1f44cb4237317fd2e36bc9b00047b67f7e844e17
   1/*
   2 * Copyright (C) 2005 Junio C Hamano
   3 */
   4#include "cache.h"
   5#include "quote.h"
   6#include "diff.h"
   7#include "diffcore.h"
   8#include "delta.h"
   9#include "xdiff-interface.h"
  10#include "color.h"
  11#include "attr.h"
  12#include "run-command.h"
  13#include "utf8.h"
  14#include "userdiff.h"
  15#include "sigchain.h"
  16#include "submodule.h"
  17#include "ll-merge.h"
  18
  19#ifdef NO_FAST_WORKING_DIRECTORY
  20#define FAST_WORKING_DIRECTORY 0
  21#else
  22#define FAST_WORKING_DIRECTORY 1
  23#endif
  24
  25static int diff_detect_rename_default;
  26static int diff_rename_limit_default = 200;
  27static int diff_suppress_blank_empty;
  28int diff_use_color_default = -1;
  29static const char *diff_word_regex_cfg;
  30static const char *external_diff_cmd_cfg;
  31int diff_auto_refresh_index = 1;
  32static int diff_mnemonic_prefix;
  33static int diff_no_prefix;
  34static struct diff_options default_diff_options;
  35
  36static char diff_colors[][COLOR_MAXLEN] = {
  37        GIT_COLOR_RESET,
  38        GIT_COLOR_NORMAL,       /* PLAIN */
  39        GIT_COLOR_BOLD,         /* METAINFO */
  40        GIT_COLOR_CYAN,         /* FRAGINFO */
  41        GIT_COLOR_RED,          /* OLD */
  42        GIT_COLOR_GREEN,        /* NEW */
  43        GIT_COLOR_YELLOW,       /* COMMIT */
  44        GIT_COLOR_BG_RED,       /* WHITESPACE */
  45        GIT_COLOR_NORMAL,       /* FUNCINFO */
  46};
  47
  48static int parse_diff_color_slot(const char *var, int ofs)
  49{
  50        if (!strcasecmp(var+ofs, "plain"))
  51                return DIFF_PLAIN;
  52        if (!strcasecmp(var+ofs, "meta"))
  53                return DIFF_METAINFO;
  54        if (!strcasecmp(var+ofs, "frag"))
  55                return DIFF_FRAGINFO;
  56        if (!strcasecmp(var+ofs, "old"))
  57                return DIFF_FILE_OLD;
  58        if (!strcasecmp(var+ofs, "new"))
  59                return DIFF_FILE_NEW;
  60        if (!strcasecmp(var+ofs, "commit"))
  61                return DIFF_COMMIT;
  62        if (!strcasecmp(var+ofs, "whitespace"))
  63                return DIFF_WHITESPACE;
  64        if (!strcasecmp(var+ofs, "func"))
  65                return DIFF_FUNCINFO;
  66        return -1;
  67}
  68
  69static int git_config_rename(const char *var, const char *value)
  70{
  71        if (!value)
  72                return DIFF_DETECT_RENAME;
  73        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
  74                return  DIFF_DETECT_COPY;
  75        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
  76}
  77
  78/*
  79 * These are to give UI layer defaults.
  80 * The core-level commands such as git-diff-files should
  81 * never be affected by the setting of diff.renames
  82 * the user happens to have in the configuration file.
  83 */
  84int git_diff_ui_config(const char *var, const char *value, void *cb)
  85{
  86        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
  87                diff_use_color_default = git_config_colorbool(var, value, -1);
  88                return 0;
  89        }
  90        if (!strcmp(var, "diff.renames")) {
  91                diff_detect_rename_default = git_config_rename(var, value);
  92                return 0;
  93        }
  94        if (!strcmp(var, "diff.autorefreshindex")) {
  95                diff_auto_refresh_index = git_config_bool(var, value);
  96                return 0;
  97        }
  98        if (!strcmp(var, "diff.mnemonicprefix")) {
  99                diff_mnemonic_prefix = git_config_bool(var, value);
 100                return 0;
 101        }
 102        if (!strcmp(var, "diff.noprefix")) {
 103                diff_no_prefix = git_config_bool(var, value);
 104                return 0;
 105        }
 106        if (!strcmp(var, "diff.external"))
 107                return git_config_string(&external_diff_cmd_cfg, var, value);
 108        if (!strcmp(var, "diff.wordregex"))
 109                return git_config_string(&diff_word_regex_cfg, var, value);
 110
 111        if (!strcmp(var, "diff.ignoresubmodules"))
 112                handle_ignore_submodules_arg(&default_diff_options, value);
 113
 114        return git_diff_basic_config(var, value, cb);
 115}
 116
 117int git_diff_basic_config(const char *var, const char *value, void *cb)
 118{
 119        if (!strcmp(var, "diff.renamelimit")) {
 120                diff_rename_limit_default = git_config_int(var, value);
 121                return 0;
 122        }
 123
 124        switch (userdiff_config(var, value)) {
 125                case 0: break;
 126                case -1: return -1;
 127                default: return 0;
 128        }
 129
 130        if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
 131                int slot = parse_diff_color_slot(var, 11);
 132                if (slot < 0)
 133                        return 0;
 134                if (!value)
 135                        return config_error_nonbool(var);
 136                color_parse(value, var, diff_colors[slot]);
 137                return 0;
 138        }
 139
 140        /* like GNU diff's --suppress-blank-empty option  */
 141        if (!strcmp(var, "diff.suppressblankempty") ||
 142                        /* for backwards compatibility */
 143                        !strcmp(var, "diff.suppress-blank-empty")) {
 144                diff_suppress_blank_empty = git_config_bool(var, value);
 145                return 0;
 146        }
 147
 148        if (!prefixcmp(var, "submodule."))
 149                return parse_submodule_config_option(var, value);
 150
 151        return git_color_default_config(var, value, cb);
 152}
 153
 154static char *quote_two(const char *one, const char *two)
 155{
 156        int need_one = quote_c_style(one, NULL, NULL, 1);
 157        int need_two = quote_c_style(two, NULL, NULL, 1);
 158        struct strbuf res = STRBUF_INIT;
 159
 160        if (need_one + need_two) {
 161                strbuf_addch(&res, '"');
 162                quote_c_style(one, &res, NULL, 1);
 163                quote_c_style(two, &res, NULL, 1);
 164                strbuf_addch(&res, '"');
 165        } else {
 166                strbuf_addstr(&res, one);
 167                strbuf_addstr(&res, two);
 168        }
 169        return strbuf_detach(&res, NULL);
 170}
 171
 172static const char *external_diff(void)
 173{
 174        static const char *external_diff_cmd = NULL;
 175        static int done_preparing = 0;
 176
 177        if (done_preparing)
 178                return external_diff_cmd;
 179        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 180        if (!external_diff_cmd)
 181                external_diff_cmd = external_diff_cmd_cfg;
 182        done_preparing = 1;
 183        return external_diff_cmd;
 184}
 185
 186static struct diff_tempfile {
 187        const char *name; /* filename external diff should read from */
 188        char hex[41];
 189        char mode[10];
 190        char tmp_path[PATH_MAX];
 191} diff_temp[2];
 192
 193typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 194
 195struct emit_callback {
 196        int color_diff;
 197        unsigned ws_rule;
 198        int blank_at_eof_in_preimage;
 199        int blank_at_eof_in_postimage;
 200        int lno_in_preimage;
 201        int lno_in_postimage;
 202        sane_truncate_fn truncate;
 203        const char **label_path;
 204        struct diff_words_data *diff_words;
 205        struct diff_options *opt;
 206        int *found_changesp;
 207        struct strbuf *header;
 208};
 209
 210static int count_lines(const char *data, int size)
 211{
 212        int count, ch, completely_empty = 1, nl_just_seen = 0;
 213        count = 0;
 214        while (0 < size--) {
 215                ch = *data++;
 216                if (ch == '\n') {
 217                        count++;
 218                        nl_just_seen = 1;
 219                        completely_empty = 0;
 220                }
 221                else {
 222                        nl_just_seen = 0;
 223                        completely_empty = 0;
 224                }
 225        }
 226        if (completely_empty)
 227                return 0;
 228        if (!nl_just_seen)
 229                count++; /* no trailing newline */
 230        return count;
 231}
 232
 233static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 234{
 235        if (!DIFF_FILE_VALID(one)) {
 236                mf->ptr = (char *)""; /* does not matter */
 237                mf->size = 0;
 238                return 0;
 239        }
 240        else if (diff_populate_filespec(one, 0))
 241                return -1;
 242
 243        mf->ptr = one->data;
 244        mf->size = one->size;
 245        return 0;
 246}
 247
 248/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 249static unsigned long diff_filespec_size(struct diff_filespec *one)
 250{
 251        if (!DIFF_FILE_VALID(one))
 252                return 0;
 253        diff_populate_filespec(one, 1);
 254        return one->size;
 255}
 256
 257static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 258{
 259        char *ptr = mf->ptr;
 260        long size = mf->size;
 261        int cnt = 0;
 262
 263        if (!size)
 264                return cnt;
 265        ptr += size - 1; /* pointing at the very end */
 266        if (*ptr != '\n')
 267                ; /* incomplete line */
 268        else
 269                ptr--; /* skip the last LF */
 270        while (mf->ptr < ptr) {
 271                char *prev_eol;
 272                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 273                        if (*prev_eol == '\n')
 274                                break;
 275                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 276                        break;
 277                cnt++;
 278                ptr = prev_eol - 1;
 279        }
 280        return cnt;
 281}
 282
 283static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 284                               struct emit_callback *ecbdata)
 285{
 286        int l1, l2, at;
 287        unsigned ws_rule = ecbdata->ws_rule;
 288        l1 = count_trailing_blank(mf1, ws_rule);
 289        l2 = count_trailing_blank(mf2, ws_rule);
 290        if (l2 <= l1) {
 291                ecbdata->blank_at_eof_in_preimage = 0;
 292                ecbdata->blank_at_eof_in_postimage = 0;
 293                return;
 294        }
 295        at = count_lines(mf1->ptr, mf1->size);
 296        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 297
 298        at = count_lines(mf2->ptr, mf2->size);
 299        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 300}
 301
 302static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 303                        int first, const char *line, int len)
 304{
 305        int has_trailing_newline, has_trailing_carriage_return;
 306        int nofirst;
 307        FILE *file = o->file;
 308
 309        if (o->output_prefix) {
 310                struct strbuf *msg = NULL;
 311                msg = o->output_prefix(o, o->output_prefix_data);
 312                assert(msg);
 313                fwrite(msg->buf, msg->len, 1, file);
 314        }
 315
 316        if (len == 0) {
 317                has_trailing_newline = (first == '\n');
 318                has_trailing_carriage_return = (!has_trailing_newline &&
 319                                                (first == '\r'));
 320                nofirst = has_trailing_newline || has_trailing_carriage_return;
 321        } else {
 322                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 323                if (has_trailing_newline)
 324                        len--;
 325                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 326                if (has_trailing_carriage_return)
 327                        len--;
 328                nofirst = 0;
 329        }
 330
 331        if (len || !nofirst) {
 332                fputs(set, file);
 333                if (!nofirst)
 334                        fputc(first, file);
 335                fwrite(line, len, 1, file);
 336                fputs(reset, file);
 337        }
 338        if (has_trailing_carriage_return)
 339                fputc('\r', file);
 340        if (has_trailing_newline)
 341                fputc('\n', file);
 342}
 343
 344static void emit_line(struct diff_options *o, const char *set, const char *reset,
 345                      const char *line, int len)
 346{
 347        emit_line_0(o, set, reset, line[0], line+1, len-1);
 348}
 349
 350static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 351{
 352        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 353              ecbdata->blank_at_eof_in_preimage &&
 354              ecbdata->blank_at_eof_in_postimage &&
 355              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 356              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 357                return 0;
 358        return ws_blank_line(line, len, ecbdata->ws_rule);
 359}
 360
 361static void emit_add_line(const char *reset,
 362                          struct emit_callback *ecbdata,
 363                          const char *line, int len)
 364{
 365        const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 366        const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 367
 368        if (!*ws)
 369                emit_line_0(ecbdata->opt, set, reset, '+', line, len);
 370        else if (new_blank_line_at_eof(ecbdata, line, len))
 371                /* Blank line at EOF - paint '+' as well */
 372                emit_line_0(ecbdata->opt, ws, reset, '+', line, len);
 373        else {
 374                /* Emit just the prefix, then the rest. */
 375                emit_line_0(ecbdata->opt, set, reset, '+', "", 0);
 376                ws_check_emit(line, len, ecbdata->ws_rule,
 377                              ecbdata->opt->file, set, reset, ws);
 378        }
 379}
 380
 381static void emit_hunk_header(struct emit_callback *ecbdata,
 382                             const char *line, int len)
 383{
 384        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 385        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 386        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 387        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 388        static const char atat[2] = { '@', '@' };
 389        const char *cp, *ep;
 390        struct strbuf msgbuf = STRBUF_INIT;
 391        int org_len = len;
 392        int i = 1;
 393
 394        /*
 395         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 396         * it always is at least 10 bytes long.
 397         */
 398        if (len < 10 ||
 399            memcmp(line, atat, 2) ||
 400            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 401                emit_line(ecbdata->opt, plain, reset, line, len);
 402                return;
 403        }
 404        ep += 2; /* skip over @@ */
 405
 406        /* The hunk header in fraginfo color */
 407        strbuf_add(&msgbuf, frag, strlen(frag));
 408        strbuf_add(&msgbuf, line, ep - line);
 409        strbuf_add(&msgbuf, reset, strlen(reset));
 410
 411        /*
 412         * trailing "\r\n"
 413         */
 414        for ( ; i < 3; i++)
 415                if (line[len - i] == '\r' || line[len - i] == '\n')
 416                        len--;
 417
 418        /* blank before the func header */
 419        for (cp = ep; ep - line < len; ep++)
 420                if (*ep != ' ' && *ep != '\t')
 421                        break;
 422        if (ep != cp) {
 423                strbuf_add(&msgbuf, plain, strlen(plain));
 424                strbuf_add(&msgbuf, cp, ep - cp);
 425                strbuf_add(&msgbuf, reset, strlen(reset));
 426        }
 427
 428        if (ep < line + len) {
 429                strbuf_add(&msgbuf, func, strlen(func));
 430                strbuf_add(&msgbuf, ep, line + len - ep);
 431                strbuf_add(&msgbuf, reset, strlen(reset));
 432        }
 433
 434        strbuf_add(&msgbuf, line + len, org_len - len);
 435        emit_line(ecbdata->opt, "", "", msgbuf.buf, msgbuf.len);
 436        strbuf_release(&msgbuf);
 437}
 438
 439static struct diff_tempfile *claim_diff_tempfile(void) {
 440        int i;
 441        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 442                if (!diff_temp[i].name)
 443                        return diff_temp + i;
 444        die("BUG: diff is failing to clean up its tempfiles");
 445}
 446
 447static int remove_tempfile_installed;
 448
 449static void remove_tempfile(void)
 450{
 451        int i;
 452        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 453                if (diff_temp[i].name == diff_temp[i].tmp_path)
 454                        unlink_or_warn(diff_temp[i].name);
 455                diff_temp[i].name = NULL;
 456        }
 457}
 458
 459static void remove_tempfile_on_signal(int signo)
 460{
 461        remove_tempfile();
 462        sigchain_pop(signo);
 463        raise(signo);
 464}
 465
 466static void print_line_count(FILE *file, int count)
 467{
 468        switch (count) {
 469        case 0:
 470                fprintf(file, "0,0");
 471                break;
 472        case 1:
 473                fprintf(file, "1");
 474                break;
 475        default:
 476                fprintf(file, "1,%d", count);
 477                break;
 478        }
 479}
 480
 481static void emit_rewrite_lines(struct emit_callback *ecb,
 482                               int prefix, const char *data, int size)
 483{
 484        const char *endp = NULL;
 485        static const char *nneof = " No newline at end of file\n";
 486        const char *old = diff_get_color(ecb->color_diff, DIFF_FILE_OLD);
 487        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 488
 489        while (0 < size) {
 490                int len;
 491
 492                endp = memchr(data, '\n', size);
 493                len = endp ? (endp - data + 1) : size;
 494                if (prefix != '+') {
 495                        ecb->lno_in_preimage++;
 496                        emit_line_0(ecb->opt, old, reset, '-',
 497                                    data, len);
 498                } else {
 499                        ecb->lno_in_postimage++;
 500                        emit_add_line(reset, ecb, data, len);
 501                }
 502                size -= len;
 503                data += len;
 504        }
 505        if (!endp) {
 506                const char *plain = diff_get_color(ecb->color_diff,
 507                                                   DIFF_PLAIN);
 508                emit_line_0(ecb->opt, plain, reset, '\\',
 509                            nneof, strlen(nneof));
 510        }
 511}
 512
 513static void emit_rewrite_diff(const char *name_a,
 514                              const char *name_b,
 515                              struct diff_filespec *one,
 516                              struct diff_filespec *two,
 517                              struct userdiff_driver *textconv_one,
 518                              struct userdiff_driver *textconv_two,
 519                              struct diff_options *o)
 520{
 521        int lc_a, lc_b;
 522        int color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
 523        const char *name_a_tab, *name_b_tab;
 524        const char *metainfo = diff_get_color(color_diff, DIFF_METAINFO);
 525        const char *fraginfo = diff_get_color(color_diff, DIFF_FRAGINFO);
 526        const char *reset = diff_get_color(color_diff, DIFF_RESET);
 527        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 528        const char *a_prefix, *b_prefix;
 529        char *data_one, *data_two;
 530        size_t size_one, size_two;
 531        struct emit_callback ecbdata;
 532        char *line_prefix = "";
 533        struct strbuf *msgbuf;
 534
 535        if (o && o->output_prefix) {
 536                msgbuf = o->output_prefix(o, o->output_prefix_data);
 537                line_prefix = msgbuf->buf;
 538        }
 539
 540        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 541                a_prefix = o->b_prefix;
 542                b_prefix = o->a_prefix;
 543        } else {
 544                a_prefix = o->a_prefix;
 545                b_prefix = o->b_prefix;
 546        }
 547
 548        name_a += (*name_a == '/');
 549        name_b += (*name_b == '/');
 550        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 551        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 552
 553        strbuf_reset(&a_name);
 554        strbuf_reset(&b_name);
 555        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 556        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 557
 558        size_one = fill_textconv(textconv_one, one, &data_one);
 559        size_two = fill_textconv(textconv_two, two, &data_two);
 560
 561        memset(&ecbdata, 0, sizeof(ecbdata));
 562        ecbdata.color_diff = color_diff;
 563        ecbdata.found_changesp = &o->found_changes;
 564        ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
 565        ecbdata.opt = o;
 566        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 567                mmfile_t mf1, mf2;
 568                mf1.ptr = (char *)data_one;
 569                mf2.ptr = (char *)data_two;
 570                mf1.size = size_one;
 571                mf2.size = size_two;
 572                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 573        }
 574        ecbdata.lno_in_preimage = 1;
 575        ecbdata.lno_in_postimage = 1;
 576
 577        lc_a = count_lines(data_one, size_one);
 578        lc_b = count_lines(data_two, size_two);
 579        fprintf(o->file,
 580                "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
 581                line_prefix, metainfo, a_name.buf, name_a_tab, reset,
 582                line_prefix, metainfo, b_name.buf, name_b_tab, reset,
 583                line_prefix, fraginfo);
 584        print_line_count(o->file, lc_a);
 585        fprintf(o->file, " +");
 586        print_line_count(o->file, lc_b);
 587        fprintf(o->file, " @@%s\n", reset);
 588        if (lc_a)
 589                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 590        if (lc_b)
 591                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 592        if (textconv_one)
 593                free((char *)data_one);
 594        if (textconv_two)
 595                free((char *)data_two);
 596}
 597
 598struct diff_words_buffer {
 599        mmfile_t text;
 600        long alloc;
 601        struct diff_words_orig {
 602                const char *begin, *end;
 603        } *orig;
 604        int orig_nr, orig_alloc;
 605};
 606
 607static void diff_words_append(char *line, unsigned long len,
 608                struct diff_words_buffer *buffer)
 609{
 610        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 611        line++;
 612        len--;
 613        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 614        buffer->text.size += len;
 615        buffer->text.ptr[buffer->text.size] = '\0';
 616}
 617
 618struct diff_words_style_elem {
 619        const char *prefix;
 620        const char *suffix;
 621        const char *color; /* NULL; filled in by the setup code if
 622                            * color is enabled */
 623};
 624
 625struct diff_words_style {
 626        enum diff_words_type type;
 627        struct diff_words_style_elem new, old, ctx;
 628        const char *newline;
 629};
 630
 631struct diff_words_style diff_words_styles[] = {
 632        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 633        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 634        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 635};
 636
 637struct diff_words_data {
 638        struct diff_words_buffer minus, plus;
 639        const char *current_plus;
 640        int last_minus;
 641        struct diff_options *opt;
 642        regex_t *word_regex;
 643        enum diff_words_type type;
 644        struct diff_words_style *style;
 645};
 646
 647static int fn_out_diff_words_write_helper(FILE *fp,
 648                                          struct diff_words_style_elem *st_el,
 649                                          const char *newline,
 650                                          size_t count, const char *buf,
 651                                          const char *line_prefix)
 652{
 653        int print = 0;
 654
 655        while (count) {
 656                char *p = memchr(buf, '\n', count);
 657                if (print)
 658                        fputs(line_prefix, fp);
 659                if (p != buf) {
 660                        if (st_el->color && fputs(st_el->color, fp) < 0)
 661                                return -1;
 662                        if (fputs(st_el->prefix, fp) < 0 ||
 663                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 664                            fputs(st_el->suffix, fp) < 0)
 665                                return -1;
 666                        if (st_el->color && *st_el->color
 667                            && fputs(GIT_COLOR_RESET, fp) < 0)
 668                                return -1;
 669                }
 670                if (!p)
 671                        return 0;
 672                if (fputs(newline, fp) < 0)
 673                        return -1;
 674                count -= p + 1 - buf;
 675                buf = p + 1;
 676                print = 1;
 677        }
 678        return 0;
 679}
 680
 681/*
 682 * '--color-words' algorithm can be described as:
 683 *
 684 *   1. collect a the minus/plus lines of a diff hunk, divided into
 685 *      minus-lines and plus-lines;
 686 *
 687 *   2. break both minus-lines and plus-lines into words and
 688 *      place them into two mmfile_t with one word for each line;
 689 *
 690 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
 691 *
 692 * And for the common parts of the both file, we output the plus side text.
 693 * diff_words->current_plus is used to trace the current position of the plus file
 694 * which printed. diff_words->last_minus is used to trace the last minus word
 695 * printed.
 696 *
 697 * For '--graph' to work with '--color-words', we need to output the graph prefix
 698 * on each line of color words output. Generally, there are two conditions on
 699 * which we should output the prefix.
 700 *
 701 *   1. diff_words->last_minus == 0 &&
 702 *      diff_words->current_plus == diff_words->plus.text.ptr
 703 *
 704 *      that is: the plus text must start as a new line, and if there is no minus
 705 *      word printed, a graph prefix must be printed.
 706 *
 707 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
 708 *      *(diff_words->current_plus - 1) == '\n'
 709 *
 710 *      that is: a graph prefix must be printed following a '\n'
 711 */
 712static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
 713{
 714        if ((diff_words->last_minus == 0 &&
 715                diff_words->current_plus == diff_words->plus.text.ptr) ||
 716                (diff_words->current_plus > diff_words->plus.text.ptr &&
 717                *(diff_words->current_plus - 1) == '\n')) {
 718                return 1;
 719        } else {
 720                return 0;
 721        }
 722}
 723
 724static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 725{
 726        struct diff_words_data *diff_words = priv;
 727        struct diff_words_style *style = diff_words->style;
 728        int minus_first, minus_len, plus_first, plus_len;
 729        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 730        struct diff_options *opt = diff_words->opt;
 731        struct strbuf *msgbuf;
 732        char *line_prefix = "";
 733
 734        if (line[0] != '@' || parse_hunk_header(line, len,
 735                        &minus_first, &minus_len, &plus_first, &plus_len))
 736                return;
 737
 738        assert(opt);
 739        if (opt->output_prefix) {
 740                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 741                line_prefix = msgbuf->buf;
 742        }
 743
 744        /* POSIX requires that first be decremented by one if len == 0... */
 745        if (minus_len) {
 746                minus_begin = diff_words->minus.orig[minus_first].begin;
 747                minus_end =
 748                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 749        } else
 750                minus_begin = minus_end =
 751                        diff_words->minus.orig[minus_first].end;
 752
 753        if (plus_len) {
 754                plus_begin = diff_words->plus.orig[plus_first].begin;
 755                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 756        } else
 757                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 758
 759        if (color_words_output_graph_prefix(diff_words)) {
 760                fputs(line_prefix, diff_words->opt->file);
 761        }
 762        if (diff_words->current_plus != plus_begin) {
 763                fn_out_diff_words_write_helper(diff_words->opt->file,
 764                                &style->ctx, style->newline,
 765                                plus_begin - diff_words->current_plus,
 766                                diff_words->current_plus, line_prefix);
 767                if (*(plus_begin - 1) == '\n')
 768                        fputs(line_prefix, diff_words->opt->file);
 769        }
 770        if (minus_begin != minus_end) {
 771                fn_out_diff_words_write_helper(diff_words->opt->file,
 772                                &style->old, style->newline,
 773                                minus_end - minus_begin, minus_begin,
 774                                line_prefix);
 775        }
 776        if (plus_begin != plus_end) {
 777                fn_out_diff_words_write_helper(diff_words->opt->file,
 778                                &style->new, style->newline,
 779                                plus_end - plus_begin, plus_begin,
 780                                line_prefix);
 781        }
 782
 783        diff_words->current_plus = plus_end;
 784        diff_words->last_minus = minus_first;
 785}
 786
 787/* This function starts looking at *begin, and returns 0 iff a word was found. */
 788static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 789                int *begin, int *end)
 790{
 791        if (word_regex && *begin < buffer->size) {
 792                regmatch_t match[1];
 793                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 794                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 795                                        '\n', match[0].rm_eo - match[0].rm_so);
 796                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 797                        *begin += match[0].rm_so;
 798                        return *begin >= *end;
 799                }
 800                return -1;
 801        }
 802
 803        /* find the next word */
 804        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 805                (*begin)++;
 806        if (*begin >= buffer->size)
 807                return -1;
 808
 809        /* find the end of the word */
 810        *end = *begin + 1;
 811        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 812                (*end)++;
 813
 814        return 0;
 815}
 816
 817/*
 818 * This function splits the words in buffer->text, stores the list with
 819 * newline separator into out, and saves the offsets of the original words
 820 * in buffer->orig.
 821 */
 822static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 823                regex_t *word_regex)
 824{
 825        int i, j;
 826        long alloc = 0;
 827
 828        out->size = 0;
 829        out->ptr = NULL;
 830
 831        /* fake an empty "0th" word */
 832        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 833        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 834        buffer->orig_nr = 1;
 835
 836        for (i = 0; i < buffer->text.size; i++) {
 837                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 838                        return;
 839
 840                /* store original boundaries */
 841                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 842                                buffer->orig_alloc);
 843                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 844                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 845                buffer->orig_nr++;
 846
 847                /* store one word */
 848                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 849                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 850                out->ptr[out->size + j - i] = '\n';
 851                out->size += j - i + 1;
 852
 853                i = j - 1;
 854        }
 855}
 856
 857/* this executes the word diff on the accumulated buffers */
 858static void diff_words_show(struct diff_words_data *diff_words)
 859{
 860        xpparam_t xpp;
 861        xdemitconf_t xecfg;
 862        mmfile_t minus, plus;
 863        struct diff_words_style *style = diff_words->style;
 864
 865        struct diff_options *opt = diff_words->opt;
 866        struct strbuf *msgbuf;
 867        char *line_prefix = "";
 868
 869        assert(opt);
 870        if (opt->output_prefix) {
 871                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 872                line_prefix = msgbuf->buf;
 873        }
 874
 875        /* special case: only removal */
 876        if (!diff_words->plus.text.size) {
 877                fputs(line_prefix, diff_words->opt->file);
 878                fn_out_diff_words_write_helper(diff_words->opt->file,
 879                        &style->old, style->newline,
 880                        diff_words->minus.text.size,
 881                        diff_words->minus.text.ptr, line_prefix);
 882                diff_words->minus.text.size = 0;
 883                return;
 884        }
 885
 886        diff_words->current_plus = diff_words->plus.text.ptr;
 887        diff_words->last_minus = 0;
 888
 889        memset(&xpp, 0, sizeof(xpp));
 890        memset(&xecfg, 0, sizeof(xecfg));
 891        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
 892        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
 893        xpp.flags = 0;
 894        /* as only the hunk header will be parsed, we need a 0-context */
 895        xecfg.ctxlen = 0;
 896        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 897                      &xpp, &xecfg);
 898        free(minus.ptr);
 899        free(plus.ptr);
 900        if (diff_words->current_plus != diff_words->plus.text.ptr +
 901                        diff_words->plus.text.size) {
 902                if (color_words_output_graph_prefix(diff_words))
 903                        fputs(line_prefix, diff_words->opt->file);
 904                fn_out_diff_words_write_helper(diff_words->opt->file,
 905                        &style->ctx, style->newline,
 906                        diff_words->plus.text.ptr + diff_words->plus.text.size
 907                        - diff_words->current_plus, diff_words->current_plus,
 908                        line_prefix);
 909        }
 910        diff_words->minus.text.size = diff_words->plus.text.size = 0;
 911}
 912
 913/* In "color-words" mode, show word-diff of words accumulated in the buffer */
 914static void diff_words_flush(struct emit_callback *ecbdata)
 915{
 916        if (ecbdata->diff_words->minus.text.size ||
 917            ecbdata->diff_words->plus.text.size)
 918                diff_words_show(ecbdata->diff_words);
 919}
 920
 921static void free_diff_words_data(struct emit_callback *ecbdata)
 922{
 923        if (ecbdata->diff_words) {
 924                diff_words_flush(ecbdata);
 925                free (ecbdata->diff_words->minus.text.ptr);
 926                free (ecbdata->diff_words->minus.orig);
 927                free (ecbdata->diff_words->plus.text.ptr);
 928                free (ecbdata->diff_words->plus.orig);
 929                if (ecbdata->diff_words->word_regex) {
 930                        regfree(ecbdata->diff_words->word_regex);
 931                        free(ecbdata->diff_words->word_regex);
 932                }
 933                free(ecbdata->diff_words);
 934                ecbdata->diff_words = NULL;
 935        }
 936}
 937
 938const char *diff_get_color(int diff_use_color, enum color_diff ix)
 939{
 940        if (diff_use_color)
 941                return diff_colors[ix];
 942        return "";
 943}
 944
 945static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
 946{
 947        const char *cp;
 948        unsigned long allot;
 949        size_t l = len;
 950
 951        if (ecb->truncate)
 952                return ecb->truncate(line, len);
 953        cp = line;
 954        allot = l;
 955        while (0 < l) {
 956                (void) utf8_width(&cp, &l);
 957                if (!cp)
 958                        break; /* truncated in the middle? */
 959        }
 960        return allot - l;
 961}
 962
 963static void find_lno(const char *line, struct emit_callback *ecbdata)
 964{
 965        const char *p;
 966        ecbdata->lno_in_preimage = 0;
 967        ecbdata->lno_in_postimage = 0;
 968        p = strchr(line, '-');
 969        if (!p)
 970                return; /* cannot happen */
 971        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
 972        p = strchr(p, '+');
 973        if (!p)
 974                return; /* cannot happen */
 975        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
 976}
 977
 978static void fn_out_consume(void *priv, char *line, unsigned long len)
 979{
 980        struct emit_callback *ecbdata = priv;
 981        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
 982        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 983        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 984        struct diff_options *o = ecbdata->opt;
 985        char *line_prefix = "";
 986        struct strbuf *msgbuf;
 987
 988        if (o && o->output_prefix) {
 989                msgbuf = o->output_prefix(o, o->output_prefix_data);
 990                line_prefix = msgbuf->buf;
 991        }
 992
 993        if (ecbdata->header) {
 994                fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
 995                strbuf_reset(ecbdata->header);
 996                ecbdata->header = NULL;
 997        }
 998        *(ecbdata->found_changesp) = 1;
 999
1000        if (ecbdata->label_path[0]) {
1001                const char *name_a_tab, *name_b_tab;
1002
1003                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
1004                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
1005
1006                fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
1007                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
1008                fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
1009                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1010                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1011        }
1012
1013        if (diff_suppress_blank_empty
1014            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1015                line[0] = '\n';
1016                len = 1;
1017        }
1018
1019        if (line[0] == '@') {
1020                if (ecbdata->diff_words)
1021                        diff_words_flush(ecbdata);
1022                len = sane_truncate_line(ecbdata, line, len);
1023                find_lno(line, ecbdata);
1024                emit_hunk_header(ecbdata, line, len);
1025                if (line[len-1] != '\n')
1026                        putc('\n', ecbdata->opt->file);
1027                return;
1028        }
1029
1030        if (len < 1) {
1031                emit_line(ecbdata->opt, reset, reset, line, len);
1032                if (ecbdata->diff_words
1033                    && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
1034                        fputs("~\n", ecbdata->opt->file);
1035                return;
1036        }
1037
1038        if (ecbdata->diff_words) {
1039                if (line[0] == '-') {
1040                        diff_words_append(line, len,
1041                                          &ecbdata->diff_words->minus);
1042                        return;
1043                } else if (line[0] == '+') {
1044                        diff_words_append(line, len,
1045                                          &ecbdata->diff_words->plus);
1046                        return;
1047                }
1048                diff_words_flush(ecbdata);
1049                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1050                        emit_line(ecbdata->opt, plain, reset, line, len);
1051                        fputs("~\n", ecbdata->opt->file);
1052                } else {
1053                        /* don't print the prefix character */
1054                        emit_line(ecbdata->opt, plain, reset, line+1, len-1);
1055                }
1056                return;
1057        }
1058
1059        if (line[0] != '+') {
1060                const char *color =
1061                        diff_get_color(ecbdata->color_diff,
1062                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
1063                ecbdata->lno_in_preimage++;
1064                if (line[0] == ' ')
1065                        ecbdata->lno_in_postimage++;
1066                emit_line(ecbdata->opt, color, reset, line, len);
1067        } else {
1068                ecbdata->lno_in_postimage++;
1069                emit_add_line(reset, ecbdata, line + 1, len - 1);
1070        }
1071}
1072
1073static char *pprint_rename(const char *a, const char *b)
1074{
1075        const char *old = a;
1076        const char *new = b;
1077        struct strbuf name = STRBUF_INIT;
1078        int pfx_length, sfx_length;
1079        int len_a = strlen(a);
1080        int len_b = strlen(b);
1081        int a_midlen, b_midlen;
1082        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1083        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1084
1085        if (qlen_a || qlen_b) {
1086                quote_c_style(a, &name, NULL, 0);
1087                strbuf_addstr(&name, " => ");
1088                quote_c_style(b, &name, NULL, 0);
1089                return strbuf_detach(&name, NULL);
1090        }
1091
1092        /* Find common prefix */
1093        pfx_length = 0;
1094        while (*old && *new && *old == *new) {
1095                if (*old == '/')
1096                        pfx_length = old - a + 1;
1097                old++;
1098                new++;
1099        }
1100
1101        /* Find common suffix */
1102        old = a + len_a;
1103        new = b + len_b;
1104        sfx_length = 0;
1105        while (a <= old && b <= new && *old == *new) {
1106                if (*old == '/')
1107                        sfx_length = len_a - (old - a);
1108                old--;
1109                new--;
1110        }
1111
1112        /*
1113         * pfx{mid-a => mid-b}sfx
1114         * {pfx-a => pfx-b}sfx
1115         * pfx{sfx-a => sfx-b}
1116         * name-a => name-b
1117         */
1118        a_midlen = len_a - pfx_length - sfx_length;
1119        b_midlen = len_b - pfx_length - sfx_length;
1120        if (a_midlen < 0)
1121                a_midlen = 0;
1122        if (b_midlen < 0)
1123                b_midlen = 0;
1124
1125        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1126        if (pfx_length + sfx_length) {
1127                strbuf_add(&name, a, pfx_length);
1128                strbuf_addch(&name, '{');
1129        }
1130        strbuf_add(&name, a + pfx_length, a_midlen);
1131        strbuf_addstr(&name, " => ");
1132        strbuf_add(&name, b + pfx_length, b_midlen);
1133        if (pfx_length + sfx_length) {
1134                strbuf_addch(&name, '}');
1135                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1136        }
1137        return strbuf_detach(&name, NULL);
1138}
1139
1140struct diffstat_t {
1141        int nr;
1142        int alloc;
1143        struct diffstat_file {
1144                char *from_name;
1145                char *name;
1146                char *print_name;
1147                unsigned is_unmerged:1;
1148                unsigned is_binary:1;
1149                unsigned is_renamed:1;
1150                uintmax_t added, deleted;
1151        } **files;
1152};
1153
1154static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1155                                          const char *name_a,
1156                                          const char *name_b)
1157{
1158        struct diffstat_file *x;
1159        x = xcalloc(sizeof (*x), 1);
1160        if (diffstat->nr == diffstat->alloc) {
1161                diffstat->alloc = alloc_nr(diffstat->alloc);
1162                diffstat->files = xrealloc(diffstat->files,
1163                                diffstat->alloc * sizeof(x));
1164        }
1165        diffstat->files[diffstat->nr++] = x;
1166        if (name_b) {
1167                x->from_name = xstrdup(name_a);
1168                x->name = xstrdup(name_b);
1169                x->is_renamed = 1;
1170        }
1171        else {
1172                x->from_name = NULL;
1173                x->name = xstrdup(name_a);
1174        }
1175        return x;
1176}
1177
1178static void diffstat_consume(void *priv, char *line, unsigned long len)
1179{
1180        struct diffstat_t *diffstat = priv;
1181        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1182
1183        if (line[0] == '+')
1184                x->added++;
1185        else if (line[0] == '-')
1186                x->deleted++;
1187}
1188
1189const char mime_boundary_leader[] = "------------";
1190
1191static int scale_linear(int it, int width, int max_change)
1192{
1193        /*
1194         * make sure that at least one '-' is printed if there were deletions,
1195         * and likewise for '+'.
1196         */
1197        if (max_change < 2)
1198                return it;
1199        return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
1200}
1201
1202static void show_name(FILE *file,
1203                      const char *prefix, const char *name, int len)
1204{
1205        fprintf(file, " %s%-*s |", prefix, len, name);
1206}
1207
1208static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1209{
1210        if (cnt <= 0)
1211                return;
1212        fprintf(file, "%s", set);
1213        while (cnt--)
1214                putc(ch, file);
1215        fprintf(file, "%s", reset);
1216}
1217
1218static void fill_print_name(struct diffstat_file *file)
1219{
1220        char *pname;
1221
1222        if (file->print_name)
1223                return;
1224
1225        if (!file->is_renamed) {
1226                struct strbuf buf = STRBUF_INIT;
1227                if (quote_c_style(file->name, &buf, NULL, 0)) {
1228                        pname = strbuf_detach(&buf, NULL);
1229                } else {
1230                        pname = file->name;
1231                        strbuf_release(&buf);
1232                }
1233        } else {
1234                pname = pprint_rename(file->from_name, file->name);
1235        }
1236        file->print_name = pname;
1237}
1238
1239static void show_stats(struct diffstat_t *data, struct diff_options *options)
1240{
1241        int i, len, add, del, adds = 0, dels = 0;
1242        uintmax_t max_change = 0, max_len = 0;
1243        int total_files = data->nr;
1244        int width, name_width;
1245        const char *reset, *set, *add_c, *del_c;
1246        const char *line_prefix = "";
1247        struct strbuf *msg = NULL;
1248
1249        if (data->nr == 0)
1250                return;
1251
1252        if (options->output_prefix) {
1253                msg = options->output_prefix(options, options->output_prefix_data);
1254                line_prefix = msg->buf;
1255        }
1256
1257        width = options->stat_width ? options->stat_width : 80;
1258        name_width = options->stat_name_width ? options->stat_name_width : 50;
1259
1260        /* Sanity: give at least 5 columns to the graph,
1261         * but leave at least 10 columns for the name.
1262         */
1263        if (width < 25)
1264                width = 25;
1265        if (name_width < 10)
1266                name_width = 10;
1267        else if (width < name_width + 15)
1268                name_width = width - 15;
1269
1270        /* Find the longest filename and max number of changes */
1271        reset = diff_get_color_opt(options, DIFF_RESET);
1272        set   = diff_get_color_opt(options, DIFF_PLAIN);
1273        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1274        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1275
1276        for (i = 0; i < data->nr; i++) {
1277                struct diffstat_file *file = data->files[i];
1278                uintmax_t change = file->added + file->deleted;
1279                fill_print_name(file);
1280                len = strlen(file->print_name);
1281                if (max_len < len)
1282                        max_len = len;
1283
1284                if (file->is_binary || file->is_unmerged)
1285                        continue;
1286                if (max_change < change)
1287                        max_change = change;
1288        }
1289
1290        /* Compute the width of the graph part;
1291         * 10 is for one blank at the beginning of the line plus
1292         * " | count " between the name and the graph.
1293         *
1294         * From here on, name_width is the width of the name area,
1295         * and width is the width of the graph area.
1296         */
1297        name_width = (name_width < max_len) ? name_width : max_len;
1298        if (width < (name_width + 10) + max_change)
1299                width = width - (name_width + 10);
1300        else
1301                width = max_change;
1302
1303        for (i = 0; i < data->nr; i++) {
1304                const char *prefix = "";
1305                char *name = data->files[i]->print_name;
1306                uintmax_t added = data->files[i]->added;
1307                uintmax_t deleted = data->files[i]->deleted;
1308                int name_len;
1309
1310                /*
1311                 * "scale" the filename
1312                 */
1313                len = name_width;
1314                name_len = strlen(name);
1315                if (name_width < name_len) {
1316                        char *slash;
1317                        prefix = "...";
1318                        len -= 3;
1319                        name += name_len - len;
1320                        slash = strchr(name, '/');
1321                        if (slash)
1322                                name = slash;
1323                }
1324
1325                if (data->files[i]->is_binary) {
1326                        fprintf(options->file, "%s", line_prefix);
1327                        show_name(options->file, prefix, name, len);
1328                        fprintf(options->file, "  Bin ");
1329                        fprintf(options->file, "%s%"PRIuMAX"%s",
1330                                del_c, deleted, reset);
1331                        fprintf(options->file, " -> ");
1332                        fprintf(options->file, "%s%"PRIuMAX"%s",
1333                                add_c, added, reset);
1334                        fprintf(options->file, " bytes");
1335                        fprintf(options->file, "\n");
1336                        continue;
1337                }
1338                else if (data->files[i]->is_unmerged) {
1339                        fprintf(options->file, "%s", line_prefix);
1340                        show_name(options->file, prefix, name, len);
1341                        fprintf(options->file, "  Unmerged\n");
1342                        continue;
1343                }
1344                else if (!data->files[i]->is_renamed &&
1345                         (added + deleted == 0)) {
1346                        total_files--;
1347                        continue;
1348                }
1349
1350                /*
1351                 * scale the add/delete
1352                 */
1353                add = added;
1354                del = deleted;
1355                adds += add;
1356                dels += del;
1357
1358                if (width <= max_change) {
1359                        add = scale_linear(add, width, max_change);
1360                        del = scale_linear(del, width, max_change);
1361                }
1362                fprintf(options->file, "%s", line_prefix);
1363                show_name(options->file, prefix, name, len);
1364                fprintf(options->file, "%5"PRIuMAX"%s", added + deleted,
1365                                added + deleted ? " " : "");
1366                show_graph(options->file, '+', add, add_c, reset);
1367                show_graph(options->file, '-', del, del_c, reset);
1368                fprintf(options->file, "\n");
1369        }
1370        fprintf(options->file, "%s", line_prefix);
1371        fprintf(options->file,
1372               " %d files changed, %d insertions(+), %d deletions(-)\n",
1373               total_files, adds, dels);
1374}
1375
1376static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1377{
1378        int i, adds = 0, dels = 0, total_files = data->nr;
1379
1380        if (data->nr == 0)
1381                return;
1382
1383        for (i = 0; i < data->nr; i++) {
1384                if (!data->files[i]->is_binary &&
1385                    !data->files[i]->is_unmerged) {
1386                        int added = data->files[i]->added;
1387                        int deleted= data->files[i]->deleted;
1388                        if (!data->files[i]->is_renamed &&
1389                            (added + deleted == 0)) {
1390                                total_files--;
1391                        } else {
1392                                adds += added;
1393                                dels += deleted;
1394                        }
1395                }
1396        }
1397        if (options->output_prefix) {
1398                struct strbuf *msg = NULL;
1399                msg = options->output_prefix(options,
1400                                options->output_prefix_data);
1401                fprintf(options->file, "%s", msg->buf);
1402        }
1403        fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
1404               total_files, adds, dels);
1405}
1406
1407static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1408{
1409        int i;
1410
1411        if (data->nr == 0)
1412                return;
1413
1414        for (i = 0; i < data->nr; i++) {
1415                struct diffstat_file *file = data->files[i];
1416
1417                if (options->output_prefix) {
1418                        struct strbuf *msg = NULL;
1419                        msg = options->output_prefix(options,
1420                                        options->output_prefix_data);
1421                        fprintf(options->file, "%s", msg->buf);
1422                }
1423
1424                if (file->is_binary)
1425                        fprintf(options->file, "-\t-\t");
1426                else
1427                        fprintf(options->file,
1428                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1429                                file->added, file->deleted);
1430                if (options->line_termination) {
1431                        fill_print_name(file);
1432                        if (!file->is_renamed)
1433                                write_name_quoted(file->name, options->file,
1434                                                  options->line_termination);
1435                        else {
1436                                fputs(file->print_name, options->file);
1437                                putc(options->line_termination, options->file);
1438                        }
1439                } else {
1440                        if (file->is_renamed) {
1441                                putc('\0', options->file);
1442                                write_name_quoted(file->from_name, options->file, '\0');
1443                        }
1444                        write_name_quoted(file->name, options->file, '\0');
1445                }
1446        }
1447}
1448
1449struct dirstat_file {
1450        const char *name;
1451        unsigned long changed;
1452};
1453
1454struct dirstat_dir {
1455        struct dirstat_file *files;
1456        int alloc, nr, percent, cumulative;
1457};
1458
1459static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1460                unsigned long changed, const char *base, int baselen)
1461{
1462        unsigned long this_dir = 0;
1463        unsigned int sources = 0;
1464        const char *line_prefix = "";
1465        struct strbuf *msg = NULL;
1466
1467        if (opt->output_prefix) {
1468                msg = opt->output_prefix(opt, opt->output_prefix_data);
1469                line_prefix = msg->buf;
1470        }
1471
1472        while (dir->nr) {
1473                struct dirstat_file *f = dir->files;
1474                int namelen = strlen(f->name);
1475                unsigned long this;
1476                char *slash;
1477
1478                if (namelen < baselen)
1479                        break;
1480                if (memcmp(f->name, base, baselen))
1481                        break;
1482                slash = strchr(f->name + baselen, '/');
1483                if (slash) {
1484                        int newbaselen = slash + 1 - f->name;
1485                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1486                        sources++;
1487                } else {
1488                        this = f->changed;
1489                        dir->files++;
1490                        dir->nr--;
1491                        sources += 2;
1492                }
1493                this_dir += this;
1494        }
1495
1496        /*
1497         * We don't report dirstat's for
1498         *  - the top level
1499         *  - or cases where everything came from a single directory
1500         *    under this directory (sources == 1).
1501         */
1502        if (baselen && sources != 1) {
1503                int permille = this_dir * 1000 / changed;
1504                if (permille) {
1505                        int percent = permille / 10;
1506                        if (percent >= dir->percent) {
1507                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1508                                        percent, permille % 10, baselen, base);
1509                                if (!dir->cumulative)
1510                                        return 0;
1511                        }
1512                }
1513        }
1514        return this_dir;
1515}
1516
1517static int dirstat_compare(const void *_a, const void *_b)
1518{
1519        const struct dirstat_file *a = _a;
1520        const struct dirstat_file *b = _b;
1521        return strcmp(a->name, b->name);
1522}
1523
1524static void show_dirstat(struct diff_options *options)
1525{
1526        int i;
1527        unsigned long changed;
1528        struct dirstat_dir dir;
1529        struct diff_queue_struct *q = &diff_queued_diff;
1530
1531        dir.files = NULL;
1532        dir.alloc = 0;
1533        dir.nr = 0;
1534        dir.percent = options->dirstat_percent;
1535        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1536
1537        changed = 0;
1538        for (i = 0; i < q->nr; i++) {
1539                struct diff_filepair *p = q->queue[i];
1540                const char *name;
1541                unsigned long copied, added, damage;
1542                int content_changed;
1543
1544                name = p->one->path ? p->one->path : p->two->path;
1545
1546                if (p->one->sha1_valid && p->two->sha1_valid)
1547                        content_changed = hashcmp(p->one->sha1, p->two->sha1);
1548                else
1549                        content_changed = 1;
1550
1551                if (!content_changed) {
1552                        /*
1553                         * The SHA1 has not changed, so pre-/post-content is
1554                         * identical. We can therefore skip looking at the
1555                         * file contents altogether.
1556                         */
1557                        damage = 0;
1558                        goto found_damage;
1559                }
1560
1561                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1562                        /*
1563                         * In --dirstat-by-file mode, we don't really need to
1564                         * look at the actual file contents at all.
1565                         * The fact that the SHA1 changed is enough for us to
1566                         * add this file to the list of results
1567                         * (with each file contributing equal damage).
1568                         */
1569                        damage = 1;
1570                        goto found_damage;
1571                }
1572
1573                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1574                        diff_populate_filespec(p->one, 0);
1575                        diff_populate_filespec(p->two, 0);
1576                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1577                                               &copied, &added);
1578                        diff_free_filespec_data(p->one);
1579                        diff_free_filespec_data(p->two);
1580                } else if (DIFF_FILE_VALID(p->one)) {
1581                        diff_populate_filespec(p->one, 1);
1582                        copied = added = 0;
1583                        diff_free_filespec_data(p->one);
1584                } else if (DIFF_FILE_VALID(p->two)) {
1585                        diff_populate_filespec(p->two, 1);
1586                        copied = 0;
1587                        added = p->two->size;
1588                        diff_free_filespec_data(p->two);
1589                } else
1590                        continue;
1591
1592                /*
1593                 * Original minus copied is the removed material,
1594                 * added is the new material.  They are both damages
1595                 * made to the preimage.
1596                 * If the resulting damage is zero, we know that
1597                 * diffcore_count_changes() considers the two entries to
1598                 * be identical, but since content_changed is true, we
1599                 * know that there must have been _some_ kind of change,
1600                 * so we force all entries to have damage > 0.
1601                 */
1602                damage = (p->one->size - copied) + added;
1603                if (!damage)
1604                        damage = 1;
1605
1606found_damage:
1607                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1608                dir.files[dir.nr].name = name;
1609                dir.files[dir.nr].changed = damage;
1610                changed += damage;
1611                dir.nr++;
1612        }
1613
1614        /* This can happen even with many files, if everything was renames */
1615        if (!changed)
1616                return;
1617
1618        /* Show all directories with more than x% of the changes */
1619        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1620        gather_dirstat(options, &dir, changed, "", 0);
1621}
1622
1623static void free_diffstat_info(struct diffstat_t *diffstat)
1624{
1625        int i;
1626        for (i = 0; i < diffstat->nr; i++) {
1627                struct diffstat_file *f = diffstat->files[i];
1628                if (f->name != f->print_name)
1629                        free(f->print_name);
1630                free(f->name);
1631                free(f->from_name);
1632                free(f);
1633        }
1634        free(diffstat->files);
1635}
1636
1637struct checkdiff_t {
1638        const char *filename;
1639        int lineno;
1640        int conflict_marker_size;
1641        struct diff_options *o;
1642        unsigned ws_rule;
1643        unsigned status;
1644};
1645
1646static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1647{
1648        char firstchar;
1649        int cnt;
1650
1651        if (len < marker_size + 1)
1652                return 0;
1653        firstchar = line[0];
1654        switch (firstchar) {
1655        case '=': case '>': case '<': case '|':
1656                break;
1657        default:
1658                return 0;
1659        }
1660        for (cnt = 1; cnt < marker_size; cnt++)
1661                if (line[cnt] != firstchar)
1662                        return 0;
1663        /* line[1] thru line[marker_size-1] are same as firstchar */
1664        if (len < marker_size + 1 || !isspace(line[marker_size]))
1665                return 0;
1666        return 1;
1667}
1668
1669static void checkdiff_consume(void *priv, char *line, unsigned long len)
1670{
1671        struct checkdiff_t *data = priv;
1672        int color_diff = DIFF_OPT_TST(data->o, COLOR_DIFF);
1673        int marker_size = data->conflict_marker_size;
1674        const char *ws = diff_get_color(color_diff, DIFF_WHITESPACE);
1675        const char *reset = diff_get_color(color_diff, DIFF_RESET);
1676        const char *set = diff_get_color(color_diff, DIFF_FILE_NEW);
1677        char *err;
1678        char *line_prefix = "";
1679        struct strbuf *msgbuf;
1680
1681        assert(data->o);
1682        if (data->o->output_prefix) {
1683                msgbuf = data->o->output_prefix(data->o,
1684                        data->o->output_prefix_data);
1685                line_prefix = msgbuf->buf;
1686        }
1687
1688        if (line[0] == '+') {
1689                unsigned bad;
1690                data->lineno++;
1691                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
1692                        data->status |= 1;
1693                        fprintf(data->o->file,
1694                                "%s%s:%d: leftover conflict marker\n",
1695                                line_prefix, data->filename, data->lineno);
1696                }
1697                bad = ws_check(line + 1, len - 1, data->ws_rule);
1698                if (!bad)
1699                        return;
1700                data->status |= bad;
1701                err = whitespace_error_string(bad);
1702                fprintf(data->o->file, "%s%s:%d: %s.\n",
1703                        line_prefix, data->filename, data->lineno, err);
1704                free(err);
1705                emit_line(data->o, set, reset, line, 1);
1706                ws_check_emit(line + 1, len - 1, data->ws_rule,
1707                              data->o->file, set, reset, ws);
1708        } else if (line[0] == ' ') {
1709                data->lineno++;
1710        } else if (line[0] == '@') {
1711                char *plus = strchr(line, '+');
1712                if (plus)
1713                        data->lineno = strtol(plus, NULL, 10) - 1;
1714                else
1715                        die("invalid diff");
1716        }
1717}
1718
1719static unsigned char *deflate_it(char *data,
1720                                 unsigned long size,
1721                                 unsigned long *result_size)
1722{
1723        int bound;
1724        unsigned char *deflated;
1725        z_stream stream;
1726
1727        memset(&stream, 0, sizeof(stream));
1728        deflateInit(&stream, zlib_compression_level);
1729        bound = deflateBound(&stream, size);
1730        deflated = xmalloc(bound);
1731        stream.next_out = deflated;
1732        stream.avail_out = bound;
1733
1734        stream.next_in = (unsigned char *)data;
1735        stream.avail_in = size;
1736        while (deflate(&stream, Z_FINISH) == Z_OK)
1737                ; /* nothing */
1738        deflateEnd(&stream);
1739        *result_size = stream.total_out;
1740        return deflated;
1741}
1742
1743static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1744{
1745        void *cp;
1746        void *delta;
1747        void *deflated;
1748        void *data;
1749        unsigned long orig_size;
1750        unsigned long delta_size;
1751        unsigned long deflate_size;
1752        unsigned long data_size;
1753
1754        /* We could do deflated delta, or we could do just deflated two,
1755         * whichever is smaller.
1756         */
1757        delta = NULL;
1758        deflated = deflate_it(two->ptr, two->size, &deflate_size);
1759        if (one->size && two->size) {
1760                delta = diff_delta(one->ptr, one->size,
1761                                   two->ptr, two->size,
1762                                   &delta_size, deflate_size);
1763                if (delta) {
1764                        void *to_free = delta;
1765                        orig_size = delta_size;
1766                        delta = deflate_it(delta, delta_size, &delta_size);
1767                        free(to_free);
1768                }
1769        }
1770
1771        if (delta && delta_size < deflate_size) {
1772                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
1773                free(deflated);
1774                data = delta;
1775                data_size = delta_size;
1776        }
1777        else {
1778                fprintf(file, "%sliteral %lu\n", prefix, two->size);
1779                free(delta);
1780                data = deflated;
1781                data_size = deflate_size;
1782        }
1783
1784        /* emit data encoded in base85 */
1785        cp = data;
1786        while (data_size) {
1787                int bytes = (52 < data_size) ? 52 : data_size;
1788                char line[70];
1789                data_size -= bytes;
1790                if (bytes <= 26)
1791                        line[0] = bytes + 'A' - 1;
1792                else
1793                        line[0] = bytes - 26 + 'a' - 1;
1794                encode_85(line + 1, cp, bytes);
1795                cp = (char *) cp + bytes;
1796                fprintf(file, "%s", prefix);
1797                fputs(line, file);
1798                fputc('\n', file);
1799        }
1800        fprintf(file, "%s\n", prefix);
1801        free(data);
1802}
1803
1804static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1805{
1806        fprintf(file, "%sGIT binary patch\n", prefix);
1807        emit_binary_diff_body(file, one, two, prefix);
1808        emit_binary_diff_body(file, two, one, prefix);
1809}
1810
1811static void diff_filespec_load_driver(struct diff_filespec *one)
1812{
1813        /* Use already-loaded driver */
1814        if (one->driver)
1815                return;
1816
1817        if (S_ISREG(one->mode))
1818                one->driver = userdiff_find_by_path(one->path);
1819
1820        /* Fallback to default settings */
1821        if (!one->driver)
1822                one->driver = userdiff_find_by_name("default");
1823}
1824
1825int diff_filespec_is_binary(struct diff_filespec *one)
1826{
1827        if (one->is_binary == -1) {
1828                diff_filespec_load_driver(one);
1829                if (one->driver->binary != -1)
1830                        one->is_binary = one->driver->binary;
1831                else {
1832                        if (!one->data && DIFF_FILE_VALID(one))
1833                                diff_populate_filespec(one, 0);
1834                        if (one->data)
1835                                one->is_binary = buffer_is_binary(one->data,
1836                                                one->size);
1837                        if (one->is_binary == -1)
1838                                one->is_binary = 0;
1839                }
1840        }
1841        return one->is_binary;
1842}
1843
1844static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
1845{
1846        diff_filespec_load_driver(one);
1847        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
1848}
1849
1850static const char *userdiff_word_regex(struct diff_filespec *one)
1851{
1852        diff_filespec_load_driver(one);
1853        return one->driver->word_regex;
1854}
1855
1856void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
1857{
1858        if (!options->a_prefix)
1859                options->a_prefix = a;
1860        if (!options->b_prefix)
1861                options->b_prefix = b;
1862}
1863
1864struct userdiff_driver *get_textconv(struct diff_filespec *one)
1865{
1866        if (!DIFF_FILE_VALID(one))
1867                return NULL;
1868
1869        diff_filespec_load_driver(one);
1870        if (!one->driver->textconv)
1871                return NULL;
1872
1873        if (one->driver->textconv_want_cache && !one->driver->textconv_cache) {
1874                struct notes_cache *c = xmalloc(sizeof(*c));
1875                struct strbuf name = STRBUF_INIT;
1876
1877                strbuf_addf(&name, "textconv/%s", one->driver->name);
1878                notes_cache_init(c, name.buf, one->driver->textconv);
1879                one->driver->textconv_cache = c;
1880        }
1881
1882        return one->driver;
1883}
1884
1885static void builtin_diff(const char *name_a,
1886                         const char *name_b,
1887                         struct diff_filespec *one,
1888                         struct diff_filespec *two,
1889                         const char *xfrm_msg,
1890                         int must_show_header,
1891                         struct diff_options *o,
1892                         int complete_rewrite)
1893{
1894        mmfile_t mf1, mf2;
1895        const char *lbl[2];
1896        char *a_one, *b_two;
1897        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1898        const char *reset = diff_get_color_opt(o, DIFF_RESET);
1899        const char *a_prefix, *b_prefix;
1900        struct userdiff_driver *textconv_one = NULL;
1901        struct userdiff_driver *textconv_two = NULL;
1902        struct strbuf header = STRBUF_INIT;
1903        struct strbuf *msgbuf;
1904        char *line_prefix = "";
1905
1906        if (o->output_prefix) {
1907                msgbuf = o->output_prefix(o, o->output_prefix_data);
1908                line_prefix = msgbuf->buf;
1909        }
1910
1911        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
1912                        (!one->mode || S_ISGITLINK(one->mode)) &&
1913                        (!two->mode || S_ISGITLINK(two->mode))) {
1914                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
1915                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
1916                show_submodule_summary(o->file, one ? one->path : two->path,
1917                                one->sha1, two->sha1, two->dirty_submodule,
1918                                del, add, reset);
1919                return;
1920        }
1921
1922        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
1923                textconv_one = get_textconv(one);
1924                textconv_two = get_textconv(two);
1925        }
1926
1927        diff_set_mnemonic_prefix(o, "a/", "b/");
1928        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
1929                a_prefix = o->b_prefix;
1930                b_prefix = o->a_prefix;
1931        } else {
1932                a_prefix = o->a_prefix;
1933                b_prefix = o->b_prefix;
1934        }
1935
1936        /* Never use a non-valid filename anywhere if at all possible */
1937        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
1938        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
1939
1940        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
1941        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
1942        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1943        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1944        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
1945        if (lbl[0][0] == '/') {
1946                /* /dev/null */
1947                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
1948                if (xfrm_msg)
1949                        strbuf_addstr(&header, xfrm_msg);
1950                must_show_header = 1;
1951        }
1952        else if (lbl[1][0] == '/') {
1953                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
1954                if (xfrm_msg)
1955                        strbuf_addstr(&header, xfrm_msg);
1956                must_show_header = 1;
1957        }
1958        else {
1959                if (one->mode != two->mode) {
1960                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
1961                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
1962                        must_show_header = 1;
1963                }
1964                if (xfrm_msg)
1965                        strbuf_addstr(&header, xfrm_msg);
1966
1967                /*
1968                 * we do not run diff between different kind
1969                 * of objects.
1970                 */
1971                if ((one->mode ^ two->mode) & S_IFMT)
1972                        goto free_ab_and_return;
1973                if (complete_rewrite &&
1974                    (textconv_one || !diff_filespec_is_binary(one)) &&
1975                    (textconv_two || !diff_filespec_is_binary(two))) {
1976                        fprintf(o->file, "%s", header.buf);
1977                        strbuf_reset(&header);
1978                        emit_rewrite_diff(name_a, name_b, one, two,
1979                                                textconv_one, textconv_two, o);
1980                        o->found_changes = 1;
1981                        goto free_ab_and_return;
1982                }
1983        }
1984
1985        if (!DIFF_OPT_TST(o, TEXT) &&
1986            ( (!textconv_one && diff_filespec_is_binary(one)) ||
1987              (!textconv_two && diff_filespec_is_binary(two)) )) {
1988                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1989                        die("unable to read files to diff");
1990                /* Quite common confusing case */
1991                if (mf1.size == mf2.size &&
1992                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
1993                        if (must_show_header)
1994                                fprintf(o->file, "%s", header.buf);
1995                        goto free_ab_and_return;
1996                }
1997                fprintf(o->file, "%s", header.buf);
1998                strbuf_reset(&header);
1999                if (DIFF_OPT_TST(o, BINARY))
2000                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2001                else
2002                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2003                                line_prefix, lbl[0], lbl[1]);
2004                o->found_changes = 1;
2005        }
2006        else {
2007                /* Crazy xdl interfaces.. */
2008                const char *diffopts = getenv("GIT_DIFF_OPTS");
2009                xpparam_t xpp;
2010                xdemitconf_t xecfg;
2011                struct emit_callback ecbdata;
2012                const struct userdiff_funcname *pe;
2013
2014                if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS) || must_show_header) {
2015                        fprintf(o->file, "%s", header.buf);
2016                        strbuf_reset(&header);
2017                }
2018
2019                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2020                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2021
2022                pe = diff_funcname_pattern(one);
2023                if (!pe)
2024                        pe = diff_funcname_pattern(two);
2025
2026                memset(&xpp, 0, sizeof(xpp));
2027                memset(&xecfg, 0, sizeof(xecfg));
2028                memset(&ecbdata, 0, sizeof(ecbdata));
2029                ecbdata.label_path = lbl;
2030                ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
2031                ecbdata.found_changesp = &o->found_changes;
2032                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
2033                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2034                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2035                ecbdata.opt = o;
2036                ecbdata.header = header.len ? &header : NULL;
2037                xpp.flags = o->xdl_opts;
2038                xecfg.ctxlen = o->context;
2039                xecfg.interhunkctxlen = o->interhunkcontext;
2040                xecfg.flags = XDL_EMIT_FUNCNAMES;
2041                if (pe)
2042                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2043                if (!diffopts)
2044                        ;
2045                else if (!prefixcmp(diffopts, "--unified="))
2046                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2047                else if (!prefixcmp(diffopts, "-u"))
2048                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2049                if (o->word_diff) {
2050                        int i;
2051
2052                        ecbdata.diff_words =
2053                                xcalloc(1, sizeof(struct diff_words_data));
2054                        ecbdata.diff_words->type = o->word_diff;
2055                        ecbdata.diff_words->opt = o;
2056                        if (!o->word_regex)
2057                                o->word_regex = userdiff_word_regex(one);
2058                        if (!o->word_regex)
2059                                o->word_regex = userdiff_word_regex(two);
2060                        if (!o->word_regex)
2061                                o->word_regex = diff_word_regex_cfg;
2062                        if (o->word_regex) {
2063                                ecbdata.diff_words->word_regex = (regex_t *)
2064                                        xmalloc(sizeof(regex_t));
2065                                if (regcomp(ecbdata.diff_words->word_regex,
2066                                                o->word_regex,
2067                                                REG_EXTENDED | REG_NEWLINE))
2068                                        die ("Invalid regular expression: %s",
2069                                                        o->word_regex);
2070                        }
2071                        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2072                                if (o->word_diff == diff_words_styles[i].type) {
2073                                        ecbdata.diff_words->style =
2074                                                &diff_words_styles[i];
2075                                        break;
2076                                }
2077                        }
2078                        if (DIFF_OPT_TST(o, COLOR_DIFF)) {
2079                                struct diff_words_style *st = ecbdata.diff_words->style;
2080                                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2081                                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2082                                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
2083                        }
2084                }
2085                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2086                              &xpp, &xecfg);
2087                if (o->word_diff)
2088                        free_diff_words_data(&ecbdata);
2089                if (textconv_one)
2090                        free(mf1.ptr);
2091                if (textconv_two)
2092                        free(mf2.ptr);
2093                xdiff_clear_find_func(&xecfg);
2094        }
2095
2096 free_ab_and_return:
2097        strbuf_release(&header);
2098        diff_free_filespec_data(one);
2099        diff_free_filespec_data(two);
2100        free(a_one);
2101        free(b_two);
2102        return;
2103}
2104
2105static void builtin_diffstat(const char *name_a, const char *name_b,
2106                             struct diff_filespec *one,
2107                             struct diff_filespec *two,
2108                             struct diffstat_t *diffstat,
2109                             struct diff_options *o,
2110                             int complete_rewrite)
2111{
2112        mmfile_t mf1, mf2;
2113        struct diffstat_file *data;
2114
2115        data = diffstat_add(diffstat, name_a, name_b);
2116
2117        if (!one || !two) {
2118                data->is_unmerged = 1;
2119                return;
2120        }
2121
2122        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2123                data->is_binary = 1;
2124                data->added = diff_filespec_size(two);
2125                data->deleted = diff_filespec_size(one);
2126        }
2127
2128        else if (complete_rewrite) {
2129                diff_populate_filespec(one, 0);
2130                diff_populate_filespec(two, 0);
2131                data->deleted = count_lines(one->data, one->size);
2132                data->added = count_lines(two->data, two->size);
2133        }
2134
2135        else {
2136                /* Crazy xdl interfaces.. */
2137                xpparam_t xpp;
2138                xdemitconf_t xecfg;
2139
2140                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2141                        die("unable to read files to diff");
2142
2143                memset(&xpp, 0, sizeof(xpp));
2144                memset(&xecfg, 0, sizeof(xecfg));
2145                xpp.flags = o->xdl_opts;
2146                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2147                              &xpp, &xecfg);
2148        }
2149
2150        diff_free_filespec_data(one);
2151        diff_free_filespec_data(two);
2152}
2153
2154static void builtin_checkdiff(const char *name_a, const char *name_b,
2155                              const char *attr_path,
2156                              struct diff_filespec *one,
2157                              struct diff_filespec *two,
2158                              struct diff_options *o)
2159{
2160        mmfile_t mf1, mf2;
2161        struct checkdiff_t data;
2162
2163        if (!two)
2164                return;
2165
2166        memset(&data, 0, sizeof(data));
2167        data.filename = name_b ? name_b : name_a;
2168        data.lineno = 0;
2169        data.o = o;
2170        data.ws_rule = whitespace_rule(attr_path);
2171        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2172
2173        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2174                die("unable to read files to diff");
2175
2176        /*
2177         * All the other codepaths check both sides, but not checking
2178         * the "old" side here is deliberate.  We are checking the newly
2179         * introduced changes, and as long as the "new" side is text, we
2180         * can and should check what it introduces.
2181         */
2182        if (diff_filespec_is_binary(two))
2183                goto free_and_return;
2184        else {
2185                /* Crazy xdl interfaces.. */
2186                xpparam_t xpp;
2187                xdemitconf_t xecfg;
2188
2189                memset(&xpp, 0, sizeof(xpp));
2190                memset(&xecfg, 0, sizeof(xecfg));
2191                xecfg.ctxlen = 1; /* at least one context line */
2192                xpp.flags = 0;
2193                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2194                              &xpp, &xecfg);
2195
2196                if (data.ws_rule & WS_BLANK_AT_EOF) {
2197                        struct emit_callback ecbdata;
2198                        int blank_at_eof;
2199
2200                        ecbdata.ws_rule = data.ws_rule;
2201                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2202                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2203
2204                        if (blank_at_eof) {
2205                                static char *err;
2206                                if (!err)
2207                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2208                                fprintf(o->file, "%s:%d: %s.\n",
2209                                        data.filename, blank_at_eof, err);
2210                                data.status = 1; /* report errors */
2211                        }
2212                }
2213        }
2214 free_and_return:
2215        diff_free_filespec_data(one);
2216        diff_free_filespec_data(two);
2217        if (data.status)
2218                DIFF_OPT_SET(o, CHECK_FAILED);
2219}
2220
2221struct diff_filespec *alloc_filespec(const char *path)
2222{
2223        int namelen = strlen(path);
2224        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2225
2226        memset(spec, 0, sizeof(*spec));
2227        spec->path = (char *)(spec + 1);
2228        memcpy(spec->path, path, namelen+1);
2229        spec->count = 1;
2230        spec->is_binary = -1;
2231        return spec;
2232}
2233
2234void free_filespec(struct diff_filespec *spec)
2235{
2236        if (!--spec->count) {
2237                diff_free_filespec_data(spec);
2238                free(spec);
2239        }
2240}
2241
2242void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2243                   unsigned short mode)
2244{
2245        if (mode) {
2246                spec->mode = canon_mode(mode);
2247                hashcpy(spec->sha1, sha1);
2248                spec->sha1_valid = !is_null_sha1(sha1);
2249        }
2250}
2251
2252/*
2253 * Given a name and sha1 pair, if the index tells us the file in
2254 * the work tree has that object contents, return true, so that
2255 * prepare_temp_file() does not have to inflate and extract.
2256 */
2257static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2258{
2259        struct cache_entry *ce;
2260        struct stat st;
2261        int pos, len;
2262
2263        /*
2264         * We do not read the cache ourselves here, because the
2265         * benchmark with my previous version that always reads cache
2266         * shows that it makes things worse for diff-tree comparing
2267         * two linux-2.6 kernel trees in an already checked out work
2268         * tree.  This is because most diff-tree comparisons deal with
2269         * only a small number of files, while reading the cache is
2270         * expensive for a large project, and its cost outweighs the
2271         * savings we get by not inflating the object to a temporary
2272         * file.  Practically, this code only helps when we are used
2273         * by diff-cache --cached, which does read the cache before
2274         * calling us.
2275         */
2276        if (!active_cache)
2277                return 0;
2278
2279        /* We want to avoid the working directory if our caller
2280         * doesn't need the data in a normal file, this system
2281         * is rather slow with its stat/open/mmap/close syscalls,
2282         * and the object is contained in a pack file.  The pack
2283         * is probably already open and will be faster to obtain
2284         * the data through than the working directory.  Loose
2285         * objects however would tend to be slower as they need
2286         * to be individually opened and inflated.
2287         */
2288        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2289                return 0;
2290
2291        len = strlen(name);
2292        pos = cache_name_pos(name, len);
2293        if (pos < 0)
2294                return 0;
2295        ce = active_cache[pos];
2296
2297        /*
2298         * This is not the sha1 we are looking for, or
2299         * unreusable because it is not a regular file.
2300         */
2301        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2302                return 0;
2303
2304        /*
2305         * If ce is marked as "assume unchanged", there is no
2306         * guarantee that work tree matches what we are looking for.
2307         */
2308        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2309                return 0;
2310
2311        /*
2312         * If ce matches the file in the work tree, we can reuse it.
2313         */
2314        if (ce_uptodate(ce) ||
2315            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2316                return 1;
2317
2318        return 0;
2319}
2320
2321static int populate_from_stdin(struct diff_filespec *s)
2322{
2323        struct strbuf buf = STRBUF_INIT;
2324        size_t size = 0;
2325
2326        if (strbuf_read(&buf, 0, 0) < 0)
2327                return error("error while reading from stdin %s",
2328                                     strerror(errno));
2329
2330        s->should_munmap = 0;
2331        s->data = strbuf_detach(&buf, &size);
2332        s->size = size;
2333        s->should_free = 1;
2334        return 0;
2335}
2336
2337static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2338{
2339        int len;
2340        char *data = xmalloc(100), *dirty = "";
2341
2342        /* Are we looking at the work tree? */
2343        if (s->dirty_submodule)
2344                dirty = "-dirty";
2345
2346        len = snprintf(data, 100,
2347                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2348        s->data = data;
2349        s->size = len;
2350        s->should_free = 1;
2351        if (size_only) {
2352                s->data = NULL;
2353                free(data);
2354        }
2355        return 0;
2356}
2357
2358/*
2359 * While doing rename detection and pickaxe operation, we may need to
2360 * grab the data for the blob (or file) for our own in-core comparison.
2361 * diff_filespec has data and size fields for this purpose.
2362 */
2363int diff_populate_filespec(struct diff_filespec *s, int size_only)
2364{
2365        int err = 0;
2366        if (!DIFF_FILE_VALID(s))
2367                die("internal error: asking to populate invalid file.");
2368        if (S_ISDIR(s->mode))
2369                return -1;
2370
2371        if (s->data)
2372                return 0;
2373
2374        if (size_only && 0 < s->size)
2375                return 0;
2376
2377        if (S_ISGITLINK(s->mode))
2378                return diff_populate_gitlink(s, size_only);
2379
2380        if (!s->sha1_valid ||
2381            reuse_worktree_file(s->path, s->sha1, 0)) {
2382                struct strbuf buf = STRBUF_INIT;
2383                struct stat st;
2384                int fd;
2385
2386                if (!strcmp(s->path, "-"))
2387                        return populate_from_stdin(s);
2388
2389                if (lstat(s->path, &st) < 0) {
2390                        if (errno == ENOENT) {
2391                        err_empty:
2392                                err = -1;
2393                        empty:
2394                                s->data = (char *)"";
2395                                s->size = 0;
2396                                return err;
2397                        }
2398                }
2399                s->size = xsize_t(st.st_size);
2400                if (!s->size)
2401                        goto empty;
2402                if (S_ISLNK(st.st_mode)) {
2403                        struct strbuf sb = STRBUF_INIT;
2404
2405                        if (strbuf_readlink(&sb, s->path, s->size))
2406                                goto err_empty;
2407                        s->size = sb.len;
2408                        s->data = strbuf_detach(&sb, NULL);
2409                        s->should_free = 1;
2410                        return 0;
2411                }
2412                if (size_only)
2413                        return 0;
2414                fd = open(s->path, O_RDONLY);
2415                if (fd < 0)
2416                        goto err_empty;
2417                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2418                close(fd);
2419                s->should_munmap = 1;
2420
2421                /*
2422                 * Convert from working tree format to canonical git format
2423                 */
2424                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2425                        size_t size = 0;
2426                        munmap(s->data, s->size);
2427                        s->should_munmap = 0;
2428                        s->data = strbuf_detach(&buf, &size);
2429                        s->size = size;
2430                        s->should_free = 1;
2431                }
2432        }
2433        else {
2434                enum object_type type;
2435                if (size_only) {
2436                        type = sha1_object_info(s->sha1, &s->size);
2437                        if (type < 0)
2438                                die("unable to read %s", sha1_to_hex(s->sha1));
2439                } else {
2440                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2441                        if (!s->data)
2442                                die("unable to read %s", sha1_to_hex(s->sha1));
2443                        s->should_free = 1;
2444                }
2445        }
2446        return 0;
2447}
2448
2449void diff_free_filespec_blob(struct diff_filespec *s)
2450{
2451        if (s->should_free)
2452                free(s->data);
2453        else if (s->should_munmap)
2454                munmap(s->data, s->size);
2455
2456        if (s->should_free || s->should_munmap) {
2457                s->should_free = s->should_munmap = 0;
2458                s->data = NULL;
2459        }
2460}
2461
2462void diff_free_filespec_data(struct diff_filespec *s)
2463{
2464        diff_free_filespec_blob(s);
2465        free(s->cnt_data);
2466        s->cnt_data = NULL;
2467}
2468
2469static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2470                           void *blob,
2471                           unsigned long size,
2472                           const unsigned char *sha1,
2473                           int mode)
2474{
2475        int fd;
2476        struct strbuf buf = STRBUF_INIT;
2477        struct strbuf template = STRBUF_INIT;
2478        char *path_dup = xstrdup(path);
2479        const char *base = basename(path_dup);
2480
2481        /* Generate "XXXXXX_basename.ext" */
2482        strbuf_addstr(&template, "XXXXXX_");
2483        strbuf_addstr(&template, base);
2484
2485        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2486                        strlen(base) + 1);
2487        if (fd < 0)
2488                die_errno("unable to create temp-file");
2489        if (convert_to_working_tree(path,
2490                        (const char *)blob, (size_t)size, &buf)) {
2491                blob = buf.buf;
2492                size = buf.len;
2493        }
2494        if (write_in_full(fd, blob, size) != size)
2495                die_errno("unable to write temp-file");
2496        close(fd);
2497        temp->name = temp->tmp_path;
2498        strcpy(temp->hex, sha1_to_hex(sha1));
2499        temp->hex[40] = 0;
2500        sprintf(temp->mode, "%06o", mode);
2501        strbuf_release(&buf);
2502        strbuf_release(&template);
2503        free(path_dup);
2504}
2505
2506static struct diff_tempfile *prepare_temp_file(const char *name,
2507                struct diff_filespec *one)
2508{
2509        struct diff_tempfile *temp = claim_diff_tempfile();
2510
2511        if (!DIFF_FILE_VALID(one)) {
2512        not_a_valid_file:
2513                /* A '-' entry produces this for file-2, and
2514                 * a '+' entry produces this for file-1.
2515                 */
2516                temp->name = "/dev/null";
2517                strcpy(temp->hex, ".");
2518                strcpy(temp->mode, ".");
2519                return temp;
2520        }
2521
2522        if (!remove_tempfile_installed) {
2523                atexit(remove_tempfile);
2524                sigchain_push_common(remove_tempfile_on_signal);
2525                remove_tempfile_installed = 1;
2526        }
2527
2528        if (!one->sha1_valid ||
2529            reuse_worktree_file(name, one->sha1, 1)) {
2530                struct stat st;
2531                if (lstat(name, &st) < 0) {
2532                        if (errno == ENOENT)
2533                                goto not_a_valid_file;
2534                        die_errno("stat(%s)", name);
2535                }
2536                if (S_ISLNK(st.st_mode)) {
2537                        struct strbuf sb = STRBUF_INIT;
2538                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2539                                die_errno("readlink(%s)", name);
2540                        prep_temp_blob(name, temp, sb.buf, sb.len,
2541                                       (one->sha1_valid ?
2542                                        one->sha1 : null_sha1),
2543                                       (one->sha1_valid ?
2544                                        one->mode : S_IFLNK));
2545                        strbuf_release(&sb);
2546                }
2547                else {
2548                        /* we can borrow from the file in the work tree */
2549                        temp->name = name;
2550                        if (!one->sha1_valid)
2551                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2552                        else
2553                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2554                        /* Even though we may sometimes borrow the
2555                         * contents from the work tree, we always want
2556                         * one->mode.  mode is trustworthy even when
2557                         * !(one->sha1_valid), as long as
2558                         * DIFF_FILE_VALID(one).
2559                         */
2560                        sprintf(temp->mode, "%06o", one->mode);
2561                }
2562                return temp;
2563        }
2564        else {
2565                if (diff_populate_filespec(one, 0))
2566                        die("cannot read data blob for %s", one->path);
2567                prep_temp_blob(name, temp, one->data, one->size,
2568                               one->sha1, one->mode);
2569        }
2570        return temp;
2571}
2572
2573/* An external diff command takes:
2574 *
2575 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2576 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2577 *
2578 */
2579static void run_external_diff(const char *pgm,
2580                              const char *name,
2581                              const char *other,
2582                              struct diff_filespec *one,
2583                              struct diff_filespec *two,
2584                              const char *xfrm_msg,
2585                              int complete_rewrite)
2586{
2587        const char *spawn_arg[10];
2588        int retval;
2589        const char **arg = &spawn_arg[0];
2590
2591        if (one && two) {
2592                struct diff_tempfile *temp_one, *temp_two;
2593                const char *othername = (other ? other : name);
2594                temp_one = prepare_temp_file(name, one);
2595                temp_two = prepare_temp_file(othername, two);
2596                *arg++ = pgm;
2597                *arg++ = name;
2598                *arg++ = temp_one->name;
2599                *arg++ = temp_one->hex;
2600                *arg++ = temp_one->mode;
2601                *arg++ = temp_two->name;
2602                *arg++ = temp_two->hex;
2603                *arg++ = temp_two->mode;
2604                if (other) {
2605                        *arg++ = other;
2606                        *arg++ = xfrm_msg;
2607                }
2608        } else {
2609                *arg++ = pgm;
2610                *arg++ = name;
2611        }
2612        *arg = NULL;
2613        fflush(NULL);
2614        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2615        remove_tempfile();
2616        if (retval) {
2617                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2618                exit(1);
2619        }
2620}
2621
2622static int similarity_index(struct diff_filepair *p)
2623{
2624        return p->score * 100 / MAX_SCORE;
2625}
2626
2627static void fill_metainfo(struct strbuf *msg,
2628                          const char *name,
2629                          const char *other,
2630                          struct diff_filespec *one,
2631                          struct diff_filespec *two,
2632                          struct diff_options *o,
2633                          struct diff_filepair *p,
2634                          int *must_show_header,
2635                          int use_color)
2636{
2637        const char *set = diff_get_color(use_color, DIFF_METAINFO);
2638        const char *reset = diff_get_color(use_color, DIFF_RESET);
2639        struct strbuf *msgbuf;
2640        char *line_prefix = "";
2641
2642        *must_show_header = 1;
2643        if (o->output_prefix) {
2644                msgbuf = o->output_prefix(o, o->output_prefix_data);
2645                line_prefix = msgbuf->buf;
2646        }
2647        strbuf_init(msg, PATH_MAX * 2 + 300);
2648        switch (p->status) {
2649        case DIFF_STATUS_COPIED:
2650                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2651                            line_prefix, set, similarity_index(p));
2652                strbuf_addf(msg, "%s\n%s%scopy from ",
2653                            reset,  line_prefix, set);
2654                quote_c_style(name, msg, NULL, 0);
2655                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2656                quote_c_style(other, msg, NULL, 0);
2657                strbuf_addf(msg, "%s\n", reset);
2658                break;
2659        case DIFF_STATUS_RENAMED:
2660                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2661                            line_prefix, set, similarity_index(p));
2662                strbuf_addf(msg, "%s\n%s%srename from ",
2663                            reset, line_prefix, set);
2664                quote_c_style(name, msg, NULL, 0);
2665                strbuf_addf(msg, "%s\n%s%srename to ",
2666                            reset, line_prefix, set);
2667                quote_c_style(other, msg, NULL, 0);
2668                strbuf_addf(msg, "%s\n", reset);
2669                break;
2670        case DIFF_STATUS_MODIFIED:
2671                if (p->score) {
2672                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2673                                    line_prefix,
2674                                    set, similarity_index(p), reset);
2675                        break;
2676                }
2677                /* fallthru */
2678        default:
2679                *must_show_header = 0;
2680        }
2681        if (one && two && hashcmp(one->sha1, two->sha1)) {
2682                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2683
2684                if (DIFF_OPT_TST(o, BINARY)) {
2685                        mmfile_t mf;
2686                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2687                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2688                                abbrev = 40;
2689                }
2690                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2691                            find_unique_abbrev(one->sha1, abbrev));
2692                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2693                if (one->mode == two->mode)
2694                        strbuf_addf(msg, " %06o", one->mode);
2695                strbuf_addf(msg, "%s\n", reset);
2696        }
2697}
2698
2699static void run_diff_cmd(const char *pgm,
2700                         const char *name,
2701                         const char *other,
2702                         const char *attr_path,
2703                         struct diff_filespec *one,
2704                         struct diff_filespec *two,
2705                         struct strbuf *msg,
2706                         struct diff_options *o,
2707                         struct diff_filepair *p)
2708{
2709        const char *xfrm_msg = NULL;
2710        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2711        int must_show_header = 0;
2712
2713        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2714                pgm = NULL;
2715        else {
2716                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2717                if (drv && drv->external)
2718                        pgm = drv->external;
2719        }
2720
2721        if (msg) {
2722                /*
2723                 * don't use colors when the header is intended for an
2724                 * external diff driver
2725                 */
2726                fill_metainfo(msg, name, other, one, two, o, p,
2727                              &must_show_header,
2728                              DIFF_OPT_TST(o, COLOR_DIFF) && !pgm);
2729                xfrm_msg = msg->len ? msg->buf : NULL;
2730        }
2731
2732        if (pgm) {
2733                run_external_diff(pgm, name, other, one, two, xfrm_msg,
2734                                  complete_rewrite);
2735                return;
2736        }
2737        if (one && two)
2738                builtin_diff(name, other ? other : name,
2739                             one, two, xfrm_msg, must_show_header,
2740                             o, complete_rewrite);
2741        else
2742                fprintf(o->file, "* Unmerged path %s\n", name);
2743}
2744
2745static void diff_fill_sha1_info(struct diff_filespec *one)
2746{
2747        if (DIFF_FILE_VALID(one)) {
2748                if (!one->sha1_valid) {
2749                        struct stat st;
2750                        if (!strcmp(one->path, "-")) {
2751                                hashcpy(one->sha1, null_sha1);
2752                                return;
2753                        }
2754                        if (lstat(one->path, &st) < 0)
2755                                die_errno("stat '%s'", one->path);
2756                        if (index_path(one->sha1, one->path, &st, 0))
2757                                die("cannot hash %s", one->path);
2758                }
2759        }
2760        else
2761                hashclr(one->sha1);
2762}
2763
2764static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2765{
2766        /* Strip the prefix but do not molest /dev/null and absolute paths */
2767        if (*namep && **namep != '/') {
2768                *namep += prefix_length;
2769                if (**namep == '/')
2770                        ++*namep;
2771        }
2772        if (*otherp && **otherp != '/') {
2773                *otherp += prefix_length;
2774                if (**otherp == '/')
2775                        ++*otherp;
2776        }
2777}
2778
2779static void run_diff(struct diff_filepair *p, struct diff_options *o)
2780{
2781        const char *pgm = external_diff();
2782        struct strbuf msg;
2783        struct diff_filespec *one = p->one;
2784        struct diff_filespec *two = p->two;
2785        const char *name;
2786        const char *other;
2787        const char *attr_path;
2788
2789        name  = p->one->path;
2790        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2791        attr_path = name;
2792        if (o->prefix_length)
2793                strip_prefix(o->prefix_length, &name, &other);
2794
2795        if (DIFF_PAIR_UNMERGED(p)) {
2796                run_diff_cmd(pgm, name, NULL, attr_path,
2797                             NULL, NULL, NULL, o, p);
2798                return;
2799        }
2800
2801        diff_fill_sha1_info(one);
2802        diff_fill_sha1_info(two);
2803
2804        if (!pgm &&
2805            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2806            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2807                /*
2808                 * a filepair that changes between file and symlink
2809                 * needs to be split into deletion and creation.
2810                 */
2811                struct diff_filespec *null = alloc_filespec(two->path);
2812                run_diff_cmd(NULL, name, other, attr_path,
2813                             one, null, &msg, o, p);
2814                free(null);
2815                strbuf_release(&msg);
2816
2817                null = alloc_filespec(one->path);
2818                run_diff_cmd(NULL, name, other, attr_path,
2819                             null, two, &msg, o, p);
2820                free(null);
2821        }
2822        else
2823                run_diff_cmd(pgm, name, other, attr_path,
2824                             one, two, &msg, o, p);
2825
2826        strbuf_release(&msg);
2827}
2828
2829static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2830                         struct diffstat_t *diffstat)
2831{
2832        const char *name;
2833        const char *other;
2834        int complete_rewrite = 0;
2835
2836        if (DIFF_PAIR_UNMERGED(p)) {
2837                /* unmerged */
2838                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2839                return;
2840        }
2841
2842        name = p->one->path;
2843        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2844
2845        if (o->prefix_length)
2846                strip_prefix(o->prefix_length, &name, &other);
2847
2848        diff_fill_sha1_info(p->one);
2849        diff_fill_sha1_info(p->two);
2850
2851        if (p->status == DIFF_STATUS_MODIFIED && p->score)
2852                complete_rewrite = 1;
2853        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2854}
2855
2856static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2857{
2858        const char *name;
2859        const char *other;
2860        const char *attr_path;
2861
2862        if (DIFF_PAIR_UNMERGED(p)) {
2863                /* unmerged */
2864                return;
2865        }
2866
2867        name = p->one->path;
2868        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2869        attr_path = other ? other : name;
2870
2871        if (o->prefix_length)
2872                strip_prefix(o->prefix_length, &name, &other);
2873
2874        diff_fill_sha1_info(p->one);
2875        diff_fill_sha1_info(p->two);
2876
2877        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2878}
2879
2880void diff_setup(struct diff_options *options)
2881{
2882        memcpy(options, &default_diff_options, sizeof(*options));
2883
2884        options->file = stdout;
2885
2886        options->line_termination = '\n';
2887        options->break_opt = -1;
2888        options->rename_limit = -1;
2889        options->dirstat_percent = 3;
2890        options->context = 3;
2891
2892        options->change = diff_change;
2893        options->add_remove = diff_addremove;
2894        if (diff_use_color_default > 0)
2895                DIFF_OPT_SET(options, COLOR_DIFF);
2896        options->detect_rename = diff_detect_rename_default;
2897
2898        if (diff_no_prefix) {
2899                options->a_prefix = options->b_prefix = "";
2900        } else if (!diff_mnemonic_prefix) {
2901                options->a_prefix = "a/";
2902                options->b_prefix = "b/";
2903        }
2904}
2905
2906int diff_setup_done(struct diff_options *options)
2907{
2908        int count = 0;
2909
2910        if (options->output_format & DIFF_FORMAT_NAME)
2911                count++;
2912        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
2913                count++;
2914        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
2915                count++;
2916        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
2917                count++;
2918        if (count > 1)
2919                die("--name-only, --name-status, --check and -s are mutually exclusive");
2920
2921        /*
2922         * Most of the time we can say "there are changes"
2923         * only by checking if there are changed paths, but
2924         * --ignore-whitespace* options force us to look
2925         * inside contents.
2926         */
2927
2928        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
2929            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
2930            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
2931                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
2932        else
2933                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
2934
2935        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
2936                options->detect_rename = DIFF_DETECT_COPY;
2937
2938        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
2939                options->prefix = NULL;
2940        if (options->prefix)
2941                options->prefix_length = strlen(options->prefix);
2942        else
2943                options->prefix_length = 0;
2944
2945        if (options->output_format & (DIFF_FORMAT_NAME |
2946                                      DIFF_FORMAT_NAME_STATUS |
2947                                      DIFF_FORMAT_CHECKDIFF |
2948                                      DIFF_FORMAT_NO_OUTPUT))
2949                options->output_format &= ~(DIFF_FORMAT_RAW |
2950                                            DIFF_FORMAT_NUMSTAT |
2951                                            DIFF_FORMAT_DIFFSTAT |
2952                                            DIFF_FORMAT_SHORTSTAT |
2953                                            DIFF_FORMAT_DIRSTAT |
2954                                            DIFF_FORMAT_SUMMARY |
2955                                            DIFF_FORMAT_PATCH);
2956
2957        /*
2958         * These cases always need recursive; we do not drop caller-supplied
2959         * recursive bits for other formats here.
2960         */
2961        if (options->output_format & (DIFF_FORMAT_PATCH |
2962                                      DIFF_FORMAT_NUMSTAT |
2963                                      DIFF_FORMAT_DIFFSTAT |
2964                                      DIFF_FORMAT_SHORTSTAT |
2965                                      DIFF_FORMAT_DIRSTAT |
2966                                      DIFF_FORMAT_SUMMARY |
2967                                      DIFF_FORMAT_CHECKDIFF))
2968                DIFF_OPT_SET(options, RECURSIVE);
2969        /*
2970         * Also pickaxe would not work very well if you do not say recursive
2971         */
2972        if (options->pickaxe)
2973                DIFF_OPT_SET(options, RECURSIVE);
2974        /*
2975         * When patches are generated, submodules diffed against the work tree
2976         * must be checked for dirtiness too so it can be shown in the output
2977         */
2978        if (options->output_format & DIFF_FORMAT_PATCH)
2979                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
2980
2981        if (options->detect_rename && options->rename_limit < 0)
2982                options->rename_limit = diff_rename_limit_default;
2983        if (options->setup & DIFF_SETUP_USE_CACHE) {
2984                if (!active_cache)
2985                        /* read-cache does not die even when it fails
2986                         * so it is safe for us to do this here.  Also
2987                         * it does not smudge active_cache or active_nr
2988                         * when it fails, so we do not have to worry about
2989                         * cleaning it up ourselves either.
2990                         */
2991                        read_cache();
2992        }
2993        if (options->abbrev <= 0 || 40 < options->abbrev)
2994                options->abbrev = 40; /* full */
2995
2996        /*
2997         * It does not make sense to show the first hit we happened
2998         * to have found.  It does not make sense not to return with
2999         * exit code in such a case either.
3000         */
3001        if (DIFF_OPT_TST(options, QUICK)) {
3002                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3003                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3004        }
3005
3006        return 0;
3007}
3008
3009static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3010{
3011        char c, *eq;
3012        int len;
3013
3014        if (*arg != '-')
3015                return 0;
3016        c = *++arg;
3017        if (!c)
3018                return 0;
3019        if (c == arg_short) {
3020                c = *++arg;
3021                if (!c)
3022                        return 1;
3023                if (val && isdigit(c)) {
3024                        char *end;
3025                        int n = strtoul(arg, &end, 10);
3026                        if (*end)
3027                                return 0;
3028                        *val = n;
3029                        return 1;
3030                }
3031                return 0;
3032        }
3033        if (c != '-')
3034                return 0;
3035        arg++;
3036        eq = strchr(arg, '=');
3037        if (eq)
3038                len = eq - arg;
3039        else
3040                len = strlen(arg);
3041        if (!len || strncmp(arg, arg_long, len))
3042                return 0;
3043        if (eq) {
3044                int n;
3045                char *end;
3046                if (!isdigit(*++eq))
3047                        return 0;
3048                n = strtoul(eq, &end, 10);
3049                if (*end)
3050                        return 0;
3051                *val = n;
3052        }
3053        return 1;
3054}
3055
3056static int diff_scoreopt_parse(const char *opt);
3057
3058static inline int short_opt(char opt, const char **argv,
3059                            const char **optarg)
3060{
3061        const char *arg = argv[0];
3062        if (arg[0] != '-' || arg[1] != opt)
3063                return 0;
3064        if (arg[2] != '\0') {
3065                *optarg = arg + 2;
3066                return 1;
3067        }
3068        if (!argv[1])
3069                die("Option '%c' requires a value", opt);
3070        *optarg = argv[1];
3071        return 2;
3072}
3073
3074int parse_long_opt(const char *opt, const char **argv,
3075                   const char **optarg)
3076{
3077        const char *arg = argv[0];
3078        if (arg[0] != '-' || arg[1] != '-')
3079                return 0;
3080        arg += strlen("--");
3081        if (prefixcmp(arg, opt))
3082                return 0;
3083        arg += strlen(opt);
3084        if (*arg == '=') { /* sticked form: --option=value */
3085                *optarg = arg + 1;
3086                return 1;
3087        }
3088        if (*arg != '\0')
3089                return 0;
3090        /* separate form: --option value */
3091        if (!argv[1])
3092                die("Option '--%s' requires a value", opt);
3093        *optarg = argv[1];
3094        return 2;
3095}
3096
3097static int stat_opt(struct diff_options *options, const char **av)
3098{
3099        const char *arg = av[0];
3100        char *end;
3101        int width = options->stat_width;
3102        int name_width = options->stat_name_width;
3103        int argcount = 1;
3104
3105        arg += strlen("--stat");
3106        end = (char *)arg;
3107
3108        switch (*arg) {
3109        case '-':
3110                if (!prefixcmp(arg, "-width")) {
3111                        arg += strlen("-width");
3112                        if (*arg == '=')
3113                                width = strtoul(arg + 1, &end, 10);
3114                        else if (!*arg && !av[1])
3115                                die("Option '--stat-width' requires a value");
3116                        else if (!*arg) {
3117                                width = strtoul(av[1], &end, 10);
3118                                argcount = 2;
3119                        }
3120                } else if (!prefixcmp(arg, "-name-width")) {
3121                        arg += strlen("-name-width");
3122                        if (*arg == '=')
3123                                name_width = strtoul(arg + 1, &end, 10);
3124                        else if (!*arg && !av[1])
3125                                die("Option '--stat-name-width' requires a value");
3126                        else if (!*arg) {
3127                                name_width = strtoul(av[1], &end, 10);
3128                                argcount = 2;
3129                        }
3130                }
3131                break;
3132        case '=':
3133                width = strtoul(arg+1, &end, 10);
3134                if (*end == ',')
3135                        name_width = strtoul(end+1, &end, 10);
3136        }
3137
3138        /* Important! This checks all the error cases! */
3139        if (*end)
3140                return 0;
3141        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3142        options->stat_name_width = name_width;
3143        options->stat_width = width;
3144        return argcount;
3145}
3146
3147int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3148{
3149        const char *arg = av[0];
3150        const char *optarg;
3151        int argcount;
3152
3153        /* Output format options */
3154        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3155                options->output_format |= DIFF_FORMAT_PATCH;
3156        else if (opt_arg(arg, 'U', "unified", &options->context))
3157                options->output_format |= DIFF_FORMAT_PATCH;
3158        else if (!strcmp(arg, "--raw"))
3159                options->output_format |= DIFF_FORMAT_RAW;
3160        else if (!strcmp(arg, "--patch-with-raw"))
3161                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3162        else if (!strcmp(arg, "--numstat"))
3163                options->output_format |= DIFF_FORMAT_NUMSTAT;
3164        else if (!strcmp(arg, "--shortstat"))
3165                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3166        else if (opt_arg(arg, 'X', "dirstat", &options->dirstat_percent))
3167                options->output_format |= DIFF_FORMAT_DIRSTAT;
3168        else if (!strcmp(arg, "--cumulative")) {
3169                options->output_format |= DIFF_FORMAT_DIRSTAT;
3170                DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
3171        } else if (opt_arg(arg, 0, "dirstat-by-file",
3172                           &options->dirstat_percent)) {
3173                options->output_format |= DIFF_FORMAT_DIRSTAT;
3174                DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
3175        }
3176        else if (!strcmp(arg, "--check"))
3177                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3178        else if (!strcmp(arg, "--summary"))
3179                options->output_format |= DIFF_FORMAT_SUMMARY;
3180        else if (!strcmp(arg, "--patch-with-stat"))
3181                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3182        else if (!strcmp(arg, "--name-only"))
3183                options->output_format |= DIFF_FORMAT_NAME;
3184        else if (!strcmp(arg, "--name-status"))
3185                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3186        else if (!strcmp(arg, "-s"))
3187                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3188        else if (!prefixcmp(arg, "--stat"))
3189                /* --stat, --stat-width, or --stat-name-width */
3190                return stat_opt(options, av);
3191
3192        /* renames options */
3193        else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
3194                 !strcmp(arg, "--break-rewrites")) {
3195                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3196                        return error("invalid argument to -B: %s", arg+2);
3197        }
3198        else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--find-renames=") ||
3199                 !strcmp(arg, "--find-renames")) {
3200                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3201                        return error("invalid argument to -M: %s", arg+2);
3202                options->detect_rename = DIFF_DETECT_RENAME;
3203        }
3204        else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
3205                 !strcmp(arg, "--find-copies")) {
3206                if (options->detect_rename == DIFF_DETECT_COPY)
3207                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3208                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3209                        return error("invalid argument to -C: %s", arg+2);
3210                options->detect_rename = DIFF_DETECT_COPY;
3211        }
3212        else if (!strcmp(arg, "--no-renames"))
3213                options->detect_rename = 0;
3214        else if (!strcmp(arg, "--relative"))
3215                DIFF_OPT_SET(options, RELATIVE_NAME);
3216        else if (!prefixcmp(arg, "--relative=")) {
3217                DIFF_OPT_SET(options, RELATIVE_NAME);
3218                options->prefix = arg + 11;
3219        }
3220
3221        /* xdiff options */
3222        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3223                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3224        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3225                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3226        else if (!strcmp(arg, "--ignore-space-at-eol"))
3227                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3228        else if (!strcmp(arg, "--patience"))
3229                DIFF_XDL_SET(options, PATIENCE_DIFF);
3230
3231        /* flags options */
3232        else if (!strcmp(arg, "--binary")) {
3233                options->output_format |= DIFF_FORMAT_PATCH;
3234                DIFF_OPT_SET(options, BINARY);
3235        }
3236        else if (!strcmp(arg, "--full-index"))
3237                DIFF_OPT_SET(options, FULL_INDEX);
3238        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3239                DIFF_OPT_SET(options, TEXT);
3240        else if (!strcmp(arg, "-R"))
3241                DIFF_OPT_SET(options, REVERSE_DIFF);
3242        else if (!strcmp(arg, "--find-copies-harder"))
3243                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3244        else if (!strcmp(arg, "--follow"))
3245                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3246        else if (!strcmp(arg, "--color"))
3247                DIFF_OPT_SET(options, COLOR_DIFF);
3248        else if (!prefixcmp(arg, "--color=")) {
3249                int value = git_config_colorbool(NULL, arg+8, -1);
3250                if (value == 0)
3251                        DIFF_OPT_CLR(options, COLOR_DIFF);
3252                else if (value > 0)
3253                        DIFF_OPT_SET(options, COLOR_DIFF);
3254                else
3255                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3256        }
3257        else if (!strcmp(arg, "--no-color"))
3258                DIFF_OPT_CLR(options, COLOR_DIFF);
3259        else if (!strcmp(arg, "--color-words")) {
3260                DIFF_OPT_SET(options, COLOR_DIFF);
3261                options->word_diff = DIFF_WORDS_COLOR;
3262        }
3263        else if (!prefixcmp(arg, "--color-words=")) {
3264                DIFF_OPT_SET(options, COLOR_DIFF);
3265                options->word_diff = DIFF_WORDS_COLOR;
3266                options->word_regex = arg + 14;
3267        }
3268        else if (!strcmp(arg, "--word-diff")) {
3269                if (options->word_diff == DIFF_WORDS_NONE)
3270                        options->word_diff = DIFF_WORDS_PLAIN;
3271        }
3272        else if (!prefixcmp(arg, "--word-diff=")) {
3273                const char *type = arg + 12;
3274                if (!strcmp(type, "plain"))
3275                        options->word_diff = DIFF_WORDS_PLAIN;
3276                else if (!strcmp(type, "color")) {
3277                        DIFF_OPT_SET(options, COLOR_DIFF);
3278                        options->word_diff = DIFF_WORDS_COLOR;
3279                }
3280                else if (!strcmp(type, "porcelain"))
3281                        options->word_diff = DIFF_WORDS_PORCELAIN;
3282                else if (!strcmp(type, "none"))
3283                        options->word_diff = DIFF_WORDS_NONE;
3284                else
3285                        die("bad --word-diff argument: %s", type);
3286        }
3287        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3288                if (options->word_diff == DIFF_WORDS_NONE)
3289                        options->word_diff = DIFF_WORDS_PLAIN;
3290                options->word_regex = optarg;
3291                return argcount;
3292        }
3293        else if (!strcmp(arg, "--exit-code"))
3294                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3295        else if (!strcmp(arg, "--quiet"))
3296                DIFF_OPT_SET(options, QUICK);
3297        else if (!strcmp(arg, "--ext-diff"))
3298                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3299        else if (!strcmp(arg, "--no-ext-diff"))
3300                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3301        else if (!strcmp(arg, "--textconv"))
3302                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3303        else if (!strcmp(arg, "--no-textconv"))
3304                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3305        else if (!strcmp(arg, "--ignore-submodules")) {
3306                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3307                handle_ignore_submodules_arg(options, "all");
3308        } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3309                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3310                handle_ignore_submodules_arg(options, arg + 20);
3311        } else if (!strcmp(arg, "--submodule"))
3312                DIFF_OPT_SET(options, SUBMODULE_LOG);
3313        else if (!prefixcmp(arg, "--submodule=")) {
3314                if (!strcmp(arg + 12, "log"))
3315                        DIFF_OPT_SET(options, SUBMODULE_LOG);
3316        }
3317
3318        /* misc options */
3319        else if (!strcmp(arg, "-z"))
3320                options->line_termination = 0;
3321        else if ((argcount = short_opt('l', av, &optarg))) {
3322                options->rename_limit = strtoul(optarg, NULL, 10);
3323                return argcount;
3324        }
3325        else if ((argcount = short_opt('S', av, &optarg))) {
3326                options->pickaxe = optarg;
3327                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3328                return argcount;
3329        } else if ((argcount = short_opt('G', av, &optarg))) {
3330                options->pickaxe = optarg;
3331                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3332                return argcount;
3333        }
3334        else if (!strcmp(arg, "--pickaxe-all"))
3335                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3336        else if (!strcmp(arg, "--pickaxe-regex"))
3337                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3338        else if ((argcount = short_opt('O', av, &optarg))) {
3339                options->orderfile = optarg;
3340                return argcount;
3341        }
3342        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3343                options->filter = optarg;
3344                return argcount;
3345        }
3346        else if (!strcmp(arg, "--abbrev"))
3347                options->abbrev = DEFAULT_ABBREV;
3348        else if (!prefixcmp(arg, "--abbrev=")) {
3349                options->abbrev = strtoul(arg + 9, NULL, 10);
3350                if (options->abbrev < MINIMUM_ABBREV)
3351                        options->abbrev = MINIMUM_ABBREV;
3352                else if (40 < options->abbrev)
3353                        options->abbrev = 40;
3354        }
3355        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3356                options->a_prefix = optarg;
3357                return argcount;
3358        }
3359        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3360                options->b_prefix = optarg;
3361                return argcount;
3362        }
3363        else if (!strcmp(arg, "--no-prefix"))
3364                options->a_prefix = options->b_prefix = "";
3365        else if (opt_arg(arg, '\0', "inter-hunk-context",
3366                         &options->interhunkcontext))
3367                ;
3368        else if ((argcount = parse_long_opt("output", av, &optarg))) {
3369                options->file = fopen(optarg, "w");
3370                if (!options->file)
3371                        die_errno("Could not open '%s'", optarg);
3372                options->close_file = 1;
3373                return argcount;
3374        } else
3375                return 0;
3376        return 1;
3377}
3378
3379int parse_rename_score(const char **cp_p)
3380{
3381        unsigned long num, scale;
3382        int ch, dot;
3383        const char *cp = *cp_p;
3384
3385        num = 0;
3386        scale = 1;
3387        dot = 0;
3388        for (;;) {
3389                ch = *cp;
3390                if ( !dot && ch == '.' ) {
3391                        scale = 1;
3392                        dot = 1;
3393                } else if ( ch == '%' ) {
3394                        scale = dot ? scale*100 : 100;
3395                        cp++;   /* % is always at the end */
3396                        break;
3397                } else if ( ch >= '0' && ch <= '9' ) {
3398                        if ( scale < 100000 ) {
3399                                scale *= 10;
3400                                num = (num*10) + (ch-'0');
3401                        }
3402                } else {
3403                        break;
3404                }
3405                cp++;
3406        }
3407        *cp_p = cp;
3408
3409        /* user says num divided by scale and we say internally that
3410         * is MAX_SCORE * num / scale.
3411         */
3412        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3413}
3414
3415static int diff_scoreopt_parse(const char *opt)
3416{
3417        int opt1, opt2, cmd;
3418
3419        if (*opt++ != '-')
3420                return -1;
3421        cmd = *opt++;
3422        if (cmd == '-') {
3423                /* convert the long-form arguments into short-form versions */
3424                if (!prefixcmp(opt, "break-rewrites")) {
3425                        opt += strlen("break-rewrites");
3426                        if (*opt == 0 || *opt++ == '=')
3427                                cmd = 'B';
3428                } else if (!prefixcmp(opt, "find-copies")) {
3429                        opt += strlen("find-copies");
3430                        if (*opt == 0 || *opt++ == '=')
3431                                cmd = 'C';
3432                } else if (!prefixcmp(opt, "find-renames")) {
3433                        opt += strlen("find-renames");
3434                        if (*opt == 0 || *opt++ == '=')
3435                                cmd = 'M';
3436                }
3437        }
3438        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3439                return -1; /* that is not a -M, -C nor -B option */
3440
3441        opt1 = parse_rename_score(&opt);
3442        if (cmd != 'B')
3443                opt2 = 0;
3444        else {
3445                if (*opt == 0)
3446                        opt2 = 0;
3447                else if (*opt != '/')
3448                        return -1; /* we expect -B80/99 or -B80 */
3449                else {
3450                        opt++;
3451                        opt2 = parse_rename_score(&opt);
3452                }
3453        }
3454        if (*opt != 0)
3455                return -1;
3456        return opt1 | (opt2 << 16);
3457}
3458
3459struct diff_queue_struct diff_queued_diff;
3460
3461void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3462{
3463        if (queue->alloc <= queue->nr) {
3464                queue->alloc = alloc_nr(queue->alloc);
3465                queue->queue = xrealloc(queue->queue,
3466                                        sizeof(dp) * queue->alloc);
3467        }
3468        queue->queue[queue->nr++] = dp;
3469}
3470
3471struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3472                                 struct diff_filespec *one,
3473                                 struct diff_filespec *two)
3474{
3475        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3476        dp->one = one;
3477        dp->two = two;
3478        if (queue)
3479                diff_q(queue, dp);
3480        return dp;
3481}
3482
3483void diff_free_filepair(struct diff_filepair *p)
3484{
3485        free_filespec(p->one);
3486        free_filespec(p->two);
3487        free(p);
3488}
3489
3490/* This is different from find_unique_abbrev() in that
3491 * it stuffs the result with dots for alignment.
3492 */
3493const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3494{
3495        int abblen;
3496        const char *abbrev;
3497        if (len == 40)
3498                return sha1_to_hex(sha1);
3499
3500        abbrev = find_unique_abbrev(sha1, len);
3501        abblen = strlen(abbrev);
3502        if (abblen < 37) {
3503                static char hex[41];
3504                if (len < abblen && abblen <= len + 2)
3505                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3506                else
3507                        sprintf(hex, "%s...", abbrev);
3508                return hex;
3509        }
3510        return sha1_to_hex(sha1);
3511}
3512
3513static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3514{
3515        int line_termination = opt->line_termination;
3516        int inter_name_termination = line_termination ? '\t' : '\0';
3517        if (opt->output_prefix) {
3518                struct strbuf *msg = NULL;
3519                msg = opt->output_prefix(opt, opt->output_prefix_data);
3520                fprintf(opt->file, "%s", msg->buf);
3521        }
3522
3523        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3524                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3525                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3526                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3527        }
3528        if (p->score) {
3529                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3530                        inter_name_termination);
3531        } else {
3532                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3533        }
3534
3535        if (p->status == DIFF_STATUS_COPIED ||
3536            p->status == DIFF_STATUS_RENAMED) {
3537                const char *name_a, *name_b;
3538                name_a = p->one->path;
3539                name_b = p->two->path;
3540                strip_prefix(opt->prefix_length, &name_a, &name_b);
3541                write_name_quoted(name_a, opt->file, inter_name_termination);
3542                write_name_quoted(name_b, opt->file, line_termination);
3543        } else {
3544                const char *name_a, *name_b;
3545                name_a = p->one->mode ? p->one->path : p->two->path;
3546                name_b = NULL;
3547                strip_prefix(opt->prefix_length, &name_a, &name_b);
3548                write_name_quoted(name_a, opt->file, line_termination);
3549        }
3550}
3551
3552int diff_unmodified_pair(struct diff_filepair *p)
3553{
3554        /* This function is written stricter than necessary to support
3555         * the currently implemented transformers, but the idea is to
3556         * let transformers to produce diff_filepairs any way they want,
3557         * and filter and clean them up here before producing the output.
3558         */
3559        struct diff_filespec *one = p->one, *two = p->two;
3560
3561        if (DIFF_PAIR_UNMERGED(p))
3562                return 0; /* unmerged is interesting */
3563
3564        /* deletion, addition, mode or type change
3565         * and rename are all interesting.
3566         */
3567        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3568            DIFF_PAIR_MODE_CHANGED(p) ||
3569            strcmp(one->path, two->path))
3570                return 0;
3571
3572        /* both are valid and point at the same path.  that is, we are
3573         * dealing with a change.
3574         */
3575        if (one->sha1_valid && two->sha1_valid &&
3576            !hashcmp(one->sha1, two->sha1) &&
3577            !one->dirty_submodule && !two->dirty_submodule)
3578                return 1; /* no change */
3579        if (!one->sha1_valid && !two->sha1_valid)
3580                return 1; /* both look at the same file on the filesystem. */
3581        return 0;
3582}
3583
3584static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3585{
3586        if (diff_unmodified_pair(p))
3587                return;
3588
3589        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3590            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3591                return; /* no tree diffs in patch format */
3592
3593        run_diff(p, o);
3594}
3595
3596static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3597                            struct diffstat_t *diffstat)
3598{
3599        if (diff_unmodified_pair(p))
3600                return;
3601
3602        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3603            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3604                return; /* no useful stat for tree diffs */
3605
3606        run_diffstat(p, o, diffstat);
3607}
3608
3609static void diff_flush_checkdiff(struct diff_filepair *p,
3610                struct diff_options *o)
3611{
3612        if (diff_unmodified_pair(p))
3613                return;
3614
3615        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3616            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3617                return; /* nothing to check in tree diffs */
3618
3619        run_checkdiff(p, o);
3620}
3621
3622int diff_queue_is_empty(void)
3623{
3624        struct diff_queue_struct *q = &diff_queued_diff;
3625        int i;
3626        for (i = 0; i < q->nr; i++)
3627                if (!diff_unmodified_pair(q->queue[i]))
3628                        return 0;
3629        return 1;
3630}
3631
3632#if DIFF_DEBUG
3633void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3634{
3635        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3636                x, one ? one : "",
3637                s->path,
3638                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3639                s->mode,
3640                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3641        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3642                x, one ? one : "",
3643                s->size, s->xfrm_flags);
3644}
3645
3646void diff_debug_filepair(const struct diff_filepair *p, int i)
3647{
3648        diff_debug_filespec(p->one, i, "one");
3649        diff_debug_filespec(p->two, i, "two");
3650        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3651                p->score, p->status ? p->status : '?',
3652                p->one->rename_used, p->broken_pair);
3653}
3654
3655void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3656{
3657        int i;
3658        if (msg)
3659                fprintf(stderr, "%s\n", msg);
3660        fprintf(stderr, "q->nr = %d\n", q->nr);
3661        for (i = 0; i < q->nr; i++) {
3662                struct diff_filepair *p = q->queue[i];
3663                diff_debug_filepair(p, i);
3664        }
3665}
3666#endif
3667
3668static void diff_resolve_rename_copy(void)
3669{
3670        int i;
3671        struct diff_filepair *p;
3672        struct diff_queue_struct *q = &diff_queued_diff;
3673
3674        diff_debug_queue("resolve-rename-copy", q);
3675
3676        for (i = 0; i < q->nr; i++) {
3677                p = q->queue[i];
3678                p->status = 0; /* undecided */
3679                if (DIFF_PAIR_UNMERGED(p))
3680                        p->status = DIFF_STATUS_UNMERGED;
3681                else if (!DIFF_FILE_VALID(p->one))
3682                        p->status = DIFF_STATUS_ADDED;
3683                else if (!DIFF_FILE_VALID(p->two))
3684                        p->status = DIFF_STATUS_DELETED;
3685                else if (DIFF_PAIR_TYPE_CHANGED(p))
3686                        p->status = DIFF_STATUS_TYPE_CHANGED;
3687
3688                /* from this point on, we are dealing with a pair
3689                 * whose both sides are valid and of the same type, i.e.
3690                 * either in-place edit or rename/copy edit.
3691                 */
3692                else if (DIFF_PAIR_RENAME(p)) {
3693                        /*
3694                         * A rename might have re-connected a broken
3695                         * pair up, causing the pathnames to be the
3696                         * same again. If so, that's not a rename at
3697                         * all, just a modification..
3698                         *
3699                         * Otherwise, see if this source was used for
3700                         * multiple renames, in which case we decrement
3701                         * the count, and call it a copy.
3702                         */
3703                        if (!strcmp(p->one->path, p->two->path))
3704                                p->status = DIFF_STATUS_MODIFIED;
3705                        else if (--p->one->rename_used > 0)
3706                                p->status = DIFF_STATUS_COPIED;
3707                        else
3708                                p->status = DIFF_STATUS_RENAMED;
3709                }
3710                else if (hashcmp(p->one->sha1, p->two->sha1) ||
3711                         p->one->mode != p->two->mode ||
3712                         p->one->dirty_submodule ||
3713                         p->two->dirty_submodule ||
3714                         is_null_sha1(p->one->sha1))
3715                        p->status = DIFF_STATUS_MODIFIED;
3716                else {
3717                        /* This is a "no-change" entry and should not
3718                         * happen anymore, but prepare for broken callers.
3719                         */
3720                        error("feeding unmodified %s to diffcore",
3721                              p->one->path);
3722                        p->status = DIFF_STATUS_UNKNOWN;
3723                }
3724        }
3725        diff_debug_queue("resolve-rename-copy done", q);
3726}
3727
3728static int check_pair_status(struct diff_filepair *p)
3729{
3730        switch (p->status) {
3731        case DIFF_STATUS_UNKNOWN:
3732                return 0;
3733        case 0:
3734                die("internal error in diff-resolve-rename-copy");
3735        default:
3736                return 1;
3737        }
3738}
3739
3740static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3741{
3742        int fmt = opt->output_format;
3743
3744        if (fmt & DIFF_FORMAT_CHECKDIFF)
3745                diff_flush_checkdiff(p, opt);
3746        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3747                diff_flush_raw(p, opt);
3748        else if (fmt & DIFF_FORMAT_NAME) {
3749                const char *name_a, *name_b;
3750                name_a = p->two->path;
3751                name_b = NULL;
3752                strip_prefix(opt->prefix_length, &name_a, &name_b);
3753                write_name_quoted(name_a, opt->file, opt->line_termination);
3754        }
3755}
3756
3757static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
3758{
3759        if (fs->mode)
3760                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
3761        else
3762                fprintf(file, " %s ", newdelete);
3763        write_name_quoted(fs->path, file, '\n');
3764}
3765
3766
3767static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
3768                const char *line_prefix)
3769{
3770        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
3771                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
3772                        p->two->mode, show_name ? ' ' : '\n');
3773                if (show_name) {
3774                        write_name_quoted(p->two->path, file, '\n');
3775                }
3776        }
3777}
3778
3779static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
3780                        const char *line_prefix)
3781{
3782        char *names = pprint_rename(p->one->path, p->two->path);
3783
3784        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
3785        free(names);
3786        show_mode_change(file, p, 0, line_prefix);
3787}
3788
3789static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
3790{
3791        FILE *file = opt->file;
3792        char *line_prefix = "";
3793
3794        if (opt->output_prefix) {
3795                struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
3796                line_prefix = buf->buf;
3797        }
3798
3799        switch(p->status) {
3800        case DIFF_STATUS_DELETED:
3801                fputs(line_prefix, file);
3802                show_file_mode_name(file, "delete", p->one);
3803                break;
3804        case DIFF_STATUS_ADDED:
3805                fputs(line_prefix, file);
3806                show_file_mode_name(file, "create", p->two);
3807                break;
3808        case DIFF_STATUS_COPIED:
3809                fputs(line_prefix, file);
3810                show_rename_copy(file, "copy", p, line_prefix);
3811                break;
3812        case DIFF_STATUS_RENAMED:
3813                fputs(line_prefix, file);
3814                show_rename_copy(file, "rename", p, line_prefix);
3815                break;
3816        default:
3817                if (p->score) {
3818                        fprintf(file, "%s rewrite ", line_prefix);
3819                        write_name_quoted(p->two->path, file, ' ');
3820                        fprintf(file, "(%d%%)\n", similarity_index(p));
3821                }
3822                show_mode_change(file, p, !p->score, line_prefix);
3823                break;
3824        }
3825}
3826
3827struct patch_id_t {
3828        git_SHA_CTX *ctx;
3829        int patchlen;
3830};
3831
3832static int remove_space(char *line, int len)
3833{
3834        int i;
3835        char *dst = line;
3836        unsigned char c;
3837
3838        for (i = 0; i < len; i++)
3839                if (!isspace((c = line[i])))
3840                        *dst++ = c;
3841
3842        return dst - line;
3843}
3844
3845static void patch_id_consume(void *priv, char *line, unsigned long len)
3846{
3847        struct patch_id_t *data = priv;
3848        int new_len;
3849
3850        /* Ignore line numbers when computing the SHA1 of the patch */
3851        if (!prefixcmp(line, "@@ -"))
3852                return;
3853
3854        new_len = remove_space(line, len);
3855
3856        git_SHA1_Update(data->ctx, line, new_len);
3857        data->patchlen += new_len;
3858}
3859
3860/* returns 0 upon success, and writes result into sha1 */
3861static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
3862{
3863        struct diff_queue_struct *q = &diff_queued_diff;
3864        int i;
3865        git_SHA_CTX ctx;
3866        struct patch_id_t data;
3867        char buffer[PATH_MAX * 4 + 20];
3868
3869        git_SHA1_Init(&ctx);
3870        memset(&data, 0, sizeof(struct patch_id_t));
3871        data.ctx = &ctx;
3872
3873        for (i = 0; i < q->nr; i++) {
3874                xpparam_t xpp;
3875                xdemitconf_t xecfg;
3876                mmfile_t mf1, mf2;
3877                struct diff_filepair *p = q->queue[i];
3878                int len1, len2;
3879
3880                memset(&xpp, 0, sizeof(xpp));
3881                memset(&xecfg, 0, sizeof(xecfg));
3882                if (p->status == 0)
3883                        return error("internal diff status error");
3884                if (p->status == DIFF_STATUS_UNKNOWN)
3885                        continue;
3886                if (diff_unmodified_pair(p))
3887                        continue;
3888                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3889                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3890                        continue;
3891                if (DIFF_PAIR_UNMERGED(p))
3892                        continue;
3893
3894                diff_fill_sha1_info(p->one);
3895                diff_fill_sha1_info(p->two);
3896                if (fill_mmfile(&mf1, p->one) < 0 ||
3897                                fill_mmfile(&mf2, p->two) < 0)
3898                        return error("unable to read files to diff");
3899
3900                len1 = remove_space(p->one->path, strlen(p->one->path));
3901                len2 = remove_space(p->two->path, strlen(p->two->path));
3902                if (p->one->mode == 0)
3903                        len1 = snprintf(buffer, sizeof(buffer),
3904                                        "diff--gita/%.*sb/%.*s"
3905                                        "newfilemode%06o"
3906                                        "---/dev/null"
3907                                        "+++b/%.*s",
3908                                        len1, p->one->path,
3909                                        len2, p->two->path,
3910                                        p->two->mode,
3911                                        len2, p->two->path);
3912                else if (p->two->mode == 0)
3913                        len1 = snprintf(buffer, sizeof(buffer),
3914                                        "diff--gita/%.*sb/%.*s"
3915                                        "deletedfilemode%06o"
3916                                        "---a/%.*s"
3917                                        "+++/dev/null",
3918                                        len1, p->one->path,
3919                                        len2, p->two->path,
3920                                        p->one->mode,
3921                                        len1, p->one->path);
3922                else
3923                        len1 = snprintf(buffer, sizeof(buffer),
3924                                        "diff--gita/%.*sb/%.*s"
3925                                        "---a/%.*s"
3926                                        "+++b/%.*s",
3927                                        len1, p->one->path,
3928                                        len2, p->two->path,
3929                                        len1, p->one->path,
3930                                        len2, p->two->path);
3931                git_SHA1_Update(&ctx, buffer, len1);
3932
3933                if (diff_filespec_is_binary(p->one) ||
3934                    diff_filespec_is_binary(p->two)) {
3935                        git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
3936                        git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
3937                        continue;
3938                }
3939
3940                xpp.flags = 0;
3941                xecfg.ctxlen = 3;
3942                xecfg.flags = 0;
3943                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
3944                              &xpp, &xecfg);
3945        }
3946
3947        git_SHA1_Final(sha1, &ctx);
3948        return 0;
3949}
3950
3951int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
3952{
3953        struct diff_queue_struct *q = &diff_queued_diff;
3954        int i;
3955        int result = diff_get_patch_id(options, sha1);
3956
3957        for (i = 0; i < q->nr; i++)
3958                diff_free_filepair(q->queue[i]);
3959
3960        free(q->queue);
3961        DIFF_QUEUE_CLEAR(q);
3962
3963        return result;
3964}
3965
3966static int is_summary_empty(const struct diff_queue_struct *q)
3967{
3968        int i;
3969
3970        for (i = 0; i < q->nr; i++) {
3971                const struct diff_filepair *p = q->queue[i];
3972
3973                switch (p->status) {
3974                case DIFF_STATUS_DELETED:
3975                case DIFF_STATUS_ADDED:
3976                case DIFF_STATUS_COPIED:
3977                case DIFF_STATUS_RENAMED:
3978                        return 0;
3979                default:
3980                        if (p->score)
3981                                return 0;
3982                        if (p->one->mode && p->two->mode &&
3983                            p->one->mode != p->two->mode)
3984                                return 0;
3985                        break;
3986                }
3987        }
3988        return 1;
3989}
3990
3991void diff_flush(struct diff_options *options)
3992{
3993        struct diff_queue_struct *q = &diff_queued_diff;
3994        int i, output_format = options->output_format;
3995        int separator = 0;
3996
3997        /*
3998         * Order: raw, stat, summary, patch
3999         * or:    name/name-status/checkdiff (other bits clear)
4000         */
4001        if (!q->nr)
4002                goto free_queue;
4003
4004        if (output_format & (DIFF_FORMAT_RAW |
4005                             DIFF_FORMAT_NAME |
4006                             DIFF_FORMAT_NAME_STATUS |
4007                             DIFF_FORMAT_CHECKDIFF)) {
4008                for (i = 0; i < q->nr; i++) {
4009                        struct diff_filepair *p = q->queue[i];
4010                        if (check_pair_status(p))
4011                                flush_one_pair(p, options);
4012                }
4013                separator++;
4014        }
4015
4016        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
4017                struct diffstat_t diffstat;
4018
4019                memset(&diffstat, 0, sizeof(struct diffstat_t));
4020                for (i = 0; i < q->nr; i++) {
4021                        struct diff_filepair *p = q->queue[i];
4022                        if (check_pair_status(p))
4023                                diff_flush_stat(p, options, &diffstat);
4024                }
4025                if (output_format & DIFF_FORMAT_NUMSTAT)
4026                        show_numstat(&diffstat, options);
4027                if (output_format & DIFF_FORMAT_DIFFSTAT)
4028                        show_stats(&diffstat, options);
4029                if (output_format & DIFF_FORMAT_SHORTSTAT)
4030                        show_shortstats(&diffstat, options);
4031                free_diffstat_info(&diffstat);
4032                separator++;
4033        }
4034        if (output_format & DIFF_FORMAT_DIRSTAT)
4035                show_dirstat(options);
4036
4037        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4038                for (i = 0; i < q->nr; i++) {
4039                        diff_summary(options, q->queue[i]);
4040                }
4041                separator++;
4042        }
4043
4044        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4045            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4046            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4047                /*
4048                 * run diff_flush_patch for the exit status. setting
4049                 * options->file to /dev/null should be safe, becaue we
4050                 * aren't supposed to produce any output anyway.
4051                 */
4052                if (options->close_file)
4053                        fclose(options->file);
4054                options->file = fopen("/dev/null", "w");
4055                if (!options->file)
4056                        die_errno("Could not open /dev/null");
4057                options->close_file = 1;
4058                for (i = 0; i < q->nr; i++) {
4059                        struct diff_filepair *p = q->queue[i];
4060                        if (check_pair_status(p))
4061                                diff_flush_patch(p, options);
4062                        if (options->found_changes)
4063                                break;
4064                }
4065        }
4066
4067        if (output_format & DIFF_FORMAT_PATCH) {
4068                if (separator) {
4069                        putc(options->line_termination, options->file);
4070                        if (options->stat_sep) {
4071                                /* attach patch instead of inline */
4072                                fputs(options->stat_sep, options->file);
4073                        }
4074                }
4075
4076                for (i = 0; i < q->nr; i++) {
4077                        struct diff_filepair *p = q->queue[i];
4078                        if (check_pair_status(p))
4079                                diff_flush_patch(p, options);
4080                }
4081        }
4082
4083        if (output_format & DIFF_FORMAT_CALLBACK)
4084                options->format_callback(q, options, options->format_callback_data);
4085
4086        for (i = 0; i < q->nr; i++)
4087                diff_free_filepair(q->queue[i]);
4088free_queue:
4089        free(q->queue);
4090        DIFF_QUEUE_CLEAR(q);
4091        if (options->close_file)
4092                fclose(options->file);
4093
4094        /*
4095         * Report the content-level differences with HAS_CHANGES;
4096         * diff_addremove/diff_change does not set the bit when
4097         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4098         */
4099        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4100                if (options->found_changes)
4101                        DIFF_OPT_SET(options, HAS_CHANGES);
4102                else
4103                        DIFF_OPT_CLR(options, HAS_CHANGES);
4104        }
4105}
4106
4107static void diffcore_apply_filter(const char *filter)
4108{
4109        int i;
4110        struct diff_queue_struct *q = &diff_queued_diff;
4111        struct diff_queue_struct outq;
4112        DIFF_QUEUE_CLEAR(&outq);
4113
4114        if (!filter)
4115                return;
4116
4117        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
4118                int found;
4119                for (i = found = 0; !found && i < q->nr; i++) {
4120                        struct diff_filepair *p = q->queue[i];
4121                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4122                             ((p->score &&
4123                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4124                              (!p->score &&
4125                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4126                            ((p->status != DIFF_STATUS_MODIFIED) &&
4127                             strchr(filter, p->status)))
4128                                found++;
4129                }
4130                if (found)
4131                        return;
4132
4133                /* otherwise we will clear the whole queue
4134                 * by copying the empty outq at the end of this
4135                 * function, but first clear the current entries
4136                 * in the queue.
4137                 */
4138                for (i = 0; i < q->nr; i++)
4139                        diff_free_filepair(q->queue[i]);
4140        }
4141        else {
4142                /* Only the matching ones */
4143                for (i = 0; i < q->nr; i++) {
4144                        struct diff_filepair *p = q->queue[i];
4145
4146                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4147                             ((p->score &&
4148                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4149                              (!p->score &&
4150                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4151                            ((p->status != DIFF_STATUS_MODIFIED) &&
4152                             strchr(filter, p->status)))
4153                                diff_q(&outq, p);
4154                        else
4155                                diff_free_filepair(p);
4156                }
4157        }
4158        free(q->queue);
4159        *q = outq;
4160}
4161
4162/* Check whether two filespecs with the same mode and size are identical */
4163static int diff_filespec_is_identical(struct diff_filespec *one,
4164                                      struct diff_filespec *two)
4165{
4166        if (S_ISGITLINK(one->mode))
4167                return 0;
4168        if (diff_populate_filespec(one, 0))
4169                return 0;
4170        if (diff_populate_filespec(two, 0))
4171                return 0;
4172        return !memcmp(one->data, two->data, one->size);
4173}
4174
4175static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4176{
4177        int i;
4178        struct diff_queue_struct *q = &diff_queued_diff;
4179        struct diff_queue_struct outq;
4180        DIFF_QUEUE_CLEAR(&outq);
4181
4182        for (i = 0; i < q->nr; i++) {
4183                struct diff_filepair *p = q->queue[i];
4184
4185                /*
4186                 * 1. Entries that come from stat info dirtiness
4187                 *    always have both sides (iow, not create/delete),
4188                 *    one side of the object name is unknown, with
4189                 *    the same mode and size.  Keep the ones that
4190                 *    do not match these criteria.  They have real
4191                 *    differences.
4192                 *
4193                 * 2. At this point, the file is known to be modified,
4194                 *    with the same mode and size, and the object
4195                 *    name of one side is unknown.  Need to inspect
4196                 *    the identical contents.
4197                 */
4198                if (!DIFF_FILE_VALID(p->one) || /* (1) */
4199                    !DIFF_FILE_VALID(p->two) ||
4200                    (p->one->sha1_valid && p->two->sha1_valid) ||
4201                    (p->one->mode != p->two->mode) ||
4202                    diff_populate_filespec(p->one, 1) ||
4203                    diff_populate_filespec(p->two, 1) ||
4204                    (p->one->size != p->two->size) ||
4205                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4206                        diff_q(&outq, p);
4207                else {
4208                        /*
4209                         * The caller can subtract 1 from skip_stat_unmatch
4210                         * to determine how many paths were dirty only
4211                         * due to stat info mismatch.
4212                         */
4213                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4214                                diffopt->skip_stat_unmatch++;
4215                        diff_free_filepair(p);
4216                }
4217        }
4218        free(q->queue);
4219        *q = outq;
4220}
4221
4222static int diffnamecmp(const void *a_, const void *b_)
4223{
4224        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4225        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4226        const char *name_a, *name_b;
4227
4228        name_a = a->one ? a->one->path : a->two->path;
4229        name_b = b->one ? b->one->path : b->two->path;
4230        return strcmp(name_a, name_b);
4231}
4232
4233void diffcore_fix_diff_index(struct diff_options *options)
4234{
4235        struct diff_queue_struct *q = &diff_queued_diff;
4236        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4237}
4238
4239void diffcore_std(struct diff_options *options)
4240{
4241        if (options->skip_stat_unmatch)
4242                diffcore_skip_stat_unmatch(options);
4243        if (!options->found_follow) {
4244                /* See try_to_follow_renames() in tree-diff.c */
4245                if (options->break_opt != -1)
4246                        diffcore_break(options->break_opt);
4247                if (options->detect_rename)
4248                        diffcore_rename(options);
4249                if (options->break_opt != -1)
4250                        diffcore_merge_broken();
4251        }
4252        if (options->pickaxe)
4253                diffcore_pickaxe(options);
4254        if (options->orderfile)
4255                diffcore_order(options->orderfile);
4256        if (!options->found_follow)
4257                /* See try_to_follow_renames() in tree-diff.c */
4258                diff_resolve_rename_copy();
4259        diffcore_apply_filter(options->filter);
4260
4261        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4262                DIFF_OPT_SET(options, HAS_CHANGES);
4263        else
4264                DIFF_OPT_CLR(options, HAS_CHANGES);
4265
4266        options->found_follow = 0;
4267}
4268
4269int diff_result_code(struct diff_options *opt, int status)
4270{
4271        int result = 0;
4272        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4273            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4274                return status;
4275        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4276            DIFF_OPT_TST(opt, HAS_CHANGES))
4277                result |= 01;
4278        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4279            DIFF_OPT_TST(opt, CHECK_FAILED))
4280                result |= 02;
4281        return result;
4282}
4283
4284/*
4285 * Shall changes to this submodule be ignored?
4286 *
4287 * Submodule changes can be configured to be ignored separately for each path,
4288 * but that configuration can be overridden from the command line.
4289 */
4290static int is_submodule_ignored(const char *path, struct diff_options *options)
4291{
4292        int ignored = 0;
4293        unsigned orig_flags = options->flags;
4294        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4295                set_diffopt_flags_from_submodule_config(options, path);
4296        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4297                ignored = 1;
4298        options->flags = orig_flags;
4299        return ignored;
4300}
4301
4302void diff_addremove(struct diff_options *options,
4303                    int addremove, unsigned mode,
4304                    const unsigned char *sha1,
4305                    const char *concatpath, unsigned dirty_submodule)
4306{
4307        struct diff_filespec *one, *two;
4308
4309        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4310                return;
4311
4312        /* This may look odd, but it is a preparation for
4313         * feeding "there are unchanged files which should
4314         * not produce diffs, but when you are doing copy
4315         * detection you would need them, so here they are"
4316         * entries to the diff-core.  They will be prefixed
4317         * with something like '=' or '*' (I haven't decided
4318         * which but should not make any difference).
4319         * Feeding the same new and old to diff_change()
4320         * also has the same effect.
4321         * Before the final output happens, they are pruned after
4322         * merged into rename/copy pairs as appropriate.
4323         */
4324        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4325                addremove = (addremove == '+' ? '-' :
4326                             addremove == '-' ? '+' : addremove);
4327
4328        if (options->prefix &&
4329            strncmp(concatpath, options->prefix, options->prefix_length))
4330                return;
4331
4332        one = alloc_filespec(concatpath);
4333        two = alloc_filespec(concatpath);
4334
4335        if (addremove != '+')
4336                fill_filespec(one, sha1, mode);
4337        if (addremove != '-') {
4338                fill_filespec(two, sha1, mode);
4339                two->dirty_submodule = dirty_submodule;
4340        }
4341
4342        diff_queue(&diff_queued_diff, one, two);
4343        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4344                DIFF_OPT_SET(options, HAS_CHANGES);
4345}
4346
4347void diff_change(struct diff_options *options,
4348                 unsigned old_mode, unsigned new_mode,
4349                 const unsigned char *old_sha1,
4350                 const unsigned char *new_sha1,
4351                 const char *concatpath,
4352                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4353{
4354        struct diff_filespec *one, *two;
4355
4356        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4357            is_submodule_ignored(concatpath, options))
4358                return;
4359
4360        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4361                unsigned tmp;
4362                const unsigned char *tmp_c;
4363                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4364                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4365                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4366                        new_dirty_submodule = tmp;
4367        }
4368
4369        if (options->prefix &&
4370            strncmp(concatpath, options->prefix, options->prefix_length))
4371                return;
4372
4373        one = alloc_filespec(concatpath);
4374        two = alloc_filespec(concatpath);
4375        fill_filespec(one, old_sha1, old_mode);
4376        fill_filespec(two, new_sha1, new_mode);
4377        one->dirty_submodule = old_dirty_submodule;
4378        two->dirty_submodule = new_dirty_submodule;
4379
4380        diff_queue(&diff_queued_diff, one, two);
4381        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4382                DIFF_OPT_SET(options, HAS_CHANGES);
4383}
4384
4385void diff_unmerge(struct diff_options *options,
4386                  const char *path,
4387                  unsigned mode, const unsigned char *sha1)
4388{
4389        struct diff_filespec *one, *two;
4390
4391        if (options->prefix &&
4392            strncmp(path, options->prefix, options->prefix_length))
4393                return;
4394
4395        one = alloc_filespec(path);
4396        two = alloc_filespec(path);
4397        fill_filespec(one, sha1, mode);
4398        diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;
4399}
4400
4401static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4402                size_t *outsize)
4403{
4404        struct diff_tempfile *temp;
4405        const char *argv[3];
4406        const char **arg = argv;
4407        struct child_process child;
4408        struct strbuf buf = STRBUF_INIT;
4409        int err = 0;
4410
4411        temp = prepare_temp_file(spec->path, spec);
4412        *arg++ = pgm;
4413        *arg++ = temp->name;
4414        *arg = NULL;
4415
4416        memset(&child, 0, sizeof(child));
4417        child.use_shell = 1;
4418        child.argv = argv;
4419        child.out = -1;
4420        if (start_command(&child)) {
4421                remove_tempfile();
4422                return NULL;
4423        }
4424
4425        if (strbuf_read(&buf, child.out, 0) < 0)
4426                err = error("error reading from textconv command '%s'", pgm);
4427        close(child.out);
4428
4429        if (finish_command(&child) || err) {
4430                strbuf_release(&buf);
4431                remove_tempfile();
4432                return NULL;
4433        }
4434        remove_tempfile();
4435
4436        return strbuf_detach(&buf, outsize);
4437}
4438
4439size_t fill_textconv(struct userdiff_driver *driver,
4440                     struct diff_filespec *df,
4441                     char **outbuf)
4442{
4443        size_t size;
4444
4445        if (!driver || !driver->textconv) {
4446                if (!DIFF_FILE_VALID(df)) {
4447                        *outbuf = "";
4448                        return 0;
4449                }
4450                if (diff_populate_filespec(df, 0))
4451                        die("unable to read files to diff");
4452                *outbuf = df->data;
4453                return df->size;
4454        }
4455
4456        if (driver->textconv_cache && df->sha1_valid) {
4457                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4458                                          &size);
4459                if (*outbuf)
4460                        return size;
4461        }
4462
4463        *outbuf = run_textconv(driver->textconv, df, &size);
4464        if (!*outbuf)
4465                die("unable to read files to diff");
4466
4467        if (driver->textconv_cache && df->sha1_valid) {
4468                /* ignore errors, as we might be in a readonly repository */
4469                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4470                                size);
4471                /*
4472                 * we could save up changes and flush them all at the end,
4473                 * but we would need an extra call after all diffing is done.
4474                 * Since generating a cache entry is the slow path anyway,
4475                 * this extra overhead probably isn't a big deal.
4476                 */
4477                notes_cache_write(driver->textconv_cache);
4478        }
4479
4480        return size;
4481}