                else
1515                        line[0] = bytes - 26 + 'a' - 1;
1516                encode_85(line + 1, cp, bytes);
1517                cp = (char *) cp + bytes;
1518                fputs(line, file);
1519                fputc('\n', file);
1520        }
1521        fprintf(file, "\n");
1522        free(data);
1523}
1524
1525static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two)
1526{
1527        fprintf(file, "GIT binary patch\n");
1528        emit_binary_diff_body(file, one, two);
1529        emit_binary_diff_body(file, two, one);
1530}
1531
1532static void diff_filespec_load_driver(struct diff_filespec *one)
1533{
1534        if (!one->driver)
1535                one->driver = userdiff_find_by_path(one->path);
1536        if (!one->driver)
1537                one->driver = userdiff_find_by_name("default");
1538}
1539
1540int diff_filespec_is_binary(struct diff_filespec *one)
1541{
1542        if (one->is_binary == -1) {
1543                diff_filespec_load_driver(one);
1544                if (one->driver->binary != -1)
1545                        one->is_binary = one->driver->binary;
1546                else {
1547                        if (!one->data && DIFF_FILE_VALID(one))
1548                                diff_populate_filespec(one, 0);
1549                        if (one->data)
1550                                one->is_binary = buffer_is_binary(one->data,
1551                                                one->size);
1552                        if (one->is_binary == -1)
1553                                one->is_binary = 0;
1554                }
1555        }
1556        return one->is_binary;
1557}
1558
1559static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
1560{
1561        diff_filespec_load_driver(one);
1562        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
1563}
1564
1565static const char *userdiff_word_regex(struct diff_filespec *one)
1566{
1567        diff_filespec_load_driver(one);
1568        return one->driver->word_regex;
1569}
1570
1571void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
1572{
1573        if (!options->a_prefix)
1574                options->a_prefix = a;
1575        if (!options->b_prefix)
1576                options->b_prefix = b;
1577}
1578
1579static const char *get_textconv(struct diff_filespec *one)
1580{
1581        if (!DIFF_FILE_VALID(one))
1582                return NULL;
1583        if (!S_ISREG(one->mode))
1584                return NULL;
1585        diff_filespec_load_driver(one);
1586        return one->driver->textconv;
1587}
1588
1589static void builtin_diff(const char *name_a,
1590                         const char *name_b,
1591                         struct diff_filespec *one,
1592                         struct diff_filespec *two,
1593                         const char *xfrm_msg,
1594                         struct diff_options *o,
1595                         int complete_rewrite)
1596{
1597        mmfile_t mf1, mf2;
1598        const char *lbl[2];
1599        char *a_one, *b_two;
1600        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1601        const char *reset = diff_get_color_opt(o, DIFF_RESET);
1602        const char *a_prefix, *b_prefix;
1603        const char *textconv_one = NULL, *textconv_two = NULL;
1604
1605        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
1606                        (!one->mode || S_ISGITLINK(one->mode)) &&
1607                        (!two->mode || S_ISGITLINK(two->mode))) {
1608                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
1609                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
1610                show_submodule_summary(o->file, one ? one->path : two->path,
1611                                one->sha1, two->sha1,
1612                                del, add, reset);
1613                return;
1614        }
1615
1616        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
1617                textconv_one = get_textconv(one);
1618                textconv_two = get_textconv(two);
1619        }
1620
1621        diff_set_mnemonic_prefix(o, "a/", "b/");
1622        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
1623                a_prefix = o->b_prefix;
1624                b_prefix = o->a_prefix;
1625        } else {
1626                a_prefix = o->a_prefix;
1627                b_prefix = o->b_prefix;
1628        }
1629
1630        /* Never use a non-valid filename anywhere if at all possible */
1631        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
1632        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
1633
1634        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
1635        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
1636        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1637        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1638        fprintf(o->file, "%sdiff --git %s %s%s\n", set, a_one, b_two, reset);
1639        if (lbl[0][0] == '/') {
1640                /* /dev/null */
1641                fprintf(o->file, "%snew file mode %06o%s\n", set, two->mode, reset);
1642                if (xfrm_msg && xfrm_msg[0])
1643                        fprintf(o->file, "%s%s%s\n", set, xfrm_msg, reset);
1644        }
1645        else if (lbl[1][0] == '/') {
1646                fprintf(o->file, "%sdeleted file mode %06o%s\n", set, one->mode, reset);
1647                if (xfrm_msg && xfrm_msg[0])
1648                        fprintf(o->file, "%s%s%s\n", set, xfrm_msg, reset);
1649        }
1650        else {
1651                if (one->mode != two->mode) {
1652                        fprintf(o->file, "%sold mode %06o%s\n", set, one->mode, reset);
1653                        fprintf(o->file, "%snew mode %06o%s\n", set, two->mode, reset);
1654                }
1655                if (xfrm_msg && xfrm_msg[0])
1656                        fprintf(o->file, "%s%s%s\n", set, xfrm_msg, reset);
1657                /*
1658                 * we do not run diff between different kind
1659                 * of objects.
1660                 */
1661                if ((one->mode ^ two->mode) & S_IFMT)
1662                        goto free_ab_and_return;
1663                if (complete_rewrite &&
1664                    (textconv_one || !diff_filespec_is_binary(one)) &&
1665                    (textconv_two || !diff_filespec_is_binary(two))) {
1666                        emit_rewrite_diff(name_a, name_b, one, two,
1667                                                textconv_one, textconv_two, o);
1668                        o->found_changes = 1;
1669                        goto free_ab_and_return;
1670                }
1671        }
1672
1673        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1674                die("unable to read files to diff");
1675
1676        if (!DIFF_OPT_TST(o, TEXT) &&
1677            ( (diff_filespec_is_binary(one) && !textconv_one) ||
1678              (diff_filespec_is_binary(two) && !textconv_two) )) {
1679                /* Quite common confusing case */
1680                if (mf1.size == mf2.size &&
1681                    !memcmp(mf1.ptr, mf2.ptr, mf1.size))
1682                        goto free_ab_and_return;
1683                if (DIFF_OPT_TST(o, BINARY))
1684                        emit_binary_diff(o->file, &mf1, &mf2);
1685                else
1686                        fprintf(o->file, "Binary files %s and %s differ\n",
1687                                lbl[0], lbl[1]);
1688                o->found_changes = 1;
1689        }
1690        else {
1691                /* Crazy xdl interfaces.. */
1692                const char *diffopts = getenv("GIT_DIFF_OPTS");
1693                xpparam_t xpp;
1694                xdemitconf_t xecfg;
1695                xdemitcb_t ecb;
1696                struct emit_callback ecbdata;
1697                const struct userdiff_funcname *pe;
1698
1699                if (textconv_one) {
1700                        size_t size;
1701                        mf1.ptr = run_textconv(textconv_one, one, &size);
1702                        if (!mf1.ptr)
1703                                die("unable to read files to diff");
1704                        mf1.size = size;
1705                }
1706                if (textconv_two) {
1707                        size_t size;
1708                        mf2.ptr = run_textconv(textconv_two, two, &size);
1709                        if (!mf2.ptr)
1710                                die("unable to read files to diff");
1711                        mf2.size = size;
1712                }
1713
1714                pe = diff_funcname_pattern(one);
1715                if (!pe)
1716                        pe = diff_funcname_pattern(two);
1717
1718                memset(&xpp, 0, sizeof(xpp));
1719                memset(&xecfg, 0, sizeof(xecfg));
1720                memset(&ecbdata, 0, sizeof(ecbdata));
1721                ecbdata.label_path = lbl;
1722                ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
1723                ecbdata.found_changesp = &o->found_changes;
1724                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
1725                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
1726                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
1727                ecbdata.file = o->file;
1728                xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1729                xecfg.ctxlen = o->context;
1730                xecfg.interhunkctxlen = o->interhunkcontext;
1731                xecfg.flags = XDL_EMIT_FUNCNAMES;
1732                if (pe)
1733                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
1734                if (!diffopts)
1735                        ;
1736                else if (!prefixcmp(diffopts, "--unified="))
1737                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
1738                else if (!prefixcmp(diffopts, "-u"))
1739                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
1740                if (DIFF_OPT_TST(o, COLOR_DIFF_WORDS)) {
1741                        ecbdata.diff_words =
1742                                xcalloc(1, sizeof(struct diff_words_data));
1743                        ecbdata.diff_words->file = o->file;
1744                        if (!o->word_regex)
1745                                o->word_regex = userdiff_word_regex(one);
1746                        if (!o->word_regex)
1747                                o->word_regex = userdiff_word_regex(two);
1748                        if (!o->word_regex)
1749                                o->word_regex = diff_word_regex_cfg;
1750                        if (o->word_regex) {
1751                                ecbdata.diff_words->word_regex = (regex_t *)
1752                                        xmalloc(sizeof(regex_t));
1753                                if (regcomp(ecbdata.diff_words->word_regex,
1754                                                o->word_regex,
1755                                                REG_EXTENDED | REG_NEWLINE))
1756                                        die ("Invalid regular expression: %s",
1757                                                        o->word_regex);
1758                        }
1759                }
1760                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
1761                              &xpp, &xecfg, &ecb);
1762                if (DIFF_OPT_TST(o, COLOR_DIFF_WORDS))
1763                        free_diff_words_data(&ecbdata);
1764                if (textconv_one)
1765                        free(mf1.ptr);
1766                if (textconv_two)
1767                        free(mf2.ptr);
1768                xdiff_clear_find_func(&xecfg);
1769        }
1770
1771 free_ab_and_return:
1772        diff_free_filespec_data(one);
1773        diff_free_filespec_data(two);
1774        free(a_one);
1775        free(b_two);
1776        return;
1777}
1778
1779static void builtin_diffstat(const char *name_a, const char *name_b,
1780                             struct diff_filespec *one,
1781                             struct diff_filespec *two,
1782                             struct diffstat_t *diffstat,
1783                             struct diff_options *o,
1784                             int complete_rewrite)
1785{
1786        mmfile_t mf1, mf2;
1787        struct diffstat_file *data;
1788
1789        data = diffstat_add(diffstat, name_a, name_b);
1790
1791        if (!one || !two) {
1792                data->is_unmerged = 1;
1793                return;
1794        }
1795        if (complete_rewrite) {
1796                diff_populate_filespec(one, 0);
1797                diff_populate_filespec(two, 0);
1798                data->deleted = count_lines(one->data, one->size);
1799                data->added = count_lines(two->data, two->size);
1800                goto free_and_return;
1801        }
1802        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1803                die("unable to read files to diff");
1804
1805        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
1806                data->is_binary = 1;
1807                data->added = mf2.size;
1808                data->deleted = mf1.size;
1809        } else {
1810                /* Crazy xdl interfaces.. */
1811                xpparam_t xpp;
1812                xdemitconf_t xecfg;
1813                xdemitcb_t ecb;
1814
1815                memset(&xpp, 0, sizeof(xpp));
1816                memset(&xecfg, 0, sizeof(xecfg));
1817                xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1818                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
1819                              &xpp, &xecfg, &ecb);
1820        }
1821
1822 free_and_return:
1823        diff_free_filespec_data(one);
1824        diff_free_filespec_data(two);
1825}
1826
1827static void builtin_checkdiff(const char *name_a, const char *name_b,
1828                              const char *attr_path,
1829                              struct diff_filespec *one,
1830                              struct diff_filespec *two,
1831                              struct diff_options *o)
1832{
1833        mmfile_t mf1, mf2;
1834        struct checkdiff_t data;
1835
1836        if (!two)
1837                return;
1838
1839        memset(&data, 0, sizeof(data));
1840        data.filename = name_b ? name_b : name_a;
1841        data.lineno = 0;
1842        data.o = o;
1843        data.ws_rule = whitespace_rule(attr_path);
1844
1845        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1846                die("unable to read files to diff");
1847
1848        /*
1849         * All the other codepaths check both sides, but not checking
1850         * the "old" side here is deliberate.  We are checking the newly
1851         * introduced changes, and as long as the "new" side is text, we
1852         * can and should check what it introduces.
1853         */
1854        if (diff_filespec_is_binary(two))
1855                goto free_and_return;
1856        else {
1857                /* Crazy xdl interfaces.. */
1858                xpparam_t xpp;
1859                xdemitconf_t xecfg;
1860                xdemitcb_t ecb;
1861
1862                memset(&xpp, 0, sizeof(xpp));
1863                memset(&xecfg, 0, sizeof(xecfg));
1864                xecfg.ctxlen = 1; /* at least one context line */
1865                xpp.flags = XDF_NEED_MINIMAL;
1866                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
1867                              &xpp, &xecfg, &ecb);
1868
1869                if (data.ws_rule & WS_BLANK_AT_EOF) {
1870                        struct emit_callback ecbdata;
1871                        int blank_at_eof;
1872
1873                        ecbdata.ws_rule = data.ws_rule;
1874                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
1875                        blank_at_eof = ecbdata.blank_at_eof_in_preimage;
1876
1877                        if (blank_at_eof) {
1878                                static char *err;
1879                                if (!err)
1880                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
1881                                fprintf(o->file, "%s:%d: %s.\n",
1882                                        data.filename, blank_at_eof, err);
1883                                data.status = 1; /* report errors */
1884                        }
1885                }
1886        }
1887 free_and_return:
1888        diff_free_filespec_data(one);
1889        diff_free_filespec_data(two);
1890        if (data.status)
1891                DIFF_OPT_SET(o, CHECK_FAILED);
1892}
1893
1894struct diff_filespec *alloc_filespec(const char *path)
1895{
1896        int namelen = strlen(path);
1897        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
1898
1899        memset(spec, 0, sizeof(*spec));
1900        spec->path = (char *)(spec + 1);
1901        memcpy(spec->path, path, namelen+1);
1902        spec->count = 1;
1903        spec->is_binary = -1;
1904        return spec;
1905}
1906
1907void free_filespec(struct diff_filespec *spec)
1908{
1909        if (!--spec->count) {
1910                diff_free_filespec_data(spec);
1911                free(spec);
1912        }
1913}
1914
1915void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
1916                   unsigned short mode)
1917{
1918        if (mode) {
1919                spec->mode = canon_mode(mode);
1920                hashcpy(spec->sha1, sha1);
1921                spec->sha1_valid = !is_null_sha1(sha1);
1922        }
1923}
1924
1925/*
1926 * Given a name and sha1 pair, if the index tells us the file in
1927 * the work tree has that object contents, return true, so that
1928 * prepare_temp_file() does not have to inflate and extract.
1929 */
1930static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
1931{
1932        struct cache_entry *ce;
1933        struct stat st;
1934        int pos, len;
1935
1936        /*
1937         * We do not read the cache ourselves here, because the
1938         * benchmark with my previous version that always reads cache
1939         * shows that it makes things worse for diff-tree comparing
1940         * two linux-2.6 kernel trees in an already checked out work
1941         * tree.  This is because most diff-tree comparisons deal with
1942         * only a small number of files, while reading the cache is
1943         * expensive for a large project, and its cost outweighs the
1944         * savings we get by not inflating the object to a temporary
1945         * file.  Practically, this code only helps when we are used
1946         * by diff-cache --cached, which does read the cache before
1947         * calling us.
1948         */
1949        if (!active_cache)
1950                return 0;
1951
1952        /* We want to avoid the working directory if our caller
1953         * doesn't need the data in a normal file, this system
1954         * is rather slow with its stat/open/mmap/close syscalls,
1955         * and the object is contained in a pack file.  The pack
1956         * is probably already open and will be faster to obtain
1957         * the data through than the working directory.  Loose
1958         * objects however would tend to be slower as they need
1959         * to be individually opened and inflated.
1960         */
1961        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
1962                return 0;
1963
1964        len = strlen(name);
1965        pos = cache_name_pos(name, len);
1966        if (pos < 0)
1967                return 0;
1968        ce = active_cache[pos];
1969
1970        /*
1971         * This is not the sha1 we are looking for, or
1972         * unreusable because it is not a regular file.
1973         */
1974        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
1975                return 0;
1976
1977        /*
1978         * If ce is marked as "assume unchanged", there is no
1979         * guarantee that work tree matches what we are looking for.
1980         */
1981        if (ce->ce_flags & CE_VALID)
1982                return 0;
1983
1984        /*
1985         * If ce matches the file in the work tree, we can reuse it.
1986         */
1987        if (ce_uptodate(ce) ||
1988            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
1989                return 1;
1990
1991        return 0;
1992}
1993
1994static int populate_from_stdin(struct diff_filespec *s)
1995{
1996        struct strbuf buf = STRBUF_INIT;
1997        size_t size = 0;
1998
1999        if (strbuf_read(&buf, 0, 0) < 0)
2000                return error("error while reading from stdin %s",
2001                                     strerror(errno));
2002
2003        s->should_munmap = 0;
2004        s->data = strbuf_detach(&buf, &size);
2005        s->size = size;
2006        s->should_free = 1;
2007        return 0;
2008}
2009
2010static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2011{
2012        int len;
2013        char *data = xmalloc(100);
2014        len = snprintf(data, 100,
2015                "Subproject commit %s\n", sha1_to_hex(s->sha1));
2016        s->data = data;
2017        s->size = len;
2018        s->should_free = 1;
2019        if (size_only) {
2020                s->data = NULL;
2021                free(data);
2022        }
2023        return 0;
2024}
2025
2026/*
2027 * While doing rename detection and pickaxe operation, we may need to
2028 * grab the data for the blob (or file) for our own in-core comparison.
2029 * diff_filespec has data and size fields for this purpose.
2030 */
2031int diff_populate_filespec(struct diff_filespec *s, int size_only)
2032{
2033        int err = 0;
2034        if (!DIFF_FILE_VALID(s))
2035                die("internal error: asking to populate invalid file.");
2036        if (S_ISDIR(s->mode))
2037                return -1;
2038
2039        if (s->data)
2040                return 0;
2041
2042        if (size_only && 0 < s->size)
2043                return 0;
2044
2045        if (S_ISGITLINK(s->mode))
2046                return diff_populate_gitlink(s, size_only);
2047
2048        if (!s->sha1_valid ||
2049            reuse_worktree_file(s->path, s->sha1, 0)) {
2050                struct strbuf buf = STRBUF_INIT;
2051                struct stat st;
2052                int fd;
2053
2054                if (!strcmp(s->path, "-"))
2055                        return populate_from_stdin(s);
2056
2057                if (lstat(s->path, &st) < 0) {
2058                        if (errno == ENOENT) {
2059                        err_empty:
2060                                err = -1;
2061                        empty:
2062                                s->data = (char *)"";
2063                                s->size = 0;
2064                                return err;
2065                        }
2066                }
2067                s->size = xsize_t(st.st_size);
2068                if (!s->size)
2069                        goto empty;
2070                if (S_ISLNK(st.st_mode)) {
2071                        struct strbuf sb = STRBUF_INIT;
2072
2073                        if (strbuf_readlink(&sb, s->path, s->size))
2074                                goto err_empty;
2075                        s->size = sb.len;
2076                        s->data = strbuf_detach(&sb, NULL);
2077                        s->should_free = 1;
2078                        return 0;
2079                }
2080                if (size_only)
2081                        return 0;
2082                fd = open(s->path, O_RDONLY);
2083                if (fd < 0)
2084                        goto err_empty;
2085                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2086                close(fd);
2087                s->should_munmap = 1;
2088
2089                /*
2090                 * Convert from working tree format to canonical git format
2091                 */
2092                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2093                        size_t size = 0;
2094                        munmap(s->data, s->size);
2095                        s->should_munmap = 0;
2096                        s->data = strbuf_detach(&buf, &size);
2097                        s->size = size;
2098                        s->should_free = 1;
2099                }
2100        }
2101        else {
2102                enum object_type type;
2103                if (size_only)
2104                        type = sha1_object_info(s->sha1, &s->size);
2105                else {
2106                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2107                        s->should_free = 1;
2108                }
2109        }
2110        return 0;
2111}
2112
2113void diff_free_filespec_blob(struct diff_filespec *s)
2114{
2115        if (s->should_free)
2116                free(s->data);
2117        else if (s->should_munmap)
2118                munmap(s->data, s->size);
2119
2120        if (s->should_free || s->should_munmap) {
2121                s->should_free = s->should_munmap = 0;
2122                s->data = NULL;
2123        }
2124}
2125
2126void diff_free_filespec_data(struct diff_filespec *s)
2127{
2128        diff_free_filespec_blob(s);
2129        free(s->cnt_data);
2130        s->cnt_data = NULL;
2131}
2132
2133static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2134                           void *blob,
2135                           unsigned long size,
2136                           const unsigned char *sha1,
2137                           int mode)
2138{
2139        int fd;
2140        struct strbuf buf = STRBUF_INIT;
2141        struct strbuf template = STRBUF_INIT;
2142        char *path_dup = xstrdup(path);
2143        const char *base = basename(path_dup);
2144
2145        /* Generate "XXXXXX_basename.ext" */
2146        strbuf_addstr(&template, "XXXXXX_");
2147        strbuf_addstr(&template, base);
2148
2149        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2150                        strlen(base) + 1);
2151        if (fd < 0)
2152                die_errno("unable to create temp-file");
2153        if (convert_to_working_tree(path,
2154                        (const char *)blob, (size_t)size, &buf)) {
2155                blob = buf.buf;
2156                size = buf.len;
2157        }
2158        if (write_in_full(fd, blob, size) != size)
2159                die_errno("unable to write temp-file");
2160        close(fd);
2161        temp->name = temp->tmp_path;
2162        strcpy(temp->hex, sha1_to_hex(sha1));
2163        temp->hex[40] = 0;
2164        sprintf(temp->mode, "%06o", mode);
2165        strbuf_release(&buf);
2166        strbuf_release(&template);
2167        free(path_dup);
2168}
2169
2170static struct diff_tempfile *prepare_temp_file(const char *name,
2171                struct diff_filespec *one)
2172{
2173        struct diff_tempfile *temp = claim_diff_tempfile();
2174
2175        if (!DIFF_FILE_VALID(one)) {
2176        not_a_valid_file:
2177                /* A '-' entry produces this for file-2, and
2178                 * a '+' entry produces this for file-1.
2179                 */
2180                temp->name = "/dev/null";
2181                strcpy(temp->hex, ".");
2182                strcpy(temp->mode, ".");
2183                return temp;
2184        }
2185
2186        if (!remove_tempfile_installed) {
2187                atexit(remove_tempfile);
2188                sigchain_push_common(remove_tempfile_on_signal);
2189                remove_tempfile_installed = 1;
2190        }
2191
2192        if (!one->sha1_valid ||
2193            reuse_worktree_file(name, one->sha1, 1)) {
2194                struct stat st;
2195                if (lstat(name, &st) < 0) {
2196                        if (errno == ENOENT)
2197                                goto not_a_valid_file;
2198                        die_errno("stat(%s)", name);
2199                }
2200                if (S_ISLNK(st.st_mode)) {
2201                        struct strbuf sb = STRBUF_INIT;
2202                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2203                                die_errno("readlink(%s)", name);
2204                        prep_temp_blob(name, temp, sb.buf, sb.len,
2205                                       (one->sha1_valid ?
2206                                        one->sha1 : null_sha1),
2207                                       (one->sha1_valid ?
2208                                        one->mode : S_IFLNK));
2209                        strbuf_release(&sb);
2210                }
2211                else {
2212                        /* we can borrow from the file in the work tree */
2213                        temp->name = name;
2214                        if (!one->sha1_valid)
2215                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2216                        else
2217                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2218                        /* Even though we may sometimes borrow the
2219                         * contents from the work tree, we always want
2220                         * one->mode.  mode is trustworthy even when
2221                         * !(one->sha1_valid), as long as
2222                         * DIFF_FILE_VALID(one).
2223                         */
2224                        sprintf(temp->mode, "%06o", one->mode);
2225                }
2226                return temp;
2227        }
2228        else {
2229                if (diff_populate_filespec(one, 0))
2230                        die("cannot read data blob for %s", one->path);
2231                prep_temp_blob(name, temp, one->data, one->size,
2232                               one->sha1, one->mode);
2233        }
2234        return temp;
2235}
2236
2237/* An external diff command takes:
2238 *
2239 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2240 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2241 *
2242 */
2243static void run_external_diff(const char *pgm,
2244                              const char *name,
2245                              const char *other,
2246                              struct diff_filespec *one,
2247                              struct diff_filespec *two,
2248                              const char *xfrm_msg,
2249                              int complete_rewrite)
2250{
2251        const char *spawn_arg[10];
2252        int retval;
2253        const char **arg = &spawn_arg[0];
2254
2255        if (one && two) {
2256                struct diff_tempfile *temp_one, *temp_two;
2257                const char *othername = (other ? other : name);
2258                temp_one = prepare_temp_file(name, one);
2259                temp_two = prepare_temp_file(othername, two);
2260                *arg++ = pgm;
2261                *arg++ = name;
2262                *arg++ = temp_one->name;
2263                *arg++ = temp_one->hex;
2264                *arg++ = temp_one->mode;
2265                *arg++ = temp_two->name;
2266                *arg++ = temp_two->hex;
2267                *arg++ = temp_two->mode;
2268                if (other) {
2269                        *arg++ = other;
2270                        *arg++ = xfrm_msg;
2271                }
2272        } else {
2273                *arg++ = pgm;
2274                *arg++ = name;
2275        }
2276        *arg = NULL;
2277        fflush(NULL);
2278        retval = run_command_v_opt(spawn_arg, 0);
2279        remove_tempfile();
2280        if (retval) {
2281                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2282                exit(1);
2283        }
2284}
2285
2286static int similarity_index(struct diff_filepair *p)
2287{
2288        return p->score * 100 / MAX_SCORE;
2289}
2290
2291static void fill_metainfo(struct strbuf *msg,
2292                          const char *name,
2293                          const char *other,
2294                          struct diff_filespec *one,
2295                          struct diff_filespec *two,
2296                          struct diff_options *o,
2297                          struct diff_filepair *p)
2298{
2299        strbuf_init(msg, PATH_MAX * 2 + 300);
2300        switch (p->status) {
2301        case DIFF_STATUS_COPIED:
2302                strbuf_addf(msg, "similarity index %d%%", similarity_index(p));
2303                strbuf_addstr(msg, "\ncopy from ");
2304                quote_c_style(name, msg, NULL, 0);
2305                strbuf_addstr(msg, "\ncopy to ");
2306                quote_c_style(other, msg, NULL, 0);
2307                strbuf_addch(msg, '\n');
2308                break;
2309        case DIFF_STATUS_RENAMED:
2310                strbuf_addf(msg, "similarity index %d%%", similarity_index(p));
2311                strbuf_addstr(msg, "\nrename from ");
2312                quote_c_style(name, msg, NULL, 0);
2313                strbuf_addstr(msg, "\nrename to ");
2314                quote_c_style(other, msg, NULL, 0);
2315                strbuf_addch(msg, '\n');
2316                break;
2317        case DIFF_STATUS_MODIFIED:
2318                if (p->score) {
2319                        strbuf_addf(msg, "dissimilarity index %d%%\n",
2320                                    similarity_index(p));
2321                        break;
2322                }
2323                /* fallthru */
2324        default:
2325                /* nothing */
2326                ;
2327        }
2328        if (one && two && hashcmp(one->sha1, two->sha1)) {
2329                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2330
2331                if (DIFF_OPT_TST(o, BINARY)) {
2332                        mmfile_t mf;
2333                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2334                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2335                                abbrev = 40;
2336                }
2337                strbuf_addf(msg, "index %.*s..%.*s",
2338                            abbrev, sha1_to_hex(one->sha1),
2339                            abbrev, sha1_to_hex(two->sha1));
2340                if (one->mode == two->mode)
2341                        strbuf_addf(msg, " %06o", one->mode);
2342                strbuf_addch(msg, '\n');
2343        }
2344        if (msg->len)
2345                strbuf_setlen(msg, msg->len - 1);
2346}
2347
2348static void run_diff_cmd(const char *pgm,
2349                         const char *name,
2350                         const char *other,
2351                         const char *attr_path,
2352                         struct diff_filespec *one,
2353                         struct diff_filespec *two,
2354                         struct strbuf *msg,
2355                         struct diff_options *o,
2356                         struct diff_filepair *p)
2357{
2358        const char *xfrm_msg = NULL;
2359        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2360
2361        if (msg) {
2362                fill_metainfo(msg, name, other, one, two, o, p);
2363                xfrm_msg = msg->len ? msg->buf : NULL;
2364        }
2365
2366        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2367                pgm = NULL;
2368        else {
2369                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2370                if (drv && drv->external)
2371                        pgm = drv->external;
2372        }
2373
2374        if (pgm) {
2375                run_external_diff(pgm, name, other, one, two, xfrm_msg,
2376                                  complete_rewrite);
2377                return;
2378        }
2379        if (one && two)
2380                builtin_diff(name, other ? other : name,
2381                             one, two, xfrm_msg, o, complete_rewrite);
2382        else
2383                fprintf(o->file, "* Unmerged path %s\n", name);
2384}
2385
2386static void diff_fill_sha1_info(struct diff_filespec *one)
2387{
2388        if (DIFF_FILE_VALID(one)) {
2389                if (!one->sha1_valid) {
2390                        struct stat st;
2391                        if (!strcmp(one->path, "-")) {
2392                                hashcpy(one->sha1, null_sha1);
2393                                return;
2394                        }
2395                        if (lstat(one->path, &st) < 0)
2396                                die_errno("stat '%s'", one->path);
2397                        if (index_path(one->sha1, one->path, &st, 0))
2398                                die("cannot hash %s", one->path);
2399                }
2400        }
2401        else
2402                hashclr(one->sha1);
2403}
2404
2405static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2406{
2407        /* Strip the prefix but do not molest /dev/null and absolute paths */
2408        if (*namep && **namep != '/')
2409                *namep += prefix_length;
2410        if (*otherp && **otherp != '/')
2411                *otherp += prefix_length;
2412}
2413
2414static void run_diff(struct diff_filepair *p, struct diff_options *o)
2415{
2416        const char *pgm = external_diff();
2417        struct strbuf msg;
2418        struct diff_filespec *one = p->one;
2419        struct diff_filespec *two = p->two;
2420        const char *name;
2421        const char *other;
2422        const char *attr_path;
2423
2424        name  = p->one->path;
2425        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2426        attr_path = name;
2427        if (o->prefix_length)
2428                strip_prefix(o->prefix_length, &name, &other);
2429
2430        if (DIFF_PAIR_UNMERGED(p)) {
2431                run_diff_cmd(pgm, name, NULL, attr_path,
2432                             NULL, NULL, NULL, o, p);
2433                return;
2434        }
2435
2436        diff_fill_sha1_info(one);
2437        diff_fill_sha1_info(two);
2438
2439        if (!pgm &&
2440            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2441            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2442                /*
2443                 * a filepair that changes between file and symlink
2444                 * needs to be split into deletion and creation.
2445                 */
2446                struct diff_filespec *null = alloc_filespec(two->path);
2447                run_diff_cmd(NULL, name, other, attr_path,
2448                             one, null, &msg, o, p);
2449                free(null);
2450                strbuf_release(&msg);
2451
2452                null = alloc_filespec(one->path);
2453                run_diff_cmd(NULL, name, other, attr_path,
2454                             null, two, &msg, o, p);
2455                free(null);
2456        }
2457        else
2458                run_diff_cmd(pgm, name, other, attr_path,
2459                             one, two, &msg, o, p);
2460
2461        strbuf_release(&msg);
2462}
2463
2464static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2465                         struct diffstat_t *diffstat)
2466{
2467        const char *name;
2468        const char *other;
2469        int complete_rewrite = 0;
2470
2471        if (DIFF_PAIR_UNMERGED(p)) {
2472                /* unmerged */
2473                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2474                return;
2475        }
2476
2477        name = p->one->path;
2478        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2479
2480        if (o->prefix_length)
2481                strip_prefix(o->prefix_length, &name, &other);
2482
2483        diff_fill_sha1_info(p->one);
2484        diff_fill_sha1_info(p->two);
2485
2486        if (p->status == DIFF_STATUS_MODIFIED && p->score)
2487                complete_rewrite = 1;
2488        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2489}
2490
2491static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2492{
2493        const char *name;
2494        const char *other;
2495        const char *attr_path;
2496
2497        if (DIFF_PAIR_UNMERGED(p)) {
2498                /* unmerged */
2499                return;
2500        }
2501
2502        name = p->one->path;
2503        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2504        attr_path = other ? other : name;
2505
2506        if (o->prefix_length)
2507                strip_prefix(o->prefix_length, &name, &other);
2508
2509        diff_fill_sha1_info(p->one);
2510        diff_fill_sha1_info(p->two);
2511
2512        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2513}
2514
2515void diff_setup(struct diff_options *options)
2516{
2517        memset(options, 0, sizeof(*options));
2518
2519        options->file = stdout;
2520
2521        options->line_termination = '\n';
2522        options->break_opt = -1;
2523        options->rename_limit = -1;
2524        options->dirstat_percent = 3;
2525        options->context = 3;
2526
2527        options->change = diff_change;
2528        options->add_remove = diff_addremove;
2529        if (diff_use_color_default > 0)
2530                DIFF_OPT_SET(options, COLOR_DIFF);
2531        options->detect_rename = diff_detect_rename_default;
2532
2533        if (!diff_mnemonic_prefix) {
2534                options->a_prefix = "a/";
2535                options->b_prefix = "b/";
2536        }
2537}
2538
2539int diff_setup_done(struct diff_options *options)
2540{
2541        int count = 0;
2542
2543        if (options->output_format & DIFF_FORMAT_NAME)
2544                count++;
2545        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
2546                count++;
2547        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
2548                count++;
2549        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
2550                count++;
2551        if (count > 1)
2552                die("--name-only, --name-status, --check and -s are mutually exclusive");
2553
2554        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
2555                options->detect_rename = DIFF_DETECT_COPY;
2556
2557        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
2558                options->prefix = NULL;
2559        if (options->prefix)
2560                options->prefix_length = strlen(options->prefix);
2561        else
2562                options->prefix_length = 0;
2563
2564        if (options->output_format & (DIFF_FORMAT_NAME |
2565                                      DIFF_FORMAT_NAME_STATUS |
2566                                      DIFF_FORMAT_CHECKDIFF |
2567                                      DIFF_FORMAT_NO_OUTPUT))
2568                options->output_format &= ~(DIFF_FORMAT_RAW |
2569                                            DIFF_FORMAT_NUMSTAT |
2570                                            DIFF_FORMAT_DIFFSTAT |
2571                                            DIFF_FORMAT_SHORTSTAT |
2572                                            DIFF_FORMAT_DIRSTAT |
2573                                            DIFF_FORMAT_SUMMARY |
2574                                            DIFF_FORMAT_PATCH);
2575
2576        /*
2577         * These cases always need recursive; we do not drop caller-supplied
2578         * recursive bits for other formats here.
2579         */
2580        if (options->output_format & (DIFF_FORMAT_PATCH |
2581                                      DIFF_FORMAT_NUMSTAT |
2582                                      DIFF_FORMAT_DIFFSTAT |
2583                                      DIFF_FORMAT_SHORTSTAT |
2584                                      DIFF_FORMAT_DIRSTAT |
2585                                      DIFF_FORMAT_SUMMARY |
2586                                      DIFF_FORMAT_CHECKDIFF))
2587                DIFF_OPT_SET(options, RECURSIVE);
2588        /*
2589         * Also pickaxe would not work very well if you do not say recursive
2590         */
2591        if (options->pickaxe)
2592                DIFF_OPT_SET(options, RECURSIVE);
2593
2594        if (options->detect_rename && options->rename_limit < 0)
2595                options->rename_limit = diff_rename_limit_default;
2596        if (options->setup & DIFF_SETUP_USE_CACHE) {
2597                if (!active_cache)
2598                        /* read-cache does not die even when it fails
2599                         * so it is safe for us to do this here.  Also
2600                         * it does not smudge active_cache or active_nr
2601                         * when it fails, so we do not have to worry about
2602                         * cleaning it up ourselves either.
2603                         */
2604                        read_cache();
2605        }
2606        if (options->abbrev <= 0 || 40 < options->abbrev)
2607                options->abbrev = 40; /* full */
2608
2609        /*
2610         * It does not make sense to show the first hit we happened
2611         * to have found.  It does not make sense not to return with
2612         * exit code in such a case either.
2613         */
2614        if (DIFF_OPT_TST(options, QUIET)) {
2615                options->output_format = DIFF_FORMAT_NO_OUTPUT;
2616                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2617        }
2618
2619        return 0;
2620}
2621
2622static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
2623{
2624        char c, *eq;
2625        int len;
2626
2627        if (*arg != '-')
2628                return 0;
2629        c = *++arg;
2630        if (!c)
2631                return 0;
2632        if (c == arg_short) {
2633                c = *++arg;
2634                if (!c)
2635                        return 1;
2636                if (val && isdigit(c)) {
2637                        char *end;
2638                        int n = strtoul(arg, &end, 10);
2639                        if (*end)
2640                                return 0;
2641                        *val = n;
2642                        return 1;
2643                }
2644                return 0;
2645        }
2646        if (c != '-')
2647                return 0;
2648        arg++;
2649        eq = strchr(arg, '=');
2650        if (eq)
2651                len = eq - arg;
2652        else
2653                len = strlen(arg);
2654        if (!len || strncmp(arg, arg_long, len))
2655                return 0;
2656        if (eq) {
2657                int n;
2658                char *end;
2659                if (!isdigit(*++eq))
2660                        return 0;
2661                n = strtoul(eq, &end, 10);
2662                if (*end)
2663                        return 0;
2664                *val = n;
2665        }
2666        return 1;
2667}
2668
2669static int diff_scoreopt_parse(const char *opt);
2670
2671int diff_opt_parse(struct diff_options *options, const char **av, int ac)
2672{
2673        const char *arg = av[0];
2674
2675        /* Output format options */
2676        if (!strcmp(arg, "-p") || !strcmp(arg, "-u"))
2677                options->output_format |= DIFF_FORMAT_PATCH;
2678        else if (opt_arg(arg, 'U', "unified", &options->context))
2679                options->output_format |= DIFF_FORMAT_PATCH;
2680        else if (!strcmp(arg, "--raw"))
2681                options->output_format |= DIFF_FORMAT_RAW;
2682        else if (!strcmp(arg, "--patch-with-raw"))
2683                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
2684        else if (!strcmp(arg, "--numstat"))
2685                options->output_format |= DIFF_FORMAT_NUMSTAT;
2686        else if (!strcmp(arg, "--shortstat"))
2687                options->output_format |= DIFF_FORMAT_SHORTSTAT;
2688        else if (opt_arg(arg, 'X', "dirstat", &options->dirstat_percent))
2689                options->output_format |= DIFF_FORMAT_DIRSTAT;
2690        else if (!strcmp(arg, "--cumulative")) {
2691                options->output_format |= DIFF_FORMAT_DIRSTAT;
2692                DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
2693        } else if (opt_arg(arg, 0, "dirstat-by-file",
2694                           &options->dirstat_percent)) {
2695                options->output_format |= DIFF_FORMAT_DIRSTAT;
2696                DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
2697        }
2698        else if (!strcmp(arg, "--check"))
2699                options->output_format |= DIFF_FORMAT_CHECKDIFF;
2700        else if (!strcmp(arg, "--summary"))
2701                options->output_format |= DIFF_FORMAT_SUMMARY;
2702        else if (!strcmp(arg, "--patch-with-stat"))
2703                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
2704        else if (!strcmp(arg, "--name-only"))
2705                options->output_format |= DIFF_FORMAT_NAME;
2706        else if (!strcmp(arg, "--name-status"))
2707                options->output_format |= DIFF_FORMAT_NAME_STATUS;
2708        else if (!strcmp(arg, "-s"))
2709                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
2710        else if (!prefixcmp(arg, "--stat")) {
2711                char *end;
2712                int width = options->stat_width;
2713                int name_width = options->stat_name_width;
2714                arg += 6;
2715                end = (char *)arg;
2716
2717                switch (*arg) {
2718                case '-':
2719                        if (!prefixcmp(arg, "-width="))
2720                                width = strtoul(arg + 7, &end, 10);
2721                        else if (!prefixcmp(arg, "-name-width="))
2722                                name_width = strtoul(arg + 12, &end, 10);
2723                        break;
2724                case '=':
2725                        width = strtoul(arg+1, &end, 10);
2726                        if (*end == ',')
2727                                name_width = strtoul(end+1, &end, 10);
2728                }
2729
2730                /* Important! This checks all the error cases! */
2731                if (*end)
2732                        return 0;
2733                options->output_format |= DIFF_FORMAT_DIFFSTAT;
2734                options->stat_name_width = name_width;
2735                options->stat_width = width;
2736        }
2737
2738        /* renames options */
2739        else if (!prefixcmp(arg, "-B")) {
2740                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
2741                        return -1;
2742        }
2743        else if (!prefixcmp(arg, "-M")) {
2744                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2745                        return -1;
2746                options->detect_rename = DIFF_DETECT_RENAME;
2747        }
2748        else if (!prefixcmp(arg, "-C")) {
2749                if (options->detect_rename == DIFF_DETECT_COPY)
2750                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2751                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2752                        return -1;
2753                options->detect_rename = DIFF_DETECT_COPY;
2754        }
2755        else if (!strcmp(arg, "--no-renames"))
2756                options->detect_rename = 0;
2757        else if (!strcmp(arg, "--relative"))
2758                DIFF_OPT_SET(options, RELATIVE_NAME);
2759        else if (!prefixcmp(arg, "--relative=")) {
2760                DIFF_OPT_SET(options, RELATIVE_NAME);
2761                options->prefix = arg + 11;
2762        }
2763
2764        /* xdiff options */
2765        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
2766                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
2767        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
2768                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
2769        else if (!strcmp(arg, "--ignore-space-at-eol"))
2770                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
2771        else if (!strcmp(arg, "--patience"))
2772                DIFF_XDL_SET(options, PATIENCE_DIFF);
2773
2774        /* flags options */
2775        else if (!strcmp(arg, "--binary")) {
2776                options->output_format |= DIFF_FORMAT_PATCH;
2777                DIFF_OPT_SET(options, BINARY);
2778        }
2779        else if (!strcmp(arg, "--full-index"))
2780                DIFF_OPT_SET(options, FULL_INDEX);
2781        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
2782                DIFF_OPT_SET(options, TEXT);
2783        else if (!strcmp(arg, "-R"))
2784                DIFF_OPT_SET(options, REVERSE_DIFF);
2785        else if (!strcmp(arg, "--find-copies-harder"))
2786                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2787        else if (!strcmp(arg, "--follow"))
2788                DIFF_OPT_SET(options, FOLLOW_RENAMES);
2789        else if (!strcmp(arg, "--color"))
2790                DIFF_OPT_SET(options, COLOR_DIFF);
2791        else if (!strcmp(arg, "--no-color"))
2792                DIFF_OPT_CLR(options, COLOR_DIFF);
2793        else if (!strcmp(arg, "--color-words")) {
2794                DIFF_OPT_SET(options, COLOR_DIFF);
2795                DIFF_OPT_SET(options, COLOR_DIFF_WORDS);
2796        }
2797        else if (!prefixcmp(arg, "--color-words=")) {
2798                DIFF_OPT_SET(options, COLOR_DIFF);
2799                DIFF_OPT_SET(options, COLOR_DIFF_WORDS);
2800                options->word_regex = arg + 14;
2801        }
2802        else if (!strcmp(arg, "--exit-code"))
2803                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2804        else if (!strcmp(arg, "--quiet"))
2805                DIFF_OPT_SET(options, QUIET);
2806        else if (!strcmp(arg, "--ext-diff"))
2807                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
2808        else if (!strcmp(arg, "--no-ext-diff"))
2809                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
2810        else if (!strcmp(arg, "--textconv"))
2811                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
2812        else if (!strcmp(arg, "--no-textconv"))
2813                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
2814        else if (!strcmp(arg, "--ignore-submodules"))
2815                DIFF_OPT_SET(options, IGNORE_SUBMODULES);
2816        else if (!strcmp(arg, "--submodule"))
2817                DIFF_OPT_SET(options, SUBMODULE_LOG);
2818        else if (!prefixcmp(arg, "--submodule=")) {
2819                if (!strcmp(arg + 12, "log"))
2820                        DIFF_OPT_SET(options, SUBMODULE_LOG);
2821        }
2822
2823        /* misc options */
2824        else if (!strcmp(arg, "-z"))
2825                options->line_termination = 0;
2826        else if (!prefixcmp(arg, "-l"))
2827                options->rename_limit = strtoul(arg+2, NULL, 10);
2828        else if (!prefixcmp(arg, "-S"))
2829                options->pickaxe = arg + 2;
2830        else if (!strcmp(arg, "--pickaxe-all"))
2831                options->pickaxe_opts = DIFF_PICKAXE_ALL;
2832        else if (!strcmp(arg, "--pickaxe-regex"))
2833                options->pickaxe_opts = DIFF_PICKAXE_REGEX;
2834        else if (!prefixcmp(arg, "-O"))
2835                options->orderfile = arg + 2;
2836        else if (!prefixcmp(arg, "--diff-filter="))
2837                options->filter = arg + 14;
2838        else if (!strcmp(arg, "--abbrev"))
2839                options->abbrev = DEFAULT_ABBREV;
2840        else if (!prefixcmp(arg, "--abbrev=")) {
2841                options->abbrev = strtoul(arg + 9, NULL, 10);
2842                if (options->abbrev < MINIMUM_ABBREV)
2843                        options->abbrev = MINIMUM_ABBREV;
2844                else if (40 < options->abbrev)
2845                        options->abbrev = 40;
2846        }
2847        else if (!prefixcmp(arg, "--src-prefix="))
2848                options->a_prefix = arg + 13;
2849        else if (!prefixcmp(arg, "--dst-prefix="))
2850                options->b_prefix = arg + 13;
2851        else if (!strcmp(arg, "--no-prefix"))
2852                options->a_prefix = options->b_prefix = "";
2853        else if (opt_arg(arg, '\0', "inter-hunk-context",
2854                         &options->interhunkcontext))
2855                ;
2856        else if (!prefixcmp(arg, "--output=")) {
2857                options->file = fopen(arg + strlen("--output="), "w");
2858                if (!options->file)
2859                        die_errno("Could not open '%s'", arg + strlen("--output="));
2860                options->close_file = 1;
2861        } else
2862                return 0;
2863        return 1;
2864}
2865
2866static int parse_num(const char **cp_p)
2867{
2868        unsigned long num, scale;
2869        int ch, dot;
2870        const char *cp = *cp_p;
2871
2872        num = 0;
2873        scale = 1;
2874        dot = 0;
2875        for (;;) {
2876                ch = *cp;
2877                if ( !dot && ch == '.' ) {
2878                        scale = 1;
2879                        dot = 1;
2880                } else if ( ch == '%' ) {
2881                        scale = dot ? scale*100 : 100;
2882                        cp++;   /* % is always at the end */
2883                        break;
2884                } else if ( ch >= '0' && ch <= '9' ) {
2885                        if ( scale < 100000 ) {
2886                                scale *= 10;
2887                                num = (num*10) + (ch-'0');
2888                        }
2889                } else {
2890                        break;
2891                }
2892                cp++;
2893        }
2894        *cp_p = cp;
2895
2896        /* user says num divided by scale and we say internally that
2897         * is MAX_SCORE * num / scale.
2898         */
2899        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
2900}
2901
2902static int diff_scoreopt_parse(const char *opt)
2903{
2904        int opt1, opt2, cmd;
2905
2906        if (*opt++ != '-')
2907                return -1;
2908        cmd = *opt++;
2909        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
2910                return -1; /* that is not a -M, -C nor -B option */
2911
2912        opt1 = parse_num(&opt);
2913        if (cmd != 'B')
2914                opt2 = 0;
2915        else {
2916                if (*opt == 0)
2917                        opt2 = 0;
2918                else if (*opt != '/')
2919                        return -1; /* we expect -B80/99 or -B80 */
2920                else {
2921                        opt++;
2922                        opt2 = parse_num(&opt);
2923                }
2924        }
2925        if (*opt != 0)
2926                return -1;
2927        return opt1 | (opt2 << 16);
2928}
2929
2930struct diff_queue_struct diff_queued_diff;
2931
2932void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
2933{
2934        if (queue->alloc <= queue->nr) {
2935                queue->alloc = alloc_nr(queue->alloc);
2936                queue->queue = xrealloc(queue->queue,
2937                                        sizeof(dp) * queue->alloc);
2938        }
2939        queue->queue[queue->nr++] = dp;
2940}
2941
2942struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
2943                                 struct diff_filespec *one,
2944                                 struct diff_filespec *two)
2945{
2946        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
2947        dp->one = one;
2948        dp->two = two;
2949        if (queue)
2950                diff_q(queue, dp);
2951        return dp;
2952}
2953
2954void diff_free_filepair(struct diff_filepair *p)
2955{
2956        free_filespec(p->one);
2957        free_filespec(p->two);
2958        free(p);
2959}
2960
2961/* This is different from find_unique_abbrev() in that
2962 * it stuffs the result with dots for alignment.
2963 */
2964const char *diff_unique_abbrev(const unsigned char *sha1, int len)
2965{
2966        int abblen;
2967        const char *abbrev;
2968        if (len == 40)
2969                return sha1_to_hex(sha1);
2970
2971        abbrev = find_unique_abbrev(sha1, len);
2972        abblen = strlen(abbrev);
2973        if (abblen < 37) {
2974                static char hex[41];
2975                if (len < abblen && abblen <= len + 2)
2976                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
2977                else
2978                        sprintf(hex, "%s...", abbrev);
2979                return hex;
2980        }
2981        return sha1_to_hex(sha1);
2982}
2983
2984static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
2985{
2986        int line_termination = opt->line_termination;
2987        int inter_name_termination = line_termination ? '\t' : '\0';
2988
2989        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
2990                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
2991                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
2992                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
2993        }
2994        if (p->score) {
2995                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
2996                        inter_name_termination);
2997        } else {
2998                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
2999        }
3000
3001        if (p->status == DIFF_STATUS_COPIED ||
3002            p->status == DIFF_STATUS_RENAMED) {
3003                const char *name_a, *name_b;
3004                name_a = p->one->path;
3005                name_b = p->two->path;
3006                strip_prefix(opt->prefix_length, &name_a, &name_b);
3007                write_name_quoted(name_a, opt->file, inter_name_termination);
3008                write_name_quoted(name_b, opt->file, line_termination);
3009        } else {
3010                const char *name_a, *name_b;
3011                name_a = p->one->mode ? p->one->path : p->two->path;
3012                name_b = NULL;
3013                strip_prefix(opt->prefix_length, &name_a, &name_b);
3014                write_name_quoted(name_a, opt->file, line_termination);
3015        }
3016}
3017
3018int diff_unmodified_pair(struct diff_filepair *p)
3019{
3020        /* This function is written stricter than necessary to support
3021         * the currently implemented transformers, but the idea is to
3022         * let transformers to produce diff_filepairs any way they want,
3023         * and filter and clean them up here before producing the output.
3024         */
3025        struct diff_filespec *one = p->one, *two = p->two;
3026
3027        if (DIFF_PAIR_UNMERGED(p))
3028                return 0; /* unmerged is interesting */
3029
3030        /* deletion, addition, mode or type change
3031         * and rename are all interesting.
3032         */
3033        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3034            DIFF_PAIR_MODE_CHANGED(p) ||
3035            strcmp(one->path, two->path))
3036                return 0;
3037
3038        /* both are valid and point at the same path.  that is, we are
3039         * dealing with a change.
3040         */
3041        if (one->sha1_valid && two->sha1_valid &&
3042            !hashcmp(one->sha1, two->sha1))
3043                return 1; /* no change */
3044        if (!one->sha1_valid && !two->sha1_valid)
3045                return 1; /* both look at the same file on the filesystem. */
3046        return 0;
3047}
3048
3049static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3050{
3051        if (diff_unmodified_pair(p))
3052                return;
3053
3054        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3055            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3056                return; /* no tree diffs in patch format */
3057
3058        run_diff(p, o);
3059}
3060
3061static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3062                            struct diffstat_t *diffstat)
3063{
3064        if (diff_unmodified_pair(p))
3065                return;
3066
3067        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3068            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3069                return; /* no tree diffs in patch format */
3070
3071        run_diffstat(p, o, diffstat);
3072}
3073
3074static void diff_flush_checkdiff(struct diff_filepair *p,
3075                struct diff_options *o)
3076{
3077        if (diff_unmodified_pair(p))
3078                return;
3079
3080        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3081            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3082                return; /* no tree diffs in patch format */
3083
3084        run_checkdiff(p, o);
3085}
3086
3087int diff_queue_is_empty(void)
3088{
3089        struct diff_queue_struct *q = &diff_queued_diff;
3090        int i;
3091        for (i = 0; i < q->nr; i++)
3092                if (!diff_unmodified_pair(q->queue[i]))
3093                        return 0;
3094        return 1;
3095}
3096
3097#if DIFF_DEBUG
3098void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3099{
3100        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3101                x, one ? one : "",
3102                s->path,
3103                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3104                s->mode,
3105                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3106        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3107                x, one ? one : "",
3108                s->size, s->xfrm_flags);
3109}
3110
3111void diff_debug_filepair(const struct diff_filepair *p, int i)
3112{
3113        diff_debug_filespec(p->one, i, "one");
3114        diff_debug_filespec(p->two, i, "two");
3115        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3116                p->score, p->status ? p->status : '?',
3117                p->one->rename_used, p->broken_pair);
3118}
3119
3120void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3121{
3122        int i;
3123        if (msg)
3124                fprintf(stderr, "%s\n", msg);
3125        fprintf(stderr, "q->nr = %d\n", q->nr);
3126        for (i = 0; i < q->nr; i++) {
3127                struct diff_filepair *p = q->queue[i];
3128                diff_debug_filepair(p, i);
3129        }
3130}
3131#endif
3132
3133static void diff_resolve_rename_copy(void)
3134{
3135        int i;
3136        struct diff_filepair *p;
3137        struct diff_queue_struct *q = &diff_queued_diff;
3138
3139        diff_debug_queue("resolve-rename-copy", q);
3140
3141        for (i = 0; i < q->nr; i++) {
3142                p = q->queue[i];
3143                p->status = 0; /* undecided */
3144                if (DIFF_PAIR_UNMERGED(p))
3145                        p->status = DIFF_STATUS_UNMERGED;
3146                else if (!DIFF_FILE_VALID(p->one))
3147                        p->status = DIFF_STATUS_ADDED;
3148                else if (!DIFF_FILE_VALID(p->two))
3149                        p->status = DIFF_STATUS_DELETED;
3150                else if (DIFF_PAIR_TYPE_CHANGED(p))
3151                        p->status = DIFF_STATUS_TYPE_CHANGED;
3152
3153                /* from this point on, we are dealing with a pair
3154                 * whose both sides are valid and of the same type, i.e.
3155                 * either in-place edit or rename/copy edit.
3156                 */
3157                else if (DIFF_PAIR_RENAME(p)) {
3158                        /*
3159                         * A rename might have re-connected a broken
3160                         * pair up, causing the pathnames to be the
3161                         * same again. If so, that's not a rename at
3162                         * all, just a modification..
3163                         *
3164                         * Otherwise, see if this source was used for
3165                         * multiple renames, in which case we decrement
3166                         * the count, and call it a copy.
3167                         */
3168                        if (!strcmp(p->one->path, p->two->path))
3169                                p->status = DIFF_STATUS_MODIFIED;
3170                        else if (--p->one->rename_used > 0)
3171                                p->status = DIFF_STATUS_COPIED;
3172                        else
3173                                p->status = DIFF_STATUS_RENAMED;
3174                }
3175                else if (hashcmp(p->one->sha1, p->two->sha1) ||
3176                         p->one->mode != p->two->mode ||
3177                         is_null_sha1(p->one->sha1))
3178                        p->status = DIFF_STATUS_MODIFIED;
3179                else {
3180                        /* This is a "no-change" entry and should not
3181                         * happen anymore, but prepare for broken callers.
3182                         */
3183                        error("feeding unmodified %s to diffcore",
3184                              p->one->path);
3185                        p->status = DIFF_STATUS_UNKNOWN;
3186                }
3187        }
3188        diff_debug_queue("resolve-rename-copy done", q);
3189}
3190
3191static int check_pair_status(struct diff_filepair *p)
3192{
3193        switch (p->status) {
3194        case DIFF_STATUS_UNKNOWN:
3195                return 0;
3196        case 0:
3197                die("internal error in diff-resolve-rename-copy");
3198        default:
3199                return 1;
3200        }
3201}
3202
3203static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3204{
3205        int fmt = opt->output_format;
3206
3207        if (fmt & DIFF_FORMAT_CHECKDIFF)
3208                diff_flush_checkdiff(p, opt);
3209        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3210                diff_flush_raw(p, opt);
3211        else if (fmt & DIFF_FORMAT_NAME) {
3212                const char *name_a, *name_b;
3213                name_a = p->two->path;
3214                name_b = NULL;
3215                strip_prefix(opt->prefix_length, &name_a, &name_b);
3216                write_name_quoted(name_a, opt->file, opt->line_termination);
3217        }
3218}
3219
3220static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
3221{
3222        if (fs->mode)
3223                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
3224        else
3225                fprintf(file, " %s ", newdelete);
3226        write_name_quoted(fs->path, file, '\n');
3227}
3228
3229
3230static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name)
3231{
3232        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
3233                fprintf(file, " mode change %06o => %06o%c", p->one->mode, p->two->mode,
3234                        show_name ? ' ' : '\n');
3235                if (show_name) {
3236                        write_name_quoted(p->two->path, file, '\n');
3237                }
3238        }
3239}
3240
3241static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p)
3242{
3243        char *names = pprint_rename(p->one->path, p->two->path);
3244
3245        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
3246        free(names);
3247        show_mode_change(file, p, 0);
3248}
3249
3250static void diff_summary(FILE *file, struct diff_filepair *p)
3251{
3252        switch(p->status) {
3253        case DIFF_STATUS_DELETED:
3254                show_file_mode_name(file, "delete", p->one);
3255                break;
3256        case DIFF_STATUS_ADDED:
3257                show_file_mode_name(file, "create", p->two);
3258                break;
3259        case DIFF_STATUS_COPIED:
3260                show_rename_copy(file, "copy", p);
3261                break;
3262        case DIFF_STATUS_RENAMED:
3263                show_rename_copy(file, "rename", p);
3264                break;
3265        default:
3266                if (p->score) {
3267                        fputs(" rewrite ", file);
3268                        write_name_quoted(p->two->path, file, ' ');
3269                        fprintf(file, "(%d%%)\n", similarity_index(p));
3270                }
3271                show_mode_change(file, p, !p->score);
3272                break;
3273        }
3274}
3275
3276struct patch_id_t {
3277        git_SHA_CTX *ctx;
3278        int patchlen;
3279};
3280
3281static int remove_space(char *line, int len)
3282{
3283        int i;
3284        char *dst = line;
3285        unsigned char c;
3286
3287        for (i = 0; i < len; i++)
3288                if (!isspace((c = line[i])))
3289                        *dst++ = c;
3290
3291        return dst - line;
3292}
3293
3294static void patch_id_consume(void *priv, char *line, unsigned long len)
3295{
3296        struct patch_id_t *data = priv;
3297        int new_len;
3298
3299        /* Ignore line numbers when computing the SHA1 of the patch */
3300        if (!prefixcmp(line, "@@ -"))
3301                return;
3302
3303        new_len = remove_space(line, len);
3304
3305        git_SHA1_Update(data->ctx, line, new_len);
3306        data->patchlen += new_len;
3307}
3308
3309/* returns 0 upon success, and writes result into sha1 */
3310static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
3311{
3312        struct diff_queue_struct *q = &diff_queued_diff;
3313        int i;
3314        git_SHA_CTX ctx;
3315        struct patch_id_t data;
3316        char buffer[PATH_MAX * 4 + 20];
3317
3318        git_SHA1_Init(&ctx);
3319        memset(&data, 0, sizeof(struct patch_id_t));
3320        data.ctx = &ctx;
3321
3322        for (i = 0; i < q->nr; i++) {
3323                xpparam_t xpp;
3324                xdemitconf_t xecfg;
3325                xdemitcb_t ecb;
3326                mmfile_t mf1, mf2;
3327                struct diff_filepair *p = q->queue[i];
3328                int len1, len2;
3329
3330                memset(&xpp, 0, sizeof(xpp));
3331                memset(&xecfg, 0, sizeof(xecfg));
3332                if (p->status == 0)
3333                        return error("internal diff status error");
3334                if (p->status == DIFF_STATUS_UNKNOWN)
3335                        continue;
3336                if (diff_unmodified_pair(p))
3337                        continue;
3338                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3339                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3340                        continue;
3341                if (DIFF_PAIR_UNMERGED(p))
3342                        continue;
3343
3344                diff_fill_sha1_info(p->one);
3345                diff_fill_sha1_info(p->two);
3346                if (fill_mmfile(&mf1, p->one) < 0 ||
3347                                fill_mmfile(&mf2, p->two) < 0)
3348                        return error("unable to read files to diff");
3349
3350                len1 = remove_space(p->one->path, strlen(p->one->path));
3351                len2 = remove_space(p->two->path, strlen(p->two->path));
3352                if (p->one->mode == 0)
3353                        len1 = snprintf(buffer, sizeof(buffer),
3354                                        "diff--gita/%.*sb/%.*s"
3355                                        "newfilemode%06o"
3356                                        "---/dev/null"
3357                                        "+++b/%.*s",
3358                                        len1, p->one->path,
3359                                        len2, p->two->path,
3360                                        p->two->mode,
3361                                        len2, p->two->path);
3362                else if (p->two->mode == 0)
3363                        len1 = snprintf(buffer, sizeof(buffer),
3364                                        "diff--gita/%.*sb/%.*s"
3365                                        "deletedfilemode%06o"
3366                                        "---a/%.*s"
3367                                        "+++/dev/null",
3368                                        len1, p->one->path,
3369                                        len2, p->two->path,
3370                                        p->one->mode,
3371                                        len1, p->one->path);
3372                else
3373                        len1 = snprintf(buffer, sizeof(buffer),
3374                                        "diff--gita/%.*sb/%.*s"
3375                                        "---a/%.*s"
3376                                        "+++b/%.*s",
3377                                        len1, p->one->path,
3378                                        len2, p->two->path,
3379                                        len1, p->one->path,
3380                                        len2, p->two->path);
3381                git_SHA1_Update(&ctx, buffer, len1);
3382
3383                xpp.flags = XDF_NEED_MINIMAL;
3384                xecfg.ctxlen = 3;
3385                xecfg.flags = XDL_EMIT_FUNCNAMES;
3386                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
3387                              &xpp, &xecfg, &ecb);
3388        }
3389
3390        git_SHA1_Final(sha1, &ctx);
3391        return 0;
3392}
3393
3394int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
3395{
3396        struct diff_queue_struct *q = &diff_queued_diff;
3397        int i;
3398        int result = diff_get_patch_id(options, sha1);
3399
3400        for (i = 0; i < q->nr; i++)
3401                diff_free_filepair(q->queue[i]);
3402
3403        free(q->queue);
3404        q->queue = NULL;
3405        q->nr = q->alloc = 0;
3406
3407        return result;
3408}
3409
3410static int is_summary_empty(const struct diff_queue_struct *q)
3411{
3412        int i;
3413
3414        for (i = 0; i < q->nr; i++) {
3415                const struct diff_filepair *p = q->queue[i];
3416
3417                switch (p->status) {
3418                case DIFF_STATUS_DELETED:
3419                case DIFF_STATUS_ADDED:
3420                case DIFF_STATUS_COPIED:
3421                case DIFF_STATUS_RENAMED:
3422                        return 0;
3423                default:
3424                        if (p->score)
3425                                return 0;
3426                        if (p->one->mode && p->two->mode &&
3427                            p->one->mode != p->two->mode)
3428                                return 0;
3429                        break;
3430                }
3431        }
3432        return 1;
3433}
3434
3435void diff_flush(struct diff_options *options)
3436{
3437        struct diff_queue_struct *q = &diff_queued_diff;
3438        int i, output_format = options->output_format;
3439        int separator = 0;
3440
3441        /*
3442         * Order: raw, stat, summary, patch
3443         * or:    name/name-status/checkdiff (other bits clear)
3444         */
3445        if (!q->nr)
3446                goto free_queue;
3447
3448        if (output_format & (DIFF_FORMAT_RAW |
3449                             DIFF_FORMAT_NAME |
3450                             DIFF_FORMAT_NAME_STATUS |
3451                             DIFF_FORMAT_CHECKDIFF)) {
3452                for (i = 0; i < q->nr; i++) {
3453                        struct diff_filepair *p = q->queue[i];
3454                        if (check_pair_status(p))
3455                                flush_one_pair(p, options);
3456                }
3457                separator++;
3458        }
3459
3460        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
3461                struct diffstat_t diffstat;
3462
3463                memset(&diffstat, 0, sizeof(struct diffstat_t));
3464                for (i = 0; i < q->nr; i++) {
3465                        struct diff_filepair *p = q->queue[i];
3466                        if (check_pair_status(p))
3467                                diff_flush_stat(p, options, &diffstat);
3468                }
3469                if (output_format & DIFF_FORMAT_NUMSTAT)
3470                        show_numstat(&diffstat, options);
3471                if (output_format & DIFF_FORMAT_DIFFSTAT)
3472                        show_stats(&diffstat, options);
3473                if (output_format & DIFF_FORMAT_SHORTSTAT)
3474                        show_shortstats(&diffstat, options);
3475                free_diffstat_info(&diffstat);
3476                separator++;
3477        }
3478        if (output_format & DIFF_FORMAT_DIRSTAT)
3479                show_dirstat(options);
3480
3481        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
3482                for (i = 0; i < q->nr; i++)
3483                        diff_summary(options->file, q->queue[i]);
3484                separator++;
3485        }
3486
3487        if (output_format & DIFF_FORMAT_PATCH) {
3488                if (separator) {
3489                        putc(options->line_termination, options->file);
3490                        if (options->stat_sep) {
3491                                /* attach patch instead of inline */
3492                                fputs(options->stat_sep, options->file);
3493                        }
3494                }
3495
3496                for (i = 0; i < q->nr; i++) {
3497                        struct diff_filepair *p = q->queue[i];
3498                        if (check_pair_status(p))
3499                                diff_flush_patch(p, options);
3500                }
3501        }
3502
3503        if (output_format & DIFF_FORMAT_CALLBACK)
3504                options->format_callback(q, options, options->format_callback_data);
3505
3506        for (i = 0; i < q->nr; i++)
3507                diff_free_filepair(q->queue[i]);
3508free_queue:
3509        free(q->queue);
3510        q->queue = NULL;
3511        q->nr = q->alloc = 0;
3512        if (options->close_file)
3513                fclose(options->file);
3514}
3515
3516static void diffcore_apply_filter(const char *filter)
3517{
3518        int i;
3519        struct diff_queue_struct *q = &diff_queued_diff;
3520        struct diff_queue_struct outq;
3521        outq.queue = NULL;
3522        outq.nr = outq.alloc = 0;
3523
3524        if (!filter)
3525                return;
3526
3527        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
3528                int found;
3529                for (i = found = 0; !found && i < q->nr; i++) {
3530                        struct diff_filepair *p = q->queue[i];
3531                        if (((p->status == DIFF_STATUS_MODIFIED) &&
3532                             ((p->score &&
3533                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3534                              (!p->score &&
3535                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3536                            ((p->status != DIFF_STATUS_MODIFIED) &&
3537                             strchr(filter, p->status)))
3538                                found++;
3539                }
3540                if (found)
3541                        return;
3542
3543                /* otherwise we will clear the whole queue
3544                 * by copying the empty outq at the end of this
3545                 * function, but first clear the current entries
3546                 * in the queue.
3547                 */
3548                for (i = 0; i < q->nr; i++)
3549                        diff_free_filepair(q->queue[i]);
3550        }
3551        else {
3552                /* Only the matching ones */
3553                for (i = 0; i < q->nr; i++) {
3554                        struct diff_filepair *p = q->queue[i];
3555
3556                        if (((p->status == DIFF_STATUS_MODIFIED) &&
3557                             ((p->score &&
3558                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3559                              (!p->score &&
3560                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3561                            ((p->status != DIFF_STATUS_MODIFIED) &&
3562                             strchr(filter, p->status)))
3563                                diff_q(&outq, p);
3564                        else
3565                                diff_free_filepair(p);
3566                }
3567        }
3568        free(q->queue);
3569        *q = outq;
3570}
3571
3572/* Check whether two filespecs with the same mode and size are identical */
3573static int diff_filespec_is_identical(struct diff_filespec *one,
3574                                      struct diff_filespec *two)
3575{
3576        if (S_ISGITLINK(one->mode))
3577                return 0;
3578        if (diff_populate_filespec(one, 0))
3579                return 0;
3580        if (diff_populate_filespec(two, 0))
3581                return 0;
3582        return !memcmp(one->data, two->data, one->size);
3583}
3584
3585static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
3586{
3587        int i;
3588        struct diff_queue_struct *q = &diff_queued_diff;
3589        struct diff_queue_struct outq;
3590        outq.queue = NULL;
3591        outq.nr = outq.alloc = 0;
3592
3593        for (i = 0; i < q->nr; i++) {
3594                struct diff_filepair *p = q->queue[i];
3595
3596                /*
3597                 * 1. Entries that come from stat info dirtyness
3598                 *    always have both sides (iow, not create/delete),
3599                 *    one side of the object name is unknown, with
3600                 *    the same mode and size.  Keep the ones that
3601                 *    do not match these criteria.  They have real
3602                 *    differences.
3603                 *
3604                 * 2. At this point, the file is known to be modified,
3605                 *    with the same mode and size, and the object
3606                 *    name of one side is unknown.  Need to inspect
3607                 *    the identical contents.
3608                 */
3609                if (!DIFF_FILE_VALID(p->one) || /* (1) */
3610                    !DIFF_FILE_VALID(p->two) ||
3611                    (p->one->sha1_valid && p->two->sha1_valid) ||
3612                    (p->one->mode != p->two->mode) ||
3613                    diff_populate_filespec(p->one, 1) ||
3614                    diff_populate_filespec(p->two, 1) ||
3615                    (p->one->size != p->two->size) ||
3616                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
3617                        diff_q(&outq, p);
3618                else {
3619                        /*
3620                         * The caller can subtract 1 from skip_stat_unmatch
3621                         * to determine how many paths were dirty only
3622                         * due to stat info mismatch.
3623                         */
3624                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
3625                                diffopt->skip_stat_unmatch++;
3626                        diff_free_filepair(p);
3627                }
3628        }
3629        free(q->queue);
3630        *q = outq;
3631}
3632
3633void diffcore_std(struct diff_options *options)
3634{
3635        if (options->skip_stat_unmatch)
3636                diffcore_skip_stat_unmatch(options);
3637        if (options->break_opt != -1)
3638                diffcore_break(options->break_opt);
3639        if (options->detect_rename)
3640                diffcore_rename(options);
3641        if (options->break_opt != -1)
3642                diffcore_merge_broken();
3643        if (options->pickaxe)
3644                diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
3645        if (options->orderfile)
3646                diffcore_order(options->orderfile);
3647        diff_resolve_rename_copy();
3648        diffcore_apply_filter(options->filter);
3649
3650        if (diff_queued_diff.nr)
3651                DIFF_OPT_SET(options, HAS_CHANGES);
3652        else
3653                DIFF_OPT_CLR(options, HAS_CHANGES);
3654}
3655
3656int diff_result_code(struct diff_options *opt, int status)
3657{
3658        int result = 0;
3659        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
3660            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
3661                return status;
3662        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
3663            DIFF_OPT_TST(opt, HAS_CHANGES))
3664                result |= 01;
3665        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
3666            DIFF_OPT_TST(opt, CHECK_FAILED))
3667                result |= 02;
3668        return result;
3669}
3670
3671void diff_addremove(struct diff_options *options,
3672                    int addremove, unsigned mode,
3673                    const unsigned char *sha1,
3674                    const char *concatpath)
3675{
3676        struct diff_filespec *one, *two;
3677
3678        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES) && S_ISGITLINK(mode))
3679                return;
3680
3681        /* This may look odd, but it is a preparation for
3682         * feeding "there are unchanged files which should
3683         * not produce diffs, but when you are doing copy
3684         * detection you would need them, so here they are"
3685         * entries to the diff-core.  They will be prefixed
3686         * with something like '=' or '*' (I haven't decided
3687         * which but should not make any difference).
3688         * Feeding the same new and old to diff_change()
3689         * also has the same effect.
3690         * Before the final output happens, they are pruned after
3691         * merged into rename/copy pairs as appropriate.
3692         */
3693        if (DIFF_OPT_TST(options, REVERSE_DIFF))
3694                addremove = (addremove == '+' ? '-' :
3695                             addremove == '-' ? '+' : addremove);
3696
3697        if (options->prefix &&
3698            strncmp(concatpath, options->prefix, options->prefix_length))
3699                return;
3700
3701        one = alloc_filespec(concatpath);
3702        two = alloc_filespec(concatpath);
3703
3704        if (addremove != '+')
3705                fill_filespec(one, sha1, mode);
3706        if (addremove != '-')
3707                fill_filespec(two, sha1, mode);
3708
3709        diff_queue(&diff_queued_diff, one, two);
3710        DIFF_OPT_SET(options, HAS_CHANGES);
3711}
3712
3713void diff_change(struct diff_options *options,
3714                 unsigned old_mode, unsigned new_mode,
3715                 const unsigned char *old_sha1,
3716                 const unsigned char *new_sha1,
3717                 const char *concatpath)
3718{
3719        struct diff_filespec *one, *two;
3720
3721        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES) && S_ISGITLINK(old_mode)
3722                        && S_ISGITLINK(new_mode))
3723                return;
3724
3725        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
3726                unsigned tmp;
3727                const unsigned char *tmp_c;
3728                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
3729                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
3730        }
3731
3732        if (options->prefix &&
3733            strncmp(concatpath, options->prefix, options->prefix_length))
3734                return;
3735
3736        one = alloc_filespec(concatpath);
3737        two = alloc_filespec(concatpath);
3738        fill_filespec(one, old_sha1, old_mode);
3739        fill_filespec(two, new_sha1, new_mode);
3740
3741        diff_queue(&diff_queued_diff, one, two);
3742        DIFF_OPT_SET(options, HAS_CHANGES);
3743}
3744
3745void diff_unmerge(struct diff_options *options,
3746                  const char *path,
3747                  unsigned mode, const unsigned char *sha1)
3748{
3749        struct diff_filespec *one, *two;
3750
3751        if (options->prefix &&
3752            strncmp(path, options->prefix, options->prefix_length))
3753                return;
3754
3755        one = alloc_filespec(path);
3756        two = alloc_filespec(path);
3757        fill_filespec(one, sha1, mode);
3758        diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;
3759}
3760
3761static char *run_textconv(const char *pgm, struct diff_filespec *spec,
3762                size_t *outsize)
3763{
3764        struct diff_tempfile *temp;
3765        const char *argv[3];
3766        const char **arg = argv;
3767        struct child_process child;
3768        struct strbuf buf = STRBUF_INIT;
3769
3770        temp = prepare_temp_file(spec->path, spec);
3771        *arg++ = pgm;
3772        *arg++ = temp->name;
3773        *arg = NULL;
3774
3775        memset(&child, 0, sizeof(child));
3776        child.argv = argv;
3777        child.out = -1;
3778        if (start_command(&child) != 0 ||
3779            strbuf_read(&buf, child.out, 0) < 0 ||
3780            finish_command(&child) != 0) {
3781                close(child.out);
3782                strbuf_release(&buf);
3783                remove_tempfile();
3784                error("error running textconv command '%s'", pgm);
3785                return NULL;
3786        }
3787        close(child.out);
3788        remove_tempfile();
3789
3790        return strbuf_detach(&buf, outsize);
3791}