diff.con commit Merge branch 'jn/rebase-cmdline-fix' (0f0169d)
   1/*
   2 * Copyright (C) 2005 Junio C Hamano
   3 */
   4#include "cache.h"
   5#include "quote.h"
   6#include "diff.h"
   7#include "diffcore.h"
   8#include "delta.h"
   9#include "xdiff-interface.h"
  10#include "color.h"
  11#include "attr.h"
  12#include "run-command.h"
  13#include "utf8.h"
  14#include "userdiff.h"
  15#include "sigchain.h"
  16#include "submodule.h"
  17#include "ll-merge.h"
  18
  19#ifdef NO_FAST_WORKING_DIRECTORY
  20#define FAST_WORKING_DIRECTORY 0
  21#else
  22#define FAST_WORKING_DIRECTORY 1
  23#endif
  24
  25static int diff_detect_rename_default;
  26static int diff_rename_limit_default = 200;
  27static int diff_suppress_blank_empty;
  28int diff_use_color_default = -1;
  29static const char *diff_word_regex_cfg;
  30static const char *external_diff_cmd_cfg;
  31int diff_auto_refresh_index = 1;
  32static int diff_mnemonic_prefix;
  33static int diff_no_prefix;
  34
  35static char diff_colors[][COLOR_MAXLEN] = {
  36        GIT_COLOR_RESET,
  37        GIT_COLOR_NORMAL,       /* PLAIN */
  38        GIT_COLOR_BOLD,         /* METAINFO */
  39        GIT_COLOR_CYAN,         /* FRAGINFO */
  40        GIT_COLOR_RED,          /* OLD */
  41        GIT_COLOR_GREEN,        /* NEW */
  42        GIT_COLOR_YELLOW,       /* COMMIT */
  43        GIT_COLOR_BG_RED,       /* WHITESPACE */
  44        GIT_COLOR_NORMAL,       /* FUNCINFO */
  45};
  46
  47static void diff_filespec_load_driver(struct diff_filespec *one);
  48static size_t fill_textconv(struct userdiff_driver *driver,
  49                            struct diff_filespec *df, char **outbuf);
  50
  51static int parse_diff_color_slot(const char *var, int ofs)
  52{
  53        if (!strcasecmp(var+ofs, "plain"))
  54                return DIFF_PLAIN;
  55        if (!strcasecmp(var+ofs, "meta"))
  56                return DIFF_METAINFO;
  57        if (!strcasecmp(var+ofs, "frag"))
  58                return DIFF_FRAGINFO;
  59        if (!strcasecmp(var+ofs, "old"))
  60                return DIFF_FILE_OLD;
  61        if (!strcasecmp(var+ofs, "new"))
  62                return DIFF_FILE_NEW;
  63        if (!strcasecmp(var+ofs, "commit"))
  64                return DIFF_COMMIT;
  65        if (!strcasecmp(var+ofs, "whitespace"))
  66                return DIFF_WHITESPACE;
  67        if (!strcasecmp(var+ofs, "func"))
  68                return DIFF_FUNCINFO;
  69        return -1;
  70}
  71
  72static int git_config_rename(const char *var, const char *value)
  73{
  74        if (!value)
  75                return DIFF_DETECT_RENAME;
  76        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
  77                return  DIFF_DETECT_COPY;
  78        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
  79}
  80
  81/*
  82 * These are to give UI layer defaults.
  83 * The core-level commands such as git-diff-files should
  84 * never be affected by the setting of diff.renames
  85 * the user happens to have in the configuration file.
  86 */
  87int git_diff_ui_config(const char *var, const char *value, void *cb)
  88{
  89        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
  90                diff_use_color_default = git_config_colorbool(var, value, -1);
  91                return 0;
  92        }
  93        if (!strcmp(var, "diff.renames")) {
  94                diff_detect_rename_default = git_config_rename(var, value);
  95                return 0;
  96        }
  97        if (!strcmp(var, "diff.autorefreshindex")) {
  98                diff_auto_refresh_index = git_config_bool(var, value);
  99                return 0;
 100        }
 101        if (!strcmp(var, "diff.mnemonicprefix")) {
 102                diff_mnemonic_prefix = git_config_bool(var, value);
 103                return 0;
 104        }
 105        if (!strcmp(var, "diff.noprefix")) {
 106                diff_no_prefix = git_config_bool(var, value);
 107                return 0;
 108        }
 109        if (!strcmp(var, "diff.external"))
 110                return git_config_string(&external_diff_cmd_cfg, var, value);
 111        if (!strcmp(var, "diff.wordregex"))
 112                return git_config_string(&diff_word_regex_cfg, var, value);
 113
 114        return git_diff_basic_config(var, value, cb);
 115}
 116
 117int git_diff_basic_config(const char *var, const char *value, void *cb)
 118{
 119        if (!strcmp(var, "diff.renamelimit")) {
 120                diff_rename_limit_default = git_config_int(var, value);
 121                return 0;
 122        }
 123
 124        switch (userdiff_config(var, value)) {
 125                case 0: break;
 126                case -1: return -1;
 127                default: return 0;
 128        }
 129
 130        if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
 131                int slot = parse_diff_color_slot(var, 11);
 132                if (slot < 0)
 133                        return 0;
 134                if (!value)
 135                        return config_error_nonbool(var);
 136                color_parse(value, var, diff_colors[slot]);
 137                return 0;
 138        }
 139
 140        /* like GNU diff's --suppress-blank-empty option  */
 141        if (!strcmp(var, "diff.suppressblankempty") ||
 142                        /* for backwards compatibility */
 143                        !strcmp(var, "diff.suppress-blank-empty")) {
 144                diff_suppress_blank_empty = git_config_bool(var, value);
 145                return 0;
 146        }
 147
 148        return git_color_default_config(var, value, cb);
 149}
 150
 151static char *quote_two(const char *one, const char *two)
 152{
 153        int need_one = quote_c_style(one, NULL, NULL, 1);
 154        int need_two = quote_c_style(two, NULL, NULL, 1);
 155        struct strbuf res = STRBUF_INIT;
 156
 157        if (need_one + need_two) {
 158                strbuf_addch(&res, '"');
 159                quote_c_style(one, &res, NULL, 1);
 160                quote_c_style(two, &res, NULL, 1);
 161                strbuf_addch(&res, '"');
 162        } else {
 163                strbuf_addstr(&res, one);
 164                strbuf_addstr(&res, two);
 165        }
 166        return strbuf_detach(&res, NULL);
 167}
 168
 169static const char *external_diff(void)
 170{
 171        static const char *external_diff_cmd = NULL;
 172        static int done_preparing = 0;
 173
 174        if (done_preparing)
 175                return external_diff_cmd;
 176        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 177        if (!external_diff_cmd)
 178                external_diff_cmd = external_diff_cmd_cfg;
 179        done_preparing = 1;
 180        return external_diff_cmd;
 181}
 182
 183static struct diff_tempfile {
 184        const char *name; /* filename external diff should read from */
 185        char hex[41];
 186        char mode[10];
 187        char tmp_path[PATH_MAX];
 188} diff_temp[2];
 189
 190typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 191
 192struct emit_callback {
 193        int color_diff;
 194        unsigned ws_rule;
 195        int blank_at_eof_in_preimage;
 196        int blank_at_eof_in_postimage;
 197        int lno_in_preimage;
 198        int lno_in_postimage;
 199        sane_truncate_fn truncate;
 200        const char **label_path;
 201        struct diff_words_data *diff_words;
 202        int *found_changesp;
 203        FILE *file;
 204        struct strbuf *header;
 205};
 206
 207static int count_lines(const char *data, int size)
 208{
 209        int count, ch, completely_empty = 1, nl_just_seen = 0;
 210        count = 0;
 211        while (0 < size--) {
 212                ch = *data++;
 213                if (ch == '\n') {
 214                        count++;
 215                        nl_just_seen = 1;
 216                        completely_empty = 0;
 217                }
 218                else {
 219                        nl_just_seen = 0;
 220                        completely_empty = 0;
 221                }
 222        }
 223        if (completely_empty)
 224                return 0;
 225        if (!nl_just_seen)
 226                count++; /* no trailing newline */
 227        return count;
 228}
 229
 230static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 231{
 232        if (!DIFF_FILE_VALID(one)) {
 233                mf->ptr = (char *)""; /* does not matter */
 234                mf->size = 0;
 235                return 0;
 236        }
 237        else if (diff_populate_filespec(one, 0))
 238                return -1;
 239
 240        mf->ptr = one->data;
 241        mf->size = one->size;
 242        return 0;
 243}
 244
 245static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 246{
 247        char *ptr = mf->ptr;
 248        long size = mf->size;
 249        int cnt = 0;
 250
 251        if (!size)
 252                return cnt;
 253        ptr += size - 1; /* pointing at the very end */
 254        if (*ptr != '\n')
 255                ; /* incomplete line */
 256        else
 257                ptr--; /* skip the last LF */
 258        while (mf->ptr < ptr) {
 259                char *prev_eol;
 260                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 261                        if (*prev_eol == '\n')
 262                                break;
 263                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 264                        break;
 265                cnt++;
 266                ptr = prev_eol - 1;
 267        }
 268        return cnt;
 269}
 270
 271static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 272                               struct emit_callback *ecbdata)
 273{
 274        int l1, l2, at;
 275        unsigned ws_rule = ecbdata->ws_rule;
 276        l1 = count_trailing_blank(mf1, ws_rule);
 277        l2 = count_trailing_blank(mf2, ws_rule);
 278        if (l2 <= l1) {
 279                ecbdata->blank_at_eof_in_preimage = 0;
 280                ecbdata->blank_at_eof_in_postimage = 0;
 281                return;
 282        }
 283        at = count_lines(mf1->ptr, mf1->size);
 284        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 285
 286        at = count_lines(mf2->ptr, mf2->size);
 287        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 288}
 289
 290static void emit_line_0(FILE *file, const char *set, const char *reset,
 291                        int first, const char *line, int len)
 292{
 293        int has_trailing_newline, has_trailing_carriage_return;
 294        int nofirst;
 295
 296        if (len == 0) {
 297                has_trailing_newline = (first == '\n');
 298                has_trailing_carriage_return = (!has_trailing_newline &&
 299                                                (first == '\r'));
 300                nofirst = has_trailing_newline || has_trailing_carriage_return;
 301        } else {
 302                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 303                if (has_trailing_newline)
 304                        len--;
 305                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 306                if (has_trailing_carriage_return)
 307                        len--;
 308                nofirst = 0;
 309        }
 310
 311        if (len || !nofirst) {
 312                fputs(set, file);
 313                if (!nofirst)
 314                        fputc(first, file);
 315                fwrite(line, len, 1, file);
 316                fputs(reset, file);
 317        }
 318        if (has_trailing_carriage_return)
 319                fputc('\r', file);
 320        if (has_trailing_newline)
 321                fputc('\n', file);
 322}
 323
 324static void emit_line(FILE *file, const char *set, const char *reset,
 325                      const char *line, int len)
 326{
 327        emit_line_0(file, set, reset, line[0], line+1, len-1);
 328}
 329
 330static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 331{
 332        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 333              ecbdata->blank_at_eof_in_preimage &&
 334              ecbdata->blank_at_eof_in_postimage &&
 335              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 336              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 337                return 0;
 338        return ws_blank_line(line, len, ecbdata->ws_rule);
 339}
 340
 341static void emit_add_line(const char *reset,
 342                          struct emit_callback *ecbdata,
 343                          const char *line, int len)
 344{
 345        const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 346        const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 347
 348        if (!*ws)
 349                emit_line_0(ecbdata->file, set, reset, '+', line, len);
 350        else if (new_blank_line_at_eof(ecbdata, line, len))
 351                /* Blank line at EOF - paint '+' as well */
 352                emit_line_0(ecbdata->file, ws, reset, '+', line, len);
 353        else {
 354                /* Emit just the prefix, then the rest. */
 355                emit_line_0(ecbdata->file, set, reset, '+', "", 0);
 356                ws_check_emit(line, len, ecbdata->ws_rule,
 357                              ecbdata->file, set, reset, ws);
 358        }
 359}
 360
 361static void emit_hunk_header(struct emit_callback *ecbdata,
 362                             const char *line, int len)
 363{
 364        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 365        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 366        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 367        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 368        static const char atat[2] = { '@', '@' };
 369        const char *cp, *ep;
 370
 371        /*
 372         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 373         * it always is at least 10 bytes long.
 374         */
 375        if (len < 10 ||
 376            memcmp(line, atat, 2) ||
 377            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 378                emit_line(ecbdata->file, plain, reset, line, len);
 379                return;
 380        }
 381        ep += 2; /* skip over @@ */
 382
 383        /* The hunk header in fraginfo color */
 384        emit_line(ecbdata->file, frag, reset, line, ep - line);
 385
 386        /* blank before the func header */
 387        for (cp = ep; ep - line < len; ep++)
 388                if (*ep != ' ' && *ep != '\t')
 389                        break;
 390        if (ep != cp)
 391                emit_line(ecbdata->file, plain, reset, cp, ep - cp);
 392
 393        if (ep < line + len)
 394                emit_line(ecbdata->file, func, reset, ep, line + len - ep);
 395}
 396
 397static struct diff_tempfile *claim_diff_tempfile(void) {
 398        int i;
 399        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 400                if (!diff_temp[i].name)
 401                        return diff_temp + i;
 402        die("BUG: diff is failing to clean up its tempfiles");
 403}
 404
 405static int remove_tempfile_installed;
 406
 407static void remove_tempfile(void)
 408{
 409        int i;
 410        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 411                if (diff_temp[i].name == diff_temp[i].tmp_path)
 412                        unlink_or_warn(diff_temp[i].name);
 413                diff_temp[i].name = NULL;
 414        }
 415}
 416
 417static void remove_tempfile_on_signal(int signo)
 418{
 419        remove_tempfile();
 420        sigchain_pop(signo);
 421        raise(signo);
 422}
 423
 424static void print_line_count(FILE *file, int count)
 425{
 426        switch (count) {
 427        case 0:
 428                fprintf(file, "0,0");
 429                break;
 430        case 1:
 431                fprintf(file, "1");
 432                break;
 433        default:
 434                fprintf(file, "1,%d", count);
 435                break;
 436        }
 437}
 438
 439static void emit_rewrite_lines(struct emit_callback *ecb,
 440                               int prefix, const char *data, int size)
 441{
 442        const char *endp = NULL;
 443        static const char *nneof = " No newline at end of file\n";
 444        const char *old = diff_get_color(ecb->color_diff, DIFF_FILE_OLD);
 445        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 446
 447        while (0 < size) {
 448                int len;
 449
 450                endp = memchr(data, '\n', size);
 451                len = endp ? (endp - data + 1) : size;
 452                if (prefix != '+') {
 453                        ecb->lno_in_preimage++;
 454                        emit_line_0(ecb->file, old, reset, '-',
 455                                    data, len);
 456                } else {
 457                        ecb->lno_in_postimage++;
 458                        emit_add_line(reset, ecb, data, len);
 459                }
 460                size -= len;
 461                data += len;
 462        }
 463        if (!endp) {
 464                const char *plain = diff_get_color(ecb->color_diff,
 465                                                   DIFF_PLAIN);
 466                emit_line_0(ecb->file, plain, reset, '\\',
 467                            nneof, strlen(nneof));
 468        }
 469}
 470
 471static void emit_rewrite_diff(const char *name_a,
 472                              const char *name_b,
 473                              struct diff_filespec *one,
 474                              struct diff_filespec *two,
 475                              struct userdiff_driver *textconv_one,
 476                              struct userdiff_driver *textconv_two,
 477                              struct diff_options *o)
 478{
 479        int lc_a, lc_b;
 480        int color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
 481        const char *name_a_tab, *name_b_tab;
 482        const char *metainfo = diff_get_color(color_diff, DIFF_METAINFO);
 483        const char *fraginfo = diff_get_color(color_diff, DIFF_FRAGINFO);
 484        const char *reset = diff_get_color(color_diff, DIFF_RESET);
 485        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 486        const char *a_prefix, *b_prefix;
 487        char *data_one, *data_two;
 488        size_t size_one, size_two;
 489        struct emit_callback ecbdata;
 490
 491        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 492                a_prefix = o->b_prefix;
 493                b_prefix = o->a_prefix;
 494        } else {
 495                a_prefix = o->a_prefix;
 496                b_prefix = o->b_prefix;
 497        }
 498
 499        name_a += (*name_a == '/');
 500        name_b += (*name_b == '/');
 501        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 502        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 503
 504        strbuf_reset(&a_name);
 505        strbuf_reset(&b_name);
 506        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 507        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 508
 509        size_one = fill_textconv(textconv_one, one, &data_one);
 510        size_two = fill_textconv(textconv_two, two, &data_two);
 511
 512        memset(&ecbdata, 0, sizeof(ecbdata));
 513        ecbdata.color_diff = color_diff;
 514        ecbdata.found_changesp = &o->found_changes;
 515        ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
 516        ecbdata.file = o->file;
 517        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 518                mmfile_t mf1, mf2;
 519                mf1.ptr = (char *)data_one;
 520                mf2.ptr = (char *)data_two;
 521                mf1.size = size_one;
 522                mf2.size = size_two;
 523                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 524        }
 525        ecbdata.lno_in_preimage = 1;
 526        ecbdata.lno_in_postimage = 1;
 527
 528        lc_a = count_lines(data_one, size_one);
 529        lc_b = count_lines(data_two, size_two);
 530        fprintf(o->file,
 531                "%s--- %s%s%s\n%s+++ %s%s%s\n%s@@ -",
 532                metainfo, a_name.buf, name_a_tab, reset,
 533                metainfo, b_name.buf, name_b_tab, reset, fraginfo);
 534        print_line_count(o->file, lc_a);
 535        fprintf(o->file, " +");
 536        print_line_count(o->file, lc_b);
 537        fprintf(o->file, " @@%s\n", reset);
 538        if (lc_a)
 539                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 540        if (lc_b)
 541                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 542        if (textconv_one)
 543                free((char *)data_one);
 544        if (textconv_two)
 545                free((char *)data_two);
 546}
 547
 548struct diff_words_buffer {
 549        mmfile_t text;
 550        long alloc;
 551        struct diff_words_orig {
 552                const char *begin, *end;
 553        } *orig;
 554        int orig_nr, orig_alloc;
 555};
 556
 557static void diff_words_append(char *line, unsigned long len,
 558                struct diff_words_buffer *buffer)
 559{
 560        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 561        line++;
 562        len--;
 563        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 564        buffer->text.size += len;
 565        buffer->text.ptr[buffer->text.size] = '\0';
 566}
 567
 568struct diff_words_style_elem
 569{
 570        const char *prefix;
 571        const char *suffix;
 572        const char *color; /* NULL; filled in by the setup code if
 573                            * color is enabled */
 574};
 575
 576struct diff_words_style
 577{
 578        enum diff_words_type type;
 579        struct diff_words_style_elem new, old, ctx;
 580        const char *newline;
 581};
 582
 583struct diff_words_style diff_words_styles[] = {
 584        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 585        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 586        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 587};
 588
 589struct diff_words_data {
 590        struct diff_words_buffer minus, plus;
 591        const char *current_plus;
 592        FILE *file;
 593        regex_t *word_regex;
 594        enum diff_words_type type;
 595        struct diff_words_style *style;
 596};
 597
 598static int fn_out_diff_words_write_helper(FILE *fp,
 599                                          struct diff_words_style_elem *st_el,
 600                                          const char *newline,
 601                                          size_t count, const char *buf)
 602{
 603        while (count) {
 604                char *p = memchr(buf, '\n', count);
 605                if (p != buf) {
 606                        if (st_el->color && fputs(st_el->color, fp) < 0)
 607                                return -1;
 608                        if (fputs(st_el->prefix, fp) < 0 ||
 609                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 610                            fputs(st_el->suffix, fp) < 0)
 611                                return -1;
 612                        if (st_el->color && *st_el->color
 613                            && fputs(GIT_COLOR_RESET, fp) < 0)
 614                                return -1;
 615                }
 616                if (!p)
 617                        return 0;
 618                if (fputs(newline, fp) < 0)
 619                        return -1;
 620                count -= p + 1 - buf;
 621                buf = p + 1;
 622        }
 623        return 0;
 624}
 625
 626static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 627{
 628        struct diff_words_data *diff_words = priv;
 629        struct diff_words_style *style = diff_words->style;
 630        int minus_first, minus_len, plus_first, plus_len;
 631        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 632
 633        if (line[0] != '@' || parse_hunk_header(line, len,
 634                        &minus_first, &minus_len, &plus_first, &plus_len))
 635                return;
 636
 637        /* POSIX requires that first be decremented by one if len == 0... */
 638        if (minus_len) {
 639                minus_begin = diff_words->minus.orig[minus_first].begin;
 640                minus_end =
 641                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 642        } else
 643                minus_begin = minus_end =
 644                        diff_words->minus.orig[minus_first].end;
 645
 646        if (plus_len) {
 647                plus_begin = diff_words->plus.orig[plus_first].begin;
 648                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 649        } else
 650                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 651
 652        if (diff_words->current_plus != plus_begin)
 653                fn_out_diff_words_write_helper(diff_words->file,
 654                                &style->ctx, style->newline,
 655                                plus_begin - diff_words->current_plus,
 656                                diff_words->current_plus);
 657        if (minus_begin != minus_end)
 658                fn_out_diff_words_write_helper(diff_words->file,
 659                                &style->old, style->newline,
 660                                minus_end - minus_begin, minus_begin);
 661        if (plus_begin != plus_end)
 662                fn_out_diff_words_write_helper(diff_words->file,
 663                                &style->new, style->newline,
 664                                plus_end - plus_begin, plus_begin);
 665
 666        diff_words->current_plus = plus_end;
 667}
 668
 669/* This function starts looking at *begin, and returns 0 iff a word was found. */
 670static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 671                int *begin, int *end)
 672{
 673        if (word_regex && *begin < buffer->size) {
 674                regmatch_t match[1];
 675                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 676                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 677                                        '\n', match[0].rm_eo - match[0].rm_so);
 678                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 679                        *begin += match[0].rm_so;
 680                        return *begin >= *end;
 681                }
 682                return -1;
 683        }
 684
 685        /* find the next word */
 686        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 687                (*begin)++;
 688        if (*begin >= buffer->size)
 689                return -1;
 690
 691        /* find the end of the word */
 692        *end = *begin + 1;
 693        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 694                (*end)++;
 695
 696        return 0;
 697}
 698
 699/*
 700 * This function splits the words in buffer->text, stores the list with
 701 * newline separator into out, and saves the offsets of the original words
 702 * in buffer->orig.
 703 */
 704static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 705                regex_t *word_regex)
 706{
 707        int i, j;
 708        long alloc = 0;
 709
 710        out->size = 0;
 711        out->ptr = NULL;
 712
 713        /* fake an empty "0th" word */
 714        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 715        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 716        buffer->orig_nr = 1;
 717
 718        for (i = 0; i < buffer->text.size; i++) {
 719                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 720                        return;
 721
 722                /* store original boundaries */
 723                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 724                                buffer->orig_alloc);
 725                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 726                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 727                buffer->orig_nr++;
 728
 729                /* store one word */
 730                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 731                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 732                out->ptr[out->size + j - i] = '\n';
 733                out->size += j - i + 1;
 734
 735                i = j - 1;
 736        }
 737}
 738
 739/* this executes the word diff on the accumulated buffers */
 740static void diff_words_show(struct diff_words_data *diff_words)
 741{
 742        xpparam_t xpp;
 743        xdemitconf_t xecfg;
 744        mmfile_t minus, plus;
 745        struct diff_words_style *style = diff_words->style;
 746
 747        /* special case: only removal */
 748        if (!diff_words->plus.text.size) {
 749                fn_out_diff_words_write_helper(diff_words->file,
 750                        &style->old, style->newline,
 751                        diff_words->minus.text.size, diff_words->minus.text.ptr);
 752                diff_words->minus.text.size = 0;
 753                return;
 754        }
 755
 756        diff_words->current_plus = diff_words->plus.text.ptr;
 757
 758        memset(&xpp, 0, sizeof(xpp));
 759        memset(&xecfg, 0, sizeof(xecfg));
 760        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
 761        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
 762        xpp.flags = 0;
 763        /* as only the hunk header will be parsed, we need a 0-context */
 764        xecfg.ctxlen = 0;
 765        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 766                      &xpp, &xecfg);
 767        free(minus.ptr);
 768        free(plus.ptr);
 769        if (diff_words->current_plus != diff_words->plus.text.ptr +
 770                        diff_words->plus.text.size)
 771                fn_out_diff_words_write_helper(diff_words->file,
 772                        &style->ctx, style->newline,
 773                        diff_words->plus.text.ptr + diff_words->plus.text.size
 774                        - diff_words->current_plus, diff_words->current_plus);
 775        diff_words->minus.text.size = diff_words->plus.text.size = 0;
 776}
 777
 778/* In "color-words" mode, show word-diff of words accumulated in the buffer */
 779static void diff_words_flush(struct emit_callback *ecbdata)
 780{
 781        if (ecbdata->diff_words->minus.text.size ||
 782            ecbdata->diff_words->plus.text.size)
 783                diff_words_show(ecbdata->diff_words);
 784}
 785
 786static void free_diff_words_data(struct emit_callback *ecbdata)
 787{
 788        if (ecbdata->diff_words) {
 789                diff_words_flush(ecbdata);
 790                free (ecbdata->diff_words->minus.text.ptr);
 791                free (ecbdata->diff_words->minus.orig);
 792                free (ecbdata->diff_words->plus.text.ptr);
 793                free (ecbdata->diff_words->plus.orig);
 794                free(ecbdata->diff_words->word_regex);
 795                free(ecbdata->diff_words);
 796                ecbdata->diff_words = NULL;
 797        }
 798}
 799
 800const char *diff_get_color(int diff_use_color, enum color_diff ix)
 801{
 802        if (diff_use_color)
 803                return diff_colors[ix];
 804        return "";
 805}
 806
 807static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
 808{
 809        const char *cp;
 810        unsigned long allot;
 811        size_t l = len;
 812
 813        if (ecb->truncate)
 814                return ecb->truncate(line, len);
 815        cp = line;
 816        allot = l;
 817        while (0 < l) {
 818                (void) utf8_width(&cp, &l);
 819                if (!cp)
 820                        break; /* truncated in the middle? */
 821        }
 822        return allot - l;
 823}
 824
 825static void find_lno(const char *line, struct emit_callback *ecbdata)
 826{
 827        const char *p;
 828        ecbdata->lno_in_preimage = 0;
 829        ecbdata->lno_in_postimage = 0;
 830        p = strchr(line, '-');
 831        if (!p)
 832                return; /* cannot happen */
 833        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
 834        p = strchr(p, '+');
 835        if (!p)
 836                return; /* cannot happen */
 837        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
 838}
 839
 840static void fn_out_consume(void *priv, char *line, unsigned long len)
 841{
 842        struct emit_callback *ecbdata = priv;
 843        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
 844        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 845        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 846
 847        if (ecbdata->header) {
 848                fprintf(ecbdata->file, "%s", ecbdata->header->buf);
 849                strbuf_reset(ecbdata->header);
 850                ecbdata->header = NULL;
 851        }
 852        *(ecbdata->found_changesp) = 1;
 853
 854        if (ecbdata->label_path[0]) {
 855                const char *name_a_tab, *name_b_tab;
 856
 857                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
 858                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
 859
 860                fprintf(ecbdata->file, "%s--- %s%s%s\n",
 861                        meta, ecbdata->label_path[0], reset, name_a_tab);
 862                fprintf(ecbdata->file, "%s+++ %s%s%s\n",
 863                        meta, ecbdata->label_path[1], reset, name_b_tab);
 864                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
 865        }
 866
 867        if (diff_suppress_blank_empty
 868            && len == 2 && line[0] == ' ' && line[1] == '\n') {
 869                line[0] = '\n';
 870                len = 1;
 871        }
 872
 873        if (line[0] == '@') {
 874                if (ecbdata->diff_words)
 875                        diff_words_flush(ecbdata);
 876                len = sane_truncate_line(ecbdata, line, len);
 877                find_lno(line, ecbdata);
 878                emit_hunk_header(ecbdata, line, len);
 879                if (line[len-1] != '\n')
 880                        putc('\n', ecbdata->file);
 881                return;
 882        }
 883
 884        if (len < 1) {
 885                emit_line(ecbdata->file, reset, reset, line, len);
 886                if (ecbdata->diff_words
 887                    && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
 888                        fputs("~\n", ecbdata->file);
 889                return;
 890        }
 891
 892        if (ecbdata->diff_words) {
 893                if (line[0] == '-') {
 894                        diff_words_append(line, len,
 895                                          &ecbdata->diff_words->minus);
 896                        return;
 897                } else if (line[0] == '+') {
 898                        diff_words_append(line, len,
 899                                          &ecbdata->diff_words->plus);
 900                        return;
 901                }
 902                diff_words_flush(ecbdata);
 903                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
 904                        emit_line(ecbdata->file, plain, reset, line, len);
 905                        fputs("~\n", ecbdata->file);
 906                } else {
 907                        /* don't print the prefix character */
 908                        emit_line(ecbdata->file, plain, reset, line+1, len-1);
 909                }
 910                return;
 911        }
 912
 913        if (line[0] != '+') {
 914                const char *color =
 915                        diff_get_color(ecbdata->color_diff,
 916                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
 917                ecbdata->lno_in_preimage++;
 918                if (line[0] == ' ')
 919                        ecbdata->lno_in_postimage++;
 920                emit_line(ecbdata->file, color, reset, line, len);
 921        } else {
 922                ecbdata->lno_in_postimage++;
 923                emit_add_line(reset, ecbdata, line + 1, len - 1);
 924        }
 925}
 926
 927static char *pprint_rename(const char *a, const char *b)
 928{
 929        const char *old = a;
 930        const char *new = b;
 931        struct strbuf name = STRBUF_INIT;
 932        int pfx_length, sfx_length;
 933        int len_a = strlen(a);
 934        int len_b = strlen(b);
 935        int a_midlen, b_midlen;
 936        int qlen_a = quote_c_style(a, NULL, NULL, 0);
 937        int qlen_b = quote_c_style(b, NULL, NULL, 0);
 938
 939        if (qlen_a || qlen_b) {
 940                quote_c_style(a, &name, NULL, 0);
 941                strbuf_addstr(&name, " => ");
 942                quote_c_style(b, &name, NULL, 0);
 943                return strbuf_detach(&name, NULL);
 944        }
 945
 946        /* Find common prefix */
 947        pfx_length = 0;
 948        while (*old && *new && *old == *new) {
 949                if (*old == '/')
 950                        pfx_length = old - a + 1;
 951                old++;
 952                new++;
 953        }
 954
 955        /* Find common suffix */
 956        old = a + len_a;
 957        new = b + len_b;
 958        sfx_length = 0;
 959        while (a <= old && b <= new && *old == *new) {
 960                if (*old == '/')
 961                        sfx_length = len_a - (old - a);
 962                old--;
 963                new--;
 964        }
 965
 966        /*
 967         * pfx{mid-a => mid-b}sfx
 968         * {pfx-a => pfx-b}sfx
 969         * pfx{sfx-a => sfx-b}
 970         * name-a => name-b
 971         */
 972        a_midlen = len_a - pfx_length - sfx_length;
 973        b_midlen = len_b - pfx_length - sfx_length;
 974        if (a_midlen < 0)
 975                a_midlen = 0;
 976        if (b_midlen < 0)
 977                b_midlen = 0;
 978
 979        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
 980        if (pfx_length + sfx_length) {
 981                strbuf_add(&name, a, pfx_length);
 982                strbuf_addch(&name, '{');
 983        }
 984        strbuf_add(&name, a + pfx_length, a_midlen);
 985        strbuf_addstr(&name, " => ");
 986        strbuf_add(&name, b + pfx_length, b_midlen);
 987        if (pfx_length + sfx_length) {
 988                strbuf_addch(&name, '}');
 989                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
 990        }
 991        return strbuf_detach(&name, NULL);
 992}
 993
 994struct diffstat_t {
 995        int nr;
 996        int alloc;
 997        struct diffstat_file {
 998                char *from_name;
 999                char *name;
1000                char *print_name;
1001                unsigned is_unmerged:1;
1002                unsigned is_binary:1;
1003                unsigned is_renamed:1;
1004                uintmax_t added, deleted;
1005        } **files;
1006};
1007
1008static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1009                                          const char *name_a,
1010                                          const char *name_b)
1011{
1012        struct diffstat_file *x;
1013        x = xcalloc(sizeof (*x), 1);
1014        if (diffstat->nr == diffstat->alloc) {
1015                diffstat->alloc = alloc_nr(diffstat->alloc);
1016                diffstat->files = xrealloc(diffstat->files,
1017                                diffstat->alloc * sizeof(x));
1018        }
1019        diffstat->files[diffstat->nr++] = x;
1020        if (name_b) {
1021                x->from_name = xstrdup(name_a);
1022                x->name = xstrdup(name_b);
1023                x->is_renamed = 1;
1024        }
1025        else {
1026                x->from_name = NULL;
1027                x->name = xstrdup(name_a);
1028        }
1029        return x;
1030}
1031
1032static void diffstat_consume(void *priv, char *line, unsigned long len)
1033{
1034        struct diffstat_t *diffstat = priv;
1035        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1036
1037        if (line[0] == '+')
1038                x->added++;
1039        else if (line[0] == '-')
1040                x->deleted++;
1041}
1042
1043const char mime_boundary_leader[] = "------------";
1044
1045static int scale_linear(int it, int width, int max_change)
1046{
1047        /*
1048         * make sure that at least one '-' is printed if there were deletions,
1049         * and likewise for '+'.
1050         */
1051        if (max_change < 2)
1052                return it;
1053        return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
1054}
1055
1056static void show_name(FILE *file,
1057                      const char *prefix, const char *name, int len)
1058{
1059        fprintf(file, " %s%-*s |", prefix, len, name);
1060}
1061
1062static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1063{
1064        if (cnt <= 0)
1065                return;
1066        fprintf(file, "%s", set);
1067        while (cnt--)
1068                putc(ch, file);
1069        fprintf(file, "%s", reset);
1070}
1071
1072static void fill_print_name(struct diffstat_file *file)
1073{
1074        char *pname;
1075
1076        if (file->print_name)
1077                return;
1078
1079        if (!file->is_renamed) {
1080                struct strbuf buf = STRBUF_INIT;
1081                if (quote_c_style(file->name, &buf, NULL, 0)) {
1082                        pname = strbuf_detach(&buf, NULL);
1083                } else {
1084                        pname = file->name;
1085                        strbuf_release(&buf);
1086                }
1087        } else {
1088                pname = pprint_rename(file->from_name, file->name);
1089        }
1090        file->print_name = pname;
1091}
1092
1093static void show_stats(struct diffstat_t *data, struct diff_options *options)
1094{
1095        int i, len, add, del, adds = 0, dels = 0;
1096        uintmax_t max_change = 0, max_len = 0;
1097        int total_files = data->nr;
1098        int width, name_width;
1099        const char *reset, *set, *add_c, *del_c;
1100
1101        if (data->nr == 0)
1102                return;
1103
1104        width = options->stat_width ? options->stat_width : 80;
1105        name_width = options->stat_name_width ? options->stat_name_width : 50;
1106
1107        /* Sanity: give at least 5 columns to the graph,
1108         * but leave at least 10 columns for the name.
1109         */
1110        if (width < 25)
1111                width = 25;
1112        if (name_width < 10)
1113                name_width = 10;
1114        else if (width < name_width + 15)
1115                name_width = width - 15;
1116
1117        /* Find the longest filename and max number of changes */
1118        reset = diff_get_color_opt(options, DIFF_RESET);
1119        set   = diff_get_color_opt(options, DIFF_PLAIN);
1120        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1121        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1122
1123        for (i = 0; i < data->nr; i++) {
1124                struct diffstat_file *file = data->files[i];
1125                uintmax_t change = file->added + file->deleted;
1126                fill_print_name(file);
1127                len = strlen(file->print_name);
1128                if (max_len < len)
1129                        max_len = len;
1130
1131                if (file->is_binary || file->is_unmerged)
1132                        continue;
1133                if (max_change < change)
1134                        max_change = change;
1135        }
1136
1137        /* Compute the width of the graph part;
1138         * 10 is for one blank at the beginning of the line plus
1139         * " | count " between the name and the graph.
1140         *
1141         * From here on, name_width is the width of the name area,
1142         * and width is the width of the graph area.
1143         */
1144        name_width = (name_width < max_len) ? name_width : max_len;
1145        if (width < (name_width + 10) + max_change)
1146                width = width - (name_width + 10);
1147        else
1148                width = max_change;
1149
1150        for (i = 0; i < data->nr; i++) {
1151                const char *prefix = "";
1152                char *name = data->files[i]->print_name;
1153                uintmax_t added = data->files[i]->added;
1154                uintmax_t deleted = data->files[i]->deleted;
1155                int name_len;
1156
1157                /*
1158                 * "scale" the filename
1159                 */
1160                len = name_width;
1161                name_len = strlen(name);
1162                if (name_width < name_len) {
1163                        char *slash;
1164                        prefix = "...";
1165                        len -= 3;
1166                        name += name_len - len;
1167                        slash = strchr(name, '/');
1168                        if (slash)
1169                                name = slash;
1170                }
1171
1172                if (data->files[i]->is_binary) {
1173                        show_name(options->file, prefix, name, len);
1174                        fprintf(options->file, "  Bin ");
1175                        fprintf(options->file, "%s%"PRIuMAX"%s",
1176                                del_c, deleted, reset);
1177                        fprintf(options->file, " -> ");
1178                        fprintf(options->file, "%s%"PRIuMAX"%s",
1179                                add_c, added, reset);
1180                        fprintf(options->file, " bytes");
1181                        fprintf(options->file, "\n");
1182                        continue;
1183                }
1184                else if (data->files[i]->is_unmerged) {
1185                        show_name(options->file, prefix, name, len);
1186                        fprintf(options->file, "  Unmerged\n");
1187                        continue;
1188                }
1189                else if (!data->files[i]->is_renamed &&
1190                         (added + deleted == 0)) {
1191                        total_files--;
1192                        continue;
1193                }
1194
1195                /*
1196                 * scale the add/delete
1197                 */
1198                add = added;
1199                del = deleted;
1200                adds += add;
1201                dels += del;
1202
1203                if (width <= max_change) {
1204                        add = scale_linear(add, width, max_change);
1205                        del = scale_linear(del, width, max_change);
1206                }
1207                show_name(options->file, prefix, name, len);
1208                fprintf(options->file, "%5"PRIuMAX"%s", added + deleted,
1209                                added + deleted ? " " : "");
1210                show_graph(options->file, '+', add, add_c, reset);
1211                show_graph(options->file, '-', del, del_c, reset);
1212                fprintf(options->file, "\n");
1213        }
1214        fprintf(options->file,
1215               " %d files changed, %d insertions(+), %d deletions(-)\n",
1216               total_files, adds, dels);
1217}
1218
1219static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1220{
1221        int i, adds = 0, dels = 0, total_files = data->nr;
1222
1223        if (data->nr == 0)
1224                return;
1225
1226        for (i = 0; i < data->nr; i++) {
1227                if (!data->files[i]->is_binary &&
1228                    !data->files[i]->is_unmerged) {
1229                        int added = data->files[i]->added;
1230                        int deleted= data->files[i]->deleted;
1231                        if (!data->files[i]->is_renamed &&
1232                            (added + deleted == 0)) {
1233                                total_files--;
1234                        } else {
1235                                adds += added;
1236                                dels += deleted;
1237                        }
1238                }
1239        }
1240        fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
1241               total_files, adds, dels);
1242}
1243
1244static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1245{
1246        int i;
1247
1248        if (data->nr == 0)
1249                return;
1250
1251        for (i = 0; i < data->nr; i++) {
1252                struct diffstat_file *file = data->files[i];
1253
1254                if (file->is_binary)
1255                        fprintf(options->file, "-\t-\t");
1256                else
1257                        fprintf(options->file,
1258                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1259                                file->added, file->deleted);
1260                if (options->line_termination) {
1261                        fill_print_name(file);
1262                        if (!file->is_renamed)
1263                                write_name_quoted(file->name, options->file,
1264                                                  options->line_termination);
1265                        else {
1266                                fputs(file->print_name, options->file);
1267                                putc(options->line_termination, options->file);
1268                        }
1269                } else {
1270                        if (file->is_renamed) {
1271                                putc('\0', options->file);
1272                                write_name_quoted(file->from_name, options->file, '\0');
1273                        }
1274                        write_name_quoted(file->name, options->file, '\0');
1275                }
1276        }
1277}
1278
1279struct dirstat_file {
1280        const char *name;
1281        unsigned long changed;
1282};
1283
1284struct dirstat_dir {
1285        struct dirstat_file *files;
1286        int alloc, nr, percent, cumulative;
1287};
1288
1289static long gather_dirstat(FILE *file, struct dirstat_dir *dir, unsigned long changed, const char *base, int baselen)
1290{
1291        unsigned long this_dir = 0;
1292        unsigned int sources = 0;
1293
1294        while (dir->nr) {
1295                struct dirstat_file *f = dir->files;
1296                int namelen = strlen(f->name);
1297                unsigned long this;
1298                char *slash;
1299
1300                if (namelen < baselen)
1301                        break;
1302                if (memcmp(f->name, base, baselen))
1303                        break;
1304                slash = strchr(f->name + baselen, '/');
1305                if (slash) {
1306                        int newbaselen = slash + 1 - f->name;
1307                        this = gather_dirstat(file, dir, changed, f->name, newbaselen);
1308                        sources++;
1309                } else {
1310                        this = f->changed;
1311                        dir->files++;
1312                        dir->nr--;
1313                        sources += 2;
1314                }
1315                this_dir += this;
1316        }
1317
1318        /*
1319         * We don't report dirstat's for
1320         *  - the top level
1321         *  - or cases where everything came from a single directory
1322         *    under this directory (sources == 1).
1323         */
1324        if (baselen && sources != 1) {
1325                int permille = this_dir * 1000 / changed;
1326                if (permille) {
1327                        int percent = permille / 10;
1328                        if (percent >= dir->percent) {
1329                                fprintf(file, "%4d.%01d%% %.*s\n", percent, permille % 10, baselen, base);
1330                                if (!dir->cumulative)
1331                                        return 0;
1332                        }
1333                }
1334        }
1335        return this_dir;
1336}
1337
1338static int dirstat_compare(const void *_a, const void *_b)
1339{
1340        const struct dirstat_file *a = _a;
1341        const struct dirstat_file *b = _b;
1342        return strcmp(a->name, b->name);
1343}
1344
1345static void show_dirstat(struct diff_options *options)
1346{
1347        int i;
1348        unsigned long changed;
1349        struct dirstat_dir dir;
1350        struct diff_queue_struct *q = &diff_queued_diff;
1351
1352        dir.files = NULL;
1353        dir.alloc = 0;
1354        dir.nr = 0;
1355        dir.percent = options->dirstat_percent;
1356        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1357
1358        changed = 0;
1359        for (i = 0; i < q->nr; i++) {
1360                struct diff_filepair *p = q->queue[i];
1361                const char *name;
1362                unsigned long copied, added, damage;
1363
1364                name = p->one->path ? p->one->path : p->two->path;
1365
1366                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1367                        diff_populate_filespec(p->one, 0);
1368                        diff_populate_filespec(p->two, 0);
1369                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1370                                               &copied, &added);
1371                        diff_free_filespec_data(p->one);
1372                        diff_free_filespec_data(p->two);
1373                } else if (DIFF_FILE_VALID(p->one)) {
1374                        diff_populate_filespec(p->one, 1);
1375                        copied = added = 0;
1376                        diff_free_filespec_data(p->one);
1377                } else if (DIFF_FILE_VALID(p->two)) {
1378                        diff_populate_filespec(p->two, 1);
1379                        copied = 0;
1380                        added = p->two->size;
1381                        diff_free_filespec_data(p->two);
1382                } else
1383                        continue;
1384
1385                /*
1386                 * Original minus copied is the removed material,
1387                 * added is the new material.  They are both damages
1388                 * made to the preimage. In --dirstat-by-file mode, count
1389                 * damaged files, not damaged lines. This is done by
1390                 * counting only a single damaged line per file.
1391                 */
1392                damage = (p->one->size - copied) + added;
1393                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE) && damage > 0)
1394                        damage = 1;
1395
1396                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1397                dir.files[dir.nr].name = name;
1398                dir.files[dir.nr].changed = damage;
1399                changed += damage;
1400                dir.nr++;
1401        }
1402
1403        /* This can happen even with many files, if everything was renames */
1404        if (!changed)
1405                return;
1406
1407        /* Show all directories with more than x% of the changes */
1408        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1409        gather_dirstat(options->file, &dir, changed, "", 0);
1410}
1411
1412static void free_diffstat_info(struct diffstat_t *diffstat)
1413{
1414        int i;
1415        for (i = 0; i < diffstat->nr; i++) {
1416                struct diffstat_file *f = diffstat->files[i];
1417                if (f->name != f->print_name)
1418                        free(f->print_name);
1419                free(f->name);
1420                free(f->from_name);
1421                free(f);
1422        }
1423        free(diffstat->files);
1424}
1425
1426struct checkdiff_t {
1427        const char *filename;
1428        int lineno;
1429        int conflict_marker_size;
1430        struct diff_options *o;
1431        unsigned ws_rule;
1432        unsigned status;
1433};
1434
1435static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1436{
1437        char firstchar;
1438        int cnt;
1439
1440        if (len < marker_size + 1)
1441                return 0;
1442        firstchar = line[0];
1443        switch (firstchar) {
1444        case '=': case '>': case '<': case '|':
1445                break;
1446        default:
1447                return 0;
1448        }
1449        for (cnt = 1; cnt < marker_size; cnt++)
1450                if (line[cnt] != firstchar)
1451                        return 0;
1452        /* line[1] thru line[marker_size-1] are same as firstchar */
1453        if (len < marker_size + 1 || !isspace(line[marker_size]))
1454                return 0;
1455        return 1;
1456}
1457
1458static void checkdiff_consume(void *priv, char *line, unsigned long len)
1459{
1460        struct checkdiff_t *data = priv;
1461        int color_diff = DIFF_OPT_TST(data->o, COLOR_DIFF);
1462        int marker_size = data->conflict_marker_size;
1463        const char *ws = diff_get_color(color_diff, DIFF_WHITESPACE);
1464        const char *reset = diff_get_color(color_diff, DIFF_RESET);
1465        const char *set = diff_get_color(color_diff, DIFF_FILE_NEW);
1466        char *err;
1467
1468        if (line[0] == '+') {
1469                unsigned bad;
1470                data->lineno++;
1471                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
1472                        data->status |= 1;
1473                        fprintf(data->o->file,
1474                                "%s:%d: leftover conflict marker\n",
1475                                data->filename, data->lineno);
1476                }
1477                bad = ws_check(line + 1, len - 1, data->ws_rule);
1478                if (!bad)
1479                        return;
1480                data->status |= bad;
1481                err = whitespace_error_string(bad);
1482                fprintf(data->o->file, "%s:%d: %s.\n",
1483                        data->filename, data->lineno, err);
1484                free(err);
1485                emit_line(data->o->file, set, reset, line, 1);
1486                ws_check_emit(line + 1, len - 1, data->ws_rule,
1487                              data->o->file, set, reset, ws);
1488        } else if (line[0] == ' ') {
1489                data->lineno++;
1490        } else if (line[0] == '@') {
1491                char *plus = strchr(line, '+');
1492                if (plus)
1493                        data->lineno = strtol(plus, NULL, 10) - 1;
1494                else
1495                        die("invalid diff");
1496        }
1497}
1498
1499static unsigned char *deflate_it(char *data,
1500                                 unsigned long size,
1501                                 unsigned long *result_size)
1502{
1503        int bound;
1504        unsigned char *deflated;
1505        z_stream stream;
1506
1507        memset(&stream, 0, sizeof(stream));
1508        deflateInit(&stream, zlib_compression_level);
1509        bound = deflateBound(&stream, size);
1510        deflated = xmalloc(bound);
1511        stream.next_out = deflated;
1512        stream.avail_out = bound;
1513
1514        stream.next_in = (unsigned char *)data;
1515        stream.avail_in = size;
1516        while (deflate(&stream, Z_FINISH) == Z_OK)
1517                ; /* nothing */
1518        deflateEnd(&stream);
1519        *result_size = stream.total_out;
1520        return deflated;
1521}
1522
1523static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two)
1524{
1525        void *cp;
1526        void *delta;
1527        void *deflated;
1528        void *data;
1529        unsigned long orig_size;
1530        unsigned long delta_size;
1531        unsigned long deflate_size;
1532        unsigned long data_size;
1533
1534        /* We could do deflated delta, or we could do just deflated two,
1535         * whichever is smaller.
1536         */
1537        delta = NULL;
1538        deflated = deflate_it(two->ptr, two->size, &deflate_size);
1539        if (one->size && two->size) {
1540                delta = diff_delta(one->ptr, one->size,
1541                                   two->ptr, two->size,
1542                                   &delta_size, deflate_size);
1543                if (delta) {
1544                        void *to_free = delta;
1545                        orig_size = delta_size;
1546                        delta = deflate_it(delta, delta_size, &delta_size);
1547                        free(to_free);
1548                }
1549        }
1550
1551        if (delta && delta_size < deflate_size) {
1552                fprintf(file, "delta %lu\n", orig_size);
1553                free(deflated);
1554                data = delta;
1555                data_size = delta_size;
1556        }
1557        else {
1558                fprintf(file, "literal %lu\n", two->size);
1559                free(delta);
1560                data = deflated;
1561                data_size = deflate_size;
1562        }
1563
1564        /* emit data encoded in base85 */
1565        cp = data;
1566        while (data_size) {
1567                int bytes = (52 < data_size) ? 52 : data_size;
1568                char line[70];
1569                data_size -= bytes;
1570                if (bytes <= 26)
1571                        line[0] = bytes + 'A' - 1;
1572                else
1573                        line[0] = bytes - 26 + 'a' - 1;
1574                encode_85(line + 1, cp, bytes);
1575                cp = (char *) cp + bytes;
1576                fputs(line, file);
1577                fputc('\n', file);
1578        }
1579        fprintf(file, "\n");
1580        free(data);
1581}
1582
1583static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two)
1584{
1585        fprintf(file, "GIT binary patch\n");
1586        emit_binary_diff_body(file, one, two);
1587        emit_binary_diff_body(file, two, one);
1588}
1589
1590static void diff_filespec_load_driver(struct diff_filespec *one)
1591{
1592        if (!one->driver)
1593                one->driver = userdiff_find_by_path(one->path);
1594        if (!one->driver)
1595                one->driver = userdiff_find_by_name("default");
1596}
1597
1598int diff_filespec_is_binary(struct diff_filespec *one)
1599{
1600        if (one->is_binary == -1) {
1601                diff_filespec_load_driver(one);
1602                if (one->driver->binary != -1)
1603                        one->is_binary = one->driver->binary;
1604                else {
1605                        if (!one->data && DIFF_FILE_VALID(one))
1606                                diff_populate_filespec(one, 0);
1607                        if (one->data)
1608                                one->is_binary = buffer_is_binary(one->data,
1609                                                one->size);
1610                        if (one->is_binary == -1)
1611                                one->is_binary = 0;
1612                }
1613        }
1614        return one->is_binary;
1615}
1616
1617static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
1618{
1619        diff_filespec_load_driver(one);
1620        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
1621}
1622
1623static const char *userdiff_word_regex(struct diff_filespec *one)
1624{
1625        diff_filespec_load_driver(one);
1626        return one->driver->word_regex;
1627}
1628
1629void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
1630{
1631        if (!options->a_prefix)
1632                options->a_prefix = a;
1633        if (!options->b_prefix)
1634                options->b_prefix = b;
1635}
1636
1637static struct userdiff_driver *get_textconv(struct diff_filespec *one)
1638{
1639        if (!DIFF_FILE_VALID(one))
1640                return NULL;
1641        if (!S_ISREG(one->mode))
1642                return NULL;
1643        diff_filespec_load_driver(one);
1644        if (!one->driver->textconv)
1645                return NULL;
1646
1647        if (one->driver->textconv_want_cache && !one->driver->textconv_cache) {
1648                struct notes_cache *c = xmalloc(sizeof(*c));
1649                struct strbuf name = STRBUF_INIT;
1650
1651                strbuf_addf(&name, "textconv/%s", one->driver->name);
1652                notes_cache_init(c, name.buf, one->driver->textconv);
1653                one->driver->textconv_cache = c;
1654        }
1655
1656        return one->driver;
1657}
1658
1659static void builtin_diff(const char *name_a,
1660                         const char *name_b,
1661                         struct diff_filespec *one,
1662                         struct diff_filespec *two,
1663                         const char *xfrm_msg,
1664                         struct diff_options *o,
1665                         int complete_rewrite)
1666{
1667        mmfile_t mf1, mf2;
1668        const char *lbl[2];
1669        char *a_one, *b_two;
1670        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1671        const char *reset = diff_get_color_opt(o, DIFF_RESET);
1672        const char *a_prefix, *b_prefix;
1673        struct userdiff_driver *textconv_one = NULL;
1674        struct userdiff_driver *textconv_two = NULL;
1675        struct strbuf header = STRBUF_INIT;
1676
1677        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
1678                        (!one->mode || S_ISGITLINK(one->mode)) &&
1679                        (!two->mode || S_ISGITLINK(two->mode))) {
1680                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
1681                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
1682                show_submodule_summary(o->file, one ? one->path : two->path,
1683                                one->sha1, two->sha1, two->dirty_submodule,
1684                                del, add, reset);
1685                return;
1686        }
1687
1688        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
1689                textconv_one = get_textconv(one);
1690                textconv_two = get_textconv(two);
1691        }
1692
1693        diff_set_mnemonic_prefix(o, "a/", "b/");
1694        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
1695                a_prefix = o->b_prefix;
1696                b_prefix = o->a_prefix;
1697        } else {
1698                a_prefix = o->a_prefix;
1699                b_prefix = o->b_prefix;
1700        }
1701
1702        /* Never use a non-valid filename anywhere if at all possible */
1703        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
1704        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
1705
1706        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
1707        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
1708        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1709        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1710        strbuf_addf(&header, "%sdiff --git %s %s%s\n", set, a_one, b_two, reset);
1711        if (lbl[0][0] == '/') {
1712                /* /dev/null */
1713                strbuf_addf(&header, "%snew file mode %06o%s\n", set, two->mode, reset);
1714                if (xfrm_msg)
1715                        strbuf_addstr(&header, xfrm_msg);
1716        }
1717        else if (lbl[1][0] == '/') {
1718                strbuf_addf(&header, "%sdeleted file mode %06o%s\n", set, one->mode, reset);
1719                if (xfrm_msg)
1720                        strbuf_addstr(&header, xfrm_msg);
1721        }
1722        else {
1723                if (one->mode != two->mode) {
1724                        strbuf_addf(&header, "%sold mode %06o%s\n", set, one->mode, reset);
1725                        strbuf_addf(&header, "%snew mode %06o%s\n", set, two->mode, reset);
1726                }
1727                if (xfrm_msg)
1728                        strbuf_addstr(&header, xfrm_msg);
1729
1730                /*
1731                 * we do not run diff between different kind
1732                 * of objects.
1733                 */
1734                if ((one->mode ^ two->mode) & S_IFMT)
1735                        goto free_ab_and_return;
1736                if (complete_rewrite &&
1737                    (textconv_one || !diff_filespec_is_binary(one)) &&
1738                    (textconv_two || !diff_filespec_is_binary(two))) {
1739                        fprintf(o->file, "%s", header.buf);
1740                        strbuf_reset(&header);
1741                        emit_rewrite_diff(name_a, name_b, one, two,
1742                                                textconv_one, textconv_two, o);
1743                        o->found_changes = 1;
1744                        goto free_ab_and_return;
1745                }
1746        }
1747
1748        if (!DIFF_OPT_TST(o, TEXT) &&
1749            ( (!textconv_one && diff_filespec_is_binary(one)) ||
1750              (!textconv_two && diff_filespec_is_binary(two)) )) {
1751                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1752                        die("unable to read files to diff");
1753                /* Quite common confusing case */
1754                if (mf1.size == mf2.size &&
1755                    !memcmp(mf1.ptr, mf2.ptr, mf1.size))
1756                        goto free_ab_and_return;
1757                fprintf(o->file, "%s", header.buf);
1758                strbuf_reset(&header);
1759                if (DIFF_OPT_TST(o, BINARY))
1760                        emit_binary_diff(o->file, &mf1, &mf2);
1761                else
1762                        fprintf(o->file, "Binary files %s and %s differ\n",
1763                                lbl[0], lbl[1]);
1764                o->found_changes = 1;
1765        }
1766        else {
1767                /* Crazy xdl interfaces.. */
1768                const char *diffopts = getenv("GIT_DIFF_OPTS");
1769                xpparam_t xpp;
1770                xdemitconf_t xecfg;
1771                struct emit_callback ecbdata;
1772                const struct userdiff_funcname *pe;
1773
1774                if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS)) {
1775                        fprintf(o->file, "%s", header.buf);
1776                        strbuf_reset(&header);
1777                }
1778
1779                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
1780                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
1781
1782                pe = diff_funcname_pattern(one);
1783                if (!pe)
1784                        pe = diff_funcname_pattern(two);
1785
1786                memset(&xpp, 0, sizeof(xpp));
1787                memset(&xecfg, 0, sizeof(xecfg));
1788                memset(&ecbdata, 0, sizeof(ecbdata));
1789                ecbdata.label_path = lbl;
1790                ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
1791                ecbdata.found_changesp = &o->found_changes;
1792                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
1793                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
1794                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
1795                ecbdata.file = o->file;
1796                ecbdata.header = header.len ? &header : NULL;
1797                xpp.flags = o->xdl_opts;
1798                xecfg.ctxlen = o->context;
1799                xecfg.interhunkctxlen = o->interhunkcontext;
1800                xecfg.flags = XDL_EMIT_FUNCNAMES;
1801                if (pe)
1802                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
1803                if (!diffopts)
1804                        ;
1805                else if (!prefixcmp(diffopts, "--unified="))
1806                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
1807                else if (!prefixcmp(diffopts, "-u"))
1808                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
1809                if (o->word_diff) {
1810                        int i;
1811
1812                        ecbdata.diff_words =
1813                                xcalloc(1, sizeof(struct diff_words_data));
1814                        ecbdata.diff_words->file = o->file;
1815                        ecbdata.diff_words->type = o->word_diff;
1816                        if (!o->word_regex)
1817                                o->word_regex = userdiff_word_regex(one);
1818                        if (!o->word_regex)
1819                                o->word_regex = userdiff_word_regex(two);
1820                        if (!o->word_regex)
1821                                o->word_regex = diff_word_regex_cfg;
1822                        if (o->word_regex) {
1823                                ecbdata.diff_words->word_regex = (regex_t *)
1824                                        xmalloc(sizeof(regex_t));
1825                                if (regcomp(ecbdata.diff_words->word_regex,
1826                                                o->word_regex,
1827                                                REG_EXTENDED | REG_NEWLINE))
1828                                        die ("Invalid regular expression: %s",
1829                                                        o->word_regex);
1830                        }
1831                        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
1832                                if (o->word_diff == diff_words_styles[i].type) {
1833                                        ecbdata.diff_words->style =
1834                                                &diff_words_styles[i];
1835                                        break;
1836                                }
1837                        }
1838                        if (DIFF_OPT_TST(o, COLOR_DIFF)) {
1839                                struct diff_words_style *st = ecbdata.diff_words->style;
1840                                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
1841                                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
1842                                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
1843                        }
1844                }
1845                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
1846                              &xpp, &xecfg);
1847                if (o->word_diff)
1848                        free_diff_words_data(&ecbdata);
1849                if (textconv_one)
1850                        free(mf1.ptr);
1851                if (textconv_two)
1852                        free(mf2.ptr);
1853                xdiff_clear_find_func(&xecfg);
1854        }
1855
1856 free_ab_and_return:
1857        strbuf_release(&header);
1858        diff_free_filespec_data(one);
1859        diff_free_filespec_data(two);
1860        free(a_one);
1861        free(b_two);
1862        return;
1863}
1864
1865static void builtin_diffstat(const char *name_a, const char *name_b,
1866                             struct diff_filespec *one,
1867                             struct diff_filespec *two,
1868                             struct diffstat_t *diffstat,
1869                             struct diff_options *o,
1870                             int complete_rewrite)
1871{
1872        mmfile_t mf1, mf2;
1873        struct diffstat_file *data;
1874
1875        data = diffstat_add(diffstat, name_a, name_b);
1876
1877        if (!one || !two) {
1878                data->is_unmerged = 1;
1879                return;
1880        }
1881        if (complete_rewrite) {
1882                diff_populate_filespec(one, 0);
1883                diff_populate_filespec(two, 0);
1884                data->deleted = count_lines(one->data, one->size);
1885                data->added = count_lines(two->data, two->size);
1886                goto free_and_return;
1887        }
1888        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1889                die("unable to read files to diff");
1890
1891        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
1892                data->is_binary = 1;
1893                data->added = mf2.size;
1894                data->deleted = mf1.size;
1895        } else {
1896                /* Crazy xdl interfaces.. */
1897                xpparam_t xpp;
1898                xdemitconf_t xecfg;
1899
1900                memset(&xpp, 0, sizeof(xpp));
1901                memset(&xecfg, 0, sizeof(xecfg));
1902                xpp.flags = o->xdl_opts;
1903                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
1904                              &xpp, &xecfg);
1905        }
1906
1907 free_and_return:
1908        diff_free_filespec_data(one);
1909        diff_free_filespec_data(two);
1910}
1911
1912static void builtin_checkdiff(const char *name_a, const char *name_b,
1913                              const char *attr_path,
1914                              struct diff_filespec *one,
1915                              struct diff_filespec *two,
1916                              struct diff_options *o)
1917{
1918        mmfile_t mf1, mf2;
1919        struct checkdiff_t data;
1920
1921        if (!two)
1922                return;
1923
1924        memset(&data, 0, sizeof(data));
1925        data.filename = name_b ? name_b : name_a;
1926        data.lineno = 0;
1927        data.o = o;
1928        data.ws_rule = whitespace_rule(attr_path);
1929        data.conflict_marker_size = ll_merge_marker_size(attr_path);
1930
1931        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1932                die("unable to read files to diff");
1933
1934        /*
1935         * All the other codepaths check both sides, but not checking
1936         * the "old" side here is deliberate.  We are checking the newly
1937         * introduced changes, and as long as the "new" side is text, we
1938         * can and should check what it introduces.
1939         */
1940        if (diff_filespec_is_binary(two))
1941                goto free_and_return;
1942        else {
1943                /* Crazy xdl interfaces.. */
1944                xpparam_t xpp;
1945                xdemitconf_t xecfg;
1946
1947                memset(&xpp, 0, sizeof(xpp));
1948                memset(&xecfg, 0, sizeof(xecfg));
1949                xecfg.ctxlen = 1; /* at least one context line */
1950                xpp.flags = 0;
1951                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
1952                              &xpp, &xecfg);
1953
1954                if (data.ws_rule & WS_BLANK_AT_EOF) {
1955                        struct emit_callback ecbdata;
1956                        int blank_at_eof;
1957
1958                        ecbdata.ws_rule = data.ws_rule;
1959                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
1960                        blank_at_eof = ecbdata.blank_at_eof_in_preimage;
1961
1962                        if (blank_at_eof) {
1963                                static char *err;
1964                                if (!err)
1965                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
1966                                fprintf(o->file, "%s:%d: %s.\n",
1967                                        data.filename, blank_at_eof, err);
1968                                data.status = 1; /* report errors */
1969                        }
1970                }
1971        }
1972 free_and_return:
1973        diff_free_filespec_data(one);
1974        diff_free_filespec_data(two);
1975        if (data.status)
1976                DIFF_OPT_SET(o, CHECK_FAILED);
1977}
1978
1979struct diff_filespec *alloc_filespec(const char *path)
1980{
1981        int namelen = strlen(path);
1982        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
1983
1984        memset(spec, 0, sizeof(*spec));
1985        spec->path = (char *)(spec + 1);
1986        memcpy(spec->path, path, namelen+1);
1987        spec->count = 1;
1988        spec->is_binary = -1;
1989        return spec;
1990}
1991
1992void free_filespec(struct diff_filespec *spec)
1993{
1994        if (!--spec->count) {
1995                diff_free_filespec_data(spec);
1996                free(spec);
1997        }
1998}
1999
2000void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2001                   unsigned short mode)
2002{
2003        if (mode) {
2004                spec->mode = canon_mode(mode);
2005                hashcpy(spec->sha1, sha1);
2006                spec->sha1_valid = !is_null_sha1(sha1);
2007        }
2008}
2009
2010/*
2011 * Given a name and sha1 pair, if the index tells us the file in
2012 * the work tree has that object contents, return true, so that
2013 * prepare_temp_file() does not have to inflate and extract.
2014 */
2015static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2016{
2017        struct cache_entry *ce;
2018        struct stat st;
2019        int pos, len;
2020
2021        /*
2022         * We do not read the cache ourselves here, because the
2023         * benchmark with my previous version that always reads cache
2024         * shows that it makes things worse for diff-tree comparing
2025         * two linux-2.6 kernel trees in an already checked out work
2026         * tree.  This is because most diff-tree comparisons deal with
2027         * only a small number of files, while reading the cache is
2028         * expensive for a large project, and its cost outweighs the
2029         * savings we get by not inflating the object to a temporary
2030         * file.  Practically, this code only helps when we are used
2031         * by diff-cache --cached, which does read the cache before
2032         * calling us.
2033         */
2034        if (!active_cache)
2035                return 0;
2036
2037        /* We want to avoid the working directory if our caller
2038         * doesn't need the data in a normal file, this system
2039         * is rather slow with its stat/open/mmap/close syscalls,
2040         * and the object is contained in a pack file.  The pack
2041         * is probably already open and will be faster to obtain
2042         * the data through than the working directory.  Loose
2043         * objects however would tend to be slower as they need
2044         * to be individually opened and inflated.
2045         */
2046        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2047                return 0;
2048
2049        len = strlen(name);
2050        pos = cache_name_pos(name, len);
2051        if (pos < 0)
2052                return 0;
2053        ce = active_cache[pos];
2054
2055        /*
2056         * This is not the sha1 we are looking for, or
2057         * unreusable because it is not a regular file.
2058         */
2059        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2060                return 0;
2061
2062        /*
2063         * If ce is marked as "assume unchanged", there is no
2064         * guarantee that work tree matches what we are looking for.
2065         */
2066        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2067                return 0;
2068
2069        /*
2070         * If ce matches the file in the work tree, we can reuse it.
2071         */
2072        if (ce_uptodate(ce) ||
2073            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2074                return 1;
2075
2076        return 0;
2077}
2078
2079static int populate_from_stdin(struct diff_filespec *s)
2080{
2081        struct strbuf buf = STRBUF_INIT;
2082        size_t size = 0;
2083
2084        if (strbuf_read(&buf, 0, 0) < 0)
2085                return error("error while reading from stdin %s",
2086                                     strerror(errno));
2087
2088        s->should_munmap = 0;
2089        s->data = strbuf_detach(&buf, &size);
2090        s->size = size;
2091        s->should_free = 1;
2092        return 0;
2093}
2094
2095static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2096{
2097        int len;
2098        char *data = xmalloc(100), *dirty = "";
2099
2100        /* Are we looking at the work tree? */
2101        if (s->dirty_submodule)
2102                dirty = "-dirty";
2103
2104        len = snprintf(data, 100,
2105                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2106        s->data = data;
2107        s->size = len;
2108        s->should_free = 1;
2109        if (size_only) {
2110                s->data = NULL;
2111                free(data);
2112        }
2113        return 0;
2114}
2115
2116/*
2117 * While doing rename detection and pickaxe operation, we may need to
2118 * grab the data for the blob (or file) for our own in-core comparison.
2119 * diff_filespec has data and size fields for this purpose.
2120 */
2121int diff_populate_filespec(struct diff_filespec *s, int size_only)
2122{
2123        int err = 0;
2124        if (!DIFF_FILE_VALID(s))
2125                die("internal error: asking to populate invalid file.");
2126        if (S_ISDIR(s->mode))
2127                return -1;
2128
2129        if (s->data)
2130                return 0;
2131
2132        if (size_only && 0 < s->size)
2133                return 0;
2134
2135        if (S_ISGITLINK(s->mode))
2136                return diff_populate_gitlink(s, size_only);
2137
2138        if (!s->sha1_valid ||
2139            reuse_worktree_file(s->path, s->sha1, 0)) {
2140                struct strbuf buf = STRBUF_INIT;
2141                struct stat st;
2142                int fd;
2143
2144                if (!strcmp(s->path, "-"))
2145                        return populate_from_stdin(s);
2146
2147                if (lstat(s->path, &st) < 0) {
2148                        if (errno == ENOENT) {
2149                        err_empty:
2150                                err = -1;
2151                        empty:
2152                                s->data = (char *)"";
2153                                s->size = 0;
2154                                return err;
2155                        }
2156                }
2157                s->size = xsize_t(st.st_size);
2158                if (!s->size)
2159                        goto empty;
2160                if (S_ISLNK(st.st_mode)) {
2161                        struct strbuf sb = STRBUF_INIT;
2162
2163                        if (strbuf_readlink(&sb, s->path, s->size))
2164                                goto err_empty;
2165                        s->size = sb.len;
2166                        s->data = strbuf_detach(&sb, NULL);
2167                        s->should_free = 1;
2168                        return 0;
2169                }
2170                if (size_only)
2171                        return 0;
2172                fd = open(s->path, O_RDONLY);
2173                if (fd < 0)
2174                        goto err_empty;
2175                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2176                close(fd);
2177                s->should_munmap = 1;
2178
2179                /*
2180                 * Convert from working tree format to canonical git format
2181                 */
2182                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2183                        size_t size = 0;
2184                        munmap(s->data, s->size);
2185                        s->should_munmap = 0;
2186                        s->data = strbuf_detach(&buf, &size);
2187                        s->size = size;
2188                        s->should_free = 1;
2189                }
2190        }
2191        else {
2192                enum object_type type;
2193                if (size_only)
2194                        type = sha1_object_info(s->sha1, &s->size);
2195                else {
2196                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2197                        s->should_free = 1;
2198                }
2199        }
2200        return 0;
2201}
2202
2203void diff_free_filespec_blob(struct diff_filespec *s)
2204{
2205        if (s->should_free)
2206                free(s->data);
2207        else if (s->should_munmap)
2208                munmap(s->data, s->size);
2209
2210        if (s->should_free || s->should_munmap) {
2211                s->should_free = s->should_munmap = 0;
2212                s->data = NULL;
2213        }
2214}
2215
2216void diff_free_filespec_data(struct diff_filespec *s)
2217{
2218        diff_free_filespec_blob(s);
2219        free(s->cnt_data);
2220        s->cnt_data = NULL;
2221}
2222
2223static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2224                           void *blob,
2225                           unsigned long size,
2226                           const unsigned char *sha1,
2227                           int mode)
2228{
2229        int fd;
2230        struct strbuf buf = STRBUF_INIT;
2231        struct strbuf template = STRBUF_INIT;
2232        char *path_dup = xstrdup(path);
2233        const char *base = basename(path_dup);
2234
2235        /* Generate "XXXXXX_basename.ext" */
2236        strbuf_addstr(&template, "XXXXXX_");
2237        strbuf_addstr(&template, base);
2238
2239        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2240                        strlen(base) + 1);
2241        if (fd < 0)
2242                die_errno("unable to create temp-file");
2243        if (convert_to_working_tree(path,
2244                        (const char *)blob, (size_t)size, &buf)) {
2245                blob = buf.buf;
2246                size = buf.len;
2247        }
2248        if (write_in_full(fd, blob, size) != size)
2249                die_errno("unable to write temp-file");
2250        close(fd);
2251        temp->name = temp->tmp_path;
2252        strcpy(temp->hex, sha1_to_hex(sha1));
2253        temp->hex[40] = 0;
2254        sprintf(temp->mode, "%06o", mode);
2255        strbuf_release(&buf);
2256        strbuf_release(&template);
2257        free(path_dup);
2258}
2259
2260static struct diff_tempfile *prepare_temp_file(const char *name,
2261                struct diff_filespec *one)
2262{
2263        struct diff_tempfile *temp = claim_diff_tempfile();
2264
2265        if (!DIFF_FILE_VALID(one)) {
2266        not_a_valid_file:
2267                /* A '-' entry produces this for file-2, and
2268                 * a '+' entry produces this for file-1.
2269                 */
2270                temp->name = "/dev/null";
2271                strcpy(temp->hex, ".");
2272                strcpy(temp->mode, ".");
2273                return temp;
2274        }
2275
2276        if (!remove_tempfile_installed) {
2277                atexit(remove_tempfile);
2278                sigchain_push_common(remove_tempfile_on_signal);
2279                remove_tempfile_installed = 1;
2280        }
2281
2282        if (!one->sha1_valid ||
2283            reuse_worktree_file(name, one->sha1, 1)) {
2284                struct stat st;
2285                if (lstat(name, &st) < 0) {
2286                        if (errno == ENOENT)
2287                                goto not_a_valid_file;
2288                        die_errno("stat(%s)", name);
2289                }
2290                if (S_ISLNK(st.st_mode)) {
2291                        struct strbuf sb = STRBUF_INIT;
2292                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2293                                die_errno("readlink(%s)", name);
2294                        prep_temp_blob(name, temp, sb.buf, sb.len,
2295                                       (one->sha1_valid ?
2296                                        one->sha1 : null_sha1),
2297                                       (one->sha1_valid ?
2298                                        one->mode : S_IFLNK));
2299                        strbuf_release(&sb);
2300                }
2301                else {
2302                        /* we can borrow from the file in the work tree */
2303                        temp->name = name;
2304                        if (!one->sha1_valid)
2305                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2306                        else
2307                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2308                        /* Even though we may sometimes borrow the
2309                         * contents from the work tree, we always want
2310                         * one->mode.  mode is trustworthy even when
2311                         * !(one->sha1_valid), as long as
2312                         * DIFF_FILE_VALID(one).
2313                         */
2314                        sprintf(temp->mode, "%06o", one->mode);
2315                }
2316                return temp;
2317        }
2318        else {
2319                if (diff_populate_filespec(one, 0))
2320                        die("cannot read data blob for %s", one->path);
2321                prep_temp_blob(name, temp, one->data, one->size,
2322                               one->sha1, one->mode);
2323        }
2324        return temp;
2325}
2326
2327/* An external diff command takes:
2328 *
2329 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2330 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2331 *
2332 */
2333static void run_external_diff(const char *pgm,
2334                              const char *name,
2335                              const char *other,
2336                              struct diff_filespec *one,
2337                              struct diff_filespec *two,
2338                              const char *xfrm_msg,
2339                              int complete_rewrite)
2340{
2341        const char *spawn_arg[10];
2342        int retval;
2343        const char **arg = &spawn_arg[0];
2344
2345        if (one && two) {
2346                struct diff_tempfile *temp_one, *temp_two;
2347                const char *othername = (other ? other : name);
2348                temp_one = prepare_temp_file(name, one);
2349                temp_two = prepare_temp_file(othername, two);
2350                *arg++ = pgm;
2351                *arg++ = name;
2352                *arg++ = temp_one->name;
2353                *arg++ = temp_one->hex;
2354                *arg++ = temp_one->mode;
2355                *arg++ = temp_two->name;
2356                *arg++ = temp_two->hex;
2357                *arg++ = temp_two->mode;
2358                if (other) {
2359                        *arg++ = other;
2360                        *arg++ = xfrm_msg;
2361                }
2362        } else {
2363                *arg++ = pgm;
2364                *arg++ = name;
2365        }
2366        *arg = NULL;
2367        fflush(NULL);
2368        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2369        remove_tempfile();
2370        if (retval) {
2371                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2372                exit(1);
2373        }
2374}
2375
2376static int similarity_index(struct diff_filepair *p)
2377{
2378        return p->score * 100 / MAX_SCORE;
2379}
2380
2381static void fill_metainfo(struct strbuf *msg,
2382                          const char *name,
2383                          const char *other,
2384                          struct diff_filespec *one,
2385                          struct diff_filespec *two,
2386                          struct diff_options *o,
2387                          struct diff_filepair *p,
2388                          int use_color)
2389{
2390        const char *set = diff_get_color(use_color, DIFF_METAINFO);
2391        const char *reset = diff_get_color(use_color, DIFF_RESET);
2392
2393        strbuf_init(msg, PATH_MAX * 2 + 300);
2394        switch (p->status) {
2395        case DIFF_STATUS_COPIED:
2396                strbuf_addf(msg, "%ssimilarity index %d%%",
2397                            set, similarity_index(p));
2398                strbuf_addf(msg, "%s\n%scopy from ", reset, set);
2399                quote_c_style(name, msg, NULL, 0);
2400                strbuf_addf(msg, "%s\n%scopy to ", reset, set);
2401                quote_c_style(other, msg, NULL, 0);
2402                strbuf_addf(msg, "%s\n", reset);
2403                break;
2404        case DIFF_STATUS_RENAMED:
2405                strbuf_addf(msg, "%ssimilarity index %d%%",
2406                            set, similarity_index(p));
2407                strbuf_addf(msg, "%s\n%srename from ", reset, set);
2408                quote_c_style(name, msg, NULL, 0);
2409                strbuf_addf(msg, "%s\n%srename to ", reset, set);
2410                quote_c_style(other, msg, NULL, 0);
2411                strbuf_addf(msg, "%s\n", reset);
2412                break;
2413        case DIFF_STATUS_MODIFIED:
2414                if (p->score) {
2415                        strbuf_addf(msg, "%sdissimilarity index %d%%%s\n",
2416                                    set, similarity_index(p), reset);
2417                        break;
2418                }
2419                /* fallthru */
2420        default:
2421                /* nothing */
2422                ;
2423        }
2424        if (one && two && hashcmp(one->sha1, two->sha1)) {
2425                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2426
2427                if (DIFF_OPT_TST(o, BINARY)) {
2428                        mmfile_t mf;
2429                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2430                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2431                                abbrev = 40;
2432                }
2433                strbuf_addf(msg, "%sindex %s..", set,
2434                            find_unique_abbrev(one->sha1, abbrev));
2435                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2436                if (one->mode == two->mode)
2437                        strbuf_addf(msg, " %06o", one->mode);
2438                strbuf_addf(msg, "%s\n", reset);
2439        }
2440}
2441
2442static void run_diff_cmd(const char *pgm,
2443                         const char *name,
2444                         const char *other,
2445                         const char *attr_path,
2446                         struct diff_filespec *one,
2447                         struct diff_filespec *two,
2448                         struct strbuf *msg,
2449                         struct diff_options *o,
2450                         struct diff_filepair *p)
2451{
2452        const char *xfrm_msg = NULL;
2453        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2454
2455        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2456                pgm = NULL;
2457        else {
2458                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2459                if (drv && drv->external)
2460                        pgm = drv->external;
2461        }
2462
2463        if (msg) {
2464                /*
2465                 * don't use colors when the header is intended for an
2466                 * external diff driver
2467                 */
2468                fill_metainfo(msg, name, other, one, two, o, p,
2469                              DIFF_OPT_TST(o, COLOR_DIFF) && !pgm);
2470                xfrm_msg = msg->len ? msg->buf : NULL;
2471        }
2472
2473        if (pgm) {
2474                run_external_diff(pgm, name, other, one, two, xfrm_msg,
2475                                  complete_rewrite);
2476                return;
2477        }
2478        if (one && two)
2479                builtin_diff(name, other ? other : name,
2480                             one, two, xfrm_msg, o, complete_rewrite);
2481        else
2482                fprintf(o->file, "* Unmerged path %s\n", name);
2483}
2484
2485static void diff_fill_sha1_info(struct diff_filespec *one)
2486{
2487        if (DIFF_FILE_VALID(one)) {
2488                if (!one->sha1_valid) {
2489                        struct stat st;
2490                        if (!strcmp(one->path, "-")) {
2491                                hashcpy(one->sha1, null_sha1);
2492                                return;
2493                        }
2494                        if (lstat(one->path, &st) < 0)
2495                                die_errno("stat '%s'", one->path);
2496                        if (index_path(one->sha1, one->path, &st, 0))
2497                                die("cannot hash %s", one->path);
2498                }
2499        }
2500        else
2501                hashclr(one->sha1);
2502}
2503
2504static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2505{
2506        /* Strip the prefix but do not molest /dev/null and absolute paths */
2507        if (*namep && **namep != '/')
2508                *namep += prefix_length;
2509        if (*otherp && **otherp != '/')
2510                *otherp += prefix_length;
2511}
2512
2513static void run_diff(struct diff_filepair *p, struct diff_options *o)
2514{
2515        const char *pgm = external_diff();
2516        struct strbuf msg;
2517        struct diff_filespec *one = p->one;
2518        struct diff_filespec *two = p->two;
2519        const char *name;
2520        const char *other;
2521        const char *attr_path;
2522
2523        name  = p->one->path;
2524        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2525        attr_path = name;
2526        if (o->prefix_length)
2527                strip_prefix(o->prefix_length, &name, &other);
2528
2529        if (DIFF_PAIR_UNMERGED(p)) {
2530                run_diff_cmd(pgm, name, NULL, attr_path,
2531                             NULL, NULL, NULL, o, p);
2532                return;
2533        }
2534
2535        diff_fill_sha1_info(one);
2536        diff_fill_sha1_info(two);
2537
2538        if (!pgm &&
2539            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2540            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2541                /*
2542                 * a filepair that changes between file and symlink
2543                 * needs to be split into deletion and creation.
2544                 */
2545                struct diff_filespec *null = alloc_filespec(two->path);
2546                run_diff_cmd(NULL, name, other, attr_path,
2547                             one, null, &msg, o, p);
2548                free(null);
2549                strbuf_release(&msg);
2550
2551                null = alloc_filespec(one->path);
2552                run_diff_cmd(NULL, name, other, attr_path,
2553                             null, two, &msg, o, p);
2554                free(null);
2555        }
2556        else
2557                run_diff_cmd(pgm, name, other, attr_path,
2558                             one, two, &msg, o, p);
2559
2560        strbuf_release(&msg);
2561}
2562
2563static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2564                         struct diffstat_t *diffstat)
2565{
2566        const char *name;
2567        const char *other;
2568        int complete_rewrite = 0;
2569
2570        if (DIFF_PAIR_UNMERGED(p)) {
2571                /* unmerged */
2572                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2573                return;
2574        }
2575
2576        name = p->one->path;
2577        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2578
2579        if (o->prefix_length)
2580                strip_prefix(o->prefix_length, &name, &other);
2581
2582        diff_fill_sha1_info(p->one);
2583        diff_fill_sha1_info(p->two);
2584
2585        if (p->status == DIFF_STATUS_MODIFIED && p->score)
2586                complete_rewrite = 1;
2587        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2588}
2589
2590static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2591{
2592        const char *name;
2593        const char *other;
2594        const char *attr_path;
2595
2596        if (DIFF_PAIR_UNMERGED(p)) {
2597                /* unmerged */
2598                return;
2599        }
2600
2601        name = p->one->path;
2602        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2603        attr_path = other ? other : name;
2604
2605        if (o->prefix_length)
2606                strip_prefix(o->prefix_length, &name, &other);
2607
2608        diff_fill_sha1_info(p->one);
2609        diff_fill_sha1_info(p->two);
2610
2611        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2612}
2613
2614void diff_setup(struct diff_options *options)
2615{
2616        memset(options, 0, sizeof(*options));
2617        memset(&diff_queued_diff, 0, sizeof(diff_queued_diff));
2618
2619        options->file = stdout;
2620
2621        options->line_termination = '\n';
2622        options->break_opt = -1;
2623        options->rename_limit = -1;
2624        options->dirstat_percent = 3;
2625        options->context = 3;
2626
2627        options->change = diff_change;
2628        options->add_remove = diff_addremove;
2629        if (diff_use_color_default > 0)
2630                DIFF_OPT_SET(options, COLOR_DIFF);
2631        options->detect_rename = diff_detect_rename_default;
2632
2633        if (diff_no_prefix) {
2634                options->a_prefix = options->b_prefix = "";
2635        } else if (!diff_mnemonic_prefix) {
2636                options->a_prefix = "a/";
2637                options->b_prefix = "b/";
2638        }
2639}
2640
2641int diff_setup_done(struct diff_options *options)
2642{
2643        int count = 0;
2644
2645        if (options->output_format & DIFF_FORMAT_NAME)
2646                count++;
2647        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
2648                count++;
2649        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
2650                count++;
2651        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
2652                count++;
2653        if (count > 1)
2654                die("--name-only, --name-status, --check and -s are mutually exclusive");
2655
2656        /*
2657         * Most of the time we can say "there are changes"
2658         * only by checking if there are changed paths, but
2659         * --ignore-whitespace* options force us to look
2660         * inside contents.
2661         */
2662
2663        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
2664            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
2665            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
2666                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
2667        else
2668                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
2669
2670        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
2671                options->detect_rename = DIFF_DETECT_COPY;
2672
2673        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
2674                options->prefix = NULL;
2675        if (options->prefix)
2676                options->prefix_length = strlen(options->prefix);
2677        else
2678                options->prefix_length = 0;
2679
2680        if (options->output_format & (DIFF_FORMAT_NAME |
2681                                      DIFF_FORMAT_NAME_STATUS |
2682                                      DIFF_FORMAT_CHECKDIFF |
2683                                      DIFF_FORMAT_NO_OUTPUT))
2684                options->output_format &= ~(DIFF_FORMAT_RAW |
2685                                            DIFF_FORMAT_NUMSTAT |
2686                                            DIFF_FORMAT_DIFFSTAT |
2687                                            DIFF_FORMAT_SHORTSTAT |
2688                                            DIFF_FORMAT_DIRSTAT |
2689                                            DIFF_FORMAT_SUMMARY |
2690                                            DIFF_FORMAT_PATCH);
2691
2692        /*
2693         * These cases always need recursive; we do not drop caller-supplied
2694         * recursive bits for other formats here.
2695         */
2696        if (options->output_format & (DIFF_FORMAT_PATCH |
2697                                      DIFF_FORMAT_NUMSTAT |
2698                                      DIFF_FORMAT_DIFFSTAT |
2699                                      DIFF_FORMAT_SHORTSTAT |
2700                                      DIFF_FORMAT_DIRSTAT |
2701                                      DIFF_FORMAT_SUMMARY |
2702                                      DIFF_FORMAT_CHECKDIFF))
2703                DIFF_OPT_SET(options, RECURSIVE);
2704        /*
2705         * Also pickaxe would not work very well if you do not say recursive
2706         */
2707        if (options->pickaxe)
2708                DIFF_OPT_SET(options, RECURSIVE);
2709        /*
2710         * When patches are generated, submodules diffed against the work tree
2711         * must be checked for dirtiness too so it can be shown in the output
2712         */
2713        if (options->output_format & DIFF_FORMAT_PATCH)
2714                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
2715
2716        if (options->detect_rename && options->rename_limit < 0)
2717                options->rename_limit = diff_rename_limit_default;
2718        if (options->setup & DIFF_SETUP_USE_CACHE) {
2719                if (!active_cache)
2720                        /* read-cache does not die even when it fails
2721                         * so it is safe for us to do this here.  Also
2722                         * it does not smudge active_cache or active_nr
2723                         * when it fails, so we do not have to worry about
2724                         * cleaning it up ourselves either.
2725                         */
2726                        read_cache();
2727        }
2728        if (options->abbrev <= 0 || 40 < options->abbrev)
2729                options->abbrev = 40; /* full */
2730
2731        /*
2732         * It does not make sense to show the first hit we happened
2733         * to have found.  It does not make sense not to return with
2734         * exit code in such a case either.
2735         */
2736        if (DIFF_OPT_TST(options, QUICK)) {
2737                options->output_format = DIFF_FORMAT_NO_OUTPUT;
2738                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2739        }
2740
2741        return 0;
2742}
2743
2744static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
2745{
2746        char c, *eq;
2747        int len;
2748
2749        if (*arg != '-')
2750                return 0;
2751        c = *++arg;
2752        if (!c)
2753                return 0;
2754        if (c == arg_short) {
2755                c = *++arg;
2756                if (!c)
2757                        return 1;
2758                if (val && isdigit(c)) {
2759                        char *end;
2760                        int n = strtoul(arg, &end, 10);
2761                        if (*end)
2762                                return 0;
2763                        *val = n;
2764                        return 1;
2765                }
2766                return 0;
2767        }
2768        if (c != '-')
2769                return 0;
2770        arg++;
2771        eq = strchr(arg, '=');
2772        if (eq)
2773                len = eq - arg;
2774        else
2775                len = strlen(arg);
2776        if (!len || strncmp(arg, arg_long, len))
2777                return 0;
2778        if (eq) {
2779                int n;
2780                char *end;
2781                if (!isdigit(*++eq))
2782                        return 0;
2783                n = strtoul(eq, &end, 10);
2784                if (*end)
2785                        return 0;
2786                *val = n;
2787        }
2788        return 1;
2789}
2790
2791static int diff_scoreopt_parse(const char *opt);
2792
2793int diff_opt_parse(struct diff_options *options, const char **av, int ac)
2794{
2795        const char *arg = av[0];
2796
2797        /* Output format options */
2798        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
2799                options->output_format |= DIFF_FORMAT_PATCH;
2800        else if (opt_arg(arg, 'U', "unified", &options->context))
2801                options->output_format |= DIFF_FORMAT_PATCH;
2802        else if (!strcmp(arg, "--raw"))
2803                options->output_format |= DIFF_FORMAT_RAW;
2804        else if (!strcmp(arg, "--patch-with-raw"))
2805                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
2806        else if (!strcmp(arg, "--numstat"))
2807                options->output_format |= DIFF_FORMAT_NUMSTAT;
2808        else if (!strcmp(arg, "--shortstat"))
2809                options->output_format |= DIFF_FORMAT_SHORTSTAT;
2810        else if (opt_arg(arg, 'X', "dirstat", &options->dirstat_percent))
2811                options->output_format |= DIFF_FORMAT_DIRSTAT;
2812        else if (!strcmp(arg, "--cumulative")) {
2813                options->output_format |= DIFF_FORMAT_DIRSTAT;
2814                DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
2815        } else if (opt_arg(arg, 0, "dirstat-by-file",
2816                           &options->dirstat_percent)) {
2817                options->output_format |= DIFF_FORMAT_DIRSTAT;
2818                DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
2819        }
2820        else if (!strcmp(arg, "--check"))
2821                options->output_format |= DIFF_FORMAT_CHECKDIFF;
2822        else if (!strcmp(arg, "--summary"))
2823                options->output_format |= DIFF_FORMAT_SUMMARY;
2824        else if (!strcmp(arg, "--patch-with-stat"))
2825                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
2826        else if (!strcmp(arg, "--name-only"))
2827                options->output_format |= DIFF_FORMAT_NAME;
2828        else if (!strcmp(arg, "--name-status"))
2829                options->output_format |= DIFF_FORMAT_NAME_STATUS;
2830        else if (!strcmp(arg, "-s"))
2831                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
2832        else if (!prefixcmp(arg, "--stat")) {
2833                char *end;
2834                int width = options->stat_width;
2835                int name_width = options->stat_name_width;
2836                arg += 6;
2837                end = (char *)arg;
2838
2839                switch (*arg) {
2840                case '-':
2841                        if (!prefixcmp(arg, "-width="))
2842                                width = strtoul(arg + 7, &end, 10);
2843                        else if (!prefixcmp(arg, "-name-width="))
2844                                name_width = strtoul(arg + 12, &end, 10);
2845                        break;
2846                case '=':
2847                        width = strtoul(arg+1, &end, 10);
2848                        if (*end == ',')
2849                                name_width = strtoul(end+1, &end, 10);
2850                }
2851
2852                /* Important! This checks all the error cases! */
2853                if (*end)
2854                        return 0;
2855                options->output_format |= DIFF_FORMAT_DIFFSTAT;
2856                options->stat_name_width = name_width;
2857                options->stat_width = width;
2858        }
2859
2860        /* renames options */
2861        else if (!prefixcmp(arg, "-B")) {
2862                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
2863                        return -1;
2864        }
2865        else if (!prefixcmp(arg, "-M")) {
2866                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2867                        return -1;
2868                options->detect_rename = DIFF_DETECT_RENAME;
2869        }
2870        else if (!prefixcmp(arg, "-C")) {
2871                if (options->detect_rename == DIFF_DETECT_COPY)
2872                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2873                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2874                        return -1;
2875                options->detect_rename = DIFF_DETECT_COPY;
2876        }
2877        else if (!strcmp(arg, "--no-renames"))
2878                options->detect_rename = 0;
2879        else if (!strcmp(arg, "--relative"))
2880                DIFF_OPT_SET(options, RELATIVE_NAME);
2881        else if (!prefixcmp(arg, "--relative=")) {
2882                DIFF_OPT_SET(options, RELATIVE_NAME);
2883                options->prefix = arg + 11;
2884        }
2885
2886        /* xdiff options */
2887        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
2888                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
2889        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
2890                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
2891        else if (!strcmp(arg, "--ignore-space-at-eol"))
2892                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
2893        else if (!strcmp(arg, "--patience"))
2894                DIFF_XDL_SET(options, PATIENCE_DIFF);
2895
2896        /* flags options */
2897        else if (!strcmp(arg, "--binary")) {
2898                options->output_format |= DIFF_FORMAT_PATCH;
2899                DIFF_OPT_SET(options, BINARY);
2900        }
2901        else if (!strcmp(arg, "--full-index"))
2902                DIFF_OPT_SET(options, FULL_INDEX);
2903        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
2904                DIFF_OPT_SET(options, TEXT);
2905        else if (!strcmp(arg, "-R"))
2906                DIFF_OPT_SET(options, REVERSE_DIFF);
2907        else if (!strcmp(arg, "--find-copies-harder"))
2908                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2909        else if (!strcmp(arg, "--follow"))
2910                DIFF_OPT_SET(options, FOLLOW_RENAMES);
2911        else if (!strcmp(arg, "--color"))
2912                DIFF_OPT_SET(options, COLOR_DIFF);
2913        else if (!prefixcmp(arg, "--color=")) {
2914                int value = git_config_colorbool(NULL, arg+8, -1);
2915                if (value == 0)
2916                        DIFF_OPT_CLR(options, COLOR_DIFF);
2917                else if (value > 0)
2918                        DIFF_OPT_SET(options, COLOR_DIFF);
2919                else
2920                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
2921        }
2922        else if (!strcmp(arg, "--no-color"))
2923                DIFF_OPT_CLR(options, COLOR_DIFF);
2924        else if (!strcmp(arg, "--color-words")) {
2925                DIFF_OPT_SET(options, COLOR_DIFF);
2926                options->word_diff = DIFF_WORDS_COLOR;
2927        }
2928        else if (!prefixcmp(arg, "--color-words=")) {
2929                DIFF_OPT_SET(options, COLOR_DIFF);
2930                options->word_diff = DIFF_WORDS_COLOR;
2931                options->word_regex = arg + 14;
2932        }
2933        else if (!strcmp(arg, "--word-diff")) {
2934                if (options->word_diff == DIFF_WORDS_NONE)
2935                        options->word_diff = DIFF_WORDS_PLAIN;
2936        }
2937        else if (!prefixcmp(arg, "--word-diff=")) {
2938                const char *type = arg + 12;
2939                if (!strcmp(type, "plain"))
2940                        options->word_diff = DIFF_WORDS_PLAIN;
2941                else if (!strcmp(type, "color")) {
2942                        DIFF_OPT_SET(options, COLOR_DIFF);
2943                        options->word_diff = DIFF_WORDS_COLOR;
2944                }
2945                else if (!strcmp(type, "porcelain"))
2946                        options->word_diff = DIFF_WORDS_PORCELAIN;
2947                else if (!strcmp(type, "none"))
2948                        options->word_diff = DIFF_WORDS_NONE;
2949                else
2950                        die("bad --word-diff argument: %s", type);
2951        }
2952        else if (!prefixcmp(arg, "--word-diff-regex=")) {
2953                if (options->word_diff == DIFF_WORDS_NONE)
2954                        options->word_diff = DIFF_WORDS_PLAIN;
2955                options->word_regex = arg + 18;
2956        }
2957        else if (!strcmp(arg, "--exit-code"))
2958                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2959        else if (!strcmp(arg, "--quiet"))
2960                DIFF_OPT_SET(options, QUICK);
2961        else if (!strcmp(arg, "--ext-diff"))
2962                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
2963        else if (!strcmp(arg, "--no-ext-diff"))
2964                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
2965        else if (!strcmp(arg, "--textconv"))
2966                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
2967        else if (!strcmp(arg, "--no-textconv"))
2968                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
2969        else if (!strcmp(arg, "--ignore-submodules"))
2970                DIFF_OPT_SET(options, IGNORE_SUBMODULES);
2971        else if (!strcmp(arg, "--submodule"))
2972                DIFF_OPT_SET(options, SUBMODULE_LOG);
2973        else if (!prefixcmp(arg, "--submodule=")) {
2974                if (!strcmp(arg + 12, "log"))
2975                        DIFF_OPT_SET(options, SUBMODULE_LOG);
2976        }
2977
2978        /* misc options */
2979        else if (!strcmp(arg, "-z"))
2980                options->line_termination = 0;
2981        else if (!prefixcmp(arg, "-l"))
2982                options->rename_limit = strtoul(arg+2, NULL, 10);
2983        else if (!prefixcmp(arg, "-S"))
2984                options->pickaxe = arg + 2;
2985        else if (!strcmp(arg, "--pickaxe-all"))
2986                options->pickaxe_opts = DIFF_PICKAXE_ALL;
2987        else if (!strcmp(arg, "--pickaxe-regex"))
2988                options->pickaxe_opts = DIFF_PICKAXE_REGEX;
2989        else if (!prefixcmp(arg, "-O"))
2990                options->orderfile = arg + 2;
2991        else if (!prefixcmp(arg, "--diff-filter="))
2992                options->filter = arg + 14;
2993        else if (!strcmp(arg, "--abbrev"))
2994                options->abbrev = DEFAULT_ABBREV;
2995        else if (!prefixcmp(arg, "--abbrev=")) {
2996                options->abbrev = strtoul(arg + 9, NULL, 10);
2997                if (options->abbrev < MINIMUM_ABBREV)
2998                        options->abbrev = MINIMUM_ABBREV;
2999                else if (40 < options->abbrev)
3000                        options->abbrev = 40;
3001        }
3002        else if (!prefixcmp(arg, "--src-prefix="))
3003                options->a_prefix = arg + 13;
3004        else if (!prefixcmp(arg, "--dst-prefix="))
3005                options->b_prefix = arg + 13;
3006        else if (!strcmp(arg, "--no-prefix"))
3007                options->a_prefix = options->b_prefix = "";
3008        else if (opt_arg(arg, '\0', "inter-hunk-context",
3009                         &options->interhunkcontext))
3010                ;
3011        else if (!prefixcmp(arg, "--output=")) {
3012                options->file = fopen(arg + strlen("--output="), "w");
3013                if (!options->file)
3014                        die_errno("Could not open '%s'", arg + strlen("--output="));
3015                options->close_file = 1;
3016        } else
3017                return 0;
3018        return 1;
3019}
3020
3021static int parse_num(const char **cp_p)
3022{
3023        unsigned long num, scale;
3024        int ch, dot;
3025        const char *cp = *cp_p;
3026
3027        num = 0;
3028        scale = 1;
3029        dot = 0;
3030        for (;;) {
3031                ch = *cp;
3032                if ( !dot && ch == '.' ) {
3033                        scale = 1;
3034                        dot = 1;
3035                } else if ( ch == '%' ) {
3036                        scale = dot ? scale*100 : 100;
3037                        cp++;   /* % is always at the end */
3038                        break;
3039                } else if ( ch >= '0' && ch <= '9' ) {
3040                        if ( scale < 100000 ) {
3041                                scale *= 10;
3042                                num = (num*10) + (ch-'0');
3043                        }
3044                } else {
3045                        break;
3046                }
3047                cp++;
3048        }
3049        *cp_p = cp;
3050
3051        /* user says num divided by scale and we say internally that
3052         * is MAX_SCORE * num / scale.
3053         */
3054        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3055}
3056
3057static int diff_scoreopt_parse(const char *opt)
3058{
3059        int opt1, opt2, cmd;
3060
3061        if (*opt++ != '-')
3062                return -1;
3063        cmd = *opt++;
3064        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3065                return -1; /* that is not a -M, -C nor -B option */
3066
3067        opt1 = parse_num(&opt);
3068        if (cmd != 'B')
3069                opt2 = 0;
3070        else {
3071                if (*opt == 0)
3072                        opt2 = 0;
3073                else if (*opt != '/')
3074                        return -1; /* we expect -B80/99 or -B80 */
3075                else {
3076                        opt++;
3077                        opt2 = parse_num(&opt);
3078                }
3079        }
3080        if (*opt != 0)
3081                return -1;
3082        return opt1 | (opt2 << 16);
3083}
3084
3085struct diff_queue_struct diff_queued_diff;
3086
3087void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3088{
3089        if (queue->alloc <= queue->nr) {
3090                queue->alloc = alloc_nr(queue->alloc);
3091                queue->queue = xrealloc(queue->queue,
3092                                        sizeof(dp) * queue->alloc);
3093        }
3094        queue->queue[queue->nr++] = dp;
3095}
3096
3097struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3098                                 struct diff_filespec *one,
3099                                 struct diff_filespec *two)
3100{
3101        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3102        dp->one = one;
3103        dp->two = two;
3104        if (queue)
3105                diff_q(queue, dp);
3106        return dp;
3107}
3108
3109void diff_free_filepair(struct diff_filepair *p)
3110{
3111        free_filespec(p->one);
3112        free_filespec(p->two);
3113        free(p);
3114}
3115
3116/* This is different from find_unique_abbrev() in that
3117 * it stuffs the result with dots for alignment.
3118 */
3119const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3120{
3121        int abblen;
3122        const char *abbrev;
3123        if (len == 40)
3124                return sha1_to_hex(sha1);
3125
3126        abbrev = find_unique_abbrev(sha1, len);
3127        abblen = strlen(abbrev);
3128        if (abblen < 37) {
3129                static char hex[41];
3130                if (len < abblen && abblen <= len + 2)
3131                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3132                else
3133                        sprintf(hex, "%s...", abbrev);
3134                return hex;
3135        }
3136        return sha1_to_hex(sha1);
3137}
3138
3139static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3140{
3141        int line_termination = opt->line_termination;
3142        int inter_name_termination = line_termination ? '\t' : '\0';
3143
3144        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3145                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3146                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3147                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3148        }
3149        if (p->score) {
3150                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3151                        inter_name_termination);
3152        } else {
3153                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3154        }
3155
3156        if (p->status == DIFF_STATUS_COPIED ||
3157            p->status == DIFF_STATUS_RENAMED) {
3158                const char *name_a, *name_b;
3159                name_a = p->one->path;
3160                name_b = p->two->path;
3161                strip_prefix(opt->prefix_length, &name_a, &name_b);
3162                write_name_quoted(name_a, opt->file, inter_name_termination);
3163                write_name_quoted(name_b, opt->file, line_termination);
3164        } else {
3165                const char *name_a, *name_b;
3166                name_a = p->one->mode ? p->one->path : p->two->path;
3167                name_b = NULL;
3168                strip_prefix(opt->prefix_length, &name_a, &name_b);
3169                write_name_quoted(name_a, opt->file, line_termination);
3170        }
3171}
3172
3173int diff_unmodified_pair(struct diff_filepair *p)
3174{
3175        /* This function is written stricter than necessary to support
3176         * the currently implemented transformers, but the idea is to
3177         * let transformers to produce diff_filepairs any way they want,
3178         * and filter and clean them up here before producing the output.
3179         */
3180        struct diff_filespec *one = p->one, *two = p->two;
3181
3182        if (DIFF_PAIR_UNMERGED(p))
3183                return 0; /* unmerged is interesting */
3184
3185        /* deletion, addition, mode or type change
3186         * and rename are all interesting.
3187         */
3188        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3189            DIFF_PAIR_MODE_CHANGED(p) ||
3190            strcmp(one->path, two->path))
3191                return 0;
3192
3193        /* both are valid and point at the same path.  that is, we are
3194         * dealing with a change.
3195         */
3196        if (one->sha1_valid && two->sha1_valid &&
3197            !hashcmp(one->sha1, two->sha1) &&
3198            !one->dirty_submodule && !two->dirty_submodule)
3199                return 1; /* no change */
3200        if (!one->sha1_valid && !two->sha1_valid)
3201                return 1; /* both look at the same file on the filesystem. */
3202        return 0;
3203}
3204
3205static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3206{
3207        if (diff_unmodified_pair(p))
3208                return;
3209
3210        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3211            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3212                return; /* no tree diffs in patch format */
3213
3214        run_diff(p, o);
3215}
3216
3217static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3218                            struct diffstat_t *diffstat)
3219{
3220        if (diff_unmodified_pair(p))
3221                return;
3222
3223        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3224            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3225                return; /* no tree diffs in patch format */
3226
3227        run_diffstat(p, o, diffstat);
3228}
3229
3230static void diff_flush_checkdiff(struct diff_filepair *p,
3231                struct diff_options *o)
3232{
3233        if (diff_unmodified_pair(p))
3234                return;
3235
3236        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3237            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3238                return; /* no tree diffs in patch format */
3239
3240        run_checkdiff(p, o);
3241}
3242
3243int diff_queue_is_empty(void)
3244{
3245        struct diff_queue_struct *q = &diff_queued_diff;
3246        int i;
3247        for (i = 0; i < q->nr; i++)
3248                if (!diff_unmodified_pair(q->queue[i]))
3249                        return 0;
3250        return 1;
3251}
3252
3253#if DIFF_DEBUG
3254void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3255{
3256        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3257                x, one ? one : "",
3258                s->path,
3259                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3260                s->mode,
3261                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3262        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3263                x, one ? one : "",
3264                s->size, s->xfrm_flags);
3265}
3266
3267void diff_debug_filepair(const struct diff_filepair *p, int i)
3268{
3269        diff_debug_filespec(p->one, i, "one");
3270        diff_debug_filespec(p->two, i, "two");
3271        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3272                p->score, p->status ? p->status : '?',
3273                p->one->rename_used, p->broken_pair);
3274}
3275
3276void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3277{
3278        int i;
3279        if (msg)
3280                fprintf(stderr, "%s\n", msg);
3281        fprintf(stderr, "q->nr = %d\n", q->nr);
3282        for (i = 0; i < q->nr; i++) {
3283                struct diff_filepair *p = q->queue[i];
3284                diff_debug_filepair(p, i);
3285        }
3286}
3287#endif
3288
3289static void diff_resolve_rename_copy(void)
3290{
3291        int i;
3292        struct diff_filepair *p;
3293        struct diff_queue_struct *q = &diff_queued_diff;
3294
3295        diff_debug_queue("resolve-rename-copy", q);
3296
3297        for (i = 0; i < q->nr; i++) {
3298                p = q->queue[i];
3299                p->status = 0; /* undecided */
3300                if (DIFF_PAIR_UNMERGED(p))
3301                        p->status = DIFF_STATUS_UNMERGED;
3302                else if (!DIFF_FILE_VALID(p->one))
3303                        p->status = DIFF_STATUS_ADDED;
3304                else if (!DIFF_FILE_VALID(p->two))
3305                        p->status = DIFF_STATUS_DELETED;
3306                else if (DIFF_PAIR_TYPE_CHANGED(p))
3307                        p->status = DIFF_STATUS_TYPE_CHANGED;
3308
3309                /* from this point on, we are dealing with a pair
3310                 * whose both sides are valid and of the same type, i.e.
3311                 * either in-place edit or rename/copy edit.
3312                 */
3313                else if (DIFF_PAIR_RENAME(p)) {
3314                        /*
3315                         * A rename might have re-connected a broken
3316                         * pair up, causing the pathnames to be the
3317                         * same again. If so, that's not a rename at
3318                         * all, just a modification..
3319                         *
3320                         * Otherwise, see if this source was used for
3321                         * multiple renames, in which case we decrement
3322                         * the count, and call it a copy.
3323                         */
3324                        if (!strcmp(p->one->path, p->two->path))
3325                                p->status = DIFF_STATUS_MODIFIED;
3326                        else if (--p->one->rename_used > 0)
3327                                p->status = DIFF_STATUS_COPIED;
3328                        else
3329                                p->status = DIFF_STATUS_RENAMED;
3330                }
3331                else if (hashcmp(p->one->sha1, p->two->sha1) ||
3332                         p->one->mode != p->two->mode ||
3333                         p->one->dirty_submodule ||
3334                         p->two->dirty_submodule ||
3335                         is_null_sha1(p->one->sha1))
3336                        p->status = DIFF_STATUS_MODIFIED;
3337                else {
3338                        /* This is a "no-change" entry and should not
3339                         * happen anymore, but prepare for broken callers.
3340                         */
3341                        error("feeding unmodified %s to diffcore",
3342                              p->one->path);
3343                        p->status = DIFF_STATUS_UNKNOWN;
3344                }
3345        }
3346        diff_debug_queue("resolve-rename-copy done", q);
3347}
3348
3349static int check_pair_status(struct diff_filepair *p)
3350{
3351        switch (p->status) {
3352        case DIFF_STATUS_UNKNOWN:
3353                return 0;
3354        case 0:
3355                die("internal error in diff-resolve-rename-copy");
3356        default:
3357                return 1;
3358        }
3359}
3360
3361static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3362{
3363        int fmt = opt->output_format;
3364
3365        if (fmt & DIFF_FORMAT_CHECKDIFF)
3366                diff_flush_checkdiff(p, opt);
3367        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3368                diff_flush_raw(p, opt);
3369        else if (fmt & DIFF_FORMAT_NAME) {
3370                const char *name_a, *name_b;
3371                name_a = p->two->path;
3372                name_b = NULL;
3373                strip_prefix(opt->prefix_length, &name_a, &name_b);
3374                write_name_quoted(name_a, opt->file, opt->line_termination);
3375        }
3376}
3377
3378static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
3379{
3380        if (fs->mode)
3381                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
3382        else
3383                fprintf(file, " %s ", newdelete);
3384        write_name_quoted(fs->path, file, '\n');
3385}
3386
3387
3388static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name)
3389{
3390        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
3391                fprintf(file, " mode change %06o => %06o%c", p->one->mode, p->two->mode,
3392                        show_name ? ' ' : '\n');
3393                if (show_name) {
3394                        write_name_quoted(p->two->path, file, '\n');
3395                }
3396        }
3397}
3398
3399static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p)
3400{
3401        char *names = pprint_rename(p->one->path, p->two->path);
3402
3403        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
3404        free(names);
3405        show_mode_change(file, p, 0);
3406}
3407
3408static void diff_summary(FILE *file, struct diff_filepair *p)
3409{
3410        switch(p->status) {
3411        case DIFF_STATUS_DELETED:
3412                show_file_mode_name(file, "delete", p->one);
3413                break;
3414        case DIFF_STATUS_ADDED:
3415                show_file_mode_name(file, "create", p->two);
3416                break;
3417        case DIFF_STATUS_COPIED:
3418                show_rename_copy(file, "copy", p);
3419                break;
3420        case DIFF_STATUS_RENAMED:
3421                show_rename_copy(file, "rename", p);
3422                break;
3423        default:
3424                if (p->score) {
3425                        fputs(" rewrite ", file);
3426                        write_name_quoted(p->two->path, file, ' ');
3427                        fprintf(file, "(%d%%)\n", similarity_index(p));
3428                }
3429                show_mode_change(file, p, !p->score);
3430                break;
3431        }
3432}
3433
3434struct patch_id_t {
3435        git_SHA_CTX *ctx;
3436        int patchlen;
3437};
3438
3439static int remove_space(char *line, int len)
3440{
3441        int i;
3442        char *dst = line;
3443        unsigned char c;
3444
3445        for (i = 0; i < len; i++)
3446                if (!isspace((c = line[i])))
3447                        *dst++ = c;
3448
3449        return dst - line;
3450}
3451
3452static void patch_id_consume(void *priv, char *line, unsigned long len)
3453{
3454        struct patch_id_t *data = priv;
3455        int new_len;
3456
3457        /* Ignore line numbers when computing the SHA1 of the patch */
3458        if (!prefixcmp(line, "@@ -"))
3459                return;
3460
3461        new_len = remove_space(line, len);
3462
3463        git_SHA1_Update(data->ctx, line, new_len);
3464        data->patchlen += new_len;
3465}
3466
3467/* returns 0 upon success, and writes result into sha1 */
3468static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
3469{
3470        struct diff_queue_struct *q = &diff_queued_diff;
3471        int i;
3472        git_SHA_CTX ctx;
3473        struct patch_id_t data;
3474        char buffer[PATH_MAX * 4 + 20];
3475
3476        git_SHA1_Init(&ctx);
3477        memset(&data, 0, sizeof(struct patch_id_t));
3478        data.ctx = &ctx;
3479
3480        for (i = 0; i < q->nr; i++) {
3481                xpparam_t xpp;
3482                xdemitconf_t xecfg;
3483                mmfile_t mf1, mf2;
3484                struct diff_filepair *p = q->queue[i];
3485                int len1, len2;
3486
3487                memset(&xpp, 0, sizeof(xpp));
3488                memset(&xecfg, 0, sizeof(xecfg));
3489                if (p->status == 0)
3490                        return error("internal diff status error");
3491                if (p->status == DIFF_STATUS_UNKNOWN)
3492                        continue;
3493                if (diff_unmodified_pair(p))
3494                        continue;
3495                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3496                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3497                        continue;
3498                if (DIFF_PAIR_UNMERGED(p))
3499                        continue;
3500
3501                diff_fill_sha1_info(p->one);
3502                diff_fill_sha1_info(p->two);
3503                if (fill_mmfile(&mf1, p->one) < 0 ||
3504                                fill_mmfile(&mf2, p->two) < 0)
3505                        return error("unable to read files to diff");
3506
3507                len1 = remove_space(p->one->path, strlen(p->one->path));
3508                len2 = remove_space(p->two->path, strlen(p->two->path));
3509                if (p->one->mode == 0)
3510                        len1 = snprintf(buffer, sizeof(buffer),
3511                                        "diff--gita/%.*sb/%.*s"
3512                                        "newfilemode%06o"
3513                                        "---/dev/null"
3514                                        "+++b/%.*s",
3515                                        len1, p->one->path,
3516                                        len2, p->two->path,
3517                                        p->two->mode,
3518                                        len2, p->two->path);
3519                else if (p->two->mode == 0)
3520                        len1 = snprintf(buffer, sizeof(buffer),
3521                                        "diff--gita/%.*sb/%.*s"
3522                                        "deletedfilemode%06o"
3523                                        "---a/%.*s"
3524                                        "+++/dev/null",
3525                                        len1, p->one->path,
3526                                        len2, p->two->path,
3527                                        p->one->mode,
3528                                        len1, p->one->path);
3529                else
3530                        len1 = snprintf(buffer, sizeof(buffer),
3531                                        "diff--gita/%.*sb/%.*s"
3532                                        "---a/%.*s"
3533                                        "+++b/%.*s",
3534                                        len1, p->one->path,
3535                                        len2, p->two->path,
3536                                        len1, p->one->path,
3537                                        len2, p->two->path);
3538                git_SHA1_Update(&ctx, buffer, len1);
3539
3540                xpp.flags = 0;
3541                xecfg.ctxlen = 3;
3542                xecfg.flags = XDL_EMIT_FUNCNAMES;
3543                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
3544                              &xpp, &xecfg);
3545        }
3546
3547        git_SHA1_Final(sha1, &ctx);
3548        return 0;
3549}
3550
3551int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
3552{
3553        struct diff_queue_struct *q = &diff_queued_diff;
3554        int i;
3555        int result = diff_get_patch_id(options, sha1);
3556
3557        for (i = 0; i < q->nr; i++)
3558                diff_free_filepair(q->queue[i]);
3559
3560        free(q->queue);
3561        DIFF_QUEUE_CLEAR(q);
3562
3563        return result;
3564}
3565
3566static int is_summary_empty(const struct diff_queue_struct *q)
3567{
3568        int i;
3569
3570        for (i = 0; i < q->nr; i++) {
3571                const struct diff_filepair *p = q->queue[i];
3572
3573                switch (p->status) {
3574                case DIFF_STATUS_DELETED:
3575                case DIFF_STATUS_ADDED:
3576                case DIFF_STATUS_COPIED:
3577                case DIFF_STATUS_RENAMED:
3578                        return 0;
3579                default:
3580                        if (p->score)
3581                                return 0;
3582                        if (p->one->mode && p->two->mode &&
3583                            p->one->mode != p->two->mode)
3584                                return 0;
3585                        break;
3586                }
3587        }
3588        return 1;
3589}
3590
3591void diff_flush(struct diff_options *options)
3592{
3593        struct diff_queue_struct *q = &diff_queued_diff;
3594        int i, output_format = options->output_format;
3595        int separator = 0;
3596
3597        /*
3598         * Order: raw, stat, summary, patch
3599         * or:    name/name-status/checkdiff (other bits clear)
3600         */
3601        if (!q->nr)
3602                goto free_queue;
3603
3604        if (output_format & (DIFF_FORMAT_RAW |
3605                             DIFF_FORMAT_NAME |
3606                             DIFF_FORMAT_NAME_STATUS |
3607                             DIFF_FORMAT_CHECKDIFF)) {
3608                for (i = 0; i < q->nr; i++) {
3609                        struct diff_filepair *p = q->queue[i];
3610                        if (check_pair_status(p))
3611                                flush_one_pair(p, options);
3612                }
3613                separator++;
3614        }
3615
3616        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
3617                struct diffstat_t diffstat;
3618
3619                memset(&diffstat, 0, sizeof(struct diffstat_t));
3620                for (i = 0; i < q->nr; i++) {
3621                        struct diff_filepair *p = q->queue[i];
3622                        if (check_pair_status(p))
3623                                diff_flush_stat(p, options, &diffstat);
3624                }
3625                if (output_format & DIFF_FORMAT_NUMSTAT)
3626                        show_numstat(&diffstat, options);
3627                if (output_format & DIFF_FORMAT_DIFFSTAT)
3628                        show_stats(&diffstat, options);
3629                if (output_format & DIFF_FORMAT_SHORTSTAT)
3630                        show_shortstats(&diffstat, options);
3631                free_diffstat_info(&diffstat);
3632                separator++;
3633        }
3634        if (output_format & DIFF_FORMAT_DIRSTAT)
3635                show_dirstat(options);
3636
3637        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
3638                for (i = 0; i < q->nr; i++)
3639                        diff_summary(options->file, q->queue[i]);
3640                separator++;
3641        }
3642
3643        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
3644            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
3645            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
3646                /*
3647                 * run diff_flush_patch for the exit status. setting
3648                 * options->file to /dev/null should be safe, becaue we
3649                 * aren't supposed to produce any output anyway.
3650                 */
3651                if (options->close_file)
3652                        fclose(options->file);
3653                options->file = fopen("/dev/null", "w");
3654                if (!options->file)
3655                        die_errno("Could not open /dev/null");
3656                options->close_file = 1;
3657                for (i = 0; i < q->nr; i++) {
3658                        struct diff_filepair *p = q->queue[i];
3659                        if (check_pair_status(p))
3660                                diff_flush_patch(p, options);
3661                        if (options->found_changes)
3662                                break;
3663                }
3664        }
3665
3666        if (output_format & DIFF_FORMAT_PATCH) {
3667                if (separator) {
3668                        putc(options->line_termination, options->file);
3669                        if (options->stat_sep) {
3670                                /* attach patch instead of inline */
3671                                fputs(options->stat_sep, options->file);
3672                        }
3673                }
3674
3675                for (i = 0; i < q->nr; i++) {
3676                        struct diff_filepair *p = q->queue[i];
3677                        if (check_pair_status(p))
3678                                diff_flush_patch(p, options);
3679                }
3680        }
3681
3682        if (output_format & DIFF_FORMAT_CALLBACK)
3683                options->format_callback(q, options, options->format_callback_data);
3684
3685        for (i = 0; i < q->nr; i++)
3686                diff_free_filepair(q->queue[i]);
3687free_queue:
3688        free(q->queue);
3689        DIFF_QUEUE_CLEAR(q);
3690        if (options->close_file)
3691                fclose(options->file);
3692
3693        /*
3694         * Report the content-level differences with HAS_CHANGES;
3695         * diff_addremove/diff_change does not set the bit when
3696         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
3697         */
3698        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
3699                if (options->found_changes)
3700                        DIFF_OPT_SET(options, HAS_CHANGES);
3701                else
3702                        DIFF_OPT_CLR(options, HAS_CHANGES);
3703        }
3704}
3705
3706static void diffcore_apply_filter(const char *filter)
3707{
3708        int i;
3709        struct diff_queue_struct *q = &diff_queued_diff;
3710        struct diff_queue_struct outq;
3711        DIFF_QUEUE_CLEAR(&outq);
3712
3713        if (!filter)
3714                return;
3715
3716        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
3717                int found;
3718                for (i = found = 0; !found && i < q->nr; i++) {
3719                        struct diff_filepair *p = q->queue[i];
3720                        if (((p->status == DIFF_STATUS_MODIFIED) &&
3721                             ((p->score &&
3722                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3723                              (!p->score &&
3724                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3725                            ((p->status != DIFF_STATUS_MODIFIED) &&
3726                             strchr(filter, p->status)))
3727                                found++;
3728                }
3729                if (found)
3730                        return;
3731
3732                /* otherwise we will clear the whole queue
3733                 * by copying the empty outq at the end of this
3734                 * function, but first clear the current entries
3735                 * in the queue.
3736                 */
3737                for (i = 0; i < q->nr; i++)
3738                        diff_free_filepair(q->queue[i]);
3739        }
3740        else {
3741                /* Only the matching ones */
3742                for (i = 0; i < q->nr; i++) {
3743                        struct diff_filepair *p = q->queue[i];
3744
3745                        if (((p->status == DIFF_STATUS_MODIFIED) &&
3746                             ((p->score &&
3747                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3748                              (!p->score &&
3749                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3750                            ((p->status != DIFF_STATUS_MODIFIED) &&
3751                             strchr(filter, p->status)))
3752                                diff_q(&outq, p);
3753                        else
3754                                diff_free_filepair(p);
3755                }
3756        }
3757        free(q->queue);
3758        *q = outq;
3759}
3760
3761/* Check whether two filespecs with the same mode and size are identical */
3762static int diff_filespec_is_identical(struct diff_filespec *one,
3763                                      struct diff_filespec *two)
3764{
3765        if (S_ISGITLINK(one->mode))
3766                return 0;
3767        if (diff_populate_filespec(one, 0))
3768                return 0;
3769        if (diff_populate_filespec(two, 0))
3770                return 0;
3771        return !memcmp(one->data, two->data, one->size);
3772}
3773
3774static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
3775{
3776        int i;
3777        struct diff_queue_struct *q = &diff_queued_diff;
3778        struct diff_queue_struct outq;
3779        DIFF_QUEUE_CLEAR(&outq);
3780
3781        for (i = 0; i < q->nr; i++) {
3782                struct diff_filepair *p = q->queue[i];
3783
3784                /*
3785                 * 1. Entries that come from stat info dirtiness
3786                 *    always have both sides (iow, not create/delete),
3787                 *    one side of the object name is unknown, with
3788                 *    the same mode and size.  Keep the ones that
3789                 *    do not match these criteria.  They have real
3790                 *    differences.
3791                 *
3792                 * 2. At this point, the file is known to be modified,
3793                 *    with the same mode and size, and the object
3794                 *    name of one side is unknown.  Need to inspect
3795                 *    the identical contents.
3796                 */
3797                if (!DIFF_FILE_VALID(p->one) || /* (1) */
3798                    !DIFF_FILE_VALID(p->two) ||
3799                    (p->one->sha1_valid && p->two->sha1_valid) ||
3800                    (p->one->mode != p->two->mode) ||
3801                    diff_populate_filespec(p->one, 1) ||
3802                    diff_populate_filespec(p->two, 1) ||
3803                    (p->one->size != p->two->size) ||
3804                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
3805                        diff_q(&outq, p);
3806                else {
3807                        /*
3808                         * The caller can subtract 1 from skip_stat_unmatch
3809                         * to determine how many paths were dirty only
3810                         * due to stat info mismatch.
3811                         */
3812                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
3813                                diffopt->skip_stat_unmatch++;
3814                        diff_free_filepair(p);
3815                }
3816        }
3817        free(q->queue);
3818        *q = outq;
3819}
3820
3821static int diffnamecmp(const void *a_, const void *b_)
3822{
3823        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
3824        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
3825        const char *name_a, *name_b;
3826
3827        name_a = a->one ? a->one->path : a->two->path;
3828        name_b = b->one ? b->one->path : b->two->path;
3829        return strcmp(name_a, name_b);
3830}
3831
3832void diffcore_fix_diff_index(struct diff_options *options)
3833{
3834        struct diff_queue_struct *q = &diff_queued_diff;
3835        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
3836}
3837
3838void diffcore_std(struct diff_options *options)
3839{
3840        /* We never run this function more than one time, because the
3841         * rename/copy detection logic can only run once.
3842         */
3843        if (diff_queued_diff.run)
3844                return;
3845
3846        if (options->skip_stat_unmatch)
3847                diffcore_skip_stat_unmatch(options);
3848        if (options->break_opt != -1)
3849                diffcore_break(options->break_opt);
3850        if (options->detect_rename)
3851                diffcore_rename(options);
3852        if (options->break_opt != -1)
3853                diffcore_merge_broken();
3854        if (options->pickaxe)
3855                diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
3856        if (options->orderfile)
3857                diffcore_order(options->orderfile);
3858        diff_resolve_rename_copy();
3859        diffcore_apply_filter(options->filter);
3860
3861        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
3862                DIFF_OPT_SET(options, HAS_CHANGES);
3863        else
3864                DIFF_OPT_CLR(options, HAS_CHANGES);
3865
3866        diff_queued_diff.run = 1;
3867}
3868
3869int diff_result_code(struct diff_options *opt, int status)
3870{
3871        int result = 0;
3872        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
3873            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
3874                return status;
3875        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
3876            DIFF_OPT_TST(opt, HAS_CHANGES))
3877                result |= 01;
3878        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
3879            DIFF_OPT_TST(opt, CHECK_FAILED))
3880                result |= 02;
3881        return result;
3882}
3883
3884void diff_addremove(struct diff_options *options,
3885                    int addremove, unsigned mode,
3886                    const unsigned char *sha1,
3887                    const char *concatpath, unsigned dirty_submodule)
3888{
3889        struct diff_filespec *one, *two;
3890
3891        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES) && S_ISGITLINK(mode))
3892                return;
3893
3894        /* This may look odd, but it is a preparation for
3895         * feeding "there are unchanged files which should
3896         * not produce diffs, but when you are doing copy
3897         * detection you would need them, so here they are"
3898         * entries to the diff-core.  They will be prefixed
3899         * with something like '=' or '*' (I haven't decided
3900         * which but should not make any difference).
3901         * Feeding the same new and old to diff_change()
3902         * also has the same effect.
3903         * Before the final output happens, they are pruned after
3904         * merged into rename/copy pairs as appropriate.
3905         */
3906        if (DIFF_OPT_TST(options, REVERSE_DIFF))
3907                addremove = (addremove == '+' ? '-' :
3908                             addremove == '-' ? '+' : addremove);
3909
3910        if (options->prefix &&
3911            strncmp(concatpath, options->prefix, options->prefix_length))
3912                return;
3913
3914        one = alloc_filespec(concatpath);
3915        two = alloc_filespec(concatpath);
3916
3917        if (addremove != '+')
3918                fill_filespec(one, sha1, mode);
3919        if (addremove != '-') {
3920                fill_filespec(two, sha1, mode);
3921                two->dirty_submodule = dirty_submodule;
3922        }
3923
3924        diff_queue(&diff_queued_diff, one, two);
3925        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
3926                DIFF_OPT_SET(options, HAS_CHANGES);
3927}
3928
3929void diff_change(struct diff_options *options,
3930                 unsigned old_mode, unsigned new_mode,
3931                 const unsigned char *old_sha1,
3932                 const unsigned char *new_sha1,
3933                 const char *concatpath,
3934                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
3935{
3936        struct diff_filespec *one, *two;
3937
3938        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES) && S_ISGITLINK(old_mode)
3939                        && S_ISGITLINK(new_mode))
3940                return;
3941
3942        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
3943                unsigned tmp;
3944                const unsigned char *tmp_c;
3945                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
3946                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
3947                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
3948                        new_dirty_submodule = tmp;
3949        }
3950
3951        if (options->prefix &&
3952            strncmp(concatpath, options->prefix, options->prefix_length))
3953                return;
3954
3955        one = alloc_filespec(concatpath);
3956        two = alloc_filespec(concatpath);
3957        fill_filespec(one, old_sha1, old_mode);
3958        fill_filespec(two, new_sha1, new_mode);
3959        one->dirty_submodule = old_dirty_submodule;
3960        two->dirty_submodule = new_dirty_submodule;
3961
3962        diff_queue(&diff_queued_diff, one, two);
3963        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
3964                DIFF_OPT_SET(options, HAS_CHANGES);
3965}
3966
3967void diff_unmerge(struct diff_options *options,
3968                  const char *path,
3969                  unsigned mode, const unsigned char *sha1)
3970{
3971        struct diff_filespec *one, *two;
3972
3973        if (options->prefix &&
3974            strncmp(path, options->prefix, options->prefix_length))
3975                return;
3976
3977        one = alloc_filespec(path);
3978        two = alloc_filespec(path);
3979        fill_filespec(one, sha1, mode);
3980        diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;
3981}
3982
3983static char *run_textconv(const char *pgm, struct diff_filespec *spec,
3984                size_t *outsize)
3985{
3986        struct diff_tempfile *temp;
3987        const char *argv[3];
3988        const char **arg = argv;
3989        struct child_process child;
3990        struct strbuf buf = STRBUF_INIT;
3991        int err = 0;
3992
3993        temp = prepare_temp_file(spec->path, spec);
3994        *arg++ = pgm;
3995        *arg++ = temp->name;
3996        *arg = NULL;
3997
3998        memset(&child, 0, sizeof(child));
3999        child.use_shell = 1;
4000        child.argv = argv;
4001        child.out = -1;
4002        if (start_command(&child)) {
4003                remove_tempfile();
4004                return NULL;
4005        }
4006
4007        if (strbuf_read(&buf, child.out, 0) < 0)
4008                err = error("error reading from textconv command '%s'", pgm);
4009        close(child.out);
4010
4011        if (finish_command(&child) || err) {
4012                strbuf_release(&buf);
4013                remove_tempfile();
4014                return NULL;
4015        }
4016        remove_tempfile();
4017
4018        return strbuf_detach(&buf, outsize);
4019}
4020
4021static size_t fill_textconv(struct userdiff_driver *driver,
4022                            struct diff_filespec *df,
4023                            char **outbuf)
4024{
4025        size_t size;
4026
4027        if (!driver || !driver->textconv) {
4028                if (!DIFF_FILE_VALID(df)) {
4029                        *outbuf = "";
4030                        return 0;
4031                }
4032                if (diff_populate_filespec(df, 0))
4033                        die("unable to read files to diff");
4034                *outbuf = df->data;
4035                return df->size;
4036        }
4037
4038        if (driver->textconv_cache) {
4039                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4040                                          &size);
4041                if (*outbuf)
4042                        return size;
4043        }
4044
4045        *outbuf = run_textconv(driver->textconv, df, &size);
4046        if (!*outbuf)
4047                die("unable to read files to diff");
4048
4049        if (driver->textconv_cache) {
4050                /* ignore errors, as we might be in a readonly repository */
4051                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4052                                size);
4053                /*
4054                 * we could save up changes and flush them all at the end,
4055                 * but we would need an extra call after all diffing is done.
4056                 * Since generating a cache entry is the slow path anyway,
4057                 * this extra overhead probably isn't a big deal.
4058                 */
4059                notes_cache_write(driver->textconv_cache);
4060        }
4061
4062        return size;
4063}