diff.con commit upload-pack: start pack-objects before async rev-list (b961219)
   1/*
   2 * Copyright (C) 2005 Junio C Hamano
   3 */
   4#include "cache.h"
   5#include "quote.h"
   6#include "diff.h"
   7#include "diffcore.h"
   8#include "delta.h"
   9#include "xdiff-interface.h"
  10#include "color.h"
  11#include "attr.h"
  12#include "run-command.h"
  13#include "utf8.h"
  14#include "userdiff.h"
  15#include "sigchain.h"
  16#include "submodule.h"
  17#include "ll-merge.h"
  18
  19#ifdef NO_FAST_WORKING_DIRECTORY
  20#define FAST_WORKING_DIRECTORY 0
  21#else
  22#define FAST_WORKING_DIRECTORY 1
  23#endif
  24
  25static int diff_detect_rename_default;
  26static int diff_rename_limit_default = 200;
  27static int diff_suppress_blank_empty;
  28int diff_use_color_default = -1;
  29static const char *diff_word_regex_cfg;
  30static const char *external_diff_cmd_cfg;
  31int diff_auto_refresh_index = 1;
  32static int diff_mnemonic_prefix;
  33static int diff_no_prefix;
  34static struct diff_options default_diff_options;
  35
  36static char diff_colors[][COLOR_MAXLEN] = {
  37        GIT_COLOR_RESET,
  38        GIT_COLOR_NORMAL,       /* PLAIN */
  39        GIT_COLOR_BOLD,         /* METAINFO */
  40        GIT_COLOR_CYAN,         /* FRAGINFO */
  41        GIT_COLOR_RED,          /* OLD */
  42        GIT_COLOR_GREEN,        /* NEW */
  43        GIT_COLOR_YELLOW,       /* COMMIT */
  44        GIT_COLOR_BG_RED,       /* WHITESPACE */
  45        GIT_COLOR_NORMAL,       /* FUNCINFO */
  46};
  47
  48static int parse_diff_color_slot(const char *var, int ofs)
  49{
  50        if (!strcasecmp(var+ofs, "plain"))
  51                return DIFF_PLAIN;
  52        if (!strcasecmp(var+ofs, "meta"))
  53                return DIFF_METAINFO;
  54        if (!strcasecmp(var+ofs, "frag"))
  55                return DIFF_FRAGINFO;
  56        if (!strcasecmp(var+ofs, "old"))
  57                return DIFF_FILE_OLD;
  58        if (!strcasecmp(var+ofs, "new"))
  59                return DIFF_FILE_NEW;
  60        if (!strcasecmp(var+ofs, "commit"))
  61                return DIFF_COMMIT;
  62        if (!strcasecmp(var+ofs, "whitespace"))
  63                return DIFF_WHITESPACE;
  64        if (!strcasecmp(var+ofs, "func"))
  65                return DIFF_FUNCINFO;
  66        return -1;
  67}
  68
  69static int git_config_rename(const char *var, const char *value)
  70{
  71        if (!value)
  72                return DIFF_DETECT_RENAME;
  73        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
  74                return  DIFF_DETECT_COPY;
  75        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
  76}
  77
  78/*
  79 * These are to give UI layer defaults.
  80 * The core-level commands such as git-diff-files should
  81 * never be affected by the setting of diff.renames
  82 * the user happens to have in the configuration file.
  83 */
  84int git_diff_ui_config(const char *var, const char *value, void *cb)
  85{
  86        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
  87                diff_use_color_default = git_config_colorbool(var, value, -1);
  88                return 0;
  89        }
  90        if (!strcmp(var, "diff.renames")) {
  91                diff_detect_rename_default = git_config_rename(var, value);
  92                return 0;
  93        }
  94        if (!strcmp(var, "diff.autorefreshindex")) {
  95                diff_auto_refresh_index = git_config_bool(var, value);
  96                return 0;
  97        }
  98        if (!strcmp(var, "diff.mnemonicprefix")) {
  99                diff_mnemonic_prefix = git_config_bool(var, value);
 100                return 0;
 101        }
 102        if (!strcmp(var, "diff.noprefix")) {
 103                diff_no_prefix = git_config_bool(var, value);
 104                return 0;
 105        }
 106        if (!strcmp(var, "diff.external"))
 107                return git_config_string(&external_diff_cmd_cfg, var, value);
 108        if (!strcmp(var, "diff.wordregex"))
 109                return git_config_string(&diff_word_regex_cfg, var, value);
 110
 111        if (!strcmp(var, "diff.ignoresubmodules"))
 112                handle_ignore_submodules_arg(&default_diff_options, value);
 113
 114        return git_diff_basic_config(var, value, cb);
 115}
 116
 117int git_diff_basic_config(const char *var, const char *value, void *cb)
 118{
 119        if (!strcmp(var, "diff.renamelimit")) {
 120                diff_rename_limit_default = git_config_int(var, value);
 121                return 0;
 122        }
 123
 124        switch (userdiff_config(var, value)) {
 125                case 0: break;
 126                case -1: return -1;
 127                default: return 0;
 128        }
 129
 130        if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
 131                int slot = parse_diff_color_slot(var, 11);
 132                if (slot < 0)
 133                        return 0;
 134                if (!value)
 135                        return config_error_nonbool(var);
 136                color_parse(value, var, diff_colors[slot]);
 137                return 0;
 138        }
 139
 140        /* like GNU diff's --suppress-blank-empty option  */
 141        if (!strcmp(var, "diff.suppressblankempty") ||
 142                        /* for backwards compatibility */
 143                        !strcmp(var, "diff.suppress-blank-empty")) {
 144                diff_suppress_blank_empty = git_config_bool(var, value);
 145                return 0;
 146        }
 147
 148        if (!prefixcmp(var, "submodule."))
 149                return parse_submodule_config_option(var, value);
 150
 151        return git_color_default_config(var, value, cb);
 152}
 153
 154static char *quote_two(const char *one, const char *two)
 155{
 156        int need_one = quote_c_style(one, NULL, NULL, 1);
 157        int need_two = quote_c_style(two, NULL, NULL, 1);
 158        struct strbuf res = STRBUF_INIT;
 159
 160        if (need_one + need_two) {
 161                strbuf_addch(&res, '"');
 162                quote_c_style(one, &res, NULL, 1);
 163                quote_c_style(two, &res, NULL, 1);
 164                strbuf_addch(&res, '"');
 165        } else {
 166                strbuf_addstr(&res, one);
 167                strbuf_addstr(&res, two);
 168        }
 169        return strbuf_detach(&res, NULL);
 170}
 171
 172static const char *external_diff(void)
 173{
 174        static const char *external_diff_cmd = NULL;
 175        static int done_preparing = 0;
 176
 177        if (done_preparing)
 178                return external_diff_cmd;
 179        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 180        if (!external_diff_cmd)
 181                external_diff_cmd = external_diff_cmd_cfg;
 182        done_preparing = 1;
 183        return external_diff_cmd;
 184}
 185
 186static struct diff_tempfile {
 187        const char *name; /* filename external diff should read from */
 188        char hex[41];
 189        char mode[10];
 190        char tmp_path[PATH_MAX];
 191} diff_temp[2];
 192
 193typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 194
 195struct emit_callback {
 196        int color_diff;
 197        unsigned ws_rule;
 198        int blank_at_eof_in_preimage;
 199        int blank_at_eof_in_postimage;
 200        int lno_in_preimage;
 201        int lno_in_postimage;
 202        sane_truncate_fn truncate;
 203        const char **label_path;
 204        struct diff_words_data *diff_words;
 205        struct diff_options *opt;
 206        int *found_changesp;
 207        struct strbuf *header;
 208};
 209
 210static int count_lines(const char *data, int size)
 211{
 212        int count, ch, completely_empty = 1, nl_just_seen = 0;
 213        count = 0;
 214        while (0 < size--) {
 215                ch = *data++;
 216                if (ch == '\n') {
 217                        count++;
 218                        nl_just_seen = 1;
 219                        completely_empty = 0;
 220                }
 221                else {
 222                        nl_just_seen = 0;
 223                        completely_empty = 0;
 224                }
 225        }
 226        if (completely_empty)
 227                return 0;
 228        if (!nl_just_seen)
 229                count++; /* no trailing newline */
 230        return count;
 231}
 232
 233static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 234{
 235        if (!DIFF_FILE_VALID(one)) {
 236                mf->ptr = (char *)""; /* does not matter */
 237                mf->size = 0;
 238                return 0;
 239        }
 240        else if (diff_populate_filespec(one, 0))
 241                return -1;
 242
 243        mf->ptr = one->data;
 244        mf->size = one->size;
 245        return 0;
 246}
 247
 248/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 249static unsigned long diff_filespec_size(struct diff_filespec *one)
 250{
 251        if (!DIFF_FILE_VALID(one))
 252                return 0;
 253        diff_populate_filespec(one, 1);
 254        return one->size;
 255}
 256
 257static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 258{
 259        char *ptr = mf->ptr;
 260        long size = mf->size;
 261        int cnt = 0;
 262
 263        if (!size)
 264                return cnt;
 265        ptr += size - 1; /* pointing at the very end */
 266        if (*ptr != '\n')
 267                ; /* incomplete line */
 268        else
 269                ptr--; /* skip the last LF */
 270        while (mf->ptr < ptr) {
 271                char *prev_eol;
 272                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 273                        if (*prev_eol == '\n')
 274                                break;
 275                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 276                        break;
 277                cnt++;
 278                ptr = prev_eol - 1;
 279        }
 280        return cnt;
 281}
 282
 283static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 284                               struct emit_callback *ecbdata)
 285{
 286        int l1, l2, at;
 287        unsigned ws_rule = ecbdata->ws_rule;
 288        l1 = count_trailing_blank(mf1, ws_rule);
 289        l2 = count_trailing_blank(mf2, ws_rule);
 290        if (l2 <= l1) {
 291                ecbdata->blank_at_eof_in_preimage = 0;
 292                ecbdata->blank_at_eof_in_postimage = 0;
 293                return;
 294        }
 295        at = count_lines(mf1->ptr, mf1->size);
 296        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 297
 298        at = count_lines(mf2->ptr, mf2->size);
 299        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 300}
 301
 302static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 303                        int first, const char *line, int len)
 304{
 305        int has_trailing_newline, has_trailing_carriage_return;
 306        int nofirst;
 307        FILE *file = o->file;
 308
 309        if (o->output_prefix) {
 310                struct strbuf *msg = NULL;
 311                msg = o->output_prefix(o, o->output_prefix_data);
 312                assert(msg);
 313                fwrite(msg->buf, msg->len, 1, file);
 314        }
 315
 316        if (len == 0) {
 317                has_trailing_newline = (first == '\n');
 318                has_trailing_carriage_return = (!has_trailing_newline &&
 319                                                (first == '\r'));
 320                nofirst = has_trailing_newline || has_trailing_carriage_return;
 321        } else {
 322                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 323                if (has_trailing_newline)
 324                        len--;
 325                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 326                if (has_trailing_carriage_return)
 327                        len--;
 328                nofirst = 0;
 329        }
 330
 331        if (len || !nofirst) {
 332                fputs(set, file);
 333                if (!nofirst)
 334                        fputc(first, file);
 335                fwrite(line, len, 1, file);
 336                fputs(reset, file);
 337        }
 338        if (has_trailing_carriage_return)
 339                fputc('\r', file);
 340        if (has_trailing_newline)
 341                fputc('\n', file);
 342}
 343
 344static void emit_line(struct diff_options *o, const char *set, const char *reset,
 345                      const char *line, int len)
 346{
 347        emit_line_0(o, set, reset, line[0], line+1, len-1);
 348}
 349
 350static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 351{
 352        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 353              ecbdata->blank_at_eof_in_preimage &&
 354              ecbdata->blank_at_eof_in_postimage &&
 355              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 356              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 357                return 0;
 358        return ws_blank_line(line, len, ecbdata->ws_rule);
 359}
 360
 361static void emit_add_line(const char *reset,
 362                          struct emit_callback *ecbdata,
 363                          const char *line, int len)
 364{
 365        const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 366        const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 367
 368        if (!*ws)
 369                emit_line_0(ecbdata->opt, set, reset, '+', line, len);
 370        else if (new_blank_line_at_eof(ecbdata, line, len))
 371                /* Blank line at EOF - paint '+' as well */
 372                emit_line_0(ecbdata->opt, ws, reset, '+', line, len);
 373        else {
 374                /* Emit just the prefix, then the rest. */
 375                emit_line_0(ecbdata->opt, set, reset, '+', "", 0);
 376                ws_check_emit(line, len, ecbdata->ws_rule,
 377                              ecbdata->opt->file, set, reset, ws);
 378        }
 379}
 380
 381static void emit_hunk_header(struct emit_callback *ecbdata,
 382                             const char *line, int len)
 383{
 384        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 385        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 386        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 387        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 388        static const char atat[2] = { '@', '@' };
 389        const char *cp, *ep;
 390        struct strbuf msgbuf = STRBUF_INIT;
 391        int org_len = len;
 392        int i = 1;
 393
 394        /*
 395         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 396         * it always is at least 10 bytes long.
 397         */
 398        if (len < 10 ||
 399            memcmp(line, atat, 2) ||
 400            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 401                emit_line(ecbdata->opt, plain, reset, line, len);
 402                return;
 403        }
 404        ep += 2; /* skip over @@ */
 405
 406        /* The hunk header in fraginfo color */
 407        strbuf_add(&msgbuf, frag, strlen(frag));
 408        strbuf_add(&msgbuf, line, ep - line);
 409        strbuf_add(&msgbuf, reset, strlen(reset));
 410
 411        /*
 412         * trailing "\r\n"
 413         */
 414        for ( ; i < 3; i++)
 415                if (line[len - i] == '\r' || line[len - i] == '\n')
 416                        len--;
 417
 418        /* blank before the func header */
 419        for (cp = ep; ep - line < len; ep++)
 420                if (*ep != ' ' && *ep != '\t')
 421                        break;
 422        if (ep != cp) {
 423                strbuf_add(&msgbuf, plain, strlen(plain));
 424                strbuf_add(&msgbuf, cp, ep - cp);
 425                strbuf_add(&msgbuf, reset, strlen(reset));
 426        }
 427
 428        if (ep < line + len) {
 429                strbuf_add(&msgbuf, func, strlen(func));
 430                strbuf_add(&msgbuf, ep, line + len - ep);
 431                strbuf_add(&msgbuf, reset, strlen(reset));
 432        }
 433
 434        strbuf_add(&msgbuf, line + len, org_len - len);
 435        emit_line(ecbdata->opt, "", "", msgbuf.buf, msgbuf.len);
 436        strbuf_release(&msgbuf);
 437}
 438
 439static struct diff_tempfile *claim_diff_tempfile(void) {
 440        int i;
 441        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 442                if (!diff_temp[i].name)
 443                        return diff_temp + i;
 444        die("BUG: diff is failing to clean up its tempfiles");
 445}
 446
 447static int remove_tempfile_installed;
 448
 449static void remove_tempfile(void)
 450{
 451        int i;
 452        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 453                if (diff_temp[i].name == diff_temp[i].tmp_path)
 454                        unlink_or_warn(diff_temp[i].name);
 455                diff_temp[i].name = NULL;
 456        }
 457}
 458
 459static void remove_tempfile_on_signal(int signo)
 460{
 461        remove_tempfile();
 462        sigchain_pop(signo);
 463        raise(signo);
 464}
 465
 466static void print_line_count(FILE *file, int count)
 467{
 468        switch (count) {
 469        case 0:
 470                fprintf(file, "0,0");
 471                break;
 472        case 1:
 473                fprintf(file, "1");
 474                break;
 475        default:
 476                fprintf(file, "1,%d", count);
 477                break;
 478        }
 479}
 480
 481static void emit_rewrite_lines(struct emit_callback *ecb,
 482                               int prefix, const char *data, int size)
 483{
 484        const char *endp = NULL;
 485        static const char *nneof = " No newline at end of file\n";
 486        const char *old = diff_get_color(ecb->color_diff, DIFF_FILE_OLD);
 487        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 488
 489        while (0 < size) {
 490                int len;
 491
 492                endp = memchr(data, '\n', size);
 493                len = endp ? (endp - data + 1) : size;
 494                if (prefix != '+') {
 495                        ecb->lno_in_preimage++;
 496                        emit_line_0(ecb->opt, old, reset, '-',
 497                                    data, len);
 498                } else {
 499                        ecb->lno_in_postimage++;
 500                        emit_add_line(reset, ecb, data, len);
 501                }
 502                size -= len;
 503                data += len;
 504        }
 505        if (!endp) {
 506                const char *plain = diff_get_color(ecb->color_diff,
 507                                                   DIFF_PLAIN);
 508                emit_line_0(ecb->opt, plain, reset, '\\',
 509                            nneof, strlen(nneof));
 510        }
 511}
 512
 513static void emit_rewrite_diff(const char *name_a,
 514                              const char *name_b,
 515                              struct diff_filespec *one,
 516                              struct diff_filespec *two,
 517                              struct userdiff_driver *textconv_one,
 518                              struct userdiff_driver *textconv_two,
 519                              struct diff_options *o)
 520{
 521        int lc_a, lc_b;
 522        int color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
 523        const char *name_a_tab, *name_b_tab;
 524        const char *metainfo = diff_get_color(color_diff, DIFF_METAINFO);
 525        const char *fraginfo = diff_get_color(color_diff, DIFF_FRAGINFO);
 526        const char *reset = diff_get_color(color_diff, DIFF_RESET);
 527        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 528        const char *a_prefix, *b_prefix;
 529        char *data_one, *data_two;
 530        size_t size_one, size_two;
 531        struct emit_callback ecbdata;
 532        char *line_prefix = "";
 533        struct strbuf *msgbuf;
 534
 535        if (o && o->output_prefix) {
 536                msgbuf = o->output_prefix(o, o->output_prefix_data);
 537                line_prefix = msgbuf->buf;
 538        }
 539
 540        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 541                a_prefix = o->b_prefix;
 542                b_prefix = o->a_prefix;
 543        } else {
 544                a_prefix = o->a_prefix;
 545                b_prefix = o->b_prefix;
 546        }
 547
 548        name_a += (*name_a == '/');
 549        name_b += (*name_b == '/');
 550        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 551        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 552
 553        strbuf_reset(&a_name);
 554        strbuf_reset(&b_name);
 555        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 556        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 557
 558        size_one = fill_textconv(textconv_one, one, &data_one);
 559        size_two = fill_textconv(textconv_two, two, &data_two);
 560
 561        memset(&ecbdata, 0, sizeof(ecbdata));
 562        ecbdata.color_diff = color_diff;
 563        ecbdata.found_changesp = &o->found_changes;
 564        ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
 565        ecbdata.opt = o;
 566        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 567                mmfile_t mf1, mf2;
 568                mf1.ptr = (char *)data_one;
 569                mf2.ptr = (char *)data_two;
 570                mf1.size = size_one;
 571                mf2.size = size_two;
 572                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 573        }
 574        ecbdata.lno_in_preimage = 1;
 575        ecbdata.lno_in_postimage = 1;
 576
 577        lc_a = count_lines(data_one, size_one);
 578        lc_b = count_lines(data_two, size_two);
 579        fprintf(o->file,
 580                "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
 581                line_prefix, metainfo, a_name.buf, name_a_tab, reset,
 582                line_prefix, metainfo, b_name.buf, name_b_tab, reset,
 583                line_prefix, fraginfo);
 584        print_line_count(o->file, lc_a);
 585        fprintf(o->file, " +");
 586        print_line_count(o->file, lc_b);
 587        fprintf(o->file, " @@%s\n", reset);
 588        if (lc_a)
 589                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 590        if (lc_b)
 591                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 592        if (textconv_one)
 593                free((char *)data_one);
 594        if (textconv_two)
 595                free((char *)data_two);
 596}
 597
 598struct diff_words_buffer {
 599        mmfile_t text;
 600        long alloc;
 601        struct diff_words_orig {
 602                const char *begin, *end;
 603        } *orig;
 604        int orig_nr, orig_alloc;
 605};
 606
 607static void diff_words_append(char *line, unsigned long len,
 608                struct diff_words_buffer *buffer)
 609{
 610        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 611        line++;
 612        len--;
 613        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 614        buffer->text.size += len;
 615        buffer->text.ptr[buffer->text.size] = '\0';
 616}
 617
 618struct diff_words_style_elem {
 619        const char *prefix;
 620        const char *suffix;
 621        const char *color; /* NULL; filled in by the setup code if
 622                            * color is enabled */
 623};
 624
 625struct diff_words_style {
 626        enum diff_words_type type;
 627        struct diff_words_style_elem new, old, ctx;
 628        const char *newline;
 629};
 630
 631struct diff_words_style diff_words_styles[] = {
 632        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 633        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 634        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 635};
 636
 637struct diff_words_data {
 638        struct diff_words_buffer minus, plus;
 639        const char *current_plus;
 640        int last_minus;
 641        struct diff_options *opt;
 642        regex_t *word_regex;
 643        enum diff_words_type type;
 644        struct diff_words_style *style;
 645};
 646
 647static int fn_out_diff_words_write_helper(FILE *fp,
 648                                          struct diff_words_style_elem *st_el,
 649                                          const char *newline,
 650                                          size_t count, const char *buf,
 651                                          const char *line_prefix)
 652{
 653        int print = 0;
 654
 655        while (count) {
 656                char *p = memchr(buf, '\n', count);
 657                if (print)
 658                        fputs(line_prefix, fp);
 659                if (p != buf) {
 660                        if (st_el->color && fputs(st_el->color, fp) < 0)
 661                                return -1;
 662                        if (fputs(st_el->prefix, fp) < 0 ||
 663                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 664                            fputs(st_el->suffix, fp) < 0)
 665                                return -1;
 666                        if (st_el->color && *st_el->color
 667                            && fputs(GIT_COLOR_RESET, fp) < 0)
 668                                return -1;
 669                }
 670                if (!p)
 671                        return 0;
 672                if (fputs(newline, fp) < 0)
 673                        return -1;
 674                count -= p + 1 - buf;
 675                buf = p + 1;
 676                print = 1;
 677        }
 678        return 0;
 679}
 680
 681/*
 682 * '--color-words' algorithm can be described as:
 683 *
 684 *   1. collect a the minus/plus lines of a diff hunk, divided into
 685 *      minus-lines and plus-lines;
 686 *
 687 *   2. break both minus-lines and plus-lines into words and
 688 *      place them into two mmfile_t with one word for each line;
 689 *
 690 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
 691 *
 692 * And for the common parts of the both file, we output the plus side text.
 693 * diff_words->current_plus is used to trace the current position of the plus file
 694 * which printed. diff_words->last_minus is used to trace the last minus word
 695 * printed.
 696 *
 697 * For '--graph' to work with '--color-words', we need to output the graph prefix
 698 * on each line of color words output. Generally, there are two conditions on
 699 * which we should output the prefix.
 700 *
 701 *   1. diff_words->last_minus == 0 &&
 702 *      diff_words->current_plus == diff_words->plus.text.ptr
 703 *
 704 *      that is: the plus text must start as a new line, and if there is no minus
 705 *      word printed, a graph prefix must be printed.
 706 *
 707 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
 708 *      *(diff_words->current_plus - 1) == '\n'
 709 *
 710 *      that is: a graph prefix must be printed following a '\n'
 711 */
 712static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
 713{
 714        if ((diff_words->last_minus == 0 &&
 715                diff_words->current_plus == diff_words->plus.text.ptr) ||
 716                (diff_words->current_plus > diff_words->plus.text.ptr &&
 717                *(diff_words->current_plus - 1) == '\n')) {
 718                return 1;
 719        } else {
 720                return 0;
 721        }
 722}
 723
 724static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 725{
 726        struct diff_words_data *diff_words = priv;
 727        struct diff_words_style *style = diff_words->style;
 728        int minus_first, minus_len, plus_first, plus_len;
 729        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 730        struct diff_options *opt = diff_words->opt;
 731        struct strbuf *msgbuf;
 732        char *line_prefix = "";
 733
 734        if (line[0] != '@' || parse_hunk_header(line, len,
 735                        &minus_first, &minus_len, &plus_first, &plus_len))
 736                return;
 737
 738        assert(opt);
 739        if (opt->output_prefix) {
 740                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 741                line_prefix = msgbuf->buf;
 742        }
 743
 744        /* POSIX requires that first be decremented by one if len == 0... */
 745        if (minus_len) {
 746                minus_begin = diff_words->minus.orig[minus_first].begin;
 747                minus_end =
 748                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 749        } else
 750                minus_begin = minus_end =
 751                        diff_words->minus.orig[minus_first].end;
 752
 753        if (plus_len) {
 754                plus_begin = diff_words->plus.orig[plus_first].begin;
 755                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 756        } else
 757                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 758
 759        if (color_words_output_graph_prefix(diff_words)) {
 760                fputs(line_prefix, diff_words->opt->file);
 761        }
 762        if (diff_words->current_plus != plus_begin) {
 763                fn_out_diff_words_write_helper(diff_words->opt->file,
 764                                &style->ctx, style->newline,
 765                                plus_begin - diff_words->current_plus,
 766                                diff_words->current_plus, line_prefix);
 767                if (*(plus_begin - 1) == '\n')
 768                        fputs(line_prefix, diff_words->opt->file);
 769        }
 770        if (minus_begin != minus_end) {
 771                fn_out_diff_words_write_helper(diff_words->opt->file,
 772                                &style->old, style->newline,
 773                                minus_end - minus_begin, minus_begin,
 774                                line_prefix);
 775        }
 776        if (plus_begin != plus_end) {
 777                fn_out_diff_words_write_helper(diff_words->opt->file,
 778                                &style->new, style->newline,
 779                                plus_end - plus_begin, plus_begin,
 780                                line_prefix);
 781        }
 782
 783        diff_words->current_plus = plus_end;
 784        diff_words->last_minus = minus_first;
 785}
 786
 787/* This function starts looking at *begin, and returns 0 iff a word was found. */
 788static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 789                int *begin, int *end)
 790{
 791        if (word_regex && *begin < buffer->size) {
 792                regmatch_t match[1];
 793                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 794                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 795                                        '\n', match[0].rm_eo - match[0].rm_so);
 796                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 797                        *begin += match[0].rm_so;
 798                        return *begin >= *end;
 799                }
 800                return -1;
 801        }
 802
 803        /* find the next word */
 804        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 805                (*begin)++;
 806        if (*begin >= buffer->size)
 807                return -1;
 808
 809        /* find the end of the word */
 810        *end = *begin + 1;
 811        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 812                (*end)++;
 813
 814        return 0;
 815}
 816
 817/*
 818 * This function splits the words in buffer->text, stores the list with
 819 * newline separator into out, and saves the offsets of the original words
 820 * in buffer->orig.
 821 */
 822static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 823                regex_t *word_regex)
 824{
 825        int i, j;
 826        long alloc = 0;
 827
 828        out->size = 0;
 829        out->ptr = NULL;
 830
 831        /* fake an empty "0th" word */
 832        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 833        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 834        buffer->orig_nr = 1;
 835
 836        for (i = 0; i < buffer->text.size; i++) {
 837                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 838                        return;
 839
 840                /* store original boundaries */
 841                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 842                                buffer->orig_alloc);
 843                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 844                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 845                buffer->orig_nr++;
 846
 847                /* store one word */
 848                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 849                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 850                out->ptr[out->size + j - i] = '\n';
 851                out->size += j - i + 1;
 852
 853                i = j - 1;
 854        }
 855}
 856
 857/* this executes the word diff on the accumulated buffers */
 858static void diff_words_show(struct diff_words_data *diff_words)
 859{
 860        xpparam_t xpp;
 861        xdemitconf_t xecfg;
 862        mmfile_t minus, plus;
 863        struct diff_words_style *style = diff_words->style;
 864
 865        struct diff_options *opt = diff_words->opt;
 866        struct strbuf *msgbuf;
 867        char *line_prefix = "";
 868
 869        assert(opt);
 870        if (opt->output_prefix) {
 871                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 872                line_prefix = msgbuf->buf;
 873        }
 874
 875        /* special case: only removal */
 876        if (!diff_words->plus.text.size) {
 877                fputs(line_prefix, diff_words->opt->file);
 878                fn_out_diff_words_write_helper(diff_words->opt->file,
 879                        &style->old, style->newline,
 880                        diff_words->minus.text.size,
 881                        diff_words->minus.text.ptr, line_prefix);
 882                diff_words->minus.text.size = 0;
 883                return;
 884        }
 885
 886        diff_words->current_plus = diff_words->plus.text.ptr;
 887        diff_words->last_minus = 0;
 888
 889        memset(&xpp, 0, sizeof(xpp));
 890        memset(&xecfg, 0, sizeof(xecfg));
 891        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
 892        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
 893        xpp.flags = 0;
 894        /* as only the hunk header will be parsed, we need a 0-context */
 895        xecfg.ctxlen = 0;
 896        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 897                      &xpp, &xecfg);
 898        free(minus.ptr);
 899        free(plus.ptr);
 900        if (diff_words->current_plus != diff_words->plus.text.ptr +
 901                        diff_words->plus.text.size) {
 902                if (color_words_output_graph_prefix(diff_words))
 903                        fputs(line_prefix, diff_words->opt->file);
 904                fn_out_diff_words_write_helper(diff_words->opt->file,
 905                        &style->ctx, style->newline,
 906                        diff_words->plus.text.ptr + diff_words->plus.text.size
 907                        - diff_words->current_plus, diff_words->current_plus,
 908                        line_prefix);
 909        }
 910        diff_words->minus.text.size = diff_words->plus.text.size = 0;
 911}
 912
 913/* In "color-words" mode, show word-diff of words accumulated in the buffer */
 914static void diff_words_flush(struct emit_callback *ecbdata)
 915{
 916        if (ecbdata->diff_words->minus.text.size ||
 917            ecbdata->diff_words->plus.text.size)
 918                diff_words_show(ecbdata->diff_words);
 919}
 920
 921static void free_diff_words_data(struct emit_callback *ecbdata)
 922{
 923        if (ecbdata->diff_words) {
 924                diff_words_flush(ecbdata);
 925                free (ecbdata->diff_words->minus.text.ptr);
 926                free (ecbdata->diff_words->minus.orig);
 927                free (ecbdata->diff_words->plus.text.ptr);
 928                free (ecbdata->diff_words->plus.orig);
 929                if (ecbdata->diff_words->word_regex) {
 930                        regfree(ecbdata->diff_words->word_regex);
 931                        free(ecbdata->diff_words->word_regex);
 932                }
 933                free(ecbdata->diff_words);
 934                ecbdata->diff_words = NULL;
 935        }
 936}
 937
 938const char *diff_get_color(int diff_use_color, enum color_diff ix)
 939{
 940        if (diff_use_color)
 941                return diff_colors[ix];
 942        return "";
 943}
 944
 945static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
 946{
 947        const char *cp;
 948        unsigned long allot;
 949        size_t l = len;
 950
 951        if (ecb->truncate)
 952                return ecb->truncate(line, len);
 953        cp = line;
 954        allot = l;
 955        while (0 < l) {
 956                (void) utf8_width(&cp, &l);
 957                if (!cp)
 958                        break; /* truncated in the middle? */
 959        }
 960        return allot - l;
 961}
 962
 963static void find_lno(const char *line, struct emit_callback *ecbdata)
 964{
 965        const char *p;
 966        ecbdata->lno_in_preimage = 0;
 967        ecbdata->lno_in_postimage = 0;
 968        p = strchr(line, '-');
 969        if (!p)
 970                return; /* cannot happen */
 971        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
 972        p = strchr(p, '+');
 973        if (!p)
 974                return; /* cannot happen */
 975        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
 976}
 977
 978static void fn_out_consume(void *priv, char *line, unsigned long len)
 979{
 980        struct emit_callback *ecbdata = priv;
 981        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
 982        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 983        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 984        struct diff_options *o = ecbdata->opt;
 985        char *line_prefix = "";
 986        struct strbuf *msgbuf;
 987
 988        if (o && o->output_prefix) {
 989                msgbuf = o->output_prefix(o, o->output_prefix_data);
 990                line_prefix = msgbuf->buf;
 991        }
 992
 993        if (ecbdata->header) {
 994                fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
 995                strbuf_reset(ecbdata->header);
 996                ecbdata->header = NULL;
 997        }
 998        *(ecbdata->found_changesp) = 1;
 999
1000        if (ecbdata->label_path[0]) {
1001                const char *name_a_tab, *name_b_tab;
1002
1003                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
1004                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
1005
1006                fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
1007                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
1008                fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
1009                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1010                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1011        }
1012
1013        if (diff_suppress_blank_empty
1014            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1015                line[0] = '\n';
1016                len = 1;
1017        }
1018
1019        if (line[0] == '@') {
1020                if (ecbdata->diff_words)
1021                        diff_words_flush(ecbdata);
1022                len = sane_truncate_line(ecbdata, line, len);
1023                find_lno(line, ecbdata);
1024                emit_hunk_header(ecbdata, line, len);
1025                if (line[len-1] != '\n')
1026                        putc('\n', ecbdata->opt->file);
1027                return;
1028        }
1029
1030        if (len < 1) {
1031                emit_line(ecbdata->opt, reset, reset, line, len);
1032                if (ecbdata->diff_words
1033                    && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
1034                        fputs("~\n", ecbdata->opt->file);
1035                return;
1036        }
1037
1038        if (ecbdata->diff_words) {
1039                if (line[0] == '-') {
1040                        diff_words_append(line, len,
1041                                          &ecbdata->diff_words->minus);
1042                        return;
1043                } else if (line[0] == '+') {
1044                        diff_words_append(line, len,
1045                                          &ecbdata->diff_words->plus);
1046                        return;
1047                }
1048                diff_words_flush(ecbdata);
1049                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1050                        emit_line(ecbdata->opt, plain, reset, line, len);
1051                        fputs("~\n", ecbdata->opt->file);
1052                } else {
1053                        /* don't print the prefix character */
1054                        emit_line(ecbdata->opt, plain, reset, line+1, len-1);
1055                }
1056                return;
1057        }
1058
1059        if (line[0] != '+') {
1060                const char *color =
1061                        diff_get_color(ecbdata->color_diff,
1062                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
1063                ecbdata->lno_in_preimage++;
1064                if (line[0] == ' ')
1065                        ecbdata->lno_in_postimage++;
1066                emit_line(ecbdata->opt, color, reset, line, len);
1067        } else {
1068                ecbdata->lno_in_postimage++;
1069                emit_add_line(reset, ecbdata, line + 1, len - 1);
1070        }
1071}
1072
1073static char *pprint_rename(const char *a, const char *b)
1074{
1075        const char *old = a;
1076        const char *new = b;
1077        struct strbuf name = STRBUF_INIT;
1078        int pfx_length, sfx_length;
1079        int len_a = strlen(a);
1080        int len_b = strlen(b);
1081        int a_midlen, b_midlen;
1082        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1083        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1084
1085        if (qlen_a || qlen_b) {
1086                quote_c_style(a, &name, NULL, 0);
1087                strbuf_addstr(&name, " => ");
1088                quote_c_style(b, &name, NULL, 0);
1089                return strbuf_detach(&name, NULL);
1090        }
1091
1092        /* Find common prefix */
1093        pfx_length = 0;
1094        while (*old && *new && *old == *new) {
1095                if (*old == '/')
1096                        pfx_length = old - a + 1;
1097                old++;
1098                new++;
1099        }
1100
1101        /* Find common suffix */
1102        old = a + len_a;
1103        new = b + len_b;
1104        sfx_length = 0;
1105        while (a <= old && b <= new && *old == *new) {
1106                if (*old == '/')
1107                        sfx_length = len_a - (old - a);
1108                old--;
1109                new--;
1110        }
1111
1112        /*
1113         * pfx{mid-a => mid-b}sfx
1114         * {pfx-a => pfx-b}sfx
1115         * pfx{sfx-a => sfx-b}
1116         * name-a => name-b
1117         */
1118        a_midlen = len_a - pfx_length - sfx_length;
1119        b_midlen = len_b - pfx_length - sfx_length;
1120        if (a_midlen < 0)
1121                a_midlen = 0;
1122        if (b_midlen < 0)
1123                b_midlen = 0;
1124
1125        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1126        if (pfx_length + sfx_length) {
1127                strbuf_add(&name, a, pfx_length);
1128                strbuf_addch(&name, '{');
1129        }
1130        strbuf_add(&name, a + pfx_length, a_midlen);
1131        strbuf_addstr(&name, " => ");
1132        strbuf_add(&name, b + pfx_length, b_midlen);
1133        if (pfx_length + sfx_length) {
1134                strbuf_addch(&name, '}');
1135                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1136        }
1137        return strbuf_detach(&name, NULL);
1138}
1139
1140struct diffstat_t {
1141        int nr;
1142        int alloc;
1143        struct diffstat_file {
1144                char *from_name;
1145                char *name;
1146                char *print_name;
1147                unsigned is_unmerged:1;
1148                unsigned is_binary:1;
1149                unsigned is_renamed:1;
1150                uintmax_t added, deleted;
1151        } **files;
1152};
1153
1154static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1155                                          const char *name_a,
1156                                          const char *name_b)
1157{
1158        struct diffstat_file *x;
1159        x = xcalloc(sizeof (*x), 1);
1160        if (diffstat->nr == diffstat->alloc) {
1161                diffstat->alloc = alloc_nr(diffstat->alloc);
1162                diffstat->files = xrealloc(diffstat->files,
1163                                diffstat->alloc * sizeof(x));
1164        }
1165        diffstat->files[diffstat->nr++] = x;
1166        if (name_b) {
1167                x->from_name = xstrdup(name_a);
1168                x->name = xstrdup(name_b);
1169                x->is_renamed = 1;
1170        }
1171        else {
1172                x->from_name = NULL;
1173                x->name = xstrdup(name_a);
1174        }
1175        return x;
1176}
1177
1178static void diffstat_consume(void *priv, char *line, unsigned long len)
1179{
1180        struct diffstat_t *diffstat = priv;
1181        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1182
1183        if (line[0] == '+')
1184                x->added++;
1185        else if (line[0] == '-')
1186                x->deleted++;
1187}
1188
1189const char mime_boundary_leader[] = "------------";
1190
1191static int scale_linear(int it, int width, int max_change)
1192{
1193        /*
1194         * make sure that at least one '-' is printed if there were deletions,
1195         * and likewise for '+'.
1196         */
1197        if (max_change < 2)
1198                return it;
1199        return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
1200}
1201
1202static void show_name(FILE *file,
1203                      const char *prefix, const char *name, int len)
1204{
1205        fprintf(file, " %s%-*s |", prefix, len, name);
1206}
1207
1208static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1209{
1210        if (cnt <= 0)
1211                return;
1212        fprintf(file, "%s", set);
1213        while (cnt--)
1214                putc(ch, file);
1215        fprintf(file, "%s", reset);
1216}
1217
1218static void fill_print_name(struct diffstat_file *file)
1219{
1220        char *pname;
1221
1222        if (file->print_name)
1223                return;
1224
1225        if (!file->is_renamed) {
1226                struct strbuf buf = STRBUF_INIT;
1227                if (quote_c_style(file->name, &buf, NULL, 0)) {
1228                        pname = strbuf_detach(&buf, NULL);
1229                } else {
1230                        pname = file->name;
1231                        strbuf_release(&buf);
1232                }
1233        } else {
1234                pname = pprint_rename(file->from_name, file->name);
1235        }
1236        file->print_name = pname;
1237}
1238
1239static void show_stats(struct diffstat_t *data, struct diff_options *options)
1240{
1241        int i, len, add, del, adds = 0, dels = 0;
1242        uintmax_t max_change = 0, max_len = 0;
1243        int total_files = data->nr;
1244        int width, name_width;
1245        const char *reset, *set, *add_c, *del_c;
1246        const char *line_prefix = "";
1247        struct strbuf *msg = NULL;
1248
1249        if (data->nr == 0)
1250                return;
1251
1252        if (options->output_prefix) {
1253                msg = options->output_prefix(options, options->output_prefix_data);
1254                line_prefix = msg->buf;
1255        }
1256
1257        width = options->stat_width ? options->stat_width : 80;
1258        name_width = options->stat_name_width ? options->stat_name_width : 50;
1259
1260        /* Sanity: give at least 5 columns to the graph,
1261         * but leave at least 10 columns for the name.
1262         */
1263        if (width < 25)
1264                width = 25;
1265        if (name_width < 10)
1266                name_width = 10;
1267        else if (width < name_width + 15)
1268                name_width = width - 15;
1269
1270        /* Find the longest filename and max number of changes */
1271        reset = diff_get_color_opt(options, DIFF_RESET);
1272        set   = diff_get_color_opt(options, DIFF_PLAIN);
1273        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1274        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1275
1276        for (i = 0; i < data->nr; i++) {
1277                struct diffstat_file *file = data->files[i];
1278                uintmax_t change = file->added + file->deleted;
1279                fill_print_name(file);
1280                len = strlen(file->print_name);
1281                if (max_len < len)
1282                        max_len = len;
1283
1284                if (file->is_binary || file->is_unmerged)
1285                        continue;
1286                if (max_change < change)
1287                        max_change = change;
1288        }
1289
1290        /* Compute the width of the graph part;
1291         * 10 is for one blank at the beginning of the line plus
1292         * " | count " between the name and the graph.
1293         *
1294         * From here on, name_width is the width of the name area,
1295         * and width is the width of the graph area.
1296         */
1297        name_width = (name_width < max_len) ? name_width : max_len;
1298        if (width < (name_width + 10) + max_change)
1299                width = width - (name_width + 10);
1300        else
1301                width = max_change;
1302
1303        for (i = 0; i < data->nr; i++) {
1304                const char *prefix = "";
1305                char *name = data->files[i]->print_name;
1306                uintmax_t added = data->files[i]->added;
1307                uintmax_t deleted = data->files[i]->deleted;
1308                int name_len;
1309
1310                /*
1311                 * "scale" the filename
1312                 */
1313                len = name_width;
1314                name_len = strlen(name);
1315                if (name_width < name_len) {
1316                        char *slash;
1317                        prefix = "...";
1318                        len -= 3;
1319                        name += name_len - len;
1320                        slash = strchr(name, '/');
1321                        if (slash)
1322                                name = slash;
1323                }
1324
1325                if (data->files[i]->is_binary) {
1326                        fprintf(options->file, "%s", line_prefix);
1327                        show_name(options->file, prefix, name, len);
1328                        fprintf(options->file, "  Bin ");
1329                        fprintf(options->file, "%s%"PRIuMAX"%s",
1330                                del_c, deleted, reset);
1331                        fprintf(options->file, " -> ");
1332                        fprintf(options->file, "%s%"PRIuMAX"%s",
1333                                add_c, added, reset);
1334                        fprintf(options->file, " bytes");
1335                        fprintf(options->file, "\n");
1336                        continue;
1337                }
1338                else if (data->files[i]->is_unmerged) {
1339                        fprintf(options->file, "%s", line_prefix);
1340                        show_name(options->file, prefix, name, len);
1341                        fprintf(options->file, "  Unmerged\n");
1342                        continue;
1343                }
1344                else if (!data->files[i]->is_renamed &&
1345                         (added + deleted == 0)) {
1346                        total_files--;
1347                        continue;
1348                }
1349
1350                /*
1351                 * scale the add/delete
1352                 */
1353                add = added;
1354                del = deleted;
1355                adds += add;
1356                dels += del;
1357
1358                if (width <= max_change) {
1359                        add = scale_linear(add, width, max_change);
1360                        del = scale_linear(del, width, max_change);
1361                }
1362                fprintf(options->file, "%s", line_prefix);
1363                show_name(options->file, prefix, name, len);
1364                fprintf(options->file, "%5"PRIuMAX"%s", added + deleted,
1365                                added + deleted ? " " : "");
1366                show_graph(options->file, '+', add, add_c, reset);
1367                show_graph(options->file, '-', del, del_c, reset);
1368                fprintf(options->file, "\n");
1369        }
1370        fprintf(options->file, "%s", line_prefix);
1371        fprintf(options->file,
1372               " %d files changed, %d insertions(+), %d deletions(-)\n",
1373               total_files, adds, dels);
1374}
1375
1376static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1377{
1378        int i, adds = 0, dels = 0, total_files = data->nr;
1379
1380        if (data->nr == 0)
1381                return;
1382
1383        for (i = 0; i < data->nr; i++) {
1384                if (!data->files[i]->is_binary &&
1385                    !data->files[i]->is_unmerged) {
1386                        int added = data->files[i]->added;
1387                        int deleted= data->files[i]->deleted;
1388                        if (!data->files[i]->is_renamed &&
1389                            (added + deleted == 0)) {
1390                                total_files--;
1391                        } else {
1392                                adds += added;
1393                                dels += deleted;
1394                        }
1395                }
1396        }
1397        if (options->output_prefix) {
1398                struct strbuf *msg = NULL;
1399                msg = options->output_prefix(options,
1400                                options->output_prefix_data);
1401                fprintf(options->file, "%s", msg->buf);
1402        }
1403        fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
1404               total_files, adds, dels);
1405}
1406
1407static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1408{
1409        int i;
1410
1411        if (data->nr == 0)
1412                return;
1413
1414        for (i = 0; i < data->nr; i++) {
1415                struct diffstat_file *file = data->files[i];
1416
1417                if (options->output_prefix) {
1418                        struct strbuf *msg = NULL;
1419                        msg = options->output_prefix(options,
1420                                        options->output_prefix_data);
1421                        fprintf(options->file, "%s", msg->buf);
1422                }
1423
1424                if (file->is_binary)
1425                        fprintf(options->file, "-\t-\t");
1426                else
1427                        fprintf(options->file,
1428                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1429                                file->added, file->deleted);
1430                if (options->line_termination) {
1431                        fill_print_name(file);
1432                        if (!file->is_renamed)
1433                                write_name_quoted(file->name, options->file,
1434                                                  options->line_termination);
1435                        else {
1436                                fputs(file->print_name, options->file);
1437                                putc(options->line_termination, options->file);
1438                        }
1439                } else {
1440                        if (file->is_renamed) {
1441                                putc('\0', options->file);
1442                                write_name_quoted(file->from_name, options->file, '\0');
1443                        }
1444                        write_name_quoted(file->name, options->file, '\0');
1445                }
1446        }
1447}
1448
1449struct dirstat_file {
1450        const char *name;
1451        unsigned long changed;
1452};
1453
1454struct dirstat_dir {
1455        struct dirstat_file *files;
1456        int alloc, nr, percent, cumulative;
1457};
1458
1459static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1460                unsigned long changed, const char *base, int baselen)
1461{
1462        unsigned long this_dir = 0;
1463        unsigned int sources = 0;
1464        const char *line_prefix = "";
1465        struct strbuf *msg = NULL;
1466
1467        if (opt->output_prefix) {
1468                msg = opt->output_prefix(opt, opt->output_prefix_data);
1469                line_prefix = msg->buf;
1470        }
1471
1472        while (dir->nr) {
1473                struct dirstat_file *f = dir->files;
1474                int namelen = strlen(f->name);
1475                unsigned long this;
1476                char *slash;
1477
1478                if (namelen < baselen)
1479                        break;
1480                if (memcmp(f->name, base, baselen))
1481                        break;
1482                slash = strchr(f->name + baselen, '/');
1483                if (slash) {
1484                        int newbaselen = slash + 1 - f->name;
1485                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1486                        sources++;
1487                } else {
1488                        this = f->changed;
1489                        dir->files++;
1490                        dir->nr--;
1491                        sources += 2;
1492                }
1493                this_dir += this;
1494        }
1495
1496        /*
1497         * We don't report dirstat's for
1498         *  - the top level
1499         *  - or cases where everything came from a single directory
1500         *    under this directory (sources == 1).
1501         */
1502        if (baselen && sources != 1) {
1503                int permille = this_dir * 1000 / changed;
1504                if (permille) {
1505                        int percent = permille / 10;
1506                        if (percent >= dir->percent) {
1507                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1508                                        percent, permille % 10, baselen, base);
1509                                if (!dir->cumulative)
1510                                        return 0;
1511                        }
1512                }
1513        }
1514        return this_dir;
1515}
1516
1517static int dirstat_compare(const void *_a, const void *_b)
1518{
1519        const struct dirstat_file *a = _a;
1520        const struct dirstat_file *b = _b;
1521        return strcmp(a->name, b->name);
1522}
1523
1524static void show_dirstat(struct diff_options *options)
1525{
1526        int i;
1527        unsigned long changed;
1528        struct dirstat_dir dir;
1529        struct diff_queue_struct *q = &diff_queued_diff;
1530
1531        dir.files = NULL;
1532        dir.alloc = 0;
1533        dir.nr = 0;
1534        dir.percent = options->dirstat_percent;
1535        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1536
1537        changed = 0;
1538        for (i = 0; i < q->nr; i++) {
1539                struct diff_filepair *p = q->queue[i];
1540                const char *name;
1541                unsigned long copied, added, damage;
1542
1543                name = p->one->path ? p->one->path : p->two->path;
1544
1545                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1546                        diff_populate_filespec(p->one, 0);
1547                        diff_populate_filespec(p->two, 0);
1548                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1549                                               &copied, &added);
1550                        diff_free_filespec_data(p->one);
1551                        diff_free_filespec_data(p->two);
1552                } else if (DIFF_FILE_VALID(p->one)) {
1553                        diff_populate_filespec(p->one, 1);
1554                        copied = added = 0;
1555                        diff_free_filespec_data(p->one);
1556                } else if (DIFF_FILE_VALID(p->two)) {
1557                        diff_populate_filespec(p->two, 1);
1558                        copied = 0;
1559                        added = p->two->size;
1560                        diff_free_filespec_data(p->two);
1561                } else
1562                        continue;
1563
1564                /*
1565                 * Original minus copied is the removed material,
1566                 * added is the new material.  They are both damages
1567                 * made to the preimage. In --dirstat-by-file mode, count
1568                 * damaged files, not damaged lines. This is done by
1569                 * counting only a single damaged line per file.
1570                 */
1571                damage = (p->one->size - copied) + added;
1572                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE) && damage > 0)
1573                        damage = 1;
1574
1575                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1576                dir.files[dir.nr].name = name;
1577                dir.files[dir.nr].changed = damage;
1578                changed += damage;
1579                dir.nr++;
1580        }
1581
1582        /* This can happen even with many files, if everything was renames */
1583        if (!changed)
1584                return;
1585
1586        /* Show all directories with more than x% of the changes */
1587        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1588        gather_dirstat(options, &dir, changed, "", 0);
1589}
1590
1591static void free_diffstat_info(struct diffstat_t *diffstat)
1592{
1593        int i;
1594        for (i = 0; i < diffstat->nr; i++) {
1595                struct diffstat_file *f = diffstat->files[i];
1596                if (f->name != f->print_name)
1597                        free(f->print_name);
1598                free(f->name);
1599                free(f->from_name);
1600                free(f);
1601        }
1602        free(diffstat->files);
1603}
1604
1605struct checkdiff_t {
1606        const char *filename;
1607        int lineno;
1608        int conflict_marker_size;
1609        struct diff_options *o;
1610        unsigned ws_rule;
1611        unsigned status;
1612};
1613
1614static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1615{
1616        char firstchar;
1617        int cnt;
1618
1619        if (len < marker_size + 1)
1620                return 0;
1621        firstchar = line[0];
1622        switch (firstchar) {
1623        case '=': case '>': case '<': case '|':
1624                break;
1625        default:
1626                return 0;
1627        }
1628        for (cnt = 1; cnt < marker_size; cnt++)
1629                if (line[cnt] != firstchar)
1630                        return 0;
1631        /* line[1] thru line[marker_size-1] are same as firstchar */
1632        if (len < marker_size + 1 || !isspace(line[marker_size]))
1633                return 0;
1634        return 1;
1635}
1636
1637static void checkdiff_consume(void *priv, char *line, unsigned long len)
1638{
1639        struct checkdiff_t *data = priv;
1640        int color_diff = DIFF_OPT_TST(data->o, COLOR_DIFF);
1641        int marker_size = data->conflict_marker_size;
1642        const char *ws = diff_get_color(color_diff, DIFF_WHITESPACE);
1643        const char *reset = diff_get_color(color_diff, DIFF_RESET);
1644        const char *set = diff_get_color(color_diff, DIFF_FILE_NEW);
1645        char *err;
1646        char *line_prefix = "";
1647        struct strbuf *msgbuf;
1648
1649        assert(data->o);
1650        if (data->o->output_prefix) {
1651                msgbuf = data->o->output_prefix(data->o,
1652                        data->o->output_prefix_data);
1653                line_prefix = msgbuf->buf;
1654        }
1655
1656        if (line[0] == '+') {
1657                unsigned bad;
1658                data->lineno++;
1659                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
1660                        data->status |= 1;
1661                        fprintf(data->o->file,
1662                                "%s%s:%d: leftover conflict marker\n",
1663                                line_prefix, data->filename, data->lineno);
1664                }
1665                bad = ws_check(line + 1, len - 1, data->ws_rule);
1666                if (!bad)
1667                        return;
1668                data->status |= bad;
1669                err = whitespace_error_string(bad);
1670                fprintf(data->o->file, "%s%s:%d: %s.\n",
1671                        line_prefix, data->filename, data->lineno, err);
1672                free(err);
1673                emit_line(data->o, set, reset, line, 1);
1674                ws_check_emit(line + 1, len - 1, data->ws_rule,
1675                              data->o->file, set, reset, ws);
1676        } else if (line[0] == ' ') {
1677                data->lineno++;
1678        } else if (line[0] == '@') {
1679                char *plus = strchr(line, '+');
1680                if (plus)
1681                        data->lineno = strtol(plus, NULL, 10) - 1;
1682                else
1683                        die("invalid diff");
1684        }
1685}
1686
1687static unsigned char *deflate_it(char *data,
1688                                 unsigned long size,
1689                                 unsigned long *result_size)
1690{
1691        int bound;
1692        unsigned char *deflated;
1693        z_stream stream;
1694
1695        memset(&stream, 0, sizeof(stream));
1696        deflateInit(&stream, zlib_compression_level);
1697        bound = deflateBound(&stream, size);
1698        deflated = xmalloc(bound);
1699        stream.next_out = deflated;
1700        stream.avail_out = bound;
1701
1702        stream.next_in = (unsigned char *)data;
1703        stream.avail_in = size;
1704        while (deflate(&stream, Z_FINISH) == Z_OK)
1705                ; /* nothing */
1706        deflateEnd(&stream);
1707        *result_size = stream.total_out;
1708        return deflated;
1709}
1710
1711static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1712{
1713        void *cp;
1714        void *delta;
1715        void *deflated;
1716        void *data;
1717        unsigned long orig_size;
1718        unsigned long delta_size;
1719        unsigned long deflate_size;
1720        unsigned long data_size;
1721
1722        /* We could do deflated delta, or we could do just deflated two,
1723         * whichever is smaller.
1724         */
1725        delta = NULL;
1726        deflated = deflate_it(two->ptr, two->size, &deflate_size);
1727        if (one->size && two->size) {
1728                delta = diff_delta(one->ptr, one->size,
1729                                   two->ptr, two->size,
1730                                   &delta_size, deflate_size);
1731                if (delta) {
1732                        void *to_free = delta;
1733                        orig_size = delta_size;
1734                        delta = deflate_it(delta, delta_size, &delta_size);
1735                        free(to_free);
1736                }
1737        }
1738
1739        if (delta && delta_size < deflate_size) {
1740                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
1741                free(deflated);
1742                data = delta;
1743                data_size = delta_size;
1744        }
1745        else {
1746                fprintf(file, "%sliteral %lu\n", prefix, two->size);
1747                free(delta);
1748                data = deflated;
1749                data_size = deflate_size;
1750        }
1751
1752        /* emit data encoded in base85 */
1753        cp = data;
1754        while (data_size) {
1755                int bytes = (52 < data_size) ? 52 : data_size;
1756                char line[70];
1757                data_size -= bytes;
1758                if (bytes <= 26)
1759                        line[0] = bytes + 'A' - 1;
1760                else
1761                        line[0] = bytes - 26 + 'a' - 1;
1762                encode_85(line + 1, cp, bytes);
1763                cp = (char *) cp + bytes;
1764                fprintf(file, "%s", prefix);
1765                fputs(line, file);
1766                fputc('\n', file);
1767        }
1768        fprintf(file, "%s\n", prefix);
1769        free(data);
1770}
1771
1772static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1773{
1774        fprintf(file, "%sGIT binary patch\n", prefix);
1775        emit_binary_diff_body(file, one, two, prefix);
1776        emit_binary_diff_body(file, two, one, prefix);
1777}
1778
1779static void diff_filespec_load_driver(struct diff_filespec *one)
1780{
1781        /* Use already-loaded driver */
1782        if (one->driver)
1783                return;
1784
1785        if (S_ISREG(one->mode))
1786                one->driver = userdiff_find_by_path(one->path);
1787
1788        /* Fallback to default settings */
1789        if (!one->driver)
1790                one->driver = userdiff_find_by_name("default");
1791}
1792
1793int diff_filespec_is_binary(struct diff_filespec *one)
1794{
1795        if (one->is_binary == -1) {
1796                diff_filespec_load_driver(one);
1797                if (one->driver->binary != -1)
1798                        one->is_binary = one->driver->binary;
1799                else {
1800                        if (!one->data && DIFF_FILE_VALID(one))
1801                                diff_populate_filespec(one, 0);
1802                        if (one->data)
1803                                one->is_binary = buffer_is_binary(one->data,
1804                                                one->size);
1805                        if (one->is_binary == -1)
1806                                one->is_binary = 0;
1807                }
1808        }
1809        return one->is_binary;
1810}
1811
1812static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
1813{
1814        diff_filespec_load_driver(one);
1815        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
1816}
1817
1818static const char *userdiff_word_regex(struct diff_filespec *one)
1819{
1820        diff_filespec_load_driver(one);
1821        return one->driver->word_regex;
1822}
1823
1824void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
1825{
1826        if (!options->a_prefix)
1827                options->a_prefix = a;
1828        if (!options->b_prefix)
1829                options->b_prefix = b;
1830}
1831
1832struct userdiff_driver *get_textconv(struct diff_filespec *one)
1833{
1834        if (!DIFF_FILE_VALID(one))
1835                return NULL;
1836
1837        diff_filespec_load_driver(one);
1838        if (!one->driver->textconv)
1839                return NULL;
1840
1841        if (one->driver->textconv_want_cache && !one->driver->textconv_cache) {
1842                struct notes_cache *c = xmalloc(sizeof(*c));
1843                struct strbuf name = STRBUF_INIT;
1844
1845                strbuf_addf(&name, "textconv/%s", one->driver->name);
1846                notes_cache_init(c, name.buf, one->driver->textconv);
1847                one->driver->textconv_cache = c;
1848        }
1849
1850        return one->driver;
1851}
1852
1853static void builtin_diff(const char *name_a,
1854                         const char *name_b,
1855                         struct diff_filespec *one,
1856                         struct diff_filespec *two,
1857                         const char *xfrm_msg,
1858                         int must_show_header,
1859                         struct diff_options *o,
1860                         int complete_rewrite)
1861{
1862        mmfile_t mf1, mf2;
1863        const char *lbl[2];
1864        char *a_one, *b_two;
1865        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1866        const char *reset = diff_get_color_opt(o, DIFF_RESET);
1867        const char *a_prefix, *b_prefix;
1868        struct userdiff_driver *textconv_one = NULL;
1869        struct userdiff_driver *textconv_two = NULL;
1870        struct strbuf header = STRBUF_INIT;
1871        struct strbuf *msgbuf;
1872        char *line_prefix = "";
1873
1874        if (o->output_prefix) {
1875                msgbuf = o->output_prefix(o, o->output_prefix_data);
1876                line_prefix = msgbuf->buf;
1877        }
1878
1879        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
1880                        (!one->mode || S_ISGITLINK(one->mode)) &&
1881                        (!two->mode || S_ISGITLINK(two->mode))) {
1882                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
1883                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
1884                show_submodule_summary(o->file, one ? one->path : two->path,
1885                                one->sha1, two->sha1, two->dirty_submodule,
1886                                del, add, reset);
1887                return;
1888        }
1889
1890        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
1891                textconv_one = get_textconv(one);
1892                textconv_two = get_textconv(two);
1893        }
1894
1895        diff_set_mnemonic_prefix(o, "a/", "b/");
1896        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
1897                a_prefix = o->b_prefix;
1898                b_prefix = o->a_prefix;
1899        } else {
1900                a_prefix = o->a_prefix;
1901                b_prefix = o->b_prefix;
1902        }
1903
1904        /* Never use a non-valid filename anywhere if at all possible */
1905        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
1906        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
1907
1908        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
1909        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
1910        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1911        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1912        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
1913        if (lbl[0][0] == '/') {
1914                /* /dev/null */
1915                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
1916                if (xfrm_msg)
1917                        strbuf_addstr(&header, xfrm_msg);
1918                must_show_header = 1;
1919        }
1920        else if (lbl[1][0] == '/') {
1921                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
1922                if (xfrm_msg)
1923                        strbuf_addstr(&header, xfrm_msg);
1924                must_show_header = 1;
1925        }
1926        else {
1927                if (one->mode != two->mode) {
1928                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
1929                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
1930                        must_show_header = 1;
1931                }
1932                if (xfrm_msg)
1933                        strbuf_addstr(&header, xfrm_msg);
1934
1935                /*
1936                 * we do not run diff between different kind
1937                 * of objects.
1938                 */
1939                if ((one->mode ^ two->mode) & S_IFMT)
1940                        goto free_ab_and_return;
1941                if (complete_rewrite &&
1942                    (textconv_one || !diff_filespec_is_binary(one)) &&
1943                    (textconv_two || !diff_filespec_is_binary(two))) {
1944                        fprintf(o->file, "%s", header.buf);
1945                        strbuf_reset(&header);
1946                        emit_rewrite_diff(name_a, name_b, one, two,
1947                                                textconv_one, textconv_two, o);
1948                        o->found_changes = 1;
1949                        goto free_ab_and_return;
1950                }
1951        }
1952
1953        if (!DIFF_OPT_TST(o, TEXT) &&
1954            ( (!textconv_one && diff_filespec_is_binary(one)) ||
1955              (!textconv_two && diff_filespec_is_binary(two)) )) {
1956                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1957                        die("unable to read files to diff");
1958                /* Quite common confusing case */
1959                if (mf1.size == mf2.size &&
1960                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
1961                        if (must_show_header)
1962                                fprintf(o->file, "%s", header.buf);
1963                        goto free_ab_and_return;
1964                }
1965                fprintf(o->file, "%s", header.buf);
1966                strbuf_reset(&header);
1967                if (DIFF_OPT_TST(o, BINARY))
1968                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
1969                else
1970                        fprintf(o->file, "%sBinary files %s and %s differ\n",
1971                                line_prefix, lbl[0], lbl[1]);
1972                o->found_changes = 1;
1973        }
1974        else {
1975                /* Crazy xdl interfaces.. */
1976                const char *diffopts = getenv("GIT_DIFF_OPTS");
1977                xpparam_t xpp;
1978                xdemitconf_t xecfg;
1979                struct emit_callback ecbdata;
1980                const struct userdiff_funcname *pe;
1981
1982                if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS) || must_show_header) {
1983                        fprintf(o->file, "%s", header.buf);
1984                        strbuf_reset(&header);
1985                }
1986
1987                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
1988                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
1989
1990                pe = diff_funcname_pattern(one);
1991                if (!pe)
1992                        pe = diff_funcname_pattern(two);
1993
1994                memset(&xpp, 0, sizeof(xpp));
1995                memset(&xecfg, 0, sizeof(xecfg));
1996                memset(&ecbdata, 0, sizeof(ecbdata));
1997                ecbdata.label_path = lbl;
1998                ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
1999                ecbdata.found_changesp = &o->found_changes;
2000                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
2001                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2002                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2003                ecbdata.opt = o;
2004                ecbdata.header = header.len ? &header : NULL;
2005                xpp.flags = o->xdl_opts;
2006                xecfg.ctxlen = o->context;
2007                xecfg.interhunkctxlen = o->interhunkcontext;
2008                xecfg.flags = XDL_EMIT_FUNCNAMES;
2009                if (pe)
2010                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2011                if (!diffopts)
2012                        ;
2013                else if (!prefixcmp(diffopts, "--unified="))
2014                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2015                else if (!prefixcmp(diffopts, "-u"))
2016                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2017                if (o->word_diff) {
2018                        int i;
2019
2020                        ecbdata.diff_words =
2021                                xcalloc(1, sizeof(struct diff_words_data));
2022                        ecbdata.diff_words->type = o->word_diff;
2023                        ecbdata.diff_words->opt = o;
2024                        if (!o->word_regex)
2025                                o->word_regex = userdiff_word_regex(one);
2026                        if (!o->word_regex)
2027                                o->word_regex = userdiff_word_regex(two);
2028                        if (!o->word_regex)
2029                                o->word_regex = diff_word_regex_cfg;
2030                        if (o->word_regex) {
2031                                ecbdata.diff_words->word_regex = (regex_t *)
2032                                        xmalloc(sizeof(regex_t));
2033                                if (regcomp(ecbdata.diff_words->word_regex,
2034                                                o->word_regex,
2035                                                REG_EXTENDED | REG_NEWLINE))
2036                                        die ("Invalid regular expression: %s",
2037                                                        o->word_regex);
2038                        }
2039                        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2040                                if (o->word_diff == diff_words_styles[i].type) {
2041                                        ecbdata.diff_words->style =
2042                                                &diff_words_styles[i];
2043                                        break;
2044                                }
2045                        }
2046                        if (DIFF_OPT_TST(o, COLOR_DIFF)) {
2047                                struct diff_words_style *st = ecbdata.diff_words->style;
2048                                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2049                                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2050                                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
2051                        }
2052                }
2053                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2054                              &xpp, &xecfg);
2055                if (o->word_diff)
2056                        free_diff_words_data(&ecbdata);
2057                if (textconv_one)
2058                        free(mf1.ptr);
2059                if (textconv_two)
2060                        free(mf2.ptr);
2061                xdiff_clear_find_func(&xecfg);
2062        }
2063
2064 free_ab_and_return:
2065        strbuf_release(&header);
2066        diff_free_filespec_data(one);
2067        diff_free_filespec_data(two);
2068        free(a_one);
2069        free(b_two);
2070        return;
2071}
2072
2073static void builtin_diffstat(const char *name_a, const char *name_b,
2074                             struct diff_filespec *one,
2075                             struct diff_filespec *two,
2076                             struct diffstat_t *diffstat,
2077                             struct diff_options *o,
2078                             int complete_rewrite)
2079{
2080        mmfile_t mf1, mf2;
2081        struct diffstat_file *data;
2082
2083        data = diffstat_add(diffstat, name_a, name_b);
2084
2085        if (!one || !two) {
2086                data->is_unmerged = 1;
2087                return;
2088        }
2089
2090        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2091                data->is_binary = 1;
2092                data->added = diff_filespec_size(two);
2093                data->deleted = diff_filespec_size(one);
2094        }
2095
2096        else if (complete_rewrite) {
2097                diff_populate_filespec(one, 0);
2098                diff_populate_filespec(two, 0);
2099                data->deleted = count_lines(one->data, one->size);
2100                data->added = count_lines(two->data, two->size);
2101        }
2102
2103        else {
2104                /* Crazy xdl interfaces.. */
2105                xpparam_t xpp;
2106                xdemitconf_t xecfg;
2107
2108                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2109                        die("unable to read files to diff");
2110
2111                memset(&xpp, 0, sizeof(xpp));
2112                memset(&xecfg, 0, sizeof(xecfg));
2113                xpp.flags = o->xdl_opts;
2114                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2115                              &xpp, &xecfg);
2116        }
2117
2118        diff_free_filespec_data(one);
2119        diff_free_filespec_data(two);
2120}
2121
2122static void builtin_checkdiff(const char *name_a, const char *name_b,
2123                              const char *attr_path,
2124                              struct diff_filespec *one,
2125                              struct diff_filespec *two,
2126                              struct diff_options *o)
2127{
2128        mmfile_t mf1, mf2;
2129        struct checkdiff_t data;
2130
2131        if (!two)
2132                return;
2133
2134        memset(&data, 0, sizeof(data));
2135        data.filename = name_b ? name_b : name_a;
2136        data.lineno = 0;
2137        data.o = o;
2138        data.ws_rule = whitespace_rule(attr_path);
2139        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2140
2141        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2142                die("unable to read files to diff");
2143
2144        /*
2145         * All the other codepaths check both sides, but not checking
2146         * the "old" side here is deliberate.  We are checking the newly
2147         * introduced changes, and as long as the "new" side is text, we
2148         * can and should check what it introduces.
2149         */
2150        if (diff_filespec_is_binary(two))
2151                goto free_and_return;
2152        else {
2153                /* Crazy xdl interfaces.. */
2154                xpparam_t xpp;
2155                xdemitconf_t xecfg;
2156
2157                memset(&xpp, 0, sizeof(xpp));
2158                memset(&xecfg, 0, sizeof(xecfg));
2159                xecfg.ctxlen = 1; /* at least one context line */
2160                xpp.flags = 0;
2161                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2162                              &xpp, &xecfg);
2163
2164                if (data.ws_rule & WS_BLANK_AT_EOF) {
2165                        struct emit_callback ecbdata;
2166                        int blank_at_eof;
2167
2168                        ecbdata.ws_rule = data.ws_rule;
2169                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2170                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2171
2172                        if (blank_at_eof) {
2173                                static char *err;
2174                                if (!err)
2175                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2176                                fprintf(o->file, "%s:%d: %s.\n",
2177                                        data.filename, blank_at_eof, err);
2178                                data.status = 1; /* report errors */
2179                        }
2180                }
2181        }
2182 free_and_return:
2183        diff_free_filespec_data(one);
2184        diff_free_filespec_data(two);
2185        if (data.status)
2186                DIFF_OPT_SET(o, CHECK_FAILED);
2187}
2188
2189struct diff_filespec *alloc_filespec(const char *path)
2190{
2191        int namelen = strlen(path);
2192        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2193
2194        memset(spec, 0, sizeof(*spec));
2195        spec->path = (char *)(spec + 1);
2196        memcpy(spec->path, path, namelen+1);
2197        spec->count = 1;
2198        spec->is_binary = -1;
2199        return spec;
2200}
2201
2202void free_filespec(struct diff_filespec *spec)
2203{
2204        if (!--spec->count) {
2205                diff_free_filespec_data(spec);
2206                free(spec);
2207        }
2208}
2209
2210void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2211                   unsigned short mode)
2212{
2213        if (mode) {
2214                spec->mode = canon_mode(mode);
2215                hashcpy(spec->sha1, sha1);
2216                spec->sha1_valid = !is_null_sha1(sha1);
2217        }
2218}
2219
2220/*
2221 * Given a name and sha1 pair, if the index tells us the file in
2222 * the work tree has that object contents, return true, so that
2223 * prepare_temp_file() does not have to inflate and extract.
2224 */
2225static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2226{
2227        struct cache_entry *ce;
2228        struct stat st;
2229        int pos, len;
2230
2231        /*
2232         * We do not read the cache ourselves here, because the
2233         * benchmark with my previous version that always reads cache
2234         * shows that it makes things worse for diff-tree comparing
2235         * two linux-2.6 kernel trees in an already checked out work
2236         * tree.  This is because most diff-tree comparisons deal with
2237         * only a small number of files, while reading the cache is
2238         * expensive for a large project, and its cost outweighs the
2239         * savings we get by not inflating the object to a temporary
2240         * file.  Practically, this code only helps when we are used
2241         * by diff-cache --cached, which does read the cache before
2242         * calling us.
2243         */
2244        if (!active_cache)
2245                return 0;
2246
2247        /* We want to avoid the working directory if our caller
2248         * doesn't need the data in a normal file, this system
2249         * is rather slow with its stat/open/mmap/close syscalls,
2250         * and the object is contained in a pack file.  The pack
2251         * is probably already open and will be faster to obtain
2252         * the data through than the working directory.  Loose
2253         * objects however would tend to be slower as they need
2254         * to be individually opened and inflated.
2255         */
2256        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2257                return 0;
2258
2259        len = strlen(name);
2260        pos = cache_name_pos(name, len);
2261        if (pos < 0)
2262                return 0;
2263        ce = active_cache[pos];
2264
2265        /*
2266         * This is not the sha1 we are looking for, or
2267         * unreusable because it is not a regular file.
2268         */
2269        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2270                return 0;
2271
2272        /*
2273         * If ce is marked as "assume unchanged", there is no
2274         * guarantee that work tree matches what we are looking for.
2275         */
2276        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2277                return 0;
2278
2279        /*
2280         * If ce matches the file in the work tree, we can reuse it.
2281         */
2282        if (ce_uptodate(ce) ||
2283            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2284                return 1;
2285
2286        return 0;
2287}
2288
2289static int populate_from_stdin(struct diff_filespec *s)
2290{
2291        struct strbuf buf = STRBUF_INIT;
2292        size_t size = 0;
2293
2294        if (strbuf_read(&buf, 0, 0) < 0)
2295                return error("error while reading from stdin %s",
2296                                     strerror(errno));
2297
2298        s->should_munmap = 0;
2299        s->data = strbuf_detach(&buf, &size);
2300        s->size = size;
2301        s->should_free = 1;
2302        return 0;
2303}
2304
2305static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2306{
2307        int len;
2308        char *data = xmalloc(100), *dirty = "";
2309
2310        /* Are we looking at the work tree? */
2311        if (s->dirty_submodule)
2312                dirty = "-dirty";
2313
2314        len = snprintf(data, 100,
2315                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2316        s->data = data;
2317        s->size = len;
2318        s->should_free = 1;
2319        if (size_only) {
2320                s->data = NULL;
2321                free(data);
2322        }
2323        return 0;
2324}
2325
2326/*
2327 * While doing rename detection and pickaxe operation, we may need to
2328 * grab the data for the blob (or file) for our own in-core comparison.
2329 * diff_filespec has data and size fields for this purpose.
2330 */
2331int diff_populate_filespec(struct diff_filespec *s, int size_only)
2332{
2333        int err = 0;
2334        if (!DIFF_FILE_VALID(s))
2335                die("internal error: asking to populate invalid file.");
2336        if (S_ISDIR(s->mode))
2337                return -1;
2338
2339        if (s->data)
2340                return 0;
2341
2342        if (size_only && 0 < s->size)
2343                return 0;
2344
2345        if (S_ISGITLINK(s->mode))
2346                return diff_populate_gitlink(s, size_only);
2347
2348        if (!s->sha1_valid ||
2349            reuse_worktree_file(s->path, s->sha1, 0)) {
2350                struct strbuf buf = STRBUF_INIT;
2351                struct stat st;
2352                int fd;
2353
2354                if (!strcmp(s->path, "-"))
2355                        return populate_from_stdin(s);
2356
2357                if (lstat(s->path, &st) < 0) {
2358                        if (errno == ENOENT) {
2359                        err_empty:
2360                                err = -1;
2361                        empty:
2362                                s->data = (char *)"";
2363                                s->size = 0;
2364                                return err;
2365                        }
2366                }
2367                s->size = xsize_t(st.st_size);
2368                if (!s->size)
2369                        goto empty;
2370                if (S_ISLNK(st.st_mode)) {
2371                        struct strbuf sb = STRBUF_INIT;
2372
2373                        if (strbuf_readlink(&sb, s->path, s->size))
2374                                goto err_empty;
2375                        s->size = sb.len;
2376                        s->data = strbuf_detach(&sb, NULL);
2377                        s->should_free = 1;
2378                        return 0;
2379                }
2380                if (size_only)
2381                        return 0;
2382                fd = open(s->path, O_RDONLY);
2383                if (fd < 0)
2384                        goto err_empty;
2385                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2386                close(fd);
2387                s->should_munmap = 1;
2388
2389                /*
2390                 * Convert from working tree format to canonical git format
2391                 */
2392                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2393                        size_t size = 0;
2394                        munmap(s->data, s->size);
2395                        s->should_munmap = 0;
2396                        s->data = strbuf_detach(&buf, &size);
2397                        s->size = size;
2398                        s->should_free = 1;
2399                }
2400        }
2401        else {
2402                enum object_type type;
2403                if (size_only) {
2404                        type = sha1_object_info(s->sha1, &s->size);
2405                        if (type < 0)
2406                                die("unable to read %s", sha1_to_hex(s->sha1));
2407                } else {
2408                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2409                        if (!s->data)
2410                                die("unable to read %s", sha1_to_hex(s->sha1));
2411                        s->should_free = 1;
2412                }
2413        }
2414        return 0;
2415}
2416
2417void diff_free_filespec_blob(struct diff_filespec *s)
2418{
2419        if (s->should_free)
2420                free(s->data);
2421        else if (s->should_munmap)
2422                munmap(s->data, s->size);
2423
2424        if (s->should_free || s->should_munmap) {
2425                s->should_free = s->should_munmap = 0;
2426                s->data = NULL;
2427        }
2428}
2429
2430void diff_free_filespec_data(struct diff_filespec *s)
2431{
2432        diff_free_filespec_blob(s);
2433        free(s->cnt_data);
2434        s->cnt_data = NULL;
2435}
2436
2437static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2438                           void *blob,
2439                           unsigned long size,
2440                           const unsigned char *sha1,
2441                           int mode)
2442{
2443        int fd;
2444        struct strbuf buf = STRBUF_INIT;
2445        struct strbuf template = STRBUF_INIT;
2446        char *path_dup = xstrdup(path);
2447        const char *base = basename(path_dup);
2448
2449        /* Generate "XXXXXX_basename.ext" */
2450        strbuf_addstr(&template, "XXXXXX_");
2451        strbuf_addstr(&template, base);
2452
2453        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2454                        strlen(base) + 1);
2455        if (fd < 0)
2456                die_errno("unable to create temp-file");
2457        if (convert_to_working_tree(path,
2458                        (const char *)blob, (size_t)size, &buf)) {
2459                blob = buf.buf;
2460                size = buf.len;
2461        }
2462        if (write_in_full(fd, blob, size) != size)
2463                die_errno("unable to write temp-file");
2464        close(fd);
2465        temp->name = temp->tmp_path;
2466        strcpy(temp->hex, sha1_to_hex(sha1));
2467        temp->hex[40] = 0;
2468        sprintf(temp->mode, "%06o", mode);
2469        strbuf_release(&buf);
2470        strbuf_release(&template);
2471        free(path_dup);
2472}
2473
2474static struct diff_tempfile *prepare_temp_file(const char *name,
2475                struct diff_filespec *one)
2476{
2477        struct diff_tempfile *temp = claim_diff_tempfile();
2478
2479        if (!DIFF_FILE_VALID(one)) {
2480        not_a_valid_file:
2481                /* A '-' entry produces this for file-2, and
2482                 * a '+' entry produces this for file-1.
2483                 */
2484                temp->name = "/dev/null";
2485                strcpy(temp->hex, ".");
2486                strcpy(temp->mode, ".");
2487                return temp;
2488        }
2489
2490        if (!remove_tempfile_installed) {
2491                atexit(remove_tempfile);
2492                sigchain_push_common(remove_tempfile_on_signal);
2493                remove_tempfile_installed = 1;
2494        }
2495
2496        if (!one->sha1_valid ||
2497            reuse_worktree_file(name, one->sha1, 1)) {
2498                struct stat st;
2499                if (lstat(name, &st) < 0) {
2500                        if (errno == ENOENT)
2501                                goto not_a_valid_file;
2502                        die_errno("stat(%s)", name);
2503                }
2504                if (S_ISLNK(st.st_mode)) {
2505                        struct strbuf sb = STRBUF_INIT;
2506                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2507                                die_errno("readlink(%s)", name);
2508                        prep_temp_blob(name, temp, sb.buf, sb.len,
2509                                       (one->sha1_valid ?
2510                                        one->sha1 : null_sha1),
2511                                       (one->sha1_valid ?
2512                                        one->mode : S_IFLNK));
2513                        strbuf_release(&sb);
2514                }
2515                else {
2516                        /* we can borrow from the file in the work tree */
2517                        temp->name = name;
2518                        if (!one->sha1_valid)
2519                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2520                        else
2521                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2522                        /* Even though we may sometimes borrow the
2523                         * contents from the work tree, we always want
2524                         * one->mode.  mode is trustworthy even when
2525                         * !(one->sha1_valid), as long as
2526                         * DIFF_FILE_VALID(one).
2527                         */
2528                        sprintf(temp->mode, "%06o", one->mode);
2529                }
2530                return temp;
2531        }
2532        else {
2533                if (diff_populate_filespec(one, 0))
2534                        die("cannot read data blob for %s", one->path);
2535                prep_temp_blob(name, temp, one->data, one->size,
2536                               one->sha1, one->mode);
2537        }
2538        return temp;
2539}
2540
2541/* An external diff command takes:
2542 *
2543 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2544 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2545 *
2546 */
2547static void run_external_diff(const char *pgm,
2548                              const char *name,
2549                              const char *other,
2550                              struct diff_filespec *one,
2551                              struct diff_filespec *two,
2552                              const char *xfrm_msg,
2553                              int complete_rewrite)
2554{
2555        const char *spawn_arg[10];
2556        int retval;
2557        const char **arg = &spawn_arg[0];
2558
2559        if (one && two) {
2560                struct diff_tempfile *temp_one, *temp_two;
2561                const char *othername = (other ? other : name);
2562                temp_one = prepare_temp_file(name, one);
2563                temp_two = prepare_temp_file(othername, two);
2564                *arg++ = pgm;
2565                *arg++ = name;
2566                *arg++ = temp_one->name;
2567                *arg++ = temp_one->hex;
2568                *arg++ = temp_one->mode;
2569                *arg++ = temp_two->name;
2570                *arg++ = temp_two->hex;
2571                *arg++ = temp_two->mode;
2572                if (other) {
2573                        *arg++ = other;
2574                        *arg++ = xfrm_msg;
2575                }
2576        } else {
2577                *arg++ = pgm;
2578                *arg++ = name;
2579        }
2580        *arg = NULL;
2581        fflush(NULL);
2582        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2583        remove_tempfile();
2584        if (retval) {
2585                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2586                exit(1);
2587        }
2588}
2589
2590static int similarity_index(struct diff_filepair *p)
2591{
2592        return p->score * 100 / MAX_SCORE;
2593}
2594
2595static void fill_metainfo(struct strbuf *msg,
2596                          const char *name,
2597                          const char *other,
2598                          struct diff_filespec *one,
2599                          struct diff_filespec *two,
2600                          struct diff_options *o,
2601                          struct diff_filepair *p,
2602                          int *must_show_header,
2603                          int use_color)
2604{
2605        const char *set = diff_get_color(use_color, DIFF_METAINFO);
2606        const char *reset = diff_get_color(use_color, DIFF_RESET);
2607        struct strbuf *msgbuf;
2608        char *line_prefix = "";
2609
2610        *must_show_header = 1;
2611        if (o->output_prefix) {
2612                msgbuf = o->output_prefix(o, o->output_prefix_data);
2613                line_prefix = msgbuf->buf;
2614        }
2615        strbuf_init(msg, PATH_MAX * 2 + 300);
2616        switch (p->status) {
2617        case DIFF_STATUS_COPIED:
2618                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2619                            line_prefix, set, similarity_index(p));
2620                strbuf_addf(msg, "%s\n%s%scopy from ",
2621                            reset,  line_prefix, set);
2622                quote_c_style(name, msg, NULL, 0);
2623                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2624                quote_c_style(other, msg, NULL, 0);
2625                strbuf_addf(msg, "%s\n", reset);
2626                break;
2627        case DIFF_STATUS_RENAMED:
2628                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2629                            line_prefix, set, similarity_index(p));
2630                strbuf_addf(msg, "%s\n%s%srename from ",
2631                            reset, line_prefix, set);
2632                quote_c_style(name, msg, NULL, 0);
2633                strbuf_addf(msg, "%s\n%s%srename to ",
2634                            reset, line_prefix, set);
2635                quote_c_style(other, msg, NULL, 0);
2636                strbuf_addf(msg, "%s\n", reset);
2637                break;
2638        case DIFF_STATUS_MODIFIED:
2639                if (p->score) {
2640                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2641                                    line_prefix,
2642                                    set, similarity_index(p), reset);
2643                        break;
2644                }
2645                /* fallthru */
2646        default:
2647                *must_show_header = 0;
2648        }
2649        if (one && two && hashcmp(one->sha1, two->sha1)) {
2650                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2651
2652                if (DIFF_OPT_TST(o, BINARY)) {
2653                        mmfile_t mf;
2654                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2655                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2656                                abbrev = 40;
2657                }
2658                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2659                            find_unique_abbrev(one->sha1, abbrev));
2660                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2661                if (one->mode == two->mode)
2662                        strbuf_addf(msg, " %06o", one->mode);
2663                strbuf_addf(msg, "%s\n", reset);
2664        }
2665}
2666
2667static void run_diff_cmd(const char *pgm,
2668                         const char *name,
2669                         const char *other,
2670                         const char *attr_path,
2671                         struct diff_filespec *one,
2672                         struct diff_filespec *two,
2673                         struct strbuf *msg,
2674                         struct diff_options *o,
2675                         struct diff_filepair *p)
2676{
2677        const char *xfrm_msg = NULL;
2678        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2679        int must_show_header = 0;
2680
2681        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2682                pgm = NULL;
2683        else {
2684                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2685                if (drv && drv->external)
2686                        pgm = drv->external;
2687        }
2688
2689        if (msg) {
2690                /*
2691                 * don't use colors when the header is intended for an
2692                 * external diff driver
2693                 */
2694                fill_metainfo(msg, name, other, one, two, o, p,
2695                              &must_show_header,
2696                              DIFF_OPT_TST(o, COLOR_DIFF) && !pgm);
2697                xfrm_msg = msg->len ? msg->buf : NULL;
2698        }
2699
2700        if (pgm) {
2701                run_external_diff(pgm, name, other, one, two, xfrm_msg,
2702                                  complete_rewrite);
2703                return;
2704        }
2705        if (one && two)
2706                builtin_diff(name, other ? other : name,
2707                             one, two, xfrm_msg, must_show_header,
2708                             o, complete_rewrite);
2709        else
2710                fprintf(o->file, "* Unmerged path %s\n", name);
2711}
2712
2713static void diff_fill_sha1_info(struct diff_filespec *one)
2714{
2715        if (DIFF_FILE_VALID(one)) {
2716                if (!one->sha1_valid) {
2717                        struct stat st;
2718                        if (!strcmp(one->path, "-")) {
2719                                hashcpy(one->sha1, null_sha1);
2720                                return;
2721                        }
2722                        if (lstat(one->path, &st) < 0)
2723                                die_errno("stat '%s'", one->path);
2724                        if (index_path(one->sha1, one->path, &st, 0))
2725                                die("cannot hash %s", one->path);
2726                }
2727        }
2728        else
2729                hashclr(one->sha1);
2730}
2731
2732static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2733{
2734        /* Strip the prefix but do not molest /dev/null and absolute paths */
2735        if (*namep && **namep != '/') {
2736                *namep += prefix_length;
2737                if (**namep == '/')
2738                        ++*namep;
2739        }
2740        if (*otherp && **otherp != '/') {
2741                *otherp += prefix_length;
2742                if (**otherp == '/')
2743                        ++*otherp;
2744        }
2745}
2746
2747static void run_diff(struct diff_filepair *p, struct diff_options *o)
2748{
2749        const char *pgm = external_diff();
2750        struct strbuf msg;
2751        struct diff_filespec *one = p->one;
2752        struct diff_filespec *two = p->two;
2753        const char *name;
2754        const char *other;
2755        const char *attr_path;
2756
2757        name  = p->one->path;
2758        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2759        attr_path = name;
2760        if (o->prefix_length)
2761                strip_prefix(o->prefix_length, &name, &other);
2762
2763        if (DIFF_PAIR_UNMERGED(p)) {
2764                run_diff_cmd(pgm, name, NULL, attr_path,
2765                             NULL, NULL, NULL, o, p);
2766                return;
2767        }
2768
2769        diff_fill_sha1_info(one);
2770        diff_fill_sha1_info(two);
2771
2772        if (!pgm &&
2773            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2774            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2775                /*
2776                 * a filepair that changes between file and symlink
2777                 * needs to be split into deletion and creation.
2778                 */
2779                struct diff_filespec *null = alloc_filespec(two->path);
2780                run_diff_cmd(NULL, name, other, attr_path,
2781                             one, null, &msg, o, p);
2782                free(null);
2783                strbuf_release(&msg);
2784
2785                null = alloc_filespec(one->path);
2786                run_diff_cmd(NULL, name, other, attr_path,
2787                             null, two, &msg, o, p);
2788                free(null);
2789        }
2790        else
2791                run_diff_cmd(pgm, name, other, attr_path,
2792                             one, two, &msg, o, p);
2793
2794        strbuf_release(&msg);
2795}
2796
2797static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2798                         struct diffstat_t *diffstat)
2799{
2800        const char *name;
2801        const char *other;
2802        int complete_rewrite = 0;
2803
2804        if (DIFF_PAIR_UNMERGED(p)) {
2805                /* unmerged */
2806                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2807                return;
2808        }
2809
2810        name = p->one->path;
2811        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2812
2813        if (o->prefix_length)
2814                strip_prefix(o->prefix_length, &name, &other);
2815
2816        diff_fill_sha1_info(p->one);
2817        diff_fill_sha1_info(p->two);
2818
2819        if (p->status == DIFF_STATUS_MODIFIED && p->score)
2820                complete_rewrite = 1;
2821        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2822}
2823
2824static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2825{
2826        const char *name;
2827        const char *other;
2828        const char *attr_path;
2829
2830        if (DIFF_PAIR_UNMERGED(p)) {
2831                /* unmerged */
2832                return;
2833        }
2834
2835        name = p->one->path;
2836        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2837        attr_path = other ? other : name;
2838
2839        if (o->prefix_length)
2840                strip_prefix(o->prefix_length, &name, &other);
2841
2842        diff_fill_sha1_info(p->one);
2843        diff_fill_sha1_info(p->two);
2844
2845        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2846}
2847
2848void diff_setup(struct diff_options *options)
2849{
2850        memcpy(options, &default_diff_options, sizeof(*options));
2851
2852        options->file = stdout;
2853
2854        options->line_termination = '\n';
2855        options->break_opt = -1;
2856        options->rename_limit = -1;
2857        options->dirstat_percent = 3;
2858        options->context = 3;
2859
2860        options->change = diff_change;
2861        options->add_remove = diff_addremove;
2862        if (diff_use_color_default > 0)
2863                DIFF_OPT_SET(options, COLOR_DIFF);
2864        options->detect_rename = diff_detect_rename_default;
2865
2866        if (diff_no_prefix) {
2867                options->a_prefix = options->b_prefix = "";
2868        } else if (!diff_mnemonic_prefix) {
2869                options->a_prefix = "a/";
2870                options->b_prefix = "b/";
2871        }
2872}
2873
2874int diff_setup_done(struct diff_options *options)
2875{
2876        int count = 0;
2877
2878        if (options->output_format & DIFF_FORMAT_NAME)
2879                count++;
2880        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
2881                count++;
2882        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
2883                count++;
2884        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
2885                count++;
2886        if (count > 1)
2887                die("--name-only, --name-status, --check and -s are mutually exclusive");
2888
2889        /*
2890         * Most of the time we can say "there are changes"
2891         * only by checking if there are changed paths, but
2892         * --ignore-whitespace* options force us to look
2893         * inside contents.
2894         */
2895
2896        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
2897            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
2898            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
2899                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
2900        else
2901                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
2902
2903        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
2904                options->detect_rename = DIFF_DETECT_COPY;
2905
2906        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
2907                options->prefix = NULL;
2908        if (options->prefix)
2909                options->prefix_length = strlen(options->prefix);
2910        else
2911                options->prefix_length = 0;
2912
2913        if (options->output_format & (DIFF_FORMAT_NAME |
2914                                      DIFF_FORMAT_NAME_STATUS |
2915                                      DIFF_FORMAT_CHECKDIFF |
2916                                      DIFF_FORMAT_NO_OUTPUT))
2917                options->output_format &= ~(DIFF_FORMAT_RAW |
2918                                            DIFF_FORMAT_NUMSTAT |
2919                                            DIFF_FORMAT_DIFFSTAT |
2920                                            DIFF_FORMAT_SHORTSTAT |
2921                                            DIFF_FORMAT_DIRSTAT |
2922                                            DIFF_FORMAT_SUMMARY |
2923                                            DIFF_FORMAT_PATCH);
2924
2925        /*
2926         * These cases always need recursive; we do not drop caller-supplied
2927         * recursive bits for other formats here.
2928         */
2929        if (options->output_format & (DIFF_FORMAT_PATCH |
2930                                      DIFF_FORMAT_NUMSTAT |
2931                                      DIFF_FORMAT_DIFFSTAT |
2932                                      DIFF_FORMAT_SHORTSTAT |
2933                                      DIFF_FORMAT_DIRSTAT |
2934                                      DIFF_FORMAT_SUMMARY |
2935                                      DIFF_FORMAT_CHECKDIFF))
2936                DIFF_OPT_SET(options, RECURSIVE);
2937        /*
2938         * Also pickaxe would not work very well if you do not say recursive
2939         */
2940        if (options->pickaxe)
2941                DIFF_OPT_SET(options, RECURSIVE);
2942        /*
2943         * When patches are generated, submodules diffed against the work tree
2944         * must be checked for dirtiness too so it can be shown in the output
2945         */
2946        if (options->output_format & DIFF_FORMAT_PATCH)
2947                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
2948
2949        if (options->detect_rename && options->rename_limit < 0)
2950                options->rename_limit = diff_rename_limit_default;
2951        if (options->setup & DIFF_SETUP_USE_CACHE) {
2952                if (!active_cache)
2953                        /* read-cache does not die even when it fails
2954                         * so it is safe for us to do this here.  Also
2955                         * it does not smudge active_cache or active_nr
2956                         * when it fails, so we do not have to worry about
2957                         * cleaning it up ourselves either.
2958                         */
2959                        read_cache();
2960        }
2961        if (options->abbrev <= 0 || 40 < options->abbrev)
2962                options->abbrev = 40; /* full */
2963
2964        /*
2965         * It does not make sense to show the first hit we happened
2966         * to have found.  It does not make sense not to return with
2967         * exit code in such a case either.
2968         */
2969        if (DIFF_OPT_TST(options, QUICK)) {
2970                options->output_format = DIFF_FORMAT_NO_OUTPUT;
2971                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2972        }
2973
2974        return 0;
2975}
2976
2977static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
2978{
2979        char c, *eq;
2980        int len;
2981
2982        if (*arg != '-')
2983                return 0;
2984        c = *++arg;
2985        if (!c)
2986                return 0;
2987        if (c == arg_short) {
2988                c = *++arg;
2989                if (!c)
2990                        return 1;
2991                if (val && isdigit(c)) {
2992                        char *end;
2993                        int n = strtoul(arg, &end, 10);
2994                        if (*end)
2995                                return 0;
2996                        *val = n;
2997                        return 1;
2998                }
2999                return 0;
3000        }
3001        if (c != '-')
3002                return 0;
3003        arg++;
3004        eq = strchr(arg, '=');
3005        if (eq)
3006                len = eq - arg;
3007        else
3008                len = strlen(arg);
3009        if (!len || strncmp(arg, arg_long, len))
3010                return 0;
3011        if (eq) {
3012                int n;
3013                char *end;
3014                if (!isdigit(*++eq))
3015                        return 0;
3016                n = strtoul(eq, &end, 10);
3017                if (*end)
3018                        return 0;
3019                *val = n;
3020        }
3021        return 1;
3022}
3023
3024static int diff_scoreopt_parse(const char *opt);
3025
3026static inline int short_opt(char opt, const char **argv,
3027                            const char **optarg)
3028{
3029        const char *arg = argv[0];
3030        if (arg[0] != '-' || arg[1] != opt)
3031                return 0;
3032        if (arg[2] != '\0') {
3033                *optarg = arg + 2;
3034                return 1;
3035        }
3036        if (!argv[1])
3037                die("Option '%c' requires a value", opt);
3038        *optarg = argv[1];
3039        return 2;
3040}
3041
3042int parse_long_opt(const char *opt, const char **argv,
3043                   const char **optarg)
3044{
3045        const char *arg = argv[0];
3046        if (arg[0] != '-' || arg[1] != '-')
3047                return 0;
3048        arg += strlen("--");
3049        if (prefixcmp(arg, opt))
3050                return 0;
3051        arg += strlen(opt);
3052        if (*arg == '=') { /* sticked form: --option=value */
3053                *optarg = arg + 1;
3054                return 1;
3055        }
3056        if (*arg != '\0')
3057                return 0;
3058        /* separate form: --option value */
3059        if (!argv[1])
3060                die("Option '--%s' requires a value", opt);
3061        *optarg = argv[1];
3062        return 2;
3063}
3064
3065static int stat_opt(struct diff_options *options, const char **av)
3066{
3067        const char *arg = av[0];
3068        char *end;
3069        int width = options->stat_width;
3070        int name_width = options->stat_name_width;
3071        int argcount = 1;
3072
3073        arg += strlen("--stat");
3074        end = (char *)arg;
3075
3076        switch (*arg) {
3077        case '-':
3078                if (!prefixcmp(arg, "-width")) {
3079                        arg += strlen("-width");
3080                        if (*arg == '=')
3081                                width = strtoul(arg + 1, &end, 10);
3082                        else if (!*arg && !av[1])
3083                                die("Option '--stat-width' requires a value");
3084                        else if (!*arg) {
3085                                width = strtoul(av[1], &end, 10);
3086                                argcount = 2;
3087                        }
3088                } else if (!prefixcmp(arg, "-name-width")) {
3089                        arg += strlen("-name-width");
3090                        if (*arg == '=')
3091                                name_width = strtoul(arg + 1, &end, 10);
3092                        else if (!*arg && !av[1])
3093                                die("Option '--stat-name-width' requires a value");
3094                        else if (!*arg) {
3095                                name_width = strtoul(av[1], &end, 10);
3096                                argcount = 2;
3097                        }
3098                }
3099                break;
3100        case '=':
3101                width = strtoul(arg+1, &end, 10);
3102                if (*end == ',')
3103                        name_width = strtoul(end+1, &end, 10);
3104        }
3105
3106        /* Important! This checks all the error cases! */
3107        if (*end)
3108                return 0;
3109        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3110        options->stat_name_width = name_width;
3111        options->stat_width = width;
3112        return argcount;
3113}
3114
3115int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3116{
3117        const char *arg = av[0];
3118        const char *optarg;
3119        int argcount;
3120
3121        /* Output format options */
3122        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3123                options->output_format |= DIFF_FORMAT_PATCH;
3124        else if (opt_arg(arg, 'U', "unified", &options->context))
3125                options->output_format |= DIFF_FORMAT_PATCH;
3126        else if (!strcmp(arg, "--raw"))
3127                options->output_format |= DIFF_FORMAT_RAW;
3128        else if (!strcmp(arg, "--patch-with-raw"))
3129                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3130        else if (!strcmp(arg, "--numstat"))
3131                options->output_format |= DIFF_FORMAT_NUMSTAT;
3132        else if (!strcmp(arg, "--shortstat"))
3133                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3134        else if (opt_arg(arg, 'X', "dirstat", &options->dirstat_percent))
3135                options->output_format |= DIFF_FORMAT_DIRSTAT;
3136        else if (!strcmp(arg, "--cumulative")) {
3137                options->output_format |= DIFF_FORMAT_DIRSTAT;
3138                DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
3139        } else if (opt_arg(arg, 0, "dirstat-by-file",
3140                           &options->dirstat_percent)) {
3141                options->output_format |= DIFF_FORMAT_DIRSTAT;
3142                DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
3143        }
3144        else if (!strcmp(arg, "--check"))
3145                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3146        else if (!strcmp(arg, "--summary"))
3147                options->output_format |= DIFF_FORMAT_SUMMARY;
3148        else if (!strcmp(arg, "--patch-with-stat"))
3149                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3150        else if (!strcmp(arg, "--name-only"))
3151                options->output_format |= DIFF_FORMAT_NAME;
3152        else if (!strcmp(arg, "--name-status"))
3153                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3154        else if (!strcmp(arg, "-s"))
3155                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3156        else if (!prefixcmp(arg, "--stat"))
3157                /* --stat, --stat-width, or --stat-name-width */
3158                return stat_opt(options, av);
3159
3160        /* renames options */
3161        else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
3162                 !strcmp(arg, "--break-rewrites")) {
3163                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3164                        return error("invalid argument to -B: %s", arg+2);
3165        }
3166        else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--find-renames=") ||
3167                 !strcmp(arg, "--find-renames")) {
3168                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3169                        return error("invalid argument to -M: %s", arg+2);
3170                options->detect_rename = DIFF_DETECT_RENAME;
3171        }
3172        else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
3173                 !strcmp(arg, "--find-copies")) {
3174                if (options->detect_rename == DIFF_DETECT_COPY)
3175                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3176                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3177                        return error("invalid argument to -C: %s", arg+2);
3178                options->detect_rename = DIFF_DETECT_COPY;
3179        }
3180        else if (!strcmp(arg, "--no-renames"))
3181                options->detect_rename = 0;
3182        else if (!strcmp(arg, "--relative"))
3183                DIFF_OPT_SET(options, RELATIVE_NAME);
3184        else if (!prefixcmp(arg, "--relative=")) {
3185                DIFF_OPT_SET(options, RELATIVE_NAME);
3186                options->prefix = arg + 11;
3187        }
3188
3189        /* xdiff options */
3190        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3191                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3192        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3193                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3194        else if (!strcmp(arg, "--ignore-space-at-eol"))
3195                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3196        else if (!strcmp(arg, "--patience"))
3197                DIFF_XDL_SET(options, PATIENCE_DIFF);
3198
3199        /* flags options */
3200        else if (!strcmp(arg, "--binary")) {
3201                options->output_format |= DIFF_FORMAT_PATCH;
3202                DIFF_OPT_SET(options, BINARY);
3203        }
3204        else if (!strcmp(arg, "--full-index"))
3205                DIFF_OPT_SET(options, FULL_INDEX);
3206        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3207                DIFF_OPT_SET(options, TEXT);
3208        else if (!strcmp(arg, "-R"))
3209                DIFF_OPT_SET(options, REVERSE_DIFF);
3210        else if (!strcmp(arg, "--find-copies-harder"))
3211                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3212        else if (!strcmp(arg, "--follow"))
3213                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3214        else if (!strcmp(arg, "--color"))
3215                DIFF_OPT_SET(options, COLOR_DIFF);
3216        else if (!prefixcmp(arg, "--color=")) {
3217                int value = git_config_colorbool(NULL, arg+8, -1);
3218                if (value == 0)
3219                        DIFF_OPT_CLR(options, COLOR_DIFF);
3220                else if (value > 0)
3221                        DIFF_OPT_SET(options, COLOR_DIFF);
3222                else
3223                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3224        }
3225        else if (!strcmp(arg, "--no-color"))
3226                DIFF_OPT_CLR(options, COLOR_DIFF);
3227        else if (!strcmp(arg, "--color-words")) {
3228                DIFF_OPT_SET(options, COLOR_DIFF);
3229                options->word_diff = DIFF_WORDS_COLOR;
3230        }
3231        else if (!prefixcmp(arg, "--color-words=")) {
3232                DIFF_OPT_SET(options, COLOR_DIFF);
3233                options->word_diff = DIFF_WORDS_COLOR;
3234                options->word_regex = arg + 14;
3235        }
3236        else if (!strcmp(arg, "--word-diff")) {
3237                if (options->word_diff == DIFF_WORDS_NONE)
3238                        options->word_diff = DIFF_WORDS_PLAIN;
3239        }
3240        else if (!prefixcmp(arg, "--word-diff=")) {
3241                const char *type = arg + 12;
3242                if (!strcmp(type, "plain"))
3243                        options->word_diff = DIFF_WORDS_PLAIN;
3244                else if (!strcmp(type, "color")) {
3245                        DIFF_OPT_SET(options, COLOR_DIFF);
3246                        options->word_diff = DIFF_WORDS_COLOR;
3247                }
3248                else if (!strcmp(type, "porcelain"))
3249                        options->word_diff = DIFF_WORDS_PORCELAIN;
3250                else if (!strcmp(type, "none"))
3251                        options->word_diff = DIFF_WORDS_NONE;
3252                else
3253                        die("bad --word-diff argument: %s", type);
3254        }
3255        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3256                if (options->word_diff == DIFF_WORDS_NONE)
3257                        options->word_diff = DIFF_WORDS_PLAIN;
3258                options->word_regex = optarg;
3259                return argcount;
3260        }
3261        else if (!strcmp(arg, "--exit-code"))
3262                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3263        else if (!strcmp(arg, "--quiet"))
3264                DIFF_OPT_SET(options, QUICK);
3265        else if (!strcmp(arg, "--ext-diff"))
3266                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3267        else if (!strcmp(arg, "--no-ext-diff"))
3268                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3269        else if (!strcmp(arg, "--textconv"))
3270                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3271        else if (!strcmp(arg, "--no-textconv"))
3272                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3273        else if (!strcmp(arg, "--ignore-submodules")) {
3274                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3275                handle_ignore_submodules_arg(options, "all");
3276        } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3277                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3278                handle_ignore_submodules_arg(options, arg + 20);
3279        } else if (!strcmp(arg, "--submodule"))
3280                DIFF_OPT_SET(options, SUBMODULE_LOG);
3281        else if (!prefixcmp(arg, "--submodule=")) {
3282                if (!strcmp(arg + 12, "log"))
3283                        DIFF_OPT_SET(options, SUBMODULE_LOG);
3284        }
3285
3286        /* misc options */
3287        else if (!strcmp(arg, "-z"))
3288                options->line_termination = 0;
3289        else if ((argcount = short_opt('l', av, &optarg))) {
3290                options->rename_limit = strtoul(optarg, NULL, 10);
3291                return argcount;
3292        }
3293        else if ((argcount = short_opt('S', av, &optarg))) {
3294                options->pickaxe = optarg;
3295                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3296                return argcount;
3297        } else if ((argcount = short_opt('G', av, &optarg))) {
3298                options->pickaxe = optarg;
3299                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3300                return argcount;
3301        }
3302        else if (!strcmp(arg, "--pickaxe-all"))
3303                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3304        else if (!strcmp(arg, "--pickaxe-regex"))
3305                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3306        else if ((argcount = short_opt('O', av, &optarg))) {
3307                options->orderfile = optarg;
3308                return argcount;
3309        }
3310        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3311                options->filter = optarg;
3312                return argcount;
3313        }
3314        else if (!strcmp(arg, "--abbrev"))
3315                options->abbrev = DEFAULT_ABBREV;
3316        else if (!prefixcmp(arg, "--abbrev=")) {
3317                options->abbrev = strtoul(arg + 9, NULL, 10);
3318                if (options->abbrev < MINIMUM_ABBREV)
3319                        options->abbrev = MINIMUM_ABBREV;
3320                else if (40 < options->abbrev)
3321                        options->abbrev = 40;
3322        }
3323        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3324                options->a_prefix = optarg;
3325                return argcount;
3326        }
3327        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3328                options->b_prefix = optarg;
3329                return argcount;
3330        }
3331        else if (!strcmp(arg, "--no-prefix"))
3332                options->a_prefix = options->b_prefix = "";
3333        else if (opt_arg(arg, '\0', "inter-hunk-context",
3334                         &options->interhunkcontext))
3335                ;
3336        else if ((argcount = parse_long_opt("output", av, &optarg))) {
3337                options->file = fopen(optarg, "w");
3338                if (!options->file)
3339                        die_errno("Could not open '%s'", optarg);
3340                options->close_file = 1;
3341                return argcount;
3342        } else
3343                return 0;
3344        return 1;
3345}
3346
3347int parse_rename_score(const char **cp_p)
3348{
3349        unsigned long num, scale;
3350        int ch, dot;
3351        const char *cp = *cp_p;
3352
3353        num = 0;
3354        scale = 1;
3355        dot = 0;
3356        for (;;) {
3357                ch = *cp;
3358                if ( !dot && ch == '.' ) {
3359                        scale = 1;
3360                        dot = 1;
3361                } else if ( ch == '%' ) {
3362                        scale = dot ? scale*100 : 100;
3363                        cp++;   /* % is always at the end */
3364                        break;
3365                } else if ( ch >= '0' && ch <= '9' ) {
3366                        if ( scale < 100000 ) {
3367                                scale *= 10;
3368                                num = (num*10) + (ch-'0');
3369                        }
3370                } else {
3371                        break;
3372                }
3373                cp++;
3374        }
3375        *cp_p = cp;
3376
3377        /* user says num divided by scale and we say internally that
3378         * is MAX_SCORE * num / scale.
3379         */
3380        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3381}
3382
3383static int diff_scoreopt_parse(const char *opt)
3384{
3385        int opt1, opt2, cmd;
3386
3387        if (*opt++ != '-')
3388                return -1;
3389        cmd = *opt++;
3390        if (cmd == '-') {
3391                /* convert the long-form arguments into short-form versions */
3392                if (!prefixcmp(opt, "break-rewrites")) {
3393                        opt += strlen("break-rewrites");
3394                        if (*opt == 0 || *opt++ == '=')
3395                                cmd = 'B';
3396                } else if (!prefixcmp(opt, "find-copies")) {
3397                        opt += strlen("find-copies");
3398                        if (*opt == 0 || *opt++ == '=')
3399                                cmd = 'C';
3400                } else if (!prefixcmp(opt, "find-renames")) {
3401                        opt += strlen("find-renames");
3402                        if (*opt == 0 || *opt++ == '=')
3403                                cmd = 'M';
3404                }
3405        }
3406        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3407                return -1; /* that is not a -M, -C nor -B option */
3408
3409        opt1 = parse_rename_score(&opt);
3410        if (cmd != 'B')
3411                opt2 = 0;
3412        else {
3413                if (*opt == 0)
3414                        opt2 = 0;
3415                else if (*opt != '/')
3416                        return -1; /* we expect -B80/99 or -B80 */
3417                else {
3418                        opt++;
3419                        opt2 = parse_rename_score(&opt);
3420                }
3421        }
3422        if (*opt != 0)
3423                return -1;
3424        return opt1 | (opt2 << 16);
3425}
3426
3427struct diff_queue_struct diff_queued_diff;
3428
3429void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3430{
3431        if (queue->alloc <= queue->nr) {
3432                queue->alloc = alloc_nr(queue->alloc);
3433                queue->queue = xrealloc(queue->queue,
3434                                        sizeof(dp) * queue->alloc);
3435        }
3436        queue->queue[queue->nr++] = dp;
3437}
3438
3439struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3440                                 struct diff_filespec *one,
3441                                 struct diff_filespec *two)
3442{
3443        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3444        dp->one = one;
3445        dp->two = two;
3446        if (queue)
3447                diff_q(queue, dp);
3448        return dp;
3449}
3450
3451void diff_free_filepair(struct diff_filepair *p)
3452{
3453        free_filespec(p->one);
3454        free_filespec(p->two);
3455        free(p);
3456}
3457
3458/* This is different from find_unique_abbrev() in that
3459 * it stuffs the result with dots for alignment.
3460 */
3461const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3462{
3463        int abblen;
3464        const char *abbrev;
3465        if (len == 40)
3466                return sha1_to_hex(sha1);
3467
3468        abbrev = find_unique_abbrev(sha1, len);
3469        abblen = strlen(abbrev);
3470        if (abblen < 37) {
3471                static char hex[41];
3472                if (len < abblen && abblen <= len + 2)
3473                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3474                else
3475                        sprintf(hex, "%s...", abbrev);
3476                return hex;
3477        }
3478        return sha1_to_hex(sha1);
3479}
3480
3481static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3482{
3483        int line_termination = opt->line_termination;
3484        int inter_name_termination = line_termination ? '\t' : '\0';
3485        if (opt->output_prefix) {
3486                struct strbuf *msg = NULL;
3487                msg = opt->output_prefix(opt, opt->output_prefix_data);
3488                fprintf(opt->file, "%s", msg->buf);
3489        }
3490
3491        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3492                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3493                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3494                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3495        }
3496        if (p->score) {
3497                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3498                        inter_name_termination);
3499        } else {
3500                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3501        }
3502
3503        if (p->status == DIFF_STATUS_COPIED ||
3504            p->status == DIFF_STATUS_RENAMED) {
3505                const char *name_a, *name_b;
3506                name_a = p->one->path;
3507                name_b = p->two->path;
3508                strip_prefix(opt->prefix_length, &name_a, &name_b);
3509                write_name_quoted(name_a, opt->file, inter_name_termination);
3510                write_name_quoted(name_b, opt->file, line_termination);
3511        } else {
3512                const char *name_a, *name_b;
3513                name_a = p->one->mode ? p->one->path : p->two->path;
3514                name_b = NULL;
3515                strip_prefix(opt->prefix_length, &name_a, &name_b);
3516                write_name_quoted(name_a, opt->file, line_termination);
3517        }
3518}
3519
3520int diff_unmodified_pair(struct diff_filepair *p)
3521{
3522        /* This function is written stricter than necessary to support
3523         * the currently implemented transformers, but the idea is to
3524         * let transformers to produce diff_filepairs any way they want,
3525         * and filter and clean them up here before producing the output.
3526         */
3527        struct diff_filespec *one = p->one, *two = p->two;
3528
3529        if (DIFF_PAIR_UNMERGED(p))
3530                return 0; /* unmerged is interesting */
3531
3532        /* deletion, addition, mode or type change
3533         * and rename are all interesting.
3534         */
3535        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3536            DIFF_PAIR_MODE_CHANGED(p) ||
3537            strcmp(one->path, two->path))
3538                return 0;
3539
3540        /* both are valid and point at the same path.  that is, we are
3541         * dealing with a change.
3542         */
3543        if (one->sha1_valid && two->sha1_valid &&
3544            !hashcmp(one->sha1, two->sha1) &&
3545            !one->dirty_submodule && !two->dirty_submodule)
3546                return 1; /* no change */
3547        if (!one->sha1_valid && !two->sha1_valid)
3548                return 1; /* both look at the same file on the filesystem. */
3549        return 0;
3550}
3551
3552static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3553{
3554        if (diff_unmodified_pair(p))
3555                return;
3556
3557        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3558            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3559                return; /* no tree diffs in patch format */
3560
3561        run_diff(p, o);
3562}
3563
3564static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3565                            struct diffstat_t *diffstat)
3566{
3567        if (diff_unmodified_pair(p))
3568                return;
3569
3570        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3571            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3572                return; /* no useful stat for tree diffs */
3573
3574        run_diffstat(p, o, diffstat);
3575}
3576
3577static void diff_flush_checkdiff(struct diff_filepair *p,
3578                struct diff_options *o)
3579{
3580        if (diff_unmodified_pair(p))
3581                return;
3582
3583        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3584            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3585                return; /* nothing to check in tree diffs */
3586
3587        run_checkdiff(p, o);
3588}
3589
3590int diff_queue_is_empty(void)
3591{
3592        struct diff_queue_struct *q = &diff_queued_diff;
3593        int i;
3594        for (i = 0; i < q->nr; i++)
3595                if (!diff_unmodified_pair(q->queue[i]))
3596                        return 0;
3597        return 1;
3598}
3599
3600#if DIFF_DEBUG
3601void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3602{
3603        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3604                x, one ? one : "",
3605                s->path,
3606                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3607                s->mode,
3608                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3609        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3610                x, one ? one : "",
3611                s->size, s->xfrm_flags);
3612}
3613
3614void diff_debug_filepair(const struct diff_filepair *p, int i)
3615{
3616        diff_debug_filespec(p->one, i, "one");
3617        diff_debug_filespec(p->two, i, "two");
3618        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3619                p->score, p->status ? p->status : '?',
3620                p->one->rename_used, p->broken_pair);
3621}
3622
3623void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3624{
3625        int i;
3626        if (msg)
3627                fprintf(stderr, "%s\n", msg);
3628        fprintf(stderr, "q->nr = %d\n", q->nr);
3629        for (i = 0; i < q->nr; i++) {
3630                struct diff_filepair *p = q->queue[i];
3631                diff_debug_filepair(p, i);
3632        }
3633}
3634#endif
3635
3636static void diff_resolve_rename_copy(void)
3637{
3638        int i;
3639        struct diff_filepair *p;
3640        struct diff_queue_struct *q = &diff_queued_diff;
3641
3642        diff_debug_queue("resolve-rename-copy", q);
3643
3644        for (i = 0; i < q->nr; i++) {
3645                p = q->queue[i];
3646                p->status = 0; /* undecided */
3647                if (DIFF_PAIR_UNMERGED(p))
3648                        p->status = DIFF_STATUS_UNMERGED;
3649                else if (!DIFF_FILE_VALID(p->one))
3650                        p->status = DIFF_STATUS_ADDED;
3651                else if (!DIFF_FILE_VALID(p->two))
3652                        p->status = DIFF_STATUS_DELETED;
3653                else if (DIFF_PAIR_TYPE_CHANGED(p))
3654                        p->status = DIFF_STATUS_TYPE_CHANGED;
3655
3656                /* from this point on, we are dealing with a pair
3657                 * whose both sides are valid and of the same type, i.e.
3658                 * either in-place edit or rename/copy edit.
3659                 */
3660                else if (DIFF_PAIR_RENAME(p)) {
3661                        /*
3662                         * A rename might have re-connected a broken
3663                         * pair up, causing the pathnames to be the
3664                         * same again. If so, that's not a rename at
3665                         * all, just a modification..
3666                         *
3667                         * Otherwise, see if this source was used for
3668                         * multiple renames, in which case we decrement
3669                         * the count, and call it a copy.
3670                         */
3671                        if (!strcmp(p->one->path, p->two->path))
3672                                p->status = DIFF_STATUS_MODIFIED;
3673                        else if (--p->one->rename_used > 0)
3674                                p->status = DIFF_STATUS_COPIED;
3675                        else
3676                                p->status = DIFF_STATUS_RENAMED;
3677                }
3678                else if (hashcmp(p->one->sha1, p->two->sha1) ||
3679                         p->one->mode != p->two->mode ||
3680                         p->one->dirty_submodule ||
3681                         p->two->dirty_submodule ||
3682                         is_null_sha1(p->one->sha1))
3683                        p->status = DIFF_STATUS_MODIFIED;
3684                else {
3685                        /* This is a "no-change" entry and should not
3686                         * happen anymore, but prepare for broken callers.
3687                         */
3688                        error("feeding unmodified %s to diffcore",
3689                              p->one->path);
3690                        p->status = DIFF_STATUS_UNKNOWN;
3691                }
3692        }
3693        diff_debug_queue("resolve-rename-copy done", q);
3694}
3695
3696static int check_pair_status(struct diff_filepair *p)
3697{
3698        switch (p->status) {
3699        case DIFF_STATUS_UNKNOWN:
3700                return 0;
3701        case 0:
3702                die("internal error in diff-resolve-rename-copy");
3703        default:
3704                return 1;
3705        }
3706}
3707
3708static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3709{
3710        int fmt = opt->output_format;
3711
3712        if (fmt & DIFF_FORMAT_CHECKDIFF)
3713                diff_flush_checkdiff(p, opt);
3714        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3715                diff_flush_raw(p, opt);
3716        else if (fmt & DIFF_FORMAT_NAME) {
3717                const char *name_a, *name_b;
3718                name_a = p->two->path;
3719                name_b = NULL;
3720                strip_prefix(opt->prefix_length, &name_a, &name_b);
3721                write_name_quoted(name_a, opt->file, opt->line_termination);
3722        }
3723}
3724
3725static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
3726{
3727        if (fs->mode)
3728                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
3729        else
3730                fprintf(file, " %s ", newdelete);
3731        write_name_quoted(fs->path, file, '\n');
3732}
3733
3734
3735static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
3736                const char *line_prefix)
3737{
3738        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
3739                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
3740                        p->two->mode, show_name ? ' ' : '\n');
3741                if (show_name) {
3742                        write_name_quoted(p->two->path, file, '\n');
3743                }
3744        }
3745}
3746
3747static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
3748                        const char *line_prefix)
3749{
3750        char *names = pprint_rename(p->one->path, p->two->path);
3751
3752        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
3753        free(names);
3754        show_mode_change(file, p, 0, line_prefix);
3755}
3756
3757static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
3758{
3759        FILE *file = opt->file;
3760        char *line_prefix = "";
3761
3762        if (opt->output_prefix) {
3763                struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
3764                line_prefix = buf->buf;
3765        }
3766
3767        switch(p->status) {
3768        case DIFF_STATUS_DELETED:
3769                fputs(line_prefix, file);
3770                show_file_mode_name(file, "delete", p->one);
3771                break;
3772        case DIFF_STATUS_ADDED:
3773                fputs(line_prefix, file);
3774                show_file_mode_name(file, "create", p->two);
3775                break;
3776        case DIFF_STATUS_COPIED:
3777                fputs(line_prefix, file);
3778                show_rename_copy(file, "copy", p, line_prefix);
3779                break;
3780        case DIFF_STATUS_RENAMED:
3781                fputs(line_prefix, file);
3782                show_rename_copy(file, "rename", p, line_prefix);
3783                break;
3784        default:
3785                if (p->score) {
3786                        fprintf(file, "%s rewrite ", line_prefix);
3787                        write_name_quoted(p->two->path, file, ' ');
3788                        fprintf(file, "(%d%%)\n", similarity_index(p));
3789                }
3790                show_mode_change(file, p, !p->score, line_prefix);
3791                break;
3792        }
3793}
3794
3795struct patch_id_t {
3796        git_SHA_CTX *ctx;
3797        int patchlen;
3798};
3799
3800static int remove_space(char *line, int len)
3801{
3802        int i;
3803        char *dst = line;
3804        unsigned char c;
3805
3806        for (i = 0; i < len; i++)
3807                if (!isspace((c = line[i])))
3808                        *dst++ = c;
3809
3810        return dst - line;
3811}
3812
3813static void patch_id_consume(void *priv, char *line, unsigned long len)
3814{
3815        struct patch_id_t *data = priv;
3816        int new_len;
3817
3818        /* Ignore line numbers when computing the SHA1 of the patch */
3819        if (!prefixcmp(line, "@@ -"))
3820                return;
3821
3822        new_len = remove_space(line, len);
3823
3824        git_SHA1_Update(data->ctx, line, new_len);
3825        data->patchlen += new_len;
3826}
3827
3828/* returns 0 upon success, and writes result into sha1 */
3829static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
3830{
3831        struct diff_queue_struct *q = &diff_queued_diff;
3832        int i;
3833        git_SHA_CTX ctx;
3834        struct patch_id_t data;
3835        char buffer[PATH_MAX * 4 + 20];
3836
3837        git_SHA1_Init(&ctx);
3838        memset(&data, 0, sizeof(struct patch_id_t));
3839        data.ctx = &ctx;
3840
3841        for (i = 0; i < q->nr; i++) {
3842                xpparam_t xpp;
3843                xdemitconf_t xecfg;
3844                mmfile_t mf1, mf2;
3845                struct diff_filepair *p = q->queue[i];
3846                int len1, len2;
3847
3848                memset(&xpp, 0, sizeof(xpp));
3849                memset(&xecfg, 0, sizeof(xecfg));
3850                if (p->status == 0)
3851                        return error("internal diff status error");
3852                if (p->status == DIFF_STATUS_UNKNOWN)
3853                        continue;
3854                if (diff_unmodified_pair(p))
3855                        continue;
3856                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3857                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3858                        continue;
3859                if (DIFF_PAIR_UNMERGED(p))
3860                        continue;
3861
3862                diff_fill_sha1_info(p->one);
3863                diff_fill_sha1_info(p->two);
3864                if (fill_mmfile(&mf1, p->one) < 0 ||
3865                                fill_mmfile(&mf2, p->two) < 0)
3866                        return error("unable to read files to diff");
3867
3868                len1 = remove_space(p->one->path, strlen(p->one->path));
3869                len2 = remove_space(p->two->path, strlen(p->two->path));
3870                if (p->one->mode == 0)
3871                        len1 = snprintf(buffer, sizeof(buffer),
3872                                        "diff--gita/%.*sb/%.*s"
3873                                        "newfilemode%06o"
3874                                        "---/dev/null"
3875                                        "+++b/%.*s",
3876                                        len1, p->one->path,
3877                                        len2, p->two->path,
3878                                        p->two->mode,
3879                                        len2, p->two->path);
3880                else if (p->two->mode == 0)
3881                        len1 = snprintf(buffer, sizeof(buffer),
3882                                        "diff--gita/%.*sb/%.*s"
3883                                        "deletedfilemode%06o"
3884                                        "---a/%.*s"
3885                                        "+++/dev/null",
3886                                        len1, p->one->path,
3887                                        len2, p->two->path,
3888                                        p->one->mode,
3889                                        len1, p->one->path);
3890                else
3891                        len1 = snprintf(buffer, sizeof(buffer),
3892                                        "diff--gita/%.*sb/%.*s"
3893                                        "---a/%.*s"
3894                                        "+++b/%.*s",
3895                                        len1, p->one->path,
3896                                        len2, p->two->path,
3897                                        len1, p->one->path,
3898                                        len2, p->two->path);
3899                git_SHA1_Update(&ctx, buffer, len1);
3900
3901                if (diff_filespec_is_binary(p->one) ||
3902                    diff_filespec_is_binary(p->two)) {
3903                        git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
3904                        git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
3905                        continue;
3906                }
3907
3908                xpp.flags = 0;
3909                xecfg.ctxlen = 3;
3910                xecfg.flags = 0;
3911                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
3912                              &xpp, &xecfg);
3913        }
3914
3915        git_SHA1_Final(sha1, &ctx);
3916        return 0;
3917}
3918
3919int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
3920{
3921        struct diff_queue_struct *q = &diff_queued_diff;
3922        int i;
3923        int result = diff_get_patch_id(options, sha1);
3924
3925        for (i = 0; i < q->nr; i++)
3926                diff_free_filepair(q->queue[i]);
3927
3928        free(q->queue);
3929        DIFF_QUEUE_CLEAR(q);
3930
3931        return result;
3932}
3933
3934static int is_summary_empty(const struct diff_queue_struct *q)
3935{
3936        int i;
3937
3938        for (i = 0; i < q->nr; i++) {
3939                const struct diff_filepair *p = q->queue[i];
3940
3941                switch (p->status) {
3942                case DIFF_STATUS_DELETED:
3943                case DIFF_STATUS_ADDED:
3944                case DIFF_STATUS_COPIED:
3945                case DIFF_STATUS_RENAMED:
3946                        return 0;
3947                default:
3948                        if (p->score)
3949                                return 0;
3950                        if (p->one->mode && p->two->mode &&
3951                            p->one->mode != p->two->mode)
3952                                return 0;
3953                        break;
3954                }
3955        }
3956        return 1;
3957}
3958
3959void diff_flush(struct diff_options *options)
3960{
3961        struct diff_queue_struct *q = &diff_queued_diff;
3962        int i, output_format = options->output_format;
3963        int separator = 0;
3964
3965        /*
3966         * Order: raw, stat, summary, patch
3967         * or:    name/name-status/checkdiff (other bits clear)
3968         */
3969        if (!q->nr)
3970                goto free_queue;
3971
3972        if (output_format & (DIFF_FORMAT_RAW |
3973                             DIFF_FORMAT_NAME |
3974                             DIFF_FORMAT_NAME_STATUS |
3975                             DIFF_FORMAT_CHECKDIFF)) {
3976                for (i = 0; i < q->nr; i++) {
3977                        struct diff_filepair *p = q->queue[i];
3978                        if (check_pair_status(p))
3979                                flush_one_pair(p, options);
3980                }
3981                separator++;
3982        }
3983
3984        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
3985                struct diffstat_t diffstat;
3986
3987                memset(&diffstat, 0, sizeof(struct diffstat_t));
3988                for (i = 0; i < q->nr; i++) {
3989                        struct diff_filepair *p = q->queue[i];
3990                        if (check_pair_status(p))
3991                                diff_flush_stat(p, options, &diffstat);
3992                }
3993                if (output_format & DIFF_FORMAT_NUMSTAT)
3994                        show_numstat(&diffstat, options);
3995                if (output_format & DIFF_FORMAT_DIFFSTAT)
3996                        show_stats(&diffstat, options);
3997                if (output_format & DIFF_FORMAT_SHORTSTAT)
3998                        show_shortstats(&diffstat, options);
3999                free_diffstat_info(&diffstat);
4000                separator++;
4001        }
4002        if (output_format & DIFF_FORMAT_DIRSTAT)
4003                show_dirstat(options);
4004
4005        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4006                for (i = 0; i < q->nr; i++) {
4007                        diff_summary(options, q->queue[i]);
4008                }
4009                separator++;
4010        }
4011
4012        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4013            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4014            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4015                /*
4016                 * run diff_flush_patch for the exit status. setting
4017                 * options->file to /dev/null should be safe, becaue we
4018                 * aren't supposed to produce any output anyway.
4019                 */
4020                if (options->close_file)
4021                        fclose(options->file);
4022                options->file = fopen("/dev/null", "w");
4023                if (!options->file)
4024                        die_errno("Could not open /dev/null");
4025                options->close_file = 1;
4026                for (i = 0; i < q->nr; i++) {
4027                        struct diff_filepair *p = q->queue[i];
4028                        if (check_pair_status(p))
4029                                diff_flush_patch(p, options);
4030                        if (options->found_changes)
4031                                break;
4032                }
4033        }
4034
4035        if (output_format & DIFF_FORMAT_PATCH) {
4036                if (separator) {
4037                        putc(options->line_termination, options->file);
4038                        if (options->stat_sep) {
4039                                /* attach patch instead of inline */
4040                                fputs(options->stat_sep, options->file);
4041                        }
4042                }
4043
4044                for (i = 0; i < q->nr; i++) {
4045                        struct diff_filepair *p = q->queue[i];
4046                        if (check_pair_status(p))
4047                                diff_flush_patch(p, options);
4048                }
4049        }
4050
4051        if (output_format & DIFF_FORMAT_CALLBACK)
4052                options->format_callback(q, options, options->format_callback_data);
4053
4054        for (i = 0; i < q->nr; i++)
4055                diff_free_filepair(q->queue[i]);
4056free_queue:
4057        free(q->queue);
4058        DIFF_QUEUE_CLEAR(q);
4059        if (options->close_file)
4060                fclose(options->file);
4061
4062        /*
4063         * Report the content-level differences with HAS_CHANGES;
4064         * diff_addremove/diff_change does not set the bit when
4065         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4066         */
4067        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4068                if (options->found_changes)
4069                        DIFF_OPT_SET(options, HAS_CHANGES);
4070                else
4071                        DIFF_OPT_CLR(options, HAS_CHANGES);
4072        }
4073}
4074
4075static void diffcore_apply_filter(const char *filter)
4076{
4077        int i;
4078        struct diff_queue_struct *q = &diff_queued_diff;
4079        struct diff_queue_struct outq;
4080        DIFF_QUEUE_CLEAR(&outq);
4081
4082        if (!filter)
4083                return;
4084
4085        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
4086                int found;
4087                for (i = found = 0; !found && i < q->nr; i++) {
4088                        struct diff_filepair *p = q->queue[i];
4089                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4090                             ((p->score &&
4091                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4092                              (!p->score &&
4093                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4094                            ((p->status != DIFF_STATUS_MODIFIED) &&
4095                             strchr(filter, p->status)))
4096                                found++;
4097                }
4098                if (found)
4099                        return;
4100
4101                /* otherwise we will clear the whole queue
4102                 * by copying the empty outq at the end of this
4103                 * function, but first clear the current entries
4104                 * in the queue.
4105                 */
4106                for (i = 0; i < q->nr; i++)
4107                        diff_free_filepair(q->queue[i]);
4108        }
4109        else {
4110                /* Only the matching ones */
4111                for (i = 0; i < q->nr; i++) {
4112                        struct diff_filepair *p = q->queue[i];
4113
4114                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4115                             ((p->score &&
4116                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4117                              (!p->score &&
4118                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4119                            ((p->status != DIFF_STATUS_MODIFIED) &&
4120                             strchr(filter, p->status)))
4121                                diff_q(&outq, p);
4122                        else
4123                                diff_free_filepair(p);
4124                }
4125        }
4126        free(q->queue);
4127        *q = outq;
4128}
4129
4130/* Check whether two filespecs with the same mode and size are identical */
4131static int diff_filespec_is_identical(struct diff_filespec *one,
4132                                      struct diff_filespec *two)
4133{
4134        if (S_ISGITLINK(one->mode))
4135                return 0;
4136        if (diff_populate_filespec(one, 0))
4137                return 0;
4138        if (diff_populate_filespec(two, 0))
4139                return 0;
4140        return !memcmp(one->data, two->data, one->size);
4141}
4142
4143static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4144{
4145        int i;
4146        struct diff_queue_struct *q = &diff_queued_diff;
4147        struct diff_queue_struct outq;
4148        DIFF_QUEUE_CLEAR(&outq);
4149
4150        for (i = 0; i < q->nr; i++) {
4151                struct diff_filepair *p = q->queue[i];
4152
4153                /*
4154                 * 1. Entries that come from stat info dirtiness
4155                 *    always have both sides (iow, not create/delete),
4156                 *    one side of the object name is unknown, with
4157                 *    the same mode and size.  Keep the ones that
4158                 *    do not match these criteria.  They have real
4159                 *    differences.
4160                 *
4161                 * 2. At this point, the file is known to be modified,
4162                 *    with the same mode and size, and the object
4163                 *    name of one side is unknown.  Need to inspect
4164                 *    the identical contents.
4165                 */
4166                if (!DIFF_FILE_VALID(p->one) || /* (1) */
4167                    !DIFF_FILE_VALID(p->two) ||
4168                    (p->one->sha1_valid && p->two->sha1_valid) ||
4169                    (p->one->mode != p->two->mode) ||
4170                    diff_populate_filespec(p->one, 1) ||
4171                    diff_populate_filespec(p->two, 1) ||
4172                    (p->one->size != p->two->size) ||
4173                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4174                        diff_q(&outq, p);
4175                else {
4176                        /*
4177                         * The caller can subtract 1 from skip_stat_unmatch
4178                         * to determine how many paths were dirty only
4179                         * due to stat info mismatch.
4180                         */
4181                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4182                                diffopt->skip_stat_unmatch++;
4183                        diff_free_filepair(p);
4184                }
4185        }
4186        free(q->queue);
4187        *q = outq;
4188}
4189
4190static int diffnamecmp(const void *a_, const void *b_)
4191{
4192        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4193        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4194        const char *name_a, *name_b;
4195
4196        name_a = a->one ? a->one->path : a->two->path;
4197        name_b = b->one ? b->one->path : b->two->path;
4198        return strcmp(name_a, name_b);
4199}
4200
4201void diffcore_fix_diff_index(struct diff_options *options)
4202{
4203        struct diff_queue_struct *q = &diff_queued_diff;
4204        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4205}
4206
4207void diffcore_std(struct diff_options *options)
4208{
4209        if (options->skip_stat_unmatch)
4210                diffcore_skip_stat_unmatch(options);
4211        if (!options->found_follow) {
4212                /* See try_to_follow_renames() in tree-diff.c */
4213                if (options->break_opt != -1)
4214                        diffcore_break(options->break_opt);
4215                if (options->detect_rename)
4216                        diffcore_rename(options);
4217                if (options->break_opt != -1)
4218                        diffcore_merge_broken();
4219        }
4220        if (options->pickaxe)
4221                diffcore_pickaxe(options);
4222        if (options->orderfile)
4223                diffcore_order(options->orderfile);
4224        if (!options->found_follow)
4225                /* See try_to_follow_renames() in tree-diff.c */
4226                diff_resolve_rename_copy();
4227        diffcore_apply_filter(options->filter);
4228
4229        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4230                DIFF_OPT_SET(options, HAS_CHANGES);
4231        else
4232                DIFF_OPT_CLR(options, HAS_CHANGES);
4233
4234        options->found_follow = 0;
4235}
4236
4237int diff_result_code(struct diff_options *opt, int status)
4238{
4239        int result = 0;
4240        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4241            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4242                return status;
4243        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4244            DIFF_OPT_TST(opt, HAS_CHANGES))
4245                result |= 01;
4246        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4247            DIFF_OPT_TST(opt, CHECK_FAILED))
4248                result |= 02;
4249        return result;
4250}
4251
4252/*
4253 * Shall changes to this submodule be ignored?
4254 *
4255 * Submodule changes can be configured to be ignored separately for each path,
4256 * but that configuration can be overridden from the command line.
4257 */
4258static int is_submodule_ignored(const char *path, struct diff_options *options)
4259{
4260        int ignored = 0;
4261        unsigned orig_flags = options->flags;
4262        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4263                set_diffopt_flags_from_submodule_config(options, path);
4264        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4265                ignored = 1;
4266        options->flags = orig_flags;
4267        return ignored;
4268}
4269
4270void diff_addremove(struct diff_options *options,
4271                    int addremove, unsigned mode,
4272                    const unsigned char *sha1,
4273                    const char *concatpath, unsigned dirty_submodule)
4274{
4275        struct diff_filespec *one, *two;
4276
4277        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4278                return;
4279
4280        /* This may look odd, but it is a preparation for
4281         * feeding "there are unchanged files which should
4282         * not produce diffs, but when you are doing copy
4283         * detection you would need them, so here they are"
4284         * entries to the diff-core.  They will be prefixed
4285         * with something like '=' or '*' (I haven't decided
4286         * which but should not make any difference).
4287         * Feeding the same new and old to diff_change()
4288         * also has the same effect.
4289         * Before the final output happens, they are pruned after
4290         * merged into rename/copy pairs as appropriate.
4291         */
4292        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4293                addremove = (addremove == '+' ? '-' :
4294                             addremove == '-' ? '+' : addremove);
4295
4296        if (options->prefix &&
4297            strncmp(concatpath, options->prefix, options->prefix_length))
4298                return;
4299
4300        one = alloc_filespec(concatpath);
4301        two = alloc_filespec(concatpath);
4302
4303        if (addremove != '+')
4304                fill_filespec(one, sha1, mode);
4305        if (addremove != '-') {
4306                fill_filespec(two, sha1, mode);
4307                two->dirty_submodule = dirty_submodule;
4308        }
4309
4310        diff_queue(&diff_queued_diff, one, two);
4311        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4312                DIFF_OPT_SET(options, HAS_CHANGES);
4313}
4314
4315void diff_change(struct diff_options *options,
4316                 unsigned old_mode, unsigned new_mode,
4317                 const unsigned char *old_sha1,
4318                 const unsigned char *new_sha1,
4319                 const char *concatpath,
4320                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4321{
4322        struct diff_filespec *one, *two;
4323
4324        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4325            is_submodule_ignored(concatpath, options))
4326                return;
4327
4328        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4329                unsigned tmp;
4330                const unsigned char *tmp_c;
4331                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4332                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4333                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4334                        new_dirty_submodule = tmp;
4335        }
4336
4337        if (options->prefix &&
4338            strncmp(concatpath, options->prefix, options->prefix_length))
4339                return;
4340
4341        one = alloc_filespec(concatpath);
4342        two = alloc_filespec(concatpath);
4343        fill_filespec(one, old_sha1, old_mode);
4344        fill_filespec(two, new_sha1, new_mode);
4345        one->dirty_submodule = old_dirty_submodule;
4346        two->dirty_submodule = new_dirty_submodule;
4347
4348        diff_queue(&diff_queued_diff, one, two);
4349        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4350                DIFF_OPT_SET(options, HAS_CHANGES);
4351}
4352
4353void diff_unmerge(struct diff_options *options,
4354                  const char *path,
4355                  unsigned mode, const unsigned char *sha1)
4356{
4357        struct diff_filespec *one, *two;
4358
4359        if (options->prefix &&
4360            strncmp(path, options->prefix, options->prefix_length))
4361                return;
4362
4363        one = alloc_filespec(path);
4364        two = alloc_filespec(path);
4365        fill_filespec(one, sha1, mode);
4366        diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;
4367}
4368
4369static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4370                size_t *outsize)
4371{
4372        struct diff_tempfile *temp;
4373        const char *argv[3];
4374        const char **arg = argv;
4375        struct child_process child;
4376        struct strbuf buf = STRBUF_INIT;
4377        int err = 0;
4378
4379        temp = prepare_temp_file(spec->path, spec);
4380        *arg++ = pgm;
4381        *arg++ = temp->name;
4382        *arg = NULL;
4383
4384        memset(&child, 0, sizeof(child));
4385        child.use_shell = 1;
4386        child.argv = argv;
4387        child.out = -1;
4388        if (start_command(&child)) {
4389                remove_tempfile();
4390                return NULL;
4391        }
4392
4393        if (strbuf_read(&buf, child.out, 0) < 0)
4394                err = error("error reading from textconv command '%s'", pgm);
4395        close(child.out);
4396
4397        if (finish_command(&child) || err) {
4398                strbuf_release(&buf);
4399                remove_tempfile();
4400                return NULL;
4401        }
4402        remove_tempfile();
4403
4404        return strbuf_detach(&buf, outsize);
4405}
4406
4407size_t fill_textconv(struct userdiff_driver *driver,
4408                     struct diff_filespec *df,
4409                     char **outbuf)
4410{
4411        size_t size;
4412
4413        if (!driver || !driver->textconv) {
4414                if (!DIFF_FILE_VALID(df)) {
4415                        *outbuf = "";
4416                        return 0;
4417                }
4418                if (diff_populate_filespec(df, 0))
4419                        die("unable to read files to diff");
4420                *outbuf = df->data;
4421                return df->size;
4422        }
4423
4424        if (driver->textconv_cache && df->sha1_valid) {
4425                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4426                                          &size);
4427                if (*outbuf)
4428                        return size;
4429        }
4430
4431        *outbuf = run_textconv(driver->textconv, df, &size);
4432        if (!*outbuf)
4433                die("unable to read files to diff");
4434
4435        if (driver->textconv_cache && df->sha1_valid) {
4436                /* ignore errors, as we might be in a readonly repository */
4437                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4438                                size);
4439                /*
4440                 * we could save up changes and flush them all at the end,
4441                 * but we would need an extra call after all diffing is done.
4442                 * Since generating a cache entry is the slow path anyway,
4443                 * this extra overhead probably isn't a big deal.
4444                 */
4445                notes_cache_write(driver->textconv_cache);
4446        }
4447
4448        return size;
4449}