diff.con commit Merge branch 'jh/dirstat' (d98a509)
   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 = 400;
  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
 631static struct 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, *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        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1273        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1274
1275        for (i = 0; i < data->nr; i++) {
1276                struct diffstat_file *file = data->files[i];
1277                uintmax_t change = file->added + file->deleted;
1278                fill_print_name(file);
1279                len = strlen(file->print_name);
1280                if (max_len < len)
1281                        max_len = len;
1282
1283                if (file->is_binary || file->is_unmerged)
1284                        continue;
1285                if (max_change < change)
1286                        max_change = change;
1287        }
1288
1289        /* Compute the width of the graph part;
1290         * 10 is for one blank at the beginning of the line plus
1291         * " | count " between the name and the graph.
1292         *
1293         * From here on, name_width is the width of the name area,
1294         * and width is the width of the graph area.
1295         */
1296        name_width = (name_width < max_len) ? name_width : max_len;
1297        if (width < (name_width + 10) + max_change)
1298                width = width - (name_width + 10);
1299        else
1300                width = max_change;
1301
1302        for (i = 0; i < data->nr; i++) {
1303                const char *prefix = "";
1304                char *name = data->files[i]->print_name;
1305                uintmax_t added = data->files[i]->added;
1306                uintmax_t deleted = data->files[i]->deleted;
1307                int name_len;
1308
1309                /*
1310                 * "scale" the filename
1311                 */
1312                len = name_width;
1313                name_len = strlen(name);
1314                if (name_width < name_len) {
1315                        char *slash;
1316                        prefix = "...";
1317                        len -= 3;
1318                        name += name_len - len;
1319                        slash = strchr(name, '/');
1320                        if (slash)
1321                                name = slash;
1322                }
1323
1324                if (data->files[i]->is_binary) {
1325                        fprintf(options->file, "%s", line_prefix);
1326                        show_name(options->file, prefix, name, len);
1327                        fprintf(options->file, "  Bin ");
1328                        fprintf(options->file, "%s%"PRIuMAX"%s",
1329                                del_c, deleted, reset);
1330                        fprintf(options->file, " -> ");
1331                        fprintf(options->file, "%s%"PRIuMAX"%s",
1332                                add_c, added, reset);
1333                        fprintf(options->file, " bytes");
1334                        fprintf(options->file, "\n");
1335                        continue;
1336                }
1337                else if (data->files[i]->is_unmerged) {
1338                        fprintf(options->file, "%s", line_prefix);
1339                        show_name(options->file, prefix, name, len);
1340                        fprintf(options->file, "  Unmerged\n");
1341                        continue;
1342                }
1343                else if (!data->files[i]->is_renamed &&
1344                         (added + deleted == 0)) {
1345                        total_files--;
1346                        continue;
1347                }
1348
1349                /*
1350                 * scale the add/delete
1351                 */
1352                add = added;
1353                del = deleted;
1354                adds += add;
1355                dels += del;
1356
1357                if (width <= max_change) {
1358                        add = scale_linear(add, width, max_change);
1359                        del = scale_linear(del, width, max_change);
1360                }
1361                fprintf(options->file, "%s", line_prefix);
1362                show_name(options->file, prefix, name, len);
1363                fprintf(options->file, "%5"PRIuMAX"%s", added + deleted,
1364                                added + deleted ? " " : "");
1365                show_graph(options->file, '+', add, add_c, reset);
1366                show_graph(options->file, '-', del, del_c, reset);
1367                fprintf(options->file, "\n");
1368        }
1369        fprintf(options->file, "%s", line_prefix);
1370        fprintf(options->file,
1371               " %d files changed, %d insertions(+), %d deletions(-)\n",
1372               total_files, adds, dels);
1373}
1374
1375static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1376{
1377        int i, adds = 0, dels = 0, total_files = data->nr;
1378
1379        if (data->nr == 0)
1380                return;
1381
1382        for (i = 0; i < data->nr; i++) {
1383                if (!data->files[i]->is_binary &&
1384                    !data->files[i]->is_unmerged) {
1385                        int added = data->files[i]->added;
1386                        int deleted= data->files[i]->deleted;
1387                        if (!data->files[i]->is_renamed &&
1388                            (added + deleted == 0)) {
1389                                total_files--;
1390                        } else {
1391                                adds += added;
1392                                dels += deleted;
1393                        }
1394                }
1395        }
1396        if (options->output_prefix) {
1397                struct strbuf *msg = NULL;
1398                msg = options->output_prefix(options,
1399                                options->output_prefix_data);
1400                fprintf(options->file, "%s", msg->buf);
1401        }
1402        fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
1403               total_files, adds, dels);
1404}
1405
1406static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1407{
1408        int i;
1409
1410        if (data->nr == 0)
1411                return;
1412
1413        for (i = 0; i < data->nr; i++) {
1414                struct diffstat_file *file = data->files[i];
1415
1416                if (options->output_prefix) {
1417                        struct strbuf *msg = NULL;
1418                        msg = options->output_prefix(options,
1419                                        options->output_prefix_data);
1420                        fprintf(options->file, "%s", msg->buf);
1421                }
1422
1423                if (file->is_binary)
1424                        fprintf(options->file, "-\t-\t");
1425                else
1426                        fprintf(options->file,
1427                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1428                                file->added, file->deleted);
1429                if (options->line_termination) {
1430                        fill_print_name(file);
1431                        if (!file->is_renamed)
1432                                write_name_quoted(file->name, options->file,
1433                                                  options->line_termination);
1434                        else {
1435                                fputs(file->print_name, options->file);
1436                                putc(options->line_termination, options->file);
1437                        }
1438                } else {
1439                        if (file->is_renamed) {
1440                                putc('\0', options->file);
1441                                write_name_quoted(file->from_name, options->file, '\0');
1442                        }
1443                        write_name_quoted(file->name, options->file, '\0');
1444                }
1445        }
1446}
1447
1448struct dirstat_file {
1449        const char *name;
1450        unsigned long changed;
1451};
1452
1453struct dirstat_dir {
1454        struct dirstat_file *files;
1455        int alloc, nr, percent, cumulative;
1456};
1457
1458static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1459                unsigned long changed, const char *base, int baselen)
1460{
1461        unsigned long this_dir = 0;
1462        unsigned int sources = 0;
1463        const char *line_prefix = "";
1464        struct strbuf *msg = NULL;
1465
1466        if (opt->output_prefix) {
1467                msg = opt->output_prefix(opt, opt->output_prefix_data);
1468                line_prefix = msg->buf;
1469        }
1470
1471        while (dir->nr) {
1472                struct dirstat_file *f = dir->files;
1473                int namelen = strlen(f->name);
1474                unsigned long this;
1475                char *slash;
1476
1477                if (namelen < baselen)
1478                        break;
1479                if (memcmp(f->name, base, baselen))
1480                        break;
1481                slash = strchr(f->name + baselen, '/');
1482                if (slash) {
1483                        int newbaselen = slash + 1 - f->name;
1484                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1485                        sources++;
1486                } else {
1487                        this = f->changed;
1488                        dir->files++;
1489                        dir->nr--;
1490                        sources += 2;
1491                }
1492                this_dir += this;
1493        }
1494
1495        /*
1496         * We don't report dirstat's for
1497         *  - the top level
1498         *  - or cases where everything came from a single directory
1499         *    under this directory (sources == 1).
1500         */
1501        if (baselen && sources != 1) {
1502                int permille = this_dir * 1000 / changed;
1503                if (permille) {
1504                        int percent = permille / 10;
1505                        if (percent >= dir->percent) {
1506                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1507                                        percent, permille % 10, baselen, base);
1508                                if (!dir->cumulative)
1509                                        return 0;
1510                        }
1511                }
1512        }
1513        return this_dir;
1514}
1515
1516static int dirstat_compare(const void *_a, const void *_b)
1517{
1518        const struct dirstat_file *a = _a;
1519        const struct dirstat_file *b = _b;
1520        return strcmp(a->name, b->name);
1521}
1522
1523static void show_dirstat(struct diff_options *options)
1524{
1525        int i;
1526        unsigned long changed;
1527        struct dirstat_dir dir;
1528        struct diff_queue_struct *q = &diff_queued_diff;
1529
1530        dir.files = NULL;
1531        dir.alloc = 0;
1532        dir.nr = 0;
1533        dir.percent = options->dirstat_percent;
1534        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1535
1536        changed = 0;
1537        for (i = 0; i < q->nr; i++) {
1538                struct diff_filepair *p = q->queue[i];
1539                const char *name;
1540                unsigned long copied, added, damage;
1541                int content_changed;
1542
1543                name = p->two->path ? p->two->path : p->one->path;
1544
1545                if (p->one->sha1_valid && p->two->sha1_valid)
1546                        content_changed = hashcmp(p->one->sha1, p->two->sha1);
1547                else
1548                        content_changed = 1;
1549
1550                if (!content_changed) {
1551                        /*
1552                         * The SHA1 has not changed, so pre-/post-content is
1553                         * identical. We can therefore skip looking at the
1554                         * file contents altogether.
1555                         */
1556                        damage = 0;
1557                        goto found_damage;
1558                }
1559
1560                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1561                        /*
1562                         * In --dirstat-by-file mode, we don't really need to
1563                         * look at the actual file contents at all.
1564                         * The fact that the SHA1 changed is enough for us to
1565                         * add this file to the list of results
1566                         * (with each file contributing equal damage).
1567                         */
1568                        damage = 1;
1569                        goto found_damage;
1570                }
1571
1572                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1573                        diff_populate_filespec(p->one, 0);
1574                        diff_populate_filespec(p->two, 0);
1575                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1576                                               &copied, &added);
1577                        diff_free_filespec_data(p->one);
1578                        diff_free_filespec_data(p->two);
1579                } else if (DIFF_FILE_VALID(p->one)) {
1580                        diff_populate_filespec(p->one, 1);
1581                        copied = added = 0;
1582                        diff_free_filespec_data(p->one);
1583                } else if (DIFF_FILE_VALID(p->two)) {
1584                        diff_populate_filespec(p->two, 1);
1585                        copied = 0;
1586                        added = p->two->size;
1587                        diff_free_filespec_data(p->two);
1588                } else
1589                        continue;
1590
1591                /*
1592                 * Original minus copied is the removed material,
1593                 * added is the new material.  They are both damages
1594                 * made to the preimage.
1595                 * If the resulting damage is zero, we know that
1596                 * diffcore_count_changes() considers the two entries to
1597                 * be identical, but since content_changed is true, we
1598                 * know that there must have been _some_ kind of change,
1599                 * so we force all entries to have damage > 0.
1600                 */
1601                damage = (p->one->size - copied) + added;
1602                if (!damage)
1603                        damage = 1;
1604
1605found_damage:
1606                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1607                dir.files[dir.nr].name = name;
1608                dir.files[dir.nr].changed = damage;
1609                changed += damage;
1610                dir.nr++;
1611        }
1612
1613        /* This can happen even with many files, if everything was renames */
1614        if (!changed)
1615                return;
1616
1617        /* Show all directories with more than x% of the changes */
1618        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1619        gather_dirstat(options, &dir, changed, "", 0);
1620}
1621
1622static void free_diffstat_info(struct diffstat_t *diffstat)
1623{
1624        int i;
1625        for (i = 0; i < diffstat->nr; i++) {
1626                struct diffstat_file *f = diffstat->files[i];
1627                if (f->name != f->print_name)
1628                        free(f->print_name);
1629                free(f->name);
1630                free(f->from_name);
1631                free(f);
1632        }
1633        free(diffstat->files);
1634}
1635
1636struct checkdiff_t {
1637        const char *filename;
1638        int lineno;
1639        int conflict_marker_size;
1640        struct diff_options *o;
1641        unsigned ws_rule;
1642        unsigned status;
1643};
1644
1645static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1646{
1647        char firstchar;
1648        int cnt;
1649
1650        if (len < marker_size + 1)
1651                return 0;
1652        firstchar = line[0];
1653        switch (firstchar) {
1654        case '=': case '>': case '<': case '|':
1655                break;
1656        default:
1657                return 0;
1658        }
1659        for (cnt = 1; cnt < marker_size; cnt++)
1660                if (line[cnt] != firstchar)
1661                        return 0;
1662        /* line[1] thru line[marker_size-1] are same as firstchar */
1663        if (len < marker_size + 1 || !isspace(line[marker_size]))
1664                return 0;
1665        return 1;
1666}
1667
1668static void checkdiff_consume(void *priv, char *line, unsigned long len)
1669{
1670        struct checkdiff_t *data = priv;
1671        int color_diff = DIFF_OPT_TST(data->o, COLOR_DIFF);
1672        int marker_size = data->conflict_marker_size;
1673        const char *ws = diff_get_color(color_diff, DIFF_WHITESPACE);
1674        const char *reset = diff_get_color(color_diff, DIFF_RESET);
1675        const char *set = diff_get_color(color_diff, DIFF_FILE_NEW);
1676        char *err;
1677        char *line_prefix = "";
1678        struct strbuf *msgbuf;
1679
1680        assert(data->o);
1681        if (data->o->output_prefix) {
1682                msgbuf = data->o->output_prefix(data->o,
1683                        data->o->output_prefix_data);
1684                line_prefix = msgbuf->buf;
1685        }
1686
1687        if (line[0] == '+') {
1688                unsigned bad;
1689                data->lineno++;
1690                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
1691                        data->status |= 1;
1692                        fprintf(data->o->file,
1693                                "%s%s:%d: leftover conflict marker\n",
1694                                line_prefix, data->filename, data->lineno);
1695                }
1696                bad = ws_check(line + 1, len - 1, data->ws_rule);
1697                if (!bad)
1698                        return;
1699                data->status |= bad;
1700                err = whitespace_error_string(bad);
1701                fprintf(data->o->file, "%s%s:%d: %s.\n",
1702                        line_prefix, data->filename, data->lineno, err);
1703                free(err);
1704                emit_line(data->o, set, reset, line, 1);
1705                ws_check_emit(line + 1, len - 1, data->ws_rule,
1706                              data->o->file, set, reset, ws);
1707        } else if (line[0] == ' ') {
1708                data->lineno++;
1709        } else if (line[0] == '@') {
1710                char *plus = strchr(line, '+');
1711                if (plus)
1712                        data->lineno = strtol(plus, NULL, 10) - 1;
1713                else
1714                        die("invalid diff");
1715        }
1716}
1717
1718static unsigned char *deflate_it(char *data,
1719                                 unsigned long size,
1720                                 unsigned long *result_size)
1721{
1722        int bound;
1723        unsigned char *deflated;
1724        z_stream stream;
1725
1726        memset(&stream, 0, sizeof(stream));
1727        deflateInit(&stream, zlib_compression_level);
1728        bound = deflateBound(&stream, size);
1729        deflated = xmalloc(bound);
1730        stream.next_out = deflated;
1731        stream.avail_out = bound;
1732
1733        stream.next_in = (unsigned char *)data;
1734        stream.avail_in = size;
1735        while (deflate(&stream, Z_FINISH) == Z_OK)
1736                ; /* nothing */
1737        deflateEnd(&stream);
1738        *result_size = stream.total_out;
1739        return deflated;
1740}
1741
1742static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1743{
1744        void *cp;
1745        void *delta;
1746        void *deflated;
1747        void *data;
1748        unsigned long orig_size;
1749        unsigned long delta_size;
1750        unsigned long deflate_size;
1751        unsigned long data_size;
1752
1753        /* We could do deflated delta, or we could do just deflated two,
1754         * whichever is smaller.
1755         */
1756        delta = NULL;
1757        deflated = deflate_it(two->ptr, two->size, &deflate_size);
1758        if (one->size && two->size) {
1759                delta = diff_delta(one->ptr, one->size,
1760                                   two->ptr, two->size,
1761                                   &delta_size, deflate_size);
1762                if (delta) {
1763                        void *to_free = delta;
1764                        orig_size = delta_size;
1765                        delta = deflate_it(delta, delta_size, &delta_size);
1766                        free(to_free);
1767                }
1768        }
1769
1770        if (delta && delta_size < deflate_size) {
1771                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
1772                free(deflated);
1773                data = delta;
1774                data_size = delta_size;
1775        }
1776        else {
1777                fprintf(file, "%sliteral %lu\n", prefix, two->size);
1778                free(delta);
1779                data = deflated;
1780                data_size = deflate_size;
1781        }
1782
1783        /* emit data encoded in base85 */
1784        cp = data;
1785        while (data_size) {
1786                int bytes = (52 < data_size) ? 52 : data_size;
1787                char line[70];
1788                data_size -= bytes;
1789                if (bytes <= 26)
1790                        line[0] = bytes + 'A' - 1;
1791                else
1792                        line[0] = bytes - 26 + 'a' - 1;
1793                encode_85(line + 1, cp, bytes);
1794                cp = (char *) cp + bytes;
1795                fprintf(file, "%s", prefix);
1796                fputs(line, file);
1797                fputc('\n', file);
1798        }
1799        fprintf(file, "%s\n", prefix);
1800        free(data);
1801}
1802
1803static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1804{
1805        fprintf(file, "%sGIT binary patch\n", prefix);
1806        emit_binary_diff_body(file, one, two, prefix);
1807        emit_binary_diff_body(file, two, one, prefix);
1808}
1809
1810static void diff_filespec_load_driver(struct diff_filespec *one)
1811{
1812        /* Use already-loaded driver */
1813        if (one->driver)
1814                return;
1815
1816        if (S_ISREG(one->mode))
1817                one->driver = userdiff_find_by_path(one->path);
1818
1819        /* Fallback to default settings */
1820        if (!one->driver)
1821                one->driver = userdiff_find_by_name("default");
1822}
1823
1824int diff_filespec_is_binary(struct diff_filespec *one)
1825{
1826        if (one->is_binary == -1) {
1827                diff_filespec_load_driver(one);
1828                if (one->driver->binary != -1)
1829                        one->is_binary = one->driver->binary;
1830                else {
1831                        if (!one->data && DIFF_FILE_VALID(one))
1832                                diff_populate_filespec(one, 0);
1833                        if (one->data)
1834                                one->is_binary = buffer_is_binary(one->data,
1835                                                one->size);
1836                        if (one->is_binary == -1)
1837                                one->is_binary = 0;
1838                }
1839        }
1840        return one->is_binary;
1841}
1842
1843static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
1844{
1845        diff_filespec_load_driver(one);
1846        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
1847}
1848
1849static const char *userdiff_word_regex(struct diff_filespec *one)
1850{
1851        diff_filespec_load_driver(one);
1852        return one->driver->word_regex;
1853}
1854
1855void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
1856{
1857        if (!options->a_prefix)
1858                options->a_prefix = a;
1859        if (!options->b_prefix)
1860                options->b_prefix = b;
1861}
1862
1863struct userdiff_driver *get_textconv(struct diff_filespec *one)
1864{
1865        if (!DIFF_FILE_VALID(one))
1866                return NULL;
1867
1868        diff_filespec_load_driver(one);
1869        if (!one->driver->textconv)
1870                return NULL;
1871
1872        if (one->driver->textconv_want_cache && !one->driver->textconv_cache) {
1873                struct notes_cache *c = xmalloc(sizeof(*c));
1874                struct strbuf name = STRBUF_INIT;
1875
1876                strbuf_addf(&name, "textconv/%s", one->driver->name);
1877                notes_cache_init(c, name.buf, one->driver->textconv);
1878                one->driver->textconv_cache = c;
1879        }
1880
1881        return one->driver;
1882}
1883
1884static void builtin_diff(const char *name_a,
1885                         const char *name_b,
1886                         struct diff_filespec *one,
1887                         struct diff_filespec *two,
1888                         const char *xfrm_msg,
1889                         int must_show_header,
1890                         struct diff_options *o,
1891                         int complete_rewrite)
1892{
1893        mmfile_t mf1, mf2;
1894        const char *lbl[2];
1895        char *a_one, *b_two;
1896        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1897        const char *reset = diff_get_color_opt(o, DIFF_RESET);
1898        const char *a_prefix, *b_prefix;
1899        struct userdiff_driver *textconv_one = NULL;
1900        struct userdiff_driver *textconv_two = NULL;
1901        struct strbuf header = STRBUF_INIT;
1902        struct strbuf *msgbuf;
1903        char *line_prefix = "";
1904
1905        if (o->output_prefix) {
1906                msgbuf = o->output_prefix(o, o->output_prefix_data);
1907                line_prefix = msgbuf->buf;
1908        }
1909
1910        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
1911                        (!one->mode || S_ISGITLINK(one->mode)) &&
1912                        (!two->mode || S_ISGITLINK(two->mode))) {
1913                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
1914                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
1915                show_submodule_summary(o->file, one ? one->path : two->path,
1916                                one->sha1, two->sha1, two->dirty_submodule,
1917                                del, add, reset);
1918                return;
1919        }
1920
1921        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
1922                textconv_one = get_textconv(one);
1923                textconv_two = get_textconv(two);
1924        }
1925
1926        diff_set_mnemonic_prefix(o, "a/", "b/");
1927        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
1928                a_prefix = o->b_prefix;
1929                b_prefix = o->a_prefix;
1930        } else {
1931                a_prefix = o->a_prefix;
1932                b_prefix = o->b_prefix;
1933        }
1934
1935        /* Never use a non-valid filename anywhere if at all possible */
1936        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
1937        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
1938
1939        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
1940        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
1941        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1942        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1943        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
1944        if (lbl[0][0] == '/') {
1945                /* /dev/null */
1946                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
1947                if (xfrm_msg)
1948                        strbuf_addstr(&header, xfrm_msg);
1949                must_show_header = 1;
1950        }
1951        else if (lbl[1][0] == '/') {
1952                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
1953                if (xfrm_msg)
1954                        strbuf_addstr(&header, xfrm_msg);
1955                must_show_header = 1;
1956        }
1957        else {
1958                if (one->mode != two->mode) {
1959                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
1960                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
1961                        must_show_header = 1;
1962                }
1963                if (xfrm_msg)
1964                        strbuf_addstr(&header, xfrm_msg);
1965
1966                /*
1967                 * we do not run diff between different kind
1968                 * of objects.
1969                 */
1970                if ((one->mode ^ two->mode) & S_IFMT)
1971                        goto free_ab_and_return;
1972                if (complete_rewrite &&
1973                    (textconv_one || !diff_filespec_is_binary(one)) &&
1974                    (textconv_two || !diff_filespec_is_binary(two))) {
1975                        fprintf(o->file, "%s", header.buf);
1976                        strbuf_reset(&header);
1977                        emit_rewrite_diff(name_a, name_b, one, two,
1978                                                textconv_one, textconv_two, o);
1979                        o->found_changes = 1;
1980                        goto free_ab_and_return;
1981                }
1982        }
1983
1984        if (!DIFF_OPT_TST(o, TEXT) &&
1985            ( (!textconv_one && diff_filespec_is_binary(one)) ||
1986              (!textconv_two && diff_filespec_is_binary(two)) )) {
1987                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1988                        die("unable to read files to diff");
1989                /* Quite common confusing case */
1990                if (mf1.size == mf2.size &&
1991                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
1992                        if (must_show_header)
1993                                fprintf(o->file, "%s", header.buf);
1994                        goto free_ab_and_return;
1995                }
1996                fprintf(o->file, "%s", header.buf);
1997                strbuf_reset(&header);
1998                if (DIFF_OPT_TST(o, BINARY))
1999                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2000                else
2001                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2002                                line_prefix, lbl[0], lbl[1]);
2003                o->found_changes = 1;
2004        }
2005        else {
2006                /* Crazy xdl interfaces.. */
2007                const char *diffopts = getenv("GIT_DIFF_OPTS");
2008                xpparam_t xpp;
2009                xdemitconf_t xecfg;
2010                struct emit_callback ecbdata;
2011                const struct userdiff_funcname *pe;
2012
2013                if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS) || must_show_header) {
2014                        fprintf(o->file, "%s", header.buf);
2015                        strbuf_reset(&header);
2016                }
2017
2018                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2019                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2020
2021                pe = diff_funcname_pattern(one);
2022                if (!pe)
2023                        pe = diff_funcname_pattern(two);
2024
2025                memset(&xpp, 0, sizeof(xpp));
2026                memset(&xecfg, 0, sizeof(xecfg));
2027                memset(&ecbdata, 0, sizeof(ecbdata));
2028                ecbdata.label_path = lbl;
2029                ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
2030                ecbdata.found_changesp = &o->found_changes;
2031                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
2032                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2033                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2034                ecbdata.opt = o;
2035                ecbdata.header = header.len ? &header : NULL;
2036                xpp.flags = o->xdl_opts;
2037                xecfg.ctxlen = o->context;
2038                xecfg.interhunkctxlen = o->interhunkcontext;
2039                xecfg.flags = XDL_EMIT_FUNCNAMES;
2040                if (pe)
2041                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2042                if (!diffopts)
2043                        ;
2044                else if (!prefixcmp(diffopts, "--unified="))
2045                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2046                else if (!prefixcmp(diffopts, "-u"))
2047                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2048                if (o->word_diff) {
2049                        int i;
2050
2051                        ecbdata.diff_words =
2052                                xcalloc(1, sizeof(struct diff_words_data));
2053                        ecbdata.diff_words->type = o->word_diff;
2054                        ecbdata.diff_words->opt = o;
2055                        if (!o->word_regex)
2056                                o->word_regex = userdiff_word_regex(one);
2057                        if (!o->word_regex)
2058                                o->word_regex = userdiff_word_regex(two);
2059                        if (!o->word_regex)
2060                                o->word_regex = diff_word_regex_cfg;
2061                        if (o->word_regex) {
2062                                ecbdata.diff_words->word_regex = (regex_t *)
2063                                        xmalloc(sizeof(regex_t));
2064                                if (regcomp(ecbdata.diff_words->word_regex,
2065                                                o->word_regex,
2066                                                REG_EXTENDED | REG_NEWLINE))
2067                                        die ("Invalid regular expression: %s",
2068                                                        o->word_regex);
2069                        }
2070                        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2071                                if (o->word_diff == diff_words_styles[i].type) {
2072                                        ecbdata.diff_words->style =
2073                                                &diff_words_styles[i];
2074                                        break;
2075                                }
2076                        }
2077                        if (DIFF_OPT_TST(o, COLOR_DIFF)) {
2078                                struct diff_words_style *st = ecbdata.diff_words->style;
2079                                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2080                                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2081                                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
2082                        }
2083                }
2084                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2085                              &xpp, &xecfg);
2086                if (o->word_diff)
2087                        free_diff_words_data(&ecbdata);
2088                if (textconv_one)
2089                        free(mf1.ptr);
2090                if (textconv_two)
2091                        free(mf2.ptr);
2092                xdiff_clear_find_func(&xecfg);
2093        }
2094
2095 free_ab_and_return:
2096        strbuf_release(&header);
2097        diff_free_filespec_data(one);
2098        diff_free_filespec_data(two);
2099        free(a_one);
2100        free(b_two);
2101        return;
2102}
2103
2104static void builtin_diffstat(const char *name_a, const char *name_b,
2105                             struct diff_filespec *one,
2106                             struct diff_filespec *two,
2107                             struct diffstat_t *diffstat,
2108                             struct diff_options *o,
2109                             int complete_rewrite)
2110{
2111        mmfile_t mf1, mf2;
2112        struct diffstat_file *data;
2113
2114        data = diffstat_add(diffstat, name_a, name_b);
2115
2116        if (!one || !two) {
2117                data->is_unmerged = 1;
2118                return;
2119        }
2120
2121        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2122                data->is_binary = 1;
2123                data->added = diff_filespec_size(two);
2124                data->deleted = diff_filespec_size(one);
2125        }
2126
2127        else if (complete_rewrite) {
2128                diff_populate_filespec(one, 0);
2129                diff_populate_filespec(two, 0);
2130                data->deleted = count_lines(one->data, one->size);
2131                data->added = count_lines(two->data, two->size);
2132        }
2133
2134        else {
2135                /* Crazy xdl interfaces.. */
2136                xpparam_t xpp;
2137                xdemitconf_t xecfg;
2138
2139                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2140                        die("unable to read files to diff");
2141
2142                memset(&xpp, 0, sizeof(xpp));
2143                memset(&xecfg, 0, sizeof(xecfg));
2144                xpp.flags = o->xdl_opts;
2145                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2146                              &xpp, &xecfg);
2147        }
2148
2149        diff_free_filespec_data(one);
2150        diff_free_filespec_data(two);
2151}
2152
2153static void builtin_checkdiff(const char *name_a, const char *name_b,
2154                              const char *attr_path,
2155                              struct diff_filespec *one,
2156                              struct diff_filespec *two,
2157                              struct diff_options *o)
2158{
2159        mmfile_t mf1, mf2;
2160        struct checkdiff_t data;
2161
2162        if (!two)
2163                return;
2164
2165        memset(&data, 0, sizeof(data));
2166        data.filename = name_b ? name_b : name_a;
2167        data.lineno = 0;
2168        data.o = o;
2169        data.ws_rule = whitespace_rule(attr_path);
2170        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2171
2172        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2173                die("unable to read files to diff");
2174
2175        /*
2176         * All the other codepaths check both sides, but not checking
2177         * the "old" side here is deliberate.  We are checking the newly
2178         * introduced changes, and as long as the "new" side is text, we
2179         * can and should check what it introduces.
2180         */
2181        if (diff_filespec_is_binary(two))
2182                goto free_and_return;
2183        else {
2184                /* Crazy xdl interfaces.. */
2185                xpparam_t xpp;
2186                xdemitconf_t xecfg;
2187
2188                memset(&xpp, 0, sizeof(xpp));
2189                memset(&xecfg, 0, sizeof(xecfg));
2190                xecfg.ctxlen = 1; /* at least one context line */
2191                xpp.flags = 0;
2192                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2193                              &xpp, &xecfg);
2194
2195                if (data.ws_rule & WS_BLANK_AT_EOF) {
2196                        struct emit_callback ecbdata;
2197                        int blank_at_eof;
2198
2199                        ecbdata.ws_rule = data.ws_rule;
2200                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2201                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2202
2203                        if (blank_at_eof) {
2204                                static char *err;
2205                                if (!err)
2206                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2207                                fprintf(o->file, "%s:%d: %s.\n",
2208                                        data.filename, blank_at_eof, err);
2209                                data.status = 1; /* report errors */
2210                        }
2211                }
2212        }
2213 free_and_return:
2214        diff_free_filespec_data(one);
2215        diff_free_filespec_data(two);
2216        if (data.status)
2217                DIFF_OPT_SET(o, CHECK_FAILED);
2218}
2219
2220struct diff_filespec *alloc_filespec(const char *path)
2221{
2222        int namelen = strlen(path);
2223        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2224
2225        memset(spec, 0, sizeof(*spec));
2226        spec->path = (char *)(spec + 1);
2227        memcpy(spec->path, path, namelen+1);
2228        spec->count = 1;
2229        spec->is_binary = -1;
2230        return spec;
2231}
2232
2233void free_filespec(struct diff_filespec *spec)
2234{
2235        if (!--spec->count) {
2236                diff_free_filespec_data(spec);
2237                free(spec);
2238        }
2239}
2240
2241void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2242                   unsigned short mode)
2243{
2244        if (mode) {
2245                spec->mode = canon_mode(mode);
2246                hashcpy(spec->sha1, sha1);
2247                spec->sha1_valid = !is_null_sha1(sha1);
2248        }
2249}
2250
2251/*
2252 * Given a name and sha1 pair, if the index tells us the file in
2253 * the work tree has that object contents, return true, so that
2254 * prepare_temp_file() does not have to inflate and extract.
2255 */
2256static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2257{
2258        struct cache_entry *ce;
2259        struct stat st;
2260        int pos, len;
2261
2262        /*
2263         * We do not read the cache ourselves here, because the
2264         * benchmark with my previous version that always reads cache
2265         * shows that it makes things worse for diff-tree comparing
2266         * two linux-2.6 kernel trees in an already checked out work
2267         * tree.  This is because most diff-tree comparisons deal with
2268         * only a small number of files, while reading the cache is
2269         * expensive for a large project, and its cost outweighs the
2270         * savings we get by not inflating the object to a temporary
2271         * file.  Practically, this code only helps when we are used
2272         * by diff-cache --cached, which does read the cache before
2273         * calling us.
2274         */
2275        if (!active_cache)
2276                return 0;
2277
2278        /* We want to avoid the working directory if our caller
2279         * doesn't need the data in a normal file, this system
2280         * is rather slow with its stat/open/mmap/close syscalls,
2281         * and the object is contained in a pack file.  The pack
2282         * is probably already open and will be faster to obtain
2283         * the data through than the working directory.  Loose
2284         * objects however would tend to be slower as they need
2285         * to be individually opened and inflated.
2286         */
2287        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2288                return 0;
2289
2290        len = strlen(name);
2291        pos = cache_name_pos(name, len);
2292        if (pos < 0)
2293                return 0;
2294        ce = active_cache[pos];
2295
2296        /*
2297         * This is not the sha1 we are looking for, or
2298         * unreusable because it is not a regular file.
2299         */
2300        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2301                return 0;
2302
2303        /*
2304         * If ce is marked as "assume unchanged", there is no
2305         * guarantee that work tree matches what we are looking for.
2306         */
2307        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2308                return 0;
2309
2310        /*
2311         * If ce matches the file in the work tree, we can reuse it.
2312         */
2313        if (ce_uptodate(ce) ||
2314            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2315                return 1;
2316
2317        return 0;
2318}
2319
2320static int populate_from_stdin(struct diff_filespec *s)
2321{
2322        struct strbuf buf = STRBUF_INIT;
2323        size_t size = 0;
2324
2325        if (strbuf_read(&buf, 0, 0) < 0)
2326                return error("error while reading from stdin %s",
2327                                     strerror(errno));
2328
2329        s->should_munmap = 0;
2330        s->data = strbuf_detach(&buf, &size);
2331        s->size = size;
2332        s->should_free = 1;
2333        return 0;
2334}
2335
2336static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2337{
2338        int len;
2339        char *data = xmalloc(100), *dirty = "";
2340
2341        /* Are we looking at the work tree? */
2342        if (s->dirty_submodule)
2343                dirty = "-dirty";
2344
2345        len = snprintf(data, 100,
2346                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2347        s->data = data;
2348        s->size = len;
2349        s->should_free = 1;
2350        if (size_only) {
2351                s->data = NULL;
2352                free(data);
2353        }
2354        return 0;
2355}
2356
2357/*
2358 * While doing rename detection and pickaxe operation, we may need to
2359 * grab the data for the blob (or file) for our own in-core comparison.
2360 * diff_filespec has data and size fields for this purpose.
2361 */
2362int diff_populate_filespec(struct diff_filespec *s, int size_only)
2363{
2364        int err = 0;
2365        if (!DIFF_FILE_VALID(s))
2366                die("internal error: asking to populate invalid file.");
2367        if (S_ISDIR(s->mode))
2368                return -1;
2369
2370        if (s->data)
2371                return 0;
2372
2373        if (size_only && 0 < s->size)
2374                return 0;
2375
2376        if (S_ISGITLINK(s->mode))
2377                return diff_populate_gitlink(s, size_only);
2378
2379        if (!s->sha1_valid ||
2380            reuse_worktree_file(s->path, s->sha1, 0)) {
2381                struct strbuf buf = STRBUF_INIT;
2382                struct stat st;
2383                int fd;
2384
2385                if (!strcmp(s->path, "-"))
2386                        return populate_from_stdin(s);
2387
2388                if (lstat(s->path, &st) < 0) {
2389                        if (errno == ENOENT) {
2390                        err_empty:
2391                                err = -1;
2392                        empty:
2393                                s->data = (char *)"";
2394                                s->size = 0;
2395                                return err;
2396                        }
2397                }
2398                s->size = xsize_t(st.st_size);
2399                if (!s->size)
2400                        goto empty;
2401                if (S_ISLNK(st.st_mode)) {
2402                        struct strbuf sb = STRBUF_INIT;
2403
2404                        if (strbuf_readlink(&sb, s->path, s->size))
2405                                goto err_empty;
2406                        s->size = sb.len;
2407                        s->data = strbuf_detach(&sb, NULL);
2408                        s->should_free = 1;
2409                        return 0;
2410                }
2411                if (size_only)
2412                        return 0;
2413                fd = open(s->path, O_RDONLY);
2414                if (fd < 0)
2415                        goto err_empty;
2416                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2417                close(fd);
2418                s->should_munmap = 1;
2419
2420                /*
2421                 * Convert from working tree format to canonical git format
2422                 */
2423                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2424                        size_t size = 0;
2425                        munmap(s->data, s->size);
2426                        s->should_munmap = 0;
2427                        s->data = strbuf_detach(&buf, &size);
2428                        s->size = size;
2429                        s->should_free = 1;
2430                }
2431        }
2432        else {
2433                enum object_type type;
2434                if (size_only) {
2435                        type = sha1_object_info(s->sha1, &s->size);
2436                        if (type < 0)
2437                                die("unable to read %s", sha1_to_hex(s->sha1));
2438                } else {
2439                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2440                        if (!s->data)
2441                                die("unable to read %s", sha1_to_hex(s->sha1));
2442                        s->should_free = 1;
2443                }
2444        }
2445        return 0;
2446}
2447
2448void diff_free_filespec_blob(struct diff_filespec *s)
2449{
2450        if (s->should_free)
2451                free(s->data);
2452        else if (s->should_munmap)
2453                munmap(s->data, s->size);
2454
2455        if (s->should_free || s->should_munmap) {
2456                s->should_free = s->should_munmap = 0;
2457                s->data = NULL;
2458        }
2459}
2460
2461void diff_free_filespec_data(struct diff_filespec *s)
2462{
2463        diff_free_filespec_blob(s);
2464        free(s->cnt_data);
2465        s->cnt_data = NULL;
2466}
2467
2468static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2469                           void *blob,
2470                           unsigned long size,
2471                           const unsigned char *sha1,
2472                           int mode)
2473{
2474        int fd;
2475        struct strbuf buf = STRBUF_INIT;
2476        struct strbuf template = STRBUF_INIT;
2477        char *path_dup = xstrdup(path);
2478        const char *base = basename(path_dup);
2479
2480        /* Generate "XXXXXX_basename.ext" */
2481        strbuf_addstr(&template, "XXXXXX_");
2482        strbuf_addstr(&template, base);
2483
2484        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2485                        strlen(base) + 1);
2486        if (fd < 0)
2487                die_errno("unable to create temp-file");
2488        if (convert_to_working_tree(path,
2489                        (const char *)blob, (size_t)size, &buf)) {
2490                blob = buf.buf;
2491                size = buf.len;
2492        }
2493        if (write_in_full(fd, blob, size) != size)
2494                die_errno("unable to write temp-file");
2495        close(fd);
2496        temp->name = temp->tmp_path;
2497        strcpy(temp->hex, sha1_to_hex(sha1));
2498        temp->hex[40] = 0;
2499        sprintf(temp->mode, "%06o", mode);
2500        strbuf_release(&buf);
2501        strbuf_release(&template);
2502        free(path_dup);
2503}
2504
2505static struct diff_tempfile *prepare_temp_file(const char *name,
2506                struct diff_filespec *one)
2507{
2508        struct diff_tempfile *temp = claim_diff_tempfile();
2509
2510        if (!DIFF_FILE_VALID(one)) {
2511        not_a_valid_file:
2512                /* A '-' entry produces this for file-2, and
2513                 * a '+' entry produces this for file-1.
2514                 */
2515                temp->name = "/dev/null";
2516                strcpy(temp->hex, ".");
2517                strcpy(temp->mode, ".");
2518                return temp;
2519        }
2520
2521        if (!remove_tempfile_installed) {
2522                atexit(remove_tempfile);
2523                sigchain_push_common(remove_tempfile_on_signal);
2524                remove_tempfile_installed = 1;
2525        }
2526
2527        if (!one->sha1_valid ||
2528            reuse_worktree_file(name, one->sha1, 1)) {
2529                struct stat st;
2530                if (lstat(name, &st) < 0) {
2531                        if (errno == ENOENT)
2532                                goto not_a_valid_file;
2533                        die_errno("stat(%s)", name);
2534                }
2535                if (S_ISLNK(st.st_mode)) {
2536                        struct strbuf sb = STRBUF_INIT;
2537                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2538                                die_errno("readlink(%s)", name);
2539                        prep_temp_blob(name, temp, sb.buf, sb.len,
2540                                       (one->sha1_valid ?
2541                                        one->sha1 : null_sha1),
2542                                       (one->sha1_valid ?
2543                                        one->mode : S_IFLNK));
2544                        strbuf_release(&sb);
2545                }
2546                else {
2547                        /* we can borrow from the file in the work tree */
2548                        temp->name = name;
2549                        if (!one->sha1_valid)
2550                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2551                        else
2552                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2553                        /* Even though we may sometimes borrow the
2554                         * contents from the work tree, we always want
2555                         * one->mode.  mode is trustworthy even when
2556                         * !(one->sha1_valid), as long as
2557                         * DIFF_FILE_VALID(one).
2558                         */
2559                        sprintf(temp->mode, "%06o", one->mode);
2560                }
2561                return temp;
2562        }
2563        else {
2564                if (diff_populate_filespec(one, 0))
2565                        die("cannot read data blob for %s", one->path);
2566                prep_temp_blob(name, temp, one->data, one->size,
2567                               one->sha1, one->mode);
2568        }
2569        return temp;
2570}
2571
2572/* An external diff command takes:
2573 *
2574 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2575 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2576 *
2577 */
2578static void run_external_diff(const char *pgm,
2579                              const char *name,
2580                              const char *other,
2581                              struct diff_filespec *one,
2582                              struct diff_filespec *two,
2583                              const char *xfrm_msg,
2584                              int complete_rewrite)
2585{
2586        const char *spawn_arg[10];
2587        int retval;
2588        const char **arg = &spawn_arg[0];
2589
2590        if (one && two) {
2591                struct diff_tempfile *temp_one, *temp_two;
2592                const char *othername = (other ? other : name);
2593                temp_one = prepare_temp_file(name, one);
2594                temp_two = prepare_temp_file(othername, two);
2595                *arg++ = pgm;
2596                *arg++ = name;
2597                *arg++ = temp_one->name;
2598                *arg++ = temp_one->hex;
2599                *arg++ = temp_one->mode;
2600                *arg++ = temp_two->name;
2601                *arg++ = temp_two->hex;
2602                *arg++ = temp_two->mode;
2603                if (other) {
2604                        *arg++ = other;
2605                        *arg++ = xfrm_msg;
2606                }
2607        } else {
2608                *arg++ = pgm;
2609                *arg++ = name;
2610        }
2611        *arg = NULL;
2612        fflush(NULL);
2613        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2614        remove_tempfile();
2615        if (retval) {
2616                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2617                exit(1);
2618        }
2619}
2620
2621static int similarity_index(struct diff_filepair *p)
2622{
2623        return p->score * 100 / MAX_SCORE;
2624}
2625
2626static void fill_metainfo(struct strbuf *msg,
2627                          const char *name,
2628                          const char *other,
2629                          struct diff_filespec *one,
2630                          struct diff_filespec *two,
2631                          struct diff_options *o,
2632                          struct diff_filepair *p,
2633                          int *must_show_header,
2634                          int use_color)
2635{
2636        const char *set = diff_get_color(use_color, DIFF_METAINFO);
2637        const char *reset = diff_get_color(use_color, DIFF_RESET);
2638        struct strbuf *msgbuf;
2639        char *line_prefix = "";
2640
2641        *must_show_header = 1;
2642        if (o->output_prefix) {
2643                msgbuf = o->output_prefix(o, o->output_prefix_data);
2644                line_prefix = msgbuf->buf;
2645        }
2646        strbuf_init(msg, PATH_MAX * 2 + 300);
2647        switch (p->status) {
2648        case DIFF_STATUS_COPIED:
2649                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2650                            line_prefix, set, similarity_index(p));
2651                strbuf_addf(msg, "%s\n%s%scopy from ",
2652                            reset,  line_prefix, set);
2653                quote_c_style(name, msg, NULL, 0);
2654                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2655                quote_c_style(other, msg, NULL, 0);
2656                strbuf_addf(msg, "%s\n", reset);
2657                break;
2658        case DIFF_STATUS_RENAMED:
2659                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2660                            line_prefix, set, similarity_index(p));
2661                strbuf_addf(msg, "%s\n%s%srename from ",
2662                            reset, line_prefix, set);
2663                quote_c_style(name, msg, NULL, 0);
2664                strbuf_addf(msg, "%s\n%s%srename to ",
2665                            reset, line_prefix, set);
2666                quote_c_style(other, msg, NULL, 0);
2667                strbuf_addf(msg, "%s\n", reset);
2668                break;
2669        case DIFF_STATUS_MODIFIED:
2670                if (p->score) {
2671                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2672                                    line_prefix,
2673                                    set, similarity_index(p), reset);
2674                        break;
2675                }
2676                /* fallthru */
2677        default:
2678                *must_show_header = 0;
2679        }
2680        if (one && two && hashcmp(one->sha1, two->sha1)) {
2681                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2682
2683                if (DIFF_OPT_TST(o, BINARY)) {
2684                        mmfile_t mf;
2685                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2686                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2687                                abbrev = 40;
2688                }
2689                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2690                            find_unique_abbrev(one->sha1, abbrev));
2691                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2692                if (one->mode == two->mode)
2693                        strbuf_addf(msg, " %06o", one->mode);
2694                strbuf_addf(msg, "%s\n", reset);
2695        }
2696}
2697
2698static void run_diff_cmd(const char *pgm,
2699                         const char *name,
2700                         const char *other,
2701                         const char *attr_path,
2702                         struct diff_filespec *one,
2703                         struct diff_filespec *two,
2704                         struct strbuf *msg,
2705                         struct diff_options *o,
2706                         struct diff_filepair *p)
2707{
2708        const char *xfrm_msg = NULL;
2709        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2710        int must_show_header = 0;
2711
2712        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2713                pgm = NULL;
2714        else {
2715                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2716                if (drv && drv->external)
2717                        pgm = drv->external;
2718        }
2719
2720        if (msg) {
2721                /*
2722                 * don't use colors when the header is intended for an
2723                 * external diff driver
2724                 */
2725                fill_metainfo(msg, name, other, one, two, o, p,
2726                              &must_show_header,
2727                              DIFF_OPT_TST(o, COLOR_DIFF) && !pgm);
2728                xfrm_msg = msg->len ? msg->buf : NULL;
2729        }
2730
2731        if (pgm) {
2732                run_external_diff(pgm, name, other, one, two, xfrm_msg,
2733                                  complete_rewrite);
2734                return;
2735        }
2736        if (one && two)
2737                builtin_diff(name, other ? other : name,
2738                             one, two, xfrm_msg, must_show_header,
2739                             o, complete_rewrite);
2740        else
2741                fprintf(o->file, "* Unmerged path %s\n", name);
2742}
2743
2744static void diff_fill_sha1_info(struct diff_filespec *one)
2745{
2746        if (DIFF_FILE_VALID(one)) {
2747                if (!one->sha1_valid) {
2748                        struct stat st;
2749                        if (!strcmp(one->path, "-")) {
2750                                hashcpy(one->sha1, null_sha1);
2751                                return;
2752                        }
2753                        if (lstat(one->path, &st) < 0)
2754                                die_errno("stat '%s'", one->path);
2755                        if (index_path(one->sha1, one->path, &st, 0))
2756                                die("cannot hash %s", one->path);
2757                }
2758        }
2759        else
2760                hashclr(one->sha1);
2761}
2762
2763static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2764{
2765        /* Strip the prefix but do not molest /dev/null and absolute paths */
2766        if (*namep && **namep != '/') {
2767                *namep += prefix_length;
2768                if (**namep == '/')
2769                        ++*namep;
2770        }
2771        if (*otherp && **otherp != '/') {
2772                *otherp += prefix_length;
2773                if (**otherp == '/')
2774                        ++*otherp;
2775        }
2776}
2777
2778static void run_diff(struct diff_filepair *p, struct diff_options *o)
2779{
2780        const char *pgm = external_diff();
2781        struct strbuf msg;
2782        struct diff_filespec *one = p->one;
2783        struct diff_filespec *two = p->two;
2784        const char *name;
2785        const char *other;
2786        const char *attr_path;
2787
2788        name  = p->one->path;
2789        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2790        attr_path = name;
2791        if (o->prefix_length)
2792                strip_prefix(o->prefix_length, &name, &other);
2793
2794        if (DIFF_PAIR_UNMERGED(p)) {
2795                run_diff_cmd(pgm, name, NULL, attr_path,
2796                             NULL, NULL, NULL, o, p);
2797                return;
2798        }
2799
2800        diff_fill_sha1_info(one);
2801        diff_fill_sha1_info(two);
2802
2803        if (!pgm &&
2804            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2805            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2806                /*
2807                 * a filepair that changes between file and symlink
2808                 * needs to be split into deletion and creation.
2809                 */
2810                struct diff_filespec *null = alloc_filespec(two->path);
2811                run_diff_cmd(NULL, name, other, attr_path,
2812                             one, null, &msg, o, p);
2813                free(null);
2814                strbuf_release(&msg);
2815
2816                null = alloc_filespec(one->path);
2817                run_diff_cmd(NULL, name, other, attr_path,
2818                             null, two, &msg, o, p);
2819                free(null);
2820        }
2821        else
2822                run_diff_cmd(pgm, name, other, attr_path,
2823                             one, two, &msg, o, p);
2824
2825        strbuf_release(&msg);
2826}
2827
2828static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2829                         struct diffstat_t *diffstat)
2830{
2831        const char *name;
2832        const char *other;
2833        int complete_rewrite = 0;
2834
2835        if (DIFF_PAIR_UNMERGED(p)) {
2836                /* unmerged */
2837                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2838                return;
2839        }
2840
2841        name = p->one->path;
2842        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2843
2844        if (o->prefix_length)
2845                strip_prefix(o->prefix_length, &name, &other);
2846
2847        diff_fill_sha1_info(p->one);
2848        diff_fill_sha1_info(p->two);
2849
2850        if (p->status == DIFF_STATUS_MODIFIED && p->score)
2851                complete_rewrite = 1;
2852        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2853}
2854
2855static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2856{
2857        const char *name;
2858        const char *other;
2859        const char *attr_path;
2860
2861        if (DIFF_PAIR_UNMERGED(p)) {
2862                /* unmerged */
2863                return;
2864        }
2865
2866        name = p->one->path;
2867        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2868        attr_path = other ? other : name;
2869
2870        if (o->prefix_length)
2871                strip_prefix(o->prefix_length, &name, &other);
2872
2873        diff_fill_sha1_info(p->one);
2874        diff_fill_sha1_info(p->two);
2875
2876        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2877}
2878
2879void diff_setup(struct diff_options *options)
2880{
2881        memcpy(options, &default_diff_options, sizeof(*options));
2882
2883        options->file = stdout;
2884
2885        options->line_termination = '\n';
2886        options->break_opt = -1;
2887        options->rename_limit = -1;
2888        options->dirstat_percent = 3;
2889        options->context = 3;
2890
2891        options->change = diff_change;
2892        options->add_remove = diff_addremove;
2893        if (diff_use_color_default > 0)
2894                DIFF_OPT_SET(options, COLOR_DIFF);
2895        options->detect_rename = diff_detect_rename_default;
2896
2897        if (diff_no_prefix) {
2898                options->a_prefix = options->b_prefix = "";
2899        } else if (!diff_mnemonic_prefix) {
2900                options->a_prefix = "a/";
2901                options->b_prefix = "b/";
2902        }
2903}
2904
2905int diff_setup_done(struct diff_options *options)
2906{
2907        int count = 0;
2908
2909        if (options->output_format & DIFF_FORMAT_NAME)
2910                count++;
2911        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
2912                count++;
2913        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
2914                count++;
2915        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
2916                count++;
2917        if (count > 1)
2918                die("--name-only, --name-status, --check and -s are mutually exclusive");
2919
2920        /*
2921         * Most of the time we can say "there are changes"
2922         * only by checking if there are changed paths, but
2923         * --ignore-whitespace* options force us to look
2924         * inside contents.
2925         */
2926
2927        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
2928            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
2929            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
2930                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
2931        else
2932                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
2933
2934        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
2935                options->detect_rename = DIFF_DETECT_COPY;
2936
2937        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
2938                options->prefix = NULL;
2939        if (options->prefix)
2940                options->prefix_length = strlen(options->prefix);
2941        else
2942                options->prefix_length = 0;
2943
2944        if (options->output_format & (DIFF_FORMAT_NAME |
2945                                      DIFF_FORMAT_NAME_STATUS |
2946                                      DIFF_FORMAT_CHECKDIFF |
2947                                      DIFF_FORMAT_NO_OUTPUT))
2948                options->output_format &= ~(DIFF_FORMAT_RAW |
2949                                            DIFF_FORMAT_NUMSTAT |
2950                                            DIFF_FORMAT_DIFFSTAT |
2951                                            DIFF_FORMAT_SHORTSTAT |
2952                                            DIFF_FORMAT_DIRSTAT |
2953                                            DIFF_FORMAT_SUMMARY |
2954                                            DIFF_FORMAT_PATCH);
2955
2956        /*
2957         * These cases always need recursive; we do not drop caller-supplied
2958         * recursive bits for other formats here.
2959         */
2960        if (options->output_format & (DIFF_FORMAT_PATCH |
2961                                      DIFF_FORMAT_NUMSTAT |
2962                                      DIFF_FORMAT_DIFFSTAT |
2963                                      DIFF_FORMAT_SHORTSTAT |
2964                                      DIFF_FORMAT_DIRSTAT |
2965                                      DIFF_FORMAT_SUMMARY |
2966                                      DIFF_FORMAT_CHECKDIFF))
2967                DIFF_OPT_SET(options, RECURSIVE);
2968        /*
2969         * Also pickaxe would not work very well if you do not say recursive
2970         */
2971        if (options->pickaxe)
2972                DIFF_OPT_SET(options, RECURSIVE);
2973        /*
2974         * When patches are generated, submodules diffed against the work tree
2975         * must be checked for dirtiness too so it can be shown in the output
2976         */
2977        if (options->output_format & DIFF_FORMAT_PATCH)
2978                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
2979
2980        if (options->detect_rename && options->rename_limit < 0)
2981                options->rename_limit = diff_rename_limit_default;
2982        if (options->setup & DIFF_SETUP_USE_CACHE) {
2983                if (!active_cache)
2984                        /* read-cache does not die even when it fails
2985                         * so it is safe for us to do this here.  Also
2986                         * it does not smudge active_cache or active_nr
2987                         * when it fails, so we do not have to worry about
2988                         * cleaning it up ourselves either.
2989                         */
2990                        read_cache();
2991        }
2992        if (options->abbrev <= 0 || 40 < options->abbrev)
2993                options->abbrev = 40; /* full */
2994
2995        /*
2996         * It does not make sense to show the first hit we happened
2997         * to have found.  It does not make sense not to return with
2998         * exit code in such a case either.
2999         */
3000        if (DIFF_OPT_TST(options, QUICK)) {
3001                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3002                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3003        }
3004
3005        return 0;
3006}
3007
3008static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3009{
3010        char c, *eq;
3011        int len;
3012
3013        if (*arg != '-')
3014                return 0;
3015        c = *++arg;
3016        if (!c)
3017                return 0;
3018        if (c == arg_short) {
3019                c = *++arg;
3020                if (!c)
3021                        return 1;
3022                if (val && isdigit(c)) {
3023                        char *end;
3024                        int n = strtoul(arg, &end, 10);
3025                        if (*end)
3026                                return 0;
3027                        *val = n;
3028                        return 1;
3029                }
3030                return 0;
3031        }
3032        if (c != '-')
3033                return 0;
3034        arg++;
3035        eq = strchr(arg, '=');
3036        if (eq)
3037                len = eq - arg;
3038        else
3039                len = strlen(arg);
3040        if (!len || strncmp(arg, arg_long, len))
3041                return 0;
3042        if (eq) {
3043                int n;
3044                char *end;
3045                if (!isdigit(*++eq))
3046                        return 0;
3047                n = strtoul(eq, &end, 10);
3048                if (*end)
3049                        return 0;
3050                *val = n;
3051        }
3052        return 1;
3053}
3054
3055static int diff_scoreopt_parse(const char *opt);
3056
3057static inline int short_opt(char opt, const char **argv,
3058                            const char **optarg)
3059{
3060        const char *arg = argv[0];
3061        if (arg[0] != '-' || arg[1] != opt)
3062                return 0;
3063        if (arg[2] != '\0') {
3064                *optarg = arg + 2;
3065                return 1;
3066        }
3067        if (!argv[1])
3068                die("Option '%c' requires a value", opt);
3069        *optarg = argv[1];
3070        return 2;
3071}
3072
3073int parse_long_opt(const char *opt, const char **argv,
3074                   const char **optarg)
3075{
3076        const char *arg = argv[0];
3077        if (arg[0] != '-' || arg[1] != '-')
3078                return 0;
3079        arg += strlen("--");
3080        if (prefixcmp(arg, opt))
3081                return 0;
3082        arg += strlen(opt);
3083        if (*arg == '=') { /* sticked form: --option=value */
3084                *optarg = arg + 1;
3085                return 1;
3086        }
3087        if (*arg != '\0')
3088                return 0;
3089        /* separate form: --option value */
3090        if (!argv[1])
3091                die("Option '--%s' requires a value", opt);
3092        *optarg = argv[1];
3093        return 2;
3094}
3095
3096static int stat_opt(struct diff_options *options, const char **av)
3097{
3098        const char *arg = av[0];
3099        char *end;
3100        int width = options->stat_width;
3101        int name_width = options->stat_name_width;
3102        int argcount = 1;
3103
3104        arg += strlen("--stat");
3105        end = (char *)arg;
3106
3107        switch (*arg) {
3108        case '-':
3109                if (!prefixcmp(arg, "-width")) {
3110                        arg += strlen("-width");
3111                        if (*arg == '=')
3112                                width = strtoul(arg + 1, &end, 10);
3113                        else if (!*arg && !av[1])
3114                                die("Option '--stat-width' requires a value");
3115                        else if (!*arg) {
3116                                width = strtoul(av[1], &end, 10);
3117                                argcount = 2;
3118                        }
3119                } else if (!prefixcmp(arg, "-name-width")) {
3120                        arg += strlen("-name-width");
3121                        if (*arg == '=')
3122                                name_width = strtoul(arg + 1, &end, 10);
3123                        else if (!*arg && !av[1])
3124                                die("Option '--stat-name-width' requires a value");
3125                        else if (!*arg) {
3126                                name_width = strtoul(av[1], &end, 10);
3127                                argcount = 2;
3128                        }
3129                }
3130                break;
3131        case '=':
3132                width = strtoul(arg+1, &end, 10);
3133                if (*end == ',')
3134                        name_width = strtoul(end+1, &end, 10);
3135        }
3136
3137        /* Important! This checks all the error cases! */
3138        if (*end)
3139                return 0;
3140        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3141        options->stat_name_width = name_width;
3142        options->stat_width = width;
3143        return argcount;
3144}
3145
3146int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3147{
3148        const char *arg = av[0];
3149        const char *optarg;
3150        int argcount;
3151
3152        /* Output format options */
3153        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3154                options->output_format |= DIFF_FORMAT_PATCH;
3155        else if (opt_arg(arg, 'U', "unified", &options->context))
3156                options->output_format |= DIFF_FORMAT_PATCH;
3157        else if (!strcmp(arg, "--raw"))
3158                options->output_format |= DIFF_FORMAT_RAW;
3159        else if (!strcmp(arg, "--patch-with-raw"))
3160                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3161        else if (!strcmp(arg, "--numstat"))
3162                options->output_format |= DIFF_FORMAT_NUMSTAT;
3163        else if (!strcmp(arg, "--shortstat"))
3164                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3165        else if (opt_arg(arg, 'X', "dirstat", &options->dirstat_percent))
3166                options->output_format |= DIFF_FORMAT_DIRSTAT;
3167        else if (!strcmp(arg, "--cumulative")) {
3168                options->output_format |= DIFF_FORMAT_DIRSTAT;
3169                DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
3170        } else if (opt_arg(arg, 0, "dirstat-by-file",
3171                           &options->dirstat_percent)) {
3172                options->output_format |= DIFF_FORMAT_DIRSTAT;
3173                DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
3174        }
3175        else if (!strcmp(arg, "--check"))
3176                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3177        else if (!strcmp(arg, "--summary"))
3178                options->output_format |= DIFF_FORMAT_SUMMARY;
3179        else if (!strcmp(arg, "--patch-with-stat"))
3180                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3181        else if (!strcmp(arg, "--name-only"))
3182                options->output_format |= DIFF_FORMAT_NAME;
3183        else if (!strcmp(arg, "--name-status"))
3184                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3185        else if (!strcmp(arg, "-s"))
3186                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3187        else if (!prefixcmp(arg, "--stat"))
3188                /* --stat, --stat-width, or --stat-name-width */
3189                return stat_opt(options, av);
3190
3191        /* renames options */
3192        else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
3193                 !strcmp(arg, "--break-rewrites")) {
3194                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3195                        return error("invalid argument to -B: %s", arg+2);
3196        }
3197        else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--find-renames=") ||
3198                 !strcmp(arg, "--find-renames")) {
3199                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3200                        return error("invalid argument to -M: %s", arg+2);
3201                options->detect_rename = DIFF_DETECT_RENAME;
3202        }
3203        else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
3204                 !strcmp(arg, "--find-copies")) {
3205                if (options->detect_rename == DIFF_DETECT_COPY)
3206                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3207                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3208                        return error("invalid argument to -C: %s", arg+2);
3209                options->detect_rename = DIFF_DETECT_COPY;
3210        }
3211        else if (!strcmp(arg, "--no-renames"))
3212                options->detect_rename = 0;
3213        else if (!strcmp(arg, "--relative"))
3214                DIFF_OPT_SET(options, RELATIVE_NAME);
3215        else if (!prefixcmp(arg, "--relative=")) {
3216                DIFF_OPT_SET(options, RELATIVE_NAME);
3217                options->prefix = arg + 11;
3218        }
3219
3220        /* xdiff options */
3221        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3222                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3223        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3224                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3225        else if (!strcmp(arg, "--ignore-space-at-eol"))
3226                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3227        else if (!strcmp(arg, "--patience"))
3228                DIFF_XDL_SET(options, PATIENCE_DIFF);
3229
3230        /* flags options */
3231        else if (!strcmp(arg, "--binary")) {
3232                options->output_format |= DIFF_FORMAT_PATCH;
3233                DIFF_OPT_SET(options, BINARY);
3234        }
3235        else if (!strcmp(arg, "--full-index"))
3236                DIFF_OPT_SET(options, FULL_INDEX);
3237        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3238                DIFF_OPT_SET(options, TEXT);
3239        else if (!strcmp(arg, "-R"))
3240                DIFF_OPT_SET(options, REVERSE_DIFF);
3241        else if (!strcmp(arg, "--find-copies-harder"))
3242                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3243        else if (!strcmp(arg, "--follow"))
3244                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3245        else if (!strcmp(arg, "--color"))
3246                DIFF_OPT_SET(options, COLOR_DIFF);
3247        else if (!prefixcmp(arg, "--color=")) {
3248                int value = git_config_colorbool(NULL, arg+8, -1);
3249                if (value == 0)
3250                        DIFF_OPT_CLR(options, COLOR_DIFF);
3251                else if (value > 0)
3252                        DIFF_OPT_SET(options, COLOR_DIFF);
3253                else
3254                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3255        }
3256        else if (!strcmp(arg, "--no-color"))
3257                DIFF_OPT_CLR(options, COLOR_DIFF);
3258        else if (!strcmp(arg, "--color-words")) {
3259                DIFF_OPT_SET(options, COLOR_DIFF);
3260                options->word_diff = DIFF_WORDS_COLOR;
3261        }
3262        else if (!prefixcmp(arg, "--color-words=")) {
3263                DIFF_OPT_SET(options, COLOR_DIFF);
3264                options->word_diff = DIFF_WORDS_COLOR;
3265                options->word_regex = arg + 14;
3266        }
3267        else if (!strcmp(arg, "--word-diff")) {
3268                if (options->word_diff == DIFF_WORDS_NONE)
3269                        options->word_diff = DIFF_WORDS_PLAIN;
3270        }
3271        else if (!prefixcmp(arg, "--word-diff=")) {
3272                const char *type = arg + 12;
3273                if (!strcmp(type, "plain"))
3274                        options->word_diff = DIFF_WORDS_PLAIN;
3275                else if (!strcmp(type, "color")) {
3276                        DIFF_OPT_SET(options, COLOR_DIFF);
3277                        options->word_diff = DIFF_WORDS_COLOR;
3278                }
3279                else if (!strcmp(type, "porcelain"))
3280                        options->word_diff = DIFF_WORDS_PORCELAIN;
3281                else if (!strcmp(type, "none"))
3282                        options->word_diff = DIFF_WORDS_NONE;
3283                else
3284                        die("bad --word-diff argument: %s", type);
3285        }
3286        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3287                if (options->word_diff == DIFF_WORDS_NONE)
3288                        options->word_diff = DIFF_WORDS_PLAIN;
3289                options->word_regex = optarg;
3290                return argcount;
3291        }
3292        else if (!strcmp(arg, "--exit-code"))
3293                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3294        else if (!strcmp(arg, "--quiet"))
3295                DIFF_OPT_SET(options, QUICK);
3296        else if (!strcmp(arg, "--ext-diff"))
3297                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3298        else if (!strcmp(arg, "--no-ext-diff"))
3299                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3300        else if (!strcmp(arg, "--textconv"))
3301                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3302        else if (!strcmp(arg, "--no-textconv"))
3303                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3304        else if (!strcmp(arg, "--ignore-submodules")) {
3305                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3306                handle_ignore_submodules_arg(options, "all");
3307        } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3308                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3309                handle_ignore_submodules_arg(options, arg + 20);
3310        } else if (!strcmp(arg, "--submodule"))
3311                DIFF_OPT_SET(options, SUBMODULE_LOG);
3312        else if (!prefixcmp(arg, "--submodule=")) {
3313                if (!strcmp(arg + 12, "log"))
3314                        DIFF_OPT_SET(options, SUBMODULE_LOG);
3315        }
3316
3317        /* misc options */
3318        else if (!strcmp(arg, "-z"))
3319                options->line_termination = 0;
3320        else if ((argcount = short_opt('l', av, &optarg))) {
3321                options->rename_limit = strtoul(optarg, NULL, 10);
3322                return argcount;
3323        }
3324        else if ((argcount = short_opt('S', av, &optarg))) {
3325                options->pickaxe = optarg;
3326                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3327                return argcount;
3328        } else if ((argcount = short_opt('G', av, &optarg))) {
3329                options->pickaxe = optarg;
3330                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3331                return argcount;
3332        }
3333        else if (!strcmp(arg, "--pickaxe-all"))
3334                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3335        else if (!strcmp(arg, "--pickaxe-regex"))
3336                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3337        else if ((argcount = short_opt('O', av, &optarg))) {
3338                options->orderfile = optarg;
3339                return argcount;
3340        }
3341        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3342                options->filter = optarg;
3343                return argcount;
3344        }
3345        else if (!strcmp(arg, "--abbrev"))
3346                options->abbrev = DEFAULT_ABBREV;
3347        else if (!prefixcmp(arg, "--abbrev=")) {
3348                options->abbrev = strtoul(arg + 9, NULL, 10);
3349                if (options->abbrev < MINIMUM_ABBREV)
3350                        options->abbrev = MINIMUM_ABBREV;
3351                else if (40 < options->abbrev)
3352                        options->abbrev = 40;
3353        }
3354        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3355                options->a_prefix = optarg;
3356                return argcount;
3357        }
3358        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3359                options->b_prefix = optarg;
3360                return argcount;
3361        }
3362        else if (!strcmp(arg, "--no-prefix"))
3363                options->a_prefix = options->b_prefix = "";
3364        else if (opt_arg(arg, '\0', "inter-hunk-context",
3365                         &options->interhunkcontext))
3366                ;
3367        else if ((argcount = parse_long_opt("output", av, &optarg))) {
3368                options->file = fopen(optarg, "w");
3369                if (!options->file)
3370                        die_errno("Could not open '%s'", optarg);
3371                options->close_file = 1;
3372                return argcount;
3373        } else
3374                return 0;
3375        return 1;
3376}
3377
3378int parse_rename_score(const char **cp_p)
3379{
3380        unsigned long num, scale;
3381        int ch, dot;
3382        const char *cp = *cp_p;
3383
3384        num = 0;
3385        scale = 1;
3386        dot = 0;
3387        for (;;) {
3388                ch = *cp;
3389                if ( !dot && ch == '.' ) {
3390                        scale = 1;
3391                        dot = 1;
3392                } else if ( ch == '%' ) {
3393                        scale = dot ? scale*100 : 100;
3394                        cp++;   /* % is always at the end */
3395                        break;
3396                } else if ( ch >= '0' && ch <= '9' ) {
3397                        if ( scale < 100000 ) {
3398                                scale *= 10;
3399                                num = (num*10) + (ch-'0');
3400                        }
3401                } else {
3402                        break;
3403                }
3404                cp++;
3405        }
3406        *cp_p = cp;
3407
3408        /* user says num divided by scale and we say internally that
3409         * is MAX_SCORE * num / scale.
3410         */
3411        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3412}
3413
3414static int diff_scoreopt_parse(const char *opt)
3415{
3416        int opt1, opt2, cmd;
3417
3418        if (*opt++ != '-')
3419                return -1;
3420        cmd = *opt++;
3421        if (cmd == '-') {
3422                /* convert the long-form arguments into short-form versions */
3423                if (!prefixcmp(opt, "break-rewrites")) {
3424                        opt += strlen("break-rewrites");
3425                        if (*opt == 0 || *opt++ == '=')
3426                                cmd = 'B';
3427                } else if (!prefixcmp(opt, "find-copies")) {
3428                        opt += strlen("find-copies");
3429                        if (*opt == 0 || *opt++ == '=')
3430                                cmd = 'C';
3431                } else if (!prefixcmp(opt, "find-renames")) {
3432                        opt += strlen("find-renames");
3433                        if (*opt == 0 || *opt++ == '=')
3434                                cmd = 'M';
3435                }
3436        }
3437        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3438                return -1; /* that is not a -M, -C nor -B option */
3439
3440        opt1 = parse_rename_score(&opt);
3441        if (cmd != 'B')
3442                opt2 = 0;
3443        else {
3444                if (*opt == 0)
3445                        opt2 = 0;
3446                else if (*opt != '/')
3447                        return -1; /* we expect -B80/99 or -B80 */
3448                else {
3449                        opt++;
3450                        opt2 = parse_rename_score(&opt);
3451                }
3452        }
3453        if (*opt != 0)
3454                return -1;
3455        return opt1 | (opt2 << 16);
3456}
3457
3458struct diff_queue_struct diff_queued_diff;
3459
3460void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3461{
3462        if (queue->alloc <= queue->nr) {
3463                queue->alloc = alloc_nr(queue->alloc);
3464                queue->queue = xrealloc(queue->queue,
3465                                        sizeof(dp) * queue->alloc);
3466        }
3467        queue->queue[queue->nr++] = dp;
3468}
3469
3470struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3471                                 struct diff_filespec *one,
3472                                 struct diff_filespec *two)
3473{
3474        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3475        dp->one = one;
3476        dp->two = two;
3477        if (queue)
3478                diff_q(queue, dp);
3479        return dp;
3480}
3481
3482void diff_free_filepair(struct diff_filepair *p)
3483{
3484        free_filespec(p->one);
3485        free_filespec(p->two);
3486        free(p);
3487}
3488
3489/* This is different from find_unique_abbrev() in that
3490 * it stuffs the result with dots for alignment.
3491 */
3492const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3493{
3494        int abblen;
3495        const char *abbrev;
3496        if (len == 40)
3497                return sha1_to_hex(sha1);
3498
3499        abbrev = find_unique_abbrev(sha1, len);
3500        abblen = strlen(abbrev);
3501        if (abblen < 37) {
3502                static char hex[41];
3503                if (len < abblen && abblen <= len + 2)
3504                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3505                else
3506                        sprintf(hex, "%s...", abbrev);
3507                return hex;
3508        }
3509        return sha1_to_hex(sha1);
3510}
3511
3512static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3513{
3514        int line_termination = opt->line_termination;
3515        int inter_name_termination = line_termination ? '\t' : '\0';
3516        if (opt->output_prefix) {
3517                struct strbuf *msg = NULL;
3518                msg = opt->output_prefix(opt, opt->output_prefix_data);
3519                fprintf(opt->file, "%s", msg->buf);
3520        }
3521
3522        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3523                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3524                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3525                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3526        }
3527        if (p->score) {
3528                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3529                        inter_name_termination);
3530        } else {
3531                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3532        }
3533
3534        if (p->status == DIFF_STATUS_COPIED ||
3535            p->status == DIFF_STATUS_RENAMED) {
3536                const char *name_a, *name_b;
3537                name_a = p->one->path;
3538                name_b = p->two->path;
3539                strip_prefix(opt->prefix_length, &name_a, &name_b);
3540                write_name_quoted(name_a, opt->file, inter_name_termination);
3541                write_name_quoted(name_b, opt->file, line_termination);
3542        } else {
3543                const char *name_a, *name_b;
3544                name_a = p->one->mode ? p->one->path : p->two->path;
3545                name_b = NULL;
3546                strip_prefix(opt->prefix_length, &name_a, &name_b);
3547                write_name_quoted(name_a, opt->file, line_termination);
3548        }
3549}
3550
3551int diff_unmodified_pair(struct diff_filepair *p)
3552{
3553        /* This function is written stricter than necessary to support
3554         * the currently implemented transformers, but the idea is to
3555         * let transformers to produce diff_filepairs any way they want,
3556         * and filter and clean them up here before producing the output.
3557         */
3558        struct diff_filespec *one = p->one, *two = p->two;
3559
3560        if (DIFF_PAIR_UNMERGED(p))
3561                return 0; /* unmerged is interesting */
3562
3563        /* deletion, addition, mode or type change
3564         * and rename are all interesting.
3565         */
3566        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3567            DIFF_PAIR_MODE_CHANGED(p) ||
3568            strcmp(one->path, two->path))
3569                return 0;
3570
3571        /* both are valid and point at the same path.  that is, we are
3572         * dealing with a change.
3573         */
3574        if (one->sha1_valid && two->sha1_valid &&
3575            !hashcmp(one->sha1, two->sha1) &&
3576            !one->dirty_submodule && !two->dirty_submodule)
3577                return 1; /* no change */
3578        if (!one->sha1_valid && !two->sha1_valid)
3579                return 1; /* both look at the same file on the filesystem. */
3580        return 0;
3581}
3582
3583static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3584{
3585        if (diff_unmodified_pair(p))
3586                return;
3587
3588        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3589            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3590                return; /* no tree diffs in patch format */
3591
3592        run_diff(p, o);
3593}
3594
3595static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3596                            struct diffstat_t *diffstat)
3597{
3598        if (diff_unmodified_pair(p))
3599                return;
3600
3601        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3602            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3603                return; /* no useful stat for tree diffs */
3604
3605        run_diffstat(p, o, diffstat);
3606}
3607
3608static void diff_flush_checkdiff(struct diff_filepair *p,
3609                struct diff_options *o)
3610{
3611        if (diff_unmodified_pair(p))
3612                return;
3613
3614        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3615            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3616                return; /* nothing to check in tree diffs */
3617
3618        run_checkdiff(p, o);
3619}
3620
3621int diff_queue_is_empty(void)
3622{
3623        struct diff_queue_struct *q = &diff_queued_diff;
3624        int i;
3625        for (i = 0; i < q->nr; i++)
3626                if (!diff_unmodified_pair(q->queue[i]))
3627                        return 0;
3628        return 1;
3629}
3630
3631#if DIFF_DEBUG
3632void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3633{
3634        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3635                x, one ? one : "",
3636                s->path,
3637                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3638                s->mode,
3639                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3640        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3641                x, one ? one : "",
3642                s->size, s->xfrm_flags);
3643}
3644
3645void diff_debug_filepair(const struct diff_filepair *p, int i)
3646{
3647        diff_debug_filespec(p->one, i, "one");
3648        diff_debug_filespec(p->two, i, "two");
3649        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3650                p->score, p->status ? p->status : '?',
3651                p->one->rename_used, p->broken_pair);
3652}
3653
3654void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3655{
3656        int i;
3657        if (msg)
3658                fprintf(stderr, "%s\n", msg);
3659        fprintf(stderr, "q->nr = %d\n", q->nr);
3660        for (i = 0; i < q->nr; i++) {
3661                struct diff_filepair *p = q->queue[i];
3662                diff_debug_filepair(p, i);
3663        }
3664}
3665#endif
3666
3667static void diff_resolve_rename_copy(void)
3668{
3669        int i;
3670        struct diff_filepair *p;
3671        struct diff_queue_struct *q = &diff_queued_diff;
3672
3673        diff_debug_queue("resolve-rename-copy", q);
3674
3675        for (i = 0; i < q->nr; i++) {
3676                p = q->queue[i];
3677                p->status = 0; /* undecided */
3678                if (DIFF_PAIR_UNMERGED(p))
3679                        p->status = DIFF_STATUS_UNMERGED;
3680                else if (!DIFF_FILE_VALID(p->one))
3681                        p->status = DIFF_STATUS_ADDED;
3682                else if (!DIFF_FILE_VALID(p->two))
3683                        p->status = DIFF_STATUS_DELETED;
3684                else if (DIFF_PAIR_TYPE_CHANGED(p))
3685                        p->status = DIFF_STATUS_TYPE_CHANGED;
3686
3687                /* from this point on, we are dealing with a pair
3688                 * whose both sides are valid and of the same type, i.e.
3689                 * either in-place edit or rename/copy edit.
3690                 */
3691                else if (DIFF_PAIR_RENAME(p)) {
3692                        /*
3693                         * A rename might have re-connected a broken
3694                         * pair up, causing the pathnames to be the
3695                         * same again. If so, that's not a rename at
3696                         * all, just a modification..
3697                         *
3698                         * Otherwise, see if this source was used for
3699                         * multiple renames, in which case we decrement
3700                         * the count, and call it a copy.
3701                         */
3702                        if (!strcmp(p->one->path, p->two->path))
3703                                p->status = DIFF_STATUS_MODIFIED;
3704                        else if (--p->one->rename_used > 0)
3705                                p->status = DIFF_STATUS_COPIED;
3706                        else
3707                                p->status = DIFF_STATUS_RENAMED;
3708                }
3709                else if (hashcmp(p->one->sha1, p->two->sha1) ||
3710                         p->one->mode != p->two->mode ||
3711                         p->one->dirty_submodule ||
3712                         p->two->dirty_submodule ||
3713                         is_null_sha1(p->one->sha1))
3714                        p->status = DIFF_STATUS_MODIFIED;
3715                else {
3716                        /* This is a "no-change" entry and should not
3717                         * happen anymore, but prepare for broken callers.
3718                         */
3719                        error("feeding unmodified %s to diffcore",
3720                              p->one->path);
3721                        p->status = DIFF_STATUS_UNKNOWN;
3722                }
3723        }
3724        diff_debug_queue("resolve-rename-copy done", q);
3725}
3726
3727static int check_pair_status(struct diff_filepair *p)
3728{
3729        switch (p->status) {
3730        case DIFF_STATUS_UNKNOWN:
3731                return 0;
3732        case 0:
3733                die("internal error in diff-resolve-rename-copy");
3734        default:
3735                return 1;
3736        }
3737}
3738
3739static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3740{
3741        int fmt = opt->output_format;
3742
3743        if (fmt & DIFF_FORMAT_CHECKDIFF)
3744                diff_flush_checkdiff(p, opt);
3745        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3746                diff_flush_raw(p, opt);
3747        else if (fmt & DIFF_FORMAT_NAME) {
3748                const char *name_a, *name_b;
3749                name_a = p->two->path;
3750                name_b = NULL;
3751                strip_prefix(opt->prefix_length, &name_a, &name_b);
3752                write_name_quoted(name_a, opt->file, opt->line_termination);
3753        }
3754}
3755
3756static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
3757{
3758        if (fs->mode)
3759                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
3760        else
3761                fprintf(file, " %s ", newdelete);
3762        write_name_quoted(fs->path, file, '\n');
3763}
3764
3765
3766static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
3767                const char *line_prefix)
3768{
3769        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
3770                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
3771                        p->two->mode, show_name ? ' ' : '\n');
3772                if (show_name) {
3773                        write_name_quoted(p->two->path, file, '\n');
3774                }
3775        }
3776}
3777
3778static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
3779                        const char *line_prefix)
3780{
3781        char *names = pprint_rename(p->one->path, p->two->path);
3782
3783        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
3784        free(names);
3785        show_mode_change(file, p, 0, line_prefix);
3786}
3787
3788static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
3789{
3790        FILE *file = opt->file;
3791        char *line_prefix = "";
3792
3793        if (opt->output_prefix) {
3794                struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
3795                line_prefix = buf->buf;
3796        }
3797
3798        switch(p->status) {
3799        case DIFF_STATUS_DELETED:
3800                fputs(line_prefix, file);
3801                show_file_mode_name(file, "delete", p->one);
3802                break;
3803        case DIFF_STATUS_ADDED:
3804                fputs(line_prefix, file);
3805                show_file_mode_name(file, "create", p->two);
3806                break;
3807        case DIFF_STATUS_COPIED:
3808                fputs(line_prefix, file);
3809                show_rename_copy(file, "copy", p, line_prefix);
3810                break;
3811        case DIFF_STATUS_RENAMED:
3812                fputs(line_prefix, file);
3813                show_rename_copy(file, "rename", p, line_prefix);
3814                break;
3815        default:
3816                if (p->score) {
3817                        fprintf(file, "%s rewrite ", line_prefix);
3818                        write_name_quoted(p->two->path, file, ' ');
3819                        fprintf(file, "(%d%%)\n", similarity_index(p));
3820                }
3821                show_mode_change(file, p, !p->score, line_prefix);
3822                break;
3823        }
3824}
3825
3826struct patch_id_t {
3827        git_SHA_CTX *ctx;
3828        int patchlen;
3829};
3830
3831static int remove_space(char *line, int len)
3832{
3833        int i;
3834        char *dst = line;
3835        unsigned char c;
3836
3837        for (i = 0; i < len; i++)
3838                if (!isspace((c = line[i])))
3839                        *dst++ = c;
3840
3841        return dst - line;
3842}
3843
3844static void patch_id_consume(void *priv, char *line, unsigned long len)
3845{
3846        struct patch_id_t *data = priv;
3847        int new_len;
3848
3849        /* Ignore line numbers when computing the SHA1 of the patch */
3850        if (!prefixcmp(line, "@@ -"))
3851                return;
3852
3853        new_len = remove_space(line, len);
3854
3855        git_SHA1_Update(data->ctx, line, new_len);
3856        data->patchlen += new_len;
3857}
3858
3859/* returns 0 upon success, and writes result into sha1 */
3860static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
3861{
3862        struct diff_queue_struct *q = &diff_queued_diff;
3863        int i;
3864        git_SHA_CTX ctx;
3865        struct patch_id_t data;
3866        char buffer[PATH_MAX * 4 + 20];
3867
3868        git_SHA1_Init(&ctx);
3869        memset(&data, 0, sizeof(struct patch_id_t));
3870        data.ctx = &ctx;
3871
3872        for (i = 0; i < q->nr; i++) {
3873                xpparam_t xpp;
3874                xdemitconf_t xecfg;
3875                mmfile_t mf1, mf2;
3876                struct diff_filepair *p = q->queue[i];
3877                int len1, len2;
3878
3879                memset(&xpp, 0, sizeof(xpp));
3880                memset(&xecfg, 0, sizeof(xecfg));
3881                if (p->status == 0)
3882                        return error("internal diff status error");
3883                if (p->status == DIFF_STATUS_UNKNOWN)
3884                        continue;
3885                if (diff_unmodified_pair(p))
3886                        continue;
3887                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3888                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3889                        continue;
3890                if (DIFF_PAIR_UNMERGED(p))
3891                        continue;
3892
3893                diff_fill_sha1_info(p->one);
3894                diff_fill_sha1_info(p->two);
3895                if (fill_mmfile(&mf1, p->one) < 0 ||
3896                                fill_mmfile(&mf2, p->two) < 0)
3897                        return error("unable to read files to diff");
3898
3899                len1 = remove_space(p->one->path, strlen(p->one->path));
3900                len2 = remove_space(p->two->path, strlen(p->two->path));
3901                if (p->one->mode == 0)
3902                        len1 = snprintf(buffer, sizeof(buffer),
3903                                        "diff--gita/%.*sb/%.*s"
3904                                        "newfilemode%06o"
3905                                        "---/dev/null"
3906                                        "+++b/%.*s",
3907                                        len1, p->one->path,
3908                                        len2, p->two->path,
3909                                        p->two->mode,
3910                                        len2, p->two->path);
3911                else if (p->two->mode == 0)
3912                        len1 = snprintf(buffer, sizeof(buffer),
3913                                        "diff--gita/%.*sb/%.*s"
3914                                        "deletedfilemode%06o"
3915                                        "---a/%.*s"
3916                                        "+++/dev/null",
3917                                        len1, p->one->path,
3918                                        len2, p->two->path,
3919                                        p->one->mode,
3920                                        len1, p->one->path);
3921                else
3922                        len1 = snprintf(buffer, sizeof(buffer),
3923                                        "diff--gita/%.*sb/%.*s"
3924                                        "---a/%.*s"
3925                                        "+++b/%.*s",
3926                                        len1, p->one->path,
3927                                        len2, p->two->path,
3928                                        len1, p->one->path,
3929                                        len2, p->two->path);
3930                git_SHA1_Update(&ctx, buffer, len1);
3931
3932                if (diff_filespec_is_binary(p->one) ||
3933                    diff_filespec_is_binary(p->two)) {
3934                        git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
3935                        git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
3936                        continue;
3937                }
3938
3939                xpp.flags = 0;
3940                xecfg.ctxlen = 3;
3941                xecfg.flags = 0;
3942                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
3943                              &xpp, &xecfg);
3944        }
3945
3946        git_SHA1_Final(sha1, &ctx);
3947        return 0;
3948}
3949
3950int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
3951{
3952        struct diff_queue_struct *q = &diff_queued_diff;
3953        int i;
3954        int result = diff_get_patch_id(options, sha1);
3955
3956        for (i = 0; i < q->nr; i++)
3957                diff_free_filepair(q->queue[i]);
3958
3959        free(q->queue);
3960        DIFF_QUEUE_CLEAR(q);
3961
3962        return result;
3963}
3964
3965static int is_summary_empty(const struct diff_queue_struct *q)
3966{
3967        int i;
3968
3969        for (i = 0; i < q->nr; i++) {
3970                const struct diff_filepair *p = q->queue[i];
3971
3972                switch (p->status) {
3973                case DIFF_STATUS_DELETED:
3974                case DIFF_STATUS_ADDED:
3975                case DIFF_STATUS_COPIED:
3976                case DIFF_STATUS_RENAMED:
3977                        return 0;
3978                default:
3979                        if (p->score)
3980                                return 0;
3981                        if (p->one->mode && p->two->mode &&
3982                            p->one->mode != p->two->mode)
3983                                return 0;
3984                        break;
3985                }
3986        }
3987        return 1;
3988}
3989
3990void diff_flush(struct diff_options *options)
3991{
3992        struct diff_queue_struct *q = &diff_queued_diff;
3993        int i, output_format = options->output_format;
3994        int separator = 0;
3995
3996        /*
3997         * Order: raw, stat, summary, patch
3998         * or:    name/name-status/checkdiff (other bits clear)
3999         */
4000        if (!q->nr)
4001                goto free_queue;
4002
4003        if (output_format & (DIFF_FORMAT_RAW |
4004                             DIFF_FORMAT_NAME |
4005                             DIFF_FORMAT_NAME_STATUS |
4006                             DIFF_FORMAT_CHECKDIFF)) {
4007                for (i = 0; i < q->nr; i++) {
4008                        struct diff_filepair *p = q->queue[i];
4009                        if (check_pair_status(p))
4010                                flush_one_pair(p, options);
4011                }
4012                separator++;
4013        }
4014
4015        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
4016                struct diffstat_t diffstat;
4017
4018                memset(&diffstat, 0, sizeof(struct diffstat_t));
4019                for (i = 0; i < q->nr; i++) {
4020                        struct diff_filepair *p = q->queue[i];
4021                        if (check_pair_status(p))
4022                                diff_flush_stat(p, options, &diffstat);
4023                }
4024                if (output_format & DIFF_FORMAT_NUMSTAT)
4025                        show_numstat(&diffstat, options);
4026                if (output_format & DIFF_FORMAT_DIFFSTAT)
4027                        show_stats(&diffstat, options);
4028                if (output_format & DIFF_FORMAT_SHORTSTAT)
4029                        show_shortstats(&diffstat, options);
4030                free_diffstat_info(&diffstat);
4031                separator++;
4032        }
4033        if (output_format & DIFF_FORMAT_DIRSTAT)
4034                show_dirstat(options);
4035
4036        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4037                for (i = 0; i < q->nr; i++) {
4038                        diff_summary(options, q->queue[i]);
4039                }
4040                separator++;
4041        }
4042
4043        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4044            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4045            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4046                /*
4047                 * run diff_flush_patch for the exit status. setting
4048                 * options->file to /dev/null should be safe, becaue we
4049                 * aren't supposed to produce any output anyway.
4050                 */
4051                if (options->close_file)
4052                        fclose(options->file);
4053                options->file = fopen("/dev/null", "w");
4054                if (!options->file)
4055                        die_errno("Could not open /dev/null");
4056                options->close_file = 1;
4057                for (i = 0; i < q->nr; i++) {
4058                        struct diff_filepair *p = q->queue[i];
4059                        if (check_pair_status(p))
4060                                diff_flush_patch(p, options);
4061                        if (options->found_changes)
4062                                break;
4063                }
4064        }
4065
4066        if (output_format & DIFF_FORMAT_PATCH) {
4067                if (separator) {
4068                        putc(options->line_termination, options->file);
4069                        if (options->stat_sep) {
4070                                /* attach patch instead of inline */
4071                                fputs(options->stat_sep, options->file);
4072                        }
4073                }
4074
4075                for (i = 0; i < q->nr; i++) {
4076                        struct diff_filepair *p = q->queue[i];
4077                        if (check_pair_status(p))
4078                                diff_flush_patch(p, options);
4079                }
4080        }
4081
4082        if (output_format & DIFF_FORMAT_CALLBACK)
4083                options->format_callback(q, options, options->format_callback_data);
4084
4085        for (i = 0; i < q->nr; i++)
4086                diff_free_filepair(q->queue[i]);
4087free_queue:
4088        free(q->queue);
4089        DIFF_QUEUE_CLEAR(q);
4090        if (options->close_file)
4091                fclose(options->file);
4092
4093        /*
4094         * Report the content-level differences with HAS_CHANGES;
4095         * diff_addremove/diff_change does not set the bit when
4096         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4097         */
4098        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4099                if (options->found_changes)
4100                        DIFF_OPT_SET(options, HAS_CHANGES);
4101                else
4102                        DIFF_OPT_CLR(options, HAS_CHANGES);
4103        }
4104}
4105
4106static void diffcore_apply_filter(const char *filter)
4107{
4108        int i;
4109        struct diff_queue_struct *q = &diff_queued_diff;
4110        struct diff_queue_struct outq;
4111        DIFF_QUEUE_CLEAR(&outq);
4112
4113        if (!filter)
4114                return;
4115
4116        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
4117                int found;
4118                for (i = found = 0; !found && i < q->nr; i++) {
4119                        struct diff_filepair *p = q->queue[i];
4120                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4121                             ((p->score &&
4122                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4123                              (!p->score &&
4124                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4125                            ((p->status != DIFF_STATUS_MODIFIED) &&
4126                             strchr(filter, p->status)))
4127                                found++;
4128                }
4129                if (found)
4130                        return;
4131
4132                /* otherwise we will clear the whole queue
4133                 * by copying the empty outq at the end of this
4134                 * function, but first clear the current entries
4135                 * in the queue.
4136                 */
4137                for (i = 0; i < q->nr; i++)
4138                        diff_free_filepair(q->queue[i]);
4139        }
4140        else {
4141                /* Only the matching ones */
4142                for (i = 0; i < q->nr; i++) {
4143                        struct diff_filepair *p = q->queue[i];
4144
4145                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4146                             ((p->score &&
4147                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4148                              (!p->score &&
4149                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4150                            ((p->status != DIFF_STATUS_MODIFIED) &&
4151                             strchr(filter, p->status)))
4152                                diff_q(&outq, p);
4153                        else
4154                                diff_free_filepair(p);
4155                }
4156        }
4157        free(q->queue);
4158        *q = outq;
4159}
4160
4161/* Check whether two filespecs with the same mode and size are identical */
4162static int diff_filespec_is_identical(struct diff_filespec *one,
4163                                      struct diff_filespec *two)
4164{
4165        if (S_ISGITLINK(one->mode))
4166                return 0;
4167        if (diff_populate_filespec(one, 0))
4168                return 0;
4169        if (diff_populate_filespec(two, 0))
4170                return 0;
4171        return !memcmp(one->data, two->data, one->size);
4172}
4173
4174static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4175{
4176        int i;
4177        struct diff_queue_struct *q = &diff_queued_diff;
4178        struct diff_queue_struct outq;
4179        DIFF_QUEUE_CLEAR(&outq);
4180
4181        for (i = 0; i < q->nr; i++) {
4182                struct diff_filepair *p = q->queue[i];
4183
4184                /*
4185                 * 1. Entries that come from stat info dirtiness
4186                 *    always have both sides (iow, not create/delete),
4187                 *    one side of the object name is unknown, with
4188                 *    the same mode and size.  Keep the ones that
4189                 *    do not match these criteria.  They have real
4190                 *    differences.
4191                 *
4192                 * 2. At this point, the file is known to be modified,
4193                 *    with the same mode and size, and the object
4194                 *    name of one side is unknown.  Need to inspect
4195                 *    the identical contents.
4196                 */
4197                if (!DIFF_FILE_VALID(p->one) || /* (1) */
4198                    !DIFF_FILE_VALID(p->two) ||
4199                    (p->one->sha1_valid && p->two->sha1_valid) ||
4200                    (p->one->mode != p->two->mode) ||
4201                    diff_populate_filespec(p->one, 1) ||
4202                    diff_populate_filespec(p->two, 1) ||
4203                    (p->one->size != p->two->size) ||
4204                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4205                        diff_q(&outq, p);
4206                else {
4207                        /*
4208                         * The caller can subtract 1 from skip_stat_unmatch
4209                         * to determine how many paths were dirty only
4210                         * due to stat info mismatch.
4211                         */
4212                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4213                                diffopt->skip_stat_unmatch++;
4214                        diff_free_filepair(p);
4215                }
4216        }
4217        free(q->queue);
4218        *q = outq;
4219}
4220
4221static int diffnamecmp(const void *a_, const void *b_)
4222{
4223        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4224        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4225        const char *name_a, *name_b;
4226
4227        name_a = a->one ? a->one->path : a->two->path;
4228        name_b = b->one ? b->one->path : b->two->path;
4229        return strcmp(name_a, name_b);
4230}
4231
4232void diffcore_fix_diff_index(struct diff_options *options)
4233{
4234        struct diff_queue_struct *q = &diff_queued_diff;
4235        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4236}
4237
4238void diffcore_std(struct diff_options *options)
4239{
4240        if (options->skip_stat_unmatch)
4241                diffcore_skip_stat_unmatch(options);
4242        if (!options->found_follow) {
4243                /* See try_to_follow_renames() in tree-diff.c */
4244                if (options->break_opt != -1)
4245                        diffcore_break(options->break_opt);
4246                if (options->detect_rename)
4247                        diffcore_rename(options);
4248                if (options->break_opt != -1)
4249                        diffcore_merge_broken();
4250        }
4251        if (options->pickaxe)
4252                diffcore_pickaxe(options);
4253        if (options->orderfile)
4254                diffcore_order(options->orderfile);
4255        if (!options->found_follow)
4256                /* See try_to_follow_renames() in tree-diff.c */
4257                diff_resolve_rename_copy();
4258        diffcore_apply_filter(options->filter);
4259
4260        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4261                DIFF_OPT_SET(options, HAS_CHANGES);
4262        else
4263                DIFF_OPT_CLR(options, HAS_CHANGES);
4264
4265        options->found_follow = 0;
4266}
4267
4268int diff_result_code(struct diff_options *opt, int status)
4269{
4270        int result = 0;
4271        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4272            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4273                return status;
4274        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4275            DIFF_OPT_TST(opt, HAS_CHANGES))
4276                result |= 01;
4277        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4278            DIFF_OPT_TST(opt, CHECK_FAILED))
4279                result |= 02;
4280        return result;
4281}
4282
4283/*
4284 * Shall changes to this submodule be ignored?
4285 *
4286 * Submodule changes can be configured to be ignored separately for each path,
4287 * but that configuration can be overridden from the command line.
4288 */
4289static int is_submodule_ignored(const char *path, struct diff_options *options)
4290{
4291        int ignored = 0;
4292        unsigned orig_flags = options->flags;
4293        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4294                set_diffopt_flags_from_submodule_config(options, path);
4295        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4296                ignored = 1;
4297        options->flags = orig_flags;
4298        return ignored;
4299}
4300
4301void diff_addremove(struct diff_options *options,
4302                    int addremove, unsigned mode,
4303                    const unsigned char *sha1,
4304                    const char *concatpath, unsigned dirty_submodule)
4305{
4306        struct diff_filespec *one, *two;
4307
4308        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4309                return;
4310
4311        /* This may look odd, but it is a preparation for
4312         * feeding "there are unchanged files which should
4313         * not produce diffs, but when you are doing copy
4314         * detection you would need them, so here they are"
4315         * entries to the diff-core.  They will be prefixed
4316         * with something like '=' or '*' (I haven't decided
4317         * which but should not make any difference).
4318         * Feeding the same new and old to diff_change()
4319         * also has the same effect.
4320         * Before the final output happens, they are pruned after
4321         * merged into rename/copy pairs as appropriate.
4322         */
4323        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4324                addremove = (addremove == '+' ? '-' :
4325                             addremove == '-' ? '+' : addremove);
4326
4327        if (options->prefix &&
4328            strncmp(concatpath, options->prefix, options->prefix_length))
4329                return;
4330
4331        one = alloc_filespec(concatpath);
4332        two = alloc_filespec(concatpath);
4333
4334        if (addremove != '+')
4335                fill_filespec(one, sha1, mode);
4336        if (addremove != '-') {
4337                fill_filespec(two, sha1, mode);
4338                two->dirty_submodule = dirty_submodule;
4339        }
4340
4341        diff_queue(&diff_queued_diff, one, two);
4342        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4343                DIFF_OPT_SET(options, HAS_CHANGES);
4344}
4345
4346void diff_change(struct diff_options *options,
4347                 unsigned old_mode, unsigned new_mode,
4348                 const unsigned char *old_sha1,
4349                 const unsigned char *new_sha1,
4350                 const char *concatpath,
4351                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4352{
4353        struct diff_filespec *one, *two;
4354
4355        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4356            is_submodule_ignored(concatpath, options))
4357                return;
4358
4359        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4360                unsigned tmp;
4361                const unsigned char *tmp_c;
4362                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4363                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4364                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4365                        new_dirty_submodule = tmp;
4366        }
4367
4368        if (options->prefix &&
4369            strncmp(concatpath, options->prefix, options->prefix_length))
4370                return;
4371
4372        one = alloc_filespec(concatpath);
4373        two = alloc_filespec(concatpath);
4374        fill_filespec(one, old_sha1, old_mode);
4375        fill_filespec(two, new_sha1, new_mode);
4376        one->dirty_submodule = old_dirty_submodule;
4377        two->dirty_submodule = new_dirty_submodule;
4378
4379        diff_queue(&diff_queued_diff, one, two);
4380        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4381                DIFF_OPT_SET(options, HAS_CHANGES);
4382}
4383
4384void diff_unmerge(struct diff_options *options,
4385                  const char *path,
4386                  unsigned mode, const unsigned char *sha1)
4387{
4388        struct diff_filespec *one, *two;
4389
4390        if (options->prefix &&
4391            strncmp(path, options->prefix, options->prefix_length))
4392                return;
4393
4394        one = alloc_filespec(path);
4395        two = alloc_filespec(path);
4396        fill_filespec(one, sha1, mode);
4397        diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;
4398}
4399
4400static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4401                size_t *outsize)
4402{
4403        struct diff_tempfile *temp;
4404        const char *argv[3];
4405        const char **arg = argv;
4406        struct child_process child;
4407        struct strbuf buf = STRBUF_INIT;
4408        int err = 0;
4409
4410        temp = prepare_temp_file(spec->path, spec);
4411        *arg++ = pgm;
4412        *arg++ = temp->name;
4413        *arg = NULL;
4414
4415        memset(&child, 0, sizeof(child));
4416        child.use_shell = 1;
4417        child.argv = argv;
4418        child.out = -1;
4419        if (start_command(&child)) {
4420                remove_tempfile();
4421                return NULL;
4422        }
4423
4424        if (strbuf_read(&buf, child.out, 0) < 0)
4425                err = error("error reading from textconv command '%s'", pgm);
4426        close(child.out);
4427
4428        if (finish_command(&child) || err) {
4429                strbuf_release(&buf);
4430                remove_tempfile();
4431                return NULL;
4432        }
4433        remove_tempfile();
4434
4435        return strbuf_detach(&buf, outsize);
4436}
4437
4438size_t fill_textconv(struct userdiff_driver *driver,
4439                     struct diff_filespec *df,
4440                     char **outbuf)
4441{
4442        size_t size;
4443
4444        if (!driver || !driver->textconv) {
4445                if (!DIFF_FILE_VALID(df)) {
4446                        *outbuf = "";
4447                        return 0;
4448                }
4449                if (diff_populate_filespec(df, 0))
4450                        die("unable to read files to diff");
4451                *outbuf = df->data;
4452                return df->size;
4453        }
4454
4455        if (driver->textconv_cache && df->sha1_valid) {
4456                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4457                                          &size);
4458                if (*outbuf)
4459                        return size;
4460        }
4461
4462        *outbuf = run_textconv(driver->textconv, df, &size);
4463        if (!*outbuf)
4464                die("unable to read files to diff");
4465
4466        if (driver->textconv_cache && df->sha1_valid) {
4467                /* ignore errors, as we might be in a readonly repository */
4468                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4469                                size);
4470                /*
4471                 * we could save up changes and flush them all at the end,
4472                 * but we would need an extra call after all diffing is done.
4473                 * Since generating a cache entry is the slow path anyway,
4474                 * this extra overhead probably isn't a big deal.
4475                 */
4476                notes_cache_write(driver->textconv_cache);
4477        }
4478
4479        return size;
4480}